Underground excavation device

Abstract

An underground excavation device (1) is provided with a body (2), a rear support (5), and a position adjustment mechanism (6). The body (2) has a front body part (11) and a rear body part (12). The front body part (11) includes a cutter head (21) provided with a plurality of disc cutters (211). The rear body part (12) includes a gripper part (30) for obtaining a reaction force during the execution of excavation, and is disposed behind the front body part (11). The rear support (5) is disposed behind the rear body part (12) so as to be movable in the up-down direction relative to the body (2), and supports the body (2). The position adjustment mechanism (6) adjusts the position of the rear support (5) relative to the body (2).

Description

Title of Invention: UNDERGROUND EXCAVATION DEVICE Technical Field

[0001] The present disclosure relates to an underground excavation device. Background Art

[0002] A tunnel excavation device includes a main beam provided in a front-rear direction, a cutter head disposed at a front part of the main beam via a cutter head support, a gripper disposed at a rear part of the main beam, and a thrust jack disposed between the cutter head support and a frame of the gripper (refer to, for example, PTL 1).

[0003] The tunnel excavation device is provided with a front support for supporting the cutter head support to a tunnel wall, and a rear support provided on the main beam rearward of the gripper in order to support the rear side of the device.

[0004] The tunnel excavation device is fixed to the tunnel by the gripper, a thrust cylinder is extended, and the cutter head is pressed against the face (surface to be excavated) and rotated. Thus, the disc cutter crushes the rock on the face and performs excavation. Next, the rear support is extended downward and is grounded in the tunnel to support the main beam on the ground, and then the fixation by the gripper is released, and the thrust cylinder is contracted to move the gripper to the cutter head side (front side). Subsequently, after the tunnel excavation device is fixed to the tunnel by the gripper, the rear support is contracted to release the support of the main beam, and the thrust cylinder is extended to perform excavation.   By repeating these operations, the tunnel excavation device can move forward while performing excavation. Citation List Patent Literature

[0005] PTL 1: JPH10-306691A Summary of Invention

[0006] Here, the rear support is configured to be bilaterally symmetrical with respect to an axis in the front-rear direction of the tunnel excavation device. Therefore, when the axis of the tunnel excavation device and the central axis of the tunnel coincide with each other in the leftright direction, the grounding state of the rear support on the tunnel is bilaterally symmetrical with respect to the central axis of the tunnel, and the rear support can appropriately support the main beam to the tunnel.

[0007] However, when the curve radius of the curved part of the tunnel is small, the grounding state of the rear support is not bilaterally symmetrical with respect to the central axis of the tunnel, and the main beam cannot be sufficiently supported.

[0008] The present disclosure can provide an underground excavation device in which a rear support can be appropriately grounded in a tunnel when the tunnel is constructed into a sharp curve. (Solution to Problem)

[0009] An underground excavation device according to the present disclosure includes a main body, a rear support, and a position adjustment mechanism. The main body includes a front body unit and a rear body unit. The front body unit includes a cutter head provided with multiple cutters. The rear body unit includes a gripper unit configured to obtain a reaction force when excavation is performed and is disposed rearward of the front body unit. The rear support is disposed rearward of the rear body unit and supports the main body. The position adjustment mechanism adjusts the position of the rear support with respect to the main body. (Effects of Invention)

[0010] According to the present disclosure, an underground excavation device can be provided in which a rear support can be appropriately grounded in a tunnel when the tunnel is constructed into a sharp curve. Brief Description of Drawings

[0011] [FIG. 1] FIG. 1 is a perspective view illustrating an underground excavation device according to an embodiment of the present disclosure. [FIG. 2] FIG. 2 is a side view of the underground excavation device according to the embodiment of the present disclosure. [FIG. 3] FIG. 3 is a partial perspective view of the underground excavation device according to the embodiment of the present disclosure, as viewed from the rear side. [FIG. 4A] FIG. 4A is a side cross-sectional view illustrating a contracted state of a rear support on a left direction side of the underground excavation device according to the embodiment of the present disclosure. [FIG. 4B] FIG. 4B is a side cross-sectional view illustrating an extended state of the rear support on the left direction side of the underground excavation device according to the embodiment of the present disclosure. [FIG. 5] FIG. 5 is an enlarged perspective view of the vicinity of a position adjustment mechanism of the underground excavation device according to the embodiment of the present disclosure. [FIG. 6] FIG. 6 is a perspective view illustrating a pair of rear supports and the position adjustment mechanism in the underground excavation device according to the embodiment of the present disclosure. [FIG. 7] FIG. 7 is a cross-sectional view taken along a line D-D' in FIG. 6. [FIG. 8] FIG. 8 is a cross-sectional view taken along a line E-E' in FIG. 6. [FIG. 9] FIG. 9 is a plan view showing the pair of rear supports and the position adjustment mechanism in the underground excavation device according to the embodiment of the present disclosure. [FIG. 10] FIG. 10 is a cross-sectional view taken along a line F-F' in FIG. 8. [FIG. 11] FIG. 11 is a perspective view illustrating a belt conveyor in the vicinity of the position adjustment mechanism in the underground excavation device according to the embodiment of the present disclosure. [FIG. 12] FIG. 12 is a back view illustrating the position of the rear support when excavating a tunnel on a straight line, using the underground excavation device according to the embodiment of the present disclosure. [FIG. 13] FIG. 13 is a plan view illustrating the position of the rear support when excavating a curved tunnel, using the underground excavation device according to the embodiment of the present disclosure. Description of Embodiments

[0012] An underground excavation device according to an embodiment of the present disclosure will be described with reference to the drawings.

[0013] The underground excavation device according to the present embodiment is a so-called open-type TBM among TBMs (tunnel boring machines). The tunnel excavation device according to the present embodiment can be used for tunnel construction by hard rock excavation.

[0014] (Overall Configuration of Underground Excavation Device) FIG. 1 is a perspective view showing an underground excavation device 1 according to the present embodiment. FIG. 2 is a side view showing the underground excavation device 1 according to the present embodiment.

[0015] The underground excavation device 1 according to the present embodiment performs excavation by rotating a cutter head 21 in a state of being supported on the inner wall of a tunnel by a gripper unit 30.

[0016] The underground excavation device 1 according to the present embodiment includes a main body 2, a platform 3, a workbench 4, a rear support 5, a position adjustment mechanism 6, and a belt conveyor 7.

[0017] The main body 2 includes a front body unit 11, a rear body unit 12, a connection part 13, and a main beam 14. As shown in FIG. 1, the front body unit 11 has the cutter head 21 at the front end and excavates bedrock. The rear body unit 12 is disposed rearward of the front body unit 11 and can be supported to the inner wall of the tunnel by the gripper unit 30. In the drawings, a front-rear direction is indicated by A, a forward direction is indicated by an arrow A1, and a rearward direction is indicated by an arrow A2. The arrow A indicates the front-rear direction in a state where the front body unit 11 is not bent with respect to the rear body unit 12 and is disposed linearly. The arrow A can also be said to be the direction in which the main beam 14 extends. Also, an arrow B shown in the drawings indicates a left-right direction (width direction) and a horizontal direction perpendicular to the front-rear direction A. Of the left-right direction B, a left side direction when facing the front direction A1 is indicated by B1, and a right side direction when facing the front direction A1 is indicated by B2.

[0018] The connection part 13 connects the front body unit 11 to the rear body unit 12 in a bendable manner. The connection part 13 has multiple thrust cylinders 13a, and one end of each thrust cylinder 13a is connected to the front body unit 11 in a rotationally movable manner, whereas the other end is connected to the rear body unit 12 in a rotationally movable manner.

[0019] The main beam 14 is coupled to the front body unit 11 and extends rearward from the front body unit 11. The main beam 14 supports the rear body unit 12 slidably along the front-rear direction A. FIG. 3 is a partial perspective view of the underground excavation device 1 as viewed from the rear side. As shown in FIGS. 2 and 3, the main beam 14 extends rearward through the inside of the rear body unit 12.

[0020] As shown in FIGS. 1 and 2, the platform 3 is attached to the rear end of the main beam 14 in a rotationally movable manner. The workbench 4 is provided to perform work of attaching a wire mesh to the inner wall of the tunnel after excavation, and is disposed on the upper side of the platform 3.

[0021] The rear support 5 supports the main body 2. The rear support 5 extends downward and supports the main body 2 in a grounded state.   The position adjustment mechanism 6 adjusts the position of the rear support 5 with respect to the main body 2. The belt conveyor 7 is provided from the front body unit 11 to the rear through the rear body unit 12 and the lower side of the platform 3, and conveys rocks, earth, and the like excavated by the cutter head 21 rearward.

[0022] Although not shown, a vehicle provided with a control device that drives the cutter head 21, the belt conveyor 7, the multiple thrust cylinders 13a, the gripper unit 30, and the like, a power supply device, a hydraulic system, and the like, is connected rearward of the platform 3.

[0023] (Front Body Unit 11) As illustrated in FIG. 1, the front body unit 11 includes the cutter head 21, a cutter head support 22 (see FIG. 2), a vertical support 23, a pair of side supports 24 (only the left side surface side is illustrated in FIG. 1), and a roof support 25. In FIG. 2, in order to show the cutter head support 22, a rear part of the side support 24 on the left side surface side, a rear part of the roof support 25 on the left side surface side, and the left side surface side of the vertical support are omitted.

[0024] The cutter head 21 is provided at the front end of the front body unit 11 and is provided rotatably with respect to the cutter head support 22. As illustrated in FIG. 1, the cutter head 21 includes multiple disc cutters 211 (an example of a cutter) provided on the surface on the excavation side. The rock excavated by the disc cutter 211 is taken into the inside of the cutter head 21 by a bucket 212.

[0025] As shown in FIG. 2, the cutter head support 22 is disposed rearward of the cutter head 21. The cutter head support 22 rotatably supports the cutter head 21.

[0026] The vertical support 23, the pair of side supports 24, and the roof support 25 are attached to the cutter head support 22 and are disposed so as to surround the cutter head support 22. The vertical support 23, the pair of side supports 24, and the roof support 25 are provided to support the cutter head support 22 to the tunnel wall in order to stabilize during excavation, and to protect the cutter head support 22 from the collapse of rocks from the tunnel wall.

[0027] The vertical support 23 is disposed below the cutter head support 22. The pair of side supports 24 are disposed on both sides of the cutter head support 22 in the width direction. The roof support 25 is disposed above the cutter head support 22.

[0028] The vertical support 23, the pair of side supports 24, and the roof support 25 are configured to be movable in a direction toward the cutter head support 22 or away from the cutter head support 22.  That is, the vertical support 23 and the roof support 25 are movable in an up-down direction with respect to the cutter head support 22. The pair of side supports 24 are movable outward or inward along the left-right direction B with respect to the cutter head support 22.

[0029] (Rear Body Unit 12) As shown in FIG. 2, the rear body unit 12 has the gripper unit 30 and a gripper carrier 31. The gripper unit 30 protrudes outward from the gripper carrier 31, presses the inner wall of the tunnel during excavation, and supports the rear body unit 12 to the inner wall of the tunnel.

[0030] The gripper unit 30 includes a pair of side grippers 32 (only the left side surface side is shown), a lower gripper 33, and an upper gripper 34.

[0031] The side grippers 32 are provided at a left part and a right part of the gripper carrier 31. The side grippers 32 are moved outward or inward along the left-right direction B by a hydraulic cylinder provided in the gripper carrier 31.

[0032] The lower gripper 33 is provided at a lower part of the gripper carrier 31. The lower gripper 33 moves in the up-down direction by extension and contraction of a hydraulic cylinder provided in the gripper carrier 31.

[0033] The upper gripper 34 is provided in an upper part of the gripper carrier 31. The upper gripper 34 moves in the up-down direction by extension and contraction of a hydraulic cylinder provided in the gripper carrier 31.

[0034] (Rear Support 5) As shown in FIG. 3, the rear support 5 is attached to the main beam 14 via the position adjustment mechanism 6 so as to be adjustable in position. The rear support 5 includes a left rear support part 5a and a right rear support part 5b. The left rear support part 5a and the right rear support part 5b are disposed with the main beam 14 interposed therebetween. The left rear support part 5a and the right rear support part 5b are configured to be bilaterally symmetrical.

[0035] Since the left rear support part 5a and the right rear support part 5b have the same configuration, the left rear support part 5a will be described as an example. FIG. 4A is a side cross-sectional view of the left rear support part 5a in a contracted state. FIG. 4B is a side cross-sectional view of the left rear support part 5a in an extended state.

[0036] The left rear support part 5a includes a shoe 41 and a rear cylinder 42. The shoe 41 is disposed at a lower end of a rod part 44 of the rear cylinder 42. The shoe 41 is grounded in the tunnel. A grounding surface 41a (see FIG. 3) of the shoe 41 is curved so as to follow the inner peripheral surface of the tunnel. As shown in FIGS. 4A and 4B, the rear cylinder 42 includes a cylinder part 43 and the rod part 44. The cylinder part 43 is attached to the position adjustment mechanism 6, described later.

[0037] The cylinder part 43 includes a cylinder tube part 45 and a cylinder inner part 46. The cylinder tube part 45 has a cylindrical shape. The cylinder tube part 45 is closed at an upper end 45a and is open at a lower end. The cylinder tube part 45 has a space inside. The cylinder inner part 46 is disposed inside the cylinder tube part 45. The cylinder inner part 46 extends downward from the upper end 45a of the cylinder tube part 45. A lower end 46a of the cylinder inner part 46 protrudes outward toward the inner peripheral surface of an inner rod 47, described below.

[0038] The rod part 44 includes the inner rod 47, an outer rod 48, and a connection member 49. The inner rod 47 is disposed inside the cylinder part 43. The inner rod 47 has a substantially cylindrical shape. The inner rod 47 is disposed outside the cylinder inner part 46. An upper end 47a of the inner rod 47 protrudes inward toward the outer peripheral surface of the cylinder inner part 46. A lower end 47b of the inner rod 47 is closed below the cylinder inner part 46.

[0039] The outer rod 48 is disposed between the inner rod 47 and the cylinder tube part 45. The outer rod 48 has a cylindrical shape. The upper end of the outer rod 48 is open. The lower end of the outer rod 48 is closed by the connection member 49. The lower end 47b of the inner rod 47 is connected to the upper surface of the connection member 49. The shoe 41 is attached to the connection member 49 via a connection pin 49a.

[0040] When hydraulic oil is supplied to a space S1 (see FIG. 4B) below the lower end 46a, which is a space between the cylinder inner part 46 and the inner rod 47, the rear cylinder 42 extends and the shoe 41 moves downward. When hydraulic oil is supplied to a space S2 (see FIG. 4A) above the lower end 46a, which is a space between the cylinder inner part 46 and the inner rod 47, the rear cylinder 42 contracts and the shoe 41 moves upward.

[0041] Since the rod part 44 of the left rear support part 5a and the right rear support part 5b in the present embodiment has a double cylindrical structure configured with the inner rod 47 and the outer rod 48, durability against a force in the horizontal direction can be improved.

[0042] (Position Adjustment Mechanism 6) FIG. 5 is an enlarged perspective view of the vicinity of the position adjustment mechanism 6 of the underground excavation device 1 according to the present embodiment. As shown in FIGS. 1 and 2, a side workbench 8 is disposed outside the rear cylinder 42 of each of the left rear support part 5a and the right rear support part 5b, but is omitted in FIG. 5.

[0043] The position adjustment mechanism 6 includes a frontrear movement mechanism 50, a rotation mechanism 60, and a left-right movement mechanism 70. The front-rear movement mechanism 50 moves the rear support 5 in the front-rear direction with respect to the main body 2  (see arrow A). The rotation mechanism 60 rotates the rear support 5 with respect to the main body 2 about a rotation axis along the up-down direction (see arrow C). The left-right movement mechanism 70 moves the rear support 5 in the left-right direction with respect to the main body 2 (see arrow B). FIG. 5 shows a state where the rear support 5 is rotated with respect to the main beam 14 such that the left rear support part 5a is located further to the front than the right rear support part 5b and where the rear support 5 is moved to the left direction B1 side with respect to the main beam 14.

[0044] (Front-Rear Movement Mechanism 50) FIG. 6 is a perspective view showing the rear support 5 and the position adjustment mechanism 6. FIG. 7 is a cross-sectional view taken along a line D-D' in FIG. 6.

[0045] As illustrated in FIGS. 6 and 7, the front-rear movement mechanism 50 includes a front-rear movement frame 51, a pair of front-rear movement cylinders 52 (an example of a front-rear movement actuator), and a pair of guide rails 53. The front-rear movement frame 51 is supported by the main beam 14 so as to be movable in the front-rear direction A along the main beam 14. The front-rear movement cylinders 52 are coupled to the main beam 14 and the frontrear movement frame 51, and move the front-rear movement frame 51 in the front-rear direction.

[0046] As shown in FIG. 6, the front-rear movement frame 51 includes an upper frame part 54 and a lower frame part 55. The upper frame part 54 is attached to the main beam 14. The lower frame part 55 is disposed below the upper frame part 54. The lower frame part 55 rotatably supports a rotation frame 61, described later.

[0047] As shown in FIG. 6, the upper frame part 54 has a front wall 56, a rear wall 57, and a pair of side walls 58. The front wall 56 is disposed perpendicularly to the front rear direction A. The rear wall 57 is disposed rearward of the front wall 56.    The rear wall 57 is disposed perpendicularly to the front-rear direction A. The rear wall 57 faces the front wall 56 in the front-rear direction A. Of the pair of side walls 58, the side wall 58 on the left direction B1 side connects the end of the front wall 56 on the left direction B1 side and the end of the rear wall 57 on the left direction B1 side. Of the pair of side walls 58, the side wall 58 on the right direction B2 side connects the end of the front wall 56 on the right direction B2 side and the end of the rear wall 57 on the right direction B2 side. The pair of side walls 58 extend above the front wall 56 and the rear wall 57. A guide fitting part 59 is disposed inside each of the parts of the pair of side walls 58 protruding above the front wall 56 and the rear wall 57. The guide fitting part 59 is formed in a recessed shape on the inner surface of the side wall 58.

[0048] As shown in FIG. 7, the main beam 14 has a pair of side surfaces 14a and a bottom surface 14b. The pair of side surfaces 14a are a surface facing the left direction B1 of the main beam 14 and a surface facing the right direction B2. The bottom surface 14b connects the lower ends of the pair of side surfaces 14a. The guide rails 53 are disposed on the pair of side surfaces 14a, respectively. The guide rails 53 are disposed along the front-rear direction A. The guide fitting part 59 of the side wall 58 on the left direction B1 side is fitted on the guide rail 53 on the left direction B1 side, and the guide fitting part 59 of the side wall 58 on the right direction B2 side is fitted on the guide rail 53 on the right direction B2 side.

[0049] The lower frame part 55 is substantially plate-shaped. As shown in FIG. 6, the lower frame part 55 is disposed at the lower ends of the front wall 56, the rear wall 57, and the pair of side walls 58. A cylindrical part 551 that supports a rotation pin 62 of the rotation mechanism 60, described later, is disposed at the center of the lower frame part 55.

[0050] The front-rear movement cylinder 52 moves the frontrear movement frame 51 in the front-rear direction A along the guide rail 53. As shown in FIG. 6, the pair of frontrear movement cylinders 52 are arranged side by side in the left-right direction B. Each of the front-rear movement cylinders 52 includes a cylinder part 52a and a rod part 52b that is inserted into the cylinder part 52a and moves with respect to the cylinder part 52a. In each of the front-rear movement cylinders 52, the cylinder part 52a is disposed forward of the rod part 52b such that the rod part 52b extends rearward with respect to the cylinder part 52a. As shown in FIG. 5, the front end of the cylinder part 52a of each of the front-rear movement cylinders 52 is supported by the bottom surface 14b of the main beam 14 so as to be rotatable about the left-right direction B. The rear end of the rod part 52b of each of the front-rear movement cylinders 52 is coupled to the front wall 56 of the frontrear movement frame 51 so as to be rotatable about the leftright direction B.

[0051] Thus, when the pair of front-rear movement cylinders 52 contract, the front-rear movement frame 51 moves in the front direction A1 with respect to the main beam 14. When the pair of front-rear movement cylinders 52 extend, the front-rear movement frame 51 moves in the rear direction A2 with respect to the main beam 14.

[0052] (Rotation Mechanism 60) As shown in FIG. 5, the rotation mechanism 60 is supported by the front-rear movement frame 51. FIG. 8 is a cross-sectional view taken along a line E-E' in FIG. 6.

[0053] As illustrated in FIGS. 7 and 8, the rotation mechanism 60 includes the rotation frame 61, the rotation pin 62, and a rotation cylinder 63 (an example of a rotation actuator). The rotation frame 61 rotates about an axis along the up-down direction with respect to the main beam 14. The rotation pin 62 rotatably supports the rotation frame 61 on the front-rear movement frame 51. The rotation cylinder 63 rotates the rotation pin 62.

[0054] As shown in FIG. 8, the rotation frame 61 includes an upper surface part 64, a front wall part 65, and a rear wall part 66. The upper surface part 64 is disposed below the lower frame part 55 of the front-rear movement frame 51. The upper surface part 64 is substantially plate-shaped. The upper surface part 64 is disposed horizontally. A through hole is formed in the up-down direction in the upper surface part 64. The upper surface part 64 has an edge part 64a around the through hole. A through hole is formed in the up-down direction in the lower frame part 55 so as to face the through hole in the upper surface part 64. The cylindrical part 551 rotatably supporting the rotation pin 62 is disposed in the through hole in the lower frame part 55. The cylindrical part 551 is disposed such that the central axis thereof extends along the up-down direction. As shown in FIG. 7, a liner 64b is disposed on the upper side of the upper surface part 64 and slides on the lower frame part 55.

[0055] As shown in FIG. 8, the front wall part 65 extends downward from the front end of the upper surface part 64. As shown in FIG. 5, a front guide fitting part 65a to be fitted on a front left-right guide rail 72, described later, is disposed on the rear surface of the front wall part 65. The front guide fitting part 65a is formed to be recessed forward, and the front left-right guide rail 72 is fitted therein.

[0056] As shown in FIG. 8, the rear wall part 66 extends downward from the rear end of the upper surface part 64. The rear wall part 66 faces the front wall part 65 in the front-rear direction A. As shown in FIG. 6, on the front surface of the rear wall part 66, a rear guide fitting part 66a to be fitted on a rear left-right guide rail 73, described later, is disposed. The rear guide fitting part 66a is formed to be recessed rearward, and the rear leftright guide rail 73 is fitted therein.

[0057] As shown in FIG. 8, the rotation pin 62 is disposed, passing through the inside of the cylindrical part 551 of the lower frame part 55 and the edge part 64a of the upper surface part 64. The rotation pin 62 is disposed at the center of the front-rear movement frame 51 in the left-right direction B. The rotation pin 62 is disposed at the center of the main beam 14 in the left-right direction B. As illustrated in FIG. 8, the rotation pin 62 includes a pin body 67 and a lid part 68. The pin body 67 has a circular columnar shape. The pin body 67 passes through the inside of the cylindrical part 551 of the lower frame part 55 and the edge part 64a of the upper surface part 64. A part of a lower end 67a of the pin body 67 protrudes outward. The part protruding outward of the lower end 67a is disposed below the edge part 64a. The part protruding outward of the lower end 67a and the edge part 64a are fixed to each other by a bolt or the like. The lid part 68 is fixed to the upper end of the pin body 67 by a bolt or the like. The lid part 68 extends outward from the upper end of the pin body 67. The lid part 68 is disposed above the cylindrical part 551.

[0058] FIG. 9 is a plan view showing the rear support 5 and the position adjustment mechanism 6. In FIG. 9, the outer shape of the main beam 14 is indicated by a two-dot chain line. The rotation cylinder 63 is coupled to the upper frame part 54 of the front-rear movement frame 51 and the lid part 68. The rotation cylinder 63 includes a cylinder part 63a and a rod part 63b that is inserted into the cylinder part 63a and moves with respect to the cylinder part 63a. The rotation cylinder 63 is disposed along the left-right direction. The right end of the cylinder part 63a is coupled to the side wall 58 on the right direction B2 side so as to be rotatable about the up-down direction. The distal end of the rod part 63b is coupled to the lid part 68 so as to be rotatable about the up-down direction. A coupling part 63c with the lid part 68 at the distal end of the rod part 63b is disposed, shifted from the central axis 62a of the rotation pin 62 to the front direction A1 side.

[0059] Thus, when the rotation cylinder 63 extends, the rotation pin 62 rotates counterclockwise about the central axis 62a as viewed in a plan view, and the rotation frame 61 fixed to the rotation pin 62 rotates counterclockwise, too (see arrow C1). Due to the rotation of the rotation frame 61, a left-right movement frame 71, described later, rotates, too, and the left rear support part 5a and the right rear support part 5b disposed at the two ends of the left-right movement frame 71 rotate, too. In FIG. 9, the left rear support part 5a and the right rear support part 5b rotated in the direction of the arrow C1 are indicated by one-dot chain lines.

[0060] Meanwhile, when the rotation cylinder 63 contracts, the rotation pin 62 rotates clockwise about the central axis 62a as viewed in a plan view, and the rotation frame 61 fixed to the rotation pin 62 rotates clockwise, too (see arrow C2). Due to the rotation of the rotation frame 61, a left-right movement frame 71, described later, rotates, too, and the left rear support part 5a and the right rear support part 5b disposed at the two ends of the left-right movement frame 71 rotate, too. In FIG. 9, the left rear support part 5a and the right rear support part 5b rotated in the direction of the arrow C2 are indicated by dotted lines.

[0061] (Left-Right Movement Mechanism 70) As shown in FIGS. 5, 6, and 8, the left-right movement mechanism 70 includes the left-right movement frame 71, the front left-right guide rail 72, the rear left-right guide rail 73, a rack 74, a pinion 75, a motor 76 (an example of a left-right movement actuator), and a motor support frame 77.

[0062] As shown in FIG. 6, the left-right movement frame 71 is formed along the left-right direction B. The left-right movement frame 71 is substantially rectangular. As shown in FIG. 8, the left-right movement frame 71 is disposed below the rotation frame 61 so as to be sandwiched between the front wall part 65 and the rear wall part 66 of the rotation frame 61. The cylinder part 43 of the left rear support part 5a is fixed to the left end of the left-right movement frame 71. The cylinder part 43 of the right rear support part 5b is fixed to the right end of the left-right movement frame 71.

[0063] As shown in FIG. 5, the front left-right guide rail 72 is disposed on a front surface 71a of the left-right movement frame 71. The front left-right guide rail 72 is disposed along the left-right direction B. The front leftright guide rail 72 is fitted in the front guide fitting part 65a of the rotation frame 61.

[0064] As shown in FIG. 6, the rear left-right guide rail 73 is disposed on a rear surface 71b of the left-right movement frame 71.   The rear left-right guide rail 73 is disposed along the left-right direction B. The rear left-right guide rail 73 is fitted in the rear guide fitting part 66a of the rotation frame 61.

[0065] As the front left-right guide rail 72 is fitted in the front guide fitting part 65a, and the rear left-right guide rail 73 is fitted in the rear guide fitting part 66a in this way, the left-right movement frame 71 is movable along the left-right direction B with respect to the rotation frame 61.

[0066] As shown in FIG. 5, the rack 74 is disposed on the front surface 71a of the left-right movement frame 71. The rack 74 is disposed along the left-right direction B. The rack 74 is disposed below the front left-right guide rail 72. The rack 74 is disposed below the rotation frame 61.

[0067] FIG. 10 is a cross-sectional view taken along a line F-F' in FIG. 8 and is a view from the rear direction A2 toward the front. As shown in FIG. 10, the pinion 75 meshes with the rack 74. The pinion 75 is disposed below the rack 74.

[0068] The motor 76 shown in FIG. 5 rotates the pinion 75. As shown in FIG. 8, the motor 76 is disposed such that the output shaft thereof extends along the front-rear direction A. The pinion 75 is fixed to the output shaft of the motor 76. The motor 76 is disposed forward of the pinion 75.

[0069] As shown in FIGS. 5 and 8, the motor support frame 77 supports the motor 76. The motor support frame 77 supports the motor 76 to the front wall part 65 of the rotation frame 61. The motor support frame 77 is disposed at the center of the rotation frame 61 in the left-right direction B. The motor support frame 77 extends downward from the rotation frame 61. The motor support frame 77 supports the motor 76 below the rotation frame 61.

[0070] As the motor 76 is rotated, the pinion 75 rotates, and the left-right movement frame 71 moves in the left-right direction B together with the rack 74 meshing with the pinion 75. Since the front left-right guide rail 72 is fitted in the front guide fitting part 65a, and the rear left-right guide rail 73 is fitted in the rear guide fitting part 66a, the left-right movement frame 71 is guided by the front guide fitting parts 65a and the rear guide fitting parts 66a of the rotation frame 61 and moves in the leftright direction B.

[0071] (Belt Conveyor 7) FIG. 11 is a perspective view showing the belt conveyor 7 in the vicinity of the position adjustment mechanism 6. In FIG. 11, the belt conveyor 7 is indicated by a solid line, and the main beam 14, the side workbench 8, the platform 3, and the workbench 4 are indicated by two-dot chain lines. The belt conveyor 7 includes a front belt conveyor part 81 and a rear belt conveyor part 82.

[0072] The front belt conveyor part 81 is disposed on the main beam 14 and is disposed from the rear side of the cutter head 21 to substantially the rear end of the main beam 14. Specifically, a rear end 81a of the front belt conveyor part 81 protrudes rearward from the rear end of the main beam 14. A front end 82a of the rear belt conveyor part 82 is disposed below the rear end 81a of the front belt conveyor part 81. The rear belt conveyor part 82 is disposed on the platform 3 and extends rearward from the platform 3. The earth and sand placed on the front belt conveyor part 81 and carried rearward falls downward from the rear end 81a, is placed on the front end 82a of the rear belt conveyor part 82, and is carried rearward.

[0073] In the position adjustment mechanism 6 in the embodiment, the front-rear movement cylinder 52 is disposed forward of the front-rear movement frame 51, and the rack 74, the pinion 75, and the motor 76 are disposed forward of the left-right movement frame 71. In this way, the frontrear movement cylinder 52, the rack 74, the pinion 75, and the motor 76 are disposed on the opposite side of the frontrear movement frame 51 from the rear end 81a of the frontside belt conveyor part 81 in the front-rear direction A. Thus, the earth and sand moving from the front belt conveyor part 81 to the rear belt conveyor part 82 are prevented from falling into the drive mechanism such as the front-rear movement cylinder 52, the rack 74, the pinion 75, and the motor 76.

[0074] (Position Adjustment of Rear Support 5) In the underground excavation device 1 according to the present embodiment, when excavating the tunnel, the gripper unit 30 protrudes and the rear body unit 12 is fixed to the tunnel. Next, the thrust cylinder 13a is extended, and the cutter head 21 is pressed against the face (surface to be excavated) and rotated. Thus, the disc cutter 221 crushes the rock of the face to perform excavation.

[0075] Next, the left rear support part 5a and the right rear support part 5b are extended downward and grounded in the tunnel so as to support the main beam 14 to the tunnel, and then the gripper unit 30 is contracted. Next, as the thrust cylinder 13a is contracted, the rear body unit 12 moves toward the cutter head (to the front).

[0076] Subsequently, after the gripper unit 30 is projected to fix the rear body unit 12 to the tunnel, the left rear support part 5a and the right rear support part 5b of the rear support 5 are contracted upward, and the thrust cylinder 13a is extended to perform excavation.    By repeating these operations, the underground excavation device 1 moves forward while performing excavation.

[0077] FIG. 12 is a diagram illustrating the position of the rear support 5 when excavating a tunnel on a straight line. FIG. 12 is a diagram of the rear support 5 and the position adjustment mechanism 6 as viewed from the rear, and the main beam 14 is indicated by a two-dot chain line.  In FIG. 12, an inner peripheral surface 100s of a tunnel 100 is indicated by a dotted line, and a central axis 100a of the tunnel 100 is shown.

[0078] Assuming that a line passing through the center of the cutter head 21 and along the main beam 14 as viewed in a plan view is a central axis 2a of the main body 2, in the state shown in FIG. 12, the pair of the left rear support part 5a and the right rear support part 5b are disposed bilaterally symmetrically with respect to the central axis 2a.

[0079] As illustrated in FIG. 12, when the tunnel 100 is on a straight line, the position of the central axis 100a of the tunnel 100 in the left-right direction coincides with the central axis 2a of the main body 2. Therefore, since the pair of the left rear support part 5a and the right rear support part 5b are disposed bilaterally symmetrically with respect to the central axis 2a, the pair of the left rear support part 5a and the right rear support part 5b are also disposed bilaterally symmetrically with respect to the central axis 100a of the tunnel 100. Thus, the rear support 5 can be appropriately disposed in accordance with the curved surface of the circular inner peripheral surface 100s of the tunnel 100, and the main body 2 can be appropriately supported from below by the pair of the left rear support part 5a and the right rear support part 5b.

[0080] FIG. 13 is a plan view illustrating a state where a curved tunnel is excavated. In the tunnel 100 curved as illustrated in FIG. 13, the central axis 100a of the tunnel and the central axis 2a of the main body 2 do not coincide with each other in the left-right direction B, and a discrepancy occurs. Therefore, the position of the rear support 5 is adjusted with respect to the main beam 14 in order to dispose the pair of the left rear support part 5a and the right rear support part 5b bilaterally symmetrically with respect to the central axis 100a of the tunnel 100. In FIG. 13, the rotation frame 61 is rotated clockwise as viewed in a top view with respect to the main beam 14, and the left-right movement frame 71 is moved to the left direction B1 side with respect to the main beam 14. The front-rear position of the front-rear movement frame 51 is adjusted so as to avoid other components of the underground excavation device 1 or to avoid a falsework 101.

[0081] Thus, even when the tunnel 100 is curved, the pair of the left rear support part 5a and the right rear support part 5b can be disposed bilaterally symmetrically with respect to the central axis 100b, and the rear support 5 can be appropriately disposed on the inner peripheral surface 100s of the tunnel 100 curved in a circular shape.

[0082] (Features, etc.) The underground excavation device 1 according to the present embodiment includes the position adjustment mechanism 6 that adjusts the position of the rear support 5 with respect to the main body 2. Thus, when constructing the tunnel into a sharp curve, the position of the rear support 5 can be adjusted such that the central axis 2a of the main body 2 coincides with the central axis 100a of the tunnel 100 when the central axis 2a of the main body 2 deviates from the central axis 100a of the tunnel 100 as viewed in a plan view, and therefore the stability of the support of the main body 2 can be improved.

[0083] In the underground excavation device 1 according to the present embodiment, the position adjustment mechanism 6 includes the front-rear movement mechanism 50 that moves the rear support 5 in the front-rear direction with respect to the main body 2. Thus, when constructing the tunnel into a sharp curve, the front-rear position can be adjusted so as to avoid interference with other components of the underground excavation device 1 or to avoid the falsework 101.

[0084] In the underground excavation device 1 according to the present embodiment, the position adjustment mechanism 6 includes the rotation mechanism 60 that rotates the rear support 5 with respect to the main body 2. Thus, when constructing the tunnel into a sharp curve, the position of the rear support 5 can be adjusted such that the central axis 2a of the main body 2 coincides with the axial line of the tunnel when the central axis 2a of the main body 2 deviates from the central axis 100a of the tunnel 100 as viewed in a plan view, and therefore the stability of the support of the main body 2 can be improved.

[0085] In the underground excavation device 1 according to the present embodiment, the position adjustment mechanism 6 includes the left-right movement mechanism 70 that moves the rear support 5 in the left-right direction B with respect to the main body 2. Thus, when constructing the tunnel into a sharp curve, the position of the rear support 5 can be adjusted such that the central axis of the main body 2 coincides with the axial line of the tunnel when the central axis of the main body 2 deviates from the axial line of the tunnel, and therefore the stability of the support of the main body 2 can be improved.

[0086] (Other Embodiments) While one embodiment of the present disclosure is described above, the present disclosure is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit and scope of the invention.

[0087] (A) In the above embodiment, the pair of front-rear movement cylinders 52 that is hydraulically operated are used as an example of the front-rear movement actuator configured to move the front-rear movement frame 51 in the front-rear direction A, but the front-rear movement actuator is not limited thereto.   For example, a cylinder that extends and contracts pneumatically or electrically may be used. Also, the front-rear movement actuator is not limited to a cylinder and may be a motor that rotates a pinion meshing with a rack as in the left-right movement mechanism 70.

[0088] (B) In the above embodiment, the rotation cylinder 63 that is hydraulically operated is used as an example of the rotation actuator that rotates the rotation frame 61, but the rotation actuator is not limited thereto. For example, a cylinder that extends and contracts pneumatically or electrically may be used. Also, the rotation actuator is not limited to a cylinder and may be a motor that rotates a gear fitted with a gear formed around the rotation pin 62.

[0089] (C) In the above embodiment, the motor 76 that rotates the pinion 75 meshing with the rack 74 is used as an example of the left-right movement actuator configured to move the left-right movement frame 71 in the left-right direction B, but the left-right movement actuator is not limited to the motor, and a cylinder such as the front-rear movement mechanism 50 may be used. The cylinder can extend and contract hydraulically, pneumatically, or electrically.

[0090] (D) In the above embodiment, in order to reduce the influence of the earth and sand carried by the belt conveyor 7, the front-rear movement cylinder 52 is disposed forward of the front-rear movement frame 51, and the motor 76 is disposed forward of the left-right movement frame 71, but may be disposed rearward thereof. In this case, in order to reduce the influence of falling earth and sand, it is preferable that the positions of the rear end 81a of the front belt conveyor part 81 and the front end 82a of the rear belt conveyor part 82 are disposed further rearward than the front-rear movement cylinder 52 and the motor 76.

[0091] (E) In the above embodiment, the position adjustment mechanism 6 includes the front-rear movement mechanism 50, the rotation mechanism 60, and the left-right movement mechanism 70, but may include only one mechanism or only two mechanisms.

[0092] (F) In the above embodiment, the rear support 5 includes the left rear support part 5a and the right rear support part 5b, and the shoe 41 of the left rear support part 5a and the shoe 41 of the right rear support part 5b are separated from each other, but the shoe 41 of the left rear support part 5a and the shoe 41 of the right rear support part 5b may be connected to each other below the main beam 14. The part connecting the shoes 41 is preferably curved along the inner peripheral surface 100s of the tunnel 100.

[0093] (Appendix 1) An underground excavation device includes: a main body including a front body unit including a cutter head provided with multiple cutters, and a rear body unit including a gripper unit configured to obtain a reaction force when excavation is performed, the rear body unit being disposed rearward of the front body unit; a rear support disposed rearward of the rear body unit so as to be movable in an up-down direction and supporting the main body; and a position adjustment mechanism configured to adjust a position of the rear support with respect to the main body.

[0094] (Appendix 2) In the underground excavation device according to Appendix 1, the position adjustment mechanism includes a front-rear movement mechanism configured to move the rear support in a front-rear direction with respect to the main body.

[0095] (Appendix 3) In the underground excavation device according to Appendix 2, the main body further includes a main beam that is coupled to the front body unit, slidably supports the rear body unit, and is disposed along the front-rear direction, and the front-rear movement mechanism includes a front-rear movement frame that is movable along the main beam, and a front-rear movement actuator configured to move the front-rear movement frame with respect to the main beam.

[0096] (Appendix 4) In the underground excavation device according to Appendix 3, the front-rear movement actuator is a frontrear movement cylinder coupled to the main beam and the front-rear movement frame and disposed forward of the frontrear movement frame.

[0097] (Appendix 5) In the underground excavation device according to any one of Appendices 1 to 4, the position adjustment mechanism includes a rotation mechanism configured to rotate the rear support with respect to the main body about a rotation axis along the up-down direction.

[0098] (Appendix 6) In the underground excavation device according to Appendix 5, the main body further includes a main beam that is coupled to the front body unit, slidably supports the rear body unit, and is disposed along the front-rear direction, and the rotation mechanism includes a rotation frame configured to rotate with respect to the main beam, and a rotation actuator that rotates the rotation frame with respect to the main beam.

[0099] (Appendix 7) In the underground excavation device according to Appendix 6, the position adjustment mechanism further includes a front-rear movement mechanism configured to move the rear support in the front-rear direction with respect to the main body, the front-rear movement mechanism includes a front-rear movement frame that is disposed above the rotation frame and is movable along the main beam, and a front-rear movement actuator configured to move the frontrear movement frame with respect to the main beam, the rotation mechanism further includes a rotation pin that is fixed to the rotation frame and is rotatably supported by the front-rear movement frame, and the rotation actuator is a rotation cylinder coupled to the front-rear movement frame and the rotation pin.

[0100] (Appendix 8) In the underground excavation device according to any one of Appendices 1 to 7, the position adjustment mechanism includes a left-right movement mechanism configured to move the rear support in the left-right direction with respect to the main body.

[0101] (Appendix 9) In the underground excavation device according to Appendix 8, the main body further includes a main beam that is coupled to the front body unit, slidably supports the rear body unit, and is disposed along the front-rear direction, and the left-right movement mechanism includes a left-right movement frame that is movable in the left-right direction with respect to the rear support, and a left-right movement actuator configured to move the left-right movement frame with respect to the rear support.

[0102] (Appendix 10) In the underground excavator according to Appendix 9, the position adjustment mechanism includes a rotation mechanism configured to rotate the rear support with respect to the main body about a rotation axis along the up-down direction, the rotation mechanism includes a rotation frame configured to rotate with respect to the main beam, and a rotation actuator configured to rotate the rotation frame with respect to the main beam, the left-right movement actuator is a motor and is supported by the rotation frame, and the left-right movement mechanism further includes a pinion coupled to an output shaft of the motor, and a rack that meshes with the pinion and is disposed along the leftright direction on the left-right movement frame. Industrial Applicability

[0103] The underground excavation device according to the present disclosure has an effect in that the rear support can be appropriately grounded in the tunnel when the tunnel is constructed into a sharp curve. Reference Signs List

[0104] 1: underground excavation device 2: main body 5: rear support 6: position adjustment mechanism 11: front body unit 12: rear body unit 21: cutter head 30: gripper unit 211: disc cutter

Claims

1. An underground excavation device comprising:a main body including a front body unit including a cutter head provided with multiple cutters, and a rear body unit including a gripper unit configured to obtain a reaction force when excavation is performed, the rear body unit being disposed rearward of the front body unit;a rear support disposed rearward of the rear body unitand supporting the main body; anda position adjustment mechanism configured to adjust a position of the rear support with respect to the main body.

2. The underground excavation device according to claim1, whereinthe position adjustment mechanism includes a frontrear movement mechanism configured to move the rear support in a front-rear direction with respect to the main body.

3. The underground excavation device according to claim 2, whereinthe main body further includes a main beam that iscoupled to the front body unit, slidably supports the rear body unit, and is disposed along the front-rear direction, andthe front-rear movement mechanism includesa front-rear movement frame that is movable along themain beam, anda front-rear movement actuator configured to move thefront-rear movement frame with respect to the main beam.

4. The underground excavation device according to claim 3, whereinthe front-rear movement actuator is a front-rear movement cylinder coupled to the main beam and the frontrear movement frame and disposed forward of the front-rear movement frame.

5. The underground excavation device according to claim1, whereinthe position adjustment mechanism includes a rotation mechanism configured to rotate the rear support with respect to the main body about a rotation axis along an up-down direction.

6. The underground excavation device according to claim 5, whereinthe main body further includesa main beam that is coupled to the front body unit, slidably supports the rear body unit, and is disposed along the front-rear direction, andthe rotation mechanism includesa rotation frame configured to rotate with respect tothe main beam, anda rotation actuator configured to rotate the rotationframe with respect to the main beam.

7. The underground excavation device according to claim6, whereinthe position adjustment mechanism further includes a front-rear movement mechanism configured to move the rear support in the front-rear direction with respect to the main body,the front-rear movement mechanism includesa front-rear movement frame that is disposed above the rotation frame and is movable along the main beam, anda front-rear movement actuator configured to move the front-rear movement frame with respect to the main beam,the rotation mechanism further includesa rotation pin that is fixed to the rotation frame and is rotatably supported by the front-rear movement frame, andthe rotation actuator is a rotation cylinder coupled to the front-rear movement frame and the rotation pin.

8. The underground excavation device according to claim 1, whereinthe position adjustment mechanism includes a leftright movement mechanism configured to move the rear support in a left-right direction with respect to the main body.

9. The underground excavation device according to claim 8, whereinthe main body further includesa main beam that is coupled to the front body unit, slidably supports the rear body unit, and is disposed along a front-rear direction, andthe left-right movement mechanism includesa left-right movement frame that is movable in the left-right direction with respect to the rear support, anda left-right movement actuator configured to move theleft-right movement frame with respect to the rear support.

10. The underground excavation device according to claim 9, whereinthe position adjustment mechanism includes a rotation mechanism configured to rotate the rear support with respect to the main body about a rotation axis along an up-down direction,the rotation mechanism includesa rotation frame configured to rotate with respect tothe main beam, anda rotation actuator configured to rotate the rotationframe with respect to the main beam,the left-right movement actuator is a motor and is supported by the rotation frame, andthe left-right movement mechanism further includesa pinion coupled to an output shaft of the motor, anda rack that meshes with the pinion and is disposed along the left-right direction on the left-right movement frame.

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