JPH068397U - Safety equipment for aerial work vehicles - Google Patents

Abstract

(57) [Abstract] [Purpose] In an aerial work vehicle, a safety device is provided that, while ensuring the stability of the vehicle body, can move the work table in a wider range if the weight mounted on the work table is small. provide. [Structure] The safety device 20 includes a mounting weight detection means 25 for detecting the weight mounted on the workbench 14 attached to the tip of the boom, and a mounting weight on the workbench 14 detected by the mounting weight detection means 25. Accordingly, the allowable range setting means 26 for calculating and setting the allowable operating range in which the movement of the workbench 14 is allowed while maintaining the stability of the vehicle body so that the range is the widest, and the position of the workbench 14 are the above-mentioned allowances. And an alarm means 28 for performing an alarm operation when the operating range is exceeded.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a safety device used to maintain the stability of the vehicle body of an aerial work vehicle.

[0002]

[Prior art]

 A boom that can be lifted and retracted is attached to the body of an aerial work vehicle, and a work platform for mounting a worker is attached to the tip of the boom. An operator on this workbench can move to an arbitrary height by controlling the operation of the boom, and can perform desired height work.

By the way, a load (hereinafter, referred to as a fall load) acts on the vehicle body of such an aerial work vehicle in a direction in which the vehicle body falls due to the weight of the boom and the weight of the work platform. For this reason, the boom operation is restricted in aerial work vehicles so that the overturning load does not exceed the maximum load (hereinafter referred to as the allowable load) that the vehicle body can support in a stable state. A safety device for alarm activation is installed. As a specific overload determination method for this safety device, the position of the workbench is calculated by detecting the hoisting angle and extension amount of the boom, and that position is used when the maximum weight is mounted on the workbench. This is done by checking whether the preset allowable operating range is exceeded to prevent an overload condition. As a result, the stability of the vehicle body is ensured as long as the workbench is loaded with the maximum weight or less.

[0004]

[Problems to be solved by the device]

 However, when the allowable operating range set in the safety device as described above corresponds only to the case where the maximum weight is mounted on the work table as described above, the work is carried with a lighter weight than that. In this case, there is a problem in that the alarm is activated even if the stability of the vehicle body still has a sufficient margin, and as a result, the workbench can be moved only within a narrow range. is there.

The present invention has been made in view of such a problem, and while ensuring the stability of the vehicle body, when the weight to be mounted on the workbench is small, the workbench can be moved over a wide range. It is an object of the present invention to provide a safety device for an aerial work vehicle that can be operated.

[0006]

[Means for Solving the Problems]

 In order to achieve the above-mentioned object, the safety device of the present invention is provided with a mounted weight detecting means for detecting the weight mounted on the workbench, and a mounted weight on the workbench detected by the mounted weight detecting means. And an allowable range setting means for calculating and setting the allowable operating range such that the range is widest.

[0007]

[Action]

 In such a safety device, when the loading weight of the workbench detected by the loading weight detection means is lighter than the maximum allowable loading weight of the workbench, the allowable range setting means allows the allowable operation corresponding to the maximum allowable loading weight. An allowable operating range wider than the range is calculated or selected and set. Since the safety device executes the alarm operation based on the allowable operating range calculated in this way, the stability of the vehicle body is ensured while the work platform is left with a margin more than necessary for the stability of the vehicle body. The situation in which the movement of the car is regulated is avoided.

[0008]

【Example】

 Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. First, FIG. 1 shows an aerial work vehicle 10 equipped with a safety device according to the present invention. At the rear of the vehicle body 11 of the aerial work vehicle 10, a swivel base 12 is attached which is horizontally rotatable with respect to the vehicle body 11. A boom 13, which is telescopically extendable and retractable, is pivotally attached to the upper portion of the swivel base 12 so as to be capable of undulating. A workbench 14 is horizontally attached to the tip of the boom 13. For this reason, an operator who has boarded the work table 14 can move to an arbitrary height through the turning operation of the turn table 12 and the hoisting / extending and retracting operation of the boom 13.

When the boom 13 and the like are actuated in this manner, a load (hereinafter referred to as a fall load) acts on the vehicle body 11 in a direction in which it falls. For this reason, the jacks 15 are attached to the side portions of the vehicle body 11 at four positions in the front, rear, left, and right directions so as to project and retract toward the side of the vehicle body 11. Each of the jacks 15 can support the vehicle body 11 against a fall load by grounding the lower end of the jack 15 in a state where it is appropriately extended to the side of the vehicle body 11.

However, if the boom 13 and the like are allowed to operate indefinitely, the falling load exceeds the allowable load that can be more stably supported by each jack 15, and the vehicle body 11 may become unstable. For this reason, the work platform 10 is equipped with the safety device 20 according to the present invention. As shown in FIG. 2, the safety device 20 includes a turning sensor 21 and an undulation sensor 2.
2. It has an extension sensor 23. As shown in FIG. 1, the turning sensor 21 is mounted around the turning base 12 and detects the turning angle of the turning base 12 with respect to the vehicle body 11. The hoisting sensor 22 is attached to the side surface of the base end portion of the boom 13, and detects the hoisting angle of the boom 13 with respect to the horizontal level. Further, the extension sensor 23 is attached near the tip of the boom 13 and detects the extension amount of the boom 13 from the fully retracted state. Each of these sensors 21, 22 and 23 outputs a detection signal (electrical signal) corresponding to each detection amount or angle.

The safety device 20 also has a stretch width sensor 24. As shown in FIG. 1, the tension sensor 24 is attached to each of the jacks 15, detects the amount of extension (stretch width) of each jack 15 from the vehicle body 11, and detects a detection signal according to the detection amount. Is output.

Further, as shown in FIG. 2, the safety device 20 has a mounted weight detector 25 mounted near the workbench 14. Here, the attachment structure of the workbench 14 to the tip of the boom 13 will be described with reference to FIG. The mounting structure is such that the supporting frame 13a held vertically at the tip of the boom 13 (not shown here) and the working table 14 are integrally mounted, and also mounted on the supporting frame 13a so as to be slidable up and down. And the slide frame 13b formed. Two springs 13c and 13c are mounted between the lower end of the slide frame 13b and the lower end of the support frame 13a, and urge the slide frame 13b upward with respect to the support frame 13a. Therefore, the slide frame 13b is held at the upper position of the support frame 13a when it is not mounted on the workbench 14. On the other hand, when the weight of the workbench 14 as a whole increases due to an operator riding on the workbench 14 or mounting tools, the workbench 14 resists the urging force of the springs 13c, 13c together with the slide frame 13b. Move downward according to the size of the payload.

Further, the mounted weight detector 25 is attached to the center of the lower end of the support frame 13a. The mounted weight detector 25 is composed of a proximity switch (magnetic switch), and when the slide frame 13b is moved downward as described above, the lower end of the slide frame 13b is mounted for a certain distance or more. When it approaches the upper part of, it outputs a detection signal. Therefore, by appropriately adjusting the biasing force of the springs 13c, 13c and the sensitivity of the mounted weight detector 25, it is possible to detect whether the mounted weight of the workbench 14 is equal to or greater than a predetermined weight.

The safety device 20 also includes an allowable range setting device 26, a calculation comparator 27, and an alarm controller 28. The allowable range setting device 26 stores two types of allowable operating range data. Here, the allowable operating range refers to the reach range of the workbench 14 when the overturning load matches the allowable load. One of the above two types of allowable operating range data corresponds to the case where the maximum allowable weight is mounted on the workbench 14 (hereinafter referred to as the total allowable range), and the other is the work. It corresponds to the case where the above-mentioned predetermined weight (for example, half the maximum allowable weight) is mounted on the table 14 (hereinafter referred to as a half-mounting allowable range). FIG. 3 is a simplified diagram of these. As can be seen from this figure, the semi-mounting allowable range S1 extends to a position farther from the vehicle body 11 than the full-mounting allowable range S2 due to the light weight of mounting on the workbench 14.

Then, when the detection signal from the mounted weight detector 25 is not input, the allowable range setting device 26 selects and reads the data of the semi-mounted allowable range S1. On the other hand, when the detection signal from the loading weight detector 25 is input, the data in the all-loading allowable range S2 is selected and read. Further, the permissible range setting device 26 corrects the read data of the permissible operating range based on the detection signal from the tension sensor 24, and calculates and sets the true permissible operating range for input to the arithmetic comparator 27. . For example, when the detection signal from the stretch width sensor 24 indicates that the jack 15 is projected to the maximum, the range of 100% of the read allowable operation range is set as the true allowable operation range, and the jack 15 is When only half of the area is overhanging, the range of 50% of the read permissible operating range is set as the true permissible operating range.

The arithmetic comparator 27 calculates the position of the workbench 14 based on the detection signals from the swing sensor 21, the undulation sensor 22 and the extension sensor 23 described above. Then, it is determined whether or not the calculated position of the workbench 14 is within the true permissible operating range set by the permissible range setting unit 26. When it is determined that the work table 14 is within the true permissible operating range, the work table 14 is further allowed to move away from the vehicle body 11. On the other hand, when it is determined that the position is outside the true permissible operating range, an alarm signal is output. When the alarm controller 28 receives the alarm signal, it generates a buzzer sound or regulates the operation of the boom 13 or the like (more, only the operation in the direction in which the workbench 14 moves away from the true permissible operating range). . As a result, the stability of the vehicle body 11 is reliably maintained.

According to the safety device 20 thus configured, when the weight of the work table 14 is less than half the maximum allowable weight and the jacks 15 have the same tension, It is possible to move the workbench 14 in a wider range than when it is set based on the time allowable range S2. For this reason, the efficiency of high-altitude work can be improved as compared with the conventional case in which the robot can be moved only within the allowable range at the time of full mounting regardless of the weight of mounting on the workbench 14.

In the above embodiment, the weight to be mounted on the workbench 14 was detected by dividing it into only two stages, light weight and heavy weight. May be set. By doing so, it is possible to perform the alarm actuation control in accordance with the actual loading weight, and to approach the moment limiter that detects the magnitude of the overturning load that actually acts on the vehicle body 11 and performs the alarm actuation control. You can

[0019]

[Effect of device]

 As described above, in the safety device of the present invention, the maximum range (allowable operating range) in which the workbench can be moved while maintaining the stability of the vehicle body is set according to the weight mounted on the workbench. The alarm is activated only when the position of exceeds the allowable operating range. Therefore, if this safety device is used, the stability of the vehicle body can be ensured when the weight of the vehicle mounted on the workbench is large, while when the weight of the vehicle is lightly loaded, an alarm is activated at a stage where the vehicle body has more stability than necessary. It is possible to prevent the movement of the work table from being hindered by the execution of. Therefore, it is possible to improve the working efficiency especially when the weight mounted on the workbench is light.

[Brief description of drawings]

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

FIG. 2 is a configuration diagram of the safety device.

FIG. 3 is an operation explanatory view of the safety device.

[Explanation of symbols]

 10 Work platform for high altitude 13 Boom 14 Work table 20 Safety device 25 Loaded weight detector S1 Allowable range for half mounting S2 Allowable range for all mounting

Claims (1)

[Scope of utility model registration request] 1. A high-altitude work vehicle comprising a boom on a vehicle body which can be freely moved up and down and extended and retracted, and a work platform is provided at the tip of the boom, wherein the position of the work platform moved by the operation of the boom is the above-mentioned. A safety device for an aerial work vehicle that performs an alarm operation so as not to exceed an allowable operating range set to maintain the stability of the vehicle body, and a mounted weight detection means for detecting the weight mounted on the workbench. And a permissible range setting means for calculating and setting the permissible operating range such that the range is the widest in accordance with the mounted weight on the work table detected by the mounted weight detecting means. Safety equipment for aerial work vehicles.