JPH1047094A - Safety device for working vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent an adverse influence from being exercised on an engine stop solenoid even when a control device (an error monitoring device) is in an error detecting state and to prevent the occurrence of useless power consumption. SOLUTION: In a safety device formed such that during the occurrence of an error, an error detecting signal from an error monitor 41 is inputted to an engine stop signal generator 43 and a working machine is forced into an emergency stop, an engine stop signal from an engine stop generator 43 forms a timing signal in a short time enough to allow the stop of an engine 11. When the error monitor 41 is in an error detecting state, no energization for along time is effected on an engine stop solenoid 16. Further, a working machine is prevented from unexpected operation in a way that with an error detecting signal transmitted from the error monitor 41, the restarting of an engine 11 is prohibited and an engine is stopped immediately after the re-starting of the engine.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hydraulically operated work vehicle such as an aerial work vehicle or a crane vehicle, and in particular, in such a work vehicle, a control device of the work machine causes a serious error. The present invention relates to a safety device for urgently stopping a work machine when an error that needs to be stopped is detected.

[0002]

2. Description of the Related Art In a hydraulic work vehicle such as an aerial work vehicle or a crane vehicle, various actuators of a work machine are operated by hydraulic oil from a hydraulic pump driven by an engine.

FIG. 4 shows an aerial work vehicle as an example of this type of work vehicle. This aerial work vehicle has a hydraulically operated working machine 2 mounted on a vehicle 1. I have. This work machine 2 is provided with an outrigger 21 on the vehicle 1, a turntable (turn post) 22 on the frame of the vehicle 1,
2, a telescopic boom 23 is mounted on the telescopic boom 23, and a bucket 24 for an operator is mounted on a distal end of the telescopic boom 23.

The work machine 2 is operated by various hydraulically operated actuators 26. As the actuator 26, for example, a telescopic cylinder for the outrigger 21, a slewing motor for the slewing table 22, an undulating cylinder of the telescopic boom 23,
There are a telescopic cylinder of the telescopic boom 23, a leveling cylinder of the bucket 24, a turning motor of the bucket 24, and the like. These actuators 26 are driven by hydraulic oil from a hydraulic pump 25 driven by the engine 11 of the vehicle 1. The hydraulic pump 25 for driving the actuator is
Some are driven by an engine for a hydraulic unit mounted on a vehicle.

In this work vehicle, the start / stop operation of the engine 11 is performed in the cab 10 for driving the vehicle, the outrigger installation section (lower operation section 31), and the bucket 24 (upper operation section 3).
2), the engine start switch 13 or the engine stop switch 15 as shown in FIG.
Can be performed by operating. In FIG. 5, when the engine start switch 13 is operated, the contact 51 is turned on by operating the engine start relay R ₁ by the signal S ₁ , and the starter 14 is energized from the battery 12 (reference S ₂ ). Is started. On the other hand, when the engine stop switch 15 is operated, the contact 52 is turned on by operating the engine stop relay R ₂ by the signal S ₃ , and the engine stop solenoid 16 is energized from the battery 12 to the engine stop solenoid 16 (symbol S ₄ ). 16 is operated (the engine 11 stops).

[0006] In this type of work vehicle, the control device 4 controls the operation of the work machine 2 based on various data relating to the work machine 2 (for example, detection data from various detectors). In addition, as shown in FIG.
When the error monitor 41 detects a serious error (an error that requires an emergency stop of the work implement), a safety device is provided to stop the work implement 2 urgently. The error that requires the work machine to be stopped urgently includes, for example, a case where an error has occurred in the detector (a case where the detector outputs an abnormal value exceeding the normal range) or a moment limiter ( There is a case where the actuator for driving the work machine is operated despite the output of the restriction signal from the overturn prevention device). The safety device for emergency stop functions as follows. That is, when an error that needs to be urgently stopped working machine occurs, it is detected by the error monitoring unit 41 → the error detection signal S ₅ from the error monitoring unit 41,
While displaying the error status error indicator 42 actuates the engine stop signal generator 43 → the actuates the engine stop relay R ₂ with an engine stop signal S ₆ from the engine stop signal generator 43 (ON contact 52 ) → The engine stop solenoid 16 is operated by energization from the battery 12 (symbol S ₄ ) → The engine 11 is stopped. At this time, the hydraulic pump 25 also stops. The error monitor 41
Error detection signal S ₅ from the, ON the power source of the controller 4
In this state, the engine is continuously output (the engine stop solenoid 16 is kept ON). In this state, even if the engine start switch 13 is turned on, the starter 14 rotates but the engine 11 does not start. I have. Therefore, when the error monitor 41 detects an error,
By making the engine 11 inoperable, the operation of the work implement 2 is prohibited.

By the way, when an error monitoring unit 41 has an error detection (signal S ₅ outbound), it is an error indicator 4
The error indicator 42 is displayed on the bucket 24 in the aerial work vehicle shown in FIG.
In many cases, only the upper operation unit 32 is provided. On the other hand, the engine start switch 13 is connected to the lower operation unit 3 in the cab 10.
1. It is installed in any of the upper operation units 32, and the engine start operation can be performed from any of them.

[0008]

However, the conventional safety device (control device 4) shown in FIG.
There is a case where the operator attempts to operate the work implement 2 without noticing that an error is detected. In particular, an operation unit not provided with the error display 42 (for example, the cab 10, the lower operation unit 3)
In 1), there are many cases where the operator tries to operate the work implement 2 without knowing that the error is detected. In a state where the error monitoring unit 41 detects the error, the error detection signal S ₅ from the error monitoring unit 41, the engine stop signal generator 43 is ON → engine stop relay R ₂ turned ON, the engine Stop solenoid 1
6 is energized (reference S ₄ ). Therefore, in this state, although the engine 11 is not started even if the engine start switch 13 is turned on, the engine stop solenoid 16 continues to be in the ON state.
If the state continues for a long time, the problem that the engine stop solenoid 16 is burned out occurs. Further, there is a problem that while the engine stop solenoid 16 is energized, the power from the battery 12 is wasted and the battery voltage is reduced.

In view of the above-mentioned conventional problems, the present invention has an adverse effect on an engine stop solenoid in a work vehicle equipped with this kind of safety device even if a control device (error monitor) is in an error detection state. An object of the present invention is to provide a safety device for a working vehicle that can prevent the occurrence of power consumption while preventing unnecessary power consumption.

[0010]

The present invention has the following structure as means for solving the above-mentioned problems.

[0011] Safety device according to the present claim 1 of the invention the present invention of claim 1, the operation of the various actuators of the working machine with hydraulic fluid from a hydraulic pump driven by the engine of the hydraulic unit mounted on the engine or the vehicle of the vehicle Further, the present invention is applied to a work vehicle in which operation of the work machine is controlled by a control device based on various data on the work machine.

The control device used in the safety device according to the first aspect of the present invention includes an error monitor that detects when an error that requires an emergency stop of the work machine occurs, and an error monitor that detects the error. An engine stop signal generator for transmitting an engine stop signal (a signal for energizing the engine stop solenoid) to the engine stop solenoid when detected.

[0013] The engine stop signal from the engine stop signal generator is a short time signal such that the engine stop solenoid operates to stop the engine.
As this timed signal output means, a timer can be used. The timer operates so that, after an error detection signal from the error monitor is input to the engine stop signal generator, the engine stop signal from the engine stop signal generator is transmitted, for example, for about 5 to 10 seconds. I do.

Further, the safety device according to the first aspect of the present invention includes an engine restart prohibiting means for prohibiting the restart of the engine based on the error detection signal when the error detection signal is transmitted from the error monitor. ing. As the engine restart prohibiting means, for example, an error interlock relay that cuts off an electric circuit of an engine start switch based on an error detection signal from an error monitor can be used. In this case, while the error detection signal is being output, the error interlock relay may be always operated.However, when the engine start switch is operated to start, the engine start switch is operated based on the start operation signal. The error link relay may be activated.

In the safety device according to the first aspect of the present invention, when the engine stop signal is transmitted from the engine stop signal generator to the engine stop solenoid based on the error detection signal from the error monitor, for example, 5 seconds. After outputting an engine stop signal for a short time of about 10 seconds (a time during which the engine can be stopped), the power supply to the engine stop solenoid is turned off. Therefore, even if the control device continues to be ON when the error monitor detects an error, the engine stop solenoid is not energized after the set time. Further, in the state where the error detection signal is output from the error monitor, the engine is not restarted by the engine restart prohibiting means (for example, the error interlocking relay) even if the engine start switch is started, so that carelessness is provided. Malfunctions of various actuators due to engine start can be prevented.

[0016] In the safety device of the present invention of claim 2 present in the second aspect of the present invention, together with a short timed signal as in the case of an engine stop signal to claim 1 from an engine stop signal generator, the engine is stopped Inputting the engine rotation detection signal from the engine rotation detector to the signal generator and detecting the engine rotation when the engine restarts while the error detection signal from the error monitor is output to the engine stop signal generator The signal causes the engine stop signal generator to retransmit the engine stop signal.

In the safety device according to the second aspect, when the error monitor detects an error during the operation, the engine is stopped by the engine stop signal (timed signal) from the engine stop signal generator. The engine can be restarted by starting the switch.
However, if the error detection signal from the error monitor is being output, even if the engine is restarted, the rotation detection signal from the engine rotation detector is input to the engine stop signal generator, and the error from the error monitor is output. Since the engine stop signal generator operates based on the detection signal and the rotation detection signal, the engine is immediately stopped. In this case, the energization of the engine stop solenoid is also short.

[0018] In the safety device of the invention according to claim 3 of the present invention the claims 3, together with a short timed signal as in the case of an engine stop signal to claim 1 from an engine stop signal generator, the engine is stopped The start operation signal from the engine start switch was output to the signal generator when the start operation signal from the engine start switch was input to the signal generator and the error detection signal from the error monitor was output to the engine stop signal generator. Thereafter, when the operation of the engine start switch is released, the engine stop signal generator re-transmits the engine stop signal.

In the safety device according to the third aspect, when the error monitor detects an error, stops the engine by the engine stop signal generator, and starts the engine start switch, the engine starter operates. Therefore, even if the engine is restarted, if the error detection signal is being output from the error monitor, the engine stop signal generator is activated when the engine start switch is released. The engine will be stopped immediately after release. In the case of the third aspect, while the error monitor detects an error,
When the engine start switch is operated to start, the starter of the engine operates, but the engine itself may not be started.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a safety device according to the present invention will be described below with reference to FIGS. 1 to 4. FIGS. 1 to 3 show first to third embodiments of the present invention, respectively. Have been.
The safety device of FIG. 1 corresponds to claim 1 of the present application, the safety device of FIG. 2 corresponds to claim 2 of the present application, and the safety device of FIG. 3 corresponds to claim 3 of the present application. Each of the safety devices shown in FIGS. 1 to 3 is applied to an aerial work vehicle as shown in FIG. 4, for example, but can also be applied to other hydraulic work vehicles such as a crane truck. The configuration of the aerial work vehicle in FIG. 4 uses the description of the related art.

In the working vehicle of each embodiment shown in FIGS. 1 to 3, when the engine start switch 13 is operated, a signal S _{1 is} generated.
The contacts 51 O by operating the engine start relay R ₁ by
N and energize the starter 14 from the battery 12 (reference S
₂ ) By doing so, the engine 11 is started. On the other hand, when the engine stop switch 15 is operated, the contact 52 is turned on by operating the engine stop relay R ₂ by the signal S ₃ , and the engine stop solenoid 16 is energized from the battery 12 to the engine stop solenoid 16 (symbol S ₄ ). 16 is operated (the engine 11 stops).

In the safety devices according to the first to third embodiments, data from various detectors relating to the work implement 2 is input to the control device 4, and various processes are performed in the control device 4. You. One of the functions of the control device 4 is to perform an emergency stop of the work implement 2 when the error monitor 41 detects a serious error (an error that requires an emergency stop of the work implement). That is, when an error that needs to be urgently stopped working machine occurs, the error monitoring unit 41 detects → the error detection signal S ₅ from the error monitoring unit 41 which displays an error status to the error display 42 on the other hand, to actuate the engine stop signal generator 43 → the engine stop signal S ₆ actuates the engine stop relay R ₂ (by turning oN the contacts 52) → is energized in the engine stop solenoid 16 (code S ₄₎ → engine 11 Is to be stopped. At this time, the hydraulic pump 25 also stops. The error detection signal S from the error monitor 41
₅ is continuously output to the engine stop signal generator 43 when the power of the control device 4 is turned on.

In the safety devices according to the first to third embodiments, the engine stop signal S ₆ from the engine stop signal generator 43 is used to stop the engine 11 by operating the engine stop solenoid 16 by the timer 44. The time signal is a short time signal (for example, 5 to 10 seconds) as short as possible.
The timer 44 is provided with an engine stop signal generator 43.
Can leave incorporated, after the error detection signal S ₅ from the error monitoring unit 41 is input to the engine stop signal generator 43, outputs only the engine stop signal S ₆ set time from the engine stop signal generator 43 You may make it. Thus, when the engine stop signal S ₆ from the engine stop signal generator 43 keep the timed signal, actuates the only engine stop relay R ₂ its set time, after the timer operation is contact 52 is turned OFF The power to the engine stop solenoid 16 is stopped. Therefore, be continuously output the error detection signal S ₅ from the error monitoring unit 41, it can be eliminated in advance a trouble that the engine stop solenoid 16 is cut - burnt, yet also eliminating wasteful power consumption of the battery 12 it can.

Hereinafter, individual embodiments will be described.

The safety device according to the first embodiment shown in FIG.
From the error monitoring unit 41 when the error detection signal S ₅ is transmitted includes an engine restart inhibition means R ₃ for prohibiting restarting of the engine based on the error detection signal S _5. In the first embodiment, the engine restart prohibiting means, using the error interlock relay R ₃ which is adapted to cut off the electric circuit of the engine start switch 13 based on the error detection signal S ₅ from the error monitoring unit 41 I have. Then, an electric circuit of the first embodiment inputs the starting operation signals S ₁ when the start operation of the engine start switch 13 to the engine stop signal generator 43, the error detection signal S ₅ and the start operation signals S ₁ Doo is when it is input to the engine stop signal generator 43 together, the operation signal S ₇ for the error interlock relay R ₃ from the engine stop signal generator 43 is to be transmitted. Incidentally, when the operation signal S ₇ for the error interlock relay R ₃ is originated, has the contacts 53 of the electrical circuit of the engine start switch 13 so as to to OFF. Thus, in the embodiment of FIG. 1, in a state in which the error detection signal S ₅ from the error monitoring unit 41 is output,
Even if the starting operation of the engine start switch 13, since the working error interlock relay R _3, the engine 11 is adapted without restarting, malfunction of the various actuators 26 by inadvertent engine start can be prevented . or,
In the embodiment of FIG. 1, the error detection signal S ₅ is even dialing, since it is not energized error interlocking relay R ₃ unless start operation of the engine start switch 13, no wasteful power consumption. In other embodiments, the above error interlocking relay R ₃ and enter the error detection signal S ₅ from the error monitoring unit 41 directly, while the error detection signal S ₅ is transmitted error interlocking relay R ₃ the can also be maintained in the actuated state, but if so, in transmission of the error detection signal S ₅ is would be energized in the error interlock relay R _3, power consumption occurs.

In the safety device according to the second embodiment shown in FIG.
The engine stop signal generator 43 includes the engine rotation detector 17
Are entering the engine rotation detection signal S ₈ from. still,
In the second embodiment, an alternator 17 is employed as an engine rotation detector. And an error monitor 4
In a state in which the error detection signal S ₅ from 1 are output to the engine stop signal generator 43, the engine start switch 1
3, when the engine 11 is started, an engine rotation detection signal S ₈ when the engine 11 is re-rotated is input to the engine stop signal generator 43, and the rotation detection signal S ₈ and the error detection signal S ₅ engine stop signal generator 43 is adapted to re-transmit the engine stop signal S ₆ by. In this second embodiment, the error detection signal S ₅ from the error monitoring unit 41 is not input to the engine stop signal generator 43 in the normal state, an engine rotation detection signal S ₈ activates the engine 11 is an engine stop Even if the signal is input to the signal generator 43, the engine stop signal generator 43 does not operate, and in this case, the engine 11 starts normally.

[0027] In the safety device of the second embodiment shown in FIG. 2, when the error monitoring unit 41 during operation detected error, to stop the engine 11 in an engine stop signal S ₆ from the engine stop signal generator 43 However, after that, when the engine start switch 13 is started, the engine 11 can be restarted. However, when the restart the engine 11 in a state that the error detection signal S ₅ from the error monitoring unit 41 is output, the engine rotation detector (alternator) rotation detection signal S ₈ from 17 engine stop signal generator 43 is input to the immediately engine 1 engine stop signal S ₆ from the engine stop signal generator 43 is transmitted
1 will stop. Since the short timed signals by the engine stop signal S ₆ is also a timer 44 in this case, the energization time for the engine stop solenoid 16 is short.

In the safety device according to the third embodiment shown in FIG.
The engine start switch 1 is connected to the engine stop signal generator 43.
Are entering the starting operation signals S ₁ from 3. Then, in a state in which the error detection signal S ₅ from the error monitoring unit 41 is output to the engine stop signal generator 43, after the start operation signals S ₁ from the engine start switch 13 has been output, the engine start switch 13 engine stop signal generator 43 is adapted to re-transmit the engine stop signal S ₆ when was to OFF. This engine stop signal S ₆
Activates the engine stop relay R ₂ → turns on the engine stop solenoid 16 → disables starting of the engine 11. In this case, the energizing time to the engine stop solenoid 16 is also only the set time of the timer 44.

[0029] Also, in the third embodiment shown in FIG. 3, in a state in which the error detection signal S ₅ is transmitted, when the start operation signals S ₁ from the engine start switch 13 is transmitted, an engine stop signal From the generator 43, immediately (without activating the timer 44) the engine stop relay R
₂ relay operation signal S ₉ for operating the are to be transmitted. Then, in the third embodiment shown in FIG. 3, when operating the engine start switch 13 in a state in which the error detection signal S ₅ from the error monitoring unit 41 is output, while the starter 14 is actuated, the engine relay operation signal S ₉ toward the engine stop relay R ₂ immediately from the engine stop signal generator 43 based on the error detection signal S ₅ from the starting operation signals S ₁ and error monitoring unit 41 of the start switch 13 is transmitted → the engine stop relay R ₂ is activated → engine stop solenoid 16 becomes impossible activation of oN and → engine 11. Therefore, in the case of the third embodiment, the error detection signal S ₅ from the error monitor 41 is used.
Is output, the engine start switch 13
Is operated, the engine 11 does not start. In addition, this third
In the case of the embodiment, the error monitoring unit error detection signal S ₅ from the 41 is not input to the engine stop signal generator 43 in the normal state, the starting operation of the engine start switch 13 signal S ₁ is an engine stop signal generator 43 , The engine stop signal generator 43 does not operate, and the engine 11 starts normally in this case as well.

[0030] In a variant of this third embodiment, it is possible not to transmit the above relay operation signal S _9. In this case, the engine 11 can be restarted by operating the engine start switch 13 after the error monitor 41 detects an error and stops the engine 11 by the engine stop signal generator 43. However, the error detection signal S
_{If 5} is being output, even if the engine 11 is restarted, the engine start switch 13 is deactivated to operate the engine stop signal generator 43 as described above,
The engine 11 is immediately stopped.

In most cases, this type of hydraulic working vehicle is completed by assembling a working machine 2 to a vehicle 1 manufactured by a vehicle manufacturer by another assembling manufacturer. In this case, FIG. As shown in the first embodiment, the work of incorporating the engine restart prohibiting means (error interlocking relay R ₃ ) into the electric circuit of the engine start switch 13 is troublesome and increases the cost. However, the second and third embodiments shown in FIG. 2 or FIG. 3 can be performed within the normal working range of the assembly maker without changing the vehicle 1 side, which is advantageous in terms of cost.

[0032]

Safety device for a work vehicle of the invention according to claim 1 to 3 according to the present invention is an engine stop signal S ₆ from the engine stop signal generator 43, the engine stop solenoid 16 is actuated allowed stops the engine 11 Since the time signal is a short time signal that can be obtained, even if the emergency stop device of the control device 4 is activated for some reason, after the engine 11 is stopped,
Immediately, the power supply to the engine stop solenoid 16 can be cut off. Therefore, the trouble that the engine stop solenoid 16 is burned out can be solved beforehand,
There is an effect that unnecessary power consumption from the battery 12 is eliminated and the problem of voltage drop is also solved.

[0033] In the invention according to claim 1, when the error detection signal S ₅ is transmitted from the error monitoring unit 41 is provided with the engine restart inhibition means R ₃ for prohibiting restarting of the engine 11 , An error detection signal S ₅ is transmitted from the error monitor 41 and the engine stop signal generator 43
After the engine 11 is stopped by the engine stop signal S ₆ from, even if an attempt is started to engine 11 without noticing that the error monitoring unit 41 is an error detection state,
The engine does not start. Therefore, when the error monitor 41 detects an error, the engine 11 and the hydraulic pump 25 cannot be driven, and the operation (runaway) of the work implement 2 due to careless engine startup can be reliably prevented.

[0034] In the invention according to claim 2, enter the engine rotation detection signal S ₈ to the engine stop signal generator 43, when the error monitoring unit 41 of the error detection state, immediately when the engine 11 is started Engine stop signal S ₆
Outgoing. On the other hand, according to the invention of claim 3 of the present application, when the error monitor 41 detects the error and releases the operation of the engine start switch 13 after the start operation,
The engine stop signal S ₆ from the engine stop signal generator 43
Outgoing. Therefore, according to the second or third aspect of the present invention, when the error monitor 41 is in the error detection state, the engine can be immediately stopped even if the engine 11 starts, and the error monitor 41 is in the error detection state. Even if the engine 11 is started without noticing that, the hydraulic pump 25 is not driven to the extent that the actuator of the work machine 2 is operated, so that there is an effect that safety can be ensured.

In the embodiment shown in FIG. 3 according to the third aspect of the present invention, even if the engine start switch 13 is started, the starter 14 operates but the engine 11 cannot be started. Is secured.

[Brief description of the drawings]

FIG. 1 is a block diagram of a working vehicle safety device according to a first embodiment of the present application.

FIG. 2 is a block diagram of a working vehicle safety device according to a second embodiment of the present application.

FIG. 3 is a block diagram of a working vehicle safety device according to a third embodiment of the present application.

FIG. 4 is a side view of an aerial work vehicle that is an example of a hydraulic work vehicle.

FIG. 5 is a block diagram of a conventional safety device for a work vehicle.

[Explanation of symbols]

1 is a vehicle, 2 is a work machine, 4 is a control device, 11 is an engine, 13 is an engine start switch, 16 is an engine stop solenoid, 17 is an engine rotation detector (alternator), 25 is a hydraulic pump, and 41 is an error monitor , 43 the engine stop signal generator, 44 is a timer, R ₁ is an engine start relay, R ₂ is an engine stop relay, R ₃ is an error interlock relay.

──────────────────────────────────────────────────の Continuation of the front page (51) Int.Cl. ⁶ Identification number Office reference number FI Technical display location B66F 11/04 B66F 11/04 F02D 29/00 F02D 29/00 B 41/38 41/38 D F02N 11/08 F02N 11/08 Z

Claims (3)

[Claims] An actuator of a work machine (2) is operated with hydraulic oil from a hydraulic pump (25) driven by an engine (11) of a vehicle (1) or a hydraulic unit mounted on the vehicle, and In a work vehicle in which the operation of the work machine (2) is controlled by the control device (4), an error has occurred in the control device (4) that necessitates an emergency stop of the work machine (2). An error monitor (41) for detecting the time, and the error monitor (41)
When an error is detected by the engine stop solenoid (1
In the safety device including an engine stop signal generator for transmitting an engine stop signal (S ₆₎ to (43) relative to 6), the engine stop signal from the engine stop signal generator (43) (S _6), the The engine stop solenoid (1)
With 6) is a short timed signals to the extent that may caused to stop the engine (11) operates, the error detection signal from the error monitoring unit (41) (S ₅₎
A safety device for a work vehicle, comprising: engine restart prohibiting means (R ₃ ) for prohibiting restart of the engine (11) based on the error detection signal when is transmitted. 2. Operating various actuators of a work machine (2) with hydraulic oil from a hydraulic pump (25) driven by an engine (11) of a vehicle (1) or a hydraulic unit mounted on the vehicle; and In a work vehicle in which the operation of the work machine (2) is controlled by the control device (4), an error has occurred in the control device (4) that necessitates an emergency stop of the work machine (2). An error monitor (41) for detecting the time, and the error monitor (41)
When an error is detected by the engine stop solenoid (1
In the safety device including an engine stop signal generator for transmitting an engine stop signal (S ₆₎ to (43) relative to 6), the engine stop signal from the engine stop signal generator (43) (S _6), the The engine stop solenoid (1)
The engine stop signal generator (43) outputs an engine rotation detection signal (S) from the engine rotation detector (17) to the engine stop signal generator (43). ₈ ), the error detection signal (S ₅ ) from the error monitor (41) is being output to the engine stop signal generator (43), and the engine (11) is restarted. the engine stop signal generator by the engine rotation detection signal (S ₈₎ (43) is the engine stop signal (S ₆₎
A safety device for a work vehicle, wherein the safety signal is transmitted again. 3. An actuator of a work machine (2) is operated with hydraulic oil from an engine (11) of a vehicle (1) or a hydraulic pump (25) driven by an engine of a hydraulic unit mounted on the vehicle, and In a work vehicle in which the operation of the work machine (2) is controlled by the control device (4), an error has occurred in the control device (4) that necessitates an emergency stop of the work machine (2). An error monitor (41) for detecting the time, and the error monitor (41)
When an error is detected by the engine stop solenoid (1
In the safety device including an engine stop signal generator for transmitting an engine stop signal (S ₆₎ to (43) relative to 6), the engine stop signal from the engine stop signal generator (43) (S _6), the The engine stop solenoid (1)
The engine stop signal generator (43) is provided with a start operation signal (S ₁ ) from an engine start switch (13) as well as a short time signal that is short enough to operate the engine (11) by stopping the engine (11). And enter
While the error detection signal (S ₅ ) from the error monitor (41) is being output to the engine stop signal generator (43), a start operation signal (S ₁ ) from the engine start switch (13) is output. after output, the when operated releases the engine start switch (13) engine stop signal generator (43) is so as to recall the engine stop signal (S _6), wherein the work Car safety equipment.