JP6832173B2 - Fuel supply device - Google Patents

Description

The present invention relates to a fuel supply device for a gas engine.

In a gas engine that uses gaseous fuel such as natural gas as fuel, it is known that the gaseous fuel supplied from the gaseous fuel source is compressed by an electric compressor using an electric motor as a drive source and supplied to an injector (for example). , Patent Document 1). Since the electric compressor can change the discharge amount per hour by changing the rotation speed of the electric motor, it is necessary to realize an appropriate discharge amount according to the operating state of the gas engine and the pressure of the gas fuel source. Can be done.

Japanese Unexamined Patent Publication No. 2014-159791

For the purpose of simplifying or downsizing the system, there are cases where it is desired to use the power of the output shaft of a gas engine instead of the electric motor as the drive source of the compressor. However, when the compressor is driven by the output of the gas engine, the number of revolutions of the compressor changes according to the number of revolutions of the gas engine, and the discharge amount of the compressor changes according to the number of revolutions of the compressor. A special configuration is required to control the fuel pressure to a predetermined value.

In view of the above background, it is an object of the present invention to drive a compressor by utilizing the output of a gas engine in a fuel supply device of a gas engine.

In order to solve the above problems, one aspect of the present invention is a fuel supply device for a gas engine, which is provided in a gas fuel passage connecting a gas fuel source and an injector, and a gas fuel passage provided with the gas engine. It is characterized by having a variable capacitance type and swash plate type compressor driven by receiving a driving force, and a pressure regulating valve provided between the compressor and the injector in the gas fuel passage.

According to this aspect, since the compressor is a variable capacitance type, the discharge amount is changed even when the rotation speed of the compressor changes according to the rotation speed of the gas engine, and the gas fuel on the downstream side of the compressor is changed. Pressure can be controlled. Further, the pressure of the gaseous fuel supplied to the injector is controlled with good stability by the pressure control by the pressure regulating valve.

Further, in the above aspect, the first pressure sensor that detects the downstream pressure of the pressure regulating valve, which is the pressure of the portion between the pressure regulating valve and the injector in the gas fuel passage, and the adjusting valve based on the downstream pressure of the pressure regulating valve. It is preferable to have a control device for controlling the opening degree of the pressure valve.

According to this aspect, the control device can control the pressure control valve downstream pressure to a desired value by controlling the opening degree of the pressure control valve based on the detected pressure control valve downstream pressure.

Further, in the above aspect, the control device includes a second pressure sensor that detects the upstream pressure of the pressure regulating valve, which is the pressure of the portion between the compressor and the pressure regulating valve in the gas fuel passage. The discharge amount of the compressor may be controlled based on the upstream pressure of the pressure valve.

According to this aspect, the control device can control the pressure regulating valve upstream pressure to a desired value by controlling the compressor based on the detected pressure regulating valve upstream pressure.

Further, in the above aspect, the control device may control the discharge amount of the compressor so that the pressure regulating valve upstream pressure has a predetermined pressure difference and becomes a higher value than the pressure regulating valve downstream pressure.

According to this aspect, since the pressure regulating valve upstream pressure is maintained high with respect to the pressure regulating valve downstream pressure, the pressure can be adjusted by the pressure regulating valve, and the value of the pressure regulating valve downstream pressure is stabilized.

Further, in the above aspect, the control device sets the required pressure of the pressure regulating valve downstream pressure based on the operating state of the gas engine, and the pressure regulating valve downstream pressure becomes the required pressure. It is good to control the opening degree.

According to this aspect, the pressure regulating valve can be controlled based on the operating state of the gas engine, and the downstream pressure of the pressure regulating valve can be controlled to a desired pressure according to the operating state of the gas engine.

Further, in the above aspect, the control device discharges the compressor so that the upstream pressure of the pressure regulating valve has a pressure difference of 0.5 MPa or more and 1.0 MPa or less from the required pressure and becomes a high value. It is good to control.

According to this aspect, the adjustment allowance by the pressure regulating valve becomes large, and the downstream pressure of the pressure regulating valve becomes more stable.

Further, in the above aspect, the compressor is provided to be rotatable and tiltable with respect to the rotation axis, and the angle between the swash plate and the plane orthogonal to the rotation axis can be 0 °. A bypass passage having a piston that reciprocates by rotation and connecting a portion of the gas fuel passage between the gas fuel source and the compressor and a portion between the compressor and the pressure regulating valve, and the bypass. It is preferable to have a first one-way valve provided in the passage, which allows the flow from the gas fuel source side to the injector side, while prohibiting the flow in the opposite direction.

According to this aspect, the compression of the gaseous fuel by the compressor can be stopped by setting the angle of the swash plate to 0 °. When the compressor is stopped, gaseous fuel flows around the compressor through the bypass passage.

Further, in the above aspect, it is preferable to have a clutch for connecting the rotating shaft and the output shaft of the gas engine.

According to this aspect, when the gas fuel is not compressed by the compressor, the clutch can be disengaged and the friction loss due to the rotation of the compressor can be omitted.

Further, in the above aspect, the control device may switch the clutch from the disengaged state to the connected state when the angle of the swash plate with respect to the plane orthogonal to the rotation axis is within a predetermined minimum range.

According to this aspect, when the angle with respect to the plane orthogonal to the rotation axis of the swash plate is in the minimum range, the rotation resistance of the compressor becomes small, so that the impact when engaging the clutch is reduced. As a result, the generation of collision noise and sudden pressure fluctuations of gaseous fuel are suppressed.

Further, in the above aspect, the first one-way valve prohibits the flow from the injector side to the gas fuel source side when the pressure difference on the injector side with respect to the pressure on the gas fuel source side is less than a predetermined value. On the other hand, when the pressure difference on the injector side with respect to the pressure on the gas fuel source side is equal to or greater than a predetermined value, it is preferable to allow the flow from the injector side to the gas fuel source side.

According to this aspect, the first one-way valve functions as a relief valve that releases the upstream pressure of the pressure regulating valve to the gas fuel source side of the first one-way valve, and an unintended increase in the upstream pressure of the pressure regulating valve is suppressed.

Further, in the above embodiment, the relief passage connecting the portion between the gas fuel source and the compressor and the portion between the compressor and the pressure regulating valve in the gas fuel passage and the relief passage are provided. A second one-way valve that allows flow from the injector side to the gas fuel source side while prohibiting reverse flow, and a pressure in the relief passage where the pressure on the injector side is applied to the gas fuel source side. It is preferable to have a relief valve that opens when the pressure is higher than a predetermined value.

According to this aspect, an unintended increase in the upstream pressure of the pressure regulating valve is suppressed.

According to the above configuration, in the fuel supply device of the gas engine, the compressor can be driven by utilizing the output of the gas engine.

Configuration diagram of the vehicle provided with the fuel supply device according to the first embodiment Schematic cross-sectional view of the compressor Cross-sectional view of the first one-way valve according to the modified example

Hereinafter, a vehicle to which the fuel supply device for the gas engine according to the present invention is applied will be described with reference to the drawings.

As shown in FIG. 1, the vehicle 1 has a gas engine 2 and a fuel supply device 3 for supplying gaseous fuel to the gas engine 2. The gaseous fuel is a known gaseous fuel such as natural gas, petroleum gas (auto gas), and hydrogen. In this embodiment, the gaseous fuel is natural gas. The gas engine 2 is a direct-injection internal combustion engine that directly supplies gaseous fuel to the combustion chamber 2A. The combustion chamber 2A may have a main chamber and a sub chamber having a small volume with respect to the main chamber, and gas fuel may be supplied to the sub chamber.

The fuel supply device 3 includes a gas tank 5 (gas fuel source) for storing gaseous fuel, an injector 6 for injecting gaseous fuel into the combustion chamber 2A, and a fuel passage 7 (gas fuel passage) connecting the gas tank 5 and the injector 6. And a compressor 10 provided in the fuel passage 7. A bypass passage 12 and a relief passage 13 are connected to the fuel passage 7 so as to bypass the compressor 10. The fuel passage 7, the bypass passage 12, and the relief passage 13 are each formed by piping.

The gas tank 5 stores gaseous fuel supplied from a fuel source outside the vehicle 1. The injector 6 is an electric injector that drives a valve body by an electric actuator such as a solenoid or a piezo element.

The compressor 10 may be a known variable capacitance type and swash plate type compressor 10. Further, it is preferable that the compressor 10 can take a no-load state in which the discharge amount becomes 0. As shown in FIG. 2, the compressor 10 has a cylindrical housing 21 extending back and forth, and a rotating shaft 22 rotatably supported by the housing 21 and having a front end projecting outward from the housing 21. At the rear portion of the housing 21, a plurality of cylinders 23 extending in parallel on the left and right sides and arranged so as to surround the rotating shaft 22 are formed. A piston 24 is received in each cylinder 23 so as to be reciprocating. A crank chamber 26 communicating with the front end of each cylinder 23 is formed in the front portion of the housing 21. A suction chamber 27 and a discharge chamber 28 are formed at the rear end of the housing 21. Each cylinder 23 communicates with each of the suction chamber 27 and the discharge chamber 28. A suction valve (not shown) that opens when the cylinder 23 side becomes low pressure with respect to the suction chamber 27 side is provided in the communication portion between the suction chamber 27 and the cylinder 23, and the cylinder is provided in the communication portion between the discharge chamber 28 and the cylinder 23. A discharge valve (not shown) that opens when the pressure on the 23 side becomes higher than that on the discharge chamber 28 side is provided. The suction chamber 27 communicates with a suction port (not shown) opened on the outer surface of the housing 21, and the discharge chamber 28 communicates with a discharge port (not shown) opened on the outer surface of the housing 21.

The rotary shaft 22 has a disc 22A protruding in the radial direction and an arm 31 protruding from the disc 22A toward the cylinder 23 so as to be integrally rotatable in a portion located in the crank chamber 26. The swash plate support 32 is rotatably supported on the arm 31 about an axis extending in the tangential direction of the rotating shaft 22, and the swash plate 33 is supported on the rear surface of the swash plate support 32 via a thrust bearing. There is. An opening is formed in the center of the swash plate support 32 and the swash plate 33, and the rotating shaft 22 extends through the center of the swash plate support 32 and the swash plate 33. The swash plate support 32 rotates integrally with the rotating shaft 22 and can swing with respect to the rotating shaft 22. The swash plate 33 is rotatable with respect to the swash plate support 32 and the rotating shaft 22, and is tiltable with respect to the rotating shaft 22. The swash plate support 32 and the swash plate 33 come into contact with the minimum inclined position where the angle formed by the swash plate 33 with the plane orthogonal to the rotation axis 22 is 0 °, and the swash plate support 32 abuts on the disk 22A. It can swing to and from the maximum tilt position.

A cylindrical slider 34 is supported on the outer periphery of the rotating shaft 22 so as to be slidable and rotatable in the axial direction. A pin 35 is projected from the outer periphery of the slider 34, and the pin 35 is rotatably connected to the swash plate support 32. A spring 36 for urging the slider 34 rearward with respect to the rotating shaft 22 is provided between the slider 34 and the rotating shaft 22. By urging the slider 34 by the spring 36, the swash plate support 32 and the swash plate 33 are urged toward the minimum inclined position.

The swash plate 33 is connected to each piston 24 via a plurality of connecting rods 38. Further, the swash plate 33 may be engaged with the inner wall of the housing 21 on the outer circumference so as not to rotate in the circumferential direction and slidably back and forth (not shown). When the rotating shaft 22 and the swash plate support 32 rotate, the swash plate 33 swings with respect to the rotating shaft 22, and each piston 24 connected to the swash plate 33 by the connecting rod 38 reciprocates.

The suction chamber 27 and the crank chamber 26 are connected by a suction pressure introduction passage 41, and the discharge chamber 28 and the crank chamber 26 are connected by a discharge pressure introduction passage 42. A common control valve 43 for opening and closing each passage is provided on the paths of the suction pressure introduction passage 41 and the discharge pressure introduction passage 42.

At the rear end of the rotating shaft 22, a bottomed tubular pressing member 45 is provided so as to be slidable in the circumferential direction and the axial direction with respect to the rotating shaft 22. A spring 46 is interposed between the pressing member 45 and the rear end of the rotating shaft 22, and the pressing member 45 is urged rearward with respect to the rotating shaft 22. The pressing member 45 is connected to an actuator 47 fixed to the housing 21. The actuator 47 is, for example, a solenoid, and can move the pressing member 45 forward against the urging force of the spring 46. The pressing member 45 is displaced between the rear position pushed most backward by the spring 46 and the front position pushed most forward by the actuator 47. When the pressing member 45 is in the rear position, the swash plate 33 can be located in the minimum tilt position.

The compressor 10 can change the discharge amount by controlling the control valve 43 and the actuator 47. The control valve 43 adjusts the pressure of the crank chamber 26 by connecting the suction chamber 27 or the discharge chamber 28 to the crank chamber 26, and changes the angle of the swash plate 33 by changing the back pressure of the piston 24. As a result, the stroke of the piston 24 changes and the discharge amount of the compressor 10 changes. When the swash plate 33 is in the minimum tilted position, the piston 24 does not stroke, the compressor 10 does not perform compression work (no load state), and the discharge amount becomes zero. When the tilt angle is increased from the state where the swash plate 33 is in the minimum tilt position, the actuator 47 is driven to move the pressing member 45 forward, and the pressing member 45 moves the swash plate support 32 to the maximum tilt position side. Press only the specified distance. As a result, gas is sucked into each cylinder 23, and a difference is generated between the suction pressure and the discharge pressure, so that the discharge amount can be controlled by the control valve 43. The control valve 43 controls the difference between the pressure on the cylinder 23 side of the piston 24 and the pressure on the crank chamber 26 side of the piston 24 by controlling the opening and closing of the suction pressure introduction passage 41 and the discharge pressure introduction passage 42, and controls the pressure difference of the swash plate 33. Change the angle. The discharge amount of the compressor 10 is determined by the stroke of the piston 24 according to the angle of the swash plate 33.

As shown in FIG. 1, the rotating shaft 22 of the compressor 10 is connected to the crankshaft 52, which is the output shaft of the gas engine 2, via a clutch 51. The clutch 51 may be, for example, an electromagnetic clutch that switches connection and disconnection by applying a voltage. The crankshaft 52, the clutch 51, the clutch 51, and the rotating shaft 22 may be connected via a power transmission mechanism such as a gear or a belt.

A pressure regulating valve 55 is provided between the compressor 10 and the injector 6 in the fuel passage 7. The pressure regulating valve 55 is a solenoid valve whose opening degree can be adjusted.

The bypass passage 12 is connected to a portion of the fuel passage 7 between the gas tank 5 and the compressor 10 and a portion between the compressor 10 and the pressure regulating valve 55. The bypass passage 12 is provided with a first one-way valve 56 that allows the flow from the gas tank 5 side to the injector 6 side while prohibiting the flow in the opposite direction.

The relief passage 13 is connected to a portion of the fuel passage 7 between the gas tank 5 and the compressor 10 and a portion between the compressor 10 and the pressure regulating valve 55. The relief passage 13 has a second one-way valve 57 that allows flow from the injector 6 side to the gas tank 5 side while prohibiting reverse flow, and the pressure on the injector 6 side is relative to the pressure on the gas tank 5 side. A relief valve 58 that opens when the value rises above a predetermined value is provided.

A first pressure sensor 61 for detecting the pressure in the fuel passage 7 at the portion between the pressure regulating valve 55 and the injector 6 in the fuel passage 7 is provided. A second pressure sensor 62 for detecting the pressure in the fuel passage 7 at the portion between the compressor 10 and the pressure regulating valve 55 in the fuel passage 7 is provided.

The fuel supply device 3 includes a compressor 10, a pressure regulating valve 55, and a control device 64 for controlling the clutch 51. Signals from the first pressure sensor 61 and the second pressure sensor 62 are input to the control device 64. The control device 64 acquires the downstream pressure of the pressure regulating valve, which is the pressure between the pressure regulating valve 55 and the injector 6 in the fuel passage 7, based on the first pressure sensor 61, and in the fuel passage 7 based on the second pressure sensor 62. The pressure control valve upstream pressure, which is the pressure between the compressor 10 and the pressure control valve 55, is acquired.

Further, the control device 64 includes an accelerator pedal sensor 66 that detects the amount of operation of the accelerator pedal provided in the vehicle 1, a vehicle speed sensor 67 that is provided in the vehicle 1 and detects the vehicle speed of the vehicle 1, and rotation of the gas engine 2. A signal from the engine speed sensor 68 that detects the number is input, and the control device 64 acquires the accelerator pedal position, the vehicle speed, and the engine speed.

The control device 64 controls the opening degree of the pressure regulating valve 55 based on the detected downstream pressure of the pressure regulating valve. Specifically, the control device 64 sets the required pressure regulating valve downstream pressure based on the operating state of the gas engine 2, and the pressure regulating valve 55 of the pressure regulating valve 55 is based on the required pressure regulating valve downstream pressure and the detected pressure regulating valve downstream pressure. Control the opening. The control device 64 may set the required pressure regulating valve downstream pressure based on the required output of the gas engine 2 calculated based on, for example, the accelerator pedal position, the vehicle speed, the engine rotation, and the like. The control device 64 performs feedback control based on the required pressure control valve downstream pressure and the detected pressure control valve downstream pressure, and controls the opening degree of the pressure control valve 55 so that the pressure control valve downstream pressure becomes the required pressure control valve downstream pressure. It is good to do it.

The control device 64 controls the discharge amount of the compressor 10 based on the upstream pressure of the pressure regulating valve. Specifically, the control device 64 controls the compressor 10 based on the required pressure regulating valve upstream pressure set based on the required pressure regulating valve downstream pressure and the detected pressure regulating valve upstream pressure. The control device 64 sets the required pressure regulating valve upstream pressure by adding a predetermined pressure difference value to the required pressure regulating valve downstream pressure, and performs feedback control based on the required pressure regulating valve upstream pressure and the detected pressure regulating valve upstream pressure. The discharge amount of the compressor 10 may be controlled so that the upstream pressure of the pressure regulating valve becomes the required upstream pressure of the pressure regulating valve. The required pressure regulating valve upstream pressure may be set to a value having a pressure difference of 0.5 MPa or more and 1.0 MPa or less from the required pressure regulating valve downstream pressure.

When controlling the compressor 10, the control device 64 drives the control valve 43 to change the angle of the swash plate 33 and change the discharge amount. Further, when the angle of the swash plate 33 is increased from 0 °, the control device 64 drives the actuator 47 to increase the angle of the swash plate 33 by the pressing member 45.

The control device 64 controls the disengagement and connection of the clutch 51. The control device 64 disengages and connects the clutch 51 within a predetermined minimum range where the angle of the swash plate 33 of the compressor 10 is a predetermined minimum range, that is, a range where the rotational load of the compressor 10 is minimized. The timing for disengaging and connecting the clutch 51 is preferably as small as the angle of the swash plate 33, and most preferably when the angle of the swash plate 33 is 0 °, that is, when the compressor 10 is in a no-load state. For example, the control device 64 disengages the clutch 51 when the angle of the swash plate 33 is 0 ° and the pressure regulating valve upstream pressure is equal to or higher than the required pressure regulating valve upstream pressure. Further, the control device 64 connects the clutch 51 when the angle of the swash plate 33 is 0 ° and the pressure regulating valve upstream pressure is equal to or less than the required pressure regulating valve upstream pressure. When the clutch 51 is disengaged, the rotational force of the crankshaft 52 is not transmitted to the rotating shaft 22 of the compressor 10, and the rotation of the rotating shaft 22 is stopped.

The operation and effect of the fuel supply device 3 configured as described above will be described. The control device 64 sets the required pressure regulating valve downstream pressure based on the operating state of the gas engine 2, and sets the required pressure regulating valve upstream pressure based on the required pressure regulating valve downstream pressure. Then, the compressor 10 is controlled based on the required pressure regulating valve upstream pressure and the detected pressure regulating valve upstream pressure, and at the same time, the pressure regulating valve 55 is controlled based on the required pressure regulating valve downstream pressure and the detected pressure regulating valve downstream pressure. .. As a result, the downstream pressure of the pressure regulating valve is adjusted to the required downstream pressure of the pressure regulating valve.

When the pressure regulating valve upstream pressure is the required pressure regulating valve upstream pressure and the angle of the swash plate 33 of the compressor 10 becomes 0 ° (no load state), the control device 64 disengages the clutch 51 and compresses the compressor 10. Stops operation. When the swash plate 33 of the compressor 10 is at 0 ° or the compressor 10 is stopped, the gaseous fuel cannot pass through the compressor 10 and flows through the bypass passage 12 to the pressure regulating valve 55. Such a state in which the gaseous fuel flows from the gas tank 5 through the bypass passage 12 to the pressure regulating valve 55 occurs when the residual pressure of the gas tank 5 is sufficiently high.

When the residual pressure of the gas tank 5 decreases and the pressure regulating valve upstream pressure becomes lower than the required pressure regulating valve upstream pressure, the control device 64 connects the clutch 51 to operate the compressor 10 and controls the control valve 43 to control the pressure regulating valve upstream. The angle of the swash plate 33 is increased so that the pressure becomes the required upstream pressure of the pressure regulating valve.

When the pressure regulating valve upstream pressure becomes equal to or higher than a predetermined relief pressure due to the operation of the compressor 10, the relief valve 58 opens, and the gaseous fuel passes through the relief passage 13 and flows to the gas tank 5 side. As a result, an excessive increase in the upstream pressure of the pressure regulating valve is suppressed.

The fuel supply device 3 can supply gaseous fuel at a desired pressure to the injector 6 by controlling the discharge amount of the compressor 10 and the opening degree of the pressure regulating valve 55. Since the compressor 10 can change the discharge amount by changing the angle of the swash plate 33, the discharge amount is also changed when the rotation speed of the compressor 10 changes according to the rotation speed of the gas engine 2. Therefore, the upstream pressure of the pressure regulating valve can be controlled.

Since the required pressure regulating valve upstream pressure is set to have a predetermined pressure difference with respect to the required pressure regulating valve downstream pressure, the pressure can be adjusted by the pressure regulating valve 55, and the pressure regulating valve downstream pressure is stabilized.

Since the rotation of the compressor 10 is stopped by the disengagement of the clutch 51, the friction loss associated with the rotation of the compressor 10 is omitted. Further, when the clutch 51 is disengaged and connected, the compressor 10 is in a no-load state, so that the impact caused by the disengagement and connection of the clutch 51 is reduced, and the generation of abnormal noise is suppressed. Further, a sudden change in the discharge amount of the compressor 10 is suppressed, and fluctuations in the pressure regulating valve upstream pressure and the pressure regulating valve downstream pressure are suppressed.

Although the description of the specific embodiment is completed above, the present invention can be widely modified without being limited to the above embodiment. For example, in the present embodiment, the relief passage 13 is provided in addition to the bypass passage 12, and the relief passage 13 is provided with the second one-way valve 57 and the relief valve 58. However, in other embodiments, the first one-way valve is provided. The relief passage 13, the second one-way valve 57, and the relief valve 58 may be omitted by allowing the 56 to have the function of the relief valve 58. In this case, as shown in FIG. 3, the first one-way valve 70 is bypassed so as to be seatable in the first valve seat 71 provided in the bypass passage 12 so as to face the gas tank 5 side and the first valve seat 71. Between the first valve body 72 provided in the passage 12 and seated on the first valve seat 71 to close the bypass passage 12, and between the first retainer 73 and the first valve body 72 fixed to the inner wall of the bypass passage 12. It has a relief portion 75 composed of a spring 74 for urging the first valve body 72 toward the first valve seat 71. The first valve body 72 is formed with a passage hole 72A penetrating in parallel with the extending direction of the bypass passage 12, and a second valve seat 72B is formed at the opening end of the passage hole 72A on the injector 6 side. Further, the first one-way valve 70 is provided in the bypass passage 12 so as to be seated on the second valve seat 72B, and is seated on the second valve seat 72B to close the passage hole 72A, and the bypass passage. A one-way valve portion provided between a second retainer 78 fixed to the inner wall of 12 and a second valve body 77, and composed of a spring 79 for urging the second valve body 77 toward the second valve seat 72B. Has 80. The spring 74 that urges the first valve body 72 has a larger spring constant than the spring 79 that urges the second valve body 77, and the first valve body is in a state where the second valve body 77 is seated on the second valve seat 72B. 72 is in a state of being seated on the first valve seat 71. When the pressure on the gas tank 5 side is equal to or higher than the pressure on the injector 6 side in the bypass passage 12, the second valve body 77 separates from the second valve seat 72B against the urging force of the spring 79, and the gas tank 5 The flow of gaseous fuel from the side to the injector 6 side is allowed. On the other hand, when the pressure on the injector 6 side is higher than the pressure on the gas tank 5 side in the bypass passage 12 within a range of a predetermined value or more and a relief pressure or less, the second valve body 77 is seated on the second valve seat 72B and is on the injector 6 side. The flow of gaseous fuel from the gas tank 5 to the gas tank 5 side is prohibited. When the pressure on the injector 6 side is higher than the relief pressure with respect to the pressure on the gas tank 5 side in the bypass passage 12, the first valve body 72 separates from the first valve seat 71 against the urging force of the spring 74, and the injector 6 side. Gas fuel flows from the gas tank 5 side.

Further, the compressor 10 may have various configurations, not limited to the configuration of the above embodiment. The compressor 10 may have a configuration in which the minimum inclination angle of the swash plate 33 is larger than 0 °.

1: Vehicle 2: Gas engine 2A: Combustion chamber 3: Fuel supply device 5: Gas tank 6: Injector 7: Fuel passage 10: Compressor 12: Bypass passage 13: Relief passage 33: Slanted plate 43: Control valve 47: Actuator 51 : Clutch 52: Crankshaft 55: Pressure regulating valve 56: First one-way valve 57: Second one-way valve 58: Relief valve 61: First pressure sensor 62: Second pressure sensor 64: Control device

Claims (10)

It is a fuel supply device for gas engines.
A gas fuel passage connecting the gas fuel source and the injector,
A variable displacement compressor and a swash plate compressor provided in the gas fuel passage and driven by the driving force of the gas engine.
A pressure regulating valve provided between the compressor and the injector in the gas fuel passage ,
A first pressure sensor that detects the downstream pressure of the pressure regulating valve, which is the pressure of the portion between the pressure regulating valve and the injector in the gas fuel passage, and
A fuel supply device including a control device that controls an opening degree of the pressure regulating valve based on the downstream pressure of the pressure regulating valve. It has a second pressure sensor that detects the upstream pressure of the pressure regulating valve, which is the pressure of the portion between the compressor and the pressure regulating valve in the gas fuel passage.
The fuel supply device according to claim 1 , wherein the control device controls the discharge amount of the compressor based on the upstream pressure of the pressure regulating valve. The control device in claim 2, wherein the pressure regulating valve upstream pressure controls the discharge amount of the compressor to a high value with a predetermined pressure differential than the pressure regulating valve downstream pressure The fuel supply device described. The control device sets the required pressure of the pressure regulating valve downstream pressure based on the operating state of the gas engine, and controls the opening degree of the pressure regulating valve so that the pressure regulating valve downstream pressure becomes the required pressure. The fuel supply device according to claim 3 , wherein the fuel supply device is characterized. The control device is characterized in that the discharge amount of the compressor is controlled so that the upstream pressure of the pressure regulating valve has a pressure difference of 0.5 MPa or more and 1.0 MPa or less from the required pressure and becomes a high value. The fuel supply device according to claim 4. The compressor is provided to be rotatable and tiltable with respect to a rotation axis, and includes a swash plate whose angle with a plane orthogonal to the rotation axis can be 0 °, and a piston that reciprocates due to the rotation of the sloping plate. Have,
A bypass passage connecting a portion of the gas fuel passage between the gas fuel source and the compressor and a portion between the compressor and the pressure regulating valve.
The fifth aspect of claim 5 , wherein the bypass passage is provided with a first one-way valve that allows a flow from the gas fuel source side to the injector side while prohibiting a reverse flow. Fuel supply device. The fuel supply device according to claim 6 , further comprising a clutch for connecting the rotary shaft and the output shaft of the gas engine. The control device according to claim 7 in which the switching from the disconnected state of the clutch to the connected state, the angle with respect to a plane perpendicular to the rotational axis of the swash plate and executes when within a predetermined minimum range The fuel supply device described in. The first one-way valve prohibits the flow from the injector side to the gas fuel source side when the pressure difference on the injector side with respect to the pressure on the gas fuel source side is less than a predetermined value, while the gas fuel source. The fuel supply device according to claim 7 or 8 , wherein the flow from the injector side to the gas fuel source side is allowed when the pressure difference on the injector side with respect to the pressure on the side is equal to or greater than a predetermined value. .. A relief passage connecting a portion of the gas fuel passage between the gas fuel source and the compressor and a portion between the compressor and the pressure regulating valve.
A second one-way valve provided in the relief passage, which allows the flow from the injector side to the gas fuel source side, while prohibiting the reverse flow.
One of claims 1 to 9 , wherein the relief passage is provided with a relief valve that opens when the pressure on the injector side is higher than a predetermined value with respect to the pressure on the gas fuel source side. The fuel supply device according to one section.

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