JP2009287186A - Multiple bit - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a multiple bit having a simple structure and capable of reducing manufacturing cost, coping with mass production, and preventing an earth removing device from being clogged with broken pieces when an outer bit is worn and broken. <P>SOLUTION: This multiple bit 8 to be mounted on a cutter head 4 of a tunnel excavator 1 to cut a working face K is provided with an inner bit 10 to be attached to the cutter head 4, the outer bit 11 formed to cover a cutting chip 10b of the inner bit 10, and a mounting means 12 for mounting the outer bit 11 on the inner bit 10. The outer bit 11 has a front cover part 11c arranged in front of cutting direction A, a rear cover part 11d arranged above the direction B of working face, and a connection part 11e for connecting them. The mounting means 12 has a front side mounting means 12a for attaching the front cover part 11c to a front part 10c in the cutting direction of the inner bit 10 and a rear side mounting means 12b for attaching the rear cover part 11d to a working face opposing part 10d of the inner bit 10. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a cutter bit that is attached to a cutter head of a tunnel excavator and cuts a face, and more particularly to a multiple bit that has a long life to cope with long-distance construction.

  A tunnel excavator generally includes a cutter head that is driven to rotate about an axis parallel to the excavation direction, and a cutter bit for cutting the face is attached to the cutter head. Since such cutter bits are worn by cutting the face, measures such as bit replacement are required for long-distance construction. A multiple bit described in Patent Document 1 is known as a cutter bit that has a long life in order to cope with long-distance construction.

  This multiple bit is attached to the inner bit attached to the cutter head of the tunnel excavator, the outer bit formed in a substantially V-shaped cross section so as to cover the inner bit, and the front part in the cutting direction of the cutter head, A front wedge member that presses the front part of the outer bit against the front part of the inner bit, and a rear wedge member that is attached to the rear part in the cutting direction of the cutter head and presses the rear part of the outer bit against the rear part of the inner bit. According to this multiple bit, when the outer bit is worn and damaged by cutting the face and divided into front and rear in the cutting direction, each divided piece is released from the restraining force by the front wedge member and the rear wedge member. Then it falls off the cutter head and the inner bit is exposed.

  That is, when the outer bit is worn by a predetermined amount, the outer bit is naturally detached from the cutter head without using a special removing device (actuator), and the inner bit is exposed.

JP 2007-327266 A

  By the way, in the multiplex bit, the outer bit is supported by being pressed against the inner bit by the front wedge member and the rear wedge member attached to the cutter head. It is necessary to weld the front wedge member and the rear wedge member to the cutter head while finely adjusting the attachment positions of the wedge member and the rear wedge member to the cutter head, and it takes time to adjust the positions. For this reason, the production period was prolonged, and it was not suitable for mass production.

  It is not practical to attach the multiple bits directly to the cutter head one by one because it takes time to adjust the position when welding the front wedge member and the rear wedge member to the cutter head as described above. . Therefore, in actuality, a plurality of components in which the multiple bit components (inner bit, outer bit, front wedge member, rear wedge member) are mounted in advance are prepared, and these pedestals are used as the cutter head. I was wearing it. In this case, the cost is increased by the amount of the pedestal.

  In the multiplex bit, the outer bit is formed to have a size that covers all portions of the inner bit. For this reason, when the outer bit is worn and broken and each piece is divided, the divided pieces become large to some extent, and the excavating earth and sand excavator (screw conveyor, mud pump, etc.) There is a possibility of clogging the earth removal device when it is discharged at the site, and impairing the earth removal function.

  The object of the present invention created in view of the above circumstances is that the structure is simplified, the manufacturing cost is reduced, the mass production can be supported, and when the outer bit is worn out and damaged, the broken piece becomes a soil removal device. It is to provide multiple bits that are hard to clog.

  In order to achieve the above object, the present invention provides a multi-bit mounted on a cutter head that is provided in a tunnel excavator and is rotationally driven to cut a face, and an inner bit that is attached to the cutter head; An outer bit formed so as to cover the cutting tip of the inner bit, and attachment means for attaching the outer bit to the inner bit so as to cover the cutting tip, wherein the outer bit has a cutting direction of the inner bit. A front cover portion disposed in the front; a rear cover portion disposed above the face direction of the inner bit; and a connecting portion that connects the front cover portion and the rear cover portion. Front mounting means for attaching the front cover portion to the front portion in the cutting direction of the inner bit, and rear attachment means for attaching the rear cover portion to the face facing portion of the inner bit. It is intended to.

  The front attachment means has a front concave portion formed at a front portion in the cutting direction of the inner bit and a front convex portion formed at a front cover portion of the outer bit so as to be engaged with the front concave portion; The rear attachment means has a rear concave portion formed in the face facing portion of the inner bit and a rear convex portion formed in the rear cover portion of the outer bit so as to engage with the rear concave portion. May be.

  The front mounting means has a front hole formed at a front portion in the cutting direction of the inner bit, and a front pin that is attached to the front cover portion of the outer bit and inserted into the front hole, and the rear mounting means. However, it may have a rear hole formed in the face facing portion of the inner bit and a rear pin attached to the rear cover portion of the outer bit and inserted into the rear hole.

  According to the multiplex bit according to the present invention, the structure is simplified, the manufacturing cost is reduced, the mass production can be supported, and when the outer bit is worn and damaged, the broken pieces are not easily clogged in the soil removal device. Can demonstrate.

  Preferred embodiments of the present invention will be described with reference to the accompanying drawings.

  FIG. 1 is a side sectional view of a tunnel excavator (shield excavator) having a cutter head to which multiple bits according to this embodiment are attached, and FIG. 2 is a front view of the shield excavator as viewed from the front in the excavation direction. is there.

  The shield machine 1 includes a cylindrical shield frame 2, a partition 3 that partitions the shield frame 2 forward and backward in the digging direction, and a cutter head 4 that is supported by the partition 3 so as to be rotatable about an axis parallel to the digging direction. An erector (not shown) for assembling the segments in the shield frame 2 in a ring shape, and a shield jack mounted on the inner surface of the shield frame 2 to take the reaction force to the segments assembled in the ring shape and advance the shield frame 2 (Not shown).

  The cutter head 4 has a central portion 5 disposed at the rotation center X and a plurality of cutter spokes 6 radially attached to the central portion 5 at intervals in the circumferential direction. By the driving means, it is rotated clockwise or counterclockwise around the rotation center X. A triangular plate-shaped fishtail bit 7 is attached to the center portion 5, and a plurality of multiple bits 8 according to the present embodiment are attached to the cut spoke 6 at intervals in the radial direction.

  The fishtail bit 7 and the multiple bit 8 are pressed against the face of the natural ground by extending the shield jack, and the cutter head 4 is rotated in this state to cut the face. An arrow A in FIG. 2 indicates a cutting direction in which the multiple bit 8 cuts the face as the cutter head 4 rotates, and is a tangential direction of a circle around the rotation center X. The cutting direction is opposite to the arrow A when the cutter head 4 is rotated in the reverse direction.

  The cutter head 4 is a spoke type in this embodiment, but may be a face plate type.

  3A is a cross-sectional view taken along the line IIIa-IIIa of FIG. 2, and FIG. 3B is a front view of the multiple bit shown in FIG. 3A viewed from the face side.

  The multiple bit 8 according to the present embodiment includes an inner bit 10 attached to the cutter spoke 6, an outer bit 11 formed so as to cover the cutting tip 10 b of the inner bit 10, and an attachment for attaching the outer bit 11 to the inner bit 10. And means 12. 10 w is a weld bead formed by welding the inner bit 10 to the cutter pork 6.

  The inner bit 10 has an inner shank 10a as a support welded to the cutter pork 6 and an inner cutting tip 10b as a cutting blade brazed to the front portion in the cutting direction A of the inner shank 10a. The inner shank 10a is made of SS material, SKC material or the like, and the inner cutting tip 10b is made of cemented carbide such as tungsten carbide. The inner shank 10a has a protruding portion that protrudes at an acute angle toward the front in the cutting direction A, and the inner cutting tip 10b is brazed to the recess formed in the protruding portion.

  The outer bit 11 includes an outer shank 11a (SS material, SKC material, etc.) formed so as to cover the inner cutting tip 10b, and an outer cutting tip 11b (tungsten) brazed to the front of the outer shank 11a in the cutting direction A. Carbite etc.). The outer shank 11a includes a front cover portion 11c disposed in front of the cutting direction A of the inner bit 10, a rear cover portion 11d disposed above the face direction B of the inner bit 10, and the front cover portion 11c and the rear. The connecting portion 11e is connected to the cover portion 11d and has a substantially V-shaped cross section. The outer shank 11a has a recess 11f having a V-shaped cross section formed to cover the inner cutting tip 10b by the inner surface of the front cover portion 11c and the inner surface of the rear cover 11d.

  The attaching means 12 includes a front attaching means 12a for attaching the front cover portion 11c of the outer bit 11 to the front portion 10c of the inner bit 10 in the cutting direction A, and a rear cover portion 11d of the outer bit 11 facing the face facing portion 10d of the inner bit 10. And rear side attaching means 12b. The front mounting means 12a has a front concave portion 121a formed in the front portion 10c of the inner bit 10, and a front convex portion 122a formed in the front cover portion 11c so as to engage with the front concave portion 121a. The attachment means 12b has a rear concave portion 121b formed in the face facing portion 10d of the inner bit 10, and a rear convex portion 122b formed in the rear cover portion 11d so as to engage with the rear concave portion 121b.

  The front concave portion 121a, the front convex portion 122a, the rear concave portion 122a, and the rear convex portion 122b are axes in a direction C that crosses the cutting direction A of the outer bit 11 due to the rotation of the cutter head 4 (in this embodiment, the radial direction of the cutter head 4). (Hereinafter also referred to as axis C). Thus, when the cutter head 4 rotates and the outer bit 11 receives a cutting reaction force from the face, the front reaction portion 121a, the front protrusion portion 122a, and the rear recess portion 121b formed in parallel with the axis C are applied to the cutting reaction force. And it can support by the back convex part 122b.

  The axis C does not necessarily have to be along the radial direction of the cutter head 4. The axis C is not limited to the radial direction of the cutter head 4 as long as the direction crosses the cutting direction A of the outer bit 11 due to the rotation of the cutter head 4. May be slightly inclined. Even if the axis C is slightly inclined from the radial direction of the cutter head 4, the front recess 121a, the front protrusion 122a, and the rear recess 121b formed in parallel with the axis C are subjected to the cutting reaction force that the outer bit 11 receives from the face. This is because it can be supported by the rear projection 122b.

  Moreover, the front recessed part 121a and the front convex part 122a are formed to spread outward, and the rear recessed part 121b and the rear convex part 122b are formed to spread outward. That is, the front concave portion 121a and the front convex portion 122a are formed so as to widen in the direction away from the inner bit 10 in the plane orthogonal to the axis C, and similarly, the rear concave portion 121b and the rear convex portion 122b are In the direction perpendicular to the axis C, it is formed in a divergent direction in a direction away from the inner bit 10.

  A predetermined gap (backlash) is set between the front concave portion 121a and the front convex portion 122a and between the rear concave portion 121b and the rear convex portion 122b. For this reason, although the outer side bit 11 can move in the range of the said play with respect to the inner side bit 10, there is no trouble in cutting of a face. In order to prevent the inner surface of the outer tip 11 from hitting the inner cutting tip 10b between the outer bit 11 and the inner bit 10, a protective material made of resin or the like may be provided to protect the inner cutting tip 10b. .

  The outer bit 11 is moved along the axis C with the front convex part 122a engaged with the front concave part 121a of the inner bit 10 and the rear convex part 122b engaged with the rear concave part 121b of the inner bit 10, respectively. And attached to the inner bit 10. Then, the slip prevention plate 17 is attached to the side part (the both ends in the direction of the axis C) of the outer bit 11 by welding. The slip prevention plate 17 is formed so as to extend in contact with the side portion of the inner bit 10, and prevents the outer bit 11 from slipping along the axis C with respect to the inner bit 10. 17 w is a weld bead formed by welding the slip prevention plate 17 to the outer bit 11.

  In the present embodiment, the slip prevention plate 17 is attached only to the rear cover portion 11d of the outer bit 11, but may be attached to either or both of the front cover portion 11c and the rear cover portion 11d.

  The operation of this embodiment will be described.

  As shown in FIG. 4A, the outer bit 11 cuts the face K of the natural ground by the rotation of the cutter head 4 and the advance of the shield machine 1. At this time, the outer side bit 11 is supported and restrained by the inner side bit 10 by the front side mounting member 12a, the rear side mounting member 12b, and the slip prevention plate 17 so as not to be detached from the inner side bit 10.

  When the outer bit 11 cuts the face K, the outer cutting tip 11b and the connecting portion 11e gradually wear. As wear progresses, the thickness of the connecting portion 11e decreases, and the stress generated there increases. When the wear proceeds to a predetermined amount (wear limit), as shown in FIG. 4B, the connecting portion 11e is broken, and the outer bit 11 is divided into a front cover portion 11c and a rear cover portion 11d.

  The divided front cover portion 11c is released from restraint by the front mounting member 12a, and the front convex portion 122a and the front concave portion 121a of the inner bit 10 are formed to spread outward, so that the cutter head 4 is rotated. When the cutter head 4 is rotated by a fine vibration or a lateral force generated by rotating the cutter head 4, the cutter head 4 is detached from the inner bit 10 and dropped off.

  The divided rear cover portion 11d is also released from the restraint by the rear mounting member 12b and the slip prevention plate 17, and the rear convex portion 122b and the rear concave portion 121b of the inner bit 10 are formed so as to spread outward. Then, it comes off the inner bit 10 and falls off from the cutter head 4.

  Then, as shown in FIG. 4C, the inner bit 10 that has been covered by the outer bit 11 so far and has not been worn out is exposed, and the face K can be cut by the new inner bit 10.

  In this way, the outer bit 11 that has reached the wear limit is automatically detached from the cutter head 4 without using a special actuator, and cutting can be continued by the inner bit 10 that has been protected from wear by the outer bit 11 until then. Therefore, the life of the entire bit is extended, and it can be used for long-distance construction.

  According to the present embodiment, since the outer bit 11 is supported by the front recess 121a and the rear recess 121b formed on the inner bit 10, the outer bit in the invention described in Patent Document 1 is pressed against the inner bit. Thus, the front wedge member and the rear wedge member to be supported are unnecessary, and the complicated operation of welding to the cutter head or the pedestal while finely adjusting the position of the wedge members is eliminated. Further, a pedestal for attaching these wedge members is also unnecessary. Therefore, the structure is simplified, the manufacturing cost is suppressed, and the mass production can be handled.

  In addition, the outer bit 11 according to the present embodiment is not large enough to cover the entire inner bit as in the invention described in Patent Document 1, but large enough to cover the cutting tip 10b of the inner bit 10. Therefore, when the outer bit 11 is worn and broken and divided, the divided pieces (the front cover portion 11c and the rear cover portion 11d) are those of the invention described in Patent Document 1. Becomes smaller. Therefore, it is difficult to clog the earth removal device when it is earthed by the earth removal device (screw conveyor, mud pump, etc.) of the shield machine 1 together with the excavation soil.

  Another embodiment of the present invention is shown in FIG.

  FIG. 5A is a side view of the multiplex bit 8x according to another embodiment mounted on the cutter head 4 (cutting pork 6) and viewed from the radial direction of the cutter head 4, and is shown in FIG. FIG. 5B is a front view of the multiplex bit 8x shown in FIG. 5A as viewed from the face side.

  The multiplex bit 8x has the same basic configuration as the multiplex bit 8 according to the previous embodiment, and is different only in the front attachment means 12a and the rear attachment means 12b for attaching the outer bit 11 to the inner bit 10. Therefore, the same parts are denoted by the same reference numerals, description thereof is omitted, and different front side attachment means 12a and rear side attachment means 12b will be mainly described.

  The rear attachment means 12b includes a rear hole 123b formed in the face facing portion 10d of the inner bit 10, and a rear pin 124b that is attached to the rear cover portion 11d of the outer bit 11 and inserted into the rear hole 123b. A plurality of (three) rear holes 123b and rear pins 124b are formed at intervals in the direction of the axis C (the radial direction of the cutter head 4). The rear pin 124b is inserted and welded into a mounting hole 125b formed in the rear cover portion 11d. 12w is a weld bead.

  The front attachment means 12a has a front hole 123a formed in the front cutting portion 10c of the inner bit 10, and a front pin 124a that is attached to the front cover portion 11c of the outer bit 11 and inserted into the front hole 123a. A plurality of (three) front holes 123a and front pins 124a are formed at intervals in the direction of the axis C. The front pin 123a is inserted and welded into an attachment hole 125a formed in the front cover portion 11c. 12w is a weld bead.

  The tips of the pins 124a and 124b are tapered, and the holes 123a and 123b are also tapered. The number of these pins 124a, 124b and the holes 123a, 123b may be one, or two or more.

  The rear cover portion 11d of the outer bit 11 is formed with a rear abutting portion 11g that comes into surface contact with the face facing portion 10d of the inner bit 10, and the front cover portion 11c faces the front portion 10c of the inner bit 10 in the cutting direction. A front contact portion 11h that comes into contact is formed. When the front contact portion 11 h is brought into contact with the inner bit 10 and the rear contact portion 11 g is brought into contact with the inner bit 10, a gap is formed between the inner bit 10 and the outer bit 11.

  In this state, the tip of the front pin 124a inserted into the mounting hole 125a is inserted into the front hole 123a, and the tip of the rear pin 124b inserted into the mounting hole 125b is inserted into the rear hole 123b. The front pin 124a is welded to the mounting hole 125a, and the rear pin 124b is welded to the mounting hole 125b. As a result, the front abutting portion 11 h comes into surface contact with the inner bit 10, the rear abutting portion 11 g comes into surface contact with the inner bit 10, and the outer bit 11 is attached to the inner bit 10 without backlash.

  Also in this embodiment, the same operation as the previous embodiment is achieved, the structure is simplified, the manufacturing cost is suppressed, the mass production is possible, and when the outer bit 11 is worn out and damaged, the broken piece is removed from the soil removing device. The effect that it is hard to be clogged up can be demonstrated. Since the outer bit 11 is attached to the inner bit 10 without play, there is no need to provide a protective material (made of resin) for protecting the inner cutting tip 10b between the inner bit 10 and the outer bit 11.

  Yet another alternative embodiment is described.

  3 (a), 3 (b), 5 (a), and 5 (b), a further outside bit (second outside bit) (not shown) formed so as to cover the outside bit 11 is further provided. Further, another mounting means (second mounting means) for mounting the second outer bit to the outer bit 11 (first outer bit) may be provided to form a triple bit.

  In the case of this triple bit, the second attachment means includes a second front attachment means for attaching the front cover portion of the second outer bit to the front portion in the cutting direction (front cover portion 11c) of the first outer bit 11, and a second outer portion. And a second rear attachment means for attaching the rear cover portion of the bit to the face facing surface portion (rear cover portion 11d) of the first outer bit. The relationship between the second outer bit and the first outer bit 11 corresponds to the relationship between the outer bit 11 and the inner bit 10 in the previous embodiment (double bit).

  According to this triple bit, when the second outer bit is worn by a predetermined amount, the second outer bit is divided into front and rear and falls off from the first outer bit 11, and thereafter becomes the state of FIG. The cutting can be continued, and the same effect as the double bit described above can be obtained.

  Similarly, quadruple bits or more are possible.

1 is a side sectional view of a tunnel excavator (shield excavator) having a cutter head equipped with multiple bits according to an embodiment of the present invention. It is the front view which looked at the above-mentioned shield machine from the front in the digging direction. 3A is a cross-sectional view taken along the line IIIa-IIIa in FIG. 2, and FIG. 3B is a front view of the multiple bit shown in FIG. 3A viewed from the face side, and is a partially enlarged view of FIG. It is also a figure. FIG. 4A is a side cross-sectional view showing a state in which the face is cut with the multiple bit according to the present embodiment, and FIG. 4B is a side cross-sectional view showing a state in which the outer bit is worn and damaged. FIG. 4C is a side sectional view showing a state in which the face is cut with the inner bit. FIG. 5A is a side view of a multiple bit according to a modified embodiment of the present invention, and FIG. 5A is a side view of the multiple bit according to this modified embodiment mounted on a cutter head and viewed from the radial direction of the cutter head. FIG. 5B is a cross-sectional view taken along the line Va-Va, and FIG. 5B is a front view of the multiple bit shown in FIG. 5A viewed from the face side.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Shield machine as a tunnel excavator 4 Cutter head 8 Multiple bit 10 Inner bit 10b Cutting tip 10c Face direction front part 10d Face face opposing part 11 Outer bit 11c Front cover part 11d Rear cover part 11e Connection part 12 Attachment means 12a Front side attachment Means 12b Rear side attachment means 121a Front concave portion 122a Front convex portion 123a Front hole 124a Front pin 121b Rear concave portion 122b Rear convex portion 123b Rear hole 124b Rear pin A Cutting direction B Face direction K Face

Claims (3)

A multi-bit mounted to cut a face on a cutter head provided in a tunnel excavator and driven to rotate,
An inner bit to be attached to the cutter head, an outer bit formed so as to cover a cutting tip of the inner bit, and attachment means for attaching the outer bit to the inner bit so as to cover the cutting tip,
The outer bit is connected to the front cover portion disposed in front of the inner bit in the cutting direction, the rear cover portion disposed above the inner bit in the face direction, and the front cover portion and the rear cover portion. And
The attachment means includes front attachment means for attaching the front cover portion to a front portion in the cutting direction of the inner bit, and rear attachment means for attaching the rear cover portion to a face facing portion of the inner bit. Multiple bits to play. The front attachment means has a front concave portion formed at a front portion in the cutting direction of the inner bit and a front convex portion formed at a front cover portion of the outer bit so as to be engaged with the front concave portion;
The rear mounting means includes a rear concave portion formed in a face facing portion of the inner bit and a rear convex portion formed in a rear cover portion of the outer bit so as to engage with the rear concave portion. The multiple bit according to 1. The front attachment means has a front hole formed in a front portion of the inner bit in the cutting direction, and a front pin that is attached to the front cover portion of the outer bit and inserted into the front hole;
The multiplex according to claim 1, wherein the rear attachment means includes a rear hole formed in a face facing portion of the inner bit and a rear pin attached to the rear cover portion of the outer bit and inserted into the rear hole. bit.

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