JPS5825889B2 - I'm not sure what to do. - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an automatic power cut-off device when a universally connected shaft is in trouble.

As is well known, various types of work are carried out on agricultural tractors and the like by attaching rotary or other drive-type working machines to the rear of the tractor.In this case, the rear PTO shaft protruding from the rear of the tractor, A configuration is adopted in which a flexible connecting shaft is interposed between the power shaft of the work machine and the motive power from the PTO shaft is transmitted to the input shaft of the work machine.

Such power transmission devices usually ensure power transmission even when the work equipment is elevated.
This causes power loss since power transmission is performed even when power transmission is not necessary, and also poses problems in terms of safety during work.

Therefore, it is required to incorporate a means for cutting off the power transmission when the working machine is elevated into the above-mentioned power transmission path.

The present invention aims to provide a device in which power transmission is automatically cut off by bending a freely connecting shaft when a working machine, which is a driven shaft, is raised above a certain level.

However, in this invention, if a working machine such as a rotary sinks to some extent in a field, the universal joint of the connecting shaft will bend in the opposite direction to the upward movement, but in such a situation, the power transmission is not cut off. The aim is to provide a device that has been devised.

Hereinafter, a specific configuration of the present invention will be described assuming that a PTO shaft of a tractor and a human power shaft of a drive-type working machine are connected by a flexible connecting shaft.

In FIG. 1, 1 is a rear PTO shaft protruding from the lower rear wall of the transmission case, 2 is a universal connection shaft having a universal joint 3, and as is well known, one end of the shaft is connected to the PTO shaft 1.
The other end is connected to an input shaft of a working machine (not shown) via a driven shaft 4 button, a universal joint, etc.

Reference numeral 5 denotes a driving shaft, the cylindrical portion 6 of which is splined to the PTO shaft 1, and movement in the axial direction is prevented by a pin member T.

A spline is engraved on the outer peripheral surface of the cylindrical portion 6 of the drive shaft 5, and a clutch drive body 8 having a spline that meshes with the spline is fitted onto the drive shaft 5 so as to be slidable only in the axial direction.

The clutch driving body 8 has an engaging pawl 9 on the rear side thereof at a predetermined interval in the circumferential direction, as shown in the second figure, and a spring 10 is elastically interposed on the opposite side of the engaging pawl 9. The clutch driving body 8 is always urged in the connecting direction.

Reference numeral 11 denotes a clutch passive body, which is mounted on the protruding shaft portion of the drive shaft 5 via a radial ball bearing 12. It has an engaging pawl 13 on the yoke 13, and is substantially integrally attached to the yoke 14 of the universal joint portion 3.

The universal joint part 3 is constructed by connecting a spider 15 to a pin 16 to the yoke 14, and this spider 1
A cylindrical shaft 17 is integrally fixed to the shaft 5, and the cylindrical shaft 17 is splined to the driven shaft 4.

Reference numerals 18 and 19 denote a pair of cam members, one of which is attached to a fixed member on the driving side and the other on the driven side, with the universal joint portion 3 as a boundary, and annular contact surfaces 18a and 19 are provided on opposing portions of the cam members.
a.

One cam member 18 has a cylindrical portion 18b attached to the clutch driving body 8 via a thrust ball bearing 20 as shown in the first figure, and the inner peripheral surface of the cylindrical portion 18b is the outer periphery of the clutch passive body 11. It is fitted onto the surface so that it can freely rotate relative to the surface.

The other cam member 19 has a bowl-shaped portion including the contact surface 19a and surrounds the universal joint portion 3, and its cylindrical portion 19b is screwed into the threaded cylinder 21 and is axially connected via the nut 22. adjustment is possible.

That is, the cam member 18 is fitted on the driving side of the universal connecting shaft 2 and is provided so as to be able to push the clutch driving body 8 while relatively rotating through the thrust ball bearing 20, and the cam member 19 is fitted on the driving side of the universal connecting shaft 2. is fitted on the driven side of the driven shaft 4.
It is attached to an exterior cylinder 24 (a non-rotating fixed member) which is fitted in a relatively rotatable manner.

The threaded cylinder 21 is pivotally supported by the shaft portion of the spider 15 via a radial ball bearing 23, and is fixed to the exterior cylinder body 24.

The contact surfaces 18a and 19a of the pair of cam members 18 and 19, which are provided facing each other with the universal joint portion 3 as a boundary, are non-parallel as shown in the first figure, and in the illustrated example, the opposing interval in the upward direction of the working machine is The abutment surface 19a is inclined with respect to the abutment surface 18a so that the opposing distance in the lowering direction of the working machine is a dog.

That is, the pair of abutment surfaces 18a and 19a are flexible so that they abut at a smaller angle when the driven shaft 4 is bent upward from the driving shaft 5 than when it is bent downward from the concentric position. The upper side of the joint part 3 always has a narrower gap than the lower side, and they are arranged non-parallel to each other.

In addition, as shown in the figure, 25 is a dustproof cover for the thrust bearing 20, and 01J ring 26, etc. are connected to the cam member 18.
The cylindrical portion 18b is circumferentially connected to the cylindrical portion 18b.

27 indicates a retaining ring for the thrust bearing 20.

Among them, the one illustrated in FIG. 3 is another specific example of the present invention, which has an improved clutch means and is basically the same as the first illustrated example, so the common partial buttons and members are The same reference numerals as in the first illustration are used.

A detailed explanation of this invention configured as above is as follows:
In a normal state, that is, in the position shown in the first illustrated example, the motive force from the PTO shaft 1 is transmitted to the driven shaft 4 in the conventional manner because the clutch engaging pawl 9 13 is engaged by the spring 10 .

From this state shown in the first diagram, the driven side of the work equipment, etc. is raised (first
(A side in the figure), the universal connecting shaft 2 is connected to its universal joint 3.
is bent.

When the lifting range of the driven side exceeds a certain level, the cam member 1
The contact surface 19a of the cam member 18 contacts the contact surface 18a of the cam member 18, and slides the clutch driving body 8 on the driving shaft 5 in the direction in which the clutch is disengaged against the spring 10. When the engagement claws 9, 13 become disengaged, the power is automatically cut off.

On the other hand, when the driven side is gradually lowered from this elevated position, the bending angle of the universal joint 3 gradually becomes smaller, and the spring 1
The clutch driving body 8 connects to the clutch passive body 1 through a drag force of 0.
1, so when the contact surfaces 18a and 19a separate, the clutch returns to the connected position.

Then, as shown in the figure, the cam member 19 is connected to the other cam member 1.
If you press the button so that you can move near and far with respect to 8, the contact surface 18
Since the facing distance between a and 19a can be adjusted, it is possible to intermittent the power at any time.

At this time, in the present invention, since the contact surfaces 18a and 19a are not parallel but non-parallel, the following advantages are exhibited.

If the abutting surfaces 18a and 19a are parallel, power transmission will be impossible (disconnection) even if the driven side is bent in the downward direction (toward B in FIG. 1) around the universal joint 3, and in this case, for example, When plowing in a wet field with a rotary or other working machine submerged, the work cannot be ensured because the power cannot be transmitted.

However, in the present invention, even if the working machine sinks to a certain extent, power transmission becomes possible and the work can be ensured.

In particular, when the input shaft of the work equipment is not located behind the axis of the PTO shaft 1, the joint portion 3 of the universally connected shaft 2 has a bending angle in advance, so that the contact surface 18a.

By making 19a non-parallel and pressing the button, the power transmission cutoff timing can be set arbitrarily.

The present invention is as described above, and when the driven shaft is bent vertically from being concentric with the driving shaft, power is automatically cut off at a relatively small angle when turning upward, and relatively when turning downward. Power transmission continues at a small angle, and by applying it to the power transmission of rotary tillers and other working equipment mounted on a tractor so that it can be raised and lowered, the working equipment can be used in a lower position. Power transmission is not cut off even when the work equipment is raised or lowered at the actual work position, and conversely, when the work equipment is lifted off the ground due to changes in direction of the tractor, etc.
The power is immediately cut off, preventing power loss and ensuring safety, and the pair of cam members do not rotate, but rotate relative to the driving shaft, driven shaft, and universally connected shaft, Therefore, even if the pair of contact surfaces are non-parallel, the narrow gap between them can always be placed on the upper side when the button is pressed, and this makes it possible to reliably maintain power disconnection when the driven shaft is bent slightly upward. There are advantages.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention, and FIG. 1 is a side sectional view of the main part thereof, FIG. 2 is a sectional view taken along the line ■-■ in FIG. 1, and FIG. 3 is a sectional view showing the other side of FIG. 1. It is a diagram. DESCRIPTION OF SYMBOLS 1... PTO shaft, 2... Universal connection shaft, 3... Permanent joint part, 4... Driven shaft, 5... Driving shaft, 8... Clutch driving body, 10... Spring , 18.19... cam member, 18a. 19a...Abutment surface.

Claims (1)

[Claims] 1. A universally connected shaft that transmits the power of the driving shaft to the driven shaft;
A clutch driving body provided on the driving shaft so as to be slidable only in the axial direction; a spring provided on the driving shaft so as to constantly bias this clutch driving body in the direction of clutch connection; and a freely connecting shaft. A clutch passive body that is fixed and works in cooperation with the clutch driving body to connect and disconnect power to the driven shaft; A pair of cam members are provided so as to be able to push the clutch driving body without relative rotation, and the other is fitted to the driven side of the universally connected shaft and is attached to a fixed member fitted to the driven shaft. Button, contact surfaces are provided opposite to each of the pair of cam members, and when the universal connecting shaft is bent from the universal joint part, both liquid contact surfaces come into contact with each other, and the clutch driving force resists the spring. is configured to separate from the clutch passive body, the pair of contact surfaces are smaller when the driven shaft is bent upward from being concentric with the driving shaft than when bent downward. Automatic power connection/disconnection at the time of cornering of the universal connecting shaft, characterized in that the upper side of the universal joint part is always arranged in a non-parallel manner with a narrower gap than the lower side so as to contact at an angle. Device.