JPH0819988B2 - 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.

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 improve these problems, a clutch cover in which a clutch disc and a hydraulically actuated piston are installed is sealed, and oil of a predetermined pressure supplied from an oil pump is circulated in the sealed space. There is provided a hydraulic clutch in which the hydraulic oil always acts on the hydraulically actuated piston in the backward direction in which the clutch is disengaged, and a hydraulic pressure higher than the hydraulic pressure in the sealed space acts on the hydraulically actuated piston to connect the clutch. .

<Problems to be Solved by the Invention> However, in the above-described conventional technique, since the gap between the clutch cover and the clutch disc is constant, there is a problem that the viscosity of the oil increases at low temperatures and the drag torque of the clutch increases. is there.

<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 the 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. The first pressure control solenoid valve for controlling the pressure of the second circuit to rise and fall, and the pressure oil town force supplied to the inside of the clutch cover are shape memory alloys. When the temperature is low, the relief passage is squeezed to increase the pressure by the spring
A back pressure valve whose opening degree is controlled according to the oil temperature so as to open the relief passage and reduce the pressure at a high temperature is provided, and the second circuit controls the supply and discharge of the pressure oil to the cylinder of the piston. Two pressure control solenoid valves are provided.

<Operation> With the above configuration, at low temperature, the valve body of the back pressure valve is made of a shape memory alloy. The shape memory action of the spring causes the valve body to narrow the relief passage to increase the relief pressure, and the pressure oil supplied to the inside of the clutch cover. The pressure is increased to positively widen the gap between the clutch cover and the clutch disc to reduce the influence of the drag torque of the clutch.

<Examples> Examples of the present invention will be described below with reference to the drawings. First
The figure shows the overall structure of the hydraulic clutch, where 1 is a crankshaft of the engine, 2 is an input shaft, 3 is a clutch disc, which is splined on the input shaft 2.

A clutch cover 6 is hermetically disposed on the input shaft 28. The clutch disc 3 is disposed in the clutch cover 6, and a piston 11 for pressing the clutch disc 3 against the clutch cover 6 is provided. 11 is a cylinder that slidably holds the piston 11, 21 is a spring that biases the piston 11 in the forward direction, and 12 is a detent member that allows the piston 11 to slide and restricts the rotation direction. is there.

Reference numeral 4 is a flex plate fixed to the crankshaft 1, and a ring gear 5 connected to a starter motor is attached to the outer diameter end of the flex plate 4. A ring gear 7 for power transmission is fixed to the flex plate 4, and a ring gear 8 meshing with the ring gear 7 is fixed to the outer surface of the clutch cover 6.

13 is an oil pump and 14 is a control valve. This control valve 14 has an oil passage 15 in the rear chamber of the piston 11.
A port 16 for supplying pressure oil pc1 via a port 19, a port 19 for supplying pressure oil pc to a space 17 in the clutch cover 6 via an oil passage 18, and a pressure oil pc2 in the space 17 on the front surface of the piston 11. And a port 20 for returning to the oil pump 13 through a gap between the clutch disc 3 and the clutch disc 3.

In the hydraulic clutch configured as described above, the rotational power of the crankshaft 1 is transmitted to the clutch cover 6 via the flex plate 4 and the ring gears 7 and 8.

On the other hand, the pressure oil pc2 from the oil pump 13 is supplied from the port 19 to the space 17 in the clutch cover 6, and the space 17 is filled with the pressure oil pc2 having a predetermined pressure. Then, a circulation action is performed in which the piston 11 is returned to the port 20 through a gap between the front surface of the piston 11 and the clutch disc 3. The piston 11 is constantly pressed by the pressure oil pc2 in the backward direction away from the clutch disc 3 to perform a clutch disengagement action.

In this state, connect the clutch with pressure oil from port 16.
The pc1 is supplied to the back surface of the piston 11 via the oil passage 15. The pressure oil pc1 has a pressure higher than that of the pressure oil pc2, whereby the piston 11 overcomes the pressing force of the pressure oil pc2 and moves forward, and the clutch disc 3 is pressed against the clutch cover 6 and transmitted to the clutch cover 6. The rotational power of the engine is transmitted to the input shaft 2 via the clutch disc 3.

FIG. 2 shows a device for controlling the hydraulic clutch having the above-mentioned structure, which has the following structure. 80 is an oil tank, inside which a filter 180 is installed.

Reference numeral 14 is an oil pump of a variable capacity type, and its suction side 9a and the oil tank 80 are connected by a pipe line 190.
On the discharge side 9b of the oil pump 14, a first circuit 110 communicating with the oil passage 18 of the hydraulic clutch and a second circuit 120 communicating with the oil passage 15 are provided.
And are branched and connected.

The first circuit 110 includes a first pressure electromagnetic control valve 130 for controlling the pressure of the second circuit 120 to rise and fall, and a space in the clutch cover 1 between the first pressure electromagnetic control valve 130 and the oil passage 18. A back pressure valve 140 for controlling the pressure oil PC constantly supplied to 17 by the oil temperature is provided. 141 is the back pressure valve 140
It is a relief passage that connects the first circuit 110 and the pipe line 190 via. The back pressure valve 140 is pushed forward by a first spring 145 and is pushed back by a shape memory alloy spring 143 in the backward direction against the spring 145, and a second spring 146 is interposed in front of the sleeve 144. And a valve body 142 that is pushed forward, and when the temperature is low, the valve body 142 narrows the relief passage 141,
The pressure of the pressure oil PC2 in the first circuit is increased, and when the temperature is high, the relief pressure is automatically controlled according to the temperature so that the pressure oil PC2 expands and the pressure of the pressure oil PC2 decreases.

On the other hand, in the second circuit 120, a second pressure control solenoid valve 150 for controlling the supply and discharge of the pressure oil PC1 to the cylinder 10 of the piston 3 is provided.
Is provided.

The first and second pressure control solenoid valves 130 and 150 and the back pressure valve
All the discharged pressure oil 140 is returned to the oil tank 80.

In addition, the space 17 in the clutch cover 1 and the oil tank 80
It is connected to a filter 180 inside by a pipe 160, and an oil cooler 170 is installed in the pipe 160.

Next, the operation of the above configuration will be described. Oil pump
Since 14 is a variable displacement type, the eccentric amount of the cam ring 93 is controlled in proportion to the flow rate of the pressure oil to discharge the pressure oil at a constant flow rate irrespective of the fluctuation of the rotation speed.

The first pressure solenoid control valve 130 is normally wide open,
The pressure oil discharged from the oil pump 14 flows to the oil passage 110, and the back pressure valve 140
Is controlled to a constant pressure by the pressure oil PC controlled to this constant pressure.
2 is supplied to the space 17 from the oil passage 18 and presses the piston 3 in the clutch disengagement direction. And the pressure oil PC2 in the space 17
Is returned to the oil tank 80 via line 160. That is, the hydraulic clutch is always biased by the pressure oil PC2 passing through the oil passage 110 to the clutch disengaged state.

In connection with the hydraulic clutch, a command current is applied to the first pressure solenoid control valve 130 and the second pressure control solenoid valve 150 from a controller (not shown), and the first pressure solenoid control valve 130 is throttled to operate in the second circuit. Increase the pressure of pressure oil PC1 to 120. 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 150 supplies the pressure oil PC1 to the oil passage 15 according to the applied electromagnetic value, and controls the connection of the clutch gently or early according to the traveling state or the like.

When the clutch is disengaged from the connected state, the second pressure control solenoid valve 150 is switched to discharge the pressure oil PC1 supplied to the cylinder 10 to the oil tank 80.

Therefore, when the outside air temperature is low, the oil temperature is naturally low, and the oil has a high viscosity. Back pressure valve 14
When 0, the shape memory alloy spring 143 contracts and deforms, and the sleeve 144 moves forward by the force of the first spring 145, increasing the set load of the second spring 146. As a result, the valve body 142 narrows the relief passage 141 to increase the relief pressure and increase the pressure of the pressure oil PC2, and the clutch cover 6 and the clutch disc 3 are released.
Widen the gap to reduce the effect of clutch drag torque due to oil viscosity. When the oil temperature rises, the shape memory alloy spring 143 stretches to retract the sleeve 144 against the force of the first spring 145, weakening the set load of the second spring 146 to lower the relief pressure, and It controls PC2 to a constant set pressure.

<Effects of the Invention> As described above, according to the present invention, the inside of the clutch cover in which the clutch disk and the hydraulically actuated piston are installed is sealed, and the oil of a predetermined pressure supplied from the oil pump is supplied into this sealed space. A hydraulic clutch in which the hydraulic oil is circulated so that the hydraulically operated piston always acts in the backward direction in which the clutch is disengaged, and a hydraulic pressure higher than the hydraulic oil in the sealed space is applied to the hydraulically operated piston to connect the clutch. In the above configuration, the pressure of the pressure oil supplied into the clutch cover is controlled by detecting the clutch oil temperature with a back pressure valve having a spring of a shape memory alloy and controlling the relief pressure so as to increase at low temperature. Therefore, there is an effect of eliminating the problem of clutch dragging due to the viscosity of oil at low temperatures.

[Brief description of drawings]

The drawings show an embodiment of the present invention. FIG. 1 is a sectional view of a hydraulic clutch, and FIG. 2 is a view in which a control circuit is incorporated in the hydraulic clutch. 2 ... Input shaft, 3 ... Clutch disc, 6 ... Clutch cover, 10 ... Cylinder, 11 ... Piston, 14 ... Oil pump, 15 ... Oil passage, 17 ... Space, 18 ... Oil passage , 11
0 ...... first circuit, 120 ... second circuit, 130 ... first pressure control solenoid valve, 140 ... back pressure valve, 142 ... valve element, 143 ... shape memory alloy spring, 150 ... second Pressure control solenoid 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
The pressure control solenoid valve and the pressure oil pressure supplied to the clutch cover are reduced by a spring made of a shape memory alloy to increase the pressure by narrowing the relief passage at low temperature, and opening the relief passage at high temperature to reduce the opening of the valve body. A back pressure valve controlled according to the oil temperature is provided, and a second pressure control solenoid valve for controlling the supply and discharge of the pressure oil to and from the cylinder of the piston is provided in the second circuit. apparatus.