JPH08284212A - Shift lever fixing device for travel work machine - Google Patents

Abstract

PURPOSE: To provide a shift lever fixing device for a travel work machine ensuring high workability by installing a mechanism laid at the base end of a shift lever in such a state as releasable from a driver's cabin. CONSTITUTION: Regarding a travel work machine with a shift lever 8 and a work lever arranged in a driver's cabin to operate a travel device and a work section via a separate operation, the shift lever 8 is rotatably connected to a support shaft 13 and a working member 14 operable with the turn of the lever 8 is provided with an engagement section 14a. Then, the section 14a is secured with a fixing mechanism 9 releasable from a driver's cabin, thereby fastening the lever 8 at a neutral position. In this case, the fixing mechanism 9 is formed out of a fixed piece 90 coupled to the section 14a for the guide thereof to the neutral position, and a cylinder section to energize and move the piece 90 to a fixed side with a spring 91, upon the stoppage and release of the feed of pressure oil.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a traveling lever for a traveling work machine in which a traveling lever installed on a traveling work machine such as a power shovel is fixed to a neutral position by a fixing mechanism that can be engaged and disengaged from a driver's seat. The present invention relates to a fixing device, and a traveling lever fixing device for a traveling work machine that automatically fixes the traveling lever to a neutral position when the operation box having the working lever is placed in the withdrawal / escape posture.

[0002]

2. Description of the Related Art Conventionally, a traveling lever is pivotally supported by a support shaft in front of a driver's seat to operate a traveling device in a forward and backward direction and is installed on a side of a driver's seat. For traveling work machines such as power shovels that operate work parts such as buckets by operating the work levers, do not accidentally operate the travel levers even if the operator touches the travel levers when getting on and off the aircraft. The fixing mechanism is provided with a stopper member for fixing to.

As such a fixing mechanism, as a simple system, a stopper member that can be brought into contact with and separated from the base side of the traveling lever is provided, and the stopper member is manually engaged and disengaged. On the other hand, in a device configured to operate the travel switching valve via a pilot valve operated by a travel lever like a large power shovel, pressure oil is supplied to this valve in the hydraulic system of the pilot valve. By installing a switching valve that cuts the vehicle, the traveling device is prevented from being operated even if the traveling lever comes into contact with the human body and swings. Further, there is also proposed a device in which the operator lever is pivoted and retracted to the upper rear portion when the operator gets on and off to secure a wide boarding / alighting space.

[0004]

However, the stopper member provided on the base side of the traveling lever is artificially operated to fix and release the traveling lever as in the above-described device having the fixing mechanism. The apparatus has a drawback that it is easy to forget the fixing operation when getting on and off, which is often performed, and it is difficult to perform the operation because the leaning forward posture makes it difficult to perform the operation.

Further, the latter type of large power shovel, in which a switching valve is installed in a hydraulic system, has a complicated structure and a high cost, and is used in a small mini power shovel which operates a traveling device through a link system. There is a problem that it cannot be applied as a fixing mechanism.

[0006]

A traveling lever fixing device for a traveling working machine according to the present invention is obtained in order to solve the problems of the above-mentioned conventional device, and has the following configuration. ing. 1) A traveling work machine in which a working unit 4 is provided on a machine base 3 having a traveling device 2, and the traveling lever 8 and the working lever 7 arranged in the driver's seat 6 are individually operated to drive and operate the traveling device 2 and the working unit 4. 1, the traveling lever 8 is rotatably provided on the support shaft 13, and a locking portion 14a is provided on the actuating member 14 that operates in accordance with the rotation of the traveling lever 8, and the locking portion 14a is provided on the driver seat. The traveling lever 8 is fixed to the neutral position by locking the engaging lever 6 from a fixing mechanism 9 that can be engaged and disengaged.

2) The fixing mechanism 9 for the traveling lever 8 engages with the locking portion 14a and guides and guides it to the neutral position 90b.
And a cylinder portion 95 that biases the fixed piece 90 toward the fixed side by a spring 91 when the pressure oil feed is stopped and released. 3) A fixing piece 90 for releasably fixing the locking portion 14a,
A guide portion 93a formed on a mounting plate 93 for mounting and supporting the cylinder portion 95 is slidably engaged and guided.

4) The work unit 4 is mounted on the machine base 3 having the traveling device 2.
Is provided, and the traveling device 2 is operated by the traveling lever 8 pivotally supported on the support shaft 13 in front of the driver's seat 6, and
A work lever 7 provided on an operation box 70 capable of switching between a work posture and an evacuation posture on the side of the driver's seat 6 is provided with a work lever 4
In the traveling work machine 1 configured to operate the traveling work machine 1, a fixing mechanism 9 that operates to fix the traveling lever 8 by disengageably engaging the fixing piece 90 with the locking portion 14a formed in the traveling lever 8 is provided. A switching device 56 is provided for switching the fixing mechanism 9 by detecting that the work lever 7 is in the withdrawal / escape posture, and the fixing mechanism 9 is operated to the fixed side by a signal from the switching device 56. 5) The switching device 56 is composed of an electromagnetic valve that stops the supply of pressure oil to the fixing mechanism 9.

[0009]

[Operation] With the above configuration, the driver seat 6 to the fixing mechanism 9
By stopping and releasing the pressure oil to be pushed, the fixing piece 90 is pushed through the spring 91 and engaged with the locking portion 14a, so that the traveling lever 8 can be easily fixed at the neutral position.
At this time, the fixed piece 90 is smoothly guided forward and backward by being guided and regulated by the guide portion 93a formed on the mounting plate 93, and the guide surface 90b promptly locks the locking portion 14a to the neutral position. Can be satisfactorily fixed. In addition, the loading / unloading posture of the operation box 70 is detected, the switching device 56 is operated, and the fixing mechanism 9 is automatically held at the neutral position.

[0010]

EXAMPLES Examples of the present invention will be described with reference to the drawings. In FIG. 1, reference numeral 1 denotes a power shovel shown as an example of a traveling work machine, which is a base pillar 2a of a crawler type traveling device 2.
A machine base 3 is provided so as to be rotatable, a working unit 4 such as a bucket is provided in front of the machine base 3 via a mounting bracket, an engine 5 is provided in the rear, and a driver's seat 6 is provided in the middle.

The driver's seat 6 is provided with a seat 6a in the middle of the machine base 3, and work levers 7 for freely operating the work unit 4 are provided on the operation box 7a on the left and right sides of the seat 6a. 8 is the driver's seat 6
Is a pair of left and right traveling levers that are erected from the machine base 3 in front of the vehicle. The traveling levers 8 and 8 are provided with a fixing mechanism 9 which will be described later. By being operated separately, the left and right traveling devices 2 and 2 can be rotated forward and backward in the respective operating directions to carry out steering and forward / backward steering.

The structure will be described in detail below with reference to FIGS. 11 is a traveling lever 8, 8 and this traveling lever 8,
8 is a bracket for integrally fixing and fixing the fixing mechanism 9 of 8 to the machine base 3, and the bases of the traveling levers 8 and 8 are provided laterally with respect to the bracket 11.
Locking portion 1 pivotally supported on 3 and formed on an operating member 14 integrally provided on the base of the traveling levers 8 and 8.
The fixing member 90 of the fixing mechanism 9 is disengageably provided on the 4a (pin-shaped projection) so as to be pressed and fixed.

At the lower end of the actuating member 14 provided at the base of the left and right traveling levers 8, 8, the valve links 15, of the traveling valves 51, 51 (FIG. 5) for individually operating the left and right traveling devices 2, 2, respectively, The other end of a connecting member 16 (FIG. 3) made of a wire or the like that is connected to 15 (FIG. 2) is fixed so that steering and forward / backward movement can be performed. Next, the structure of the fixing mechanism 9, which is a feature of the present invention, will be described.

The fixing mechanism 9 includes a fixing piece 90 and a spring 91 when the fixing piece 90 is stopped and released from the pressure oil supply.
A mounting plate 93 having a cylinder portion 92 for urging and moving toward the fixed side is fixed to the bracket 11 at the middle rear portion of the traveling levers 8 and 8 by fixing the cylinder portion 92. Between the bracket 11 and the floor of the machine base 3 is compactly housed and installed.

In the cylinder portion 92, a piston shaft 94 having a butterfly-shaped fixing piece 90 fixed to its head is slidably inserted into a cylinder 95, and the other end portion of the piston shaft 94 is attached to the cylinder 95.
It is tensioned by the spring 91 installed inside. Then, from the port 96 provided at the center of the cylinder 95 to the pressure chamber 94a.
When the pressure oil is fed into the inside, the piston shaft 94 presses the spring 91 and contracts, thereby retracting the fixed piece 90 to the “unfixed state” as shown in FIG. 8 and 8 are switched to a freely operable traveling state.

On the other hand, the fixing piece 90 is formed in a two-forked U-shape in a plan view, and the locking portion (locking pin) 1 in a side view.
4a has guiding surfaces 90b, 90b inclined in a valley shape at the top and bottom of an engaging recess 90a that engages in a sandwiched manner, forming a butterfly shape as a whole, and releasing the supply of pressure oil to the pressure chamber 94a. Then, the piston shaft 94 is extended by the tension of the spring 91, and the guide surfaces 90b, 90b of the fixed piece 90 provided at the front portion of the piston shaft 94 are provided with the operating members 14 provided at the base portions of the traveling levers 8, 8. The locking portion 14a (pin) that protrudes in the direction is guided and engaged with the inside of the engaging concave portion 90a to maintain the levers 8 and 8 in a fixed state at the neutral position as shown in FIG.

The fixing piece 90 is as shown in FIG.
By sliding both of the outer side surfaces into the guide portion 93a formed in the notch groove on the mounting plate 93, the mechanism for preventing rotation of the fixed piece 90 during the forward / backward movement is prevented with a simple structure and locked. The parts 14a and 14a can be fixed accurately. Next, a hydraulic operation system diagram adopted in this embodiment will be described with reference to FIG.

The pressure oil generated by the hydraulic motor 5a driven by the engine 5 is operated by the work levers 7, 7 respectively, and the working valves 50, 50 are operated by the travel levers 8, 8. 51, 51 actuate the working unit cylinders 70 (boom cylinder), 71 (bucket cylinder), 72 (arm cylinder), 73 (swing cylinder), drive the working unit 4 and actuate the traveling motors 80, 81. The traveling devices 2 and 2 are driven.

The port 96 (FIG. 4) of the cylinder portion 92 of the fixing mechanism 9 is connected to a pilot passage 55 provided in series in the circuit leading to the working valves 50, 50 communicating with the hydraulic pump 5a. At the same time, an electromagnetic valve 56 is provided in the lower oil passage as a switching device for feeding pressure oil to the pilot passage 55 and for switching the stop release.

Next, a mechanism for holding the traveling levers 8, 8 in the neutral position when the operation box 70 is raised will be described. As shown in FIG. 6, when the operation box 70 for supporting the work lever 7 is transformed from the work posture shown by the chain line with the mounting shaft 71 as a fulcrum to the getting on / off retract posture shown by the solid line, The solenoid valve 56 is turned off to stop and release the pilot pressure oil, and the oil tank 5
A change-over switch 58 for changing back to 7 is provided on the lower surface of the operation box 70 so as to be able to come into contact with and separate from the lower surface.

Although the changeover switch 58 is mainly operated by turning the operation box 70, it may be provided so as to be operated independently. Further, the starter main switch 5S of the engine 5 is arranged at the rear of the mounting shaft 71 of the operation box 70, and when the operation box 70 is switched to the loading / unloading posture, the side surface of the starter main switch 5S turns from ON to OFF. Safety is secured by switching to the state of.

In the traveling work machine 1 configured as described above, when the operator stops the machine and gets off the vehicle, the changeover switch 58 is turned off by the operation of inevitably raising the operation box 70 to the retracted posture. Then, the electromagnetic valve 56 is switched as shown in FIG. And the fixing mechanism 9
The pilot pressure oil in the cylinder portion 92 constituting the above is stopped and released and returned to the oil tank 57.

As a result, the piston shaft 94 is attached to the spring 9
By being pressed by 1, the locking portion 14a of the traveling lever 8 provided at the tip of the piston shaft 94 is guided to the guide surface 90.
The guide levers b and 90b can be securely locked in the engaging recess 90a, and the traveling levers 8 and 8 can be fixed and maintained at the neutral position. At this time, the connecting member 16 (FIGS. 2 and 4) is pivotally attached to the actuating member 14 vertically below the support shaft 13, and the locking portion 14a is provided on the rear portion of the support shaft 13 so as to project from the rear in the projecting direction. By the fixing mechanism 9 installed in the above, the vertical movement can be favorably fixed with a compact structure.

Further, the fixed piece 90 is guided so as to prevent axial rotation by a simple constitution of the forward / backward movement and the fixed posture of the guide portion 93a formed on the mounting plate 93, and the traveling levers 8, 8 are moved to predetermined positions. It can be satisfactorily fixed without rattling. Therefore, even if the operator touches the traveling levers 8 and 8 carelessly when getting on and off, the traveling lever 8 can maintain the neutral position.

Further, since the traveling levers 8 and 8 are held at the neutral position by the retracted posture of the operation box 70, safety is ensured, and when the operation is performed, the operation box 7 is operated.
By returning 0 to the original work posture, the changeover switch 58 is turned on to switch the electromagnetic valve 56 to send the pressure oil to the fixing mechanism 9, the fixing piece 90 is disengaged from the engaging portion 14a, and the traveling lever 8, 8 can be made operable for traveling work.

[0026]

The present invention having the above-described structure can achieve the following effects. A) According to the invention of claim 1, the locking portion provided on the actuating member of the traveling lever can be locked by the fixing mechanism operable from the driver's seat to fix the traveling lever at the neutral position.

Therefore, the operation of fixing and releasing the traveling lever can be performed easily and quickly, the work can be efficiently performed, and even if the operator touches carelessly when getting on and off the vehicle. The traveling lever can be reliably fixed and maintained, and erroneous operation and the like can be prevented. B) According to the invention of claim 2, the fixing mechanism is released by the pressure oil at the time of driving work, the traveling lever is put in a workable posture, and the fixing piece is pushed by the spring force when the pressure oil is stopped and released. Since the traveling lever is fixed, a fixing mechanism that operates without malfunction with a simple configuration can be compactly installed on the base side of the traveling lever.

Further, the guide surface formed on the fixed piece can favorably guide and fix the engaging portion to the neutral position. C) According to the invention of claim 3, the fixing piece can be guided to the guide portion of the mounting plate to prevent the shaft from rotating and the traveling lever can be accurately fixed, and the guide portion also serves as the mounting plate for mounting the fixing mechanism. By configuring the fixing mechanism, a high-performance fixing mechanism can be easily configured.

D) According to the fourth aspect of the invention, the switching device detects the switching of the fixed piece that engages with the locking portion of the traveling lever to the loading / unloading posture of the operation box having the work lever, and operates the fixing mechanism. The travel lever can be fixed. Therefore, the operator can automatically fix or release the traveling lever when the operator inevitably retracts or returns the operation box when getting on or off.

E) According to the fifth aspect of the invention, the electromagnetic lever is operated by switching the loading / unloading posture of the operation box, and the fixing mechanism is fixed or released, so that the traveling lever can be reliably fixed.

[Brief description of drawings]

FIG. 1 is a side view of a traveling work machine according to an embodiment of the present invention.

FIG. 2 is an exploded perspective view showing configurations of a traveling lever and a fixing mechanism.

FIG. 3 is a side view showing a configuration of a traveling lever and a fixing mechanism with a partial cross section.

FIG. 4 is a side view showing a working state in which a fixing mechanism is released.

FIG. 5 is a plan view showing a hydraulic system.

FIG. 6 is a schematic diagram showing an operation of a fixing mechanism.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Traveling work machine 3 Platform 4 Working part 5 Engine 5a Hydraulic pump 6 Driver's seat 7 Work lever 7a Operation box 8 Traveling lever 9 Fixing mechanism 13 Spindle 14 Actuating member 14a Locking part 56 Electromagnetic valve (switching device) 58 Changeover switch 90 fixing piece (fixing member) 91 spring 93 mounting plate 95 cylinder part

Front page continuation (72) Inventor Hisao Nagata 667 Isuyacho, Higashi Izumo-cho, Yatsuka-gun, Shimane Prefecture 1 Inside Mitsubishi Agricultural Machinery Co., Ltd.

Claims (5)

[Claims] 1. A working unit 4 is provided on a machine base 3 having a traveling device 2, and a traveling lever 8 and a working lever 7 arranged in a driver's seat 6 are operated separately to drive and operate the traveling device 2 and the working unit 4. In the traveling work machine 1, the traveling lever 8 is rotatably provided on the support shaft 13, and the operating member 14 that operates in accordance with the rotation of the traveling lever 8 is provided with a locking portion 14a. A traveling lever fixing device for a traveling work machine provided so that the traveling lever 8 is fixed to a neutral position by locking the vehicle from a driver's seat 6 with a fixing mechanism 9 that can be engaged and disengaged. 2. A fixing mechanism 9 for fixing the traveling lever 8,
A fixed piece 90 having a guide surface 90b which engages with the locking portion 14a and guides and guides it to the neutral position, and the fixed piece 90 is urged toward the fixed side by a spring 91 when the pressure oil feed is stopped and released. The traveling lever fixing device for the traveling work machine according to claim 1, wherein the traveling lever fixing device comprises a cylinder portion 95 to be moved. 3. A mounting plate 93 for mounting and supporting a fixing member 90 for releasably fixing the locking portion 14a and a cylinder portion 95.
The traveling lever fixing device for a traveling work machine according to claim 2, wherein the guide portion 93a formed on the guide is slidably engaged and guided. 4. A work unit 4 is provided on a machine base 3 having a traveling device 2, and the traveling device 2 is operated by a traveling lever 8 pivotally supported on a spindle 13 in front of a driver's seat 6, In the traveling work machine 1 in which the working portion 4 is operated by the working lever 7 provided on the operation box 70 which can be switched between the working posture and the evacuating / retracting posture on the side of the driver's seat 6, a member formed on the traveling lever 8 is provided. A fixing mechanism 9 is provided which engages the fixing piece 90 with the stopper 14a in a disengageable manner so as to fix the traveling lever 8. The fixing mechanism 9 detects that the work lever 7 is in the loading / unloading posture. A traveling lever fixing device for a traveling work machine, which is provided with a switching device 56 for switching the switching mechanism and operates the fixing mechanism 9 to the fixed side by a signal from the switching device 56. 5. The traveling lever fixing device for a traveling work machine according to claim 4, wherein the switching device 56 is an electromagnetic valve for stopping the supply of the pressure oil to the fixing mechanism 9.