JPH0635319B2 - Boom control device for aerial work vehicles - Google Patents

Description

Description: TECHNICAL FIELD OF THE INVENTION The present invention relates to an aerial work vehicle, and more particularly, to boom control of an aerial work vehicle that allows a work basket to easily and quickly approach an object at a high place. Regarding the device.

[Conventional technology and problems]

For example, an aerial work vehicle is used when wiring electric wires on a high pole. This work vehicle for aerial work is provided with a work basket on the top of a boom that is normally lifted and lowered by a hydraulic cylinder device, and a worker can enter the work basket to perform various works.

FIG. 6 shows a conventional aerial work vehicle and a mode of work. In the figure, reference numeral 1 indicates a utility pole as a target of work. An aerial work vehicle 2 is provided close to the utility pole 1. The work vehicle 2 has a lower boom 4 which is pivotally supported on a base 3 so that it can be elevated, and an upper boom 5 is pivotally attached to the lower boom 4, and a work basket 6 is attached to the tip thereof. There is. The lower boom 4 is lifted and lowered by the lower boom drive device 7, while the upper boom 5 is lifted and lowered by the upper boom drive device 9 via the toggle link 8. In the work vehicle 2 configured as described above, in order to bring the work basket 6 at the lowest position closer to the high position of the electric pole 1, the upper boom drive device 9 and the lower boom drive device 7 are alternately operated. , Work basket 6
Must be moved stepwise in the order of S →→→→.

Therefore, it takes a long time for the work basket 6 to reach a target place, and it requires skill to move the work basket up and down or advance and retreat, which may cause a danger by a slight operation error. Further, in order to return the work basket to the lowest position S after the work is completed, the work basket 6 must be moved stepwise in the order of →→→→ S. However, if the work basket 6 is moved from to and is accidentally tilted to the position ', the position of the center of gravity of the work vehicle exceeds the safety limit, and there is a risk of falling.

Therefore, in order to solve the problem of the upper part, an intermediate arm in which the base end of the upper boom and the tip end of the lower boom are connected via a pin, and a direction opposite to the rotating direction of the lower boom in conjunction with the elevation motion of the lower boom. An aerial work vehicle has been proposed, which is provided with a correction link mechanism that gives the movement of the upper arm to the intermediate arm, and moves the upper boom in the direction opposite to the lower boom in conjunction with the elevation movement of the lower boom.

However, this aerial work vehicle requires a middle arm and a correction link mechanism, which complicates the boom structure and increases the boom weight. As a result, the center of gravity of the vehicle becomes high, which adversely affects the tipping angle performance of the vehicle.

[Object of the Invention]

The present invention has been made in consideration of such circumstances.
The object is to improve the tipping angle performance of an aerial work vehicle without complicating the boom structure and increasing the weight.

[Outline of Invention]

The boom control device of the present invention stores the upper boom angle at the end of the operation of the upper boom, and holds the upper boom angle at the stored corner during the operation of the lower boom.

Example of Invention

FIG. 1 schematically shows the overall structure of an aerial work vehicle. 3'is a base, 4'is a lower boom, 5'is an upper boom,
6'is a basket, 7'is a lower boom cylinder, 8'is a toggle link, 9'is an upper boom cylinder, and 10 'is a boom angle meter. This boom angle type is for detecting the elevation angle of the upper boom (eg, horizontal line).

FIG. 2 schematically shows a drive control system for the upper boom cylinder 9'and the lower boom cylinder 7 '.

The upper boom operating lever 24 and the lower boom operating lever 25 are operated to raise and lower the upper boom 5'and the lower boom 4 ', respectively. When raising is instructed,
The contents of the output signals 24i and 25i are different when the descent is instructed and when neither is instructed.
Boom angle meter 10 'generates a signal B ₂ showing the upper boom angle.

The controller CA receives the signals 24i, 25i, B ₂ and
Based on these, the upper boom rising signal 26i. Any of the upper boom lowering signal 27i, the lower boom raising signal 28i, and the lower boom lowering signal 29i is generated. These signals 26i
.About.29i are given to the solenoid proportional valves 26 and 28 to change the operating positions of the solenoid valves. The cylinder 9'operates by receiving the hydraulic pressure from the hydraulic pump 27 via the solenoid valves 26 and 28 to drive the boom.

FIG. 3 shows the details of the control device.

The analog multiplexer MPX outputs signals B ₂ , 24i,
25i, based on a switching signal MPXS described later,
One of these is selected and output.

The A / D (analog / digital) converter ADC converts the output of the multiplexer MPX into a digital signal.

The output of the A / D converter ADC is supplied to the microcomputer DP via the input port IP. The microcomputer DP is a central processing unit CPU, a program memory R
It consists of OM and data memory RAM. The operation will be described later. The signal generated by the data processing device DP is passed through the output port OP and D / A (digital / analog).
Converter DA1, DA2, analog multiplexer MPX
Given to.

The solenoid proportional valve amplifier A1 outputs the lower boom up signal 28i or the lower boom down signal 29i based on the output of the D / A converter DA1.

The electromagnetic proportional valve amplifier A2 outputs the upper boom raising signal 26i or the upper boom lowering signal 2 based on the output of the D / A converter DA2.
7i is output.

FIG. 4 shows a solenoid proportional valve amplifier A2 and a solenoid proportional valve 2 shown in FIG.
6, a servo mechanism including an upper boom cylinder 9 ', an angle meter 10', and a microcomputer DP is shown.

FIG. 5 shows the control operation of the microcomputer DP of FIG.

After the operation is started, first, the multiplexer MPX is caused to select the lower boom operation signal 25i and the signal 25i is input (10
2). When either the ascending or descending instruction is given to the lower boom, the lower boom ascending signal 28i or the descending signal 29i is output (104).

Next, the multiplexer MPX is caused to select the upper boom operation signal 24i and the signal 24i is input (106). Then, it is judged whether or not the upper boom operation lever 24 is being operated, that is, whether the upper boom is instructed to move up or down (108). Output signal 27i (11
0). Then, the multiplexer MPX is caused to select the angle signal B ₂ , the angle is input (112), and the data memory RA
It is stored in M (114). Then, the process returns to step 102 and the above operation is repeated.

As described above, when the upper boom operation lever 24 is operated, a signal for raising or lowering the upper boom is output from the electromagnetic proportional valve amplifier A ₂ via the D / A converter DA2 by the upper boom operation signal 24i. Outputs a signal 26i or 27i to cause an ascending or descending. Such control operation can be said to be control in which the switch SW is opened in FIG. 4, that is, control by an open loop.

When the upper boom operation lever 24 is not being operated in step 108, the multiplexer MPX is caused to select the angle signal B ₂ , the angle is input (116), and the signal B _m indicating the upper boom angle stored in the data memory RAM is input. (120). If the input upper boom angle B ₂ is larger than the stored upper boom angle B _m , the routine proceeds to step 122, and if it is smaller, the routine proceeds to step 126. Step 12
In Nos. ₂ and 126, the deviation between the upper boom angle B ₂ and the stored upper boom angle B _m is calculated, multiplied by the proportional coefficient K, and amplified. Following steps 122 and 126, signals are output to operate the upper boom so that the deviation becomes 0 (124, 127). Then, the process returns to step 102 and the above operation is repeated. As a result of the above control, the angle of the upper boom is controlled so as to match the angle stored in the memory. That is, even if the upper boom angle changes if left unattended due to the operation of the lower boom, the upper boom angle is changed by the operation of the servo mechanism by the software of the microcomputer to the angle B _m (upper angle) stored in the data memory. It is maintained at the upper boom angle when the last operation of the boom control lever was completed.

Such control operation can be said to be control in which the switch SW is closed in FIG. 4, that is, control by a closed loop, and steps 122 and 126 correspond to the subtractor SB and the servo amplifier SA.

As described above, when the upper boom is operated with the upper boom operation lever, the upper boom angle at the end of the operation is changed to the data memory RAM.
When the lower boom is operated later, the upper boom angle is held at the stored angle B _m .

〔The invention's effect〕

As described above, according to the present invention, since the servo mechanism for controlling the upper boom is maintained so as to maintain the stored boom angle B _m during the operation of the lower boom, the structure of the boom is complicated. In addition, the fall angle performance of the vehicle can be improved without increasing the weight of the boom, and the work basket can be safely and quickly moved to the destination.

[Brief description of drawings]

FIG. 1 is a diagram schematically showing the whole of an aerial work vehicle, FIG. 2 is a diagram schematically showing a control system of an upper boom cylinder 9 ′ and a lower boom cylinder 7 ′, and FIG. 3 is a detail of a control device. 4 is a block diagram showing a servo mechanism for controlling an upper boom, FIG. 5 is a flowchart showing a control operation, and FIG. 6 is a diagram showing a boom of a conventional aerial work vehicle. 4 '... lower boom, 5' ... upper boom, 6 '... basket, 7' ... lower boom cylinder, 8 '... toggle link, 9' ... upper boom cylinder, 10 '... boom angle meter , 24 ... upper boom operating lever, 25 ... lower boom operating lever, CPU ... central processing unit, RAM ... data memory.

Claims (1)

[Claims] 1. A boom control device for a bending type aerial work vehicle having an upper boom and a lower boom, wherein the boom control device is operated to drive the upper boom, and is operated to drive the lower boom. Lower boom operating means, upper boom angle detecting means for detecting the upper boom angle, memory for storing the upper boom angle at the end of operation of the upper boom by the upper boom operating means, and lower boom operating means When the boom is being operated and the upper boom is not being operated by the upper boom operating means, the upper boom angle and the upper boom angle stored in the memory are compared to determine the deviation between them. Means for generating an operation output by performing control calculation for the upper boom operation means, and means for generating an operation output according to the operation of the boom operation means during operation of the upper boom by the upper boom operation means, Aerial boom control device and means for driving the upper boom in response to the operation output.