JP2003083192A - Pump device for feeding fuel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To simplify a structure of a fuel tank and to shorten a high pressure tube. SOLUTION: A fuel injection valve 17 is mounted on an intake pipe 15 of an engine 6, and a fuel pump 19 is mounted adjacent to the fuel injection valve 17. The fuel injection valve 17 and the fuel pump 19 are connected by the high- pressure resin tube 18. The fuel tank 21 is mounted on a position higher than the fuel pump 19. The fuel pump 19 and the fuel tank 21 are connected by a low-pressure resin tube 20. The fuel in the fuel tank 21 is fed to the fuel pump 19 by free dropping, and pressurized to the fuel injection pressure to be fed to the fuel injection valve 17. A brushless motor formed by integrating a field magnet of a motor to an impeller, is used in the fuel pump 19.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fuel supply pump device, and more particularly, to a fuel supply pump device for supplying fuel that is freely dropped from a fuel tank arranged above an engine to a fuel injection device.

[0002]

2. Description of the Related Art FIG. 8 is a block diagram of a system for supplying fuel to an engine of a vehicle or a ship. In the figure, a fuel pump 110 is installed in the fuel tank 100.
A conduit 130 is provided between the fuel pump 110 and the engine 120.
A fuel adjusting valve 140 is provided in the middle of the conduit 130. When the fuel pump 110 is energized, the fuel in the fuel tank 100 is sucked into the fuel pump 110 from the bottom of the fuel pump 110 and is fed to the engine 120 through the conduit 130. When the pressure in the conduit 130 becomes higher than the predetermined value, the relief valve 150 of the fuel adjusting valve 140 operates to return the fuel into the fuel tank 100 (arrow f). The pressure in the conduit 130 is reduced by opening the relief valve 150. This type of fuel supply device is disclosed in Japanese Utility Model Publication No. 52-34507.

[0003]

SUMMARY OF THE INVENTION As described above, the so-called in-tank type fuel supply device in which the fuel pump is provided in the fuel tank has the following problems.
First, a holder for holding the fuel pump in the fuel tank is required, and a retainer and bolts for fixing the holder in the fuel tank are also required. As a result, as the number of parts increases, the structure of the fuel tank becomes complicated and the number of manufacturing steps increases.

In view of the above conventional problems, an object of the present invention is to
An object of the present invention is to provide a fuel supply pump device that can contribute to simplifying the structure of a fuel tank.

[0005]

In order to achieve the above object, the pump device of the present invention comprises a fuel inlet, a pump cover having a fuel reservoir for accumulating the fuel sucked from the inlet, and an impeller. A pump housing having a passage formed along the rotation direction of the accommodating portion and the impeller, a fuel suction port for guiding the fuel in the fuel storage chamber to one end of the passage, and a fuel suction port provided at the other end of the passage. A fuel discharge port and a recirculation passage that opens when the pressure in the high-pressure tube connected to the discharge port is equal to or higher than a predetermined value and circulates the fuel discharged from the discharge port to the fuel reservoir chamber. The feature is that it has.

When the fuel pressure rises above a predetermined value,
The return passage is opened and the pressure in the high pressure tube is adjusted to the predetermined value. In particular, since the recirculated fuel is depressurized in the fuel storage chamber, there is a fuel cooling effect.

The present invention is also directed to a motor section including a field magnet integrally provided with the impeller, and an armature arranged to face the field magnet in a state of being fluidly separated by a wall surface of the pump housing. It is characterized in that it is equipped with. According to this feature, since the field magnet of the motor unit is integrated with the pump unit, the connecting unit for transmitting the output of the motor unit to the pump unit is unnecessary.

Further, according to the present invention, a pump-side permanent magnet provided on the impeller, and a motor-side permanent magnet arranged to face the pump-side permanent magnet in a state of being fluidly separated by a wall surface of the pump housing. And a motor having a rotor to which the motor-side permanent magnet is fixed. According to this feature, the output of the motor section is transmitted to the pump section by the magnetic force of the permanent magnet.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is an exploded side view of essential parts of a motorcycle having a fuel pump device according to an embodiment of the present invention. The frame of the motorcycle is the front part of the vehicle (left side of the drawing)
A main frame 1 having a front end coupled to a head pipe (not shown) located at, an upper rear frame 2 and a lower rear frame 3 extending obliquely rearward from the main frame 1. The upper rear frame 2 is connected to the main frame 1 by a bracket 5, and the lower rear frame 3 is connected to the main frame 1 by a bracket 7. The upper rear frame 2 and the lower rear frame 3 are connected to each other toward the rear of the vehicle body.

An engine 6 is arranged below the main frame 1. The engine 6 is at the bottom of the main frame 1,
Suspended by brackets 4, 5 and bracket 7. The engine 6 and the brackets 4, 5 and 7 are connected to each other via bolts 8, 9 and 10, respectively. The engine 6 includes a head portion 11, a cylinder portion 12, and a crank portion 13. An intake pipe 15 extending forward of the vehicle body is coupled to the intake port 14 of the head portion 11. A fuel injection valve 17 is provided in the middle of the intake pipe 15.

The fuel injection valve 17 is a high pressure resin tube 18
Is connected to the discharge port of the fuel pump 19. Fuel pump 1
A low pressure resin tube 2 extending rearward of the vehicle body at the suction port 9
0 is connected, and the end of the low pressure resin tube 20 is
It is connected to a connecting tube 22 which is inserted into the fuel tank 21. A strainer 2 is provided in the middle of the low pressure resin tube 20.
3 is provided. The fuel tank 21 is the upper rear frame 2
The brackets 24 and 25 are connected to each other. A fuel supply port having a lid 26 is provided above the fuel tank 21.

The fuel tank 21 is arranged above the fuel pump 19, and the drop (head difference) in the fuel tank 21 allows the fuel in the fuel tank 21 to freely fall into the fuel pump 19. The fuel fed by free fall is sucked into the fuel pump 19, the pressure is increased, and the fuel is discharged from the fuel pump 19. The fuel discharged from the fuel pump 19 is sent under pressure through the high-pressure resin tube 18 to the fuel injection valve 17. When the fuel injection valve 17 opens, the pumped fuel is taken in by the intake pipe 1
5 is injected into the engine 6 through the intake port 14 together with air.

In this way, the fuel pump 19 is connected to the fuel tank 2
Unlike the case where the fuel pump is mounted inside the fuel tank, the mounting member is unnecessary by disposing the fuel tank outside the fuel tank 1, so that the structure of the fuel tank is simplified. Further, since the fuel pump 19 can be arranged close to the fuel injection valve 17, the high-pressure resin tube 18 that requires high pressure resistance can be shortened. Unlike the case where the motor part of the fuel pump 19 is used in a state where it is immersed in fuel, there is no need to use a fuel resistant material, so the degree of freedom in material selection is expanded.

Next, the fuel pump 19 will be described in detail.
2 is a cross-sectional view of the fuel pump 19, and FIG. 3 is A of FIG.
It is sectional drawing in the -A position. In both figures, the fuel pump 19 has a pump housing (hereinafter, simply referred to as “housing”) 27. The housing 27 has a bearing recess 271 at the center, and the bearing recess 271.
It has an annular recess 272 arranged concentrically with. The annular recess 272 of the housing 27 has a peripheral edge portion 28 of the impeller 28.
Two are accommodated. A magnet 29 serving as a field magnet of the motor unit is fixed to the inner surface of the peripheral portion 282 housed in the annular recess 272.

The housing 27 is covered with a pump cover 30. The pump cover 30 has a bearing recess 301 on the side facing the housing 27, and a fuel storage chamber 303 covered with a cap 302 on the side opposite to the housing 27.

A rotary shaft 281 is provided at the center of the impeller 28.
Is fixed. The rotating shaft 281 is a bearing 3 that is fitted into a bearing recess 271 provided in the housing 27 and a bearing recess 301 provided in the pump cover 30, respectively.
It is rotatably supported by 1, 32. Rotating shaft 281
May be press-fitted into the impeller 28 or may be molded integrally with the impeller 28. The bearings 31 and 32 may be either metal or bearing.

A fuel inlet 30 is provided in the fuel storage chamber 303.
4 is opened, and a mouthpiece 305 to which the low pressure resin tube 20 is coupled is provided at the suction port 304. Base 3
The low pressure resin tube 2 to be joined to the outer periphery of 05
Steps are formed so that 0s cannot be easily removed.

A suction port 306 is formed in the bottom of the fuel storage chamber 303, that is, in the wall on the housing 27 side.
The suction port 306 is a passage 273 in the housing 27.
Leads to. The passage 273 is formed concentrically with the rotating shaft 281, and the end portion thereof, that is, the other end of the suction port 306 is provided at the discharge port 3
It will be 07. The discharge port 307 is provided with a base 308 to which the high pressure resin tube 18 is coupled. Base 30
On the outer periphery of 8, the high pressure resin tube 18 is provided with the base 30
A step is formed to fix the connector connected to the connector 8 so that the connector does not fall out.

A regulator chamber 33 is provided between the discharge port 307 and the fuel storage chamber 303. The regulator chamber 33 is connected to the discharge port 307 through the opening 331 and is connected to the fuel storage chamber 303 through the side opening 332. A valve (relief valve) 34 for opening and closing the opening 331 is provided in the regulator chamber 33, and the relief valve 34 is a stopper (bolt) 3 held (screwed) in the regulator chamber 33.
5 is slidably supported. Stopper 35 and relief valve 3
A coil spring 36 is interposed between the relief valve 34 and the valve 4 to urge the relief valve 34 toward the opening 331.

A cylindrical guide 37 is fitted and inserted into a boss 274 forming the recess 271 of the housing 27, and a core 38 and a coil 39 wound around the core 38 are provided in the guide 37. The core 38 and the coil 39, as an armature, form a motor section M by pairing with the magnet 29 of the impeller 28. A substrate 40 forming a circuit for generating a rotating magnetic field in the armature is fixed to the outer peripheral end of the guide 37. The motor cover 41 is inserted into the inner peripheral end of the guide 37.

The coil 39 and the substrate 40 are guided by the guide 37.
Although it is fixed to the boss 274 of the housing 27 through the above, the present invention is not limited to this, and the outer periphery of the core 38 may be fitted and fixed to the inner peripheral wall surface 272a of the annular recess 272.

In the above structure, the fuel that has reached the fuel pump 19 from the fuel tank 21 by natural fall is accumulated in the fuel reservoir chamber 303. When the coil 39 is energized and its magnetic field acts on the magnet 29 as a field magnet, the impeller 28 rotates in the direction of arrow R. Then, the fuel stored in the fuel storage chamber 303 is sucked into the housing 27 through the suction port 306, pressurized through the passage 273, and discharged from the discharge port 307 side. Outlet 30
The fuel discharged from 7 is fed to the fuel injection valve 17 via the high-pressure resin tube 18.

A regulator mechanism operates to maintain the pressure of the fuel fed to the fuel injection valve 17 at a predetermined value. That is, when the pressure in the high-pressure resin tube 18 reaches a value higher than the valve opening pressure of the relief valve 34, the coil spring 36 urging the relief valve 34 is compressed and the relief valve 34 is pushed up to open. 331 is open. Then, the fuel in the high-pressure resin tube 18 flows into the regulator chamber 33 through the opening 331 and is returned to the fuel reservoir chamber 303 through the side opening 332.

When the fuel is returned by the regulator function, not only the pressure inside the high-pressure resin tube 18 is maintained at a predetermined value, but also the fuel circulating in the fuel storage chamber 303 is cooled by decompression. Therefore, the occurrence of percolation due to the high temperature of the fuel is suppressed.

FIG. 4 is a sectional view showing a first modification of the fuel pump 19, and the same reference numerals as those in FIGS. 1 and 2 are the same or equivalent parts. In this first modification, a core and a coil as an armature are arranged on the outer circumference of a magnet as a field magnet fixed to the impeller. In FIG. 4, a boss portion 283 is formed on the impeller 28. A field magnet 29 is mounted on the outer periphery of the boss portion 283. Further, shafts 275 and 309 are provided in the housing 27 and the pump cover 30, and the impeller 28 is rotatably supported by the shafts 275 and 309 via bearings 31 and 32.

A guide 37 is fitted and fixed to the central protrusion 276 of the housing 27, and a core 38 and a coil 39 wound around the core 38 are provided on the outer periphery of the guide 37. A substrate 40 is provided at the end of the guide 37. The fuel pump 19 of the first modified example operates in the same manner as that described in FIGS. According to the first modified example, unlike the case where the magnet is arranged on the peripheral portion of the impeller, the diameter of the entire fuel pump 19 can be reduced.

FIG. 5 is a sectional view showing a second modification of the fuel pump 19. In the above example, the rotor of the motor unit and the impeller of the pump unit are integrally formed. On the other hand, in the second modified example, the rotor of the motor unit and the impeller of the pump unit are separate bodies, and they are coupled by a magnetic coupling. In FIG. 5, the motor unit M has a cylindrical housing 42, and a magnet 43 is arranged on the inner periphery thereof. Housing 42
Both ends of are covered with caps 44 and 45. Cap 4
Bearings 46 and 47 are fitted to 4 and 45, respectively, and the rotor 48 of the motor unit M is rotatably supported by the bearings 46 and 47 via a shaft 51. The rotor 48 is provided with a core 49 and a coil 50 wound around the core 49. Power supply terminals 52 and 53 are fixed to the cap 45, and power is supplied to the coil 50 from the power supply terminals 52 and 53 through the brush 54.

A plate 55 having a magnet 60 for power transmission is fixed to the end of the shaft 51 of the rotor 48 of the motor M. The motor cover 5 is provided on the housing 42 of the motor unit M to cover the end of the housing 42 and the plate 55.
6 is provided. A pump cover 57 is provided on the motor cover 56. Pump cover 57 and motor cover 5
An impeller 58 of the pump portion P is provided in the space between the impeller 58 and the rotary shaft 76 of the pump cover 5.
7 and the bearing 5 provided on the motor cover 56, respectively.
Supported by 9,61. Impeller 5 of pump part P
A magnet 62 corresponding to the magnet 60 provided on the plate 55 on the motor section M side is fixed to the magnet 8 whose magnetic poles are set so as to attract the magnet 60.

The pump cover 57 has the same function as that shown in FIGS. 1 and 2 except that it does not have a regulator mechanism. Therefore, when power is supplied to the terminals 52 and 53 and the motor section M is energized, the plate 55 and the pump section P which are attracted to each other by the magnetic force of the magnets 60 and 62.
The impeller 58 integrally rotates and the fuel in the fuel storage chamber 571 formed in the pump cover 57 is fed to the fuel injection valve 17.

FIG. 6 is a sectional view showing a third modification of the fuel pump 19. In the above-mentioned example, the brush feeding mechanism is used for the motor section. In the third modified example, the motor section M is a brushless motor. In FIG. 6, a cylindrical guide 64 is fixed to the housing 63 of the motor unit M, and a core 65 and a coil 66 wound around the core 65 are provided on the outer periphery of the guide 64. Bearings 67 are provided on the inner circumference of the guide 64.
68 is inserted and fixed, and the bearings 67 and 68 support the rotor 69 of the motor unit M. The rotor 69 is formed in a bowl shape, and the hub portion 6 to which the magnet 60 for power transmission is fixed
A peripheral portion 6 that holds 91 and the field magnet 70 on the inner periphery.
And 92.

A cap 71 is fixed to the housing 63. At the same time as the cap 71 is a lid of the motor unit M,
Impeller 58 of pump part P in cooperation with pump cover 57
To form a space for housing.

In the third modification, when the coil 66 is energized and the motor section M is energized, the rotor 69 and the impeller 58 of the pump section P, which are attracted to each other by the magnetic forces of the magnets 60 and 62, rotate integrally, The fuel in the fuel storage chamber 571 formed by the pump cover 57 is used as the fuel injection valve 17
Be delivered to.

FIG. 7 is a sectional view showing a fourth modification of the fuel pump 19, and the same reference numerals as those in the third modification are the same or equivalent parts. In the fourth modified example, the motor unit M has a bowl-shaped housing 72 and a cap 73 that covers the housing 72. Bearings 67 and 68 are fitted into the inner periphery of the hub 731 of the cap 73, and the rotor 742 is rotatably supported by these bearings 67 and 68. The rotor 742 includes a shaft 741 and a plate fixed to one end of the shaft 741 and holds the field magnet 69 on the inner peripheral surface. Axis 74
At the other end of 1, a power transmission magnet 60 facing the pump portion P is provided.

A pump housing 75 is fixed to the cap 73. The pump cover 5 is attached to the pump housing 75.
7 is covered to form a space for rotatably housing the impeller 58 of the pump portion P.

In the fourth modification, when the coil 66 is energized to energize the motor section M, the rotor 742 and the impeller 58 of the pump section P, which are attracted to each other by the magnetic forces of the magnets 60 and 62, rotate integrally, The fuel in the fuel storage chamber 571 formed by the pump cover 57 is used as the fuel injection valve 1
Delivered to 7.

[0036]

As is apparent from the above description, according to the first aspect of the invention, the pressure in the high-pressure pipe connected to the discharge port can be maintained at a pressure suitable for fuel injection. Further, since the fuel returned to the fuel storage chamber is cooled, percolation can be prevented.

According to the invention of claim 2, since the rotor of the motor section is integrated with the pump section, a mechanism for connecting the output of the motor section to the pump section is not required and the structure of the fuel pump is simplified. .

According to the invention of claim 3, the output of the motor section is transmitted to the pump section by the magnetic force of the permanent magnet.
By setting this magnetic force, it is possible to prevent the motor section from being overloaded.

[Brief description of drawings]

FIG. 1 is an exploded side view of a main part of a motorcycle including a fuel supply device according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view of a fuel pump.

3 is a sectional view taken along the line AA in FIG.

FIG. 4 is a sectional view of a fuel pump according to a first modification.

FIG. 5 is a sectional view of a fuel pump according to a second modification.

FIG. 6 is a cross-sectional view of a fuel pump according to a third modified example.

FIG. 7 is a sectional view of a fuel pump according to a fourth modification.

FIG. 8 is a diagram showing a conventional fuel supply system.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Main frame, 6 ... Engine, 14 ... Intake port, 15 ... Intake pipe, 17 ... Fuel injection valve, 18 ... High pressure resin tube, 19 ... Fuel pump, 20 ... Low pressure resin tube, 21 ... Fuel tank, 23 ... Strainer, 28 ... Impeller, 29 ... Field magnet, 33 ... Regulator chamber, 34 ... Relief valve, 303 ... Fuel sump chamber

Claims (3)

[Claims] 1. A fuel inlet, a pump cover having a fuel reservoir for storing the fuel sucked from the inlet, an impeller accommodating portion, and a passage formed along the rotational direction of the impeller. A pump housing, a fuel suction port for guiding the fuel in the fuel reservoir to one end of the passage, a fuel discharge port provided at the other end of the passage, and a high-pressure tube connected to the discharge port. And a recirculation passage that recirculates the fuel discharged from the discharge port into the fuel reservoir chamber when the pressure of the pressure is equal to or higher than a predetermined value. 2. A field permanent magnet integrally provided with the impeller, and an armature arranged to face the field permanent magnet in a state of being fluidly separated by a wall surface of the pump housing. A motor unit is provided, and the motor unit is provided.
The fuel supply pump device described. 3. A pump-side permanent magnet provided on the impeller, a motor-side permanent magnet that is disposed to face the pump-side permanent magnet in a state of being fluidly separated by a wall surface of the pump housing, and the motor-side. The fuel supply pump device according to claim 1, further comprising a motor having a rotor to which a permanent magnet is fixed.