JPH0434220A - Hydraulic circuit structure of hydraulic control type clutch and transmission - Google Patents

Abstract

PURPOSE:To improve fuel cost efficiency of an engine by providing a means for controlling the amount of eccentricity of a cam ring to a variable capacity type pump, and changing the pump characteristics by leading a part of clutch control hydraulic oil which is controlled by pressure control solenoid valve into the control means. CONSTITUTION:Hydraulic oil PC2 which passes a first circuit 11 of discharge pressure oil of an oil pump 9 is always energized in the clutch disengaged condition. As for hydraulic oil which passes a second circuit 12, on the other hand, a solenoid selector valve 40 operates by command signals of a controller at the time of controlling a transmission, and supplies hydraulic oil PC3 to shift and select cylinder. At this time, supply of hydraulic oil PC1 to an hydraulic clutch CL is shut off. The hydraulic clutch is connected and controlled when a command current is applied to a pressure control solenoid valve 15 and high hydraulic oil PC1 is supplied to a second passage 7 after the transmission is controlled. Hydraulic oil PC1 is introduced into a cylinder 92b of the oil pump 9, pushes a cam ring 93 back by a piston, and controls the amount of eccentricity. Its pressure drops to the pressure D which is necessary for the control of hydraulic clutch CL.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a hydraulic circuit structure of a hydraulically controlled clutch transmission for an automobile.

<Prior Art> As shown in FIG. 4, the pressure oil discharged by the variable displacement pump 9 and the transmission TH, which is shift/select-controlled by the hydraulically controlled clutch C, the shift cylinder 41, and the select cylinder 42, is The present applicant has provided a mechanical automatic transmission controlled by a control unit such as a side-m electromagnetic valve or an electromagnetic switching valve in Japanese Patent Application No. 1-92809. As shown in FIG. 5, the variable displacement pump 9 used in this prior art has a rotor 96 with vanes 97 provided in a housing 98 so as to be slidable in the radial direction.
A cam ring 93 that surrounds the outer periphery of the rotor 96 and forms a pump chamber with the tip of a vane 97 in sliding contact with the rotor 96 is provided so as to be eccentrically movable with respect to the rotor 96, and the cam ring 93 is always kept eccentric. A cylinder 9 in which a piston 90 that pushes in a direction is provided in the housing 98.
The structure is such that it is slidable inside 2 and is pressed by a spring 91. 9a is a suction port, 9b is a discharge port, and 99 is a thrust roller.

<Problems to be Solved by the Invention> In the variable displacement pump 9 used in this prior art, when the discharge pressure increases and the force F applied to the cam ring 93 by the vane 97 increases, the spring 91 flexes and the cam ring 93 moves. The discharge flow rate decreases. As shown in FIG. 6, the pump characteristics of the discharge flow rate and pressure are determined by the set load of the spring 91, and the line B is determined by the spring constant of the spring 91.

By the way, 1. The flow rate of the pressure oil required to control the hydraulic clutch C [and the transmission TH is a certain constant flow rate, as shown by C in FIG.
The pressure E required to control the hydraulic clutch C is higher than the pressure required to control the hydraulic clutch C, and the working pressure must match the pressure E required to control the higher transmission TH. In the control pressure of the hydraulic clutch C[, a wasteful flow rate F is generated, and the fuel saving effect is small.

<Means for Solving the Problems> The present invention has been made to improve the above-mentioned problems, and its characteristic configuration is that a clutch is installed in a clutch cover connected to an engine crankshaft. A hydraulic clutch that biases a disc and a piston that presses the clutch disc in the clutch engagement direction, and constantly circulates and supplies pressure oil that presses the piston in the clutch disengagement direction within the clutch cover, and a hydraulic clutch that uses pressure oil to shift.・With a transmission that operates in select mode,
A variable displacement pump that sucks and discharges oil from an oil tank,
A first circuit that communicates with the discharge side of the variable displacement pump and a pressure oil supply side into the clutch cover, and a second circuit that communicates with the cylinder of the piston and the shift/select cylinder, the second circuit being connected to the piston. The variable displacement pump is equipped with a pressure control solenoid valve that controls the supply and discharge of pressure oil to the cylinder and a solenoid switching valve that controls the pressure oil to the shift/select cylinder. In addition to the means for pushing the cam ring, the cam ring has a means for controlling the eccentricity of the cam ring, and a part of the clutch control pressure oil controlled by the pressure control solenoid valve is guided to the eccentricity control means to change the pump characteristics. It is equipped with a pump discharge pressure control circuit.

Function> The above configuration not only ensures the flow rate of pressure oil necessary for controlling the clutch and transmission, but also controls the pressure to drop to the level necessary for controlling the clutch when controlling the clutch.

<Example> Hereinafter, an example of the present invention will be described based on the drawings. In FIG. 1, C[ is a hydraulic clutch.

This hydraulic clutch CF includes a clutch disc 2 in a clutch cover 1 connected to a crankshaft (circle) of an engine, and a piston 3 that presses the clutch disc 2 in the clutch connection direction. a first passage 5 for constantly circulating pressure oil into the internal space 4 to press the piston 3 in the clutch disengaging direction; and a first passage 5 for supplying and discharging pressure oil to the cylinder 6 of the piston 3. 2 passages 7.

8 is an oil tank, and a filter 18 is installed inside the oil tank.

9 is a variable displacement oil pump, and its suction port 9a
and the oil tank 8 are connected through a pipe line 19. Furthermore, a first circuit 11 communicating with the first passage 5 of the hydraulic clutch C1 and a second circuit 12 communicating with the second passage are branched and connected to the discharge port 9b of the oil pump 9.

The first circuit 11 is provided with a check valve 13 that controls the pressure oil PC2 constantly supplied to the space inside the clutch cover 1 to a constant pressure.

On the other hand, the second circuit 12 includes an electromagnetic switching valve 4 that controls the supply of pressure oil PC3 to the shift and select cylinders 41 and 42.
0 and the cylinder 6 of the piston 3 of the hydraulic clutch C[
A pressure control solenoid valve 15 is provided to control the supply and discharge of pressure oil PC1 to and from the pressure oil PC1.

All of the pressure oil discharged from the pressure control solenoid valve 15 is returned to the oil tank 8.

Further, the space 4 in the clutch cover 1 and the filter 18 in the oil tank 8 are connected by a pipe W&16, and the pipe line 16
A diaphragm 17 is installed. As shown in FIG. 2, the variable displacement oil pump 9 is rotatably provided with a rotor 96 in which a vane 797 is slidably provided in a radial direction within a housing 98. A cylinder 92a in which a cam ring 93 whose tip end slidably contacts to form a pump chamber is provided so as to be eccentrically movable with respect to the rotor 96, and a piston 90 which always pushes the cam ring 93 in an eccentric direction is provided in the housing 98.
A cylinder 9 having an eccentric direction pushing means for a cam ring which is slidable inside and pressed by a spring 91, and a pressure oil input boat 100 in a housing 98 on the opposite side.
2b, and a cam ring eccentricity control means comprising a piston 94 which is pressed by a spring 95 and comes into contact with the cam ring 93 inside the cylinder 92b.

Next, the operation of the above configuration will be explained. oil pump 9
The discharge pressure oil flows into the first circuit R11 and the second circuit 12, and the pressure oil flowing in the first circuit 11 is controlled to a constant pressure by the check valve 13 and 17, and the pressure controlled to this constant pressure is oil PC2
is supplied from the first passage 5 into the space 4 and presses the piston 3 in the clutch disengaging direction. Then, the pressure oil PC2 in the space 4 is returned to the oil tank 8 via the pipe line 16.

That is, the hydraulic clutch C[ is always biased to the clutch disengaged state by the pressure oil PC2 passing through the first circuit 11. On the other hand, when the pressure oil flowing into the second circuit 12 controls the transmission TN, the electromagnetic switching valve 40 is activated by a command signal from the circuit controller, and the pressure oil PC3 is supplied to the shift and select cylinders 41 and 42. Ru. At this time, the supply of pressure oil PC1 to the hydraulic clutch C[ is cut off, so the pressure oil PC1 is not introduced into the cylinder 92b of the oil pump 9.

Therefore, the cam ring 93 of the oil pump 9 is
It is pushed in the eccentric direction by a spring 91 of 2a 1m, and has the pump characteristics shown by the line Bl in FIG. 3, and has a discharge pressure of pressure E necessary for controlling the transmission TH.

Hydraulic clutch C[ after control of transmission TN
The connection is such that a command current is applied from the circuit controller to the pressure control solenoid valve 15, and pressure oil PC1 having a higher pressure than the pressure oil PC2 is supplied to the 2311i path 7 according to the applied electromagnetic value to advance the piston 3. The clutch is connected slowly or quickly depending on the driving condition.

When the clutch is connected, the pressure oil PC1 is introduced from the pipe 51 into the cylinder 92b of the oil pump 9, and the piston 94 pushes back the cam ring 93 to control the amount of eccentricity to be reduced. As a result, the pump characteristics change to line B2 in Figure 3, and the discharge pressure of the oil pump 9 changes to the hydraulic clutch C[
The pressure will drop to the level required for control. The pressure E required to control the transmission IM and the pressure required to control the hydraulic clutch C[, which is controlled lower than this pressure E, are determined by the pressure E required for controlling the transmission TI4 and the hydraulic clutch C[, as shown in FIG. Control is performed after securing the necessary flow rate C.

<Effects of the Invention> As described above, according to the present invention, the clutch cover connected to the crankshaft of the engine is provided with a clutch disc and a piston that presses the clutch disc in the clutch #parent direction, and the clutch A hydraulic clutch constantly circulates and supplies pressure oil inside the cover that pushes the piston in the direction of clutch disengagement, and a shift/shift mechanism using the pressure oil.
In a transmission that performs select operation, a variable displacement pump that sucks and discharges oil from an oil tank, a first circuit that communicates with the discharge side of the variable displacement pump and a pressure oil supply side into the clutch cover, a cylinder of a piston, and a second circuit that communicates with the shift/select cylinder; the second circuit includes a pressure control solenoid valve that controls the supply and discharge of pressure oil to the cylinder of the piston; and an electromagnetic switch that controls the pressure oil to the shift/select cylinder. In addition to means for pushing the cam ring in the eccentric direction with a constant spring constant, the variable displacement pump has means for controlling the amount of eccentricity of the cam ring, and the eccentric amount control means is provided with a means for controlling the eccentricity of the cam ring. Since the configuration has a small pump discharge pressure control circuit that guides a part of the clutch control pressure oil controlled by the control solenoid valve and changes the pump characteristics, when the hydraulic clutch is engaged, the hydraulic pressure of the hydraulic clutch working pressure oil PC1 is reduced. This controls the eccentricity of the cam ring of the variable displacement oil pump, and the discharge pressure is controlled to the pressure required for the hydraulic clutch, which is lower than the pressure required to control the transmission. There is no waste in flow rate, and the driving force of the variable displacement oil pump is more labor-saving than before.
Improves engine fuel efficiency.

[Brief explanation of the drawing]

FIG. 1 shows an embodiment of the present invention, in which a control circuit is integrated into a hydraulic clutch, FIG. 2 is a sectional view of a variable displacement oil pump used in the present invention, and FIG. 3 is a variable displacement type oil pump in the present invention. Pump characteristic diagram of the oil pump, Figure 4 is a cross-sectional side view of a hydraulically controlled clutch/transmission, Figure 5 is a cross-sectional view of a conventional variable displacement oil pump, and Figure 6 is a pump of a conventional variable displacement oil pump. The characteristic diagram, FIG. 7, is a diagram showing wastage of pressure oil flow rate when a clutch/transmission is operated by a conventional variable displacement oil pump. 1...Clutch cover, 2...Clutch disc,
3... Piston, 4... Space, 5... First passage,
6... Cylinder, 7... Second passage, 8... Oil tank, 9... Oil pump, 11... First circuit,
12...Second circuit, 13...Check valve, 15...
・Pressure control solenoid valve, 40...Solenoid switching valve, 90...
Piston, 91...Spring, 92a, 92b...
...Cylinder, 94...Piston, 95...Spring, 100...Pressure oil input boat. Patent application Hito Hino Motors Co., Ltd.

Claims (1)

[Claims] A clutch cover connected to the engine crankshaft includes a clutch disc and a piston that presses the clutch disc in the direction of clutch engagement, and pressurized oil is constantly supplied within the clutch cover to press the piston in the direction of clutch disengagement. In the hydraulic clutch that circulates and supplies the oil, and in the transmission that performs shift/select operations using pressure oil, there is a variable displacement pump that sucks and discharges oil from the oil tank, and a variable displacement pump that pumps oil into the discharge side of the variable displacement pump and into the clutch cover. A first circuit that communicates with the pressure oil supply side and a second circuit that communicates with the cylinder of the piston and the shift/select cylinder, and the second circuit includes a pressure control solenoid valve that controls the supply and discharge of pressure oil to and from the cylinder of the piston. and an electromagnetic switching valve for controlling pressure oil to the shift/select cylinder. and a pump discharge pressure control circuit for guiding a part of the clutch control pressure oil controlled by the pressure control solenoid valve to the eccentricity control means and changing pump characteristics. Hydraulic circuit structure of a clutch transmission.