JPH0324359A - Clutch control device of industrial vehicle - Google Patents

Abstract

PURPOSE:To prevent a vehicle from being moved by creep of a torque converter by automatically performing disconnecting control of a hydraulic clutch when a condition that an axle pedal and inching pedal have not been operated for a fixed time is detected. CONSTITUTION:A controller 8 diagnoses according to signals of sensors 13, 14 that an axle pedal 10 and inching pedal 11 have not been operated for a fixed time, and then carries out releasing control of the hydraulic clutch 5 of an automatic transmission 3 via a driving circuit 9 and a clutch control valve 7 when the above condition is continued for a fixed time. Thus, even when a vehicle is left without disconnecting the hydraulic clutch 5 of the automatic transmission 3, the hydraulic clutch 5 is released automatically after a fixed time elapses and so the vehicle with not be started to move by creep of a torque converter 2. Also, the oil temperature of the torque converter 2 is prevented from rising unnecessarily high even when rotation of the engine 1 is continued.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a clutch control device for controlling a clutch of a transmission mounted on an industrial vehicle such as a forklift truck or a shovel loader.

(Prior Technology) Conventionally, industrial vehicles such as forklift trunks and shovel loaders have been equipped with torque converters in their power systems. Engine power is transmitted to the transmission through this torque converter, and the power changed by the transmission is transmitted to the drive wheels so that the vehicle can move. (Problem to be solved by the invention) In industrial vehicles equipped with a torque converter in the power system as described above. If you forget to disengage the transmission clutch while idling and leave the vehicle unattended, the torque converter will creep, causing the vehicle to start moving, which can be dangerous.

Also, if you forget to disengage the clutch even when you apply the parking brake to stop the vehicle. The torque converter stalls and the engine continues to rotate. There are problems such as the oil temperature inside the torque converter rising unnecessarily and causing the oil to deteriorate prematurely.

This invention has been made to improve the above-mentioned problems, and it is an object of the present invention to provide a clutch control device for an industrial vehicle that can automatically disengage the transmission clutch after a certain period of time even if the clutch of the transmission is forgotten.

(Means and effects for solving the problem) This invention is intended to achieve the above object. In industrial vehicles equipped with a torque converter and transmission in the power system. When the vehicle is stopped or traveling below a certain speed with the hydraulic clutch of the transmission engaged, it is detected whether the accelerator pedal or inching pedal has been depressed for a certain period of time, and if the accelerator pedal and inching pedal have not been depressed, the automatic This invention provides a clutch control device for an industrial vehicle that prevents the vehicle from running out of control or the oil temperature in the torque converter from rising unnecessarily due to forgetting to disengage the clutch by controlling the hydraulic clutch to disengage automatically. be. (Example) An example of the present invention will be described in detail with reference to the drawings. 1st
In the figure, 1 is an engine mounted on an industrial vehicle (not shown), and the output of this engine 1 is transmitted to drive wheels 4 via a torque converter 2 and an automatic transmission 3, and the drive wheels 4 are rotated to drive the vehicle. It looks like this.

In the automatic transmission m3, a hydraulic clutch 5 is provided at each speed stage, and hydraulic pressure is supplied to these hydraulic clutches 5 from a hydraulic pump 6 via a clutch control valve 7.

The clutch control valve 7 is an electromagnetic valve (solenoid valve), and is switched and controlled by a drive circuit 9 connected to the output side of a controller 8 consisting of a microcomputer. and 1l are an accelerator pedal and an inching pedal installed in front of the driver's seat of the industrial vehicle.
12 is a forward/reverse switching lever.

The depression positions of the accelerator pedal 10 and the inching pedal 11 are determined by position detectors l3 and l such as potentiometers.
4 and sent to the controller 8. The operating position of the forward/reverse selector lever 12 is detected by the forward/reverse selector switch 15! The signals are input to the III controller 8, respectively. Figure 2 shows a flowchart of the control program of this invention. Subprograms are executed at regular intervals using interrupt control, etc. Then, in step ■, the subprogram routine is executed, and the shift lever position, header position, and vehicle speed are read. After that, the process proceeds to step ■, where it is determined whether or not the accelerator pedal 10 has been depressed based on the signal from the position detector l3. If it has not been depressed, the process proceeds to step ■, where the forward/reverse switching lever l2 is set to forward or reverse. In other words, it is determined whether the hydraulic clutch 5 has been forgotten to be disengaged.
If the hydraulic clutch 5 has been forgotten to be disengaged, the process proceeds to step (3), and it is determined from the signal from the position detector 14 whether the inching pedal 11 has been depressed. If the pedal is not pressed, proceed to step ■ and determine whether the vehicle speed is below a certain level. If the vehicle speed is below a certain level, the timer measures a preset time in step ■ and determines whether time amplification is being performed. If time amplification is being performed, the process proceeds to step ■ and controller 8 controls drive circuit 9. Outputs a signal to. The hydraulic clutch 5 is automatically controlled to be disengaged.

If time amplification is not performed, the subprogram routine ends with the counter value unchanged.

On the other hand, if it is determined in step ■ that the accelerator pedal 10 is depressed, and if it is determined in step ■ that the forward/reverse switching lever 12 is in the neutral position. Furthermore, if it is determined in step (2) that the inching pedal 1l is being depressed, and if it is determined in step (2) that the vehicle speed is not below a certain level, the timer is cleared and the subprogram routine ends.

(Effects of the Invention) As detailed above, in each invention, even if you forget to disengage the hydraulic clutch of the transmission and leave the vehicle unattended, the hydraulic clutch is automatically disengaged after a certain period of time. It is possible to solve problems such as the machine starting to move.

Also, if you forget to disengage the hydraulic clutch and apply the parking brake to stop, the hydraulic clutch will be automatically disengaged after a certain period of time, causing the torque converter oil temperature to rise unnecessarily even if the engine continues to rotate. This eliminates the problem of premature oil deterioration.

[Brief explanation of drawings]

Fig. 1 is a block diagram showing an embodiment of the present invention, and Fig. 2 is a flowchart of a control program. 5... Hydraulic clutch, 10... Accelerator pedal. 11... Inteng pedal no. 12... Forward/forward switching lever

Claims (1)

[Claims] In industrial vehicles equipped with a torque converter and transmission in the power system, if the vehicle is stopped or is running at a certain speed or less with the hydraulic clutch of the transmission engaged, the accelerator pedal and inching pedal are depressed for a certain period of time. A clutch control device for industrial vehicles that detects whether the clutch is depressed and automatically disengages the hydraulic clutch if the clutch is not depressed.