WO2007004677A1

WO2007004677A1 - Fuel pump

Info

Publication number: WO2007004677A1
Application number: PCT/JP2006/313415
Authority: WO
Inventors: Takao Ikarugi; Keizo Hayama; Shinichiro Horisoko; Masahiko Narushima
Original assignee: Mitsuba Corporation; Honda Giken Kogyo Kabushiki Kaisha
Priority date: 2005-07-06
Filing date: 2006-07-05
Publication date: 2007-01-11
Also published as: JP4939413B2; CN101213362A; JPWO2007004677A1; BRPI0612098B1; BRPI0612098A2; CN101213362B

Abstract

A fuel pump enabling a reduction in the size of a fuel feeder and an increase in the durability thereof. The fuel pump (1) comprises a pump part (P) disposed on the lower part of a cylindrical yoke (3) and a brush type motor part (M) disposed on the upper part of the yoke (3) and driving the pump part (P). A pump bracket (10) covering the pump part (P) side end part of the yoke (3) comprises a fuel suction part (10c) sucking a fuel into the pump part (P) and a fuel discharge part (10d) discharging the fuel to the outside of the pump part (P). An upper side bracket (4) forming the motor part (M) comprises a pressure regulating device (17).

Description

Specification

Fuel pump

Technical field

[0001] The present invention belongs to the technical field of fuel pumps mounted on vehicles such as motorcycles.

Background art

[0002] Generally, in a fuel pump that constitutes a fuel supply device for this type of vehicle, an in-tank configured to be provided with a fuel pump provided at the bottom of the fuel tank and to be driven while the fuel pump is immersed in fuel. There is a formula. In this case, the fuel pump is configured such that the pump portion is disposed below the cylindrical case body and the motor portion that drives the pump portion is disposed above the case body, so that the fuel in the fuel tank is reduced. However, a stable fuel supply can be achieved.

[0003] By the way, as a motor unit used in a fuel pump, an electric power source is configured such that a commutator is provided on a motor shaft, an external power supply is supplied via a brush that is in sliding contact with the commutator, and thereby the motor shaft is rotated. There is a type using a motor, and in such a type, a fuel discharge part is provided on the motor part side (Patent Document 1).

Assuming that a fuel pump using such a brush type motor unit is incorporated in an in-tank type fuel supply device, the fuel discharged from the fuel pump is used through a pipe that penetrates the inside and outside of the fuel tank. A structure that is guided to the engine side has been proposed (Patent Document 2).

Patent Document 1: JP-A-10-47291

Patent Document 2: Special Publication 2003,044357

Disclosure of the invention

Problems to be solved by the invention

However, in the conventional fuel pump, the fuel discharge portion is provided on the motor portion side, and when the fuel discharged from the fuel discharge portion is guided to the engine side, the fuel discharge portion facing upward Pull the pipe connected to the bottom and pull it out of the fuel tank. Yes. For this reason, the pressure loss increases as the piping to the engine becomes longer, and the fuel pump output must be increased in order to obtain the desired output. There is a problem that the configuration of the apparatus is complicated and the fuel supply apparatus is enlarged.

Therefore, it is proposed that the fuel discharge part is formed in the lower pump part, not the upper motor part, and the piping to the engine side is shortened. In this case, fuel is contained in the motor part. However, since the fuel does not flow, there is a problem in that the movement of the fuel entering the motor unit side is stopped (stagnation), and the escape of the air entering with the fuel is lost. . In particular, when the motor unit is configured using a brush-type electric motor, brush abrasion powder is generated, but the abrasion powder stagnates with the fuel in the motor section and adheres to the commutator. As a result, there is a possibility that a short circuit may occur, and air accumulates in the upper part of the fuel pump, so that the sliding part between the commutator and the brush arranged in the upper part may be in a gas atmosphere. If this happens, there will be a problem in the durability of the fuel pump, and there are problems to be solved by the present invention.

Means for solving the problem

The present invention has been created in view of the above-described circumstances for the purpose of solving these problems. The invention of claim 1 is directed to a fuel pump provided at the bottom of a fuel tank. In configuring the pump part built in the lower part and the motor part built in the upper part of the case body and driving the pump part, a fuel suction part for sucking fuel into the pump part is provided on the pump part side of the case body. And a fuel discharge part for discharging the fuel to the outside of the pump part, and an air venting means is provided on the motor part side of the case body.

The invention of claim 2 is that, in claim 1, the air venting means is formed on the upper end surface of the case body.

The invention of claim 3 is the pressure regulating device according to any one of claims 1 and 2, wherein the air venting means is based on the fact that a predetermined pressure is reached! It is what. The invention of claim 4 is the invention according to any one of claims 1 and 2, wherein the air venting means is constituted by a through hole formed in the case body.

The invention of claim 5 is the fuel pump according to any one of claims 1 to 4, wherein the fuel pump is supported in the fuel tank via a pump stay, and the pump stage communicates with the fuel tank, A fuel supply part is formed below the bottom of the fuel tank to store fuel and supply it to the suction part.

A sixth aspect of the present invention is the motor unit according to any one of the first to fifth aspects, wherein the motor unit is configured by a brush type electric motor.

The invention's effect

[0006] With the inventions of claims 1 and 3, the fuel pump can be made compact, the piping to the engine side can be shortened, and the fuel pump has excellent durability and durability. be able to.

With the invention of claim 2, it is possible to efficiently extract air from the motor unit.

According to the invention of claim 4, the structure can be simplified and the cost can be reduced.

With the invention of claim 5, the number of parts can be reduced and the configuration can be simplified, while the fuel supply to the fuel pump can be performed stably and reliably.

According to the invention of claim 6, the abrasion powder of the brush can be discharged from the motor portion together with the flow of fuel, and a fuel pump having excellent durability can be obtained.

Brief Description of Drawings

FIG. 1 is a cross-sectional front view of a fuel pump.

FIG. 2 is a perspective view of a partition plate.

FIG. 3 is an enlarged cross-sectional view of the main part.

Explanation of symbols

[0008] 1 Fuel pump

2 Fuel tank

2a base 2b Through hole

3 York

5 Armature

5a Armature axis

6 Commutator

7 Brush

8 Permanent magnet

9 Lower bracket

10 Pump bracket

10c Fuel inlet

lOd Fuel outlet

11 Impeller

13 Pump stay unit

13c piece

13f Fuel supply unit

13g fuel taxiway

14 Partition plate

15 Fuel filter

17 Pressure regulator

BEST MODE FOR CARRYING OUT THE INVENTION

Next, embodiments of the present invention will be described with reference to the drawings.

In the drawings, reference numeral 1 denotes a fuel pump constituting a fuel supply device. The fuel pump 1 is attached to a fuel tank 2 to be described later, and is a pump part P located below the bottom 2a side of the fuel tank 2 And a motor part M above the pump part P. The motor part M and the pump part P are configured to include a cylindrical yoke 3 that constitutes the case body of the present invention, and an upper step 3a is formed on the cylindrical end surface of the upper end of the yoke 3. An outer peripheral edge portion of the ring-shaped upper bracket 4 constituting the upper end portion of the case body is caulked to the upper step portion 3a. [0010] 5 is a armature that constitutes the motor part M, and the upper end of the armature shaft (motor shaft) 5a that constitutes the armature 5 is a bearing part that is recessed in the shaft core part of the upper bracket 4 It is rotatably supported by 4a. Further, the force with which the commutator 6 is physically fitted to the upper end portion of the armature shaft 5a is a conductive commutator piece 6b on the outer peripheral surface of the ring-shaped portion 6a made of resin. It is composed of a plurality provided in the circumferential direction. On the other hand, a pair of brush holders 4b are formed in the circumferential direction on the lower end surface of the upper bracket 4, and the brushes 7 biased toward the inner diameter side are respectively applied to the brush holder 4b. The tip end surface of each brush 7 on the inner diameter side is set so as to abut on the commutator piece 6b in a resilient manner. In addition, a plurality of ring-shaped core members 5b are externally fitted below the outer fitting portion of the commutator 6 of the armature shaft 5a, and the outer periphery of the combined core member 5b is predetermined. The commutator piece 6b is provided with a plurality of coils 5c that are electrically connected to each other, thereby forming the armature 5.

Reference numeral 8 denotes a pair of permanent magnets fixed to the inner peripheral surface of the yoke 3 facing the armature 5 at a predetermined interval in the circumferential direction. The permanent magnet 8 and the outer surface of the armature 5 are fixed to each other. Zhou is set to be in close proximity to each other!

[0011] Further, the lower end 5d of the armature shaft 5a has a through hole 9a formed in the shaft core portion of the ring-shaped lower bracket 9 fixed to the lower end portion of the leg yoke 3 constituting the pump portion P. And is rotatably supported by a bearing 9b disposed in the through hole 9a. Then, as will be described later, by supplying an external power source to the brush 7, the coils 5c are excited via the commutator piece 6b. It is set to rotate in the yoke 3!

[0012] The outer peripheral edge portion of the lower bracket 9 is disposed in abutting manner below the lower bracket 9, and together with the outer peripheral edge portion of the pump bracket 10 constituting the lower end portion of the case body of the present invention. A lower step 3b formed on the yoke 3 is caulked and the lower bracket 9 and the pump bracket 10 constitute a pump part P.

A recess 9c that opens downward is formed on the lower surface of the lower bracket 9, and the lower bracket 9 abuts the pump bracket 10 against the outer peripheral edge of the outer diameter side of the recess 9c. With the bracket 9 and the pump bracket 10, the pump chamber PR is formed Yes. A lower end portion 5d of the armature shaft 5a that protrudes downward through the through hole 9a of the lower bracket 9 protrudes into the pump chamber PR, and the protruding lower end portion 5d has an outer peripheral edge portion. The impeller 11 in which the blade portion 11a is formed is supported in a penetrating manner by being key-fitted, whereby the impeller 11 is set to rotate as the motor portion M is driven.

[0013] Further, on the outer diameter side of the concave portion 9c of the lower bracket 9, a ring-shaped concave portion 9d serving as a fuel flow path is formed facing the blade portion 11a of the impeller 11, and the ring shape A motor-side discharge unit 9e is established which communicates with the recess 9d and penetrates in the vertical direction and communicates between the motor unit M and the pump unit P. On the other hand, the upper surface of the pump bracket 10 is formed with a recess 10a that protrudes into the pump chamber PR and loosely fits the lower end portion 5d of the armature shaft 5a that supports the impeller 11 in a non-rotating manner, and the impeller blade portion 11a A ring-shaped recess 10b serving as a fuel flow path is formed facing the (lower bracket ring-shaped recess 9e). Furthermore, a cylindrical hole fuel suction portion 10c that penetrates in the vertical direction in a state of communicating with the ring-shaped recess 10b and sucks fuel is formed, and is located at a different circumferential position from the fuel suction portion 10c. In addition, a cylindrical fuel discharge portion 10d that penetrates in the vertical direction while communicating with the ring-shaped recess 10b and protrudes downward to discharge the fuel to the outside is formed.

12 is a check valve provided in the fuel discharge section 10d. The check valve 12 includes a bottomed cylindrical valve body 12a and a through-hole 12b opened at the bottom located above the valve body 12a. A spherical valve body 12c for sealing, and when the pressure of the fuel discharged from the fuel discharge portion 10d reaches a predetermined pressure, the valve body 12c opens the through hole 12b of the valve body 12a, and the fuel Is set to discharge to the discharge guiding path 13g side described later. Note that the check valve 12 is arranged so as to be movable in the vertical direction in the fuel discharge part 10d, and has a function as a relief valve, so that the fuel in the pipe connected to the discharge guiding path 13g side can be When the temperature becomes high and the pressure becomes high, the valve body 12a is displaced upward to reduce the fuel pressure on the discharge guiding passage 13g side.

On the other hand, a ring-shaped through hole 2b is formed in the bottom 2a of the fuel tank 2, and the through hole 2b is provided with a pump stay unit (corresponding to the pump stage of the present invention) 13. It is set to be sealed. The pump stay unit 13 has a function of supporting the fuel pump 1 in the fuel tank 2.

That is, a bottomed cylindrical portion 13a is formed at a lower portion of the pump stay unit 13, and a flange portion 13b protruding to the outer diameter side is formed on the outer peripheral surface of the bottomed cylindrical portion 13a. ing. Then, the flange portion 13b is set to abut against the fuel tank through hole 2b and fixed so that the fuel tank penetration 2a is covered with the bottomed tubular portion 13a. In this state, The bottomed cylindrical portion 13a is configured to project in a protruding manner below the fuel tank 2.

Further, the pump stay unit 13 has a predetermined gap in the circumferential direction from the upper cylinder end of the bottomed cylindrical part 13a which is an upper part of the flange part 13b and is a part fitted into the fuel tank 2. A plurality of stage pieces 13c extending upward are formed as a body, and a fixed piece 13d bent toward the inner diameter side is formed at the upper end of these stage pieces 13c. Then, the pump stay unit 13 fixes the fixed piece 13d to the upper bracket 9 of the fuel pump 1 disposed in the fuel tank 2, so that the stage piece 13c is in close proximity to the yoke 3 and the fuel pump 1 The fuel pump 1 is fixedly supported in a standing posture in which the pump part P is in the lower side in the fuel tank 2. Further, on the inner peripheral surface of the bottomed cylindrical portion 13a projecting outward (downward) from the fuel tank 2 of the pump stay unit 13, a step portion 13e having a small diameter on the lower side is formed. In 3e, a disc-shaped partition plate 14 is fixed in a sealing and abutting manner, and the partition plate 14 is set so as to partition the inside of the bottomed cylindrical portion 13a vertically. Yes. Here, the partition plate 14 is disposed below the bottom side 2a of the fuel tank 2, and faces the pump bracket 10 of the fuel pump 1 supported upright by the step piece 13c and the fixed piece 13d. It is set to do!

The partition plate 14 is provided with a fuel filter 15, and the fuel flowing into the bottomed tubular portion 13 a side from the upper force of the partition plate 14 through the through hole 2 b of the fuel tank bottom 2 a is disposed in the fuel filter 15. The lower part partitioned by the partition plate 14 of the bottomed cylindrical part 13a is set to flow downward through the installation part, so that the fuel supplied by the fuel filtered by the fuel filter 15 is stored. Part 13f is configured. [0016] A cylindrical suction guide passage 14a is formed on the outer diameter side portion of the partition plate 14 facing the pump bracket 10 so as to face the fuel suction portion 10c and project upward. The suction guide passage 14a is formed in communication with the fuel supply portion 13f through a through hole 14b provided in the partition plate 14, and the projecting tip of the suction guide passage 14a has the above-described fuel. It is connected by being fitted into a cylindrical fuel suction part 10c on the pump 1 side in a sealing manner. Thus, with the rotation of the impeller 11 of the fuel pump 1, the filtered fuel stored in the fuel supply section 13f is supplied to the fuel suction section 10c via the suction guide path 14a. It is composed.

Further, on the outer diameter side of the partition plate 14, a discharge through hole 14 c is formed on the outer diameter side located at a portion facing the fuel discharge portion 10 d of the pump bracket 10. The discharge through hole 14c is configured as a through hole that vertically penetrates the partition plate 14, and is set so that the fuel discharge portion 10d on the fuel pump 1 side penetrates in a sealed manner. Then, the penetrating tip of the fuel discharge portion 10d fitted into the discharge through-hole 14c is sealed with a discharge guide passage (corresponding to the guide passage of the present invention) 13g formed in the bottomed tubular portion 13a. It is set to fit into the shape. The discharge guiding path 13g is partitioned from the fuel supply part 13f formed in the bottomed cylindrical part 13a, and is formed adjacent to the fuel supply part 13f. The bottom side of the bottomed cylindrical part 13a The force is also formed so as to extend toward the outer diameter side, and is set so that a pipe (not shown) from the engine side is connected to the extending end portion of the discharge guiding path 13g. .

[0017] Also, an external force bra (not shown) is connected to the outer peripheral portion of the bottomed cylindrical portion 13a exposed from the fuel tank 2 of the pump stay unit 13 and below the fuel tank bottom 2c. A force bra portion 13h for inputting an external power source is formed. Then, the external power input through the force bra portion 13h is transmitted through the L-shaped first terminal plate 16, the conductive plate 16a facing up and down, and the second terminal plate 16b. It is set to be supplied to the brush 7 disposed on the upper bracket 4 of the fuel pump 1.

[0018] Further, in the fuel pump 1 of the present embodiment, the upper bracket 4 constituting the motor unit M is provided with a pressure adjusting device 17 as an air venting means, and the pressure in the fuel pump 1 ( When the fluid pressure reaches a predetermined pressure, the fuel in the fuel pump 1 is discharged to the fuel tank 2 side, and the pressure in the fuel pump 1 is adjusted. At the same time, the air that has entered the fuel pump 1 is discharged. It is configured so that it can be extracted (discharged) to the outside along with the fuel to be discharged.

The upper bracket 4 in which the pressure adjusting device 17 is arranged is formed with a concave hole 4c that is a cylindrical concave groove that is located at a portion where the brush holder 4b is not formed and the upper side force also faces downward. Here, a pressure adjusting device 17 is provided. The groove bottom 4d of the recessed hole 4c is located at the center of the cylinder, and communicates between the inside of the yoke 3 (in the fuel pump 1) and the inside of the fuel tank 2. A through-hole 4e is established.

On the other hand, the pressure adjusting device 17 includes a holder 17a fixed to the groove bottom 4d of the upper bracket recessed hole 4c. The holder 17a extends along the groove bottom 4d and penetrates the groove bottom. A first plate 17c formed with a first series of through-holes 17b communicating with the holes 4e, and integrally connected to the first plate 17c and located on the opening side of the concave holes 4c, and the first series of through-holes 17b A second plate 17e having a second communication hole 17d concentric with the second plate 17e is formed. In the holder 17a, a spherical valve body 17f that can seal the first series of through holes 17b, and a biasing machine that urges the valve body 17f in the direction of sealing the first series of through holes 17b. It is configured with 17g. When pressure exceeding the urging force of the urging ammunition 17g is generated in the fuel pump 1 (motor part M), the valve body 17f moves up against the urging force of the urging ammunition 17g, and the bottom of the groove The through hole 4e and the first series of through holes 17b are opened in communication, and the fuel in the fuel pump 1 enters the concave hole 4c from these through holes 4e and the first through hole 17b, and The second communication hole 17d located on the opening side is set to flow outside the upper bracket 4, that is, inside the fuel tank 2.

[0020] In the fuel pump 1 configured as described above, an external force bra connected to the force bra 13h.

When power is supplied to the brush 7 from the first terminal plate 16, the conductive plate 16a, and the second terminal plate 16b (not shown) and the motor unit M is driven, the pump unit P is rotated along with the rotation of the armature shaft 5a. The impeller 11 rotates. As a result, the fuel stored in the fuel supply unit 13f in a filtered state from the fuel tank 2 is sucked into the pump unit P via the fuel suction unit 10c. The sucked fuel passes through the lower bracket ring-shaped recess 9d and the pump bracket ring-shaped recess 10b formed in the opposite portion of the impeller blade portion 11a. The flow path is set so that the fuel is guided to the motor side discharge part 9e of the upper bracket 9 and the fuel discharge part 10d of the pump bracket 10 and the fuel passing through the fuel guide path 13g is guided to the engine side. In this case, in a state where the pressure in the fuel pump P is smaller than the urging force of the urging ammunition 17g of the pressure adjusting device 17, the valve body 17f is pressed against the first continuity hole 17b, 17b is closed. Then, when the pressure in the fuel pump 1 increases during the pump operation of the fuel pump P and becomes larger than the urging force of the urging ammunition 17g, the valve body 17f opens and the fuel is moved to the fuel tank side. This is set to adjust the pressure in the fuel pump 1!

At this time, when air enters the fuel pump 1, the air accumulates on the upper side of the fuel pump 1, so that the air is supplied together with the fuel from the first through hole 17 b located on the upper side of the yoke 3. It is configured so that it can be discharged efficiently.

[0021] Further, in this case, the fuel stored in the fuel supply unit 13f moves as a flow path from the fuel suction unit 10c formed in the pump bracket 10 of the pump unit P to the fuel discharge unit 10d. Therefore, a fuel flow path is not formed between the inner peripheral surface of the yoke 3 (permanent magnet 8) of the motor part M and the armature 5, so that the yoke 3 (permanent magnet) of the motor part M is formed. 8) The gap between the inner peripheral surface and armature 5 can be set as small as possible, and the fuel flow path is only at the pump part P, so the pressure loss can be reduced accordingly. Has been. Further, the fuel discharge part 10d is guided to the engine side through a fuel guide path 13g arranged adjacent to the fuel supply part 13e of the pump stay unit 13, and thus, Unlike the fuel supply device, the piping from the fuel discharge part of the fuel pump to the engine side does not need to be a complicated structure that draws out the fuel tank power seal, and the fuel supply device can be made compact. It is structured as follows.

In the present embodiment configured as described, the fuel pump 1 constituting the fuel supply device is configured such that the brush 7 is in sliding contact with the commutator 6 provided on the armature shaft 5a, and the outer periphery of the armature 5 The inner peripheral surface of the permanent magnet 8 provided on the inner peripheral surface of the yoke 3 is provided close to each other. In this case, the fuel pump 1 is provided in a standing manner with the pump bracket 10 of the pump part P positioned on the lower side, the fuel suction part 10c and the fuel discharge part 10d However, the motor M is filled with fuel, but it flows inside the yoke 3, that is, between the inner peripheral surface of the yoke 3 to which the permanent magnet 8 is fixed and the outer peripheral surface of the armature 5. The path can be made compact without being formed. In addition, since the fuel discharge part 10d is formed below the fuel tank 2 and the piping to the engine side can be shortened, the pressure loss can be reduced, and the fuel supply device can be connected only by the fuel pump. It can also reduce the impact.

In this case, since the pressure adjusting device 17 is provided within the diameter of the pump portion P, further compactness can be achieved.

In this case, the fuel discharge portion 10d is formed on the pump portion P side of the fuel pump 1, while the pressure adjustment device 17 as an air venting means is provided on the motor portion M side. When the pressure in 1 reaches the specified pressure, the fuel is returned to the fuel tank 2 to adjust the pressure in the fuel pump 1, and the fuel is stagnated when the fuel is returned to the fuel tank 2 side. The motor that can move without causing the air that has entered the motor part M side to be discharged into the fuel tank 2 together with the fuel, so that the air does not accumulate in the motor part M. Part M can always be in a liquid atmosphere, and the durability of the fuel pump 1 can be improved.

[0023] Further, in the embodiment of the present invention, the pressure adjusting device 17 as the air vent means is provided in the upper bracket 4 constituting the upper end portion of the fuel pump 1, so The air accumulated in the fuel can be discharged more effectively, and the fuel pump 1 can be made excellent in terms of durability.

[0024] Furthermore, the fuel pump 1 of the present embodiment has a force that is supported in the fuel tank 2 by the step piece 13c and the fixed piece 13d of the pump stay unit 13. In this case, the pump stay unit 13 The through hole 2b of the bottom 2a of the tank 2 is covered and sealed, and a bottomed cylindrical portion 13a is formed below the fuel tank bottom 2a, and the bottomed cylindrical portion 13a has a fuel A fuel supply unit 13f that stores fuel to be supplied to the fuel suction unit 10c of the pump 1 is formed. As a result, there is no need to separately provide the steering member that supports the fuel pump 1 and the fuel supply unit, and the number of parts can be reduced and the configuration can be simplified. However, since the fuel supply section 13f is located lower than the fuel tank 2, the fuel tank Fuel can be supplied to the fuel pump 1 without being affected even if the oil level in 2 changes, and it can be reliably supplied to the fuel pump 1 even if the fuel in the fuel tank 2 is low. Thus, a stable fuel supply becomes possible. In addition, since the amount of effective fuel in the fuel tank 2 can be increased, the fuel tank 2 can be further miniaturized.

[0025] In addition, when a brush-type electric motor is used as the motor part M, the wear powder of the brush can be discharged together with the fuel to the fuel tank 2 side without stagnation in the motor part M. Can be further improved.

The present invention is of course not limited to the above-described embodiment, and the air vent means includes a vent valve (relief) in addition to the pressure adjusting device as in the first embodiment. In this case, the fuel in the fuel pump is discharged when the pressure in the fuel pump reaches a preset pressure, and the motor is discharged together with the discharged fuel. You can evacuate the air.

Furthermore, it is possible to form a through-hole penetrating the inside and outside of the motor part in the upper bracket constituting the motor part. Even in this case, the air in the fuel pump can be extracted.

Even in this case, the motor unit may be configured to use a brushless type electric motor, so that the fuel flows on the motor unit side without stagnation, and air can be vented as the fuel returns.

Industrial applicability

[0027] The present invention is useful for a fuel pump mounted on a vehicle such as a motorcycle, and it is not necessary to form a fuel flow path in the yoke. Further, the fuel discharge portion faces the lower side of the fuel tank. Because it is configured, the piping to the engine side can be shortened, so pressure loss can be suggested, and the fuel supply system can be removed outside the compressor by using only the fuel pump.

In addition, since the pressure adjusting device is provided on the motor unit side, it can always be in a liquid atmosphere, and the durability of the fuel pump can be improved.

Claims

The scope of the claims

[1] The fuel pump provided at the bottom of the fuel tank is composed of a pump part built in the lower part of the case body and a motor part built in the upper part of the case body to drive the pump part. A fuel suction part for sucking fuel into the pump part and a fuel discharge part for discharging fuel to the outside of the pump part are provided on the pump part side of the case body, and an air venting means is provided on the motor part side of the case body. A fuel pump characterized by being provided.

[2] The fuel pump according to claim 1, wherein the air vent means is formed on an upper end surface of the case body.

[3] The fuel pump according to any one of claims 1 and 2, wherein the air venting means is configured by a pressure adjusting device that opens the inside and outside of the case body when a predetermined pressure is reached.

[4] According to any one of claims 1 and 2, the air vent means comprises a through hole formed in the case body! A fuel pump.

[5] According to any one of claims 1 to 4, the fuel pump is supported in the fuel tank via a pump stay, and the pump stage communicates with the fuel tank, A fuel pump in which a fuel supply part is formed below the bottom of the tank to store fuel and supply it to the suction part.

6. The fuel pump according to any one of claims 1 to 5, wherein the motor unit is configured by a brush-type electric motor.