BACKGROUND
Technical field
[0001] The present disclosure relates to a member for supporting a rotation of a panel in
a foldable container, and more specifically, to a technology for supporting a rotation
operation of a front panel and a rear panel, which have a large load among the panels
of the container, to enable stable stand-up of the front panel and the rear panel
and also a smooth folding rotation operation.
Background Art
[0002] In general, a container has a shape of a large box formed of metal plates and is
mainly used for cargo transportation. Such a container is sized according to a certain
standard and is widely used for its advantage that it not only allows ease of cargo
storage and transport, but also can protect the cargo loaded therein. Containers are
transported individually by dedicated large cargo vehicles or transported in large
quantities by a dedicated train or a dedicated vessel. However, when transported by
the modes of transport, whether the containers are loaded with cargo or empty without
cargo therein, they occupy the same space of transport.
[0003] Therefore, when the containers without the cargo loaded therein are transferred to
another place or stored in a certain place, the containers in their fixed volume cause
a problem that they unnecessarily occupy a large volume, thus taking a large amount
of transportation space and transportation costs. In other words, after the containers
loaded with the cargo have transported the cargo, when they are stored or retrieved
in empty state, the containers with such invariable volume take up a large amount
of space and costs for storage and transportation.
[0004] In particular, when transferring a container using a large cargo vehicle, since one
container is mounted on one cargo vehicle and transported, transportation efficiency
may decrease and transportation cost may greatly increase. In addition, since the
container occupies a very large amount of space, when several containers are stacked,
there is a risk of an accident due to the height of the stacked containers.
[0005] In order to improve this, in the related art, a foldable container that can save
stacking space and can be folded for easy and convenient transportation of empty containers
has been disclosed.
[0006] A foldable container according to the related art has been disclosed in
Korean Patent Publication No. 10-1064803,
Korean Patent Publication No. 10-1439073, and
Korean Patent Publication No. 10-1489626. Referring to these, both side plates between the bottom plate and the roof plate
are configured as an upper plate and a bottom plate, in which the upper plate and
the bottom plate, the upper plate and the roof plate, and the bottom plate and the
bottom plate are pivotally coupled to each other by a plurality of hinge devices so
as to be folded to each other. Such a hinge device is configured to include hinge
blocks provided on each of the plates folded to each other, and connection blocks
for connecting these hinge blocks, in which the hinge blocks and the connection blocks
are hingedly coupled through hinge pins respectively.
[0007] However, since the foldable container according to the related art includes, for
the hinge device, the hinge blocks installed on each of the plates to be folded to
each other, the connecting blocks connecting the respective hinge blocks, and the
hinge pins that hingedly couple the respective hinge blocks and the connecting blocks,
there are shortcomings that the entire structure of the hinge device is complex, heavy,
and not easy to manufacture and mount.
SUMMARY
Technical Problem
[0008] In order to solve the problems of the related art described above, an object of the
present disclosure is to provide a structure that allows the side walls of a foldable
container to be easily folded by manpower.
[0009] In addition, another object of the present disclosure is to provide a structure for
folding a side wall of a container, in which, while a top plate is removed, a torsion
bar is placed at a lower end of the side wall panel and the torque of the torsion
bar is utilized to allow the side wall to be smoothly folded.
[0010] In addition, an object of the present disclosure is to facilitate the folding and
unfolding of the side wall by accumulating elastic force in the torsion bar during
the process of folding the side wall of the container and utilizing the accumulated
elastic energy in the process of unfolding the side wall of the container.
[0011] In addition, it is an object of the present disclosure to provide a method for improving
the lifespan of the torsion bar by developing a technology capable of reducing twist
angle of the torsion bar involved in rotations of a front panel and a rear panel since
these have a considerably greater load.
Technical Solution
[0012] The present disclosure provides a rotation support member for supporting a rotation
operation of a front panel and a rear panel in a container including the front panel
and the rear panel rotatably coupled to a bottom plate, and third and fourth torsion
bars serving as reference axes of rotation for the front panel and the rear panel,
in which the rotation support member includes: a first rotation support member including
one end fixedly coupled to a post coupling point 220 of the front panel which is spaced
apart by a predetermined distance from a lower end of the front panel, and the other
end positioned at a bottom plate coupling point 210 positioned on a side spaced apart
by a predetermined distance from a front end of the bottom plate; and a first rotation
support member including one end fixedly coupled to a post coupling point 220 of the
rear panel which is spaced apart by a predetermined distance from the lower end of
the rear panel, and the other end positioned at a bottom plate coupling point 210
positioned on a side spaced apart by a predetermined distance from a rear end of the
bottom plate,in which the other end of the first rotation support member is coupled
to the third torsion bar at the bottom plate coupling point 210 such that the front
panel is rotated with respect to the third torsion bar, and the other end of the second
rotation support member is coupled to the fourth torsion bar at the bottom plate coupling
point 210 such that the rear panel is rotated with respect to the fourth torsion bar.
[0013] The first rotation support member is coupled to and rotated integrally with the front
panel at the post coupling point, and the second rotation support member is coupled
to and rotated integrally with the rear panel at the post coupling point.
[0014] The first rotation support member has an L-shape including a parallel member 200a
parallel to a ground and a vertical member 200b perpendicular to the ground when the
front panel is in a stand-up state, and the second rotation support member has an
L-shape including a parallel member 200a parallel to a ground and a vertical member
200b perpendicular to the ground when the rear panel is in a stand-up state.
[0015] The parallel member has a length L such that a height of the container in a folded
state is 1/4 of a height of the container in an unfolded state.
Advantageous Effects
[0016] According to the present disclosure, with the structure described above, after the
top plate of the container is removed with a forklift, the side wall panel can be
easily folded simply by manpower and the height can be reduced by 1/4 in the folded
state such that four containers can be folded and stacked, and thus the effects of
easy storage and movement of the containers are provided.
[0017] In addition, with the structure of the rotation support member, the front panel and
the rear panel can stand up stably even when no additional preliminary torque is applied
to the torsion bar, and the twist angle of the torsion bar in the folded state can
be reduced, resulting in a beneficial effect on the torsion bar lifespan.
BRIEF DESCRIPTION OF THE DRAWING
[0018]
FIG. 1 illustrates an overall appearance of a foldable container according to the
present disclosure.
FIG. 2 illustrates the foldable container from which a top plate is removed according
to the present disclosure.
FIG. 3 illustrates a first side panel of the foldable container being folded according
to the present disclosure.
FIG. 4 illustrates a second side panel of the foldable container being folded according
to the present disclosure.
FIG. 5 is a diagram illustrating a front panel of the foldable container being folded
according to the present disclosure.
FIG. 6 illustrates a rear panel of the foldable container being folded according to
the present disclosure.
FIG. 7 illustrates the foldable container fully folded according to the present disclosure.
FIG. 8 illustrates a structure of a torsion bar provided in a longitudinal direction
on a bottom plate of the foldable container according to the present disclosure.
FIG. 9 is a graph showing the relative magnitudes of a moment and a torque according
to the present disclosure, in which the moment is generated based on the weights of
the first and second side panels of the foldable container during folding, and the
torque is generated by the torsion bar.
FIG. 10 illustrates the overall process of folding and unfolding the foldable container
according to the present disclosure.
FIG. 11 illustrates a partial lower portion of the bottom plate of the foldable container
according to the present disclosure.
FIG. 12 illustrates a rotation support member of the foldable container according
to the present disclosure.
FIGS. 13 and 14 are explanatory diagrams illustrating the operating principle of the
rotation support member and the torsion bar of the foldable container according to
the present disclosure.
BEST MODE
[0019] Hereinafter, embodiments of the present disclosure will be described in detail with
reference to the accompanying drawings. It should be noted that, in adding reference
numerals to the constituent elements of the drawings, the same constituent elements
are denoted by the same reference numerals even if they are illustrated in different
drawings. In the following description of the present disclosure, a detailed description
of known functions and configurations incorporated herein will be omitted when it
may make the subject matter of the present disclosure rather unclear.
[0020] The objectives, specific advantages and novel features of the present disclosure
will become more apparent from the following detailed description and the preferred
embodiments, which are associated with the accompanying drawings. In addition, terms
described herein are terms defined in consideration of functions in the present invention,
which may vary according to the intention or convention of a user or an operator.
Therefore, definitions of these terms should be made based on the contents throughout
the present specification.
[0021] FIG. 1 illustrates an overall appearance of a foldable container according to the
present disclosure, in which the side wall panel of the container is in a vertically
unfolded state, which will be referred to herein as an "unfolded state" for convenience.
FIG. 2 illustrates the foldable container from which a top plate is removed according
to the present disclosure, FIG. 3 is a diagram illustrating a first side panel of
the foldable container being folded according to the present disclosure, FIG. 4 illustrates
a second side panel of the foldable container being folded according to the present
disclosure, FIG. 5 illustrates the front panel of the foldable container being folded
according to the present disclosure, and FIG. 6 illustrates a rear panel of the foldable
container being folded according to the present disclosure, and FIG. 7 illustrates
the foldable container fully folded according to the present disclosure, which will
be referred to herein as a "folded state" for convenience. FIG. 8 illustrates a structure
of a torsion bar provided in a longitudinal direction on a bottom plate of the foldable
container according to the present disclosure, FIG. 9 is a graph showing the relative
magnitudes of a moment and a torque according to the present disclosure, in which
the moment is generated based on the weights of the first and second side panels of
the foldable container during folding and the torque is generated by the torsion bar,
and FIG. 10 illustrates the overall process of folding and unfolding the container.
It is designed such that the use of a forklift is necessary only in the process of
removing or lifting the top plate, while all other operations are possible with human
power. Since the forklift is present anywhere in the field where containers are loaded
or moved, even when there are some operations that use the forklift, it will not cause
any problem in the efficiency of work.
[Foldable Container Structure and Folding Method]
[0022] A foldable container of the present disclosure (hereinafter, it may be referred to
as "container") has a bottom plate 110, a top plate 120 spaced apart above the bottom
plate 110, and side wall panels 130 installed on both sides between the bottom plate
110 and the top plate 120. The side wall panel 130 includes four vertically-arranged
panels, which will be referred to as a front panel 131, a rear panel 135, a first
side panel 137, and a second side panel 139, respectively. Posts P for bearing the
load of the container in the vertical direction are provided on edges of the rectangles
of the front panel 131 and the rear panel 135, respectively.
[0023] The feature of the foldable container according to the present disclosure is that
the four side wall panels 130 can be simply folded by manpower using a torsion bar
provided at the lower end, while the top plate 120 is completely removed using a forklift.
That is, when the side wall panel is folded by the moment due to its self weight,
the torque generated from the twisting torsion bar applies a rotational force opposite
to the moment due to self weight, thereby allowing the it to be folded smoothly.
[0024] First, a method for folding a container according to the present disclosure will
be described.
[0025] For the container of the present disclosure, the process of lifting the top plate
120 using a forklift is performed first. A plurality of coupling members 125, to which
the forks of the forklift are inserted and coupled, are provided on the top plate,
that is, on an upper surface of the top plate of the container in a transverse direction.
Hereinafter, the transverse direction of the container refers to the width direction
of the container, and the longitudinal direction of the container refers to the direction
from the front panel toward the rear panel. In addition, FIG. 2 illustrates the top
plate completely lifted up by the forklift (illustration of the forklift is omitted
for convenience of description). The characteristic of the present disclosure is that
the top plate 120 is first completely separated from the side wall panel 130 by the
forklift, as illustrated in FIG. 2. This is completely different from the related
art where the folding operation is performed with the top plate remaining attached
to the side wall panel. The top plate removed by the forklift is moved to the side
of the container and positioned.
[0026] Then, the first side panel 137 is folded as illustrated in FIG. 3, and the second
side panel 139 is folded over the first side panel 137 as illustrated in FIG. 4. According
to the present disclosure, in order to fold the first and second side panels, first
and second torsion bars T1 and T2 are positioned under the first and second side panels.
This will be described with reference to the detailed illustration in FIG. 8. Since
the first side panel and the second side panel are folded by the same principle as
each other and it is also the same that four of the first and second torsion bars
are arranged along the longitudinal direction of the container, only the process of
folding the first side panel will be described below as an example.
[0027] Referring to FIG. 8, there is provided a fixture 110a that is fixedly coupled to
the bottom plate 110 of the container so as not to rotate in the process of rotating
of the first side panel 137. The fixture 110a is fixed to a frame of the bottom plate
and not rotated. In addition, there is provided a rotating body 137a that is fixedly
coupled to the first side panel 137 and rotated together when the first side panel
is rotated. In this example, the "rotation" means an operation of pivoting of the
side wall panel based on the lower end in order to be folded. In addition, one end
of the first torsion bar T1 is coupled by serration to the fixture 110a and the other
end is coupled by serration to the rotating body 137a. When the first side panel 137
is rotated to be folded, the rotating body 137a is rotated, and as a result, the first
torsion bar T1 is twisted and rotational elastic energy is accumulated (this is referred
to as "torsion bar torque" for convenience). The torsion bar torque applies a rotational
force in the direction opposite to the rotational force direction of the moment generated
by the self weight of the first side panel, thereby preventing the first side panel
from being suddenly folded by the self weight, while ensuring a smooth folding operation.
[0028] The principle of the rotation of the first side panel, the torque of the first torsion
bar, and the like will be separately described in detail in the [Rotation Operation
of Side Panel and Torsion Bar] provided below.
[0029] FIG. 5 illustrates the front panel of the foldable container being folded according
to the present disclosure, and FIG. 6 illustrates the rear panel of the foldable container
being folded according to the present disclosure.
[0030] According to the present disclosure, in order to fold the front and rear panels,
third and fourth torsion bars T3 and T4 are positioned under the front and rear panels.
Since the third torsion bar positioned under the front panel and the fourth torsion
bar positioned under the rear panel have the same principle of operation during rotation,
and the third torsion bar and the fourth torsion bar are the same that two are arranged
along the transverse direction of the container, only the process of folding the rear
panel 135 will be described below as an example. Meanwhile, the principle of the rotation
of the rear panel, the torque of the fourth torsion bar, and the like will be separately
described in detail in the [Rotation Operation of Rear Panel and Torsion Bar] provided
below.
[0031] FIG. 7 illustrates the top plate 120 is placed by a forklift onto the top of the
container in the fully folded state, which will be referred to herein as a "folded
state" for convenience. In order to place the top plate 120 in the correct position
in the folded state, in the present disclosure, L-shaped corner support members 150
positioned at four corners of the bottom plate 110 are adopted.
[0032] Referring to FIG. 6, the corner support members 150 are L-shaped members formed at
the four corners of the bottom plate 110, and have a first support surface 151 and
a second support surface 153 that are perpendicular to each other. The corner support
members 150 serve to support, from the outside, the corner ends of the posts P of
the front panel and the rear panel when the container is in the unfolded state, and
serve to support the four corners of the top plate 120 placed on the container when
the container is in the folded state.
[Rotation Operation of Side Panel and Torsion Bar]
[0033] The structure of the torsion bar of FIG. 8 and the graph of FIG. 9 will be described.
The graph of FIG. 9 shows the moment M generated by the self weight of the container
in the process of changing the rotation angle of the bottom plate 110 from 0° to 90°,
and the torsional elastic energy resulting from the rotation of the first torsion
bar, that is, the torsion bar torque T. In the graph, the horizontal axis represents
the rotation angle of the first side panel of the container, and the vertical axis
represents the torque. Referring to the graph, the relationship of the moment and
the torque according to the angle in the rotation process is divided into three sections:
Section A, Section B, and Section C.
[0034] Section A is a process of starting the folding operation of the side wall of the
container, and in this section, the torsion bar torque T is formed to be greater than
the moment M generated by the self weight of the container. This can be achieved by
mounting the first torsion bar T1 that is twisted at a predetermined angle in advance,
with the first side panel 137 being in stand-up position. That is, the first torsion
bar is twisted by a predetermined angle (about 7° in the present disclosure) in advance
in the direction in which the first torsion bar will be twisted when the first side
panel is rotated (This will be referred to herein as "preliminary torque" for convenience).
The reason for doing this is to ensure the stability of the folding process. That
is, this is to prevent the first side panel 137 from being suddenly rotated and collapsed
from the stand-up state. In this example, in order to fold the first side panel, it
is necessary to apply a force from the outside, and to be specific, the force needs
to be applied up to an angle corresponding to the point X in the graph. In the present
disclosure, by selecting a torsion bar of an appropriate specification, and the like,
the amount of necessary force is appropriately adjusted so as to allow a rotation
up to the X point by pushing only with human force.
[0035] Section B is a section in which the moment M due to the self weight of the first
side panel is greater than the torsion bar torque T, and is a section in which the
folding operation is performed by the self weight without requiring a separate external
torque. However, the smaller the difference between the moment M and the torsion bar
torque T in this section (the smaller the size of the arrow in the B section of the
graph), the smoother the first side panel folds.
[0036] Section C is a process in which the rotation operation of the first side panel is
finished, and in this section, the torsion bar torque T is slightly larger than the
moment M generated by the self weight. That is, while it requires additional external
force to achieve the fully folded state, because the additional external force is
small, it is sufficient for a human to press the first side panel from above.
[0037] According to the present disclosure, the torque value of the torsion bar is appropriately
selected in consideration of the magnitude of the moment value generated by the self
weight of the side wall panel, such that the external power (torque) is required only
at the beginning and the end of the folding operation, and the size of the required
external power is also sufficiently adjustable by human power.
[0038] According to the present disclosure, with the top plate removed, the first side panel
maintains the vertical position in a self-supporting state due to the preliminary
torque of the torsion bar itself. Then, it requires only a little external force to
rotate it to the X point, after which the rotation operation is automatically performed
by the self weight of the side panel. Then, it requires a human to apply the external
force only in the last predetermined section of the rotation operation to make the
folded state. In the present disclosure, the points X and Y were appropriately selected
in order to provide the necessary preliminary torque while reducing Section B, that
is, reducing the size of the arrow.
[Rotation Operation of Rear Panel and Torsion Bar]
[0039] FIG. 11 illustrates a partial lower portion of the bottom plate of the foldable container
according to the present disclosure, and illustrates the lower portion adjacent to
the rear panel 135. FIG. 12 illustrates a rotation support member according to the
present disclosure, and FIGS. 13 and 14 are explanatory diagrams illustrating the
operating principle of the rotation support member and the torsion bar.
[0040] In general, since most of the vertical load of the container is born by the post
(P in FIG. 12) positioned on the side of the front panel 131 and the rear panel 135,
the strength of the front panel 131 and the rear panel 135 is important, and therefore,
the load they receive is much greater than that of the first and second side panels.
Therefore, in order to enable the rotation operation of the front panel and the rear
panel by human force, the torsion bar provided for this and its arrangement structure
are important. According to the present disclosure, in order to rotate the front panel
131 and the rear panel 135, the third and fourth torsion bars T3 and T4 are provided.
Since the front panel 131 and the rear panel 135 are the same as each other in both
the rotation operation and the principle, the rear panel 135 and the fourth torsion
bar T4 will be described below as an example.
[0041] Two of the fourth torsion bars T4 are arranged side by side on the bottom plate 110
of the container in the transverse direction, and only one of them is illustrated
in FIG. 11. One end of the fourth torsion bar T4 is coupled by serration to a fixed
coupling part 110b fixed to the frame of the bottom plate 110, and the other end of
the fourth torsion bar is coupled to a rotation support member 200 while passing through
the outer frame of the bottom plate.
[0042] The rotation support member is an L-shaped member, with one end being coupled to
a post coupling point 220 at the post P spaced apart from the lower end of the rear
panel by a predetermined distance, and the other end being coupled to the fourth torsion
bar T4 at a bottom plate coupling point 210 located on the side spaced apart from
the end of the bottom plate by a predetermined distance (it is fixedly coupled using
a separate connecting member between the fourth torsion bar and the other end). The
corner of the post P is supported from the outside by the corner support member 150.
[0043] As described above, the rear panel and the front panel are subjected to a greater
load than the side panel, while the width of the container in the transverse direction
is smaller than the length in the longitudinal direction, and accordingly, since the
third and fourth torsion bars must have higher torsional torque, in consideration
of the lifespan of the third and fourth torsion bars and also the load of the front
panel and the rear panel, the present disclosure adopts the L-shaped rotation support
member for their rotation operation.
[0044] Referring to the rotation operation of the rear panel 135, the rotation operation
is performed based on the third torsion bar located on the side spaced apart from
the end of the bottom plate by a predetermined distance as the reference axis, which
is different from the rotation of the side panel that is performed based on the axis
located immediately thereunder. The rotation support member has the following roles
and functions.
<Ensuring stability>
[0045] In the description of the rotation operation of the side panel, it is described that
the first and second torsion bars twisted by a predetermined angle in advance are
mounted to provide the "preliminary torque" in order to ensure stability (to prevent
the side panel from being suddenly rotated and collapsed from the stand-up state).
[0046] However, stability is ensured by the rotation support member 200 without requiring
the "preliminary torque" to be applied to the fourth torsion bar T4 involved in the
rotation of the rear panel.
[0047] That is, in FIG. 13, the rear panel is supported by the corner support member 150
supporting the outer corner of the lower end thereof, so that the rotation in the
direction of the arrow A is constrained, and further, the rotation in the direction
B is also constrained by the rotation support member 200 and its self load (that is,
in the absence of the rotation support member, rotation occurs in the direction B).
For the side panel, the preliminary torque is applied to the torsion bar to prevent
the inward folding operation, but for this rear panel, even when the preliminary torque
is not applied to the torsion bar, the rotation operation is kept from occurring,
thereby ensuring stability. In other words, in order for the rear panel 135 to be
rotated inward, it requires to apply the external force up to the point where the
post coupling point 220 is located directly above the bottom plate coupling point
210, and therefore, the rear panel is maintained in a stable state unless the external
force is applied (FIG. 14). In the actual operation of folding the rear panel, the
rear panel is rotated by pushing from the outside by the power of a human by the angle
θ shown in FIG. 14. When the rear panel is rotated beyond the angle shown in FIG.
14, the rear panel is gently folded by the mutual relationship between the moment
M by the self weight of the rear panel and the torsion bar torque T by the fourth
torsion bar, which has already been described with reference to the folding operation
of the side panel.
<Ensuring Durability of Torsion Bar>
[0048] Since it is difficult to expect the effect of torsional elastic energy any more when
the twist angle of the torsion bar exceeds the point where plastic deformation occurs,
the torsion bar should be twisted only at an angle below which plastic deformation
does not occur, and even at an angle at which plastic deformation does not occur,
it is still advantageous to prevent excessive twisting in consideration of the lifespan.
[0049] It has been described that according to the present disclosure, stability is ensured
by the rotation support member 200 even without the "preliminary torque" applied to
the fourth torsion bar of the container. This has the effect of reducing the amount
of twist of the fourth torsion bar as a result. For example, when a 7° torsion angle
is provided in the initial state (side panel stand-up state) to provide the preliminary
torque to the side panel, in the folded state in which the side panel is completely
rotated by 90°, there is the effect that the first and second torsion bars have a
torsion angle of 97°.
[0050] Meanwhile, according to the present disclosure, the fourth torsion bar of the rear
panel does not have a preliminary torque due to the existence of the rotation support
member 200, and the fourth torsion bar is in a state where there is no torsion in
the state illustrated in FIG. 14 (in this state, the post coupling point 220 is located
directly above the bottom plate coupling point 210). In this state, when the rear
panel is completely rotated and folded, the twist angle of the fourth torsion bar
is (90 - θ), and the maximum twist angle is significantly reduced. This leads to the
effect of increasing the life of the fourth torsion bar.
[0051] The rotation support member is provided equally on the front panel and the rear panel,
and includes a first rotation support member coupled to the front panel and a second
rotation support member coupled to the rear panel.
[0052] The present disclosure has been described in detail. However, it should be understood
that the detailed description and specific examples, while indicating preferred embodiments
of the disclosure, are given by way of illustration only, since various changes and
modifications within the scope of the disclosure will become apparent to those skilled
in the art from this detailed description.