JP2002054180A - Structure and locking device for monolever - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a simple structure for a monolever, having little play and allowing the motion of a control lever to be reliably taken out exteriorly, and a locking device therefor. SOLUTION: A rotational shaft (12) rotated while following the tilting of the control lever (14) is mounted at the supporting point of tilting of the control lever (14). The end part of the rotational shaft (12) is protruded from a body (10), and a mechanism for conducting locking in a neutral position is mounted on the rotational shaft (12) installed in such a manner as to be able to be held in an arbitrary rotational position. The locking mechanism is provided with a locking lever (18) mounted on the rotational shaft (12) in a protruding manner and a bifurcated lever (21) fixedly installed in a vertical shaft (20) installed rotatably in order to be approximately orthogonal to the rotational shaft (12) in the vicinity of the rotational shaft (12) and conducting the locking in the neutral position while supporting the locking lever (18) in such a manner as to sandwich it by a locking slit (22) whose end part is opened when rotated to the side of the locking lever (18). The bifurcated lever (21) is preferably provided with a tapered part (23) in the end opening of the locking slit (22).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a monolever structure and a monolever locking device used for various operations of construction machines and the like.

[0002]

2. Description of the Related Art In construction machines such as bulldozers, mono-lever-type traveling operation levers and work implement operation levers are used. Then, while the driver is away from the driver's seat, the traveling operation lever and the work equipment operation lever are moved,
If the driver starts the engine without knowing it, the vehicle or the work machine may move unexpectedly and cause danger. Therefore, when the driver gets off the vehicle, it is common practice to lock the travel operation lever and the work implement operation lever.

FIG. 7 is a drawing showing the structure of a first example of a conventional monolever locking device. An operation lever 14 for traveling is attached to an upper part of a mono-lever type pressure proportional control valve 10a for traveling operation attached to the console frame 2 of the vehicle body. By tilting the operation lever 14 in the front-rear direction, forward and backward control and speed control of the vehicle can be performed. When the vehicle is tilted in the left-right direction, the vehicle turns left and right. When the operation lever 14 is tilted back and forth, the operation lever 14 is held at an arbitrary position and can be maintained at a desired speed. A first lever 51 is fixed substantially horizontally below the operation lever 14, and when the operation lever 14 is tilted in the front-rear direction, the tip end of the first lever 51 swings up and down. The distal end of a second lever 53 fixed to a first shaft 52 having a left-right axial center and rotatably attached to the console frame 2 and the distal end of the first lever 51 They are connected by one link 54. Second lever 5
A plate 55 is protrudingly provided at the base end of 3. A second shaft 56 is rotatably attached to the console frame 2 below the first shaft 52 at a right angle to the axis of the first shaft 52 and perpendicular to the axis of the first shaft 52. 2-axis 56
When the second shaft 56 rotates, the plate 5
A bifurcated plate 57 that engages with No. 5 is attached. Second
A third lever 58 is provided at one end of the shaft 56 in a direction orthogonal to the axis.
Is attached. Further, a third shaft 60 is rotatably attached to the console frame 2 in parallel with the second shaft 56, and a fourth radial lever 6 fixed to the third shaft 60 is provided.
1 and the third lever 58 are connected by a second link 62. A fifth lever 63 is attached to one end of the third shaft 60 in a radial direction.
They are connected by 4.

Next, the operation of the above configuration will be described.
When the driver leaves the vehicle, the driver sets the operation lever 14 to the neutral position and turns the boarding / closing breaker to the open position. Accordingly, the third shaft 60 and the second shaft 56 rotate via the above link mechanisms, and the forked plate 57 sandwiches the plate 55 as shown by a thin two-dot chain line. Therefore, the swing of the second lever 53 is locked, and the swing of the first lever 51 is also locked with it. As a result, the operation of the operation lever 14 in the front-rear direction becomes impossible. The operation lever 14 is not moved.

FIG. 8 is a diagram showing the configuration of a second example of a conventional monolever locking device. Console frame 2
An operating lever 14 for the working machine is mounted on the upper part of the mono-lever type pressure proportional operating valve 10b for operating the working machine attached to the work machine. The operation lever 14 is tilted back and forth, and performs operations of, for example, each position of raising, holding (neutral position), lowering, and floating the work implement. When the work implement is raised or lowered, the operation lever 14 automatically returns to the neutral position when released, and in the floating position, the operation lever 14 is locked at that position by a detent (not shown). .
At the lower part of the operation lever 14, a plate 71 having an engagement hole 72 at a distal end portion is fixed forward. Console frame 2 to which pressure proportional operation valve 10b is attached
On the front side of the vehicle, a boarding / closing prevention breaker 32 having a first lever 80 is rotatably attached to the side of the driver's seat. The boarding / closing prevention circuit breaker 32 is in a horizontal position during driving to prevent the driver from getting off the vehicle, and the driver always pushes down when leaving the vehicle. A second lever 82 is rotatably mounted on a shaft 81 provided horizontally in the left-right direction in front of the operation lever 14.
The lever 82 is connected by a link 83. Second
A plate 84 having a locking pin 85 is fixedly provided on the operation lever 14 side opposite to the shaft 81 of the lever 82. The engagement hole 72 of the plate 71 and the locking pin 85 of the plate 84 are engaged with each other when the operation lever 14 is set to the neutral position and the breaker 32 is opened, and the operation lever 14 is tilted. Is to be locked.

Next, the operation of the above configuration will be described.
When the driver leaves the vehicle, as shown by a thin two-dot chain line in the figure, the getting-off / off prevention circuit breaker 32 is pushed down to the open position. As a result, the plate 84 rotates upward, and when the operation lever 14 is at the holding position, the locking pin 85 engages with the engagement hole 72 to lock the operation lever 14. When the operating lever 14 is in the floating position, the locking pin 8
5 hits the plate 71, rotates the operation lever 14 to the neutral position, and then engages the locking pin 85 with the engaging hole 72.

[0007]

However, the above configuration has the following problems. 1) In the mono lever having the mono lever structure of the first example shown in FIG. 7, it is necessary to attach the first lever 51 to the mono lever 14 in order to take out the movement of the operation lever 14 to the outside. In such an apparatus for locking the mono lever, since the first lever 51 attached to the operation lever 14 is locked at a position via a plurality of links, the play of each part is accumulated and a large play is provided. If the operation lever 14 is accidentally moved even in the locked state, the pressure proportional control valve 1
0a may be activated. Further, since the structure is complicated and the number of link parts is large, there is a problem that the weight is heavy and the cost is high. 2) In the mono lever having the mono lever structure of the second example shown in FIG. 8, it is necessary to fix the plate 71 to the mono lever 14 by welding or the like in order to take out the movement of the operation lever 14 to the outside. In such a device for locking a monolever, when such a configuration is applied to, for example, a monolever lock device for traveling operation, when the operation lever 14 is at a raised position (a position where the operation lever 14 is tilted backward). However, there is a problem that the purpose of locking the mono lever at the neutral position cannot be achieved because the engaging hole 72 and the locking pin 85 do not engage even when the getting-off / off prevention circuit breaker 32 is opened.

That is, in the conventional monolever structure, it is necessary to attach another member to the lever portion in order to take out the movement of the monolever to the outside. Therefore, the movement of the other member greatly fluctuates according to the movement of the lever. As described above, a link is required, and reliable alignment is difficult. Therefore, such a device for locking the monolever structure has a complicated structure, large play, and is unreliable.

The present invention has been made in view of the above problems, and has as its object to provide a monolever structure and a monolever locking device that have a simple structure, little play, and can reliably take out the movement of the operation lever to the outside.

[0010]

In order to achieve the above object, a first invention of a monolever structure and a monolever locking device according to the present invention comprises operating levers provided on a body for front and rear and left and right. In a monolever structure capable of tilting operation in at least one direction, a rotation shaft that rotates following the tilting of the operation lever is provided at a tilting fulcrum of the operation lever, and an end of the rotation shaft projects from the body. Configuration. According to the above configuration, in the monolever structure of the present invention, since the end of the rotation shaft is protruded from the upper body of the monolever, the movement of the monolever can be directly taken out to the outside with a simple structure.

According to a second aspect of the present invention, in the monolever structure according to the first aspect, a mechanism for locking the rotation shaft at a neutral position is provided. According to the above configuration, since the lock mechanism that locks the operation lever at the neutral position is provided on the rotation shaft provided at the tilting fulcrum of the operation lever, the operation lever can be directly locked, so that there is little play in the apparatus. Therefore,
Even if the operating lever is erroneously operated in the locked state, the pressure proportional control valve does not operate and the locking can be reliably performed.

According to a third aspect based on the second aspect, the lock mechanism includes a locking lever protruding from the rotating shaft and a rotatable member substantially in the vicinity of the rotating shaft and substantially orthogonal to the rotating shaft. A bifurcated lever that is fixed to the provided vertical shaft and that locks in the neutral position by holding the locking lever with the locking slit opened at the tip when rotated to the locking lever side I have.
According to this configuration, the locking lever provided directly on the rotation shaft of the operation lever is clamped by the locking slit of the bifurcated lever provided rotatably, whereby the operation lever is locked at the neutral position. Therefore, since the structure is simple and the number of parts is small, the cost can be reduced and the number of failures can be reduced.

A fourth invention is based on the second or third invention,
The lock mechanism is configured to interlock with a boarding / closing prevention circuit breaker provided on the side of the driver's seat so as to lock when the boarding / closing prevention circuit breaker is in an open state. According to this configuration, when the driver gets off the driver's seat, the operating lever is always locked to the neutral position when the breaker is set to the open state, and pressure proportional control is performed even if the operating lever is accidentally moved in the locked state. Since the valve does not operate, it can be securely locked.

According to a fifth aspect based on the third aspect, the forked lever has a tapered portion at the tip opening of the locking slit, and this tapered portion is provided when the forked lever is rotated about a vertical axis. The engaging lever is engaged with a locking lever parked at a rotation position deviating from the neutral position to guide the locking lever to the center position of the locking slit. According to this configuration, even when the operation lever is parked at a position deviated from the neutral position, the locking lever of the operation lever rotation shaft is securely locked by the tapered portion at the tip of the forked lever, and the forked lever is It is guided to the center position of the locking slit, whereby the operating lever is returned to the neutral position. Therefore, the locking lever is engaged with the locking slit, and the operation lever is securely locked, so that lock operability is good.

[0015]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view showing a monolever structure and a monolever locking device according to an embodiment of the present invention. In the following, a description will be given of a mono lever for traveling operation of a construction machine as an example, but the present invention is not limited to this.

FIG. 1 is a perspective view showing the structure of a mono-lever locking device 1. A body 10 which is a pressure proportional control valve having an operation lever 14 for traveling operation is attached to the console frame 2. The operating lever 14 can perform forward and backward control and speed control by tilting forward and backward, and can perform left and right turning control by tilting left and right. The body 10, which is a pressure proportional control valve, is provided with a rotating shaft 12 having a left-right axis that rotates following the forward and backward tilting of the operating lever 14. Is fixed. A vertical axis 20 orthogonal to the rotation axis 12 is rotatably attached to the console frame 2 near the rotation axis 12, and is engaged with the locking lever 18 when the vertical axis 20 rotates. Engagement slit 2
A two-pronged lever 21 is rotatably mounted. The opening of the locking slit 22 has tapered portions 2 on both sides.
3, 23 are formed. A first lever 24 is attached to a lower end portion of the vertical shaft 20, and the first lever 24 and the forked lever 21 rotate in synchronization with each other. An opening 30a is provided on the front side surface of the console frame 2.
, A lever shaft 31 is rotatably attached to the bracket 30. On one end of the lever shaft 31, a boarding / breaking prevention breaker 32 is attached with its tip protruding outside through the opening 30a, and a second lever 33 is attached on the other end. The boarding / alighting prevention circuit breaker 32 is provided on the driver's seat (not shown) on the side where the driver gets on and off. The second lever 33 and the first lever 24 are connected by a link 34. A toggle spring 35 is attached to the second lever 33, and defines a boarding / alighting prevention position shown by a solid line and a release position shown by a thin two-dot chain line.

FIG. 2 is a front sectional view of the body 10 which is a pressure proportional control valve. A rotating shaft 12 having a brake device 13 at one end is rotatably attached to the upper body 11. The other end of the rotating shaft 12 protrudes from the upper body 11, and a locking lever 18 is attached to the protruding portion.
An operation lever 14 is attached to the rotation shaft 12 by a pin 15 so as to be tiltable in the left-right direction. The operation lever 14 is moved in the front-rear direction about the rotation shaft 12 (the direction perpendicular to the plane of the drawing).
The rotation shaft 12 can rotate following the tilt of the operation lever 14 and is stopped at an arbitrary rotation position by the brake device 13. The lower body 16 is provided with four valves 17a, 17b, 17c, and 17d at the front, rear, left, and right. The valves 17a, 17b, 17c, and 17c are tilted by operating the operation lever 14 in the front and rear and / or left and right directions.
17d is operated, and the vehicle moves forward and backward and / or turns left and right at a speed corresponding to the tilt angle. When the operation lever 14 is tilted back and forth, the rotation shaft 12 is parked at an arbitrary position as described above, and the vehicle can keep moving forward or backward at an arbitrary speed. The operation lever 14 can be tilted about the other axis in the left-right direction without rotating the rotation shaft 12.

FIG. 3 is a side view showing the relationship between the body 10 which is a pressure proportional control valve and the forked lever 21, and FIG. 4 is a plan view. A locking lever 18 is fixed to the rotating shaft 12 of the body 10, which is a pressure proportional control valve. Rotating shaft 12
, A vertical shaft 20 is rotatably supported by a vertical shaft bracket 25 attached to the console frame 2. A forked lever 21 is fixed to the upper end of the vertical shaft 20, and a first lever 24 is fixed to the lower end. The forked lever 21 is formed with a locking slit 22 having an open end, and tapered portions 23, 2 on both sides of the opening.
3 are provided. In FIG. 3, when the operation lever 14 is tilted back and forth as shown by the thin two-dot chain line, the locking lever 18 also rotates as shown by the thin two dot chain line. In FIG. 4, when the first lever 24 is rotated in the direction of the arrow, the forked lever 21 is rotated to a position shown by a thin two-dot chain line, and the locking slit 22 is engaged with the locking lever 18.

FIG. 5 is a development view taken along the line AA of FIG. When the operating lever 14 is tilted back and forth, the locking lever 18 located at the neutral a position moves to the b or c position indicated by a thin two-dot chain line. The moved locking lever 18 can be parked at any position. The opening width B of the tapered portion 23 of the forked lever 21 is the maximum movement width C of the locking lever 18 (the locking lever 18).
(Outer width at positions b and c). Therefore, when the forked lever 21 is rotated in the direction of the arrow, b
Or, the locking lever 18 parked at the position c is the tapered portion 2
3 to rotate to reach the neutral position a, engages with the locking slit 22, and the traveling operation lever 11 is locked.

The operation of the mono-lever lock device 1 will be described below with reference to FIG. When the driver is operating in the driver's seat, as shown by a solid line in the figure, the getting-off / prevention circuit breaker 32 is in the horizontal getting-on / off preventing position, and the driver cannot get out of the driver's seat. . At this time, the second
The lever 33 rotates clockwise in the figure, and the link 34 and the first
The vertical shaft 20 is rotated counterclockwise through the lever 24, and the locking slit 22 and the tapered portion 23 of the forked lever 21 are
It is released from the locking lever 18 of the body 10 which is a pressure proportional control valve. Therefore, the traveling operation lever 11 is in a state where forward and backward operation is possible. On the other hand, when the driver leaves the driver's seat, the getting-off / off prevention breaker 32 is lowered to the open position shown by the thin two-dot chain line in order to get off. The second lever 33 rotates counterclockwise, rotates the bifurcated lever 21 clockwise via the link 34 and the first lever 24, holds the locking lever 18 with the locking slit 22, and moves the operating lever 14 in the front-rear direction. Lock the tilt. In this case, as described above, the operation lever 1
4 is returned to the neutral position by the tapered portion 23 of the bifurcated lever 21 and is securely locked even if it is in the forward or backward position deviating from the neutral position.

FIG. 6 is a side view showing a relationship between a body 10 which is a pressure proportional control valve of another embodiment and a switch lever 18a. A switch lever 18a is fixed to the rotating shaft 12 of the body 10, which is a pressure proportional control valve. A limit switch 27 is provided on a bracket 26 attached to the console frame 2. When the operation lever 14 is swung to the right backward position in FIG. 6, the rotation shaft 12 rotates, and the switch lever 18a fixed to the rotation shaft 12 rotates. Then, the switch lever 18a pushes the shaft 27a of the limit switch 27 downward to operate the limit switch 27. Then, a back buzzer (not shown) issues an alarm to notify the driver that the operation lever 14 is in the reverse position. That is, with such a monolever structure, the movement of the monolever can be directly taken out, and the limit switch 27 and the like can be reliably operated with a simple structure.

As described above, in the monolever structure of the present invention, since the end of the rotating shaft is protruded from the upper body of the monolever, the movement of the monolever can be directly taken out to the outside with a simple structure. . In addition, since the locking device having the monolever structure of the present invention is provided with a mechanism for locking the tilting to the rotation shaft of the monolever, a locking device with less play can be configured, and the tilting operation of the operation lever can be reliably stopped. Also, since the locking lever provided on the rotating shaft is sandwiched and locked by the slit from the rotating direction,
There is little backlash, so that there is no possibility that the corresponding pressure proportional control valve will be actuated even if the operating lever is accidentally moved. Furthermore, since the structure is simple and the number of parts is small, the cost can be reduced. A tapered portion is provided at the tip opening of the bifurcated lever that engages the locking lever of the rotating shaft, and the locking lever is guided to the center locking slit. Can be locked in position.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a configuration of a monolever lock device of the present invention.

FIG. 2 is a partial front sectional view of a body which is a pressure proportional control valve.

FIG. 3 is a side view showing a relationship between a locking lever and a forked lever.

FIG. 4 is a plan view showing a relationship between a locking lever and a forked lever.

FIG. 5 is a development view as viewed from an arrow A in FIG. 4;

FIG. 6 is a side view showing a relationship between a body and a switch lever.

FIG. 7 is a partial side sectional view showing a first example of a conventional monolever locking device.

FIG. 8 is a side view showing a second example of the conventional mono-lever locking device.

[Explanation of symbols]

1: Locking device, 2: Console frame, 10: Body, 12: Rotating shaft, 14: Operation lever, 18: Locking lever, 20: Vertical shaft, 21: Bifurcated lever, 22: Locking slit, 23: Taper Part, 24: first lever, 31: lever shaft, 32: boarding / closing prevention circuit breaker, 33: second lever, 3
4: Link.

Claims (5)

[Claims] 1. A mono-lever structure in which an operation lever provided on a body can be tilted in at least one of a front and rear direction and a left and right direction, wherein a tilt fulcrum of the operation lever (14) follows the tilt of the operation lever (14). A rotating shaft (12) for rotating the rotating shaft (12), and an end of the rotating shaft (12) is projected from the body (10). 2. The monolever lock device according to claim 1, wherein a mechanism for locking the pivot shaft (12) at a neutral position is provided. 3. The mono-lever locking device according to claim 2, wherein the locking mechanism includes a locking lever (18) protruding from the rotating shaft (12) and a rotating lever (18) proximate to the rotating shaft (12). The locking slit () is fixed to a vertical shaft (20), which is rotatably provided substantially orthogonal to the moving shaft (12), and has a tip end opened when rotated toward the locking lever (18). A mono-lever locking device, comprising: a forked lever (21) for holding a locking lever (18) with a 22) and locking it at a neutral position. 4. The mono-lever lock device according to claim 2, wherein the lock mechanism is interlocked with a boarding / alighting prevention breaker (32) provided on a side of a driver's seat. A mono-lever locking device characterized in that it is locked when in an open state. 5. The mono-lever locking device according to claim 3, wherein the bifurcated lever has a tapered portion at an opening at a distal end of a locking slit, and the tapered portion. When the bifurcated lever (21) is rotated around the vertical axis (20), the bifurcated lever (21) engages with the locking lever (18) parked at the rotation position deviated from the neutral position, and the locking lever ( A mono-lever locking device, wherein 18) is guided to a center position of a locking slit (22).