JPH10318073A - Fuel pump - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve sealability and durability of a fuel pump. SOLUTION: A strainer 15 is arranged on a fuel suction port 12a of a casing 10. A discharge nozzle 13a is formed on a casing cover 13 of the casing 10. A rotor housing recession 22 is formed in the vicinity of the discharge nozzle 13a. A rotor 30 is rotatably housed therein. A motor 50 is arranged on an upstream side of the rotor 30 for rotationally driving the rotor 30, and on the upstream side of the motor 50 a fuel filter 40 is arranged. Fuel flows around an armature 53 of the motor 50, with cooling it.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fuel pump mounted on a vehicle and used in particular, and more particularly to a motor-driven fuel pump used immersed in fuel.

[0002]

2. Description of the Related Art Generally, in an automobile employing an electronically controlled fuel injection system, fuel in a fuel tank is pumped up by a fuel pump, passed through a fuel filter, and supplied to a fuel injector via a discharge pipe. ing. Here, the fuel pump is generally disposed in a fuel tank to facilitate suction of the fuel, and is installed so as to be immersed in the fuel.

An example of this type of conventional general fuel pump will be described with reference to FIG. 7. In this fuel pump 400, fuel sucked from an inlet 401 is pressurized by rotation of a rotor 402, and The fuel is discharged from the discharge port 404 through the gap 403, and the fuel cools the motor 403 when passing through the motor 403.

The pressure of the fuel after being pressurized by the rotor 402 is, for example, about 3 kgf / cm ² , and this fuel pressure is applied to the motor section 403 located downstream of the rotor 402. Therefore, the fuel pump 40
0 housing body 405 and housing upper 40
6 and the joint 409 between the housing body 405 and the housing lower 408 are required to have sealing properties against the fuel pressure after pressurization.

Further, since the housing upper 406 and the housing lower 408 are subjected to a force in the detaching direction corresponding to the cross-sectional area due to the pressure of the fuel, the housing upper 406 and the housing lower 408 each have a pressure resistance including an engaging force with the housing body 405. Is required. In the current fuel pump 400, the housing body 405, the housing upper 406, and the housing lower 408 are fixed by crimping the ends 405a, 405b of the housing body 405 over the housing upper 406 and the housing lower 408.

[0006]

In order to secure the sealing performance and pressure resistance that can withstand the fuel pressure after pressurization, a high finishing accuracy is required for the joining surfaces of the members or the thickness of the members is increased. There are various restrictions such as thickening of the material and limited use of materials. Therefore, the greater the number of such seal portions and pressure-resistant portions, the lower the productivity and the higher the cost.

In particular, in the future, it is naturally considered that the fuel pressure may be further increased in order to cope with an increase in the output of the engine, and the demands for sealing and pressure resistance will become more severe. It is difficult to respond.

US Pat. No. 5,392,750 discloses a fuel pump in which a fuel filter is provided in a case. In this fuel pump, a rotor is disposed downstream of the fuel filter, and a motor section is further disposed downstream of the rotor. However, the above-mentioned problems regarding the sealing property and the pressure resistance cannot be solved at all.

Japanese Patent Application Laid-Open No. 58-101263 discloses a fuel pump having a structure in which a motor section is separated from a pump section so that the pressure of fuel pressurized by a rotor is not applied to the motor section. However, in this fuel pump, the motor section is not cooled by the fuel, so a separate cooling mechanism is required to cool the motor section, and the installation space is limited as in automobiles. It is not suitable for mounting on something. Also, instead of providing another cooling mechanism, it is conceivable to cool a motor part by discharging a part of the discharged fuel to a motor part at a low pressure,
This results in poor pump efficiency.

[0010] The present invention has been made in view of such problems of the conventional technology, and an object to be solved by the present invention is to provide a high-pressure rotor by installing the rotor at the discharge end of the case. The purpose of the present invention is to improve the sealing performance and pressure resistance of the fuel pump by limiting the portion to the narrowest possible range.

[0011]

The present invention has the following features to attain the object mentioned above. (1) The present invention provides a casing having a fuel inlet and a fuel outlet, a rotor installed inside the casing and boosting fuel sucked from the fuel inlet and sending it to the fuel outlet, and the casing. A motor pump, which is installed inside and rotatably drives the rotor, and a cooling passage through which fuel for cooling the motor unit is provided inside the casing and adjacent to the motor unit. The fuel pump is characterized in that the rotor is disposed at a downstream end in a casing adjacent to the fuel discharge port.

In this fuel pump, when the rotor is rotated by the motor section, the fuel sucked up from the fuel suction port is discharged from the fuel discharge port after cooling the motor section. Since the rotor is arranged at the downstream end in the casing, the motor section can be arranged under low pressure, the area where high pressure is applied is narrowed, and the high pressure seal section is also reduced.

[0013] In the fuel pump described in the above (1), a fuel filter can be provided upstream of the rotor in the casing. In this case, the fuel filter can be arranged under low pressure.

(2) The present invention relates to a casing having a fuel inlet and a fuel outlet, and a rotor installed inside the casing and boosting fuel sucked from the fuel inlet and sending it to the fuel outlet. A motor unit installed inside the casing to rotationally drive the rotor, and a cooling passage through which fuel for cooling the motor unit is provided inside the casing adjacent to the motor unit.
A fuel filter installed inside the casing, wherein the motor unit, the fuel filter, and the rotor are arranged in the casing in order from upstream to downstream, and the rotor is The casing is provided at a downstream end in the vicinity of the discharge port, a bypass passage is provided in the casing to bypass the cooling passage, and the casing includes a plurality of the fuel suction ports, and a part of the fuel intake port is provided. The fuel pump is characterized in that an inlet is connected to an inlet of the fuel filter via the cooling passage, and another fuel inlet is connected to an inlet of the fuel filter via the bypass passage.

In this fuel pump, when the rotor is rotated by the motor, a part of the fuel flows into the fuel filter through the cooling passage, and the other fuel flows into the fuel filter through the bypass passage. The fuel that has passed through any of the paths is boosted in pressure by the rotor after passing through the fuel filter, and is discharged from the fuel discharge port. The fuel passing through the cooling passage cools the motor unit, and dust generated in the motor unit is removed by the fuel filter.

In this fuel pump, since the rotor is disposed at the downstream end in the casing, the motor section and the fuel filter can be disposed under low pressure, the area to which high pressure is applied is reduced, and the high pressure seal section is reduced. Become. In addition, since the fuel supply device has a path through which fuel can be supplied to the fuel filter without passing through the motor portion, the pressure loss upstream of the rotor can be reduced.

(3) The present invention relates to a casing having a fuel inlet and a fuel outlet, and a rotor installed inside the casing and boosting the fuel sucked from the fuel inlet and sending it to the fuel outlet. A motor unit installed inside the casing to rotationally drive the rotor, and a cooling passage through which fuel for cooling the motor unit is provided inside the casing adjacent to the motor unit.
A fuel filter provided inside the casing, wherein the fuel suction port is disposed below the casing, and the fuel filter opens a side facing the fuel suction port to open the fuel suction port. The fuel filter is disposed so as to surround a rotor and at least a part of the motor unit, and is disposed so that a flow direction of fuel in the fuel filter is substantially horizontal, and the rotor is close to the fuel discharge port. And a fuel pump disposed at a downstream end in a casing.

In this fuel pump, when the rotor is rotated by the motor section, the fuel sucked up from the fuel suction port is filtered by the fuel filter, and is discharged from the fuel discharge port after cooling the motor section.

In this fuel pump, since the rotor is disposed at the downstream end in the casing, the motor section can be disposed under low pressure, and the region to which high pressure is applied is narrowed.
The number of high pressure seals is also reduced. Further, the suction head of the fuel pump can be made small, and the fuel pump can be made compact.

[0020] In the fuel pump according to the above (3),
When the fuel filter is arranged so as to surround at least a part of the rotor and the motor part, when surrounding both the rotor and the motor part, when surrounding all or part of the rotor without surrounding the motor part, The case where the whole or a part of the motor unit is surrounded without surrounding the rotor is meant to include both the case of surrounding a part of the rotor and a part of the motor unit.

In the fuel pump described in (3), the motor section can be arranged upstream of the fuel filter, or the fuel filter can be arranged upstream of the motor section. It is preferable to arrange the filter upstream of the fuel filter because dust generated in the motor unit can be removed by the fuel filter.

[0022]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a fuel pump according to the present invention will be described below with reference to FIGS. [First Embodiment] First, a first embodiment of a fuel pump according to the present invention will be described with reference to FIGS.

The fuel pump 1A according to the first embodiment
Is provided inside a casing 10 with a rotor housing 20, a rotor 30, and a fuel filter (hereinafter simply referred to as a filter).
It is configured to house the motor 40 and the motor unit 50, and is used by being installed in a fuel tank (not shown) of an automobile.

The casing 10 includes a casing body 11 having a substantially cylindrical shape with an open top and bottom, and a casing body 11
And a casing cover 13 closing an upper opening of the casing body 11.

The casing body 11 has an upper thin portion 11a.
And a thick portion 11b at the lower portion, and a step portion 11c is formed on the inner surface side of the boundary portion. The lower casing 12 has an annular shape, and has a central opening serving as a fuel intake port 12a covered with a suction strainer 15. The lower casing 12 is a casing main body 11 from below.
And is fixed to the casing body 11 by caulking the upper edge.

The casing body 11 and the lower casing 12
An annular gasket 16 is arranged on the entire periphery of an annular corner formed at the connecting portion with the filter, and the lower edge of the filter 40 is placed on the gasket 16. The packing 16 seals between the casing main body 11 and the lower casing 12 and the filter 40 so that fuel does not flow without passing through the filter 40. Filter 4
0 and the suction strainer 15
Is interposed.

The filter 40 is housed such that its outer peripheral surface is closely contacted with the inner peripheral surface of the casing main body 11 without any gap, and the fuel that has passed through the suction strainer 15 flows through the filter 40 from bottom to top in FIG. It is installed as follows. The motor unit 5 is provided above the filter 40.
0 is set.

The motor unit 50 includes a motor shaft 51 serving as a rotating shaft, a bracket 52 supporting a lower end of the motor shaft 51, an armature 53 attached to the motor shaft 51, a plurality of magnets 54, and a brush 55 And the main configuration.

The motor shaft 51 is arranged in a vertical position with its axis centered vertically. The bracket 52 is
An annular outer ring portion 52a and an inner ring portion 52b are connected by a plurality of arms 52c. The outer ring portion 52a is fitted to the thick portion 11b of the casing body 11, and
b is fixed to the casing body 11 by abutting against the upper surface of the center of the filter 40. A bearing 56 that rotatably supports the lower end of the motor shaft 51 is fixed to the inner ring portion 52b, and a thrust bearing 57 that receives a thrust load of the motor shaft 51 is fixed. Also,
There is a space between the adjacent arms 52c, through which fuel can pass. Motor shaft 51
Is rotatably supported by a bearing 58 fixed to the center of the rotor housing 20 described later.

The armature 53 is fixed to the motor shaft 51 between bearings 56 and 58 and has a commutator 59 projecting upward. The commutator 59 has a brush 55 urged by a spring 61 fixed to the casing body 11. Are slidably in contact.

The magnet 54 is disposed so as to face the outer peripheral surface of the armature 53, and the thick portion 11b of the casing body 11 is provided.
Are fixed to the inner peripheral surface at predetermined intervals in the circumferential direction, and a space is provided between adjacent magnets 54 so that fuel can pass therethrough.

The rotor housing 20 is installed above the brush 55, the commutator 59, and the spring 61. The rotor housing 20 has its outer peripheral surface hooked to the step portion 11c of the casing 11 and the thin portion 11a.
And is attached to the casing body 11 so as to be in close contact with the inner peripheral surface of the thick portion 11b.

A through hole 2 is provided at the center of the rotor housing 20.
The bearing 58 for rotatably supporting the motor shaft 51 is fixed to the through hole 21, and the upper portion of the motor shaft 51 penetrates through the through hole 21 and protrudes upward.

A rotor housing recess 22 is formed in the center of the upper surface side of the rotor housing 20, in which the rotor 30 fixed to the motor shaft 51 is rotatably housed. The predetermined portion of the rotor accommodating concave portion 22 is
It has become.

The rotor housing 20 has a suction hole 24 for allowing fuel to flow into the rotor housing recess 22,
A terminal hole 25 for accommodating a power supply terminal 62 connected to the brush 60, and a valve mounting hole 2 for accommodating a relief valve 70
6 are provided so as to penetrate the upper and lower surfaces of the rotor housing 20. Note that the terminal hole 25 and the valve mounting hole 26 are arranged radially outside the rotor housing recess 22.

The casing cover 13 is covered on the rotor housing 20, and its lower surface is in close contact with the upper surface of the rotor housing 20, and its outer peripheral surface is in close contact with the inner peripheral surface of the thin portion 11 a of the casing body 11. I have. By caulking the upper end of the thin portion 11a of the casing body 11 inward and hooking the outer peripheral edge of the upper surface of the casing cover 13, the casing body 11, the casing cover 13, and the rotor housing 20 are integrally fastened. .

On the upper surface of the casing cover 13, a discharge nozzle (fuel discharge port) 13a connected to the discharge recess 23 of the rotor housing 20 and a connector nozzle 13b serving as a connection port to a power supply are provided to project upward. . The bottom of the connector nozzle 13b is closed, and the power supply terminal 62 is penetrated and fixed to the closed portion in a sealed state.

Further, a relief groove 27 is formed on the bottom surface of the casing cover 13 so as to communicate with a valve mounting hole of the rotor housing 20. When the motor unit 50 is started and the rotor 30 is driven to rotate in the fuel pump 1A, fuel in the fuel tank is sucked into the casing 10 through the suction strainer 15, and the suction strainer 15
As a result, relatively large dust and the like existing in the fuel are removed. The fuel that has passed through the suction strainer 15 flows into the filter 40 and rises. The filter 40 filters the fuel and removes fine foreign matters such as rust present in the fuel.

The fuel filtered by the filter 40 passes between the arms 52c of the bracket 52, passes between the casing main body 11, the magnet 54, and the armature 53, and reaches the lower part of the rotor housing 20.
To cool. That is, a passage for fuel for cooling the motor unit 50, that is, a cooling passage 60 is formed around the armature 53. In other words, the armature 53 rotates in the fuel passing through the cooling passage 60. Therefore, as long as the fuel pump 50 is operated to discharge fuel, the motor unit 5
0 is always cooled by the fuel and does not overheat.
As a result, it is possible to prevent the fuel in the fuel tank from being heated, to prevent the generation of fuel vapor in the fuel tank, and to prevent the fuel tank from being pressurized.

The fuel that has reached the lower portion of the rotor housing 20 enters the rotor accommodating recess 22 through the suction hole 24, where it is pressurized by the rotation of the rotor 30 (for example, about 3 kg / cm ² ) and discharged from the discharge recess 23. The fuel is discharged to the nozzle 13a and fed to a fuel injection system (not shown).

When the fuel pressure in the discharge recess 23 exceeds the set value of the relief valve 70, the relief valve 70 opens, and fuel flows from the discharge recess 23 through the relief valve 70 and the valve housing hole 26, It is returned to the low-pressure section located below the rotor housing 20.

In the fuel pump 1A, the filter 40 and the motor unit 50 are disposed in the low-pressure section upstream of the rotor 30, and only the casing cover 13 is disposed in the high-pressure section downstream of the rotor 30. I have. Therefore,
A portion located below the rotor housing 20, more precisely, a portion below and radially outside the rotor housing recess 22 is a low-pressure portion.

As a result, the casing cover 13 and the rotor housing 20 to which the pump discharge pressure is directly applied are required to have a strength capable of withstanding the discharge pressure, and the material selection and the design of the wall thickness and the like must be matched. However, the casing main body 11 to which the pump discharge pressure is not applied only needs to have strength enough to withstand the low pressure before the pressure is increased by the rotor 30, and it is sufficient to select a material and a design such as a wall thickness that can withstand this low pressure. Become.

Accordingly, in the fuel pump 1A, the area of the high-pressure section is narrowed and the area of the low-pressure section is widened as compared with the conventional pump, so that weight reduction and cost reduction can be realized.

As shown in FIG. 3, the seal portion which should withstand the pump discharge pressure has a contact portion 1 between the lower surface of the outer edge of the casing cover 13 and the upper surface of the outer edge of the rotor housing 20.
8, the contact portion 19 between the outer peripheral surface of the casing cover 13 or the outer peripheral surface of the rotor housing 20 and the inner peripheral surface of the casing body 11 has sufficient sealing force to withstand the low pressure before the rotor 30 is pressurized. Become.

Therefore, in the fuel pump 1A, the number of high-pressure seal portions and the seal area are significantly reduced as compared with the conventional one. By the way, the high-pressure seal part requires strict conditions, such as forming the seal surface with high finishing accuracy and applying a high surface pressure to the seal surface. The larger the size, the more labor is required for processing, the lower the productivity and the higher the cost. Therefore, the fuel pump 1A having a small high-pressure seal portion and a small area has a very high production efficiency, and can realize a reduction in processing time and cost.

The casing 30 has a rotor 30
Since only the low pressure before the pressure is increased is applied, the coupling means between the casing body 11 and the casing cover 13 can be changed from "caulking coupling" to snap-fit coupling. Here, the snap-fit connection means that, for example, an engaging projection is provided on the outer peripheral surface of the casing cover 13, an engaging hole is provided in the thin portion 11 a of the casing body 11, and the engaging projection is This is coupling means that fits into and engages with the hole. If this snap-fit connection is adopted, the cost can be further reduced.

The casing body 11 and the spring 6
1 is made of metal, and the spring 61 is
When the fuel is passed through the filter 40, the static electricity generated when the fuel passes through the filter 40 is transferred to the brush 55 and the spring 6.
1. It can be grounded via the casing body 11. Alternatively, the bracket 52 is also made of metal, and by optimizing the shape of the fuel passage of the bracket 52, the electric charges separated on the fuel side and the filter 40 side by the filter 40 are:
Since the fuel passes through the bracket 52 from the casing body 11 and comes into contact with the fuel again to neutralize it electrically, it is possible to prevent static electricity.

In this fuel pump 1A, as shown in FIG. 2, by removing the lower casing 12 from the casing body 11, the filter 40
Can be pulled out from the lower opening of the filter 4
If 0 is clogged, only this filter 40 can be replaced, which is economical.

Second Embodiment Next, a fuel pump according to a second embodiment of the present invention will be described with reference to FIGS.

The fuel pump 1B according to the second embodiment
The rotor housing 120 is provided inside the casing 110.
, A rotor 130, a fuel filter (hereinafter simply referred to as a filter) 140 and a motor unit 150, and a suction strainer 180 fixed to a lower portion of the casing 110. It is installed and used in

The casing 110 has a cylindrical casing body 111 having both ends opened in the left and right directions in FIG. 4 (hereinafter, unless otherwise specified, left and right means the left and right directions in FIG. 2). A discharge cover 112 for closing the left opening, a casing cover 113 for closing the right opening of the casing body 111,
And a cap 114 for closing the opening of the casing cover 113.

The body 111a of the casing body 111 is
It consists of a cylindrical body that cuts a part of the cylinder in a plane parallel to the axis and has an opening closed by a flat plate, the axis of which is arranged in a horizontal position, and has a flat plate portion 111b at the bottom. ing.

The flat plate portion 111b is the suction strainer 1
80 covered by the suction strainer 18
A spacer 181 is installed in the internal space 182 of the “0”. A circular through hole 111c is provided at the left edge of the body 111a.
Are connected to each other.

The pump unit 200 and the filter 140 are provided inside the casing body 111.
The pump unit 200 includes the discharge cover 1
12 and cap 114 and the rotor housing 12
0, the rotor 130, the motor shaft 151, the armature 153, and the magnet 15 of the motor unit 150.
4 and a main body 210 that connects the rotor housing 120 and the cap 114.

The body 210 has a cylindrical shape with left and right ends opened, and is installed in a horizontal attitude concentric with the axis of the casing body 111. Body 210
Has a thick portion 211 at the center thereof, and thin portions 212 and 213 extend from both left and right ends of the thick portion 211.

The discharge cover 112 and the rotor housing 120 are attached to the thin portion 212 on the left side.
A cap 114 is attached to the thin portion 213 on the right side, and the discharge cover 112, the rotor housing 120, and the cap 114 allow the body 210 to be mounted.
Left and right openings are closed.

The rotor housing 120 has a disk shape.
The outer peripheral surface is attached to the body 210 so as to be in close contact with the inner peripheral surfaces of the thick portion 211 and the thin portion 212. A through hole 121 is provided at the center of the rotor housing 120, and a bearing 158 for rotatably supporting one end of the motor shaft 151 is fixed to the through hole 121. A rotor housing recess 122 is formed at the center of the left end surface of the rotor housing 120.
A rotor 130 fixed to one end of a motor shaft 151 penetrating the bearing 158 is rotatably housed. The predetermined portion of the rotor housing recess 122 is
It has become.

The discharge cover 112 is disposed adjacent to the right side of the rotor housing 120, and the right end face of the substrate portion 112a having a circular cross section is
20 is attached to the body 210 such that the outer peripheral surface of the substrate portion 112a is in close contact with the inner peripheral surface of the thin portion 212, and a pump chamber 224 is provided between the discharge cover 112 and the rotor housing 120. I have.

The engagement protrusion 11 having a circular cross section provided on the left side of the substrate 112a in the discharge cover 112.
2b is fitted into the through hole 111c of the front wall 111d of the casing body 111, and the left end surface of the substrate 112a is in close contact with the inner surface of the front wall 111d. Engagement protrusion 112
b, the pump chamber 2 located in the discharge recess 123
A discharge nozzle (fuel discharge port) 112c connected to 24 is protruded leftward with its axis centered in a horizontal posture.

A bearing mounting hole 112d is provided on the right end surface of the discharge cover 112, and a bearing 157 which receives a thrust load of the motor shaft 151 is fixed to the bearing mounting hole 112d.

The cap 114 has a substantially cylindrical shape and includes a large-diameter portion 114a having an open left end and a small-diameter portion 114b having a closed right end.
13 is attached to the body 210 in close contact with the inner peripheral surface of the body 13, and the tip of the thin portion 213 is caulked radially inward to prevent the cap 114 from being detached from the body 210.

The cap 114 has a cylindrical bearing support 114c inside the large diameter portion 114a and the small diameter portion 114b.
And a bracket 114d. A bearing 156 for rotatably supporting the right end of the motor shaft 151 is fixed to the bearing support 114c.
The motor shaft 151 is supported by the bearing 6 and the bearing 158 so that the axis of the motor shaft 151 is disposed in a horizontal posture and is rotatable.

In the motor shaft 151, the bearing 15
An armature 153 having a commutator 159 is fixed between the armatures 6 and 158, and magnets 154 are fixed to the inner peripheral surface of the body 210 facing the outer peripheral surface of the armature 153 at predetermined circumferential intervals.

Here, the body 210 and the magnet 15
4, the rotor housing 120 and the space surrounded by the cap 114 form a first fuel passage (cooling passage) 221, and the armature 153 rotates in the fuel flowing through the first fuel passage 221. I have.

The spring 161 is attached to the bracket 114d.
The brush 155 is attached to the commutator 159 by a spring 161 slidably. Also, bracket 1
A power terminal 162 connected to the brush 155 is fixed to 14d.

At the closed end of the small-diameter portion 114b of the cap 114, a connector nozzle 114e serving as a connection port to a power source is provided to protrude rightward.
The power supply terminal 162 is connected to the closing portion 114f provided in the middle of e.
Are fixed in a sealed state.

The small-diameter portion 114b of the cap 114 is fitted and fixed to the engaging hole 113a of the casing cover 113. More specifically, a casing cover 113 is fixed to a right opening of the casing body 111 in a sealed state, and a small-diameter portion 114b of a cap 114 is fitted in an engagement hole 113a provided in the casing cover 113 in a sealed state. It is fixed.

As described above, the pump unit 200 is housed and fixed in the casing main body 111,
Body 210 of pump body 200 and casing body 11
A hollow portion 22 having a substantially C-shaped cross-section
0 is formed, and a filter 140 set so that the flow direction of the fuel is horizontal is installed in the hollow portion 220.

The front wall 111d of the casing body 111 is provided with a plurality of stoppers 111e extending horizontally rightward in the cavity 220 at predetermined intervals in the circumferential direction. 140 end faces are abutted.

The body 11 of the casing body 111
1a, the casing cover 113, the small diameter portion 114b of the cap 114, and the annular space surrounded by the right end of the filter 140 constitute a second fuel passage (bypass passage) 222,
A substantially C-shaped space surrounded by the body 111a, the front wall 111d, the left end of the filter 140, and the body 210 of the pump unit 200 forms a third fuel passage 223.

The second fuel passage 222 and the third fuel passage 2
In order to ensure that the filter 140 passes when the fuel flows between the pump unit 23 and the pump unit 2, the outer peripheral surface of the filter 140 is in contact with the inner peripheral surface of the casing body 111.
The casing main body 111 is configured so as to be in close contact with the outer peripheral surface of the body 210 in other words. It has a thick part 111f formed in a shape and dimensions. Since the casing main body 111 has a very complicated shape as described above, it is preferable that the casing main body 111 is formed of resin.

The fuel pump 1B is connected to the casing body 1 from the flat portion 111b of the casing body 111.
11, a first fuel inlet 191 that extends through the body 111 of the pump unit 200 and the center of the lower left end of the first fuel passage 221 and a second fuel passage 222 that passes through the body 111a from the flat plate portion 111b. Are provided with two second fuel inlets 192 connected to the bottom of the fuel cell. These fuel inlets 191 and 192 are respectively connected to the strainer 18.
0 and faces the internal space 182.

The small diameter portion 114b of the cap 114 is provided with a communication hole 201 for communicating the first fuel passage 221 and the second fuel passage 222. Further, the fuel pump 1 </ b> B is provided with a communication hole 202 which penetrates through the thin portion 212 of the body 210 and the rotor housing 120 and communicates the third fuel passage 223 with the pump chamber 224.

In this fuel pump 1B, the motor unit 15
When the rotor 130 is started and the rotor 130 is driven to rotate, the fuel in the fuel tank passes through the suction strainer 180, and is sucked into the casing 110 through the first fuel inlet 191 and the second fuel inlets 192 and 192.

Here, the fuel sucked from the second fuel inlet 192 is, of course, directly transferred to the second fuel passage 222.
Flows into. On the other hand, the fuel sucked from the first suction port 191 flows into the left end portion of the first fuel passage 221, flows around the armature 153, flows to the right end portion of the first fuel passage 221, and further communicates with the communication hole 201. Through the second fuel passage 222, where it merges with the fuel flowing from the second fuel inlet 192.

The fuel that has joined in the second fuel passage 222 flows through the filter 140 into the third fuel passage 223, further flows through the communication hole 202 into the pump chamber 224, where the pressure is increased by the rotation of the rotor 130. (For example, about 3kg
/ cm ² ), and is ejected to the ejection nozzle 112c and sent to a fuel injection system (not shown).

Also in this embodiment, the suction strainer 180 removes relatively large dust and the like present in the fuel, and the filter 40 filters the fuel to remove fine foreign matters such as rust present in the fuel. You. Further, the first fuel passage 221 constitutes a cooling passage, and the armature 153 rotates in the fuel flowing through the first fuel passage 221, and when passing through the first fuel passage 221, the motor unit 150 is cooled by the fuel. Therefore, the motor unit 150 does not overheat.

Further, in the fuel pump 1B, since the motor unit 150 is disposed upstream of the filter 140, even if dust generated in the motor unit 150 enters the fuel, the dust is removed from the fuel by the filter 140. Removed.

In the fuel pump 1 B, the motor section 150 and the filter 140 are provided in a low-pressure section upstream of the rotor 130.
Are arranged, and only the discharge cover 112 is arranged in the high-pressure section downstream of the rotor 130. Therefore, the portion of the pump unit 200 located to the right of the rotor housing 120 and the portion located outside the body 210 of the pump unit 200 are all low-pressure portions.

As a result, the discharge cover 112 to which the pump discharge pressure is directly applied and the rotor housing 12
0 is required to have a strength that can withstand this discharge pressure, and it is necessary to design materials such as thickness and thickness to match the strength.
The casing body 111, the casing cover 113, the body 210 of the pump unit 200, and the cap 114 to which the pump discharge pressure is not applied only need to have strength enough to withstand the low pressure before the rotor 130 is pressurized. It is only necessary to design the thickness and thickness.

Therefore, in the fuel pump 1B, the area of the high-pressure section is narrowed and the area of the low-pressure section is widened as compared with the conventional pump, so that the weight and cost can be reduced.

As shown in FIG. 6, the seal portion that must withstand the pump discharge pressure is only the contact portion 118 between the right edge of the outer edge of the discharge cover 112 and the left edge of the outer edge of the rotor housing 120. 120
119a between the outer peripheral surface of the body and the inner peripheral surface of the body 210
Also, the outer peripheral surface of the discharge cover 112 and the body 21
The contact portion 119b between the outer peripheral surface of the discharge cover 112 and the inner peripheral surface of the casing body 111 has a sealing force that can withstand a low pressure before the rotor 130 is pressurized. Will be enough.

Therefore, also in this fuel pump 1B, as in the case of the first embodiment, the number of high-pressure seal portions and the seal area are significantly smaller than those of the conventional one.
It is possible to improve production efficiency, shorten processing time, and reduce costs.

As described above, the path through which the fuel flows into the second fuel passage 222 disposed immediately upstream of the filter 140 extends from the first fuel inlet 191 to the first fuel passage 2.
Route flowing through 21 (hereinafter referred to as a first route)
And a path directly flowing from the second fuel inlet 192 (hereinafter, referred to as a second path). The first path has a greater resistance to fuel than the second path. Most of the fuel passes through the second path having a small resistance and flows into the second fuel passage 222, and only the minimum amount of fuel necessary for cooling the motor unit 150 passes through the first path. become. Therefore, the pressure loss upstream of the pump chamber 224 can be suppressed even at a high fuel flow rate, and the occurrence of vapor lock can be prevented.

The ratio of the amount of fuel passing through the first path and the amount of fuel passing through the second path is determined by the opening area of the first fuel inlet 191, the total opening area of the second fuel inlet 192, and the opening area of the communication hole 201. , The cross-sectional shape and the cross-sectional dimension of the first fuel passage 221 are determined.

In the fuel pump 1B, the first fuel inlet 191 and the second fuel inlet 192, and the communication hole 20
2 is disposed at a lower position, and further, the pump unit 200 is installed with its axis being horizontal.
Since the filter 140 in which the flow direction of the fuel is set horizontally is installed around the pump unit 200, the suction head of the fuel pump 1B can be made very small, and the fuel pump can be made more compact.

[0088]

As described above, according to the fuel pump of the present invention, a casing having a fuel inlet and a fuel outlet, and a fuel pump installed inside the casing and boosting the fuel sucked from the fuel inlet. A rotor for delivering the fuel to the fuel discharge port, a motor installed inside the casing for driving the rotor, and a fuel for cooling the motor provided inside the casing adjacent to the motor. A cooling passage, wherein the rotor is disposed at the downstream end in the casing close to the fuel discharge port, so that the motor unit can be installed under a low pressure, and the high-pressure part is limited to an extremely narrow area. Since the number of high-pressure seal portions can be reduced, the fuel pump can be reduced in thickness, weight, and cost.

Further, according to the fuel pump of the present invention, a casing having a fuel inlet and a fuel outlet, and a fuel installed inside the casing and pressurized from the fuel inlet and fed to the fuel outlet. A rotor, a motor section installed inside the casing and driving the rotor to rotate, a cooling passage provided inside the casing adjacent to the motor section and through which fuel for cooling the motor section flows, and the casing A motor filter, the fuel filter, and the rotor are arranged in the casing in order from upstream to downstream, and the rotor is a casing close to the fuel discharge port. The casing is provided with a bypass passage that bypasses the cooling passage. A plurality of intake ports are provided, some of which are connected to the inlet of the fuel filter via the cooling passage, and other fuel inlets are connected to the inlet of the fuel filter via the bypass passage. Since the motor unit and the fuel filter can be installed under low pressure, the high-pressure part can be limited to an extremely narrow area, and the high-pressure seal part can be reduced, so that the fuel pump can be made thinner, lighter, and lower in cost. Not only can this be achieved, but also pressure loss on the suction side of the fuel pump can be reduced and vapor lock can be prevented.

Further, according to the fuel pump of the present invention, there is provided a casing having a fuel inlet and a fuel outlet, and a fuel pump installed inside the casing and pressurized from the fuel inlet and sent to the fuel outlet. A rotor, a motor section installed inside the casing and driving the rotor to rotate, a cooling passage provided inside the casing adjacent to the motor section and through which fuel for cooling the motor section flows, A fuel filter installed in the inside, wherein the fuel suction port is disposed below the casing, and the fuel filter opens a side facing the fuel suction port to form the rotor and the motor section. It is arranged so as to surround at least a part thereof, and is installed in a posture such that the flow direction of the fuel in the fuel filter is substantially horizontal, By serial rotor disposed in the downstream end of the casing adjacent to the fuel discharge port,
The motor section and the fuel filter can be installed under low pressure, and the high pressure section can be limited to an extremely narrow area,
Since the high pressure seal part can be reduced, not only can the fuel pump be made thinner, lighter, and lower in cost, but also the suction head of the fuel pump can be made very small and the fuel pump can be made more compact. Can be.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a first embodiment of a fuel pump according to the present invention.

FIG. 2 is an exploded view of the fuel pump according to the first embodiment.

FIG. 3 is an enlarged sectional view of a main part of the fuel pump according to the first embodiment.

FIG. 4 is a longitudinal sectional view of a second embodiment of the fuel pump according to the present invention.

FIG. 5 is a sectional view taken along line II of FIG. 4;

FIG. 6 is an enlarged sectional view of a main part of the fuel pump according to the second embodiment.

FIG. 7 is a longitudinal sectional view of a conventional fuel pump.

[Explanation of symbols]

 1A, 1B Fuel pump 10 Casing 12a Fuel inlet 13a Discharge nozzle (fuel discharge port) 30 Rotor 40 Fuel filter 50 Motor unit 60 Cooling passage 110 Casing 112c Discharge nozzle (fuel discharge port) 130 Rotor 140 Fuel filter 150 Motor unit 191 First 1 fuel inlet 192 second fuel inlet 221 first fuel passage (cooling passage) 222 second fuel passage (bypass passage)

Claims (4)

[Claims] A casing having a fuel inlet and a fuel outlet; a rotor installed inside the casing, for boosting fuel sucked from the fuel inlet and sending the fuel to the fuel outlet; A motor unit installed inside and rotatably driving the rotor; and a cooling passage provided inside the casing adjacent to the motor unit and through which fuel for cooling the motor unit flows. The fuel pump according to claim 1, wherein the rotor is disposed at a downstream end in a casing adjacent to the fuel discharge port. 2. The fuel pump according to claim 1, wherein a fuel filter is provided upstream of the rotor in the casing. 3. A casing having a fuel inlet and a fuel outlet, a rotor installed inside the casing, for boosting fuel sucked from the fuel inlet and delivering the fuel to the fuel outlet, A motor section installed inside and driving the rotor to rotate; a cooling passage provided inside the casing adjacent to the motor section and through which fuel for cooling the motor section flows; and installed inside the casing. A fuel filter, comprising: a casing in which the motor unit, the fuel filter, and the rotor are arranged in order from upstream to downstream in the casing, and the rotor is located near the fuel discharge port. The casing is provided with a bypass passage bypassing the cooling passage, and a casing is provided in the casing. Includes a plurality of the fuel inlets, some of which are connected to the inlet of the fuel filter via the cooling passage, and other fuel inlets are connected to the inlet of the fuel filter via the bypass passage. A fuel pump, characterized in that: 4. A casing having a fuel inlet and a fuel outlet, a rotor installed inside the casing, for boosting fuel sucked from the fuel inlet and sending the fuel to the fuel outlet, A motor section installed inside and driving the rotor to rotate; a cooling passage provided inside the casing adjacent to the motor section, through which fuel for cooling the motor section flows; and installed inside the casing. And a fuel filter comprising:
The fuel filter is disposed so as to open a side facing the fuel suction port and surround at least a part of the rotor and the motor unit, and a flow direction of fuel in the fuel filter becomes substantially horizontal. The fuel pump is installed in such a posture, and the rotor is arranged at a downstream end in a casing adjacent to the fuel discharge port.