JP2000247599A - Safety device for vertical elevation type high place working machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the safety device for a vertical elevation type high placed working machine which enables the safe and efficient high place work, without impairing the workability while securely preventing the falling of the car body. SOLUTION: This safety device has a height detector 16 to detect the height of a working table; the first and the second load detectors 17a and 17b to detect the working load of the working table; and the regulating and deciding part 33 of a controller 30 to regulate the elevating operation of the working table, and the operation of a crawler device, depending on the detecting results. While the regulating and deciding part 33 regulates the elevating operation of the working table not to pull down the car body, according to the height of the working table detected by the height detector 16, and the working load of the working table detected by the first and the second load detectors 17a and 17b, running of the car body is enabled when the working load of the working table is small, even through the working load of the working table is large to a specific level, and the height of the working table is relatively low.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vertical lifting device provided on a movable vehicle body, which has a work table, and the work table can be raised and lowered vertically above the vehicle body. The present invention relates to a safety device for an aerial work vehicle.

[0002]

2. Description of the Related Art Conventionally, there has been known a vertical lifting type aerial work vehicle having a structure in which a vertical lifting device such as a scissor link is provided on a vehicle body so that a worktable can be raised and lowered vertically. Generally, in such an aerial work vehicle, a worker on a work table can operate a lever provided on the work table to move the vehicle body and raise and lower the work table. I have.

In such an aerial work platform, in order to prevent the body from tipping over, when the load applied to the work platform becomes larger than a predetermined reference load, an operation for raising the work platform further is performed. Some safety devices have a prohibited configuration. In addition, in order to prevent the risk of the vehicle body falling over when traveling over a step when traveling with a large load on the work platform, when the load on the work platform is large, not only the raising operation of the work platform, There is also used a safety device configured to prohibit the running of the vehicle body to prevent the vehicle body from tipping over.

[0004]

However, as described above, in the safety device that inhibits not only the operation of raising the worktable but also the running of the vehicle, the load applied to the worktable exceeds a certain reference load. Occasionally, regardless of the height of the worktable, traveling is prohibited, so the load is higher than the reference load, but the height of the worktable is relatively low. Workability is very poor in
There was a problem that work could not be performed efficiently.

[0005] The present invention has been made in view of such a problem, and it is possible to prevent a fall of a vehicle body reliably, without impairing workability, and to perform a safe and efficient work at a high place. An object of the present invention is to provide a safety device for a lifting type aerial work platform.

[0006]

In order to achieve the above object, a safety device for a vertical lifting type aerial work vehicle according to the present invention is provided with a traveling body provided with a traveling device and a vehicle body provided on the vehicle body. A vertical lifting device (for example, the scissor link 13 and the telescopic cylinder 15 in the embodiment), a vertically movable work table attached to the vertical lifting device, and a vehicle running means for operating the running device to run the vehicle body ( For example, the left and right crawler device operation levers 22a and 22b, the crawler device operation control unit 32 of the controller 30, and the left and right crawler device operation valves 42a and 42 in the embodiment.
b) etc., and a workbench elevating means for operating the vertical elevating device to vertically elevate and lower the workbench (for example, the workbench elevating operation lever 21 in the embodiment, the workbench elevating operation control unit 31 of the controller 30 and the telescopic cylinder operating valve) 41 etc.), the height detecting means (for example, the height detector 16 in the embodiment)
And load detecting means (for example, the first and second load detectors 17a and 17b in the embodiment) and regulating means (for example, the regulation judging unit 3 of the controller 30 in the embodiment).
3) is provided. Here, the height detecting means detects the height of the worktable, and the load detecting means detects the load applied to the worktable. The restricting means is configured to raise the worktable by the vertical lifting device and the vehicle body by the traveling device in accordance with the height of the worktable detected by the height detecting means and the load of the worktable detected by the load detecting means. Regulations that prohibit the running of the vehicle.

In the safety device having such a configuration, when the load applied to the workbench is large to some extent, the workbench is prevented from ascending and the body is prevented from tipping over to prevent the vehicle from tipping over. Regulations are based not only on the load on the workbench but also on the height of the workbench. There is no. For this reason, safe and efficient work at high places can be performed without impairing the workability while reliably preventing the vehicle body from tipping over. As such a regulation, the fall and fall of the vehicle body is prevented by appropriately restricting the raising and lowering operation of the work table and the traveling of the vehicle body in accordance with the height of the work table and the load load of the work table. Even if the height of the worktable is relatively low even if it is large, or even if the height of the worktable is relatively high, even if the load load on the worktable is small, the vehicle can travel and secure sufficient workability Is preferable.

[0008] More specifically, the restricting means may be configured such that the height of the workbench is equal to or less than a predetermined height (for example, the reference height Ho in the embodiment) and the load is a first predetermined height. When the load exceeds a predetermined load (for example, the first reference load W1 in the embodiment), the lifting operation of the workbench by the vertical lifting device is prohibited, and the height of the workbench is equal to or less than the predetermined height and the applied load is The second which is larger than the first predetermined load
A predetermined load (for example, the second reference load W in the embodiment)
2) above, or when the height of the workbench exceeds a predetermined height and the applied load exceeds the first predetermined load, the workbench is raised by the vertical lifting device and the traveling device is used. It is preferable to prohibit the running operation of the vehicle body. With this configuration, the above-described effect can be obtained with a simple configuration.

[0009]

Preferred embodiments of the present invention will be described below with reference to the drawings. FIG. 2 shows a vertical lifting type aerial work vehicle (hereinafter referred to as an aerial work vehicle) equipped with the safety device according to the present invention. The aerial work vehicle 10 includes a crawler traveling device 12 as a traveling device
The crawler traveling device 12 allows the vehicle to travel. Further, a scissor link 13 as a vertical lifting device is provided on the vehicle body 11, and a work table 14 for mounting a worker is attached to an upper end of the scissor link 13.

Each of the left and right crawler devices 12 includes a starting wheel 12a, an idle wheel 12b, and both wheels 12a, 12b.
And the crawler belt 12c is provided so as to extend over the vehicle body. The starting wheel 12a is rotationally driven by hydraulic pressure to drive the crawler belt 12c and the idler wheel 12b, thereby causing the vehicle body 11 to travel. You can do it.

One lower end 13a of the scissor link 13
Is connected to the upper part of the vehicle body 11 and the other lower end 13
b is mounted in a horizontal slide groove (not shown) formed in the upper part of the vehicle body 11 so as to be slidable back and forth. One upper end 13c is pivotally connected to the lower part of the worktable 14, and the other upper end 13d is slidable back and forth in a horizontal slide groove (not shown) formed in the lower part of the worktable 14. Attached to. Also, the vehicle body 11
A hydraulic telescopic cylinder 15 is provided so as to extend between the telescopic cylinder 15 and the scissor link 13.
, The scissors link 13 can expand and contract in the up and down direction to move the workbench 14 up and down. Note that the solid line in FIG. 2 indicates the upward movement position of the work table 14, and the two-dot chain line indicates the downward movement position of the work table 14.

A handrail 14a for preventing the worker from falling is provided on the upper surface side of the worktable 14, and as shown in FIG. The lifting operation lever 21 and the left and right crawler devices 12
Box 20 on which left and right crawler device operating levers 22a and 22b for issuing a command to operate the device are provided.
Is provided.

Each of the workbench lifting operation lever 21 and the left and right crawler device operation levers 22a and 22b can be tilted forward or backward from the neutral position. These levers 21, 22a, and 22b are all manually operated, but are configured to automatically return to the neutral position when the hand is released from the tilted state.

A potentiometer for detecting the tilting state of the lever 21 (whether it is in a neutral position, forward tilting, or rearward tilting) is provided at the base of the worktable elevating operation lever 21. In this potentiometer, The detected information is output as a telescopic cylinder operation signal. At the bases of the left and right crawler operation levers 22a and 22b, potentiometers are provided to detect the tilting state of the levers 22a and 22b (neither the neutral position, the forward tilting or the backward tilting state). The information detected by each potentiometer is output as left and right crawler device operation signals.

A height detector 16 is provided below the work table 14, as shown in FIG. This height detector 1
A limit switch 6 outputs an off signal when the arm 16a is at the initial position (shown by a solid line), and outputs an on signal when the arm 16a is swung from the initial position (shown by a broken line). Is output. Further, a projection 131 as shown in FIG. 4 is formed on the upper end 13c of the scissor link 13 pivotally connected to the lower part of the work table 14, and the upper end 1 is formed by the expansion and contraction operation of the scissor link 13.
3c moves up and down as it rotates around the pivot 18.

Here, the position of the height detector 16 is determined when the height of the worktable 14 (for example, measured from the upper surface of the vehicle body 11) coincides with a predetermined reference height Ho. Is adjusted so as to contact the arm 16a. Therefore, when the height of the work table 14 is equal to or less than the reference height Ho and the projection 131 is located below the arm 16a, or when the projection 131 is in contact with the arm 16a, Since the arm 16a is located at the initial position where the arm 16a does not swing, the height detector 16 outputs an off signal. On the other hand, when the height of the work table 14 is higher than the reference height Ho and the protrusion 131 pushes the arm 16a upward, the arm 16a is in a swinging state, and the height is detected. The device 16 outputs an ON signal. Therefore, by detecting the on / off signal output from the height detector 16, it is possible to detect whether or not the height of the work table 14 exceeds the reference height Ho. In addition,
The solid line in FIG. 4 indicates a state in which the height of the worktable 14 matches the reference height Ho and the protrusion 131 is in contact with the arm 16a, and the broken line indicates that the height H of the worktable 14 is the reference height. This shows a state in which the protrusion 131 pushes the arm 16a upward above the height Ho.

Although not shown, the telescopic cylinder 15
The first and second load detectors 17a and 17b composed of pressure switches are provided in the oil passage on the bottom side. The first load detector 17a is configured to determine whether the pressure in the oil passage is equal to a predetermined first pressure.
When the pressure has not reached the reference pressure P1, an off signal is output, and when the pressure in the oil passage has reached the first reference pressure P1, an on signal is output. On the other hand, the second load detector 1
7b indicates that the pressure in the oil passage is a predetermined second reference pressure P
When the pressure in the oil passage has not reached 2 (> P1), an off signal is output. When the pressure in the oil passage has reached the second reference pressure P2, an on signal is output. Therefore, when the pressure in the oil passage on the bottom side of the telescopic cylinder 15 has not reached the first reference pressure P1, the first and second load detectors 17a, 17
7b outputs an off signal, and when the pressure in the oil passage is equal to or higher than the first reference pressure P1 and equal to or lower than the second reference pressure P2, an on signal is output from the first load detector 17a and the second load is output. An off signal is output from the detector 17b. Further, the pressure in the oil passage is equal to the second reference pressure P2.
When the above is the case, the first and second load detectors 17a, 17
7b both output an ON signal.

The pressure in the oil passage on the bottom side of the telescopic cylinder 15 has a one-to-one correspondence with the load applied to the workbench 14. Here, the first reference pressure P1 is determined in advance as a reference value of the load applied to the workbench 14. It is set to a value corresponding to the determined reference load W1, and the second reference pressure P2 is
Reference load W2 which is predetermined as a reference value of the applied load of
(> W1), the work table 14 is detected by detecting a combination of on / off signals output from the first and second load detectors 17a and 17b.
Whether the applied load exceeds the first reference load W1;
And whether or not the second reference load W2 is exceeded.

FIG. 1 is a block diagram showing the configuration of a control system including a safety device according to the present invention. As shown in this figure, the controller 30 includes a workbench elevating operation control unit 31,
A crawler device operation control unit 32 and a regulation determination unit 33 are provided. Then, the telescopic cylinder operation signal output by the operation of the workbench elevating operation lever 21 is transmitted to the workbench elevating operation control unit 31 by the left and right crawler device operation levers 22a, 22b.
The left and right crawler device operation signals output by the operation of 22b are input to the crawler device operation control unit 32. Also, the height detector 16 and the first and second load detectors 17
The on / off signals from a and 17b are input to the regulation determining unit 33.

The telescopic cylinder 15 is operated by receiving the supply of hydraulic pressure. The supply of hydraulic pressure to the telescopic cylinder 15 is controlled by a telescopic cylinder operating valve 41 which is electromagnetically driven by a signal from the worktable elevating / lowering operation control unit 31. It is made by operation. The left and right crawler devices 12 also operate by receiving the supply of the hydraulic pressure as described above. The supply control of the hydraulic pressure to the left and right crawler devices 12 is electromagnetically driven by a signal from the crawler device operation control unit 32. The operation is performed by operating the telescopic cylinder operation valves 42a and 42b.

In the aerial work vehicle 10 having the above-described structure, when an operator on the work table 14 tilts the work table elevating operation lever 21, a telescopic cylinder operation signal corresponding to the operation is output, and the controller 30 is operated. Is input to the worktable elevating / lowering operation control unit 31. Workbench elevating operation controller 3
Numeral 1 electromagnetically drives the telescopic cylinder operating valve 41 in accordance with information on the operating direction of the workbench elevating operation lever 21 included in the input signal. As a result, the hydraulic pressure is supplied to the telescopic cylinder 15, and the scissor link 13 expands and contracts, and the work table 14 moves up and down (up or down) according to the operation of the work table elevating operation lever 21.

When the worker on the worktable 14 tilts the left and right crawler device operation levers 22a and 22b, a crawler device operation signal corresponding to the operation is output, and the crawler device operation control unit 32 of the controller 30 outputs. Is input to The crawler device operation control unit 32 controls the left and right crawler device operation levers 22 included in the input signal.
The left and right crawler device operation valves 42a and 42b are electromagnetically driven in accordance with the information on the operation directions of the a and 22b. As a result, the left and right crawler devices 12 are supplied with hydraulic pressure to operate, and the vehicle body 11 travels according to the operation of the crawler device operation levers 22a and 22b.

Here, the left and right crawler devices 12 can be rotated independently in desired directions in the forward and reverse directions. It is possible to move forward or backward. In addition, the vehicle body 11 can be turned by rotating only one of the left and right sides or the left and right sides in the opposite direction. In the case of the former, the rotation (pivot turn) is performed with the crawler device 12 on the non-rotating side being the fulcrum, and in the case of the latter, the rotation (spin turn) is performed on the spot.

With such a configuration, the aerial work vehicle 1
0, the vehicle body 11 can be moved from above the work table 14 and the work table 14 can be moved up and down. But you can do it all by yourself

When the work table 14 is raised and lowered as described above, the height of the work table 14 changes. However, when the work table 14 is lower than the reference height Ho, the height detector 16 Outputs an off signal, and outputs an on signal when the reference height Ho is exceeded. Also, when loading / unloading of the luggage to / from the work table 14, the work table 1
The load of No. 4 changes, but when the load of the work table 14 is equal to or less than the first reference load W1, both the first load detector 17a and the second load detector 17b output an off signal. When the applied load exceeds the first reference load W1 and is equal to or less than the second reference load W2, an ON signal is output from the first load detector 17a to the second load detector 17a.
b outputs an off signal. Further, when the applied load exceeds the second reference load W2, an ON signal is output from each of the first load detector 17a and the second load detector 17b.

The regulation judging section 33 of the controller 30 performs the control based on the combination of the off signal or the on signal inputted from the height detector 16, the first load detector 17a and the second load detector 17b as described above. The determination shown in Table 5 is performed, and the extension operation of the telescopic cylinder 15 and the operation of the crawler device 12 are appropriately regulated. That is, an off signal is output from the height detector 16 (that is, the workbench 1
4 is less than or equal to the reference height Ho) and the ON signal is output from the first load detector 17a (when the load on the workbench 14 exceeds the first reference load W1). The control signal is output to the workbench elevating / lowering operation control unit 31 to extend the telescopic cylinder 15 (that is, the workbench 1 moves).
4 ascending operation) is prohibited.

An off signal is output from the height detector 16 (that is, the height of the work table 14 is equal to the reference height Ho).
Below) and when the ON signal is output from the second load detector 17b (the load on the work table 14 is
Or when the ON signal is output from the height detector 16 (that is, when the work table 1
4 when the height H exceeds the reference height Ho) and when the ON signal is output from the first load detector 17a (that is, when the load on the workbench 14 exceeds the first reference load W1). Is in effect), a control signal is output to the workbench elevating operation control unit 31 to prohibit the extension operation of the telescopic cylinder 15 (that is, the operation to elevate the workbench 14), and the crawler traveling device operation control unit 32 The control signal is output, and the operation of the left and right crawler devices 12 (that is, the traveling of the vehicle body) is also prohibited.

As described above, in the aerial work vehicle 10, when the height of the work table 14 is equal to or lower than the reference height Ho, the work table 1
If the load of No. 4 is equal to or less than the first reference load W1, no regulation is performed, and the work table 14 can be raised and the vehicle can travel, but when the load of the work table 14 exceeds the first reference load W1, Then, the raising operation of the work table 14 is prohibited. When the load applied to the workbench 14 also exceeds the second reference load W2, traveling of the vehicle body is also prohibited. on the other hand,
In a state where the height of the work table 14 is higher than the reference height Ho, if the load load of the work table 14 is equal to or less than the first reference load W1, no regulation is performed, and the work table 14 can be raised and the vehicle can travel. However, when the load on the workbench 14 exceeds the first reference load W1, not only the raising operation of the workbench 14 but also the traveling of the vehicle body is prohibited.

Here, the reference height Ho, the first reference load W1
Each of the values of the second reference load W2 and the second reference load W2 are previously calculated and determined so that the vehicle body 11 does not fall down when the above-described regulation is performed. It is supposed to be. On the other hand, even if the load applied to the worktable 14 is relatively large, the height of the worktable 14 is relatively low. When the load is small, the vehicle can travel, and the traveling of the vehicle is not unnecessarily restricted and the workability is not impaired.

As described above, in the aerial work vehicle 10, the fall and fall of the vehicle body 11 is prevented by appropriately regulating the operation of raising and lowering the work table 14 and running the vehicle body according to the height of the work table 14 and the load applied to the work table 14. At the same time, even when the load applied to the work table 14 is somewhat large (exceeds the first reference load W1 and is equal to or less than the second reference load), the height of the work table 14 is relatively low (the reference height Ho is equal to or less). Even when the height of the work table 14 is relatively high (exceeds the reference height Ho), when the load applied to the work table 14 is small (the first reference load W1 or less), the vehicle body can travel and sufficient work can be performed. Nature can be ensured.

As described above, in the safety device according to the present invention, when the load of the work table 14 is large to some extent, the raising operation of the work table 14 and the vehicle body running are prohibited to prevent the vehicle body 11 from tipping over. And the load of the work table 14 and the work table 1
Since the determination can be performed based on a combination of the two values of the height 4, the travel restriction is not given regardless of the height of the worktable 14 as in the related art, and the workability is not sacrificed. For this reason, safe and efficient work at high places can be performed without impairing the workability while reliably preventing the vehicle body from tipping over.

Although the safety device for the vertical lifting type aerial work vehicle according to the present invention has been described above, the present invention is not limited to the configuration shown in the above embodiment. For example, the height of the worktable 14 is divided into two steps based on the reference height Ho, and the load applied to the worktable 14 is divided into three steps based on the first and second reference loads W1 and W2. However, the number of these categories is not particularly limited. Each of the sections can be divided into multiple sections, and the traveling speed of the vehicle body 11 can be regulated stepwise according to the load applied to the worktable 14 and the height of the worktable 14.

The absolute load of the work table 14 may be determined by, for example, detecting the pressure in the oil passage on the bottom side of the telescopic cylinder 15. Also,
The absolute height of the work table 14 may be determined by detecting the length of the telescopic cylinder 15, for example.

Further, the vertical lifting device for raising and lowering the work table 14 is not limited to the scissor link 13, but is constituted by a vertical support provided on the vehicle body and a lift device which moves up and down in the vertical support. Or the like. Further, the traveling device for traveling the vehicle body 11 does not have to be a crawler device, and may be a tire wheel or the like.

[0035]

As described above, the safety device for a vertical lifting type aerial work vehicle according to the present invention comprises a height detecting means for detecting the height of the workbench and a load for detecting the load applied to the workbench. Detecting means, and raising and lowering of the worktable by the vertical elevating device and traveling of the vehicle body by the traveling device according to the height of the worktable detected by the height detecting means and the load of the worktable detected by the load detecting means. And regulating means for regulating the operation. In the safety device having such a configuration, when the load on the workbench is large to a certain extent, the body is prevented from tipping over by prohibiting the raising operation of the workbench and the vehicle body traveling. Since the operation is performed not only based on the load applied to the work table but also based on the height of the work table, there is no need to restrict the traveling, regardless of the height of the work table, thereby sacrificing the workability. For this reason, safe and efficient work at high places can be performed without impairing the workability while reliably preventing the vehicle body from tipping over.

When the height of the work table is equal to or less than a predetermined height and the applied load exceeds a predetermined first predetermined load, the restricting means operates the vertical lifting device. The lifting operation of the platform is prohibited, and when the height of the platform is equal to or less than the predetermined height and the applied load exceeds a second predetermined load that is larger than the first predetermined load, or the height of the platform is a predetermined height. And the applied load is the first
When the load exceeds a predetermined load, it is preferable to prohibit the lifting operation of the workbench by the vertical lifting device and the traveling operation of the vehicle body by the traveling device. If you do this,
The above effects can be obtained with a simple configuration.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a control system including a safety device according to the present invention.

FIG. 2 is a perspective view showing a vertical lifting type aerial work vehicle equipped with the safety device.

FIG. 3 is a perspective view of an operation box provided with a worktable elevating operation lever and left and right crawler device operation levers.

FIG. 4 is an explanatory diagram showing an off state and an on state of a limit switch constituting the height detector.

FIG. 5 is a chart showing criteria for determination in a regulation determining unit.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Vertical lifting type aerial work platform 11 Body 12 Crawler device (traveling device) 13 Scissors link (vertical lifting device) 14 Work table 15 Telescopic cylinder (vertical lifting device) 16 Height detector (height detecting means) 17a, 17b First and second load detectors (load detecting means) 21 Workbench elevating operation lever (workbench elevating means) 22a, 22b Crawler device operating lever (vehicle body running means) 30 Controller 31 Workbench elevating operation controller (workbench elevating / lowering) Means) 32 Crawler device operation control unit (vehicle body traveling unit) 33 Regulation determination unit (restriction unit) 41 Telescopic cylinder operation valve (workbench elevating unit) 42a, 42b Crawler device operation valve (vehicle body traveling unit)

Claims (2)

[Claims] 1. A vehicle body having a traveling device and capable of traveling, a vertical elevating device provided on the vehicle body, a worktable attached to the vertical elevating device and capable of vertically elevating, operating the traveling device And a workbench elevating means for operating the vertical elevating device to vertically elevate and lower the workbench. Height detection means for detecting the height of the worktable; load detection means for detecting the load applied to the worktable; and detection of the height and the load of the worktable detected by the height detection means. Restricting means for restricting a vertical movement of the work table by the vertical lifting device and a traveling operation of the vehicle body by the traveling device in accordance with the load of the work table detected by the means. Characteristic Vertical lift-type aerial work platforms of the safety device to be. 2. The vertical lifting and lowering device according to claim 1, wherein the height of the worktable is equal to or less than a predetermined height and the load is greater than a first predetermined load. Prohibiting the lifting operation of the worktable by the device, when the height of the worktable is equal to or less than the predetermined height and the applied load exceeds a second predetermined load larger than the first predetermined load, or When the height of the worktable is higher than the predetermined height and the applied load is higher than the first predetermined load, the operation of raising the worktable by the vertical lifting device and the vehicle body by the traveling device The safety device for a vertically aerial work platform according to claim 1, wherein the traveling operation of the vehicle is prohibited.