JPH0434012B2 - - Google Patents

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a control device for a starting clutch that is provided between an engine and a transmission and that automatically controls starting, particularly a friction type starting clutch. be.

[Conventional technology]

Conventionally, automatic clutches such as electromagnetic clutches and fluid clutches have been widely used as starting clutches for automobiles. These automatic clutches made it possible to start smoothly while keeping the engine speed almost constant, but they required larger devices and
There are inherent problems such as increased cost and increased power loss.

To overcome these drawbacks, a friction type hydraulic clutch has been proposed as a starting clutch.

[Problem to be solved by the invention]

However, in the case of the friction type starting clutch mentioned above,
Since there is inevitably a gap between the piston and the clutch plate, it takes time for the piston to come into pressure contact with the clutch plate after pressing the accelerator pedal.
There is a problem in that the accelerator response becomes poor and the engine overspeeds, resulting in a large shock when the starting clutch is engaged.

In addition, even during start-up, if the clutch is strongly engaged, the engine speed will drop rapidly.
It was difficult to start the vehicle while maintaining an appropriate engine speed commensurate with the throttle opening.

SUMMARY OF THE INVENTION An object of the present invention is to provide a starting clutch control device that uses a friction clutch, has good accelerator response, and can perform automatic and smooth starting control.

[Means to solve the problem]

In order to achieve the above object, the present invention provides a clutch control valve between the hydraulic pressure supply source and the friction type starting clutch, which regulates the output hydraulic pressure by balancing the spring load and the hydraulic pressure in the spring chamber. The hydraulic pressure in the spring chamber is controlled by a solenoid valve, and the opening and closing of this solenoid valve is controlled based on at least the engine speed and vehicle speed.

[Effect]

When the vehicle is stopped, open the solenoid valve to drain the hydraulic pressure in the spring chamber. Therefore, a low hydraulic pressure balanced only with the spring load is introduced from the clutch control valve to the starting clutch, and the piston of the starting clutch and the clutch plate are in contact with each other, or the distance between the two is very small. As a result, when the accelerator pedal is depressed, the starting clutch engages instantly, resulting in good accelerator response.

On the other hand, when starting, the solenoid valve is opened and closed to adjust the oil pressure to the spring chamber in order to provide the starting clutch with oil pressure that maintains the proper engine speed. As a result, the engine speed is kept almost constant during start-up, making it possible to achieve an extremely smooth start-up.

〔Example〕

The drawing shows an example of a control device for a starting clutch according to the invention. 1 is a wet multi-disc starting clutch which presses clutch plates 3 and 4 as the piston 2 moves from side to side to connect and disconnect power, 5 is an input shaft directly connected to the engine, and 6 is connected to the transmission. 10 is a clutch control valve, 20 is a solenoid valve, and 22 is a control means such as a microcomputer.

The clutch control valve 10 has an axially slidable spool 11 and a spring 12 biasing the spool 11 to the left. Line pressure is introduced to the input port 13 in the center via an oil passage 30 from a hydraulic pressure supply source (not shown) such as a regulator valve. Further, an oil passage 31 branched from the oil passage 30 is connected to the spring chamber 14 that accommodates the spring 12.
1 is provided with an opening 32 that is opened and closed by the needle 21 of the solenoid valve 20. An output port 15 provided adjacent to the right side of the input port 13 is connected to the starting clutch 1 via an oil passage 33.
An oil passage 34 branched from this oil passage 33 is connected to a return port 16 at the left end of the clutch control valve 10. Note that 17 is a drain port.

The solenoid valve 20 is turned on and off by a signal from the control means 22, and moves the needle 21 forward and backward to open and close the opening 32. Signals are input to the control means 22 from an engine speed sensor 23, a throttle opening sensor 24, and a vehicle speed sensor 25. Furthermore, data on an appropriate engine speed corresponding to the throttle opening degree is stored in advance in the control means 22 in order to perform a smooth start.
These data are set, for example, based on the starting characteristics of the fluid clutch.

The operation of the starting clutch control device having the above configuration will be explained.

First, when the vehicle is stopped, the solenoid valve 20 is OFF and the needle 21 opens the opening 32, so the clutch control valve 10
The spring chamber 14 is drained, and a low oil pressure balanced only by the spring force of the spring 12 is applied to the oil passage 3.
3, it acts on the oil chamber 7 of the starting clutch 1. As a result, the piston 2 is moved to a position where the piston 2 and the clutch plate 4 come into contact with each other, or the distance between them becomes very small.

Next, when the accelerator pedal is depressed, the engine speed increases and the control means 22 adjusts the solenoid valve 20 based on the signal from the throttle opening sensor 24 to reduce the opening of the opening 32. Then, the oil pressure in the spring chamber 14 of the clutch control valve 10 rises, and the spool 11 is pushed to the left by the sum of this oil pressure and the spring force of the spring 12, so the output oil pressure of the clutch control valve 10 increases and the oil pressure increases. The oil pressure applied to chamber 7 also increases. As a result, the piston 2 comes into pressure contact with the clutch plate 4, and the starting clutch 1 begins to be engaged, so that the rotational speed of the input shaft 5, that is, the engine rotational speed, decreases due to the load on the power transmission system. This decrease in engine speed is detected by the engine speed sensor 23, and the control means 22 adjusts the solenoid valve 20 to increase the opening degree of the opening 32. As a result, spring chamber 1
4 decreases, and the hydraulic pressure applied to the oil chamber 7 of the starting clutch 1 decreases, so the pressing force of the piston 2 against the clutch plate 4 becomes weaker and the engine speed increases. While repeating the above operations, the starting clutch is gradually engaged while maintaining the engine speed at an appropriate value depending on the throttle opening.

When the vehicle speed exceeds a certain value, a signal from the vehicle speed sensor 25 causes the control means 22 to close the solenoid valve 2.
2 is turned on continuously, the opening 32 is closed, and line pressure is introduced into the spring chamber 14. Therefore, the maximum oil pressure acts on the oil chamber 7 of the starting clutch 1, and the piston 2 strongly presses the clutch plate 4, ending the starting state and transitioning to the running state.

〔Effect of the invention〕

As is clear from the above explanation, according to the present invention, in the stopped state, a constant low oil pressure is applied to the oil chamber of the starting clutch via the clutch control valve, so that the piston of the starting clutch and the clutch plate are This reduces the gap, improves accelerator response, and prevents engine overspeed.

Also, during the start, the hydraulic pressure to the spring chamber of the clutch control valve is adjusted by controlling the opening and closing of the solenoid valve, thereby gradually engaging the starting clutch while keeping the engine speed constant. This makes it possible to achieve smooth starting performance without any shock.

[Brief explanation of drawings]

The drawing is an overall configuration diagram of a starting clutch control device according to the present invention. 1... Starting clutch, 2... Piston, 4...
Clutch plate, 7... Oil chamber, 10... Clutch control valve, 11... Spool, 12... Spring, 13... Input port, 14... Spring chamber, 15... Output port, 16... Return port,
20... Solenoid valve, 22... Control means,
23...Engine speed sensor, 24...Throttle opening sensor, 25...Vehicle speed sensor, 32...
Opening.

Claims (1)

[Claims] 1. In a vehicle equipped with a friction-type starting clutch operated by hydraulic pressure, a spring 12 for biasing a spool 11 in one direction is provided between a hydraulic pressure supply source and the starting clutch 1; an input port 13 through which hydraulic pressure is introduced from a supply source;
A spring chamber 14 receives control hydraulic pressure from a hydraulic pressure supply source via a solenoid valve 20, and an output port 15 outputs hydraulic pressure to the starting clutch 1. A clutch control valve 10 is provided to adjust the pressure to balance, and signals are input from at least an engine rotation speed sensor 23 and a vehicle speed sensor 25, and when the vehicle is stopped, the output oil pressure of the clutch control valve 10 is adjusted to a low oil pressure corresponding only to the spring force. The solenoid valve 20 is opened/closed to adjust the hydraulic pressure of the spring chamber 14 so that the output hydraulic pressure of the clutch control valve 10 is maintained at a predetermined engine speed at the time of starting. A control device for a starting clutch, characterized in that it is provided with a control means 22 for controlling a starting clutch.