JPH11201043A - Fluid pump - Google Patents

Abstract

PROBLEM TO BE SOLVED: To achieve reduction of the number of parts, compactness, and light weight while avoiding strength deterioration of a pump main body in a hydraulic pump having a diaphragm between the pump main body and a cover, and a relief valve between an intake chamber and a discharge chamber. SOLUTION: A pump main body 35 is provided with a pump main body main part 35a, an intake part side protruded part 35b protruded from the pump main body main part 35a, a discharge side protruded part 35c protruded from the pump main body main part 35a, and a communication wall part 35d connecting the intake side protruded part 35b to the discharge side protruded part 35c and connected to the pump main body main part 35a, a part including the intake side protruded part 35b forms intake chambers 52, 53 in the pump main body 35, a relief valve 63 is provided in the pump main body 35 at the part including the discharge side protruded part 35c, a discharge chamber 61 and a return chamber 62 connected to the discharge chamber 61 through the relief valve 63, and relief passages 70 communicating the return chamber 62 with the intake chamber 52, 53 are formed in the connection wall part 35d.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a diaphragm for forming a pump chamber between a pump body and a pulsating pressure chamber between the pump body and a cover. The diaphragm is sandwiched between the pump body and the cover which are fastened to each other. Between a suction chamber connected to the pump chamber via a suction-side check valve and a discharge chamber connected to the pump chamber via a discharge-side check valve.
The present invention relates to a fluid pump provided with a relief valve, and more particularly to a fluid pump suitably used as a vehicle fuel pump.

[0002]

2. Description of the Related Art Conventionally, such a fluid pump has been already known, for example, from Japanese Utility Model Application Laid-Open No. 64-51764, in which a pump body and a first pump body fastened to one side of the pump body are known. A diaphragm is sandwiched between the cover and the pump body, and a suction chamber and a discharge chamber are formed between the pump body and a second cover fastened to the other surface side of the pump body with a partition wall interposed therebetween, A relief valve that opens and closes a communication hole provided in the partition wall through the discharge chamber is housed in the suction chamber.

[0003]

SUMMARY OF THE INVENTION In the above prior art,
Since the cover is fastened to both sides of the pump body,
This leads to an increase in the number of parts of the fluid pump and an increase in cost. In order to solve such a problem, a suction chamber and a discharge chamber are formed in the pump body at positions separated from each other along the circumferential direction of the pump chamber, and a fluid returned from the discharge chamber by the relief valve is connected to a conduit. The thickness of the pump body other than the part corresponding to the suction chamber and the part corresponding to the discharge chamber and the relief valve is made as thin as possible by reducing the number of parts and cost. It is conceivable to reduce the size and weight of the fluid pump while achieving the above. However, if the pump main body is made too thin, the strength of the pump main body is reduced. Therefore, it is necessary to provide a reinforcing rib on the pump main body.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a fluid pump capable of reducing the number of parts, reducing the size and the weight while avoiding a decrease in the strength of the pump body. And

[0005]

In order to achieve the above-mentioned object, the present invention provides a pump system in which a pump chamber is formed with a pump body and a pulsating pressure chamber is formed with a cover. Between a pump body and a cover, and between a suction chamber connected to the pump chamber via a suction-side check valve and a discharge chamber connected to the pump chamber via a discharge-side check valve. In a fluid pump in which a relief valve is interposed, a pump body has a concave portion forming a pump chamber between itself and the diaphragm on one surface, and a suction protruding from the other surface of the pump main portion. A side protrusion, a discharge-side protrusion protruding from the other surface of the pump main body at a position separated from the suction-side protrusion along the circumferential direction of the pump chamber, and between the suction-side protrusion and the discharge-side protrusion. Connect the pump body main The suction chamber is formed in the pump body at a portion including the suction-side protrusion, and the relief is formed in the pump body at a portion including the discharge-side protrusion. A valve is provided, a return chamber connected to the discharge chamber and the discharge chamber via a relief valve is formed, and a relief passage communicating between the return chamber and the suction chamber is formed in the communication wall portion. It is characterized by that.

According to such a configuration, the thickness of the main part of the pump main body in the pump main body is made as small as possible, so that the size and weight of the fluid pump can be reduced, and the number of parts can be reduced. Since the connecting wall portion connecting the side protrusions is integrally connected to the pump main body, the connecting wall portion can function as a reinforcing rib of the pump main body, and the strength of the pump main body is reduced. Can be avoided.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described based on embodiments of the present invention shown in the accompanying drawings.

FIGS. 1 to 11 show a first embodiment in which the present invention is applied to a fuel pump. FIG. 1 is a side view of a scooter-type motorcycle equipped with a fuel pump.
2 is an exploded side view showing an attachment structure of the fuel pump to the vehicle body frame, FIG. 3 is a plan view of FIG. 2 as viewed in the direction indicated by an arrow 3, and FIG. 5 is a rear view of the fuel pump viewed from the direction of arrow 5 in FIG. 3, FIG. 6 is a sectional view taken along line 6-6 in FIG. 5, FIG. 7 is a sectional view taken along line 7-7 in FIG. 5, and FIG. 9 as viewed from the direction of arrows 8-8 in FIG.
FIG. 10 is a view of the cover as viewed from the direction of arrows 9-9 in FIG.
Is a view of the diaphragm viewed from the same direction as the cover of FIG. 9,
FIG. 11 is an enlarged view of a portion viewed from the arrow 11 in FIG.

First, in FIG. 1, a body frame 15 of this scooter type motorcycle is connected to a head pipe 16, a down tube 17 extending obliquely downward from the head pipe 16 to the rear, and a lower end of the down tube 17. The main frames 18 are formed so as to extend diagonally upward toward the rear.

A body cover 20 made of synthetic resin is supported on the body frame 15. The body cover 20 is connected to a leg shield front part 21 that covers the front side of the head pipe 16 and to the leg shield front part 21. A leg shield rear portion 22 that covers the rear side of the head pipe 16, a step floor 23 connected to a lower end of the leg shield rear portion 22, and a leg shield rear portion 22 and a step floor 2 that cover below the step floor 23.
3 undercover 24 and step floor 23
And a side cover 25 connected to the under cover 24 to cover the rear portion of the vehicle body from both sides.

A front wheel WF is pivotally supported at the lower end of a front fork 26 slidably supported by the head pipe 16.
A steering handle 27 is connected to an upper end of the front fork 26. A front end of a power unit 28 including an engine is supported on the main frame 18 so as to be vertically swingable, and a rear wheel WR is pivotally supported at a rear end of the power unit 28.

A seat 29 on which an occupant sits is provided on the side cover 25 so as to be openable and closable, and a storage box 30 for storing a helmet and the like is provided below the seat 29 in the side cover 25. It is provided so that it can be opened and closed by the seat 29. Furthermore, mainframe 18…
A fuel tank 31 is mounted on the front of the vehicle so as to be covered with a step floor 23 and an under cover 24.

Referring to FIGS. 2 and 3, a cross member 32 is provided between the left and right main frames 18 between the storage box 30 and the fuel tank 31, and is fixed to the cross member 32. Stay 33
A fuel pump 34 as a fluid pump is attached so as to be disposed between the front portion of the side cover 25 and the storage box 30.

4 to 7, the fuel pump 34 includes a pump body 35, a cover 36 fastened to the pump body 35 by a plurality of, for example, four screw members 38, And a diaphragm 37 sandwiched between the covers 36.

The pump body 35 includes a pump body main portion 35a formed in a relatively thin rectangular shape, and the pump body main portion 3a.
5 and the pump body main part 3
5a, the discharge side protrusion 35c, and the suction side protrusion 35
b and the main part 3 of the pump body
A communication wall portion 35d connected to 5a is integrally provided.

[0016] the central portion of one surface 35a ₁ of the pump main portion 35a is a circular recess 39 is provided as shown in FIG. On the other hand, the cover 36 is formed in a relatively thin rectangular shape corresponding to the pump main body 35a.
As shown in FIG. 9, a circular recess 4 corresponding to the recess 39 is provided at the center of the surface facing the pump main body 35a.
0 is provided.

The diaphragm 37 is made of a thin plate made of synthetic resin or a thin metal plate.
The gasket 41 is interposed between the pump body 35 and the cover 36, and the gasket 42 is interposed between the pump body 35 and the cover 36. The screw members 38 inserted into the insertion holes 43 provided at four locations, for example, are screwed into the screw holes 44 provided on the cover 36 corresponding to the insertion holes 43 respectively.

When the diaphragm 37 is sandwiched between the pump body 35 and the cover 36, a pump chamber 45 is formed by the diaphragm 37 and the concave portion 39 of the pump body main portion 35a, and the diaphragm 37 and the cover 36 are formed.
A pulsating pressure chamber 46 is formed by the concave portion 40 of FIG. The cover 36 has a negative pressure introducing pipe 47 communicating with the pulsating pressure chamber 46.
Are integrally provided so as to protrude laterally, and the intake negative pressure of the engine is introduced into the pulsating pressure chamber 46 via a conduit (not shown) connected to the negative pressure introducing pipe 47.

In the pump body 35, the suction side protrusion 35b and the discharge side protrusion 35c are connected to the pump chamber 45.
At a position spaced apart along the circumferential direction of the
180 degrees apart positions along the circumferential direction of 5 are projected substantially in parallel from the other surface 35a ₂ of the pump main portion 35a, the suction side protrusion 35b as along one diameter line of the pump chamber 45 Connecting wall 35 connecting between the discharge side protrusion 35c
d is continuously provided substantially perpendicular to and integral with the other surface 35a ₂ of the pump main portion 35a.

The suction side projection 35b and the pump main body 3
The 5a, concave portion 48 which opening is provided on one surface 35a ₁ of the pump main portion 35a, the suction side projections 35b, allowed to open at one end to the closed end of the recess 48 in the small circular than the recess 48 A fitting hole 49 and a bottomed hole 50 formed in a circular shape smaller in diameter than the fitting hole 49 and connected eccentrically to the other end of the fitting hole 49 are provided. In addition, diaphragm 37
The portion corresponding to the concave portion 48 of the gasket 41 sandwiched between the pump body 35 is cut out so that the diaphragm 37 faces the open end of the concave portion 48.

A part of the strainer 51 is fitted and fixed in the fitting hole 49 so as to be received at a step between the fitting hole 49 and the bottomed hole 50. A first suction chamber 52 is formed between the diaphragm 37 and the strainer 51 in the suction side protrusion 35b, and communicates with the first suction chamber 52 through the strainer 51 in the suction side protrusion 35b between the diaphragm 37 and the strainer 51. A second suction chamber 53 is formed. A suction pipe 54 communicating with the first suction chamber 52 is integrally connected to the suction side protrusion 35b.
Is extended from the suction side protrusion 35b along a straight line extending between the suction side protrusion 35b and the discharge side protrusion 35c. The fuel tank 31 is connected to the suction pipe 54 via a conduit (not shown), and the fuel in the fuel tank 31 is sucked into the suction pipe 54.

A concave portion 55 corresponding to the concave portion 48 is provided on a surface of the cover 36 facing the pump body 35, and a portion corresponding to the concave portion 55 of the gasket 42 sandwiched between the diaphragm 37 and the cover 36 is The notch is cut out so that the diaphragm 37 faces the open end of the concave portion 55. Thus, between the diaphragm 37 and the cover 36, a regulator chamber 56 adjacent to the second suction chamber 53 via the diaphragm 37 is formed.

[0023] the pump main portion 35a at the portion corresponding to the discharge side projections 35c, a concave portion 58 which opens on one side 35a ₁ is provided on the discharge side projections 35c, the concave portion 58
A press-fitting hole 59 having a smaller circular shape and one end opened at the closed end of the recess 58; and a bottomed hole 6 formed in a circular shape smaller in diameter than the press-fitting hole 59 and coaxially connected to the other end of the press-fitting hole 59.
0 is provided. Further, a portion corresponding to the concave portion 58 of the gasket 41 sandwiched between the diaphragm 37 and the pump main body 35 is cut out so that the diaphragm 37 faces the opening end of the concave portion 58.

A ring-shaped valve seat member 64 is press-fitted into the press-fit hole 59 so as to be received at a step portion between the press-fit hole 59 and the bottomed hole 60, and a pump is inserted between the diaphragm 37 and the valve seat member 64. A discharge chamber 61 is formed in the main body 35a, and a return chamber 62 is formed in the discharge side protrusion 35c between the closed end of the bottomed hole 60 and the valve seat member 64.

A relief valve 63 is provided in the discharge side protruding portion 35c.
4, a spherical valve body 65 housed in the return chamber 62 so as to be able to be seated on the valve seat member 64 from the return chamber 62 side,
The valve spring 5 is provided with a valve spring 66 provided between the closed end of the bottomed hole 60 and the valve body 65 by exerting a spring force in a direction in which the valve seat 5 is seated on the valve seat member 64.

The relief valve 63 opens when the fuel pressure in the discharge chamber 61 becomes equal to or higher than the set pressure, and releases the fuel pressure in the discharge chamber 61 to the return chamber 62 side.
2 is connected to the discharge chamber 61 via the relief valve 63.

A discharge pipe 67 extending outwardly through the discharge chamber 61 is integrally connected to the side of the pump main body 35a. The discharge pipe 67 is connected to the engine via a conduit (not shown). A carburetor (not shown) in the intake system is connected, and fuel discharged from the discharge pipe 67 is supplied to the carburetor.

A concave portion 68 corresponding to the concave portion 58 is provided on a surface of the cover 36 facing the pump body 35, and a portion corresponding to the concave portion 68 of the gasket 42 sandwiched between the diaphragm 37 and the cover 36 is The notch is cut out so that the diaphragm 37 faces the open end of the recess 68. Thus, between the diaphragm 37 and the cover 36, a regulator chamber 69 adjacent to the discharge chamber 61 via the diaphragm 37 is formed.

Further, a relief passage 70 is formed in the communication wall portion 35d for guiding the fuel released from the discharge chamber 61 to the return chamber 62 when the relief valve 63 is opened to the second suction chamber 53.

[0030] In FIG. 11, the pump body main portion 35a in the pump body 35, a bottom of the suction-side inlet passage 72 which opens to the one surface 35a ₁ at the outer side of the pump chamber 45
When a bottomed on the suction side outlet passage 73 that opens to the one surface 35a ₁ as in the outer side adjacent to the suction side inlet passage 72 of the pump chamber 45, the suction-side inlet passage 72 to the second suction chamber 53 An inlet-side communication passage 74 that allows communication, and an outlet-side communication passage 7 that allows the suction-side outlet passage 73 to communicate with the pump chamber 45.
A communication recess 76 is provided on the surface of the cover 36 facing the pump body 35, the communication recess 76 having a size that allows the opening ends of the suction-side inlet passage 72 and the suction-side outlet passage 73 to face in common. Can be

A portion of the diaphragm 37 corresponding to the communication recess 76 is cut out so as to form a tongue-shaped suction-side check valve 77. The base of the suction-side check valve 77 is sandwiched and fixed between the pump body 35 and the cover 36, and the distal end of the suction-side check valve 77 can close the open end of the suction-side inlet passage 72. As the fuel pressure in the suction-side inlet passage 72 becomes higher than the fuel pressure in the communication recess 76, that is, the fuel pressure in the pump chamber 45, the suction-side check valve 77 opens, and the fuel in the suction-side inlet passage 72 is opened. As the pressure becomes lower than the fuel pressure in the pump chamber 45, the suction-side check valve 77 closes.

At the open end of the suction-side outlet passage 73, the inner surface on the suction-side inlet passage 72 side is formed with a communication recess 76.
It is formed as an inclined surface 73 a that is inclined in a direction approaching the suction-side inlet passage 72 toward the side. Moreover, the projected area of the inclined surface 73a on an imaginary plane including the axis of the suction-side outlet passage 73 and facing the inclined surface 73a may be set to 50 to 60% of the cross-sectional area of the suction-side inlet passage 72. desirable.

A communication recess 76 provided in the cover 36
Are connected from the opening end of the suction-side inlet passage 72 to the suction-side outlet passage 7.
3 and a second concave portion 76b corresponding to the open end of the suction-side outlet passage 73. The first concave portion 76a moves toward the second concave portion 76b. The second recess 76b is formed so as to be deeper.
Is formed deeper than the deepest portion of the first concave portion 76a. That is, the first concave portion 76a and the second concave portion 76b
A step 76c facing the suction-side outlet passage 73 is formed between them.

A pump chamber 45 is provided in the pump main body 35a.
The discharge-side inlet passage 78 with a bottom opening to the one surface 35a ₁ at the outer side, at the outer side of the pump chamber 45 so as to be adjacent to the discharge side inlet passage 78 with a bottom opening to the one surface 35a ₁ The discharge side outlet passage 79 and the discharge side inlet passage 78
An inlet-side communication passage 80 for connecting the pump chamber 45 to the pump chamber 45 and an outlet-side communication passage 81 for connecting the discharge-side outlet passage 79 to the discharge chamber 61 are provided on the surface of the cover 36 facing the pump body 35. A communication recess 82 having a size that allows the opening ends of the discharge-side inlet passage 78 and the discharge-side outlet passage 79 to face in common is provided.

The portion of the diaphragm 37 corresponding to the communication recess 82 is cut out so as to form a tongue-shaped discharge side check valve 83. The base of the discharge-side check valve 83 is sandwiched and fixed between the pump body 35 and the cover 36, and the distal end of the discharge-side check valve 83 can close the open end of the discharge-side inlet passage 78. As the fuel pressure in the discharge-side inlet passage 78, that is, the pump chamber 45 becomes higher than the fuel pressure in the communication recess 82, that is, the fuel pressure in the discharge chamber 61, the discharge-side check valve 83 opens, and the pump chamber 45 is opened. The discharge-side check valve 83 closes as the fuel pressure of the discharge chamber 61 becomes lower than the fuel pressure of the discharge chamber 61.

At the open end of the discharge-side outlet passage 79, the inner surface on the discharge-side inlet passage 78 side is formed as an inclined surface 79a that is inclined in a direction approaching the discharge-side inlet passage 78 toward the communication recess 82. . Moreover, the projected area of the inclined surface 79a on an imaginary plane including the axis of the discharge-side outlet passage 79 and facing the inclined surface 79a is set to 50 to 60% of the cross-sectional area of the discharge-side inlet passage 78. desirable.

Further, the communicating recess 8 provided in the cover 36
Reference numeral 2 denotes a first recess 82a corresponding to a portion from the opening end of the discharge-side inlet passage 78 to an opening end of the discharge-side outlet passage 79, and a second recess 82b corresponding to the opening end of the discharge-side outlet passage 79. The first concave portion 82a is formed so as to become deeper toward the second concave portion 82b, and the second concave portion 82a is formed.
b is formed deeper than the deepest portion of the first concave portion 82a. That is, the first concave portion 82a and the second concave portion 82
Between steps b, a step 82c facing the discharge-side outlet passage 79 is formed.

The pump body main part 3 in the pump body 35
On both sides of 5a, flange portions 85, 85 projecting outward are provided.
Are provided integrally. On the other hand, the body frame 15
Stay 3 fixed to the cross member 32
3, the pump body main portion 35a is formed in its cross-section substantially U-shaped so as to embrace the other surface 35a ₂ side, the bolt is inserted through each of the flange portions 85, 85 8
6, 86 are nuts 87 fixed to the stay 33,
87 and screwed into the fuel pump 34
Is attached to the stay 33.

In such a fuel pump 34, the intake negative pressure pulsating according to the operation of the engine is generated by the pulsating pressure chamber 46.
The diaphragm 37 operates so as to increase or decrease the volume of the pump chamber 45 in response to being introduced into the pump chamber 45, and the pressure of the pump chamber 45 decreases as the volume increases and the pump chamber 45 decreases as the volume decreases. The pressure increase is repeated.

When the pressure in the pump chamber 45 drops, the suction-side check valve 77 opens and the discharge-side check valve 83 closes in accordance with the pressure drop, so that the fuel in the fuel tank 31 flows from the suction pipe 54 through the suction pipe 54. 1 suction chamber 52, strainer 5
1, the second suction chamber 53, the inlet communication passage 74, the suction inlet passage 72, the suction check valve 77, the communication recess 76, the suction outlet passage 73, and the pump chamber 4 through the outlet communication passage 75.
5 will be inhaled. On the other hand, when the pressure in the pump chamber 45 increases, the suction-side check valve 7
7 is closed and the discharge side check valve 83 is opened,
The fuel in the pump chamber 45 flows from the inlet communication passage 80 to the discharge inlet passage 78, the discharge check valve 83, the communication recess 82,
The gas is supplied to the vaporizer via the discharge-side outlet passage 79, the outlet-side communication passage 81, the discharge chamber 61, and the discharge pipe 67.

Further, when the fuel pressure in the discharge chamber 61 becomes higher than the set pressure, the relief valve 63 opens and a part of the discharge chamber 61 is transferred to the second suction chamber 53 via the relief valve 63, the return chamber 62 and the relief passage 70. Is returned, the discharge pipe 6
7 does not exceed the set pressure.

A regulator chamber 56 adjacent to the second suction chamber 53 via the diaphragm 37 is formed in the cover 36, and the pulsation of the fuel pressure in the suction path from the suction pipe 54 to the pump chamber 45 reduces the pressure in the regulator chamber 56. Is attenuated by the flexure of the diaphragm 37 at the portion corresponding to. Further, a regulator chamber 69 adjacent to the discharge chamber 61 via the diaphragm 37 is formed in the cover 36, and pulsation of fuel pressure in a discharge path from the pump chamber 45 to the discharge pipe 67 corresponds to the regulator chamber 69. Of the diaphragm 37.

Next, the operation of the first embodiment will be described. The pump main body 35 holding the diaphragm 37 between the cover 36 and the pump main body 35a is formed relatively thin. discharge side collision projecting of the suction side protrusion 35b protruding from the other surface 35a _2, from the other surface 35a ₂ of the pump main portion 35a at a position separated from the suction side projections 35b along the circumferential direction of the pump chamber 45 Part 35
and c, and the suction-side protrusion 35b and is drawn between the discharge-side protrusions 35c connected to the other surface 35a ₂ of the pump main portion 35a contacts wall portion 35d as it has integrally suction side projections 35
b, the first and second suction chambers 52 and 53 are formed in the pump body 35, and the relief valve 63 is provided in the pump body 35 in the part including the discharge side protrusion 35c. A return chamber 62 connected to the discharge chamber 61 via a relief valve 63 is formed, and a relief passage 70 communicating between the return chamber 62 and the second suction chamber 53 is formed in the communication wall 35d. Therefore, the thickness of the pump main body 35a in the pump main body 35 can be made as small as possible, so that the size and weight of the fuel pump 34 can be reduced, and the number of parts can be reduced. In addition, the communication wall 35d is the pump main body 35a.
Since the connecting wall 35d functions as a reinforcing rib of the pump main body 35a, the strength of the pump main body 35 is reduced despite the thin pump main body 35a. Drops can be avoided.

[0044] Also the second suction chamber 53 and the suction-side and discharge-side inlet passage which opens on one side 35a ₁ of the pump body 35 communicates individually to the pump chamber 45 72 and 78, the pump chamber 4
5 and leads individually to the discharge chamber 61 open to the one surface 35a ₁ and the suction side and the discharge side outlet passage 73,79 is,
A pair of suction-side inlet and outlet passages 7 respectively
2,73, and discharge-side inlet and outlet passages 78,7
9 is provided on the pump main body 35 so as to be adjacent to the periphery of the pump chamber 45, and a suction side inlet and outlet passages 72, 7 are provided on a surface of the cover 36 facing the pump main body 35.
3, and communication recesses 76, 82 corresponding to the discharge-side inlet and outlet passages 78, 79, respectively. The diaphragm 37 has a tongue-shaped check valve capable of opening and closing the open ends of the inlet passages 72, 78. 77 and 83 are provided. Therefore, both check valves 77 and 83 can be arranged around the pump chamber 45, and the pump body 3
5 and cover 36 can be made as thin as possible.

As described above, the thickness of the pump main body main portion 35a in the pump main body 35 can be reduced as much as possible, and the overall thickness of the pump main body 35 and the cover 36 can be reduced as much as possible. The fuel pump 34 can be effectively arranged in a narrow space between the storage box 30 and the front part of the side cover 25 in the vehicle body cover 20.

The suction-side and discharge-side inlet-side passages 7 at the open ends of the suction-side outlet passage 73 and the discharge-side outlet passage 79.
Since the inner surfaces on the sides 2 and 78 are the inclined surfaces 73a and 79a, the communication recesses are formed so that bubbles and the like do not get caught on the opening edges of the outlet passages 73 and 79 when the check valves 77 and 83 are opened. Each exit passage 73, 79 from 76, 82
Fuel flow to the fuel cell. Therefore, even though the flow path from each of the inlet passages 72, 78 to each of the outlet passages 73, 79 via the communication recesses 76, 82 is substantially U-shaped, the pressure loss is suppressed to the utmost and fuel can be efficiently used. Can be sent.

Further, steps 76c, 8 facing the suction-side and discharge-side outlet passages 73, 79 are formed in the communication recesses 76, 82, respectively.
Since 2c is formed, the air bleeding property can be improved. That is, at the moment when the check valves 77 and 83 are closed, the communication recess 7 is formed from the outlet passages 73 and 79.
6 and 82, the fuel tends to flow back to the inlet passages 72 and 78. At this time, air bubbles in the fuel which is going to flow back are caught by the steps 76c and 82c, and the inlet passages 73 and 82c.
Backflow to the side 78 is prevented, and the air bleeding property between the second suction chamber 53 and the pump chamber 45 and between the pump chamber 45 and the discharge chamber 61 is improved.

As a second embodiment of the present invention, a relief passage 70 'communicating between the first suction chamber 52 and the return chamber 62 is provided in the communication wall 35d of the pump body 35 as shown by a chain line in FIG. May be formed so as to be coaxially connected in the suction pipe 54.

According to the second embodiment, when casting the pump body 35, the inside of the suction pipe 54 and the relief passage 70 'can be simultaneously formed by the rod-shaped core. Processing becomes easy.

FIGS. 12 and 13 show a third embodiment of the present invention. FIG. 12 is a perspective view showing a state in which a fuel pump is mounted on a vehicle body frame, and FIG.
It is a 3 line expanded sectional view.

The pump body 35 'of the fuel pump 34' has a pump body main part 35a formed in a relatively thin rectangular shape, a suction side protrusion 35b projecting from the pump body main part 35a, and a pump body main part 35a. And a communication wall 35d 'connecting the suction side protrusion 35b and the discharge side protrusion 35c to the pump main body 35a and integrally connecting the discharge side protrusion 35c with the pump main body 35a. Part 35
Engaging recesses 89, 89 are provided on both sides of the pump body main portion 35a at d '.

On the other hand, the cross beam 32 of the vehicle body frame 15 has an engaging arm portion 90a for resiliently engaging the distal end portion with each of the engaging concave portions 89, 89 so as to hold the communication wall portion 35d 'from both sides. , 90b on the distal end side of the support member 90 is fixed.

According to the third embodiment, the flange portion 8 provided integrally with the pump body 35 in the first embodiment.
The fuel pump 34 'can be attached to the vehicle body frame 15 without the need for the fuel pump 34'.
Of the pump body 3 as much as the assembly of the pump body 3 to the body frame 15 is improved and the flange portions 85 and 85 become unnecessary.
In addition to facilitating the processing of the 5 ', the fuel pump 34'
Can be further reduced in weight.

Although the embodiments of the present invention have been described in detail, the present invention is not limited to the above embodiments, and various design changes can be made without departing from the present invention described in the appended claims. It is possible to do.

For example, in each of the embodiments described above, the fuel pump is described, but the present invention can be widely applied as a fluid pump other than the fuel pump.

[0056]

As described above, according to the present invention, while reducing the number of parts, the thickness of the main part of the pump main body in the pump main body can be made as small as possible, and the fluid pump can be reduced in size and weight. The connecting wall portion connecting the suction side and the discharging side projection is integrally connected to the main pump body portion, so that the connecting wall portion functions as a reinforcing rib of the main pump body portion. A reduction in the strength of the main body can be avoided.

[Brief description of the drawings]

FIG. 1 is a side view of a scooter type motorcycle equipped with a fuel pump according to a first embodiment.

FIG. 2 is an exploded side view showing a mounting structure of the fuel pump to a vehicle body frame.

FIG. 3 is a plan view as viewed in the direction of arrow 3 in FIG. 2;

FIG. 4 is a front view of the fuel pump as viewed from the direction of arrow 4 in FIG. 3;

FIG. 5 is a rear view of the fuel pump as viewed from the direction of arrow 5 in FIG. 3;

FIG. 6 is a sectional view taken along line 6-6 in FIG. 5;

FIG. 7 is a sectional view taken along line 7-7 of FIG. 5;

FIG. 8 is a view of the pump body as viewed from the direction of arrows 8-8 in FIG. 7;

9 is a view of the cover as viewed from the direction of arrows 9-9 in FIG. 7;

FIG. 10 is a view of the diaphragm as viewed from the same direction as the cover of FIG. 9;

FIG. 11 is an enlarged view of a portion viewed from an arrow 11 of FIG. 6;

FIG. 12 is a perspective view showing a state in which the fuel pump of the third embodiment is mounted on a vehicle body frame.

FIG. 13 is an enlarged sectional view taken along line 13-13 of FIG.

[Explanation of symbols]

34, 34 '... fuel pump as a fluid pump 35, 35' ... pump body 35a ... pump body main part 35a ₁ ... one surface of pump body main part 35a ₂ ... pump body main part 35b ··· suction side projection 35c ··· discharge side projection 35d, 35d '··· communication wall 36 ··· cover 37 ··· diaphragm 45 ··· pump chamber 46 ··· pulsation Pressure chamber 53 ・ ・ ・ Suction chamber 61 ・ ・ ・ Discharge chamber 62 ・ ・ ・ Return chamber 63 ・ ・ ・ Relief valve 70, 70 '・ ・ ・ Relief passage 77 ・ ・ ・ Suction side check valve 83 ・ ・ ・ Discharge side check valve

Claims (1)

[Claims] A pump body (35, 35 ');
A pump chamber (45) and a cover (36).
Diaphragm (37) forming pulsating pressure chamber (46) between
Are mutually connected pump bodies (35, 35 ') and
Between the suction side check valve (7) and the cover (36).
7) a suction chamber connected to the pump chamber (45) via
(53) and the port through the discharge side check valve (83).
Between the pump chamber (45) and the discharge chamber (61).
In the fluid pump in which the relief valve (63) is interposed,
The pump body (35, 35 ') is provided with the diaphragm (3).
7) a recess (39) forming a pump chamber (45) between
On one side (35a₁) Of the pump body (35a)
And the other surface (35a) of the pump main body (35a). _Two) Or
Suction side projection (35b) projecting from the pump chamber (4
Along the circumferential direction of 5), separate from the suction side protrusion (35b).
The other surface (35a) of the pump main body (35a)
_Two), A discharge-side protrusion (35c), and a suction-side protrusion.
(35b) and the discharge side protrusion (35c).
The other side (35a) of the main body (35a)_Two)
Walls (35d, 35d ') are integrally provided, and the suction side
The pump body (35, 3) includes the protrusion (35b).
5 ′), the suction chamber (53) is formed,
The pump body (35, 3) includes the protrusion (35c).
When the relief valve (63) is provided in 5 '),
The discharge chamber (61) and the discharge chamber (61)
Return chamber (62) connected via a relief valve (63)
Is formed on the connecting wall (35d, 35d ').
Communication between the return chamber (62) and the suction chamber (53)
That the relief passages (70, 70 ') are formed.
Fluid pump.