JPH07252097A - Safety device of high lift work vehicle - Google Patents

Abstract

PURPOSE:To secure a safety device of a high lift work vehicle capable of preventing any damage to a workbench from occurring. CONSTITUTION:A load detecting means 21 detecting such a load as acting on a direction of uplifting a workbench 15, is installed in an interval between this workbench 15 and a workbench holding member 14. In succession, the detected load of the workbench 15 detected by a load detecting means is compared with the preset load by a controller, and also this safety device is provided with a warning means which outputs a warning signal when the detected load has exceeded the setting load, and after receiving this warning signal, performing a warning operation. With this constitution, in the case where the workbench 15 inerferes with an obstacle when the workbench 15 is lowered, the warning signal is transmitted out of the controller at a time when the detected load has exceeded the allowable load, and further the warning is carried out by an alarm buzzer and a lowering operation of the workbench 15 is stopped and thus the warning is carried out by the warning means.

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 particularly to a safety device for protecting a workbench of a vertically elevated work vehicle.

[0002]

2. Description of the Related Art For example, as an aerial work vehicle capable of moving a worker, luggage and the like to a desired height, a workbench is mounted on a vehicle body via a scissor link, and the scissor link is attached by a telescopic cylinder. There is a vertically elevating aerial work vehicle configured to be operated to raise and lower a workbench. In such an aerial work vehicle, the vehicle body is moved to a position below a desired work position to raise the workbench, and the vehicle is moved while the workbench is raised so that work can be performed at a high position. The position can also be moved. After the work is completed, the worktable is lowered by retracting the telescopic cylinder and stored on the vehicle body.

[0003]

When the vehicle body is run while the workbench is raised, an obstacle such as a beam may be located below the workbench. in this case,
If the worker lowers the work table without noticing the obstacle, the work table and the obstacle come into contact with each other, and if the work is further lowered, the work table and the like are damaged.

The present invention has been made in view of these problems, and an object thereof is to provide a safety device for an aerial work vehicle capable of preventing damage to a workbench.

[0005]

In order to achieve the above-mentioned object, in the safety device for an aerial work vehicle of the present invention, a workbench holding member provided so as to be vertically movable with respect to the vehicle body. A workbench is attached, and between the workbench and the workbench holding member, load detection means for detecting a load acting in a direction of pushing up the workbench is arranged. The controller detects the work load detected by the load detection means by the preset load, and outputs a warning signal when the detected load exceeds the preset load. It is also configured to have an alarm means for receiving the alarm and performing an alarm operation.

According to the safety device for an aerial work vehicle thus constructed, when the work table and the obstacle interfere with each other when the work table is lowered, a load acts in the direction of pushing up the work table, The load is detected by the load detecting means. The detected load detected by the load detection means is compared with the allowable load preset by the controller, and when the detected load exceeds the allowable load, an alarm signal is transmitted from the controller. This alarm signal is input to the alarm means. Then, the alarm means issues an alarm with an alarm buzzer or an alarm lamp, or stops the descending operation to issue an alarm.

In order to achieve the above object, an aerial work vehicle having substantially the same structure as the aerial work vehicle having the safety device for an aerial work vehicle configured as described above is used. A load detecting means for detecting a load acting in the lateral direction of the work table may be arranged between the table holding member and the table holding member. According to the safety device for an aerial work vehicle configured in this manner, when the workbench and the obstacle interfere with each other when the aerial work vehicle travels, a load acts in the lateral direction of the workbench, and The load is detected by the load detecting means. The detected load detected by the load detection means is compared with an allowable load preset by the controller, and when the detected load exceeds the allowable load, an alarm signal is transmitted from the controller,
The same warning as above is given, or the traveling of the vehicle body is stopped.

Further, in each aerial work vehicle constructed as described above, the load detecting means may be constructed so that the load acting in the direction of pushing down the workbench can be detected. As a result, the load is detected by the load detecting means when the load on the workbench is increased and when the workbench upper surface interferes with an obstacle when the workbench is raised. The detected load detected by the load detection means is compared with the allowable load preset by the controller, and when the detected load exceeds the allowable load, an alarm signal is transmitted from the controller to issue an alarm similar to the above, Stop raising the workbench.

In each of the aerial work vehicles constructed as described above, when the alarm signal is transmitted from the controller, the lifting and lowering operation of the workbench is stopped by the lifting device operation restricting means. You may. Thus, when the alarm signal is transmitted from the controller, the operation of the lifting device can be restricted in addition to the alarm buzzer by the alarm means and the alarm operation by the alarm lamp.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention will be described below with reference to the drawings. First, a crawler type aerial work vehicle provided with a safety device for an aerial work vehicle according to the present invention will be described with reference to FIG. This aerial work vehicle 10 includes a vehicle body 1
The crawler type traveling device 12 is provided on the left and right sides of the vehicle 1, and the traveling device 12 is configured to travel freely. A scissor link 13 is mounted on the vehicle body 11, and a workbench holding member 14 is mounted on the upper end of the scissor link 13. A workbench 15 is arranged on the workbench holding member 14 via a load cell (load detection means) 21. The scissor link 13 is adapted to be vertically expanded and contracted by an elevating cylinder 17, and the workbench 15 is vertically moved in accordance with the expansion and contraction of the elevating cylinder 17.

The workbench 15 is provided with a handrail 16 for protecting a worker who is on the workbench 15. An operating device 18 is attached to the handrail 16,
An operator who has boarded the workbench 15 performs a lifting / lowering control operation of the workbench 15 (extending and retracting operation of the telescopic cylinder 17) and the traveling device 12.
Carry out the traveling control operation. An operation signal from the operation device 18 is transmitted to the controller 30 as shown in FIG. 3, and drive control of the telescopic cylinder 17 and the traveling device 12 is performed via an alarm means 31 whose details will be described later.

In the aerial work vehicle constructed as described above, a certain limit is imposed on the load that can be loaded on the workbench 15 in order to ensure stability during traveling and safety of the scissors link 13 and the like. It is provided, and the limited load is set as a predetermined load. This load is detected by the load cell 21 provided between the workbench holding member 14 and the workbench 15. The detected load is compared with the predetermined load by the controller 30, and when the detected load exceeds the predetermined load, the controller 30 sends an alarm signal to the alarm means 31. The alarm means 31 that has received the alarm signal operates the operating device 1 to ensure safety.
Regardless of the operation signal from 8, the operation of the traveling device 12 and the telescopic cylinder 17 is stopped, and an operation signal is sent to the alarm buzzer 32 to sound an alarm.

The load cell 21 is mounted on the workbench 1 as described above.
The load of 5 (the load acting in the direction of pushing down the workbench 15) can be detected, and the load acting in the direction of pushing up the workbench 15 can be detected. Here, when the vehicle body 11 is run when the workbench 15 is raised, an obstacle such as the beam 51 may be located below the workbench 15 against the intention of the operator.
In this case, if the workbench 15 is lowered in the direction of the arrow as it is, the lower surface 15a of the workbench 15 and the beam 51 come into contact with each other. Then, when the workbench 15 is further lowered, a load acts in the direction of pushing up the workbench 15 from below by the reaction force from the beam 51.

The load cell 21 detects the load acting in the direction of pushing up the workbench 15, and the detected push-up load is
The controller 30 compares the detected push-up load with the predetermined push-up load, and when the detected push-up load exceeds the predetermined push-up load, the controller 30 sends an alarm signal to the alarm means 31. And
In the same manner as described above, the alarm unit 31 stops the contraction operation of the telescopic cylinder 17 and sounds the alarm buzzer 32 to alert the operator and prevent the workbench 15 and the beam 51 from being damaged. Here, the predetermined push-up load is the workbench 15 when nothing is loaded on the workbench 15.
It may be set to the same load as the load. However, in order to further improve safety, the controller 30 stores the detected load (loading load or push-up load) of the load cell 21 when the lowering operation of the workbench 15 is started, and when the detected load changes (loading load). The controller 30 may send an alarm signal to the alarm means 31 when the load decreases or the push-up load increases).

Furthermore, the direction of the load that can be detected by the load cell 21 is not limited to the direction of pushing up or pushing down,
The load acting in the lateral direction of the workbench 15 may be configured to be detectable. According to the aerial work vehicle 10 configured in this way, as shown in FIG. 2, the load cell 21 further moves the vehicle body 11 in the arrow direction even though the front surface 15b of the work table 15 is in contact with the beam 51. The load acting in the lateral direction of the workbench 15 when the vehicle is driven to the position is detected. Here, during normal work, a lateral load does not act on the workbench 15. Therefore, when the load cell 21 detects a lateral load, the controller 30 sends an alarm signal to the alarm means 31 to prevent damage to the workbench 15 or the like.

In the above embodiment, the safety device according to the present invention is used in the vertical lifting type work vehicle using the scissors link 13, but the present invention is not limited to this. Instead, it can be used in an aerial work vehicle that uses an elevating device composed of a plurality of telescopic posts.

In the above embodiment, the alarm means 3 is used.
Although the alarm buzzer 32 is sounded by the operation signal from 1, the operator may be alerted by turning on the display lamp. In the above embodiment, the operation of the telescopic cylinder 17 is stopped by the alarm means 31 that has received the alarm signal from the controller 30, but a lifting device operation restriction means is additionally provided and the alarm signal from the controller 30 is provided. The operation of the telescopic cylinder 17 may be stopped when is transmitted to the lifting device operation restriction means. This allows
It is possible to stop the operation of the telescopic cylinder 17 when the ascending / descending operation is performed even though the alarm sound is given.

[0018]

As described above, in the safety device for an aerial work vehicle of the present invention, the load detecting means for detecting the load acting in the direction of pushing up the workbench is arranged between the workbench and the workbench holding member. I have set up. Then, the controller detects the work load detected by the load detection means by the controller and compares it with a preset load, and outputs a warning signal when the detected load exceeds the preset load. It also has an alarm means for performing an alarm operation.

Thus, when the workbench and the obstacle interfere with each other when the workbench is lowered, the load acting in the direction of pushing up the workbench is detected by the load detection means, and the allowable load preset by the controller is set. Compared to. When the detected load exceeds the allowable load,
An alarm signal is transmitted from the controller, and an alarm is issued by an alarm buzzer or an alarm is issued by stopping the descending operation. For this reason, even if the worker performs the lowering operation of the work table even though the lower surface of the work table is in contact with the obstacle, the work table is not damaged.

Further, according to the safety device for an aerial work vehicle, the load detecting means for detecting the load acting in the lateral direction of the workbench is arranged between the workbench and the workbench holding member. When the workbench and the obstacle interfere with each other when the local work vehicle travels, a load acts in the lateral direction of the workbench, and the load is detected by the load detection means. The detected load detected by the load detection means is compared with the allowable load preset by the controller, and when the detected load exceeds the allowable load, the controller sends an alarm signal.
Since the alarm is activated by the alarm means as in the above, damage to the workbench can be prevented.

Further, in each of the aerial work vehicles constructed as described above, when the load detecting means is constructed so as to be able to detect the load acting in the direction of pushing down the workbench, the workbench rises. The load when the upper surface of the work table interferes with the obstacle during operation is detected by the load detecting means. The detected load detected by the load detection means is compared with the allowable load preset by the controller,
When the detected load exceeds the allowable load, an alarm signal is transmitted from the controller and an alarm operation is performed by the alarm means. Therefore, it is possible to prevent the workbench and the lifting device from being damaged, and it is possible to ensure the stability of the aerial work vehicle.

In each of the aerial work vehicles configured as described above, when the alarm signal is transmitted from the controller, the lifting and lowering operation of the workbench is stopped by the lifting device operation restricting means. You may. Thus, when the alarm signal is transmitted from the controller, the operation of the lifting device can be restricted in addition to the alarm buzzer by the alarm means and the alarm operation by the alarm lamp.

Further, in the case where the lifting / lowering device operation restricting means is used to stop the raising / lowering operation of the work table when the alarm signal is transmitted from the controller, when the alarm signal is transmitted from the controller. In addition to the alarm buzzer by the alarm means and the alarm operation by the alarm lamp, the operation of the lifting device can be restricted.

[Brief description of 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 a side view of the aerial work vehicle.

FIG. 3 is a block diagram of operation control of the work platform for aerial work.

[Explanation of symbols]

 11 vehicle body 12 traveling device 13 scissor link 14 workbench holding member 15 workbench 21 load cell (load detection means)

Claims (4)

[Claims] 1. A workbench holding member provided so as to be vertically movable up and down with respect to a vehicle body, a workbench attached to the workbench holding member, and the workbench and the workbench holding member. A load detecting means disposed between the load detecting means and a load detecting means for detecting a load acting in a direction of pushing up the work table, and a detected load of the work table detected by the load detecting means is compared with a predetermined load set in advance, A controller for outputting an alarm signal when the detected load exceeds the predetermined load, and an alarm unit for receiving an alarm signal from the controller and performing an alarm operation. Work vehicle safety device. 2. A workbench holding member which is vertically movable with respect to a vehicle body, a workbench attached to the workbench holding member, and the workbench and the workbench holding member. A load detecting means disposed between the load detecting means and a load detecting means for detecting a load acting in the horizontal direction of the work table, and a detected load of the work table detected by the load detecting means is compared with a predetermined load set in advance, A controller for outputting an alarm signal when the detected load exceeds the predetermined load, and an alarm unit for receiving an alarm signal from the controller and performing an alarm operation. Work vehicle safety device. 3. The safety of an aerial work vehicle according to claim 1 or 2, wherein the load detecting means is also configured to detect a load acting in a direction of pushing down the workbench. apparatus. 4. A lifting / lowering device operation restricting means for restricting the operation of the lifting / lowering device in response to an alarm signal from the controller.
Safety device for aerial work vehicles described in.