Shield tunneling machine

Abstract

To enable a shield boring machine to smoothly execute curve construction and enable a tail seal to be exchanged from inside of the machine.SOLUTION: A rear drum plate 5b consists of a rear drum inner cylinder part 5ba positioned on a front drum plate 5a side and mounted with a shield jack 9b, and a rear drum outer cylinder part 5bb that is installed so as to follow the rear drum inner cylinder part 5ba and expands and contracts the rear drum plate 5b by moving in an axial direction. The rear drum outer cylinder part 5bb comprises: first and second fixing member grooves 21, 22 and a transmission member groove 23 that are formed in a circumferential direction on an inner peripheral surface extending backward; a fixing member 17 that is engaged with the first fixing member groove 21 and fixes the rear drum outer cylinder part 5bb to the rear drum inner cylinder part 5ba at a position where length of the rear drum plate 5b is long, and is engaged with the second fixing member groove 22 and fixes the rear drum outer cylinder part 5bb to the rear drum inner cylinder part 5ba at a position where the length of the rear drum plate 5b is short; and an expanding and contracting force transmission member 18 that is engaged with the transmission member groove 23 and moves the rear drum outer cylinder part 5bb in an axial direction by expansion and contraction of the shield jack 9b.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a shield tunneling machine.

Background Art

[0002] A shield tunneling machine is known as a device used for excavating a shield tunnel such as a tunnel or a subway by excavating the ground.

[0003] In this shield tunneling machine, a cutter head is rotatably installed at the tip of the skin plate in the advancing direction, and a plurality of bits are arranged on the cutter head in a circumferential and radial manner. Then, by pressing the cutter head against the excavation surface (face) and rotating it while advancing, the ground is excavated in a circular shape. At this time, inside the shield tunneling machine, segments assembled in a cylindrical shape are pushed out behind the skin plate as the shield tunneling machine advances.

[0004] When constructing a curved section of a shield tunnel using such a shield tunneling machine, the shield tunneling machine is bent by a mid-bending jack to conform to the curve.

[0005] Here, a tail seal for sealing between the skin plate and the segment in shield construction to prevent groundwater from entering the shield tunneling machine is provided at the rear end of the skin plate constituting the shield tunneling machine. This tail seal moves as the shield tunneling machine advances while being pressed against the outer peripheral surface of the segment. In addition, the length of shield tunnels is increasing (generally, a length of 1.5 km or more is called a long distance, and a length of 3.0 km or more is called an ultra-long distance). Due to deterioration and damage of the tail seal (such as deformation of the seal member itself, detachment or deformation of the wire brush, etc.) associated with such an increase in the length of the shield tunnel, various troubles such as problems occurring in the segment or an abnormal increase in the thrust force have occurred. Therefore, in order to avoid such troubles, it is necessary to replace the tail seal during tunneling.

[0006] Regarding the curved construction of a shield tunneling machine, for example, it is described in Patent Document 1. For the folding mechanism of a shield tunneling machine in which the shield body is divided into two parts front and back and connected in a bendable manner, the skin plates on the inner side of the bend of the front body and the rear body are inscribed on the inner peripheral side of the tunnel wall surface, and the outer side of the bend at the front end of the front body and the outer side of the bend at the rear end of the rear body are moved along the outer peripheral side of the tunnel wall surface to perform sharp curve construction. A technique is disclosed.

[0007] Regarding the replacement of the tail seal in a shield tunneling machine, for example, it is described in Patent Document 2. The skin plate of the rear body part is made double, and by tunneling and advancing with the inner skin plate left in the ground, the inner peripheral surface of the outer skin plate that has been covered by the inner skin plate until then is exposed in the pit, and a new tail seal is attached to this inner peripheral surface from the pit. A technique is disclosed.

Prior Art Documents

Patent Documents

[0008]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0009] Now, in the construction of the shield tunnel described above, depending on the construction site, sharp curve tunneling may be required. At this time, depending on the maximum folding angle of the shield tunneling machine, it may be difficult to follow the required sharp curve, or overexcavation may increase.

[0010] Also, in order to prevent troubles caused by deterioration or damage of the tail seal, it is necessary to perform the replacement work of the tail seal from inside the shield machine during tunneling.

[0011] The present invention has been made in view of the above-described technical background, and an object thereof is to provide a technique capable of smoothly performing curved construction by a shield tunneling machine.

[0012] Further, the present invention has been made in view of the above-described technical background, and an object thereof is to provide a technique capable of performing the replacement work of the tail seal of the shield tunneling machine from inside the shield machine.

Means for Solving the Problems

[0013] To solve the above problems, the shield tunneling machine of the present invention according to claim 1 includes a front body portion where a cutter head is installed, a rear body inner cylinder portion located on the front body portion side and provided with a plurality of shield jacks, a rear body outer cylinder portion that is installed following the rear body inner cylinder portion and partially overlaps with the rear body inner cylinder portion and is movable in the axial direction, and a rear body portion having a tail seal provided at the rear end of the rear body outer cylinder portion. The rear body outer cylinder portion has, on its inner peripheral surface, a first fixing member engaging portion, a second fixing member engaging portion, and a transmission member engaging portion formed in the circumferential direction from the front to the rear, respectively. In a concave shape A fixing member that detachably engages with the first fixing member engaging portion and fixes the rear body outer cylinder portion to the rear body inner cylinder portion in a first state where the length of the rear body portion is relatively long, and detachably engages with the second fixing member engaging portion and fixes the rear body outer cylinder portion to the rear body inner cylinder portion in a second state where the length of the rear body portion is relatively short, and an expansion / contraction force transmission member that detachably engages with the transmission member engaging portion and fixes the spreader of the shield jack to the rear body outer cylinder portion are provided. It is fixed to a fixed base provided on an intermediate ring body annularly provided on the rear barrel inner cylinder portion along the inner peripheral surface of the rear barrel inner cylinder portion, The shield tunneling machine of the present invention according to claim 20 is the above

[0016] Claim 2 In the invention described above, the first fixing member engaging portion, the second fixing member engaging portion, and the transmission member engaging portion are a first fixing member groove portion, a second fixing member groove portion, and a transmission member groove portion respectively formed on the inner peripheral surface of the rear body outer cylinder portion into which the fixing member or the expansion / contraction force transmission member fits. Claim 1 This is characterized by that.

[0017] Claim 3 The shield tunneling machine of the present invention described in [reference] is as described above Claim 1 or 2 In the invention described above, a spacer is provided between the telescopic force transmission member pushed by the shield jack and wherein equipment for driving a shield tunneling machine is installed the end face of the segment provided on the rear end side of the equipment body to form a tunnel, which is characterized in that.

[0018] The shield tunneling machine of the present invention according to claim 4 is as described above Claim 1 or 2 In the invention described above, restricting means for restricting the circumferential displacement of the outer cylinder portion of the rear body with respect to the inner cylinder portion of the rear body is provided, which is characterized in that.

[0019] Claim 5 The shield tunneling machine of the present invention described in [reference] is as described above Claim 4 In the invention described in [reference], the restricting means is formed on either the outer cylinder portion of the rear body or the inner cylinder portion of the rear body, and has a fitting groove extending along the axial direction, and is provided on the outer cylinder portion of the rear body or the inner cylinder portion of the rear body where the fitting groove is not formed, and is composed of a fitting member that fits into the fitting groove and is movable along the fitting groove, which is characterized in that.

Effect of the Invention

[0020] According to the present invention, by moving the outer cylinder portion of the rear body from the first state to the second state, it becomes possible to shorten the length of the rear body portion and smoothly perform curved construction.

[0021] Further, if the outer cylinder portion of the rear body is moved from the first state to the second state so that the dimension in which the tail seal is exposed inside the machine, it becomes possible to perform the replacement work of the tail seal from inside the shield machine.

Brief Description of the Drawings

[0022]

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Embodiments for Carrying Out the Invention

[0023] Hereinafter, embodiments as an example of the present invention will be described in detail with reference to the drawings. In the drawings for explaining the embodiments, the same reference numerals are generally given to the same components, and the repeated explanations thereof are omitted.

[0024] First, the overall configuration of the shield tunneling machine according to this embodiment will be described with reference to FIG. 1. FIG. 1 is a main part configuration diagram showing the inside of the shield tunneling machine according to this embodiment as seen through from the side.

[0025] The shield tunneling machine 1 according to this embodiment is, for example, a mud pressure balance shield machine that excavates while filling the chamber 4 between the cutter head 2 and the equipment main body 3 with mud having impermeability and plastic fluidity (properties that can be freely deformed and moved) generated by injecting an additive into the earth and sand excavated by the cutter head 2 and kneading them, thereby generating a mud pressure that resists the face earth pressure and ensuring the stability of the face during excavation.

[0026] The cutter head 2 is a shield cutter head for excavating the ground, and is installed at the front of the tip head of the shield tunneling machine 1 so as to be rotatable in the forward and reverse directions along the circumferential direction of the equipment main body 3.

[0027] On the front surface of this cutter head 2 (the surface facing the face), a center bit CB, bits B, and scraper tools (not shown) are mounted. The center bit CB and bits B are mainly excavation parts for breaking down the ground, and the scraper tools are mainly cutting parts for cutting the ground. Note that, instead of the bits B, for example, roller cutters or the like may be mounted.

[0028] In addition, a copy cutter CC is installed on the outer periphery of the cutter head 2. The copy cutter CC has a role of performing overexcavation during curved construction and attitude control of the shield tunneling machine 1. Also, a plurality of stirring rods SB are mounted around the center inside the back surface of the cutter head 2. The stirring rod SB is formed of, for example, a columnar protruding member, and has a role of stirring and mixing the earth and sand and the additive in the chamber 4 when the cutter head 2 rotates. Note that, for example, a vibration sensor is incorporated in this stirring rod SB.

[0029] The machine body 3 is a main component that drives the shield tunneling machine 1. Equipment such as that which drives the shield tunneling machine 1 is surrounded and protected by the skin plate 5 that constitutes the outer shell of the machine body 3. The skin plate 5 has a front body plate (front body section) 5a and a rear body plate (rear body section) 5b behind it. The front body plate 5a and the rear body plate 5b are constituted by, for example, cylindrical steel plates, and are engaged by the spherical bearing section at the tip of the rear body plate 5b entering in a state of contacting the inner peripheral surface of the front body plate 5a.

[0030] The rear body plate 5b is constituted by a rear body inner cylinder section 5ba located on the front body plate 5a side and a rear body outer cylinder section 5bb installed following the rear body inner cylinder section 5ba. Details of the structure of the rear body plate 5b will be described later.

[0031] The hollow space inside the skin plate 5 is partitioned into a face side and a machine interior side by a partition wall 7 provided inside the front body plate 5a. The aforementioned chamber 4 is provided on the face side of the partition wall 7 (that is, between the cutter head 2 and the partition wall 7). Earth and sand etc. excavated by the cutter head 2 are taken into the chamber 4 through a through hole (not shown) that penetrates the front and back surfaces of the cutter head 2.

[0032] On the other hand, inside the machine interior side of the hollow space of the skin plate 5, a cutter drive body 8, a mid-fold jack 9a, a shield jack 9b, a screw conveyor 10, an erector 11, and tail seals 12Ba, 12Bb etc. are installed. Also, at the tip of the rod 9ba that constitutes the shield jack 9b, a spreader 15 for transmitting the thrust of the shield jack 9b over a wide range of the segment SG (described later) is attached via a block 9bb for aligning the position of the rod 9ba of the shield jack 9b and the position of the segment SG. Although not shown in the figure, various equipment such as an earth pressure detection section for detecting the earth pressure inside the chamber 4 and an additive injection section for injecting the above-mentioned additive (soil conditioning material) into the chamber 4 are installed in the machine body 3 in addition to the above.

[0033] The cutter drive body 8 is a motor (drive source) that rotates the cutter head 2 in the forward and reverse directions, and is installed in a plurality of rows along the circumferential direction of the cutter head 2 at a position near the outer periphery within the front surface of the cutter head 2. Here, the outer peripheral support drive method is exemplified as the cutter drive method.

[0034] The intermediate folding jack 9a is a device for correcting the propulsion direction and attitude of the shield tunneling machine 1, and is installed in a plurality of rows along the circumferential direction of the equipment body 3 in a state straddling the boundary between the front body plate 5a and the rear body plate 5b so as to connect the front body plate 5a and the rear body plate 5b within the equipment body 3. By supplying pressure oil to this intermediate folding jack 9a and propelling the shield tunneling machine 1 in a state where the front body plate 5a and the rear body plate 5b are refracted in a predetermined direction and angle, it is possible to control the propulsion direction and attitude of the shield tunneling machine 1.

[0035] The shield jack 9b is a device that generates a propulsion force for advancing the shield tunneling machine 1 by taking reaction force from the segment SG installed behind the equipment body 3, and is installed in the rear body inner cylinder part 5ba that constitutes the rear body plate 5b. This shield jack 9b is arranged in a state straddling the boundary between the front body plate 5a and the rear body plate 5b, and is installed in a plurality of rows along the circumferential direction of the equipment body 3.

[0036] The screw conveyor 10 is a device for discharging the earth and sand taken into the chamber 4 outside the machine, and is installed so as to penetrate the partition wall 7 from the chamber 4 and continuously extend obliquely upward toward the rear. Here, a ribbon screw conveyor is exemplified.

[0037] The erector 11 is an assembling device that grips the segment SG and rotates in the circumferential direction of the excavation pit, and is transferred to the assembling position in the circumferential direction of the excavation pit. It is attached to an intermediate ring body 16 provided along the inner peripheral surface of the rear body inner cylinder part 5ba, and is installed in the hollow inside of the rear body plate 5b in a state where it can rotate along the circumferential direction of the excavation pit by a hydraulic motor (not shown) for erector drive or the like.

[0038] The tail seals 12Ba and 12Bb are provided between the inner circumference of the skin plate 5 and the outer circumference of the segment SG at the rear end of the rear barrel outer cylinder part 5bb that constitutes the rear barrel plate 5b. During the tunneling operation, it is a water stop structure part that prevents groundwater, earth and sand, backfill materials, etc. (hereinafter referred to as groundwater, etc.) from entering the machine interior of the equipment main body 3 from the outside of the rear end side of the shield tunneling machine 1. It is composed of a springy metal brush and elastic metal plates arranged before, after, and inside the brush so as to sandwich the brush.

[0039] The tail seals 12Ba and 12Bb are installed at two locations, for example, at the inner circumference of the rearmost end side of the skin plate 5, in a state of being spaced apart from each other along the front-rear direction of the shield tunneling machine 1 (the central axis direction of the shield tunneling machine 1, the extending direction of the excavation pit). And each of the tail seals 12Ba and 12Bb is installed in a state where a plurality of them are arranged annularly along the inner circumference of the skin plate 5 so as to surround the outer circumference of the segment SG. Also, a seal chamber 12R is formed between these tail seals 12Ba and 12Bb. Note that the number of installed tail seals is not limited to two locations. For example, it may be installed at three or more locations along the front-rear direction of the shield tunneling machine 1.

[0040] Also, each of the tail seals 12Ba and 12Bb is installed in a cantilever state on the inner circumference of the skin plate 5. That is, one end side (one end side in the front-rear direction of the equipment main body 3) of each of the tail seals 12Ba and 12Bb is fixed to the inner circumference of the skin plate 5, bends in a state of inclining toward the segment SG between the one end side and the other end side (the other end side in the front-rear direction of the equipment main body 3) of the tail seals 12Ba and 12Bb, and further, the other end side of the tail seals 12Ba and 12Bb contacts the segment SG in a state of being pressed by the spring force of the tail seals 12Ba and 12Bb.

[0041] In addition, a sealant supply pipe 14 is installed on the outer periphery of the rear body plate 5b. The sealant supply pipe 14 is a pipe for supplying a sealant such as grease to the seal chamber 12R, and a plurality of them are installed on the outer periphery of the rear body plate 5b. By filling the sealant into the seal chamber 12R through the sealant supply pipe 14, the gap between the inner periphery of the skin plate 5 and the outer periphery of the segment SG is sealed. In combination with the tail seals 12Ba and 12Bb, it is possible to prevent groundwater and the like from entering the interior of the shield tunneling machine 1 during the tunneling operation.

[0042] Furthermore, a backfill material supply passage (not shown) is installed on the outer wall of the rear body plate 5b. The backfill material supply passage is, for example, a pipe for supplying a backfill material made of a cement-based hardening material or solidifying material to the gap between the excavation pit behind the skin plate 5 and the segment SG. By filling the gap between the excavation pit and the segment SG with the backfill material, ground settlement is prevented. Furthermore, the segment SG and the ground are integrated, and water leakage from the joint of the segment SG is prevented.

[0043] In addition, the backfill material supply passage is provided at two locations, for example, sandwiching the top of the skin plate 5. While the sealant supply pipe 14 is provided at a plurality of locations on the outer periphery of the skin plate 5, the backfill material supply passage is provided only near the top of the skin plate 5. This is because the sealant has high viscosity and must be evenly supplied to the inner periphery of the skin plate 5 in order to adhere to the outer periphery of the segment SG, while the backfill material has low viscosity and will flow down to the lower part of the outer periphery of the segment SG by its own weight if supplied near the top of the skin plate 5.

[0044] Note that the formation locations and the number of formations of the sealant supply pipe 14 and the backfill material supply passage are not limited to those described above. For example, more sealant supply pipes 14 may be provided, and the backfill material supply passage may be provided at only one location at the top in the axial direction of the skin plate 5.

[0045] Next, the rear body plate 5b of the shield tunneling machine 1 will be described with reference to FIG. 2. FIG. 2 is a main part configuration diagram of the rear body plate 5b seen from the side. In FIG. 2, the rear body outer cylinder portion 5bb has moved to a state where the rear body plate 5b is the longest.

[0046] The structure of the rear body plate 5b will be described. The rear body plate 5b is composed of a rear body inner cylinder portion 5ba located on the front body plate 5a side and a rear body outer cylinder portion 5bb installed subsequent to the rear body inner cylinder portion 5ba, and the rear body inner cylinder portion 5ba and the rear body outer cylinder portion 5bb partially overlap in the axial direction. Further, the rear body outer cylinder portion 5bb is movable in the axial direction so as to slide with the rear body inner cylinder portion 5ba. Therefore, the overall length of the rear body plate 5b expands and contracts due to the movement of the rear body outer cylinder portion 5bb.

[0047] As shown in FIG. 2, on the inner peripheral surface of the rear body outer cylinder portion 5bb, a first fixing member groove portion (first fixing member engaging portion) 21, a second fixing member groove portion (second fixing member engaging portion) 22, and a transmission member groove portion (transmission member engaging portion) 23 are formed in the circumferential direction from the front to the rear. In the present application, the "circumferential direction" refers to the direction within a plane perpendicular to the axial direction of the rear body outer cylinder portion 5bb.

[0048] In the first fixing member groove portion 21 and the second fixing member groove portion 22, a fixing member 17 for fixing the rear barrel outer cylinder portion 5bb to the rear barrel inner cylinder portion 5ba so that the rear barrel outer cylinder portion 5bb cannot move is detachably and selectively fitted (engaged) by bolts. That is, as shown in the figure, when the fixing member 17 is fitted into the first fixing member groove portion 21 and fixed to a fixing base 16a provided on an intermediate ring body 16 provided on the rear barrel inner cylinder portion 5ba by bolts, the rear barrel outer cylinder portion 5bb is fixed to the rear barrel inner cylinder portion 5ba at an extended position, that is, in a state where the length of the rear barrel plate 5b is relatively long (the first state). Further, the rear barrel outer cylinder portion 5bb shrinks to a length at which the position where the first fixing member groove portion 21 was located becomes the position of the second fixing member groove portion 22, and when the fixing member 17 is fitted into the second fixing member groove portion 22 at that length and fixed to the fixing base 16a provided on the intermediate ring body 16 provided on the rear barrel inner cylinder portion 5ba by bolts, the rear barrel outer cylinder portion 5bb is fixed to the rear barrel inner cylinder portion 5ba at a shrunk position, that is, in a state where the length of the rear barrel plate 5b is relatively short (the second state).

[0049] In this embodiment, the rear barrel outer cylinder portion 5bb is configured to move in two stages in this way, but it may be configured to move in three or more stages. In this case, a fixing member groove portion is further formed in addition to the first fixing member groove portion 21 and the second fixing member groove portion 22. Also, in this embodiment, the rear barrel outer cylinder portion 5bb is fixed to the rear barrel inner cylinder portion 5ba by fixing the fixing member 17 to the fixing base 16a provided on the intermediate ring body 16 provided on the rear barrel inner cylinder portion 5ba, but the fixing member 17 may be fixed to a fixing base provided other than the intermediate ring body 16 of the rear barrel inner cylinder portion 5ba.

[0050] In addition, in the groove portion 23 for the transmission member, a telescopic force transmission member 18 (Fig. 16, etc.) that is fixed to the shield jack 9b and moves the rear cylinder outer cylinder portion 5bb in the axial direction by the expansion and contraction of the shield jack 9b is detachably fitted (engaged) by bolts. Therefore, the rear cylinder outer cylinder portion 5bb moves to the aforementioned first state or second state by the expansion and contraction of the shield jack 9b.

[0051] In this embodiment, the engaging portion for the first fixing member, the engaging portion for the second fixing member, and the engaging portion for the transmission member are the first fixing member groove portion 21, the second fixing member groove portion 22, and the transmission member groove portion 23 formed in a concave shape, and the fixing member 17 and the telescopic force transmission member 18 are fitted therein. However, it is not necessary for them to be concave as long as the fixing member 17 and the telescopic force transmission member 18 can be engaged. However, as will be described later, since the spreader 15 moves so as to slide on the inner peripheral surface of the rear cylinder outer cylinder portion 5bb, if a block for bolt-fastening the fixing member 17 and the telescopic force transmission member 18 is provided, the block will protrude toward the inner diameter side and interfere with the spreader 15, which is not desirable.

[0052] Here, Fig. 3 is a cross-sectional view showing the shield tunneling machine of Fig. 1 along line A of Fig. 2, Fig. 4 is a view extracting a part of Fig. 3, and Fig. 5 is a cross-sectional view showing the shield tunneling machine of Fig. 1 along line B of Fig. 2.

[0053] As shown in Fig. 3, an intermediate ring body 16 is annularly provided along the inner peripheral surface of the rear cylinder inner cylinder portion 5ba, and a plurality of (eight in this embodiment) shield jacks 9b are installed in the circumferential direction at regular intervals on the intermediate ring body 16. Further, between the shield jacks 9b, a fixing member 17 for fixing the rear cylinder outer cylinder portion 5bb to the rear cylinder inner cylinder portion 5ba is positioned in a state of being fitted into a first fixing member groove portion 21 formed in the rear cylinder outer cylinder portion 5bb.

[0054] Furthermore, between the shield jacks 9b at two positions each above and below and the fixing member 17, a rolling stopper (restricting means) 19 for restricting the circumferential displacement of the rear cylinder outer cylinder portion 5bb with respect to the rear cylinder inner cylinder portion 5ba is provided. Note that the rolling stopper 19 prevents rolling (circumferential displacement of the rear cylinder outer cylinder portion 5bb) that is likely to occur during curved construction, which will be described later.

[0055] As shown in FIG. 4 and FIG. 8 to be described later, the rolling stopper 19 includes a fitting groove 19a extending along the axial direction of the rear cylinder outer cylinder portion 5bb, and a fitting member 19b provided on the rear cylinder inner cylinder portion 5ba and fitted into the fitting groove 19a and movable along the fitting groove 19a. The fitting groove 19a is formed by a space sandwiched between a pair of plate-like bodies 20 installed in parallel on the inner peripheral surface of the rear cylinder outer cylinder portion 5bb. In the present embodiment, the fitting groove 19a is formed in the rear cylinder outer cylinder portion 5bb and the fitting member 19b is provided on the rear cylinder inner cylinder portion 5ba. Conversely, the fitting groove 19a may be formed in the rear cylinder inner cylinder portion 5ba and the fitting member 19b may be provided on the rear cylinder outer cylinder portion 5bb.

[0056] As shown in FIG. 5, the spreader 15 attached to the tip of the shield jack 9b has a pressing surface 15f (a surface facing the tip surface of the segment SG and pressing the segment SG) formed in a substantially arc shape in a front view that is longer along the circumferential direction of the rear cylinder outer cylinder portion 5bb than the tip surface of the rod 9ba of the shield jack 9b or the tip surface of the block 9bb. With such a shape, the thrust of the shield jack 9b is diffused and transmitted to the segment SG.

[0057] In FIG. 5, at both ends of the spreader 15 on the inner peripheral surface side of the rear cylinder outer cylinder portion 5bb, legs (restricting protrusions) 15a for restricting the displacement of the spreader 15 outward in the radial direction of the rear cylinder outer cylinder portion 5bb are formed.

[0058] The spreader 15 is attached to the tip of the block 9bb for aligning the position of the rod 9ba of the shield jack 9b and the position of the segment SG. As shown in FIG. 2, the block 9bb has a portion that presses the segment SG (i.e., the portion to which the spreader 15 is attached) located radially outside the outer cylinder portion 5bb of the rear body compared to the portion pressed by the rod 9ba of the shield jack 9b. Therefore, when the segment SG is pressed by the shield jack 9b, the spreader 15 tends to displace radially outward of the outer cylinder portion 5bb of the rear body. At this time, if the leg portion 15a that restricts the displacement radially outward of the outer cylinder portion 5bb of the rear body is not formed, the displacement of the spreader 15 radially outward of the outer cylinder portion 5bb of the rear body will be allowed, and when the shield jack 9b is extended to drive the shield tunneling machine 1, a force that expands radially outward will act on the annular segment SG that is being pressed by the spreader 15. On the other hand, when the leg portion 15a is formed as in the present embodiment, no force that expands radially outward acts on the segment SG.

[0059] In the present embodiment, the displacement of the spreader 15 radially outward of the outer cylinder portion 5bb of the rear body is restricted by the two leg portions 15a formed at both ends on the inner peripheral surface side of the outer cylinder portion 5bb of the rear body in the spreader 15, but the number of protrusions may be one or three or more.

[0060] Note that instead of forming protrusions such as the leg portion 15a on the spreader 15 side, it is also conceivable to form protrusions on the inner peripheral surface of the outer cylinder portion 5bb of the rear body to restrict the displacement of the spreader 15. However, in the shield tunneling machine 1 of the present embodiment, as described above, the outer cylinder portion 5bb of the rear body is configured to move axially by sliding with the inner cylinder portion 5ba of the rear body. Therefore, providing protrusions on the inner peripheral surface of the outer cylinder portion 5bb of the rear body that contacts the inner cylinder portion 5ba of the rear body will hinder the movement. Thus, it is not desirable to provide such protrusions.

[0061] In addition, a first fixing member groove portion 21, a second fixing member groove portion 22, and a transmission member groove portion 23 described above are formed on the inner peripheral surface of the rear cylinder outer cylinder portion 5bb. Therefore, when the spreader 15 reaches the positions of the groove portions 22 and 23, the leg portions 15a fit into the groove portions 22 and 23. And in order to prevent the fitting, it is necessary to make the portions of the groove portions 22 and 23 through which the leg portions 15a of the spreader 15 pass flush with the inner peripheral surface of the rear cylinder outer cylinder portion 5bb. A member (flat plate 24) for making the fixing member groove portion 22 and the transmission member groove portion 23 at the portions through which the leg portions 15a pass flush with the inner peripheral surface of the rear cylinder outer cylinder portion 5bb will be described later.

[0062] Here, FIG. 6 is a plan view showing the spreader and its peripheral mechanism in the present embodiment, and FIG. 7 is a plan view showing the spreader and its peripheral mechanism as a comparative example.

[0063] As shown in FIG. 6, in the spreader 15 of the present embodiment, a concave portion 15b is formed on the surface opposite to the pressing surface 15f to avoid interference with the fixing member 17 when the shield jack 9b is maximally contracted. When the concave portion 15b is not formed, as shown in FIG. 7, in order to prevent the spreader 15 from interfering with the fixing member 17 when the shield jack 9b is maximally contracted, the retracted position of the spreader 15 cannot be made more forward. On the other hand, when the concave portion 15b is formed as in the present embodiment, even if the retracted position of the spreader 15 when the shield jack 9b is maximally contracted is more forward than the case shown in FIG. 7, the spreader 15 does not interfere with the fixing member 17. As a result, it becomes possible to maximize the amount of retraction of the rear cylinder outer cylinder portion 5bb with respect to the rear cylinder inner cylinder portion 5ba when the shield jack 9b contracts, and the length of the rear cylinder plate 5b in the second state described above can be made shorter.

[0064] FIG. 8 is a plan view showing a half circumference of the inner peripheral surface of the rear body outer cylinder portion in a shield tunneling machine according to an embodiment of the present invention. FIG. 9 is a plan view showing the axial direction of the rear body outer cylinder portion developed along line C in FIG. 5. FIG. 10 is a plan view showing the axial direction of the rear body outer cylinder portion developed along line D in FIG. 5. FIG. 11 is a plan view showing the axial direction of the rear body outer cylinder portion developed along line E in FIG. 5.

[0065] In FIG. 8, in the rear body outer cylinder portion 5bb of the shield tunneling machine 1, the above-described first fixing member groove portion 21, second fixing member groove portion 22, and transmission member groove portion 23 are formed. As shown in the figure, these fixing member groove portions 21, 22 and transmission member groove portion 23 are annular grooves formed over the entire circumference in the circumferential direction of the inner peripheral surface of the rear body outer cylinder portion 5bb. To specifically explain the formation process of these fixing member groove portions 21, 22 and transmission member groove portion 23, two half-circumference rear body outer cylinder portions 5bb in a flat plate shape are produced, each is bent into a semi-circular shape, and the ends are joined by welding to obtain a cylindrical rear body outer cylinder portion 5bb. Then, the inner circumference of the rear body outer cylinder portion 5bb is machined by a lathe to form the fixing member groove portions 21, 22 and transmission member groove portion 23 which are annular grooves.

[0066] Note that the first fixing member groove portion 21, second fixing member groove portion 22, and transmission member groove portion 23 do not necessarily need to be formed annularly over the entire circumference in the circumferential direction of the inner peripheral surface of the rear body outer cylinder portion 5bb as in the present embodiment, and may be formed spotwise at the locations where the fixing member 17 and the telescopic force transmission member 18 are fixed.

[0067] However, when the first fixing member groove portion 21, second fixing member groove portion 22, and transmission member groove portion 23 are formed spotwise, it takes time because they must be formed only at discontinuous specific locations, and thermal stress is applied to the metal rear body outer cylinder portion 5bb to cause distortion. If they are formed annularly as in the present embodiment, such problems do not occur.

[0068] Now, as shown in FIG. 9, in the axial direction of the rear trunk outer cylinder portion 5bb along line C of FIG. 5, holes 21a and 22a are formed for fitting the above-described fixing member 17 into the first fixing member groove portion 21 and the second fixing member groove portion 22 and fixing it to the rear trunk outer cylinder portion 5bb with bolts.

[0069] Also, as shown in FIG. 10, in the axial direction of the rear trunk outer cylinder portion 5bb along line D of FIG. 5, a hole 23a is formed for fitting the expansion / contraction force transmission member 18 into the transmission member groove portion 23 and fixing it to the rear trunk outer cylinder portion 5bb with bolts.

[0070] Furthermore, as shown in FIG. 11, in the axial direction of the rear trunk outer cylinder portion 5bb along line E of FIG. 5, a flat plate (smoothing member) 24 is provided to make the second fixing member groove portion 22 and the transmission member groove portion 23 flush with the inner peripheral surface of the rear trunk outer cylinder portion 5bb to prevent the spreader 15 from fitting in. That is, as described above, since the leg portion 15a of the spreader 15 moves along the inner peripheral surface of the rear trunk outer cylinder portion 5bb, without any countermeasure, the leg portion 15a of the spreader 15 would fit into the second fixing member groove portion 22 and the transmission member groove portion 23 and would not be able to move smoothly. Therefore, by installing the flat plate 24 at the location where the leg portion 15a of the spreader 15 passes through the second fixing member groove portion 22 and the transmission member groove portion 23, the leg portion 15a is prevented from fitting in. In the case where the leg portion 15a is not provided, the flat plate 24 is installed at the entire passing location of the spreader 15 in the second fixing member groove portion 22 and the transmission member groove portion 23.

[0071] In addition, in the present embodiment, since the range of the fixing member 17 when it is fitted and fixed in the second fixing member groove portion 22 overlaps with the range through which the spreader 15 (specifically, the leg portion 15a of the spreader 15 in contact with the inner peripheral surface of the rear barrel outer cylinder portion 5bb) passes (that is, the portion of the flat plate 24 installed in the second fixing member groove portion 22), when the fixing member 17 is fitted into the second fixing member groove portion 22, it interferes with the flat plate 24 installed in the second fixing member groove portion 22, so it is necessary to remove the flat plate 24. Therefore, as shown in FIG. 11, the flat plate 24 of the second fixing member groove portion 22 is detachably fixed by bolts. However, if the position when the fixing member 17 is fitted into the second fixing member groove portion 22 does not overlap with the portion through which the spreader 15 passes, it goes without saying that the flat plate 24 installed in the second fixing member groove portion 22 may also be fixed to the rear barrel outer cylinder portion 5bb.

[0072] Further, in the present embodiment, since the range of the expansion and contraction force transmission member 18 when it is fitted and fixed in the transmission member groove portion 23 does not overlap with the range through which the spreader 15 (specifically, the leg portion 15a of the spreader 15 in contact with the inner peripheral surface of the rear barrel outer cylinder portion 5bb) passes (that is, the portion of the flat plate 24 installed in the transmission member groove portion 23), when the expansion and contraction force transmission member 18 is fitted into the transmission member groove portion 23, it does not interfere with the flat plate 24 installed in the transmission member groove portion 23, so there is no need to remove the flat plate 24. On the other hand, in order to prevent damage to the segment SG, it is better to cover the transmission member groove portion 23. Therefore, as shown in FIG. 11, the flat plate 24 of the transmission member groove portion 23 is fixed to the rear barrel outer cylinder portion 5bb. However, when the range when the expansion and contraction force transmission member 18 is fitted into the transmission member groove portion 23 overlaps with the range through which the spreader 15 passes, the flat plate 24 installed in the transmission member groove portion 23 is made detachable by bolts.

[0073] Note that it is desirable to fix the flat plate 24 to the rear barrel outer cylinder portion 5bb by stagger welding (intermittent fillet welding in which welded portions and non-welded portions exist alternately) to reduce the heat input during welding.

[0074] (Example 1)

[0075] Next, as Example 1, the telescopic operation of the rear body plate 5b in the shield tunneling machine 1 having the above configuration will be described with reference to FIGS. 12 to 26. Here, FIGS. 12 to 19 are diagrams continuously showing the contraction operation of the rear body plate of the shield tunneling machine in FIG. 1, and FIGS. 20 to 26 are diagrams continuously showing the extension operation of the rear body plate of the shield tunneling machine in FIG. 1. In these drawings, (a) is a conceptual diagram of the rear body plate seen from the plane, and (b) is an explanatory diagram of the rear body plate seen from the side. Further, in (a), a set of two adjacent shield jacks out of the eight shield jacks installed in this embodiment are shown, and the other sets of shield jacks operate in the same manner.

[0076] In addition, in the shield tunneling machine 1 that performs the telescopic operation of the rear body plate 5b, in FIG. 2, when in the first state, the dimension of the rear body outer cylinder portion 5bb is such that the length of the portion that does not overlap with the rear body inner cylinder portion 5ba (effective length: FL) is 1970 mm, the length (L1) other than the tail seals 12Ba and 12Bb within the effective length is 1490 mm, the length (L2) of the tail seals 12Ba and 12Bb is 480 mm, and the distance (L3) between the first fixing member groove portion 21 and the second fixing member groove portion 22 is 300 mm. And since the movable length of the rear body outer cylinder portion 5bb corresponds to the distance (L3) between the first fixing member groove portion 21 and the second fixing member groove portion 22, it is 300 mm. However, these dimensions are only examples, and the present invention is not limited to these dimensions.

[0077] First, the contraction operation of the rear body plate 5b of the shield tunneling machine 1 (the operation in which the rear body outer cylinder portion 5bb moves from the first state to the second state) will be described. Note that the rear body plate 5b is contracted mainly when shifting from straight tunneling to curved tunneling.

[0078] As shown in FIG. 12, in the straight-line construction, the rear barrel outer cylinder portion 5bb is set to the first state and the length of the rear barrel plate 5b is increased. For example, segments SG with a width of 900 mm are continuously installed in the excavation pit. In this state, the fixing member 17 is fitted into the first fixing member groove portion 21 and fixed to the fixing base 16a, and a flat plate 24 is installed in the second fixing member groove portion 22. The segment SG is a tunnel lining member for forming a tunnel by being assembled annularly in the shield tunneling machine 1.

[0079] In order to shift from the straight-line construction to the curved construction and change the rear barrel outer cylinder portion 5bb to the second state and contract the rear barrel plate 5b to shorten its length, first, as shown in FIG. 13, the shield jack 9b is stroked by a predetermined length (a length that allows the telescopic force transmission member 18 to be fitted into the transmission member groove portion 23) to move the shield tunneling machine 1 forward, thereby forming a space sufficient for assembling a segment SG with a width of, for example, 300 mm for the curved construction.

[0080] Next, the flat plate 24 installed in the second fixing member groove portion 22 is removed, and as shown in FIG. 14, the fixing member 17 fixed to the fixing base 16a is removed and transferred from the first fixing member groove portion 21 to the second fixing member groove portion 22.

[0081] Next, as shown in FIG. 15, while some of the shield jacks 9b are pressed against the segment SG (that is, in a state where anti-buckling measures are taken to prevent the backward movement of the shield tunneling machine 1), the other shield jacks 9b are pulled by a predetermined length. The length by which the shield jack 9b is pulled is a length that allows the telescopic force transmission member 18 described later to be fitted into the transmission member groove portion 23 and fixed to the tip of the shield jack 9b, and further allows a spacer 18a (FIG. 20, etc.) to be attached to the tip thereof. In this embodiment, the anti-buckling measures are performed using a total of four shield jacks 9b, two on the upper part and two on the lower part. However, it goes without saying that the anti-buckling measures may be performed using shield jacks 9b other than these.

[0082] Next, as shown in Fig. 16, the telescopic force transmission member 18 is fitted into the groove portion 23 for the transmission member and fixed to the rear body outer cylinder portion 5bb with bolts, and fixed to the tip of the shield jack 9b (specifically, to the spreader 15 provided on the shield jack 9b) with tension bolts.

[0083] Next, as shown in Fig. 17, the shield jack 9b is pulled until the fixing member 17 fitted into the second fixing member groove portion 22 hits the fixing base 16a. As a result, the rear body outer cylinder portion 5bb moves forward, and the rear body plate 5b enters a second state where its length is relatively shortened. Here, since the distance between the first fixing member groove portion 21 and the second fixing member groove portion 22 (the length of L3 in Fig. 2) is 300 mm, the length of the rear body plate 5b is shortened by 300 mm.

[0084] When the rear body outer cylinder portion 5bb has moved forward in this way, the fixing member 17 is fixed to the fixing base 16a with bolts, and as shown in Fig. 18, the telescopic force transmission member 18 is removed and the shield jack 9b is further pulled. As a result, the transition to the state during curve construction, in which the followability to the curve is good and curve construction can be performed smoothly, is completed.

[0085] Thereafter, while the shield tunneling machine 1 performs curve excavation, as shown in Fig. 19, segments SG for curve construction (for example, segments SG with a width of 300 mm) are installed.

[0086] Next, the extension operation of the rear body plate 5b of the shield tunneling machine 1 (the operation in which the rear body outer cylinder portion 5bb moves from the second state to the first state) will be described. Note that the rear body plate 5b is extended mainly when transitioning from curve construction to straight-line construction.

[0087] If the curve construction is completed with the rear barrel outer cylinder part 5bb in the second state and the rear barrel plate 5b shortened, as shown in Fig. 20, some of the shield jacks 9b are pressed against the segment SG, and the telescopic force transmission member 18 is fitted into the groove part 23 on the extension line of the other shield jacks 9b and fixed to the rear barrel outer cylinder part 5bb with bolts. Further, a spacer 18a is attached to the segment SG side of the telescopic force transmission member 18. As shown in the figure, since a space is required to attach the spacer 18a to the telescopic force transmission member 18, a slight gap is formed between the spacer 18a attached to the telescopic force transmission member 18 and the segment SG.

[0088] Next, as shown in Fig. 21, the shield jack 9b is extended to press the spreader 15 against the telescopic force transmission member 18, and the fixing member 17 fitted in the second fixing member groove part 22 is removed. As a result, the fastening between the rear barrel outer cylinder part 5bb and the fixing base 16a provided on the intermediate ring body 16 is released, and the rear barrel outer cylinder part 5bb becomes movable in the axial direction.

[0089] Next, as shown in Fig. 22, the shield jack 9b is extended to press the spacer 18a against the segment SG and move the rear barrel inner cylinder part 5ba forward to a position where the fixing member 17 can be fitted into the first fixing member groove part 21 and fixed to the fixing base 16a. As a result, the rear barrel inner cylinder part 5ba moves forward, and the rear barrel plate 5b becomes in the first state where its length is relatively long. Here, since the distance between the first fixing member groove part 21 and the second fixing member groove part 22 (the length of L3 in Fig. 2) is 300 mm, the length of the rear barrel plate 5b becomes 300 mm longer.

[0090] Incidentally, as described above, since a slight gap is formed between the spacer 18a and the segment SG, when the shield jack 9b extends and the spacer 18a is pressed against the segment SG via the telescopic force transmission member 18, the rear body outer cylinder portion 5bb moves backward by the amount of the gap. Then, the tail seals 12Ba and 12Bb move backward by moving in a direction opposite to their original movement (forward movement) with respect to the segment SG. However, since the amount of movement is slight corresponding to the aforementioned gap, problems such as deformation of the shapes of the tail seals 12Ba and 12Bb do not occur.

[0091] Next, as shown in FIG. 23, the fixing member 17 is fitted into the first fixing member groove portion 21 and fixed to the fixing base 16a, and is also fixed to the rear body outer cylinder portion 5bb with bolts. Further, a flat plate 24 is installed in the second fixing member groove portion 22.

[0092] Next, as shown in FIG. 24, the shield jack 9b to which the telescopic force transmission member 18 and the spacer 18a are not attached is pressed against the segment SG. Then, the shield jack 9b to which the telescopic force transmission member 18 and the spacer 18a are attached is slightly pulled to form a gap between the spacer 18a and the segment SG, and the telescopic force transmission member 18 and the spacer 18a are removed.

[0093] Next, as shown in FIG. 25, the shield jack 9b is extended to move the shield tunneling machine 1 forward to form a space sufficient for assembling the segment SG for straight-line construction.

[0094] Next, as shown in FIG. 26, when the shield jack 9b is pulled, the transition to the state during straight-line construction in which straight-line construction can be performed smoothly is completed.

[0095] After that, while performing straight-line excavation with the shield tunneling machine 1, the segment SG for straight-line construction (for example, the segment SG with a width of 900 mm) is installed.

[0096] Thus, according to the shield tunneling machine 1 of this embodiment, the rear barrel outer cylinder portion 5bb constituting the rear barrel plate 5b is axially movable so as to slide with the rear barrel inner cylinder portion 5ba, and the overall length of the rear barrel plate 5b expands and contracts by the movement of the rear barrel outer cylinder portion 5bb. Therefore, by moving the rear barrel outer cylinder portion 5bb from the first state to the second state, it becomes possible to smoothly perform curved construction. As a result, not only is the followability to the curve improved, but overexcavation does not increase either.

[0097] (Embodiment 2)

[0098] Next, as Embodiment 2, the replacement of the tail seal 12Ba in the shield tunneling machine 1 having the above configuration will be described with reference to FIGS. 27 to 41. Here, FIGS. 27 to 41 are diagrams continuously showing the replacement procedure of the tail seal of the shield tunneling machine of Embodiment 2. In these drawings, (a) is a conceptual diagram of the rear barrel plate viewed from the plane, and (b) is an explanatory diagram of the rear barrel plate viewed from the side. Also, in (a), a pair of two adjacent shield jacks out of the eight shield jacks installed in this embodiment are shown, and the other sets of shield jacks operate in the same manner.

[0099] Note that in the shield tunneling machine 1 in which the tail seal 12Ba is replaced, in FIG. 2, when in the first state, the dimension of the rear barrel outer cylinder portion 5bb is such that the length of the portion that does not overlap with the rear barrel inner cylinder portion 5ba (effective length: FL) is 1610 mm, the length (L1) other than the tail seals 12Ba and 12Bb within the effective length is 1130 mm, the length (L2) of the tail seals 12Ba and 12Bb is 480 mm, and the distance (L3) between the first fixing member groove portion 21 and the second fixing member groove portion 22 is 350 mm. And since the movable length of the rear barrel outer cylinder portion 5bb corresponds to the distance (L3) between the first fixing member groove portion 21 and the second fixing member groove portion 22, it is 350 mm. However, these dimensions are examples, and the present invention is not limited to these dimensions.

[0100] The tail seal to be replaced is the front tail seal 12Ba out of the two tail seals 12Ba and 12Bb provided at the front and rear positions. This is because the rear tail seal 12Bb directly receives the pressure of groundwater and earth and sand, and thus this tail seal 12Bb cannot be removed for replacement.

[0101] Then, due to the respective dimensions of the rear barrel outer cylinder part 5bb described above, when the rear barrel outer cylinder part 5bb is in the second state (the position where the length of the rear barrel plate 5b becomes relatively short), the front tail seal 12Ba comes off from the segment SG and is exposed inside the machine.

[0102] Now, in the replacement of the tail seal 12Ba, as shown in Fig. 27, the rear barrel outer cylinder part 5bb is set in the first state. In this first state, the fixing member 17 is fitted into the first fixing member groove part 21 and fixed to the fixing base 16a, and a flat plate 24 is installed in the second fixing member groove part 22.

[0103] Next, as shown in Fig. 28, the shield jack 9b is stroked by a predetermined length (the length at which the expansion and contraction force transmission member 18 can be fitted into the transmission member groove part 23) to move the shield tunneling machine 1 forward.

[0104] Next, after removing the flat plate 24 installed in the second fixing member groove part 22, the fixing member 17 is removed from the rear barrel inner cylinder part 5ba, and as shown in Fig. 29, the removed fixing member 17 is relocated to the second fixing member groove part 22.

[0105] Next, as shown in Fig. 30, with a part of the shield jack 9b (the lower shield jack 9b in the case shown in Fig. 30(a)) pressed against the segment SG (that is, in a state where buckling prevention measures are taken), the other shield jack 9b (the upper shield jack 9b in the case shown in Fig. 30(a)) is pulled by a predetermined length and pressed against the segment SG via the buckling prevention member 25.

[0106] Next, as shown in Fig. 31, the shield jack 9b pressed against the segment SG (the lower shield jack 9b in the case shown in Fig. 31(a)) is pulled by a predetermined length, the telescopic force transmission member 18 is fitted into the groove portion 23 for the transmission member, and fixed to the rear body outer cylinder portion 5bb with bolts, and fixed to the tip of the shield jack 9b (specifically, to the spreader 15 provided on the shield jack 9b) with a tension bolt.

[0107] Next, as shown in Fig. 32, the shield jack 9b to which the telescopic force transmission member 18 is fixed is pulled by a predetermined length to draw in the rear body outer cylinder portion 5bb. Specifically, the shield jack 9b is pulled until the fixing member 17 fitted in the second fixing member groove portion 22 hits the fixing base 16a. As a result, the rear body outer cylinder portion 5bb moves forward, and the rear body plate 5b becomes relatively shorter in length to enter the second state. Here, since the distance between the first fixing member groove portion 21 and the second fixing member groove portion 22 (the length of L3 in Fig. 2) is 350 mm, the length of the rear body plate 5b is shortened by 350 mm. And as the rear body outer cylinder portion 5bb moves forward, as shown in the figure, the tail seal 12Ba comes off from the segment SG and is exposed inside the machine. The fixing member 17 is fixed to the fixing base 16a with bolts.

[0108] Next, as shown in Fig. 33, the tail seal 12Ba of the portion that does not interfere with the back buckling prevention member 25 is replaced with a new tail seal 12Ba. In Fig. 33, the tail seal 12Ba of the portion to be replaced is indicated by a mesh line.

[0109] After replacing a part of the tail seal 12Ba in this way, as shown in Fig. 34, the telescopic force transmission member 18 is removed from the groove portion 23 for the transmission member, the back buckling prevention member 25 is interposed between the removed shield jack 9b and the segment SG, and the shield jack 9b is extended to press the back buckling prevention member 25 against the segment SG.

[0110] Next, as shown in Fig. 35, remove the back-ring prevention member 25 located at the portion where the tail seal 12Ba has not been replaced, fit the expansion and contraction force transmission member 18 into the groove portion 23 for the transmission member, and fix it to the rear body outer cylinder portion 5bb with bolts and also fix it to the tip of the shield jack 9b (specifically, to the spreader 15 provided on the shield jack 9b) with a tension bolt. However, since the back-ring prevention member 25 is interposed between the shield jack 9b and the segment SG at the portion where the tail seal 12Ba has been replaced, and the fixing member 17 is fixed to the fixing base 16a, the attachment of the expansion and contraction force transmission member 18 may be omitted.

[0111] If the position of the back-ring prevention member 25 is swapped in this way, then as shown in Fig. 36, replace the tail seal 12Ba at the portion where it no longer interferes with the newly installed back-ring prevention member 25 (that is, the remaining portion of the tail seal 12Ba) with a new tail seal 12Ba. As a result, the entire tail seal 12Ba will be replaced.

[0112] Then, as shown in Fig. 37, remove the back-ring prevention member 25 and install the segment SG. Then, the new tail seal 12Ba that was exposed inside the machine will be pushed radially outward by the segment SG and will be located on the outer periphery of the installed segment SG. Thereby, the replacement of the tail seal 12Ba in the shield tunneling machine 1 is completed. Note that in the state where the segment SG is installed, back-ring prevention is performed by the shield jack 9b to which the expansion and contraction force transmission member 18 is not fixed.

[0113] If the replacement of the tail seal 12Ba is completed in this way and the segment SG is installed, as shown in Fig. 38, a spacer 18a is attached to the segment SG side of the telescopic force transmission member 18, and further, the fixing member 17 fitted in the second fixing member groove portion 22 is removed. As a result, the rear cylinder outer cylinder portion 5bb is released from the fastening with the fixing base 16a and becomes movable in the axial direction. As shown in the figure, since a space is required for attaching the spacer 18a to the telescopic force transmission member 18, a slight gap is formed between the spacer 18a attached to the telescopic force transmission member 18 and the segment SG.

[0114] Next, as shown in Fig. 39, the shield jack 9b is extended to move the rear cylinder inner cylinder portion 5ba forward, the fixing member 17 is fitted into the first fixing member groove portion 21 and fixed to the fixing base 16a, and is also fixed to the rear cylinder outer cylinder portion 5bb with bolts. Further, a flat plate 24 is installed in the second fixing member groove portion 22. As a result, the rear cylinder inner cylinder portion 5ba moves forward, and the first state in which the length of the rear cylinder plate 5b becomes relatively long is obtained. Here, since the distance between the first fixing member groove portion 21 and the second fixing member groove portion 22 (the length of L3 in Fig. 2) is 350 mm, the length of the rear cylinder plate 5b becomes 350 mm longer.

[0115] As described above, since a slight gap is formed between the spacer 18a and the segment SG, when the shield jack 9b extends and the spacer 18a is pressed against the segment SG via the telescopic force transmission member 18, the rear cylinder outer cylinder portion 5bb moves backward by the amount of the gap. Then, the tail seals 12Ba, 12Bb move backward by moving in the direction opposite to the original movement (forward movement) with respect to the segment SG. However, since the amount of movement is slight corresponding to the above-mentioned gap, problems such as deformation of the shapes of the tail seals 12Ba, 12Bb do not occur.

[0116] Next, as shown in Fig. 40, with the shield jack 9b to which the telescopic force transmission member 18 and the spacer 18a are not attached pressed against the segment SG, the shield jack 9b to which the telescopic force transmission member 18 and the spacer 18a are attached is slightly pulled to form a gap between the spacer 18a and the segment SG, and the telescopic force transmission member 18 and the spacer 18a are removed.

[0117] Next, as shown in Fig. 41, the shield jack 9b is pulled to install the segment SG.

[0118] Thus, according to the shield tunneling machine 1 of the present embodiment, since the rear body outer cylinder portion 5bb constituting the rear body plate 5b is axially movable so as to slide on the rear body inner cylinder portion 5ba, by moving the rear body outer cylinder portion 5bb from the first state to the second state, the tail seal 12Ba comes off from the segment SG and is exposed inside the machine. Therefore, it becomes possible to perform the replacement work of the tail seal 12Ba from inside the shield machine. Thereby, troubles caused by deterioration or damage of the tail seal 12Ba can be prevented in advance.

[0119] As described above, the invention made by the present inventor has been specifically described based on the embodiments. However, the embodiments disclosed in this specification are illustrative in all respects and are not limited to the disclosed technology. That is, the technical scope of the present invention should not be construed restrictively based on the description in the above embodiments, but should be construed in accordance with the description in the claims. All changes that do not deviate from the gist of the claimed technology and the claims and are equivalent to the claimed technology are included.

Industrial Applicability

[0120] In the above description, the case where the present invention is applied to an earth pressure balance shield tunneling machine has been described. However, the present invention is not limited thereto. For example, it can also be applied to other shield tunneling machines such as a slurry shield tunneling machine having a mechanism for stabilizing the face by applying a predetermined pressure to the slurry in the chamber and transporting the excavated soil and sand by circulating the slurry.

Explanation of Symbols

[0121] 1 Shield tunneling machine 2 Cutter head 3 Machine body 5 Skin plate 5a Front body plate (front body part) 5b Rear body plate (rear body part) 5ba Inner cylinder part of rear body 5bb Outer cylinder part of rear body 9a Middle folding jack 9b Shield jack 9ba Rod 9bb Block 12Ba, 12Bb Tail seal 12R Seal chamber 15 Spreader 15a Legs (restricting projections) 15b Concave part 15f Pressing surface 16 Intermediate ring body 16a Fixed base 17 Fixing member 18 Telescopic force transmission member 18a Spacer 19 Rolling stopper (restricting means) 19a Fitting groove 19b Fitting member 20 Plate-like body 21 Groove part for first fixing member (engagement part for first fixing member) 22 Groove part for second fixing member (engagement part for second fixing member) 23 Groove part for transmission member (engagement part for transmission member) 21a, 22a, 23a Holes 24 Flat plate (smoothing member) 25 Back ring prevention member SG Segment

Claims

1. a front body portion provided with a cutter head, a rear body inner cylinder portion located on the front body portion side and provided with a plurality of shield jacks, a rear body outer cylinder portion that is installed following the rear body inner cylinder portion and partially overlaps with the rear body inner cylinder portion and is movable in the axial direction, and a rear body portion provided with a tail seal at the rear end of the rear body outer cylinder portion, comprising, in the rear body outer cylinder portion, a first fixing member engaging portion, a second fixing member engaging portion, and a transmission member engaging portion that are each formed in a concave shape in the circumferential direction from the front to the rear on the inner circumferential surface, fixed to a fixing base provided on an intermediate ring body annularly provided along the inner circumferential surface of the rear body inner cylinder portion, detachably engaged with the first fixing member engaging portion to fix the rear body outer cylinder portion to the rear body inner cylinder portion in a first state where the length of the rear body portion is relatively long, and detachably engaged with the second fixing member engaging portion to fix the rear body outer cylinder portion to the rear body inner cylinder portion in a second state where the length of the rear body portion is relatively short, and a fixing member, and a telescopic force transmission member that is detachably engaged with the transmission member engaging portion to fix the spreader of the shield jack to the rear body outer cylinder portion is provided, a shield tunneling machine characterized by the above.

2. The first fixing member engaging portion, the second fixing member engaging portion, and the transmission member engaging portion are a first fixing member groove portion, a second fixing member groove portion, and a transmission member groove portion respectively formed on the inner circumferential surface of the rear body outer cylinder portion into which the fixing member or the telescopic force transmission member fits. The shield tunneling machine according to claim 1, characterized by the above.

3. A spacer is provided between the telescopic force transmission member pushed by the shield jack and the end face of a segment for forming a tunnel, which is provided on the rear end side of the equipment body where equipment for driving the shield tunneling machine is installed. The shield tunneling machine according to claim 1 or 2, characterized by the above.

4. Regulating means for regulating the circumferential displacement of the rear body outer cylinder portion with respect to the rear body inner cylinder portion is provided. The shield tunneling machine according to claim 1 or 2, characterized by the above.

5. The regulating means is a fitting groove formed in either the rear body outer cylinder portion or the rear body inner cylinder portion and extending along the axial direction, and a fitting member provided on the rear body outer cylinder portion or the rear body inner cylinder portion where the fitting groove is not formed, which fits into the fitting groove and is movable along the fitting groove. The shield tunneling machine according to claim 4, characterized in that...

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