JP2000281294A - Fall-down preventing device for working car - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the possibility of fall-down of a vehicle even when malfunction or wrong operation of a reguration releasing switch occurs. SOLUTION: When an operating device 41 is operated in a preset setting time after a regulation releasing switch 43 is operated in a state where an operation regulating circuit 65 regulates the operations of actuators 8, 11, 13, 23, an operation control circuit 63 allows a regulation release control circuit 67 to release the regulation of the operation regulating circuit 65, and allows the actuators 8, 11, 13, 23 to operate based on the operation of the operating device 41. When the operating device 41 is operated after the setting time is over, the operating device stops the regulation release of the regulation release control circuit 67 to allow the operation regulating circuit 65 to perform the operation regulation.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for preventing a work vehicle from overturning, and more particularly, to a work vehicle which is at least movable up and down on a vehicle body and which does not fall over by movement of a boom having a work table at its tip. The present invention relates to a work vehicle overturn prevention device including an operation restricting unit that restricts movement of a boom beyond a limit movement range, and a restriction releasing unit that releases restriction of the operation restricting unit.

[0002]

2. Description of the Related Art In an aerial work vehicle equipped with a telescopic boom having a worktable at its tip on a movable vehicle body, when the worktable is moved, a moment in a direction in which the vehicle body is overturned (hereinafter referred to as "actual moment"). Acts). For this reason, an aerial work vehicle is provided with an overturn prevention device that does not overturn the vehicle. This fall prevention device generally includes a moment limiter that restricts the turning operation of the worktable and the operation of the telescopic boom when the actual moment exceeds the allowable overturning moment that causes the vehicle to fall, 2. Description of the Related Art There is a work range restricting device that determines a range in advance, sequentially detects a position of a work table, and regulates a turning operation of the work table and each operation of a telescopic boom in which the position of the work table exceeds an allowable work range.

Here, the allowable overturning moment and the allowable working range are set to values and ranges smaller than the overturn starting moment and the limit working range where the vehicle actually starts to overturn in consideration of the safety of the vehicle.

In addition, the overturn prevention device is provided with a restriction release switch operated by an operator when releasing the restriction of the moment limiter and the work range restriction device. When this restriction release switch is operated, the restriction operation of the moment limiter and the work range restriction device is forcibly released, and the workbench is moved to a position beyond the allowable overturning moment or the allowable work range within a range where the vehicle does not overturn. be able to.

[0005]

However, since the regulation release switch is provided in a state of being exposed to the outside of the vehicle body and the workbench, if the aerial work vehicle is placed in a place where it rains, the switch may be exposed to rain. Water droplets enter the regulation release switch and short-circuit it to keep the regulation release switch ON, thereby releasing the regulation of the moment limiter or the work range regulating device. For this reason, the operator may move the boom without knowing that the regulation of the overturn prevention device has been released, which may cause the vehicle to fall over the allowable overturning moment or the allowable working range. .

Further, the allowable overturning moment and the allowable working range are set smaller than the overturn starting moment and the limit operating range where the vehicle actually starts to overturn. Do not fall. For this reason, in order to further widen the working range at the work site, there is a case where the operator releases the regulation by operating and fixing the regulation release switch so that it is always in the ON state.
As a result, the working range is widened, but the possibility of the vehicle falling over increases.

Therefore, in order to prevent an increase in the risk of the vehicle falling over, a fall prevention device has been proposed in which a display lamp is turned on when the regulation is lifted to call attention of an operator.

However, even if the display lamp is turned on, the restriction can be released by operating the restriction release switch, so that the work table can be moved to a position beyond the allowable overturning moment or the allowable work range. However, there is a problem that it is not possible to prevent an increase in the possibility of the vehicle falling over.

SUMMARY OF THE INVENTION The present invention has been made in view of such a problem, and provides a work vehicle overturn prevention device capable of preventing the vehicle from overturning even if there is a malfunction or an improper operation of a regulation release switch. The purpose is to:

[0010]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, a fall prevention device for a work vehicle (for example, an aerial work vehicle 1 in the embodiment) of the present invention is provided at least on an upper part of a vehicle body so as to be able to move up and down. A boom (for example, telescopic boom 9 in the embodiment) having a worktable at the tip, and an actuator (for example, a turning motor 8, a telescopic cylinder 11, an up-and-down cylinder 13, and a swinging motor 23 in the embodiment) provided on a vehicle body and operating the boom ), Operation operation means for operating the actuator (for example, the operation device 41 in the embodiment), and operation restriction means for restricting the operation of the actuator beyond the limit movement range of the worktable (for example, the operation restriction circuit in the embodiment) 65) and regulation release means for releasing the regulation of the operation regulation means (for example, the regulation release control circuit in the embodiment). 7), the time counting means for measuring the elapsed time from when the restriction releasing means is actuated (e.g.,
The counter circuit 69 according to the embodiment), and when the operation control unit is operated within a preset time after the control release unit is operated in a state where the operation control unit is controlling the operation of the actuator, the restriction release is performed. The restriction of the operation restricting means is released by the means, the actuator is operated based on the operation of the operation operation means, and when the operation operation means is operated after the set time is exceeded, the restriction release of the restriction release means is stopped and the operation restriction is stopped. It is preferable to have operation control means (for example, the operation control circuit 63 in the embodiment) for performing operation restriction by means.

After the regulation release means is operated in a state where the operation of the actuator is regulated by the operation regulation means,
When the operation operation means is operated within a preset time, the operation control means releases the operation restriction of the operation restriction means by the restriction release means, and operates the actuator based on the operation of the operation operation means. When the operation operation means is operated after the set time has elapsed, the operation control means stops the restriction release of the restriction release means and causes the operation restriction means to perform the operation restriction.

Since the operation of the operation restricting means cannot be released unless the operation operating means is operated within a set time after the operation of the restriction releasing means, the state in which the restriction of the operation restricting means is released by the worker. Therefore, it is possible to prevent the possibility that the vehicle may fall over by operating the operation operation means without knowing that the vehicle is falling down. Further, it is possible to prevent an unauthorized operation of fixing the operation so that the operator can always release the restriction release means. The predetermined time is a time that can be arbitrarily set by an operator.

[0013] Further, the device for preventing the work vehicle from overturning according to the present invention comprises:
A boom provided at least in an upper part of the vehicle body so as to be able to move up and down and having a worktable at a tip thereof, an actuator provided on the vehicle body for operating the boom, an operation operation means for operating the actuator, and exceeding a limit movement range of the worktable An apparatus for preventing a work vehicle from tipping over, comprising: an operation restricting means for restricting the operation of an actuator; and a restriction releasing means (for example, a restriction release control circuit 67 in the embodiment) operated when releasing the restriction of the operation restricting means. A restriction release determining means (for example, a restriction release determination circuit 81 in the embodiment) for determining whether or not the restriction release means is activated; The restriction determining circuit 83) and the restriction release determining means determine that the restriction releasing means is not operating, and An operation control unit (for example, the operation control circuit 63 in the embodiment) that releases the operation restriction of the operation restriction unit when the restriction release unit is operated when it is determined that the operation restriction unit is operating by the unit. May be provided.

After the operation operation means is operated, the restriction release determination means determines that the restriction release means is not operating, and the operation restriction determination means determines that the operation restriction means is operating. In such a case, the operation control means enables the operation of the restriction release means and activates the operation of the restriction release means.When the restriction release means operates, the operation of the operation restriction means is stopped. Set to ON state, or always ON with the operator operating and fixing the regulation release means
Even in the state, when the operation restricting unit is in the restricting state, the operation of the ON-state restriction releasing unit is invalidated and the restriction of the operation restricting unit is not released. For this reason, it is possible to prevent the operator from operating the operation operation means without knowing that the vehicle is in the non-regulated state, to prevent the vehicle from tipping over, and to prevent the operator from operating illegally. Can be.

If the restriction release determining means determines that the restriction release means is operating, and if the operation restriction determining means determines that the operation restriction means is not operating, the operation control means sets the restriction. After the operation of the release means is stopped and the operation restriction determining means is operated, the operation of the restriction release means may be enabled. If the restriction release means is operating in a state where the operation restriction means is not activated, the operation control means invalidates the operation of the restriction release means,
Activating the operation restriction determining means to bring the state into the restricted state enables the operation of the restriction release means. For this reason, rain water drops enter the regulation release means and the regulation release means is always set to O.
Even if the state is set to the N state, or even if the operator operates and fixes the regulation release means and always keeps the ON state, the operation of the regulation release means becomes invalid if the operation regulation determination means is not operated, so that the non-regulated state remains unchanged. By preventing the operation operation means from being operated, it is possible to prevent the vehicle from tipping over. Also,
It is possible to prevent unauthorized operation by the operator.

Further, regulation release means (for example, regulation release switch 43 and regulation release control circuit 67 in the embodiment).
It is preferable to have a transmission unit (for example, the display lamp 57 in the embodiment) that can be notified when the operation restriction of the operation restriction unit can be released by the operation. By the transmission means operating when the restriction state can be released,
The operator can easily recognize the release time of the restriction state. Here, the transmission means only needs to be recognizable by the operator, and for example, a sounding of a buzzer, a turning on of a display lamp, or displaying the fact on a monitor can be exemplified.

The restriction release means has a restriction release operation means (for example, a restriction release switch 43 in the embodiment) for operating this operation. The restriction release means and the restriction release operation means include at least the restriction release means and the restriction release means. A power supply source (for example, battery 53 in the embodiment) for operating the release operation means is connected, and the operation control means controls the restriction release means and the restriction release operation means after power is supplied from the power supply source. Release operation means is operated and ON
When the state is changed, the operation of the restriction release means is invalidated. When the restriction release operation means is operated to be turned off, the operation of the restriction release means is enabled. When the restriction release operation means is operated to be turned on, the restriction release means is operated. May be activated to release the operation restriction of the operation restriction means.

After the power of the power supply source is supplied to the regulation release means and the regulation release operation means, the regulation release operation means is turned on.
In the state, the operation control unit invalidates the restriction release of the restriction release unit. Therefore, the regulation release operation means is always ON.
Even if a malfunction or improper operation occurs, the operation of the regulation release means is invalidated and the operation regulation means operates, so that it is possible to prevent the vehicle from overturning when the overturn prevention device starts to operate. it can.

Further, when the regulation release means in the ON state is operated to be turned off, the operation control means enables the operation of the regulation release means, and the regulation release means is further operated to operate the regulation release means.
When the state is set to N, the restriction release means may be activated to release the operation restriction of the operation restriction means. By changing the regulation release means from the ON state to the OFF state, the disabled regulation release means can be recovered, and work requiring regulation release can be performed to improve work efficiency.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a preferred embodiment of the present invention will be described with reference to FIGS. This embodiment has a telescopic boom that can move up and down and swing freely on the vehicle body, and a work platform that has a function of restricting each operation of the telescopic boom and a work table whose position exceeds an allowable working range. An embodiment will be described.

[0021]

First Embodiment FIGS. 1 and 2 show a first embodiment.
This will be described using. Before describing the overturn prevention device of the present invention, an aerial work vehicle equipped with the overturn prevention device will be described first. As shown in FIG. 1, the aerial work vehicle 1 is configured based on a truck. Each of the left and right front and rear sides of the vehicle body 3 projects laterally of the vehicle body 3, and a lower end portion of the vehicle 1 is grounded. An outrigger jack 5 is provided to stably support the vehicle, and a turntable 7 is provided at the front of the vehicle body 3 so as to protrude upward and freely turn. A turning motor 8 is provided inside the vehicle body 3.
Is configured to be able to turn.

An extensible boom 9 is pivotally connected to the upper part of the swivel 7. The extensible boom 9 has three telescopic boom members nested therein, and a telescopic cylinder 11 is built in the telescopic boom 9. The telescopic boom 9 moves by operating. Both ends of an up-and-down cylinder 13 are pivotally connected between an intermediate portion of the telescopic boom 9 and a bottom of the swivel 7, and the telescopic boom 9 is configured to be up-and-down operation by the telescopic operation of the up-and-down cylinder 13. .

A vertical post 15 is provided at the end of the telescopic boom 9 so as to be vertically swingable. Vertical post 1
The lower end of the telescopic boom 9 is pivotally connected to a leveling cylinder 17 incorporated in the lower end of the telescopic boom 9. keeping. At the tip of the vertical post 15, a horizontal arm 1 that can swing freely
9 is connected, and a worktable 21 on which a worker can ride is attached to the distal end of the horizontal arm 19. A swing motor 23 is built in the horizontal arm 19, and the swing motor 23 operates to swing the work table 21 with respect to the vertical post 17. For this reason, the work table 21 can be swung in a horizontal plane and moved to a desired high position.

An operating device 41 is provided on a side portion of the swivel table 7 and the work table 21. By manually operating a first operating lever L1 provided on these operating devices 41, the rotating motor 8, the up-and-down The operation of the cylinder 13 and the telescopic cylinder 11 is operated, and the telescopic boom 9 is raised, contracted, and swiveled to move the workbench 21 to a desired high position. Further, by manually operating the second operation lever L2 provided on the operation device 41, the operation of the swing motor 23 is operated, and the work table 21 can be swung. A restriction release switch 43 is provided near the first operation lever L1 and the second operation lever L2. When the restriction release switch 43 is pressed, each operation restriction of the telescopic boom 9 and the work table 21 can be released.

Further, the aerial work vehicle 1 is provided with a fall prevention device. When the work table 21 is moved, a moment in the direction of tipping the vehicle body 3 (hereinafter referred to as “actual moment”) acts. (Hereinafter, referred to as an “allowable work range”), and the position of the work table 21 exceeds the allowable work range.
1 to regulate the turning operation and the respective operations of the telescopic boom 9. For this reason, the fall of the vehicle can be prevented beforehand by operating the fall prevention device.

The overturn prevention device 40, as shown in FIG.
Operation device 41, restriction release switch 43, count setting switch 47, workbench position detection sensor 49, power switch 51, battery 53, controller 55, and display lamp 5
7, an up-and-down cylinder 13, a telescopic cylinder 11, a turning motor 8, and a swaying motor 23 (hereinafter collectively referred to as "actuators 8, 11, 13, 23"), and actuators 8, 11, 13, 23. (Hereinafter, referred to as “valve 59”).

Since the operation device 41 has been described above, its description is omitted. The restriction release switch 43 is manually operated by an operator, and is operated to release the restriction of each operation of the telescopic boom 9 and the work table 21 shown in FIG. 1. When pressed, the switch is turned on, and when released, it is turned off. It is configured to be. The counter setting switch 47 shown in FIG. 2 is provided in the vicinity of the operating device 41 and is set in advance by the manufacturer of the aerial work vehicle 1, and sets the elapsed time from when the regulation release switch 43 is pressed and turned on. It is. The workbench position detection sensor 49 is for detecting the current position of the workbench 21, and, for example, determines the position of the workbench 21 based on the length of the telescopic boom 9, the undulation angle, the swivel angle, and the swivel angle of the workbench 21. Can be detected. The power switch 51 is provided on a power line 61 connecting the controller 55 and the battery 53. When the operator connects the power switch 51, the power of the battery 53 is supplied to the controller 55.

The operating device 41, the regulation release switch 43, the count setting switch 47, and the worktable position detecting sensor 49 are electrically connected to the controller 55.
The controller 55 includes the operation control circuit 63 and the operation restriction circuit 6
5, a regulation release control circuit 67, a counter circuit 69, a workbench position specifying circuit 71, a work area determination circuit 73, and a memory 75.
And a restriction release switch operation determination circuit 77.

The operation control circuit 63 controls the operation of each valve 59 based on the operation signal from the operation device 41 to control the operation of each of the actuators 8, 11, 13, and 23, and the restriction release switch 43 can be operated. The display lamp 57 is turned on when the state is correct. Note that a buzzer or a display device may be used instead of the display lamp 57. In the memory 75, an allowable work range in which the vehicle does not fall down is set. The workbench position specifying circuit 71 calculates the position of the workbench 21 based on the position signal from the workbench position detection sensor 49, and the work area determination circuit 73 determines the allowable work range and work set in the memory 75. By comparing with the position of the worktable 21 calculated by the position specifying circuit 71,
It is determined whether or not the position of the work table 21 exceeds the allowable work range.

The operation restriction circuit 65 includes a work area determination circuit 73.
Accordingly, when it is determined that the position of the work table 21 exceeds the allowable work range, the operation of the actuators 8, 11, 13, and 23 in the direction away from the allowable work range is restricted. The counter circuit 69 counts the elapsed time from when the regulation release switch 43 is turned ON.

The restriction release control circuit 67 includes an operation restriction circuit 65.
When the operation device 41 is operated within a set time after the regulation release switch 43 is turned ON in a state in which the operation of the actuators 8, 11, 13, and 23 is regulated, the ON operation of the regulation release switch 43 is enabled. The control of the operation control circuit 65 is released. Then, the actuators 8, 11, 13, and 23 operate via the operation control circuit 63 based on the operation signal of the operation device 41. When the operation device 41 is operated after the set time has elapsed, the restriction release control circuit 67 stops the ON operation of the restriction release switch 43 and activates the operation restriction circuit 65 to operate the work platform 21 exceeding the allowable work range. Restrict movement.

That is, the restriction release control circuit 67 cannot release the operation of the operation restriction circuit 65 unless the operation device 41 is operated within the set time after the restriction release switch 43 is turned ON. 43 is always O
Even if it is in the N state, the operation of the regulation release switch 43 is invalidated after the lapse of the set time, so that the operation regulation circuit 65 is actuated to enter the regulation state. For this reason, even if the operator operates the operation device 41 without knowing that the regulation of the operation regulation circuit 65 is released, the regulation state is established after the lapse of the set time, and the vehicle may fall. Can be prevented beforehand. Further, it is possible to prevent an unauthorized operation of fixing the operation so that the operator can always release the restriction release switch 43.

The regulation release switch operation determination circuit 77 invalidates the operation of the regulation release switch 43 when the regulation release switch 43 is operated and turned on after the power of the battery 53 connected to the controller 55 is supplied, and further the regulation is performed. When the release switch 43 is operated to be in the OFF state, the operation of the restriction release switch 43 becomes effective, and when the restriction release switch 43 is further operated to be turned on, the operation restriction circuit 6 is activated.
Release the operation restriction of 5. That is, the regulation release switch 43
Is temporarily turned off, the function of the disabled regulation release switch 43 is restored, and work requiring removal of the regulation can be performed, thereby improving work efficiency.

Next, the operation of the overturn prevention device 40 according to the first embodiment will be described. First, the vehicle body 3 shown in FIG.
After moving the vehicle with the telescopic boom 9 retracted to the vicinity of the work site, the outrigger jack 5
And the lower end thereof is grounded to stably support the vehicle body 3.

Then, a worker (not shown) gets on the work table 21 and supplies power to the controller 55 by connecting the power switch 51 shown in FIG. The count setting switch 47 is set in advance by a manufacturer to set the set time. When power is supplied to the controller 55, the regulation release switch operation determination circuit 77 operates. At this time, the regulation release switch 43 is in the ON state (the state in which it is pressed).
If so, the regulation release switch operation determination circuit 77 invalidates the ON state operation of the regulation release switch 43. And
The operation of the regulation release switch 43 can be made effective when the operator sets the regulation release switch 43 to the OFF state (the state where it is not pressed). At this time, the operation control circuit 6
3 turns on the display lamp 57. Therefore, the worker can recognize that the regulation release switch 43 is in an operable state by turning on the display lamp 57.

Next, the operator manually operates the first operation lever L1 and the second operation lever L2 of the work table 21 shown in FIG. The work table 21 is moved close to the work site by swinging. More specifically, the power of the battery 53 is supplied to the controller 55 shown in FIG. 2, the regulation release switch 43 is in the OFF state, and the operation regulating circuit 65 operates. Then, the operator operates the first operation lever L1 and the second operation lever L2 of the work table 21 shown in FIG. The operation signals of the operation levers L1, L2 are sent to the operation control circuit 63, and based on the operation signals, the operation control circuit 63 controls the operation of the valve 59 to activate the actuators 8, 11, 13, 23 such as the up-and-down cylinder 13. When activated, the work table 21 shown in FIG. 1 moves toward the work site.

As the work table 21 moves, the work table position detection sensor 49 shown in FIG. 2 sequentially detects the position of the work table 21, and this position signal is sent to the work table position specifying circuit 71 to determine the position of the work table 21. It is calculated sequentially. The work area determination circuit 73 reads the allowable work range from the memory 75,
It is determined whether or not the calculated position of the worktable 21 exceeds the allowable work range. If the position of the work table 21 does not exceed the allowable work range while the work table 21 is moving toward the work site, the work table 21 reaches the work site. On the other hand, if the position of the work table 21 exceeds the allowable work range, the operation restricting circuit 65 operates to cut off the operation control signals of the actuators 8, 11, 13, and 23 in the direction away from the allowable work range. Therefore, the vehicle can be prevented from falling down.

Next, when the work table 21 is moved to the work site, the worker on the work table 21 performs work at a high place. At this time, in order to increase the work range by moving the position of the work table 21 in a direction in which the vehicle may be overturned (in a direction away from the allowable work range) in order to improve the ease of work at the work site, Then, the operator presses the regulation release switch 43 to turn it on. An indicator lamp 57 indicates whether the regulation release switch 43 can be operated.
Can be confirmed by the lighting of.

When the restriction release switch 43 is pressed while the operation restriction circuit 65 is operating, the release signal is received by the counter circuit 69, and the elapsed time from when the counter circuit 69 receives the release signal is counted. The elapsed time is sent to the regulation release control circuit 67. Then, the operator operates the operation device 41 within the set time set by the count setting switch 47. When the restriction release control circuit 67 receives the operation signal, the restriction release control circuit 67 causes the operation restriction circuit 65 to operate the actuators 8, 11, 13, 23.
Release the operation restriction of. Then, the operator operates the operation device 41.
1st operation lever L1 and 2nd operation lever L shown in FIG.
2 and the operation control circuit 63 based on the operation signal.
Controls the operation of valve 59 to control actuators 8,11,
Operate 13,23. For this reason, the work table 21 can move beyond the allowable work range, and can easily perform work at a high place. On the other hand, when the operation device 41 is operated after the set time has passed, the regulation release control circuit 67 invalidates the release signal of the regulation release switch 43 and stops the regulation release,
The operation regulation by the operation regulation circuit 65 is performed. For this reason, even if the regulation release switch 43 is always in the ON state, the operation of the regulation release switch 43 is invalidated after the lapse of the set time, so that the operation regulation circuit 65 is activated to enter the regulation state. For this reason, even if the operator operates the operation device 41 without knowing that the regulation is released, the regulation state is established after the lapse of the set time, so that the possibility of the vehicle falling down is prevented beforehand. It is possible to prevent an unauthorized operation of fixing the operation so that the operator can always release the regulation release switch 43.

[0040]

Second Embodiment Next, a second embodiment will be described with reference to FIGS. In the second embodiment, only differences from the above-described first embodiment will be described, and the same components as those in the first embodiment will be denoted by the same reference numerals and description thereof will be omitted. As shown in FIG. 3, the controller 55 of the fall prevention device 40 according to the second embodiment includes a restriction release determination circuit 81 that determines whether the restriction release switch 43 is activated, and whether the operation restriction circuit 65 is activated. , And does not include the counter setting switch 47 and the counter circuit 69 of the overturn prevention device 40 according to the first embodiment.

After the operation device 41 is operated, the regulation release determination circuit 81 determines that the regulation release switch 43 is not operated (is in the OFF state), and the operation regulation determination circuit 83 activates the operation regulation circuit 65. When it is determined that the switch is operating (in the regulation state), the regulation release control circuit 67 enables the operation of the regulation release switch 43.

In this way, the operation regulating circuit 65
In the state where is operated, when rain water drops enter the regulation release switch 43 and the regulation release switch 43 is always in the ON state, or when the operator operates and fixes the regulation release switch 43 and always keeps the ON state. However, since the regulation release control circuit 67 invalidates the operation of the regulation release switch 43,
The operation restricting circuit 65 is activated, and the operator operates the operating device 41 without knowing that the restriction of the operation restricting circuit 65 is released, and the workbench exceeds the allowable working range and the vehicle falls. This can be prevented from occurring. Further, it is possible to prevent an unauthorized operation of fixing the operation so that the operator can always release the restriction release switch 43.

When it is determined by the restriction release determination circuit 81 that the restriction release control circuit 67 is operating, and when the operation restriction determination circuit 83 determines that the operation restriction circuit 65 is not operating. Is the regulation release control circuit 6
7 stops the operation of the restriction release and activates the operation restriction circuit 65. Then, in this state, the regulation release switch 4
When 3 is operated, the regulation release control circuit 67 validates this operation. That is, if the regulation release switch 43 is ON before the regulation is applied, the regulation release switch 4
3 is disabled, and the operation of the regulation release switch 43 is enabled when the regulation state is entered. Therefore, when the regulation is applied, the regulation cannot be released even if the regulation release switch 43 is ON, so that rain water drops enter the regulation release switch 43 and the regulation release switch 43 is always set to the ON state. Or when the worker operates the regulation release switch 43 and always keeps the ON state, the operation restriction circuit 65 is in the operating state. By operating the operating device 41 without knowing that the work table is out of the allowable work range, the vehicle can be prevented from falling down. Further, it is possible to prevent an unauthorized operation of fixing the operation so that the operator can always release the restriction release switch 43.

[0044]

As described above, according to the work vehicle overturn prevention device of the present invention, after the restriction release means is operated in a state where the operation restriction means restricts the operation of the actuator, a preset value is set. When the operation operation means is operated within the set time, the operation control means releases the restriction of the operation restriction means by the restriction release means, operates the actuator based on the operation of the operation operation means, and exceeds the set time. When the operation operation means is operated later, the operation of the restriction release means can be restricted by stopping the restriction release of the restriction release means and performing the operation restriction by the operation restriction means. It is possible to prevent the possibility that the vehicle may fall down by operating the operation operation means without knowing that the regulation has been released. Possible to prevent unauthorized operation of operating fixed so that the operating state.

Further, there is provided a restriction release determining means for determining whether the restriction release means has been activated or not, and an operation restriction determination means for determining whether the operation restriction means has been activated. When the release determination means determines that the restriction release means has not been operated and the operation restriction determination means has determined that the operation restriction means has been activated, the operation control means enables the operation of the restriction release means, and the restriction release means Is activated, the operation restriction of the operation restriction means is released, so that rain water drops enter the restriction release means and the restriction release means is always turned on, or the operator operates and fixes the restriction release means to always turn on the restriction release means. Even in the state, when the operation restricting means is in the restricting state, the operation of the ON-state restriction releasing means is invalidated and the restriction release of the operation restricting means is stopped, so that the worker does not know that it is in the non-restricted state. Operation It is possible to prevent the manipulating means, it is possible to prevent the overturning of the vehicle in advance. In addition, it is possible to prevent an unauthorized operation by the operator.

Further, if the restriction release determining means determines that the restriction release means is operating, and if the operation restriction determining means determines that the operation restriction means is not operating, the operation restriction means is activated. If the operation of the restriction release means is stopped after the operation of the restriction release means is stopped and the operation of the restriction release means is enabled after the operation restriction determination means is activated, incorrect operation of the restriction release means or improper operation of the restriction release means by an operator. Since it becomes invalid, it is possible to prevent the operation operation means from being operated in the non-restricted state and to prevent the vehicle from tipping over. In addition, it is possible to prevent an unauthorized operation by the operator.

In the case where there is provided a transmitting means for notifying that the operation restriction of the operation restricting means can be released by the restriction releasing means, the transmitting means operates when the restriction state can be released. The operator can easily recognize the timing of releasing the restriction state, and by releasing the restriction, the work range can be expanded and the work efficiency can be improved.

Further, the restriction releasing means has a restriction releasing operation means for operating this operation, and a power supply source for operating at least these elements is connected, and the operation control means supplies the restriction releasing means and the restriction releasing operation means with electric power. When the regulation release operation means is operated and turned on after the power is supplied from the supply source, the operation of the regulation release means is invalidated. When the regulation release operation means is operated and turned off, the operation of the regulation release means is disabled. Enabled, and the regulation release operation means is operated to
When the restriction release means is activated in the N state to release the operation restriction of the operation restriction means, even if a malfunction or an illegal operation is performed such that the restriction release operation means is always in the ON state,
Since the operation of the regulation release means is invalidated and the operation regulation means is activated to be in the regulated state, it is possible to prevent the vehicle from overturning at the start of the operation of the overturn prevention device,
By changing the regulation release means from the ON state to the OFF state,
It is possible to recover the function of the disabled regulation release means and perform a work that requires removal of regulation, thereby improving the work efficiency.

[Brief description of the drawings]

FIG. 1 is a perspective view of an aerial work vehicle equipped with a fall prevention device according to a first embodiment of the present invention.

FIG. 2 is a block diagram of a fall prevention device according to the first embodiment of the present invention.

FIG. 3 is a block diagram of a fall prevention device according to a second embodiment of the present invention.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 work platform aerial vehicle (work vehicle) 3 body 8 turning motor (actuator) 9 telescopic boom (boom) 11 telescopic cylinder (actuator) 13 up / down cylinder (actuator) 21 work table 23 swing motor (actuator) 40 fall prevention device 41 Operation device (operation operation means) 43 Regulation release switch (regulation release operation means) 53 Battery (power supply source) 57 Indicator lamp (transmission means) 63 Operation control circuit (operation control means) 65 Operation restriction circuit (operation restriction means) 67 Regulation release control circuit (restriction release means) 69 Counter circuit (time counting means) 81 Regulation release determination circuit (restriction release determination means) 83 Operation restriction determination circuit (operation restriction determination means) L1 First operation lever (operation operation means) L2 2nd operation lever (operation operation means)

Claims (5)

[Claims] 1. A boom provided at an upper part of a vehicle body so as to be able to move up and down at least and having a worktable at a tip thereof, an actuator provided on the vehicle body to operate the boom, and an operation operation means for operating the actuator. An overturning prevention device for a work vehicle, comprising: an operation restricting unit that restricts operation of the actuator that exceeds a limit movement range of the worktable; and a restriction release unit that releases restriction of the operation restriction unit. Time counting means for measuring an elapsed time since the operation of the actuator, and after the regulation release means is operated in a state in which the operation regulating means regulates the operation of the actuator, within a set time set in advance When the operation operation unit is operated, the restriction of the operation restriction unit is released by the restriction release unit, and the operation of the operation operation unit is performed. Operating the actuator, and when the operation operating means is operated after the set time has passed, operation control means for stopping the restriction release of the restriction release means and performing operation restriction by the operation restriction means. Features a work vehicle fall prevention device. 2. A boom provided at least at an upper part of a vehicle body so as to be able to move up and down and having a worktable at a tip thereof; an actuator provided on the vehicle body to operate the boom; and operation operation means for operating the actuator. An overturning prevention device for a work vehicle, comprising: an operation restricting unit that restricts operation of the actuator that exceeds a limit movement range of the worktable; and a restriction release unit that releases restriction of the operation restriction unit. A restriction release determining means for determining whether or not the operation is performed, an operation restriction determining means for determining whether or not the operation restricting means is activated, and after the operation operation means is operated, the restriction release means is used by the restriction release determining means. Is not operating, and when it is determined by the operation restriction determining means that the operation restricting means is operating An operation control unit for releasing the operation restriction of the operation restriction unit when the restriction release unit is activated. 3. When the restriction release determining means determines that the restriction release means is operating, and when the operation restriction determining means determines that the operation restricting means is not operating, 3. The work vehicle according to claim 2, wherein the operation control means stops the operation of the restriction release means, and activates the operation of the restriction release means after activating the operation restriction determination means. Fall prevention device. 4. The work vehicle according to any one of claims 1 to 3, further comprising a transmission unit that notifies when the operation restriction of the operation restriction unit can be released by the restriction release unit. Prevention device. 5. The restriction release means has a restriction release operation means for operating this operation, and the restriction release means and the restriction release operation means actuate at least the restriction release means and the restriction release operation means. A power supply source is connected, and the operation control unit operates the restriction release operation unit after the power from the power supply source is supplied to the restriction release unit and the restriction release operation unit to turn the restriction release unit on. Then, the operation of the regulation release means is invalidated. Further, when the regulation release operation means is operated and turned off, the operation of the regulation release means is enabled. When the regulation release operation means is further operated and turned on, the operation is performed. 5. The work vehicle fall prevention device according to claim 1, wherein the restriction release means is activated to release the operation restriction of the operation restriction means.