Cutter heads for shield tunneling machines and obstacle cutting

Abstract

The present invention provides a shield tunneling machine, which is provided with: a plurality of obstacle cutting cutter heads, which include a base material and a plurality of hard blades fixed to the base material in a state of protruding further in the excavation direction than the base material and harder than the base material, and cut underground obstacles; a cutter disc, which is provided with the obstacle cutting cutter heads and rotates along with excavation; and a shield tunneling machine body, which is provided with a cutter disc at the front end in the excavation direction. The plurality of obstacle cutting cutter heads are respectively configured such that the plurality of hard blades are arranged at intervals in the rotation direction of the cutter disc, and in the rotation direction of the cutter disc, the hard blades located on the outermost side in the rotation direction of the cutter disc are arranged closer to the inside than the base materials located at both ends in the rotation direction of the cutter disc.

Description

Technical Field

[0001] The invention relates to a shield tunneling machine and a cutter head for cutting obstacles, and in particular to a shield tunneling machine and a cutter head for cutting obstacles which can cut underground obstacles. Background Art

[0002] Conventionally, a shield boring machine capable of cutting underground obstacles is known, such as disclosed in Japanese Patent No. 6487277.

[0003] The Japanese Patent Gazette No. 6487277 discloses a shield tunneling machine having an obstacle cutting cutter head, wherein the obstacle cutting cutter head comprises a base material and a plurality of superhard blades fixed to the base material. The plurality of superhard blades are arranged at intervals in the rotation direction of the cutter head. In order to facilitate contact with obstacles, the obstacle cutting cutter head is provided with superhard blades at both ends in the rotation direction of the cutter head.

[0004] However, in the shield tunneling machine described in the above-mentioned Japanese Patent Gazette No. 6487277, since superhard blades are arranged at both ends in the rotation direction of the cutter head, although it is easy for the entire range of the superhard blades at both ends to contact obstacles, there is a problem that the superhard blades at both ends are easily damaged.

[0005] Prior art literature

[0006] Patent Literature

[0007] Patent Document 1: Japanese Patent No. 6487277 Summary of the invention

[0008] 1. Technical issues to be resolved

[0009] The present invention has been made to solve the above-mentioned problems, and one object of the present invention is to provide a shield tunneling machine and an obstacle cutting bit capable of suppressing the damage of a hard blade.

[0010] (II) Technical solutions and beneficial effects

[0011] In order to achieve the above-mentioned purpose, the shield tunneling machine of the present invention comprises: a plurality of obstacle cutting cutter heads, which include a base material and a plurality of hard blades fixed to the base material in a state of protruding further in the excavation direction than the base material and being harder than the base material, and cut underground obstacles; a cutter disc, which is provided with the obstacle cutting cutter heads and rotates along with excavation; and a shield tunneling machine body, which is provided with a cutter disc at the front end in the excavation direction, and the plurality of obstacle cutting cutter heads are respectively constructed such that the plurality of hard blades are arranged at intervals in the rotation direction of the cutter disc, and in the rotation direction of the cutter disc, the outermost hard blades in the rotation direction of the cutter disc are arranged closer to the inside than the base materials located at the two ends of the cutter disc in the rotation direction.

[0012] In the shield tunneling machine of the present invention, as described above, the outermost hard blades located in the rotation direction of the cutter disc are arranged closer to the inside than the base materials located at the two ends of the rotation direction of the cutter disc, so that the hard blades are not arranged at the two ends of the cutter head for cutting obstacles in the rotation direction of the cutter disc, and the two ends can be formed by the base materials that are softer than the hard blades (high toughness and not easy to be damaged). Therefore, the outermost hard blades located in the rotation direction of the cutter disc can be firmly clamped by the base materials from both sides of the rotation direction, and the exposure of the hard blades can be suppressed, and the overall contact between the obstacles and the hard blades can be prevented. As a result, the defects of the hard blades can be suppressed. In addition, in the case where hard blades are arranged at both ends of the rotation direction of the cutter disc as in the prior art, when the hard blades arranged at the rear end of the rotation direction of the cutter disc (hereinafter referred to as the hard blades at the rear end) contact with the obstacle, a large force will be applied to the hard blades at the rear end toward the rear of the rotation direction of the cutter disc. Here, since the hard blade at the rear end is supported mainly only by the tensile force of the base material located in front of the rotation direction of the cutter disc, the hard blade at the rear end is easily peeled off from the base material to the rear of the rotation direction of the cutter disc. On the other hand, as in the present invention, the hard blade located on the outermost side of the rotation direction of the cutter disc is firmly clamped by the base material from both sides of the rotation direction, thereby effectively preventing the hard blade at the rear end from being damaged or peeling off from the base material.

[0013] In the above-mentioned shield tunneling machine, preferably, the obstacle cutting bit has a first inclined surface provided on the outer peripheral side of both the base material and the hard blade in the radial direction of the cutter disc, and the first inclined surface is inclined from the front end in the excavation direction to the opposite direction of the excavation direction as it moves from the inner peripheral side in the radial direction of the cutter disc toward the outer peripheral side. If it is configured in this way, the front end in the excavation direction can be made thinner compared to the case where the first inclined surface is not provided at the front end of the obstacle cutting bit (the case where the front end is made rectangular). As a result, the heat generation near the front end in the excavation direction during cutting can be suppressed, so that the problem of the obstacle cutting bit (hard blade) being easily broken can be suppressed. In addition, as the first inclined surface is inclined from the front end in the excavation direction to the opposite direction of the excavation direction as it moves from the inner peripheral side in the radial direction toward the outer peripheral side, the chips can be made to flow along the first inclined surface, so that the chips can be effectively taken into the chamber.

[0014] In this case, preferably, the plurality of hard blades have a flat surface which is provided at the front end in the excavation direction in a manner continuous with the first inclined surface and is orthogonal to the excavation direction. With such a configuration, compared with the case where the obstacle is cut using the front end having a surface inclined relative to the excavation direction, the contact area of ​​the hard blade with the obstacle can be made larger by using the flat surface, thereby suppressing the problem of stress concentration on the hard blade. Therefore, the damage of the hard blade can be further suppressed.

[0015] In the structure in which the hard blade has a flat surface, preferably, the flat surfaces of the plurality of hard blades are arranged on the same plane. If so, the flat surfaces of the plurality of hard blades can be arranged at the same position in the excavation direction, so when cutting an obstacle, the plurality of hard blades can contact the obstacle at the same time. Therefore, the obstacle can be effectively cut.

[0016] In the above-mentioned shield tunneling machine, preferably, the obstacle cutting cutter head has a pair of second inclined surfaces provided at both ends of the base material in the rotation direction of the cutter disc, and the pair of second inclined surfaces are inclined from the outer end surface of the outermost hard blade in the rotation direction of the cutter disc toward the two end sides, i.e., the outer side, of the obstacle cutting cutter head in the rotation direction of the cutter disc in the opposite direction of the excavation direction. If so configured, the problem of contact between the obstacle and the base material can be suppressed by utilizing the pair of second inclined surfaces provided at both ends of the base material in the rotation direction of the cutter disc. As a result, the wear of the base material can be suppressed. In addition, the contact between the base material and the obstacle that does not contribute to cutting can be reduced, and the reduction in the excavation performance of the obstacle cutting cutter head can be suppressed.

[0017] In the above-mentioned shield tunneling machine, preferably, the obstacle cutting bit has a recessed portion provided on the surface of the inner peripheral side in the radial direction of the cutter disc, and the recessed portion is formed to be recessed from the inner peripheral side in the radial direction of the cutter disc toward the outer peripheral side, and has a concave shape along the rotation direction of the cutter disc. If so configured, when the obstacle cutting bit passes through the space generated by cutting, the recessed portion of the shape along the rotation direction of the cutter disc can be utilized to suppress the contact between the obstacle and the surface of the obstacle cutting bit on the inner peripheral side in the radial direction of the cutter disc. That is, the recessed portion can be utilized to enable the obstacle cutting bit to avoid the obstacle. As a result, it is possible to suppress the force acting on the obstacle cutting bit from the inner peripheral side toward the outer peripheral side, thereby further suppressing the damage of the hard blade.

[0018] In this case, preferably, the obstacle cutting bit is provided in a plurality of types in such a manner that the amount of depression of the concave portion decreases in stages from the inner circumference of the cutter disc toward the outer circumference in the radial direction. If so configured, the amount of depression of the concave portion can be set to an appropriate value corresponding to the position in the radial direction of the cutter disc, thereby effectively suppressing the surface contact between the obstacle and the inner circumference. As a result, the damage of the hard blade can be further suppressed.

[0019] In the above-mentioned shield tunneling machine, preferably, the obstacle cutting cutter head is provided with a plurality of types in such a manner that the number of hard blades contained in one obstacle cutting cutter head increases in stages as the number of hard blades is increased from the inner peripheral side of the radius of the cutter disc toward the outer peripheral side. If so configured, more hard blades can be provided for the obstacle cutting cutter head on the outer peripheral side of the radius of the cutter disc, where the circumferential speed of the obstacle cutting cutter head is particularly fast (the amount of movement per unit time of the obstacle cutting cutter head is particularly large). As a result, even on the outer peripheral side of the radius of the cutter disc, obstacles can be effectively cut. In addition, the closer the position is to the outer peripheral side of the radius of the cutter disc, the faster the circumferential speed of the obstacle cutting cutter head is, and the more heat is generated due to friction with the obstacle, causing the temperature of the obstacle cutting cutter head to rise. Therefore, the anti-fracture ability of the hard blade is significantly reduced compared to the inner peripheral side. Therefore, by configuring more hard blades on the outer peripheral side of the radius of the cutter disc as described above, redundancy can be improved.

[0020] The obstacle cutting tool head of the present invention comprises: a base material, which is arranged on a cutter disc that rotates along with excavation; and a plurality of hard blades, which are fixed to the base material in a state of protruding further in the excavation direction than the base material and are harder than the base material. The obstacle cutting tool head is constructed such that the plurality of hard blades are arranged at intervals in the rotation direction of the cutter disc, and in the rotation direction of the cutter disc, the outermost hard blades in the rotation direction of the cutter disc are arranged closer to the inside than the base materials located at both ends in the rotation direction of the cutter disc.

[0021] The obstacle cutting bit of the present invention is configured as described above, and can suppress the damage of the hard blade in the same manner as in the above-mentioned shield tunneling machine. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a schematic longitudinal sectional view of the shield tunneling machine according to the embodiment.

[0023] Figure 2 This is a schematic front view of the shield tunneling machine according to the embodiment as viewed from the excavation direction side (front side).

[0024] Figure 3 is along Figure 2 A cross-sectional view of the 500-500 line.

[0025] Figure 4 This is a diagram for comparing the amounts of depression of the recessed portions of the three types of obstacle excavation bits according to the embodiments.

[0026] Figure 5 It is a perspective view of the second bit (bit for cutting away obstacles) according to the embodiment.

[0027] Figure 6 These are three views showing the second bit (bit for cutting away obstacles) of the embodiment from three directions.

[0028] Figure 7 These are three views showing the first bit (bit for cutting away obstacles) of the embodiment from three directions.

[0029] Figure 8 This is a schematic diagram for explaining the arrangement of the obstacle excavation bits in the radial direction of the cutter head according to the embodiment.

[0030] Fig. 9 This is a diagram of the obstacle excavation bit according to the modified example as viewed from the excavation direction side (front side). DETAILED DESCRIPTION

[0031] [Description of preferred embodiment]

[0032] Hereinafter, embodiments will be described based on the drawings.

[0033] [Implementation Method]

[0034] Reference Figures 1 to 8 A shield tunneling machine 100 according to the embodiment will be described.

[0035] (Overall structure of shield tunneling machine)

[0036] like Figure 1As shown, the shield boring machine 100 includes a shield boring machine body 1, a cutter head 2 provided at the front end of the shield boring machine body 1 in the excavation direction, a plurality of obstacle cutting bits 3 provided on the cutter head 2, and a plurality of soil excavation bits S.

[0037] In each figure, the X1 direction indicates the excavation direction of the shield tunneling machine 100, and the X2 direction indicates the opposite direction of the excavation direction. In addition, the Z direction indicates the up-down direction, and the Y direction indicates the lateral direction (width direction) perpendicular to the X and Z directions.

[0038] RO represents the rotation direction of the cutter head 2, and RA represents the radial direction of the cutter head 2. RA1 represents the direction from the inner circumference to the outer circumference of the radial direction of the cutter head 2, and RA2 represents the opposite direction of RA1.

[0039] The cutterhead 2 is configured to rotate around a central axis α extending in the excavation direction as excavation proceeds. In addition, the rotation of the cutterhead 2 is configured to be switchable between forward and reverse rotation according to excavation conditions, etc. The shield tunneling machine 100 has a function of removing obstacles O present on the excavation path by cutting using the obstacle cutting cutter head 3.

[0040] The obstacle O is an H-shaped steel pile, reinforced concrete, etc. located underground. The shield tunneling machine 100 is equipped with a dedicated obstacle cutting blade 3 for cutting the obstacle O. In addition, if the obstacle O exists in a relatively soft foundation, when cutting the obstacle, the obstacle O may retreat (move) due to the contact between the obstacle cutting blade 3 and the obstacle O, and the cutting may not be performed properly. Therefore, when cutting an obstacle in the case of a relatively soft foundation, a foundation improvement project is performed in advance to inject a liquid medicine into the foundation to reinforce the foundation.

[0041] In the present embodiment, an example is shown in which the shield tunneling machine 100 is a soil pressure type shield tunneling machine. In the soil pressure type shield tunneling machine 100, mud material is injected into the chamber 11 and mixed with the excavated soil by the cutter head 2, so that the excavated soil becomes soil with impermeability and plastic fluidity. The excavated soil (soil) fills the chamber 11 and the soil discharge device 13. The shield tunneling machine 100 maintains a state in which the chamber 11 and the soil discharge device 13 are filled with the excavated soil (soil), and uses the thrust of the shield jack 12 to generate pressure in the chamber 11, thereby counteracting the pressure on the side of the stratum soil body (the soil pressure of the excavation face and the groundwater pressure). The shield tunneling machine 100 excavates while achieving a balance of pressure by using the balance between the excavation amount and the soil discharge amount.

[0042] (Structure of the shield tunneling machine body)

[0043] like Figure 1As shown, the shield boring machine body 1 includes a body 10 , a chamber 11 , a shield jack 12 , and an earth removal device 13 .

[0044] The main body 10 is composed of a cylindrical front main body 10a and a rear main body 10b. The front main body 10a is provided with a cutterhead 2 at the front end in the excavation direction, and is given a propulsion force by the shield jack 12 to use the cutterhead 2 to excavate the stratum soil. The rear main body 10b is a part that moves while arranging the fan-shaped segments SG on the wall surface using an assembling machine not shown in the figure in order to form the surrounding wall of the tunnel along with the excavation of the front main body 10a (advance in the X1 direction). The internal space of the main body 10 is divided into two spaces by a partition wall 14: a chamber 11 on the excavation direction side (X1 direction side) and a working space WS on the opposite side of the excavation direction (X2 direction side).

[0045] The chamber 11 is provided on the rear surface side (X2 direction side) of the cutter head 2. The chamber 11 is a space (soil chamber) surrounded by the cutter head 2, the front body 10a and the partition wall 14. The soil pressure in the chamber 11 is maintained in a substantially balanced state with the pressure acting on the cutter head 2 from the ground body side.

[0046] The shield jack 12 is configured to push the segment SG backward (in the X2 direction) to advance the main body 10 (shield boring machine 100 ). A plurality of shield jacks 12 are mounted on the rear main body portion 10 b so as to be aligned in the circumferential direction of the main body 10 .

[0047] The soil removal device 13 is composed of a screw conveyor and includes a cylindrical housing 13a disposed obliquely in the main body 10 and a screw 13b disposed in the housing 13a.

[0048] One end opening of the shell 13a is connected to the lower side of the chamber 11. The screw 13b is configured to impart a conveying force toward the other end opening of the shell 13a to the excavated soil taken from the chamber 11 by rotating. The other end opening of the shell 13a is configured to be able to discharge the soil. A soil conveying device B (for example, a belt conveyor) is provided on the downstream side of the soil discharge device 13, and the soil conveying device B conveys the soil discharged from the soil discharge device 13 (shell 13a) to the outside. In addition, the soil discharge device 13 has not only the function of discharging the soil in the chamber 11, but also the function of discharging the soil in the chamber 11 and adjusting the pressure in the chamber 11.

[0049] (Structure of the blade)

[0050] like Figure 2As shown, the cutter disc 2 is formed to be circular when viewed from the excavation direction. A plurality of obstacle cutting bits 3 and a plurality of soil excavation bits S are provided on the cutter disc 2. Specifically, the obstacle cutting bits 3 and the soil excavation bits S are fixed to the front surface (the surface on the X1 direction side) of the cutter disc 2 by welding, for example. The cutter disc 2 is configured to excavate the stratum soil by using the soil excavation bits S by rotating around the central axis α. In addition, the obstacle cutting bits 3 and the soil excavation bits S may be fixed to the cutter disc 2 by bolting instead of welding.

[0051] The cutter head 2 is provided with a switching mechanism (not shown) which switches between the following two states by moving the obstacle cutting cutter head 3 forward and backward in the X direction: a state in which the obstacle O is cut by the obstacle cutting cutter head 3 (obstacle cutting state) (see Figure 3 and a state where the soil is being excavated by the soil excavation cutter head S (soil excavation state). The switching mechanism is an actuator such as a jack that moves the obstacle cutting cutter head 3 in the front-rear direction (X direction).

[0052] Specifically, the switching mechanism is configured so that, under normal circumstances (soil excavation state), the front end of the obstacle cutting bit 3 is arranged at a position on the opposite side of the excavation direction (X2 direction side) than the front end of the soil excavation bit S. That is, the switching mechanism is configured so that, under normal circumstances, the obstacle cutting bit 3 is arranged (retreat) at a position retreated from the soil excavation bit S, thereby preventing (suppressing) wear of the obstacle cutting bit 3.

[0053] In addition, the switching mechanism is configured to switch from the soil excavation state to the obstacle cutting state when encountering an obstacle O. That is, the switching mechanism is configured to move the front end (the end in the X1 direction) of the obstacle cutting bit 3 to a position closer to the excavation direction (X1 direction) than the front end (the end in the X1 direction) of the soil excavation bit S. Thus, the shield tunneling machine 100 can cut the obstacle O using the obstacle cutting bit 3.

[0054] The cutter head 2 includes: a plurality of (four) radial first spokes 20 , a single rotation center 21 , an annular outer ring 22 , a plurality of soil inlets 23 for taking excavated soil into the chamber 11 , and a plurality of (four) radial second spokes 24 .

[0055] The first spoke portion 20 extends linearly from the inner circumference side (central axis α) of the cutter head 2 toward the outer circumference side in the radial direction (RA direction) of the cutter head 2. The plurality of (four) radial first spoke portions 20 are arranged in a cross shape when viewed from the excavation direction (viewed from the X1 direction side). That is, the center line β1 of one side group of two first spoke portions 20 arranged linearly and the center line β2 of the other side group of two first spoke portions 20 arranged linearly are orthogonal to each other.

[0056] When viewed from the excavation direction (viewed from the X1 direction side), the obstacle cutting bits 3 are arranged on the first spoke portion 20 along the center lines β1 and β2 (radial direction of the cutter head 2) of the first spoke portion 20. In addition, when viewed from the excavation direction (viewed from the X1 direction side), the main cutting bits S1 of the soil excavation bit S are provided on the first spoke portion 20 so as to sandwich the obstacle cutting bits 3 from both sides of the rotation direction (RO direction) of the cutter head 2.

[0057] The rotation center portion 21 is disposed on the central axis α. The inner peripheral ends of the plurality of (four) first spoke portions 20 are connected to the rotation center portion 21. A fishtail cutter head 21a is provided on the front surface of the rotation center portion 21.

[0058] The outer ring 22 is disposed at the outermost circumference of the cutter head 2 (near the inner surface of the tunnel). The outer circumferential ends of the first spoke portion 20 and the second spoke portion 24 are connected to the outer ring 22 .

[0059] When viewed from the excavation direction (viewed from the X1 direction side), the leading cutter bits S2 of the plurality of soil excavation cutter bits S are arranged on the outer peripheral ring 22 at predetermined intervals in a row along the rotation direction of the cutter head 2 .

[0060] The second spoke 24 extends linearly from the inner circumference of the cutter head 2 toward the outer circumference along the radial direction of the cutter head 2. The second spoke 24 is provided between the plurality of (four) first spokes 20 in the rotation direction of the cutter head 2.

[0061] When viewed from the excavation direction (viewed from the X1 direction side), the leading cutter head S2 of the soil excavation cutter head S is arranged on the second spoke portion 24 in a manner arranged along the center line γ (radial direction of the cutter head 2) of the second spoke portion 24. In addition, when viewed from the excavation direction (viewed from the X1 direction side), the main cutter head S1 of the soil excavation cutter head S is arranged on the second spoke portion 24 in a manner sandwiching the leading cutter head S2 from both sides in the rotation direction of the cutter head 2.

[0062] like Figure 1 As shown, a beam-shaped cutter bar M1 extending in the X direction, an annular member M2, and a cutter drive source M3 are provided on the rear surface side of the cutter head 2 as a mechanism for rotating the cutter head 2.

[0063] The front end of the tool rod M1 is mounted on the cutter disc 2 and the rear end is mounted on the annular component M2. The annular component M2 is configured to be rotatable around the central axis α by a bearing supported on the partition wall 14 of the front main body 10a. The cutter disc 2 is configured to be rotationally driven by a tool drive source M3 through the tool rod M1 and the annular component M2. The tool drive source M3 is arranged behind the partition wall 14 and is configured to impart a driving torque to the annular component M2 for rotational drive. That is, the cutter disc 2, the tool rod M1 and the annular component M2 are configured to rotate (revolve) as a whole using the tool drive source M3. The tool drive source M3 is, for example, composed of a hydraulic motor.

[0064] (Structure of the obstacle cutting head)

[0065] like Figure 2 As shown, a plurality of types of cutter heads are provided in the obstacle cutting cutter head 3. Specifically, three types of cutter heads are provided in the obstacle cutting cutter head 3, namely, a first cutter head 4, a second cutter head 5, and a third cutter head 6. A plurality of the first cutter head 4, the second cutter head 5, and the third cutter head 6 are provided.

[0066] Among the three types of cutter heads, the first cutter head 4 is arranged at the innermost peripheral side in the radial direction (RA direction) of the cutter disc 2. Among the three types of cutter heads, the third cutter head 6 is arranged at the outermost peripheral side in the radial direction of the cutter disc 2. The second cutter head 5 is arranged between the first cutter head 4 and the third cutter head 6 in the radial direction of the cutter disc 2.

[0067] The first blade head 4, the second blade head 5 and the third blade head 6 have the same basic structure. The first blade head 4, the second blade head 5 and the third blade head 6 are different from each other in the following two aspects.

[0068] like Figure 4 As shown, the first difference is that the obstacle cutting bit 3 is provided with a plurality of types in such a manner that the recessed amounts (D1, D2, D3) of the recessed portions (47, 57, 67) provided on the inner peripheral surface (43a, 53a, 63a) decrease in stages from the inner peripheral side toward the outer peripheral side in the radial direction of the cutter head 2. That is, the recessed amount D1 of the recessed portion 47 of the first bit 4, the recessed amount D2 of the recessed portion 57 of the second bit 5, and the recessed amount D3 of the recessed portion 67 of the third bit 6 decrease in sequence (in the order of the first bit 4, the second bit 5, and the third bit 6).

[0069] The second difference is that the obstacle cutting blade head 3 is provided with a plurality of types in such a manner that the number of hard blades (42, 52, 62) included in one obstacle cutting blade head 3 increases in stages from the inner peripheral side toward the outer peripheral side in the radial direction of the cutter head 2. That is, at least the number of hard blades 62 of the third blade head 6 is greater than the number of hard blades 42 of the first blade head 4.

[0070] In the drawings, the hard inserts 42 , 52 , and 62 are shown with hatching (oblique lines) in order to easily distinguish the hard inserts 42 , 52 , and 62 from the base materials 41 , 51 , and 61 . However, the hatching does not indicate a cross section.

[0071] Hereinafter, the second blade head 5 having four hard blades 52 will be described first. Then, the third blade head 6 having the same shape as the second blade head 5 except that the recessed amount of the recessed portion 67 is different from that of the recessed portion 57 will be described, and finally, the first blade head 4 having two hard blades 42 will be described.

[0072] 〈Structure of the Second Cutting Head〉

[0073] like Figure 2 As shown, a plurality of second blade heads 5 (three blade heads each) are provided on each first spoke portion 20. The plurality of (three blade heads) 4 are arranged at equal intervals on the center line β1 (β2).

[0074] like Figure 5 and Figure 6 As shown, the second bit 5 (obstacle cutting bit 3 ) includes a base material 51 (substrate) and a plurality of (four) hard blades 52 fixed to the base material 51 so as to protrude in the excavation direction (X1 direction) from the base material 51 .

[0075] The base material 51 is made of a material tougher than the hard blade 52. The base material 51 is made of, for example, a steel material such as S45C. The hard blade 52 is made of a material harder than the base material 51. The hard blade 52 is made of, for example, a cemented carbide.

[0076] When viewed from the excavation direction (viewed from the X1 direction side), the second cutter head 5 is arranged with the radius of the cutter head 2 as the short side direction and the rotation direction (RO direction) of the cutter head 2 as the long side direction. A plurality of (four) hard blades 52 are arranged at intervals in the rotation direction of the cutter head 2.

[0077] The second cutter head 5 is not provided with hard blades 52 at both ends of the rotation direction of the cutter disc 2, and both ends of the second cutter head 5 in the rotation direction of the cutter disc 2 are only composed of the base material 51. That is, the second cutter head 5 (each of the plurality of cutter heads 3 for obstacle cutting) is configured such that, in the rotation direction of the cutter disc 2, the hard blades 52 located at the outermost sides in the rotation direction of the cutter disc 2 are arranged closer to the inside than the base materials 51 located at both ends in the rotation direction of the cutter disc 2. In short, all the hard blades 52 of the second cutter head 5 are clamped by the base material 51 from both sides in the rotation direction of the cutter disc 2.

[0078] That is, the second cutting head 5 (obstacle cutting head 3 ) is configured to firmly support the hard cutting blade 52 from both sides in the rotation direction of the cutter head 2 by the base material 51 , thereby preventing the hard cutting blade 52 from being damaged.

[0079] The inner peripheral surface 53a and the outer peripheral surface 53b both extend in the excavation direction. In addition, the excavation direction side surface extends in a direction intersecting the excavation direction.

[0080] A plurality of (four) hard blades 52 extend approximately along the radial direction (RA direction) of the cutter head 2 and are arranged parallel to each other. In addition, the hard blades 52 and the base material 51 are arranged in a continuous manner with no step difference on their respective exposed outer surfaces, and form a surface 53a on the inner circumference side. In addition, the hard blades 52 and the base material 51 are arranged coplanarly (arranged on the same plane) on the surface 53b on the outer circumference side of the obstacle cutting bit 3.

[0081] The second cutting head 5 (obstacle cutting cutting head 3 ) has a first inclined surface 54 provided on the outer peripheral sides of both the base material 51 and the hard insert 52 in the radial direction of the cutting disc 2 .

[0082] The first inclined surface 54 is provided over the entire area of ​​the second cutting head 5 in the rotation direction of the cutter head 2 (the long side direction of the obstacle cutting cutting head 3). The first inclined surface 54 is inclined from the front end in the excavation direction to the opposite direction of the excavation direction as it moves from the inner peripheral side in the radial direction of the cutter head 2 to the outer peripheral side. That is, the second cutting head 5 (obstacle cutting cutting head 3) is formed such that the thickness in the radial direction of the cutter head 2 gradually decreases (becomes thinner at the front end) as it moves toward the excavation direction.

[0083] As an example, the inclination angle of the first inclined surface 54 relative to the surface orthogonal to the excavation direction (the flat surface 55 described later) is preferably 20 degrees or more and less than 45 degrees. In addition, the inclination angle of the first inclined surface 54 relative to the surface orthogonal to the excavation direction is more preferably 25 degrees or more and less than 35 degrees. Moreover, the inclination angle of the first inclined surface 54 relative to the surface orthogonal to the excavation direction is more preferably about 30 degrees.

[0084] The first inclined surface 54 is formed by a first inclined surface 54a on the hard blade side and a first inclined surface 54b on the base material side, wherein the first inclined surface 54a on the hard blade side is formed by the hard blade 52; and the first inclined surface 54b on the base material side is formed by the base material 51. The first inclined surface 54a on the hard blade side and the first inclined surface 54b on the base material side are alternately arranged in the rotation direction (RO direction) of the cutter head 2. In addition, the first inclined surface 54a on the hard blade side protrudes in the excavation direction by a predetermined distance compared with the first inclined surface 54b on the base material side (base material 51). As an example, the protrusion amount d of the first inclined surface 54a on the hard blade side from the base material 51 in the excavation direction is preferably about 1.6 mm or more and 2.0 mm or less.

[0085] Furthermore, the plurality of (four) base material side first inclined surfaces 54b are (substantially) located on the same plane. Furthermore, the plurality of base material side first inclined surfaces 54b are (substantially) located on the same plane except for the surfaces located at both ends.

[0086] In addition, as for the thickness of the obstacle cutting bit 3 in the short side direction (radial direction of the cutter head 2), it is preferably 60 mm or more as an example, taking into account the rigidity of the entire obstacle cutting bit 3, deformation when cutting obstacles, and firm fixation to the cutter head 2. Here, as described above, the obstacle cutting bit 3 is formed so that the front end gradually becomes thinner as it moves toward the excavation direction by the first inclined surface 54. As a result, the cutting amount of the obstacle cutting bit 3 can be reduced.

[0087] As a result, the obstacle cutting blade head 3 can make the hard blade 52 more resistant to fracture. Specifically, the obstacle cutting blade head 3 generates heat to remove the obstacle. Therefore, the smaller the range of removal, the less heat is generated. Moreover, the resistance of the hard blade 52 to fracture decreases as the temperature rises. Therefore, by reducing the heat generation and reducing the temperature rise of the hard blade 52, the reduction in the resistance to fracture of the hard blade 52 can be suppressed. As a result, the possibility of damage to the hard blade 52 can be reduced. In addition, by reducing the cutting amount of the obstacle cutting blade head 3, cutting can be performed in an energy-saving manner.

[0088] The second blade 5 (the obstacle cutting blade 3 (the base material 51 and the plurality of hard blades 52 )) has a flat surface 55 provided at the front end in the excavation direction so as to be continuous with (the end in the excavation direction of) the first inclined surface 54 .

[0089] The flat surface 55 extends in a direction substantially perpendicular to the excavation direction.

[0090] The flat surface 55 is formed by a hard blade side flat surface 55a and a base material side flat surface 55b, wherein the hard blade side flat surface 55a is formed by a hard blade 52; and the base material side flat surface 55b is formed by a base material 51. The hard blade side flat surface 55a and the base material side flat surface 55b are alternately arranged in the rotation direction of the cutter head 2. In addition, the hard blade side flat surface 55a protrudes in the excavation direction more than the base material side flat surface 55b by a predetermined distance (thickness). As an example, the hard blade side flat surface 55a protrudes in the excavation direction more than the base material side flat surface 55b by 1.6 mm. In addition, the hard blade side flat surface 55a is an example of a "flat surface" in the claims.

[0091] In addition, multiple (four) hard blade side flat surfaces 55a are (approximately) located (arranged) on the same plane. In addition, multiple (three) parent material side flat surfaces 55b are (approximately) located (arranged) on the same plane. That is, multiple (four) hard blade side flat surfaces 55a and multiple (three) parent material side flat surfaces 55b all extend in a direction (approximately) orthogonal to the excavation direction (X direction). The end surfaces on both sides of the rotation direction of the hard blade side flat surface 55a are exposed. In addition, the hard blade side flat surface 55a is arranged closer to the X1 direction side than the parent material side flat surface 55b. That is, the hard blade side flat surface 55a is discontinuous with the parent material side flat surface 55b.

[0092] The second blade head 5 (obstacle cutting blade head 3) is configured so that all the hard blades 52 are cut by the end surface of the front end side of the hard blade 52 in the advancing direction (rotational direction) of the obstacle cutting blade head 3. By configuring in this way, the tensile stress acting on the hard blade 52 in the advancing direction (rotational direction) of the obstacle cutting blade head 3 can be reduced compared with the case where the cutting is performed by the center or the rear side of the hard blade 52. In addition, in order to prevent the hard blade 52 from being damaged, the two end surfaces of the hard blade 52 in the rotational direction are slightly chamfered.

[0093] The second cutting head 5 (obstacle cutting cutting head 3 ) has a pair of second inclined surfaces 56 provided at both ends of the base material 51 in the rotation direction of the cutter head 2 .

[0094] The pair of second inclined surfaces 56 are inclined from the outer end surface 52a of the hard blade 52 located at the outermost side in the rotation direction of the cutter head 2 toward the opposite direction of the excavation direction as they go from the inner side of the obstacle cutting bit 3 in the rotation direction of the cutter head 2 toward both end sides, i.e., the outer side. The second inclined surfaces 56 are provided over the entire area of ​​the second cutter head 5 in the radial direction (RA direction) of the cutter head 2 (the short side direction of the obstacle cutting bit 3).

[0095] As an example, the inclination angle of the second inclined surface 56 relative to the surface (flat surface 55) perpendicular to the excavation direction is preferably greater than 20 degrees and less than 45 degrees. In addition, the inclination angle of the second inclined surface 56 relative to the surface perpendicular to the excavation direction is more preferably greater than 25 degrees and less than 35 degrees. Moreover, the inclination angle of the second inclined surface 56 relative to the surface perpendicular to the excavation direction is more preferably about 30 degrees.

[0096] The second inclined surface 56 is formed by an outer peripheral portion 56 a and an inner peripheral portion 56 b .

[0097] The outer peripheral side portion 56a is a surface that functions as the first inclined surface 54 (overlaps with the first inclined surface 54). The inner peripheral side portion 56b is arranged on the inner peripheral side of the outer peripheral side portion 56a in the radial direction of the cutter head 2. The inner peripheral side portion 56b (the end portion in the excavation direction) is continuous with the flat surface 55, while the outer peripheral side portion 56a is not continuous with the flat surface 55.

[0098] The second cutting head 5 (obstacle cutting head 3 ) has a recessed portion 57 provided on a surface 53 a on the inner peripheral side in the radial direction of the cutting disc 2 .

[0099] The recessed portion 57 is recessed from the inner peripheral side toward the outer peripheral side in the radial direction of the cutter head 2 and is formed in a concave shape along the rotation direction of the cutter head 2 .

[0100] When viewed from the excavation direction (viewed from the X1 direction side), the recess 57 is formed by connecting a plurality of flat surfaces along the rotation direction of the cutter head 2. The boundary of the plurality of flat surfaces is also the boundary between the hard blade 52 and the base material 51. That is, the recess 57 is not formed in a smooth arc shape.

[0101] As described above, the depression amount D2 (see Figure 4 ) is smaller than the depression amount D3 of the concave portion 67 of the third blade head 6 (refer to Figure 4 ) is larger. In addition, the depression amount D2 of the concave portion 57 of the second blade head 5 is larger than the depression amount D1 of the concave portion 47 of the first blade head 4 (refer to Figure 4 That is, in the rotation direction of the cutter disc 2, the curvature of the (virtual) arc along the inner surface of the recess 57 is smaller than the curvature of the (virtual) arc along the inner surface of the recess 47, and is larger than the curvature of the (virtual) arc along the inner surface of the recess 67.

[0102] In addition, the recessed portion 57 is not provided on the entire area of ​​the surface 53a on the inner circumference side in the radial direction of the cutter disc 2. As for the surface 53a on the inner circumference side in the radial direction of the cutter disc 2, the portions on both end sides in the rotation direction of the cutter disc 2 are formed as flat surfaces that are not recessed in the radial direction of the cutter disc 2. That is, as for the surface 53a on the inner circumference side in the radial direction of the cutter disc 2, the portions on both end sides in the rotation direction of the cutter disc 2 are formed by surfaces that are orthogonal to the radial direction of the cutter disc 2.

[0103] 〈Structure of the third blade〉

[0104] like Figure 4 As shown, the third blade head 6 has a recessed portion 67 and, as described above, has the same shape as the second blade head 5 except that the recessed amount D3 of the recessed portion 67 is different from the recessed amount D2 of the recessed portion 57 of the second blade head 5. Therefore, the following description is briefly given.

[0105] The third bit 6 (obstacle cutting bit 3 ) includes a base material 61 (substrate) and a plurality of (four) hard blades 62 fixed to the base material 61 so as to protrude in the excavation direction (X1 direction) from the base material 61 .

[0106] like Figure 2 As shown, the third cutter head 6 is configured such that, in the rotation direction (RO direction) of the cutter disc 2, the outermost hard blades 62 in the rotation direction of the cutter disc 2 are arranged closer to the inside than the base materials 61 at both ends in the rotation direction of the cutter disc 2. In short, all the hard blades 62 of the third cutter head 6 are clamped from both sides by the base material 61 in the rotation direction of the cutter disc 2.

[0107] The third blade head 6 is disposed on the outer peripheral side of the second blade head 5 in the radial direction of the blade disc 2. A plurality of third blade heads 6 (seven or eight each) are provided on each first spoke portion 20. The plurality of third blade heads 6 are arranged at equal intervals on the center line β1 (β2).

[0108] The plurality of (four) hard inserts 62 (exposed outer surfaces thereof) are arranged across the inner peripheral surface 63a, the excavation direction side surface (flat surface 65), and the outer peripheral surface 63b of the obstacle cutting bit 3.

[0109] The third cutting head 6 (obstacle cutting cutting head 3 ) has a first inclined surface 64 provided on the outer peripheral sides of both the base material 61 and the hard insert 62 in the radial direction of the cutting disc 2 .

[0110] The third bit 6 (the obstacle cutting bit 3 (the base material 61 and the plurality of hard blades 62 )) has a flat surface 65 provided at the front end in the excavation direction so as to be continuous with (the end in the excavation direction of) the first inclined surface 64 .

[0111] The third cutting head 6 (obstacle cutting cutting head 3 ) has a pair of second inclined surfaces 66 provided at both ends of the base material 61 in the rotation direction of the cutting disc 2 .

[0112] 〈Structure of the first blade〉

[0113] like Figure 2 As shown, a plurality (two) of the first blade heads 4 are provided on the front surface of the rotation center portion 21. The two first blade heads 4 are arranged at positions symmetrical to the center line β2 on the center line β1.

[0114] like Figure 7 As shown, the first bit 4 (obstacle cutting bit 3 ) includes a base material 41 (substrate) and a plurality of (two) hard blades 42 fixed to the base material 41 so as to protrude in the excavation direction (X1 direction) from the base material 41 .

[0115] The plurality of (two) hard blades 42 are arranged at intervals in the rotation direction of the cutter head 2. In addition, the plurality of (two) hard blades 42 are not arranged parallel to each other like the plurality of (four) hard blades 42 of the second cutter head 5. That is, when viewed from the excavation direction (viewed from the X1 direction side), the plurality of (two) hard blades 42 are arranged so as to be separated from each other as they go toward the outer peripheral side in the radial direction of the cutter head 2 (arranged in an eight-shaped shape).

[0116] Here, when the plurality (two) hard blades 42 of the first cutter head 4 are arranged in parallel with each other, the angle of the corner of the inner circumference of the hard blade 42 becomes blunt when the plurality (two) hard blades 42 are arranged in the above-mentioned figure eight shape as viewed from the excavation direction (viewed from the X1 direction side). That is, the hard blade 42 is not easily damaged. In addition, the second cutter head 5 and the third cutter head 6 may also arrange the hard blade 42 in the figure eight shape like the first cutter head 4.

[0117] As an example, the length of the first blade head 4 in the longitudinal direction (the length of the blade head 2 along the rotation direction) is about two-thirds of the length of the second blade head 5 in the longitudinal direction (see Figure 4 ).

[0118] The first cutter head 4 (each of the plurality of cutter heads 3 for obstacle cutting) is configured such that, in the rotation direction of the cutter disc 2, the outermost hard blades 42 in the rotation direction of the cutter disc 2 are arranged closer to the inside than the base materials 41 at both ends in the rotation direction of the cutter disc 2. In short, all the hard blades 42 of the first cutter head 4 are clamped and supported by the base materials 41 from both sides in the rotation direction of the cutter disc 2.

[0119] The plurality of (two) hard inserts 42 (exposed outer surfaces thereof) are arranged across the inner peripheral surface 43a, the excavation direction side surface (flat surface 45), and the outer peripheral surface 43b of the obstacle cutting bit 3.

[0120] The first cutting head 4 (obstacle cutting cutting head 3 ) has a first inclined surface 44 provided on the outer peripheral sides of both the base material 41 and the hard insert 42 in the radial direction (RA direction) of the cutting head 2 .

[0121] The first blade 4 (the obstacle cutting blade 3 (the base material 41 and the plurality of hard blades 42 )) has a flat surface 45 provided at the front end in the excavation direction so as to be continuous with (the end in the excavation direction of) the first inclined surface 44 .

[0122] The first cutting head 4 (obstacle cutting cutting head 3 ) has a pair of second inclined surfaces 46 provided at both ends of the base material 41 in the rotation direction of the cutting disc 2 .

[0123] The first cutting head 4 has a recessed portion 47 provided on a surface 43 a on the inner peripheral side in the radial direction of the cutting disc 2 .

[0124] (Arrangement of the obstacle cutting head in the radial direction of the cutter head)

[0125] Reference Figure 8 , cutter head 2 (refer to Figure 2 ) in the radial direction (RA direction) of the obstacle cutting tool head 3 will be described.

[0126] When viewed from the excavation direction (viewed from the X1 direction side), the plurality of obstacle cutting bits 3 are configured to be able to cut the obstacle O (see Figure 2 ) is cut in its entirety (approximately) as a whole, with the portion overlapping the cutter disc 2.

[0127] That is, the plurality of obstacle cutting bits 3 are continuously arranged without gaps in the radial direction of the cutter disc 2. Specifically, the plurality of obstacle cutting bits 3 on the center line β1 and the plurality of obstacle cutting bits 3 on the center line β2 are alternately arranged without gaps in the radial direction of the cutter disc 2. In addition, the plurality of obstacle cutting bits 3 on the center line β1 and the plurality of obstacle cutting bits 3 on the center line β2 may overlap each other in the radial direction of the cutter disc 2.

[0128] In summary, the shield tunneling machine 100 (refer to Figure 2 ) is configured so that when the cutter head 2 is rotated, the surfaces of the inner circumference side (outer circumference side) of the plurality of obstacle cutting bits 3 on the center line β1 and the surfaces of the outer circumference side (inner circumference side) of the plurality of obstacle cutting bits 3 on the center line β2 pass through a substantially overlapping position. In other words, the plurality of obstacle cutting bits 3 are arranged so that when the cutter head 2 is rotated, no uncut portion is generated between the cut portions, and no step difference is generated on the cutting surface of the obstacle O, so that the entire cutting surface of the obstacle O can be cut uniformly.

[0129] (Effects of Embodiments)

[0130] In this embodiment, the following effects can be obtained.

[0131] In the present embodiment, as described above, the hard blade 42 (52, 62) located at the outermost side in the rotation direction of the cutter disc 2 is arranged closer to the inner side than the base material 41 (51, 61) located at both ends in the rotation direction (RO direction) of the cutter disc 2, so that the hard blade 42 (52, 62) is not arranged at both ends of the obstacle cutting cutter head 3 in the rotation direction of the cutter disc 2, and the two ends can be formed by the base material 41 (51, 61) that is softer than the hard blade 42 (52, 62) (high toughness and not easy to be damaged). Therefore, the hard blade 42 (52, 62) located at the outermost side in the rotation direction of the cutter disc 2 can be firmly clamped by the base material 41 (51, 61) from both sides in the rotation direction, and the exposure of the hard blade 42 (52, 62) can be suppressed, and the obstacle O can be prevented from contacting the entire hard blade 42 (52, 62). As a result, the damage of the hard blade 42 (52, 62) can be suppressed. In addition, in the case where hard blades are arranged at both ends of the rotation direction of the cutter disc as in the prior art, when the hard blade arranged at the rear end of the rotation direction of the cutter disc (hereinafter referred to as the hard blade at the rear end) contacts an obstacle, a large force is applied to the hard blade at the rear end toward the rear of the rotation direction of the cutter disc. Here, since the hard blade at the rear end is in a state of being supported mainly only by the tensile force of the base material located in front of the rotation direction of the cutter disc, the hard blade at the rear end is easily peeled off from the base material toward the rear of the rotation direction of the cutter disc. On the other hand, as in the present embodiment, the hard blade 42 (52, 62) located at the outermost side of the rotation direction of the cutter disc 2 is firmly clamped by the base material 41 (51, 61) from both sides of the rotation direction, thereby effectively preventing the hard blade 42 (52, 62) at the rear end from being damaged or the hard blade 42 (52, 62) from being peeled off from the base material 41 (51, 61).

[0132] In the present embodiment, as described above, the obstacle cutting bit 3 has the first inclined surface 44 (54, 64) provided on the outer peripheral side of both the base material 41 (51, 61) and the hard blade 42 (52, 62) in the radial direction (RA direction) of the cutter head 2, and the first inclined surface 44 (54, 64) is inclined from the front end in the excavation direction to the opposite direction of the excavation direction as it moves from the inner peripheral side in the radial direction of the cutter head 2 toward the outer peripheral side. As a result, the front end in the excavation direction can be made thinner compared to the case where the first inclined surface 44 (54, 64) is not provided at the front end of the obstacle cutting bit 3 (the case where the front end is made rectangular). As a result, the heat generation near the front end in the excavation direction during cutting can be suppressed, so the problem that the obstacle cutting bit 3 (hard blade 42 (52, 62)) is easily broken can be suppressed. In addition, the first inclined surface 44 (54, 64) is inclined from the front end in the excavation direction to the opposite direction of the excavation direction as it moves from the inner peripheral side to the outer peripheral side in the radial direction, so that the chips can flow along the first inclined surface 44 (54, 64), thereby effectively taking the chips into the chamber.

[0133] In the present embodiment, as described above, the plurality of hard blades 42 (52, 62) have a flat surface 45 (55, 65) which is provided at the front end in the excavation direction in a manner continuous with the first inclined surface 44 (54, 64) and is substantially orthogonal to the excavation direction. Thus, compared with the case where the obstacle O is cut by the front end having a surface inclined with respect to the excavation direction, the contact area of ​​the hard blade 42 (52, 62) with respect to the obstacle O can be made larger by the flat surface 45 (55, 65), thereby suppressing the problem of stress concentration on the hard blade 42 (52, 62). Therefore, the damage of the hard blade 42 (52, 62) can be further suppressed.

[0134] In the present embodiment, as described above, the hard blade side flat surfaces 55a of the plurality of hard blades 52 (42, 62) are arranged on substantially the same plane. With such a configuration, the hard blade side flat surfaces 55a of the plurality of hard blades 52 (42, 62) can be arranged at substantially the same position in the excavation direction, so when cutting the obstacle O, the plurality of hard blades 52 (42, 62) can be brought into contact with the obstacle O at the same time. Therefore, the obstacle O can be effectively cut.

[0135] In the present embodiment, as described above, the obstacle cutting bit 3 has a pair of second inclined surfaces 46 (56, 66) provided at both ends of the base material 41 (51, 61) in the rotation direction of the cutter head 2, and the pair of second inclined surfaces 46 (56, 66) are inclined from the outer end surface (52a) of the hard blade 42 (52, 62) located at the outermost side in the rotation direction of the cutter head 2 toward the outer side from the inner side of the obstacle cutting bit 3 in the rotation direction of the cutter head 2. In this way, the problem of the obstacle O contacting the base material 41 (51, 61) can be suppressed by using the pair of second inclined surfaces 46 (56, 66) provided at both ends of the base material 41 (51, 61) in the rotation direction of the cutter head 2. As a result, the wear of the base material 41 (51, 61) can be suppressed. In addition, the contact between the base material 41 ( 51 , 61 ) that does not contribute to cutting and the obstacle O can be reduced, and the reduction in the cutting performance of the obstacle cutting bit 3 can be suppressed.

[0136] In the present embodiment, as described above, the obstacle cutting bit 3 has the recessed portion 47 (57, 67) provided on the surface 43a (53a, 63a) on the inner peripheral side in the radial direction of the cutter disc 2, and the recessed portion 47 (57, 67) is formed to be recessed from the inner peripheral side in the radial direction of the cutter disc 2 toward the outer peripheral side, and is formed to be concave in the direction of rotation of the cutter disc 2. Thus, when the obstacle cutting bit 3 passes through the space generated by cutting, the recessed portion 47 (57, 67) having a shape along the direction of rotation of the cutter disc 2 can be used to suppress the obstacle O from contacting the surface 43a (53a, 63a) on the inner peripheral side in the radial direction of the cutter disc 2 of the obstacle cutting bit 3. That is, the recessed portion 47 (57, 67) can be used to allow the obstacle cutting bit 3 to avoid the obstacle O. As a result, it is possible to suppress the force from the inner peripheral side to the outer peripheral side from acting on the obstacle cutting bit 3, so that the damage of the hard insert 42 (52, 62) can be further suppressed.

[0137] In the present embodiment, as described above, the obstacle cutting bit 3 is provided with a plurality of types in such a manner that the recessed amount of the recessed portions 47, 57, and 67 decreases in stages from the inner peripheral side toward the outer peripheral side in the radial direction of the cutter head 2. Thus, the recessed amount of the recessed portions 47, 57, and 67 can be set to an appropriate value corresponding to the position in the radial direction of the cutter head 2, so that the obstacle O can be effectively prevented from contacting the inner peripheral side surfaces 43a, 53a, and 63a. As a result, the damage of the hard blades 42, 52, and 62 can be further prevented.

[0138] In the present embodiment, as described above, the obstacle cutting bit 3 is provided with a plurality of types in such a manner that the number of hard blades 42, 52, and 62 included in one obstacle cutting bit 3 increases in stages from the inner peripheral side to the outer peripheral side in the radial direction of the cutter disc 2. As a result, more hard blades 42, 52, and 62 can be provided for the obstacle cutting bit 3 on the outer peripheral side in the radial direction of the cutter disc 2, where the circumferential speed of the obstacle cutting bit 3 is particularly fast (the amount of movement per unit time of the obstacle cutting bit 3 is particularly large). As a result, the obstacle O can be effectively cut even on the outer peripheral side in the radial direction of the cutter disc 2. In addition, the closer the position is to the outer peripheral side in the radial direction of the cutter disc 2, the faster the circumferential speed of the obstacle cutting bit 3 is, and the more heat is generated by friction with the obstacle O, so that the temperature of the obstacle cutting bit 3 rises. Therefore, the fracture resistance of the hard blade 42 (52, 62) is significantly lower than that of the inner peripheral side. Therefore, by arranging more hard inserts 42 (52, 62) on the outer peripheral side in the radial direction of the cutter head 2 as described above, redundancy can be improved.

[0139] [Modifications]

[0140] In addition, it should be understood that the embodiments and modifications disclosed this time are only illustrative and non-limiting in all aspects. The scope of the present invention is indicated by the claims rather than the description of the embodiments above, and includes all changes (modifications) within the meaning and scope equivalent to the claims.

[0141] For example, in the above-mentioned embodiment, the present invention is applied to an example of a mud pressure shield tunneling machine, but the present invention is not limited thereto. The present invention can also be applied to a slurry shield tunneling machine. In the case of a slurry shield tunneling machine, mud water is fed into the chamber to slurry the excavated soil, and the slurry excavated soil is discharged from the soil discharge device.

[0142] In addition, in the above embodiment, an example is shown in which three types of obstacle cutting blades (first blade, second blade, and third blade) are provided on the blade disc, but the present invention is not limited thereto. In the present invention, one, two, or four or more types of obstacle cutting blades may also be provided on the blade disc.

[0143] In addition, in the above-mentioned embodiment, an example is shown in which the obstacle cutting blade is provided on the spoke of the blade disc, but the present invention is not limited thereto. In the present invention, the obstacle cutting blade may also be provided on the face plate of the blade disc or the like.

[0144] In addition, in the above-mentioned embodiment, only an example in which a plurality of obstacle cutting bits are arranged on the cutter head is shown, and the present invention is not limited to this.

[0145] In the above embodiment, an example is shown in which the inclined surface (first inclined surface) is provided on the radial outer peripheral side of the cutter head, but the present invention is not limited thereto. The present invention may also provide an inclined surface on the radial inner peripheral side of the cutter head.

[0146] In the above embodiment, the example in which the front surface of the cutter head is formed into a flat shape is shown, but the present invention is not limited thereto. In the present invention, the center portion of the cutter head may be formed into a cone shape protruding forward (in the excavation direction).

[0147] In addition, in the above-mentioned embodiment, an example is shown in which two or four hard blades are provided for one obstacle cutting blade head, but the present invention is not limited thereto. In the present invention, three or more hard blades may be provided for one obstacle cutting blade head.

[0148] In addition, in the above-mentioned embodiment, an example of arranging the plurality of hard blades of the second blade head (third blade head) in parallel is shown, but the present invention is not limited to this. In the present invention, the plurality of hard blades of the second blade head (third blade head) may also be arranged non-parallel. For example, the plurality of hard blades of the second blade head (third blade head) may also be arranged in a manner (in an eight-shaped shape) that separates from each other as they move from the inner peripheral side of the blade disc toward the outer peripheral side, as in the first blade head.

[0149] In addition, in the above-mentioned embodiment, an example is shown in which the front ends (flat surfaces) of the respective hard blades included in one obstacle cutting bit are located on the same plane, but the present invention is not limited thereto. In the present invention, the front ends (flat surfaces) of the respective hard blades included in one obstacle cutting bit may also be arranged at positions staggered in the excavation direction.

[0150] In addition, in the above-mentioned embodiment, an example is shown in which a plurality of flat surfaces are connected to form the concave portion of the obstacle cutting bit in a manner along the rotation direction of the cutter head when viewed from the excavation direction side, but the present invention is not limited thereto. In the present invention, the concave portion of the obstacle cutting bit may also be formed in an arc shape in a manner along the rotation direction of the cutter head when viewed from the excavation direction side.

[0151] In addition, in the above-mentioned embodiment, an example is shown in which a plurality of obstacle cutting bits are arranged at equal intervals in the radial direction of the cutter disc, but the present invention is not limited thereto. In the present invention, a plurality of obstacle cutting bits may also be arranged in the radial direction of the cutter disc in a manner that gradually increases or decreases the intervals toward the outer peripheral side.

[0152] In addition, in the above-mentioned embodiment, an example of forming a hard blade from a superhard alloy is shown, but the present invention is not limited to this. In the present invention, a hard blade can also be formed from a material harder than a base material such as tool steel. In addition, superhard alloy is a brittle material, while tool steel is more ductile than superhard alloy and is not a brittle material.

[0153] In addition, in the above-mentioned embodiment, an example is shown in which the concave portion is provided in the entire area of ​​the obstacle cutting bit in the excavation direction (X direction), but the present invention is not limited thereto. In the present invention, the concave portion may be provided only in the area where the hard blade exists in the obstacle cutting bit in the excavation direction (X direction).

[0154] In addition, in the above-mentioned embodiment, an example is shown in which the exposed outer surfaces of the hard blade and the base material are arranged continuously without step difference on the surface of the inner peripheral side of the obstacle cutting bit, but the present invention is not limited to this. In the present invention, it is also possible to Fig. 9 As in the obstacle cutting bit 203 of the modified example shown in FIG. 1 , the exposed outer surfaces of the hard blade 52 and the base material 251 are arranged on the inner peripheral surface 253a of the obstacle cutting bit 203 so as to generate a step ST. For example, the inner peripheral surface 253a of the base material 251 clamped by the hard blade 52 may be formed so as to extend in a direction substantially orthogonal to the radial direction of the cutter head, and a small step ST may be provided between the hard blade 52 and the base material 251. By forming the base material 251 in this way, the obstacle cutting bit 203 can be easily manufactured.

Claims

1. A shield tunneling machine, comprising: A plurality of obstacle cutting bits, which include a base material and a plurality of hard blades fixed to the base material in a state of protruding further in the excavation direction than the base material and harder than the base material, and cut underground obstacles; a cutter head provided with the obstacle cutting cutter head and rotating along with the excavation; and The shield tunneling machine body is provided with the cutter head at the front end in the tunneling direction. The plurality of obstacle cutting tool heads are configured such that the plurality of hard blades are arranged at intervals in the rotation direction of the cutter disc, and the hard blades located at the outermost sides in the rotation direction of the cutter disc are arranged closer to the inside than the base materials located at both ends in the rotation direction of the cutter disc. The obstacle cutting bit has a first inclined surface provided on the outer peripheral sides of both the base material and the hard blade in the radial direction of the cutter head. The first inclined surface is inclined from the front end in the excavation direction toward the opposite direction to the excavation direction as it moves from the inner peripheral side toward the outer peripheral side in the radial direction of the cutter head.

2. The shield tunneling machine according to claim 1, characterized in that: The plurality of hard blades have a flat surface which is provided at a front end in the excavation direction so as to be continuous with the first inclined surface and is perpendicular to the excavation direction.

3. The shield tunneling machine according to claim 2, characterized in that: The flat surfaces of the plurality of hard blades are arranged on the same plane.

4. The shield tunneling machine according to any one of claims 1 to 3, characterized in that: The obstacle cutting bit has a pair of second inclined surfaces provided at both ends of the base material in the rotation direction of the cutter head. The pair of second inclined surfaces are inclined from the outer end surface of the hard blade located at the outermost side in the rotation direction of the cutter disc toward the opposite direction of the excavation direction as they move from the inner side of the obstacle cutting bit in the rotation direction of the cutter disc toward both end sides, i.e., the outer side.

5. The shield tunneling machine according to any one of claims 1 to 3, characterized in that: The obstacle cutting bit has a recessed portion provided on the inner peripheral surface of the cutter head in the radial direction. The recessed portion is recessed from the inner peripheral side toward the outer peripheral side in the radial direction of the cutter disc and is formed in a concave shape along the rotation direction of the cutter disc.

6. The shield tunneling machine according to claim 5, characterized in that: The obstacle cutting blade head is provided in a plurality of types so that the recessed amount of the recessed portion decreases in stages from the inner peripheral side toward the outer peripheral side in the radial direction of the blade.

7. The shield tunneling machine according to any one of claims 1 to 3, characterized in that: The obstacle cutting bit is provided in a plurality of types such that the number of the hard blades included in one obstacle cutting bit increases in stages from the inner peripheral side toward the outer peripheral side in the radial direction of the cutter head.

8. A shield tunneling machine comprising: A plurality of obstacle cutting bits, which include a base material and a plurality of hard blades fixed to the base material in a state of protruding further in the excavation direction than the base material and harder than the base material, and cut underground obstacles; a cutter head provided with the obstacle cutting cutter head and rotating along with the excavation; and The shield tunneling machine body is provided with the cutter head at the front end in the tunneling direction. The plurality of obstacle cutting tool heads are configured such that the plurality of hard blades are arranged at intervals in the rotation direction of the cutter disc, and the hard blades located at the outermost sides in the rotation direction of the cutter disc are arranged closer to the inside than the base materials located at both ends in the rotation direction of the cutter disc. The obstacle cutting bit has a recessed portion provided on the inner peripheral surface of the cutter head in the radial direction. The recessed portion is formed to be recessed from the inner peripheral side toward the outer peripheral side in the radial direction of the cutter disc and is formed in a concave shape along the rotation direction of the cutter disc. The obstacle cutting blade head is provided in a plurality of types so that the recessed amount of the recessed portion decreases in stages from the inner peripheral side toward the outer peripheral side in the radial direction of the blade.

9. A tool head for cutting obstacles, comprising: A base material is provided on a cutter head that rotates as excavation progresses; and A plurality of hard blades are fixed to the base material in a state of protruding further in the excavation direction than the base material and are harder than the base material. The obstacle cutting tool head is configured such that the plurality of hard blades are arranged at intervals in the rotation direction of the cutter disc, and the hard blades located at the outermost sides in the rotation direction of the cutter disc are arranged closer to the inside than the base materials located at both ends in the rotation direction of the cutter disc. The obstacle cutting bit has a first inclined surface provided on the outer peripheral sides of both the base material and the hard blade in the radial direction of the cutter head. The first inclined surface is inclined from the front end in the excavation direction toward the opposite direction to the excavation direction as it moves from the inner peripheral side toward the outer peripheral side in the radial direction of the cutter head.

Images