JP2593332Y2 - 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 an aerial work vehicle equipped with a telescopic boom that can be raised and lowered, and more particularly to a safety device for an aerial work vehicle used for electric work.

[0002]

2. Description of the Related Art A telescopic boom provided on an aerial work vehicle as described above is composed of a base end boom movably mounted on a vehicle body and a base end boom nested into the base end boom. Is done. A work table is attached to the tip of the tip boom, and the operator who gets on the work table can move to an arbitrary height through the raising / lowering operation of the telescopic boom.

[0003] In an aerial work vehicle used for electric work, the distal end boom is formed of an electrically insulating material to electrically insulate the worktable from the base end boom and the vehicle body. Thereby, even when the worker who got on the work table performs hot-line work, an electric shock accident of this worker can be prevented.

[0004]

However, when the working position is relatively low, the telescopic boom may reach the working position by raising it even in the fully contracted state while the telescopic boom is in the fully contracted state. When the hot-line work is performed in such a state, there is a problem that insulation between the work table and the base end boom cannot be secured because the work table and the base end boom are close to each other.

The present invention has been made in view of such circumstances, and provides a safety device for an aerial work vehicle that can ensure insulation between a work table and a vehicle body even when working at a low position. It is intended to be.

[0006]

In order to achieve the above object, a safety device according to the present invention detects that a distal end boom has extended a predetermined amount or more from a full contraction state with respect to a proximal end boom, and detects a detection signal. Extension state detection means for outputting the extension boom when the detection signal from the extension state detection means is not inputted, and the extension boom is controlled when the detection signal from the extension state detection means is inputted. And control means for allowing the user to raise the subject.

[0007]

With such a safety device, when the distal end boom extends for a predetermined amount or more and the workbench is separated from the base end boom to some extent, a detection signal is output from the extended state detecting means. Then, the control means allows the telescopic boom to be raised, that is, the operation, only when the detection signal is input. Therefore, even when the work is performed at a low position, insulation between the work table and the vehicle body can be ensured.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to the drawings. First, FIG. 1 shows an aerial work platform 10 equipped with a safety device according to the present invention. The track-and-rail aerial work vehicle 10 is configured based on a truck running on a road. For this reason, tires 12 are attached to the front, rear, left and right of the vehicle body 11, respectively. At the front of the vehicle body 11, a turntable 13 that can freely turn horizontally with respect to the vehicle body 11 is attached. A telescopic boom 14 is attached to an upper part of the swivel base 13.

The telescopic boom 14 includes a base boom 14 a pivotally attached to the swivel base 13 so as to be able to move up and down, and a base boom 14 a.
a middle boom 14b telescopically inserted into the middle boom 14b, and the tip boom 14 telescopically inserted into the middle boom 14b.
and c are nested. The base boom 14a and the intermediate boom 14b correspond to the "base boom" in the claims. The base end boom 14a and the intermediate boom 14b are formed in a prismatic shape from a steel material (conductive material). On the other hand, the tip boom 14c is formed in a prism shape from fiber reinforced plastic (FRP), that is, an electrically insulating material.

At the tip of the tip boom 14c, a work table 15
Is attached. Further, iron wheels 16 are attached to the front and rear and left and right of the vehicle body 11 (rear of the respective tires 12) so as to extend and retract.

The track-and-rail aerial work vehicle 1 constructed as described above
0 is a railway rail (hereinafter simply referred to as a rail)
The vehicle travels on the road and moves to near the work site located along R. At this time, each iron wheel 16 is pulled up and stored with respect to the vehicle body 11 as shown by a chain line in the figure. On a railroad crossing near the work site, the work vehicle 10 stopped so as to cross the rail R extends the center jack 18 attached to the lower center of the vehicle body 11 downward to lift the vehicle body 11 itself. Then, the vehicle body 11 is turned around the center jack 18 so as to be parallel to the rail R. Here, each iron wheel 16 protrudes downward as shown in the figure. Thereafter, the center jack 18 is reduced, and each iron wheel 16 is placed on the rail R for railway. Thereby, each tire 12 also comes into contact with the rail R. Therefore, by driving the tire 12, the work vehicle 10
You can travel up and arrive at the work site.

After arriving at the work site, an operator (not shown) boarding the work table 15 can raise and lower the boom 14 and extend and retract the turntable 13 to operate the rail rail R.
You can move to any height, such as above. In addition,
Each operation of the swivel 13, the telescopic boom 14, the iron wheel 16, and the like is performed using hydraulic pressure. For example, the raising and lowering operation of the telescopic boom 14 is performed by expanding and contracting a hydraulic raising and lowering cylinder 19 attached between the base end boom 14a and the swivel base 13.

Here, a trolley wire T is stretched above the railway rail R. The trolley wire T is
It is set at a low position corresponding to the height of the pantograph of the train. An operator who has boarded the work table 15 may perform maintenance and inspection work on the trolley wire T in a state where electricity is conducted to the trolley wire T, that is, in a live state. In some cases, work may be performed on overhead lines on roads using the track-and-rail aerial work vehicle 10. In this case, the iron wheel 16
Is stored in the vehicle body 11.

As shown in FIG. 2, the safety device according to the present invention includes a work detector on rail 21, a relay 22 for regulation control, an extension state detector 23, and an elevation controller (control means). 24.

The on-rail work detector 21 comprises a limit switch mounted near the iron wheel 16 on the vehicle body 11, and is turned off when the iron wheel 16 is in the retracted state, and is turned off when the iron wheel 16 is in the extended state. Turn on. A battery B is connected to one terminal of the work detector 21 on the rail.

The regulation control relay 22 includes a relay coil C
R and dual switches 22a and 22b. The relay coil CR is connected to the work detector 2 on the rail.
1 is connected to the other terminal. The upper switch in the figure (hereinafter, referred to as an upper switch 22a) of the dual switches is turned off when the relay coil CR is in a non-excited state, and is turned on when the relay coil CR is in an excited state. On the other hand, a lower switch in the figure (hereinafter, referred to as a lower switch 22b) of the dual-type switch is
It turns on when the relay coil CR is in the non-excited state, and turns off when the relay coil CR is in the excited state. The battery B is connected to one terminal of each of the switches 22a and 22b.

As shown in detail in FIG. 3, the extension state detector 23 comprises a limit switch mounted on the upper surface of the tip of the intermediate boom 14a. A cam 27 that protrudes upward is formed between the top end of the top end boom 14c and a position at a predetermined distance L in the longitudinal direction from the foremost end. The switch arm 23a of the extension state detector 23
Is located below the extension state detector 23, the cam 2
7 is pushed upward by the upper surface. In this state, the extension state detector 23 is turned off. On the other hand, when the cam 27 moves forward below the extended state detector 23, the switch arm 23a is urged downward by a spring built in the extended state detector 23. In this state, the extension state detector 23 is turned on. Note that, as shown in FIG. 2, one terminal of the extension state detector 23 is connected to the other terminal of the upper switch 22a.

The raising controller 24 includes a raising operation switch 25.
And a solenoid 26. The raising operation switch 25 is turned on / off according to the operation of the worker. One terminal of the raising operation switch 25 is connected to the other terminal of the extension state detector 23 and the other terminal of the lower switch 22b. Further, a solenoid 26 connected to the other terminal of the raising operation switch 25 is provided in an electromagnetic control valve (not shown) for controlling the supply of hydraulic oil to the raising and lowering cylinder 19 in order to raise the telescopic boom 14. It is a solenoid. That is, the electromagnetic control valve is switched by the solenoid 26 being energized, thereby supplying hydraulic oil to the up-and-down cylinder 19 and extending it.

Next, the safety device 20 constructed as described above will be described.
The operation of will be described. As described above, when the steel wheel 16 is overhanging and the aerial work vehicle 10 is on the rail R, the on-rail work detector 21 is turned on, and the battery B
Is supplied to the relay coil CR of the regulation control relay 22 to excite it. Therefore, the upper switch 22a of the relay 22 is turned on. At this time, if the extension amount of the distal boom 14c from the fully contracted state with respect to the intermediate boom 14b is less than the predetermined amount L, the cam 2
Since 7 pushes up the switch arm 23a of the extension state detector 23, the extension state detector 23 is turned off. Therefore, even if the up / down operation switch 25 is turned on in this state, power from the battery B is not supplied to the solenoid 26, and the raising operation of the telescopic boom 14 is restricted.

On the other hand, the middle boom 14 of the tip boom 14c
If the extension amount from the fully contracted state for b is equal to or more than the predetermined amount L, the cam 27 is detached from the switch arm 23a of the extended state detector 23, and the extended state detector 23 is turned on. Therefore, if the up / down operation switch 25 is turned on in this state, the electric power from the battery B is supplied to the solenoid 2
6, the telescopic boom 14 can be raised.

As described above, the elevating operation of the telescopic boom 14 is performed only in a state where the distal boom 14c extends a predetermined amount L or more with respect to the intermediate boom 14b and the work table 15 is sufficiently separated from the intermediate boom 14b and the proximal end boom 14a. By permitting, the work table 15
Electrical insulation between the vehicle and the vehicle body 11 (rail R) can be ensured. Therefore, the electric shock accident of the worker who boarded the work table 15 can be reliably prevented.

When performing high-altitude work on a road with the aerial work vehicle 10 in a state where the iron wheels 16 are stored, the on-rail work detector 21 is turned off and the regulation control relay 22 is turned off.
Is not excited. For this reason,
When the lower switch 22b of the relay 22 is turned on and the up / down operation switch 25 is turned on, power from the battery B is supplied to the solenoid 26, and the telescopic boom 14 can be raised.

[0023]

As described above, according to the safety device of the present invention, the distal end boom is extended in advance by a predetermined amount or more with respect to the base end boom to secure the electrical insulation state between the work table and the base end boom. Otherwise, the telescopic boom cannot be raised. Therefore, if the safety device is used, even when performing work at a high position in a low position where the workbench can be reached only by the raising operation without extending the telescopic boom, the electrical insulation is performed as described above. By ensuring the state, it is possible to reliably prevent the electric shock of the worker who is on the work table.

[Brief description of the drawings]

FIG. 1 is a side view of an aerial work vehicle equipped with a safety device according to the present invention.

FIG. 2 is an electric circuit diagram of the safety device.

FIG. 3 is an enlarged view of a telescopic boom of the aerial work vehicle.

[Description of Signs] 10 Rail-based aerial work platform 14 Telescopic boom 14a Base end boom 14b Intermediate boom 14c Tip boom 15 Workbench 20 Safety device 21 Rail work state detector 22 Regulatory control relay 23 Extension state detector 24 Suspension controller (control means) T Trolley wire R rail

Claims (1)

(57) [Scope of request for utility model registration] 1. A telescopic boom, comprising: a base end boom movably mounted on a vehicle body; and a distal end boom nested into the base end boom. With a work table at the tip,
The tip boom is a safety device for an aerial work platform formed of an electrically insulating material, and detects that the tip boom has extended a predetermined amount or more from a fully contracted state with respect to the base boom. Extension state detection means for outputting a signal, when the detection signal from the extension state detection means is not input, restricts the elevating operation of the telescopic boom, and when the detection signal from the extension state detection means is input. And a control means for allowing the telescopic boom to be raised.