JP2011163130A - Fuel supply device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fuel supply device that improves fuel consumption, prevents vapor from generating, and improves fuel injection from a fuel injection valve when restarting at high temperature. <P>SOLUTION: The fuel supply device includes: a fuel passage 15 which communicates with a fuel pump 11 and an injector 3; a check valve 14 which checks a reverse flow into a fuel tank 2; a branch communication passage 15a which is diverged on the downstream of the check valve 14; and a branch passage 16 which is diverged on the upstream of the check valve 14. A pressure regulator 20 includes: a housing 21 on which a fuel inlet 21a communicating with the branch communication passage 15a, a central port 21c communicating with the branch passage 16, and a fuel outlet 21b are formed; and a pressure regulating member 22 which defines a pressure regulating chamber 23 communicating with the fuel inlet 21a, and displaces in a valve opening direction where the pressure regulating chamber 23 is made to be communicated with the fuel outlet 21b in accordance with a fuel pressure in the pressure regulating chamber 23. The pressure regulating member 22 is applied with a pressure in the valve opening direction by an operating pressure of fuel introduced from the central port 21c, and then switches a pressure of fuel supplied to the injector 3 to a set pressure on a low pressure side. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a fuel supply device, particularly a vehicle internal combustion engine that supplies fuel stored in a fuel tank to a fuel consumption unit by a fuel pump and regulates the supply pressure of the fuel to the fuel consumption unit by a pressure regulator. The present invention relates to a suitable fuel supply apparatus.

  2. Description of the Related Art Conventionally, a fuel supply device for an internal combustion engine mounted on a vehicle uses a pressure regulator to adjust a fuel supply pressure (hereinafter referred to as a fuel pressure) from a fuel pump that pumps up fuel in a fuel tank to a fuel injection valve as a fuel consumption unit. It comes to press. In general, the pressure regulator divides a chamber into two chambers by a diaphragm and opens and closes a fuel pressure regulating valve by using the displacement of the central portion of the diaphragm spring, while the other side of the diaphragm has a spring ( By suppressing the displacement of the diaphragm by a compression coil spring), the pressure regulating valve is kept open and closed so that the pressure in the pressure regulating chamber reaches a set pressure. In many cases, the pressure regulator is disposed in the fuel tank together with the fuel pump.

  As a fuel supply device equipped with this type of pressure regulator, for example, the discharged fuel from the pump is introduced into the back pressure chamber of the pressure regulator through the back pressure boosting circuit. It is known that the fuel pressure regulated in the pressure regulating chamber can be switched to a high pressure by switching the electromagnetic valve (for example, see Patent Document 1).

  The fuel supply device disclosed in Patent Document 1 uses a pressure regulator that is different from a pressure regulator that regulates the fuel supplied to the fuel injection valve and a throttle element that cooperates with the pressure regulator to increase the pressure of the fuel for increasing the back pressure. Is adjusted to a preset pressure.

  In addition, it is determined whether or not vapor can be generated in the fuel supply path. When vapor can be generated, pressurized fuel is introduced into the back pressure chamber of the pressure regulator so as to increase the fuel pressure. What was made into is known (for example, refer patent document 2).

  In the fuel supply device disclosed in Patent Document 2, an electromagnetic valve is provided on the downstream side of the back pressure chamber, and when the vapor can be generated, the electromagnetic valve is shifted from the open state to the closed state. By introducing the pressurized fuel into the back pressure chamber, the fuel pressure supplied to the fuel injection valve is increased to suppress the generation of vapor.

  In addition, a recirculation flow path having a plurality of throttle elements is connected to the fuel supply line from the fuel pump to the fuel injection valve, and the discharge pressure of the fuel pump and the pressure in the fuel tank are intermediate between the plurality of throttle elements. It is known that the pressure is taken out and introduced into the back pressure chamber, and the fuel that has passed through the reflux passage is returned to the fuel tank (see, for example, Patent Document 3).

  In the fuel supply device disclosed in Patent Document 3, an electromagnetic valve for switching the supply state of fuel to be introduced into the back pressure chamber is further provided upstream of the plurality of throttle elements, and the electromagnetic valve is in a closed state. By switching between the valve open states, the injection pressure from the fuel injection valve can be adjusted in two stages of high pressure and low pressure.

  In addition, a pressure regulator is provided on the return line that returns the fuel supplied to the fuel injection valve to the fuel tank, and an electromagnetic valve is provided on the return line further downstream of the pressure regulator. It is known that the set pressure by the pressure regulator is switched from the low pressure side to the high pressure side by shifting from the open state to the closed state (see, for example, Patent Document 4).

  In the fuel supply device disclosed in Patent Document 4, a back pressure pipe for introducing the fuel in the return pipe into the back pressure chamber is formed between the pressure regulator and the electromagnetic valve. Further, when the engine is stopped, the solenoid valve is shifted to a closed state so that the fuel on the supply line between the pressure regulator and the check valve can be sealed. For this reason, generation | occurrence | production of a vapor | steam can be suppressed by hold | maintaining a high temperature and high pressure state of a fuel at the time of an engine stop.

JP 2007-278113 A JP 2007-218222 A JP 2001-090624 A JP-A-2005-09331

  However, in the conventional fuel supply device, the fuel supplied to the fuel injection valve is introduced into the pressure regulator and adjusted to the set pressure. However, the set pressure is adjusted to the set pressure on the high pressure side and the low pressure side. In order to switch between the set pressures, it was necessary to provide a solenoid valve. For this reason, since the set pressure is switched between the set pressure on the high pressure side and the set pressure on the low pressure side by switching the fuel supply state to the back pressure chamber with the solenoid valve, for example, while the engine is running There is a problem in that energization is performed to operate the solenoid valve, and the supply of fuel to the back pressure chamber must be shut off, resulting in deterioration of fuel consumption.

  The present invention has been made to solve the conventional problems as described above, and can switch the set pressure between the set pressure on the high pressure side and the set pressure on the low pressure side without providing a solenoid valve. In addition to improving fuel efficiency, since no solenoid valve is provided, the generation of vapor can be reliably suppressed compared to the conventional method, and fuel injection from the fuel injection valve can be improved at high temperature restart. It is an object of the present invention to provide a fuel supply device that can be used.

  In order to achieve the above object, the fuel supply device according to the present invention (1) supplies the fuel stored in the fuel tank to the fuel injection valve by the fuel pump and the supply pressure of the fuel supplied to the fuel injection valve A fuel supply device that regulates the pressure of the fuel by a pressure regulator, a supply pipe that supplies the fuel pressurized by the fuel pump to the fuel injection valve, and a fuel pipe provided in the supply pipe to the fuel tank. A check valve for blocking the flow of the fuel, a first branch pipe branched from the supply pipe on the fuel injection valve side of the check valve, and supplying fuel from the supply pipe to the pressure regulator; A second branch pipe that branches from the supply pipe on the fuel pump side of the check valve and supplies fuel from the supply pipe to the pressure regulator. The regulator includes a housing in which a first fuel inlet for introducing fuel from the first branch pipe, a second fuel inlet for introducing fuel from the second branch pipe, and a fuel outlet for discharging the introduced fuel are formed. And a pressure regulating chamber communicating with the first fuel introduction port in the housing, and in a valve opening direction communicating the pressure regulating chamber with the fuel discharge port according to the fuel pressure in the pressure regulating chamber. A pressure adjusting member that displaces, and the pressure adjusting member is displaced in the valve opening direction when an operation pressure is applied by the fuel introduced through the second fuel introduction port, and the fuel injection The pressure of the fuel supplied to the valve is switched from the set pressure on the high pressure side to the set pressure on the low pressure side.

  With this configuration, whether the fuel having the operating pressure pressurized by the fuel pump is introduced into the pressure regulator through the second branch pipe by switching the fuel pump between the driving state and the non-driving state. Can be switched.

  For this reason, for example, when the engine is in an operating state and the fuel pump is in a driving state, fuel having an operating pressure pressurized by the fuel pump is introduced into the pressure regulator through the second branch pipe, so the setting on the low pressure side Pressure. After that, when the fuel pump is stopped when the engine is stopped, the fuel pressurized by the fuel pump is not introduced into the pressure regulator via the second branch pipe, and is switched from the set pressure on the low pressure side to the set pressure on the high pressure side. It is done. Further, when the fuel in the supply pipe on the fuel injection valve side with respect to the check valve expands and the fuel pressure rises, the fuel pressure is adjusted to a preset set pressure on the high pressure side so that the fuel pressure does not rise too much. Then, when the engine is restarted and shifts to the operating state, the fuel pump is in the driving state, so that the fuel pressurized by the fuel pump is again introduced into the pressure regulator through the second branch pipe. The pressure can be switched again to the set pressure on the low pressure side.

  Thus, by switching the driving state of the fuel pump without providing the solenoid valve, the fuel supply pressure to the fuel injection valve can be switched between the high-pressure side set pressure and the low-pressure side set pressure. As a result, it is possible to improve fuel efficiency without requiring electric power for operating the solenoid valve as compared with the conventional fuel supply device.

  In addition, since the set pressure can be reliably switched according to the driving state of the fuel pump without providing a solenoid valve, the generation of vapor due to a failure of the solenoid valve or the like is reliably suppressed as compared with the conventional one, The fuel injection from the fuel injection valve can be improved during the high temperature restart. Furthermore, when the pressure exceeds a preset pressure on the high pressure side, the fuel is discharged from the pressure regulating chamber through the fuel discharge port, so that fuel leakage from the components constituting the fuel injection valve can be prevented. it can.

  In the fuel supply device described in (1), (2) the pressure regulator is characterized in that fuel is introduced from the second fuel introduction port by driving the fuel pump.

  With this configuration, the set pressure of the pressure regulating chamber can be switched between the set pressure on the high-pressure side and the set pressure on the low-pressure side according to the driving state and non-driving state of the fuel pump. No fuel consumption can be improved.

  Further, in the fuel supply device according to the above (1) or (2), (3) the pressure regulator closes the communication between the pressure regulating chamber and the fuel discharge port with respect to the pressure regulating member. Urging means for urging the pressure, and the set pressure on the high-pressure side is such that the pressure regulating member is in a state where fuel having an operating pressure is not supplied from the fuel pump via the second fuel introduction port. It is determined by the urging force received from the urging means.

  With this configuration, the pressure regulator becomes the set pressure on the high pressure side in the non-driven state of the fuel pump in which the pressure adjusting member does not receive the pressure of the fuel introduced from the second fuel introduction port. In addition, even when the temperature of the fuel between the check valve and the fuel injection valve rises, the pressure can be increased up to the set pressure on the high pressure side, and the generation of vapor is reliably suppressed as compared with the conventional one, The fuel injection from the fuel injection valve can be improved during the high temperature restart.

  Further, in the fuel supply device described in (3) above, (4) the set pressure on the low pressure side is the operation force introduced from the urging force of the urging means on the pressure regulating member and the second fuel introduction port. It is determined by the difference from the force applied to the pressure regulating member by the fuel having pressure.

  With this configuration, when the fuel pump is in a driving state, the set pressure on the low pressure side can be set without using a solenoid valve.

  In the fuel supply device according to (3), (5) the pressure regulator includes a control valve that is displaced according to an operating pressure of fuel introduced from the second fuel introduction port, and a displacement of the control valve. Another biasing means for biasing the pressure regulating member in the valve opening direction with a biasing force according to the pressure, and the set pressure on the low pressure side is the biasing force of the biasing means on the pressure regulating member And the biasing force of the other biasing means according to the displacement of the control valve.

  With this configuration, when the fuel pump is in a driving state, the set pressure on the low pressure side can be set without using a solenoid valve.

  In the fuel supply device according to any one of (1) to (5), (6) the pressure regulator may be configured such that the fuel pressure in the pressure regulating chamber has a set pressure on the high pressure side when the fuel pump is not driven. When exceeding, it is reduced to the set pressure on the high pressure side.

  With this configuration, the pressure regulator functions as a relief valve that relieves the fuel in the pressure regulation chamber when the pressure exceeds a preset pressure on the high pressure side, so the fuel between the check valve and the fuel injection valve Therefore, the fuel pressure can be adjusted so that the fuel pressure does not increase excessively, and the fuel leakage from the fuel injection valve due to excessive fuel pressure increase can be prevented.

  Further, in the fuel supply device described in (1) to (6) above, (7) the fuel introduced into the pressure regulator from the second fuel introduction port when the fuel pump is in a non-driven state, It is possible to return to the fuel tank through a branch pipe.

  With this configuration, the second branch pipe that supplies fuel to the second fuel inlet when the fuel pump is not driven functions as a fuel discharge path that can return the fuel to the fuel tank. Therefore, the operating pressure of the fuel introduced into the second fuel introduction port can be sufficiently reduced when the fuel pump shifts to the non-driving state.

  Further, in the fuel supply device described in (1) to (7) above, (8) the pressure regulator includes a back pressure chamber defined on the opposite side of the pressure regulating member from the pressure regulating member in the housing. The back pressure chamber is maintained at the internal pressure of the fuel tank.

  With this configuration, it is not necessary to introduce the operating pressure fluid into the chambers other than the pressure regulating chamber as in the conventional case, and the second fuel introduction pipe also serves as the fuel introduction passage when the pressure is switched to the set pressure on the low pressure side. It becomes a low-cost pressure regulator that enables compact and simple piping.

  According to the present invention, the set pressure can be switched between the set pressure on the high-pressure side and the set pressure on the low-pressure side without providing the solenoid valve, and not only the fuel consumption can be improved, Since it is not provided, the generation of vapor can be reliably suppressed as compared with the conventional case, and the fuel injection from the fuel injection valve can be improved during the high temperature restart.

1 is a schematic configuration diagram illustrating a fuel supply device according to a first embodiment of the present invention. It is sectional drawing in the valve opening state of the pressure regulator which concerns on the 1st Embodiment of this invention. It is sectional drawing in the valve closing state of the pressure regulator which concerns on the 1st Embodiment of this invention. FIG. 4A is a graph showing a change in the state of the fuel. FIG. 4A shows a change in the state of the fuel when the fuel supply device according to the first embodiment of the present invention is provided, and FIG. It is a graph showing the state change of the fuel at the time of providing the fuel supply apparatus of. It is a schematic block diagram which shows the fuel supply apparatus which concerns on the 2nd Embodiment of this invention. It is sectional drawing in the valve opening state of the pressure regulator which concerns on the 2nd Embodiment of this invention. It is sectional drawing in the valve closing state of the pressure regulator which concerns on the 2nd Embodiment of this invention. It is a schematic block diagram which shows the fuel supply apparatus which concerns on the 3rd Embodiment of this invention. It is sectional drawing in the valve opening state of the pressure regulator which concerns on the 3rd Embodiment of this invention. It is sectional drawing in the valve closing state of the pressure regulator which concerns on the 3rd Embodiment of this invention.

  Embodiments of the present invention will be described below with reference to the drawings.

(First embodiment)
FIG. 1 shows a fuel supply apparatus according to a first embodiment of the present invention. In the present embodiment, the present invention is applied to a fuel supply device for a vehicle engine (internal combustion engine). Although the overall configuration of the fuel supply system is not shown, the fuel supply apparatus according to the present embodiment is of a so-called in-tank type and is stored in a sub-tank in the fuel tank. A pump is used. This jet pump, for example, branches a return passage of fuel discharged from the fuel pump side so that fuel is transferred through the communication passage by the amount of fuel consumed by the engine, and the inside of the branch passage. This is a known device that transfers the fuel in the fuel tank into the sub-tank on the fuel pump side according to the return flow rate.

  First, the configuration will be described.

  As shown in FIG. 1, the fuel supply device according to the present embodiment includes a fuel tank 2 that stores fuel consumed by the engine 1, such as gasoline, and a plurality of fuels stored in the fuel tank 2. A fuel pumping circuit 10 that pumps and supplies the fuel to the injector 3 and a fuel that is supplied from the fuel pumping circuit 10 to the injector 3 are introduced to adjust the system pressure P1 to a preset pressure on the low pressure side, and the engine And a pressure regulator 20 that can maintain the fuel pressure between the set pressure on the high-pressure side and the set pressure on the low-pressure side when 1 is stopped. The pressure regulator 20 is disposed in the fuel tank 2 together with the fuel pump 11. The injector 3 constitutes the fuel injection valve of the present invention, and only one injector 3 is shown in FIG.

  The engine 1 is a multi-cylinder internal combustion engine mounted on an automobile, for example, a four-cycle gasoline engine. An injector 3 provided corresponding to a plurality of cylinders of the engine 1 is, for example, an end 3a on the injection hole side. Are exposed in intake ports (not shown) of a plurality of cylinders. Further, the fuel from the fuel pumping circuit 10 is distributed to each injector 3 via the delivery pipe 4.

  The fuel pumping circuit 10 includes a fuel pump 11 that pumps up and discharges fuel in the fuel tank 2, a suction filter 12 that blocks intake of foreign matter on the suction port side of the fuel pump 11, and a discharge port of the fuel pump 11. A fuel filter 13 that removes foreign matter in the discharged fuel on the side and a check valve 14 that is located downstream of the fuel filter 13 are configured.

  The fuel pump 11 has, for example, a pump operating part having an impeller for operating the pump and a built-in direct-current motor that drives the pump operating part. The fuel pump 11 pumps up fuel from the fuel tank 2 and discharges the fuel under pressure. The discharge amount per unit time can be variably controlled by changing the rotation speed [rpm] of the built-in motor. The check valve 14 opens in the fuel supply direction from the fuel pump 11 to the injector 3 side, and closes and pressurizes in the reverse flow direction of fuel from the injector 3 side to the fuel pump 11 side. It is designed to prevent backflow of supplied fuel.

  Further, the fuel pump 11 is driven and stopped by controlling whether or not the internal motor is energized by an electronic control unit (hereinafter referred to as ECU) 6 which will be described later, and the fuel discharge amount per unit time is changed. The energization of the built-in motor is controlled so that The fuel pump 11 may be constituted by a pump that takes only two states, a driving state and a non-driving state in which fuel is discharged at a constant discharge amount.

  The pressure regulator 20 includes a housing 21 having a fuel inlet 21a into which a part of the fuel discharged from the fuel pump 11 is introduced and a fuel outlet 21b through which the fuel is discharged. The pair of concave housing members 18 and 19 are formed by caulking and coupling with their outer peripheral flange portions 18j and 19j (see FIG. 2). Here, the fuel inlet 21a according to the present embodiment constitutes a first fuel inlet according to the present invention.

  The fuel inlet 21a and the fuel outlet 21b shown in FIG. 1 are spaced apart at equal intervals in the circumferential direction of the housing 21, but at least one is formed at any position in the circumferential direction of the housing 21. The opening shape is arbitrary. Moreover, although the housing members 18 and 19 are what pressed the steel plate or the stainless steel plate in the concave shape, for example, you may shape | mold the molten material in the shape of illustration.

  Inside the housing 21, a partition-shaped pressure regulating member 22 that divides the inside of the housing 21 into two chambers is provided. The pressure regulating member 22 includes a partition wall portion 24 that defines a pressure regulating chamber 23 that communicates with the fuel introduction port 21 a between the pressure regulating member 22 and the pressure regulating chamber 23 at an opening degree corresponding to the fuel pressure in the pressure regulating chamber 23. Is integrated with a movable valve body portion 25 that is displaced in the valve opening direction so as to communicate with the fuel discharge port 21b, and the partition wall portion 24 always receives the fuel pressure in the pressure regulating chamber 23 on one side thereof. ing. The partition wall portion 24 of the pressure regulating member 22 also forms a back pressure chamber 26 for applying a back pressure to the pressure regulating chamber 23 between the housing 21 and the other surface side. A compression coil spring 27 is provided to urge the movable valve body 25 of the pressure regulating member 22 in the valve closing direction. Further, at least one atmospheric pressure introduction hole 19 a is formed in the other housing member 19 that forms the back pressure chamber 26 together with the pressure regulating member 22. Here, the compression coil spring 27 constitutes an urging means according to the present invention.

  More specifically, the partition wall portion 24 of the pressure adjusting member 22 includes, for example, a base material layer (for example, polyamide synthetic fiber) and a rubber layer (for example, hydrogenated nitrile rubber, fluorine rubber, or the like) that hardly deteriorates against fuel. The movable valve body portion 25 of the pressure regulating member 22 is, for example, a metal (for example, tool steel, stainless steel, etc.) supported by the central portion of the partition wall portion 24. ) Made of disc-shaped valve body plate. The movable valve body 25 and the partition wall 24 are fixed by, for example, vulcanization adhesion of the rubber layer.

  As shown in FIGS. 1 and 2, the first valve seat portion 31 and the second valve seat are arranged inside the housing 21 so as to face the movable valve body portion 25 of the pressure regulating member 22 inside the pressure regulating chamber 23. The parts 32 are arranged concentrically. The first valve seat portion 31 forms a discharge hole 31h communicating with the fuel discharge port 21b, and the discharge hole 31h corresponds to the displacement of the movable valve body portion 25 on the inner end side opened inside the pressure regulating chamber 23. To change the opening. Further, the second valve seat portion 32 forms an operation pressure fuel introduction hole 32h that changes the opening degree according to the displacement of the movable valve body portion 25 on the inner end side that opens inside the pressure regulating chamber 23, A fuel having an operating pressure pressurized to such an extent that an operating force can be applied to the movable valve body 25 is selectively introduced into the operating pressure fuel introduction hole 32h.

  Further, the movable valve body portion 25 of the pressure regulating member 22 has a flat surface 25a facing the first valve seat portion 31 and the second valve seat portion 32, and the first valve seat portion 31 and the second valve seat. The parts 32 are opposed to the movable valve body part 25 of the pressure regulating member 22 in the same direction (downward in FIG. 1), and are parallel valves arranged so as to be positioned substantially on the same plane. It has a seating surface.

  However, when the movable valve body portion 25 of the pressure regulating member 22 contacts the first valve seat portion 31, the inner end of the discharge hole 31 h of the first valve seat portion 31 is liquid-tightly closed by the movable valve body portion 25. However, although the opening degree of the operation pressure fuel introduction hole 32h of the second valve seat portion 32 is restricted by the movable valve body portion 25, it does not have to be closed liquid tightly.

  Specifically, the first valve seat portion 31 and the second valve seat portion 32 are configured by inner end portions of an outer cylindrical member 35 and an inner cylindrical member 36 that have different diameters and are arranged coaxially. The outer cylindrical member 35 and the inner cylindrical member 36 are fixed to one housing member 18 formed in a plurality of stepped concave shapes so as to become deeper inward in the radial direction. Also, one housing member 18 of the housing 21 includes a first annular wall portion 18a that is spaced radially outward with respect to the outer tubular member 35, a second annular wall portion 18b that supports the outer tubular member 35, and A third annular wall portion 18c for supporting the inner cylindrical member 36; a first lid wall portion 18d for connecting the first annular wall portion 18a and the second annular wall portion 18b; and a second annular wall portion. 18b and the third annular wall portion 18c, and a third lid wall portion 18f connected to the outer end portion of the third annular wall portion 18c.

  The fuel introduction port 21 a formed in the housing 21 is located on the outer peripheral surface side (radially outer side) of the outer cylindrical member 35, and the fuel discharge port 21 b formed in the housing 21 is the inner periphery of the outer cylindrical member 35. It is located on the surface side (in the radial direction).

  That is, the fuel introduction port 21 a of the housing 21 opens to the first lid wall portion 18 d located between the outer cylindrical member 35 and the first annular wall portion 18 a of the one housing member 18. One housing member 18, the partition wall portion 24 of the pressure regulating member 22, and the outer cylindrical member 35 form an annular introduction-side passage 37 that introduces fuel from the fuel introduction port 21 a and receives the fuel pressure in the partition wall portion 24. ing. The fuel discharge port 21b of the housing 21 opens to the outer cylindrical member 35 and the second lid wall portion 18e located between the second annular wall portion 18b of the one housing member 18 and the inner cylindrical member 36. The discharge hole 31h of the first valve seat portion 31 is substantially cylindrical on the inner peripheral surface side of the outer cylindrical member 35 and outside the inner cylindrical member 36 by the outer cylindrical member 35 and the inner cylindrical member 36. And is communicated with the fuel discharge port 21b of the housing 21 through an annular discharge passage 38 between one housing member 18, the outer cylindrical member 35, and the inner cylindrical member 36. Further, the operation pressure fuel introduction hole 32 h of the second valve seat portion 32 is formed in a substantially cylindrical shape inside the inner cylindrical member 36, and the third lid wall portion 18 f of one housing member 18 includes A central port 21c communicating with the operation pressure fuel introduction hole 32h of the second valve seat portion 32 is formed. Here, the center port 21c according to the present embodiment constitutes a second fuel introduction port according to the present invention.

  In the present embodiment, the fuel introduction port 21a is disposed to open to the first lid wall portion 18d, and the fuel discharge port 21b is disposed to open to the second lid wall portion 18e. However, the fuel introduction port 21a is the first lid wall portion 18e. It may have an opening shape that extends to the annular wall portion 18a and the fuel discharge port 21b extends to the second annular wall portion 18b. The fuel introduction port 21a opens to the first annular wall portion 18a, and the fuel discharge port 21b. May open to the second annular wall 18b.

  On the other hand, the fuel inlet 21 a of the pressure regulator 20 is connected to a fuel passage 15, which is a circuit portion downstream of the check valve 14 of the fuel pumping circuit 10, via a branch communication passage 15 a. The port 21c is connected to a branch passage 16 branched in a circuit portion upstream of the check valve 14 of the fuel pumping circuit 10. Here, the branch communication passage 15 a of the fuel passage 15 includes, for example, a branch portion 15 b formed by a part 17 of the filter case that houses the suction filter 12 and the filter element (not shown) of the fuel filter 13 together with the fuel pump 11. And an annular passage portion 15 c formed between a part 17 of the filter case and the housing 21 of the pressure regulator 20. The fuel passage 15, the branch communication passage 15a, and the branch passage 16 according to the present embodiment constitute a supply pipe, a first branch pipe, and a second branch pipe according to the present invention, respectively.

  Then, when the fuel pump 11 shifts to the non-driven state, the supply of the operation pressure fuel through the center port 21c is stopped, and the operation pressure P2 inside the operation pressure fuel introduction hole 32h becomes low, that is, the fuel tank 2 When opening to the internal pressure space or the atmospheric pressure space, the effective effective pressure receiving area where the movable valve body portion 25 of the pressure regulating member 22 receives the fuel pressure in the valve opening direction is an annular shape of the partition wall portion 24 around the movable valve body portion 25. Only on the pressure-receiving surface side. On the other hand, when the operating pressure fuel is supplied from the fuel pump 11 through the center port 21c and the operating pressure P2 inside the operating pressure fuel introduction hole 32h becomes high, the effective pressure receiving area of the pressure regulating member 22 is the partition wall portion 24. This includes not only the annular pressure receiving surface, but also the substantially circular pressure receiving surface in the central portion facing the second valve seat portion 32 and the operating pressure fuel introduction hole 32h. Therefore, the effective pressure receiving area of the pressure adjusting member 22 is changed according to the operating pressure P2 inside the operating pressure fuel introduction hole 32h, and the effective pressure receiving area of the pressure adjusting member 22 is increased or decreased to open the movable valve body 25. The thrust in the valve direction changes, and the amount of deflection and the spring force of the compression coil spring 27 that urges the movable valve body 25 in the valve closing direction from the back pressure chamber 26 side change.

  Thereby, the movable valve body 25 is displaced in the valve closing direction or the valve opening direction with respect to the first valve seat portion 31 and the second valve seat portion 32 in accordance with the operation pressure P2 inside the operation pressure fuel introduction hole 32h. When the amount of fuel discharged from the pressure regulating chamber 23 to the fuel discharge port 21b decreases due to the displacement of the movable valve body 25 in the valve closing direction, the fuel pressure inside the pressure regulating chamber 23 is increased to the high pressure side fuel pressure. When the amount of fuel discharged from the pressure regulating chamber 23 to the fuel discharge port 21b increases due to the displacement of the movable valve body 25 in the valve opening direction, the fuel pressure inside the pressure regulating chamber 23 is The fuel pressure is adjusted to a low fuel pressure that is a normal fuel pressure during traveling.

  Thus, the pressure regulator 20 introduces a part of the fuel discharged from the fuel pump 11 and supplied to the injector 3 of the engine 1 into the pressure regulating chamber 23, and the fuel in the pressure regulating chamber 23 is set in advance. By adjusting the pressure to the set pressure, the pressure of the fuel supplied to the injector 3 can be adjusted. Further, when the operating pressure P2 inside the operating pressure fuel introduction hole 32h decreases, such as when the fuel pump 11 is shifted to a non-driven state, the fuel downstream of the check valve 14 can be held at a high pressure.

  The set pressure on the low pressure side of the pressure regulator 20 is, for example, 200 [kPa] (gauge pressure; hereinafter the same), and when the fuel temperature in the delivery pipe 4 becomes relatively low during traveling, the fuel vapor Is set so that the fuel pressure is less likely to occur.

  Further, the set pressure on the high pressure side of the pressure regulator 20 is, for example, 400 [kPa], and even if the fuel temperature in the delivery pipe 4 becomes high immediately after the engine 1 is stopped or the like, the fuel pressure (usually fuel vapor hardly occurs) 324 kPa or more).

  In addition to a backup memory composed of a nonvolatile memory such as a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), an EEPROM (Electrically Erasable and Programmable Read Only Memory, registered trademark), the ECU 6 The ECU 6 includes an input interface circuit, an output interface circuit, and the like. The ECU 6 receives an ON / OFF signal of an ignition switch of the vehicle and is supplied with power from a battery. Further, various sensor groups are connected to the input interface circuit of the ECU 6, and sensor information from these sensor groups is taken into the ECU 6 through an input interface circuit including an A / D converter and the like. The output interface circuit of the ECU 6 is connected to the injector 3, the fuel pump 11, a switching element for variably controlling the current of the fuel pump 11, and the like.

Next, the operation will be described.
In the fuel supply device of the present embodiment configured as described above, the ECU 6 is controlled to drive the fuel pump 11 while the engine 1 is in operation. At this time, the fuel is required to be pumped to the delivery pipe 4 with a set pressure on the low-pressure side set based on the fuel efficiency and the reliability of the fuel pump 11.

  In this state, as shown in FIG. 2, since the fuel is supplied from the fuel pump 11 to the operating pressure fuel introduction hole 32h of the pressure regulator 20, the operation pressure P2 inside the operation pressure fuel introduction hole 32h becomes high. The effective pressure receiving area of the pressure regulating member 22 is expanded to include not only the annular pressure receiving surface of the partition wall 24 but also the substantially circular pressure receiving surface facing the second valve seat portion 32 and the operating pressure fuel introduction hole 32h. Therefore, the thrust in the valve opening direction of the movable valve body portion 25 increases as the effective pressure receiving area of the pressure regulating member 22 increases, and the amount of deflection of the compression coil spring 27 that biases the movable valve body portion 25 in the valve closing direction. As the spring pressure increases, the movable valve body 25 is displaced in the valve opening direction with respect to the first valve seat 31 and the second valve seat 32. Then, the displacement of the movable valve body 25 in the valve opening direction increases the amount of fuel discharged from the pressure regulating chamber 23 to the fuel discharge port 21b, and the pressure of the fuel inside the pressure regulating chamber 23 is set to the low pressure side set pressure. Thus, the pressure is adjusted to the normal fuel pressure.

  On the other hand, when the engine 1 is stopped, the discharge pressure of the fuel pump 11 becomes 0 [kPa]. At this time, as shown in FIG. 3, the pressurized fuel is not supplied to the operation pressure fuel introduction hole 32h of the pressure regulator 20, and the operation pressure P2 inside the operation pressure fuel introduction hole 32h is low. The substantial effective pressure receiving area where the pressure regulating member 22 receives the fuel pressure in the valve opening direction is only near the annular pressure receiving surface of the partition wall 24 around the movable valve body 25. Accordingly, the set pressure of the pressure regulator 20 is on the high pressure side in the pumping stop state of the fuel pumping circuit 10 to be regulated. That is, when the fuel pressure in the pressure regulating chamber 23 exceeds the set pressure on the high pressure side, the pressure regulator 20 displaces the movable valve body portion 25 in the valve opening direction so that the pressure regulating chamber 23 communicates with the fuel discharge port 21b. Functions as a relief valve.

  Further, since the branch passage 16 is connected to the fuel passage 15 on the upstream side of the check valve 14, the branch passage 16 is supplied to the center port 21c when the fuel pump 11 shifts to the non-driven state. It functions as a fuel discharge path that can return the returned fuel to the fuel tank 11.

  FIG. 4 (a) shows a change in state with respect to the fuel temperature and the fuel pressure in the fuel supply apparatus including the pressure regulator 20 configured as described above.

  First, immediately after the engine 1 is stopped (time T1), the fuel pressure is a set pressure on the low pressure side, which is a normal fuel pressure when the engine 1 is operating. The engine room temperature starts to rise by stopping the cooling water circulation of the engine 1 or stopping the fan for introducing cooling air from the outside of the vehicle to the engine room. The temperature of the fuel remaining in the passage 15 also starts to rise (time T1 → T2).

  At this time, the pressure regulator 20 causes the operating pressure P2 inside the operating pressure fuel introduction hole 32h to become low due to the stop of the fuel pump 11, that is, when the fuel pump shifts to the non-driven state, and the inside of the pressure regulating chamber 23 The self-pressure is increased in the range where the fuel pressure is equal to or lower than the set pressure on the high pressure side (time T2). This self-pressurization keeps the fuel in a liquid and prevents vapor generation.

  Then, the temperature of the fuel starts to decrease as the temperature of the engine room decreases (time T2 → T4). At this time, since the pressure regulator 20 is maintained at the set pressure on the high pressure side, the pressure of the fuel is reduced without generating vapor.

  On the other hand, as shown in FIG. 4 (b), the fuel state change in the fuel supply apparatus having the conventional pressure regulator is changed after the engine 1 is stopped (time T1). Since the set pressure during operation of the engine 1 does not shift from the set pressure on the high pressure side, the fuel pressure does not increase even though the fuel temperature rises. Therefore, the fuel becomes gas (time T2), and vapor is generated.

  Thus, in the present embodiment, the fuel having the operating pressure pressurized by the fuel pump 11 is pressured via the branch passage 16 by switching the fuel pump 11 between the driving state and the non-driving state. Whether or not to be introduced into the regulator 20 can be switched.

  For this reason, for example, when the engine 1 is in an operating state and the fuel pump 11 is in a driving state, fuel having an operating pressure pressurized by the fuel pump 11 is introduced into the pressure regulator 20 via the branch passage 16. Set pressure on the side. After that, when the engine 1 is stopped, the fuel pressurized by the fuel pump 11 is not introduced into the pressure regulator 20 via the branch passage 16, and the fuel passage 15 and the branch on the injector 3 side of the check valve 14 are branched. Even if the fuel in the communication passage 15a expands and the fuel pressure rises, the fuel pressure is maintained at a high pressure, so that it is possible to switch from the set pressure on the low pressure side to the set pressure on the high pressure side, and to set the fuel pressure not to rise too much It can be adjusted to the set pressure on the high pressure side. When the engine 1 is restarted and shifts to the operating state, the fuel pump 11 is in a driving state, so that the fuel pressurized by the fuel pump 11 is again introduced into the pressure regulator 20 via the branch passage 16. Therefore, it can be switched to the set pressure on the low pressure side again.

  Thus, by switching the driving state of the fuel pump 11 without providing a solenoid valve, the fuel supply pressure to the injector 3 can be switched between the high-pressure side set pressure and the low-pressure side set pressure. As a result, it is possible to improve fuel efficiency without requiring electric power for operating the solenoid valve as compared with the conventional fuel supply device.

  In addition, since the set pressure can be switched reliably according to the driving state of the fuel pump 11 without providing the solenoid valve, the generation of vapor due to the failure of the solenoid valve or the like is surely suppressed as compared with the conventional case. Moreover, the fuel injection from the injector 3 can be made favorable at the time of high temperature restart. Further, when the pressure exceeds a preset pressure on the high pressure side, the fuel is discharged from the pressure adjusting chamber 23 through the fuel discharge port 21b, so that fuel leakage from the components constituting the injector 3 is prevented. Can do.

  Further, the branch passage 16 that supplies fuel to the center port 21c when the fuel pump 11 is not driven functions as a fuel discharge path that can return the fuel to the fuel tank 11. Therefore, when the fuel pump 11 shifts to the non-driving state, the operating pressure of the fuel introduced into the center port 21c can be sufficiently reduced.

  Further, in addition to the fact that the operating pressure fluid does not need to be introduced into a chamber other than the pressure regulating chamber as in the prior art, the branch passage 16 also serves as a fuel introduction passage at the set pressure on the low pressure side, so that the compact and simple piping It becomes a low-cost pressure regulator that can be used.

  In the above description, the case where the operation pressure fuel directly applies pressure to the displacement portion of the pressure adjusting member has been described. However, the present invention is not limited to this, and the operation pressure of the fuel is determined as the mechanical operation force as described below. The displacement portion may be displaced by converting into

(Second Embodiment)
A fuel supply device according to a second embodiment of the present invention will be described with reference to FIGS.

  The configuration of the fuel supply device according to the second embodiment is substantially the same as the configuration of the fuel supply device according to the first embodiment described above, and the respective components are shown in FIGS. Description will be made using the same reference numerals as those of the first embodiment shown, and only differences will be described in detail.

  As shown in FIG. 5, the fuel supply apparatus according to the present embodiment includes a fuel tank 2, a fuel pumping circuit 10 that pumps and supplies fuel stored in the fuel tank 2 to an injector 3, and the fuel pumping circuit 10. The pressure supplied from the fuel to the injector 3 is introduced to adjust the system pressure P1 to a preset system pressure P1, and the system pressure P1 can be maintained between the set pressure on the high pressure side and the set pressure on the low pressure side. Regulator 40. The pressure regulator 40 is disposed in the fuel tank 2 together with the fuel pump 11.

  The pressure regulator 40 includes a housing 41 having a substantially circular cross section in which a fuel introduction port 41a, a return port 41b and an operation pressure introduction port 41c are formed, and a fuel tank that supplies fuel from the fuel pump 11 when the valve is opened in the housing 41. And a fuel pressure regulating valve 45 that regulates the fuel by discharging into the fuel tank 2 and a fuel pressure regulating valve 45 so that the closed state of the fuel pressure regulating valve 45 is maintained until the fuel pressure from the fuel pump 11 reaches a set pressure on the high pressure side. A compression coil spring 46 for setting a high pressure to bias 45 in the valve closing direction, a pressure receiving member 47 as a control valve for biasing the fuel pressure regulating valve 45 in the valve opening direction based on the operating pressure P2, and a compression coil for pressure reduction And a spring 48. Here, the high pressure setting compression coil spring 46 and the decompression compression coil spring 48 according to the present embodiment constitute an urging means and another urging means according to the present invention, respectively. Further, the fuel introduction port 41a, the return port 41b, and the operation pressure introduction port 41c constitute a first fuel introduction port, a fuel discharge port, and a second fuel introduction port according to the present invention, respectively.

  Here, the set pressure on the high pressure side is, for example, 400 [kPa] as in the first embodiment, and even if the fuel temperature in the delivery pipe 4 becomes high immediately after the engine 1 is stopped, the fuel It is a set value of the fuel pressure (usually 324 kPa or more) at which vapor does not easily occur. The set pressure on the low pressure side is, for example, 200 [kPa], and is set to a fuel pressure at which fuel vapor hardly occurs when the fuel temperature in the delivery pipe 4 becomes relatively low during traveling.

  The pressure regulator 40 defines a pressure regulating chamber 43 and a back pressure chamber 44 in the housing 41, and has a diaphragm-shaped partition wall having a displacement portion 42a that is displaced according to the differential pressure between the chambers 43 and 44. The member 42 is included, and the fuel pressure regulating valve 45 is opened and closed in accordance with the displacement of the displacement portion 42 a in the pressure regulating chamber 43.

  The partition member 42 includes a central displacement portion 42a made of, for example, a hard, substantially disk-shaped material, and an elastic film-like flexible annular portion 42b surrounding the displacement portion 42a. The displacement portion 42a can be displaced in the vertical direction in the figure in accordance with the biasing force received from the back pressure chamber 44 side. Alternatively, the partition member 42 has a substantially disk shape as a whole, and has a seal portion that slidably slides between the pressure regulating chamber 43 and the back pressure chamber 44 on the outer periphery thereof, while being liquid-tightly partitioned. It may be a thing.

  The displacement portion 42a of the partition member 42 has, for example, a circular center hole, and the annular valve seat 45b on which the substantially spherical valve body 45a of the fuel pressure regulating valve 45 can be seated is constituted by the displacement portion 42a of the partition member 42. Yes. The valve seat surface of the annular valve seat 45b has a conical surface, for example.

  Further, the substantially spherical valve body 45a of the fuel pressure regulating valve 45 is fixed and supported to the housing 41 via a vertical stem member 45c, and is urged upward in FIG. 5 by a compression coil spring 46 for high pressure setting. The displacement portion 42a of the partition wall member 42 is restricted from moving upward in FIG. 5 by the substantially spherical valve body 45a. That is, the substantially spherical valve body 45a and the stem member 45c of the fuel pressure regulating valve 45 also function as a stopper that defines the movement limit of the displacement portion 42a of the partition wall member 42 to the upper side in the figure (the set pressure increase side).

  The pressure receiving member 47 defines an operating pressure chamber 49 for introducing fuel having the operating pressure P2 into the housing 41, and receives the operating pressure P2 in the operating pressure chamber 49. The pressure receiving member The operating force in the valve opening direction of the fuel pressure regulating valve 45 is transmitted from 47 to the displacement portion 42a of the partition wall member 42 as a mechanical operating force, not as a fluid pressure. Further, between the pressure receiving member 47 and the displacement portion 42a of the partition wall member 42, there is a compression coil spring 48 for pressure reduction that transmits an operating force in the valve opening direction of the fuel pressure regulating valve 45 from the pressure receiving member 47 to the displacement portion 42a. It is intervened.

  As shown in FIG. 6, when the operating force in the valve opening direction of the fuel pressure regulating valve 45 is transmitted from the pressure receiving member 47 to the displacement portion 42a, the pressure regulator 40 causes the displacement portion 42a of the partition wall member 42 to move to the fuel pressure regulating valve. The fuel pressure regulating valve 45 is opened by displacing the substantially spherical valve body 45a of FIG. 45 downward in the drawing, that is, in the valve opening direction of the fuel pressure regulating valve 45. The fuel in the pressure regulating chamber 43 leaks to the back pressure chamber 44 side through the fuel pressure regulating valve 45, so that the fuel pressure in the pressure regulating chamber 43 is regulated to the low pressure side. The fuel leaking to the back pressure chamber 44 side is discharged into the fuel tank 2 from the return port 41b.

  Specifically, when the fuel pump 11 is driven, the fuel having the operating pressure P2 discharged from the fuel pump 11 is introduced into the operating pressure chamber 49 of the pressure regulator 40. The operation pressure P 2 is introduced into the operation pressure chamber 49, so that the pressure receiving member 47 receives the operation pressure P 2 in the operation pressure chamber 49 and opens the fuel pressure regulating valve 45 to the displacement portion 42 a of the partition wall member 42. Transmit operating force in the direction. Therefore, the fuel discharged from the fuel pump 11 is regulated to a low pressure side set pressure, for example, 200 [kPa] in the pressure regulating chamber 43, and supplied to the delivery pipe 4 through the fuel passage 15 as a low fuel pressure system pressure P1. The At this time, the fuel pressure in the pressure regulating chamber 43 is equal to the system pressure P1, the pressure receiving member 47 receives the operating pressure P2, and the urging force F2 of the compression coil spring 48 for pressure reduction is increased. The urging force acting on the partition wall member 42 from the 43 side is the sum of P1 × S and the urging force F2 of the compression coil spring 48 for pressure reduction, and this urging force (P1 × S + F2) and the compression coil spring 46 for setting the high pressure The urging force F1 is balanced in a state in which a set pressure on the low pressure side is generated. That is, P1 * S = F1-F2 = 400 * S-200 * S = 200 * S, and a pressure regulation state of 200 [kPa], which is the set pressure on the low pressure side, is obtained.

  On the other hand, as shown in FIG. 7, in the pressure receiving member 47, the operating pressure P2 of the fuel supplied into the operating pressure chamber 49 reaches the internal pressure or the atmospheric pressure P3 of the fuel tank 2 (hereinafter referred to as the internal pressure P3 of the fuel tank 2). When the pressure decreases, the urging force (reaction force) from the compression coil spring 48 for pressure reduction returns to the return position shown in FIG. 7 and closes the fuel pressure regulating valve 45. Therefore, when the inside of the operation pressure chamber 49 is opened to the fuel tank 2 internal pressure space or the atmospheric pressure space, the fuel between the check valve 14 and the injector 3 is regulated to the set pressure on the high pressure side by the pressure regulator 40. .

  In this case, the pressure regulator 40 can regulate the fuel in the pressure regulating chamber 43 between a preset low-pressure side set pressure and a preset high-pressure side pressure, and reverse when the operating pressure P2 decreases. The fuel between the stop valve 14 and the injector 3 is self-pressurized to a high pressure in the pressure regulating chamber 43.

  Specifically, when the engine 1 is stopped, the pressure regulator 40 reduces the operating pressure P2 that is the fuel pressure discharged from the fuel pump 11 to the internal pressure P3 of the fuel tank 2 in the operating pressure chamber 49 in the housing 41. Therefore, the inside of the operation pressure chamber 49 is the internal pressure of the fuel tank 2 or the atmospheric pressure P3, and the pressure receiving member 47 is in the return position shown in FIG. Therefore, at this time, the fuel pressure regulating valve 45 is closed, and the fuel between the check valve 14 and the injector 3 is introduced into the pressure regulating chamber 43, and the pressure is within a range below the set pressure on the high pressure side. It can be raised.

  While the engine 1 is stopped, the fuel pressure in the pressure regulating chamber 43 is equal to the system pressure P1, the biasing force of the compression coil spring 48 for pressure reduction when the pressure receiving member 47 is in the return position is small, and the partition member Assuming that the pressure receiving area 42 is S, the biasing force P1 × S acting on the partition wall member 42 from the pressure regulating chamber 43 side is in a state of being balanced with the biasing force F1 of the compression coil spring 46 for high pressure setting.

  Returning to FIG. 5, in the present embodiment, the high pressure setting compression coil spring 46 is compressed within the back pressure chamber 44 between the inner bottom 41 e of the housing 41 and the partition wall member 42. The compression coil spring 46 for setting high pressure, which is an elastic member, has a built-in load sufficiently larger than the built-in load of the compression coil spring 48 for pressure reduction. The substantially spherical valve body 45a of the fuel pressure regulating valve 45 serving as a stopper and While the stem member 45c restricts the movement of the displacement part 42a of the partition wall member 42 to the upper side in FIG. 5, an urging force is applied to hold the fuel pressure regulating valve 45 in a surely closed state, and the pressure regulating chamber When the fuel pressure in 43 exceeds the set pressure on the high pressure side, the fuel pressure control valve 45 is opened to limit the increase in the fuel pressure in the pressure control chamber 43 and the fuel in the pressure control chamber 43 is adjusted to the set pressure on the high pressure side. Can be pressed.

  Further, since the branch passage 16 is connected to the fuel passage 15 on the upstream side of the check valve 14, the branch passage 16 is connected to the operation pressure introduction port 41c when the fuel pump 11 shifts to the non-driven state. It functions as a fuel discharge path capable of returning the supplied fuel to the fuel tank 11. The return port 41b formed in the housing 41 is an open hole that opens the back pressure chamber 44 to a space outside the housing 41, and is discharged into the fuel tank 2 from the fuel pressure regulating valve 45 when the valve is opened. It is also a return fuel passage.

  The substantially spherical valve body 45a of the fuel pressure regulating valve 45 can be supported by the housing 41 in the pressure regulating chamber 43, and the fuel is discharged from the pressure regulating chamber 43 into the fuel tank 2 when the fuel pressure regulating valve 45 is opened. You may form the return port to make inside the cylindrical valve body support member supported by the housing 41.

  Thus, in the present embodiment, the fuel having the operating pressure pressurized by the fuel pump 11 is pressured via the branch passage 16 by switching the fuel pump 11 between the driving state and the non-driving state. Whether or not to be introduced into the regulator 40 can be switched.

  For this reason, for example, when the engine 1 is in an operating state and the fuel pump 11 is in a driving state, fuel having an operating pressure pressurized by the fuel pump 11 is introduced into the pressure regulator 40 via the branch passage 16. Set pressure on the side. Thereafter, when the engine 1 is stopped, the fuel pressurized by the fuel pump 11 is not introduced into the pressure regulator 40 via the branch passage 16 and is branched into the fuel passage 15 on the injector 3 side from the check valve 14 and into the branch. Even if the fuel in the communication passage 15a expands and the fuel pressure rises, the fuel pressure is maintained at a high pressure, so that it is possible to switch from the set pressure on the low pressure side to the set pressure on the high pressure side, and set in advance so that the fuel pressure does not rise too much. It can be adjusted to the set pressure on the high pressure side. When the engine 1 is restarted and shifts to the operating state, the fuel pump 11 is in a driving state, so that the fuel pressurized by the fuel pump 11 is again introduced into the pressure regulator 40 via the branch passage 16. Therefore, it can be switched to the set pressure on the low pressure side again.

  Thus, by switching the driving state of the fuel pump 11 without providing a solenoid valve, the fuel supply pressure to the injector 3 can be switched between the high-pressure side set pressure and the low-pressure side set pressure. As a result, it is possible to improve fuel efficiency without requiring electric power for operating the solenoid valve as compared with the conventional fuel supply device.

  In addition, since the set pressure can be switched reliably according to the driving state of the fuel pump 11 without providing the solenoid valve, the generation of vapor due to the failure of the solenoid valve or the like is surely suppressed as compared with the conventional case. Moreover, the fuel injection from the injector 3 can be made favorable at the time of high temperature restart. Further, when the pressure exceeds a preset pressure on the high pressure side, the fuel is discharged from the pressure regulating chamber 43 via the return port 41b, so that fuel leakage from the components constituting the injector 3 can be prevented. it can.

  In addition, the branch passage 16 that supplies fuel to the operation pressure introduction port 41 c when the fuel pump 11 is not driven functions as a fuel discharge path that can return the fuel to the fuel tank 11. Therefore, the operating pressure of the fuel introduced into the operating pressure introduction port 41c can be sufficiently reduced when the fuel pump 11 shifts to the non-driving state.

  Further, in addition to the fact that the operating pressure fluid does not need to be introduced into a chamber other than the pressure regulating chamber as in the prior art, the branch passage 16 also serves as a fuel introduction passage at the set pressure on the low pressure side, so that the compact and simple piping It becomes a low-cost pressure regulator that can be used.

  In the above-described second embodiment, the operation pressure chamber 49 is described as being located on the opposite side of the pressure adjustment chamber 43 from the back pressure chamber 44. However, as shown below, the pressure receiving chamber The member may be disposed on the back pressure chamber side.

(Third embodiment)
A fuel supply apparatus according to a third embodiment of the present invention will be described with reference to FIGS.

  The configuration of the fuel supply device according to the third embodiment is substantially the same as the configuration of the fuel supply device according to the first and second embodiments described above. Description will be made using the same reference numerals as those in the first and second embodiments shown in FIG. 7, and only differences will be described in detail.

  As shown in FIG. 8, the fuel supply device of the present embodiment includes a pressure regulator 60 and is disposed in the fuel tank 2 together with the fuel pump 11. The pressure regulator 60 includes a housing 61 having a substantially circular cross section in which a fuel introduction port 61a, a return port 61b, and an operation pressure introduction port 61c are formed, a diaphragm-like pressure regulating member 62 and a partition wall that define the interior of the housing 61. And a high pressure setting compression coil spring 66 for biasing the pressure regulating member 62 in the valve closing direction so that the pressure of the fuel supplied to the injector 3 can be self-boosted to the set pressure on the high pressure side. A control valve 71 that biases the pressure regulating member 62 in the valve opening direction based on the operating pressure P2, a tension spring 78 for pressure reduction, and a stopper 79 that defines the downward movement limit of the control valve 71 in FIG. It is comprised including. The high-pressure setting compression coil spring 66 and the decompression tension spring 78 according to the present embodiment constitute an urging means and another urging means according to the present invention.

  Here, the set pressure on the high pressure side is, for example, 400 [kPa] as in the first embodiment, and even if the fuel temperature in the delivery pipe 4 becomes high immediately after the engine 1 is stopped, the fuel It is a set value of the fuel pressure (usually 324 kPa or more) at which vapor does not easily occur. The set pressure on the low pressure side is, for example, 200 [kPa], and is a fuel pressure set value at which fuel vapor is unlikely to occur when the fuel temperature in the delivery pipe 4 becomes relatively low during traveling.

  The pressure regulating member 62 includes a partition wall portion 85 forming a pressure regulating chamber 83 communicating with the fuel introduction port 61a in the housing 61, and an opening corresponding to the fuel pressure in the pressure regulating chamber 83 to the pressure regulating chamber 83 at the central port 61d. A movable valve body portion 74 that is displaced in the valve opening direction to be communicated is integrated, and the partition wall portion 85 always receives the fuel pressure in the pressure regulating chamber 83 on one surface side thereof. The partition wall portion 85 of the pressure regulating member 62 also forms a back pressure chamber 84 for applying back pressure to the pressure regulating chamber 83 between the housing 61 on the other surface side. A compression coil spring 66 for setting a high pressure is provided.

  Further, the partition wall 85 of the pressure adjusting member 62 is integrally formed with, for example, a base material layer (for example, polyamide synthetic fiber) and a rubber layer (for example, hydrogenated nitrile rubber or fluororubber) that hardly deteriorates against fuel. The movable valve body 74 of the pressure regulating member 62 is a circle made of, for example, metal (for example, tool steel, stainless steel, etc.) supported by the central portion of the partition wall 85. It is composed of a plate-shaped valve plate. The movable valve body 74 and the partition wall 85 are fixed by, for example, vulcanization adhesion of the rubber layer.

  On the other hand, a valve seat portion 81 is disposed inside the housing 61 so as to face the movable valve body portion 74 of the pressure regulating member 62 inside the pressure regulating chamber 83. The valve seat portion 81 has a fuel discharge hole 82 b that changes its opening according to the displacement of the movable valve body portion 74 on the inner end side that opens inside the pressure regulating chamber 83.

  The partition member 72 has a center hole 82c, and one end of the decompression tension spring 78 extends toward the operation pressure chamber 75 via the center hole 82c. The center hole 82c functions as a throttle and maintains the pressure of the fuel supplied into the operation pressure chamber 75 when the fuel pump 11 is driven, while the fuel pump 11 is stopped. Since the return port 61b is open to atmospheric pressure, the fuel in the operation pressure chamber 75 is returned to the fuel pump 11 side via the operation pressure introduction port 61c.

  The control valve 71 defines an operation pressure chamber 75 for introducing fuel having the operation pressure P2 into the housing 61, and receives the operation pressure P2 in the operation pressure chamber 75. The operating force in the valve opening direction is transmitted from 71 to the movable valve body 74 of the pressure regulating member 62 as a mechanical operating force, not as a fluid pressure. Further, the tension spring 78 for pressure reduction is interposed between the control valve 71 and the movable valve body 74 so as to transmit the operation force in the valve opening direction from the control valve 71 to the movable valve body 74. .

  As shown in FIG. 9, when the operating force in the valve opening direction is transmitted from the control valve 71 to the pressure regulating member 62, the pressure regulator 60 moves the movable valve body 74 of the pressure regulating member 62 to the valve seat 81. Is displaced downward in the figure. The fuel in the pressure regulating chamber 83 leaks to the outside of the housing 61 from the center port 61d through the fuel discharge hole 82b, so that the fuel pressure in the pressure regulating chamber 83 is regulated to the low pressure side. The fuel leaking from the center port 61d is discharged into the fuel tank 2.

  The control valve 71 is opened to the movable valve body 74 by the mechanical operating force of the pressure reducing tension spring 78 when the fuel from the fuel pump 11 is supplied into the operating pressure chamber 75 as the operating pressure P2. Transmit operating force in the direction. Therefore, when the discharge pressure from the fuel pump 11 is supplied into the operation pressure chamber 75 as the operation pressure P2, the fuel from the fuel pump 11 is set to the low pressure side set pressure in the pressure adjusting chamber 83, that is, the normal set pressure. It will be regulated.

  Specifically, when the engine 1 is in operation, the fuel at the operating pressure P <b> 2 introduced into the operating pressure chamber 75 of the pressure regulator 60 is introduced from the fuel pump 11. Then, when the operation pressure P2 is introduced into the operation pressure chamber 75, the control valve 71 receives the operation pressure P2 in the operation pressure chamber 75 and moves to the position of the stopper 79. Due to the movement of the control valve 71, the decompression tension spring 78 extends from its natural length, and the operating force in the valve opening direction is transmitted to the movable valve body 74 of the pressure regulating member 62. Accordingly, the fuel discharged from the fuel pump 11 is regulated to a low pressure side set pressure, for example, 200 [kPa] in the pressure regulating chamber 83, and supplied to the delivery pipe 4 through the fuel passage 15 as the low pressure system pressure P1. The At this time, the fuel pressure in the operation pressure chamber 75 is equal to the system pressure P1, the control valve 71 receives the operation pressure P2, and the biasing force of the tension spring 78 for pressure reduction increases from 0 to F2. The downward biasing force acting on the pressure member 62 in FIG. 9 is the sum of P1 × S and the biasing force F2 of the tension spring 78 for pressure reduction, and this biasing force (P1 × S + F2) and the compression coil spring 66 for setting the high pressure. The upward biasing force F <b> 1 in FIG. 9 is balanced in a state where a set pressure on the low pressure side is generated. That is, P1 * S = F1-F2 = 400 * S-200 * S = 200 * S, and a pressure regulation state of 200 [kPa], which is the set pressure on the low pressure side, is obtained.

  On the other hand, as shown in FIG. 10, when the engine 1 is stopped, the control valve 71 causes the operating pressure P2 supplied into the operating pressure chamber 75 to be the internal pressure of the fuel tank 2 or the atmospheric pressure P3 (hereinafter referred to as the internal pressure of the fuel tank 2). 10 and the return position shown in FIG. 10 by the urging force (reaction force) from the position adjustment spring 73 and the tension spring 78 for pressure reduction, and the movable valve body 74 is used for setting the high pressure. The valve spring 81 is pressed against the valve seat 81 by the urging force of the compression coil spring 66. The position adjustment spring 73 has a biasing force as small as possible under the condition that the control valve 71 can be returned to the return position in this state, so that the set pressure on the low pressure side and the set pressure on the high pressure side are set. Does not affect the.

  Therefore, when the operation pressure chamber 75 is opened to the internal pressure space or the atmospheric pressure space of the fuel tank 2, the fuel in the pressure adjustment chamber 83 and the fuel between the check valve 14 and the injector 3 are set on the low pressure side. The fuel pressure is regulated between the pressure and the set pressure on the high pressure side. When the fuel pump 11 shifts to a non-driving state and the fuel between the check valve 14 and the injector 3 becomes high temperature and expands, the movable valve body 74 until the fuel pressure reaches the set pressure on the high pressure side. The valve is closed and the fuel self-pressurizes. When the fuel further expands and the fuel pressure exceeds the set pressure on the high pressure side, the biasing force acting on the movable valve body 74 from the pressure regulating chamber 83 side exceeds the biasing force of the compression coil spring 66 for setting the high pressure. The movable valve body 74 is displaced downward in the drawing with respect to the valve seat 81 to open the fuel discharge hole 82b. The fuel in the pressure adjusting chamber 83 leaks out of the housing 61 from the center port 61d through the fuel discharge hole 82b, so that the pressure of the fuel in the pressure adjusting chamber 83 is adjusted to the set pressure on the high pressure side. .

  Specifically, when the engine 1 is stopped, the operating pressure P2 of the fuel supplied from the fuel pump 11 in the operating pressure chamber 75 is reduced to the internal pressure P3 of the fuel tank 2, so that the operating pressure chamber 75 contains fuel. The internal pressure of the tank 2 is equal to the atmospheric pressure P3, the control valve 71 returns to the return position shown in FIG. 10, and the decompression tension spring 78 returns to the natural length. At this time, the movable valve body 74 is closed, and the fuel between the check valve 14 and the injector 3 is introduced into the pressure regulating chamber 83, and the pressure is self-adjusted in a range equal to or lower than the set pressure on the high pressure side. The pressure is increased.

  Further, assuming that the pressure receiving area of the pressure regulating member 62 is S, the fuel pressure P1 in the pressure regulating chamber 83 further rises in a state where the control valve 71 is at the return position, and the pressure regulating member 62 is moved from the pressure regulating chamber 83 side. When the applied biasing force P1 × S exceeds the biasing force F1 of the high pressure setting compression coil spring 66, the movable valve body 74 of the pressure regulating member 62 is opened, and the fuel pressure P1 in the pressure regulating chamber 83 is high. Decreases to the set pressure on the side.

  Further, since the branch passage 16 is connected to the fuel passage 15 on the upstream side of the check valve 14, the branch passage 16 is connected to the operation pressure introduction port 61c when the fuel pump 11 shifts to the non-driven state. It functions as a fuel discharge path capable of returning the supplied fuel to the fuel tank 11.

  In this way, the pressure regulator 60 introduces the fuel discharged from the fuel pump 11 and supplied to the injector 3 of the engine 1 into the pressure regulating chamber 83, whereby the fuel in the pressure regulating chamber 83 is set to a preset low pressure. When the fuel pump 11 shifts to the non-driving state, the fuel pressure of the fuel between the check valve 14 and the injector 3 is set to the high pressure set pressure in the pressure regulating chamber 83. It is possible to prevent the generation of vapor by self-boosting until it reaches. Moreover, it functions as a relief valve so that the fuel pressure of the fuel does not exceed the set pressure on the high pressure side.

  Further, in the present embodiment, the compression coil spring 66 for setting the high pressure is contracted between the partition member 72 of the housing 61 and the movable valve body 74 of the pressure regulating member 62 in the back pressure chamber 84. The compression coil spring 66 for high pressure setting is an elastic member for setting high pressure, and applies an urging force for maintaining the reliable valve closing state of the movable valve body 74, and the fuel pressure in the pressure regulating chamber 83 is reduced. When the pressure exceeds the set pressure on the high pressure side, the movable valve body 74 is opened to limit the increase in the fuel pressure in the pressure regulating chamber 83, and the fuel in the pressure regulating chamber 83 can be regulated to the set pressure on the high pressure side. . The return port 61b formed in the housing 61 is an open hole that opens the back pressure chamber 84 to a space outside the housing 61, and returns fuel that is discharged from the operation pressure chamber 75 into the fuel tank 2. It is also a passage.

  Thus, in the present embodiment, the fuel having the operating pressure pressurized by the fuel pump 11 is pressured via the branch passage 16 by switching the fuel pump 11 between the driving state and the non-driving state. Whether or not to be introduced into the regulator 60 can be switched.

  For this reason, for example, when the engine 1 is in an operating state and the fuel pump 11 is in a driving state, fuel having an operating pressure pressurized by the fuel pump 11 is introduced into the pressure regulator 60 via the branch passage 16. Set pressure on the side. Thereafter, when the fuel pump 11 is in a stopped state when the engine 1 is stopped, the fuel pressurized by the fuel pump 11 is not introduced into the pressure regulator 60 via the branch passage 16, and the set pressure on the high pressure side is set from the set pressure on the low pressure side. Switch to pressure. Further, when the fuel in the fuel passage 15 on the injector 3 side of the check valve 14 expands and the fuel pressure rises, the fuel pressure is adjusted to a preset pressure on the high pressure side so that the fuel pressure does not rise too much. . When the engine 1 is restarted and shifts to the operating state, the fuel pump 11 is in a driving state, so that the fuel pressurized by the fuel pump 11 is again introduced into the pressure regulator 60 via the branch passage 16. Therefore, it can be switched to the set pressure on the low pressure side again.

  Thus, by switching the driving state of the fuel pump 11 without providing a solenoid valve, the fuel supply pressure to the injector 3 can be switched between the high-pressure side set pressure and the low-pressure side set pressure. As a result, it is possible to improve fuel efficiency without requiring electric power for operating the solenoid valve as compared with the conventional fuel supply device.

  In addition, since the set pressure can be switched reliably according to the driving state of the fuel pump 11 without providing the solenoid valve, the generation of vapor due to the failure of the solenoid valve or the like is surely suppressed as compared with the conventional case. Moreover, the fuel injection from the injector 3 can be made favorable at the time of high temperature restart. Furthermore, when the pressure exceeds a preset pressure on the high pressure side, the fuel is discharged from the pressure regulating chamber 83 through the center port 61d, so that fuel leakage from the components constituting the injector 3 can be prevented. it can.

  In addition, the branch passage 16 that supplies fuel to the operation pressure introduction port 61 c when the fuel pump 11 is not driven functions as a fuel discharge path that can return the fuel to the fuel tank 11. Therefore, the operating pressure of the fuel introduced into the operating pressure introduction port 61c can be sufficiently reduced when the fuel pump 11 shifts to the non-driven state.

  Further, in addition to the fact that the operating pressure fluid does not need to be introduced into a chamber other than the pressure regulating chamber as in the prior art, the branch passage 16 can also serve as a fuel introduction passage at the set pressure on the low pressure side.

  As described above, the fuel supply device according to the present invention can switch the set pressure between the set pressure on the high-pressure side and the set pressure on the low-pressure side without providing a solenoid valve, and improve fuel consumption. In addition to the fact that the solenoid valve is not provided, the generation of vapor is reliably suppressed compared to the conventional case, and the fuel injection from the fuel injection valve can be improved at high temperature restart. Yes, it is useful as a fuel supply device suitable for a vehicle internal combustion engine that supplies fuel stored in a fuel tank to a fuel consumption unit by a fuel pump and regulates the supply pressure of the fuel to the fuel consumption unit by a pressure regulator It is.

2 Fuel tank 3 Injector 4 Delivery pipe 11 Fuel pump 14 Check valve 15 Fuel passage 15a Branch communication passage 16 Branch passage 20, 40, 60 Pressure regulator 21, 41, 61 Housing 21a Fuel introduction port 21b Fuel discharge port 21c Center port 22 Pressure regulating member 23, 43, 83 Pressure regulating chamber 25, 74 Movable valve body 26, 44, 84 Back pressure chamber 27 Compression coil spring 41a, 61a Fuel inlet 41b, 61b Return port 41c, 61c Operating pressure inlet port 42, 72 Bulkhead member 45 Fuel pressure regulating valve 46 Compression coil spring for high pressure setting 47 Pressure receiving member 48 Compression coil spring for pressure reduction 49, 75 Operation pressure chamber 62 Pressure regulating member 66 Compression coil spring for high pressure setting 71 Control valve 73 Compression coil spring 78 Depressurizing tension spring 82b Fuel discharge hole

Claims (8)

A fuel supply device that supplies fuel stored in a fuel tank to a fuel injection valve by a fuel pump and adjusts a supply pressure of fuel supplied to the fuel injection valve by a pressure regulator,
A supply pipe for supplying fuel pressurized by the fuel pump to the fuel injection valve;
A check valve provided in the supply pipe for blocking the flow of the fuel from the fuel injection valve to the fuel tank;
A first branch pipe branched from the supply pipe on the fuel injection valve side from the check valve, and supplying fuel from the supply pipe to the pressure regulator;
A second branch pipe that branches from the supply pipe on the fuel pump side than the check valve and supplies fuel from the supply pipe to the pressure regulator;
The pressure regulator includes a first fuel introduction port for introducing fuel from the first branch pipe, a second fuel introduction port for introducing fuel from the second branch pipe, and a fuel discharge port for discharging the introduced fuel. And a valve opening for defining a pressure regulating chamber communicating with the first fuel introduction port in the housing and communicating the pressure regulating chamber with the fuel discharge port in accordance with the fuel pressure in the pressure regulating chamber. A pressure regulating member that is displaced in the direction,
The pressure adjusting member is displaced in the valve opening direction when an operation pressure is applied by the fuel introduced through the second fuel introduction port, and the pressure of the fuel supplied to the fuel injection valve is increased on the high pressure side. The fuel supply device is characterized in that the set pressure is switched from the set pressure to the set pressure on the low pressure side.   2. The fuel supply device according to claim 1, wherein the pressure regulator introduces fuel from the second fuel introduction port by driving the fuel pump. 3. The pressure regulator has a biasing means for biasing the pressure regulating member in a valve closing direction for closing communication between the pressure regulating chamber and the fuel discharge port.
The set pressure on the high pressure side is determined by the urging force that the pressure adjusting member receives from the urging means in a state where fuel having an operating pressure is not supplied from the fuel pump via the second fuel introduction port. The fuel supply device according to claim 1, wherein:   The set pressure on the low pressure side is the difference between the biasing force of the biasing means on the pressure regulating member and the force applied to the pressure regulating member by the fuel having the operating pressure introduced from the second fuel introduction port. The fuel supply device according to claim 3, wherein the fuel supply device is determined by: The pressure regulator includes a control valve that is displaced according to an operating pressure of fuel introduced from the second fuel introduction port;
And another urging means for urging the pressure regulating member in the valve opening direction with an urging force corresponding to the displacement of the control valve,
The set pressure on the low pressure side is determined by a difference between an urging force of the urging unit with respect to the pressure adjusting member and an urging force of the other urging unit according to the displacement of the control valve. The fuel supply device according to claim 3.   2. The pressure regulator according to claim 1, wherein when the fuel pressure in the pressure regulating chamber exceeds the set pressure on the high pressure side in a non-driven state of the fuel pump, the pressure regulator decreases the set pressure on the high pressure side. The fuel supply device according to any one of claims 1 to 5.   The fuel introduced into the pressure regulator from the second fuel introduction port when the fuel pump is not driven can be returned to the fuel tank through the second branch pipe. The fuel supply device according to claim 6. The pressure regulator has a back pressure chamber defined on the side opposite to the pressure regulating chamber with respect to the pressure regulating member in the housing.
The fuel supply device according to any one of claims 1 to 7, wherein the back pressure chamber is held at an internal pressure of the fuel tank.

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