JP2001289267A - Clutch controller for working vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To smoothly execute the shift operation in safety by connecting and disconnecting a forward and backward switching clutch in a working vehicle having the wet multiple disc forward and backward switching clutch. SOLUTION: A directional control valve 51 is mounted for controlling the hydraulic fluid to be supplied to the forward and backward switching clutch 13a, and a potentiometer 41 is mounted on a clutch pedal 34 to detect a depressing amount. The current outputted from a controller 60 to a forward solenoid 52 or a backward solenoid 53 is reduced in interlocking with the depressing operation of a clutch pedal 34, and the directional control valve 52 is returned to a neutral position (a) to cut the forward and backward switching clutch 13A.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a clutch control device for a work vehicle, and more particularly to a clutch control device for a work vehicle having a wet-type multi-plate forward / reverse switching clutch.

[0002]

2. Description of the Related Art In agricultural work vehicles such as tractors, the rotational power of an engine is transmitted to a transmission in a transmission case via a main clutch, and the main clutch is turned on and off. In many cases, the speed change operation is performed. A forward / reverse switching device is provided at the first stage of the transmission, and in general, an electromagnetic control valve is switched by operating a lever to engage / disengage a wet-type multi-plate forward / backward switching clutch to correct the rotational power of the engine. The transmission is switched to reverse or reverse rotation and transmitted to the subsequent transmission.

Here, it is conceivable that the rotational power of the engine is cut off only by the forward / reverse switching clutch instead of the main clutch. In such a case, the forward / backward switching clutch is turned on / off by operating the lever, and the operability is poor and the power is rapidly connected / disconnected, which causes a problem in safety.

Therefore, in a work vehicle having a wet-type multi-plate forward / reverse switching clutch, there is a technical problem to be solved in order to smoothly and safely perform a shift operation by turning on / off the forward / reverse switching clutch. Therefore, an object of the present invention is to solve this problem.

[0005]

SUMMARY OF THE INVENTION The present invention has been proposed to achieve the above-mentioned object, and comprises a wet-type multi-plate forward / reverse switching clutch 13a and a forward / reverse switching clutch 13a.
a control valve 51 for supplying hydraulic oil to the vehicle, and connecting the forward / reverse switching clutch 13a in accordance with the operating position of the operating lever 29 provided on the vehicle body to set the forward / backward traveling direction. A single pedal 34 capable of detecting the stepping operation is provided on the body of the work vehicle. When the stepping operation of the pedal 34 is detected, the control valve 51 is set to the shut-off position in preference to the operation position of the operation lever 29. And a clutch control device for a working vehicle provided with control means 60 for changing the power transmission state of the forward / reverse switching clutch 13a to the disengagement side, and a wet multi-plate forward / reverse switching clutch biased to the power transmission "off" side 13a and a control valve 51 for supplying hydraulic oil to the forward / reverse switching clutch 13a, and the forward / reverse switching clutch 13 is provided in accordance with the operating position of an operating lever 29 provided on the vehicle body. The traveling direction and connected at the working vehicle that sets back and forth, single pedal 3 of the vehicle body the working vehicle
4 and the forward / reverse switching clutch 13a.
A control valve 50 for shutting off hydraulic oil supplied to the forward / reverse switching clutch 13a is provided in an oil passage communicating with the control valve 50, and the depression operation of the pedal 34 is transmitted to the control valve 50 by mechanical interlocking means to operate the control valve 50. A clutch control device for a working vehicle, a wet multi-plate forward / backward switching clutch 13a urged to the "off" side of power transmission, and a control valve 51 for supplying hydraulic oil to the forward / backward switching clutch 13a In a work vehicle in which the forward / reverse switching clutch 13a is connected in accordance with the operation position of the operation lever 29 provided on the vehicle body to set the traveling direction back and forth, a stepping operation on the body of the work vehicle can be detected. A control valve for providing a single pedal 34 and for shutting off hydraulic oil supplied to the forward / reverse switching clutch 13a is provided in an oil passage communicating with the forward / reverse switching clutch 13a. 0, and when a predetermined amount of depression of the pedal 34 is detected, the control valve 51 is set to the shut-off position prior to the operation position of the operation lever 29, and the power transmission state of the forward-reverse switching clutch 13a is set. Of the working vehicle, which is provided with a control means 60 for changing the position of the pedal 34 to the cut side, and which is operated by transmitting a stepping operation of a stroke larger than a predetermined amount of the pedal 34 to the control valve 50 by a mechanical interlocking means. It is intended to provide a clutch control device.

[0006]

An embodiment of the present invention will be described below in detail with reference to the drawings. FIG. 1 shows a side surface of a tractor 10 as an example of a work vehicle, and FIG. 2 shows a power transmission path of the tractor 10. An engine 11 is mounted on a front portion of the vehicle body of the tractor 10, and the rotational power of the engine 11 is transmitted through a forward / reverse switching device 13 in a transmission case 12 and is shifted by a main transmission 14 and an auxiliary transmission 15. From the front differential 19 to the front wheels 20, 20 via the constant speed double speed switching device 18.
Is transmitted to Part of the power is from PTO clutch 21 to P
It is branched to a TO shaft 22 and transmitted to a rotary working machine 24 connected to a rear portion of the vehicle body by a link mechanism 23.
The forward / reverse switching device 13 is provided with a wet-type multi-plate forward / reverse switching clutch 13a. The forward / reverse switching clutch 13a is moved in accordance with the operation position of a forward / reverse switching lever 29 described later. To set the traveling direction of the vehicle forward and backward.

A driver's seat 25 is provided above the transmission case 12. In the vicinity of the driver's seat 25, there are provided a position lever 26, which is a means for setting the elevation of the working machine, a tillage adjusting dial 27, which is a means for setting the working depth of the working machine. A steering handle 28 as a steering operation unit is provided, and a forward / reverse switching lever 29 and a work implement elevating lever 30 are provided near the steering handle 28. The rotation operation of the steering handle 28 is transmitted to the power steering steering unit 31, and hydraulic oil is supplied to the steering cylinder 32 according to the amount of steering of the steering handle 28, and the steering is performed by the expansion and contraction operation of the steering cylinder 32. Front wheel 2 which is a wheel
0,20 turns. Reference numeral 33 denotes a shift lever, and 3
Reference numeral 4 denotes a single clutch pedal provided on the vehicle body.

Next, a clutch control device according to the present invention will be described. FIG. 3 shows the overall configuration of the clutch control device,
A turning base 34a of the clutch pedal 34 is provided with a potentiometer 41 as a turning angle detecting means of the clutch pedal 34, and an arm 42 which turns integrally with the clutch pedal 34 is provided in a protruding manner. A bracket 44 is fixed to the floor 43 below the clutch pedal 34,
A pivot arm 45 is pivotally attached to the bracket 44. The rotating arm 45 includes an upper piece 45a, a side piece 45b, and a lower piece 4
5c, the center of which is a pin 4
At 6, it is pivotally supported by the bracket 44 and is urged counterclockwise in FIG.

The lower end of a tension damper 47 is connected to the tip of the side piece 45b of the rotary arm, and the piston rod 47a projecting from the upper end of the tension damper 47 and the arm 42 of the clutch pedal are connected by a link rod 48. Connected. A spring 47b is provided in the tension damper 47, and the piston rod 4 is moved by the spring 47b.
7a is urged to be drawn into the case. That is, the link rod 48 is pulled downward by the pulling action of the pull damper 47, and the clutch pedal 34 is urged in the counterclockwise direction in FIG. It has been returned to the depressed position. When the operator depresses the clutch pedal 34, the piston rod 47 of the tension damper 47 is moved through the ring rod 48.
When a is pulled upward and the clutch pedal 34 is depressed to the full stroke position, as indicated by a two-dot chain line,
The tension damper 47 itself is configured to move upward.

Further, a non-latch type safety switch 49 is provided on the rotation locus of the upper piece 45a of the rotation arm, and the rotation arm 45 is moved clockwise in the drawing as shown by a two-dot chain line in FIG. When the upper arm 45a rotates, the upper switch 45a comes into contact with the push pin 49a of the safety switch so that the safety switch 49 is turned on. A mechanically operated control valve 50 is provided, and when the rotating arm 45 is rotated clockwise in the figure as shown by a two-dot chain line in the figure, the lower piece 45c is connected to the push pin 50a of the control valve. The spool of the control valve 50 is formed so as to be switched upon contact. That is, the link rod 48, the tension damper 47, the rotating arm 45, and the like constitute mechanical interlocking means for transmitting the depression operation of the clutch pedal 34 to the control valve 50.
Reference numeral 51 denotes a direction control valve for controlling hydraulic oil supplied to the forward / reverse switching clutch 13a.

FIG. 4 is a circuit diagram of the clutch control device.
The hydraulic oil sent from the hydraulic pressure source 55 passes through the control valve 50 to reach the directional control valve 51, and the forward / reverse switching clutch 13
a is supplied to the forward port F or the reverse port R. When the operator operates the forward / reverse switching lever 29 to the forward position, a current is output from the controller 60 as a control means to the forward solenoid 52, and the direction control valve 51 is moved from the neutral position (a) to the forward position. (B)
, And the hydraulic oil is supplied from the direction control valve 51 to the forward port F of the forward / reverse switching clutch 13a. When the operator operates the forward / reverse switching lever 29 to the reverse position, a current is output from the controller 60 to the reverse solenoid 53, and the direction control valve 51 is moved from the neutral position (a) to the reverse position (c). The operation oil is supplied from the direction control valve 51 to the reverse port R of the forward / reverse switching clutch 13a. When the direction control valve 51 is switched to the forward position (a) or the reverse position (b),
A current is output from the controller 60 to the booster circuit 54, and the hydraulic oil supplied to the forward / reverse switching clutch 13a is controlled so as to obtain a predetermined boosting characteristic.

When the vehicle is running, the main transmission 1
4 or the speed change of the auxiliary transmission device 15, the transmission of power must be temporarily interrupted. At that time, it is not easy to operate the forward / reverse switching clutch 13a by operating the forward / reverse switching lever 29. Therefore, the operator depresses the clutch pedal 34 to reduce the amount of hydraulic oil supplied to the forward / reverse switching clutch 13a. Control. 1 to 4
For example, when the operator starts to depress the clutch pedal 34 during forward running of the vehicle body, the turning angle of the clutch pedal 34 is detected by the potentiometer 41, and the controller 60 responds to the depression amount of the clutch pedal 34. Thus, the current to the forward solenoid 52 is reduced, and the direction control valve 51 is returned to the neutral position (a). Accordingly, the amount of hydraulic oil supplied to the forward / reverse switching clutch 13a decreases, the forward / reverse switching clutch 13a is turned off, and power transmission to the main transmission 14 is stopped.

When the clutch pedal 34 is depressed to the full stroke position, the tension damper 47 itself moves upward to rotate the rotating arm 45, and the safety switch 49 is turned on by the upper piece 45a. Becomes
When the controller 60 detects this ON signal, regardless of the magnitude of the detection signal of the potentiometer 41,
The current to the forward solenoid 52 is forcibly cut off to return the direction control valve 51 to the neutral position (A). In addition, since the lower piece 45c pushes the push pin 50a of the control valve 50 by the rotation of the rotation arm 45, the control valve 50 is mechanically switched from the open position (d) to the closed position (e). Instead, the hydraulic oil sent from the hydraulic pressure source 55 is shut off.

That is, when the clutch pedal 34 is depressed to the full stroke position, the direction control valve 51 is set to the neutral position (a), the hydraulic source 55 is shut off, and the supply of hydraulic oil to the forward / reverse switching clutch 13a is stopped. Since the power is forcibly stopped, even if the potentiometer 41 fails for some reason, the rotational power of the engine 11 can be forcibly shut off. Further, the forward / reverse switching clutch 13
A hydraulic pressure gauge 5 is provided for each of the forward port F and the reverse port R of FIG.
6 and 57, and a rotation sensor (not shown) is provided on the drive pinion of the rear differential 16 so that at least one of the oil pressure gauges 56 and 57 generates a hydraulic pressure. When the vehicle body is rotating and moving, the engine 11 can be forcibly stopped to prevent an accidental accident from occurring.

When the depression of the clutch pedal 34 is released from the above state, the clutch pedal 34 returns to the non-depressed position by the tension action of the tension damper 47. Clutch pedal 34 by general return spring
In the configuration in which the tension is applied, the pedal operation is too hard, or the potentiometer 41 easily malfunctions due to large swinging. However, in the present embodiment, the damping effect of the tension damper 47 makes it extremely difficult. A smooth pedal operation can be obtained, and a malfunction of the potentiometer 41 due to the swing of the pedal can be prevented.
The present invention can be variously modified without departing from the spirit of the present invention, and it goes without saying that the present invention extends to the modified ones.

[0016]

As described in detail in the above embodiment, the invention according to the first aspect of the present invention moves the operating lever 29 to the operating position when the depression operation of the single pedal 34 is detected. Since the control valve 51 is preferentially set to the shut-off position and the power transmission of the forward / reverse switching clutch 13a is changed to the disengagement side,
The forward / reverse switching clutch 13a can be turned on / off by the pedal 34, and the shift operation can be performed smoothly and safely.

According to a second aspect of the present invention, a control valve 50 for arbitrarily shutting off hydraulic oil supplied to a wet-type multi-plate type forward / reverse switching clutch 13a is provided, and the depression of a single pedal 34 is controlled by mechanical interlocking means. Since the control valve 50 is operated by transmitting the control valve 50, the forward / reverse switching clutch 13a can be turned on / off without using an electrical detection means such as a sensor, and the speed change operation can be reliably performed.

The third aspect of the present invention is provided with a control valve 50 which can arbitrarily shut off hydraulic oil supplied to a wet-type multi-plate type forward / reverse switching clutch 13a, when a single pedal 34 is a predetermined amount of depression operation. Sets the control valve 51 to the shut-off position prior to the operation position of the operation lever 29, changes the power transmission of the forward / reverse switching clutch 13a to the disengagement side,
When the step 4 is a stepping operation larger than a predetermined amount, the stepping operation of the pedal 34 is transmitted to the control valve 50 by a mechanical interlocking means to be operated, so that the speed change operation can be performed smoothly and reliably.

[Brief description of the drawings]

 The figure shows an embodiment of the present invention.

FIG. 1 shows an embodiment of the present invention and is a side view of a tractor.

FIG. 2 is an explanatory diagram showing a power transmission path of a tractor.

FIG. 3 is an explanatory diagram showing an overall configuration of a clutch control device.

FIG. 4 is a circuit diagram of a clutch control device.

[Description of Signs] 10 Tractor 34 Clutch pedal 41 Potentiometer 45 Rotating arm 47 Tension damper 50 Control valve 51 Direction control valve

Continued on the front page F term (reference) 3D036 EA01 EB02 EB21 EB32 GA04 GA33 GA48 GB14 GB15 GC03 GC07 GD01 GG26 GH16 GJ13 3J057 AA03 BB04 EE09 GA21 GA47 GA49 GB18 GC10 HH05 JJ01

Claims (3)

[Claims] 1. A forward / reverse switching clutch 13 of a wet multi-plate type.
a, and a control valve 51 for supplying hydraulic oil to the forward / reverse switching clutch 13a. The forward / reverse switching clutch 13a is connected in accordance with the operating position of the operating lever 29 provided on the vehicle body to set the forward / backward traveling direction. A single pedal 3 capable of detecting a stepping operation on the body of the work vehicle.
4, when the depression operation of the pedal 34 is detected, the control valve 51 is set to the shut-off position prior to the operation position of the operation lever 29, and the power transmission state of the forward / reverse switching clutch 13a is set to the off-side. Control means 60 for changing to
A clutch control device for a working vehicle, comprising: 2. An operation provided on a vehicle body, comprising: a wet-type, multi-plate type forward / reverse switching clutch 13a urged to the power transmission "OFF"side; and a control valve 51 for supplying hydraulic oil to the forward / reverse switching clutch 13a. In a working vehicle in which the forward / reverse switching clutch 13a is connected in accordance with the operating position of the lever 29 to set the traveling direction back and forth, a single pedal 34 is provided on the body of the working vehicle and the forward / backward switching clutch is provided. 1
The forward / reverse switching clutch 13
a control valve 50 for shutting off hydraulic oil supplied to the control valve 50, and a stepping operation of the pedal 34 is transmitted to the control valve 50 by a mechanical interlocking means to be operated. Clutch control unit. 3. An operation provided on a vehicle body, comprising: a wet multi-plate forward / backward switching clutch 13a biased to the power transmission "off"side; and a control valve 51 for supplying hydraulic oil to the forward / backward switching clutch 13a. In a work vehicle in which the forward / reverse switching clutch 13a is connected in accordance with the operation position of the lever 29 to set the traveling direction back and forth, a single pedal 34 capable of detecting a stepping operation on the body of the work vehicle is provided. A control valve 50 for shutting off hydraulic oil supplied to the forward / reverse switching clutch 13a is provided in an oil passage communicating with the forward / reverse switching clutch 13a, and when a predetermined amount of depression of the pedal 34 is detected. Control means 6 for setting the control valve 51 to the shut-off position prior to the operation position of the operation lever 29 and changing the power transmission state of the forward / reverse switching clutch 13a to the disengagement side. 0, and a clutch control device for a work vehicle, wherein a stepping operation of a stroke larger than a predetermined amount of the pedal 34 is transmitted to the control valve 50 by a mechanical interlocking means to be operated. .