JP2001152781A - Apparatus and method for controlling shield machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an apparatus and a method for controlling a shield machine capable of synchronizing stroke amounts of a jack performing shrinkage operation at the time of measuring digging and a jack performing expansion operation mutually and sufficiently. SOLUTION: In a shield machine provided with a drilling jack 20 capable of separating a front barrel shield 1 and an intermediate barrel shield 2 from each other by a distance and bringing them close to each other and a shield jack 18 capable of advancing a rear barrel shield 3 using an existing segment 19 as a reaction force receiver, stroke sensors 57, 58 detecting stroke amounts of the propulsion jack 20 and the shield jack 18, respectively, an electromagnetic selector valve 50 capable of communicating and shutting off hold pressure adjusting pipe passages 48a, 48b which receive only pressure oil from a hydraulic cylinder for propulsion jack 34 and lead it into a tank 46 through check valves 47a, 47b, and a controller 41 controlling the operation of the electromagnetic selector valve in accordance with the results of detection of the stroke sensors 57, 58 are provided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shield excavator that performs so-called excavation, and more particularly, to sufficiently synchronize the strokes of a jack that operates to contract and a jack that operates to extend during excavation. The present invention relates to a control device and a control method for a shield machine capable of performing the following.

[0002]

2. Description of the Related Art Conventionally, there is a shield machine as a tunnel excavator for soft soil layers. The shield excavator includes a shield body, a cutter rotatably supported on the front side of the shield body in the excavation direction, and a cutter for excavating the ground, a cutter driving device for rotating and driving the cutter, and a rotation of the cutter driving device. A rotation transmission mechanism for transmitting the rotation to the cutter.

When excavating in a tunnel, the cutter is rotationally driven by the driving force of the cutter driving device, and the ground is excavated by a bit provided on the cutter. At this time, the segments are sequentially assembled by an erector provided at the rear of the shield body, and the shield jack is used by using the existing segment as a reaction force receiver of a shield jack arranged in a ring at the rear of the shield body. By extending, a propulsive force is applied to the cutter during the cutter excavation. In this case, since the rotary reaction force of the cutter is small because the soft soil layer is to be excavated, it can be countered only by the frictional force on the segment end by the shield jack, and when spring water in the tunnel occurs, the segment has a watertight structure due to the segment. The excavator is designed to prevent submersion.

However, when such a shield excavator is used for excavating hard rock in a so-called mountain tunnel or the like, the rotational reaction force of the cutter becomes large, so that the frictional force of the shield jack alone cannot be used. Not applicable for rock drilling.

On the other hand, as a tunnel excavator for hard rock,
Conventionally, there is a tunnel boring machine (TBM). This tunnel boring machine is a cutter that is rotatably supported in the forward direction of the excavation direction and excavates the ground, a cutter driving device that rotationally drives the cutter, a rotation transmission mechanism that transmits the rotation of the cutter driving device to the cutter, And a conveyor for sending excavated earth and sand backward.

At the time of tunnel excavation, similarly to the shield excavator, the cutter is rotationally driven by the driving force of the cutter driving device,
The ground is excavated by a bit (roller bit) provided on the cutter. However, since hard rock is targeted for excavation, the rotary reaction force of the cutter is large, so that it protrudes radially from the cutter and the rotation transmission mechanism. Grippers and support legs are provided, and the rock is gripped by these to oppose the cutter rotation reaction force. In addition, by operating these grippers and support legs, it is possible to easily change the excavation direction and make a turn.

However, when such a tunnel boring machine is used for soft soil layers, if spring water is generated, the whole machine may be submerged or the gripper and the support leg may be buried in the pit wall. Therefore, it cannot be applied to soft soil layers as it is.

[0008] As described above, the conventional tunnel excavator includes:
It is necessary to use different types of excavator for soft soil layer and hard rock excavation, and the work efficiency in construction will be low, and if the soil layer changes during construction, excavation must be stopped It was not possible.

Therefore, in order to solve this, for example,
As described in Japanese Patent Application Laid-Open No. 9-158681, the shield body has a two-part structure of a front trunk and a rear trunk,
A tunnel excavator has been proposed which has a structure in which they can slide in the axial direction with respect to each other, and makes the shield body expandable and contractable by causing them to reciprocate relative to each other while sliding them.

In this excavator, when excavating a soft soil layer, it is used in the same manner as a conventional shield machine. In other words, the existing segment is used as a reaction force receiver for the shield jack provided on the rear body, the jack connecting the front body and the rear body (for example, sometimes referred to as a thrust jack or a propulsion jack) is extended in the axial direction, and the front body is extended. Excavation is performed with a cutter while propelling forward.

After digging for one stroke of the thrust jack in this manner, the cutter is stopped, the thrust jack is contracted, and the rear trunk is drawn toward the front trunk. In the above-described conventional technology, the excavation is continued by alternately repeating the operation of excavating the front trunk while moving forward and the operation of pulling the rear trunk thereafter (so-called excavation). Thereby, even when springing in the tunnel, the submersion of the entire machine can be prevented by the watertight structure of the segments and the shield body.

[0012]

However, the following problems exist in the shield machine in which the above-described conventional excavator is applied at the time of excavating a soft soil layer.

That is, as described above, after the excavation for one stroke of the thrust jack is completed, the thrust jack is contracted to pull the rear trunk toward the front trunk.
If only the thrust jack is simply contracted, the front trunk is retracted instead of the rear trunk being advanced by the face earth pressure.

Therefore, although there is no specific explanation in the above prior art, usually, the thrust jack is contracted and the shield jack is extended at the same time (ie, the contraction stroke of the thrust jack and the extension stroke of the shield jack are synchronized). The rear torso is drawn toward the front torso so that the front torso does not retreat relatively to the ground. As a specific method at this time, the thrust jack is stopped by receiving the propulsive force of the shield jack by releasing the holding pressure of the pressurized oil on the contraction side of the stopped thrust jack (for example, the oil chamber on the bottom side of the hydraulic cylinder). Make it shrink. At this time, the operator (operator) manually adjusts the operation speed of the shield jack while watching the detection value of the face earth pressure detected by, for example, the earth pressure gauge, and also adjusts the pressure of the variable relief valve (for example, the electromagnetic proportional relief valve). It is performed manually, and the holding pressure is gradually reduced so that the rear trunk advances slowly.

Conventionally, such complicated and difficult operations have been manually performed by the operator, and it has been difficult to synchronize the stroke amounts of the thrust jack and the shield jack with sufficient accuracy. Therefore, for example, when the amount of contraction stroke of the thrust jack becomes larger than the amount of extension stroke of the shield jack, there is a possibility that the front body is retracted by the face earth pressure as described above. When the front trunk is retracted, the earth pressure on the face decreases, which may adversely affect the ground above the face. Conversely, if the contraction stroke of the thrust jack is smaller than the extension stroke of the shield jack, the stopped cutter is pressed against the ground and the bit of the cutter bites into the face, and the next excavation When the cutter starts rotating when the operation is resumed, an excessive load is applied to a part of the bit, which may reduce the durability of the bit.

SUMMARY OF THE INVENTION An object of the present invention is to provide a control apparatus and a control method for a shield excavator capable of sufficiently synchronizing the strokes of a jack that contracts and a jack that expands during the excavation. .

[0017]

(1) In order to achieve the above-mentioned object, the present invention provides a split structure having a leading cylinder and a trailing cylinder slidable at least partially in the axial direction. Shield body, a cutter provided at the foremost side of the shield body, cutter driving means, a first jack for axially sliding the preceding cylinder and the following cylinder relative to each other, and an existing segment. And a second jack for advancing the trailing cylinder as a reaction force receiver, wherein the first and second jacks respectively detect the stroke amounts of the first and second jacks. A connection pipe is provided via a second detection means and a check valve for receiving only the hydraulic oil from the hydraulic cylinder driving the first jack and guiding it to the tank.
The control valve includes a control valve that can be shut off, and a first control unit that controls an operation of the control valve according to detection results of the first and second detection units.

In a shield excavator of the so-called digging type in which the shield body has a divided structure having a leading body and a trailing body, a leading jack is first moved by sliding a leading body and a trailing body toward and away from each other. The cutter is driven by cutter driving means to excavate the face of the ground while moving the cutter away from the trailing body and moving the cutter forward. Then, after the first jack has excavated for one stroke, the driving of the cutter is stopped. Thereafter, the second jack is extended by using the existing segment as a reaction force receiver to extend the following cylinder, and the first jack is contracted to bring the preceding cylinder and the following cylinder closer, thereby suppressing the retreat of the preceding cylinder. The following cylinder is drawn toward the preceding cylinder.

At this time, in the present invention, the first and second detecting means detect the stroke amounts of the first and second jacks, respectively, and the first control means controls the operation of the control valve according to the detection results. I do. Thus, for example, when the difference between the extension stroke amount of the second jack and the contraction stroke amount of the first jack becomes larger than a predetermined threshold value, the control valve is driven to communicate the connection pipe line and The holding pressure in the oil chamber on the bottom side of the hydraulic cylinder of one jack is released to the tank, and the first jack can be stroked to the contraction side so that the stroke difference between the second jack and the first jack is always the predetermined value. It can be within the threshold. Therefore, by setting the threshold sufficiently small,
The stroke amounts of the contracting first jack and the extending second jack can be sufficiently synchronized with each other.

(2) In the above (1), preferably,
The first control means calculates a difference between an extension stroke amount of the second jack detected by the second detection means and a contraction stroke amount of the first jack detected by the first detection means. And first signal generation means for generating a drive signal for driving the control valve in accordance with the calculation result.

(3) According to another aspect of the present invention, there is provided a shield body having a divided structure including a leading body and a trailing body slidable at least partially in the axial direction. A cutter provided on the forefront side of the shield body, cutter driving means, a first jack that slides the preceding cylinder and the following cylinder axially toward and away from each other, and an existing segment as a reaction force receiver. In a shield machine control device provided in a shield machine equipped with a second jack for advancing the trailing cylinder, a third detecting means for detecting a face pressure of the ground, and a check valve, The control valve is provided in a connection pipe that receives only the hydraulic oil from the hydraulic cylinder that drives the first jack and guides the connection pipe to the tank. The operation of the control valve And a second control means for controlling the.

In the present invention, the third detecting means detects the face pressure of the ground, and the second control means controls the operation of the control valve according to the detection result. For example, when the difference between the earth pressure reference value and the detected face earth pressure becomes smaller than a predetermined threshold value, the control valve is driven to connect the connection pipe line and the bottom side of the hydraulic cylinder of the first jack. The holding pressure in the oil chamber is released to the tank, and the first jack is stroked toward the contraction side so that the face pressure can be reduced.
The stroke difference from the jack can always be within the predetermined threshold. Thus, by setting the threshold value sufficiently small, the stroke amounts of the first jack that contracts and the second jack that extends can be sufficiently synchronized with each other.

(4) In the above (3), preferably,
The second control means calculates a difference between a preset earth pressure reference value and the face earth pressure detected by the third detection means, and the control valve operates in accordance with a result of the calculation. And a second signal generating means for generating a driving signal for driving the driving circuit.

(5) In the above (1) or (3), preferably, a throttle means is provided in the connection conduit.

Thus, by appropriately setting the degree of throttle, the flow rate of the pressure oil flowing from the bottom oil chamber of the hydraulic cylinder for driving the first jack to the tank is restricted, and the control valve is fully opened. In this case, the contraction speed of the first jack can be prevented from being higher than the maximum extension speed of the second jack. That is, the synchronization of the stroke amounts of the first jack and the second jack can be more reliably ensured.

(6) In order to achieve the above object, according to the present invention, at least a part of the shield main body has a divided structure including a leading cylinder and a trailing cylinder, and the leading cylinder and the trailing cylinder are divided into first and second cylinders. A method of controlling a shield excavator in which one jack slides in the axial direction so that the trailing cylinder can be moved forward and backward, and the existing segment is used as a reaction force receiving member to allow the trailing cylinder to move forward. When the first jack is contracted and the trailing cylinder is drawn toward the preceding cylinder while suppressing the retreat of the preceding cylinder, the contraction stroke amount of the first jack and the extension stroke amount of the second jack are detected. Calculating the difference between the detected extension stroke amount of the second jack and the contraction stroke amount of the first jack, and a hydraulic system for driving the first jack. The operation of the control valve provided in the connecting line leading to the receiving tank through only the check valve pressure oil from Sunda, automatically controlled in accordance with the magnitude of the calculated difference with a predetermined threshold value.

(7) In order to achieve the above object, according to the present invention, at least a part of the shield body has a divided structure including a leading cylinder and a trailing cylinder, and the leading cylinder and the trailing cylinder are divided into first and second cylinders. A method of controlling a shield excavator in which one jack slides in the axial direction so that the trailing cylinder can be moved forward and backward, and the existing segment is used as a reaction force receiving member to allow the trailing cylinder to move forward. When the first jack is retracted and the trailing cylinder is drawn toward the preceding cylinder while suppressing the retreat of the preceding cylinder, the earth pressure of the ground is detected, and the earth pressure reference value and the detected face earth pressure are detected. And the operation of a control valve provided in a connection conduit for guiding only the pressure oil from the hydraulic cylinder driving the first jack to the receiving tank via the check valve is determined by comparing the calculated difference with a predetermined value. Noshiki Automatically controlled in accordance with the magnitude of the value.

[0028]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a side sectional view showing the entire structure of a shield machine according to the present embodiment, and FIG.
FIG. 3 is a cross-sectional view taken along line III-III in FIG. 1, and FIG. 4 is a cross-sectional view taken along line IV-IV in FIG.

In FIG. 1 to FIG. 4, the shield machine is a body of the shield machine, and a front body shield 1 and a middle body shield 1 2, a shield body 4 having a three-node structure in which the rear trunk shield 3 is connected so as to be able to bend (bend), and the front trunk shield 1 is provided. A bulkhead 9 for isolating from the mud therein, a cutter head 5 rotatably supported by the bulkhead 9 and excavating a mountain (not shown), and a cutter driving device for rotating and driving the cutter head 5 ( An electric motor or a hydraulic motor) 10, a rotation transmission mechanism (gear box) 11 attached to the partition wall 9 and transmitting a driving force from the cutter driving device 10 to the cutter head 5. Serial of soil discharge device immediately conveys the excavated earth and sand the generated drilling chamber P formed on the rear on the rear side to discharge of the cutter head 5, for example, and a screw conveyor 7.

Between the front body shield 1 and the middle body shield 2, there is provided a center folding mechanism 14 for connecting them to each other rotatably. This middle folding mechanism 14
A seal that seals between the sliding portion 15 provided at the front end portion of the middle body shield 2 and the sliding portion 15 provided at the rear end portion of the front body shield 1 (to prevent earth and sand and groundwater from entering). And a member 16.

At this time, the middle body shield sliding portion 15
As shown in FIG. 1, is disposed so as to enter inside the rear end of the front body shield 1, and in this portion, a double cylinder structure (sliding portion 15 is an inner cylinder, The rear end of the body shield 1 is an outer cylinder. A ring girder 8 provided behind the partition 9 in the front body shield 1 and a ring girder 13 provided in front of the middle body shield 2.
A total of four left and right propulsion jacks 20 each having a hydraulic cylinder (see FIG. 5 to be described later) are provided between them. The shield 2 is slid in the axial direction so as to approach / separate from each other, and the entire shield body 4 can be expanded and contracted in the axial direction.

The propulsion jack 20 is located on the left
The function of changing the excavation direction by changing the angle formed between the front body shield 1 and the middle body shield 2 through the middle bending mechanism 14 by making a stroke difference between the book and the two books on the right side. (The same function as the below-described folding jack 17).

Similarly to the above-mentioned middle folding mechanism 14, a middle folding mechanism 25 for rotatably connecting them is provided between the middle body shield 2 and the rear body shield 3. A sliding portion 26 located at a front end portion and a seal member 27 located at a rear end portion of the middle body shield 2 and sealing between the sliding portion 26 are provided.

At this time, between the ring girder 6 provided at the rear part of the middle body shield 2 and the ring girder 12 provided at the front part of the rear body shield 3, there are two pairs of right and left middle folds. A jack 17 is provided, and the middle body shield 2 and the rear body shield 3 are bent through the middle bending mechanism 25 by the expansion and contraction operation of the middle bending jack 17, and the excavation direction is changed by changing the angle between them. It is supposed to be.

On the side of the ring girder 12 provided on the rear trunk shield 3 on the side opposite to the center bending jack 17,
A pair of right and left shield jacks 18 each having a hydraulic cylinder (see FIG. 5 described later) are attached. By extending these shield jacks 18 and pressing the existing segments 19 assembled in the rear trunk shield 3 via the press ring 21, the pressing reaction force is reduced by the ring girder 12, the center bent jack 17, the ring girder 6, and the middle trunk. Through the shield 2, the ring girder 13, the propulsion jack 20, the ring girder 8, and the front body shield 1, the cutter head 5 is provided with a propulsion force.

The cutter head 5 includes a center frame 28 located at a radially central portion, and a center frame 28.
And three cut-spokes 29 extending radially outward from the outer periphery. A large number of cutter bits 30 are provided on the center frame 28 and each of the cut spokes 29, respectively. At least one of the cut-spokes 29 has a copy cutter 29.
a is provided, and when the curved portion of the tunnel is constructed, the copy cutter 29a excavates the inside surface of the curve and takes in the earth and sand, so that a wider area can be dug out and the passage through which the shield machine passes. It can be secured. However, due to the middle folding operation of the middle trunk shield 2 and the rear trunk shield 3 by the above-mentioned middle folding jack 17, the amount of extra digging by the copy cutter 29a is reduced.

The earth removal device 7 has a sediment intake port 7a opened at the lower part of the excavation chamber P, and a casing 7b for forming an earth removal path for excavation soil therein, and a casing 7b.
b, a screw shaft 7c arranged axially in b.
And a motor 7d for driving the screw shaft 7c.

Reference numeral 31 denotes a backfill pressure jack.

In the above, the essential part of the present embodiment is that the hydraulic cylinder of the propulsion jack 20 and the shield jack 18 are used in the so-called refilling process after the excavation process.
In which the operation of the hydraulic cylinder is controlled. FIG. 5 is a hydraulic circuit diagram showing a main part of a hydraulic drive device including the hydraulic actuators provided in the shield machine shown in FIGS. 1 to 4.

In FIG. 5, the hydraulic drive unit supplies an electric motor (or an engine) 32, a hydraulic pump 33 driven by the electric motor 32, and a hydraulic oil discharged from the hydraulic pump 33. Four hydraulic cylinders 34 and four hydraulic cylinders 35
And the hydraulic cylinders 34, 35 from the hydraulic pump 33.
To control the direction and flow rate of pressurized oil supplied to the tank 4
One control valve 36 and four control valves 37, a relief valve 39 which is provided in a pipe branched from a discharge pipe 38 of the hydraulic pump 33 and regulates the maximum value of the pump discharge pressure, and is connected to the discharge pipe 38. A pressure gauge 40 and a controller 41.

The hydraulic cylinders 34 and 35 are composed of four hydraulic jack cylinders 34 for extending and retracting the four propulsion jacks 20, respectively, and four hydraulic cylinders for shield jacks of extending and retracting the four shield jacks 24, respectively. 35. Each of the hydraulic cylinders 34 and 35 has a stroke amount (extension stroke amount and contraction stroke amount) of each cylinder.
The known stroke sensors 57 and 58 are provided to detect the signal, and the detection signal is input to the controller 41.

The control valves 36 and 37 are respectively connected to the four propulsion jack hydraulic cylinders 34 and the four propulsion jack control valves 36.
And four shield jack control valves 37 connected to the four shield jack hydraulic cylinders 35, respectively. Note that these 8
The two control valves 36 and 37 are connected in parallel with each other.

Further, these eight control valves 3
6, 37 are solenoid valves 36a, 36b having solenoids.
Alternatively, the solenoid valves 37a and 37b are provided, and when a control signal (drive current) from the controller 41 is input to each solenoid valve, the corresponding solenoid is excited and the spool is switched.

That is, each control valve 36 for the propulsion jack receives the control signal Spa (or Spb) to the solenoid of the solenoid valve 36a (or the solenoid valve 36b, the same relationship in parentheses in the following paragraphs). The position is switched to the right position (or the left position) in FIG.
2a (or 42b) is communicated with the pump discharge line 38. As a result, the pressure oil from the hydraulic pump 33 passes through the pilot-operated check valve 43a (or 43b) provided in the pressure oil supply pipe 42a (or 42b), and the bottom-side oil chamber 34a of the hydraulic cylinder 34 for the propulsion jack. (Or the rod-side oil chamber 34b) to extend (or contract) the hydraulic cylinder 34 for the propulsion jack. The return oil at this time is on the rod side of the hydraulic cylinder 34 for the propulsion jack since the pilot operation check valve 43b (or 43a) is opened by the flow of the pressure oil through the pilot line 44a (or 44b). The oil is returned from the oil chamber 34b (or the bottom oil chamber 34a) to the tank 46 through the tank pipe 45 via the pilot operated check valve 43b (or 43a) and the pressure oil supply pipe 42b (or 42a).

When the drive current value of the control signal Spa (or Spb) becomes 0, the control valve 36 for the propulsion jack returns to the neutral position shown in FIG. 5 by the restoring force of the springs 36c and 36d, and supplies the hydraulic oil. The upstream part of the pipes 42a, 42b (the part closer to the control valve 36 than the pilot operated check valves 43a, 43b, the same applies hereinafter) is connected to the tank pipe 45.
And these pressures are used as tank pressures.

At this time, downstream portions of the hydraulic oil supply pipes 42a and 42b to the hydraulic cylinders 34 for the propulsion jacks (portions closer to the hydraulic cylinder 34 than the pilot operation check valves 43a and 43b, and so on) Check valves 47a, 47
b, it is connected to holding pressure adjusting pipes 48a, 48b connected to the tank pipe 45. That is, the holding pressure adjusting pipes 48a and 48b are connected to the bottom oil chamber 34a and the rod side of the hydraulic cylinder 34 for the propulsion jack via the check valves 47a and 47b and the downstream portion of the hydraulic oil supply pipes 42a and 42b. This means that it is connected to the oil chamber 34b. The holding pressure adjusting pipes 48a and 48b are provided with a throttle means 49,
An electromagnetic switching valve 50 is provided downstream of the switching valve 50 and is capable of connecting and disconnecting the holding pressure adjusting pipe 48 in response to a control signal from the controller 41. In addition, the holding pressure adjusting pipe 4
8 is provided with a relief valve 60 for protecting the circuit. The relief valve 60 is configured so that the pressure in the holding pressure adjusting pipeline 48 is set by a spring 60a (a fixed value, for example, 350 km). / Cm ² ), and the pressure oil is released to the tank 46.

The electromagnetic switching valve 50 includes a solenoid driving unit 50
When the control signal Sh is input to a, the communication position is switched to the lower communication position 50A in FIG. 5, and the holding pressure adjustment pipeline 48a and the holding pressure adjustment pipeline 48b are communicated. Accordingly, the pressure oil in the downstream portion of the pressure oil supply pipe 42a (or 42b) is supplied to the check valve 47a (or 47b), the holding pressure adjustment pipe 48a, the throttle means 49, the holding pressure adjustment pipe 48b, and Tank line 45
Through the tank 46. When the control signal Sh is turned OFF, the electromagnetic switching valve 50 is restored by the restoring force of the spring 50b.
Returns to the shut-off position 50B on the upper side in FIG. 5, so that the holding pressure adjustment pipeline 48a and the holding pressure adjustment pipeline 48b are shut off.

On the other hand, similarly to the above, the shield jack control valve 37 is connected to the solenoid valve 37a (or the solenoid valve 37).
b, hereinafter, when the control signal Ssa (or Ssb) is input to the solenoid of FIG.
The position is switched to the middle right position (or the left position), and the pressure oil supply pipe 51a (or 51b) communicates with the pump discharge pipe 38. As a result, the pressure oil from the hydraulic pump 33 passes through the pilot-operated check valve 52a (or 52b) provided in the pressure oil supply pipe line 51a (or 51b) and the bottom-side oil chamber 35a of the shield jack hydraulic cylinder 35. (Or the rod-side oil chamber 35b) to extend (or contract) the shield jack hydraulic cylinder 35. At this time, the return oil is supplied to the rod side oil chamber 35b (of the hydraulic cylinder 35 for the shield jack) since the pilot operation check valve 52b (or 52a) is opened by the flow of the pressure oil through the pilot line 53a. Alternatively, from the bottom side oil chamber 35a), through the pilot operated check valve 52b (or 52a) and the pressure oil supply line 51b (or 51a), the tank line 45 is connected.
Is returned to the tank 46.

When the drive current value of the control signal Ssa (or Ssb) becomes 0, the shield jack control valve 37 returns to the neutral position shown in FIG. 5 by the restoring force of the springs 37c and 37d, and the pressure oil is supplied. The upstream portions of the pipes 51a and 51b (portions closer to the control valve 37 than the pilot operated check valves 52a and 52b, and so on) are communicated with the tank pipe 45 so that their pressure is set to the tank pressure. I have.

At this time, the downstream portions of the hydraulic oil supply pipes 51a and 51b to the hydraulic cylinders 35 for shield jacks (portions closer to the hydraulic cylinder 35 than the pilot operated check valves 52a and 52b, and so on) Check valve 54a,
It is connected to the holding pressure maintaining line 55 connected to the tank line 45 via 54b. The holding pressure maintaining line 55 is provided with a relief valve 56. When the pressure in the holding pressure maintaining line 55 exceeds the pressure set by the spring 56 a (fixed value, for example, 350 km / cm ² ), the hydraulic oil is released. The tank line 45
The tank is opened to the tank 46 via the.

In the above configuration, the front body shield 1
Constitutes a preceding cylinder described in the claims, the middle trunk shield 2 and the rear trunk shield 3 constitute a trailing cylinder, and the cutter head 5 constitutes a cutter.

Further, the cutter driving device 10 constitutes a cutter driving means, the propulsion jack 20 constitutes a first jack for sliding the preceding cylinder and the following cylinder in the axial direction with respect to each other, and the shield jack 18 comprises the first jack. A second jack for advancing the following cylinder with the existing segment as a reaction force receiver is constituted, and stroke sensors 57 and 58 constitute first and second detecting means for detecting stroke amounts of the first and second jacks, respectively. .

The hydraulic cylinder 34 for the propulsion jack
Constitute a hydraulic cylinder for driving the first jack, and the holding pressure adjusting pipes 48a, 48b are provided with check valves 47a, 47b.
A connection pipe that receives only the hydraulic oil from the hydraulic cylinder that drives the first jack and guides it to the tank via
The electromagnetic switching valve 50 constitutes a control valve capable of connecting / disconnecting the connection pipe line, and the controller 41 controls the first control means for controlling the operation of the control valve according to the detection results of the first and second detection means. Constitute.

Next, the operation of the shield machine described above will be described.

(1) Excavation Step First, while the press ring 21 connected to the shield jack 18 is in contact with the existing segment 19, the controller 41 operates the control valve 3 for the propulsion jack.
The control signal Spa is output to the electromagnetic valve 36a of No. 6, the propulsion jack hydraulic cylinder 34 is extended, the propulsion jack 20 is extended in the axial direction, and the front trunk shield 1 is propelled forward.
And while promoting in this way, the controller 41
Although a detailed description is omitted, the cutter driving device 10 is controlled to rotate the cutter head 5 in the forward direction, and excavation is performed by the roller bit device 37 of the cutter head 5.

The excavated earth and sand is stirred and plastically fluidized in the excavating chamber P by the cutter spokes 29 of the cutter head 5, thereby preventing the collapse of the ground and preventing water from stopping. The plastically fluidized earth and sand is taken into the earth discharging device 7 and discharged backward.

(2) Refilling Step As described above, a predetermined distance (usually,
After excavation for a distance of one stroke), so-called refilling is performed. In addition, as a preparation stage of the rearrangement, the controller 41 controls the cutter driving device 10 to stop the rotation of the cutter head 5 although the detailed description is omitted.

FIG. 6 shows a control flow of the rearrangement process executed by the controller 41. In FIG. 6, first, in step 100, the controller 41 controls the solenoid valves 36 a, of the four propulsion jack control valves 36.
36b, the control signals Spa and Spb are both turned off, and the propulsion jack control valve 36 is
The neutral position is set by the restoring force of c and 36d. At this time, in the above (1) excavation process, the hydraulic cylinder 34 for the propulsion jack is driven in the extending direction, and high-pressure oil is supplied to the bottom-side oil chamber 34a. Therefore, when the propulsion jack control valve 36 is restored to the neutral position, the pressure communicated with the bottom side oil chamber 34a by the action of the closed pilot operated check valve 43a and the closed electromagnetic switching valve 50. The downstream part of the oil supply pipe 42a and the part of the holding pressure adjusting pipe 48 upstream of the throttle means 49 via the check valve 47a are held at the high pressure.

Then, the routine proceeds to step 200, where the controller 41 sets the control valve 3 for the shield jack.
The control signal Ssa is output to the solenoid valve 37a of No. 7 to extend the shield jack hydraulic cylinder 35 and start driving the shield jack 18 to extend in the axial direction.

Thereafter, the routine proceeds to step 300, where the holding pressure in the holding pressure adjusting pipe 48 is appropriately released as will be described later, so that the contraction stroke of the propulsion jack 20 and the extension stroke of the shield jack 18 are synchronized. While controlling, the propulsion jack 20 is contracted by receiving the propulsive force generated by the extension operation of the shield jack 18.

Then, in step 400, it is determined whether or not the propulsion jack 20 has reached a fully contracted state (or a predetermined contraction stroke amount close to the fully contracted state). Steps 200 to 400 are performed until this determination is satisfied. repeat. As a result, the middle trunk shield 2 and the rear trunk shield 3 are drawn toward the front trunk shield 1 while the front trunk shield 1 does not relatively recede from the ground.

When the determination at step 400 is satisfied, the flow of FIG. 6 is terminated, and the refining process is terminated.

(3) Segment assembling step When the rearrangement step is completed as described above, the controller 41 turns off the control signal Ssa to the solenoid valve 37a of the shield jack control valve 37 and sends the control signal to the solenoid valve 37b. Ssb is output, and the shield jack hydraulic cylinder 37 is contracted to contract the four shield jacks 18 in the axial direction. Then, a new segment 19 is assembled and arranged in a space created between the press ring 21 and the existing segment 19. Segment 1
A back-filling agent is injected into a hollow portion formed around the periphery of the nozzle 9 by, for example, back-filling material injection means (not shown), thereby filling the hollow portion.

Thereafter, the above (1) excavation process → (2)
Replacement process → (3) Segment excavation is repeated by repeating the assembly process. At this time, as described above, by making a stroke difference between the right and left by the propulsion jack 20 and the shield jack 18 having two right and left sides, the front body shield 1 and the middle body shield 2 or the middle body shield 2 and the rear body shield are provided. 3
It is possible to change the direction of excavation and change the direction of the excavation easily to make a turn. Also, at the time of springing in the tunnel, the watertight structure of the segment 19 and the shield body 4 can prevent the entire machine from being submerged.

In the above operation, the main part of the present embodiment lies in the tuning control of step 300 shown in FIG. 6, as described above. The detailed procedure of the tuning control by the controller 41 is shown in the flowchart of FIG.

In FIG. 7, step 20 in FIG.
0, the driving of the shield jack 18 is started in the extending direction.
The stroke amounts of the propulsion jack 20 and the shield jack 18 detected at 7, 58 are input.

Thereafter, in step 320, the extension stroke amount Xs of the shield jack 18 and the propulsion jack 20 are calculated by the calculation means (not shown, which corresponds to the first calculation means in the claims) provided in the controller 41.
The difference Xs-Xp from the contraction stroke amount Xp is calculated.

Then, the routine proceeds to step 330, where the stroke difference Xs-Xp is determined by a predetermined threshold value Xo (a relatively small positive value) stored in a storage means (not shown) in the controller 41 in advance. ) Is determined. If Xs-Xp <Xo, the determination is not satisfied, and the routine returns to step 310 and returns to steps 310 to 330.
repeat.

If Xs−Xp ≧ Xo, the determination is satisfied, it is determined that the propulsion (pressing) of the shield jack 18 is excessive, and the routine proceeds to step 340, where the controller 4
1 by means of signal generating means (not shown, corresponding to the first signal generating means described in the claims).
The control signal Sh to the solenoid drive unit 50a of 0 is generated and output to drive the electromagnetic switching valve 50 to the open state.

Thereafter, Step 350 and Step 36
At 0, the current stroke amounts Xp and Xs of the propulsion jack 20 and the shield jack 18 are input again, and the stroke difference Xs-Xp is calculated.
It is determined whether Xp <Xo. If Xs−Xp ≧ Xo, the determination is not satisfied, and the routine returns to step 340 to repeat steps 340 to 370.

If Xs-Xp <Xo, the determination is satisfied, and it is considered that the excessive propulsion state of the shield jack 18 has been resolved. In step 380, the control signal to the electromagnetic switching valve solenoid drive unit 50 is transmitted. Sh is turned OFF to return to the shut-off position, and the process returns to the beginning.

In the present embodiment, the above step 3
By executing the tuning control consisting of 10 to 380, the extension stroke amount Xs of the shield jack 18 is obtained.
And the stroke difference Xs-Xp of the contraction stroke amount Xp of the propulsion jack 20 can always be within the predetermined threshold value Xo. Therefore, by setting this threshold value Xo sufficiently small, the propulsion jack 20 that performs the contracting operation can be obtained.
The stroke amounts of the shield jacks 18 that extend and operate can be sufficiently synchronized with each other. As a result, it is possible to prevent the front body shield 1 from retreating or the cutter bit 30 from digging into the face due to the face earth pressure, which may occur when the stroke amounts are not sufficiently synchronized. It is possible to prevent an adverse effect and a decrease in the durability of the cutter bit 30.

Further, the throttle means 4 is connected to the holding pressure adjusting pipe 48a.
By setting the degree of the throttle appropriately in advance, the flow rate of the pressure oil flowing out from the bottom side oil chamber 34a of the hydraulic cylinder 34 for the propulsion jack to the tank 46 is limited, and the electromagnetic switching valve 50 is provided. Can be prevented from increasing the contraction speed of the propulsion jack 20 higher than the maximum extension speed of the shield jack 18 (uniquely determined structurally or in terms of performance). Thereby, the synchronization of the stroke amounts of the propulsion jack 20 and the shield jack 18 can be more reliably and smoothly ensured.

However, as long as the stroke amount of the propulsion jack 20 that contracts and the shield jack 18 that extends can be tuned with higher accuracy than in the prior art, the throttling means 49 is not necessarily required and may be omitted. Needless to say, it is good.

In the above embodiment of the present invention, the ON-OFF type electromagnetic switching valve 50 is provided in the holding pressure adjusting pipe 48a. However, the present invention is not limited to this, and the driving current value of the control signal Sh is not limited to this. May be provided with an electromagnetic proportional valve whose opening degree changes proportionally according to. In this case, for example, the larger the difference in the stroke amount between the propulsion jack 20 and the shield jack 18, the larger the opening of the solenoid proportional valve is, and the smaller the difference in the stroke amount is, the smaller the opening of the solenoid proportional valve is. By controlling the opening in accordance with the value of the difference in the stroke amount, a function similar to that of the servo valve is provided, and more precise and precise tuning control can be performed. In this case, the aperture means 49 may be omitted.

Further, in the embodiment of the present invention, when the contracting propulsion jack 20 and the extending jack shield 18 are synchronized, Xs−Xp ≧ Xo, that is, the extension stroke of the shield jack 18 is adjusted. The amount Xs is controlled so as to be slightly larger than the contraction stroke amount Xp of the propulsion jack 20 (= so as to slightly press the cutter head), but the invention is not limited to this. That is, on the contrary, the extension stroke amount Xs of the shield jack 18 is equal to the contraction stroke amount Xp of the propulsion jack 20.
The control may be performed so as to be slightly smaller (= so as to be slightly in a state in which the front trunk shield is retracted). In this case, at step 320 or step 360 in FIG.
Xs is calculated, and at step 330, Xp−Xs
Is determined to be less than or equal to Xo, and in step 370, it is determined whether Xp−Xs is less than Xo.
In this case, a similar effect is obtained.

Further, in the above-described embodiment of the present invention, the tuning control is performed based on the difference in the stroke amount between the shield jack 18 and the propulsion jack 20, but the present invention is not limited to this. May be performed. Such a modification will be described with reference to FIGS.

In this modification, a well-known earth pressure sensor 59 (see FIG. 2, corresponding to the third detecting means in the claims) disposed on the partition wall 9 facing the excavation chamber P instead of the difference in the stroke amount. ), The tuning control is performed based on the face earth pressure value input to the controller 41. FIG. 8 is a control flow of a rearrangement process executed by the controller 41 in this case, and FIG. FIG. 6 is a flowchart showing a detailed procedure, each of which is shown in FIG.
7 and FIG. 6 and 7 are given numbers with a suffix A added, and newly added procedures are given new numbers.

In this modification, as shown in FIG. 8, the control valve 36 for the propulsion jack is first set to the neutral position in step 100, and then in step 110, the face pressure value detected by the earth pressure sensor 59 ( Initial earth pressure value)
Enter Thereafter, in step 120, the storage means (not shown) provided in the controller 41
The input earth pressure value is stored as the reference earth pressure value Ps.

After the shield jack 18 is started to be driven in the direction in which the shield jack 18 extends in step 200, the current face pressure Pn detected by the earth pressure sensor 59 is input in step 310A of FIG. Thereafter, in step 320A, the reference earth pressure value Ps stored in step 120 and the step 310A are calculated by a calculating means (not shown, corresponding to the second calculating means in the claims) provided in the controller 41. Calculates the pressure difference Ps-Pn from the current earth pressure value Pn input in.

Then, the routine proceeds to step 330A, where the pressure difference Ps-Pn is determined by the predetermined threshold value Ps stored in the storage means (not shown) in the controller 41 in advance.
Determine if it is greater than or equal to o (a relatively small positive value). If Ps-Pn <Po, the determination is not satisfied, and the routine returns to step 310A and repeats steps 310A to 330A.

If Ps−Pn ≧ Po, it is determined that the propulsion (pressing) of the shield jack 18 is insufficient (that is, the front trunk shield 1 is slightly retracted), and the process proceeds to step 340A. The control signal Sh to the solenoid driving unit 50a of the electromagnetic switching valve 50 is generated and output by a provided signal generating means (not shown, corresponding to the second signal generating means in the claims), and the electromagnetic switching valve is provided. 50 is driven to the open state.

Thereafter, Step 350A and Step 3
At 60A, the face pressure value Pn detected by the earth pressure sensor 59 is input again, and after calculating the pressure difference Ps-Pn, it is determined at step 370A whether Ps-Pn <Po.
If Ps−Pn ≧ Po, the determination is not satisfied, and the routine returns to step 340A and returns to steps 340A to 340A.
Repeat 70A.

When Ps−Pn <Po, it is considered that the insufficiently propelled state of the shield jack 18 has been resolved, and
At step 380A, the solenoid-operated valve solenoid drive unit 50a
The control signal Sh is turned off to return the electromagnetic switching valve 50 to the shut-off position, and the process returns to the beginning.

In the above, the controller 41 constitutes the second control means for controlling the operation of the control valve according to the detection result of the third detection means.

In this modification, by executing the above control, the stroke difference Xs-Xp between the extension stroke amount Xs of the shield jack 18 and the contraction stroke amount Xp of the propulsion jack 20 is always set to the predetermined threshold value. (Earth pressure difference) It can be within the stroke difference corresponding to Po. Accordingly, by setting the threshold value Po to a sufficiently small value, the stroke amount of the propulsion jack 20 performing the contracting operation and the stroke amount of the shield jack 18 performing the extending operation can be sufficiently synchronized with each other, as in the embodiment of the present invention. it can.

In the above modification, when the contracting propulsion jack 20 and the extending extending shield jack 18 are synchronized, the extension stroke Xs of the shielding jack 18 is set so that Ps−Pn ≧ Po. The contraction stroke amount Xp is controlled to be slightly smaller than the contraction stroke amount Xp (= slightly retracted to the front body shield). However, the present invention is not limited to this. May be controlled so as to be slightly larger than the contraction stroke amount Xp (i.e., to be in a slightly pressed state of the cutter). In this case, Pn-Ps is calculated in steps 320A and 360A in FIG.
At 0A, it is determined whether this Pn-Ps is equal to or less than Po, and at step 370A, it is determined whether this Pn-Ps is less than Po.

Further, the above-described modified example in which the tuning control is performed based on the difference in the earth pressure value and the above-described embodiment of the present invention in which the tuning control is performed based on the difference in the stroke amount are combined, and the difference in the earth pressure value is calculated. Synchronization control may be performed based on both stroke value differences. In this case, when one of the difference between the stroke amount and the difference between the earth pressure values becomes equal to or more than the corresponding threshold value, the electromagnetic switching valve 50 is driven to the open state, and both of them are threshold. When the value becomes less than the value, the electromagnetic switching valve 50 may be returned to the shut-off position.

Further, in one embodiment of the present invention, the present invention relates to a shield excavator provided with a shield body 4 having a three-bar structure of a front trunk shield 1, a middle trunk shield 2, and a rear trunk shield 3. Although the description has been given of the case where the present invention is applied, the present invention is not limited to this. That is, even if the shield body has a two-node structure of a front trunk shield and a rear trunk shield that can be folded in each other, or a shield body of a single-node structure that does not have a middle fracture structure, some of the trunks or The present invention can be applied as long as a part of the trunk performs digging and excavation in a divided structure of a leading trunk and a trailing trunk that can slide with each other, and it is needless to say that the same effects can be obtained in those cases.

[0091]

According to the present invention, the operation of the control valve is controlled by the first control means in accordance with the stroke amounts of the first and second jacks detected by the first and second detection means. In some cases, the stroke amounts of the first jack that contracts and the second jack that expands can be sufficiently synchronized with each other. As a result, the retreat of the front body due to the face pressure of the cutting face and the biting of the cutter bit into the face, which may occur in the case of insufficient synchronization of the stroke amounts, do not occur. A decrease in durability can be prevented.

[Brief description of the drawings]

FIG. 1 is a side sectional view showing the entire structure of a shield machine according to an embodiment of the present invention.

FIG. 2 is a view as viewed from an arrow A in FIG.

FIG. 3 is a cross-sectional view taken along the line III-III in FIG.

FIG. 4 is a cross-sectional view taken along the line IV-IV in FIG.

FIG. 5 is a hydraulic circuit diagram showing a main part of a hydraulic drive device provided in the shield machine shown in FIGS. 1 to 4;

6 is a control flow of a rearrangement process executed by the controller shown in FIG.

FIG. 7 is a flowchart showing a detailed procedure of tuning control in step 300 shown in FIG. 6;

FIG. 8 is a control flow of a rearrangement process executed by a controller in a modification in which tuning control is performed based on an earth pressure value.

FIG. 9 is a flowchart showing a detailed procedure of tuning control in step 300A shown in FIG. 8;

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Front trunk shield (preceding trunk) 2 Middle trunk shield (trailing trunk) 3 Rear trunk shield (trailing trunk) 4 Shield body 5 Cutter head (cutter) 10 Cutter driving device (cutter driving means) 18 Shield jack (second) Jack) 19 segment 20 propulsion jack (first jack) 34 hydraulic cylinder for propulsion jack (hydraulic cylinder driving first jack) 41 controller (first control means; second control means) 46 tank 47a, b check valve 48a , B Holding pressure adjusting pipe (connection pipe) 50 Solenoid switching valve (control valve) 57 Stroke sensor (first detecting means) 58 Stroke sensor (second detecting means) 59 Earth pressure sensor (third detecting means)

Claims (7)

[Claims] 1. A shield body having a divided structure having a leading body and a trailing body slidable at least partially in the axial direction, a cutter provided at the foremost side of the shield body, and a cutter. A driving means, a first jack for sliding the preceding cylinder and the following cylinder in the axial direction to each other, and a second jack for moving the following cylinder forward by using an existing segment as a reaction force receiver. A control device for a shield excavator provided in a shield excavator, wherein the first and second detection means for detecting stroke amounts of the first and second jacks, respectively, and the first jack is driven via a check valve. A control valve that is provided in a connection pipe that receives only the hydraulic oil from the hydraulic cylinder and guides the connection pipe to the tank, and that is capable of communicating and shutting off the connection pipe; and a control valve that is provided in accordance with a detection result of the first and second detection units. Control valve Controller of the shield machine and having a first control means for controlling the operation. 2. The control apparatus for a shield machine according to claim 1, wherein said first control means includes an extension stroke amount of said second jack detected by said second detection means and said first stroke amount.
A first calculating means for calculating a difference between the first stroke and the contraction stroke amount of the first jack detected by the detecting means; and a first signal generating means for generating a drive signal for driving the control valve according to a result of the calculation. A control device for a shield excavator, comprising: 3. A shield body having a divided structure having a leading body and a trailing body slidable at least partially in the axial direction, a cutter provided at the forefront side of the shield body, and a cutter. A driving means, a first jack for sliding the preceding cylinder and the following cylinder in the axial direction to each other, and a second jack for moving the following cylinder forward by using an existing segment as a reaction force receiver. In a shield excavator control device provided in a shield excavator, a third detecting means for detecting the face earth pressure of the ground, and only a pressure oil from a hydraulic cylinder driving the first jack via a check valve. A control valve provided in a connection pipe for receiving and leading to the tank, the control valve being capable of communicating and shutting off the connection pipe; and a second control means for controlling an operation of the control valve in accordance with a detection result of the third detection means. Characterized by having The control device of the shield machine to. 4. The control apparatus for a shield machine according to claim 3, wherein said second control means determines a difference between a preset earth pressure reference value and said face pressure detected by said third detection means. A control apparatus for a shield machine, comprising: a second calculating means for calculating, and a second signal generating means for generating a drive signal for driving the control valve according to a result of the calculation. 5. The control apparatus for a shield machine according to claim 1, wherein a throttle means is provided in said connection conduit. 6. A shield body having at least a part thereof having a divided structure including a leading cylinder and a trailing cylinder, wherein the leading cylinder and the trailing cylinder are slid in the axial direction by a first jack so as to be able to be moved in and out of perspective. In addition, the existing segment was
A control method of a shield machine in which the trailing cylinder can be advanced by a jack, wherein the second jack is extended and the first jack is contracted to suppress the retreat of the leading cylinder while moving the trailing cylinder to the leading cylinder. Side, the contraction stroke amount of the first jack and the extension stroke amount of the second jack are detected, respectively, and the difference between the detected extension stroke amount of the second jack and the contraction stroke amount of the first jack is detected. The operation of a control valve provided in a connection pipe for guiding only pressure oil from a hydraulic cylinder driving the first jack to a receiving tank via a check valve is determined by calculating the difference between the calculated difference and a predetermined threshold. A method for controlling a shield machine, wherein automatic control is performed according to the magnitude of the value. 7. A shield body having at least a part thereof having a divided structure including a leading cylinder and a trailing cylinder, wherein the leading cylinder and the trailing cylinder are slid in the axial direction with respect to each other by a first jack so as to be able to be moved toward and away from each other. In addition, the existing segment was
A control method of a shield machine in which the trailing cylinder can be advanced by a jack, wherein the second jack is extended and the first jack is contracted to suppress the retreat of the preceding cylinder and move the trailing cylinder to the preceding cylinder. Side, the face pressure of the ground is detected, the difference between the ground pressure reference value and the detected face pressure is calculated, and only the hydraulic oil from the hydraulic cylinder driving the first jack is checked. A method for controlling a shield machine, wherein an operation of a control valve provided in a connection pipe leading to a receiving tank via a valve is automatically controlled in accordance with a magnitude of the calculated difference and a predetermined threshold value. .