JP2604311B2 - Safety equipment for aerial work vehicles - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a safety device for an aerial work vehicle, and more specifically, to enable the work table to be displaced horizontally with respect to a lifting device by turning the work table or increasing the area of the work table. The present invention relates to a safety device for an aerial work vehicle.

[0002]

2. Description of the Related Art An aerial work vehicle has a higher work table height,
There is a general demand for a wider working range, but on the other hand, there is a problem that if the working table is made higher and wider, it tends to fall. In order to solve these demands and problems, in the case of an aerial work platform where the workbench can be displaced horizontally with respect to the elevating device, if the workbench height is low, the workbench should have a large horizontal displacement. When the height of the workbench is high, a work range control device is provided as a safety device to reduce the horizontal displacement of the workbench and restrict the work range so as not to overturn when the workbench height is high. Often.

[0003] Depending on the working range regulation method and accuracy, this working range restricting device can vary from a simple one with only a few limit switches to one equipped with a high-performance sensor and arithmetic unit. is there.

[0004] Incidentally, since the working range control device is a device related to a fall, its reliability is important, and it is effective to increase the reliability. It is to be.

[0005]

However, it is often not appropriate to have a plurality of identical work range control devices in terms of economy and simplicity of the devices.

Accordingly, an object of the present invention is to provide a dual safety device for a high-altitude work vehicle having a simple configuration and high reliability.

[0007]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention relates to an aerial work vehicle capable of displacing a vertically movable work table with respect to a lifting device. If the output data of the first detecting means, the horizontal displacement first detecting means of the work table, and the first detecting means exceed predetermined allowable set values in each state of the aerial work vehicle, A first control device including an arithmetic control circuit for stopping an actuator that operates the platform, and separately from the two detection units of the first control device, a height second detection unit of the worktable; Horizontal displacement second detection means,
The two second detection means have a separate circuit without the intervention of the arithmetic control circuit, and the second actuator is configured to stop the actuator when both the second detection means are in the detection state.
A control device is provided.

[0008]

[Operation] According to the above configuration, the first control device controls both first and second control units.
When the output data of the detection means exceeds a predetermined allowable set value in each state of the aerial work vehicle, the actuator that horizontally displaces the work table is stopped. In addition, the second control device, when both the second detection means having a separate circuit without the operation control circuit is in the detection state,
The actuator is stopped.

Therefore, since the first control device and the second control device each stop the actuator, the reliability is high with a duplicated safety device, and the configuration of the second control device is simpler than that of the first control device. Become.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in more detail with reference to the embodiments shown in the drawings.

The aerial work vehicle 1 has a traveling body 3 equipped with a crawler 2 and a three-stage scissor link mechanism 5 as an elevating device for elevating and lowering a work table 4. The work table 4 is moved up and down by opening and closing 5.

The work table 4 is provided on a frame 7 supported by a scissors link mechanism 5 so as to be horizontally turnable, and turns right or left by a right or left rotation of a drive motor 8 as an actuator. The worktable 4 is provided with a slide deck 9 in order to widen a work range. The worktable 4 can slide outward from one end of the worktable 4 by rotating a drive motor 10 as an actuator clockwise or counterclockwise. Or into the stand 4.

The base 7 is provided with a connecting portion of the fixed side link 5a of the scissor link mechanism 5 connected to the base 7, and the height of the work table 4 is changed due to the change in the angle of the fixed side link 5a due to the opening and closing of the scissor link mechanism 5. A potentiometer 11 is provided as first height detecting means for detecting the height.

The gantry 7 is provided with limit switches LS1, LS2 and LS3 as first horizontal displacement detecting means for detecting the turning state of the work table 4, and the work table 4 has a slide deck. As horizontal displacement first detecting means for detecting the sliding state of No. 9,
A limit switch LS4 and a limit switch LS5 are provided.

The limit switch LS1, the limit switch LS2, and the limit switch LS3 are turned on or off as the work table 4 turns, whereby
The work table 4 is arranged so as to detect a neutral state of turning, a right turning state, a left turning state, a full right turning, and a full left turning, respectively.

The limit switches LS4 and LS5 are turned on or off as the slide deck 9 slides, so that the slide state of the slide deck 9 is minimum, minimum to intermediate, intermediate to maximum, and maximum. Are arranged to detect that

Further, the work table 4 has a slide deck 9
A limit switch LS6 is provided as horizontal displacement second detection means for detecting the sliding state of
A limit switch LS7 is provided as a height second detection unit that operates when the moving-side link 5b of the scissors link mechanism 5 comes in contact with the moving part.

The limit switch LS6 is arranged so as to be turned on while the slide state of the slide deck 9 is at a minimum to an intermediate position, and the limit switch LS7 is turned on when the work table 4 is at or below a preset height. Are located in

The potentiometer 11 and the limit switches LS1, LS2, LS3, LS4, LS5, L
S6 and LS7 constitute the safety device 12 with an electric circuit as shown in FIG.

The safety device 12 includes the potentiometer 1
1 and each limit switch LS1, LS2, LS3, LS
4, a first control device 14 having an arithmetic unit 13 to which LS5 is connected, and a second control device 15 including a limit switch LS6 and a limit switch LS7.

The arithmetic unit 13 outputs data on the height of the worktable 4 output from the potentiometer 11, data on the turning state of the worktable 4 output from the limit switches LS1, LS2 and LS3, and outputs from the limit switches LS4 and LS5. The data of the sliding state of the slide deck 9 is compared with a predetermined allowable set value in each state of the aerial work vehicle 1 to calculate whether or not the aerial work vehicle 1 has room to fall down. Always judge.

At the moment when each data is going to exceed the predetermined allowable set value, the arithmetic unit 13 sets the relays R5, R6, R7, R8,
R9 and R10 are turned off.

The relay R5 is a coil C5 for turning the worktable 4 to the left, and the relay R6 is a coil C6 for turning the worktable 4 to the right.
The relay R7 is a coil C7 that increases the sliding amount of the slide deck 9, the relay R8 is a coil C8 that reduces the sliding amount of the slide deck 9, and the relay R9 extends the cylinders 6 and 6 to connect the scissor link mechanism 5. The relay R10 is connected to a coil C9 that closes and raises the worktable 4, and a relay R10 is a coil C10 that reduces the cylinders 6 and 6 to open the scissor link mechanism 5 and lower the worktable 4, respectively.

The aerial work vehicle 1 of this embodiment has a work table 4 of 5
m of the first control device 14
As shown in FIG. 7, when the work table 4 is lifted within 2 m, the slide deck 9 is slid to a maximum of 800 mm, and the work table 4 is allowed to turn left and right. A value has been entered.

The height of the work table 4 is raised from 2 m to 3.5 m.
Within this range, the worktable 4 can be turned left and right while the slide deck 9 is slid to an intermediate position of 400 mm.
Is allowed to slide up to a maximum of 800 mm.

Further, when the work table 4 is raised by 3.5 m or more, the work table 4 can be turned left and right without sliding the slide deck 9, and the work table 4 can be turned neutral. The slide deck 9 is placed in the middle 400
An allowable value that allows the slide to the millimeter is input.

Therefore, the arithmetic unit 13 outputs the data of the height of the work table 4 output from the potentiometer 11, the data of the turning state of the work table 4 output from the limit switches LS1, LS2, LS3, the limit switch LS
At the moment when any of the data of the slide state of the slide deck 9 outputted from the LS5 and LS5 is about to exceed the allowable value, the relays R5, R6, R7, R8, R9, R
A corresponding signal of 10 is turned off to emit a signal.

The limit switch LS of the second control device 15
6 and the limit switch LS7 form a parallel circuit, and the coil C5 in which the workbench 4 moves in a dangerous direction
(Left turn), coil C6 (right turn), coil C7
(Large slide amount), and is directly connected to the coil C9 (work table rise).

Therefore, the limit switch LS7 is
FF or higher and the limit switch L
When the slide state of the slide deck 9 at which S6 is turned off becomes intermediate or higher, the second control device 15 separates the coil C5 (turn left), coil C6 (turn right), and coil C7 separately from the first control device 14. (The slide amount is large) and the coil C9 (workbench rising) is cut, and these coils C5, C6,
The operation of the drive motor 8 for extending and turning the cylinders 6 and 6 and the drive motor 10 for sliding which are operated by C9 and C9 is stopped.

As shown in FIG. 8, the second control device 15 of this embodiment turns off the limit switch LS6 when the slide amount of the slide deck 9 becomes 400 mm or more.
F, the limit switch LS7 is set to be turned off when the work table 4 is raised by 3.5 m or more.
When the slide amount of the slide deck 9 becomes 400 mm or more when the work table 4 is raised by 3.5 m or more, the operation of the drive motor 8 for extending and turning the cylinders 6 and 6 and the drive motor 10 for slide are stopped. That is, the second control device 1
Reference numeral 5 adopts a regulation value that is less than the regulation value of the first control device 14 within a safe range.

As described above, the safety device 12 is a highly reliable dual control device composed of the first control device 14 having the operation device 13 and the second control device 15 including the two limit switches LS6 and LS7. Although it is a safety device, the second control device 15 becomes simple, and the relationship of the first control device 14 and the second control device 15 on the electric circuit is such that the coils C5, C6, C7, and C9 are connected in series. Since the connection is established, even if there is a failure that cannot be controlled by the first control device 14, the control by the second control device 15 works, so that it is safe.

[0032]

As described above, the safety device for an aerial work platform according to the present invention comprises: a work table height first detection means; a work table horizontal displacement first detection means; When the output data of the means exceeds a predetermined allowable set value in each state of the aerial work vehicle, a first control device comprising an arithmetic control circuit for stopping an actuator that operates the work table; Separately from the two detection means of the first control device, the work table has a height second detection means and a horizontal displacement second detection means of the work table, and both the second detection means have the arithmetic control circuit. A second control device that has a separate circuit without any intervention and is configured to stop the actuator when both the second detection units are in the detection state is provided, so that the configuration is simple and reliable. It is possible to provide a highly safe double safety device.

[Brief description of the drawings]

FIG. 1 is an electric circuit diagram of the safety device of the present invention.

FIG. 2 is a perspective view of an aerial work vehicle.

FIG. 3 is an enlarged view of a work table.

FIG. 4 is a plan view showing an arrangement of a turning limit switch.

FIG. 5 is a side view showing an arrangement of a limit switch for a slide.

FIG. 6 is a side view showing an arrangement of a limit switch LS7.

FIG. 7 is a schematic diagram illustrating a work allowable range of a first control device.

FIG. 8 is a schematic diagram illustrating a work allowable range of a second control device.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... High work vehicle, 2 ... Crawler, 3 ... Running body, 4 ... Work table, 5 ... Scissor link mechanism, 6 ... Cylinder, 7 ... Stand, 8 ... Drive motor for turning, 9 ... Slide deck, 1
0: drive motor for slide, 11: potentiometer, 12: safety device, 13: arithmetic device, 14: first control device, 15: second control device, LS1, LS2, LS3
LS4, LS5, LS6, LS7 ... Limit switch

Claims (1)

(57) [Claims] An aerial work vehicle capable of horizontally displacing a vertically movable work table with respect to an elevating device, a first height detection means for the work table, and a first horizontal displacement detection for the work table. And an arithmetic control circuit for stopping the actuator for operating the work table when the output data of the first detection means exceeds a predetermined allowable set value in each state of the aerial work vehicle. A first control device, separately from both the detection means of the first control device, a second height detection means for the workbench, and a second horizontal displacement detection means for the workbench,
The two second detection means have a separate circuit without the intervention of the arithmetic control circuit, and the second actuator is configured to stop the actuator when both the second detection means are in the detection state.
A safety device for an aerial work vehicle, comprising a control device.