JPS62211296A - Boom operation regulation controller in height service car - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention provides that, when operating the boom of an aerial work vehicle, the boom is automatically controlled within a permissible operating range that does not exceed the overturning moment of the aerial work vehicle. The present invention relates to a boom operation regulation control device for a high-altitude work vehicle for controlling the boom operation so that the vehicle fits within the vehicle.

(Prior Art) Conventionally, when the boom 102 of the aerial work vehicle 101 is lowered in a state of being extended to its maximum length as shown in FIG. When the undulation angle of the boom 102 is large, that is, in a range that does not reach point A, the overturning moment is small, so it is possible to lower the boom 102 while it is extended to its maximum length. When the tip 102T of the boom 102 reaches point A, the aerial work vehicle 101 moves the boom 102 to avoid falling.
In order to automatically stop the lowering of the boom 102, the operator retracts the boom 102 until the tip of the boom 102+1102 is located at point B to reduce the overturning moment, and then lowers the boom 102. Tip 102T of boom 102
After shortening to point B, line LN3 remains at that length.
Even if the boom 102 is lowered until the luffing angle is minimized along the line LN2, the tip 102T of the boom 102 is
That is, the control line LN2, which is set to prevent the aerial work vehicle 101 from overturning, will not be crossed.

(Problem to be Solved by the Invention) In the conventional boom operation regulation control method described above, when the boom is extended to its maximum length and lowered, the boom stops descending midway, so the operator must It was necessary to lower the boom by retracting the boom to a predetermined length and then lowering it again, or by simultaneously performing the lowering and retracting operations.

Therefore, in any case, it is necessary to operate two operating levers, a boom raising/lowering operating lever and a telescoping operating lever, and there is a problem in that it is difficult to operate the boom smoothly.

Therefore, in the present invention, when operating the boom hoisting operation means to raise and lower the boom, the technology to be solved is to control the boom so that it automatically falls within the allowable operating range without operating the boom extension/retraction operation means. This is a major issue.

(Means for solving the problem) The technical means for solving the above problem is to control the boom operation regulation control device of the aerial work vehicle by detecting the boom's heave angle and outputting a signal corresponding to the detected heave angle. A boom hoisting angle detector and a boom extension/contraction length detector that detects the extension/contraction length of the boom and outputs a signal corresponding to the detected extension/contraction length are provided,
Furthermore, an operation signal corresponding to the operation amount from the boom hoisting operation means is inputted, and a drive signal is output to a valve for controlling the lift cylinder to operate the boom hoisting, and the boom hoisting angle detector and the boom The boom attitude is calculated by inputting the signal from the telescopic length detector, and if the calculated boom attitude exceeds the pre-stored allowable operating range, the boom is adjusted so that the boom falls within the allowable operating range. This configuration includes an operation regulation control circuit that outputs a correction drive signal to the lζth valve that controls the telescope cylinder.

(Function) According to the boom operation regulation control device for an aerial work vehicle having the above configuration, when the driver performs boom hoisting operation,
An operation signal corresponding to the operation amount is output from the boom raising/lowering operation means, and the operation signal is input to the operation regulation control circuit.

When the operation signal is input, the operation regulation control circuit outputs a drive signal corresponding to the operation signal to the valve for controlling the lift cylinder, and operates the boom to raise and lower. The operation regulation control circuit also calculates the attitude of the boom by manually inputting detection signals from the boom hoisting angle detector and the boom extension/contraction length detector,
If the calculated boom attitude exceeds the pre-stored allowable operating range, a correction drive signal is output to the telescope cylinder control valve to retract the tip of the zoom to within the allowable operating range, and the boom is It is automatically controlled so as not to go out of the permissible operating range at all times.

(Example) Hereinafter, an example of the present invention will be specifically described based on the drawings. In Fig. 1 showing the whole of the aerial work vehicle, 1 is a vehicle body, 2 is a swivel table installed horizontally rotatably on the vehicle body 1, and is equipped with a pinion 4 that meshes with a fixed large gear 3 on the vehicle body side. It is designed to be driven by a hydraulic motor 5.

The boom is raised and lowered by a lift cylinder 7 attached to a swivel base 2 so as to be rotatable up and down, and is extendable and retractable by a telescope cylinder 8. A workbench 9 is installed at the tip of the boom. An operation panel 10 is attached to the workbench 9, and the operation panel 10 is provided with a lift lever 11 for boom raising/lowering operation and a telescope lever 12 for boom extension/retraction operation, as shown in the electric control circuit of FIG. Furthermore, a swing lever 13 for turning operation and a drive lever 14 for traveling operation are provided.

The aforementioned shaft lever 11. Telescope lever 12. The swing lever 13 and the drive lever 14 are each equipped with, for example, a potentiometer, and are configured to output a voltage signal corresponding to the operating angle of each lever.

On the other hand, a boom undulation angle sensor 15, which is made of, for example, a potentiometer, is installed near the lift cylinder 7 and operates in accordance with the stroke of the lift cylinder 7 and outputs a voltage signal corresponding to the undulation angle of the boom 6. Further, a boom extension/retraction length sensor 16, which is configured of, for example, a potentiometer, is installed near the telescope cylinder 8, and is operated in response to the stroke of the telescope cylinder 8 and outputs a voltage signal corresponding to the extension/retraction length of the boom 6. In addition, switches SW1 and S are used for lift operation, telescope operation, and swing operation from the ground side.
W2 and SW3 are provided, and these switches are connected to the I10 port of the microcomputer CPU.

Further, the aerial work vehicle is provided with a lift solenoid valve 17 that supplies the required pressure oil to the lift cylinder 7, and a telescope solenoid valve 18 that supplies the required pressure oil to the telescope cylinder 8, Furthermore, a swing solenoid valve 19 for supplying pressure oil from a hydraulic pump (not shown) to the hydraulic motor 5, and a drive for supplying required pressure oil to a travel motor (not shown) for driving the aerial work vehicle. A solenoid valve 20 is provided.

The lift lever 11. The voltage signals output from each of the telescope lever 12, the swing lever 13, and the drive lever 14, and the voltage signals output from each of the boom heave angle sensor 15 and boom extension/contraction length sensor 16 were converted into digital signals. It is then output to the microcomputer CPU.

The microcomputer CPU performs calculations and processing to be described later in accordance with a calculation control program stored in a storage element (not shown), and then outputs control signals for controlling each of the valves. The control signal outputted from the microcomputer CPU is applied to the lift solenoid valve 17. Telescope solenoid valve 18. Swing solenoid valve 19
and a drive circuit 24 for supplying drive current to each of the drive solenoid valves 20.

Next, the operation of this embodiment will be explained based on FIGS. 3 and 4.

Figure 3 shows a boom operation regulation control flowchart, and Figure 4 shows when the operating lever is tilted forward (+) or near (-) from the neutral state.
It shows the nonlinear output characteristics of the valve drive signal with respect to the operation signal output from the operation lever.

In step ST1 of the flowchart shown in FIG. 3, the microcomputer CPU is initialized, and in step ST2, the microcomputer CPU receives output signals from the boom heave angle sensor 15 and the boom extension/contraction length sensor 16 and calculates the attitude of the boom 6. In step ST3, the signal corresponding to the tilt angle of the lift lever 11 or the output signal of the ground side operation switch SW1 is input, and in step ST4, the valve drive amount for the lift solenoid valve 17 is calculated based on the nonlinear output characteristics shown in FIG. Based on the valve drive amount, a drive signal is output to the lift solenoid valve 17 to supply pressure oil to the lift cylinder and operate the boom.

In step ST5, the microcomputer CPU determines whether the boom tip position based on the boom attitude is outside a preset regulation line, that is, the regulation line LN2 shown in FIG. 1.

As a result of the judgment, the boom tip position is normal untilFilLN2
If it is determined that the boom tip position is not outside the regulation line LN2, the process proceeds to step ST9, while if it is determined that the boom tip position is outside the regulation line LN2, the process proceeds to step ST6.

In step ST6, it is determined whether the lift lever 11 or the switch SW1 is being operated in the direction of lowering the boom 6. If it is determined that the lift lever 11 or the switch SW1 is being operated in the lowering direction, the process proceeds to step ST7; otherwise, The process proceeds to step ST8. In step ST7, the telescope cylinder 8 is regulated in the contraction direction according to the following equation, for example.

However, in the above formula, I is the telescope valve driving amount,
Kp is proportional gain, KD is differential gain, E is regulation line LN
Indicates the deviation from 2.

Based on the above formula, depending on the deviation from the regulation line LN2, that is, when the boom 6 crosses the regulation line LN2,
A drive port is calculated so that the telescope cylinder 8 is smoothly contracted up to 2.

On the other hand, in step ST8, if the lift lever 11 or the switch SW1 is not operated in the direction of lowering the boom 6, that is, when the telescope cylinder 8 is extended to cross the regulation line LN2, the extension of the telescope cylinder 8 is stopped. Change the drive amount to the desired amount. In step ST9, step ST7 or step S
The control signal based on the drive m calculated at T8 is sent to the drive circuit 2.
4, and a drive current is applied from the drive circuit 24 to the telescope solenoid valve 18 to control the telescope cylinder 8 so that the boom 6 does not exceed the regulation line LN2.

(Effects of the Invention) As described above, according to the present invention, when the boom is raised or lowered by operating the boom hoisting operation means, the boom automatically retracts within the allowable operating range without operating the boom extension/contraction operation means. This has the advantage that the boom can be operated smoothly and safely.

[Brief explanation of drawings]

Fig. 1 is an external view of the aerial work vehicle, Fig. 2 is a block diagram of an electric control circuit according to an embodiment of the present invention, Fig. 3 is a control flowchart of this embodiment, and Fig. 4 is a nonlinear valve drive signal. The output characteristic diagram, FIG. 5, is an explanatory diagram showing a conventional technique. 1...Car 2...Swivel Platform 6...Boom 7...Lift cylinder 8...Telescope cylinder 9...Work platform 11...Lift lever 12...Telescope Lever 15...Boom elevation angle sensor 16...Boom telescopic length sensor 17...Lift solenoid valve 18...Telescope solenoid valve 23...A
D converter 24...drive circuit

Claims (1)

[Claims] A boom is attached to a swivel platform that is rotatably installed on the vehicle body, and is raised and lowered by the hydraulic drive of a lift cylinder, and extends and retracted by the hydraulic drive of a telescope cylinder.
The aerial work vehicle is equipped with operating means for raising and lowering the boom and extending and retracting the boom. A boom extension/contraction length detector is provided that detects the extension/contraction length and outputs a signal corresponding to the detected extension/contraction length, and further inputs an operation signal corresponding to the operation amount from the boom hoisting operation means to control the lift cylinder. A drive signal is output to the valve for raising and lowering the boom, and signals from the boom raising and lowering angle detector and the boom extension/contraction length detector are input to calculate the attitude of the boom, and the calculated boom attitude is calculated. The height control circuit is equipped with an operation regulation control circuit that outputs a correction drive signal to a valve for controlling the telescope cylinder so that the boom falls within the allowable operating range when the boom exceeds a pre-stored allowable operating range. Boom operation regulation control device for industrial work vehicles.