JP2003095599A - Safety device of work vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a vehicle whose brake is not applied in a stopped state from moving and the speed of a traveling vehicle from changing. SOLUTION: A safety device 80 is arranged in a vehicle for high lift work, which is provided with front and rear wheels, which are driven by the drive force of the engine E loaded on the vehicle, for making the vehicle run, a third brake for restraining the running of the vehicle by applying brake to the front and rear wheels, a jack, which supports the vehicle with a roller, which is arranged at the lower end and can rotate freely, grounded, a boom installed on the vehicle, and a controller 85, which controls the operation of the jack and the boom. The vehicle for high lift work travels with the roller grounded and the front and rear wheels also grounded. This safety device 80 has a third brake operation sensor 83 which detects whether the third brake is activated or not, and the controller 85 is constituted so as to allow the operation control of a jack and boom work device only when the braking state of the front and rear wheels are detected by the third brake operation sensor 83.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a work vehicle safety device, and more particularly, to a work vehicle safety device provided with a jack having a roller at a lower end thereof, the roller being able to travel while being grounded. Regarding the device.

[0002]

2. Description of the Related Art Repairing paint applied to the surface of a bridge (the handrail part where cars and people pass) and the back of the bridge (the back side of parts where cars and people pass, the side facing the sea and rivers, etc.) In this case, for example, an overfence work vehicle or an aerial work vehicle referred to as a bridge inspection vehicle, which is equipped with a jack having a roller at its lower end and is capable of traveling while the roller is grounded, is used.

In this aerial work vehicle, a traveling device having front wheels and rear wheels for driving the vehicle by receiving the driving force of an engine mounted on the vehicle and a brake pedal are depressed. In addition to the normal brake that releases the braking state when the front and rear wheels are in the braking state and the brake pedal is released, and the parking brake that keeps the rear wheels in the braking state when the parking lever is operated,
A brake (hereinafter, referred to as "third brake") that maintains the front wheels and the rear wheels in a braking state even when the brake pedal is stepped on after operating the operation switch and then the pedal is released. It is equipped on the vehicle with jacks that are provided at the front, rear, left and right ends of the vehicle and that have rotatable rollers at the lower end, and that ground the rollers to support the vehicle and a jack operation device that drives the jack in response to operation. And a boom device for moving the workbench to a desired position.

Since this aerial work vehicle can travel with the jack grounded, if the jack operation device is operated while the vehicle is traveling with the jack grounded, the vehicle support becomes unstable due to the operation of the jack. There is a risk of becoming. For this reason,
For aerial vehicles, if the third brake is not activated,
That is, if the vehicle is not in the braking state, a safety device for controlling the operation of the jack is mounted.

[0005]

However, this safety device is designed so that even when the third brake is in the non-actuated state,
When the boom operation device is operated, the operation of the boom device is permitted.Therefore, when the boom device operates and the center of gravity of the vehicle moves, depending on the condition of the ground on which the vehicle is placed, the vehicle may not operate. May move and the work table may come into contact with the work target or the like.

Further, since this safety device allows the operation of the boom operating device while the vehicle is traveling, and also allows the operation of changing the engine speed according to the boom operation when the boom is operated during traveling, If a boom operation is performed during this, there is a problem that the vehicle speed may suddenly change.

The present invention has been made in view of the above problems, and is for a working vehicle which is capable of traveling while the rollers arranged at the lower end of the jack are grounded when the vehicle is in a non-braking state. Another object of the present invention is to provide a safety device for a working vehicle that prevents a stopped vehicle from moving or the speed of a traveling vehicle to change.

[0008]

In order to solve the above problems, a safety device for a working vehicle according to the present invention is a traveling device for driving a vehicle by receiving a driving force of an engine mounted on the vehicle (for example, a vehicle). , Front wheel 3, rear wheel 4 in the embodiment)
And traveling braking means for braking the traveling device to restrict the traveling of the vehicle (for example, the third braking device 90 in the embodiment).
And a jack that is provided at both left and right ends of the vehicle and has rotatable rollers at its lower end, and that supports the vehicle by grounding the roller, and a work device that is mounted on the vehicle and performs a predetermined work (for example, Form boom 30) and operation control means for controlling the operation of the jack and the working device (for example,
In a working vehicle (for example, the overfence working vehicle 1 in the embodiment) including the controller 85) in the embodiment, a safety device for the working vehicle in which the traveling device is driven in the grounded state while the roller is grounded. Therefore, the vehicle has a braking detection means (for example, the third brake operation sensor 83 in the embodiment) that detects whether or not the traveling device is braking the traveling device, and the operation control means
When the traveling detection device detects that the traveling device is in the braking state, the jack and the work device are allowed to operate, and when the braking detection device detects that the traveling device is in the non-braking state, the jack And configured to regulate the operation of at least one of the working devices.

According to the work vehicle safety device having the above structure, the operation control means allows the operation of the jack and the work device only when the traveling device is in the braking state, so that the vehicle is securely locked. It is possible to operate the jack and the work device. Therefore, the vehicle does not move even if the boom device operates and the position of the center of gravity of the vehicle moves, and as a result, it is possible to eliminate the risk that the workbench abuts the work target or the like.

Further, in the safety device for a work vehicle having the above structure, a jack operation device for outputting a jack operation signal according to an operation and a work operation device for outputting a work operation signal according to an operation (for example, in the embodiment). And a boom operation device 70), and the operation control means is configured to perform operation control of the jack in response to the jack operation signal and also perform operation control of the work device in response to the work operation signal. When it is detected that the traveling device is in the braking state, the throttle opening of the engine may be controlled according to the operation of the jack operating device and the work operating device.

According to the work vehicle safety device having the above structure, when the traveling device is detected to be in the braking state, the throttle opening of the engine is controlled according to the operation of the jack operation device and the work operation device. . Therefore, the operator can operate the operating speed of the jack and the working device.

In the work vehicle safety device having the above structure, the operation control means responds to the operation of the jack operation device and the work operation device when the braking detection means detects that the traveling device is in the non-braking state. It may be configured to limit the throttle opening degree of the engine.

According to the safety device for a working vehicle having the above structure, when the traveling device is detected to be in the non-braking state, the throttle opening degree of the engine is restricted according to the operation of the jack operating device and the work operating device. To do. Therefore, for example, when the engine controller controls the throttle opening degree of the engine according to the accelerator operation, the throttle opening degree of the engine follows the accelerator operation if the traveling device is in the non-braking state. As a result, even if the accelerator is operated and the jack is operated or the work device is operated while the vehicle is traveling, the operation of the jack and the work device is restricted because the travel device is in the non-braking state, and the accelerator is operated. If it is constant, the engine speed does not change according to the jack operation or the operation of the work device. As a result, it is possible to prevent the traveling speed of the traveling vehicle from changing.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention will be described below with reference to FIGS. The present embodiment shows a mode of an overfence work vehicle capable of traveling with the rollers arranged at the lower end of the jack grounded. Before first describing the safety device of the present invention, an overfence work vehicle equipped with this safety device will be described. As shown in FIG. 1, the overfence work vehicle 1 includes a front wheel 3 and a rear wheel 4 that form a traveling device on the front, rear, left, and right sides, and a driver's seat 12
A track-type traveling body 10 capable of traveling from above, a revolving support column 20 provided on the traveling body 10, a boom 30 attached to the upper part of the revolving support column 20 by a foot pin 21 so as to be vertically swingable, and a boom 30. And a workbench 40 for mounting a worker mounted on the tip of the.
The front wheels 3 are configured to be rotatable and steerable, and the rear wheels 4 are configured to be rotationally driven by receiving a driving force of an engine E shown in FIG.

The swivel column 20 is attached to the traveling body 10 so as to be rotatable 360 degrees around a vertical axis, and a rotating shaft extending in the vertical direction is hydraulically driven by a swivel motor 51 incorporated in the traveling body 10. It can be swiveled around. The boom 30 includes a first telescopic boom 31 and a first telescopic boom 31.
Holder 34 attached to the tip of telescopic boom 31
And a second telescopic boom 35 built in the holder 34. The first telescopic boom 31 has a structure in which a base boom 32 and a tip boom 33 are assembled in a telescopic manner, and can be telescopically operated in the longitudinal direction by hydraulically driving a built-in first telescopic cylinder 53. . Further, the first telescopic boom 31 can be undulated in the upper and lower planes by hydraulically driving the undulating cylinder 52 provided between the first telescopic boom 31 and the swivel column 20.

The holder 34 is formed in a hollow cylindrical shape, and is rocked by a vertical holding cylinder 57 provided between the first telescopic boom 31 and the tip boom 33 so that the holder 34 is always kept in a vertical state. Has become. The second telescopic boom 35 has a configuration in which a base end boom 36, a first intermediate boom 37, a second intermediate boom 38, and a tip boom 39 are assembled in a telescopic manner, and a second telescopic cylinder 54 incorporated therein is hydraulically driven. By doing so, expansion and contraction operation can be performed in the longitudinal direction (vertical direction).

A boom moving cylinder 55 is provided between the second telescopic boom 35 and the holder 34, and a rod 55b of the boom moving cylinder 55 is moved (expanded and retracted) with respect to a cylinder tube 55a supported by the holder 34. ), The entire second telescopic boom 35 is held by the holder 34.
It can be moved up and down.

The workbench 40 comprises a floor member 41 and a handrail 42 provided on the upper surface side thereof for worker protection, and the connecting member 4 provided on the upper surface side of the end portion of the floor member 41.
3 is connected to the lower end of the tip boom 39 of the second telescopic boom 35. A swing motor 56 is provided in the workbench 40.
Is provided, and by hydraulically driving it, it is possible to rotate the coupling member 43 around the vertical axis and horizontally rotate (oscillate) the work table 40.

Jacks 60 are provided at four positions on the front, rear, left and right sides of the traveling body 10, and these four jacks 60 are provided.
A jack cylinder 62 is built in the vehicle, and the traveling body 10 can be supported in a stable state by extending the jack cylinder 62 by the extension movement of the jack cylinder 62 so as to contact the ground. A roller 61 is attached to a lower end portion of each jack 60, so that the traveling body 10 is jacked by the jacks 60, 6.
Rollers 61, 61, ... While being supported by 0 ,.
It is also possible to roll and move.

A boom operating device 70 is provided on the workbench 40. The boom operating device 70 will be described with reference to FIG. And a hoisting lever 72 for issuing a hoisting command for the first telescopic boom 31 and the first telescopic boom 31.
And a second telescopic lever 7 for issuing a telescopic command for the second telescopic boom 35.
4, and a boom moving lever 75 for issuing a command to move the second telescopic boom 35 in the holder 34 in the vertical direction,
A swing lever 76 for issuing a swing command for the workbench 40
And are provided. The second telescopic lever 74 and the boom moving lever 75 may be configured to be operated by one lever.

When the turning lever 71 is tilted, a forward / reverse rotation operation command signal of the turning motor 51 is output in response to this, and when the hoisting lever 72 is tilted, an extension / contraction operation command signal of the hoisting cylinder 52 is output accordingly. It When the first telescopic lever 73 is tilted, a telescopic operation command signal for the first telescopic cylinder 53 is output in response to this.
When the second telescopic lever 74 is tilted, the second
A telescopic operation command signal for the telescopic cylinder 54 is output. Further, when the boom moving lever 75 is tilted, a telescopic operation command signal for the boom moving cylinder 55 is output accordingly, and when the swing lever 76 is tilted, the forward / backward rotation operation command signal for the swing motor 56 is accordingly output. Is output. Then, these output operation command signals are input to the operation control circuit 87 of the controller 85 that constitutes the safety device 80 described later. The swing motor 51, the hoisting cylinder 52, the first telescopic cylinder 53, the second telescopic cylinder 54, the boom moving cylinder 55, and the swing motor 56 will be collectively referred to as the boom actuators 51, 52, and 5 below.
3, 54, 55, 56. In addition, the second telescopic lever 7
4 and the boom moving lever 75 are configured to be operated by one lever, the extension / contraction operation command signal and the extension / contraction operation command signal are output according to the operation of the lever.

A jack operating device 65 is provided at the rear portion of the traveling body 10 shown in FIG. 1, and the jack operating device 65 drives the jacks 60, 60 ...
4 jack drive levers 66, 66 ...
And one jack command lever 67 for issuing a drive command for each jack 60. When the jack driving lever 66 of the jack 60 to be driven is operated to tilt the jack command lever 67, the jack operation device 65 outputs a stretching operation command signal of the jack cylinder 62 of the jack 60 to be driven accordingly. The output operation command signal causes the safety device 8 to be described later.
It is input to the operation control circuit 87 of the controller 85 that configures 0.

Next, the safety device 80 including the controller 85 will be described. The safety device 80 includes a power switch 81, a PTO switch 82, a third brake operation sensor 83, a parking brake switch 84, a jack operating device 65, a boom operating device 70, and a controller 85. Since the jack operating device 65 and the boom operating device 70 have been described above, their description will be omitted. Hereinafter, each constituent element of the safety device 80 will be described.

The power switch 81 is a switch that electrically connects or disconnects between the battery 46 mounted on the vehicle and the controller 85. When this switch is connected, power is supplied to the controller 85 and the controller 85 is in an operating state. become. The PTO switch 82 is a power take-off mechanism (hereinafter referred to as “PTO mechanism”) connected to the engine E.
Is written. ) Is a switch operated when operating. Here, the PTO mechanism has a function of taking out the driving force of the engine E, and operates so as to take out the driving force of the engine E when the PTO SW 82 is turned on.

The third brake operation sensor 83 has a function of detecting that the third brake device 90 shown in FIG. 2 is in an operated state. The third brake device 90 detected by this sensor will be operated by a brake pedal 91, a master cylinder 92 operated by the brake pedal 91, and pressure oil discharged from the master cylinder 92, when further described with reference to FIG. And a brake master 93 that discharges pressure oil, a front brake 94 and a rear brake 95 that operate by the pressure oil discharged from the brake master 93 to brake the front wheels 3 and the rear wheels 4, and a master cylinder 9
2 and a brake master 93. An electromagnetic valve 96 arranged in an oil passage connecting between the brake master 93 and the brake master 93 for preventing the reverse flow of oil supplied from the master cylinder 92 to the brake master 93, and a valve controller 97 for controlling the operation of the electromagnetic valve 96. And is configured.

The valve controller 97 is electrically provided with the above-mentioned P brake SW 84 which is closed when a parking brake (not shown) is in an operating state and a third brake switch 99 which is closed when the third brake device 90 is operated. The valve controller 97 operates when both the P brake SW 84 and the third brake switch 99 are closed. When the brake master 93 operates and the front brake 94 and the rear brake 95 operate, the valve controller 97 controls the operation of the electromagnetic valve 96 so as to shut off the oil passage 100 connecting the electromagnetic valve 96 and the brake master 93. The valve controller 97 includes the above-described third brake actuation sensor 8
3 is provided, and when the valve controller 97 is in the operating state, the third brake operation sensor 83 detects this operating state. When the third brake device 90 is not in the operating state, the third brake device 90 is operated by the brake pedal 9
When 1 is stepped on, the front wheels 3 and the rear wheels 4 are braked by the front brake 94 and the rear brake 95, and when the brake pedal 91 is released, this braking state is released, which operates as a so-called normal brake.

The above-mentioned switches (81, 82, 84),
The sensor 83 and the operating device (65, 70) are electrically connected to the controller 85 shown in FIG. The controller 85 has a function of controlling the operation of the boom 30 and the jack 60 in accordance with signals from switches, sensors, and an operation device, and is configured to have a state determination circuit 86 and an operation control circuit 87. The state determination circuit 86 is PTO SW8.
2 from the operation signal for operating the PTO mechanism, an operation signal from the third brake operation sensor 83 indicating that the third brake device 90 is in an operating state, and an operation signal indicating that the P brake from the P brake SW 84 is in an operating state. It is determined whether or not a signal (these three operation signals are collectively referred to as an "operation allowance signal") is received, and the determination result is the operation control circuit 8
7 has the function of sending.

The operation control circuit 87 receives the operation permission signal from the state determination circuit 86 only when the jack 6 is operated.
0 and the operation of the boom 30 are permitted, and the function of restricting the operation of the jack 60 and the boom 30 is received when the operation permission signal is not received. More specifically, when the operation control circuit 87 receives an operation command signal from the boom operating device 70 while receiving the operation permission signal from the state determination circuit 86, the operation control circuit 87 controls the operation of the boom 30 according to the command signal. In addition to controlling the operation of the control valve Vb, the throttle opening of the engine E is controlled via the engine controller EC to control the operation of the boom actuators 51, 52, 53, 54, 55, 56. The operation command signal from the boom operation device 70 includes a tilting direction signal indicating the lever tilting direction and a tilting amount signal indicating the lever tilting amount (actuator operating speed). The control circuit 87 controls the operation of the control valve Vb according to the tilt direction signal and the tilt amount signal, and controls the throttle opening of the engine E according to the tilt amount signal.

When the operation control circuit 87 receives an operation command signal from the jack operating device 65 while receiving the operation permission signal from the state determination circuit 86, the operation control circuit 87 controls the operation of the jack 60 according to the command signal. To control the operation of the control valve Vj
Controls the operation of 2 ...

The PTO mechanism and engine controller E
C and the control valves Vb and Vj are electrically connected to the operation control circuit 87.

According to the safety device 80 having the above-described structure, as shown in FIG. 4, in order to move the workbench 40 to the lower side of the bridge B, first, FIGS. The SW 81 is put in the connected state and power is supplied to the controller 85 to operate the controller 85. Further, while the vehicle is stopped, a parking brake (not shown) is operated to close the P brake SW 84, and the third brake switch 99 is closed to operate the valve controller 97. Then, the brake pedal 93 is operated to operate the brake master 93 to operate the front brake 94 and the rear brake 95, and the valve controller 97 controls the operation of the electromagnetic valve 96 to control the electromagnetic valve 96 and the brake master 93. The oil passage 100 connecting the two is cut off. As a result, the front wheels 3 and the rear wheels 4 are in the braking state, and the vehicle is maintained in the braking state. When the valve controller 97 operates, the third brake operation sensor 83 outputs an operation signal indicating that the valve controller 97 is operating.

Then, the PTO SW 82 is brought into the connected state to operate the PTO mechanism. Here, the controller 85
When the state determination circuit 86 receives the operation signal from the PTO SW 82, the operation signal from the third brake operation sensor 83, and the operation signal from the P brake SW 84, the state determination circuit 86 determines that the operation permission signal including these signals is received, and this determination is made. The result is sent to the operation control circuit 87 of the controller 85. The operation control circuit 87 receives the determination result of the operation permission signal and then the jack drive lever 66 of the jack operating device 65.
When the jack command lever 67 is operated, the operation of the control valve Vj is controlled according to the operation to supply the hydraulic oil discharged from the hydraulic pump P to the jack cylinder 62 corresponding to the operated jack drive lever 66. To do. Similarly, the other jack cylinders 62 ... As a result, the jacks 60 ... Extend and the front wheels 3 and the rear wheels 4 are grounded, and the rollers 61 are grounded to support the vehicle.

Next, the lever 71 of the boom operating device 70
When each of .about.76 is operated, the operation control circuit 87 controls the operation of the control valve Vb in accordance with each operation command signal, and the hydraulic oil discharged from the hydraulic pump 50 is supplied to the swing motor 5.
1. Control valve Vb according to lever operations corresponding to 1, undulation cylinder 52, first telescopic cylinder 53, second telescopic cylinder 54, boom moving cylinder 55, and swing motor 56.
Controls the supply of hydraulic oil. As a result, the boom 30 operates and the workbench 40 moves below the bridge B shown in FIG.

Now, let us consider a case where the operation of the boom 30 is allowed when the third brake 90 is in the non-operating state. When the third brake 90 is in the non-operating state, it is considered that the vehicle is in the drivable state unless the parking brake or the normal brake is operating. When the boom 30 operates in such a state, the center of gravity of the vehicle moves, and depending on the state of the ground on which the vehicle is placed, the vehicle may move and the workbench 40 may come into contact with the work target or the like.

However, the safety device 8 according to the present invention
According to 0, the third brake 90 is configured not to allow the operation of the boom 30 unless it is in the operating state, that is, the third brake 90 is configured to allow the operation of the boom 30 only when the vehicle is in the braking state. Therefore, if the boom 30 does not operate when the boom 30 is operated, the worker notices that the vehicle is not in the braking state. For this reason, the boom 30 can be operated after the vehicle is reliably brought into the braking state, and as a result, it is possible to prevent the vehicle from moving and the work table 40 coming into contact with the work target or the like.
If the operation of the boom 30 is not permitted when the boom 30 is operated, an alarm indicating that the third brake 90 is in the non-operated state may be issued by voice.

Next, when the operation of operating the jack 60 or the boom 30 is performed while the vehicle is traveling with the roller 61 of the jack 60 grounded and the front wheels 3 and the rear wheels 4 grounded. We assume and consider. Since the third brake 90 is in the inoperative state while the vehicle is traveling, the operation control circuit 87 regulates the operation of the boom 30 even if the operation of operating the boom 30 is performed during traveling as described above. In addition, the accelerator control of the engine E according to the tilt amount of the levers 71 to 76 is restricted.
As a result, the throttle opening of the engine E is controlled by the engine controller EC according to the accelerator operation. Therefore, when the vehicle is traveling with a constant accelerator operation, the boom 30 does not operate even if a lever operation with a large tilt amount is erroneously performed, and the engine speed is the accelerator speed. Since the rotation speed corresponding to the operation is maintained, the speed of the traveling vehicle does not suddenly change.

In the above embodiment, the PTO S
W82 and power supply SW81 are not in an interlocking relationship, that is, for example, when PTO SW82 is connected, power supply SW81
Since there is no relationship that will also be connected, PTO S
The power supply SW81 can be brought into the connected state while the W82 is left unconnected. Therefore, if the controller 85 has a function of activating at least one of an alarm buzzer and a voice alarm (not shown) when the vehicle tilt angle exceeds an allowable angle, the vehicle tilt angle while the vehicle is traveling. Is about to exceed the allowable angle, the controller 85 activates at least one of an alarm buzzer and a voice alarm. As a result, it is possible to inform the operator of the inclination of the vehicle,
The safety of the vehicle can be secured.

Next, in the above-described embodiment, consideration will be given on the assumption that the vehicle is a vehicle equipped with an automatic transmission. In this case, as shown in FIG. 5, the vehicle has an automatic PTO mechanism 1 as a PTO mechanism.
01 is mounted, and the automatic PTO mechanism 101 is configured to take out the driving force from the drive shaft 103 of the engine E via the hydraulic multi-plate clutch 102. Here, the hydraulic pressure supply source of the hydraulic multi-plate clutch 102 utilizes a power steering pump Ps that is rotationally driven by obtaining the driving force of the engine E. The power steering pump Ps discharges from the power steering pump Ps when the engine E is idling. Since the hydraulic pressure is low, the pressing force of the hydraulic multi-plate clutch 102 is insufficient, which may cause the clutch to slip and be damaged. Therefore, when the driving force of the engine E is taken out via the hydraulic multi-plate clutch 102, the engine speed needs to be higher than the speed corresponding to the idling state.

Therefore, the third brake 90 is in the non-operating state, and the engine E is operated via the hydraulic multi-plate clutch 102.
When the driving force is taken out (the PTO mechanism is in the operating state), the stopped vehicle may suddenly start moving. However, according to the safety device 80 described above, when the third brake 90 is in the inoperative state, the controller 8
5 controls the operation of the boom 30 and the jack 60 so as to control the accelerator control of the engine E according to the tilt amount of the levers 71 to 76. Therefore, when the vehicle is in the braking state, the accelerator operation of the engine E is not normally performed, so that the engine speed is maintained at the speed corresponding to the idling state. As a result, it is possible to prevent the stopped vehicle from suddenly starting to move.

Although the front wheels 3 and the rear wheels 4 are shown as the traveling devices in the above-described embodiments, the present invention is not limited to this, and the rollers 61 that are rotationally driven may be used as the traveling devices. In this case, a hydraulic motor or an electric motor, which is a drive source, is attached to the roller 61.

[0041]

As described above, according to the safety device of the present invention, only when the traveling device is in the braking state,
By allowing the operation of the jack and the work device by the operation control means, it becomes possible to operate the jack and the work device while the vehicle is securely locked, so that the boom device operates and the center of gravity of the vehicle is changed. Even if the vehicle moves, the vehicle does not move, and it is possible to eliminate the risk that the workbench abuts the work object or the like.

Further, when the throttle opening of the engine is controlled according to the operation of the jack operation device and the work operation device when the traveling device is detected to be in the braking state, the operation of the jack and the work device is performed. The speed can be controlled by the operator.

Furthermore, when the throttle opening of the engine is restricted in accordance with the operation of the jack operating device and the work operating device when the traveling device is detected to be in the non-braking state, for example, the engine throttle opening When the engine controller controls the opening according to the accelerator operation, the throttle opening of the engine follows the accelerator operation. As a result, even if the accelerator operation is performed and the jack operation or the work device operation is performed while the vehicle is traveling, the engine speed does not change if the accelerator operation is constant. Therefore, it is possible to prevent the traveling speed of the traveling vehicle from changing.

[Brief description of drawings]

FIG. 1 is a left side view of an overfence work vehicle according to an embodiment of the present invention.

FIG. 2 shows a block diagram of a third brake in the embodiment of the present invention.

FIG. 3 shows a block diagram of a safety device according to an embodiment of the present invention.

FIG. 4 is a diagram for explaining the operation of the safety device according to the embodiment of the present invention.

FIG. 5 is an automatic PT according to an embodiment of the present invention.
The schematic block diagram of O mechanism is shown.

[Explanation of symbols]

1 Overfence work vehicle (work vehicle) 3 front wheels (travel device) 4 Rear wheels (travel device) 10 Running body (vehicle) 30 boom (working equipment) 60 jacks 61 Laura 65 Jack operating device 70 Boom control device (work control device) 80 safety device 83 Third brake operation sensor (braking detection means) 85 controller (operation control means) 90 Third brake device (travel braking means) E engine

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Takaaki Ohba             1015 1152 Yamashita, Ryoke, Ageo City, Saitama Prefecture               Aichi Corporation Ageo Kogyo             Inside the hall (72) Inventor Asahi Tanaka             1015 1152 Yamashita, Ryoke, Ageo City, Saitama Prefecture               Aichi Corporation Ageo Kogyo             Inside the hall (72) Inventor Jun Kubo             1015 1152 Yamashita, Ryoke, Ageo City, Saitama Prefecture               Aichi Corporation Ageo Kogyo             Inside the hall (72) Inventor Takashi Sasaki             1015 1152 Yamashita, Ryoke, Ageo City, Saitama Prefecture               Aichi Corporation Ageo Kogyo             Inside the hall F-term (reference) 3D026 EA07 EA16 EA26 EA43 EA57                       EA63 EA77                 3F333 AA11 AB02 AB04 CA15 FA09                       FA20 FA22 FA34

Claims (3)

[Claims] 1. A traveling device for driving the vehicle by receiving a driving force of an engine mounted on the vehicle to drive the vehicle, and traveling braking means for braking the traveling device to restrict traveling of the vehicle.
A jack which is provided at both left and right ends of the vehicle and has a rotatable roller at its lower end, and which grounds the roller to support the vehicle; and a work device mounted on the vehicle for performing a predetermined work, A safety device for a working vehicle, comprising: a working vehicle including an operation control means for controlling the operation of the jack and the working device, which drives the traveling device in a grounded state while grounding the roller. And a braking detection unit that detects whether or not the traveling device is braking the traveling device, and the operation control unit detects that the traveling device is in a braking state by the braking detection unit. When the jack and the working device are allowed to operate and the traveling detection device detects that the traveling device is in the non-braking state, the jack and the front device Safety device for a working vehicle, characterized by being configured to regulate at least one of the operation of the working device. 2. A jack operating device that outputs a jack operating signal in response to an operation, and a work operating device that outputs a work operating signal in response to an operation, wherein the operation control means responds to the jack operating signal. The operation control of the jack is performed, and the operation control of the work device is performed in response to the work operation signal. When the traveling detection device detects that the traveling device is in the braking state, The work vehicle safety device according to claim 1, wherein the throttle opening of the engine is controlled according to operations of a jack operation device and the work operation device. 3. The operation control means, when the braking detection means detects that the traveling device is in a non-braking state, the throttle of the engine according to the operation of the jack operation device and the work operation device. The safety device for a working vehicle according to claim 2, wherein the safety device is configured to limit the opening degree.