JP7303067B2 - Bits for shield machines and obstacle cutting - Google Patents

Description

The present invention relates to a shield machine and an obstacle-cutting bit, and more particularly to a shield machine and an obstacle-cutting bit capable of cutting an underground obstacle.

2. Description of the Related Art Conventionally, a shield machine capable of cutting underground obstacles is known (see Patent Literature 1, for example).

The aforementioned Patent Document 1 discloses a shield machine equipped with an obstacle-cutting bit including a base material and a plurality of carbide tips fixed to the base material. A plurality of carbide tips are spaced apart in the direction of rotation of the cutter head. The obstacle-cutting bit has cemented carbide tips at both ends in the rotating direction of the cutter head for the purpose of facilitating contact with the obstacle.

Japanese Patent No. 6487277

However, in the shield machine described in Patent Document 1, since the carbide tips are arranged at both ends in the rotation direction of the cutter head, obstacles tend to come into contact with the entirety of the carbide tips at both ends. There is a problem that the cemented carbide tips at both ends are easily damaged.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and one object of the present invention is to provide a shield machine and a bit for cutting an obstacle that can suppress chipping of hard tips. It is to be.

In order to achieve the above object, the shield machine of the present invention includes a base material, and a plurality of hard chips that are fixed to the base material in a state of protruding from the base material in the excavation direction and are harder than the base material. Includes a plurality of obstacle cutting bits for cutting underground obstacles, a cutter head that rotates with excavation, and a shield with a cutter head installed at the tip of the excavation direction Each of the plurality of obstacle-cutting bits has a plurality of hard tips spaced apart in the rotation direction of the cutter head. The hard tip located on the outermost side of the cutter head is arranged inside the base material located on both ends in the rotation direction of the cutter head , and the obstacle cutting bit is arranged between the base material and the base material in the radial direction of the cutter head. The first inclined surfaces are provided on both outer peripheral sides of the hard tip. is slanted in the opposite direction .

In the shield machine of the present invention, as described above, the hard tip located on the outermost side in the rotating direction of the cutter head is arranged inside the base material located on both ends in the rotating direction of the cutter head, thereby Without arranging hard tips on both ends of the obstacle-cutting bit in the rotational direction of the head, both ends can be formed of a base material that is softer (higher toughness and less likely to chip) than the hard tips. Therefore, the outermost hard tip in the rotating direction of the cutter head can be firmly sandwiched between the base material from both sides in the rotating direction, and the exposure of the hard tip is suppressed so that the entire hard tip does not come into contact with an obstacle. can be prevented. As a result, chipping of the hard tip can be suppressed. When hard tips are arranged at both ends of the cutter head in the rotation direction as in the conventional art, the hard tips arranged at the rear end in the rotation direction of the cutter head (hereinafter referred to as the hard tip at the rear end) become obstacles. At the time of contact, a large force acts rearward in the rotating direction of the cutter head on the hard tip at the trailing end. Here, since the hard tip at the rear end is mainly supported only by the tensile force of the base material positioned forward in the rotational direction of the cutter head, the hard tip at the rear end is positioned rearward in the rotational direction of the cutter head. Easy to peel off from material. On the other hand, as in the present invention, the outermost hard tip in the rotating direction of the cutter head is firmly sandwiched between the base material from both sides in the rotating direction. can be effectively prevented from peeling off from the base material. In addition, compared to the case where the tip of the obstacle-cutting bit is not provided with the first inclined surface (the tip is rectangular), the tip in the digging direction can be tapered. As a result, the amount of heat generated in the vicinity of the tip in the excavation direction during cutting can be suppressed, so that the obstacle-cutting bit (hard tip) can be suppressed from being easily broken. In addition, by inclining the first inclined surface in the direction opposite to the excavation direction from the tip of the excavation direction as it goes from the inner peripheral side to the outer peripheral side in the radial direction, chips are flowed along the first inclined surface. so that chips can be effectively entrained in the chamber.

In this case, preferably, the plurality of hard tips are provided at the tip in the excavation direction so as to be continuous with the first inclined surface, and have a flat surface substantially orthogonal to the excavation direction. With this configuration, compared to the case where the tip having a surface inclined with respect to the excavation direction cuts the obstacle, the flat surface makes the contact area of the hard tip with respect to the obstacle relatively large, Concentration of stress on the hard tip can be suppressed. Therefore, it is possible to further suppress breakage of the hard tip.

In the configuration in which the hard chips have flat surfaces, preferably, the flat surfaces of the plurality of hard chips are arranged substantially on the same plane. With this configuration, the flat surfaces of the plurality of hard tips can be arranged at approximately the same position in the excavation direction, so that the plurality of hard tips can be brought into contact with the obstacle at the same time when cutting the obstacle. can. Therefore, the obstacle can be cut effectively.

In the above shield machine, preferably, the obstacle-cutting bit has a pair of second inclined surfaces provided at both ends of the base material in the rotating direction of the cutter head, and the pair of second inclined surfaces From the inner side of the bit for cutting obstacles toward the outer side, which is both end sides, in the rotational direction of the cutter head, the outer end face of the hard tip located on the outermost side in the rotational direction of the cutter head is inclined in the direction opposite to the digging direction. . According to this configuration, the pair of second inclined surfaces provided at both ends of the base material in the rotation direction of the cutter head can prevent obstacles from coming into contact with the base material. As a result, wear of the base material can be suppressed. In addition, it is possible to reduce the contact between the base material that does not contribute to cutting and the obstacle, thereby suppressing the deterioration of the drilling performance of the obstacle-cutting bit.

In the above-described shield machine, preferably, the obstacle-cutting bit has a recess provided on a radially inner peripheral surface of the cutter head, and the recess extends from the radially inner peripheral side to the outer peripheral side of the cutter head. It is recessed toward the side and is formed in a concave shape along the rotating direction of the cutter head. With this configuration, when the obstacle-cutting bit passes through the space created by cutting, the concave portion shaped along the rotation direction of the cutter head causes the obstacle-cutting bit to move radially inward of the cutter head. It is possible to prevent obstacles from coming into contact with the circumferential surface. That is, the recess allows the obstacle-cutting bit to escape from the obstacle. As a result, it is possible to suppress the force directed from the inner peripheral side to the outer peripheral side from acting on the obstacle-cutting bit, so it is possible to further suppress breakage of the hard tip.

In this case, preferably, a plurality of types of obstacle-cutting bits are provided so that the amount of depression of the concave portion gradually decreases from the radially inner side to the outer side of the cutter head. With this configuration, the depth of the concave portion can be set to an appropriate value according to the radial position of the cutter head, thereby effectively suppressing the contact of the obstacle with the inner peripheral surface. can do. As a result, chipping of the hard tip can be further suppressed.

In the shield machine, preferably, the number of hard chips included in one obstacle-cutting bit increases stepwise from the radially inner side to the outer side of the cutter head. A plurality of types are provided as follows. With this configuration, the peripheral speed of the obstacle-cutting bit becomes particularly high (the amount of movement of the obstacle-cutting bit per unit time becomes particularly large). More hard tips can be provided for the bit. As a result, the obstacle can be effectively cut even on the outer peripheral side in the radial direction of the cutter head. As the peripheral speed of the obstacle-cutting bit increases toward the outer circumference of the cutter head in the radial direction, more heat is generated due to friction with the obstacle, and the temperature of the obstacle-cutting bit rises. . For this reason, the decrease in transverse rupture strength of the hard tip is greater than that on the inner peripheral side. Therefore, as described above, redundancy can be enhanced by arranging more hard tips on the radially outer peripheral side of the cutter head.

The obstacle-cutting bit of the present invention is fixed to a base material that is installed on a cutter head that rotates along with excavation, and is fixed to the base material in a state of protruding in the excavation direction beyond the base material, and is harder than the base material. a plurality of hard tips, the plurality of hard tips being spaced apart in the rotation direction of the cutter head, and the outermost hard tip positioned in the rotation direction of the cutter head in the rotation direction of the cutter head, Further comprising an inclined surface configured to be arranged inside the base material positioned at both ends in the rotation direction of the cutter head, and provided on the outer peripheral side of both the base material and the hard tip in the radial direction of the cutter head, The inclined surface is inclined in the direction opposite to the excavation direction from the tip in the excavation direction as it goes from the inner peripheral side to the outer peripheral side in the radial direction of the cutter head.

In the obstacle-cutting bit of the present invention, by being configured as described above, it is possible to suppress breakage of the hard tip, as in the case of the shield machine. In addition, compared to the case where the tip of the obstacle-cutting bit does not have an inclined surface (the tip has a rectangular shape), the tip in the digging direction can be tapered. As a result, the amount of heat generated in the vicinity of the tip in the excavation direction during cutting can be suppressed, so that the obstacle-cutting bit (hard tip) can be suppressed from being easily broken. In addition, by inclining the inclined surface in the direction opposite to the excavation direction from the tip of the excavation direction toward the outer peripheral side in the radial direction, chips can flow along the inclined surface. Chips can be effectively entrained in the chamber.

According to the present invention, as described above, chipping of the hard tip can be suppressed.

1 is a schematic longitudinal sectional view of a shield machine according to an embodiment; FIG. 1 is a schematic front view of a shield machine according to an embodiment as seen from the direction of excavation (front side); FIG. Figure 500 is a cross-sectional view along line 500-500 of Figure 2; FIG. 10 is a diagram for comparing recessed amounts of recesses of three types of obstacle-excavating bits according to the embodiment; FIG. 4 is a perspective view of a second bit (obstacle-excavating bit) according to the embodiment; FIG. 4 is a trihedral view showing a second bit (obstacle-excavating bit) according to the embodiment from three directions; FIG. 3 is a trihedral view showing the first bit (obstacle-excavating bit) according to the embodiment from three directions; FIG. 4 is a schematic diagram for explaining the arrangement of obstacle-excavating bits in the radial direction of the cutter head according to the embodiment; It is the figure which looked at the bit for excavating an obstacle by a modification from the excavation direction side (front side).

Hereinafter, embodiments will be described based on the drawings.

[Embodiment]
A shield machine 100 according to an embodiment will be described with reference to FIGS. 1 to 8. FIG.

(Overall Configuration of Shield Machine)
As shown in FIG. 1, the shield machine 100 includes a shield machine main body 1, a cutter head 2 installed at the tip of the shield machine main body 1 in the excavation direction, and a plurality of obstacles installed on the cutter head 2. A cutting bit 3 and a plurality of earth and sand excavation bits S are provided.

Here, in each figure, the X1 direction indicates the excavation direction of the shield machine 100, and the X2 direction indicates the opposite direction. Also, the vertical direction is indicated by the Z direction, and the horizontal direction (width direction) perpendicular to the X and Z directions is indicated by the Y direction.

Furthermore, the direction of rotation of the cutter head 2 is indicated by RO, and the radial direction of the cutter head 2 is indicated by RA. Further, of the radial directions of the cutter head 2, the direction from the inner peripheral side to the outer peripheral side is indicated by RA1, and the opposite direction is indicated by RA2.

The cutter head 2 is configured to rotate about a central axis α extending in the direction of excavation as the excavation progresses. It should be noted that the rotation of the cutter head 2 can be switched between normal rotation and reverse rotation according to the excavation situation and the like. The shield excavator 100 has a function of cutting and removing an obstacle O present on the tunneling path by means of the obstacle cutting bit 3 .

Obstacles O are H-shaped steel piles, reinforced concrete, and the like in the ground. The shield machine 100 is equipped with a dedicated obstacle-cutting bit 3 for cutting the obstacle O. As shown in FIG. If the obstacle O is in the soft ground, the obstacle O may escape (move) when the obstacle cutting bit 3 comes into contact with the obstacle O when cutting the obstacle. It may not be done properly. Therefore, in the case of soft ground, ground improvement work is carried out in advance to harden the ground by injecting a chemical solution into the ground before cutting an obstacle.

In this embodiment, an example in which the shield machine 100 is a mud pressure type shield machine is shown. In the mud pressure type shield excavator 100, the mud excavated by the cutter head 2 is mixed with the mud excavated by the cutter head 2 in the chamber 11, and the excavated earth and sand are converted into mud having water impermeability and plastic fluidity. be. The excavated soil (mud) fills the chamber 11 and the earth removing device 13 . The shield machine 100 maintains a state in which the chamber 11 and the earth removing device 13 are filled with excavated earth and sand (mud), and generates pressure in the chamber 11 by the thrust of the shield jack 12, so that the ground is removed. To counter the pressure (face earth pressure and ground water pressure). The shield excavator 100 excavates while balancing the pressure by balancing the amount of excavation and the amount of excavated soil.

(Construction of main body of shield machine)
As shown in FIG. 1, the shield machine main body 1 includes a body 10, a chamber 11, a shield jack 12, and an earth removing device 13. As shown in FIG.

The body 10 is composed of a cylindrical front body 10a and a rear body 10b. The front body portion 10a is a portion in which the cutter head 2 is installed at the tip in the excavation direction, and propulsive force is imparted by the shield jack 12 so that the cutter head 2 excavates the natural ground. The rear section 10b advances while arranging the segments SG on the wall surface by an erector (not shown) in order to form the peripheral wall of the tunnel as the front section 10a excavates (advances in the X1 direction). The internal space of the body 10 is partitioned by a partition wall 14 into two spaces, a chamber 11 on the excavation direction side (X1 direction side) and a work space WS on the opposite side to the excavation direction (X2 direction side).

The chamber 11 is provided on the rear surface side (X2 direction side) of the cutter head 2 . The chamber 11 is a space (mud chamber) surrounded by the cutter head 2, the front body 10a and the partition wall 14. As shown in FIG. The mud pressure in the chamber 11 is maintained in approximately equilibrium with the pressure acting on the cutter head 2 from the ground side.

The shield jack 12 is configured to push the segment SG backward (X2 direction) to propel the body 10 (shield machine 100). A plurality of shield jacks 12 are attached to the rear body portion 10 b so as to be arranged along the circumferential direction of the body 10 .

The earth removing device 13 is composed of a screw conveyor. The earth unloading device 13 includes a cylindrical casing 13a arranged at an angle inside the body 10, and a screw 13b arranged inside the casing 13a.

One end opening of the casing 13 a is connected to the lower side of the chamber 11 . The screw 13b is configured to rotate to impart a conveying force to the excavated earth and sand taken from the chamber 11 toward the other end opening of the casing 13a. The other end opening of the casing 13a is configured to discharge earth and sand. On the downstream side of the earth removing device 13, an earth and sand conveying device B (for example, a belt conveyor) is provided for conveying the earth and sand discharged from the earth removing device 13 (casing 13a) toward the outside of the pit. The earth removing device 13 has not only the function of discharging the earth and sand inside the chamber 11 but also the function of discharging the earth and sand inside the chamber 11 to adjust the pressure inside the chamber 11 .

(Configuration of cutter head)
As shown in FIG. 2, the cutter head 2 is formed in a circular shape when viewed from the excavation direction. The cutter head 2 is provided with a plurality of obstacle cutting bits 3 and a plurality of earth and sand excavation bits S. Specifically, for example, the cutter head 2 has an obstacle-cutting bit 3 and an earth-and-sand excavating bit S fixed to its front surface (X1-direction side surface) by welding. The cutter head 2 is configured to excavate the natural ground with the earth and sand excavation bit S by rotating around the central axis α. The obstacle-cutting bit 3 and the earth-and-sand excavating bit S may be fixed to the cutter head 2 by bolting instead of welding.

The cutter head 2 has a state in which an obstacle O is cut by the obstacle-cutting bit 3 (obstacle-cutting state) (see FIG. 3) by moving the obstacle-cutting bit 3 back and forth in the X direction (see FIG. 3); A switching mechanism (not shown) is provided for switching between two states (earth and sand excavation state), ie, a state in which the earth and sand excavation bit S is used to excavate the earth and sand. The switching mechanism is an actuator such as a jack that moves the obstacle-cutting bit 3 back and forth (in the X direction).

Specifically, the switching mechanism is arranged so that the tip of the obstacle-cutting bit 3 is arranged on the side opposite to the excavation direction (X2 direction side) from the tip of the earth-and-sand excavating bit S in the normal state (earth and sand excavation state). is configured to That is, the switching mechanism normally prevents (suppresses) wear of the obstacle-cutting bit 3 by arranging (retracting) the obstacle-cutting bit 3 at a position retreated from the earth and sand excavation bit S. ).

Further, the switching mechanism is configured to switch from the earth and sand excavation state to the obstacle cutting state when an obstacle O is encountered. That is, the switching mechanism is configured to move the tip (X1-direction end) of the obstacle-cutting bit 3 in the excavation direction (X1-direction) more than the tip (X1-direction end) of the earth-and-sand excavation bit S. It is As a result, the shield machine 100 can cut the obstacle O with the obstacle-cutting bit 3 .

The cutter head 2 includes a plurality (four) of radial first spokes 20, a single rotation center 21, an annular outer ring 22, and a plurality of earth and sand intake ports for taking excavated earth and sand into the chamber 11. 23 and a plurality of (four) radial second spoke portions 24 .

The first spoke portion 20 linearly extends along the radial direction (RA direction) of the cutter head 2 from the inner peripheral side (center axis line α) of the cutter head 2 toward the outer peripheral side. A 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 set of the two linearly arranged first spoke portions 20 and the center line β2 of the other side set of the two linearly arranged first spoke portions 20 are orthogonal to each other. .

Obstacle-cutting bits 3 are provided on the first spoke portion 20 along center lines β1 and β2 (radial direction of the cutter head 2) of the first spoke portion 20 when viewed from the excavation direction (viewed from the X1 direction side). are placed side by side. Further, the first spoke portion 20 is provided with an obstacle-cutting bit 3 for sand excavation so as to be sandwiched from both sides in the rotation direction (RO direction) of the cutter head 2 when viewed from the excavation direction (viewed from the X1 direction side). A main bit S1 of bit S is provided.

The rotation center portion 21 is arranged on the central axis α. The rotation center portion 21 is connected to the inner peripheral side ends of the plurality (four) of the first spoke portions 20 . A fishtail bit 21 a is provided on the front surface of the rotation center portion 21 .

The outer ring 22 is arranged at the outermost peripheral position of the cutter head 2 (near the inner surface of the tunnel). The outer peripheral ring 22 is connected to the outer peripheral ends of the first spokes 20 and the second spokes 24 .

On the outer peripheral ring 22, when viewed from the excavation direction (viewed from the X1 direction), preceding bits S2 of a plurality of earth and sand excavation bits S are arranged at a predetermined distance in the rotation direction of the cutter head 2. ing.

The second spoke portion 24 linearly extends along the radial direction of the cutter head 2 from the inner peripheral side to the outer peripheral side of the cutter head 2 . The second spoke portions 24 are provided between the plurality (four) of the first spoke portions 20 in the rotation direction of the cutter head 2 .

The second spoke portion 24 has a leading bit of the earth and sand excavation bit S along the center line γ (radial direction of the cutter head 2) of the second spoke portion 24 when viewed from the excavation direction (viewed from the X1 direction side). It is installed so that S2 may line up. Further, the second spoke portion 24 is provided with the main bit S1 of the sand excavating bit S so as to sandwich the preceding bit S2 from both sides in the rotation direction of the cutter head 2 when viewed from the excavation direction (viewed from the X1 direction side). is set up.

As shown in FIG. 1, a beam-like cutter column M1 extending in the X direction, an annular member M2, and a cutter driving source M3 are provided on the rear side of the cutter head 2 as a mechanism for rotating the cutter head 2. ing.

The cutter column M1 has a front end attached to the cutter head 2 and a rear end attached to the annular member M2. The annular member M2 is configured to be rotatable about the central axis α by bearings supported by the partition wall 14 of the front body portion 10a. The cutter head 2 is configured to be rotationally driven by a cutter drive source M3 via a cutter column M1 and an annular member M2. The cutter driving source M3 is arranged behind the partition wall 14, and is configured to apply driving torque to the annular member M2 to rotate it. That is, the cutter head 2, the cutter column M1, and the annular member M2 are configured to be integrally rotated (turned) by the cutter drive source M3. The cutter driving source M3 is composed of, for example, a hydraulic motor.

(Structure of bit for cutting obstacles)
As shown in FIG. 2, the obstacle-cutting bit 3 is provided with a plurality of types of bits. Specifically, the obstacle-cutting bit 3 is provided with three types of bits: a first bit 4 , a second bit 5 and a third bit 6 . A plurality of first bits 4, second bits 5, and third bits 6 are provided.

The first bit 4 is arranged on the innermost side among the three types of bits in the radial direction (RA direction) of the cutter head 2 . The third bit 6 is arranged on the outermost side of the three types of bits in the radial direction of the cutter head 2 . The second bit 5 is arranged between the first bit 4 and the third bit 6 in the radial direction of the cutter head 2 .

The first bit 4, the second bit 5 and the third bit 6 have the same basic configuration. The differences between the first bit 4, the second bit 5 and the third bit 6 are mainly the following two points.

As shown in FIG. 4, the first difference is that the obstacle-cutting bit 3 has inner peripheral surfaces (43a, 53a, A plurality of types are provided so that the depression amounts (D1, D2, D3) of the recesses (47, 57, 67) provided in 63a) are gradually reduced. That is, the recess amount D1 of the recess 47 of the first bit 4, the recess amount D2 of the recess 57 of the second bit 5, and the recess amount D3 of the recess 67 of the third bit 6 are in this order (first bit 4, second bit 5 and third bit 6).

The second difference is that the hard chips (42, 52, 62) are provided in a plurality of types so that the number of 62) increases step by step. That is, at least the number of hard tips 62 of the third bit 6 is greater than the number of hard tips 42 of the first bit 4 .

In each figure, the hard tips 42, 52 and 62 are hatched (diagonal lines) so that the hard tips 42, 52 and 62 can be easily distinguished from the base materials 41, 51 and 61. However, this hatching does not indicate a cross section.

The second bit 5 having four hard tips 52 will first be described below. After that, the third bit 6, which has the same shape as the second bit 5 except that the recessed portion 67 is different from the recessed portion 57, will be described. Finally, the first bit 4 having two hard tips 42 will be described. .

<Configuration of the second bit>
As shown in FIG. 2 , a plurality (three each) of the second bits 5 are installed on each of the first spoke portions 20 . A plurality (three) of first bits 4 are arranged on the center line β1 (β2) at regular intervals.

As shown in FIGS. 5 and 6, the second bit 5 (obstacle-cutting bit 3) is attached to a base material 51 (shank) while protruding in the excavation direction (X1 direction) from the base material 51. and a plurality (four) of hard tips 52 secured to 51 .

The base material 51 is made of a material having higher toughness than the hard tip 52 . The base material 51 is made of a steel material such as S45C, for example. The hard tip 52 is made of a material harder than the base material 51 . The hard tip 52 is made of cemented carbide, for example.

The second bit 5 is arranged so that when viewed from the excavation direction (viewed from the X1 direction), the radial direction of the cutter head 2 is generally the lateral direction, and the rotational direction (RO direction) of the cutter head 2 is the longitudinal direction. are placed in A plurality of (four) hard tips 52 are arranged at intervals in the rotation direction of the cutter head 2 .

The second bit 5 does not have a hard tip 52 at both ends of the cutter head 2 in the rotational direction, and has only base material 51 at both ends in the rotational direction of the cutter head 2 . That is, the second bit 5 (each of the plurality of obstacle-cutting bits 3 ) has a hard tip 52 located on the outermost side in the rotational direction of the cutter head 2 , which is positioned so that the cutter head 2 rotates. It is configured to be arranged inside the base material 51 positioned at both ends in the direction. In short, the second bit 5 has all the hard tips 52 sandwiched by the base material 51 from both sides in the rotating direction of the cutter head 2 .

That is, the second bit 5 (obstacle-cutting bit 3) is configured such that chipping of the hard tip 52 can be suppressed by firmly supporting the hard tip 52 from both sides in the rotation direction of the cutter head 2 by the base material 51. is configured to

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

The plurality (four) of hard tips 52 generally extend in the radial direction (RA direction) of the cutter head 2 and are arranged parallel to each other. The hard tip 52 and the base material 51 are arranged such that their exposed outer surfaces are continuous without steps, forming an inner peripheral surface 53a. Further, the hard tip 52 and the base material 51 are arranged flush (arranged on the same plane) on the outer peripheral surface 53b of the obstacle-cutting bit 3 .

The second bit 5 (obstacle-cutting bit 3 ) has a first inclined surface 54 provided on the outer peripheral sides of both the base material 51 and the hard tip 52 in the radial direction of the cutter head 2 .

The first inclined surface 54 is provided over the entire area of the second bit 5 in the rotating direction of the cutter head 2 (longitudinal direction of the obstacle-cutting bit 3). The first inclined surface 54 is inclined in the direction opposite to the excavation direction from the tip in the excavation direction as it goes from the inner peripheral side to the outer peripheral side in the radial direction of the cutter head 2 . That is, the second bit 5 (obstacle-cutting bit 3) is formed such that the thickness in the radial direction of the cutter head 2 gradually decreases (tapers) toward the digging direction.

As an example, the inclination angle of the first inclined surface 54 with respect to the surface perpendicular to the excavation direction (flat surface 55 described later) is preferably 20 degrees or more and less than 45 degrees. Further, the inclination angle of the first inclined surface 54 with respect to the plane orthogonal to the excavation direction is more preferably 25 degrees or more and less than 35 degrees. Furthermore, the inclination angle of the first inclined surface 54 with respect to the plane orthogonal to the excavation direction is more preferably about 30 degrees.

The first inclined surface 54 is formed by a hard-tip-side first inclined surface 54 a formed by the hard tip 52 and a base-material-side first inclined surface 54 b formed by the base material 51 . The hard tip side first inclined surfaces 54a and the base material side first inclined surfaces 54b are alternately arranged in the rotation direction (RO direction) of the cutter head 2 . The hard-tip-side first inclined surface 54a protrudes by a predetermined distance in the excavation direction from the base material-side first inclined surface 54b (base material 51). As an example, the amount d of protrusion of the hard-tip-side first inclined surface 54a from the base material 51 in the excavation direction is preferably about 1.6 mm or more and 2.0 mm or less.

The plurality (four) of the base material side first inclined surfaces 54b are (substantially) located on the same plane. In addition, the plurality of base material side first inclined surfaces 54b are positioned (substantially) on the same plane except for the surfaces positioned at both ends.

As an example, the thickness of the obstacle-cutting bit 3 in the transverse direction (radial direction of the cutter head 2) depends on the overall rigidity of the obstacle-cutting bit 3, deformation during cutting of the obstacle, and It is preferable to set the length to 60 mm or more in consideration of firmly fixing to the cutter head 2 . Here, as described above, the obstacle-cutting bit 3 is formed by the first inclined surface 54 so as to gradually taper in the digging direction. This makes it possible to reduce the cutting amount of the obstacle cutting bit 3 .

As a result, the obstacle-cutting bit 3 can make the transverse rupture strength of the hard tip 52 relatively large. Specifically, the work done by the obstacle-cutting bit 3 to remove the obstacle is converted into heat. Therefore, the smaller the area to be removed, the smaller the amount of heat generated. Since the bending strength of the hard tip 52 decreases as the temperature rises, by reducing the amount of heat generated, the temperature rise of the hard tip 52 can be reduced, and the reduction in bending strength of the hard tip 52 can also be reduced. becomes possible. This can reduce the possibility that the hard tip 52 will be damaged. Further, by reducing the cutting amount of the obstacle cutting bit 3, cutting can be performed with energy saving.

The second bit 5 (obstacle-cutting bit 3 (base material 51 and a plurality of hard tips 52)) is provided at the tip in the excavation direction so as to be continuous with (the end in the excavation direction) the first inclined surface 54. It has a flat surface 55 .

The flat surface 55 extends in a direction substantially orthogonal to the excavation direction.

The flat surface 55 is formed of a hard chip side flat surface 55 a composed of the hard chip 52 and a base material side flat surface 55 b composed of the base material 51 . The hard tip side flat surface 55a and the base material side flat surface 55b are alternately arranged in the rotation direction of the cutter head 2 . The hard chip side flat surface 55a protrudes from the base material side flat surface 55b by a predetermined distance (thickness) in the excavation direction. As an example, the hard tip side flat surface 55a protrudes from the base material side flat surface 55b by 1.6 mm in the excavation direction. The hard chip side flat surface 55a is an example of the "flat surface" in the scope of claims.

The plurality (four) of the hard tip side flat surfaces 55a are (substantially) positioned (arranged) on the same plane. In addition, the plurality (three) of the base material side flat surfaces 55b are (substantially) positioned (arranged) on the same plane. That is, both the plurality (four) of the hard tip side flat surfaces 55a and the plurality (three) of the base material side flat surfaces 55b extend in a direction (substantially) perpendicular to the digging direction (X direction). Both end surfaces in the rotational direction of the hard tip side flat surface 55a are exposed. The hard chip side flat surface 55a is arranged on the X1 direction side of the base material side flat surface 55b. That is, the hard tip side flat surface 55a and the base material side flat surface 55b are discontinuous.

The second bit 5 (obstacle-cutting bit 3) is arranged so that all the hard tips 52 are cut by the front end face of the hard tip 52 in the traveling direction (rotational direction) of the obstacle-cutting bit 3. It is configured. By configuring in this way, the tensile stress generated in the hard tip 52 can be reduced compared to cutting at the center or rear side of the hard tip 52 in the traveling direction (rotational direction) of the obstacle-cutting bit 3. can be done. Both end surfaces of the hard tip 52 in the rotational direction are slightly chamfered for the purpose of preventing chipping of the hard tip 52 .

The second bit 5 (the obstacle-cutting bit 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 .

The pair of second inclined surfaces 56 extend from the inner side of the obstacle-cutting bit 3 in the rotating direction of the cutter head 2 toward the outer side, which is both end sides, of the outermost hard tip 52 in the rotating direction. From the outer end face 52a, it is inclined in the direction opposite to the digging direction. The second inclined surface 56 is provided over the entire area of the second bit 5 in the radial direction (RA direction) of the cutter head 2 (the lateral direction of the obstacle-cutting bit 3).

As an example, the inclination angle of the second inclined surface 56 with respect to the surface (flat surface 55) perpendicular to the excavation direction is preferably 20 degrees or more and less than 45 degrees. Further, the inclination angle of the second inclined surface 56 with respect to the plane perpendicular to the excavation direction is more preferably 25 degrees or more and less than 35 degrees. Further, the angle of inclination of the second inclined surface 56 with respect to the plane orthogonal to the excavation direction is more preferably about 30 degrees.

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

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

The second bit 5 (the obstacle-cutting bit 3 ) has a recess 57 provided in the radially inner peripheral surface 53 a of the cutter head 2 .

The recessed portion 57 is recessed from the radially inner peripheral side of the cutter head 2 toward the outer peripheral side thereof, and is formed in a concave shape along the rotating direction of the cutter head 2 .

The concave portion 57 is formed by connecting a plurality of flat surfaces along the rotation direction of the cutter head 2 when viewed from the excavation direction (viewed from the X1 direction side). The boundaries of the plurality of flat surfaces are also the boundaries between the hard tip 52 and the base material 51 . That is, the concave portion 57 is not formed in a smooth arc shape.

As described above, the depression amount D2 of the recess 57 of the second bit 5 (see FIG. 4) is larger than the depression amount D3 of the recess 67 of the third bit 6 (see FIG. 4). Further, the depression amount D2 of the recess 57 of the second bit 5 is smaller than the depression amount D1 of the recess 47 of the first bit 4 (see FIG. 4). That is, in the rotation direction of the cutter head 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 the curvature of the (virtual) arc along the inner surface of the recess 67 greater than the curvature of the (virtual) arc along.

Note that the recessed portion 57 is not provided over the entire surface 53a of the cutter head 2 on the inner peripheral side in the radial direction. The radially inner peripheral surface 53 a of the cutter head 2 is formed into a flat surface that is not recessed in the radial direction of the cutter head 2 at both ends in the rotational direction of the cutter head 2 . That is, the radially inner peripheral surface 53 a of the cutter head 2 is formed by a surface orthogonal to the radial direction of the cutter head 2 at both ends in the rotational direction of the cutter head 2 .

<Structure of the 3rd bit>
As shown in FIG. 4, the third bit 6 has a recess 67, except that the depth D3 of the recess 67 differs from the depth D2 of the recess 57 of the second bit 5 as described above. , and the second bit 5 have the same shape. Therefore, a brief description will be given below.

The third bit 6 (obstacle-cutting bit 3) includes a base material 61 (shank) and a plurality (two) of which are fixed to the base material 61 in a state of protruding from the base material 61 in the excavation direction (X1 direction). and a hard tip 62 of .

As shown in FIG. 2 , the third bit 6 has hard tips 62 located on the outermost side of the cutter head 2 in the rotational direction (RO direction) of the cutter head 2 . It is configured to be arranged inside the base material 61 located at the . In short, the third bit 6 has all the hard tips 62 sandwiched by the base material 61 from both sides in the rotating direction of the cutter head 2 .

The third bit 6 is arranged on the outer peripheral side of the second bit 5 in the radial direction of the cutter head 2 . A plurality of third bits 6 (7 or 8 each) are installed on each first spoke portion 20 . The plurality of third bits 6 are arranged on the center line β1 (β2) at regular intervals.

The plural (four) hard tips 62 (exposed outer surfaces) are composed of an inner peripheral side surface 63a, a digging direction side surface (flat surface 65), and an outer peripheral side surface 63b of the obstacle-cutting bit 3. It is arranged so as to straddle the

The third bit 6 (obstacle-cutting bit 3 ) has a first inclined surface 64 provided on the outer peripheral sides of both the base material 61 and the hard tip 62 in the radial direction of the cutter head 2 .

The third bit 6 (the obstacle-cutting bit 3 (base material 61 and a plurality of hard tips 62)) is provided at the tip in the excavation direction so as to be continuous with (the end in the excavation direction) the first inclined surface 64. It has a flat surface 65 .

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

<Structure of the 1st bit>
As shown in FIG. 2 , a plurality (two) of the first bits 4 are installed on the front surface of the rotation center portion 21 . The two first bits 4 are arranged on the center line β1 at symmetrical positions with respect to the center line β2.

As shown in FIG. 7, the first bit 4 (obstacle-cutting bit 3) is fixed to a base material 41 (shank) in a state of protruding from the base material 41 in the excavation direction (X1 direction). and a plurality (two) of hard tips 42 which are connected to each other.

A plurality (two) of hard tips 42 are arranged at intervals in the rotation direction of the cutter head 2 . The plurality (two) of hard tips 42 are not arranged parallel to each other, unlike the plurality (four) of hard tips 42 of the second bit 5 . That is, the plurality (two) of hard tips 42 are arranged so as to be spaced apart from each other toward the radially outer peripheral side of the cutter head 2 when viewed from the excavation direction (viewed from the X1 direction side) ( are arranged in a V shape).

Here, when compared with the case of arranging a plurality (two) of hard tips 42 of the first bit 4 in parallel with each other, a plurality (two) of hard tips 42 are seen from the excavation direction (as seen from the X1 direction). When the hard tip 42 is arranged in the above-described V-shape, the angle of the corner portion on the inner peripheral side of the hard tip 42 becomes blunt. That is, the hard tip 42 is less likely to chip. The hard tips 42 of the second bit 5 and the third bit 6 may be arranged in the same manner as the first bit 4 in the shape of an inverted V.

As an example, the length in the longitudinal direction of the first bit 4 (the length along the direction of rotation of the cutter head 2) is approximately two-thirds the length in the longitudinal direction of the second bit 5. (see Figure 4).

The first bit 4 (each of the plurality of obstacle-cutting bits 3) has a hard tip 42 located on the outermost side in the rotational direction of the cutter head 2, which is positioned in the rotational direction of the cutter head 2. It is configured to be arranged inside the base material 41 positioned at both ends. In short, the first bit 4 is supported with all the hard tips 42 sandwiched by the base material 41 from both sides in the rotating direction of the cutter head 2 .

The plural (two) hard tips 42 (exposed outer surfaces thereof) are composed of an inner peripheral side surface 43a of the obstacle cutting bit 3, a digging direction side surface (flat surface 45), and an outer peripheral side surface 43b. It is arranged so as to straddle the

The first bit 4 (obstacle-cutting bit 3) has a first inclined surface 44 provided on the outer peripheral side of both the base material 41 and the hard tip 42 in the radial direction (RA direction) of the cutter head 2. there is

The first bit 4 (obstacle-cutting bit 3 (base material 41 and a plurality of hard tips 42)) is provided at the tip in the excavation direction so as to be continuous with (the end in the excavation direction) the first inclined surface 44. It has a flat surface 45 .

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

The first bit 4 has a recessed portion 47 provided in a radially inner peripheral surface 43 a of the cutter head 2 .

(Arrangement of bits for cutting obstacles in the radial direction of the cutter head)
The arrangement of the obstacle-cutting bit 3 in the radial direction (RA direction) of the cutter head 2 (see FIG. 2) will be described with reference to FIG.

The plurality of obstacle-cutting bits 3 are arranged so as to be able to cut (substantially) the entire portion of the obstacle O (see FIG. 2) that overlaps with the cutter head 2 when viewed from the excavation direction (viewed from the X1 direction side). It is configured.

That is, the plurality of obstacle-cutting bits 3 are arranged continuously without gaps in the radial direction of the cutter head 2 . Specifically, in the radial direction of the cutter head 2, a plurality of obstacle-cutting bits 3 on the center line β1 and a plurality of obstacle-cutting bits 3 on the center line β2 are alternately arranged without gaps. there is In the radial direction of the cutter head 2, 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 short, in the shield machine 100 (see FIG. 2), when the cutter head 2 is rotated, the inner peripheral side (outer peripheral side) surfaces of the plurality of obstacle-cutting bits 3 on the center line β1 and the center line It is configured to pass through a position where the outer peripheral side (inner peripheral side) surfaces of the plurality of obstacle-cutting bits 3 on β2 substantially overlap. In other words, when the cutter head 2 is rotated, the plurality of obstacle-cutting bits 3 are arranged so that no part is not cut between the parts to be cut, so that there is no step on the cutting surface of the obstacle O. By doing so, it is arranged so that the entire cutting surface of the obstacle ◯ can be cut evenly.

(Effect of Embodiment)
The following effects can be obtained in this embodiment.

In the present embodiment, as described above, the hard tips 42 (52, 62) located on the outermost side in the rotation direction of the cutter head 2 are attached to the base materials 41 located on both ends in the rotation direction (RO direction) of the cutter head 2. By arranging the hard tips 42 (52, 62) on both ends of the obstacle-cutting bit 3 in the rotating direction of the cutter head 2, the hard tips 42 (51, 61) are arranged inside the two ends (51, 61). 52, 62) which is softer (higher toughness and less likely to chip). Therefore, the outermost hard tip 42 (52, 62) in the rotational direction of the cutter head 2 can be firmly sandwiched between the base materials 41 (51, 61) from both sides in the rotational direction, and the hard tip 42 (52) , 62) to prevent the obstacle O from contacting the entire hard chip 42 (52, 62). As a result, chipping of the hard tip 42 (52, 62) can be suppressed. When hard tips are arranged at both ends of the cutter head in the rotational direction, as in the conventional art, the hard tips arranged at the rear end in the rotational direction of the cutter head (hereinafter referred to as the hard tip at the rear end) may become obstacles. At the time of contact, a large force acts on the hard tip at the trailing end toward the rear in the direction of rotation of the cutter head. Here, since the hard tip at the rear end is mainly supported only by the tensile force of the base material positioned forward in the rotational direction of the cutter head, the hard tip at the rear end is positioned rearward in the rotational direction of the cutter head. Easy to peel off from material. On the other hand, as in the present embodiment, the outermost hard tip 42 (52, 62) in the rotational direction of the cutter head 2 is firmly sandwiched between the base materials 41 (51, 61) from both sides in the rotational direction, whereby It is possible to effectively prevent the end hard tips 42 (52, 62) from being chipped and the hard tips 42 (52, 62) from being separated from the base material 41 (51, 61).

In the present embodiment, as described above, the obstacle-cutting bit 3 is configured to extend both the outer peripheries of the base material 41 (51, 61) and the hard tip 42 (52, 62) in the radial direction (RA direction) of the cutter head 2. The first inclined surfaces 44 (54, 64) extend in the excavation direction from the radially inner side of the cutter head 2 toward the outer peripheral side. From the tip of the pit, it slopes in the direction opposite to the direction of excavation. As a result, the tip of the obstacle-cutting bit 3 can be tapered in the excavation direction compared to the case where the tip of the obstacle-cutting bit 3 is not provided with the first inclined surface 44 (54, 64) (when the tip is rectangular). . As a result, the amount of heat generated in the vicinity of the tip in the excavation direction during cutting can be suppressed, so that the obstacle-cutting bit 3 (hard tip 42 (52, 62)) can be suppressed from being easily broken. In addition, by inclining the first inclined surface 44 (54, 64) in the direction opposite to the excavation direction from the tip of the excavation direction toward the outer peripheral side in the radial direction, the first inclined surface 44 ( 54, 64) so that the chips can be effectively entrained in the chamber.

In this embodiment, as described above, the plurality of hard tips 42 (52, 62) are provided at the leading end of the excavation direction so as to be continuous with the first inclined surface 44 (54, 64), and are substantially perpendicular to the excavation direction. It has a flat surface 45 (55, 65). As a result, the hard tip 42 (52, 62) cuts the obstacle O with the flat surface 45 (55, 65), compared to the case where the obstacle O is cut by the tip having a surface inclined with respect to the excavation direction. can be made relatively large to suppress concentration of stress on the hard tip 42 (52, 62). Therefore, chipping of the hard tip 42 (52, 62) can be further suppressed.

In this embodiment, as described above, the hard tip side flat surfaces 55a of the plurality of hard tips 52 (42, 62) are arranged substantially on the same plane. With this configuration, the hard tip side flat surfaces 55a of the plurality of hard tips 52 (42, 62) can be arranged at substantially the same position in the excavation direction. can be brought into contact with the obstacle O. Therefore, the obstacle O can be cut effectively.

In this embodiment, as described above, the obstacle-cutting bit 3 includes 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 ) extend in the rotational direction of the cutter head 2 from the inner side of the obstacle-cutting bit 3 toward the outer side, i.e., both end sides. From the outer end face (52a) of the hard tip 42 (52, 62) located on the outermost side of the tip, it is inclined in the direction opposite to the digging direction. As a result, 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 causes the obstacle O to the base material 41 (51, 61). contact can be suppressed. As a result, wear of the base material 41 (51, 61) can be suppressed. Moreover, the contact between the base material 41 (51, 61) that does not contribute to cutting and the obstacle O can be reduced, and the deterioration of the excavation performance of the obstacle-cutting bit 3 can be suppressed.

In this embodiment, as described above, the obstacle-cutting bit 3 has the recesses 47 (57, 67) provided in the radially inner peripheral surface 43a (53a, 63a) of the cutter head 2. The recesses 47 (57, 67) are recessed from the radially inner side to the outer side of the cutter head 2 and are formed in a concave shape along the rotation direction of the cutter head 2. As shown in FIG. As a result, when the obstacle-cutting bit 3 passes through the space created by cutting, the recess 47 (57, 67) shaped along the rotational direction of the cutter head 2 allows the cutter head of the obstacle-cutting bit 3 to move. It is possible to suppress the obstacle O from coming into contact with the radially inner peripheral surface 43a (53a, 63a) of 2. That is, the obstacle-cutting bit 3 can escape from the obstacle O by the concave portion 47 (57, 67). As a result, it is possible to suppress the force from acting on the obstacle-cutting bit 3 from the inner peripheral side to the outer peripheral side, so that chipping of the hard tip 42 (52, 62) can be further suppressed. can.

In the present embodiment, as described above, in the obstacle-cutting bit 3, the depression amounts of the concave portions 47, 57, and 67 decrease stepwise from the radially inner peripheral side to the outer peripheral side of the cutter head 2. As shown, multiple types are provided. As a result, the depth of the recesses 47, 57 and 67 can be set to an appropriate value according to the position of the cutter head 2 in the radial direction. Contact can be effectively suppressed. As a result, chipping of the hard tips 42, 52 and 62 can be further suppressed.

In this embodiment, as described above, the hard chips 42 and 52 included in one obstacle-cutting bit 3 increase from the radially inner side to the outer side of the cutter head 2 toward the outer peripheral side. and 62 are provided in a plurality of types so that the number thereof increases stepwise. As a result, the peripheral speed of the obstacle-cutting bit 3 becomes particularly fast (the amount of movement of the obstacle-cutting bit 3 per unit time becomes particularly large). 3, more hard tips 42, 52 and 62 can be provided. As a result, the obstacle O can be effectively cut even on the outer peripheral side of the cutter head 2 in the radial direction. In addition, since the peripheral speed of the obstacle-cutting bit 3 increases toward the radially outer side of the cutter head 2, the amount of heat generated by friction with the obstacle O increases. Temperature rises. Therefore, the decrease in the transverse rupture strength of the hard tip 42 (52, 62) is greater than that on the inner peripheral side. Therefore, redundancy can be enhanced by arranging more hard tips 42 (52, 62) on the radially outer peripheral side of the cutter head 2 as described above.

[Modification]
It should be noted that the embodiments and modifications disclosed this time should be considered as examples in all respects and not restrictive. The scope of the present invention is indicated by the scope of claims rather than the description of the above-described embodiments, and includes all modifications (modifications) within the scope and meaning equivalent to the scope of claims.

For example, in the above embodiment, an example in which the present invention is applied to a mud pressure shield machine is shown, but the present invention is not limited to this. The present invention may be applied to a slurry shield machine. In the case of a slurry shield tunneling machine, slurry is fed into the chamber to slurry the excavated earth and sand, and the slurried excavated earth and sand is discharged from the earth removing device.

In the above embodiment, an example in which three types of obstacle-cutting bits (first bit, second bit, and third bit) are installed in the cutter head is shown, but the present invention is not limited to this. do not have. In the present invention, one, two, four or more types of obstacle-cutting bits may be installed on the cutter head.

Further, in the above-described embodiment, an example in which the obstacle-cutting bit is installed on the spoke of the cutter head is shown, but the present invention is not limited to this. In the present invention, the obstacle cutting bit may be installed on the face plate of the cutter head or the like.

Moreover, in the above-described embodiment, only an example of the arrangement of the plurality of obstacle-cutting bits with respect to the cutter head is shown, and the present invention is not limited to this.

Further, in the above-described embodiment, an example in which the inclined surface (first inclined surface) is provided on the radially outer peripheral side of the cutter head has been shown, but the present invention is not limited to this. In the present invention, an inclined surface may be provided on the radially inner peripheral side of the cutter head.

Further, in the above-described embodiment, an example in which the front surface of the cutter head is formed in a flat shape has been shown, but the present invention is not limited to this. In the present invention, the central portion of the cutter head may be formed in a cone shape or the like that protrudes forward (digging direction).

Further, in the above embodiment, an example in which two or four hard tips are provided for one obstacle-cutting bit has been shown, but the present invention is not limited to this. In the present invention, 3 or 5 or more hard tips may be provided for one obstacle-cutting bit.

Moreover, in the above-described embodiment, an example in which a plurality of hard tips of the second bit (third bit) are arranged in parallel has been shown, but the present invention is not limited to this. In the present invention, the hard tips of the second bit (third bit) need not be arranged in parallel. For example, like the 1st bit, the plurality of hard tips of the 2nd bit (3rd bit) are spaced apart from each other as they go from the inner peripheral side to the outer peripheral side of the cutter head (in a V-shape). ) may be placed.

Further, in the above embodiment, an example is shown in which the tips (flat surfaces) of the hard tips included in one obstacle-cutting bit are positioned on the same plane, but the present invention is not limited to this. do not have. In the present invention, the tip (flat surface) of each hard tip included in one obstacle-cutting bit may be arranged at a position shifted in the digging direction.

Further, in the above-described embodiment, an example is shown in which the concave portion of the obstacle-cutting bit is formed by connecting a plurality of flat surfaces along the rotation direction of the cutter head when viewed from the excavation direction side. The invention is not limited to this. In the present invention, the concave portion of the obstacle-cutting bit may be formed in an arcuate shape along the rotation direction of the cutter head when viewed from the excavation direction side.

Further, in the above-described embodiment, an example in which a plurality of obstacle-cutting bits are arranged at regular intervals in the radial direction of the cutter head has been shown, but the present invention is not limited to this. In the present invention, in the radial direction of the cutter head, the plurality of obstacle-cutting bits may be arranged with gradually increasing or decreasing intervals toward the outer peripheral side.

Further, in the above embodiment, an example in which the hard tip is made of cemented carbide is shown, but the present invention is not limited to this. In the present invention, the hard tip may be made of a material harder than the base material, such as tool steel. Cemented carbide is a brittle material, whereas tool steel is more ductile than cemented carbide and is not a brittle material.

Further, in the above-described embodiment, an example is shown in which recesses are provided in the entire area of the obstacle-cutting bit in the excavation direction (X direction), but the present invention is not limited to this. In the present invention, in the excavation direction (X direction), the recess may be provided only in the range where the hard tip is present with respect to the obstacle-cutting bit.

Further, in the above-described embodiment, the exposed outer surfaces of the hard tip and the base material on the inner peripheral surface of the obstacle-cutting bit are arranged so as to be continuous without steps. , the present invention is not limited to this. In the present invention, like the obstacle-cutting bit 203 of the modified example shown in FIG. The surface may be arranged so as to create a step ST. For example, the inner peripheral surface 253 a of the base material 251 sandwiched between the hard tips 52 is formed to extend in a direction substantially perpendicular to the radial direction of the cutter head, so that a slight gap is formed between the hard tip 52 and the base material 251 . A step ST may be provided. By forming the base material 251 in this manner, the obstacle-cutting bit 203 can be easily manufactured.

1 Shield Machine Main Body 2 Cutter Head 3, 203 Obstacle Excavation Bit 41, 51, 61, 251 Base Material 42, 52, 62 Hard Tip 43a, 53a, 63a, 253a Inner Surface 44, 54, 64 1 slanted surface 46, 56, 66 2nd slanted surface 47, 57, 67 recessed portion 52a outer end surface (of the hard tip located on the outermost side in the direction of rotation of the cutter head) 55a flat surface on the hard tip side (flat surface)
100 Shield Machine O Obstacle

Claims (8)

and a plurality of hard tips that are harder than the base material and that are fixed to the base material in a state of protruding from the base material in the excavation direction, for cutting underground obstacles. an obstacle-cutting bit;
a cutter head on which the obstacle-cutting bit is installed and which rotates along with excavation;
a shield excavator body in which the cutter head is installed at the tip in the tunneling direction;
In the plurality of obstacle-cutting bits, the plurality of hard tips are arranged at intervals in the rotation direction of the cutter head, and are arranged on the outermost side in the rotation direction of the cutter head. The hard tip positioned is arranged inside the base material positioned at both ends in the rotation direction of the cutter head ,
The obstacle-cutting bit has a first inclined surface provided on the outer peripheral side of both the base material and the hard tip in the radial direction of the cutter head,
The shield excavator, wherein the first inclined surface is inclined in a direction opposite to the excavation direction from a tip in the excavation direction as it goes from an inner peripheral side to an outer peripheral side in a radial direction of the cutter head. 2. The shield excavator according to claim 1 , wherein said plurality of hard tips are provided at a tip in said excavation direction so as to be continuous with said first inclined surface, and have a flat surface substantially orthogonal to said excavation direction. 3. The shield machine according to claim 2 , wherein said flat surfaces of each of said plurality of hard tips are arranged substantially on the same plane. 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 of the hard tip positioned on the outermost side in the rotational direction of the cutter head, as they go from the inner side of the obstacle-cutting bit toward the outer side, i.e., both end sides, in the rotational direction of the cutter head. The shield excavator according to any one of claims 1 to 3 , wherein the outer end face is inclined in a direction opposite to the excavation direction. The obstacle-cutting bit has a recess provided on the radially inner peripheral surface of the cutter head,
5. The recess according to any one of claims 1 to 4 , wherein the recess is recessed from the inner peripheral side to the outer peripheral side in the radial direction of the cutter head and is formed in a concave shape along the rotating direction of the cutter head. Shield machine according to paragraph. 6. The obstacle-cutting bit according to claim 5 , wherein a plurality of types of said bits for cutting obstacles are provided so that the amount of depression of said concave portion gradually decreases as it goes from the radially inner peripheral side to the outer peripheral side of said cutter head. A shield machine as described. The number of hard chips included in one obstacle-cutting bit increases stepwise from the inner peripheral side to the outer peripheral side in the radial direction of the cutter head. The shield machine according to any one of claims 1 to 6 , provided with a type. A base material installed on a cutter head that rotates as the excavation progresses,
a plurality of hard chips that are fixed to the base material in a state of protruding in the excavation direction from the base material and are harder than the base material,
The plurality of hard tips are spaced apart in the rotation direction of the cutter head, and the outermost hard tip in the rotation direction of the cutter head is the cutter head. It is configured to be arranged inside the base material located at both ends in the rotational direction of the
further comprising an inclined surface provided on the outer peripheral side of both the base material and the hard tip in the radial direction of the cutter head,
The inclined surface is inclined in a direction opposite to the excavation direction from the tip of the excavation direction as it goes from the radially inner peripheral side to the outer peripheral side of the cutter head.

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