JPH0542155Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field] This invention is designed to prevent the propulsion jack from receiving a reaction force from the ground when the propulsion jack, which is being operated under no load during the excavation operation of a shield excavator, receives a reaction force from the ground. This invention relates to a hydraulic circuit for an automatic direction control device for a shield tunneling machine that is designed to avoid resistance.

[Prior Art] A shield tunneling machine is provided with a plurality of propulsion jacks in the circumferential direction of a shield frame for digging. The shield tunneling machine moves forward by supplying pressure oil to the propulsion jack while the rear end of the propulsion jack is supported by the segment, thereby causing the piston rod to protrude.

In addition, when making a curve as the shield tunneling machine moves forward, high-pressure oil is supplied to certain of the multiple propulsion jacks to extend their piston rods, while no-load following operation is required in which high-pressure oil is not supplied to the remaining propulsion jacks but low-pressure oil is supplied to them to extend their piston rods.

The hydraulic circuit of the conventional automatic direction control device applied to the above-mentioned shield tunneling machine will be explained with reference to FIG. A main switching valve 4 is connected to the tip of the pipe 3,
A return pipe 5 for returning oil to the tank 1 is connected to the main switching valve 4 .

Another pipe line 6, 11 is connected to the main switching valve 4,
The pipe line 6 branches into two pipe lines 7a and 7b, and the pipe line 7
a, 7b are connected to the propulsion jacks 10a, 10 via propulsion jack side switching valves 8a, 8b and pipes 9a, 9b.
It is connected to the head side oil chambers 22a and 22b of b. Further, the pipe line 11 is branched into two pipe lines 12a and 12b, which are connected to rod side oil chambers 23a and 23b of the propulsion jacks 10a and 10b.

The no-load following valve block 13 is the switching valve 1
4. A pressure reducing valve 15 that reduces the pressure of the oil sent from the switching valve 14, a flow path 16 through which the oil from the pressure reducing valve 15 flows, a check valve 17a that prevents oil from flowing back toward the pressure reducing valve 15, 17b, the pipe line 7a and the switching valve 14 are connected by a pipe line 18, and the pipe line 9a,
9b and check valves 17a, 17b are pipes 19a, 19
connected by b.

A conduit 21 is connected to a conduit 20 connected to the conduit 11, and the conduit 21 is connected to conduits 19a and 19b. In the figure, 24 and 25 are safety valves. Also, although two propulsion jacks are shown in the diagram, in reality,
More than two propulsion jacks are arranged in parallel with the propulsion jacks 10a, 10b. Furthermore, the set pressures P ₁ and P ₂ of the safety valves 24 and 25 and the pressure reducing valve 15
The set pressure P ₃ is adjusted so that P ₁ ≒P ₂ ≫P ₃ .

When the shield tunneling machine goes straight, pipe 3
The main switching valve 4 is opened so that the lines 6, 5 and 11 communicate with each other, the switching valves 8a and 8b are opened so that the pipes 7a and 7b and 9a and 9b communicate with each other, and the switching valve 14 is closed.
Therefore, the oil discharged from the hydraulic pump 2 is transferred to the propulsion jack 1 from the pipe 3, the main switching valve 4, the pipes 6, 7a, 7b, the switching valves 8a, 8b, and the pipes 9a, 9b.
The oil is sent to the head side oil chambers 22a and 22b of 0a and 10b, the piston rod protrudes, and the shield excavator moves straight. Also, due to the protrusion of the piston rods of the propulsion jacks 10a and 10b, the rod side oil chamber 23
The oil in a and 23b is supplied to the pipes 12a, 12b, 11,
It returns to the tank 1 through the main switching valve 4 and the pipe 5.

When making a curve in a shield tunneling machine, it is necessary to perform no-load follow-up operation by supplying low-pressure oil to part of the propulsion jack.

For example, when the propulsion jack 10b is operated in a no-load follow-up operation, the main switching valve 4 is maintained in the switching state when the shield tunneling machine goes straight, and the switching valve 8b is closed as shown in FIG. The oil in line 18 is opened to flow to the pressure reducing valve 15. Half of the high pressure oil discharged from the hydraulic pump 2 is supplied to the head side oil chamber 22a of the propulsion jack 10a from the pipe 3, the main switching valve 4, the pipes 6 and 7a, the switching valve 8a, and the pipe 9a, The piston rod of the propulsion jack 10a pushes the shield excavator.

On the other hand, since the switching valve 8b is closed and the switching valve 14 is open, the remaining half of the high-pressure oil discharged from the hydraulic pump 2 passes through the pipe 18, the switching valve 14, and the pressure reducing valve 15, and then passes through the pressure reducing valve 15. The pressure is reduced and the oil becomes low pressure oil, which flows through the pipe 16, the check valve 17b, and the pipes 19b and 9b.
to the head side oil chamber 22b of the propulsion jack 10b.
sent to. Therefore, the piston rod of the propulsion jack 10b moves forward under no load, following the piston rod of the propulsion jack 10a.

When the piston rod of the propulsion jack 10b receives a reaction force from the earth, the piston rod tries to retreat, so the oil pressure in the head side oil chamber 22b is reduced to the line 9.
b, 19b, 21, 20, and escapes to tank 1 via safety valve 25.

[Problem to be solved by the invention] However, in the above-mentioned hydraulic circuit, when the propulsion jack in a no-load follow-up operation receives a reaction force from the ground, the hydraulic pressure is transferred to the tank via the safety valve 25 which is set at high pressure. Because it is necessary to escape to 1,
There was a problem in that the propulsion jack, which is being operated under no load, resists the ground due to the set pressure of the safety valve 25, and therefore the tunnel boring machine cannot curve smoothly.

The present invention was developed in view of the above-mentioned circumstances, with the purpose of reducing the resistance of the propulsion jack against the ground during no-load follow-up operation, so that the shield tunneling machine can curve smoothly.

[Means for Solving the Problems] The present invention supplies liquid to the head side liquid chambers or rod side liquid chambers of a plurality of propulsion jacks arranged in parallel via a main switching valve and a propulsion jack side switching valve. The liquid from the hydraulic pump is connected to the middle part of the pipe connecting the main switching valve and the propulsion jack side switching valve, and the liquid is supplied to the head side liquid chamber of the propulsion jack which is operated under no load. It is equipped with a switching valve and a pressure reducing valve so that it can be sent under reduced pressure, as well as a safety valve that returns the liquid to the tank in the event that a reaction force from the ground is applied to the head side liquid chamber of the propulsion jack during no-load follow-up operation. A shield retreat prevention pressure control valve equipped with a non-leak valve, disposed between a no-load follow-up valve block and a conduit connecting the no-load follow-up valve block and the propulsion jack side switching valve and the propulsion jack head side liquid chamber. It has a structure with blocks.

[Operation] When the shield tunneling machine moves straight ahead, the pressure liquid discharged from the hydraulic pump is sent to the head side liquid chamber of the propulsion jack via the main switching valve and the switching valve. When the shield tunnel machine curves, the pressure fluid discharged from the hydraulic pump is sent to the head side liquid chamber of the propulsion jack, which does not perform no-load follow-up operation, through the main switching valve and the switching valve, and the no-load follow-up operation is carried out. The liquid is supplied to the head side liquid chamber of the propulsion jack via the main switching valve, no-load following valve block, and shield backback prevention pressure control valve block. In addition, if the reaction force of the ground is applied to the head side liquid chamber of the propulsion jack during no-load follow-up operation, the liquid pressure will be equal to the set pressure of the shield backback prevention pressure control valve block and the no-load follow-up valve block. Return to tank via low safety valve. Therefore, the resistance of the propulsion jack against the ground during no-load follow-up operation is small, and therefore the shield tunneling machine can curve smoothly.

[Embodiments] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

FIG. 1 shows an embodiment of the present invention, and in this embodiment, the pipes 20, 21, the safety valve 25, and the check valves 17a, 17b are removed from the conventional example shown in FIG.
In addition, a safety valve 27 is connected to the middle part of the flow path 16 of the no-load follow-up valve block 13 via a flow path 26, so that oil can be returned from the safety valve 27 to the tank 1. is connected to a shield backback prevention pressure control valve block 28 which is provided with non-leak valves 29a and 29b and is connected to the no-load following valve block 13. Components in FIG. 1 that are the same as those shown in FIG. 3 are given the same reference numerals. Furthermore, the set pressure of the safety valve 24
P ₁ , the set pressure P ₃ of the pressure reducing valve 15, and the set pressure P ₄ of the safety valve 27 are adjusted to satisfy P ₁ ≫P ₃ ≧P ₄ .

When the shield tunneling machine goes straight, pipe 3
The main switching valve 4 is opened so that 6, 5 and 11 communicate with each other, and the switching valves 8a and 8b are opened so that pipes 7a, 7b and 9a, 9b communicate with each other, and the pipe 18 and flow path 16 are cut off. Then, close the switching valve 14 and open the flow paths 16 and 1.
Non-leak valve 29 so that 9a and 19b are shut off.
Close a and 29b. Therefore, the high pressure oil discharged from the hydraulic pump 2 is sent to the head side oil chambers 22a, 22b of the propulsion jacks 10a, 10b through the same path as in the case of FIG. Therefore, the piston rods of the propulsion jacks 10a, 10b protrude, and the shield tunneling machine moves straight.

For example, when the propulsion jack 10b is operated under no load to curve the shield tunneling machine, the main switching valve 4 is held in the switching state when the shield tunneling machine moves straight, and the switching valve 8b is turned as shown in FIG. When the oil in the pipe line 18 is closed, the switching valve 14 is transferred to the pressure reducing valve 15.
The non-leak valve 29b is opened so that the channel 16 and the pipe 19b communicate with each other.

Half of the high pressure oil projected from the hydraulic pump 2 is supplied to the head side oil chamber 22a of the propulsion jack 10a from the pipe 3, the main switching valve 4, the pipes 6 and 7a, the switching valve 8a, and the pipe 9a, As in the case of Figure 3,
The piston rod of the propulsion jack 10a pushes the shield excavator.

On the other hand, since the switching valve 8b is closed and the switching valve 14 is open, the remaining half of the high-pressure oil discharged from the hydraulic pump 2 passes through the pipe 18, the switching valve 14, and the pressure reducing valve 15, and then passes through the pressure reducing valve 15. The pressure is reduced and the oil becomes low pressure oil, which flows through the pipe 16, the non-leak valve 29b, and the pipe 19.
The oil is supplied to the head-side oil chamber 22b of the propulsion jack 10b through the oil pumps b and 9b. Therefore, the piston rod of the propulsion jack 10b moves forward under no load, following the piston rod of the propulsion jack 10a.

When the piston rod of the propulsion jack 10b receives a reaction force from the earth, the piston rod tries to retreat, so the oil pressure in the head side oil chamber 22b is transferred to the pipes 9b, 19b, the non-leak valve 29b, the flow path 16,
26, escapes to tank 1 via safety valve 27. Since the set pressure of the safety valve 27 is low, the resistance of the propulsion jack 10b against the ground is small, so that the tunnel boring machine can smoothly curve while moving forward.

A block diagram of a control device to which the hydraulic circuit of FIG. 1 is applied is shown in FIG. 2, in which 31 is a shield tunneling machine attitude detection device, and 32 is a propulsion jack of FIG. 1 for direction control of the shield tunneling machine. 10a, 10b
33 is a load pushing operation jack operation command signal, 34 is a no-load follow-up operation jack operation command signal, 35 and 36 are the ones shown in FIG. Switching valves 8a, 8b, 14 provided in the hydraulic circuit,
Valves such as non-leak valves 29a and 29b are shown.

The attitude detection device 31 detects the attitude change of the shield tunneling machine.
is detected by the driving jerk selection calculation device 32.
The calculation device 32 calculates which of the propulsion jacks 10a and 10b shown in FIG. , 14, a load pushing operation jack operation command signal 33 or a no-load following operation jack operation command signal 34 is given to the non-leak valve 29a or 29b. Therefore, when the propulsion jack 10a is operated to push a load and the propulsion jack 10b is operated to follow a load, the switching valve 8a shown in FIG. The switching valve 1 shown in FIG. 1 is switched open as shown in FIG.
4. The non-leak valve 29 is opened and the operation as described above is performed. Therefore, the propulsion jacks that are operated with load pushing and the propulsion jacks that are operated with no-load follow-up are automatically selected, and the propulsion jacks that are operated with no-load follow-up are always extended at the same timing as the propulsion jacks that are operated with load push. It turns out.
For this reason, unlike in the conventional case, a stationary propulsion jack that is not operated with a load or a no-load follow-up operation (in the conventional case, when changing the direction of a shield excavator, it is necessary to There is some propulsion jerk, but there is no such propulsion jerk in the present invention.)
There is no sudden stretching and the work can be carried out safely.

In addition, in order to automatically control the direction of the shield tunneling machine, it is necessary to change the thrust of the propulsion jack as appropriate.
This thrust change needs to be done in a timely manner.
For this reason, among the total number of propulsion jacks, the load pushing operation jack and the no-load follow-up operation jack are extended together as described above, and the switching valves 8a, 8b, 14 in FIG. , appropriately switch the non-leak valves 29a and 29b. For this reason, it is possible to switch a propulsion jack that is currently operating by pushing a load by manually operating the propulsion jack during direction control to a no-load follow-up operation, or to switch a propulsion jack that is operating a no-load follow-up operation to push the load. Since there is no need to switch to operation, the propulsion force can be changed quickly without any time delay.

The non-leak valves 29a, 29b may be ordinary switching valves. In this case, due to the internal leakage of the switching valve, the pressure oil in the load pushing operation jack circuit slightly escapes to the low pressure side, resulting in energy loss, but this does not impede the effects of the present invention.

Although the embodiments of the present invention have been explained using oil, it is possible to implement the invention not only with oil but also with other liquids, and to make various changes without departing from the gist of the present invention. Of course.

[Effects of the invention] According to the hydraulic circuit of the shield tunneling machine automatic direction control device of the invention, when the propulsion jack during no-load follow-up operation receives a reaction force from the ground, the shield The tunneling machine has the excellent effect of being able to move forward easily and curve smoothly.

[Brief explanation of the drawing]

Fig. 1 is an explanatory diagram of one embodiment of the present invention, Fig. 2 is a block diagram of a control device to which the present invention is applied, and Fig. 3 is a block diagram of a control device to which the present invention is applied.
The figure is an explanatory diagram of a conventional example. In the figure, 1 is a tank, 2 is a hydraulic pump, 3 is a pipe,
4 is the main switching valve, 5, 6, 7a, 7b are pipelines, 8
a, 8b are propulsion jack side switching valves, 9a, 9b are pipes, 10a, 10b are propulsion jacks, 11 are pipes, 12a, 12b are pipes, 13 is a no-load following valve block, 14 is a switching valve, 15 is a pressure reducing valve, 1
6 is a flow path, 18, 19a, 19b are pipes, 22
Reference numerals a and 22b indicate oil chambers on the head side, 23a and 23b indicate oil chambers on the rod side, 27 a safety valve, 28 a shield backback prevention pressure control valve block, and 29a and 29b non-leak valves.

Claims (1)

[Scope of utility model registration request] A hydraulic pump capable of supplying liquid to the head side liquid chambers or rod side liquid chambers of a plurality of propulsion jacks arranged in parallel via a main switching valve and a propulsion jack side switching valve, and the main switching valve. A switching valve and a pressure reducing valve are provided so that the liquid from the hydraulic pump can be reduced in pressure and sent to the head side liquid chamber of the propulsion jack which is connected to the middle part of the pipe connecting the propulsion jack side switching valve and is operated under no load. and a no-load follow-up valve block equipped with a safety valve that returns liquid to the tank when a reaction force from the earth is applied to the head-side liquid chamber of a propulsion jack that is in no-load follow-up operation, and the no-load follow-up valve block. and a pipeline connecting the propulsion jack side switching valve and the propulsion jack head side liquid chamber, and a shield retreat prevention pressure control valve block equipped with a non-leak valve is provided. Hydraulic circuit of directional control device.