JPH07127665A - Clutch operational mechanism - Google Patents

Abstract

PURPOSE:To eliminate any shock by calculating return operation speed from ON position to OFF position of a clutch pedal based on a clutch operational quantity, and varying a current value increase rate against the clutch operational quantity to a larger side as the speed is larger. CONSTITUTION:Current supply to a solenoid proportional flow rate control valve 7 is stopped when a clutch pedal 6 is stepped into the clutch OFF position in compliance with detected information of a pedal sensor 9, and the operational speed of the clutch pedal 6 is calculated when return operation is executed, so as to find out a current increment coefficient. The increment coefficient is set larger as the operational speed is larger. A target current value related to the pedal operational position is then outputted to the proportional flow rate control valve 7 by multiplying a preliminarily determined standard variable characteristic value by the increment cofficient and corresponding to the pedal operational range based on the detection value of the pedal sensor 9. Therefore a half clutch condition can be roalized without timing delay by rapid pressure oil increase when the return operational speed of the clutch pedal 6 is quick, and consequently, clutch operation with less shock can be performed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention uses a return urging force by an urging mechanism when a hydraulic piston operated by pressure oil supply is pressed to switch to a clutch engaged state and the pressure oil supply to the hydraulic piston is released. A multi-disc friction clutch in which the hydraulic piston retracts and switches to the clutch disengaged state, clutch operation amount detection means for detecting the depression operation amount of the clutch pedal biased back to the clutch engaged position, and pressure oil for the hydraulic piston. The proportional flow rate control valve for controlling the amount to a flow rate proportional to the supplied current value, and the proportional flow rate such that the larger the stepping operation amount detected by the clutch operation amount detecting means, the smaller the value. The present invention relates to a clutch operating mechanism provided with control means for controlling a current value for a control valve.

[0002]

2. Description of the Related Art In the above clutch operating mechanism, conventionally, the control characteristics of the operating position of the clutch pedal and the current value for the proportional flow rate control valve are set in advance, and the depression amount of the clutch pedal is detected by the clutch operating amount. As an example of the means, a potentiometer may be detected, the operation position of the clutch pedal may be determined based on the detected value, and a current value corresponding to the operation position may be supplied to the proportional flow control valve. As a characteristic, the current value is set to smoothly change so that the larger the amount of depression of the clutch pedal is, the smaller the current value becomes. That is, when the clutch pedal is not operated, the maximum current is supplied to the proportional flow rate control valve, the operating pressure by the hydraulic piston is maximum, and the clutch engagement state is maintained reliably, and the current value gradually decreases as the pedal is depressed. Then, the hydraulic operating force gradually decreases, the current supply is stopped just before the maximum stepped position, and the clutch disengaged state is revealed by the return urging force of the urging mechanism.

[0003]

However, in the above-mentioned conventional structure, the current value for the proportional flow rate control valve is determined in correspondence with the operating position of the clutch pedal, so that the following problems occur. In other words, when the pedal is returned from the clutch disengaged state (state where the hydraulic oil in the oil chamber of the hydraulic piston is empty) in which the clutch pedal is operated to the maximum depressing position, current supply to the proportional flow control valve is started gradually. The current value gradually increases, but at this time, since the hydraulic operating force gradually increases against the return urging force of the urging mechanism, pressure oil that can counteract the urging force is generated in the oil chamber of the hydraulic piston. The clutch operating pressure will not be generated until it is supplied. As a result, when the return operation is performed quickly, the hydraulic operation state tends to be delayed relative to the pedal operation in the initial operation of the clutch pedal, and the pedal return operation is performed excessively. Even if the person intends to perform the returning operation to the half-clutch state, the clutch friction plate may be abruptly pressed to cause a shock due to the excessive operation. The present invention aims to eliminate the above-mentioned problems.

[0004]

According to a characteristic configuration of the present invention, in the clutch operating mechanism described at the beginning, the control means is based on a detection result of the clutch operation amount detecting means, and a clutch disengaged position of the clutch pedal. From the above, the operation speed of the returning operation to the clutch engaged position side is calculated, and the higher the operation speed, the more the increase rate of the current value with respect to the clutch operation amount is controlled to be changed to the larger side. It is in.

[0005]

When the clutch pedal is returned from the clutch disengaged position, which is the maximum depressing state, to the clutch engaged position side, the higher the return operation speed is, the increasing rate of the current value with respect to the clutch operation amount, that is, the hydraulic pressure. Since the hydraulic pressure increase rate with respect to the piston is controlled to be changed to a large side, when the operation is performed slowly, the hydraulic pressure increases correspondingly, and when the quick return operation is performed, the hydraulic pressure rapidly increases.

[0006]

Therefore, even if the clutch pedal is quickly returned, the hydraulic pressure of the hydraulic piston rises quickly, so that the hydraulic operation can follow the pedal operation without delay as much as possible. The proper half-clutch state can be revealed without the returning operation, and smooth clutch operation can be performed with less shock.

[0007]

Embodiments will be described below with reference to the drawings. Figure 1
Wet multi-plate friction type main clutch for agricultural tractors 1
The operation system diagram of is shown. This main clutch 1 is shown in FIG.
As shown in FIG.
When the friction plates 3 and 4 are pressed to switch to the clutch engaged state and the pressure oil supply to the hydraulic piston 2 is released, the hydraulic piston 2 is retracted by the return urging force of the return spring 5 [an example of urging mechanism]. The clutch engagement / disengagement operation is performed by depressing and releasing the clutch pedal 6.

More specifically, the hydraulic control valve 7 for controlling the pressure oil to the oil chamber 2a of the hydraulic piston 2 is constructed as an electromagnetic proportional flow rate control valve for controlling the pressure oil amount in proportion to the supplied current value. It is configured such that the value of the current supplied to the electromagnetic proportional flow rate control valve 7 is changed and controlled by a control device 8 [an example of control means] equipped with a microcomputer based on the operation amount of the clutch pedal 6. is there. The clutch pedal 6 is biased back to the clutch engaged position, and when a depression operation is performed against the biasing force, the rotation amount of the clutch pedal 6 is a potentiometer-type pedal sensor 9 [clutch operation amount detection Example of Means], and the detection value of the pedal sensor 9 is given to the control device 8. Therefore, when the clutch pedal 6 is not operated, the clutch is engaged, the hydraulic piston 2 is pressed by the pressure oil to be in the power transmission state, and the oil pressure is gradually released with the pedal depression operation, and the return spring 5 is released. The hydraulic piston 2 is returned by this and the clutch is disengaged.

Then, the control device 8 calculates the operation speed of the returning operation of the clutch pedal 6 from the clutch disengaged position to the clutch engaged position side based on the detection result of the pedal sensor 9, and the operation speed is high. It is configured to control so as to increase the rate of increase of the current value with respect to the clutch operation amount. FIG. 4 shows a control procedure of the control device 8. When the clutch pedal 6 is depressed to the clutch disengaged position from the detection information of the pedal sensor 9, until the clutch pedal 6 is returned,
When the current supply to the electromagnetic proportional flow control valve 7 is stopped [steps 1 to 4] and the returning operation is performed, the pedal sensor 9
The operation speed of the clutch pedal 6 is calculated from the output of the above, and the current increase coefficient K is obtained based on the operation speed [steps 5 and 6]. The increase coefficient K is set to have a larger value as the operation speed increases. next,
The target current value I for the pedal operation position is calculated by multiplying the standard change characteristic value Ia which is predetermined as shown in FIG. 3 by the current increase coefficient K [step 7]. Then, based on the detection value of the pedal sensor 9,
The target current value is sequentially output to the proportional flow control valve 7 corresponding to the pedal operation position [step 8]. By controlling the current in this manner, when the return operation speed of the clutch pedal 6 is high, the current increase rate is also large, and the quick increase in the pressure oil causes the half-clutch state to occur with a small timing delay with respect to the pedal operation. You will be able to appear.

[Other Embodiments] As described above, instead of changing the coefficient for the target current according to the operation speed, a plurality of current value change characteristics having different rising rates are stored in advance, and the operation is performed. Control may be performed so as to switch to different change characteristics depending on the speed.

It should be noted that reference numerals are added to the claims to facilitate the comparison with the drawings, but the present invention is not limited to the configurations of the accompanying drawings by the entry.

[Brief description of drawings]

FIG. 1 is a control block diagram.

FIG. 2 is a sectional view of a main clutch

FIG. 3 Current control characteristic diagram

FIG. 4 is a control flowchart.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Multi-plate friction type clutch 2 Hydraulic piston 5 Energizing mechanism 6 Clutch pedal 7 Proportional flow control valve 8 Control means 9 Clutch operation amount detection means

Claims (1)

[Claims] 1. When the hydraulic piston (2) which is operated by the pressure oil supply is pressed to switch to the clutch engaged state, and when the pressure oil supply to the hydraulic piston (2) is released, the biasing mechanism (5) is used for returning. A multi-disc friction clutch (1) in which the hydraulic piston (2) is retracted by the force to switch to a clutch disengaged state, and a clutch for detecting the amount of depression of a clutch pedal (6) that is biased back to the clutch engaged position. An operation amount detection means (9) and a proportional flow control valve (7) for controlling the amount of pressure oil for the hydraulic piston (2) to a flow rate proportional to the supplied current value.
And a control means (8) for controlling the current value to the proportional flow control valve (7) such that the larger the depression operation amount detected by the clutch operation amount detection means (9), the smaller the value. The control means (8) is based on a detection result of the clutch operation amount detection means (9), and includes a clutch operation position of the clutch pedal (6) and a clutch engagement position. A clutch operating mechanism configured to calculate an operating speed of a returning operation to a side, and control so as to change the increasing rate of the current value with respect to the clutch operating amount to a larger side as the operating speed is higher.