[TECHNICAL FIELD]
[0001] The present invention relates to a flush toilet, and in particular relates to a type
of flush toilet in which the toilet bowl is flushed with a swirling flow of water.
[BACKGROUND ART]
[0002] For a flush toilet, a flushing method is known in which flush water is discharged
through one or more discharge ports into the toilet bowl part, and waste is pushed
out to a drain pipe by means of the flow of the flush water. Hereinafter, the force
of pushing waste out from the inside of the toilet to the drain pipe will be referred
to as the "draining force". Also, in order to prevent a residue of waste being left
on the inner wall surface of the toilet bowl part, a flow of water is required to
flush a wide range of the inner wall surface of the toilet bowl part. Hereinafter,
the force of flushing the inner wall of a toilet bowl will be referred to as the "flushing
force".
[0003] In recent years, a functional unit, such as a pubic lavage device and a warm air
device, is often provided in a rear part of a flush toilet. In Patent Document 1,
in order to prevent a nozzle or the like of a pubic lavage device from getting dirty,
the nozzle is covered with a cover member that is nearly flush with the inner wall
surface of a rear end part of the toilet bowl. In Patent Document 1, although dirt
of the nozzle is regarded as a problem, it is held that dirt of the cover member for
the nozzle is considered on the premise that a user needs to wipe the dirt off (see
paragraph [0032] in Patent Document 1) .
[PRIOR ART REFERENCE]
[PATENT DOCUMENT]
[0004] [Patent Document 1] Japanese Unexamined Patent Application Publication No.
2010-174451
[DISCLOSURE OF INVENTION]
[PROBLEM(S) TO BE SOLVED BY THE INVENTION]
[0005] As described previously, for a flush toilet, the two functions of the draining force
and the flushing force are required. Accordingly, flush toilets need to be designed
so that the course of flush water can be sophisticatedly changed without weakening
the flow of the flush water. In addition, the flush toilets need to be structured
so that a functional unit, such as a pubic lavage device, can be mounted thereon.
[0006] A main purpose of the present invention is to propose new design of a flush toilet
for improving the flushing force and the draining force.
[MEANS TO SOLVE THE PROBLEM(S)]
[0007] A flush toilet according to one embodiment of the present invention includes: a body
part with a toilet bowl part formed therein, including a first upper surface positioned
higher and a second upper surface positioned lower; a water conveyance shelf formed
along a circumferential direction of the toilet bowl part on an inner wall surface
of the toilet bowl part; and a discharge port formed so that water is discharged therethrough
to the water conveyance shelf.
[0008] The water conveyance shelf includes a first shelf part formed at a corresponding
position of the first upper surface and also includes a second shelf part formed at
a corresponding position of the second upper surface. The second shelf part is positioned
lower than the first shelf part.
[0009] A flush toilet according to another embodiment of the present invention includes:
a toilet bowl part; a water conveyance shelf formed along a circumferential direction
on an inner wall surface of the toilet bowl part and including a first shelf part
positioned higher and a second shelf part positioned lower; a first discharge port
formed above the first shelf part; and a second discharge port formed above the second
shelf part and positioned lower than the first discharge port.
[0010] The first shelf part and the second shelf part are smoothly connected by a shelf
inclined surface.
[0011] Optional combinations of the aforementioned constituting elements, and implementations
of the present invention, including the constituting elements and expressions, in
the form of methods, apparatuses, or systems may also be practiced as additional modes
of the present invention.
[ADVANTAGEOUS EFFECTS OF INVENTION]
[0012] The present invention facilitates improvement in the flushing force and the draining
force of a flush toilet.
[BRIEF DESCRIPTION OF DRAWINGS]
[0013] Embodiments will now be described, by way of example only, with reference to the
accompanying drawings which are meant to be exemplary, not limiting, and wherein like
elements are numbered alike in several Figures, in which:
Fig. 1 is an external perspective view of a flush toilet;
Fig. 2 is a top view of the flush toilet;
Fig. 3 is a sectional side view of a toilet bowl;
Fig. 4 is a sectional front view of the toilet bowl;
Fig. 5 is a schematic diagram that shows flows of water toward a storage region;
Fig. 6 is a diagram that schematically shows a height relationship between a first
shelf part and a second shelf part in a first embodiment;
Fig. 7 is a diagram that schematically shows a height relationship between the first
shelf part and the second shelf part in a comparative example;
Fig. 8 is an external perspective view of a flush toilet;
Fig. 9 is a top view of the flush toilet;
Fig. 10 is a sectional side view of the toilet bowl;
Fig. 11 is a sectional front view of the toilet bowl;
Fig. 12 is a schematic diagram that shows flows of water toward the storage region;
Fig. 13 is a diagram that schematically shows a height relationship between the first
shelf part and the second shelf part in a second embodiment; and
Fig. 14 is a diagram that schematically shows a height relationship between the first
shelf part and the second shelf part in a comparative example.
[MODE FOR CARRYING OUT THE INVENTION]
(First Embodiment)
[0014] Fig. 1 is an external perspective view of a flush toilet 100.
[0015] In a body part 144 of the flush toilet 100, a toilet bowl 106 is formed. Also, in
the body part 144, flush water stored in an external tank is discharged to the toilet
bowl 106 through a first discharge port 102 and a second discharge port 104. Part
of the flush water is also discharged through a third discharge port, which will be
described later in association with Fig. 2. The third discharge port may be a so-called
jet discharge port. The first discharge port 102 is formed on a side surface (the
negative direction side of the y-axis) of the toilet bowl 106. The second discharge
port 104 is formed on a rear end surface (the negative direction side of the x-axis)
of the toilet bowl 106. Along the entire periphery of the inner wall of the toilet
bowl 106, a water conveyance shelf 108 is annularly formed. The flush water discharged
through the second discharge port 104 (hereinafter, referred to as "second flush water")
flows upon the water conveyance shelf 108, and most of the flush water flows down
into the toilet bowl 106 before the first discharge port 102, while the remaining
flush water is merged into the flush water discharged through the first discharge
port 102 (hereinafter, referred to as "first flush water"). The first flush water
swirls upon the water conveyance shelf 108, thereby flushing the entirety of the toilet
bowl 106, particularly the front surface and the both side surfaces of the inner wall.
[0016] The upper surface of the toilet bowl 106 is formed as a stepped surface including
a first upper surface 110 positioned higher and a second upper surface 112 positioned
lower. The second upper surface 112 in the first embodiment forms a flat bottom surface
of a recess part 138 in the upper surface. However, the second upper surface 112 need
not necessarily be flat, and it may be formed as a surface curved downward or upward,
or a projection or a cutout may be formed in part of the second upper surface 112.
On the recess part 138 (upon the second upper surface 112), a functional unit (not
illustrated) for providing the pubic lavage function or the warm air function, for
example, is mounted. The second upper surface 112 and the first upper surface 110
are smoothly connected by two upper inclined surfaces 140a and 140b, so that an annular
upper surface having a height difference is formed.
[0017] The water conveyance shelf 108 includes a first shelf part 114 positioned higher
and a second shelf part 116 positioned lower. The first shelf part 114 is formed at
a corresponding position of the first upper surface 110, and the second shelf part
116 is formed at a corresponding position of the second upper surface 112. The "corresponding
position" means a position corresponding, in a vertical direction (z-axis direction),
to another position and, in other words, it means a position that overlaps another
position in plan view. More specifically, the first shelf part 114 (higher shelf)
is formed so as to correspond to 90 percent or more of the inner peripheral line of
the first upper surface 110 (higher surface), and the second shelf part 116 (lower
shelf) is formed so as to correspond to 90 percent or more of the inner peripheral
line of the second upper surface 112 (lower surface) (see also Fig. 2). As is evident
from Fig. 2, the first shelf part 114 is longer than the second shelf part 116.
[0018] A height difference is provided between the first shelf part 114 and the second shelf
part 116 in the water conveyance shelf 108 so as to be commensurate with the height
difference (step) between the first upper surface 110 and the second upper surface
112 in the upper surface part. The first shelf part 114 and the second shelf part
116 are connected by a smooth inclined surface (shelf inclined surface 120a) (which
will be detailed in association with Fig. 2). Being "smooth" in the present specification
means that surfaces are continuously connected with each other, or surfaces are connected
with each other without including a discontinuous surface.
[0019] In the toilet bowl 106, the upper surface (the first upper surface 110, second upper
surface 112, and upper inclined surfaces 140a and 140b) extends inward, so as to form
an overhang 118 (a rim folded part) over the entire periphery. The overhang 118 is,
in a manner, a roof for the water conveyance shelf 108, and the water conveyance shelf
108 and the overhang 118 form a water passage. The overhang 118 of the first embodiment
is annularly formed along the entire inner periphery of the toilet bowl 106. Although
the details will be described later, the water conveyance shelf 108, excluding part
thereof, includes a surface substantially in parallel with the overhang 118 mainly
in a horizontal direction (the water flowing direction). More specifically, the lower
surface of the overhang 118 (the surface facing the water conveyance shelf 108) is
substantially parallel with the upper surface of the water conveyance shelf 108 in
the water flowing direction.
[0020] Fig. 2 is a top view of the flush toilet 100. Fig. 3 is a sectional side view of
the toilet bowl 106. Fig. 4 is a sectional front view of the toilet bowl 106. Fig.
5 is a schematic diagram that shows flows of water toward a storage region 122.
[0021] The water conveyance shelf 108 is an annular shelf formed along the entire periphery
of the inner wall surface of the toilet bowl 106. The first shelf part 114 and the
second shelf part 116 are smoothly connected by the shelf inclined surface 120a and
a shelf inclined surface 120b. Each of the shelf inclined surfaces 120a and 120b is
located within the rear half of the inner peripheral surface of the toilet bowl 106
in plan view (in the negative direction of the z-axis in Fig. 2). Although the details
will be described later, the shelf inclined surface 120a is an inclined surface on
which the second flush water flows upward, and the shelf inclined surface 120b is
an inclined surface on which the first flush water flows downward. The shelf inclined
surfaces 120a and 120b are positioned symmetrically with respect to a central axis
M (in an x-axis direction in Fig. 2) of the toilet bowl 106. Each of the first shelf
part 114 and the second shelf part 116 may be a shelf extending in a horizontal direction,
or the first shelf part 114 may be gently inclined upward around the front end part
thereof, as shown in Fig. 3. In this case, the shelf inclined surfaces 120a and 120b
are formed to be steeper than the inclination in the first shelf part 114. The first
shelf part 114 extends horizontally.
[0022] Namely, the water conveyance shelf 108 is an annular shelf formed symmetrically with
respect to the central axis M and having a height difference, in which the first shelf
part 114 and the second shelf part 116 are smoothly connected by the shelf inclined
surfaces 120a and 120b.
[0023] The overhang 118 is formed along the entire periphery of the rim in the toilet bowl
106. The overhang 118 includes a first overhang 130 formed at a higher position corresponding
to the first upper surface 110, and a second overhang 132 formed at a lower position
corresponding to the second upper surface 112. The first overhang 130 and the second
overhang 132 are smoothly connected by inclined surface overhangs 134a and 134b. The
inclined surface overhang 134a corresponds to the upper inclined surface 140a and
the shelf inclined surface 120a, and the inclined surface overhang 134b corresponds
to the upper inclined surface 140b and the shelf inclined surface 120b. Accordingly,
each of the inclined surface overhangs 134a and 134b is also located within the rear
half of the inner peripheral surface of the toilet bowl 106 in plan view (in the negative
direction of the z-axis in Fig. 2). The inclined surface overhangs 134a and 134b are
positioned symmetrically with respect to the central axis M (in an x-axis direction
in Fig. 2) of the toilet bowl 106.
[0024] Namely, the overhang 118 is an annular overhang (a rim folded part) formed symmetrically
with respect to the central axis M and having a height difference, in which the first
overhang 130 and the second overhang 132 are smoothly connected by the inclined surface
overhangs 134a and 134b.
[0025] Since each of the overhang 118 and the water conveyance shelf 108 of the first embodiment
is formed symmetrically with respect to the central axis M, the flush toilet 100 is
designed so that the overall harmony can be easily maintained.
[0026] The second discharge port 104 is formed on the shelf inclined surface 120b side,
on the right side in the rear end part of the second shelf part 116. The first discharge
port 102 is formed above the first shelf part 114.
[0027] Most of the flush water flowing into the toilet bowl 106 through the first discharge
port 102 or the second discharge port 104 is discharged into a sewage pipe (not illustrated)
through an outlet 128 of a storage region 122, but part of the flush water is pooled
in the storage region 122 to seal the toilet bowl 106 and the sewage pipe. On a side
surface of the storage region 122, a third discharge port 124 is further formed. Part
of the flush water supplied from the tank of the flush toilet 100 is discharged as
first flush water S1 through the first discharge port 102 (course C1), another part
of the flush water is discharged as second flush water S2 through the second discharge
port 104 (course C2), and the rest of the flush water is discharged as "third flush
water S3" through the third discharge port 124 (course C3). Each of the courses C1-C3
shows the main flow of the flush water from the corresponding discharge port. Waste
brought by the first flush water S1 and the second flush water S2 into the storage
region 122 is pushed out by the third flush water S3 through the outlet 128 located
posteriorly in the storage region 122.
[0028] The first discharge port 102 is formed on an upper part (rim) of the left side surface
(the negative direction side of the y-axis) of the flush toilet 100 viewed from the
front. The first flush water S1 discharged through the first discharge port 102 largely
swirls in the counterclockwise direction upon the water conveyance shelf 108 (first
shelf part 114) to widely flush the front surface and the both side surfaces of the
inner wall surface of the toilet bowl 106. While swirling upon the first shelf part
114, the first flush water S1 loses kinetic energy before reaching the shelf inclined
surface 120b, so as to deviate from the course and flow down into the storage region
122 (see S1 in Fig. 2).
[0029] The second flush water S2 discharged through the second discharge port 104 flows
through the water conveyance shelf 108 (second shelf part 116) to locally flush an
upper part of the rear end surface of the toilet bowl 106, and then deviates from
the course because of the upward inclination (height difference) of the shelf inclined
surface 120a, so as to flow down into the storage region 122 (see S2 in Fig. 2).
[0030] The shelf inclined surface 120a is positioned in a rear and side part with respect
to an opening R (see Fig. 3) of the storage region 122. More specifically, when the
midpoint in an x direction (a longitudinal direction) of the opening R is defined
as P, the shelf inclined surface 120a is formed at a position on the rear end side
and the left side with respect to the midpoint P in plan view. Accordingly, after
flowing up along the shelf inclined surface 120a, the second flush water S2 flows
along a side of a receiving surface 142 and then directly flows down into the storage
region 122 (see also Fig. 2). As shown in Fig. 3, most of the second shelf part 116
and the first shelf part 114 are formed in a horizontal direction.
[0031] In the first embodiment, the first shelf part 114 is formed at a position higher
than the second upper surface 112 of the recess part 138 (see Fig. 4).
[0032] Part of the second flush water S2 may be merged into the first flush water S1 without
flowing down, but it may be desirable that the main flow of the second flush water
S2 flows down without being merged into the first flush water S1. The "main flow"
means 60 percent or above, preferably 80 percent or above and more preferably 95 percent
or above, of the total amount of the second flush water S2 discharged through the
second discharge port 104. To the total amount of the second flush water S2, the proportion
of water flowing down without being merged into the first flush water S1 can be obtained
by simulation calculation based on the position and size of the second discharge port
104, the flow rate of the second flush water S2, the shape and climbing angle of the
shelf inclined surface 120a, and other various parameters.
[0033] The first flush water S1 swirls along the inner wall of the toilet bowl 106 and then
flows down from the right side, thereby widely providing the flushing force and water
discharge force. Also, the second flush water S2 flushes the rear end surface of the
toilet bowl 106, which is particularly likely to get dirty, and then flows down from
the rear left side, thereby locally providing the flushing force and water discharge
force to the rear end surface. Further, the third flush water S3 stirs the storage
region 122 and pushes the waste out through the outlet 128, thereby providing the
draining force.
[0034] As shown in Fig. 5, waste 126 is gathered in the storage region 122. There is waste
that floats on the pooled water, such as waste 126a-126c, and waste that sinks, such
as waste 126d. Each of the first flush water S1 and the second flush water S2 flows
down into the storage region 122 from a different direction and sinks the waste 126a-126c
into the storage region 122. The third flush water S3 pushes the waste 126a-126d thus
gathered in the bottom part of the storage region 122 out through the outlet 128.
Hereinafter, the force of sinking the waste 126 into the storage region 122 will be
referred to as the "sinking force". In order to certainly sink floating waste 126,
it is desirable to allow a certain amount of flush water to flow down from a sufficient
height.
[0035] In the case of Fig. 5, the sinking force of the first flush water S1 is applied to
the waste 126a and 126b, but, since the waste 126c is not present immediately below
the flow of the first flush water S1, the waste 126c is less likely to receive the
sinking force of the first flush water S1. However, since the waste 126c is present
immediately below the flow of the second flush water S2, the waste 126c receives the
sinking force of the second flush water S2. In the first embodiment, since the first
flush water S1 and the second flush water S2 flows down from the left and right directions,
the sinking force can be effectively provided to floating waste 126.
[0036] The description will now return to Fig. 2. After flushing the rear end surface of
the toilet bowl 106, most of the second flush water S2 flows down during or after
the flowing up along the shelf inclined surface 120a. Generally, in order to change
the water flowing direction within the toilet bowl 106, the shape of the inner wall
surface of the toilet bowl 106, particularly the curvature of a water passage in plan
view (x-y plane), is often changed. However, the design for largely changing the water
flowing direction by changing the curvature on an x-y plane is difficult. Meanwhile,
in the first embodiment, the water flowing direction is changed by means of the inclination
in a vertical direction (z direction) of the shelf inclined surface 120a. Since the
angle of the shelf inclined surface 120a can be changed relatively easily, the design
for water flow control can be easily provided.
[0037] Also, the second flush water S2 may be made to flow down by allowing the second flush
water S2 that has flowed up along the shelf inclined surface 120a to hit on the back
surface of the overhang 118 (which will be detailed in association with Fig. 6). In
this case, the overhang 118 may be desirably formed to largely extend at a point where
the second flush water S2 flowing up along the shelf inclined surface 120a enters
the first shelf part 114. Since the second flush water S2 that does not flow down
will be merged into the first flush water S1, the second flush water S2 can be efficiently
and entirely used.
[0038] Fig. 6 is a diagram that schematically shows a height relationship between the first
shelf part 114 and the second shelf part 116 in the first embodiment. Fig. 7 is a
diagram that schematically shows a height relationship between the first shelf part
114 and the second shelf part 116 in a comparative example.
[0039] The difference between Fig. 6 and Fig. 7 is whether or not the shelf inclined surface
120a is parallel with the overhang 118 near the second shelf part 116.
[0040] Based on the floor surface (mounting surface) of the flush toilet 100, the height
of the second shelf part 116 is defined as H2, and the height of the first shelf part
114 is defined as H1. With regard to the overhang 118, the height of the back surface
of the second overhang 132 corresponding to the second upper surface 112 is defined
as H3, and the height of the back surface of the first overhang 130 corresponding
to the first upper surface 110 is defined as H4. Also, the height of the second upper
surface 112 (upper surface of the second overhang 132) is defined as H5, and the height
of the first upper surface 110 (upper surface of the first overhang 130) is defined
as H6.
[0041] The height of a water passage formed between the second shelf part 116 and the second
overhang 132 is defined as T2 (= H3-H2). Also, the height of a water passage formed
between the first shelf part 114 and the first overhang 130 is defined as T1 (= H4-H1).
[0042] The boundary point between the second shelf part 116 and the shelf inclined surface
120a is defined as P1, the boundary point between the shelf inclined surface 120a
and the first shelf part 114 is defined as P3, and the middle point between P1 and
P3 is defined as P2. Also, the position of the first discharge port 102 is defined
as P4.
[0043] The second flush water S2 discharged through the second discharge port 104 flows
through the second shelf part 116 and flows up along the shelf inclined surface 120a,
losing kinetic energy, so as to flow down toward the storage region 122 while swirling.
The second flush water S2 may be made to hit on the back surface of the first overhang
130 and rebound therefrom in the direction toward the storage region 122. Accordingly,
it is desirable that a sufficient size of the overhang 118 is formed at least at the
point where the second flush water S2 flowing up along the shelf inclined surface
120a enters the first shelf part 114. More specifically, it is desirable that the
first overhang 130 is formed at least in the section between P3 and P4.
[0044] The shelf inclined surface 120a and the inclined surface overhang 134a are at least
partially parallel with each other in the water flowing direction. More specifically,
at least in the section between P1 and P2, the shelf inclined surface 120a and the
back surface of the overhang 118 (inclined surface overhang 134a) positioned thereabove
are substantially parallel with each other. The "substantially parallel" means that
the difference between the climbing angle of the shelf inclined surface 120a and the
climbing angle of the inclined surface overhang 134a is 5 percent or less, preferably
1 percent or less. The "substantially parallel" in the present specification means
that the difference in surface angle between the two surfaces is 5 percent or less,
preferably 1 percent or less. As shown in the comparative example of Fig. 7, when
the climbing angle of the inclined surface overhang 134a is steeper than the climbing
angle of the shelf inclined surface 120a, a dead region 136 (an unflushed region)
is formed below the inclined surface overhang 134a, and it may be unable to flush
the region sufficiently. The experiments performed by the inventors and others have
found that, in the configuration as shown in the comparative example of Fig. 7, when
the second flush water S2 passes P1 and is then diffused in a vertical direction,
a sufficient amount of the second flush water S2 is less likely to reach the back
surface of the overhang 118 around P3. However, by configuring the shelf inclined
surface 120a and the inclined surface overhang 134a to be substantially parallel with
each other in the section between P1 and P2, as shown in Fig. 6, the formation of
the dead region 136 can be prevented.
[0045] Within the section between P1 and P2, the shelf inclined surface 120a is substantially
parallel with not only the inclined surface overhang 134a but also the upper inclined
surface 140a in the water flowing direction.
[0046] Since the shelf inclined surface 120a is smoothly connected to the second shelf part
116, the second flush water can be smoothly led to the shelf inclined surface 120a
while the force of the flush water can be maintained.
[0047] After the second flush water flows up along the shelf inclined surface 120a and passes
P3, part of the flush water flows down therefrom, and another part of the flush water
hits on the back surface of the first overhang 130 and rebounds therefrom. Accordingly,
the shelf inclined surface 120a needs to have a certain degree of gradient. The shelf
inclined surface 120a may desirably include a gradient surface of 10 degrees or greater,
preferably 35 degrees or greater.
[0048] Within the section between P1 and P2, the shelf inclined surface 120a and the inclined
surface overhang 134a are substantially parallel with each other in the inclination
direction. Similarly, the second shelf part 116 and the second overhang 132 are substantially
parallel with each other in a horizontal direction, and the first shelf part 114 and
the first overhang 130 are also substantially parallel with each other in a horizontal
direction. The same applies to the shelf inclined surface 120b and the inclined surface
overhang 134b. Although both the water conveyance shelf 108 and the overhang 118 are
annularly formed along the entire periphery of the toilet bowl 106, it is desirable
that 80 percent or more, preferably 90 percent or more, of the entire periphery of
the water conveyance shelf 108 is substantially parallel with the overhang 118. Alternatively,
it is desirable that 80 percent or more, preferably 90 percent or more, of the entire
periphery of the water conveyance shelf 108 is substantially parallel with the upper
surface (the first upper surface 110, second upper surface 112, upper inclined surface
140a, and upper inclined surface 140b). By configuring the water conveyance shelf
108 so that the overhang 118 and the water conveyance shelf 108, or the upper surface
and the water conveyance shelf 108, are substantially parallel with each other, the
overall harmony in the design of the flush toilet 100 can be improved.
[0049] Compared to the height difference D1 (= H6-H5) between the first upper surface 110
and the second upper surface 112, the height difference D2 (= H1-H2) between the first
shelf part 114 and the second shelf part 116 is smaller. This is because the height
T2 (= H3-H2) of the water passage in the second shelf part 116 is smaller than the
height T1 (= H4-H1) of the water passage in the first shelf part 114. Thus, compared
to the height difference D1 between the first upper surface 110 and the second upper
surface 112, the height difference D2 in the water conveyance shelf 108 is slightly
moderated.
[0050] In order to make the height difference D1 and the height difference D2 equal to each
other, the second shelf part 116 may be formed at a position lower than H2 in Fig.
6. In this case, however, the potential energy of the second flush water will be smaller.
Also, when the water passage in the second shelf part 116 is narrower, the pressure
of the second flush water can be increased, and hence, the rear end surface can be
strongly flushed.
[0051] Also, in order to make the height difference D1 and the height difference D2 equal
to each other, the first shelf part 114 may be formed at a position higher than H1
in Fig. 6. In this case, however, since the height T1 will be smaller, the opening
of the first discharge port 102 will also be smaller, and hence, the amount of water
discharged through the first discharge port 102 will be reduced. Since the first flush
water S1 needs to be sufficiently provided to the long first shelf part 114, and,
particularly, a sufficient amount of water needs to be provided to the front end part
of the toilet bowl 106, adding structural restriction on the amount of water discharged
through the first discharge port 102 is unfavorable.
[0052] Accordingly, in the first embodiment, the height difference D2 is provided between
the first shelf part 114 and the second shelf part 116 so as to be commensurate with
the height difference D1 between the first upper surface 110 and the second upper
surface 112, and the water conveyance shelf 108 is formed so that T2 is smaller than
T1 (T2<T1, D2<D1). With such a configuration, the flushing properties and the harmony
of design can be balanced with each other.
[0053] In the first embodiment, the height T2 of the water passage in the second shelf part
116 is smaller than the height T1 of the water passage in the first shelf part 114.
It is desirable that at least an average of the height of the water passage in the
second shelf part 116 is smaller than an average of the height of the water passage
in the first shelf part 114.
[0054] In the section between P1 and P4, the vertical width of the water passage is increased
from T2 to T1. In the first embodiment, the vertical width of the water passage is
maintained at T2 in the section between P1 and P2, and is then increased from T2 to
T1 in the section between P2 and P3. The vertical width of the water passage has only
to be increased at least within the section between P1 and P4. However, it is more
suitable to maintain the vertical width of the water passage at T2 also in the section
between P1 and P2 because the dead region 136 (unflushed region) is less likely to
be formed, as described previously.
[0055] The rear end surface of the toilet bowl 106 is particularly likely to get dirty.
It will be desirable if such a region likely to get dirty can be flushed with flush
water at a higher flow rate. Since the section between P2 and P3 is less likely to
get dirty compared to the section between P1 and P2, it is suitable to increase the
vertical width of the water passage in the section between P2 and P3 rather than in
the section between P1 and P2.
[0056] The second flush water S2 discharged through the second discharge port 104 flows
up along the shelf inclined surface 120a and passes P2, and then diffuses in a vertical
direction in the section between P2 and P3. Part of the flush water flows down therefrom,
and another part of the flush water hits on the back surface of the first overhang
130 and flows down therefrom.
[0057] The overhang 118 forms a water passage and prevents scattering of waste or flush
water toward the first upper surface 110 and the second upper surface 112. Particularly,
the second overhang 132 prevents scattering of waste or flush water toward a functional
unit mounted on the second upper surface 112. Upward scattering of waste that has
scattered toward the rear end surface can be prevented by the back surface of the
second overhang 132, which is flushed with the second flush water S2 afterward.
[0058] In the first embodiment, the flowing path of the second flush water S2 is changed
(deviated from the course) to the flowing down direction by means of the inclination
in a longitudinal direction of the shelf inclined surface 120a. By combining the shelf
inclined surface 120a and the overhang 118, the water flowing direction can be changed
more easily and efficiently.
[0059] In the first embodiment, even when a recess part (the second upper surface 112) is
formed in the rear end part of the flush toilet 100, the restriction on the design
of the water conveyance shelf 108 due to the recess part can be even utilized positively.
By means of the height difference in the water conveyance shelf 108, the flow rate
of the flush water can be increased or reduced, or the flow of flush water can be
positively deviated from the course on the water conveyance shelf 108.
[0060] The first flush water S1 swirls upon the first shelf part 114 retaining the potential
energy. The first flush water S1 then deviates from the course before the shelf inclined
surface 120b and flows down into the storage region 122.
[0061] The second flush water S2 flows through a narrow water passage on the second shelf
part 116 at a high flow rate to flush the rear end surface, and then flows up along
the shelf inclined surface 120a and deviates from the course. Also, part of the second
flush water S2 splashing from the shelf inclined surface 120a strongly rebounds from
the overhang 118 toward the storage region 122.
[0062] In this way, in the first embodiment, the flow of the second flush water S2 is deviated
from the course to the flowing down direction by means of the height difference in
the shelf inclined surface 120a. After flowing through the shelf inclined surface
120b, part of the first flush water S1 may be merged into the second flush water S2.
However, since the second flush water S2 will slow down if the first flush water S1,
which has flowed around in the toilet bowl 106 and has slowed down, is merged into
the second flush water S2, it is desirable that the proportion of the first flush
water S1 to be merged into the second flush water S2 after flowing around is a small
amount less than 20 percent, preferably less than 10 percent.
[0063] The present invention has been described with reference to the first embodiment.
The embodiment is intended to be illustrative only, and it will be obvious to those
skilled in the art that various modifications and changes could be developed within
the scope of claims of the present invention and that such modifications and changes
also fall within the scope of claims of the present invention. Therefore, the description
in the present specification and the drawings should be regarded as exemplary rather
than limitative.
[0064] In the flowing, modifications of the first embodiment will be described.
(First Modification)
[0065] In the first embodiment, a stepped surface including the first upper surface 110
and the second upper surface 112 is provided to form a recess part, on which a functional
unit is mounted, in the rear end part of the flush toilet 100. However, the present
invention is also applicable to designing when the water conveyance shelf 108 is formed
so as to correspond to a step on the upper surface, which is not limited to a recess
part. The width of the water conveyance shelf 108 need not necessarily be constant
and may be changed depending on a place. Also, the water conveyance shelf 108 need
not necessarily be horizontal and may be inclined or curved with respect to a horizontal
plane. Further, the water conveyance shelf 108 need not necessarily be continuously
provided along the entire periphery of the toilet bowl 106 and may partially include
a discontinuous region (such as a cutout).
(Second Modification)
[0066] In the first embodiment, each of the back surface of the overhang 118 and the upper
surface of the water conveyance shelf 108 forms a horizontal surface.
Accordingly, the cross section of the water passage between the overhang 118 and the
water conveyance shelf 108 is rectangular (see the region U in Fig. 4). As a modification,
the overhang 118 and the water conveyance shelf 108 may be smoothly connected, so
that the cross section of the water passage includes an arc. In the present invention,
the overhang 118 is an optional component and is not an essential component.
[0067] According to the description above, the following inventions can be found.
[0068] A flush toilet according to one embodiment of the present invention includes: a body
part with a toilet bowl part formed therein, including a first upper surface positioned
higher and a second upper surface positioned lower; a water conveyance shelf formed
along a circumferential direction of the toilet bowl part on an inner wall surface
of the toilet bowl part; and a discharge port formed so that water is discharged therethrough
to the water conveyance shelf.
[0069] The water conveyance shelf includes a first shelf part formed at a corresponding
position of the first upper surface and also includes a second shelf part formed at
a corresponding position of the second upper surface. The second shelf part is positioned
lower than the first shelf part.
[0070] A height difference is provided in the water conveyance shelf so as to be commensurate
with the height difference in the upper surface, and, by means of the height difference
in the water conveyance shelf, the flow of water can be controlled.
[0071] The second shelf part may be smoothly connected with the first shelf part by a shelf
inclined surface.
[0072] By smoothly connecting the first shelf part and the second shelf part, the force
of flush water can be maintained more easily.
[0073] The first upper surface and the second upper surface may be smoothly connected by
an upper inclined surface. The shelf inclined surface may be an inclined surface substantially
parallel with the upper inclined surface at least in a section between the boundary
point between the second shelf part and the shelf inclined surface and the center
point in the shelf inclined surface.
[0074] By making the shelf inclined surface and the upper inclined surface parallel with
each other, the overall harmony in design can be maintained more easily.
[0075] On the upper inclined surface of the body part, an overhang part extending inward
may be further formed. The shelf inclined surface may be an inclined surface substantially
parallel with the overhang part at least in a section between the boundary point between
the second shelf part and the shelf inclined surface and the center point in the shelf
inclined surface.
[0076] The toilet bowl part may include a first discharge port and a second discharge port
formed therein. The first discharge port may be formed so that water is discharged
therethrough to the first shelf part, and the second discharge port may be formed
so that water is discharged therethrough to the second shelf part.
[0077] By making the height difference between the first shelf part and the second shelf
part smaller than the height difference between the first upper surface and the second
upper surface, the overall harmony in design can be maintained more easily.
[0078] Along the entire periphery of the upper surface of the body part, an overhang part
extending inward may be further formed. The water conveyance shelf may be annularly
formed along the entire periphery of the toilet bowl part, and at least 80 percent
of the entire periphery of the water conveyance shelf may be substantially parallel
with the overhang part.
[0079] An average of the interval between the first shelf part and the first upper surface
may be greater than an average of the interval between the second shelf part and the
second upper surface.
[0080] Within a range between the boundary point between the second shelf part and the shelf
inclined surface and the first discharge port formed in the toilet bowl part, the
interval between the water conveyance shelf and an upper surface part may be increased
toward the first discharge port.
[0081] In a rear end part of the upper surface of the toilet bowl part, a recess part may
be formed. The second upper surface may correspond to the bottom surface of the recess
part. Within a range between the boundary point between the second shelf part and
the shelf inclined surface and the first discharge port formed in the toilet bowl
part, the interval between the water conveyance shelf and an upper surface part may
be increased toward the first discharge port.
[0082] A flush toilet according to another embodiment of the present invention includes:
a body part with a toilet bowl part formed therein; a water conveyance shelf formed
along a circumferential direction on an inner wall surface of the toilet bowl part
and including a first shelf part positioned higher and a second shelf part positioned
lower; a first discharge port formed so that water is discharged therethrough to the
first shelf part; and a second discharge port positioned lower than the first discharge
port and formed so that water is discharged therethrough to the second shelf part.
[0083] The first shelf part and the second shelf part may be smoothly connected by a shelf
inclined surface.
[0084] By smoothly connecting the first shelf part and the second shelf part with the shelf
inclined surface therebetween, the force of flush water can be maintained, and, also
by means of the height difference in the shelf inclined surface, flush water can be
led in the flowing down direction.
[0085] At least at a point where flush water that has flowed through the second shelf part
and flowed up along the shelf inclined surface enters the first shelf part, an overhang
part may be formed on the upper surface of the toilet bowl part.
[0086] In a bottom part of the toilet bowl part, a storage region may be formed to pool
flush water. The main flow of water discharged through the second discharge port may
be made to flow down into the storage region without being merged into water discharged
through the first discharge port in the first shelf part.
[0087] By allowing the main flow of water discharged through the second discharge port to
flow down before being merged into water discharged through the first discharge port,
the draining force can be increased more easily.
[0088] The amount of water discharged through the second discharge port and flowing up along
the shelf inclined surface to be merged into water discharged through the first discharge
port may be less than 20 percent of the total amount of the water discharged through
the second discharge port.
[0089] The shelf inclined surface along which water discharged through the second discharge
port flows up may include a gradient surface of 10 degrees or greater.
[0090] The water conveyance shelf may be annularly formed along the entire periphery of
the toilet bowl part, in which the first shelf part and the second shelf part are
connected by two shelf inclined surfaces. Each of the two shelf inclined surfaces
may be formed in the rear half of the toilet bowl part in plan view.
[0091] The first shelf part may be longer than the second shelf part.
[0092] A shelf inclined surface along which flush water that has flowed through the second
shelf part flows up toward the first shelf part may be formed in a side part, in plan
view, with respect to a storage region formed in a bottom part of the toilet bowl
part.
(Second Embodiment)
[0093] Fig. 8 is an external perspective view of a flush toilet 200.
[0094] In a body part 244 of the flush toilet 200, a toilet bowl 206 is formed. Also, in
the body part 244, flush water stored in an external tank is discharged to the toilet
bowl 206 through a first discharge port 202 and a second discharge port 204. Part
of the flush water is also discharged through a third discharge port, which will be
described later in association with Fig. 9. The third discharge port may be a so-called
jet discharge port. The first discharge port 202 is formed on a side surface (the
negative direction side of the y-axis) of the toilet bowl 206. The second discharge
port 204 is formed on a rear end surface (the negative direction side of the x-axis)
of the toilet bowl 206. Along the entire periphery of the inner wall of the toilet
bowl 206, a water conveyance shelf 208 is annularly formed. The flush water discharged
through the second discharge port 204 (hereinafter, referred to as "second flush water")
flows upon the water conveyance shelf 208, and most of the flush water flows down
into the toilet bowl 206 before the first discharge port 202, while the remaining
flush water is merged into the flush water discharged through the first discharge
port 202 (hereinafter, referred to as "first flush water"). The first flush water
swirls upon the water conveyance shelf 208, thereby flushing the entirety of the toilet
bowl 206, particularly the front surface and the both side surfaces of the inner wall.
[0095] The upper surface of the toilet bowl 206 is formed as a stepped surface including
a first upper surface 210 positioned higher and a second upper surface 212 positioned
lower. The second upper surface 212 in the second embodiment forms a flat bottom surface
of a recess part 238 in the upper surface. However, the second upper surface 212 need
not necessarily be flat, and it may be formed as a surface curved downward or upward,
or a projection or a cutout may be formed in part of the second upper surface 212.
On the recess part 238 (upon the second upper surface 212), a functional unit (not
illustrated) for providing the pubic lavage function or the warm air function, for
example, is mounted. The second upper surface 212 and the first upper surface 210
are smoothly connected by two upper inclined surfaces 240a and 240b, so that an annular
upper surface having a height difference is formed.
[0096] The water conveyance shelf 208 includes a first shelf part 214 positioned higher
and a second shelf part 216 positioned lower. The first shelf part 214 is formed at
a corresponding position of the first upper surface 210, and the second shelf part
216 is formed at a corresponding position of the second upper surface 212. The "corresponding
position" means a position corresponding, in a vertical direction (z-axis direction),
to another position and, in other words, it means a position that overlaps another
position in plan view. More specifically, the first shelf part 214 (higher shelf)
is formed so as to correspond to 90 percent or more of the inner peripheral line of
the first upper surface 210 (higher surface), and the second shelf part 216 (lower
shelf) is formed so as to correspond to 90 percent or more of the inner peripheral
line of the second upper surface 212 (lower surface) (see also Fig. 9). As is evident
from Fig. 9, the first shelf part 214 is longer than the second shelf part 216.
[0097] A height difference is provided between the first shelf part 214 and the second shelf
part 216 in the water conveyance shelf 208 so as to be commensurate with the height
difference (step) between the first upper surface 210 and the second upper surface
212 in the upper surface part. The first shelf part 214 and the second shelf part
216 are connected by a smooth inclined surface (shelf inclined surface 220a) (which
will be detailed in association with Fig. 9). Being "smooth" in the present specification
means that surfaces are continuously connected with each other, or surfaces are connected
with each other without including a discontinuous surface.
[0098] In the toilet bowl 206, the upper surface (the first upper surface 210, second upper
surface 212, and upper inclined surfaces 240a and 240b) extends inward, so as to form
an overhang 218 (a rim folded part) over the entire periphery. The overhang 218 is,
in a manner, a roof for the water conveyance shelf 208, and the water conveyance shelf
208 and the overhang 218 form a water passage. The overhang 218 of the second embodiment
is annularly formed along the entire inner periphery of the toilet bowl 206. Although
the details will be described later, the water conveyance shelf 208, excluding part
thereof, includes a surface substantially in parallel with the overhang 218 mainly
in a horizontal direction (the water flowing direction). More specifically, the lower
surface of the overhang 218 (the surface facing the water conveyance shelf 208) is
substantially parallel with the upper surface of the water conveyance shelf 208 in
the water flowing direction.
[0099] Fig. 9 is a top view of the flush toilet 200. Fig. 10 is a sectional side view of
the toilet bowl 206. Fig. 11 is a sectional front view of the toilet bowl 206. Fig.
12 is a schematic diagram that shows flows of water toward a storage region 222.
[0100] The water conveyance shelf 208 is an annular shelf formed along the entire periphery
of the inner wall surface of the toilet bowl 206. The first shelf part 214 and the
second shelf part 216 are smoothly connected by the shelf inclined surface 220a and
a shelf inclined surface 220b. Each of the shelf inclined surfaces 220a and 220b is
located within the rear half of the inner peripheral surface of the toilet bowl 206
in plan view (in the negative direction of the z-axis in Fig. 9). Although the details
will be described later, the shelf inclined surface 220a is an inclined surface on
which the second flush water flows upward, and the shelf inclined surface 220b is
an inclined surface on which the first flush water flows downward. The shelf inclined
surfaces 220a and 220b are positioned symmetrically with respect to a central axis
M (in an x-axis direction in Fig. 9) of the toilet bowl 206. Each of the first shelf
part 214 and the second shelf part 216 may be a shelf extending in a horizontal direction,
or the first shelf part 214 may be gently inclined upward around the front end part
thereof, as shown in Fig. 10. In this case, the shelf inclined surfaces 220a and 220b
are formed to be steeper than the inclination in the first shelf part 214. The first
shelf part 214 extends horizontally.
[0101] Namely, the water conveyance shelf 208 is an annular shelf formed symmetrically with
respect to the central axis M and having a height difference, in which the first shelf
part 214 and the second shelf part 216 are smoothly connected by the shelf inclined
surfaces 220a and 220b.
[0102] The overhang 218 is formed along the entire periphery of the rim in the toilet bowl
206. The overhang 218 includes a first overhang 230 formed at a higher position corresponding
to the first upper surface 210, and a second overhang 232 formed at a lower position
corresponding to the second upper surface 212. The first overhang 230 and the second
overhang 232 are smoothly connected by inclined surface overhangs 234a and 234b. The
inclined surface overhang 234a corresponds to the upper inclined surface 240a and
the shelf inclined surface 220a, and the inclined surface overhang 234b corresponds
to the upper inclined surface 240b and the shelf inclined surface 220b. Accordingly,
each of the inclined surface overhangs 234a and 234b is also located within the rear
half of the inner peripheral surface of the toilet bowl 206 in plan view (in the negative
direction of the z-axis in Fig. 9). The inclined surface overhangs 234a and 234b are
positioned symmetrically with respect to the central axis M (in an x-axis direction
in Fig. 9) of the toilet bowl 206.
[0103] Namely, the overhang 218 is an annular overhang (a rim folded part) formed symmetrically
with respect to the central axis M and having a height difference, in which the first
overhang 230 and the second overhang 232 are smoothly connected by the inclined surface
overhangs 234a and 234b.
[0104] Since each of the overhang 218 and the water conveyance shelf 208 of the second embodiment
is formed symmetrically with respect to the central axis M, the flush toilet 200 is
designed so that the overall harmony can be easily maintained.
[0105] The second discharge port 204 is formed on the shelf inclined surface 220b side,
on the right side in the rear end part of the second shelf part 216. The first discharge
port 202 is formed above the first shelf part 214.
[0106] Most of the flush water flowing into the toilet bowl 206 through the first discharge
port 202 or the second discharge port 204 is discharged into a sewage pipe (not illustrated)
through an outlet 228 of a storage region 222, but part of the flush water is pooled
in the storage region 222 to seal the toilet bowl 206 and the sewage pipe. On a side
surface of the storage region 222, a third discharge port 224 is further formed. Part
of the flush water supplied from the tank of the flush toilet 200 is discharged as
first flush water S1 through the first discharge port 202 (course C1), another part
of the flush water is discharged as second flush water S2 through the second discharge
port 204 (course C2), and the rest of the flush water is discharged as "third flush
water S3" through the third discharge port 224 (course C3). Each of the courses C1-C3
shows the main flow of the flush water from the corresponding discharge port. Waste
brought by the first flush water S1 and the second flush water S2 into the storage
region 222 is pushed out by the third flush water S3 through the outlet 228 located
posteriorly in the storage region 222.
[0107] The first discharge port 202 is formed on an upper part (rim) of the left side surface
(the negative direction side of the y-axis) of the flush toilet 200 viewed from the
front. The first flush water S1 discharged through the first discharge port 202 largely
swirls in the counterclockwise direction upon the water conveyance shelf 208 (first
shelf part 214) to widely flush the front surface and the both side surfaces of the
inner wall surface of the toilet bowl 206. While swirling upon the first shelf part
214, the first flush water S1 loses kinetic energy before reaching the shelf inclined
surface 220b, so as to deviate from the course and flow down into the storage region
222 (see S1 in Fig. 9).
[0108] The second flush water S2 discharged through the second discharge port 204 flows
through the water conveyance shelf 208 (second shelf part 216) to locally flush an
upper part of the rear end surface of the toilet bowl 206, and then deviates from
the course because of the upward inclination (height difference) of the shelf inclined
surface 220a, so as to flow down into the storage region 222 (see S2 in Fig. 9).
[0109] The shelf inclined surface 220a is positioned in a rear and side part with respect
to an opening R (see Fig. 10) of the storage region 222. More specifically, when the
midpoint in an x direction (a longitudinal direction) of the opening R is defined
as P, the shelf inclined surface 220a is formed at a position on the rear end side
and the left side with respect to the midpoint P in plan view. Accordingly, after
flowing up along the shelf inclined surface 220a, the second flush water S2 flows
along a side of a receiving surface 242 and then directly flows down into the storage
region 222 (see also Fig. 9). As shown in Fig. 10, most of the second shelf part 216
and the first shelf part 214 are formed in a horizontal direction.
[0110] In the second embodiment, the first shelf part 214 is formed at a position higher
than the second upper surface 212 of the recess part 238 (see Fig. 11).
[0111] Part of the second flush water S2 may be merged into the first flush water S1 without
flowing down, but it may be desirable that the main flow of the second flush water
S2 flows down without being merged into the first flush water S1. The "main flow"
means 60 percent or above, preferably 80 percent or above and more preferably 95 percent
or above, of the total amount of the second flush water S2 discharged through the
second discharge port 204. To the total amount of the second flush water S2, the proportion
of water flowing down without being merged into the first flush water S1 can be obtained
by simulation calculation based on the position and size of the second discharge port
204, the flow rate of the second flush water S2, the shape and climbing angle of the
shelf inclined surface 220a, and other various parameters.
[0112] The first flush water S1 swirls along the inner wall of the toilet bowl 206 and then
flows down from the right side, thereby widely providing the flushing force and water
discharge force. Also, the second flush water S2 flushes the rear end surface of the
toilet bowl 206, which is particularly likely to get dirty, and then flows down from
the rear left side, thereby locally providing the flushing force and water discharge
force to the rear end surface. Further, the third flush water S3 stirs the storage
region 222 and pushes the waste out through the outlet 228, thereby providing the
draining force.
[0113] As shown in Fig. 12, waste 226 is gathered in the storage region 222. There is waste
that floats on the pooled water, such as waste 226a-226c, and waste that sinks, such
as waste 226d. Each of the first flush water S1 and the second flush water S2 flows
down into the storage region 222 from a different direction and sinks the waste 226a-226c
into the storage region 222. The third flush water S3 pushes the waste 226a-226d thus
gathered in the bottom part of the storage region 222 out through the outlet 228.
Hereinafter, the force of sinking the waste 226 into the storage region 222 will be
referred to as the "sinking force". In order to certainly sink floating waste 226,
it is desirable to allow a certain amount of flush water to flow down from a sufficient
height.
[0114] In the case of Fig. 12, the sinking force of the first flush water S1 is applied
to the waste 226a and 226b, but, since the waste 226c is not present immediately below
the flow of the first flush water S1, the waste 226c is less likely to receive the
sinking force of the first flush water S1. However, since the waste 226c is present
immediately below the flow of the second flush water S2, the waste 226c receives the
sinking force of the second flush water S2. In the second embodiment, since the first
flush water S1 and the second flush water S2 flows down from the left and right directions,
the sinking force can be effectively provided to floating waste 226.
[0115] The description will now return to Fig. 9. After flushing the rear end surface of
the toilet bowl 206, most of the second flush water S2 flows down during or after
the flowing up along the shelf inclined surface 220a. Generally, in order to change
the water flowing direction within the toilet bowl 206, the shape of the inner wall
surface of the toilet bowl 206, particularly the curvature of a water passage in plan
view (x-y plane), is often changed. However, the design for largely changing the water
flowing direction by changing the curvature on an x-y plane is difficult. Meanwhile,
in the second embodiment, the water flowing direction is changed by means of the inclination
in a vertical direction (z direction) of the shelf inclined surface 220a. Since the
angle of the shelf inclined surface 220a can be changed relatively easily, the design
for water flow control can be easily provided.
[0116] Also, the second flush water S2 may be made to flow down by allowing the second flush
water S2 that has flowed up along the shelf inclined surface 220a to hit on the back
surface of the overhang 218 (which will be detailed in association with Fig. 13).
In this case, the overhang 218 may be desirably formed to largely extend at a point
where the second flush water S2 flowing up along the shelf inclined surface 220a enters
the first shelf part 214. Since the second flush water S2 that does not flow down
will be merged into the first flush water S1, the second flush water S2 can be efficiently
and entirely used.
[0117] Fig. 13 is a diagram that schematically shows a height relationship between the first
shelf part 214 and the second shelf part 216 in the second embodiment. Fig. 14 is
a diagram that schematically shows a height relationship between the first shelf part
214 and the second shelf part 216 in a comparative example.
[0118] The difference between Fig. 13 and Fig. 14 is whether or not the shelf inclined surface
220a is parallel with the overhang 218 near the second shelf part 216.
[0119] Based on the floor surface (mounting surface) of the flush toilet 200, the height
of the second shelf part 216 is defined as H2, and the height of the first shelf part
214 is defined as H1. With regard to the overhang 218, the height of the back surface
of the second overhang 232 corresponding to the second upper surface 212 is defined
as H3, and the height of the back surface of the first overhang 230 corresponding
to the first upper surface 210 is defined as H4. Also, the height of the second upper
surface 212 (upper surface of the second overhang 232) is defined as H5, and the height
of the first upper surface 210 (upper surface of the first overhang 230) is defined
as H6.
[0120] The height of a water passage formed between the second shelf part 216 and the second
overhang 232 is defined as T2 (= H3-H2). Also, the height of a water passage formed
between the first shelf part 214 and the first overhang 230 is defined as T1 (= H4-H1).
[0121] The boundary point between the second shelf part 216 and the shelf inclined surface
220a is defined as P1, the boundary point between the shelf inclined surface 220a
and the first shelf part 214 is defined as P3, and the middle point between P1 and
P3 is defined as P2. Also, the position of the first discharge port 202 is defined
as P4.
[0122] The second flush water S2 discharged through the second discharge port 204 flows
through the second shelf part 216 and flows up along the shelf inclined surface 220a,
losing kinetic energy, so as to flow down toward the storage region 222 while swirling.
The second flush water S2 may be made to hit on the back surface of the first overhang
230 and rebound therefrom in the direction toward the storage region 222. Accordingly,
it is desirable that a sufficient size of the overhang 218 is formed at least at the
point where the second flush water S2 flowing up along the shelf inclined surface
220a enters the first shelf part 214. More specifically, it is desirable that the
first overhang 230 is formed at least in the section between P3 and P4.
[0123] The shelf inclined surface 220a and the inclined surface overhang 234a are at least
partially parallel with each other in the water flowing direction. More specifically,
at least in the section between P1 and P2, the shelf inclined surface 220a and the
back surface of the overhang 218 (inclined surface overhang 234a) positioned thereabove
are substantially parallel with each other. The "substantially parallel" means that
the difference between the climbing angle of the shelf inclined surface 220a and the
climbing angle of the inclined surface overhang 234a is 5 percent or less, preferably
1 percent or less. The "substantially parallel" in the present specification means
that the difference in surface angle between the two surfaces is 5 percent or less,
preferably 1 percent or less. As shown in the comparative example of Fig. 14, when
the climbing angle of the inclined surface overhang 234a is steeper than the climbing
angle of the shelf inclined surface 220a, a dead region 236 (an unflushed region)
is formed below the inclined surface overhang 234a, and it may be unable to flush
the region sufficiently. The experiments performed by the inventors and others have
found that, in the configuration as shown in the comparative example of Fig. 14, when
the second flush water S2 passes P1 and is then diffused in a vertical direction,
a sufficient amount of the second flush water S2 is less likely to reach the back
surface of the overhang 218 around P3. However, by configuring the shelf inclined
surface 220a and the inclined surface overhang 234a to be substantially parallel with
each other in the section between P1 and P2, as shown in Fig. 13, the formation of
the dead region 236 can be prevented.
[0124] Within the section between P1 and P2, the shelf inclined surface 220a is substantially
parallel with not only the inclined surface overhang 234a but also the upper inclined
surface 240a in the water flowing direction.
[0125] Since the shelf inclined surface 220a is smoothly connected to the second shelf part
216, the second flush water can be smoothly led to the shelf inclined surface 220a
while the force of the flush water can be maintained.
[0126] After the second flush water flows up along the shelf inclined surface 220a and passes
P3, part of the flush water flows down therefrom, and another part of the flush water
hits on the back surface of the first overhang 230 and rebounds therefrom. Accordingly,
the shelf inclined surface 220a needs to have a certain degree of gradient. The shelf
inclined surface 220a may desirably include a gradient surface of 10 degrees or greater,
preferably 35 degrees or greater.
[0127] Within the section between P1 and P2, the shelf inclined surface 220a and the inclined
surface overhang 234a are substantially parallel with each other in the inclination
direction. Similarly, the second shelf part 216 and the second overhang 232 are substantially
parallel with each other in a horizontal direction, and the first shelf part 214 and
the first overhang 230 are also substantially parallel with each other in a horizontal
direction. The same applies to the shelf inclined surface 220b and the inclined surface
overhang 234b. Although both the water conveyance shelf 208 and the overhang 218 are
annularly formed along the entire periphery of the toilet bowl 206, it is desirable
that 80 percent or more, preferably 90 percent or more, of the entire periphery of
the water conveyance shelf 208 is substantially parallel with the overhang 218. Alternatively,
it is desirable that 80 percent or more, preferably 90 percent or more, of the entire
periphery of the water conveyance shelf 208 is substantially parallel with the upper
surface (the first upper surface 210, second upper surface 212, upper inclined surface
240a, and upper inclined surface 240b). By configuring the water conveyance shelf
208 so that the overhang 218 and the water conveyance shelf 208, or the upper surface
and the water conveyance shelf 208, are substantially parallel with each other, the
overall harmony in the design of the flush toilet 200 can be improved.
[0128] Compared to the height difference D1 (= H6-H5) between the first upper surface 210
and the second upper surface 212, the height difference D2 (= H1-H2) between the first
shelf part 214 and the second shelf part 216 is smaller. This is because the height
T2 (= H3-H2) of the water passage in the second shelf part 216 is smaller than the
height T1 (= H4-H1) of the water passage in the first shelf part 214. Thus, compared
to the height difference D1 between the first upper surface 210 and the second upper
surface 212, the height difference D2 in the water conveyance shelf 208 is slightly
moderated.
[0129] In order to make the height difference D1 and the height difference D2 equal to each
other, the second shelf part 216 may be formed at a position lower than H2 in Fig.
13. In this case, however, the potential energy of the second flush water will be
smaller. Also, when the water passage in the second shelf part 216 is narrower, the
pressure of the second flush water can be increased, and hence, the rear end surface
can be strongly flushed.
[0130] Also, in order to make the height difference D1 and the height difference D2 equal
to each other, the first shelf part 214 may be formed at a position higher than H1
in Fig. 13. In this case, however, since the height T1 will be smaller, the opening
of the first discharge port 202 will also be smaller, and hence, the amount of water
discharged through the first discharge port 202 will be reduced. Since the first flush
water S1 needs to be sufficiently provided to the long first shelf part 214, and,
particularly, a sufficient amount of water needs to be provided to the front end part
of the toilet bowl 206, adding structural restriction on the amount of water discharged
through the first discharge port 202 is unfavorable.
[0131] Accordingly, in the second embodiment, the height difference D2 is provided between
the first shelf part 214 and the second shelf part 216 so as to be commensurate with
the height difference D1 between the first upper surface 210 and the second upper
surface 212, and the water conveyance shelf 208 is formed so that T2 is smaller than
T1 (T2<T1, D2<D1). With such a configuration, the flushing properties and the harmony
of design can be balanced with each other.
[0132] In the second embodiment, the height T2 of the water passage in the second shelf
part 216 is smaller than the height T1 of the water passage in the first shelf part
214. It is desirable that at least an average of the height of the water passage in
the second shelf part 216 is smaller than an average of the height of the water passage
in the first shelf part 214.
[0133] In the section between P1 and P4, the vertical width of the water passage is increased
from T2 to T1. In the second embodiment, the vertical width of the water passage is
maintained at T2 in the section between P1 and P2, and is then increased from T2 to
T1 in the section between P2 and P3. The vertical width of the water passage has only
to be increased at least within the section between P1 and P4. However, it is more
suitable to maintain the vertical width of the water passage at T2 also in the section
between P1 and P2 because the dead region 236 (unflushed region) is less likely to
be formed, as described previously.
[0134] The rear end surface of the toilet bowl 206 is particularly likely to get dirty.
It will be desirable if such a region likely to get dirty can be flushed with flush
water at a higher flow rate. Since the section between P2 and P3 is less likely to
get dirty compared to the section between P1 and P2, it is suitable to increase the
vertical width of the water passage in the section between P2 and P3 rather than in
the section between P1 and P2.
[0135] The second flush water S2 discharged through the second discharge port 204 flows
up along the shelf inclined surface 220a and passes P2, and then diffuses in a vertical
direction in the section between P2 and P3. Part of the flush water flows down therefrom,
and another part of the flush water hits on the back surface of the first overhang
230 and flows down therefrom.
[0136] The overhang 218 forms a water passage and prevents scattering of waste or flush
water toward the first upper surface 210 and the second upper surface 212. Particularly,
the second overhang 232 prevents scattering of waste or flush water toward a functional
unit mounted on the second upper surface 212. Upward scattering of waste that has
scattered toward the rear end surface can be prevented by the back surface of the
second overhang 232, which is flushed with the second flush water S2 afterward.
[0137] In the second embodiment, the flowing path of the second flush water S2 is changed
(deviated from the course) to the flowing down direction by means of the inclination
in a longitudinal direction of the shelf inclined surface 220a. By combining the shelf
inclined surface 220a and the overhang 218, the water flowing direction can be changed
more easily and efficiently.
[0138] In the second embodiment, even when a recess part (the second upper surface 212)
is formed in the rear end part of the flush toilet 200, the restriction on the design
of the water conveyance shelf 208 due to the recess part can be even utilized positively.
By means of the height difference in the water conveyance shelf 208, the flow rate
of the flush water can be increased or reduced, or the flow of flush water can be
positively deviated from the course on the water conveyance shelf 208.
[0139] The first flush water S1 swirls upon the first shelf part 214 retaining the potential
energy. The first flush water S1 then deviates from the course before the shelf inclined
surface 220b and flows down into the storage region 222.
[0140] The second flush water S2 flows through a narrow water passage on the second shelf
part 216 at a high flow rate to flush the rear end surface, and then flows up along
the shelf inclined surface 220a and deviates from the course. Also, part of the second
flush water S2 splashing from the shelf inclined surface 220a strongly rebounds from
the overhang 218 toward the storage region 222.
[0141] In this way, in the second embodiment, the flow of the second flush water S2 is deviated
from the course to the flowing down direction by means of the height difference in
the shelf inclined surface 220a. After flowing through the shelf inclined surface
220b, part of the first flush water S1 may be merged into the second flush water S2.
However, since the second flush water S2 will slow down if the first flush water S1,
which has flowed around in the toilet bowl 206 and has slowed down, is merged into
the second flush water S2, it is desirable that the proportion of the first flush
water S1 to be merged into the second flush water S2 after flowing around is a small
amount less than 20 percent, preferably less than 10 percent.
[0142] The present invention has been described with reference to the second embodiment.
The embodiment is intended to be illustrative only, and it will be obvious to those
skilled in the art that various modifications and changes could be developed within
the scope of claims of the present invention and that such modifications and changes
also fall within the scope of claims of the present invention. Therefore, the description
in the present specification and the drawings should be regarded as exemplary rather
than limitative.
[0143] In the flowing, a modification of the second embodiment will be described.
(Modification)
[0144] In the second embodiment, a stepped surface including the first upper surface 210
and the second upper surface 212 is provided to form a recess part, on which a functional
unit is mounted, in the rear end part of the flush toilet 200. However, the present
invention is also applicable to designing when the water conveyance shelf 208 is formed
so as to correspond to a step on the upper surface, which is not limited to a recess
part. The width of the water conveyance shelf 208 need not necessarily be constant
and may be changed depending on a place. Also, the water conveyance shelf 208 need
not necessarily be horizontal and may be inclined or curved with respect to a horizontal
plane. Further, the water conveyance shelf 208 need not necessarily be continuously
provided along the entire periphery of the toilet bowl 206 and may partially include
a discontinuous region (such as a cutout).
[0145] According to the description above, the following inventions can be found.
[0146] A flush toilet according to one embodiment of the present invention includes: a body
part with a toilet bowl part formed therein; a water conveyance shelf formed along
a circumferential direction on an inner wall surface of the toilet bowl part and including
a first shelf part positioned higher and a second shelf part positioned lower; a first
discharge port formed so that water is discharged therethrough to the first shelf
part; and a second discharge port positioned lower than the first discharge port and
formed so that water is discharged therethrough to the second shelf part.
[0147] The first shelf part and the second shelf part may be smoothly connected by a shelf
inclined surface.
[0148] By smoothly connecting the first shelf part and the second shelf part with the shelf
inclined surface therebetween, the force of flush water can be maintained, and, also
by means of the height difference in the shelf inclined surface, flush water can be
led in the flowing down direction.
[0149] At least at a point where flush water that has flowed through the second shelf part
and flowed up along the shelf inclined surface enters the first shelf part, an overhang
part may be formed on the upper surface of the toilet bowl part.
[0150] In a bottom part of the toilet bowl part, a storage region may be formed to pool
flush water. The main flow of water discharged through the second discharge port may
be made to flow down into the storage region without being merged into water discharged
through the first discharge port in the first shelf part.
[0151] By allowing the main flow of water discharged through the second discharge port to
flow down before being merged into water discharged through the first discharge port,
the draining force can be increased more easily.
[0152] The amount of water discharged through the second discharge port and flowing up along
the shelf inclined surface to be merged into water discharged through the first discharge
port may be less than 20 percent of the total amount of the water discharged through
the second discharge port.
[0153] The shelf inclined surface along which water discharged through the second discharge
port flows up may include a gradient surface of 10 degrees or greater.
[0154] The water conveyance shelf may be annularly formed along the entire periphery of
the toilet bowl part, in which the first shelf part and the second shelf part are
connected by two shelf inclined surfaces. Each of the two shelf inclined surfaces
may be formed in the rear half of the toilet bowl part in plan view.
[0155] The first shelf part may be longer than the second shelf part.
[0156] By making the second shelf part shorter, the flush water from the second discharge
port can be made to strongly flow upward while the kinetic energy of the flush water
is maintained. The main flow of the flush water from the second discharge port flows
down, and the flush water that does not flow down will be merged into the flush water
from the first discharge port.
[0157] A shelf inclined surface along which flush water that has flowed through the second
shelf part flows up toward the first shelf part may be formed in a side part, in plan
view, with respect to a storage region formed in a bottom part of the toilet bowl
part.
[0158] By forming an upward shelf inclined surface in a side part with respect to the storage
region, the water flowing down from the shelf inclined surface and from the first
shelf part located posteriorly to the shelf inclined surface can be led to the storage
region more easily.
[0159] A flush toilet according to another embodiment of the present invention includes:
a body part with a toilet bowl part formed therein, including a first upper surface
positioned higher and a second upper surface positioned lower; a water conveyance
shelf formed along a circumferential direction of the toilet bowl part on an inner
wall surface of the toilet bowl part; and a discharge port formed so that water is
discharged therethrough to the water conveyance shelf.
[0160] The water conveyance shelf includes a first shelf part formed at a corresponding
position of the first upper surface and also includes a second shelf part formed at
a corresponding position of the second upper surface. The second shelf part is positioned
lower than the first shelf part.
[0161] A height difference is provided in the water conveyance shelf so as to be commensurate
with the height difference in the upper surface, and, by means of the height difference
in the water conveyance shelf, the flow of water can be controlled.
[0162] The second shelf part may be smoothly connected with the first shelf part by a shelf
inclined surface.
[0163] By smoothly connecting the first shelf part and the second shelf part, the force
of flush water can be maintained more easily.
[0164] The first upper surface and the second upper surface may be smoothly connected by
an upper inclined surface. The shelf inclined surface may be an inclined surface substantially
parallel with the upper inclined surface at least in a section between the boundary
point between the second shelf part and the shelf inclined surface and the center
point in the shelf inclined surface.
[0165] By making the shelf inclined surface and the upper inclined surface parallel with
each other, the overall harmony in design can be maintained more easily.
[0166] On the upper inclined surface of the toilet bowl part, an overhang part extending
inward may be further formed. The shelf inclined surface may be an inclined surface
substantially parallel with the overhang part at least in a section between the boundary
point between the second shelf part and the shelf inclined surface and the center
point in the shelf inclined surface.
[0167] The toilet bowl part may include a first discharge port and a second discharge port
formed therein. The first discharge port may be formed so that water is discharged
therethrough to the first shelf part, and the second discharge port may be formed
so that water is discharged therethrough to the second shelf part.
[0168] On an upper end of the inner wall of the toilet bowl part, a first discharge port
and a second discharge port may be formed. The first discharge port may be formed
on the first shelf part, and the second discharge port may be formed on the second
shelf part. Within a range between the boundary point between the second shelf part
and the shelf inclined surface and the first discharge port, the interval between
the water conveyance shelf and an upper surface part may be increased toward the first
discharge port.
[0169] By making the height difference between the first shelf part and the second shelf
part smaller than the height difference between the first upper surface and the second
upper surface, the overall harmony in design can be maintained more easily.
[0170] On an upper end of the inner wall of the toilet bowl part, a first discharge port
and a second discharge port may be formed. The first discharge port may be formed
on the first shelf part, and the second discharge port may be formed on the second
shelf part.
[0171] Along the entire periphery of the upper surface of the toilet bowl part, an overhang
part extending inward may be further formed. The water conveyance shelf may be annularly
formed along the entire periphery of the toilet bowl part, and at least 80 percent
of the entire periphery of the water conveyance shelf may be substantially parallel
with the overhang part.
[0172] An average of the interval between the first shelf part and the first upper surface
may be greater than an average of the interval between the second shelf part and the
second upper surface.
[0173] Within a range between the boundary point between the second shelf part and the shelf
inclined surface and the first discharge port formed in the toilet bowl part, the
interval between the water conveyance shelf and an upper surface part may be increased
toward the first discharge port.
[0174] In a rear end part of the upper surface of the toilet bowl part, a recess part may
be formed. The second upper surface may correspond to the bottom surface of the recess
part.
[EXPLANATION OF REFERENCE NUMERALS]
[0175]
- 100
- flush toilet
- 102
- first discharge port
- 104
- second discharge port
- 106
- toilet bowl
- 108
- water conveyance shelf
- 110
- first upper surface
- 112
- second upper surface
- 114
- first shelf part
- 116
- second shelf part
- 118
- overhang
- 120
- shelf inclined surfaces
- 122
- storage region
- 124
- third discharge port
- 126
- waste
- 128
- outlet
- 130
- first overhang
- 132
- second overhang
- 134
- inclined surface overhangs
- 136
- dead region
- 140
- upper inclined surfaces
- 142
- receiving surface
- 144
- body part
- 200
- flush toilet
- 202
- first discharge port
- 204
- second discharge port
- 206
- toilet bowl
- 208
- water conveyance shelf
- 210
- first upper surface
- 212
- second upper surface
- 214
- first shelf part
- 216
- second shelf part
- 218
- overhang
- 220
- shelf inclined surfaces
- 222
- storage region
- 224
- third discharge port
- 226
- waste
- 228
- outlet
- 230
- first overhang
- 232
- second overhang
- 234
- inclined surface overhangs
- 236
- dead region
[INDUSTRIAL APPLICABILITY]
[0176] The present invention is applicable to a flush toilet.