JPS5825889B2 - Automatic transmission of radiation from the aging process - Google Patents

Description

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention relates to an automatic power interruption device when a universal connecting shaft is bent.

As is well known, agricultural tractors and the like are used to tow a driven work machine such as a rotary at the rear of the tractor to carry out various tasks. In this case, a universal connecting shaft is interposed between the rear PTO shaft protruding from the rear of the tractor and the human power shaft of the work machine, and a configuration is adopted in which the driving force from the PTO shaft is transmitted to the input shaft of the work machine.

In such a power transmission device, it is common to ensure power transmission even when the working machine is raised or lowered.
This not only results in power loss because power transmission is performed even when power transmission is not required, but also creates problems in terms of safety during work.

Therefore, it is necessary to incorporate a means in the power transmission path for cutting off the power transmission when the working machine is raised.

SUMMARY OF THE PRESENT EMBODIMENT An object of the present invention is to provide a device which automatically cuts off the power transmission by bending a universal connecting shaft when a working machine, which is a driven shaft, is raised above a certain level.

In addition, this invention aims to provide a device that is designed not to cut off the power transmission in a situation where the universal joint of the connecting shaft bends in the opposite direction to the upward movement when a working machine such as a rotary is sunk to a certain extent in a farm field or the like.

A specific configuration of the present invention will be described below assuming that a PTO shaft of a tractor and a manpower shaft of a drive type working machine are connected by a universal connecting shaft.

In FIG. 1, reference numeral 1 denotes a rear PTO shaft protruding from the lower rear wall of a transmission case, and 2 denotes a universal connecting shaft having a universal joint 3. As is well known, one end of the PTO shaft 1 is connected to the universal joint 3.
The other end is connected to an input shaft of a working machine (not shown) via a driven shaft 4 and a universal joint or the like.

Reference numeral 5 denotes a driving shaft, the cylindrical portion 6 of which is spline-connected to the PTO shaft 1, and the pin member T prevents movement in the axial direction.

Splines are formed on the outer peripheral surface of the cylindrical portion 6 of the driving shaft 5, and a clutch driving body 8 having splines that mesh with the splines is fitted onto the outside of the driving shaft 5 so as to be slidable only in the axial direction.

The clutch drive body 8 has an engagement pawl 9 at a predetermined circumferential interval on its rear side, as shown in FIG. 2, and a spring 10 is resiliently mounted on the opposite side of the engagement pawl 9 to constantly urge the clutch drive body 8 in the connection direction.

Reference numeral 11 denotes a clutch passive body which is attached via a radial ball bearing 12 to the protruding shaft portion of the driving shaft 5, and has an engaging pawl 13 on the side opposite to the engaging pawl 9 of the clutch driving body 8 as shown in FIG. 2, and is essentially attached integrally to a yoke 14 of the universal joint portion 3.

The universal joint 3 is constructed by connecting a spider 15 to the yoke 14 via a pin 16.
A cylindrical shaft 17 is fixed integrally to the driven shaft 5, and the cylindrical shaft 17 is spline-connected to the driven shaft 4.

18 and 19 are a pair of cam members, one attached to a fixed member on the driving side and the other attached to a fixed member on the driven side, with the universal joint 3 as the boundary.
a, respectively.

One of the cam members 18 has its cylindrical portion 18b attached to the clutch driving body 8 via a thrust ball bearing 20 as shown in FIG. 1, and the inner peripheral surface of the cylindrical portion 18b is fitted onto the outer peripheral surface of the clutch driven body 11 so as to be freely rotatable relative to the outer peripheral surface of the clutch driven body 11.

The other cam member 19 has a cup-shaped portion including its contact surface 19a which surrounds the universal joint portion 3, and its cylindrical portion 19b is screwed into a screw cylinder 21 so as to be adjustable in the axial direction via a nut 22.

That is, the cam member 18 is fitted to the driving side of the universal connecting shaft 2 and is provided so as to be able to push and move the clutch driving body 8 while rotating relatively through a thrust ball bearing 20, and the cam member 19 is fitted to the driven side of the universal connecting shaft 2 and is ... driven shaft 4.
The coil spring 22 is attached to an exterior cylindrical body 24 (a non-rotating fixed member) which is fitted to the coil spring 22 so as to be rotatable relative to the coil spring 22.

The screw cylinder 21 is journalled to the shaft of the spider 15 via a radial ball bearing 23 and is fixed to an exterior cylindrical body 24 .

The contact surfaces 18a, 19a of a pair of cam members 18, 19 arranged opposite each other with the universal joint portion 3 as a boundary are made non-parallel as shown in FIG. 1, and in the illustrated example, the contact surface 19a is inclined with respect to the contact surface 18a so that the distance between them in the direction of ascending the working machine is small and the distance between them in the direction of descending the working machine is large.

In other words, the pair of contact surfaces 18a, 19a are arranged non-parallel to each other with a narrower gap always on the upper side of the universal joint portion 3 than on the lower side, so that the contact angle is smaller when the driven shaft 4 is bent upward from its concentric position relative to the driving shaft 5 than when it is bent downward.

In addition, as shown in the figure, reference numeral 25 denotes a dust cover for the thrust bearing 20, and a cam member 18 is provided with a cam ring 26 and the like.
The tubular portion 18b is in contact with the circumferential surface of the tubular portion 18b.

Reference numeral 27 denotes a retaining ring for the thrust bearing 20.

Of these, the example shown in FIG. 3 is another embodiment of the present invention, which has an improved clutch means but is otherwise basically the same as the example shown in FIG. 1, and therefore the common buttons and members are designated by the same reference numerals as those shown in FIG. 1.

The present invention configured as described above will be described in detail below.
In the normal state, that is, in the posture of the first illustrated example, the driving force from the PTO shaft 1 is transmitted to the driven shaft 4 in the conventional manner since the clutch engagement pawl 9, 13 is engaged by the spring 10.

From this state shown in FIG. 1, the driven side of the working machine or the like is raised (first
When the universal joint shaft 2 is moved to the A side in the figure, the universal joint portion 3
is bent.

When the lift range of the driven side reaches a certain level, the cam member 1
When the contact surface 19a of the cam member 18 comes into contact with the contact surface 18a of the cam member 18, the clutch driving body 8 is slid on the driving shaft 5 against the spring 10 in the direction in which the clutch is disengaged, and when the amount of sliding reaches or exceeds the point at which the clutch engagement pawls 9, 13 are disengaged, the power is automatically cut off.

On the other hand, when the driven side is gradually lowered from this raised position, the bending angle of the universal joint 3 gradually becomes smaller, and the spring 1
The clutch driving body 8 moves to the clutch passive body 1 through a resistance of 0.
1, so that when the contact surfaces 18a, 19a separate from each other, the clutch is again in 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, the contact surface becomes 18.
Since the distance between the opposing ends 19a and 19b can be adjusted, it is possible to cut off power at any time.

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

If the contact surfaces 18a, 19a were parallel, power transmission would be impossible (disconnected) even if the driven side was bent downward (toward B in Figure 1) around the universal joint 3. In this case, for example, when plowing work is performed in a sunken state in wet rice fields or the like with a working machine such as a rotary, the power transmission would be impossible and the work could not be performed.

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

In particular, when the input shaft of the working machine is not located behind the axis of the PTO shaft 1, the joint portion 3 of the universal connecting shaft 2 has a predetermined bending angle, so that the contact surface 18a is as described above.

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

As described above, this invention is such that when the driven shaft is bent upward or downward from its concentric position relative to the driving shaft, power transmission is automatically cut off at a relatively small angle when bent upward, and power transmission continues at a relatively small angle when bent downward. By applying this to the power transmission of a working machine such as a rotary tiller that is mounted on a tractor so that it can be raised and lowered, the working machine can be used at a lowered position and the power transmission is not cut off even when it is raised and lowered at a position where work is actually performed. Conversely, when the working machine is raised above the ground by changing the direction of the tractor, etc.,
The power is immediately cut off, preventing power loss and ensuring safety. In addition, the pair of cam members are non-rotating and rotate relative to the driving shaft, driven shaft and universal connecting shaft. Therefore, even if the pair of contact surfaces are not parallel, the narrow gap portion can always be positioned on the upper side when buttoned, which has the advantage that the power can be reliably maintained cut off when the driven shaft is bent upwards slightly.

[Brief description of the drawings]

The drawings show an embodiment of the present invention, with Fig. 1 being a side cross-sectional view of the main part, Fig. 2 being a cross-sectional view taken along line 1-1 in Fig. 1, and Fig. 3 being a cross-sectional view showing the other side of Fig. 1. 1... PTO shaft, 2... universal connecting shaft, 3... tear-free coupling portion, 4... driven shaft, 5... driving shaft, 8... clutch driving body, 10... spring, 18. 19... cam member, 18a. 19a... contact surface.

Claims (1)

[Claims] 1. A universal connecting shaft that transmits the power of a driving shaft to a 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 urge the clutch driving body in the clutch connecting direction; a clutch driven body fixed to the universal connecting shaft and cooperating with the clutch driving body to connect and disconnect power to the driven shaft; and a pair of cam members, one of which is fitted to the driving side of the universal connecting shaft and is provided so as to be able to push and move the clutch driving body while rotating relatively, with the other being fitted to the driven side of the universal connecting shaft and attached to a fixed member fitted to the driven shaft. a button provided on each of the pair of cam members, and a contact surface is provided opposite the pair of cam members, and when the universal connecting shaft is bent from the universal coupling portion, the two contact surfaces come into contact with each other to separate the clutch driving body from the clutch driven body against the spring, and the pair of contact surfaces are arranged non-parallel with a narrower gap always on the upper side of the universal coupling portion than on the lower side so that the contact angle is smaller when the driven shaft is bent upward from the concentric state relative to the driving shaft than when the driven shaft is bent downward.