JPS5910480B2 - Filling rate control device for closed mechanical shield machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a control device for controlling the filling rate of earth and sand in a screw conveyor of a closed mechanical shielding machine.

Generally, as shown in FIG. 1, a sealed mechanical shield machine excavates a face by rotating a packet d to which a cutter C is attached by a cutter drive device fixed to a shield body a.

The screw conveyor e protrudes into the bucket) d, and a screw conveyor drive device f provided at the end of the screw conveyor e drives the screw conveyor e to discharge earth and sand from inside the packet d.

The discharged earth and sand is dropped onto the earth discharge conveyor i through a rotary hopper h driven by a rotary hopper drive device g and connected to the rear of the screw conveyor, and is further discharged to the rear.

Note that j is a shield jack.

The shield machine configured in this manner is controlled by matching the shield jack propulsion speed with the screw conveyor rotation speed, as shown in Figure 2, in order to prevent face collapse due to excavation of the excavated ground. Not in an aggressive way.

This is because in order to prevent face collapse, it is necessary to prevent the earth pressure within the packet and the outflow of groundwater, but with conventional control methods, as seen in JP-A-52-128633, for example, earth pressure is used alone. It is not controlled using a fully automatic control system that prevents groundwater from flowing out.

Therefore, the present invention prevents the face from collapsing during excavation work using a closed mechanical shield machine, and in order to ensure safe excavation, earth pressure is controlled using the conventional method, and to prevent groundwater from flowing out, earth and sand is filled in the screw conveyor. It is an object of the present invention to provide a filling rate control device for a closed mechanical shield machine that controls the filling rate.

The present invention is characterized in that a packet with a cutter is rotatably supported within the shield body, a screw conveyor is provided inside the shield body so as to protrude into the packet with μ cutters, and a rotary hopper is provided at the rear of the screw conveyor. In a hermetically sealed mechanical shield machine with a series of The control system compares the output of the conveyor filling rate setting device and outputs a correction signal using the proportional-integral action regulator or proportional action regulator, and generates a function that determines the correspondence between the screw conveyor rotation speed and the rotary hopper rotation speed. a second control system that adds the output of the function generator to the correction signal of the first control system; and a value obtained by converting the sign of the detected value of the rotary hopper rotation speed and the output signal of the second control system. and a third control system that connects the resulting value to the rotary hopper rotation speed control unit via the proportional-integral operation regulator or the proportional-integral operation regulator, and controls the screw conveyor by controlling the rotary hopper rotation speed. The objective is to control the sediment filling rate within the area.

By manipulating the rotation speed of the rotary hopper in this way and controlling the filling rate of earth and sand in the screw conveyor, when the detection value of the filling rate detector is greater than the set value, the rotation speed of the rotary hopper is increased and the soil is discharged. The quantity is increased, and when the detected value is smaller than the set value, this operation is reversed to prevent groundwater from flowing out of the excavated ground, resulting in stable excavation.

Embodiments of the present invention will be described in detail below with reference to FIG.

The filling rate inside the screw conveyor is determined by converting the code of the screw conveyor filling rate setting device 1 using the code converter 2, and detecting the earth and sand filling rate using a gamma ray densitometer or an ultrasonic densitometer installed at the rear of the screw conveyor body. The output of the ratio detector 3 and the value passed through the sample-and-hold circuit 4 are added by an adder 5, and the result is added to a proportional-integral action regulator 6 (a proportional action regulator may also be used).

) as input. However, the sample hold circuit 4 receives the output of the rotary hopper rotation angle meter 7 and samples and holds the output of the conveyor filling rate detector 3 using the output signal of the sample signal generator 8 which generates a sample signal at a specified angle. is configured to do so.

Next, the proportional-integral operation regulator 6 receives the output of the adder 5, performs a proportional-integral calculation, and then outputs the output and adds it to a value to be described later.

However, if the proportional-integral action regulator 6 is replaced with a proportional action regulator, proportional calculation will be performed.

The relationship between the screw conveyor rotation speed and the rotary hopper rotation speed is determined by a function generator 9 (a coefficient generator may also be used).

), a signal 10 corresponding to the target value of the screw conveyor rotation speed is input to the function generator 9, and the output of the function generator 9 and the output of the proportional-integral operation regulator 6 are added by the adder 11.

Further, an adder 14 adds the output of the adder 11 and a value obtained by converting the output of the rotary hopper rotation speed detector 12 into a sign converter 13, and the resulting value is added to a proportional-integral action regulator 15 (also known as a proportional-integral action regulator). good.

), after calculating the proportional integral, the rotary hopper rotation speed control section 1
6 and rotate the rotary hopper.

However, if the proportional-integral action regulator 15 is replaced with a proportional action regulator, it is a matter of course that the calculation is proportional.

Next, its effect will be explained. In order to prevent groundwater from flowing out of the excavated ground, a certain value is set in the screw conveyor filling rate setting device 1, and the output of the screw conveyor filling rate detector 3 is compared with the sample-held value.

As a result of the comparison, if the value obtained by sample-holding the output of the screw conveyor filling rate detector 3 is larger than the set value, a signal to increase the rotation speed of the rotary hopper is sent to the rotary hopper rotation speed control section 16, and the screw conveyor Decrease the filling rate by increasing the amount of soil discharged inside.

Note that the sample hold command is issued when the output of the rotary hopper rotation angle meter 7 reaches a specified angle.

Conversely, when the filling rate in the screw conveyor is small, the rotation speed of the rotary hopper is decreased, the filling rate is increased, and the filling rate in the screw conveyor is maintained at the set value.

The above is the main flow of controlling the filling rate in the screw conveyor, but in order to further improve the control performance, the rotation speed of the rotary hopper is fed back and the output of the proportional-integral operation regulator 6 for controlling the filling rate in the screw conveyor is adjusted. A proportional-integral operation regulator 15 for controlling the rotary hopper rotation speed is provided so that the output of the rotary hopper rotation speed detector 12 corresponds to the output.

In addition, since there is a close relationship between the screw conveyor rotation speed and the rotary hopper rotation speed, this correspondence is set in the function generator 9 to match the fluctuation of the target value equivalent signal 10 of the screw conveyor rotation speed. A feedforward control system is installed to directly change the rotation speed of the rotary hopper.

This feedforward control system not only reduces transient control deviations (but also reduces the offset when the proportional-integral action regulator 6 is replaced with a proportional action regulator).

According to the present invention, the output of the screw conveyor filling rate detector is sampled and held by the sample hold circuit when the output of the rotary hopper rotation angle meter matches a specified angle, and the output of the screw conveyor filling rate detector is sampled and held. The first control system compares the output of the setting device and outputs a correction signal using the proportional-integral action regulator or the proportional action regulator, and the function generator sets the correspondence between the screw conveyor rotational speed and the rotary hopper rotational speed. , a second control system that adds the output of the function generator to the correction signal of the first control system; and a value obtained by sign-converting the detected value of the rotary hopper rotation speed and the output signal of the second control system; The third control system connects the value to the rotary hopper rotation speed control operating end via the proportional integral action regulator or the proportional action regulator, and controls the rotary hopper rotation speed to control the soil filling rate in the screw conveyor. By controlling this, the following effects can be achieved.

(1) If the screw conveyor filling rate detector is installed near the rotary hopper inlet, the soil in the screw conveyor will fall into the hopper when the rotary hopper window is at an angle to receive the soil in the screw conveyor. However, at the same time, the filling rate suddenly decreases.

However, if the rotation speed of the rotary hopper is lowered just because the filling rate has decreased, after the hopper socket closes, the filling rate will become larger than the value before the rotary hopper socket opened, and the average In particular, the rotation rate of the rotary hopper fluctuates even when there is no need to change it, which is undesirable.

Therefore, in the present invention, for example, the angle at which the rotary hopper starts opening is not limited to a specified angle.

) When that angle is reached, the output of the filling rate detector inside the screw conveyor is held and the value of the sudden drop in the filling rate is ignored.In other words, the disturbance is removed, so there is no fluctuation in the rotary hopper rotation speed. .

(2) Since there is a close relationship between the screw conveyor rotation speed and the rotary hopper rotation speed, a signal corresponding to the screw conveyor rotation speed is used as a feedforward signal by a function generator, so the detected value of the filling rate in the screw conveyor is fed back. Control performance is improved compared to control using only signals.

Furthermore, if the main controller (proportional-integral action regulator) is replaced with a proportional action regulator, an offset in the filling rate remains, but its value is very small.

(3) Since a minor loop is created based on the rotation speed of the rotary hopper, the output of the main controller (proportional-integral operation regulator) and the output of the function generator, which receives a signal equivalent to the screw conveyor rotation speed, are based on the rotation speed of the rotary hopper. Since the relationship is linearly proportional, stable control can easily be obtained in the entire range from low rotation to high rotation of the screw conveyor.

In short, according to the present invention, the earth and sand filling rate in the screw conveyor can be stably controlled, so face excavation can be performed safely and excavation efficiency can be improved.

[Brief explanation of the drawing]

Fig. 1 is a side view schematically showing a hermetic mechanical shielding machine, Fig. 2 is a block diagram showing a conventional intra-packet control system, and Fig. 3 is a filling rate control device for a hermetic mechanical shielding machine according to the present invention. FIG. 2 is a block diagram showing an embodiment of the present invention.

Claims (1)

[Claims] 1. A sealed mechanical shield in which a packet with a cutter is rotatably supported within the shield body, a screw conveyor is provided within the shield body protruding into the packet with a cutter, and a rotary hopper is connected to the rear of the screw conveyor. In the machine, the output of the filling rate detector in the screw conveyor is sampled and held by the sample and hold circuit when the output of the rotary hopper rotation angle meter matches the specified angle.
The first control system compares the value with the output of the filling rate setting device in the screw conveyor and outputs a correction signal using the proportional-integral action regulator or the proportional action regulator, and the correspondence between the screw conveyor rotation speed and the rotary hopper rotation speed. a second control system in which the relationship is set by a function generator and the output of the function generator is added to the correction signal of the first control system; a value obtained by converting the sign of the detected value of the rotary hopper rotation speed; and the second control system. A third control system connects the output signal of A filling rate control device for a closed mechanical shield machine, which is characterized by controlling the filling rate of earth and sand in a screw conveyor.