JPH041159B2 - - Google Patents

Description

Detailed Description of the Invention (Field of Industrial Application) This invention is directed to a shield excavator that controls the number of cutter drive motors of a shield excavator used for tunnel excavation work, and controls the propulsion speed of a shield jack. The present invention relates to a control device.

(Prior art) As a conventional method of operating a shield excavator in tunnel excavation work, when the power source for driving the cutter is an electric motor, the operator uses an ammeter to measure the current flowing through the electric motor (in the case of a hydraulic motor, the operator uses a pressure meter to measure the current flowing through the electric motor). ), and the propulsion speed of the shield jack, that is, the depth of cut of the cutter, is determined by taking into account the hardness and soil quality of the ground face to prevent the cutting load of the cutter from becoming overloaded.

In addition, when an electric motor is operated under light or medium load, both mechanical efficiency and power factor are extremely reduced, so the control of the number of electric motors that drive the cutter is mainly focused on energy conservation, and the number of electric motors that drive the cutter is controlled to increase the number of electric motors to achieve the rated load. It is being controlled to save power.

If the power source for driving the cutter is a hydraulic motor, overload of the cutter power is prevented by detecting the cutter pressure and controlling the discharge amount of the shield pump.

(Problems to be Solved by the Invention) As mentioned above, when an electric motor is used as a power source for driving a cutter, the conventional method of controlling the number of electric motors is not sufficient to simply save energy, and it is difficult to control the propulsion speed of the shield jack. The current situation is that it has not been developed to take this into account.

On the other hand, when using a hydraulic motor, the pilot pressure of the shield pump is controlled by controlling the cutter pressure against the spring force of the torque converter valve, and the shield jack propulsion speed is adjusted. Although it is necessary to adjust the gain according to the soil quality, in the case of torque converter valve control, the spring constant is constant, so the relationship between the cutter pressure and the shield pump pilot pressure is constant, which means that the gain cannot be adjusted. be.

This invention was made in view of the above points, and focuses on the fact that currently the power source for driving cutters is generally an electric motor.In addition to saving energy by controlling the number of electric motors, it also promotes shield jacking. The purpose of the present invention is to provide a control device for a shield excavator that enables automatic operation by speed control (gain adjustment and operation mode selection possible depending on soil quality).

(Means for Solving the Problems) The gist of the present invention for achieving the above object is that the current value or torque value of the electric motor for driving the cutter changes depending on the cutting load of the cutter on the earth face. A detector that detects the current value and an upper and lower limiter connected to the detector and a comparator based on a deviation comparison between the detection signal from the detector and a preset current value or torque value constant,
A control device for a shield excavator is characterized in that it controls the number of electric motors and further controls the propulsion of a shield jack via a gain adjustment circuit.

(Function) According to the control device of the present invention, the current value or torque value flowing through the cutter drive motor is detected,
At the same time, it is possible to control the number of motors to bring the motor closer to the rated load, and at the same time, it is possible to select a shield jack propulsion speed gain that corresponds to changes in the motor drive current or torque to match the soil type, and to reduce the amount of deviation from the rated current value or rated torque value. It is possible to control the propulsion speed of the shield jack according to the speed. In other words, the rated current value or torque value can be determined (selected) based on the soil mode of the motor drive current or torque.

(Example) Hereinafter, an example of the present invention will be described based on the drawings.

The drawing is a schematic configuration diagram of the present invention.

In the figure, reference numeral 1 denotes a main body of an excavator, and a cutter 2 is provided on the front surface of a shield frame 1a forming the outer shell of the machine.The cutter 2 is rotationally driven by a plurality of electric motors 3. It is propelled and driven by the jack 4.

5 is a detector for detecting the current value or torque value flowing through the cutter driving electric motor 3 of the cutter 2, which changes depending on the cutting resistance against the earth face;
is a comparator (comparison calculator) connected to this detector 5, which determines the upper limit current value and lower limit current value by comparing the deviation between the detection signal from the detector 5 and a preset current value or torque value constant. The upper and lower limit limiters 7 are connected to the comparator 6 via the gain adjustment circuit 8 and the amplifier 9, and are used to control the amount of pressure oil supplied to the shield jack 4. Control.

In the figure, numeral 10 is a machine-side or local potentiometer, and numeral 11 is a setting device.

In the above configuration, the current value or torque value flowing through the cutter driving electric motor 3 is detected by the detector 5, and this is input to the comparator 6 to set a preset constant of the current value or torque value of the cutter driving electric motor 3. Based on the deviation comparison with controlled.

Also, by comparing the deviation between the input from the detector 5 in the comparator 6 and the preset current value or torque value constant of the cutter drive motor 3, the upper limit current value and the lower limit current value (or the upper limit torque value or the lower limit torque value) are determined. ), when the input is large, the proportional valve 7 is throttled down via the amplifier 9 by the function of the gain adjustment circuit 8 to reduce the input, and when the input is small, the proportional valve 7 is opened. This increases the input power, thereby obtaining an appropriate propulsion speed of the shield jack 4.

Furthermore, since the gain of the gain adjustment circuit 8 can be easily adjusted from the outside, it is possible to obtain the optimum propulsion speed of the shield jack 4 suitable for each mountain.

(Effects) According to the invention configured as described above, by setting the constant of the current value or torque value of the cutter drive motor, the number of cutter drive motors is controlled from the calculation by the upper and lower limiters, and each High efficiency operation is achieved by driving the motor close to its rated load, resulting in energy savings.In addition to controlling the number of cutter drive motors, the upper and lower limit current values (or upper limit torque value or lower limit torque value), the opening of the proportional valve is adjusted by the function of the gain adjustment circuit and the optimum gain adjustment that matches the ground, and the pressure oil supplied to the shield jack is adjusted. By adjusting the supply amount, the optimum propulsion speed of the shield jack is obtained according to the amount of deviation from the rated current value or the rated torque value, thereby achieving automatic operation of the shield excavator.

[Brief explanation of drawings]

The drawings show an embodiment of the invention, with FIG. 1 being a configuration diagram and FIG. 2 being a gain adjustment circuit diagram. DESCRIPTION OF SYMBOLS 1... Excavator main body, 1a... Shield frame, 2... Cutter, 3... Cutter drive electric motor, 4... Shield jack, 5... Detector, 6
... Comparator, 7 ... Proportional valve, 8 ... Gain adjustment circuit, 9 ... Amplifier, 10 ... Machine side or local potentiometer, 11 ... Setting device.

Claims (1)

[Claims] 1. A detector that detects the current value or torque value of the cutter drive motor that changes depending on the cutting load of the cutter on the earth face, and a detector that is connected to the detector and receives a detection signal from the detector and a preset current. A control device for a shield excavator, characterized in that the number of electric motors is controlled by an upper and lower limiter using a comparator based on a deviation comparison between a value or a torque value and a constant, and further, propulsion control of a shield jack is performed via a gain adjustment circuit. .