JP4550605B2 - Actuator locking device for work vehicle - Google Patents

Description

  The present invention relates to an actuator lock device for a work vehicle.

  2. Description of the Related Art Conventionally, in a work vehicle, there is known an actuator lock device that prevents a work machine or a steering operation from being performed when an operator leaves the driver's seat. For example, according to the technique disclosed in Patent Document 1, the base end portion of the lock lever of the actuator lock device is attached to a fulcrum provided on the floor or the lower part of the side of the driver's seat, and in the front-rear direction around the fulcrum. Rotate.

  The base end portion of the lock lever is connected to the lock valve via a link rod provided under the driver's seat or under the floor. When operating the work vehicle, the lock lever is in front and the passage for the operator to pass is closed to prohibit the operator from passing. When the operator leaves the seat, the passage is secured by rotating the lock lever backward. At the same time, the lock valve is actuated via the link rod, the hydraulic system is shut off, and the work machine and the steering operation cannot be performed even if the operation lever is moved.

  According to Patent Document 2, a control box is provided in front of the driver's seat, and a lock lever of an actuator lock device is installed in the control box. During operation of the work vehicle, the lock lever falls to the operator side and closes the passage for the operator to pass. When leaving the seat, the lock lever is raised in front of the vehicle to secure the passage, and the lock valve installed inside the control box is activated to shut off the hydraulic system so that work equipment and steering operations cannot be performed. I have to.

Japanese Utility Model Publication No. 5-57052 (FIGS. 1 to 4) JP 2002-285588 A (FIG. 4)

  However, the prior art has the following problems. That is, according to the technique disclosed in Patent Document 1, when the lock valve and the link rod are provided in the lower part of the driver's seat, the lock valve and the hydraulic piping are located immediately below the driver's seat where the operator is seated. . For this reason, there is a problem that the noise generated by these reaches the operator's ear and feels noisy.

  On the other hand, when a lock valve or a link rod is provided under the floor, it is necessary to provide a hole in the floor so that the back and forth movement of the lock lever does not hit the floor. Therefore, there is a problem that noise generated by the lock valve and hydraulic piping under the floor reaches the operator's ear through this hole.

  Moreover, according to the technique disclosed in Patent Document 2, a control box with a lock lever attached is installed in front of the driver's seat. For this reason, the passage is narrowed by the control box, which may hinder the passage of the operator.

  The present invention has been made paying attention to the above-described problems, and an object of the present invention is to provide a work vehicle having an actuator lock device that does not interfere with traffic and has low noise.

In order to achieve the above object, the present invention provides:
In an actuator lock device for a work vehicle,
A passage in the driver's cab through which an operator passes when sitting on a driver's seat installed on the cab floor of the work vehicle;
A console box arranged on the side or front of the driver seat;
Actuator operating means provided in the console box;
A pilot valve operated by the operating means;
Pilot piping for supplying pilot pressure from the pilot valve to the pilot pressure input portion of the drive valve;
A lock valve inserted into the pilot pipe;
An open / close lever for opening and closing the lock valve;
A lock lever that is rotatably installed about a rotation axis that is substantially perpendicular to the cab floor, and that closes / opens a passage in the cab;
A plate having one end fixed to the lock lever and rotating around the lock lever in synchronism with the rotation of the lock lever;
A link rod having one end rotatably connected to the other end of the plate and the other end rotatably connected to the opening / closing lever;
It has.

According to the present invention, since the lock lever is rotatably installed on the floor, the gap between the hole on the floor surface and the lock lever can be reduced. Therefore, even if noise is generated under the floor, it is difficult for the noise to reach the operator's ear. Moreover, a wide passage can be secured.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 shows a side view of a wheel loader 11 as an example of a work vehicle, with the left side in the drawing as the front. In the following description, the left and right directions are represented by the direction of the wheel loader 11 viewed from the rear of the vehicle body.

  In FIG. 1, the wheel loader 11 includes a front vehicle body 17 and a rear vehicle body 15. The front vehicle body 17 and the rear vehicle body 15 are connected by refractive joints 29 and 29 that are rotatable in a horizontal plane.

  The front vehicle body 17 and the rear vehicle body 15 are connected by a pair of left and right steering cylinders 30L and 30R. Due to the expansion and contraction of the steering cylinders 30L and 30R, the front vehicle body 17 articulates (refracts) the rear vehicle body 15 in a horizontal plane, and performs a steering operation during traveling or the like.

  A work machine 20 is attached to the front end portion of the front body 17. The work machine 20 includes a lift arm 21 whose base end is attached to the front vehicle body 17 via an arm pin 28 so as to be swingable. The front vehicle body 17 and the lift arm 21 are connected by a pair of left and right lift cylinders 23 and 23. By expanding and contracting the lift cylinders 23, the lift arm 21 swings up and down around the arm pin 28.

  A bucket 22 is swingably attached to the tip of the lift arm 21 via a bucket pin 27. Further, an intermediate portion of the tilt arm 24 is swingably attached to the intermediate portion of the lift arm 21.

  One end of the tilt arm 24 and the front vehicle body 17 are connected by a tilt cylinder 25. The other end of the tilt arm 24 and the bucket 22 are connected by a tilt rod 26. By expanding and contracting the tilt cylinder 25, the bucket 22 swings up and down around the bucket pin 27.

  A driver's cab 12 is mounted on the upper portion of the rear vehicle body 15. The cab 12 is provided on its side surface with an entrance / exit where an operator enters and exits and a door 13 which closes the entrance / exit. A driver's seat 14 on which an operator is seated is installed inside the cab 12.

  In FIG. 2, the top view inside the cab 12 is shown. In FIG. 2, left and right console boxes 32L and 32R are installed on the left and right sides of the driver's seat 14, respectively. In the left console box 32L, a joystick lever 43 for steering, which is one of the actuator operation means, stands. The right console box 32R has two working machine operation levers 48, 48 for operating the working machine 20 as one of the actuator operating means.

  A console panel 34 is installed in front of the driver's seat 14. A monitor 47 in which a speedometer, a fuel gauge and the like (not shown) are arranged is installed at a substantially central portion of the console panel 34. Between the left console box 32L and the console panel 34, a passage 31 through which an operator sits on the driver's seat 14 is provided.

  A lock lever 36 is erected from the floor 44 of the cab 12 near the left end of the console panel 34. FIG. 3 shows a side view of the lock lever 36. FIG. 4 shows a plan view of the lock lever 36 with the floor 44 omitted.

  As shown in FIG. 3, the lock lever 36 forms an upright portion 36 </ b> A that forms a straight portion that extends substantially vertically from the base end portion, and a straight portion that is bent at a substantially right angle from the upright portion 36 </ b> A and extends in a substantially horizontal direction. The horizontal part 36B is provided with the traffic prevention part 36C which forms the linear part which bent at an obtuse angle from the horizontal part 36B, and was extended diagonally upward.

  The vicinity of the base end portion of the lock lever 36 is fixed to the floor 44 by a bearing 37. As a result, the lock lever 36 is rotatable about the vertical axis.

  As shown by a two-dot chain line in FIGS. 2 and 4, a state where the horizontal portion 36 </ b> B and the passage prevention portion 36 </ b> C of the lock lever 36 close the passage 31 is said to be in the passage stop position. Here, the blockage means that the lock lever 36 blocks the passage 31 to the extent that the operator cannot pass.

  Further, as indicated by solid lines in FIGS. 2 and 4, the lock lever 36 is in a state where the horizontal portion 36 </ b> B and the passage prevention portion 36 </ b> C of the lock lever 36 rotate to the left from the passage 31 to open the passage 31. Says it is in a position. Here, the term “open” means that the lock lever 36 is retracted from the passage 31 so that the operator can pass.

  As shown in FIGS. 3 and 4, one end portion of the plate 51 is fixed to the proximal end portion of the lock lever 36 at a substantially right angle with the upright portion 36 </ b> A. A fixing pin 60 is fixed to the other end portion of the plate 51 in a downward direction substantially parallel to the upright portion 36A.

  One end of a link rod 38 having spherical joints attached to both ends is rotatably connected to the fixing pin 60. The link rod 38 passes through the inside of the support ring 62 suspended from the floor 44. When the lock lever 36 is rotated, the plate 51 rotates, whereby the link rod 38 moves in the vehicle front-rear direction (see arrow 61).

  A lock valve 39 is provided under the floor below the driver's seat 14. As will be described later, a steering pilot pipe 41 is connected to the lock valve 39. An opening / closing lever 50 is provided on the side surface of the lock valve 39.

  The open / close lever 50 rotates about 90 degrees between an open position indicated by a two-dot chain line and a closed position indicated by a solid line. When the opening / closing lever 50 is set to the open position, the lock valve 39 is opened, and when the opening / closing lever 50 is set to the closed position, the lock valve 39 is closed.

  The front end of the opening / closing lever 50 is rotatably connected to the other end of the link rod 38. When the lock lever 36 is rotated, the link rod 38 moves in the front-rear direction. Accordingly, the opening / closing lever 50 rotates and the lock valve 39 can be opened / closed.

  At this time, when the lock lever 36 is set to the closed position, the opening / closing lever 50 is moved to the open position, and the lock valve 39 is opened. When the lock lever 36 is set to the passable position, the opening / closing lever 50 is moved to the closed position, and the lock valve 39 is closed.

  Next, FIG. 5 shows an A arrow view of the P portion in FIG. Further, FIG. 6 shows a B arrow view of the part P in FIG. 3 in detail.

  As shown in FIG. 5, a spring pin 52 is erected in a substantially central portion of the plate 51 downward. One end of a spring 49 is fixed to the spring pin 52. The other end of the spring 49 is fixed to a spring post 53 erected downward from the floor 44.

  As shown in FIG. 6, the spring 49 attracts the plate 51 toward the spring post 53 via the spring pin 52 by the biasing force. As a result, the lock lever 36 is stable only when the lock lever 36 is in the closed position indicated by the two-dot chain line and the allowed pass position indicated by the solid line, and does not stop between the closed position and the allowed position. It is like that.

  Next, the hydraulic circuit will be described. FIG. 7 is an explanatory diagram of a hydraulic circuit that drives the steering cylinders 30L and 30R. As shown in FIG. 7, a steering pilot pipe 41 through which steering pilot oil flows reaches an inlet of the lock valve 39 from a pilot hydraulic power source 40 such as a hydraulic pump. The steering pilot pipe 41 reaches the inlet of the steering pilot valve 42 that is a pilot valve from the outlet of the lock valve 39. The steering pilot pipe 41 reaches from the outlet of the steering pilot valve 42 to the pilot pressure input portion of the steering valve 57 that is a drive valve that drives the actuator.

  A steering pipe 46 through which steering oil flows from the main hydraulic source 45 such as a hydraulic pump reaches the inlet of the steering valve 57. The steering pipe 46 reaches the steering cylinders 30L and 30R from the outlet of the steering valve 57.

  First, the case where the lock lever 36 (not shown in FIG. 7) is in the closed position and the lock valve 39 is open will be described. When the operator operates the steering operation lever 43, the steering pilot valve 42 is activated by the movement. As a result, the steering pilot oil corresponding to the movement of the steering operation lever 43 passes through the lock valve 39 and is input to the pilot pressure input portion of the steering valve 57. The steering valve 57 is operated by the steering pilot oil, and the steering oil drives the steering cylinders 30L and 30R to extend and contract. As a result, the front vehicle body 17 articulates with respect to the rear vehicle body 15, and a steering operation is performed.

  Next, the case where the lock lever 36 is in the passable position and the lock valve 39 is closed will be described. When the lock valve 39 is closed, even if the steering operation lever 43 is operated, the flow of the steering pilot oil is blocked by the lock valve 39 and does not reach the pilot pressure input portion of the steering valve 57. As a result, even if the steering operation lever 43 is operated, the steering cylinders 30L and 30R are not driven and the steering operation is not performed.

  Hereinafter, the movement of the operator will be described. When the lock lever 36 is in the passable position, the operator enters the cab 12 from the outside of the vehicle and sits on the driver's seat 14 through the passage 31. At this time, since the lock valve 39 is closed as described above, even if the operator accidentally touches the steering operation lever 43, the steering operation is not performed.

  The operator seated on the driver's seat 14 rotates the lock lever 36 to the closed position. As a result, the lock valve 39 is opened as described above, and the steering operation is performed when the operator operates the steering operation lever 43.

  Then, when the operator leaves the driver's seat 14, the lock lever 36 is moved to the passable position, and the lock valve 39 is closed. Thereby, even if the operator accidentally touches the steering operation lever 43, the steering operation is not performed.

  As described above, in the present invention, the lock lever 36 is erected from the floor 44 obliquely forward of the driver's seat 14. Accordingly, when the lock lever 36 is in a passable state, the width of the passage 31 through which the operator passes becomes wider and easier to pass than when the lock lever 36 is on the side of the operator seat.

  Further, since the lock lever 36 is supported on the floor 44 by the bearing 37, it is not necessary to provide a hole in the floor 44 so that the lock lever 36 does not interfere with the floor surface as in the prior art. Noise rarely enters the cab. And since there is no control box like a prior art, an operator's passage is not obstructed.

  In the above description, the lock lever 36, the entrance / exit and the door 13 are located only on the left side of the driver's seat 14, but the present invention is not limited to this. The lock lever 36, the entrance / exit, and the door 13 may be on the right side of the driver's seat 14 or on both the left and right sides.

  In the above description, the lock valve 39 is inserted into the steering pilot pipe 41 and shuts off the steering pilot oil. However, the present invention is not limited to this. For example, the lock valve 39 is inserted into the steering pipe 46 to remove the steering oil. You may make it interrupt. However, as shown in the embodiment, when the steering pilot oil is shut off, the flow rate to be cut off is small, and the small lock valve 39 can be used.

  In the above description, when the lock lever 36 is in the passable position, only the steering cylinders 30L and 30R cannot be operated. However, the present invention is not limited to this. For example, at least one of the lift cylinders 23 and 23 and the tilt cylinder 25 that drive the work machine 20 may not be driven. Further, at least one of the steering cylinders 30L and 30R, the lift cylinders 23 and 23 and the tilt cylinder 25 that drive the work implement 20 may be disabled.

  In the above description, the joystick lever for steering and the work implement operating lever have been described as examples of the actuator operating means. However, the present invention is not limited to this. For example, a steering handle or a work machine operation joystick lever may be used, or a steering or work machine operation switch may be used.

  In the above description, the wheel loader 11 of the type in which the cab 12 is mounted on the upper part of the front vehicle body 17 has been described as an example. However, the present invention is not limited to this, and the cab 12 It may be mounted on the upper part of the vehicle body 15.

  Further, the present invention is not limited to the wheel loader 11 and can be applied to general work vehicles such as a hydraulic excavator. Furthermore, the present invention is not limited to the type of work vehicle having the cab 12 surrounding the operator's four sides, and can be applied to a small work vehicle having only a roof covering the operator's head.

A side view of a wheel loader (embodiment). The perspective view of a driver's cab interior (embodiment). The side view of a lock lever (embodiment). The top view of a lock lever (embodiment). P section detail drawing of Drawing 3 (embodiment). FIG. 5 is a detailed view of a Q part in FIG. The schematic diagram of hydraulic piping (embodiment).

Explanation of symbols

11: Wheel loader, 12: Driver's cab, 13: Door, 14: Driver's seat, 15: Rear vehicle body, 17: Front vehicle body, 20: Working machine, 21: Lift arm, 22: Bucket, 23: Lift cylinder, 24 : Tilt arm, 25: Tilt cylinder, 26: Tilt rod, 27: Bucket pin, 28: Arm pin, 29: Refraction joint, 30L, 30R: Steering cylinder, 31: Passage, 32L, 32R: Console box, 34: Console panel , 36: lock lever, 37: bearing, 38: link rod, 39: lock valve, 40: pilot hydraulic pressure source, 41: steering pilot piping, 42: steering pilot valve, 43: joystick lever, 44: floor, 45: main Hydraulic source, 46: Steering piping, 47: Monitor, 48: Working machine operation lever, 49: Spring, 5 : Closing lever, 51: plate, 52: spring pin, 53: spring post, 57: steering valve, 60: fixing pins, 62: support ring.

Claims (1)

In an actuator lock device for a work vehicle,
A passage in the driver's cab through which an operator passes when sitting on a driver's seat installed on the cab floor of the work vehicle;
A console box arranged on the side or front of the driver seat;
Actuator operating means provided in the console box;
A pilot valve operated by the operating means;
Pilot piping for supplying pilot pressure from the pilot valve to the pilot pressure input portion of the drive valve;
A lock valve inserted into the pilot pipe;
An open / close lever for opening and closing the lock valve;
A lock lever that is rotatably installed about a rotation axis that is substantially perpendicular to the cab floor, and that closes / opens a passage in the cab;
A plate having one end fixed to the lock lever and rotating around the lock lever in synchronism with the rotation of the lock lever;
A link rod having one end rotatably connected to the other end of the plate and the other end rotatably connected to the opening / closing lever;
An actuator locking device for a work vehicle, comprising:

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