JPH0819987B2 - Control device for hydraulic clutch - Google Patents

Description

TECHNICAL FIELD The present invention relates to a control device for a hydraulic clutch of an automobile.

<Prior Art> A flywheel fixed to a crankshaft of an engine is provided with a clutch disc provided on an input shaft.
A hydraulic clutch in which a hydraulically actuated piston provided on the back side of the clutch is pressed in the clutch connecting direction to press the clutch disc in the clutch disengaging direction by a spring force is known, for example, from Japanese Utility Model Publication No. Sho 59-88524.

In the hydraulic clutch described above, a hydraulically actuated piston is used to engage and disengage the clutch, but the clutch disengagement operation is performed by a spring, so that there is a problem in the responsiveness of clutch engagement and disengagement.

Further, the hydraulic clutch is a so-called dry type, and it is necessary to take measures against wear of the clutch disc that is repeatedly and severely pressed by the hydraulic piston.

In order to solve these problems, a wet hydraulic clutch in which an oil spray is provided in a clutch cover in which a clutch disk and a hydraulically actuated piston are installed, and oil is sprayed toward the clutch disk by this oil spray. The applicant of the present application is Japanese Patent Application No. 62-7419.
It is provided in No. 4.

<Problems to be Solved by the Invention> However, in the above-mentioned conventional technique, the control device for the hydraulic clutch is two oil pumps, a large number of electromagnetic control valves, a flow control valve, and a complicated piping circuit structure. In addition to the fact that the inspection cannot be easily obtained, there is a problem that the size is increased, the weight is increased, the cost is increased, and a clutch engagement shock occurs when the clutch is engaged at the forward end of the hydraulically actuated piston.

<Means for Solving the Problems> The present invention has been made to solve the above-mentioned problems, and has a characteristic configuration in that a clutch is provided in a clutch cover connected to a crankshaft of an engine. In a hydraulic clutch that includes a disc and a piston that presses this clutch disc in the clutch connecting direction, and constantly supplies pressure oil that presses the piston in the clutch disengaging direction into the clutch cover, the oil in the oil tank The first circuit includes a variable displacement pump that sucks and discharges, a first circuit that communicates with a discharge side of the variable displacement pump and a pressure oil supply side into the clutch cover, and a second circuit that communicates with a cylinder of a piston. First, a first pressure control solenoid valve for controlling the pressure of the second circuit to be raised and lowered and the pressure oil supplied into the clutch cover are controlled to a constant pressure. A relief valve is provided, and a second pressure control solenoid valve for controlling the supply and discharge of pressure oil to and from the cylinder of the piston is provided in the second circuit. Between the second pressure control solenoid valve and the cylinder of the piston. The pressure oil circuit is provided with a pressure control valve for temporarily reducing the back pressure of the cylinder as a signal pressure at the forward end of the piston.

<Operation> With the above configuration, a wet hydraulic clutch is controlled by one oil pump, two pressure control solenoid valves, one relief valve and one pressure control valve. In addition, a simple piping circuit is possible, and the pressure of the pressure oil supplied to the cylinder is controlled by the pressure control valve to reduce the pressure in the cylinder when the clutch at the piston forward end is engaged, thereby reducing the clutch engagement shock. Is.

<Examples> Examples of the present invention will be described below with reference to the drawings. First
In the figure, C is a hydraulic clutch. This hydraulic clutch C includes a clutch disc 2 in a clutch cover 1 connected to a crankshaft (not shown) of an engine,
A piston 3 for pressing the clutch disk 2 in the clutch connection direction, and a space 4 in the clutch cover 1.
A first passage 5 for supplying pressure oil for constantly circulating supply of pressure oil to press the piston 3 in the clutch disengaging direction
And a second for supplying and discharging pressure oil to and from the cylinder 6 of the piston 3.
And a passage 7.

The present invention is a device for controlling the hydraulic clutch C having the above-mentioned configuration, and its configuration is as follows. Reference numeral 8 denotes an oil tank in which a filter 18 is installed.

9 is a variable displacement type oil pump, and its suction side 9a
And the oil tank 8 are connected by a pipe 19.
The discharge side 9b of the oil pump 9 has a first circuit 11 communicating with the first passage 5 of the hydraulic clutch C and a second circuit 11 communicating with the second passage.
The circuit 12 is branched and connected.

The first circuit 11 includes a first pressure control solenoid valve 13 for controlling the pressure of the second circuit 12 to move up and down, and a first pressure control solenoid valve.
A relief valve 14 for controlling the pressure oil PC1 constantly supplied to the space inside the clutch cover 1 to a constant pressure is provided between 13 and the first passage 5. 40 is the relief valve 14
It is a pipeline connecting the first circuit 11 and the pipeline 19 via the.

Pressure oil between the second pressure control solenoid valve 15 and the cylinder 6
The circuit 20 of pc1 is provided with a pressure control valve 22 for temporarily reducing the back pressure of the cylinder 6 as a signal pressure.

This pressure control valve 22 has a spool valve 23 that opens and closes between the inlet port 22a and the outlet port 22b of the pressure oil pc1, one end of which has a large pressure receiving surface 23a with a large pressure receiving area, and the other end of which has a pressure receiving area. Forming a small pressure receiving surface 23b.

An orifice 29 is provided in the circuit 20 on the cylinder 6 side from the outlet port 22b, and the downstream side of the orifice 29 and the rear chamber 24b on the large pressure receiving surface 23a are communicated with each other by a pilot passage 27 for pressure oil. A pilot passage 28 communicates with the chamber 26 on the pressure receiving surface 23b side.

Further, the upstream side of the orifice 29 and the large pressure receiving surface 23
A pilot passage 30 communicates with the a-side antechamber 24a. The spring 25 for pressing the spool valve 23 in the closing direction is provided in the front chamber 24a.

On the other hand, the second circuit 12 is provided with a second pressure control solenoid valve 15 for controlling the supply and discharge of the pressure oil PC1 to and from the cylinder 6 of the piston 3.

All the pressure oil discharged from the first and second pressure control solenoid valves 13 and 15 and the relief valve 14 is returned to the oil tank 8.

The space 4 in the clutch cover 1 and the oil tank 8
The pipe 18 is connected to the filter 18 therein, and an oil cooler 17 is installed in the pipe 16.

Next, the operation of the above configuration will be described. Since the oil pump 9 is of a variable displacement type, the eccentric amount of the cam ring 93 is controlled in proportion to the flow rate of the pressure oil, so that the pressure oil can be discharged at a constant flow rate irrespective of the fluctuation of the rotation speed.

The first pressure control solenoid valve 13 is normally wide open, the pressure oil discharged from the oil pump 9 flows into the first circuit 11, and is controlled to a constant pressure by the relief valve 14, and the pressure oil controlled to this constant pressure is used. PC2 is supplied into the space 4 from the first passage 5 and presses the piston 3 in the clutch disengagement direction. The pressure oil PC2 in the space 4 is returned to the oil tank 8 via the pipe 16.

That is, the hydraulic clutch C is the pressure oil PC passing through the first circuit 11.
The clutch is always disengaged by 1.

Therefore, for connection of the hydraulic clutch C, a command current is applied to the first pressure control solenoid valve 13 and the second pressure control solenoid valve 15 from a controller (not shown), and the first pressure control solenoid valve 13 is throttled to operate the second pressure control solenoid valve 13. Increase the pressure of pressure oil PC1 to circuit 12. The pressure increase of the pressure oil PC1 is controlled to be higher than that of the pressure oil PC2.
Then, the second pressure control solenoid valve 15 supplies the pressure oil PC1 to the cylinder 6 through the second passage 7 according to the applied voltage value, advances the piston 3 and presses the clutch disc 2 against the clutch cover 1. To connect the clutch.

The spool valve 23 of the pressure control valve 22 passes through the spring 25 and the pilot passages 27, 28 until the piston 3 reaches the forward end and the back pressure in the cylinder 6 rises and a differential pressure is generated before and after the orifice 29. The inlet / outlet ports 22a, 22b are opened by the pressure oil force introduced into the rear chamber 24b and the chamber 26, but when back pressure is generated at the forward end of the piston 3, the spool valve 23 due to the differential pressure before and after the orifice 29. Is moved in the closing direction by the pressure introduced into the spring 25 and the front chamber 24a to reduce the pressure. As a result, the pressure in the cylinder 6 is reduced, and the shock when the clutch is engaged is reduced.

When the clutch is disconnected from the connected state, the second pressure control solenoid valve 15 is switched to discharge the pressure oil PC1 supplied to the cylinder 6 to the oil tank 8.

<Effects of the Invention> As described above, according to the present invention, it is possible to control a wet hydraulic clutch with one oil pump and four control valves, and the circuit is extremely simplified, the weight is reduced, and the size is reduced. The cost can be reduced, and the clutch connection shock can be reduced to achieve a quiet clutch connection.

[Brief description of drawings]

FIG. 1 shows an embodiment of the present invention, in which a hydraulic clutch and a control circuit are incorporated. 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 ... 2 circuits, 13 ...
1st pressure control solenoid valve, 14 …… Relief valve, 15 …… Second pressure control solenoid valve, 22 …… Flow control valve.

Claims (1)

[Claims] 1. A clutch cover, which is connected to a crankshaft of an engine, includes a clutch disc, and a piston for pressing the clutch disc in a clutch connecting direction. The piston is pressed in the clutch cover in a clutch disengaging direction. In a hydraulic clutch that constantly circulates the pressure oil to be supplied, a variable displacement pump that sucks and discharges the oil in the oil tank, and a first side that communicates with the discharge side of this variable displacement pump and the pressure oil supply side into the clutch cover. One circuit and a second circuit leading to the cylinder of the piston,
A first circuit for controlling the pressure of the second circuit to rise and fall in the first circuit
A second pressure control electromagnetic valve for providing a pressure control solenoid valve and a relief valve for controlling the pressure oil supplied to the inside of the clutch cover to a constant pressure, and for supplying and discharging the pressure oil to and from the cylinder of the piston in the second circuit. A valve is provided, and a pressure control valve for temporarily reducing the back pressure of the cylinder as a signal pressure at the forward end of the piston is provided in the pressure oil circuit between the second pressure control solenoid valve and the cylinder of the piston. A hydraulic clutch control device characterized by the above.