JP2005227828A - Operating device for working machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent a push-pull cable from buckling or damaging without interposing a spring in an operating device for a working machine in which an operating member is connected to an operated member with the push-pull cable. <P>SOLUTION: The operating device is equipped with a limiting means (26) of limiting the manipulated variable of the operating member (20) in a "push direction" of the push-pull cable (24). <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an operating device for a work machine, and more particularly to an operating device for a work machine in which an operating member and an operated member are connected by a push-pull cable.

  A wheel loader, which is a typical example of a work machine, includes an operation device in which a manual lever as an operation member operated by an operator and a hydraulic direction control valve as an operated member are connected by a push-pull cable ( For example, see Patent Document 1).

  As is well known, in the push-pull cable, an inner cable is slidably inserted into an outer tube, and an operation amount and an operation force of a manual lever are transmitted by the inner cable. This push-pull cable is strong against pull (pull) due to its structure, but it can buckle when a large force exceeding the specified size is applied to push (push), and can be damaged if it is repeated. There is sex. For example, a large force is applied when a force is further applied to push the manual lever while the directional control valve reaches the end of its operation stroke. Especially in work machines, the operator inadvertently supports the body with the manual lever at the operating end when the machine is largely tilted or vibrated, or the operator intends to use the manual lever at the operating end to speed up the operation of the working device. Large force is easily applied to push-pull cables.

As means for preventing this buckling, a technique has been developed in which a coil spring is interposed between a manual lever and a push-pull cable to elastically absorb an unreasonable force (for example, see Patent Document 2).
JP-A-9-228423 (FIG. 1) Japanese Utility Model Publication No. 7-24626 (FIG. 1)

  However, the conventional working machine operating device having the above-described configuration has the following problems to be solved.

Spring equipment:
In the operation of the working device of the work machine, for example, the operation of the directional control valve that is the operated member that controls the operation of the hydraulic actuator by the manual lever that is the operating member, a fine operation transmission, so-called fine operation is required. However, if an elastic spring is interposed in the middle of the push-pull cable for transmitting the operation, the transmission of the operation becomes unstable and the operability is impaired.

Buckling, damage:
Therefore, there is a demand for an operating device that prevents buckling and damage of the push-pull cable without providing a spring and with a simple structure.

  The present invention has been made in view of the above-mentioned facts, and its technical problem is to prevent buckling and damage of the push-pull cable in the operating device of the work machine in which the operating member and the operated member are connected by the push-pull cable. Another object of the present invention is to provide an operating device for a work machine that can be prevented without interposing a spring.

  According to the present invention, in order to solve the above technical problem, an operation member, a push-pull cable connected to the operation member and transmitting the operation amount to the operated member by pushing and pulling, and a push-pull cable “push direction” There is provided a working machine operating device characterized by comprising a limiting means for limiting the amount of operation of the operating member.

  Preferably, the restriction means abuts on the operation member and restricts an operation amount thereof. The restricting means is provided on a base to which the operation member is attached, and is formed so that the position of contact with the operation member can be adjusted. The operated member is a directional control valve that controls the operation of the hydraulic actuator of the working device of the work machine.

  According to the operating device for a work machine configured in accordance with the present invention, there is provided limiting means for limiting the operation amount of the operating member in the “pushing direction” of the push-pull cable connecting the operating member and the operated member. Therefore, by restricting the operation of the operation member before the push-pull cable pushes the operated member excessively in the “pushing direction”, it prevents the push-pull cable from applying a large force, thereby buckling and damage. This can be prevented without interposing a spring.

  Referring to the accompanying drawings illustrating a preferred embodiment of an operation device for a directional control valve for controlling a work device of a wheel loader that is a typical work machine, for a work machine operation device configured according to the present invention. This will be described in more detail.

  The wheel loader will be described with reference to FIG. The wheel loader indicated by the whole number 2 is attached to a refraction steering type machine body in which a front machine body 4 and a rear machine body 5 are refractorably connected, and to a front wheel device 6 and a rear machine body 5 attached to the front machine body 4. The front body 4 includes a lift arm 8 that is a working device that is freely swingable in the vertical direction, and a bucket 9 that is attached to the tip of the lift arm 8. Is provided with a driver's cab 12 provided with a driver's seat 10 and an engine compartment 14 disposed at the rear end.

  The driver's seat 10 is provided with an operating device 16 for operating the working device. The operation device 16 controls the expansion and contraction operations of the lift cylinder 18 that is a hydraulic actuator that moves the ft arm 8 up and down and the tilt cylinder 19 that is a hydraulic actuator that tilts the bucket 9 back and forth.

  This will be described with reference to FIGS. The outline of the operation device 16 will be described. The operation device 16 is connected to the manual lever 20 as the operation member and the operation amount and the operation force connected to the manual lever 20 to the direction control valve 22 as the operated member by pushing and pulling. A push-pull cable 24 is provided, and a restricting means 26 for restricting an operation amount of the push-pull cable 24 by the manual lever 20 in the “pushing direction” is provided in the vicinity of the base end portion of the manual lever 20.

  Generally, in the wheel loader 2, a plurality of operated members such as a direction control valve 22 a that controls the operation of the lift cylinder 18 and a direction control valve 22 b that controls the operation of the tilt cylinder 19 are operated by the operation device 16. . In the operating device 16 in the present embodiment, the combination of the manual lever 20 and the direction control valve 22a for the lift cylinder 18 will be described, and other combinations that may be substantially the same will be complicated and illustrated. Is omitted.

  The manual lever 20 will be described with reference to FIG. 4 together with FIG. The manual lever 20 includes a rectangular parallelepiped base portion 20a, a round bar-like lever 20b that is screwed into the base portion 20a, and a knob 20c that is attached to the tip of the lever 20b. A box-shaped console 28 serving as a base is provided on the side of the driver's seat 10 (FIG. 1). A bracket 30 having a shaft portion 30a on which the axis X is positioned is provided.

  The base portion 20a is formed with a bearing hole 20d that penetrates between a pair of opposed side surfaces of the rectangular parallelepiped and is fitted to the shaft portion 30a of the bracket 30. The lever 20 b protrudes above the console 28 through an opening formed in the top plate 28 b of the console 28. A rubber boot 32 is attached between the opening of the top plate 28b and the lever 20b. Further, on one of the pair of side surfaces of the base portion 20a parallel to the bearing hole 20d, the side surface F (right side surface in FIG. 2) is provided with a plate piece 20e to which one end of the push-pull cable 24 is attached. It extends in a direction substantially perpendicular to the extending direction of and is integrally attached.

  Thus, the manual lever 20 is freely attached to the wheel loader 2 in the front-rear direction (right and left in FIG. 1) about the axis X, and is set to the “neutral holding position” in the non-operation state indicated by the solid line in FIG. To the front indicated by Y1 and the rear indicated by Y2. When operated in the Y1 direction, a force in the pushing direction acts on the push-pull cable 24, and when operated in the Y2 direction, a force in the pulling direction acts (the push-pull cable 24 will be described in detail later).

  A description will be given mainly with reference to FIG. The direction control valve 22 including the direction control valves 22 a and 22 b is attached to the inside of the front body 4 (FIG. 1) of the wheel loader 2. These directional control valves 22a and 22b are well-known and include a stem S slidably fitted to the valve body, and the other end of the push-pull cable 24 is connected to the stem S. The operation of the stem S is locked by the internal mechanism from the “neutral holding position” in the state shown in FIG. 3 by the operation of the manual lever 20, and the “maximum pushing position” in the Y1 direction and the “maximum pulling position” in the Y2 direction. It is put in and out.

  The push-pull cable 24 is a well-known one that is commercially available, and an inner cable 24b is slidably inserted into the outer tube 24a. Both ends of the outer tube 24a are metal and one end is connected to the console 28 (FIG. 2). ) The other end is fixed to a bracket 34 provided on the front body 4, and one end of the inner cable 24b is connected to the plate piece 20e of the manual lever 20 and the other end is connected to the stem S of the direction control valve 22a. At both ends of the push-pull cable 24, boots 24c that protect the portions where the inner cable 24b enters and exits are attached.

  Thus, when the manual lever 20 is operated in the front-rear direction Y1Y2 shown in FIG. 2, the stem S of the direction control valve 22a is pushed in the Y1 direction and pulled out in the Y2 direction. The maximum operation amount (stroke) in the Y1 and Y2 directions is defined by the “maximum push-in position” and “maximum pull-out position” of the directional control valve 22a in a state where the restriction means 26 described later is not provided.

  The limiting means 26 will be described with reference to FIGS. 4 and 5 together with FIG. The limiting means 26 is provided inside the console 28 to which the manual lever 20 is attached, and contacts the side surface F of the base portion 20a of the manual lever 20 to limit the operation amount of the manual lever 20 in the Y1 direction. The restricting means 26 is formed by bending the belt plate into an L shape and attaching one bent side to the side wall 28a of the console 28 described above and a screw hole formed at the tip of the other side of the bracket 26a. A combined bolt 26b and a lock nut 26c for fixing the bolt 26b to the bracket 26a are provided. The tip of the bolt 26b protruding from the bracket 26a contacts the side surface F of the base 20a of the manual lever 20 when the manual lever 20 is operated by a predetermined amount.

  This contact is defined in a state when the manual lever 20 is operated in the Y1 direction of FIG. 2 in which a force in a direction of pressing the push-pull cable 24 is applied (a state indicated by a two-dot chain line in FIG. 2). Specifically, when the manual lever 20 is operated in the Y1 direction, the side surface of the base portion 20a at the position of the operation amount of the manual lever 20 defined by the “maximum pushing position” of the direction control valve 22a or an operation amount less than that. It sets so that F and the front-end | tip of the volt | bolt 26b of the limitation means 26 may contact | abut.

  As a simple setting method, since the tip position of the bolt 26b of the limiting means 26 can be adjusted by the screwing amount into the bracket 26a, the manual lever 20 is first moved to the “maximum pushing position” of the direction control valve 22a in the Y1 direction. Until the position locked by the screw is screwed so that the tip of the bolt 26b contacts the side surface F of the manual lever 20 in this state, and the manual lever 20 is moved in the opposite Y2 direction by the bolt 26b. The position is set, and finally the bolt 20b is fixed by the lock nut 26c.

  The operation of the work machine operating device 16 as described above will be described mainly with reference to FIG.

Operation of operation means:
When operating the manual lever 20 as an operation member in the direction of the arrow Y1 from the manual lever 20 “neutral holding position” indicated by a solid line, the “neutral holding position” and “position contacting the limiting means 26” indicated by a two-dot chain line ” Is operated between. Conversely, when operating from the “neutral holding position” in the direction of the arrow Y2, the operation is performed between the “neutral holding position” and the “position defined by the maximum drawing position of the direction control valve 22a”.

Push-pull cable buckling and damage:
Therefore, when the manual lever 20 is operated in the Y1 direction in which a force in the direction of pressing the push-pull cable 24 is applied, the maximum operating position is defined by “the maximum push-out / draw-out position of the direction control valve 22a”. It is defined before “position”. That is, even if a large force is applied to the manual lever 20 in this contact state, it is received by the restricting means 26, so that the push-pull cable 24 does not act to buckle or damage the push-pull cable 24.

Installation on work machine:
Since the restricting means 26 has a simple structure including a bracket 26a, a bolt 26b, and a lock nut 26c, it can be easily installed on the work machine. Moreover, it can be installed in the console 28 to which the manual lever 20 is attached, and the appearance and appearance of the work machine are not deteriorated. Furthermore, since the contact position of the restricting means 26 with the manual lever 20 can be adjusted, the size of the mounting position need not be strict and the restricting means 26 can be easily installed. And position adjustment is easy.

Operated member:
In particular, the directional control valve for controlling the operation of the working device in the work machine is frequently operated by the manual lever 20. Further, when the work machine is operated, the machine body is greatly tilted and vibrated, and a large force by the operator is applied to the manual lever 20 unconsciously or intentionally at the end of the operation stroke. Therefore, the operating device 16 provided with the limiting means 26 is suitable for the operating device for the direction control valve that controls the operation of the hydraulic actuator of the working device.

Operating amount limiting means:
Since the operating device 16 including the limiting unit 26 can limit the operation amount of the operation member, the operation amount of the operation member can be limited to an arbitrary amount up to the middle of the maximum operation position. That is, for example, depending on the type of work equipment, the opening of the direction control valve can be set so that the direction control valve is in a half-open state even when the operation member is operated to the maximum, and the operating speed of the hydraulic actuator is controlled. The operation amount of the means can be set so as to be always slow without fine adjustment operation.

  As mentioned above, although this invention was demonstrated in detail based on embodiment, this invention is not limited to said Example, A various deformation | transformation or correction is possible within the scope of the present invention. For example, although the manual lever 20 is used as the operation member, a foot pedal may be used. The restricting means 26 is attached to the base 28 to which the operation member 20 is attached. However, the restriction means 26 may come into contact with the attachment base 28 on the operation member 20 side. Further, the restricting means 26 may not include a position adjusting member such as a bolt or a lock nut if it is not necessary to adjust the contact position.

The side view of the wheel loader which is a typical example of the working machine provided with the operating device comprised according to this invention. FIG. 2 is an enlarged view showing a part of an operation member side portion of the operation device of FIG. The enlarged view of the part of the to-be-operated member to which the operation member shown in FIG. 2 is connected. The expanded sectional view seen in the AA arrow direction of FIG. The expanded sectional view seen in the BB arrow direction of FIG.

Explanation of symbols

2: Wheel loader (work machine)
20: Manual lever (operation member)
22a: Direction control valve (operated member)
24: Push-pull cable 26: Limiting means 28: Console (base)

Claims (5)

  An operation member, a push-pull cable connected to the operation member and transmitting the operation amount to the operated member by pushing and pulling, and a limiting unit for limiting the operation amount of the operation member in the push-pull cable “push direction”. An operating device for a work machine, characterized in that   The operating device for a work machine according to claim 1, wherein the limiting means is in contact with the operating member and limits an operation amount thereof.   The operating device for a working machine according to claim 2, wherein the limiting means is provided on a base to which the operating member is attached.   The operating device for a work machine according to claim 2 or 3, wherein the limiting means is formed so as to be capable of adjusting a position in contact with the operating member.   The operating device for a work machine according to any one of claims 1 to 4, wherein the operated member is a directional control valve that controls an operation of a hydraulic actuator of the working device of the work machine.

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