JPH0319360B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an excavation control device for an earth pressure type shield excavator.

When excavating a tunnel with an earth pressure type shield excavator, in order to stabilize the face, it is effective to maintain an appropriate degree of filling of earth and sand temporarily stored in the cutter to counteract the earth pressure and water pressure of the face. It is.

Conventionally, therefore, a method has been devised in which the earth pressure inside the cutter is measured and the rotation of the screw conveyor is varied to control the amount of soil discharged so that the measured earth pressure falls within an allowable range. However, in this method,
Although it is effective in the case of highly fluid silty soil, the reliability of the measured value of soil pressure inside the stub is low in the case of low-flowing soil, so it is necessary to maintain the degree of soil filling in the stub at an appropriate level. was difficult.

Therefore, a method was devised that added a "feed forward control" function to the above method, which changes the rotational speed of the screw conveyor based on the excavated volume signal obtained from the shield jack stroke. However, in this method, the relationship between the number of revolutions of the screw conveyor and the amount of soil discharged is not necessarily constant, so there is still a problem that there is a large error in the amount of soil discharged relative to the amount of excavated soil.

In view of these circumstances, the present invention balances the amount of excavated soil and the amount of discharged soil, and at the same time, maintains the soil pressure inside the stub within an allowable range, thereby controlling the degree of filling of the stub with soil, thereby achieving stable excavation. The present invention has been made to provide an excavation control device for an earth pressure type shield excavator that can perform the following operations.

Embodiments of the present invention will be described below with reference to the drawings.

In the figure, 1 is an earth pressure type shield excavator, 2 is a screw conveyor, 3 is a hydraulic motor rotated by the drive of a variable displacement hydraulic pump 4,
Reference numeral 5 indicates an earth pressure meter that measures the earth pressure within the cutter 6, 7 indicates a stroke detector that detects the stroke of the shield jack 8, and 9 indicates a belt conveyor 10 for transporting earth and sand.
11 is a rotation detector.

12 is a converter that converts the signal detected by the stroke detector 7 into an excavated volume signal, and a controller 14 that outputs a control signal via a variable gain amplifier 13 is connected to the converter 12. , and the control signal from the controller 14 is input to the pump 4 via an amplifier 15. In addition, controller 1
4 consists of an adder 16 and an arithmetic unit 17. Also 18
is the signal from the load detector 9 and the rotation detector 11
This is a converter that obtains a discharged soil amount (weight) signal from the signal from the converter and the signal from the earth and sand unit weight setter 19, and the signal from the converter 18 is sent as a feedback signal to the adder 16 in the controller 14. It is configured to be input. Furthermore, 20 is an adder 21
This is an earth pressure signal controller consisting of a regulator 22 and an arithmetic unit 23, in which the signal from the earth pressure gauge 5 is sent to an amplifier 24.
The feedback signal is inputted to the adder 21 as a feedback signal, added to the signal from the target earth pressure setting device 25, and then calculated by the calculator 23 via the adjuster 22, and the adjustment signal from the calculator 23 is input to the variable gain The signal is configured to be input to an amplifier 13.

As described above, we have constructed a system that controls the amount of soil discharged to be equal to the amount of excavated soil, and a system that further finely adjusts the amount of soil discharged so that the earth pressure measurement value is within the allowable range. be.

In the former system, the stroke signal of the shield jack 8 detected by the stroke detector 7 is converted into an excavated earth volume signal by the converter 12,
The signal is input to the controller 14 via the amplifier 13. Further, a discharged soil volume signal is determined by the converter 18 from the signals of the load detector 9, the rotation detector 11, and the earth and sand unit weight setting device 19, and becomes a feedback signal for the controller 14. Note that the signal from the setting device 19 may be input to the input side of the controller 14 instead of being input to the converter 18. Controller 14
Then, the adder 16 adds the excavated soil volume signal and the discharged soil volume signal, and if there is a difference, the calculation unit 1
At step 7, a control signal is applied to the pump 4, and the pump 4 discharges pressure oil at a flow rate proportional to the applied control signal, thereby rotating the motor 3 of the screw conveyor 2. Now, if the gain of the variable gain amplifier 13 is 1, the amount of soil discharged from the screw conveyor 2 is proportional to the rotational speed of the screw conveyor 2, so that the amount of soil discharged from the screw conveyor 2 will eventually pass through the belt conveyor 10. The rotation speed of the screw conveyor 2 is controlled so that the amount of soil is equal to the amount of excavated soil.

On the other hand, in the latter system, the target earth pressure setting device 2
A setting signal from the cutter 6 is applied to the adder 21 of the controller 20, and a signal of the measured value of the soil pressure gauge 5 inside the cutter 6 is applied to the adder 21 via the amplifier 24 as a backup signal. Here, the regulator 22 has a dead zone for the deviation signal,
The measured earth pressure has a permissible range. Therefore, when the measured earth pressure falls outside the allowable range, the output from the computing unit 23 becomes the gain control input of the amplifier 13, which acts to give a multiplier to the amount of soil discharged relative to the amount of excavated soil. That is, if the measured earth pressure is within the allowable earth pressure range, the gain of the amplifier 13 is 1.0, and control is performed so that the amount of excavated earth is equal to the amount of earth discharged. Also, if the measured earth pressure exceeds the allowable earth pressure range, amplifier 1
The gain of 3 is higher than 1 (for example, about 1.1), and the amount of discharged soil is controlled to be somewhat larger than the amount of excavated soil. On the other hand, if the measured earth pressure becomes smaller than the allowable earth pressure range, the amount of soil discharged is controlled to be somewhat smaller than the amount of excavated soil. In this way, the amount of soil discharged is finely adjusted so that the earth pressure inside the cutter 6 is maintained within an allowable range.

In the above embodiment, a load detector and a rotation detector were used to measure the amount of discharged soil, but it may be controlled by feeding back the amount of discharged soil actually measured by, for example, a Zuritrotsuko load measuring device. Alternatively, the present invention may be used in a shield excavator using a rotary sand discharge device other than a screw conveyor, such as a rotary feeder, and various other changes may be made without departing from the gist of the present invention. Of course.

As mentioned above, according to the present invention, (i) Since the earth and sand discharge device is controlled so that the amount of discharged soil and the amount of excavated soil are equal, it is no longer necessary to control the earth and sand discharge device by relying only on the soil pressure gauge as in the past. Compared to the case where the earth pressure gauge is out of order, the earth pressure inside the cutlet is no longer destabilized, and stable excavation can be performed and the face can be stabilized.

(ii) If the discharge device is controlled only by relying on the soil pressure gauge as in the past, the soil pressure gauge will easily go awry due to things such as soil adhering to the soil pressure gauge.
During intermediate excavation, it was necessary to relieve the pressure inside the cutter and then adjust the soil pressure gauge for errors, but according to the present invention, the soil discharge device can be controlled so that the amount of soil removed and the amount of excavated soil are equal. This eliminates the troublesome adjustment work described above.

(iii) As in the past, if the discharge device was controlled solely by the soil pressure gauge, there was a risk that the soil pressure gauge would be damaged by the gravel when excavating a gravel layer, making it impossible to excavate. For example, since the earth and sand discharge device is controlled so that the amount of soil discharged and the amount of excavated soil are equal, it is possible to stably excavate even gravel layers.

(iv) The amount of soil removed is detected based on the weight of the soil, and the amount of soil removed is detected at the position of the belt conveyor behind the rotary soil discharge device. It is also possible to always obtain an accurate amount of soil removal.

It can produce excellent effects such as

[Brief explanation of the drawing]

The figure is an explanatory diagram of the apparatus of the present invention. 1... Shield excavator, 2... Screw conveyor, 3... Motor, 4... Pump, 5... Earth pressure gauge, 6... Katsuta, 7... Stroke detector, 8
...Shield jack, 9...Load detector, 10
... Belt conveyor, 11 ... Rotation detector, 12
...Converter, 14...Controller, 18...Converter,
19... Setting device, 20... Controller, 25... Setting device.

Claims (1)

[Scope of Claims] 1. In an earth pressure type shield excavator equipped with a rotary earth and sand discharge device, a load detection device is installed on a belt conveyor that is disposed behind the discharge device and carries out the earth and sand discharged from the discharge device to the outside. an excavated soil volume measuring device, and signals from both of these measuring devices. 1. An excavation control device for an earth pressure type shield excavator, comprising: a calculation controller that calculates the amount of earth and sends a control signal to the ejection device so that the amount of earth removed and the amount of excavated earth become equal. 2. In an earth pressure shield excavator equipped with a rotary earth and sand discharge device, a load detector, a rotation detector, and a There is an excavated soil measuring device, which measures the amount of soil discharged by the belt conveyor based on the signal from the soil unit weight setting device, and an excavated soil measuring device, and the signals from both of these measuring devices are calculated and the soil is discharged. an arithmetic controller that sends a control signal to the discharge device so that the amount of excavated soil is equal to the amount of excavated soil; an earth pressure detector that detects the earth pressure in the cutter; and a signal from the detector and a target earth pressure setting signal. An excavation control device for an earth pressure type shield excavator, comprising: an adjustment device for finely adjusting a signal from an excavated earth volume measuring device that is calculated and sent to the arithmetic controller.