Tunnel boring machine

Abstract

To provide a tunnel boring machine capable of suppressing vibrations caused by a sudden change in the attitude of the boring machine body due to unbalanced resistance generated by an unintended change in the attitude of the boring machine body.SOLUTION: This tunnel boring machine 100 comprises a cutter head 1, an excavator main body 2, a plurality of shield jacks 3, and a control unit 6 that continuously, rather than intermittently, performs control to maintain an orientation of the excavator main body 2 in the target direction by bringing an actual vertical stroke difference, which is the actual stroke difference between the plurality of shield jacks 3 on the top and bottom, closer to the target vertical stroke difference, which is the target value for the stroke difference between the plurality of shield jacks 3 on the top and bottom, and by bringing an actual left-right stroke difference, which is the actual stroke difference between the plurality of shield jacks 3 on the left and right, closer to a target left-right stroke difference, which is the target value for the stroke difference between the plurality of shield jacks 3 on the left and right.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a tunnel boring machine equipped with a shield jack for generating thrust. [Background technology]

[0002] BACKGROUND ART Conventionally, a tunnel boring machine equipped with a shield jack that generates thrust has been known (see, for example, Patent Document 1).

[0003] The above-mentioned Patent Document 1 discloses a tunnel boring machine equipped with a plurality of shield jacks and a direction control device that controls the drive of the plurality of shield jacks to control the excavation direction of the tunnel boring machine. In order to control the excavation direction of the tunnel boring machine, a plurality of verification points are set for verifying the vertical and horizontal stroke differences of the shield jacks. The direction control device is configured to compare a target value for the stroke difference at the verification point reached with the actual value of the stroke difference each time the direction control device reaches a verification point, and adjust the stroke difference to the target value at the verification point at the excavation destination, thereby controlling the excavation direction. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 7334550 Summary of the Invention [Problem to be solved by the invention]

[0005] However, with the shield machine in Patent Document 1, each time it reaches a verification point, it adjusts the stroke difference to a target value at the destination verification point, controls the excavation direction, and corrects the attitude of the shield machine, but when it is excavating between two adjacent verification points, the stroke difference is not adjusted and the attitude of the shield machine is not corrected.As a result, if the attitude of the shield machine changes while excavating between two adjacent verification points due to changes in resistance to the shield machine's advancement or directional control, there is a problem in that unbalanced resistance is generated, causing a sudden change in attitude and vibration.

[0006] The present invention has been made to solve the above-mentioned problems, and one object of the present invention is to provide a tunnel boring machine that is capable of suppressing vibrations caused by sudden changes in the attitude of the boring machine body due to unbalanced resistance that occurs when the attitude of the boring machine body changes in an unintended direction. [Means for solving the problem]

[0007] In order to achieve the above-mentioned object, the tunnel boring machine of the present invention comprises a cutter head that excavates the natural ground by rotation, an boring machine main body including a cylindrical trunk that rotatably supports the cutter head, a plurality of shield jacks that are arranged in a ring shape along the inner surface of the trunk and press against the segments to generate thrust, and a control unit that continuously, rather than intermittently, performs control to maintain the orientation of the boring machine main body in the target direction by bringing the actual vertical stroke difference, which is the actual difference in stroke between the plurality of shield jacks on the top and bottom, closer to the target vertical stroke difference, which is the target value for the difference in stroke between the plurality of shield jacks on the top and bottom, and bringing the actual left-right stroke difference, which is the actual difference in stroke between the plurality of shield jacks on the left and right, closer to the target left-right stroke difference, which is the target value for the difference in stroke between the plurality of shield jacks on the left and right.

[0008] As described above, the tunnel boring machine of this invention is equipped with a control unit that continuously, rather than intermittently, controls the orientation of the tunnel boring machine body toward the target direction by bringing the actual vertical stroke difference, which is the actual difference between the strokes of the multiple upper and lower shield jacks, closer to the target vertical stroke difference, which is the target value for the stroke difference between the multiple upper and lower shield jacks, and bringing the actual horizontal stroke difference, which is the actual difference between the strokes of the multiple left and right shield jacks, closer to the target horizontal stroke difference, which is the target value for the stroke difference between the multiple left and right shield jacks. This makes it possible to continuously (constantly) control and monitor the vertical and horizontal stroke differences of the shield jacks to maintain the orientation of the tunnel boring machine body toward the target direction. This avoids the conventional situation in which the stroke difference adjustment is not performed while excavating between two adjacent verification points. As a result, when the attitude of the shield boring machine changes due to changes in resistance to the shield boring machine's advancement or directional control, unbalanced resistance is generated, which can suppress vibrations caused by a sudden change in the attitude of the tunnel boring machine body. In other words, it is possible to suppress vibrations caused by sudden changes in the attitude of the excavator body due to unbalanced resistance that occurs when the attitude of the excavator body changes in an unintended direction.

[0009] In the above-described tunnel boring machine, the control unit is preferably configured to continuously perform control to maintain the orientation of the excavator main body toward the target direction by causing the actual vertical stroke difference to reach the target vertical stroke difference and the actual lateral stroke difference to reach the target lateral stroke difference while the shield jack is extending by the set stroke, which is the stroke of the shield jack set by the user. With this configuration, continuous control utilizing the period until the set stroke is reached allows the actual vertical stroke difference and the actual lateral stroke difference to smoothly approach the target vertical stroke difference and the target lateral stroke difference, respectively. This effectively prevents abrupt changes in the attitude of the excavator main body, thereby further suppressing vibration.

[0010] The above-mentioned tunnel boring machine preferably further includes a hydraulic oil circuit for supplying hydraulic oil to the multiple shield jacks, and the control unit is configured to execute pressure control for adjusting the pressure of hydraulic oil supplied to each of the shield jacks via the hydraulic oil circuit when the multiple shield jacks press against the segments to generate thrust, thereby continuously performing control to maintain the actual vertical stroke difference at the target vertical stroke difference and the actual lateral stroke difference at the target lateral stroke difference, thereby maintaining the orientation of the tunnel boring machine main body toward the target direction. This configuration allows the multiple shield jacks to be extended by a predetermined amount through pressure control, thereby suppressing vibrations caused by sudden changes in the attitude of the tunnel boring machine main body due to unbalanced resistance generated by unintended fluctuations in the attitude of the tunnel boring machine main body. Furthermore, pressure control allows control of the pressure of hydraulic oil supplied to the shield jacks, thereby preventing the extended shield jacks from separating from the segments due to insufficient hydraulic oil supply.

[0011] In the above-described tunnel boring machine, the control unit is preferably configured to acquire integrated values for each of the deviation of the actual vertical stroke difference from the target vertical stroke difference and the deviation of the actual lateral stroke difference from the target lateral stroke difference, and to perform PI control, which is proportional-integral control, thereby continuously performing control to correct each of the target vertical stroke difference and the target lateral stroke difference. With this configuration, the vertical deviation and the lateral deviation can be integrated by I control, which is an integral control type of PI control, thereby enabling control to more reliably eliminate the vertical deviation and the lateral deviation. As a result, each of the actual vertical stroke difference and the actual lateral stroke difference can be accurately brought closer to the target vertical stroke difference and the target lateral stroke difference. This makes it possible to more effectively suppress vibrations caused by sudden changes in the attitude of the excavator body due to unbalanced resistance generated when the attitude of the excavator body changes in an unintended direction.

[0012] In the above-mentioned tunnel boring machine, the plurality of shield jacks are preferably divided into a plurality of blocks each consisting of a plurality of adjacent shield jacks, and the control unit is configured to control the drive of the shield jacks for each block and continuously perform control to maintain the orientation of the tunnel boring machine body toward the target direction. With this configuration, control can be performed in units of blocks each consisting of a plurality of shield jacks, and therefore, unlike when a plurality of shield jacks are controlled individually, it is possible to avoid the control becoming complicated.

[0013] In the above tunnel boring machine, the control unit is preferably configured to continuously perform control to suppress changes in the attitude of the boring machine body that cause vibrations by maintaining the orientation of the boring machine body toward the target orientation. With this configuration, the control unit can more reliably perform control to suppress changes in the attitude of the boring machine body that cause vibrations.

[0014] In this case, it is preferable to further include a means for measuring vibration, and the vibration measuring means is configured to be able to grasp the relationship between the magnitude of vibration and the deviation between the target vertical stroke difference and the actual vertical stroke difference, and the relationship between the deviation between the target lateral stroke difference and the actual lateral stroke difference. With this configuration, the relationship between an increase in vibration and a change in the attitude of the tunnel boring machine becomes clear, and the effect of control also becomes clear. Furthermore, it becomes possible to determine whether operation should be performed, and the occurrence of vibration can be effectively suppressed.

[0015] The above-mentioned tunnel boring machine preferably further includes a hydraulic oil circuit for supplying hydraulic oil to the plurality of shield jacks, and the control unit is configured to execute speed control for adjusting the amount of hydraulic oil supplied to each of the shield jacks via the hydraulic oil circuit when the plurality of shield jacks press against the segments to generate thrust, thereby continuously performing control to maintain the orientation of the tunnel boring machine main body toward the target orientation by bringing the target vertical stroke difference closer to the actual vertical stroke difference and bringing the target lateral stroke difference closer to the actual lateral stroke difference, and the hydraulic oil circuit includes a main line through which the amount of hydraulic oil adjusted during speed control flows, and a sub-line configured to merge with the main line and supply hydraulic oil to the shield jacks to maintain the internal pressure of the shield jacks at or above a predetermined value and maintain the abutting state between the shield jacks and the segments. With this configuration, the plurality of shield jacks can be extended by speed control, thereby suppressing vibrations caused by a sudden change in the attitude of the tunnel boring machine main body due to unbalanced resistance generated when the attitude of the tunnel boring machine main body fluctuates in an unintended direction. Furthermore, the sub-line can control the pressure of the hydraulic oil supplied to the shield jack, so that it is possible to prevent the shield jack being extended from separating from the segment due to an insufficient supply of hydraulic oil. [Effects of the Invention]

[0016] According to the present invention, as described above, it is possible to suppress vibrations caused by sudden changes in the attitude of the excavator body due to unbalanced resistance that occurs when the attitude of the excavator body changes in an unintended direction. [Brief explanation of the drawings]

[0017] [Figure 1] 1 is a cross-sectional side view of a tunnel boring machine according to a first (second) embodiment. FIG. [Figure 2] FIG. 10 is a schematic diagram for explaining the mechanism of vibration generation. [Figure 3]FIG. 2 is a rear view of a plurality of shield jacks of the tunnel boring machine according to the first embodiment. [Figure 4] FIG. 2 is a diagram showing a hydraulic oil circuit of the tunnel boring machine according to the first embodiment. [Figure 5] FIG. 2 is a diagram showing an input operation unit of the tunnel boring machine according to the first embodiment. [Figure 6] 5 is a flowchart of attitude control including pressure control executed by a control unit of the tunnel boring machine according to the first embodiment. [Figure 7] FIG. 10 is a diagram showing a hydraulic oil circuit of a tunnel boring machine according to a second embodiment. [Figure 8] 10 is a flowchart of attitude control including speed control executed by a control unit of a tunnel boring machine according to a second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0018] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0019] [First embodiment] (Tunnel boring machine configuration) A tunnel boring machine 100 according to a first embodiment will be described with reference to FIGS.

[0020] In the drawings, the excavation direction (forward) of the tunnel boring machine 100 is indicated by the X1 direction, and the opposite direction is indicated by the X2 direction. Also in the drawings, the right side of the tunnel boring machine 100, which is perpendicular to the X direction, is indicated by the Y1 direction, and the left side thereof is indicated by the Y2 direction. Also in the drawings, the upward direction is indicated by the Z1 direction, and the downward direction is indicated by the Z2 direction. Also in the drawings, the center of rotation extending in the front-to-back direction of the cutterhead 1 is indicated by the central axis C1, the center of yawing extending in the up-down direction of the tunnel boring machine 100 is indicated by the central axis C2, and the center of pitching of the tunnel boring machine 100 extending in the left-to-right direction is indicated by the central axis C3.

[0021] As shown in FIG. 1, the tunnel boring machine 100 comprises a cutter head 1, an excavator body 2, a shield jack 3, a hydraulic oil circuit 4, an input operation unit 5, and a control unit 6.

[0022] Here, the control unit 6 of the tunnel boring machine 100 of the first embodiment is configured to perform control continuously, rather than intermittently, to bring the actual vertical stroke difference closer to the target vertical stroke difference and to bring the actual left-right stroke difference closer to the target left-right stroke difference, thereby maintaining the orientation of the boring machine body 2 toward the target orientation. In other words, the control unit 6 is configured to continuously perform control to correct the actual vertical stroke difference and the actual left-right stroke difference so as to eliminate each of the deviation of the actual vertical stroke difference from the target vertical stroke difference and the deviation of the actual left-right stroke difference from the target left-right stroke difference. Hereinafter, this type of control will be referred to as "attitude control."

[0023] The "actual vertical stroke difference" is the stroke difference between the top and bottom positions calculated from the actual strokes of the multiple shield jacks 3, and is obtained by the stroke meter 7 described later. The "actual left-right stroke difference" is the stroke difference between the rightmost and leftmost positions calculated from the actual strokes of the multiple shield jacks 3, and is obtained by the stroke meter 7 described later. The "target vertical stroke difference" is the target value of the stroke difference between the topmost and bottommost positions in the vertical direction, and is obtained based on various parameters input by the worker via the input operation unit 5. The "target left-right stroke difference" is the target value of the stroke difference between the rightmost and leftmost positions in the horizontal direction, and is obtained based on various parameters input by the worker via the input operation unit 5.

[0024] In short, the control unit 6 constantly controls the attitude of the tunnel boring machine 100 through attitude control, thereby preventing the orientation of the tunnel boring machine 100 from deviating unintentionally in the up / down or left / right direction from its original orientation due to the effects of the machine's own weight, unevenness in the hardness of the ground, gradients, curved construction, etc. As a result, the control unit 6 is configured to continuously perform control to suppress changes in the attitude of the excavator main body 2 that cause vibrations, by maintaining the orientation of the excavator main body 2 toward the target orientation. The control content performed by the control unit 6 will be described in detail below.

[0025] An example of how vibration occurs during excavation will be described with reference to Figure 2. When the orientation of a tunnel boring machine continues to deviate significantly from its intended orientation in an unintended vertical or horizontal direction due to factors such as the effects of the machine's own weight, as listed above, frictional resistance between the boring machine body and the natural ground and resistance to the lateral load applied to the shield jack gradually increase, causing stick-slip (relatively small vibrations) and chatter vibrations of the shield jack, resulting in vibrations. If the resistance increases further, movements accompanied by sudden and excessive changes in posture occur, causing even greater vibrations.

[0026] (Cutter head configuration) The cutter head 1 shown in Figure 1 has multiple cutter bits on its front and is configured to excavate the ground by rotating. The cutter head 1 rotates by torque obtained from a drive motor (not shown). The soil excavated by the cutter head 1 flows into the chamber 1a and is mixed with the mud-making material inside the chamber 1a.

[0027] (Excavator body configuration) The excavator main body 2 has a cylindrical trunk 20. The trunk 20 includes a front trunk 20a and a rear trunk 20b. A bending jack 20c is provided between the front trunk 20a and the rear trunk 20b. The excavator main body 2 supports the cutter head 1 so that it can rotate about the central axis C1. The excavator main body 2 is provided with a partition wall 22 that separates the chamber 1a on the front side from a working space 21 on the rear side. The excavator main body 2 is also provided with a screw conveyor 23 that discharges earth and sand from the chamber 1a to the working space 21 side.

[0028] The excavator body 2 is also provided with an erector 24 on the rear side (X2 direction side) of the excavator body 2, which builds a ring of segments 8 that will become the tunnel wall. When the tunnel boring machine 100 advances, the segments 8 built by the erector 24 are pressed against by the pressing member 31 of the shield jack 3 from the front side. The shield jack 3 presses the segments 8 rearward. The tunnel boring machine 100 advances forward due to the reaction force of this pressing force. When the shield jack 3 is extended, the pressing member 31 of the shield jack 3 is maintained in contact with the segments 8 by so-called pressure control by the control unit 6, which will be described later.

[0029] (Shield jack configuration) The shield jacks 3 are configured to generate thrust by pressing the segments 8. A plurality of shield jacks 3 are provided in a single circular row along the inner circumferential surface of the fuselage 20. As an example, in this embodiment, 48 shield jacks 3 are provided.

[0030] As shown in FIG. 3, the multiple shield jacks 3 are divided into multiple blocks B (groups) each consisting of multiple shield jacks that are adjacent to each other. Specifically, the 48 shield jacks 3 are divided into eight blocks B each consisting of six shield jacks that are adjacent to each other. Four of the eight blocks B are arranged on each of the left and right sides of the central axis C2. Four of the eight blocks B are arranged above and below the central axis C3. No block B is arranged in a position that straddles the central axis C2 and the central axis C3. In short, the eight blocks B are arranged symmetrically and in a balanced manner with respect to each of the central axes C2 and C3. In FIGS. 3 and 4, the eight blocks B are illustrated as the first block B to the eighth block B.

[0031] Each block B is provided with one stroke meter 7 (eight in total) for measuring the stroke length of the shield jack 3. The stroke meter 7 is located near the center of the circumference of each block B. The measurement value of the stroke meter 7 is used to obtain the left / right force point correction amount and the top / bottom force point correction amount used for pressure control by the control unit 6. Details will be described later.

[0032] As shown in Figure 1, the shield jack 3 includes a jack body 30 and a pressing member 31 arranged behind the jack body 30. The jack body 30 has a head-side oil chamber 33 located on the head side of a piston 32 that moves within a cylinder, and a rod-side oil chamber 34 located on the rod side of the piston 32.

[0033] The pressing member 31 is installed at the rod tip of the piston 32 and is a member for pressing the segment 8 to generate thrust. When the shield jack 3 extends, hydraulic oil is supplied from the hydraulic oil circuit 4 to the head side oil chamber 33, and hydraulic oil is discharged from the rod side oil chamber 34 to the hydraulic oil circuit 4. At this time, the pressing member 31 abuts against the segment 8. Conversely, when the shield jack 3 retracts, hydraulic oil is discharged from the head side oil chamber 33 to the hydraulic oil circuit 4, and hydraulic oil is supplied from the hydraulic oil circuit 4 to the rod side oil chamber 34. At this time, the pressing member 31 moves away from the segment 8. Only one pressing member 31 is provided for every two adjacent shield jacks 3 (24 in total). Note that one pressing member may be provided for each shield jack (48 in total), or only one pressing member may be provided for three or more adjacent shield jacks.

[0034] (Configuration of hydraulic oil circuit) As shown in Fig. 4, the hydraulic oil circuit 4 is a so-called pressure control circuit. The hydraulic oil circuit 4 is a circuit for supplying hydraulic oil to the multiple shield jacks 3 and discharging hydraulic oil from the multiple shield jacks 3 to extend and retract the multiple shield jacks 3. The drive of the hydraulic oil circuit 4 is controlled by a control unit 6.

[0035] The hydraulic oil circuit 4 includes a tank 40, a hydraulic pump 41 that pressurizes the hydraulic oil in the tank 40 to multiple shield jacks 3, a first line 42 connected to the head side oil chamber 33, a second line 43 connected to the rod side oil chamber 34, a directional control valve 44, and a pressure reducing valve 45 provided in the first line 42.

[0036] The directional switching valve 44 switches between an extended state and a retracted state of the shield jack 3. The extended state is a state in which hydraulic oil is supplied to the head side oil chamber 33 via the first line 42 and is discharged from the rod side oil chamber 34 via the second line 43. The retracted state is a state in which hydraulic oil is discharged from the head side oil chamber 33 via the first line 42 and is supplied to the rod side oil chamber 34 via the second line 43.

[0037] One pressure reducing valve 45 is provided for each block B. Under the control of the control unit 6, the pressure reducing valve 45 is configured to reduce the hydraulic pressure of the hydraulic oil from the hydraulic pump 41 and adjust the hydraulic pressure of the hydraulic oil supplied to the shield jacks 3 of each block B. In the pressure control, the control unit 6 performs control so that the force points of the multiple shield jacks 3 become equal to the left / right force point correction amounts and the up / down force point correction amounts acquired in advance by the control unit 6.

[0038] (Configuration of input operation section) 5 is an operation unit that accepts input operations of the machine target azimuth angle A1 (machine target yawing angle), the machine pitching angle A2, and the set stroke, which are parameters for the attitude control performed by the control unit 6. The machine target azimuth angle A1 and the machine pitching angle A2 together form the "target azimuth."

[0039] The input operation unit 5 is a touch panel for inputting information. The input operation unit may also include a keyboard or the like. The input operation unit 5 may be configured to display an illustration 5a of a schematic circular vertical cross section of the tunnel boring machine 100 on a touch screen, and allow the operator to simultaneously select both the machine target azimuth angle A1 and the machine pitching angle A2 by touching the position of a target point to which the tunnel boring machine 100 is to move. A predetermined mark 5b (for example, a circle centered on the touch position) is displayed at the point touched by the operator.

[0040] (Configuration of control unit) 1 is configured as a control board including, for example, hardware such as a CPU (Central Processing Unit), a ROM (Read Only Memory), and a RAM (Random Access Memory). Below, the control configuration of the control unit 6 will be described with regard to the posture control including the pressure control executed by the control unit 6.

[0041] As described above, the control unit 6 is configured to continuously perform control to maintain the orientation of the excavator body 2 toward the target orientation (machine target orientation angle A1 and machine pitching angle A2) by bringing the actual vertical stroke difference closer to the target vertical stroke difference and bringing the actual lateral stroke difference closer to the target lateral stroke difference. In this way, the control unit 6 suppresses the expansion of changes in the attitude of the excavator body 2, which is a cause of vibration. Regarding attitude control, the control unit 6 is configured to continuously perform control to maintain the orientation of the excavator body 2 toward the target orientation by controlling the drive of the shield jacks 3 for each block B. In other words, the smallest unit to be controlled by the control unit 6 is one block B. Therefore, the control unit 6 controls the drive of the six shield jacks 3 that make up one block B so that their strokes are (approximately) the same.

[0042] The control unit 6 is configured to continuously perform control to maintain the orientation of the excavator body 2 in the target direction by making the actual vertical stroke difference reach the target vertical stroke difference and making the actual left-right stroke difference reach the target left-right stroke difference while the shield jack 3 extends by the set stroke set by the user.

[0043] As an example, when the set stroke is set to 1000 mm, the control unit 6 continuously controls the shield jacks 3 to gradually extend at a rate of change such that the actual vertical stroke difference reaches the target vertical stroke difference while each shield jack 3 extends by 1000 mm on average. As a result, the actual vertical stroke difference smoothly approaches the target vertical stroke difference while the shield jacks 3 extend by 1000 mm on average.

[0044] Similarly, in the left-right direction, when the set stroke is set to 1000 mm, the control unit 6 continuously controls the shield jack 3 to gradually extend at a rate of change such that the actual left-right stroke difference reaches the target left-right stroke difference while the shield jack 3 extends by 1000 mm on average. As a result, the actual left-right stroke difference smoothly approaches the target left-right stroke difference while the shield jack 3 extends by 1000 mm on average.

[0045] In addition, when the segments 8 are pressed by the multiple shield jacks 3 to generate thrust, the control unit 6 is configured to perform pressure control to adjust the pressure of the hydraulic oil supplied to each of the shield jacks 3 via the hydraulic oil circuit 4, thereby continuously performing control to bring the actual vertical stroke difference closer to the target vertical stroke difference and to bring the actual left-right stroke difference closer to the target left-right stroke difference, thereby maintaining the orientation of the excavator main body 2 in the target direction.

[0046] The control unit 6 is configured to continuously perform control to correct each of the target vertical stroke difference and the target horizontal stroke difference by acquiring an integrated value for each of the deviation of the actual vertical stroke difference from the target vertical stroke difference and the deviation of the actual horizontal stroke difference from the target horizontal stroke difference and performing PI control, which is proportional-integral control. As a result, the control unit 6 obtains a corrected horizontal stroke correction value and a corrected vertical stroke correction value that are used to obtain the horizontal force point correction amount and the vertical force point correction amount.

[0047] (Control processing of the control unit) The control process of the attitude control executed by the control unit 6 will be described with reference to FIG.

[0048] First, in step S1, the machine target azimuth angle A1, machine pitching angle A2, and set stroke are input via the input operation unit 5. By inputting the machine target azimuth angle A1, machine pitching angle A2, and set stroke, a smooth machine trajectory is determined that extends from the current position to a position excavated by the set stroke.

[0049] In step S2, a target left-right stroke difference and a target up-down stroke difference are acquired based on the machine target azimuth angle A1, the machine pitching angle A2, and the set stroke, and then the process proceeds to step S3.

[0050] In step S3, it is determined whether or not excavation has begun by the tunnel boring machine 100. If excavation by the tunnel boring machine 100 has begun, the process proceeds to step S4.

[0051] In step S4, the stroke length is obtained as measured by the stroke meter 7 provided in each block B. Then, the process proceeds to step S5.

[0052] In step S5, the actual left-right stroke difference and the actual up-down stroke difference are calculated from the stroke lengths acquired in step S4 using least squares plane calculations. Then, the process proceeds to step S6. The reason for using least squares plane calculations is to calculate the most likely attitude of the tunnel boring machine 100 from the values of multiple stroke meters 7, without being affected by the number or position of the stroke meters 7 or the accuracy of the stroke meters 7.

[0053] In step S6, the deviation of the left-right stroke difference and the deviation of the up-down stroke difference are calculated. In detail, after calculating "(target left-right stroke difference - initial left-right stroke difference) / (set stroke) x actual average stroke + initial left-right stroke difference = trajectory target left-right stroke difference", it is further calculated as "(trajectory target left-right stroke difference - actual left-right stroke difference) = deviation of left-right stroke difference". The initial left-right stroke difference is the actual left-right stroke difference at the start of excavation.

[0054] Similarly, in the vertical direction, "(target vertical stroke difference - initial vertical stroke difference) / (set stroke) x actual average stroke + initial vertical stroke difference = trajectory target vertical stroke difference" is calculated, and then "(trajectory target vertical stroke difference - actual vertical stroke difference) = deviation of vertical stroke difference" is calculated. The initial vertical stroke difference is the actual vertical stroke difference at the start of excavation. Then, proceed to step S7.

[0055] In step S7, the deviation of the left-right stroke difference and the deviation of the up-down stroke difference are integrated. In detail, the deviation of the left-right stroke difference is integrated to obtain a left-right deviation integrated value, as in "Σ (deviation of the left-right stroke difference) = integrated left-right deviation value." Similarly, in the up-down direction, the deviation of the up-down stroke difference is integrated to obtain a up-down deviation integrated value, as in "Σ (deviation of the up-down stroke difference) = integrated up-down deviation value." Then, the process proceeds to step S8.

[0056] In step S8, the corrected left / right stroke correction value and the corrected up / down stroke correction value are calculated. Specifically, they are calculated by "(deviation of left / right stroke difference) × proportional gain + (accumulated value of left / right deviation) × integral gain = corrected left / right stroke correction value." Similarly, in the up / down direction, they are calculated by "(deviation of up / down stroke difference) × proportional gain + (accumulated value of up / down deviation) × integral gain = corrected up / down stroke correction value." Then, the process proceeds to step S9.

[0057] The above steps S6 to S8 are steps related to PI control executed by the control unit 6. If the control unit were to execute only P control (proportional control), the actual left-right stroke difference and the actual up-down stroke difference could be made to approach the target left-right stroke difference and the target up-down stroke difference, respectively, but would not be able to match them. This is because, when the deviation becomes small, the control amount becomes too small with P control alone, and does not lead to a change in posture. Control with P control alone is also difficult when there is a bias that shows behavior opposite to the control amount. Therefore, by having the control unit 6 execute PI control, it becomes possible to make the actual left-right stroke difference and the actual up-down stroke difference approach and (approximately) match the target left-right stroke difference and the target up-down stroke difference, respectively.

[0058] In step S9, the left / right force point correction amount and the up / down force point correction amount are calculated. Specifically, they are calculated by "corrected left / right stroke correction value × left / right force point conversion coefficient = left / right force point correction amount." Similarly, in the up / down direction, they are calculated by "corrected up / down stroke correction value × up / down force point conversion coefficient = up / down force point correction amount." This force point correction amount is added to the current force point to determine the corrected force point. Then, the process proceeds to step S10.

[0059] The force point conversion coefficient is a dimensionless coefficient that is determined by the operator, taking into consideration machine characteristics such as machine shape, which affect the ease with which the machine bends, and soil quality, which also affect the ease with which the machine bends. The force point conversion coefficient is a coefficient obtained from accumulated data such as past excavation results. For example, if the machine is easy to bend, the force point conversion coefficient will be small, and if the machine is difficult to bend, the force point conversion coefficient will be large.

[0060] In step S9, if the calculated left-right corrected force point is equal to or greater than a predetermined left-right limit value, the left-right corrected force point is set to the same value as the predetermined left-right limit value. Similarly, if the calculated top-bottom corrected force point is equal to or greater than a predetermined top-bottom limit value, the top-bottom corrected force point is set to the same value as the predetermined top-bottom limit value.

[0061] In step S10, pressure control is performed based on the left / right corrected force point and the up / down corrected force point. That is, control is performed to reduce the hydraulic pressure of the hydraulic oil sent to the shield jacks 3 for each block B so that the force points of the multiple shield jacks 3 become the left / right corrected force point and the up / down corrected force point. Then, the process proceeds to step S11.

[0062] In step S11, it is determined whether the machine positional deviation is within the allowable range. If the machine positional deviation is within the allowable range, the process proceeds to step S12, and if it is outside the allowable range, the process returns to step S1. If the machine positional deviation is outside the allowable range, the worker may be notified of this by issuing an alarm sound or displaying an alarm message on the input operation unit. Furthermore, the worker may determine whether the machine positional deviation is within the allowable range.

[0063] In step S12, it is determined whether excavation has finished. If excavation has finished, the process proceeds to END, and if excavation has not finished, the process returns to step S4.

[0064] As explained above, the control unit 6 is configured to continuously control the pressure of the shield jack 3 (perform feedback control) while repeatedly correcting the left-right force point correction amount and the up-down force point correction amount during ongoing excavation. This allows the attitude of the tunnel boring machine 100 to be continuously (sustainably) maintained in a state facing the target orientation, thereby suppressing the occurrence of vibrations.

[0065] (Vibration measurement means) As shown in FIG. 3, the tunnel boring machine 100 is equipped with an accelerometer 9 for measuring vibrations. In one example, the accelerometer 9 is disposed on the inner periphery of each of the shield jacks 3. The tunnel boring machine 100 is configured to use the accelerometer 9 to grasp the relationship between the magnitude of vibration, the deviation between the target vertical stroke difference and the actual vertical stroke difference, and the relationship between the deviation between the target horizontal stroke difference and the actual horizontal stroke difference. A single or multiple accelerometers 9 may be installed to measure vibrations in real time. Note that vibration measurement may also be performed using a sensor other than the accelerometer 9. For example, vibration measurement may be performed using a stroke meter. While FIG. 3 shows an example in which eight accelerometers 9 are provided, the number is not necessarily eight; two or more may be used. The more accelerometers used, the more precise the vibration measurement. The accelerometer 9 is an example of a "means for measuring vibrations" in the claims.

[0066] (Effects of the first embodiment) In the first embodiment, the following effects can be obtained.

[0067] As described above, the first embodiment includes a control unit 6 that continuously, rather than intermittently, controls the excavator body 2 to maintain its orientation toward the target direction by bringing the actual vertical stroke difference, which is the actual stroke difference between the multiple shield jacks 3 at the top and bottom, closer to the target vertical stroke difference, which is the target value for the stroke difference between the multiple shield jacks 3 at the top and bottom, and bringing the actual horizontal stroke difference, which is the actual stroke difference between the multiple shield jacks 3 at the left and right, closer to the target horizontal stroke difference, which is the target value for the stroke difference between the multiple shield jacks 3 at the left and right. This allows the vertical and horizontal stroke differences of the shield jacks 3 to be continuously (always) controlled and monitored to maintain the orientation of the excavator body 2 toward the target direction. This avoids the conventional situation in which the stroke difference adjustment is not performed while excavating between two adjacent verification points. As a result, when the attitude of the shield machine 100 changes due to changes in resistance to the advancement of the shield machine 100 or directional control, unbalanced resistance is generated, and vibrations caused by a sudden change in the attitude of the excavator body 2 can be suppressed. That is, it is possible to suppress vibrations caused by sudden changes in the attitude of the excavator body 2 due to unbalanced resistance that occurs when the attitude of the excavator body 2 changes in an unintended direction.

[0068] In the first embodiment, as described above, the control unit 6 is configured to continuously perform control to maintain the orientation of the excavator body 2 toward the target orientation by causing the actual vertical stroke difference to reach the target vertical stroke difference and the actual lateral stroke difference to reach the target lateral stroke difference while the shield jack 3 extends by the set stroke, which is the stroke of the shield jack 3 set by the user. This allows the actual vertical stroke difference and the actual lateral stroke difference to smoothly approach the target vertical stroke difference and the target lateral stroke difference, respectively, through continuous control utilizing the period until the set stroke is reached. This effectively prevents abrupt changes in the attitude of the excavator body 2, thereby further suppressing vibration.

[0069] As described above, the first embodiment includes the hydraulic oil circuit 4 that supplies hydraulic oil to the multiple shield jacks 3. When the multiple shield jacks 3 press against the segments 8 to generate thrust, the control unit 6 executes pressure control to adjust the pressure of hydraulic oil supplied to each of the shield jacks 3 via the hydraulic oil circuit 4. This adjusts the actual vertical stroke difference to the target vertical stroke difference and the actual lateral stroke difference to the target lateral stroke difference, thereby continuously performing control to maintain the orientation of the excavator body 2 toward the target direction. This allows the multiple shield jacks 3 to be extended by a predetermined amount through pressure control, thereby suppressing vibrations that are caused by a sudden change in the attitude of the excavator body 2 due to unbalanced resistance that occurs when the attitude of the excavator body 2 changes to an unintended direction. Furthermore, the pressure of the hydraulic oil supplied to the shield jacks 3 can be controlled through pressure control, thereby preventing the extended shield jacks 3 from moving away from the segments 8 due to a lack of hydraulic oil supply.

[0070] As described above, in the first embodiment, the control unit 6 is configured to continuously perform control to correct each of the target vertical stroke difference and the target horizontal stroke difference by acquiring an integrated value for each of the deviation of the actual vertical stroke difference from the target vertical stroke difference and the deviation of the actual horizontal stroke difference from the target horizontal stroke difference and performing PI control, which is proportional-integral control. This allows the vertical deviation and the horizontal deviation to be integrated by I control, which is an integral control within the PI control, thereby enabling control to more reliably eliminate the vertical deviation and the horizontal deviation. As a result, each of the actual vertical stroke difference and the actual horizontal stroke difference can be accurately brought closer to the target vertical stroke difference and the target horizontal stroke difference. This makes it possible to more effectively suppress vibrations caused by a sudden change in the attitude of the excavator body 2 due to unbalanced resistance generated when the attitude of the excavator body 2 changes in an unintended direction.

[0071] In the first embodiment, as described above, the multiple shield jacks 3 are divided into multiple blocks B, each grouping adjacent shield jacks, and the control unit 6 is configured to control the driving of the shield jacks 3 for each block B, and continuously perform control to maintain the orientation of the excavator main body 2 in the target direction. This allows control to be performed in units of block B, each grouping multiple shield jacks 3, and therefore, unlike when multiple shield jacks are controlled individually, it is possible to avoid complicating control.

[0072] In the first embodiment, as described above, the control unit 6 is configured to continuously perform control to suppress changes in the attitude of the excavator body 2 that cause vibrations, by maintaining the orientation of the excavator body 2 toward the target orientation. This allows the control unit 6 to more reliably perform control to suppress changes in the attitude of the excavator body 2 that cause vibrations.

[0073] In this case, it is preferable that the tunnel boring machine 100 further comprises a means for measuring vibration (accelerometer 9), and is configured so that the means for measuring vibration (accelerometer 9) can grasp the relationship between the magnitude of vibration and the deviation between the target vertical stroke difference and the actual vertical stroke difference, and the relationship between the deviation between the target left-right stroke difference and the actual left-right stroke difference. This makes the relationship between an increase in vibration and a change in the attitude of the tunnel boring machine 100 clear, and also clarifies the effect of control. It also makes it possible to determine whether to carry out operation, and the occurrence of vibration can be effectively suppressed.

[0074] [Second embodiment] A second embodiment will be described with reference to Figures 1, 7, and 8. In this second embodiment, an example will be described in which a control unit 206 performs so-called speed control, unlike the first embodiment in which the control unit 6 performs so-called pressure control. In the figures, the same components as those in the first embodiment are denoted by the same reference numerals.

[0075] As shown in FIG. 1, a tunnel boring machine 200 of the second embodiment includes a hydraulic oil circuit 204 and a control unit 206.

[0076] (Configuration of hydraulic oil circuit) 7 is a so-called speed control circuit. The hydraulic oil circuit 204 is a circuit for supplying hydraulic oil to the multiple shield jacks 3 and discharging hydraulic oil from the multiple shield jacks 3 to extend and retract the multiple shield jacks 3. The drive of the hydraulic oil circuit 204 is controlled by a control unit 206.

[0077] The hydraulic oil circuit 204 includes a tank 40, a hydraulic pump 41 that pressurizes the hydraulic oil in the tank 40 to multiple shield jacks 3, a first line 42 connected to the head side oil chamber 33, a second line 43 connected to the rod side oil chamber 34, a directional control valve 44, and a flow control valve 45a provided in the first line 42.

[0078] The first line 42 includes a main line 42a and a sub-line 42b.

[0079] The main line 42a is a line through which hydraulic oil flows at a rate adjusted by a flow control valve 45a during speed control. The sub-line 42b is configured to merge with the main line 42a. The sub-line 42b is a line that supplies hydraulic oil to the shield jack 3 to maintain the internal pressure of the shield jack 3 at or above a predetermined value and maintain the abutting state between the shield jack 3 and the segments 8. A pressure control valve 46 is provided in the sub-line 42b, and hydraulic oil flows at a lower pressure than in the main line 42a.

[0080] One flow rate control valve 45a is provided for each block B. Under the control of the control unit 206, the flow rate control valve 45a is configured to limit the amount of hydraulic oil from the hydraulic pump 41 to adjust the amount of hydraulic oil supplied to the shield jacks 3 of each block B. In speed control, the control unit 206 controls the speed of the multiple shield jacks 3 so that it becomes a shield jack block speed calculated for each block, which will be described later.

[0081] (Configuration of control unit) 1 is configured as a control board including, for example, hardware such as a CPU, ROM, RAM, etc. The control configuration of the control unit 206 will be described below with respect to the attitude control including the velocity control executed by the control unit 206.

[0082] The control unit 206 is configured to continuously perform control to bring the actual vertical stroke difference closer to the target vertical stroke difference and to bring the actual left-right stroke difference closer to the target left-right stroke difference, thereby maintaining the orientation of the excavator body 2 toward the target orientation. The control unit 206 is configured to continuously perform control to bring the target vertical stroke difference closer to the actual vertical stroke difference and to bring the target left-right stroke difference closer to the actual left-right stroke difference, thereby maintaining the orientation of the excavator body 2 toward the target orientation, by executing speed control to adjust the amount of hydraulic oil supplied to each of the shield jacks 3 via the hydraulic oil circuit 204 when thrust is generated by pressing the segments 8 with the multiple shield jacks 3.

[0083] (Control processing of the control unit) The control process of the attitude control executed by the control unit 206 will be described with reference to Fig. 8. Note that steps S1 to S6, step S11 and step S12 are the same as those in the first embodiment, and therefore description thereof will be omitted.

[0084] After the processing of step S6, the process proceeds to step S20. In step S20, the shield jack block speed is calculated for each block.

[0085] In detail, the calculation is performed using the following formulas: "average speed of shield jack × speed adjustment range (%) / 100 = speed adjustment amount," "average speed of shield jack + average speed of shield jack × maximum speed adjustment range (%) / 100 = maximum speed," "average speed of shield jack - average speed of shield jack × maximum speed adjustment range (%) / 100 = minimum speed," "ABS (left / right stroke deviation / 2 / speed adjustment amount) = deviation correction time (left / right)," "ABS (up / down stroke deviation / 2 / speed adjustment amount) = deviation correction time (up / down)," "left / right stroke deviation / 2 × block center Y bearing amount / jack PCR / deviation correction time (left / right) = each shield jack block speed (left / right component)," "up / down stroke deviation / 2 × block center Z bearing amount / jack PCR / deviation correction time (up / down) = each shield jack block speed (up / down component)," and "average speed of shield jack + shield jack block speed (left / right component) + shield jack block speed (up / down component) = each shield jack block speed." Then, the process proceeds to step S21. The "jack PCR" refers to the mounting radius of the shield jack 3. In other words, it is the distance from the central axis C1 to the center of the shield jack 3.

[0086] Furthermore, in step S20, if the calculated speed of each shield jack block exceeds a predetermined maximum speed or is less than a predetermined minimum speed, it is adjusted to a value within the range of not less than the predetermined minimum speed and not more than the predetermined maximum speed.

[0087] In step S21, speed control is performed based on the speed of each shield jack block. That is, control is performed to limit the amount of hydraulic oil sent to the shield jacks 3 for each block B so that the speed of the shield jacks in each block B becomes the calculated speed of each shield jack block. Then, the process proceeds to step S11.

[0088] As explained above, the control unit 206 is configured to continuously control the speed of the shield jack 3 (perform feedback control) while excavation continues, while repeatedly correcting the speed of each shield jack block. This allows the attitude of the tunnel boring machine 100 to be continuously (sustainably) maintained in a state facing the target direction, and the occurrence of vibrations is suppressed.

[0089] The other configurations of the second embodiment are the same as those of the first embodiment.

[0090] (Effects of the second embodiment) In the second embodiment, the following effects can be obtained.

[0091] As described above, the second embodiment is provided with a control unit 206 that continuously, rather than intermittently, performs control to maintain the orientation of the excavator body 2 toward the target orientation by bringing the actual vertical stroke difference, which is the actual stroke difference between the multiple upper and lower shield jacks 3, closer to the target vertical stroke difference, which is the target value for the stroke difference between the multiple upper and lower shield jacks 3, and bringing the actual horizontal stroke difference, which is the actual stroke difference between the multiple left and right shield jacks 3, closer to the target horizontal stroke difference, which is the target value for the stroke difference between the multiple left and right shield jacks 3. This makes it possible to suppress vibrations caused by a sudden change in the attitude of the excavator body 2 due to unbalanced resistance that occurs when the attitude of the excavator body 2 fluctuates in an unintended direction, as in the first embodiment.

[0092] In the second embodiment, as described above, there is provided a hydraulic oil circuit 204 that supplies hydraulic oil to a plurality of shield jacks 3, and the control unit 206 is configured to perform speed control to adjust the amount of hydraulic oil supplied to each of the shield jacks 3 via the hydraulic oil circuit 204 when the plurality of shield jacks 3 press against the segments 8 to generate thrust, thereby continuously performing control to keep the orientation of the excavator body 2 toward the target orientation by bringing the target vertical stroke difference closer to the actual vertical stroke difference and bringing the target left-right stroke difference closer to the actual left-right stroke difference, and the like. The hydraulic oil circuit 204 includes a main line 42a through which the amount of hydraulic oil adjusted during speed control flows, and a sub-line 42b that is configured to merge with the main line 42a and supplies hydraulic oil to the shield jack 3 to maintain the internal pressure of the shield jack 3 at or above a predetermined value and maintain the abutting state between the shield jack 3 and the segments 8. This makes it possible to extend the multiple shield jacks 3 by controlling the speed, thereby suppressing vibrations caused by sudden changes in the attitude of the excavator body 2 due to unbalanced resistance that occurs when the attitude of the excavator body 2 changes in an unintended direction. Also, because the sub-line 42b can control the supply pressure of hydraulic oil into the shield jacks 3, it is possible to prevent the extending shield jacks 3 from moving away from the segments 8 due to insufficient supply of hydraulic oil.

[0093] Other effects of the second embodiment are the same as those of the first embodiment.

[0094] [Variations] The embodiments and modifications disclosed herein should be considered to be illustrative in all respects and not restrictive. The scope of the present invention is defined by the claims rather than the description of the above embodiments, and further includes all modifications (modifications) within the meaning and scope of the claims.

[0095] For example, in the above first and second embodiments, an example was shown in which the present invention was applied to a mud pressure type tunnel boring machine, but the present invention is not limited to this and may also be applied to a mud water type tunnel boring machine.

[0096] Furthermore, in the above first and second embodiments, an example was shown in which the tunnel boring machine was equipped with 48 shield jacks, but the present invention is not limited to this. In the present invention, the tunnel boring machine may be equipped with a number of shield jacks other than 48.

[0097] In the first and second embodiments, an example was shown in which a plurality of shield jacks were divided into blocks and controlled by the control unit, but the present invention is not limited to this. In the present invention, the control unit may control each shield jack individually without dividing the plurality of shield jacks into blocks.

[0098] In addition, in the first and second embodiments, an example was shown in which the number of shield jacks in one block was six, but the present invention is not limited to this. In the present invention, the number of shield jacks in one block may be any number other than six.

[0099] In the first and second embodiments, the target left-right stroke difference and the target up-down stroke difference are corrected and then used to calculate the point of effort, but the present invention is not limited to this. In the present invention, the target left-right stroke difference and the target up-down stroke difference may be used to calculate the point of effort as is without correction.

[0100] In addition, in the first and second embodiments, the control unit executes PI control, but the present invention is not limited to this. In the present invention, the control unit may execute P control or PID control instead of PI control.

[0101] In addition, in the first embodiment, the control unit executes pressure control, and in the second embodiment, the control unit executes speed control, but the present invention is not limited to this. In the present invention, the control unit may execute both pressure control and speed control.

[0102] Furthermore, in the above first and second embodiments, an example in which eight stroke meters are provided is shown, but the present invention is not limited to this. In the present invention, the number of stroke meters may be different from eight. In this case, at least three stroke meters are provided. The more stroke meters, the better. Also, there may be blocks in which no stroke meters are provided. Furthermore, the more the stroke meters are dispersed and arranged so that they are spaced apart from each other in a direction perpendicular to the excavation direction, the more the measurement accuracy improves.

[0103] In addition, in the first and second embodiments, the set stroke is 1000 mm, but the present invention is not limited to this. In the present invention, the set stroke may be set to a length other than 1000 mm, such as 500 mm or 1500 mm.

[0104] Furthermore, in the first and second embodiments, for convenience of explanation, the processing operation of the control unit is described using a flow-driven flowchart in which processing is performed in order according to a processing flow, but the present invention is not limited to this. In the present invention, the processing operation of the control unit may be performed by event-driven processing in which processing is performed on an event-by-event basis. In this case, the processing may be performed completely event-driven, or may be performed in a combination of event-driven and flow-driven. [Explanation of symbols]

[0105] 1 cutter head 2 Excavator body 3 Shield Jack 4, 204 Hydraulic oil circuit 6, 206 Control section 8 segments 9. Accelerometer (a means of measuring vibration) 20 Torso 42a Main Line 42b Subline 100, 200 Tunnel Boring Machine Block B

Claims

1. a cutter head that excavates the ground by rotating; an excavator body including a cylindrical body and rotatably supporting the cutter head; a plurality of shield jacks arranged in an annular pattern along the inner circumferential surface of the fuselage and pressing the segments to generate thrust; a control unit that continuously, rather than intermittently, performs control to maintain the orientation of the excavator body in a target direction by bringing an actual vertical stroke difference, which is the actual stroke difference between the plurality of shield jacks at the top and bottom, closer to a target vertical stroke difference, which is a target value for the stroke difference between the plurality of shield jacks at the top and bottom, and bringing an actual left-right stroke difference, which is the actual stroke difference between the plurality of shield jacks at the left and right, closer to a target left-right stroke difference, which is a target value for the stroke difference between the plurality of shield jacks at the left and right.

2. 2. The tunnel boring machine according to claim 1, wherein the control unit is configured to continuously perform control such that the actual vertical stroke difference reaches the target vertical stroke difference and the actual left-right stroke difference reaches the target left-right stroke difference while the shield jack is extended by a set stroke, which is a stroke of the shield jack set by a user, thereby maintaining the orientation of the boring machine body toward the target direction.

3. Further, a hydraulic oil circuit is provided to supply hydraulic oil to the plurality of shield jacks.

2. The tunnel boring machine according to claim 1, wherein the control unit is configured to continuously perform control to maintain the orientation of the boring machine body toward the target direction by executing pressure control that adjusts the pressure of hydraulic oil supplied to each of the shield jacks via the hydraulic oil circuit when the plurality of shield jacks press against the segments to generate thrust, thereby maintaining the actual vertical stroke difference at the target vertical stroke difference and maintaining the actual left-right stroke difference at the target left-right stroke difference.

4. 2. The tunnel boring machine according to claim 1, wherein the control unit is configured to continuously perform control to correct each of the target vertical stroke difference and the target horizontal stroke difference by obtaining an integrated value for each of the deviation of the actual vertical stroke difference from the target vertical stroke difference and the deviation of the actual horizontal stroke difference from the target horizontal stroke difference and performing PI control which is proportional-integral control.

5. The plurality of shield jacks are divided into a plurality of blocks each including a plurality of adjacent shield jacks, 2. The tunnel boring machine according to claim 1, wherein the control unit is configured to continuously perform control to maintain the orientation of the boring machine body toward the target orientation by controlling the drive of the shield jack for each block.

6. 2. A tunnel boring machine as described in claim 1, wherein the control unit is configured to continuously perform control to suppress attitude changes of the boring machine body that cause vibrations by maintaining the orientation of the boring machine body toward the target orientation.

7. Further comprising means for measuring vibration; 7. A tunnel boring machine according to claim 6, wherein the vibration measuring means is configured to be able to grasp the relationship between the magnitude of vibration and the deviation between the target vertical stroke difference and the actual vertical stroke difference, and the relationship between the deviation between the target left-right stroke difference and the actual left-right stroke difference.

8. Further, a hydraulic oil circuit is provided to supply hydraulic oil to the plurality of shield jacks. the control unit is configured to continuously perform control to maintain the orientation of the excavator body toward the target direction by executing speed control to adjust the amount of hydraulic oil supplied to each of the shield jacks via the hydraulic oil circuit when the segments are pressed by the multiple shield jacks to generate thrust, thereby making the target vertical stroke difference closer to the actual vertical stroke difference and making the target lateral stroke difference closer to the actual lateral stroke difference, The hydraulic oil circuit includes: a main line through which the amount of hydraulic oil adjusted during the speed control flows; 2. The tunnel boring machine according to claim 1, further comprising: a sub-line configured to merge with the main line and supplying hydraulic oil to the shield jack to maintain a pressure inside the shield jack at or above a predetermined value and maintain a state of contact between the shield jack and the segments.

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