JPS6242997Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to working machines such as a hydraulic shovel, a hydraulic crane, and a hydraulic bulldozer.

Conventionally, a driving guide has been provided with a switching lever that can be switched between a running position and a parking position, and a working lever that operates an actuator of a working device such as a shovel or a crane. A working machine is known that has a circuit configuration that prevents the actuator from malfunctioning even when the actuator is operated.

FIGS. 1 and 2 show a specific example of the working machine according to the above-mentioned prior art. In FIG. 1, reference numeral 1 denotes a driver's cab mounted on the vehicle body side of the work machine; A power source such as an engine, and working equipment such as a shovel and crane (none of which are shown) are mounted on the vehicle body, and wheels or tracks operated by a traveling motor (described later) are provided on the vehicle body side, and the vehicle is driven by these wheels and tracks. is configured to do so. A driver's seat 2 is provided in the operator's cab 1, and an entrance 3 is formed on one side of the operator's seat 2 for workers to enter and exit, and a door is attached to the entrance 3 as necessary. . Reference numerals 4 and 4 designate operation panels provided on the sides of the driver's seat 2, and each operation panel 4 is provided with a pilot lever 5 and a switching lever 6 as work levers.

Figure 2 shows the hydraulic circuit for controlling the work equipment.
7 is a pilot valve operated by the pilot lever 5, and 8 is a main switching valve that is switched by pressure oil from the pilot valve 7. By switching the main switching valve 8, a shovel, a crane, etc. can be operated. An actuator is actuated to do so. 9 is the switching lever 6
The switching valve 9 is a positioning type three-position switching valve operated by a parking position A, a high-speed driving system B,
The low-speed traveling device has three positions. 10 is a travel motor for driving the work machine, 11 is a port 11A,
11B, the traveling motor control section 11 is connected to a pilot pump 14 via pipes 12 and 13 and also to a tank 15, and one pipe 13 is connected to the above-mentioned pipe via a branch pipe 16. The pilot valve 7 is connected to the pilot valve 7.
Then, the travel motor control unit 11 sets the switching valve 9 to the parking position A so that pressure oil is supplied to the port 11A to apply the parking brake to the travel motor 10, and sets the high-speed travel device B to the port 11A.
Pressure oil is supplied to ports A and 11B to cause the travel motor 10 to travel at high speed, and by setting it to the low speed travel position C, pressure oil is supplied to port 11B to cause the hydraulic motor 10 to travel at low speed. During this time, pressure oil is supplied to the pilot valve 7 via the branch pipe 16 only when the switching valve 9 is set to each traveling position A or C, and the main switching valve 8 is switched by operating the pilot valve 7. When the switching valve 9 is set to the parking position A, the supply of pressure oil to the pilot valve 7 is stopped, and the main switching valve 8 is configured not to operate even if the pilot lever 5 is operated. .

With the above configuration, the operator can
If the switching lever 6 is operated to switch the switching valve 9 to the parking position A when leaving the vehicle, the pressure oil from the pilot pump 14 will be transferred to the port 1 of the travel motor control 11.
1A to put the drive motor 10 in the parking brake state, and no pressure oil is supplied to the pilot valve 7. Therefore, when an operator gets in or out of the operator's cab 1, part of his or her body or clothing may come into contact with the pilot lever 5. Even if the main switching valve 8 is switched, the main switching valve 8 will not switch. Therefore, when the switching lever 6 is switched to the parking position, there is an advantage that even if the pilot lever 5 is erroneously operated, malfunction of the actuator can be prevented.

However, in the above conventional technology,
There is a drawback that when getting into or out of the driver's cab 1, the user may forget to switch the switching lever 6 to the parking position A. As a result, the parking brake is not applied to the travel motor 10, and the vehicle body may move when the vehicle is parked on a slope or the like.

In order to eliminate the above drawbacks, as shown in FIGS. 3 and 4, an obstacle position is provided near the entrance of the driver's cab that becomes an obstacle to getting in and out of the driver's cab.
A working machine is also known that is provided with a switching lever that can be moved to a non-obstructive position that does not obstruct entry/exit, and has a circuit configuration that stops the supply of pressure oil to the pilot valve when the switching lever is set to the non-obstructive position. .

That is, in FIGS. 3 and 4, the same components as those in FIGS. 1 and 2 described above are given the same reference numerals. One end of the switching lever 21 is rotatably supported on the operation panel 4, and the other end extends toward the entrance/exit 3,
It is switched to a non-fault position A shown by a solid line in FIG. 3 and a fault position B shown by a two-dot chain line. Reference numeral 22 denotes a positioning type two-position switching valve, which is connected to the switching lever 21 via a connecting member 23 such as a cable or link, and is connected to the switching lever 21 in the middle of the branch pipe 24 as shown in FIG. One end of the branch pipe 24 is connected to the pipe 12, and the other end is connected to the pilot valve 7. Then, by setting the switching lever 21 to the failure position B, the switching valve 22 becomes the connection position N, and the pilot pump 14
By supplying pressurized oil to the pilot valve 7 from 1 to 7 and setting it to the non-failure position A, the switching valve 22 is set to the cutoff position H and connected to the tank 15.

With the above configuration, the worker can
If the switching lever 21 is in the obstruction position B when getting on and off from the driver's cab 1, it will be a hindrance, so the operator switches the lever 21 to the non-obstruction position A before getting in and out of the cab. Therefore, when the operator exits the operator's cab 1, he or she must operate the operating lever 21 to set the switching valve 22 to the cutoff position H. At this point, the supply of pressure oil to the pilot valve 7 is stopped and the pilot lever 5 is turned off. Even if the actuator is operated incorrectly, malfunction of the actuator can be prevented.

However, in the above-mentioned other prior art, the switching valve 22 is required, which complicates the circuit configuration, and therefore has the disadvantage of being expensive. In addition, since the switching levers 6 and 21 are not linked, the parking brake can be activated and released by operating the switching lever 6, and the parking brake can be activated and released by operating the switching lever 21 from the fault position B to the non-fault position A. This has the drawback that the lever operation must be performed twice, including the operation to stop the supply of pressure oil to the valve 7, and the operation is complicated.

The purpose of this invention is to improve the shortcomings of each of the prior art technologies mentioned above.The main feature of this invention is that it adopts the circuit configuration shown in Figure 2, and when the switching lever is in the parking position, the work lever (pilot The actuator of the work device is configured so that it will not malfunction even if the operator operates the operating lever, and a moving lever that can be moved between a faulty position and a non-faulty position is provided near the entrance to the operator's cab, and the switching lever is moved to the driving position. The vehicle is provided with an interlocking mechanism that moves the movable lever to the obstructed position when the movable lever is in the disabled position, and switches the switching lever to the parking position when the movable lever is moved to the non-disturbed position.

As a result of the above configuration, there is no need for a complicated circuit configuration as shown in Fig. 4, so it can be manufactured at low cost, and since the moving lever is interlocked with the switching lever, at the start of operation, the switching lever is set to run at high speed or low speed. All you have to do is switch to the driving position, and when you leave the driver's seat, you only have to move the moving lever to the non-obstructing position, so operation is simple.Moreover, if you move the moving lever to the non-obstructing position, the switching lever can also be moved to the parking position. Therefore, even if the pilot lever is operated erroneously, malfunction of the actuator can be reliably prevented.

The present invention will be explained below along with embodiments shown in FIGS. 5 to 7.

Since the present invention also employs the circuit configuration shown in FIG. 2, the same components as in FIGS. 1 and 2 are given the same reference numerals and their explanations will be omitted. In the figure, 31 is a moving lever provided on the operation panel 4 so as to be able to move forward and backward, and the moving lever 31 is guided by guide rollers 32, 32 provided inside the operation panel 4.
An operating section 31A is formed at the tip, and
A projection 33 is installed horizontally on the rear end side, and the switching lever 6 of the switching valve 9 is in contact with the projection 33. Reference numeral 34 indicates a link, the lower end of which is rotatably supported via a pin 35, and a long groove 36 is formed at its upper end, and the projection 33 is fitted into the long groove 36. Also, 37 is a spring,
One end of the spring 37 is connected to a pin 38, and the other end is connected to a pin 39 provided on the link 34. Reference numerals 41 and 42 are stoppers provided on the operation panel 4 to restrict rotation of the link 34. The interlocking mechanism 43 of this embodiment includes a protrusion 33, a link 34, a long groove 36, a spring 37, and the like. In addition, the switching lever 6 has a parking position a in the right position shown by the solid line in FIG. Further, the right position of the moving lever 31 indicated by a solid line indicates a non-fault position d, and the left position indicated by a two-dot chain line indicates a fault position e.

Here, the operation of the interlocking mechanism 43 will be described.
When the switching lever 6 is moved to the left from the parking position a, the switching lever 6 moves the moving lever 31 to the left via the projection 33, so that the link 34 also rotates counterclockwise. Before the switching lever 6 reaches the high-speed traveling position b, the spring 37 reaches its maximum extension state.
When the link 34 reaches the high-speed traveling position b, the link 34 is reversed by the spring 37 and rotates to a position where it comes into contact with the stopper 42, and along with this, the moving lever 31
moves from the non-faulty position d to the faulty position e. When the movable lever 31 is in the disabled position e, the movable lever 31 is not interlocked with the switching lever 6, so the switching lever 6 can be moved to each position a, b, c, while the movable lever 31 is in the stop position. 42
It remains in contact with the On the other hand, when the moving lever 31 is pushed from the fault position e to the non-fault position d while the switching lever 6 is in each traveling position b, c, the protrusion 33 comes into contact with the switching lever 6, and the switching lever 6 is moved to the right. be moved towards Furthermore, when the switching lever 6 passes the high-speed travel position b, the spring 37 becomes fully extended, and the link 3 rotates clockwise.
4 is reversed by the spring 37 to a position where it abuts against the stopper 41. As a result, the moving lever 31 connected to the link 34 via the protrusion 33 is held in the non-obstructed position d, and the switching lever 6 is also held in the parking position a, so that the switching lever 6 overcomes the spring 37. It remains in this position unless force is applied.

The working machine of the present invention is constructed as described above, but before starting work, the switching lever 6 is in the parking position a,
The moving lever 31 is also in the non-obstructed position d. Therefore,
As shown in FIG. 2, the switching valve 9 is in the parking position A, and no pressure oil is supplied to the pilot valve 7.

When starting work, the worker enters through the doorway 3, takes a seat in the driver's seat 2, and then moves the switching lever 6 to either travel position b or c. At this time, the moving lever 31 is moved by the spring 37 to the failure position e. As a result, the traveling motor 10 enters a traveling state, and by operating the pilot lever 5, the main switching valve 8 is switched via the pilot valve 7, and the actuator can be operated.

Furthermore, since the moving lever 31 protruding toward the doorway 3 becomes an obstacle when the operator leaves the driver's seat 2, the moving lever 31 is pushed from the obstruction position e to the non-obstruction position d. As described above, the switching lever 6 moves to the parking position a in conjunction with this pushing operation and is held at that position, so that the travel motor 10
The parking brake is applied and no pressure oil is supplied to the pilot valve 7. Therefore, even if the operator's body or clothes touch the pilot lever 5 when getting on or off the vehicle, malfunction of the actuator can be reliably prevented.

In the above embodiment, a hydraulic pilot system using the pilot pump 14 and the pilot valve 7 was described, but the invention is not limited to this.
In addition, although the interlocking mechanism 43 is a link mechanism consisting of the protrusion 33, the link 34, the long groove 36, the spring 37, etc., and the movable lever 31 is movable in the horizontal direction, the movable lever 34 is similar to that of the other prior art described above. It may also be possible to move between the faulty position and the non-faulty position by being rotated as shown in FIG.

As described in detail above, the working machine according to the present invention is capable of interlocking the moving lever and the switching lever, so when leaving the driver's seat, the switching lever can be parked by simply moving the moving lever to the non-obstructing position. It can be switched to any position, is easy to operate, and can be manufactured inexpensively since there is no need to provide an additional switching valve in the hydraulic circuit.

[Brief description of the drawings]

1 and 2 show working machines according to the prior art, FIG. 1 is a perspective view of the operator's cab, FIG. 2 is a hydraulic circuit diagram, and FIGS. 3 and 4 show working machines according to other prior art. 3 is a perspective view of the driver's cab, FIG. 4 is a hydraulic circuit diagram, FIGS. 5 to 7 are a working machine according to the present invention, FIG. 5 is a perspective view of the driver's cab, and FIG. 6 is a perspective view of the operator's cab. 7 is a specific configuration diagram of the interlocking mechanism, and FIG. 7 is a sectional view of FIG. 6. 1...Driver's cabin, 3...Entrance/exit, 4...Operation panel,
5...Pilot lever, 6...Operation lever, 7
...Pilot valve, 8...Main switching valve, 9...Switching valve, 10...Travel motor, 31...Movement lever,
33...Protrusion, 34...Link, 36...Long groove,
43...Interlocking mechanism.

Claims (1)

[Scope of utility model registration request] A switching lever that can be operated to switch between a traveling position and a parking position and a working lever that operates an actuator of a working device are provided in the driver's cab, and when the switching lever is switched to the parking position, even if the working lever is operated, the In a working machine in which the actuator is prevented from malfunctioning, the actuator is movable near the entrance of the operator's cab between an obstacle position that becomes an obstacle to getting in and out when getting on and off the operator's cab, and a non-obstruction position that does not become an obstacle to getting in and out. A moving lever is provided, and an interlocking mechanism is provided for moving the switching lever to a fault position when the switching lever is set to a traveling position, and switching the switching lever to a parking position when moving the moving lever to a non-faulting position. A working machine characterized by: