JPH06322792A - Speed switching device for running lever - Google Patents

Abstract

PURPOSE:To simplify the coupling mechanism of a running lever and to reduce a space for a speed switching device to such a low value as possible. CONSTITUTION:A central boss 23 is mounted on a shaft 22, a support frame 26 for a running lever is fixed to the central boss 23, and detent plates 27 and 27 are fixed with a given distance therebetween. A telescopic shaft 29 is fitted internally of an outer cylinder 28 for the running lever and a lower end part 29a of the telescopic shaft is loosely fitted in the support frame 26. A moving boss 45 is pivotally mounted on a lower end part 29a of the telescopic shaft, a speed switching rod 48 is coupled to a plate 47 protruded from the moving boss 45, and the plate 47 is loosely fitted in a gap part between the detect plates 27 and 27.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a traveling lever device provided in a construction machine, and more particularly to a traveling lever speed switching device for operating forward and backward movement and turning of a vehicle body with a single lever.

[0002]

2. Description of the Related Art Among construction machines equipped with a traveling device using a hydraulic motor, there is known one in which the traveling operation of the machine body is performed by one traveling lever to simplify the operation. The traveling lever device having such a configuration connects the left and right hydraulic control valves via a link to a traveling lever that can swing back and forth, and moves the traveling lever back and forth to operate the left and right hydraulic control valves by approximately the same amount. Then, the aircraft is moved forward and backward at a speed according to the operation amount of the traveling lever. Further, the traveling lever is pivoted to the left and right around the axis to cause a difference in the operation amount of the left and right hydraulic control valves to pivot the machine body.

A hydraulic selector is connected to the lower end of the traveling lever through a link, and the hydraulic selector is pushed and pulled by moving the traveling lever up and down to switch the traveling mode of the machine to high speed or low speed.

[0004]

In the conventional traveling lever device of this type, the left and right hydraulic control valves and the hydraulic selectors are operated to be switched by the forward / backward swinging and lateral turning of the traveling lever, vertical movement and the like. However, the connecting mechanism was complicated and required a large space. Therefore, there is a technical problem to be solved in order to simplify the connecting mechanism of the traveling lever device and reduce the space of the speed switching device, and an object of the present invention is to solve this problem.

[0005]

DISCLOSURE OF THE INVENTION The present invention has been proposed in order to achieve the above-mentioned object, and a traveling lever swingable back and forth is moved back and forth to move the machine body forward and backward, and the traveling lever is pivoted. In a traveling lever device that pivots left and right to rotate the aircraft and further lowers the traveling lever to change the speed, a central boss is pivotally attached to a shaft provided in the left and right direction, A support frame for the travel lever is fixed to the boss, and a rotation stop plate is fixed to the lower portion of the central boss at a predetermined interval, and the lower end of the telescopic shaft fitted inside the outer cylinder of the travel lever is supported by the boss. It is loosely fitted in the frame, and a lower boss is pivotally attached to the lower end of the telescopic shaft so that it can swing around its axis, and a plate is projected on the lower boss to allow play in the gap of the rotation stop plate. Insert
A speed switching device for a traveling lever, characterized in that a speed switching rod is connected to the plate.

[0006]

[Operation] When the traveling lever is swung forward or backward, the central boss integrated with the support frame is turned forward or backward,
The left and right hydraulic control valves, which are connected via links, operate by approximately the same amount, and the aircraft moves forward and backward. When the traveling lever is rotated to the left or right around the axis, the link acts in the torsional direction to cause a difference in the operation amount of the left and right hydraulic control valves, and the machine body turns to either the left or right direction.

At that time, the telescopic shaft fitted in the outer cylinder of the traveling lever rotates in the same direction in the support frame, but the downward movement boss is provided in the gap portion of the detent plate fixed to the lower part of the support frame. The plate is locked and the lower boss and the plate do not rotate. Therefore, it is possible to prevent the speed switching rod connected to the plate of the lower moving boss from being twisted with respect to the rotation of the outer cylinder of the traveling lever and the expansion / contraction shaft.

When the traveling lever is moved downward, the telescopic shaft and the downward moving boss are moved downward in the supporting frame, and the plate of the downward moving boss is also slid downward along the gap of the rotation stop plate to switch the speed. Switch the hydraulic selector for.

[0009]

An embodiment of the present invention will be described in detail below with reference to the drawings. FIG. 1 is a side view of an ultra-small power shovel 11, in which traveling bodies 12a and 12b such as crawlers are attached to the left and right of a lower frame (not shown), and an upper frame 14 is mounted on the upper part of the lower frame via a turning device 13. Is mounted so that it can freely rotate. An engine part such as an engine is installed in the rear part of the upper frame 14, and a hydraulic excavator 15 is provided in the front part of the upper frame 14. Further, the control device 16 is provided on the front upper surface of the upper frame 14, and the operator seat 17 is fixedly mounted on the rear upper surface of the upper frame 14.

FIG. 2 is a perspective view of the control device 16. A traveling lever 19 is provided at the center of a lever stand 18 so as to be swingable back and forth, and left and right operation levers 20 and 21 are provided on both sides thereof.
Are provided so as to be swingable back and forth and left and right respectively. 3 and 4 show a connecting portion of the traveling lever 19, in which a central boss 23 is pivotally attached to a shaft 22 provided in the left-right direction, and a left boss 24 and a right boss 25 are pivotally attached to both sides thereof. A support frame 26 for the traveling lever 19 is fixedly mounted on the central boss 23, and a rotation stopper plate 27 is provided at a lower portion of the central boss 23 at a predetermined interval.
27 is fixed. The traveling lever 19 has a support frame 26.
The outer cylinder 28 is loosely fitted in the outer cylinder 28, and the telescopic shaft 29 is loosely inserted into the outer cylinder 28 to form a triple axis structure.

An arm 30 curved outward is fixed to one side of the upper end of the outer cylinder 28, and one side of a handle 31 is pivotally attached to the arm 30. The center of the lower end of the handle 31 is the expansion shaft 2
9, which is pivotally attached to the upper end portion of 9 as shown by the chain double-dashed line in FIG.
When the handle 31 is pressed downward, the handle 31 rotates around the pin 32 of the arm 30 and the expansion / contraction shaft 29 with respect to the outer cylinder 28.
Is configured to fly downwards. When the downward pressing of the handle 31 is released, the handle 31 is returned to its original position by the bias of the spring 33.

The outer cylinder 28 and the telescopic shaft 29 are supported by the support frame 26.
On the other hand, an interlocking plate 34 is integrally rotatable about an axis and is provided at a lower portion of the outer cylinder 28 at an upper position of the support frame 26 so as to integrally rotate with the outer cylinder 28. Further, the bell crank arm 35 is fixed to the left boss 24, and the right boss 25
The bell crank arm 36 is fixed to the link crank arm 36, one end of the bell crank arm 35 and one side portion of the interlocking plate 34 are connected by a link 37, and one end of the bell crank arm 36 and the other side portion of the interlocking plate 34 are connected by a link 38. To do.

On the other hand, if the handle 31 is pushed forward,
As shown by the chain double-dashed line in FIG.
Rotate forward around. If so, link 37,3
8 pushes one end of the bell crank arms 35 and 36, respectively, and the left boss 24 and the right boss 25 rotate and the rod 39,
40 down, hydraulic control valve 4 for left driving
1 and the hydraulic control valve 42 for right traveling are operated by approximately the same amount, and the machine body travels forward at a speed according to the operation amount of the traveling lever 19.

On the contrary, if the handle 31 is pushed rearward, the bell crank arms 35 and 36 rotate in the opposite direction to the above, although not shown, and the left and right hydraulic control valves 41 and 42 are opposite to each other. Is operated to move the aircraft backward. Also, if the handle 31 is twisted to the left or right, the outer cylinder 2
8 and the telescopic shaft 29 rotate around the axis of the traveling lever 19,
The links 37 and 38 connected to the interlocking plate 34 are pushed and pulled, and an angular difference occurs between the left and right of the rotation of the bell crank arms 35 and 36. Therefore, a difference occurs in the operation amount of the left and right hydraulic control valves 41, 42, and the machine body turns in either the left or right direction.

5 and 6 show the main part of the support frame 26. The front side of the support frame 26 fixedly mounted on the central boss 23 is obliquely cut out to open, and the rear side of the support frame 26 has a T-shape. The groove 43 is opened and the supporting frame 26 is formed.
An interlocking plate 34 is rotatably supported on the upper end surface of the. A pin 44 is provided on the lower end 29a of the expandable shaft 29 so as to project rearward, and the tip of the pin 44 projects rearward from the groove 43 of the support frame 26.

Therefore, as described above, when the handle 31 is twisted left and right to rotate the traveling lever 19 around the axis, the pin 44 moves left and right in the horizontal portion of the groove 43 shown in FIG. 28 and the expansion / contraction shaft 29 are guided to rotate, and the rotation angle is regulated. Here, the lower boss 45 is pivotally attached to the lower end 29a of the telescopic shaft 29 by a bolt 46 so that the lower boss 45 is pivotally mounted, and a plate 47 is provided on the front side of the lower boss 45 so as to project. It is loosely inserted into the gap of 27. This plate 47
Connect the upper end of speed switching rod 48 to pin 49,
As shown in FIG. 4, both ends of the pin 49 are fixed to the rotation stopper plates 27, 2
It is inserted into the long holes 50, 50 opened in 7. The lower end of the speed switching rod 48 is connected to an arm 53 of a hydraulic selector provided on the swivel joint 51 for speed switching.

As described above with reference to FIG. 4, when the handle 31 is pushed forward or backward to move the traveling lever 19 forward or backward, the detent plates 27, 27 fixed to the central boss 23 are also attached to the shaft 22.
Although it rotates about the
9 does not interfere with the detent plates 27, 27, and the traveling lever 19
The speed switching rod 48 is not pushed and pulled by the forward and backward movements of.

Although not shown, the lower end of the lower boss 45 may be connected to the upper end of the speed switching rod 48, and only the plate 47 may be loosely inserted into the gap between the detent plates 27, 27. In that case, the elongated holes 50, 50 are unnecessary, and even with such a configuration, the same operation as described above occurs. Further, the support frame 26 of the traveling lever 19 may be provided behind the shaft 22, and in such a case, the projecting direction of the plate 47 of the lower moving boss 45 is opposite to the front-rear direction.

Here, as described above with reference to FIG. 3, the handle 3
When the telescopic shaft 29 is slid downward with respect to the outer cylinder 28 by pressing 1 downward, the lower end portion 29a of the telescopic shaft slides on the lower end portion of the outer cylinder 28 as indicated by the two-dot chain line in FIG. And then descend. In that case, the lower boss 45 moves downward in the support frame 26 together with the lower end 29a of the expansion shaft.
The plate 47 also descends in the gap between the rotation stopping plates 27, 27. Therefore, the speed switching rod 48 is pushed down,
The arm 52 of the hydraulic selector shown in FIG. 4 is pushed downward to switch the hydraulic selector to the high speed position.

When the telescopic shaft 29 and the lower boss 45 move downward in the support frame 26, the pin 44 projecting from the lower end 29a of the telescopic shaft moves downward in the vertical portion of the groove 43 shown in FIG. The descending amounts of the telescopic shaft 29 and the lower boss 45 are regulated. The groove 43 is T-shaped, and when the telescopic shaft 29 and the lower boss 45 are moved downward, the pin 44 is located below the vertical portion of the groove 43. In such a state, the traveling lever 19 is moved left and right. You can't twist. That is, when the hydraulic selector is switched to the high speed position, the machine body cannot be turned, and it is possible to prevent the machine body from tipping over due to a rapid high speed turn.

Further, when the traveling lever 19 is twisted left and right to turn the machine body, the pin 44 is located at either the left or right end of the horizontal portion of the groove 43, and in this state, the telescopic shaft 29. Can not be moved down. That is, the hydraulic selector cannot be switched to the high speed position while the aircraft is turning,
Similar to the above, it is possible to prevent the body from tipping over due to a sharp turn at high speed.

When the outer cylinder 28 and the telescopic shaft 29 are rotated about the axis by twisting the handle 31 left and right, the plate 47 of the lower moving boss 45 is inserted into the gap between the rotation stop plates 27, 27. Therefore, the lower boss 45 does not rotate and the traveling lever 19
The speed switching rod 48 is not pushed or pulled by the rotation of. The present invention can be variously modified without departing from the spirit of the present invention, and it goes without saying that the present invention extends to the modified one.

[0023]

Since the present invention is configured as described in detail in the above one embodiment, the lower boss can be prevented from rotating together with the traveling lever when the traveling lever is rotated left and right. Torsional force does not act on the speed switching rod. Therefore,
The durability of parts is improved. Further, by integrally disposing the member for turning operation of the machine body and the member for speed switching operation, the connecting mechanism of the traveling lever device is simplified, the space of the speed switching device is reduced, and the size of the device is reduced. Can contribute to

[Brief description of drawings]

FIG. 1 is a side view of a micro power shovel.

FIG. 2 is a perspective view of a control device.

FIG. 3 is a partially cutaway front view of a connecting portion of a traveling lever.

FIG. 4 is a partially cutaway side view of a connecting portion of a traveling lever.

FIG. 5 is a sectional view of a main part of a supporting frame.

FIG. 6 is a partially cutaway view of a portion taken along the line AA of FIG.

[Explanation of symbols]

 19 Traveling lever 22 Shaft 23 Central boss 26 Support frame 27 Rotation stop plate 28 Outer cylinder 29 Expansion shaft 29a Lower end 45 Downward movement boss 47 Plate 48 Speed switching rod

Front page continuation (72) Inventor Kazushi Ochi 1 Yakura, Tobe-cho, Iyo-gun, Ehime, Engineering Department, Iseki Agricultural Machinery Co., Ltd. Within the corporation

Claims (1)

[Claims] 1. A forward / backward swingable traveling lever is moved back and forth to move the aircraft forward and backward, and the traveling lever is pivoted left and right around an axis to swivel the aircraft, and further, the traveling lever is moved downward. In a traveling lever device that performs speed switching by means of a central boss, the central boss is pivotally attached to a shaft provided in the left-right direction, and the supporting frame of the traveling lever is fixedly mounted on the central boss, and a predetermined interval is provided below the central boss. With the rotation stopper plate fixed, the lower end of the telescopic shaft fitted inside the outer cylinder of the travel lever is loosely fitted in the support frame, and the lower boss is attached to the lower end of the telescopic shaft. The speed change of the traveling lever is characterized in that the speed change rod is pivotally mounted around the lower movement boss, the plate is projected from the lower boss, the plate is loosely inserted into the gap of the rotation stop plate, and the speed change rod is connected to the plate. apparatus.