JPH0913431A - Control device of working vehicle - Google Patents

Abstract

PURPOSE: To ensure the safety of starting at the time of return by providing a condition detecting means for an actuator operating lever to confirm that the operating lever is returned to the nonworking position at the time of restarting after the urgency stop by a switch. CONSTITUTION: A hydraulic remote-control valve 7 is operated by an operating lever 9 and an actuator is operated to conduct work such as excavation or the like. If urgency stop is needed because of a sudden work trouble during work, an urgency stop switch 15 is pressed to stop the device. Subsequently, at the time of restarting work after the trouble is solved, the condition (ON-N (neutral position)-OFF of the operating lever 9 is detected, and only if the lever 9 is in the non-operating condition, restart is enabled. The detecting means may include a lever condition detecting sensor, an actuator operating condition detecting sensor, a limit switch, a pressure switch, and a solenoid switching valve for opening and closing a pilot circuit. Thus, at the time of restart after the urgency stop, unexpected operation can be prevented to ensure the safety.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control device for a work vehicle in which a work machine having an actuator is mounted on a vehicle body to perform work such as excavation.

[0002]

2. Description of the Related Art FIG. 8 is a circuit diagram showing an embodiment configuration of a safety device for a working machine such as a construction machine described in JP-A-6-49867. In the safety device according to the embodiment of the related art shown in FIG. 8, an engine 31, a starter motor 32 for driving the engine 31, a relay 33 for controlling the starter motor 32, a hydraulic power source 34 driven by the engine 31, 35, a hydraulic motor 37 connected to the hydraulic power source 34 via a directional control valve 36, and the output side of the directional control valve 3
6, a pilot valve 39 having an input side connected to the hydraulic power source 35 via the switching valve 38, and a switch 40 for turning the switching valve 38 ON / OFF by switching, and the switching valve 38 is in the communication state. If it has been switched,
The relay 33 prevents the starter motor 32 from operating.

[0003]

The purpose of the safety device according to the embodiment of the prior art shown in FIG. 8 is to start the engine with the operating means for operating the actuator being operated by mistake while the engine is stopped. It is to prevent the actuator from accidentally moving. However, in the safety device in FIG. 8, even when the operation lever 41 of the pilot valve 39 is tilted and locked in that state, it is stopped by switching the switching valve 38 to the tank communication oil passage position a. The engine 31 can be started. Therefore, when the engine 31 is started as described above, the operation lever 41 is moved to the neutral position (non-operation state position).
When the switching valve 38 is switched to the communication oil passage position B without forgetting to return to the above, the direction switching valve 36 is switched and the hydraulic motor 37 starts rotating. That is, the actuator starts to move unexpectedly, which makes the work unsatisfactory. An object of the present invention is to provide a control device that can solve the above problems.

[0004]

According to the present invention, a work machine having an actuator is mounted on a vehicle body to perform work such as excavation, and an emergency stop switch is provided so that when a sudden work problem occurs, In a work vehicle in which an actuator stop means is provided by operating an emergency stop switch, a lever operation state detection means for detecting an operation state of a work lever for operating the actuator is provided to operate the emergency stop switch. After that, the lever operation state detection means detects the non-operation state of the work lever, and the emergency stop switch is returned to the original non-operation state so that the stopped state of the actuator stop means is released. . And in the above case,
The respective signals from the lever operation state detection means and the emergency stop switch are input to the controller, and the lever non-operation state signal from the lever operation state detection means and the non-operation state return signal from the emergency stop switch are input to the controller. Is input and the controller processes both of the above signals to output a stop state release command signal to the actuator stopping means from the controller.

Further, in another embodiment of the control device of the present invention, in addition to the lever operation state detecting means and the emergency stop switch, an operation prohibition state detecting means for detecting a state in which the operation of the actuator causes a work defect is provided. Signals from the operation prohibition state detection means, the lever operation state detection means, and the emergency stop switch are input to the controller, and the controller receives the operation permission signal from the operation inhibition state detection means and the lever operation. The lever non-operation state signal from the state detection means and the non-operation state return signal from the emergency stop switch are input, and the controller performs judgment processing of the plurality of signals to stop the actuator from the actuator stop means. The state release command signal is output.

In the control device of the present invention, a sensor for detecting the lever operation state, a limit switch, or a pressure switch is set as the lever operation state detection means. As the operation prohibition state detecting means, a sensor for detecting the operation prohibition state of the actuator, a limit switch, or a pressure switch is set. As the actuator stopping means, an electromagnetic switching valve that opens and closes the pilot circuit leading to the pilot port of the actuator control pilot switching valve is set.

[0007]

When the work vehicle according to the present invention is working, if an unexpected work failure occurs, the emergency stop switch is operated to stop the actuator of the work machine. Then, when it is desired to operate the actuator again after completing the solution of the work trouble, the lever non-operation state signal from the lever operation state detection means is sent to the controller.
Also, the non-operation state return signal from the emergency stop switch is input, and the controller performs a judgment process on both of the above signals, thereby outputting a stop state release command signal to the actuator stopping means from the controller. Therefore, in the above case, the stopped state of the actuator stop means is released, but when the work lever is in the operation state position, even if the emergency stop switch is returned to the original non-operation state position, the stop state of the actuator stop means is released. Since it is not released, the operation of the actuator cannot be started.

In a work vehicle equipped with a control device according to another embodiment of the present invention, when an emergency stop switch is operated and work trouble elimination is completed and the actuator is to be actuated again, the controller detects the operation inhibition state. The operation permission signal from the means, the lever non-operation state signal from the lever operation state detection means, and the non-operation state return signal from the emergency stop switch are input, and the controller performs judgment processing on the plurality of signals, thereby the controller Outputs a stop state cancellation command signal to the actuator stopping means. Therefore, in the above case, the stopped state of the actuator stop means is released, but in the case of at least one of the case where the work lever is in the operation state position and the case where the operation prohibition state exists, an emergency stop is performed. Even if the operation switch is returned to the original non-operation state, the stopped state of the actuator stopping means is not released, so that the operation of the actuator cannot be started.

[0009]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a front view of a hydraulic working vehicle equipped with the control device of the present invention. In the hydraulic work vehicle shown in FIG.
An upper revolving structure 2 is provided above the lower traveling structure 1, and a vertically long working machine 3 for excavating a deep groove wall is mounted on a side of the lower traveling structure 1. Then, an endless body 4 (shown by phantom lines) having a large number of excavating blades (not shown) is laid around between the upper end and the lower end of the working machine 3, and the endless body 4 is moved. The hydraulic motor 5 which is an actuator is rotationally driven. FIG. 2 is a circuit diagram of a first embodiment control device of the present invention mounted on a work vehicle. In the figure, 6 is a pilot switching valve for controlling the hydraulic motor 5, 7 is a hydraulic remote control valve for operating the hydraulic motor 5, 8 and 8'are pilot valves for the hydraulic remote control valve 7, and 9 is a working lever for the hydraulic remote control valve 7. Reference numeral 10 is an electromagnetic switching valve that is actuator stopping means, 11 is a pilot hydraulic power source, and 12, 1
2'is the pilot valves 8 and 8'from the pilot ports 13 and 1 of the hydraulic motor control pilot switching valve 6, respectively.
3'is a pilot conduit, 14 is a sensor which is a lever operation state detecting means of the work lever 9, 15 is an emergency stop switch, and 16a is a controller. FIG. 3 is a perspective view of a main part of the hydraulic remote control valve 7 that locks the operation state of the work lever 9. In the figure, 17 is a lever lock fitting. FIG. 4 shows an emergency stop switch 15 with the work lever 9 locked in the operating position.
It is a circuit diagram which shows the state which operated. FIG. 5 is a flow chart for explaining the control device of the first embodiment of the present invention.

Next, the configuration of the control apparatus according to the first embodiment of the present invention will be described with reference to FIGS. In the present invention, the sensor 14 for detecting the operating state of the work lever 9 for operating the hydraulic motor 5 and the emergency stop switch 15 are provided, and the signals from the sensor 14 and the emergency stop switch 15 are sent to the controller 16a. To the controller 16a, the lever non-operation state signal from the sensor 14 (the work lever 9 is in the neutral position N) and the non-operation state from the emergency stop switch 15 (see FIGS. 2 and 4).
The return signal is input when the knob of the emergency stop switch 15 shown in FIG. 7 is not pushed and the return signal is input, and the controller 16a processes both signals to determine the actuator (hydraulic motor 5).
A stop state release command signal is output to the electromagnetic switching valve 10 that is a stop means.

Next, the operation of the control apparatus according to the first embodiment of the present invention will be described. When excavation work is performed by operating the work implement 3 of the work vehicle, when a sudden work defect (for example, breakage of an unillustrated excavating blade) occurs, the emergency stop switch 15 is shown in FIG. Operation to the push-in position b. The operation signal of the emergency stop switch 15 is input to the controller 16a. The controller 16a makes a determination based on the operation signal, and the controller 1
A stop command signal is output from 6a to the solenoid 18 of the electromagnetic switching valve 10. Since the solenoid 18 is energized, the electromagnetic switching valve 10 is switched from the open oil passage position C to the cutoff oil passage position D. Therefore, the pilot lines 12, 12 '
Is shut off and the pilot switching valve 6 returns to the neutral position, so that the hydraulic motor 5 can be stopped and the working machine 3 can be stopped quickly. When it is desired to operate the hydraulic motor 5 of the work machine 3 again after completing the solution of the work trouble,
A lever non-operation state signal (state in which the work lever 9 is in the neutral position N) from the sensor 14 to the controller 16a and a non-operation state from the emergency stop switch 15 (emergency stop switch 15 shown in FIGS. 2 and 4). The position of the sign a) at which the knob is not pushed and the return signal is input, and the controller 16a processes both signals to determine
Solenoid 1 of electromagnetic switching valve 10 from controller 16a
A stop state cancellation command signal is output to the signal No. 8. As a result, the solenoid 18 is de-energized, so that the electromagnetic switching valve 10
Due to the spring force of the built-in spring 19, the electromagnetic switching valve 10 is switched from the shutoff oil passage position D to the open oil passage position C. Therefore, by tilting the work lever 9 from the neutral position N, the operation of the hydraulic motor 5 can be started. However, in the above case, when the work lever 9 is in the operation state position (e.g., the E position shown in FIG. 4 other than the neutral position N) after the operation of the emergency stop switch 15, the emergency stop switch 15 is returned to the original non-operation position. Operation state position (Fig. 2, Fig. 4
Even if the electromagnetic switching valve 10 is returned to the shut-off oil passage position D even after returning to the (a position) shown in (1), the operation of the hydraulic motor 5 cannot be started.

In this embodiment, the sensor 14 for detecting the lever operation state is used as the lever operation state detecting means, but a limit switch (not shown) can be used. Further, FIG. 6 is a circuit diagram of a main part when the pressure switch 20 is arranged as the lever operation state detecting means. In the figure, 21 is a shuttle valve for selecting the pilot pressure in the pilot lines 12, 12 '.

Next, FIG. 7 is a circuit diagram of a main part of the control device according to the second embodiment of the present invention. In the figure, the same components as those of the control device of the first embodiment shown in FIG. 2 are designated by the same reference numerals. 22 is an operation prohibition that detects a state in which the operation of the hydraulic motor 5 of the work machine 3 causes a work defect (for example, a state where hard rock buried in the soil is suddenly exposed at the portion of the excavating blade) A sensor that is a state detection means,
16b is a controller. Next, the configuration of the second embodiment control device of the present invention will be described with reference to FIG. In the present invention,
In addition to the sensor 14 for detecting the operating state of the work lever 9 and the emergency stop switch 15, a sensor 22 for detecting a state in which the hydraulic motor 5 causes a work defect is provided. Stop switch 1
5, each signal from the sensor 5 is input to the controller 16b, and the controller 16b receives an operation permission signal from the sensor 22, a lever non-operation state signal from the sensor 14, and a non-operation state return signal from the emergency stop switch 15. Is input and the controller 16b processes the plurality of signals to output a stop state release command signal from the controller 16b to the solenoid operated directional control valve 10 which is the actuator (hydraulic motor 5) stop means.

Next, the operation of the control device according to the second embodiment of the present invention will be described. In the present invention, the emergency stop switch 15
After completing the operation of resolving the work defect after operating the, and wanting to operate the hydraulic motor 5 again, the controller 16b sends an operation permission signal from the sensor 22, a lever non-operation state signal from the sensor 14, and an emergency stop signal. Switch 1
The non-operation state return signal from 5 is input, and the controller 16b performs determination processing on the plurality of signals,
A controller 16b outputs a stop state release command signal to the solenoid operated directional control valve 10. Therefore, in the above case, the electromagnetic switching valve 10 switches from the shutoff oil passage position D to the open oil passage position C, so that the operation of the hydraulic motor 5 can be started.
However, in the above case, after operating the emergency stop switch 15, the state of at least one of the case where the work lever 9 is in the operation state position (a position other than the neutral position N) and the case where the operation state exists are present. Sometimes, even if the emergency stop switch 15 is returned to the original non-operating state position B, the electromagnetic switching valve 10 is still in the cutoff oil passage position D, so the hydraulic motor 5
Cannot be started. In this embodiment, the sensor 2 for detecting the operation prohibited state is used as the operation state detecting means.
2 is used, but a limit switch not shown,
A pressure switch or the like can be used.

[0015]

As described above, when the work vehicle according to the present invention is working, when an unexpected work failure occurs, the emergency stop switch is operated to stop the actuator of the work machine. Then, when the countermeasure for eliminating the work trouble is completed and the actuator is desired to be operated again, the lever non-operation state signal from the lever operation state detection means and the non-operation state return signal from the emergency stop switch are input to the controller. When the controller processes the both signals, the controller outputs a stop state release command signal to the actuator stopping means. Therefore, in the above case, the stopped state of the actuator stop means is released, but when the work lever is in the operation state position, even if the emergency stop switch is returned to the original non-operation state position, the stop state of the actuator stop means is released. Since it is not released, the operation of the actuator cannot be started. In a work vehicle equipped with a control device according to another embodiment of the present invention, when the emergency stop switch is operated and the work trouble is resolved and the actuator is to be actuated again, the controller detects the operation prohibition state detection means. When the operation allowance signal, the lever non-operation state signal from the lever operation state detection means, and the non-operation state return signal from the emergency stop switch are input, and the controller processes the plurality of signals, the controller stops the actuator. The stop state release command signal is output to the means. Therefore, in the above case, the stopped state of the actuator stop means is released, but in the case of at least one of the case where the work lever is in the operation state position and the case where the operation prohibition state exists, an emergency stop is performed. Even if the operation switch is returned to the original non-operation state, the stopped state of the actuator stopping means is not released, so that the operation of the actuator cannot be started. Therefore, in a work vehicle equipped with the control device of the present invention, when an emergency stop switch is operated and the operator wants to operate the actuator again after completing the solution of the work defect, the unexpected actuator at the time of the return operation of the emergency stop switch is used. Can be prevented.

[Brief description of the drawings]

FIG. 1 is a front view of a hydraulic working vehicle equipped with a control device of the present invention.

FIG. 2 is a circuit diagram of the safety device according to the first embodiment of the present invention.

FIG. 3 is a perspective view of a main part of a hydraulic remote control valve that locks an operating state of a work lever.

FIG. 4 is a circuit diagram showing operating states of a work lever and an emergency stop switch.

FIG. 5 is a flow chart for explaining the control device according to the first embodiment of the present invention.

FIG. 6 is a circuit diagram of a main part when a pressure switch is arranged as a lever operation state detecting means.

FIG. 7 is a circuit diagram of a main part of a control device according to a second embodiment of the present invention.

FIG. 8 is a circuit diagram showing a control device according to an embodiment of the prior art.

[Explanation of symbols]

 3 Working machine 5,37 Hydraulic motor 6 Pilot switching valve for hydraulic motor control 7 Hydraulic remote control valve 9 Working lever 10 Electromagnetic switching valve 12,12 'Pilot line 14,22 Sensor 15 Emergency stop switch 16a, 16b Controller 17 Lever Lock fitting 20 Pressure switch

Claims (7)

[Claims] 1. A work machine having an actuator is mounted on a vehicle body to perform work such as excavation, an emergency stop switch is provided, and the emergency stop switch is operated when a sudden work defect occurs. In the work vehicle in which the actuator stop means is provided by means of the above, a lever operation state detection means for detecting the operation state of the work lever for operating the actuator is provided, and the lever operation state detection means is provided after the operation of the emergency stop switch. Of the work vehicle characterized by detecting the non-operating state of the working lever, and releasing the stopped state of the actuator stopping means by returning the emergency stop switch to the original non-operating state. Control device. 2. The control device for a working vehicle according to claim 1, wherein signals from the lever operation state detection means and the emergency stop switch are input to the controller, and the lever operation state is input to the controller. The lever non-operation state signal from the detection means and the non-operation state return signal from the emergency stop switch are input, and the controller performs judgment processing on both of the above signals to release the stop state from the actuator stop means from the controller. A control device for a work vehicle, which outputs a command signal. 3. The control device for a work vehicle according to claim 1, further comprising an operation prohibition state detecting means for detecting a state in which the operation of the actuator causes a work defect, and the operation prohibition state detecting means. Signals from the lever operation state detection means and the emergency stop switch are input to the controller, and the controller receives the operation permission signal from the operation prohibition state detection means and the lever non-operation from the lever operation state detection means. Status signal,
And a non-operation state return signal from the emergency stop switch is input, and the controller outputs a stop state release command signal to the actuator stopping means by the controller processing the plurality of signals. A control device for a work vehicle characterized by: 4. The control device for a work vehicle according to claim 1, claim 2, and claim 3, wherein the lever operation state detection means and the operation prohibition state detection means each detect a lever operation state. A control device for a work vehicle, wherein the sensor is set as a sensor for detecting an operation prohibition state of the actuator. 5. The control device for a work vehicle according to claim 1, claim 2, and claim 3, wherein the lever operation state detecting means and the operation prohibition state detecting means respectively detect a lever operation state. A control device for a work vehicle, which is set to a limit switch for detecting a switch or actuator operation prohibition state. 6. The control device for a work vehicle according to claim 1, claim 2, and claim 3, wherein the lever operation state detection means and the operation inhibition state detection means detect the lever operation state, respectively. A control device for a work vehicle, wherein the switch and the pressure switch are set to detect the operation prohibition state of the actuator. 7. The control device for a work vehicle according to claim 1, claim 2, and claim 3, wherein a pilot circuit is provided that connects the actuator stopping means to a pilot port of an actuator control pilot switching valve. A control device for a work vehicle, characterized by being set as an electromagnetic switching valve that can be opened and closed.