JP3901469B2 - Control method of shield jack in shield machine - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for controlling a shield jack in a shield machine.
[0002]
[Prior art]
When excavating a tunnel with a shield machine, the shield body moves forward by pushing a segment placed behind it with a number of shield jacks arranged at predetermined intervals on the rear inner peripheral surface of the shield body. It has been made.
[0003]
Conventionally, when a shield main body is advanced by a shield jack, high pressure oil is supplied to the shield jack selected for advancement and pressing operation is performed, and the remaining shield jack is supplied with low pressure oil, and is simply segmented. It was made to follow operation to follow.
[0004]
[Problems to be solved by the invention]
According to the conventional shield jack control method, if work such as direction correction occurs during excavation, the pressing position of the shield jack with respect to the segment will shift, but the pressing force is applied to all the selected shield jacks. In this state, the pressing position is difficult to shift, and therefore an excessive displacement force acts on the segment, and the segment and the shield jack may be damaged.
[0005]
Accordingly, an object of the present invention is to provide a method for controlling a shield jack in a shield machine capable of preventing a segment, a shield jack, and the like from being damaged due to a displacement force during tunnel excavation.
[0006]
[Means for Solving the Problems]
In order to solve the above problems, a shield jack control method in the shield machine of the present invention is a control method for a plurality of shield jacks arranged at predetermined intervals along the rear inner peripheral surface of the shield body. ,
Shield jack pressing force is selected to propulsion is generated, with a predetermined time interval one by one, or one by plural with a predetermined time interval, the No pressing force smaller or pressing action It is a method to stop.
[0007]
Further, the shield jack control method in another shield machine of the present invention is a control method of a plurality of shield jacks arranged at predetermined intervals along the rear inner peripheral surface of the shield body,
Shield jack pressing force is selected to propulsion is generated, with a predetermined time interval one by one, or one by plural with a predetermined time interval, the No pressing force smaller or pressing action when going to stop, for the shield jacks located on the opposite side, at the same time or alternately with the shield jack is a method for stopping the small or without pressing action of the pressing force.
[0008]
According to each control method above, the pressing force by the shield jack is temporarily reduced or stopped one by one or several at a time, so the pressing force is not evenly applied to the segment In addition, the shifting force generated between the shield jack and the segment is released.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the control method of the shield jack in the shield machine in embodiment of this invention is demonstrated based on FIGS.
[0010]
First, a schematic configuration of the shield machine will be described.
As shown in FIG. 1 and FIG. 2, a large number, for example, 24 of shield jacks 2 are arranged at a predetermined interval on the rear inner peripheral surface of the shield main body 1 of the shield machine. Is provided with a hydraulic device for generating a pressing force on the shield jack 2 to apply a propulsive force to the shield body 1.
[0011]
As shown in FIG. 3, the hydraulic device 3 includes an oil tank 11 and an oil supply pipe that is provided between the oil tank 11 and each shield jack 2 and is connected to the hydraulic pump 12 to supply high-pressure oil. 13, an oil return pipe 14 provided between the shield jack 2 and the hydraulic tank 11, and an operation valve for operating a shield jack (oil path) provided in the middle of the oil supply pipe 13 and the oil return pipe 14. A four-port, three-position electromagnetic switching valve for switching) 15 and oil supply side branch pipes 13a connected across the oil supply pipe 13 and the head side of each shield jack 2 respectively. A head-side selection valve (a 2-port 2-position electromagnetic switching valve that turns the oil passage on and off is used) 16 is connected across the oil return pipe 14 and the rod side of each shield jack 2. A rod-side selection valve (a 2-port 2-position electromagnetic switching valve for turning on / off the oil passage) 17 provided on each of the oil return side branch pipes 14a and a downstream side of the operation valve 15 of the oil supply pipe 13 And a pressure reducing valve 18 and a follow-up switching valve (a two-port, two-position type electromagnetic valve for turning on / off the oil passage) and connected to the portion and a portion downstream of the selection valve 15 of each oil supply side branch pipe 13a. 19 is provided and a low-pressure oil supply pipe 20 for supplying low-pressure oil, a portion downstream of the operation valve 15 of the oil supply pipe 13 and an oil return pipe downstream of the operation valve 15. 14 and an oil relief pipe 22 provided with a relief valve 21 in the middle.
[0012]
In addition, a check valve 23 for flowing only the low-pressure oil on the low-pressure oil supply pipe 20 side to the oil supply-side branch pipe 13a side is provided at a connection portion between the low-pressure oil supply pipe 20 and each oil supply-side branch pipe 13a. In addition, check valves are provided where necessary. In FIG. 3, reference numeral 24 denotes an unload circuit.
[0013]
At least a control device (not shown) for controlling each operation valve 15, each selection valve 16, 17 and follow-up switching valve 19 is provided.
Next, a method for controlling the shield jack in the above configuration will be described with reference to FIGS.
[0014]
When the shield main body 1 is moved straight, a pressing force equal to all the shield jacks 2 is generated, and the shield main body 1 is advanced (promoted) by the reaction force from the segment S to perform excavation. In this case, no problem occurs because there is no displacement at the contact portion between the rod portion of the shield jack 2 and the segment S.
[0015]
By the way, when the direction of the shield body 1 is changed to, for example, the left side, as shown by the oblique lines in FIG. 2, the right half (for the sake of clarity, a pressing force is generated on the right shield jack. The left-hand shield jack will be described as a follow-up, but in practice, the number and position of the shield jacks to be selected are determined each time according to the direction change degree). A pressing force is generated.
[0016]
At this time, the supply of the high-pressure oil supplied to the shield jacks 2 (NO. 1 to NO. 12) arranged from the upper side to the lower side is temporarily stopped by the control device. That is, the on / off operation of the head side selection valve 16 of each shield jack 2 is turned off for a predetermined time (several seconds) in order at predetermined intervals, as shown in the time chart of FIG. Is done. Of course, after a predetermined time has elapsed, the state is returned to the on state. While the head side selection valve 16 is in the off state, the follow-up switching valve 19 is turned on and the low pressure oil is supplied from the low pressure oil supply pipe 20 and pushed to the segment S with a small pressing force. There is a tracking state.
[0017]
In this way, the shield jack 2 pressing the segment S is reduced in order by a predetermined time (with a predetermined time interval), that is, the pressing force is released, and the low pressure follow-up state is achieved. Therefore, the displacement force generated between the segment S and the rod portion of the shield jack 2 is released, and therefore damage can be prevented from occurring on the segment S and shield jack 2 side. As long as the same excavation operation continues, a series of operations for temporarily stopping the supply of high-pressure oil to the selected shield jack 2 is repeated.
[0018]
By the way, in the said embodiment, although demonstrated so that pressing force might be cancelled | released only about the shield jack 2 selected in order to change a direction, it is good also considering all the shield jacks 2 as the control object.
[0019]
In this case, for example, after first releasing the pressing force of the first shield jack 2 (NO.1) positioned on the upper right side, the pressing of the thirteenth shield jack 2 (NO.13) positioned on the opposite side is released. After releasing the pressure and then releasing the pressing force of the second shield jack 2 (NO.2), the pressing force of the 14th shield jack 2 (NO.14) located on the opposite side is released, Next, the same control as described above may be continued for the remaining shield jacks 2 in order, such as the third and fifteenth shield jacks 2.
[0020]
In this way, compared to the case where the pressing force is released only for the selected group of shield jacks 2, the shields that are positioned in order and on the opposite side of all the shield jacks 2 are targeted. The control procedure (control logic) is simplified by releasing the jack pressing force. Moreover, the influence on the attitude | position change of a shield main body can also be suppressed.
[0021]
Further, in the above embodiment, when the pressing force of the selected shield jack 2 is released, the low pressure oil is supplied and the tracking state is maintained. However, the head side selection valve 16 and the rod side selection valve 17 are in the following state. And the oil supply may be completely stopped, that is, the pressing operation may be stopped. Thus, when the pressing operation is stopped, the rod portion of the shield jack 2 can be completely separated from the segment S.
[0022]
Furthermore, in the above-described embodiment, the shield jacks 2 have been described so that the pressing force is reduced or stopped one by one in order . For example, the plurality of shield jacks 2 are sequentially increased in the pressing force. It can be small or stopped.
[0023]
【The invention's effect】
As described above, according to the control method of the shield jack of the present invention, the pressing force by the shield jack is reduced or stopped one by one or plural at a predetermined time interval. When the pressing force is not evenly applied, the displacement force generated between the shield jack and the segment is released, and therefore it is possible to prevent the segment, the shield jack and the like from being damaged.
[Brief description of the drawings]
FIG. 1 is a schematic sectional view of a main part of a shield machine according to an embodiment of the present invention.
FIG. 2 is a rear view showing an arrangement state of shield jacks in the shield machine.
FIG. 3 is a hydraulic circuit diagram of a shield jack in the shield machine.
FIG. 4 is an operation time chart of a head side selection valve with respect to the shield jack.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Shield body 2 Shield jack 13 Oil supply pipe 13a Oil supply side branch pipe 14 Oil return pipe 14a Oil return side branch pipe 15 Operation valve 16 Head side selection valve 17 Rod side selection valve

Claims (2)

A control method for a plurality of shield jacks arranged at predetermined intervals along the rear inner peripheral surface of the shield body,
Shield jack pressing force is selected to propulsion is generated, with a predetermined time interval one by one, or one by plural with a predetermined time interval, the No pressing force smaller or pressing action A method for controlling a shield jack in a shield machine, wherein the shield jack is stopped. A control method for a plurality of shield jacks arranged at predetermined intervals along the rear inner peripheral surface of the shield body,
Shield jack pressing force is selected to propulsion is generated, with a predetermined time interval one by one, or one by plural with a predetermined time interval, the No pressing force smaller or pressing action when going to stop, for the shield jacks located on the opposite side, at the same time or alternately with the shield jack of shield jacks in the shield machine is characterized in that stopping the small or without pressing action of the pressing force Control method.

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