JPS5927697Y2 - Power take-off shaft automatic stop device for tractors - Google Patents

Description

[Detailed explanation of the invention] This invention has a button on the tractor and when the work equipment rises,
The present invention relates to a power take-off shaft automatic stopping device that prevents danger due to rotation of a rotary blade of a working machine by cutting off power transmission to the power take-off shaft, and eliminates waste of power.

Conventionally, a power take-off shaft automatic stop device has been proposed in which a lift arm is connected to a release fork of a power take-off clutch by a hydraulic control device or a link and an arm.

However, with this automatic stop device, the amount of movement associated with the rotation of the lift arm is significantly larger than the amount of clutch release, so it is difficult to operate the clutch in a timely manner and without strain, and there are obstacles to implementing this device. It had become.

Therefore, the present invention provides a cam that rotates in conjunction with the lift arm, is configured so that the power take-off clutch can be operated by the cam, and is further provided with a lever on the cam, and the cam is lifted by operating the lever. It is configured so that its relative position with respect to the arm can be changed, and thereby the cam profile can be created in a shape that adapts to the clutch release characteristics, and the engagement and disengagement timing of the power take-off clutch can be arbitrarily adjusted. It is an object of the present invention to provide an automatic stopping device for a power take-off shaft in a tractor, which eliminates the above-mentioned drawbacks by being able to release the stopping device.

Hereinafter, based on the example shown in the illustration, the main part will be explained in detail.

As shown in FIG. 1, the tractor 1 has an engine 3 mounted on the front part of a body 2, and a driver's seat 7 consisting of a steering wheel 5, a seat 6, etc. from the middle to the rear part.

A transmission 8 is arranged below the driver's seat 7, and transmits the power of the engine 3 to the rear wheels 10 by changing the speed.
The power is also transmitted to the power take-off shaft 12 via the power take-off clutch 11 .

A hydraulic actuating device 13 consisting of a piston and a cylinder is disposed at the top of the mission 8 and has a lift fork shaft 15 whose both ends protrude from the hydraulic case.

As shown in FIG. 2, a lift arm 16 is fixed to the lift fork shaft 15 by a spline 15a, and the tip of the arm 16 is connected to a traction link 18 via a lift rod 17.

A cam 20 is loosely fitted onto the lift fork shaft 15, and the cam 20 is attached to one side of the lift arm 16 with a bolt 25 via a washer 21, a spring 22, and a washer 23. There is.

Further, chrysanthemum seats 16a and 20a are provided on one side of the lift arm 16 and one side of the cam 20, respectively.
In the joined state, the arm 16 and the cam 20 rotate together.

Further, a lever 26 is fixed to the cam 20, and a guide plate 27 is further provided along the rotation surface of the lever 260.

On the other hand, an arm 28 is provided adjacent to the cam 20 so as to be rotatable by being fitted on a fulcrum pin 28c.
8a is in contact with the cam 20.

Further, a link 30 is connected to the other end 28b of the arm 28, and the further link 30 is connected to a lever 32 fixed to another cam 31.

The cam 31 has a cylindrical shape with a part cut out,
Furthermore, the lever 3 fixed to the release fork shaft 33
It is in contact with 5.

The release fork shaft 33 extends into the transmission 8 and fixes the release fork 36.

Further, the release fork 36 can operate the power take-off clutch 11 and disconnect/disconnect power transmission to the power take-off shaft 12 .

In addition, 40 in FIG. 1 is a manual operation lever for the power take-off shaft which allows the release fork shaft 33 to be directly operated.

Since the present invention has the above configuration, the tractor 1
When turning, etc., the hydraulic actuator 13 is operated by the operating lever, and the lift arm 1 is moved through the lift fork shaft 15.
Turn 6 to raise the work equipment.

At the same time, the cam 20 rotates together with the lift arm 16 because the chrysanthemum seat 20a is joined to the chrysanthemum seat 16a of the lift arm 16 by the biasing force of the spring 22, and as the lift arm 16 rises, the cam 20 rotates together with the lift arm 16. The protrusion A is arm 2
8 is pushed, and the arm 28 is rotated counterclockwise.

As a result, the cam 3
1 rotates, and the lever 35 is further pushed by the cam 31, thereby rotating the release fork shaft 33.

The fork shaft 33 rotates the release fork 36 integrated therewith to operate the power take-off clutch 11 in the disengaged direction, and power transmission to the power take-off shaft 12 is interrupted.

Conversely, the lift arm 16 is operated by the hydraulic actuator 13.
When the working machine is lowered via
Power transmission to 2 is connected.

Then, the lever 26VC resists the joining force of the chrysanthemum seats 16a and 20a due to the force of the spring 23, and the cam 2
By rotating the guide plate 27 within the automatic range a of the guide plate 27 with respect to the lift arm 16, the contact position between the cam 20 and the arm 28 can be changed, and the timing of engagement and engagement of the power take-off clutch 11 can be changed.

Further, when the lever 26 is rotated in the direction of arrow C until it reaches the release range, even if the cam 20 rotates as the work equipment is raised and lowered by the lift arm 16, its protrusion A will not touch the arm 28. There is no contact, and the power take-off clutch 11 remains connected.

button, the link 30 is directly connected to the release fork shaft 33 as shown in FIG. 3, without using the cam 31 as in the above embodiment.
Of course, it may also be connected to the lever 35 of.

Further, in FIG. 3, 37 is a running latch, and 38 is a fork shaft for the running latch.

As explained above, according to the present invention, the lift arm 1
Since the power take-off clutch 11 is operated by the cam 20 interlocked with the lift arm 6, the cam profile can be made into a shape adapted to the clutch release characteristics, and the optimum position can be achieved regardless of the amount of rotation of the lift arm 16. The power take-off clutch 11 can be operated at this time.

Furthermore, since the relative position between the lift arm 16 and the cam 20 can be changed, the power take-off clutch 11 can be engaged and engaged at any position within the entire lifting range of the lift arm 16 by an extremely simple operation using the lever 26. , cam 2
By rotating the protrusion A to a position where the protrusion A does not come into contact with the arm 28 even when the lift arm 16 is rotated, the automatic stopping device of the power take-off shaft 12 due to the lifting of the working machine can be released.

Furthermore, the cam 20 having the lever 26 may be provided on the lift fork shaft 15, and the structure is extremely simple and compact, and is mechanically stable, so the operation is reliable. Furthermore, there is no deviation in the disconnection and connection positions of the power take-off clutch 11 when the lift arm 16 is raised and lowered.

[Brief explanation of the drawing]

Figure 1 is a side view of a tractor to which the present invention is applied;
FIG. 2 is an exploded perspective view of the main parts of the present invention, and FIG. 3 is a side view showing another embodiment. 1...Tractor, 11...Power take-off clutch, 12...Power take-off shaft, 13...
... Hydraulic actuation device, 15 ... Lift fork shaft, 16 ... Lift arm, 20 ... Cam, 26 ... Lever 28 ...・Arm, 36...Release fork.

Claims (1)

[Scope of utility model registration request] A cam that has a lever on the lift fork shaft that fixes the lift arm in a tractor that raises and lowers the work equipment by rotating the lift arm using a hydraulic actuator and transmits power to the work equipment via a power take-off clutch. The cam is always connected to the lift arm and is biased to rotate together with the lift arm, and its relative position with the lift arm can be changed by operating a lever against the biasing force. Further, the cam is brought into contact with an arm that is linked to the release fork of the power take-off clutch,
Based on the rotation of the cam, the power take-off clutch is disconnected when the lift arm is raised, and the power take-off clutch is connected when the lift arm is lowered, so that the protrusion of the loosened cam does not come into contact with the arm. A power take-off shaft automatic stopping device configured to change the position of a cam and release the operation of a power take-off clutch by the cam.