JPH0131792Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a device for preventing a hydraulic clutch from rotating in a tractor.

Conventionally, hydraulic clutches used for live PTO of tractors have a piston body installed on the driven side, facing the clutch plate interposed between the drive shaft and the driven shaft, and pressed against the clutch plate by the force of a bullet. There is a hydraulic clutch in which the clutch is set to "on" and the piston body is moved back using pressure oil from an oil port ring fixed to the fuselage side to "disengage". However, in this type of hydraulic clutch, the temperature When the temperature becomes low and the viscosity of the oil increases, there is a drawback that even if the clutch is operated to ``disengage'', the driven shaft side will become tangled. For this reason, a brake device has been proposed to prevent the rotation, but this device utilizes the movement of a piston, etc. when the clutch is "disengaged" to create frictional resistance with a spring, friction plate, etc. Therefore, in order to create frictional resistance and apply the brakes only when the clutch is reliably "disengaged," it is necessary to create frictional resistance in a small section before the piston finishes moving completely. In addition, it was difficult to accurately control the dimensions, and the brakes sometimes became stiff in the half-clutch state, resulting in a loss of power.

The present invention was devised in view of the above-mentioned circumstances, and includes a plurality of small pistons that slide in the axial direction of the driven shaft and are biased toward the piston body in the oil port ring. At the same time, the plurality of small pistons are retracted by hydraulic pressure that causes the clutch to be "disengaged," and a friction body, which the plurality of retracted small pistons abuts simultaneously, is placed opposite the axial end surface of the oil port ring on the driven shaft. By fixing the clutch to the ``disengage'' position, multiple small pistons are retracted using the hydraulic pressure when the clutch is ``disengaged'', making it possible to use a compact hydraulic clutch in a tractor that operates only when the clutch is ``disconnected''. The purpose of this invention is to provide an anti-tangle device.

The structure of the present invention will be explained with reference to an embodiment shown in the drawings. Reference numeral 1 is a center case provided at the bottom of the tractor body, and an oil port ring 2 is fixed to the inner wall of the center case 1. Support 3 is fixed. The oil port ring 2 is prevented from rotating by a joint bolt 4 screwed onto the center case 1, and a hydraulic clutch 7 is connected to the inner peripheral surface of the oil port ring 2 via a hub 5 spline-fitted to a driven shaft 6. is rotatably locked. Further, on the drive shaft 8 side in front of the hydraulic clutch 7, clutch plates 10 and mating plates 11 are alternately arranged between a cover 9 attached to the rear end of the drive shaft 8. A piston body 12, which is disposed opposite to the clutch plate 10 and is slidable back and forth, is pressed toward the clutch plate 10 by the force of the bullet 13, so that the clutch is engaged, and the drive shaft 8 is connected through the cover 9. Torque is transmitted to the driven shaft 6.
Then, when pressurized oil is sent to the port 14 provided in the joint bolt 4 via a pressure control valve (not shown) and pressurized, the oil groove 1 provided in the hub 5 is pressurized.
Piston body 12 communicating with port 14 via 5
The pressure inside the cylinder 16 increases, and the piston body 1
2 retreats against the ammunition 13, the pressing force between the clutch plate 10 and the mating plate 11 is released, and the clutch is "disengaged".

A plurality of through holes 17 passing through in the axial direction of the driven shaft 6 are bored in the oil port ring 2, and the front open end of the through hole 17 is closed by a plug 18. A small piston 19 is slidably fitted into the through hole 17 whose front opening end is closed.
is biased in the direction of the piston body 12 by a spring 21 wound around the piston shaft 20 on the rear open end side, so that it slides inward from the outer peripheral surface of the oil port ring 2. ing. The front end of the piston shaft 20 is pressed by the plug 18, and the rear end is in contact with a pin 22 slidably inserted into the rear open end of the through hole 17, and the plug 18 side of the through hole 17 is It is communicatively connected to the port 14 via an oil groove 15. And the spring 21
is compressed only when the port 14 is pressurized, the pressure inside the cylinder 16 rises, and the piston body 12 is retracted to apply the pressure that causes the clutch to be "disengaged".

Reference numeral 23 denotes a boss provided facing the rear end surface of the oil port ring 2 in the axial direction. The boss 23 is fixed to the driven shaft 6 by spline fitting, and as the small piston 19 moves back, ,
A plurality of pins 2 protrude integrally with the small piston 19
2 act as a friction body that simultaneously contacts and generates frictional resistance (see Figure 2).

In the above configuration, in order to disengage the hydraulic clutch which is currently engaged, first operate the pressure control valve to pressurize the port 14 of the joint bolt 4, which will communicate with the port 14. The pressure inside the cylinder 16 increases gradually, and the piston body 12 retreats against the ammunition 13, and when it retreats to a predetermined position, the clutch can be "disengaged".

At this time, since the plug 18 side of the through hole 17 to which the small piston 19 is biased is in communication with the port 14 via the oil groove 15, a pressure of the same strength as the pressure inside the cylinder 16 is applied. The spring 21 that biases and supports the small piston 19 is strong enough to be compressed only when the pressure that causes the clutch to "disengage" is applied, so the small piston 19 ensures that the clutch "disengages". Then, it slides against the spring 21, and as a result, the plurality of pins 22 that protrude integrally with the small piston 19 simultaneously come into contact with the opposing sides of the boss 23. Therefore, the pin 22 will not protrude in the half-clutch state where the clutch is not "disengaged", and after the clutch is definitely "disengaged", a large frictional resistance is generated between it and the boss 23 and the driven shaft 6 is It can apply the brakes and prevent the hydraulic clutch from spinning. Moreover, since the small piston 19 that slides inward from the outer peripheral surface of the oil port ring 2 comes into contact with the boss 23 provided on the rear end surface of the oil port ring 2 in the axial direction, the anti-entanglement device prevents the rotation of the oil port ring 2. It does not protrude from the outer circumferential surface, and the entire structure can be made compact.

In short, the present invention provides a piston body on the driven side opposite to a clutch plate interposed between a driving shaft and a driven shaft, and presses the piston body against the clutch plate with the force of a bullet to cause the clutch to " In the hydraulic clutch, the piston body is retracted by hydraulic pressure from an oil port ring fixed to the fuselage side, and the piston is disconnected.
Inside the oil port ring, a plurality of small pistons that slide in the axial direction of the driven shaft are biased toward the piston body, and the plurality of small pistons are applied with hydraulic pressure that causes the clutch to be "disengaged." As a result, the friction body, which the plurality of small pistons that have retreated simultaneously come into contact with, is fixed to the driven shaft opposite the axial end surface of the oil port ring, so that when the hydraulic clutch is disengaged, the oil port Although the small piston that retreats outward from the ring comes into contact with a friction body fixed to the driven shaft and can easily prevent the small piston from rotating, the small piston is removed by using the hydraulic pressure that disconnects the hydraulic clutch. Since the clutch is moved backward, the clutch does not come into contact with the friction body before it is "disengaged," and it is possible to reliably prevent output loss, etc., from being applied to the driven shaft in a half-engaged state. Then, the small piston provided inside the oil port ring moves back and comes into contact with the friction body facing the axial end face of the oil port ring, so the anti-entanglement device does not protrude from the outer peripheral surface of the oil port ring. The whole can be made compact. In addition, since the plurality of small pistons simultaneously contact the side surface of the friction body, a large frictional resistance is generated, and rotation can be reliably prevented, resulting in extremely useful practical effects.

[Brief explanation of the drawing]

The drawings show an embodiment of the device for preventing the hydraulic clutch from rotating in a tractor according to the present invention, in which FIG. 1 is a longitudinal cross-sectional view, and FIG. 2 is a side view of a friction body. In the figure, 2 is an oil port ring, 6 is a driven shaft,
10 is a clutch plate, 12 is a piston body, 13 is a bullet, 19 is a small piston, and 23 is a friction body.

Claims (1)

[Scope of utility model registration request] A piston body is provided on the driven side opposite to the clutch plate interposed between the driving shaft and the driven shaft,
The piston body is pressed against the clutch plate by the bias of the bullet to make the clutch engage, and the piston body is retreated by hydraulic pressure from an oil port ring fixed to the fuselage side to disengage the hydraulic pressure. In the clutch, within the oil port ring, a plurality of small pistons that slide in the axial direction of the driven shaft are biased toward the piston body, and
The plurality of small pistons are caused to retreat by the hydraulic pressure that causes the clutch to be "disengaged," and the friction body, which the plurality of small pistons that have retreated simultaneously come into contact with, is fixed to the driven shaft opposite to the axial end surface of the oil port ring. A device for preventing a hydraulic clutch from rotating in a tractor, which is characterized by: