TECHNICAL FIELD
[0001] The present invention relates to a fuel supply module that is primarily for supplying
fuel to a fuel injection valve of an engine and, in particular, to an improvement
of a fuel supply module that includes a module body formed from a mounting base mounted
on an outer wall of a fuel tank, a fuel feed pipe projecting from an upper face of
the mounting base, and a pump holding part provided so as to be connected to a lower
part of the mounting base, an electric pump that pumps up fuel within the fuel tank
and discharges the fuel to the fuel feed pipe via a fuel passage being held in the
pump holding part.
BACKGROUND ART
[0002] Such a fuel supply module is already known, as disclosed in Patent Publication 1.
Patent Publication 1: Japanese Patent Application Laid-open No.
2007-291867
DISCLOSURE OF INVENTION
PROBLEMS TO BE SOLVED BY THE INVENTION
[0003] In such a conventional fuel supply module, since the module body is molded as a unit,
when a plurality of types of module bodies having, for example, different directions
for a fuel feed pipe are molded, a plurality of types of molds are required so as
to correspond to the types of module bodies. The total production cost for the plurality
of types of molds is therefore high, this affects the cost of the fuel supply module,
and it is thus very difficult to reduce the cost.
[0004] The present invention has been accomplished in the light of such circumstances, and
it is an object thereof to provide at low cost a fuel supply module that includes
a plurality of types of module bodies having, for example, different directions for
a fuel feed pipe.
MEANS FOR SOLVING THE PROBLEMS
[0005] In order to attain the above object, according to a first aspect of the present invention,
there is provided a fuel supply module comprising a module body formed from a mounting
base mounted on an outer wall of a fuel tank, a fuel feed pipe projecting from an
upper face of the mounting base, and a pump holding part provided so as to be connected
to a lower part of the mounting base, an electric pump that pumps up fuel within the
fuel tank and discharges the fuel to the fuel feed pipe via a fuel passage being held
in the pump holding part,
characterized in that the module body is divided into a first block comprising the mounting base, a second
block comprising the fuel feed pipe and a boss supporting a base of the fuel feed
pipe, and a third block comprising the pump holding part, a support tube is formed
on the first block, a boss extension part extending downward in the axial direction
from the boss is fitted into an inner periphery of the support tube, the support tube
and the second block are welded to each other, the third block is welded to an end
face of the boss extension part, the first and third blocks are welded to each other,
and the boss extension part and the third block are provided with first and second
through holes respectively, the first and second through holes communicating directly
with each other to form the fuel passage.
[0006] According to a second aspect of the present invention, in addition to the first aspect,
welded bonding planes of the boss extension part and the third block are disposed
closer to the interior of the fuel tank than the support tube.
[0007] According to a third aspect of the present invention, in addition to the second aspect,
a clearance for opening the peripheral edge of the welded bonding planes of the boss
extension part and the third block to the internal space of the fuel tank is provided
in a lower face of the first block.
[0008] According to a fourth aspect of the present invention, in addition to any one of
the first to third aspects, the welded bonding planes of the boss extension part and
the third block and the welded bonding planes of the first and third blocks are disposed
on the same plane.
[0009] The boss corresponds to a first boss 5a in an embodiment of the present invention,
which is described later.
EFFECTS OF THE INVENTION
[0010] In accordance with the first aspect of the present invention, for some of the first
to third blocks, a plurality of types having different shapes and dimensions are prepared,
and the plurality of types of some of the blocks are combined with another block and
welded to each other, thus giving a plurality of types of module bodies having different
shapes and dimensions. When such a plurality of types of module bodies are produced,
it is therefore only necessary to prepare molds corresponding to the plurality of
types of some of the blocks, and compared with a case in which a plurality of types
of entire molds are prepared so as to correspond to the types, the production cost
of the molds can be greatly reduced. Moreover, since the module body is divided into
first to third blocks, the shape of each block can be simplified, the shape of a mold
corresponding to each block can therefore also be simplified, and this also contributes
to a reduction of the production cost of the molds. In this way, fuel supply modules
that include a plurality of types of module bodies can be provided at low cost.
[0011] Moreover, since the support tube is formed on the first block, the boss extension
part extending downward in the axial direction from the boss is fitted into the inner
periphery of the support tube, a first bonding plane at the upper end of the support
tube and a second bonding plane of the second block are welded, a third bonding plane
at the lower end of the boss extension part and a fourth bonding plane of the third
block are welded, and the boss extension part and the third block are respectively
provided with the first and second through holes that communicate directly with each
other to form the fuel passage, welded parts of the first and second bonding planes
are disposed on the atmosphere side of welded parts of third and fourth bonding planes
through which the fuel passage runs, and the pressure of the fuel passage does not
act on the welded parts of the first and second bonding planes. There can therefore
be expected an effect in preventing high pressure fuel discharged from the electric
pump from leaking to the exterior by blocking it with the welded parts of the first
and second bonding planes even if, due to weld failure, etc., it leaks past the welded
parts of the third and fourth bonding planes, on which the pressure thereof acts.
[0012] In accordance with the second aspect of the present invention, since the welded third
and fourth bonding planes are disposed closer to the interior of the fuel tank than
the support tube, even if fuel leaks past the welded parts of the third and fourth
bonding planes, it can be returned immediately to the fuel tank and this, coupled
with the presence of the welded parts of the first and second bonding planes, enables
the leakage of fuel to the exterior to be more reliably prevented.
[0013] In accordance with the third aspect of the present invention, since the clearance
for opening the peripheral edge of the welded third and fourth bonding planes to the
internal space of the fuel tank is provided in the lower face of the first block,
if fuel leaks past the welded parts of the third and fourth bonding planes, it can
immediately be returned smoothly to the fuel tank through the clearance, thereby enabling
the leakage of fuel to the exterior to be more reliably prevented.
[0014] In accordance with the fourth aspect of the present invention, welding of the boss
extension part, that is, the second block and the third block, and welding of the
first and third block can be carried out at the same time by use of the same hot plate,
thus contributing to an improvement in productivity.
BRIEF DESCRIPTION OF DRAWINGS
[0015]
[FIG. 1] FIG.1 is a plan view showing a state in which a fuel supply module related
to an embodiment of the present invention is mounted on a fuel tank (first embodiment).
[FIG. 2] FIG.2 is a sectional view along line 2-2 in FIG. 1 (first embodiment).
[FIG. 3] FIG.3 is an exploded view of a module body in FIG. 2 (first embodiment).
EXPLANATION OF REFERENCE NUMERALS AND SYMBOLS
[0016]
- B
- Module body
- B to B4
- First to fourth blocks
- M
- Fuel supply module
- P1 to P6
- Bonding planes (first to sixth bonding planes)
- T
- Fuel tank
- 2
- Electric pump
- 4
- Mounting base
- 4a
- Support tube
- 5
- Fuel feed pipe
- 5a
- Boss (first boss)
- 7
- Pump holding part
- 10
- Outer wall (ceiling wall)
- 40
- Fuel passage
- 42
- Clearance
- 45
- First through hole
- 46
- Second through hole
BEST MODE FOR CARRYING OUT THE INVENTION
[0017] A mode for carrying out the present invention is explained below by reference to
a preferred embodiment of the present invention shown in the attached drawings.
EMBODIMENT 1
[0018] First, in FIG. 1 and FIG. 2, a fuel supply module M of the present invention is mounted
on a ceiling wall 10 of a fuel tank T mounted in a vehicle such as a motorcycle, the
fuel supply module M supplying fuel within the fuel tank T to a fuel injection valve
I of an engine.
[0019] The fuel supply module M includes a module body B made of a synthetic resin, an electric
pump 2 held on a lower part of the module body B, and a fuel strainer 3 mounted at
the lower end of the electric pump 2. Furthermore, the module body B is formed from
a mounting base 4, a fuel feed pipe 5 projecting from an upper face of the mounting
base 4, a coupler 6 similarly projecting from the upper face of the mounting base
4, and a pump holding part 7 provided so as to be connected to a lower part of the
mounting base 4.
[0020] On the other hand, the ceiling wall 10 of the fuel tank T is provided with an opening
11 through which the electric pump 2 is inserted into the interior of the fuel tank
T, and is fixedly provided with a mounting ring 12 that surrounds the opening 11.
This mounting ring 12 is fixedly provided with a plurality of mounting bolts 15 projecting
from an upper face thereof.
[0021] The mounting base 4 is superimposed on the upper face of the mounting ring 12 so
that its outer peripheral part blocks the opening 11. The outer peripheral part of
the mounting base 4 is provided with a plurality of bolt holes 14, and the mounting
base 4 is fixed to the mounting ring 12 via the plurality of mounting bolts 15 inserted
through these bolt holes 14 and a plurality of nuts 16 screwed and tightened onto
the mounting bolts 15. In this arrangement, an annular seal 9 for sealing the opening
11 is disposed between the mounting base 4 and the ceiling wall 10 of the fuel tank
T.
[0022] A circular first boss 5a supporting a base of the fuel feed pipe 5 is formed on a
central part of the upper face of the mounting base 4. The fuel feed pipe 5 projects
horizontally from an outer peripheral face of the first boss 5a, and an outer end
part of the fuel feed pipe 5 is connected to a fuel supply pipe 18 communicating with
the fuel injection valve I of the engine. A rectangular second boss 6a supporting
the base of the coupler 6 is formed on the upper face of the mounting base 4 so as
to be adjacent to the first boss 5a.
[0023] Furthermore, the pump holding part 7, which is cylindrical and is fitted around the
outer periphery of an upper end part of the electric pump 2, is provided so as to
be connected to a lower face of the mounting base 4. A plurality of latching holes
19 are provided in a peripheral wall of the pump holding part 7. A plurality of resilient
latching tabs 20 are provided on the outer periphery of an upper end part of the electric
pump 2, and these latching holes 19 and latching tabs 20 latch together when the upper
end part of the electric pump 2 is fitted into the inner periphery of the pump holding
part 7 so that the electric pump 2 is held by the pump holding part 7.
[0024] The electric pump 2 is formed from an electric motor 23 having a rotor 25 facing
in the vertical direction, and a fuel pump 24 driven by the electric motor 23. The
electric motor 23 is formed from a cylindrical stator 26 having a plurality of magnets
26a fixedly arranged on the inner periphery in the peripheral direction, an upper
bearing bracket 27 joined to the upper end of the stator 26 by swaging, a lower bearing
bracket 28 joined to a lower end part of the stator 26, and the rotor 25, which has
a rotor shaft 25a supported by the upper and lower bearing brackets 27 and 28.
[0025] The fuel pump 24 is arranged as a Wesco type from a pump case 31 and a pump impeller
32, the pump case 31, together with the lower bearing bracket 28, being joined to
the stator 26 by swaging so as to form a pump chamber 30 between itself and a lower
face of the lower bearing bracket 28, and the pump impeller 32 being rotatably housed
in the pump chamber 30 and connected to a lower end part of the rotor shaft 25a.
[0026] The pump case 31 is provided with a suction port 33 opening in the pump chamber 30,
and the fuel strainer 3, which is disposed in a bottom part within the fuel tank T
so as to communicate with the suction port 33, is mounted on the pump case 31. The
lower bearing bracket 28 is provided with a discharge port 34 providing communication
between the pump chamber 30 and the interior of the stator 26.
[0027] Formed integrally with the upper bearing bracket 27 is a fuel discharge pipe 36 projecting
thereabove and having a final discharge port 35 communicating with the interior of
the stator 26, and provided in the interior of the fuel discharge pipe 36 is a check
valve 37 for preventing backflow of fuel into the final discharge port 35. A connection
tube 38 joined to the inside of the pump holding part 7 is formed integrally with
the mounting base 4, and the fuel discharge pipe 36 is fitted via a seal 39 into an
inner peripheral face of the connection tube 38.
[0028] A fuel passage 40 is provided in the module body B, the fuel passage 40 providing
communication between the fuel discharge pipe 36 and the fuel feed pipe 5 via the
interior of the connecting tube 38, and a regulator valve 41 is mounted on the module
body B, the regulator valve 41 regulating the pressure within the fuel passage 40
to a predetermined pressure that is suitable for the injection of fuel from the fuel
injection valve I.
[0029] In FIG. 1 and FIG. 2, the module body B is divided into a first block B1 that includes
the mounting base 4, a second block B2 that includes the fuel feed pipe 5 and the
first boss 5a supporting the base thereof, a third block B3 that includes the pump
holding part 7 and the connection tube 38, and a fourth block B4 that includes the
coupler 6 and the second boss 6a supporting the base thereof, and they are all molded
individually using a synthetic resin as a material.
[0030] A cylindrical support tube 4a is formed integrally with the first block B1 so as
to project from the upper face thereof. Furthermore, a tapered first bonding plane
P1 is formed at the upper end of the support tube 4a. On the other hand, formed on
the second block B2 are a boss extension part 5b extending coaxially downward from
the first boss 5a and fitted into an inner periphery of the support tube 4a, and a
tapered second bonding plane P2 surrounding an upper part of the boss extension part
5b with an annular groove 21 interposed therebetween. This second bonding plane P2
and the first bonding plane P1 are welded to each other by ultrasonic welding, etc.
Burrs formed during welding are received by the annular groove 21.
[0031] The boss extension part 5b runs through the support tube 4a, a lower end face thereof
is formed as a third bonding plane P3 perpendicular to the axis of the first boss
5a, and a longitudinal first through hole 45 is provided in the second block B2, the
first through hole 45 opening on the third bonding plane P3 while communicating with
the fuel feed pipe 5. Furthermore, formed on the second block B2 is a semi-cylindrical
connection tube 56 extending below the third bonding plane P3, and provided therein
is a return hole 50 providing communication between the fuel feed pipe 5 and the upper
end of the interior of the connection tube 56.
[0032] The connection tube 56 is equipped with the regulator valve 41. This regulator valve
41 includes a bottomed cylindrical valve housing 60 molded separately from the mounting
base 4 and press-fitted into the connection tube 56 via a seal 68, and this valve
housing 60 has formed in an upper end wall a valve hole 61 and a conical valve seat
62, the valve hole 61 running through the upper end wall and communicating with the
return hole 50, and the valve seat 62 being connected to the inner end of the valve
hole 61. Housed within the valve housing 60 are a ball-shaped valve body 63, a poppet-type
valve retainer 64, and a valve spring 65, the valve body 63 being capable of being
seated on the valve seat 62, the valve retainer 64 rotatably supporting the valve
body 63 on the opposite side to the valve seat 62, the valve spring 65 urging the
valve body 63 via the valve retainer 64 with a predetermined set load in the direction
in which the valve seat 62 is seated, and a guide member 66 supporting a fixed end
part of the valve spring 65 and slidably supporting a stem portion 64a of the valve
retainer 64 in an open-and-close direction of the valve body 63 being press-fitted
into and fixed to an inner peripheral face of the valve housing 60. The set load,
on the valve body 63, of the valve spring 65 is regulated by adjusting the press-fit
depth of the guide member 66 into the inner peripheral face of the valve housing 60.
The guide member 66 is provided with an open hole 67 providing communication between
the interior and the exterior thereof. After the connection tube 56 is equipped with
the regulator valve 41, a lower end part of the connection tube 56 is hot-swaged to
stop the regulator valve 41 from falling out.
[0033] A fourth bonding plane P4 facing the third bonding plane P3 of the second block B2
is formed on an upper face of the third block B3. Formed on a lower face of the first
block B1 is a bonding plane P5 arranged on the same plane as the lower end face of
the boss extension part 5b fitted into the support tube 4a, that is, the third bonding
plane P3, and formed on an upper face of the third block B3 is a sixth bonding plane
P6 facing the fifth bonding plane P5 so as to be arranged on the same plane as the
fourth bonding plane P4. Provided in the third block B3 are a second through hole
46 and the connection tube 38, the second through hole 46 opening on the fourth bonding
plane P4 and being capable of communicating with the first through hole 45, and the
interior of the connection tube 38 communicating with the second through hole 46.
Formed in the third and fourth bonding planes P3 and P4 are annular grooves 47 and
48 surrounding openings of the first and second through holes 45 and 46 respectively.
[0034] The third bonding plane P3 and the fourth bonding plane P4, and the fifth bonding
plane P5 and the sixth bonding plane P6 are welded to each other, and since the third
bonding plane P3 and the fifth bonding plane P5, and the fourth bonding plane P4 and
the sixth bonding plane P6 are each arranged on the same plane, these bonding planes
can be welded to each other at the same time using the same hot plate. Welding the
third and fourth bonding planes P3 and P4 to each other allows the first through hole
45 and the second through hole 46 to communicate directly with each other, thus forming
the fuel passage 40, which provides communication between the fuel discharge pipe
36 of the electric pump 2 and the fuel feed pipe 5. In this arrangement, since burrs
formed during welding of the third and fourth bonding planes P3 and P4 to each other
are received by the annular grooves 47 and 48, it is possible to prevent the burrs
from projecting toward the first and second through holes 45 and 46.
[0035] A recess-shaped clearance 42 is provided in a lower face of the first block B1, the
clearance 42 opening peripheral edge parts of the welded third and fourth bonding
planes P3 and P4 to the interior of the fuel tank T.
[0036] Furthermore, provided on an upper face of the first block B1 are a seventh bonding
plane P7 and a through hole 22, the seventh bonding plane P7 being adjacent to the
support tube 4a, and the through hole 22 running through a central part of the seventh
bonding plane P7. On the other hand, formed integrally with a lower face of the second
boss 6a of the fourth block B4 are an eighth bonding plane P8 and a semi-cylindrical
protection tube 51, the eighth bonding plane P8 facing the seventh bonding plane P7,
and the protection tube 51 projecting downward from a central part of the eighth bonding
plane P8 and running through the through hole 22. Embedded in the fourth block B4
is a power supply terminal 53 having opposite end parts extending to the coupler 6
and the interior of the protection tube 51. The power supply terminal 53 within the
protection tube 51 is connected to a current-carrying terminal 54 projecting from
an upper face of the electric motor 23, via a lead 57 passing through the latching
hole 19 of the pump holding part 7.
[0037] The seventh and eighth bonding planes P7 and P8 are thus welded to each other, thereby
integrally joining the first and fourth blocks B1 and B4 to each other.
[0038] The operation of this embodiment is now explained.
[0039] In the electric pump 2, when the electric motor 23 operates, the pump impeller 32
is rotated by means of the rotor shaft 25a. Accompanying this, fuel within the fuel
tank T is sucked into the pump chamber 30 via the suction port 33 while being filtered
through the fuel strainer 3, pressurized by means of the pump impeller 32, then pumped
to the interior of the stator 26 via the discharge port 34, supplied from the final
discharge port 35 to the fuel injection valve I via the fuel discharge pipe 36, the
fuel passage 40, that is, the first and second through holes 45 and 46, the fuel feed
pipe 5, and the fuel supply pipe 18, and is injected into the engine, which is not
illustrated.
[0040] In this process, since the pressure of the fuel passage 40, that is, the discharge
pressure of the electric pump 2, acts on the valve body 63 of the regulator valve
41 via the return hole 50 and the valve hole 61, when the discharge pressure of the
electric pump 2 exceeds a predetermined value, the valve body 63 opens against the
set load of the pressure-regulating spring 65, and part of the fuel within the fuel
passage 40 is discharged to the interior of the valve housing 60; when the pressure
of the fuel passage 40 returns to the predetermined value, the valve body 63 is closed
again by the set load of the pressure-regulating spring 65. Since the pressure of
the fuel passage 40 is thus automatically regulated at a predetermined value, the
fuel injection pressure from the fuel injection valve I is controlled appropriately.
[0041] Furthermore, fuel discharged from the regulator valve 41 falls onto an upper face
of the upper bearing bracket 27, and is returned to the fuel tank T via the latching
hole 19 of the pump holding part 7, etc.
[0042] When assembling the module body B, the connection tube 56 of the second block B2
is firstly equipped with the regulator valve 41, subsequently the boss extension part
5b of the second block B2 is fitted into the support tube 4a of the first block B1,
and the first and second bonding planes P1 and P2 are welded as described above. Furthermore,
the seventh bonding plane P7 of the first block B1 and the eighth bonding plane P8
of the fourth block B4 are welded as described above. In this way, an assembly of
the mounting base 4, the fuel feed pipe 5, and the coupler 6 is first produced.
[0043] Subsequently, the fourth bonding plane P4 and the sixth bonding plane P6 of the third
block B3 are welded to the third bonding plane P3 of the second block B2 and the fifth
bonding plane P5 of the first block B1 respectively as described above, thus completing
the module body B.
[0044] In such a fuel supply module M, since the module body B is formed as described above
by dividing it into the first block B1, which includes the mounting base 4, the second
block B2, which includes the fuel feed pipe 5 and the first boss 5a supporting the
base thereof, the third block B3, which includes the pump holding part 7, and the
fourth block B4, which includes the coupler 6 and the second boss 6a supporting the
base thereof, individually molding them, and welding them, it is possible to obtain
a plurality of types of module bodies B having different shapes and dimensions by
preparing a plurality of types of some of the first to fourth blocks B1 to B4 having
different shapes and dimensions and combining and welding the plurality of types of
some of the blocks with another block. Therefore, when such a plurality of types of
module bodies B are produced, since it is only necessary to prepare molds corresponding
to the plurality of types of some of the blocks, compared with a case in which a plurality
of types of an entire mold are prepared according to the types, it is possible to
greatly reduce the production cost of the molds. Moreover, dividing the module body
B into the first to fourth blocks B1 to B4 enables the shape of each block to be simplified,
the shape of the mold corresponding to each block is therefore also simplified, and
this also contributes to a reduction in the production cost of the mold. In this way,
fuel supply modules that include a plurality of types of module bodies can be provided
at low cost.
[0045] In this arrangement, since in particular the support tube 4a is formed on the first
block B1, the boss extension part 5b extending downward in the axial direction from
the first boss 5a is fitted into the inner periphery of the support tube 4a, the first
bonding plane P1 at the upper end of the support tube 4a and the second bonding plane
P2 of the second block B2 are welded, the third bonding plane P3 at the lower end
of the boss extension part 5b and the fourth bonding plane P4 of the third block B3
are welded, the fifth bonding plane P5 on the lower face of the first block B1 and
the sixth bonding plane P6 on the upper face of the third block B3 are welded, and
the boss extension part 5b and the third block B3 are respectively provided with the
first and second through holes 45 and 46, which communicate directly with each other
to form the fuel passage 40, the welded parts of the first and second bonding planes
P1 and P2 are disposed on the atmosphere side of the welded parts of the third and
fourth bonding planes P3 and P4, through which the fuel passage 40 runs, and the pressure
of the fuel passage 40 therefore does not act on the welded parts of the first and
second bonding planes P1 and P2. There can therefore be expected an effect in preventing
high pressure fuel discharged from the electric pump 2 from leaking to the exterior
by blocking it with the first and second bonding planes P1 and P2 even if, due to
weld failure, etc, it leaks past the welded parts of the third and fourth bonding
planes P3 and P4, on which the pressure thereof acts.
[0046] Moreover, since in particular the welded third and fourth bonding planes P3 and P4
are disposed closer to the interior of the fuel tank T than the support tube 4a, even
if fuel leaks past the welded parts of the third and fourth bonding planes P3 and
P4, it can be returned to the fuel tank T, and this, coupled with the presence of
the welded parts of the first and second bonding planes P1 and P2, enables the leakage
of fuel to the exterior to be more reliably prevented.
[0047] Moreover, since the clearance 42 for opening the periphery of the welded third and
fourth bonding planes P3 and P4 to the internal space of the fuel tank T is provided
in the first block B1, if fuel leaks past the welded parts of the third and fourth
bonding planes P3 and P4, it can be returned to the fuel tank T smoothly through the
clearance 42, thereby enabling the leakage of fuel to the exterior to be more reliably
prevented.
[0048] The present invention is not limited to the above-mentioned embodiment, and may be
modified in a variety of ways as long as the modifications do not depart from the
spirit and scope thereof.