JPH06135699A - Placed load detection/display device for elevated spot working vehicle - Google Patents

Abstract

PURPOSE:To correctly detect the placed load even if the height of a working floor differs and to enable an operator to find the placed load. CONSTITUTION:A placed load detection/display device is constituted of a pressure sensor 6 for detecting the pressure in the extension chamber 5a of an elevator cylinder 5 which raises and lowers a working floor, stroke detecting sensor 7 for detecting the stroke, calculation circuit 9 which corrects the detected pressure according to the stroke and calculates the movable load on the basis of the corrected pressure, and a load display device 15.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for detecting and displaying a load on a work floor of an aerial work vehicle in which a work floor is mounted on a vehicle body so as to be able to move up and down.

[0002]

2. Description of the Related Art In an aerial work vehicle, it is stipulated by a structural standard that an alarm is to be issued when the vehicle is loaded with a maximum load, that is, an allowable load on the work floor. For this reason, it is necessary to detect the load on the work floor.As a device for detecting the load, the pressure in the extension chamber of the lifting cylinder of the lifting mechanism is measured, and the load is calculated by the pressure. Is being considered.

[0003]

In the case of a lifting mechanism called a scissors type in which the lifting mechanism for lifting the work floor expands and contracts the expansion link with the lifting cylinder, the expansion and contraction amount of the expansion link,
That is, since the angle of the lifting cylinder with the horizontal is different depending on the height of the working floor, the pressure in the extension chamber of the lifting cylinder is different depending on the height of the working floor even if the load is the same. For this reason, the above-described conventional load detecting device cannot accurately detect the load.

Further, since the operator cannot know the load when working at a high place with an aerial work vehicle, he / she cannot determine how heavy a heavy object installed at a high place is. Inconvenient during installation work.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a load detection display device for an aerial work vehicle which can solve the above-mentioned problems.

[0006]

[Means for Solving the Problems] A pressure sensor 6 for detecting the pressure in an extension chamber 5a of a lifting cylinder 5, a means for detecting the working floor height, and the detected pressure is corrected by the working floor height, and the correction is made. A load detection and display device for an aerial work vehicle comprising an arithmetic circuit 9 for calculating a load based on pressure and a load indicator 15 for displaying the calculated load.

[0007]

[Operation] The detected pressure in the extension chamber of the lifting cylinder 5 is corrected by the working floor height, and the load is calculated based on the corrected pressure. Therefore, even if the working floor height is different, it can be accurately detected. The load can be displayed on the load indicator 15 so that the operator can know it.

[0008]

[Example] As shown in FIG. 1, a lifting mechanism 2 is attached to a vehicle body 1.
The work floor 3 is attached via the above to construct an aerial work vehicle.
It becomes a scissor type that expands and contracts with the lifting cylinder 5
The angle formed with the horizontal of is increased as the height of the work floor 3 is increased. As shown in FIG. 2, a pressure sensor 6 for measuring the pressure in the extension chamber 5a and a stroke detection sensor 7 for detecting the stroke are attached to the lifting cylinder 5, and the detection value of each sensor is stored in the microcomputer 8. It is input and the payload is calculated.

The microcomputer 8 is provided with an arithmetic circuit 9, a correction circuit 10, an initial value setting device 11, a memory circuit 12, etc., and calculates the total weight of the working floor 3 by the pressure in the extension chamber 5a to obtain the initial value. The setting load is set by the setting unit 11 to subtract the work floor weight in an empty state to calculate the load, and the correction circuit 10 can accurately calculate the load even if the elevation cylinder 5 is at a different angle from the horizontal. There is. That is, since the angle formed by the stroke of the lifting cylinder 5 and the horizontal of the lifting cylinder 5 is determined by the shape and size of the extension link 4 and the mounting structure of the lifting cylinder 5, the lifting cylinder with respect to the stroke of the lifting cylinder 5 is beforehand determined. The horizontal angle of 5 is obtained by actual measurement or calculation, the coefficient for correcting the extension chamber pressure is determined by actual measurement or link calculation according to the angle formed with the horizontal of the lifting cylinder 5, and the lifting cylinder 5 that has detected the correction coefficient The stroke is stored in the correction circuit 10 and the correction coefficient is called according to the detected stroke to correct the detected pressure to calculate the total weight of the work floor to calculate the load.

For example, the extension chamber pressure of the lifting cylinder 5 with respect to the working floor height (stroke of the lifting cylinder 5) when the same load is placed on the working floor 3 in the aerial work vehicle shown in FIG. 1 is shown in FIG. Since the working floor shown in the figure becomes lower in pressure, the correction coefficient is determined corresponding to the working floor height as shown by the solid line A in FIG. When the loaded load calculated by the arithmetic circuit 9 exceeds the allowable loaded load, the lamp 13 and the buzzer 14 are operated, and a signal is output to the hydraulic circuit of the lifting cylinder (not shown) to stop the lifting cylinder. For example, the hydraulic pump is stopped or the directional control valve is returned to the neutral position.

As shown in FIG. 2, the calculated load is the load indicator 15, for example, the load indicator 1 of the operation panel 16.
No. 5 is displayed so that the operator can visually check the load. On the operation panel 16, an elevating operation lever 17 for switching a direction control valve for supplying pressure oil to the elevating cylinder 5,
A steering lever 18 and the like for controlling the operation of the steering and driving wheels of the vehicle body 1 are provided.

The calculated load capacity is stored in the storage circuit 12 together with the work year, month, day, hour and minute, and the stored data is transmitted to an external reading device 19 such as a data extracting personal computer or a memory card writer. It can be printed out and read on a memory card. As a result, the operating state of the aerial work vehicle can be known for a long period of time, and the loaded load can be known in time series, and the date and time of overloading can be known. It is advantageous for maintenance. It should be noted that a rotation sensor such as a potentiometer may be provided at the rotation fulcrum of the telescopic link instead of the stroke of the lifting cylinder 5 to detect the rotational angle of the telescopic link, thereby detecting the work floor height. .

[0013]

The detected extension chamber pressure is corrected by the working floor height, and the load is calculated by the corrected pressure.
Even if the height of the work floor 3 is different, the load can be accurately detected, the load indicator 15 allows the operator to know the load, and a heavy object can be easily installed at a high place.

[Brief description of drawings]

FIG. 1 is an external perspective view of an aerial work vehicle.

FIG. 2 is a circuit diagram for calculating a payload.

FIG. 3 is a chart showing a relationship between a stroke of a lifting cylinder and pressure.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Car body, 2 ... Elevating mechanism, 3 ... Work floor, 4 ... Telescopic link, 5 ... Elevating cylinder, 5a ... Extension chamber, 6 ... Pressure sensor, 7 ... Stroke detection sensor, 9 ... Arithmetic circuit, 15 ...
Load indicator.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Masayuki Nagahama 3-20-1 Nakase, Kawasaki-ku, Kawasaki-shi, Kanagawa Komatsu Ltd. Kawasaki Plant

Claims (2)

[Claims] 1. An aerial work vehicle in which a work floor 3 is mounted on a vehicle body 1 via an elevating mechanism 2 for elongating and contracting an extendable link 4 by an elevating cylinder 5, and the pressure in an extension chamber 5a of the elevating cylinder 5 is increased. A pressure sensor 6, a means for detecting the height of the working floor 3, an arithmetic circuit 9 for correcting the pressure by the working floor height, and calculating a load based on the compensation pressure, and the calculation circuit 9. A load detection and display device for an aerial work vehicle comprising a load indicator 15 for displaying the load. 2. The relationship between the stroke of the lifting cylinder 5 and the angle between the lifting cylinder 5 and the horizontal, which is determined by the structure of the lifting mechanism 2, and the angle between the lifting cylinder 5 and the horizontal, and the extension chamber of the lifting cylinder 5. The load detection display device for an aerial work vehicle according to claim 1, wherein the detected pressure is corrected based on the relationship between the pressures in 5a.