JP2004278355A - Fuel supply device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fuel supply device having a simple constitution of a pressure regulator, and capable of decompressing and adjusting fuel with a stable characteristic. <P>SOLUTION: Since the pressure regulator 18 for arranging a valve element 36 downstream of a valve seat 38 is smaller in the acting area of fuel pressure upstream of the valve seat 38 than the pressure regulator 18 for arranging the valve element upstream of the valve seat 38, and operating the valve element by using a diaphragm, a pressure adjusting characteristic is easily changed by fuel pressure downstream of the valve seat 38. Then, the pressure adjusting characteristic of the pressure regulator 18 is prevented from changing by the influence of a jet nozzle 28 by adopting a constitution for introducing upstream fuel to the jet nozzle 28 from a valve seat 38 port of the pressure regulator 18. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a fuel supply device that supplies fuel in a fuel tank to an internal combustion engine (hereinafter, referred to as an engine) using a jet pump and a fuel pump.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, as a fuel supply device for supplying fuel in a fuel tank to an engine, a fuel supply device having a jet nozzle for flowing the fuel in the fuel tank is known (for example, see Patent Document 1).
Jet nozzles are used, for example, to introduce fuel in a fuel tank into a sub-tank containing a fuel pump, or to flow fuel in a fuel tank across a step at the bottom of a fuel tank. I do. The jet nozzle disclosed in Patent Literature 1 injects fuel discharged from a pressure regulator that adjusts the pressure of fuel supplied from a fuel pump to an engine. Is introduced into the sub tank.
[0003]
[Patent Document 1]
WO 99/61777 pamphlet [0004]
[Problems to be solved by the invention]
By the way, in the case of supplying excess fuel discharged from the pressure regulator to the jet nozzle as in Patent Literature 1, the fuel flow is restricted by the jet nozzle. The fuel pressure to open to the side acts.
On the other hand, in the pressure regulator of Patent Document 1, the pressure of the fuel is received by the diaphragm that moves integrally with the valve body, and the valve body is opened to the upstream side of the valve seat. As a result, the fuel pressure upstream of the valve seat with a much larger area than the flow passage area of the valve seat acts on the diaphragm, and the fuel pressure downstream of the valve seat that attempts to open the valve element upstream is reduced. The effect on the pressure regulation characteristics of the regulator is reduced.
In this way, in the pressure regulator that opens the valve body to the upstream side of the valve seat using the diaphragm, even if the fuel discharged from the pressure regulator is throttled by the jet pump, the pressure of the fuel is adjusted with relatively stable characteristics. can do.
However, since such a pressure regulator uses a diaphragm, its structure is complicated and it is difficult to reduce its size.
[0005]
The present invention has been made in view of such a problem, and an object of the present invention is to provide a fuel supply device that has a simple configuration of a pressure regulator and that can adjust fuel pressure with stable characteristics. And
[0006]
[Means for Solving the Problems]
In the fuel supply device according to the first aspect of the present invention, the configuration of the pressure regulator is simplified by providing the valve body of the pressure regulator downstream of the valve seat. What displaces the valve element provided downstream of the valve seat from the valve seat is the fuel pressure upstream of the valve seat received in the flow passage area of the valve seat opening. Also, the valve body is urged by the urging means, and receives the fuel pressure downstream of the valve seat in the flow passage area of the valve seat opening. Tries to sit on the valve seat. In a pressure regulator provided with a valve body downstream of the valve seat, neither the fuel pressure upstream of the valve seat that attempts to unseat the valve body, nor the fuel pressure downstream of the valve seat that attempts to seat the valve body, Acts on the valve element with substantially the same area. Therefore, compared to a pressure regulator in which a valve element is provided upstream of the valve seat and the valve element is operated using a diaphragm, the fuel pressure in the pressure regulator in which the valve element is provided downstream of the valve seat is higher than that of the valve seat. The pressure control characteristic is likely to fluctuate due to the fuel pressure downstream of the valve seat because the area on which the pressure acts is small. Therefore, by adopting a configuration in which the fuel nozzle upstream of the valve seat of the pressure regulator is introduced into the jet nozzle without providing a jet nozzle downstream of the valve seat of the pressure regulator, the pressure regulation characteristic of the pressure regulator is reduced. It can be prevented from fluctuating due to the influence. Therefore, in the fuel supply device according to the first aspect of the present invention, the configuration of the pressure regulator can be simplified, and the fuel pressure can be adjusted with stable characteristics.
[0007]
In the fuel supply device according to the second aspect of the present invention, the fuel discharged from the vapor discharge port provided in the pressurized flow path of the fuel pump is injected from the jet nozzle. The nozzle allows the fuel in the fuel tank to flow.
[0008]
In the fuel supply device according to the third aspect of the present invention, the fuel outside the sub-tank and in the fuel tank flows into the sub-tank by injecting the fuel with the jet nozzle.
[0009]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
(First embodiment)
FIG. 1 is a schematic diagram showing a first embodiment of a fuel supply device according to the present invention. The fuel supply device supplies, for example, fuel in a fuel tank of a vehicle to an engine (not shown).
[0010]
The sub tank 16 in which the fuel pump 24 is stored is stored in the fuel tank 10. The sub-tank 16 is pressed against the bottom of the fuel tank 10 by urging means (not shown). The sub-tank 16 is provided with a fuel inlet 30 for introducing the fuel in the fuel tank 10 into the sub-tank 16. The fuel inlet 30 is provided with a check valve (not shown) for preventing backflow of the fuel in the sub tank 16.
[0011]
The jet nozzle 28 is provided near the fuel inlet 30 of the sub tank 16. The jet nozzle 28 has an injection port 29 for injecting fuel into the fuel introduction port 30. The fuel pressurized by the fuel pump 24 is introduced into the injection port 29 through the first pipe 26. A flow path for introducing the fuel around the jet nozzle 28 from the fuel inlet 30 into the sub-tank 16 is formed near the injection port 29. When fuel is injected from the jet nozzle 28, fuel around the injection port 29 is introduced into the sub tank 16 by the suction pressure of the injected fuel.
[0012]
The in-tank type fuel pump 24 is housed in the sub tank 16. The suction filter 34 is connected to a fuel inlet 74 (see FIG. 3) of the fuel pump 24. The fuel filter 22 is connected to a fuel discharge port 44 (see FIG. 2) of the fuel pump 24. The fuel pump 24 sucks the fuel in the sub-tank 16 through the suction filter 34 and supplies the pressurized fuel to the injector 14 through the fuel filter 22.
[0013]
FIG. 2 is a sectional view showing the fuel pump 24.
The housing 50 houses the discharge-side cover 46, the armature 68, the permanent magnet 70, the pump casing 66, the impeller 59, the suction-side cover 62, and the like.
[0014]
Four arc-shaped permanent magnets 70 are provided at predetermined intervals on the inner peripheral wall of the housing 50. These permanent magnets 70 are arranged such that magnetic poles having different poles are alternately formed in the circumferential direction.
[0015]
The armature 68 is accommodated in the housing 50 so as to be rotatable together with the rotating shaft 72. A commutator 48 is provided at one end of the armature 68. The rotating shaft 72 is pressed into the iron core 52. A coil 56 is wound around a plurality of bobbins 54 provided on the iron core 52. The commutator 48 includes a plurality of segments that are insulated from each other. A coil 56 wound around each bobbin 54 is electrically connected to any of the segments of the commutator 48.
[0016]
A boost passage 60 is formed between the suction side cover 62 and the pump casing 66. An impeller 59 is rotatably accommodated in the pressurizing flow channel 60. A large number of blade grooves are formed on the outer periphery of the disk-shaped impeller 59. When the impeller 59 rotates together with the rotating shaft 72 of the armature 68, the fuel in the boost passage 60 is pressurized. The fuel sucked into the pressurizing flow channel 60 from the fuel suction port 74 (see FIG. 3) formed in the suction side cover 62 is sent out from the pressurizing flow channel 60 through the communication path 58 of the pump casing 66. Further, the fuel is discharged from the fuel pump 24 through a fuel discharge port 44 formed in the discharge side cover 46.
[0017]
FIG. 3 is a plan view showing the suction side cover 62 forming the pressurizing flow path 60. The suction side cover 62 is formed with a C-shaped groove 63 for forming a step-up flow path. A fuel inlet 74 for sucking fuel is formed at one end of the groove 63. A vapor discharge port 64 for discharging vapor is formed at the center of the groove 63.
[0018]
As shown in FIG. 1, the first pipe 26 for introducing the fuel discharged from the vapor discharge port 64 to the jet nozzle 28 is connected to the vapor discharge port 64. The vapor generated in the pressurized flow path by the rotation of the impeller 59 is discharged from the vapor discharge port 64 together with the fuel that is being pressurized, and the fuel discharged from the vapor discharge port 64 is injected into the sub tank 16 by the jet nozzle 28.
[0019]
The pressure regulator 18 is connected to a third pipe 20 branched from the second pipe 12 for supplying the fuel discharged from the fuel filter 22 to the injector 14. The pressure regulator 18 has a valve seat 42 communicating with the second pipe 12 via the third pipe 20. The fuel introduced from the second pipe 12 to the pressure regulator 18 is discharged to the sub tank 16 when the valve seat 42 is opened. A spherical valve element 36 is provided downstream of a valve seat 38 formed around the valve seat port 42. The discharge side opening of the pressure regulator 18 is provided with a leaf spring 32 that urges the valve body 36 upstream and seats the valve body 36 on the valve seat 38 from the downstream side. A plurality of through holes 40 are formed in the leaf spring 32. The fuel flowing out of the valve seat port 42 is discharged to the sub-tank 16 through a through hole 40 formed in the leaf spring 32. When the fuel in the second pipe 12 exceeds a predetermined pressure, the pressure moves the valve body 36 downstream against the urging force of the leaf spring 32. When the valve element 36 moves to the downstream side and separates from the valve seat 38, the valve seat port 42 is opened, the fuel in the second pipe 12 is discharged through the valve seat port 42, and the pressure of the fuel in the second pipe 12 is adjusted. Is done. The fuel discharged from the pressure regulator 18 may be discharged into the sub tank 16 as shown in FIG. 1 or may be discharged into the fuel tank 10 outside the sub tank 16.
[0020]
According to the first embodiment described above, since the diaphragm is not used, the configuration of the pressure regulator 18 is simple. Further, the fuel pressure acting on the valve body 36 of the pressure regulator 18 is a pressure Pp of the fuel in the second pipe 12 which is pressurized by the fuel pump 24 and a drain pressure Pd. The force F acting on the valve body 36 by these pressures is as follows.
F = (Pp−Pd) × area of valve seat opening
Although both the pressure Pp and the drain pressure Pd of the fuel in the second pipe 12 pressurized by the fuel pump 24 act on the valve element 36 with the same area, the fuel in the second pipe 12 pressurized by the fuel pump 24 is used. Since the pressure Pp is sufficiently higher than the drain pressure Pd, the force acting on the valve element 36 does not greatly change due to the fluctuation of the drain pressure Pd. That is, according to the first embodiment, since the pressure regulation characteristic of the pressure regulator 18 is stable, the pressure characteristic of the fuel supplied to the injector 14 is stable.
[0022]
Further, the fuel having a pressure lower than the pressure of the fuel discharged from the fuel discharge port 44 of the fuel pump 24 is derived from the vapor discharge port 64, and the fuel derived from the vapor discharge port 64 is introduced to the jet nozzle 28. The jet nozzle 28 can be operated without reducing the efficiency of the fuel pump 24.
[0023]
(Second embodiment)
FIG. 4 is a schematic diagram showing a second embodiment of the fuel supply device according to the present invention.
The second embodiment of the present invention is different from the first embodiment in that fuel introduced into the jet nozzle 28 is led out from the second pipe 12. Parts that are substantially the same as those in the first embodiment are given the same reference numerals, and descriptions thereof are omitted.
[0024]
A fourth pipe 76 for introducing the fuel discharged from the fuel discharge port 44 of the fuel pump 24 to the jet nozzle 28 is connected to the second pipe 12. The fuel pressurized by the rotation of the impeller 59 flows into the second pipe 12 through the fuel filter 22. The amount of fuel in the second pipe 12 is introduced into the jet nozzle 28 through the fourth pipe 76 in an amount corresponding to the flow path area of the injection port 29 of the jet nozzle 28, and is injected into the sub tank 16 by the jet nozzle 28.
[0025]
By drawing the fuel to be introduced into the jet nozzle 28 from the upstream side of the valve seat 42 of the pressure regulator 18, the pressure regulation characteristics of the pressure regulator 18 can be stabilized. Therefore, as in the second embodiment, the fuel completely pressurized by the fuel pump 24 may be directly introduced into the jet nozzle 28 without passing through the pressure regulator 18.
[0026]
Note that, needless to say, the present invention is not limited to the above-described embodiments, and modifications can be appropriately made without departing from the technical idea of the present invention.
[Brief description of the drawings]
FIG. 1 is a schematic diagram showing a first embodiment of a fuel supply device according to the present invention.
FIG. 2 is a sectional view showing a fuel pump of the fuel supply device according to the first embodiment.
FIG. 3 is a plan view showing a suction side cover of the fuel supply device according to the first embodiment.
FIG. 4 is a schematic view showing a second embodiment of the fuel supply device according to the present invention.
[Explanation of symbols]
Reference Signs List 10 fuel tank 16 sub tank 18 pressure regulator 24 fuel pump 28 jet nozzle 36 valve body 38 valve seat 42 valve seat opening 60 boosting flow path 64 vapor discharge port 78 second jet nozzle

Claims (3)

A fuel pump housed in a fuel tank and sucking fuel in the fuel tank to increase the pressure;
A pressure regulator that discharges fuel from a pipe that supplies fuel pressurized by the fuel pump to an internal combustion engine, a valve seat having a valve seat opening to the pipe, and a valve body provided downstream of the valve seat. A pressure regulator having biasing means for biasing the valve body in a direction to seat the valve on the valve seat;
A jet nozzle that introduces and injects fuel pressurized by the fuel pump from an upstream side of the valve seat port, and causes the fuel in the fuel tank to flow by suction pressure generated by injecting the fuel;
A fuel supply device comprising: 2. The fuel supply device according to claim 1, wherein the jet nozzle injects fuel introduced from a vapor outlet provided in a pressurization flow path of the fuel pump. 3. The fuel tank further includes a sub tank that houses the fuel pump and is housed in the fuel tank.
3. The fuel according to claim 1, wherein the jet nozzle causes fuel outside the sub-tank and in the fuel tank to flow into the sub-tank by suction pressure generated by injecting fuel. 4. Feeding device.

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