JP3068531B2 - 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 in which an operator on a worktable movable to a desired position performs an aerial work.

[0002]

2. Description of the Related Art An aerial work vehicle is provided with a work table on a vehicle body via a moving device (such as a boom device or a scissor device). The moving device is operated to move the work table to a desired position. In addition, a worker at the work table can perform work at a high place. When performing an aerial work using such an aerial work vehicle, the worker moors his / her body to a workbench using a body holding device called a so-called safety belt. This safety belt is composed of a belt wound around the body of the worker, and a safety rope having one end connected to the belt and a hook provided at the other end. By being locked by a lock provided on the work table, even if the work table falls down, it does not fall to the ground.

[0003] In the safety belt having such a configuration, if an operator forgets to hook the hook on the latch, the original purpose of the safety belt cannot be achieved. Therefore, real fairness 7-201
As disclosed in Japanese Unexamined Patent Publication No. 59-59, a lock detecting means for detecting a locked state of a hook is provided near a lock provided on a work table, and the locked state of the hook is detected by the lock detecting means. Means have been proposed in which the movement of the workbench is restricted when is not detected, or a warning is issued to the worker.

[0004]

However, during work at high altitudes, if the worker cannot work for some reason with the hook of the safety belt detached from the latch, or the latch is detected. If the locking means cannot be detected even when the hook is locked due to the failure of the means, there is a possibility that the work table cannot be moved at all by the movement restricting function. In addition, due to this regulation, it was not possible to try to move the moving device without having the operator board the work table as a start-up inspection, which was inconvenient.

[0005] The present invention has been made in view of such a problem, and an operator who has boarded a work platform of an aerial work platform does not lock the hook of the safety belt with the lock fitting on the work table side. It is an object of the present invention to provide a safety device for an aerial work vehicle configured to prevent movement of a work table by preventing movement of the work table by restricting movement of the work table in a state, and to prevent the work table from being displaced by the restriction. And

[0006]

In order to achieve the above object, a safety device for an aerial work vehicle according to the present invention has a work table disposed on a vehicle body via a moving device, and operates the moving device. The work platform is moved to a desired position, and a worker at the work platform carries out work at a height. Input means for inputting an operation of the moving device, which is disposed on the vehicle body, a first locking member attached to a worker who is on the work table, and a first attachment means attached to the work table. Lock detecting means for detecting whether or not the second locking tool is locked, and the locking detecting means detecting a locking state between the first locking tool and the second locking tool. In this case, the mobile device is activated by selectively receiving inputs from the first input means and the second input means, and the lock detection is performed. When the means detects the unlocked state of the first locking tool and the second locking tool, the operation of the moving device is restricted in response to the input from the first input means, but the operation of the second input means is restricted. And control means for controlling the operation of the moving device in response to the input.

Here, the control means is driven via the control means by an input from the first input means and controls the supply of hydraulic pressure to the moving device to control the operation of the moving device; A second control valve driven by the control means in response to input from the two-input means to control supply of hydraulic pressure to the moving device to control the operation of the moving device; and a hydraulic pressure driven by the control means to the first control valve. And a restricting valve for interrupting the supply of the liquid, when the lock detecting means detects the non-locked state of the first locking tool and the second locking tool and the input from the first input means is performed. Alternatively, control may be performed to control the operation of the moving device by the first input means by driving the regulating valve to cut off the supply of the hydraulic pressure to the first control valve.

Alternatively, the control means comprises a first input means and a second input means.
A control valve that is driven through the control means by an input from any of the input means and controls supply of hydraulic pressure to the moving device to control the operation of the moving device; and A restriction valve for interrupting the supply, wherein the lock detecting means detects a non-locked state between the first lock and the second lock and when an input is made from the first input means,
The control of restricting the operation of the moving device by the first input means may be performed by driving the control valve to cut off the supply of the hydraulic pressure to the control valve.

[0009] Further, an alarm means is provided, and the control means detects the non-locked state of the first locking tool and the second locking tool by the locking detection means, and inputs from the first input means. When
It is desirable to perform control for issuing an alarm using an alarm unit.

Accordingly, when the lock detecting means detects the non-locked state between the first locking tool and the second locking tool, the operation of the moving device by the first input means is restricted. Since the work table cannot be moved, it is possible to alert the worker to forget to lock the locking tool, and it is possible to prevent the worker from falling off the work table.
Here, in the case where the alarm means is provided, it is possible to call attention audibly or visually. Further, since the above-mentioned regulation does not affect the movement of the worktable by the second input means, it is possible to prevent the movement of the worktable from being disabled at all by the restriction.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a preferred embodiment of the present invention will be described with reference to the drawings. First, an aerial work vehicle equipped with the safety device according to the present invention will be described with reference to FIG. The aerial work vehicle 10 includes a movable body 11.
A swivel 12 is provided on the upper side, and a boom 13 is disposed on the swivel 12. The swivel 12 is the swivel 12
The swing operation is performed by a swing motor provided at a lower portion, and the boom 13 is configured to be nested by a plurality of boom members.
The telescopic cylinder is configured to be telescopic by the telescopic operation. The boom 13 is arranged so as to be able to move up and down with respect to the vehicle body 11 by an expansion and contraction operation of an up / down cylinder provided at the base end of the boom 13. A vertical post 14 is provided at the end of the boom 13 so as to always maintain a vertical position, and a work table 15 is disposed on the vertical post 14 so as to be horizontally pivotable.

According to the aerial work vehicle 10 constructed as described above, the extension and retraction operation of the boom 13, the up-and-down operation and the swivel base 12 are performed.
The work table 15 can be moved to a desired height by performing the turning operation of (the boom 13 and the swivel table 12 correspond to the moving device in the scope of the claims). The control of the expansion / contraction / raising / lowering operation of the boom 13 and the turning operation of the swivel table 12 are provided on the upper operating device 42 (corresponding to first input means in the claims) provided on the work table 15 or on the vehicle body 11. The operation is performed by an operation input operation from the lower operation device 43 (corresponding to the second input means in the claims).

As shown in FIG. 3, the work table 15 is made of an insulating material such as FRP or the like so that a worker M can be mounted thereon, and the work table body 15a and the vertical post 1
4 and a bracket cover 15c that covers the outer periphery of the work table bracket 15b. An upper operation device 42 for inputting the operation of the boom 13 is provided on the upper part of the work table 15, and a hook lock 22 (corresponding to a second lock in the claims) is provided on the work table bracket 15b. ) Is attached.

The safety belt 25 (corresponding to the first stopper in the claims) is a belt 2 wound around the body of the worker M.
6 and a rope 26a having one end connected to the belt 26 and the other end to which the hook 21 is attached. The rope 26a is formed of an insulating material and insulates electric conduction from the worktable 15 side. The worker M who performs the work at a high place has the body moored to the work table 15 by hooking the hook 21 at the end of the rope 26 a to the hook hook 22.

As shown in FIG. 4, the base of the hook locking member 22 is fixed to the work table bracket 15b, and a hook locking hole 22a in which the hook 21 can be locked (inserted) is formed at the end. Have been. Further, the hook lock 22 has a hook detection swingable around the hinge 24a between a non-detection position covering a part of the hook lock hole 22a and a detection position for opening the hook lock hole 22a. Working piece 24
A hook lock detector 23 (corresponding to a lock detecting means in the claims) for detecting a lock state of the hook 21 is provided on a side portion of the hook lock hole 22a. I have.

The hook lock detector 23 is a so-called limit switch. The hook 21 is locked in the hook lock hole 22a, and the hook detection operating piece 24 rotates in the R direction to push the arm 23a upward. It is turned on only when. Since the hook detecting operation piece 24 is constantly urged by the spring 27 in the non-detection position direction (the direction opposite to R), when the hook 21 is not locked by the hook locking metal fitting 22, the hook locking detection is performed. The container 23 is off.

Next, the configuration and operation of the safety device of the present invention will be described.
This will be described with reference to FIGS. FIG. 1 is a hydraulic circuit diagram, and FIG. 5 is a block diagram showing a signal path. As will be described in detail later, the controller 41 that has received input signals from the upper operating device 42, the lower operating device 43, and the hook engagement detector 23, controls the first control valve 38, the second control valve 36, and the regulating valve 3
A plurality of operating cylinders 17 (e.g., the above-mentioned up-and-down cylinder, telescopic cylinder, and swivel motor) for electromagnetically driving the hydraulic circuit 7 to control the hydraulic circuit so as to raise and lower the boom 13, extend and retract, and rotate the swivel table 12. ), The boom 13 and the swivel base 12 are operated. Here, the first control valve 38 is disposed on the work table 15 side, and the second control valve 36 is disposed on the vehicle body 11 side (near the swivel table 12). The hydraulic circuit including the controller 41 and each valve corresponds to the control means in the claims.

The hydraulic pump 31 sucks hydraulic oil from an oil tank 32 through a strainer 33 and supplies hydraulic pressure to a solenoid type main switching valve 34 through an oil passage 51. The main switching valve 34 unloads the hydraulic pressure from the hydraulic pump 31 at the neutral position 34a to release the oil from the oil passage 52 to the oil tank 32, but supplies the oil pressure from the oil passage 53 to the jack switching valve 35 at the switching position 34b. However, at the switching position 34c, the oil passage 5
4 to the second control valve 36. Also, the hydraulic pump 31
A relief valve 39 is provided in order to prevent the oil pressure discharged from the oil passage 51 to the oil passage 51 from exceeding a specified value.

The jack switching valve 35, which is a manual type directional control valve, unloads the hydraulic pressure supplied from the oil passage 53 and releases it from the oil passage 55 to the oil tank 32 at the neutral position 35a. Or switching position 35
By switching to "b", hydraulic pressure is supplied to the jack 16 to cause it to expand and contract. The jack switching valve 35
Although there are actually a plurality of jacks and jacks 16, only one representative is shown in FIG. Note that the jack switching valve 35 may be operated by an electromagnetic method as a solenoid type directional control valve.

The oil pressure in the oil passage 54 branches to an oil passage 54a and an oil passage 54b on the way, and the oil pressure is supplied to a second solenoid-operated directional control valve.
It is supplied to the control valve 36. The second control valve 36 is in the neutral position 3
6a, the oil pressure supplied from the oil passage 54a is
7, but the oil pressure in the oil passage 54b is blocked. In the switching position 36b or the switching position 36c, the oil passage 54
The hydraulic pressure supplied from a is blocked, and the hydraulic pressure in the oil passage 54b is supplied to the oil passage 58 or the oil passage 59 to operate the working cylinder 17.

The oil pressure in the oil passage 57 branches midway into an oil passage 57c and an oil passage 57d, and the oil pressure in the oil passage 57c is further increased by an oil passage 57a.
The oil is branched into an oil passage 57b and supplied to a first control valve 38 which is a solenoid type directional control valve. In the neutral position 38a, the first control valve 38 allows the oil pressure supplied from the oil passage 57a to escape from the oil passage 60 to the oil tank 32, but blocks the oil pressure supplied from the oil passage 57b. At the switching position 38b or the switching position 38c, the hydraulic pressure supplied from the oil passage 57a is blocked, and the hydraulic pressure of the oil passage 57b is supplied to the oil passage 61 or the oil passage 62 to operate the operation cylinder 17. In addition,
Second control valve 36, first control valve 38 and working cylinder 17
Are present in plurals, but only one is shown as a representative in FIG.

The oil pressure in the oil passage 57d is supplied to a regulating valve 37 which is a solenoid type shutoff valve. At the normal position 37a of the regulating valve 37, the oil pressure supplied from the oil passage 57d is blocked, and the oil pressure of the oil passage 57 becomes the first oil pressure via the oil passage 57c.
The oil pressure in the oil passage 57 is supplied to the first control valve 38 by releasing the oil pressure supplied from the oil passage 57 d to the oil tank 32 through the oil passage 56 at the switching position 37 b. Not to be.

As described above, the operating cylinder 17 can be operated by supplying the hydraulic pressure controlled by the first control valve 38 or the second control valve 36, and switches these control valves to switch the supply oil passage. Thereby, the operating direction can be changed. Here, when the regulating valve 37 is at the normal position 37a, the operation of the working cylinder 17 is controlled from the first control valve side (the first control valve 3).
8) or the operation is controlled from the second control valve side (whether to operate with the hydraulic pressure using the second control valve 36). That is, when the operation of the operating cylinder 17 is controlled from the second control valve 36 side, the second control valve 36 may be switched to the switching position 36b or 36c.
Since no hydraulic pressure is supplied to the control valve 38, the first control valve 3
The operation of the operation cylinder 17 cannot be controlled from the side 8.

On the other hand, when the operation of the working cylinder 17 is controlled from the first control valve 38 side, the second control valve 36 is positioned at the neutral position 36a and the regulating valve 37 is moved to the normal position 3.
7a, the hydraulic pressure is supplied to the first control valve 38, and then the first control valve 38 may be switched to the switching position 38b or 38c. However, even when the second control valve 36 is in the neutral position 36a, the regulating valve 37 is in the switching position 37.
b, the oil pressure of the oil passage 57 is moved from the oil passage 57d to the regulating valve 37.
The operation of the operation cylinder 17 cannot be controlled from the first control valve 38 side because the oil is released to the oil tank 32 via the oil passage 56 and the oil passage 56.

The main switching valve 34, the first control valve 38, the second
The solenoids of the control valve 36 and the regulating valve 37 are electromagnetically controlled by input signals from the upper operating device 42, the lower operating device 43, and the hook engagement detector 23 transmitted via a controller 41 mounted in the vehicle body 11. Driven. Basically, the first control valve 38 is driven by an input signal from the upper operation device 42, and the second control valve 36 is driven by an input signal from the lower operation device 43.

When the first control valve 38 is driven by an input operation from the upper operation device 42 to control the operation of the operating cylinder 17 from the first control valve 38 side, the second control valve 36 is moved to the neutral position 36a. There is a need to. That is, the lower operation device 43 must be in a non-operation state. here,
In a state where the hook 21 of the safety belt 25 is locked in the hook locking hole 22a of the hook locking bracket 22 and the locking detector 23 is on (detecting the hook locking state), the upper operation device 42 is operated. Even if the input signal is sent to the controller 41, the regulating valve 37 remains at the normal position 37a, the hydraulic pressure is supplied to the first control valve 38, and the operation of the operating cylinder 17 can be controlled from the first control valve 38 side. It is. That is, when the hook 21 is in the locked state, the operation of the boom 13 from the upper operation device 42 is possible.

On the other hand, in a state where the hook 21 of the safety belt 25 is not locked in the hook locking hole 22a and the hook locking detector 23 is off (detecting the hook non-locked state), the upper operating device 42 is operated. When the input signal is sent to the controller 41, the solenoid of the regulating valve 37 is energized by the controller 41, and the regulating valve 37 is moved to the normal position 37.
a is switched to the switching position 37b. As a result, no hydraulic pressure is supplied to the first control valve 38,
The operation control of the operation cylinder 17 from the control valve 38 side is regulated. That is, when the hook 21 is in the unlocked state, the operation of the boom 13 from the upper operation device 42 cannot be performed.

As described above, even if the worker M is on the work table 15 and the hook 21 is forgotten to be locked in the hook locking hole 22a, even if the operator M performs an input operation from the upper operating device 42. Since the boom 13 cannot be operated, forgetting to lock the hook 21 can be called out, and the danger of falling can be prevented. Further, along with the regulation of the operation of the boom 13, an alarm may be issued from the alarm device 18 (corresponding to the alarm means in the claims) mounted on the vehicle body 11 via the controller 41. The alarm 18 may emit an alarm sound by a speaker or the like, or may emit an alarm by color or text on a panel or the like. As a result, it is possible to audibly or visually call attention to forgetting to lock the hook 21, and the safety is further improved.

Even if the operation of the boom 13 by the upper operating device 42 is regulated by the operation of the regulating valve 37 as described above, since the hydraulic pressure is supplied to the second control valve 36, the lower operating device 43 It is possible to drive the second control valve 36 to control the operation of the working cylinder 17. That is, the operation of the boom 13 by the lower operation device 43 is always possible regardless of whether the hook 21 is locked or unlocked. When the operation cylinder 17 is operated from the second control valve 36 side,
Since the second control valve 36 blocks the hydraulic pressure supply to the first control valve 38, the operation of the boom 13 by the lower operation device 43 has priority over the operation by the upper operation device 42.

As described above, the hook 21 is connected to the hook locking hole 2.
In the state where the boom 13 is not locked to 2a, only the operation of the boom 13 by the upper operation device 42 is restricted, and the operation of the boom 13 by the lower operation device 43 is not affected. For this reason, during the work at high places, the worker M locks the hook 21 of the safety belt with the locking fitting 2.
If the work becomes impossible for some reason with the hook 2 removed, or the hook lock detector 23 breaks down and the lock state is detected even if the hook 21 is locked in the hook lock hole 22a. Upper operation device 4
The boom 13 can be operated by the lower operation device 43 even when the operation of the boom 13 by the second control device 2 is being restricted, and it is possible to prevent the movement of the worktable from being disabled at all. In addition, it is possible to move the moving device without carrying an operator on the worktable (performed at the time of starting inspection).

In the above embodiment, when there is an input operation from the upper operation device 42 in the state where the hook 21 is not locked, the main switching valve 34 is switched to the neutral position 34a via the controller 41 and the hydraulic pump 31 The hydraulic pressure may be unloaded. Or the controller 41
However, the input signal from the upper operation device 42 may not be received when the hook 21 is in the unlocked state, or the solenoid of the first control valve 38 may not be energized even if the input signal is received. Alternatively, the power supply of the upper operation device 42 may be different from the main power supply, and the power supply of the upper operation device 42 may be started only when the hook engagement detector 23 is on. A similar effect can be obtained by any of these methods.

Unlike the above embodiment, a control valve 72 for controlling the operation of the boom 13 is provided only on the vehicle body 11 side, and the control valve 72 is driven by an input from either the upper operating device 42 or the lower operating device 43. By making it possible,
If the boom 13 can be operated from either the upper operating device 42 or the lower operating device 43, the switching valve 71 is normally in the normal position 71a and the hydraulic pressure is supplied to the control valve 72 as shown in FIG. However, when the hook 21 is not locked and there is an input from the upper operation device 42, the hook 21 is driven by the controller 41 to be located at the switching position 71b, and the hydraulic pressure is released to the oil tank 32 to release the hydraulic pressure. Is not supplied to the control valve 72. Alternatively, the controller 41 does not receive an input from the upper operation device 42 when the hook 21 is in the unlocked state, or does not drive the control valve 72 even if the input is received.
Thereby, the same effect as described above can be obtained.

In the above embodiment, a case where a boom type elevating means is used as the elevating means of the work table 15 has been described. However, the present invention is not limited to this.
A lifting device of another configuration such as a scissor type lifting device or a lifting and lowering device using a bending and stretching arm may be used.

[0034]

As described above, according to the safety device for an aerial work vehicle according to the present invention, the lock detecting means includes the first lock and the second lock.
When an input is made by the first input means while detecting a non-locked state with the locking tool, the control means drives the regulating valve so that hydraulic pressure is not supplied to the first control valve. In addition, the moving device cannot be operated by the first input means. Thereby, it is possible to alert the worker to forget to lock the locking tool, and it is possible to prevent the worker from falling off the worktable.

On the other hand, even if the unlocked state is detected, the supply of the hydraulic pressure to the second control valve is not restricted, and the operation of the moving device from the second input means is always possible. During high-altitude work, if the worker becomes unable to work for some reason with the locking device unlocked, or the locking detection means breaks down, the locked state of the locking device can be detected. It is possible to prevent the operation of the moving device from being disabled at all, for example, when the moving device runs out. In addition, it is possible to move the moving device without the operator boarding the work table.

A control valve for controlling the operation of the boom 13 is provided only on the vehicle body side, and this control valve is connected to the first input means and the second input means.
If the lock detecting means detects a non-locked state between the first locking tool and the second locking tool, the first input means can be driven by any of the input means. Therefore, when the input is performed, the control means drives the regulating valve so that the hydraulic pressure is not supplied to the control valve, so that the same effect can be obtained. Alternatively, the same effect can be obtained even if the control means does not receive the input from the first input means when detecting the unlocked state, or does not drive the control valve even if it receives the input.

[0037] Further, an alarm means is provided, and the locking detecting means is provided with a first detecting means.
If an input is made by the first input means while detecting a non-locked state between the locking tool and the second locking tool, the control means may issue an alarm by the alarm means, It is possible to audibly or visually alert the user to forget to lock the locking tool, thereby further improving safety.

[Brief description of the drawings]

FIG. 1 is a hydraulic circuit of a safety device according to the present invention.

FIG. 2 is a side view of an aerial work vehicle equipped with the safety device of the present invention.

FIG. 3 is a view showing a state in which a hook of a safety belt is attached to a hook locking metal fitting on a workbench side.

FIG. 4 is a diagram showing details of a configuration of a hook engagement detector on a hook engagement fitting.

FIG. 5 is a block diagram showing a signal path of the safety device of the present invention.

FIG. 6 is a hydraulic circuit of the safety device of the present invention.

[Explanation of symbols]

 Reference Signs List 15 work table 21 hook 22 hook lock fitting 23 hook lock detector 36 second control valve 37 regulating valve 38 first control valve 41 controller 42 upper operating device 43 lower operating device

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A 6-83698 (JP, U) JP-A 5-61198 (JP, U) JP-A 62-11899 (JP, U) JP-A 3- 82400 (JP, U) Japanese Utility Model 5-77198 (JP, U) Japanese Utility Model 7-23796 (JP, U) Japanese Utility Model 4-77600 (JP, U) Japanese Utility Model 6-16394 (JP, U) Jpn. 7-20159 (JP, Y2) European Patent Application Publication 118218 (EP, A1) (58) Fields investigated (Int. Cl. ⁷ , DB name) B66F 9/24 B66F 9/22

Claims (4)

(57) [Claims] A work table is provided on a vehicle body via a moving device, and the moving device is operated to move the work table to a desired position. A safety device for an aerial work vehicle, the first input means being arranged on the workbench and inputting an operation of the moving device; and an operating input of the moving device arranged on the vehicle body. A second input means for performing the following, and a first input means attached to the worker on the work table
Locking detecting means for detecting whether a locking tool and a second locking tool attached to the worktable are locked, and wherein the locking detecting means includes the first locking tool and the second locking tool. (2) When detecting the locked state with the locking member , the input from the first input means and the second input means is selectively received to operate the moving device, and the locking detection means First
A non-locked state between the locking tool and the second locking tool is detected .
Sometimes, the input from the first input means is
The operation of the moving device is restricted, but the input from the second input means is restricted.
A safety device for an aerial work vehicle, comprising control means for receiving a force and performing control for operating the moving device. 2. The first control, wherein the control means is driven via the control means by an input from the first input means and controls supply of hydraulic pressure to the moving device to control operation of the moving device. A valve, a second control valve that is driven through the control unit by an input from the second input unit and controls supply of hydraulic pressure to the moving unit to control operation of the moving unit; A restriction valve that is driven to interrupt the supply of hydraulic pressure to the first control valve, wherein the locking detection means detects a non-locked state between the first locking tool and the second locking tool. In addition, when the input from the first input means is performed, the operation of the moving device by the first input means is regulated by driving the regulating valve to cut off the supply of the hydraulic pressure to the first control valve. The high place according to claim 1, wherein the control is performed. Work car safety devices. 3. The control means, which is driven via the control means by an input from one of the first input means and the second input means, controls supply of hydraulic pressure to the moving device, and A control valve for controlling the operation of the moving device; and a regulating valve driven by the control means for interrupting the supply of the hydraulic pressure to the control valve, wherein the locking detection means includes the first locking member and the second locking member. (2) When the unlocked state with the locking member is detected and the input from the first input means is performed, the control valve is driven to shut off the supply of the hydraulic pressure to the control valve to thereby stop the second operation. 2. The safety device for aerial work vehicles according to claim 1, wherein control for restricting operation of the moving device by one input means is performed. 4. An alarming means, wherein said control means detects said lock detecting means in a non-locked state between said first locking tool and said second locking tool and outputs a signal from said first input means. The safety device for aerial work vehicles according to any one of claims 1 to 3, wherein a control for issuing an alarm using the alarm unit is performed when the input of (1) is performed.