JP2010229900A - Fuel injection device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fuel injection device capable of properly removing a foreign substance adhered to a fuel filter in a fuel tank, and preventing the intrusion of the foreign substance on a pressure regulator side. <P>SOLUTION: The fuel injection device includes: a plunger pump 1 sucking fuel stored in the fuel tank 2 and supplying the fuel to a fuel injection valve; a pressure regulator 25 adjusting the fuel supplied from the plunger pump 1 to a predetermined pressure; return piping 34 returning the fuel from the pressure regulator 25 to the fuel tank 2; and a return jet nozzle 36 disposed inside the fuel tank 2 and jetting the returned fuel fed from the return piping 34 toward the fuel filter 8 in the fuel tank 2. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a fuel injection device, and more particularly to a fuel injection device for supplying power to a fuel pump of a fuel injection device that supplies fuel to an internal combustion engine.

  Conventionally, a fuel injection device for supplying fuel in a fuel tank to an internal combustion engine is often used. In such a fuel injection device, a fuel filter is disposed inside the fuel tank, The passed fuel is supplied to the internal combustion engine.

  As such a fuel injection device, for example, by using an electromagnetic pump and reciprocating the plunger, the fuel in the fuel tank is sucked and supplied to the fuel injection valve, and the excess fuel from the pressure regulator is returned. A technique for returning to a fuel tank through an opening is disclosed (for example, see Patent Document 1).

JP 2003-239830 A

  However, in general, foreign matters in the fuel may adhere to the fuel filter disposed in the fuel tank. In the invention described in Patent Document 1, the return fuel from the pressure regulator is supplied from the return opening to the fuel tank. Since it is only sent to the inside, the foreign matter adhering to the fuel filter cannot be effectively removed. In addition, when the pump is stopped, there is a problem that foreign matter in the fuel tank may enter through the return opening and enter the pressure regulator.

  The present invention has been made in view of the foregoing points, and is a fuel capable of properly removing foreign matter in the fuel tank attached to the fuel filter and preventing foreign matter from entering the pressure regulator side. It aims at providing an injection device.

In order to achieve the above object, a fuel injection device according to claim 1 comprises a pump that sucks fuel stored in a fuel tank and supplies the fuel to a fuel injection valve;
A fuel filter disposed in the fuel tank and filtering the fuel and sending it to the pump;
A pressure regulator for adjusting the fuel supplied from the pump to a predetermined pressure;
A return pipe for returning fuel from the pressure regulator to the fuel tank;
A return injection nozzle disposed inside the fuel tank and configured to inject return fuel sent from the return pipe toward the fuel filter;
It is characterized by having.

  According to a second aspect of the present invention, in the first aspect, the return jet nozzle is bent so that a tip end portion thereof is directed to the fuel filter.

  According to a third aspect of the present invention, in the first or second aspect, the tip portion of the return ejection nozzle is formed with a throttle portion having a small diameter so that the opening area thereof is reduced. And

  According to a fourth aspect of the present invention, in any one of the first to third aspects, the tip portion of the return injection nozzle is disposed at a position spaced apart from the bottom surface of the fuel tank by a predetermined distance. It is characterized by.

  According to the first aspect of the present invention, since the return injection nozzle for injecting the return fuel sent from the return pipe toward the fuel filter is provided, the foreign matter adhering to the fuel filter can be properly removed. .

  According to the second aspect of the present invention, the tip of the return jet nozzle is bent so as to be directed to the fuel filter, so that foreign matter adhering to the fuel filter can be properly removed and the return jet nozzle It can suppress that the foreign material in a fuel tank enters from a front-end | tip part.

  According to the third aspect of the present invention, the throttle portion having a small diameter is formed at the tip end portion of the return jet nozzle so that the opening area thereof becomes small, so the jet speed of the return fuel can be increased. As a result, the effect of removing foreign matter adhering to the fuel filter can be enhanced, and the opening area of the tip of the return injection nozzle is reduced by the throttle, so that the foreign matter in the fuel in the fuel tank is returned to the return injection nozzle. It is possible to further suppress the entry from the front end portion.

  According to the fourth aspect of the present invention, the tip portion of the return jet nozzle is disposed at a position spaced apart from the bottom surface of the fuel tank by a predetermined distance, so that the foreign matter precipitated in the fuel tank is returned to the return pipe. And entering the pressure regulator can be prevented.

1 is a schematic cross-sectional view showing an embodiment of a fuel injection device according to the present invention. It is an enlarged view which shows the return injection nozzle part of the fuel-injection apparatus in this embodiment.

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

  FIG. 1 shows an embodiment of a fuel injection device according to the present invention. As shown in FIG. 1, the present embodiment includes an electromagnetically driven plunger pump 1 constituting the fuel injection device. . The plunger pump 1 is attached to the lower surface side of the fuel tank 2, and the plunger pump 1 includes a pump body 3. Inside the pump body 3, a movable iron core guide hole 4 and a plunger hole 5 formed larger in diameter than the movable iron core guide hole 4 are continuously formed coaxially. An inflow opening 6 is formed at the end of 5. An insertion tube portion 7 that extends upward and communicates with the inflow opening 6 is integrally formed at the end of the pump body 3, and the upper end portion of the insertion tube portion 7 is inserted and fixed to the bottom of the fuel tank 2. Has been. A fuel filter 8 installed inside the fuel tank 2 is connected to the upper end portion of the insertion cylinder portion 7.

  A cylindrical housing 9 made of a conductive material and constituting a solenoid is attached to the other end of the pump body 3, and an end surface of the housing 9 is attached to an end of the housing 9 opposite to the pump body 3. A fixed iron core 10 made of a conductive material that penetrates is coaxially arranged. A discharge passage 11 penetrating in the axial direction is formed at the center of the fixed iron core 10. A coil bobbin 12 is accommodated inside the housing 9 and on the outer peripheral side of the fixed iron core 10, and an electromagnetic coil 13 is wound around the outer periphery of the coil bobbin 12. A magnetic pole disk 14 is disposed between the coil bobbin 12 and the pump body 3.

  Inside the movable core guide hole 4 and the coil bobbin 12 of the pump body 3, a movable core 15 made of a magnetic material having a hollow cylindrical shape is slidably arranged in the axial direction. An urging spring 16 that urges the movable iron core 15 toward the pump body 3 is disposed between the urging springs 10 and 10.

  A plunger 17 is disposed in the plunger hole 5 of the pump body 3 so as to be movable in the axial direction. One end of the plunger 17 is applied to the end surface of the movable iron core 15 by the biasing force of the biasing spring 18. It is in contact. Thus, the movable iron core 15 and the plunger 17 are held in a locked state in contact with each other by the biasing force of the biasing springs 16 and 18.

  A space between the plunger 17 and the inflow opening 6 inside the plunger hole 5 is a pump chamber 19, and a suction side check valve 20 is disposed in the pump chamber 19 so as to face the inflow opening 6. . Further, the pump chamber 19 and the movable iron core guide hole 4 are communicated with each other by an outflow pipe 21 passing through the outside of the pump body 3, and a discharge side check valve 22 is disposed in the middle of the outflow pipe 21. . That is, the plunger 17, the suction side check valve 20, and the discharge side check valve 22 constitute a pump unit.

  Further, a fuel joint 23 branched from a middle portion of the discharge path 11 is connected to the discharge path 11 of the fixed iron core 10. A fuel injection valve (not shown) is connected to the fuel joint 23 via a fuel supply path 24. To be connected to. A pressure regulator 25 is fixed to the end of the discharge path 11 of the fixed iron core 10.

  The pressure regulator 25 has a fuel chamber 27 and a spring chamber 28 partitioned by a diaphragm 26, and an inflow passage 29 communicating with the discharge passage 11 is connected to the fuel chamber 27. An outflow passage 33 is connected to the fuel chamber 27 via a valve seat 30, and a valve body 31 is disposed in the valve seat 30. The upper portion of the valve body 31 is in contact with the diaphragm 26, and the valve body 31 is urged in a direction in which the valve body 31 is in contact with the valve seat 30 by a diaphragm spring 32 housed in the spring chamber 28. A return pipe 34 is connected to the outflow path 33 of the pressure regulator 25, and a return fuel passage 35 that opens to the bottom surface of the fuel tank 2 is connected to the return pipe 34.

  Further, in the present embodiment, a return injection nozzle 36 is connected to the opening portion of the return fuel passage 35. As shown in FIG. The tip of the ejection nozzle 36 is configured to face the fuel filter 8. Further, the distal end portion of the return jet nozzle 36 is a throttle portion 37 having a small diameter so that the opening area thereof is small. Note that the return ejection nozzle 36 may be formed, for example, in a straight line and inclined so that the tip portion is directed toward the fuel filter 8.

  Next, the operation of this embodiment will be described.

  In the present embodiment, when a drive pulse signal is input to the electromagnetic coil 13 of the plunger pump 1 in synchronization with the operation of the internal combustion engine, the movable iron core 15 resists the biasing force of the biasing spring 16 from its original position. The plunger 17 is moved so as to follow the movable core 15 by the urging force of the urging spring 18 as the movable core 15 is moved. The movement of the plunger 17 increases the volume in the pump chamber 19 and decreases the pressure in the pump chamber 19, thereby closing the discharge-side check valve 22 and opening the suction-side check valve 20, so that the fuel tank The fuel in 2 is sucked into the pump chamber 19 through the inflow opening 6 and the inflow pipe 21.

  Next, when the energization of the electromagnetic coil 13 is cut off, the movable iron core 15 is returned to its original position by the urging force of the urging spring 16, and accordingly, the plunger 17 is also synchronized with the movable iron core 15. Returned to the position. As a result, the volume in the pump chamber 19 decreases and the pressure in the pump chamber 19 increases, the suction side check valve 20 is closed and the discharge side check valve 22 is opened. The fuel thus discharged is discharged into the movable iron core guide hole 4 through the outflow pipe 21. Then, when the energization / interruption driving pulse signal is continuously input to the electromagnetic coil 13, the plunger 17 reciprocates in the pump chamber 19, and the fuel pressurized from the pump chamber 19 flows out of the outflow pipe 21. Then, it is continuously discharged to the discharge path 11 of the fixed core 10 through the inner side of the movable core guide hole 4 and the movable core 15.

  A part of the fuel in the discharge path 11 is supplied to the fuel injection valve via the fuel joint 23 and the fuel supply path 24, and the other part of the fuel in the discharge path 11 is a pressure regulator via the inflow path 29. 25. When fuel is supplied to the pressure regulator 25, the fuel chamber 27 is filled with fuel, the valve body 31 is pushed up through the diaphragm 26, the valve seat 30 is opened, and the diaphragm spring 32 in the spring chamber 28 is set at a set pressure. In balance with the urging force, the fuel pressure discharged from the discharge passage 11 can be held at a predetermined set pressure. Therefore, the fuel supplied from the discharge passage 11 via the fuel joint 23 and the fuel supply passage 24 is sent to the fuel injection valve with a predetermined fuel pressure, and the fuel is supplied to the internal combustion engine based on a predetermined injection signal by the fuel injection valve. Is injected.

  On the other hand, when the valve body 31 opens the valve seat 30, the fuel flowing into the outflow passage 33 from the fuel chamber 27 is returned to the fuel tank 2 from the return pipe 34, the return fuel passage 35 and the return jet nozzle 36. The At this time, in the present embodiment, the return injection nozzle 36 is bent from its midway part so that the tip part is directed to the fuel filter 8, so that the return fuel flow injected from the return injection nozzle 36 is directly directed to the fuel filter. 8 can be ejected and foreign matter adhering to the fuel filter 8 can be properly removed, and when the foreign matter in the fuel stored in the fuel tank 2 is precipitated when the pump is stopped, the return is returned. It can suppress entering from the front-end | tip part of the ejection nozzle 36. FIG. In addition, since the tip of the return jet nozzle 36 is located above the bottom surface of the fuel tank 2, foreign matter that has settled in the fuel tank 2 is prevented from entering the pressure regulator 25 through the return pipe 34. can do.

  Further, since the throttle portion 37 is formed at the tip of the return jet nozzle 36, the flow rate of the return fuel jetted from the return jet nozzle 36 can be increased. As a result, the foreign matter adhering to the fuel filter 8 can be increased. The removal effect can be enhanced. Moreover, since the opening area of the front end portion of the return injection nozzle 36 is reduced by the throttle portion 37, it is possible to further suppress foreign matters in the fuel in the fuel tank 2 from entering from the front end portion of the return injection nozzle 36.

  As described above, in the present embodiment, the return jet nozzle 36 is bent from its midway part so that the tip part is directed to the fuel filter 8, so that foreign matter adhering to the fuel filter 8 is appropriately removed. In addition, the foreign matter in the fuel tank 2 can be prevented from entering from the tip of the return jet nozzle 36. Further, since the throttle portion 37 is formed at the tip of the return jet nozzle 36, the effect of removing foreign matter adhering to the fuel filter 8 can be enhanced, and the throttle portion 37 can reduce the tip of the return jet nozzle 36. Since the opening area is reduced, it is possible to further prevent foreign matters in the fuel in the fuel tank 2 from entering from the tip of the return jet nozzle 36.

  In the above embodiment, the case where a plunger type pump is applied as the fuel injection device has been described. However, an electric motor type pump can also be applied.

  The present invention is not limited to the above-described embodiment, and various modifications can be made based on the gist of the present invention.

DESCRIPTION OF SYMBOLS 1 Plunger pump 2 Fuel tank 3 Pump body 4 Movable iron core guide hole 5 Plunger hole 6 Inflow opening 7 Insertion cylinder part 8 Fuel filter 9 Housing 10 Fixed iron core 11 Discharge path 12 Coil bobbin 13 Electromagnetic coil 15 Movable iron core 17 Plunger 19 Pump chamber 20 Inhalation Side check valve 21 Outflow piping 22 Discharge side check valve 23 Fuel joint 25 Pressure regulator 27 Fuel chamber 28 Spring chamber 34 Return piping 36 Return jet nozzle 37 Restriction section

Claims (4)

A pump that sucks the fuel stored in the fuel tank and supplies it to the fuel injection valve;
A fuel filter disposed in the fuel tank and filtering the fuel and sending it to the pump;
A pressure regulator for adjusting the fuel supplied from the pump to a predetermined pressure;
A return pipe for returning fuel from the pressure regulator to the fuel tank;
A return injection nozzle disposed inside the fuel tank and configured to inject return fuel sent from the return pipe toward the fuel filter;
A fuel injection device comprising:   2. The fuel injection device according to claim 1, wherein the return injection nozzle is bent so that a tip portion thereof is directed to the fuel filter.   3. The fuel injection device according to claim 1, wherein a throttle portion having a small diameter is formed at a tip portion of the return jet nozzle so that an opening area thereof is small.   4. The fuel injection device according to claim 1, wherein a tip end portion of the return injection nozzle is disposed at a position spaced apart from a bottom surface of the fuel tank by a predetermined distance. 5.

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