JPS5849134B2 - Unstable switching operation mechanism of operating lever - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a tension clutch and a travel brake for a traveling device of a mobile agricultural machine, for example, which are interlocked and connected to one swing operation lever, and the clutch is engaged by forward and reverse swings of this operation lever. a first operating state in which the brake is released;
The present invention relates to a mechanism for switching between a second operating state in which the clutch is disengaged and the brake is operated in a braking action in a manner contrary to each other.

Generally speaking, an operating mechanism in which the actuating device can be operated only by linear movement (swinging back and forth) of a lever has excellent operability.

Of the travel clutch and travel brake, for the brake, as seen in the drive brake of a car, in order to ensure its effectiveness, it is necessary to lock the operating lever at the position where the operating force to the brake is greatest. There is.

Furthermore, due to the nature of brakes, for example, when a brake drum and a brake shoe are pressed into contact with each other, the operation reaction force becomes extremely large, but before that, the reaction force is small.

Under these circumstances, in conventional clutch brakes in which the clutch and brake are operated sequentially, a recessed groove in a direction perpendicular to the operating path is installed in the guide panel, etc. that forms the guide groove of the swing operating lever. Conventionally, the operating lever was locked and held in the groove by bending the lever perpendicular to the swinging operation, and the operating state of the clutch and brake was maintained by locking and holding the lever. Said demand for movement has not been met in clutch brakes.

SUMMARY OF THE INVENTION An object of the present invention is to provide an operating mechanism that allows a clutch brake to be turned on and off using only a linear motion, and that can reliably maintain the turned-off state.

A technical feature of the present invention is that when the traveling clutch, which has a large operating reaction force in the operating state, is activated to a first operating state, the operating reaction force causes the operating lever to undergo an unstable switching action around its fulcrum. The structure is configured to be stably maintained in the first operating state, and when the travel brake is activated with a small operation reaction force in the operating state, the second operating state is set.
The operating lever is configured to be stably maintained in the second operating state by the action of an unstable switching spring provided separately, and the following effects are achieved.

According to the present invention, the first drive clutch, which has a large operation reaction force,
Maintaining unstable switching in the operating state is ensured by a strong unstable switching action around the lever fulcrum that utilizes the large operation reaction force, and also prevents instability in the second operating state of the travel brake where the operation reaction force is small. Since the switching is maintained reliably by the action of another unstable switching spring that does not utilize the operation reaction force, the clutch and brake can be reliably turned on and off with a simple linear motion.

As a means for unstable switching, it is also conceivable to configure the partner of the clutch and brake with an unstable switching mechanism that utilizes the operation reaction force, or a switching mechanism that uses the action of an unstable switching spring.

However, in the former case, the flake cannot maintain a stable position due to its small operation reaction force, and after passing the dead point of unstable switching, the braking force weakens. The disadvantage is that the brake cannot be applied reliably in order to operate, and in the case of the latter, a clutch with a large operation reaction force has the disadvantage that the spring force acts in addition to its own operation reaction force, so the clutch's The disadvantage is that it is very difficult to operate.

As is clear from this, in the present invention, by rationally combining a switching mechanism that uses operation reaction force and a switching mechanism that uses a spring, the clutch brake, which was previously thought to be impossible, This enables reliable on/off operation using only linear motion.

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows a mobile threshing machine as an example of a working vehicle equipped with the traveling clutch brake of the present invention, which is equipped with a pair of left and right crawler traveling devices 1 at the bottom and a vehicle body 3 with an engine 2 mounted at the rear. A threshing device 4 is removably mounted on the front part of the vehicle, and a grain bagging section 5 for bagging the grains from the threshing device 4 is installed at the rear of the vehicle body.

FIG. 2 shows the drive structure of the traveling device 1, in which the power of the engine output shaft 6 is transmitted to the input shaft 9 of the traveling transmission case 8 via the transmission belt 7, and the speed is appropriately changed by operating the speed change lever 10. Thereafter, the power is transmitted to the traveling device 1 via the drive shaft 11, and the power to the traveling device 1 is actuated by the tension clutch (first actuating device) 12 which acts on the transmission belt 7. It is configured to be controlled and released intermittently by the operation of a travel brake (second actuation device) 13 installed in the transmission case 8.

The tension arm 14 of the tension clutch 12 is always urged toward the clutch release side by a spring 15, and is interlocked and connected to an operating lever 17 pivotally connected to a steering wheel 16 via a release wire 18 and a stroke absorbing spring 19. ing.

Further, the traveling brake 13 is constructed as a friction brake with a set of internally expanding shoes using a cam, and its brake lever 20 is interlocked and connected to the same operating lever 17 via a release wire 21.

FIG. 3 shows the operating lever 17 and the release wire 18.2.
1, the operating lever 17 is supported by the operating knob 16 via a support shaft 22 so as to be swingable in the front and rear direction, and the operating lever 17 has a balance-shaped first arm 23 and a cantilever. A second arm 24 having a shape of A wire in which the tip of the lower arm portion of the first arm 23 and the operating end of the travel brake release wire 21 are connected, and the operating side outer wire ends of both relief wires 18 and 21 are connected from the operating handle 16. It is supported by the receiving metal fitting 26 at the same position.

Further, an unstable switching spring 28 is stretched across the tip of the second arm 24 and a pin 27 provided on the control handle 16.

When the operating lever 17 is at the forward swing limit position shown in a in FIG. 3, the clutch wire operating point and brake wire operating point of the first arm 23 are at positions Pa and Qa, respectively, and the wire 18 is pulled The tension clutch L2 is engaged and operated, and the wire 21 is loosened and the travel brake 13 is released. At this time, the clutch wire operating point P of the first arm 23 is
A is in a position forward beyond the dead point D, and the position of the operating lever 17 is unstable due to the strong tension of the wire 18, which receives the belt tension reaction force, the restoring force of the tension return spring 15, and the stroke absorption spring 19. Stably maintained by switching action.

Further, when the operating lever 17 is at the rearward swing limit position shown in b in FIG. 15, the wire 21 is tensioned and the travel brake 13 is in a second operating state.

Moreover, at this time, the unstable switching spring 28 crosses the dead point H and stably holds the operating lever 17 at the b position.

When the operating lever 17 is in position C in FIG.
The tension clutch 12 is in an important conversion state with almost no power transmission, and the travel brake 13 is in a braking start state.

As shown in Figure 3, the tension clutch 1
2 is engaged when the clutch wire operating point is between Pa and PcO, is disengaged when it is between PC and pbO, and is disengaged when the travel brake 13 brake wire operating point is between Oa and QcO, and is engaged between Qc and QbO. At a certain time, when both wire operating points are at or near Pc and Qc, the traveling device 1 is in a completely neutral state where neither driving nor braking is performed, or almost no power transmission and braking are performed. A nearly neutral state is brought about.

Although the unstable switching spring 28 is relatively weak, the brake lever 20 is capable of sufficiently resisting the brake shoe inner expansion cam operation reaction force, which is smaller than the clutch reaction force.

[Brief explanation of the drawing]

The drawings show an implementation fI1 of the unstable switching operation mechanism of the operating lever according to the present invention, and FIG. 1 is an overall side view of the mobile threshing machine;
FIG. 2 is a side view of the traveling device drive section, and FIG. 3 is a side view of the unstable switching operation section. 12.13... Actuation device, 17... Operation lever 28
...Unstable switching spring.

Claims (1)

[Claims] 1 Traveling clutch 12 with a difference in operation reaction force in the operating state
and the traveling brake 13 are interlocked and connected to one rocking operating lever 17, and by swinging the operating lever 17 forward and backward, when one is activated or deactivated, the other is deactivated or activated. In this structure, when the traveling clutch 12, which has a large operation reaction force toward the operation state, is activated to the first operation state, the operation reaction force causes the operation lever to 17 is configured to be stably held in the first operating state by an unstable switching action around its fulcrum, and when the travel brake 13, which has a small operation reaction force in the operating state, is activated to enter the second operating state, An unstable switching operation mechanism for an operating lever, characterized in that the operating lever 17 is stably maintained in the second operating state by the action of an unstable switching spring 28 provided separately.