JP2657724B2 - Control equipment for construction machinery - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control device for a construction machine. In particular, the present invention relates to a control device for a construction machine provided with a plurality of operating devices for operating a plurality of fluid actuators such as a hydraulic excavator.

[0002]

2. Description of the Related Art Among construction machines, for example, a hydraulic excavator has a lower traveling body provided with traveling means such as a crawler device, and an upper revolving body is mounted on the lower traveling body so as to be pivotable in the left-right direction. Can be A boom is attached to the upper swing body so as to swing vertically, and the swing position in the vertical direction is controlled by a hydraulic cylinder. An arm is also attached to the tip of the boom so as to be pivotable in the vertical direction, and the vertical position of the arm is controlled by another hydraulic cylinder. In addition, at the tip of the arm,
The bucket is also mounted to be pivotable in the vertical direction,
Its operation is controlled by a hydraulic cylinder.

As described above, a hydraulic shovel has a plurality of working cylinders, and these cylinders are controlled by hydraulic circuits of different systems. It is already known to electronically control the operation of such a hydraulic cylinder. An electronic control circuit configured for this purpose generally includes voltage signal generating means for mechanically receiving an operation amount of a control lever and generating a voltage signal according to the operation amount. The voltage signal from the voltage signal generator is amplified by a voltage amplifier and supplied to the calculator. The operation means receives the output of the voltage amplifier, generates a current output signal, and inputs the output signal to the current amplifier. An electromagnetic proportional valve is provided that operates on the output signal of the current amplifier, and the output signal of the electromagnetic proportional valve is provided to the flow control valve. The flow control valve generates a flow corresponding to the output signal of the proportional solenoid valve and supplies the flow to the actuator. With this configuration, the operator of the construction machine can operate each cylinder by arbitrarily operating the control lever.

[0004] The configuration of this conventional control device has a flow rate characteristic uniquely determined according to the operation amount of the control lever.
Therefore, when the operator wants to change the operation amount of each cylinder in accordance with the work content, the operation amount of the control lever must be appropriately adjusted. That is, when it is desired to increase the operating speed of each operating unit driven by the hydraulic cylinder, it is necessary to perform an operation of increasing the operation amount of the control lever, and in the opposite case, reduce the operation amount of the control lever.
If the work content can be predicted in advance, it is sometimes desirable that the operation amount of the operation unit be a desired size even if the operation amount of the control lever is set to a normal value. Control was not possible.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems of the conventional steering apparatus for construction machines. That is, an object of the present invention is to provide a control device capable of changing the relationship between the operation amount of the control lever and the operation speed of the operation unit.

[0006]

In order to solve the above-mentioned problems, in the steering device according to the present invention, the arithmetic means provided between the voltage amplifier and the current amplifier is constituted by a plurality of arithmetic units having different characteristics. Further, there is provided switching means for arbitrarily switching the output of the voltage amplifier and switching connection to the selected one of the arithmetic units.

That is, a construction machine control device according to the present invention comprises: a control lever; voltage signal generating means for mechanically receiving an operation amount of the control lever and generating a voltage signal corresponding to the operation amount; A voltage amplifier for amplifying a voltage signal from the generating means, an arithmetic means for receiving an output of the voltage amplifier to generate a current output signal, a current amplifier for amplifying an output signal of the arithmetic means, and an output signal of the current amplifier And a flow control valve that generates a flow corresponding to the output signal of the solenoid proportional valve and supplies the flow to the actuator. The arithmetic means is constituted by a plurality of arithmetic units having different characteristics, and switching means for arbitrarily switching the output of the voltage amplifier and switching and connecting to the selected one of the arithmetic units is provided.

[0008]

According to the above construction of the present invention, even if the operation amount of the control lever is the same and the output of the voltage signal generating means does not change, the arithmetic unit having different characteristics is selected by switching the switching means. The control flow rate of the flow control valve can be changed. Therefore, a desired operation can be obtained without finely adjusting the operation of the control lever by selecting an arithmetic unit that obtains the most preferable characteristics according to the work content predicted in advance.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows a hydraulic excavator as an example of a construction machine to which the present invention is applied. This power shovel has a lower traveling body 1 provided with traveling means such as a crawler 1a. An upper swing body 2 is mounted on the lower running body 1 so as to be swingable in the left-right direction. One end of a boom 3 is mounted on the upper swing body 2 so as to be swingable in the vertical direction. The vertical position of the boom 3 is controlled by a hydraulic cylinder 4. An arm 5 is attached to the end of the boom 3 so as to be pivotable in the vertical direction. The vertical position of the arm 5 is controlled by a hydraulic cylinder 6. A shovel 7 is attached to the tip of the arm 5 so as to be vertically pivotable. The position of the excavator 7 is the hydraulic cylinder 8
Is controlled by

FIG. 2 shows an example of a hydraulic control circuit for controlling the operation of the hydraulic cylinders 4, 6, 8. FIG. 2 shows an actuation circuit for one of these cylinders, the operation of the other cylinder being controlled by a similar hydraulic control circuit. In FIG. 2, a hydraulic pump 10 as a hydraulic pressure source is connected to a hydraulic cylinder 12 via a flow control valve 11. The hydraulic cylinder 12 is one of the hydraulic cylinders 4, 6, 8 in the hydraulic shovel of FIG. Flow control valve 1
1 has pressure receivers 11a and 11b at both ends.
Depending on which of the control pressures is applied to the hydraulic pump 1a or 11b, the hydraulic pump 1
It is determined whether a discharge pressure of 0 is supplied.

A control lever 13 is provided to control the supply of hydraulic pressure to the hydraulic cylinder 12. Control lever 1
3 is coupled to a voltage signal generator 14, which generates a voltage signal according to the operation amount of the control lever 13. The output of the voltage signal generator 14 is connected to a voltage amplifier 15. The voltage amplifier 15 amplifies a voltage signal from the voltage generator 14, and its output is connected to a switch 16 having a plurality of contacts. Each contact of the switching unit 16 is connected to a computing unit 17
a, 17b, 17c, and 17d. These computing units 17a, 17b, 17c, 17d have different characteristics, and the output is
8 is connected. The output of the current amplifier 18 is connected to two electromagnetic proportional valves 19a, 19b. The electromagnetic proportional valves 19a and 19b are connected to the pressure receivers 11a, 1
1b, and generates a control oil pressure for the pressure receivers 11a and 11b according to the output signal of the current amplifier 18. This control oil pressure changes according to the characteristics of the computing units 17a to 17d selected by the switching unit 16. 20
Is a reservoir for hydraulic oil.

[0012] A typical example of the use of a hydraulic excavator is a heavy excavation operation using the maximum power of a machine,
Quick work requiring relatively fast work, intermediate soil removal work, trench excavation work, leveling work as light work,
There is a slope forming operation. The load in these operations can be predicted in advance. When using the control device of the present invention, the degree and nature of the load are predicted in accordance with the work content, and the most appropriate one of the arithmetic units 17a to 17d is selected by the switching unit 16. With this selection, it is possible to control the flow rate appropriately in accordance with the work content without significantly controlling the operation amount by the control lever 13.

[0013]

As apparent from the above description, according to the present invention, the arithmetic means provided between the voltage amplifying means and the current amplifying means is constituted by a plurality of arithmetic units having different characteristics. Is switched by the switching means, so that it is possible to control the flow rate to the actuator using an appropriate computing unit according to the work content. Therefore, fine adjustment by the control lever as required in the conventional device is not required, and the operation becomes easy.

[Brief description of the drawings]

FIG. 1 is a side view showing an example of a hydraulic excavator which is a construction machine to which the present invention is applied.

FIG. 2 is a circuit diagram illustrating an example of a hydraulic control circuit of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Hydraulic pump 11 Flow control valve 12 Hydraulic cylinder 13 Control lever 14 Voltage signal generator 15 Voltage amplifier 16 Switching device 17a Operation unit 18 Current amplifier 19a Electromagnetic proportional valve

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Hideo Konishi 1-3-2 Kitaaoyama, Minato-ku, Tokyo Inside New Caterpillar Mitsubishi Corporation (72) Inventor Hiroshi Nosaka 2-5-1 Marunouchi, Chiyoda-ku, Tokyo Inside Mitsubishi Heavy Industries, Ltd. (72) Inventor Manabu Tamura 2-5-1 Marunouchi, Chiyoda-ku, Tokyo Inside Mitsubishi Heavy Industries, Ltd. (56) References JP-A-3-231309 (JP, A) Jpn. (JP, U)

Claims (1)

(57) [Claims] 1. A control lever, voltage signal generating means for mechanically receiving an operation amount of the control lever and generating a voltage signal according to the operation amount, and amplifying a voltage signal from the voltage signal generation means. A voltage amplifier for generating a current output signal in response to the output of the voltage amplifier, a current amplifier for amplifying the output signal of the calculation means, and an electromagnetic proportional valve operated with the output signal of the current amplifier. A control device for a construction machine comprising: a flow control valve that generates a flow rate corresponding to the output signal of the electromagnetic proportional valve and supplies the flow rate to an actuator; wherein the calculation unit is configured by a plurality of calculation units having different characteristics; A control device for a construction machine, comprising switching means for arbitrarily switching an output of an amplifier and switching connection to a selected one of the arithmetic units.