JPH0643231U - Hydraulic governor - Google Patents

Abstract

(57) [Summary] [Structure] A power piston 3 built in the housing 2 and connected to the fuel injection device, and the housing 2 thereof.
Built in the power piston 3 and hydraulic pump 10
Between the control valve 19, a compensating piston 4 incorporated in the housing 2 of the control valve 19 and interlocking with the power piston 3, and a pair of oil chambers partitioned by the compensating piston 4 and communicating with the tank 7. 5, 5 and a variable throttle valve 8 interposed between one of the oil chambers 5 and the tank 7. A communication passage 40 that connects the one oil chamber 5 side and the other oil chamber 6 side is provided. The communication passage 40 is opened and closed by the compensating piston 4, and is opened when the power piston 3 is displaced from the idle position by a certain amount or more in the fuel reducing direction. [Effect] Prolonged settling time and engine stalling during sudden deceleration of the engine can be prevented without impairing the compensator function.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a hydraulic governor that controls the fuel injection amount of a diesel engine according to the engine speed.

[0002]

[Prior art]

 A conventional hydraulic governor 101 shown in FIG. 3 includes a housing 102, a power piston 103 that is built in the housing 102 and is connected to a fuel injection device (not shown), and a power piston that is built in the housing 102 and is also a power piston. 103 and a hydraulic pump 104, a control valve 105, a compensating piston 108 which is built into the housing 102 of the control valve 105 and is connected to the power piston 103 via compression springs 106 and 107, and the compensating piston. A pair of oil chambers 110 and 111, which are partitioned by 108 and communicate with the tank 109, and a variable throttle valve 112 interposed between the one oil chamber 110 and the tank 109 are provided.

The spool 105a of the control valve 105 is interlocked with the flyweight 113, and is displaced upward in the figure as the engine speed increases, and the displacement of the spool 105a causes the pump 104 to move to the oil chamber 114 above the power piston 103. High-pressure oil is supplied from the power piston 103, the power piston 103 is displaced downward in the figure, and the displacement of the power piston 103 reduces the fuel injection amount. Further, the spool 105a is displaced downward in the figure when the engine speed decreases, and the movement of the spool 105a also supplies high-pressure oil to the oil chamber 115 below the power piston 103, so that the power piston 103 is It is displaced upward and upward, and the displacement of the power piston 103 increases the fuel injection amount.

Due to the displacement of the power piston 103 in the fuel decrease direction, the volume of one oil chamber 110 partitioned by the compensating piston 108 increases. Due to the increase in the volume of the oil chamber 110, the oil pressure between the one oil chamber 110 and the variable throttle valve 112 becomes a negative pressure. By applying this negative pressure to the spool 105a of the control valve 105, the displacement of the spool 105a downward in the figure, that is, in the fuel increasing direction is promoted. Further, the displacement of the power piston 103 in the fuel increasing direction reduces the volume of the one oil chamber 110. Due to the decrease in the volume of the oil chamber 110, the oil pressure between the one oil chamber 110 and the variable throttle valve 112 becomes a positive pressure. The positive pressure acts on the spool 105a of the control valve 105, so that the displacement of the spool 105a in the upper part of the drawing, that is, in the fuel reducing direction is promoted. With this compensator function, the response speed of the change of the fuel injection amount to the change of the engine speed becomes faster, and the hunting is prevented. Further, the adjustment time of the engine speed is adjusted by adjusting the opening of the variable throttle valve 112.

[0005]

[Problems to be solved by the device]

 In order to prevent hunting of the engine, it is preferable to reduce the opening of the variable throttle valve 112, but if the opening is too small, the settling time becomes long when the engine is rapidly decelerated from the high speed range to the low speed range. There was a problem that it stalls with. That is, when the engine is rapidly decelerated, it takes time to decelerate because the difference in the number of revolutions is large. Then, the hydraulic pressure between the one oil chamber 110 partitioned by the compensating piston 108 and the variable throttle valve 112 becomes a negative pressure as described above at the beginning of deceleration, but via the variable throttle valve 112 with the passage of time. Oil flows in from the tank 109 and becomes a positive pressure. Then, the positive pressure prevents the compensating piston 108 from displacing upward in the figure, and the displacement of the power piston 103 interlocking with the compensating piston 108 in the fuel increasing direction is prevented, It takes a long time to set the engine speed, and the engine stalls easily.

An object of the present invention is to provide a hydraulic governor capable of solving the above-mentioned problems of the conventional technology.

[0007]

[Means for Solving the Problems]

 The first aspect of the present invention is characterized in that a housing, a power piston that is built in the housing and is connected to a fuel injection device, and a control that is built in the housing and is interposed between the power piston and the hydraulic pump. A valve, a compensating piston that is built into the housing and that works with the power piston, a pair of oil chambers that are partitioned by the compensating piston and that communicate with the tank, and an intervening valve between one of the oil chambers and the tank. And a variable throttle valve that controls the fuel injection amount by operating the power piston according to the displacement of the control valve according to the engine speed, and by adjusting the displacement of the power piston in the fuel decrease direction. The volume of the chamber is increased and the control valve can be connected to one oil chamber. In the hydraulic governor to which the hydraulic pressure between the throttle valves acts, a communication passage that connects the one oil chamber side and the other oil chamber side is provided, and the communication passage is opened and closed by the compensating piston. The point is that the power piston is opened by a certain amount of displacement from the idle position in the fuel reduction direction.

The second aspect of the present invention is characterized in that a housing, a power piston that is built in the housing and is connected to the fuel injection device, and a space between the power piston and the hydraulic pump that is built in the housing. An intervening control valve, a compensating piston built into the housing and interlocking with the power piston via a compression spring, a pair of oil chambers that are partitioned by the compensating piston and communicate with the tank, and the oil It is equipped with a variable throttle valve interposed between one of the chambers and the tank.The displacement of the control valve according to the engine speed operates the power piston to adjust the fuel injection amount, and in the direction of decreasing fuel of the power piston. Displacement increases the volume of the one oil chamber, In the hydraulic governor in which the hydraulic pressure between one of the oil chambers and the variable throttle valve acts on the valve, a regulating member is built in the other of the pair of oil chambers, and this regulating member reduces the fuel consumption of the power piston from the idle position. If it is displaced by a certain amount or more in the direction, the displacement of the compensating piston in the fuel decrease direction is restricted. In this case, it is preferable that the control member is constituted by a cam, the cam can be rotationally operated from the outside of the housing, and the rotation of the cam adjusts the regulation amount of the displacement of the power piston in the fuel reducing direction.

[0009]

[Action]

 According to the configuration of the first aspect of the present invention, when the power piston is displaced from the idle position in the fuel reducing direction by a certain amount or more, the communication passage of the pair of oil chambers partitioned by the compensating piston is opened. When the communication passage is opened, the space between one oil chamber and the variable throttle valve communicates with the tank via the other oil chamber side, so there is no positive pressure, and there is no increase in the fuel increase direction of the compensating piston. It is possible to prevent generation of pressure that prevents displacement. As a result, it is possible to prevent the displacement of the power piston interlocking with the compensating piston in the direction of increasing fuel during the sudden deceleration of the engine, and to prevent the engine speed from settling longer and stalling. Also, if the power piston position is on the fuel increase side relative to the idle position where the engine speed becomes the idling speed, the communication passage is closed by the compensating piston, so the compensator function is not impaired. Absent.

According to the configuration of the second aspect of the present invention, when the power piston is displaced from the idle position in the fuel reducing direction by a certain amount or more, the compensating piston comes into contact with the restricting member, and the power piston is displaced in the fuel reducing direction. Be blocked. Further, the compression spring interposed between the compensating piston and the power piston is elastically deformed when the displacement of the compensating piston is restricted by the restricting member, so that the elastic force acts on the power piston. As a result, the power piston linked to the compensating piston can be quickly returned to the direction of increasing fuel, and the settling time and engine stall during sudden deceleration of the engine can be prevented. Also, when the power piston position is on the fuel increase side relative to the idle position where the engine speed becomes the idling speed, displacement of the compensating piston in the fuel decrease direction is not blocked, so the compensator is not blocked. There is no loss of functionality. By configuring the restricting member with a cam, the restricting amount of the displacement of the compensating piston in the fuel reducing direction can be adjusted and set to an optimum value.

[0011]

【Example】

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

The hydraulic governor 1 shown in FIG. 1 includes a housing 2, and a power piston 3 is built in the housing 2. The power piston 3 is connected via a link mechanism 3a to an output lever 3b that is swingably attached to the housing 2 around the output shaft 3c, and the output lever 3b is used in a fuel injection device such as a fuel injection pump or a unit injector. It is connected to a control rack (not shown). A pair of oil chambers 15 and 16 partitioned by the power piston 3 are formed in the housing 2. The pressure receiving area of the power piston 3 is smaller in the oil chamber 15 on the upper side in the drawing than in the oil chamber 16 on the lower side 16.

A hydraulic pump 10 is built in the housing 2. The pump 10 is a gear pump having a driving gear 11 and a driven gear 12 that mesh with each other. The driving gear 11 is driven by an engine, and the driven gear 12 is a sleeve 13 rotatably inserted in a housing. It is integrated. A flyweight 18 is attached to the upper end of the sleeve 13, and the flyweight 18 is connected to the spool 14. The spool 14 and the sleeve 13 constitute a control valve 19. When the sleeve 13 is rotated by the rotation of the engine and the flyweight 18 is displaced by centrifugal force, the spool 14 is displaced in the vertical direction in the figure according to the displacement amount. Pressure oil is supplied from the pump 10 to the power piston 3 via the control valve 13.

Further, the housing 2 has a compensating piston 4 built therein. A connecting rod 30 is integrated with the compensating piston 4, the rod 30 is inserted into the power piston 3, and a compression spring 31 is sandwiched between a flange 30 a provided on the outer periphery of the rod 30 and the power piston 4. , 32 are provided. A pair of oil chambers 5, 6 which are partitioned by the compensating piston 4 and communicate with the tank 7 are formed in the housing 2. A needle valve (variable throttle valve) 8 is interposed between the one oil chamber 5 and the tank 7.

The one oil chamber 5 partitioned by the compensating piston 4 and the need valve 8 communicate with the insertion hole 13 ′ of the sleeve 13 of the control valve 19. As a result, the hydraulic pressure between the one oil chamber 5 and the needle valve 8 acts on the spool 14 of the control valve 19.

The spool 14 of the control valve 19 is displaced upward in the figure as the engine speed increases, and the displacement of the spool 14 causes an oil passage that connects the control valve 19 and the oil chamber 16 below the power piston 3 to each other. 16a is connected to the tank 7, and high-pressure oil is supplied from the pump 10 to the oil chamber 15 above the power piston 3 through the oil passage 15a. As a result, the power piston 3 is displaced downward in the figure, and the displacement of the power piston 3 reduces the fuel injection amount and the engine speed. Further, the spool 14 is displaced downward in the figure when the engine speed decreases, and the displacement of the spool 14 causes the oil passage 16a that connects the control valve 19 and the oil chamber 16 below the power piston 3 to the pump 10. High pressure oil is also supplied from the pump 10 to the oil chamber 16 on the lower side of the power piston 3. As a result, the power piston 3 is displaced upward in the figure, and the displacement of the power piston 3 increases the fuel injection amount and the engine speed.

Due to the fuel decrease direction of the power piston 3, that is, the downward displacement in the figure, the volume of one oil chamber 5 partitioned by the compensating piston 4 increases. Due to the increase in the volume of the oil chamber 5, the hydraulic pressure between the one oil chamber 5 and the needle valve 8 becomes a negative pressure. This negative pressure acts on the spool 14 of the control valve 19 to promote the displacement of the spool 14 downward in the drawing, that is, in the fuel increasing direction. Further, the displacement of the power piston 3 in the fuel increasing direction, that is, the upward displacement in the figure reduces the volume of one oil chamber 5 partitioned by the compensating piston 4. Due to the decrease in the volume of the oil chamber 5, the oil pressure between the one oil chamber 5 and the needle valve 8 becomes a positive pressure. The positive pressure acts on the spool 14 of the control valve 19 to promote the displacement of the spool 14 in the upper direction of the drawing, that is, in the fuel reducing direction. With this compensator function, the response speed of the change of the fuel injection amount to the change of the engine speed becomes faster and hunting is prevented. Further, by adjusting the opening of the needle valve 8, the settling time of the engine speed is adjusted.

Further, a control lever 25 is swingably attached to the housing 2, and a compression spring 27 is connected to the control lever 25 via a link mechanism 26. The spring 27 forms the spool 14 of the control valve 19 as shown in FIG. An elastic force that pushes in the middle downward direction, that is, in the direction of increasing fuel, is applied. The elastic force is changed by operating the control lever 25. As a result, when the control lever 25 is operated, the spool 14 is displaced and the engine speed changes.

A communication passage 40 is provided that connects one oil chamber 5 partitioned by the compensating piston 4 and the other oil chamber 6 to each other. The communication passage 40 is closed by the compensating piston 4 in the state shown in FIG. From this state, when the power piston 3 is displaced beyond the idle position by a certain amount in the fuel decrease direction, the compensating piston 4 interlocked with the power piston 3 is displaced downward, the communication passage 40 is opened, and the oil chambers 5 and 6 are separated from each other. Communicate.

As a result, when the power piston 3 is displaced in the fuel reduction direction from the idle position and the communication passage 40 is opened during sudden deceleration of the engine, the oil passage between the one oil chamber 5 and the needle valve 8 is changed to the other oil. Since it communicates with the tank 7 through the chamber 6 side, it does not become a positive pressure. That is, it is possible to prevent the generation of the pressure that prevents the displacement of the compensating piston 4 in the fuel increasing direction. As a result, it is possible to prevent the engine rotation speed from being settled for a long time or to stall during sudden engine deceleration. Further, when the position of the power piston 3 is on the fuel increase side relative to the idle position where the engine speed becomes the idling speed, the communication passage 40 is closed, so the compensator function is not impaired, and engine hunting is performed. Can be effectively prevented.

A shim 45 (regulating member) is built in the other oil chamber 6 partitioned by the compensating piston 4. The shim 45 contacts the rod 30 of the compensating piston 4 when the power piston 3 is displaced from the idle position by a certain amount or more in the fuel reducing direction, and the compensating piston 4 is displaced in the fuel reducing direction. Block. Further, the one compression spring 31 interposed between the compensating piston 4 and the power piston 3 is elastically deformed when the displacement of the compensating piston 4 is restricted by the shim 45, so that the elastic force is increased. It acts on the piston 3. As a result, the power piston 3 that is driven by the compensating piston 4 can be quickly returned to the direction of increasing fuel, and the settling time and the engine stall during the sudden deceleration of the engine can be prevented. When the position of the power piston 3 is on the fuel increase side of the idle position where the engine speed becomes the idling speed, the shim 45 prevents the displacement of the compensating piston 4 in the fuel decrease direction. Therefore, the compensator function is not impaired and engine hunting can be effectively prevented. The position where the compensating piston 4 is restricted from being displaced by the shim 45 in the fuel reducing direction is located below the position where the compensating piston 4 opens the communication passage 40, that is, on the fuel reducing direction side. The communication passage 40 is open when the compensating piston 4 is restricted from being displaced in the fuel reducing direction by the shim 45.

2 (1) and 2 (2) show different embodiments. The difference from the above embodiment is that the displacement of the compensating piston 4 in the fuel reducing direction is changed by the cam 45 'instead of the shim 45. The point is to regulate. That is, the cam 45 'is rotatably inserted around the support shaft 46 in the housing 2, the end of the support shaft 46 projects outside the housing 2, and the plate 47 is fixed to the projecting end. The plate 47 is provided with a long hole 48 located concentrically with the support shaft 46, and the plate 47 is fixed to the housing 2 by a screw 49 inserted into the long hole 48. As a result, when the screw 49 is loosened and the plate 47 is rotated, the cam 45 'rotates around the support shaft 46. By rotating the cam 45 ', the amount of regulation of the displacement of the compensating piston 4 in the fuel reducing direction can be adjusted and set to an optimum value.

[0023]

[Effect of device]

 According to the hydraulic governor of the present invention, it is possible to prevent the settling time from being prolonged and the engine to be stopped during a sudden deceleration of the engine without impairing the compensator function for preventing the engine hunting.

[Brief description of drawings]

FIG. 1 is an explanatory diagram of a configuration of a hydraulic governor according to an embodiment of the present invention.

FIG. 2 is a partial sectional view and a partial side view of a hydraulic governor according to another embodiment of the present invention.

FIG. 3 is a structural explanatory view of a conventional hydraulic governor.

[Explanation of symbols]

 1 Hydraulic Governor 2 Housing 3 Power Piston 4 Compensating Piston 5 One Oil Chamber 6 The Other Oil Chamber 8 Variable Throttle Valve 40 Communication Passage 45 Regulation Member 45 'Cam

Claims (3)

[Scope of utility model registration request] 1. A housing, a power piston incorporated in the housing and connected to a fuel injection device, a control valve incorporated in the housing and interposed between the power piston and a hydraulic pump, and the housing. A built-in compensating piston that works with the power piston, a pair of oil chambers that are partitioned by the compensating piston and that communicate with the tank, and a variable throttle valve that is interposed between one of the oil chambers and the tank. The power piston is actuated by the displacement of the control valve according to the engine speed to adjust the fuel injection amount, and the displacement of the power piston in the fuel decrease direction increases the volume of the one oil chamber, Hydraulic pressure between one oil chamber and the variable throttle valve acts on the control valve. In the hydraulic governor, a communication passage that connects the one oil chamber side and the other oil chamber side is provided,
The hydraulic governor is characterized in that the communication passage is opened and closed by the compensating piston and is opened when the power piston is displaced from the idle position by a certain amount in the fuel reducing direction. 2. A housing, a power piston incorporated in the housing and connected to the fuel injection device, a control valve incorporated in the housing and interposed between the power piston and a hydraulic pump, and the housing. A built-in compensating piston that interlocks with the power piston via a compression spring,
A pair of oil chambers that are partitioned by the compensating piston and communicate with the tank, and a variable throttle valve that is interposed between one of the oil chambers and the tank are provided, and the control valve is displaced according to the engine speed. The power piston operates to adjust the fuel injection amount, the displacement of the power piston in the fuel decrease direction increases the volume of the one oil chamber, and the control valve causes the volume between the one oil chamber and the variable throttle valve to be increased. In the hydraulic governor in which hydraulic pressure acts, a regulating member is built in the other of the pair of oil chambers, and the regulating member reduces the fuel of the compensating piston when the power piston is displaced from the idle position by a certain amount in the fuel reducing direction. A hydraulic governor that regulates displacement in the direction. 3. The regulating member is constituted by a cam, and the cam is rotatable from the outside of the housing, and the regulating amount of the displacement of the power piston in the fuel reducing direction is adjusted by the rotation of the cam. The hydraulic governor according to claim 2.