JP4413800B2 - Cutter bit - Google Patents

Description

The present invention is, for example, relates to a cutter bit for use in drilling machines, such as tunnel drilling shield machine.

  In recent years, in shield construction, from the viewpoints of ground conditions and cost reduction, the evolution of long-distance excavation is desired by reducing the number of shafts. For this reason, excavation between shafts, that is, exchanging cutter bits in the ground is necessary. In general, a cutter bit is known in which a cemented carbide chip is attached to a steel shank (base material).

  A general cutter bit tip used in the shield construction is a cemented carbide of JIS: E5 material having a hardness of 86 to 87 HRA. This E5 chip has a low wear resistance as compared with other materials (JIS: E4 to E1), but has a high reliability because it is resistant to chipping against impact. In addition, when brazing a steel base material, the E5 tip has less stress and strain than other materials (JIS: E4 to E1) that have a higher frictional resistance than the E5 tip, resulting in cracks. It is a factor that is often adopted that is difficult.

  And when a carbide | carbonized_material chip | tip carries out a chip | tip wear, a cutter bit will be replaced | exchanged. The cutter bit can be replaced by water-stopping the ground in front of the shield machine by an auxiliary method and manually from within the chamber, or by installing an exchange device on the shield machine. That is, if the life of the cutter bit is extended, the replacement of the cutter bit is reduced, and the excavation efficiency is improved.

  Conventionally, the cutter bit aiming at extending the lifetime is disclosed below. Specifically, there is a cutter bit in which a hard tip is implanted so that a tip portion protrudes from a tip surface of a base metal (base material). The tip of this cutter bit is planted in a plurality of stages from the front end to the base end, and the material of at least some of the chips is different from other chips (for example, , See Patent Document 1).

  In addition, there is a cutter bit that consists of a multi-layered chip in which a chip made of cemented carbide with different materials such as hardness and toughness is brazed by inserting a copper plate between them, and this multilayered chip is brazed to the base metal. Yes (see, for example, Patent Document 2).

  In addition, there is one in which a hard tip and a soft tip are alternately laminated and fixed to a cutter bit body (base material) (see, for example, Patent Document 3).

  In addition, there is one in which the cutting edge portion of the tip is made of ultrafine particle cemented carbide and the main body portion of the tip excluding the cutting edge portion is made of medium or coarse cemented carbide and joined to the base metal by brazing. (For example, refer to Patent Document 4).

JP 2003-193895 A JP-A-9-78986 Japanese Utility Model Publication No. 5-16897 Japanese Utility Model Publication No. 4-53879

  In order to extend the life, it is conceivable to use a soft cemented carbide tip and a hard cemented carbide tip together as in the conventional cutter bit described above. However, in a conventional cutter bit (see Patent Documents 1 to 3), a hard cemented carbide is brazed directly to a base material. The base material has a large thermal expansion, and the hard cemented carbide tip has a small thermal expansion. For this reason, there is a problem that cracks are likely to occur in the hard cemented carbide chip due to stress strain, making it difficult to manufacture.

  Moreover, the conventional cutter bit (see Patent Document 4) has no problem in that the soft cemented carbide tip of the tip body is brazed to the base material, but the cutting edge is composed of a hard cemented carbide tip. Therefore, there is a problem that the toughness is low and the cutting edge portion is easily damaged.

  As described above, it is difficult for a conventional cutter bit to appropriately use a soft cemented carbide tip and a hard cemented carbide tip together, and it has not been possible to obtain a substantially long-life cutter bit.

In view of the above circumstances, an object of the present invention is to provide a cutter bit capable of extending the life in a form in which a soft cemented carbide chip and a hard cemented carbide chip are appropriately used in combination .

In order to achieve the above object, a cutter bit according to claim 1 of the present invention is a cutter bit used in an excavator in which a chip made of cemented carbide is brazed to a base material made of steel. A chip composed of a soft tip made of a cemented carbide of a relatively soft material and a hard tip made of a cemented carbide of a material harder than the soft tip, and a material similar to the soft tip, Is made of a soft material, and includes at least a bonding material interposed between the hard tip and the base material and used for mutual brazing, and the hard tip is inserted into a through hole provided in the soft tip. And the bonding material is interposed between the soft tip and the hard tip and the base material .

  The cutter bit according to a second aspect of the present invention is characterized in that, in the first aspect, the hardness of the soft tip is 84 to 89 HRA, and the hardness of the hard tip is 85 to 92 HRA.

A cutter bit according to a third aspect of the present invention is the cutter bit according to the first or second aspect, wherein the cutter bit is provided in the bonding material by a material equivalent to the material of the bonding material, and a part of the through hole of the soft tip is provided. Further, a reinforcing portion to be inserted into a concave portion provided in the base material is provided .

A cutter bit according to a fourth aspect of the present invention is the cutter bit according to the first aspect , wherein the cutter bit is provided in the bonding material by a material equivalent to the material of the bonding material, and a part of the through hole of the soft tip and the base material A reinforcing portion to be inserted into the concave portion provided in is provided .

A cutter bit according to a fifth aspect of the present invention is the cutter bit according to any one of the first to fourth aspects, wherein the soft tip is divided and arranged .

A cutter bit according to a sixth aspect of the present invention is the cutter bit according to any one of the first to fifth aspects, wherein the hard tip is divided and arranged .

A cutter bit according to a seventh aspect of the present invention is the cutter bit according to any one of the first to sixth aspects, wherein the material is made of a cemented carbide which is harder and softer than the base material, or a super soft material. A material softer than a hard alloy is disposed at a portion where the base material is exposed .

  The cutter bit according to the present invention includes a soft tip made of a cemented carbide of a relatively soft material, a hard tip made of a cemented carbide of a material harder than the soft tip, and a soft tip whose material approximates that of the soft tip. It is made of a softer material and includes at least a bonding material interposed between the hard tip and the base material and used for mutual brazing. According to this cutter bit, high wear resistance is obtained by the hard tip, and the impact resistance is improved because the soft tip cushions the impact applied to the hard tip. As a result, it is possible to obtain a cutter bit that can extend the service life and perform long-distance excavation without replacement in the middle.

  Hereinafter, preferred embodiments of a cutter bit according to the present invention will be described in detail with reference to the accompanying drawings. Note that the present invention is not limited to the embodiments.

  FIG. 1 is a view of a cutter face to which a cutter bit according to the present invention is applied as viewed from the board side. As shown in FIG. 1, the cutter face 1 is formed in a disk shape, and is rotatably disposed at the tip of an excavator (not shown). A cutter bit is attached to the surface 11 of the cutter face 1. The cutter bits include a preceding bit 21, an outer periphery protection bit 22, a cutter bit 23A as a main bit 23, and a trim bit 23B. The leading bit 21 is arranged on the outer edge of the opening 12 provided on the board surface 11 of the cutter face 1 and on the board surface 11. The outer peripheral protection bit 22 is disposed on the outer peripheral edge of the board surface 11 of the cutter face 1. The main bit 23 is disposed at the inner edge of the opening 12, the trim bit 23 </ b> B projects outward from the outer peripheral edge of the board surface 11 of the cutter face 1, and the cutter bit 23 </ b> A is provided elsewhere. A center bit 24 is disposed at the center of the cutter face 1.

  The excavator (not shown) rotates the cutter face 1 to excavate the ground by the preceding bit 21, and the excavated earth and sand is excavated by the main bit 23 through the opening 12 (not shown). ). The outer periphery protection bit 22 is for protecting the outer periphery of the cutter face 1.

  Hereinafter, the cutter bit will be described. First, the first embodiment of the leading bit 21 will be described. 2 is a front view showing Embodiment 1 of a preceding bit that is a cutter bit according to the present invention, FIG. 3 is a plan view of the preceding bit shown in FIG. 2, and FIG. 4 is a side view of the preceding bit shown in FIG. 5 is a sectional view taken along the line II in FIG. 3, and FIG. 6 is a sectional view showing another example of the preceding bit shown in FIG.

  As shown in FIGS. 2 to 5, the leading bit 21 is provided with a chip 212 made of cemented carbide with respect to a base material 211 made of steel. The chip 212 includes a soft chip 212A and a hard chip 212B.

  The soft tip 212A is made of a cemented carbide made of a relatively soft material. The material of the flexible chip 212A in the present embodiment is JIS: E5, which is a hardness of 86 to 87HRA. The soft tip 212A is provided with a through hole 212Aa penetrating from the bit front end to the bit base end. In this embodiment, the through-hole 212Aa is formed in a circular opening shape, and a plurality of (three places) are provided. The opening shape of the through hole 212Aa is not limited to a circular shape.

  The hard tip 212B is made of a cemented carbide made of a material harder than the soft tip 212A. The material of the hard chip 212B in the present embodiment is JIS: E4 to E1 having a hardness of 87 to 92HRA, and preferably JIS: E2 having a hardness of 89 to 91HRA. The hard tip 212B is formed in a rod shape so as to be inserted into the through hole 212Aa of the soft tip 212A in accordance with the opening shape. That is, the hard chip 212B is formed in a cylindrical shape in the present embodiment.

  In the chip 212, a soft chip 212A and a hard chip 212B are fixed to each other by brazing. The brazing material used for brazing is composed of at least one of, for example, silver brazing, copper brazing, phosphor copper brazing, nickel brazing, palladium brazing, and the same applies to all the following embodiments.

  A bonding material 213 is interposed between the chip 212 and the base material 211. The bonding material 213 is made of a material similar to the cemented carbide of the soft tip 212A and softer than the soft tip 212A. The material of the bonding material 213 in the present embodiment is a cemented carbide which is softer than the soft tip 212A and harder than the base material 211. The bonding material 213 is interposed between the soft tip 212A and the hard tip 212B, and the base material 211, and is used for mutual fixation by brazing.

  As shown in FIG. 5, the bonding member 213 is provided with a reinforcing portion 213A. The reinforcing portion 213A is provided on the bonding material 213 by a material equivalent to the material of the bonding material 213, and protrudes toward the tip 212 side and the base material 211 side. The reinforcing portion 213A is inserted into a part of the through hole 212Aa of the soft tip 212A and a recess provided in the base material 211 and fixed by brazing.

  As shown by a one-dot chain line in FIG. 2 to FIG. 4, a hardened layer 214 is provided at a portion of the base material 211 that is exposed to the outside of the preceding bit 21. The hardfacing 214 is a material made of a cemented carbide that is harder and softer than the base material 211, or a softer material than the soft tip 212A, and has a hardness HV = 600 that is softer than JIS: E5, for example. It is made of a material of ˜1000, and is cut directly and to a predetermined depth on the outer surface of the base material 211 and is provided by welding. The softer material than the soft tip 212A is a material made of one of martensite, austenite, high manganese / austenite, high chromium iron, and tungsten carbide.

  The soft tip 212A and the hard tip 212B may be divided into a plurality from the bit tip to the bit base as shown in FIG. 6, and may be fixed by brazing.

  The leading bit 21 configured in this way is fixed to the board surface 11 of the cutter face 1 by welding via a base material 211 as shown in FIG. When the cutter face 1 rotates, the side of the tip 212, which is the soft tip 212A, comes into contact with the ground to excavate the ground. That is, the leading bit 21 has high wear resistance due to the hard tip 212B, and the impact resistance is improved because the soft tip 212A cushions the impact applied to the hard tip 212B. As a result, the life of the leading bit 21 can be extended, and long-distance excavation can be performed without replacing the leading bit 21 in the middle.

  In addition, the preceding bit 21 described above has a bonding material 213 made of a material that is similar to the cemented carbide of the soft tip 212A and softer than the soft tip 212A, interposed between the tip 212 and the base material 211. It is brazed. That is, the base material 211 has a large thermal expansion, and the soft chip 212A and the hard chip 212B have a small thermal expansion. However, since the bonding material 213 relaxes the stress strain between them, the chip 212 (particularly the hard chip 212B) is cracked. It is possible to prevent the situation that occurs. As a result, the manufacture of the preceding bit 21 having the above configuration is facilitated.

  Further, the preceding bit 21 described above is provided with a reinforcing portion 213 </ b> A on the bonding material 213. As a result, the bonding between the chip 212 and the base material 211 can be further strengthened.

  Furthermore, the preceding bit 21 described above is provided with a hardened layer 214 at a portion of the base material 211 that is exposed to the outside. The hardfacing 214 acts as a wear stop for the base material 211. As a result, the life of the leading bit 21 can be extended, and long-distance excavation can be performed without replacing the leading bit 21 in the middle.

  The preceding bit 21 described above is provided by dividing the flexible chip 212A into a plurality of pieces. As a result, even if a part of the soft tips 212A divided during excavation is lost, it is possible to prevent the other soft tips 212A from being lost together. Long-distance excavation can be performed without exchanging 21 on the way.

  Next, a second embodiment of the leading bit 21 will be described. 7 is a front view showing a second embodiment of a preceding bit which is a cutter bit according to the present invention, FIG. 8 is a plan view of the preceding bit shown in FIG. 7, and FIG. 9 is a side view of the preceding bit shown in FIG. 10 is a sectional view taken along line II-II in FIG. Note that, in the second embodiment of the preceding bit 21, the same parts as those of the first embodiment of the preceding bit 21 described above are denoted by the same reference numerals.

  As shown in FIGS. 7 to 10, the leading bit 21 is provided with a chip 212 made of cemented carbide with respect to a base material 211 made of steel. The chip 212 includes a soft chip 212A and a hard chip 212B.

  The soft tip 212A is made of a cemented carbide made of a relatively soft material. The material of the flexible chip 212A in the present embodiment is JIS: E5, which is a hardness of 86 to 87HRA.

  The hard tip 212B is made of a cemented carbide made of a material harder than the soft tip 212A. The material of the hard chip 212B in the present embodiment is JIS: E4 to E1 having a hardness of 87 to 92HRA, and preferably JIS: E2 having a hardness of 89 to 91HRA.

  The chip 212 is provided with a base material 211 extending to the tip of the bit, and as shown in FIGS. 7 and 10, is arranged in notches 211A provided on both sides and the center of the base material 211 as viewed from the front. . Then, on both sides of the leading bit 21, the soft tip 212A is arranged on the most lateral side (outer side) with respect to the notch 211A notched in an approximately L shape that opens upward and laterally in FIGS. The hard chip 212B is laminated inside the soft chip 212A. In this case, the soft tip 212A and the hard tip 212B are fixed to each other by brazing. Further, in the central portion of the leading bit 21, a part of the portion exposed to the bit tip portion of the base material 211 has a hard tip 212B with respect to the notch 211A opened upward in FIGS. A material equivalent to the cemented carbide of the hard tip 212B is arranged.

  A bonding material 213 is interposed between the chip 212 and the base material 211. The bonding material 213 is made of a material similar to the cemented carbide of the soft tip 212A and softer than the soft tip 212A. The material of the bonding material 213 in the present embodiment is a cemented carbide which is softer than the soft tip 212A and harder than the base material 211. The bonding material 213 is interposed between the soft tip 212A and the hard tip 212B (including a material equivalent to the cemented carbide alloy of the hard tip 212B) and the base material 211, and serves to fix each other by brazing.

  As shown by the alternate long and short dash line in FIGS. 7 to 9, a hardened layer 214 is provided at a portion of the base material 211 that is exposed to the outside of the preceding bit 21. The hardfacing 214 is a material made of a cemented carbide that is harder and softer than the base material 211, or a softer material than the soft tip 212A, and has a hardness HV = 600 that is softer than JIS: E5, for example. It is made of a material of ˜1000, and is cut directly and to a predetermined depth on the outer surface of the base material 211 and is provided by welding. The softer material than the soft tip 212A is a material made of one of martensite, austenite, high manganese / austenite, high chromium iron, and tungsten carbide.

  The preceding bit 21 configured in this manner is fixed to the board surface 11 of the cutter face 1 by welding via a base material 211 as shown in FIG. When the cutter face 1 is rotated, the soft tip 212A disposed on the side of the tip 212 comes into contact with the ground to excavate the ground. That is, the leading bit 21 has high wear resistance due to the hard tip 212B, and the impact resistance is improved because the soft tip 212A cushions the impact applied to the hard tip 212B. As a result, the life of the leading bit 21 can be extended, and long-distance excavation can be performed without replacing the leading bit 21 in the middle.

  In addition, the preceding bit 21 described above has a bonding material 213 made of a material that is similar to the cemented carbide of the soft tip 212A and softer than the soft tip 212A, interposed between the tip 212 and the base material 211. It is brazed. That is, the base material 211 has a large thermal expansion, and the soft chip 212A and the hard chip 212B have a small thermal expansion. However, since the bonding material 213 relaxes the stress strain between them, the chip 212 (particularly the hard chip 212B) is cracked. It is possible to prevent the situation that occurs. As a result, the manufacture of the preceding bit 21 having the above configuration is facilitated.

  Further, the above-described preceding bit 21 is provided with a hardened layer 214 at a portion of the base material 211 that is exposed to the outside. The hardfacing 214 acts as a wear stop for the base material 211. As a result, the life of the leading bit 21 can be extended, and long-distance excavation can be performed without replacing the leading bit 21 in the middle. In addition, in the preceding bit 21 described above, a material equivalent to the hard tip 212B or the cemented carbide alloy of the hard tip 212B is disposed through a bonding material 213 in a part of the portion exposed at the bit tip portion of the base material 211. It is. The hard tip 212B (including a material equivalent to the cemented carbide of the hard tip 212B) acts as a wear stop for the base material 211. As a result, the life of the leading bit 21 can be extended, and long-distance excavation can be performed without replacing the leading bit 21 in the middle.

  Although not shown in the figure, in the above-described second embodiment of the preceding bit 21, the soft tip 212A and the hard tip 212B are divided into a plurality from the bit tip to the bit base, and brazed. It is good also as a structure fixed by. As a result, even if some of the divided soft chips 212A and hard chips 212B are lost during excavation, it is possible to prevent the other soft chips 212A and hard chips 212B from being lost together. Therefore, long-distance excavation can be performed without exchanging the leading bit 21 halfway. Further, when the soft chip 212A and the hard chip 212B are divided, it is preferable that the soft chip 212A and the hard chip 212B are divided in steps from the bit tip to the bit base end. Thereby, the situation where both the soft chip 212A and the hard chip 212B are lost can be prevented.

  Although not explicitly shown in the drawing, in the second embodiment of the preceding bit 21 described above, a part of the portion that is exposed at the bit front end portion of the base material 211 at the center thereof is the upper part of FIGS. 7 and 10. A material equivalent to the soft tip 212A or the cemented carbide of the soft tip 212A may be disposed in the notch 211A that opens toward the top. In this case, brazing may be performed without interposing the bonding material 213 between the soft tip 212A (including a material equivalent to the cemented carbide of the soft tip 212A) and the base material 211. The soft tip 212A (including a material equivalent to the cemented carbide of the soft tip 212A) arranged as described above also acts as a wear stop for the base material 211. As a result, the life of the leading bit 21 can be extended, and long-distance excavation can be performed without replacing the leading bit 21 in the middle.

  Next, the outer periphery protection bit 22 will be described. 11 is a front view showing an embodiment of an outer periphery protection bit which is a cutter bit according to the present invention, FIG. 12 is a plan view of the outer periphery protection bit shown in FIG. 11, and FIG. 13 is a side view of the outer periphery protection bit shown in FIG. 14 is a sectional view taken along line III-III in FIG. 13, and FIG. 15 is a sectional view taken along line IV-IV in FIG.

  As shown in FIGS. 11 to 15, the outer peripheral protection bit 22 is provided with a chip 222 made of cemented carbide with respect to a base material 221 made of steel. The chip 222 includes a soft chip 222A and a hard chip 222B.

  The soft tip 222A is made of a cemented carbide made of a relatively soft material. The material of the soft tip 222A in the present embodiment is JIS: E5, which is a hardness of 86 to 87HRA.

  The hard tip 222B is made of a cemented carbide made of a material harder than the soft tip 222A. The material of the hard tip 222B in the present embodiment is JIS: E4 to E1 having a hardness of 87 to 92HRA, and preferably JIS: E2 having a hardness of 89 to 91HRA.

  The chip 222 is provided with a base material 221 extending to the tip of the bit, and is disposed in notches 221A provided on both sides and the center of the base material 221 when viewed from the front as shown in FIGS. . Then, on both side portions of the outer peripheral protection bit 22, the soft tip 222A is arranged on the most lateral side (outer side) with respect to the notch 221A notched in a substantially L shape that opens upward and laterally in FIGS. In addition, a hard chip 222B is laminated inside the soft chip 222A. In this case, the soft tip 222A and the hard tip 222B are fixed to each other by brazing. Further, in the center portion of the outer peripheral protection bit 22, a part of the portion exposed to the bit tip portion of the base material 221 has a hard tip 222B with respect to the notch 221A opened upward in FIGS. Alternatively, a material equivalent to the cemented carbide of the hard tip 222B is arranged.

  A bonding material 223 is interposed between the chip 222 and the base material 221. The bonding material 223 is made of a material that is similar to the cemented carbide of the soft tip 222A and is softer than the soft tip 222A. The material of the bonding material 223 in the present embodiment is a cemented carbide which is softer than the soft tip 222A and harder than the base material 221. The bonding material 223 is interposed between the soft tip 222A and the hard tip 222B (including a material equivalent to the cemented carbide alloy of the hard tip 222B) and the base material 221, and is used for mutual fixation by brazing.

  As shown by a one-dot chain line in FIGS. 11 to 13, a hardfacing 224 is provided at a portion of the base material 221 that is exposed to the outside of the outer peripheral protection bit 22. The hardfacing 224 is a material made of a cemented carbide that is harder and softer than the base material 221 or softer than the soft tip 222A, and has a hardness HV = 600 that is softer than JIS: E5, for example. It is made of a material of ~ 1000, and is cut directly and to a predetermined depth on the outer surface of the base material 221 and provided by welding. The softer material than the soft tip 222A is a material made of one of martensite, austenite, high manganese / austenite, high chromium iron, and tungsten carbide.

  As shown in FIG. 11, the outer peripheral protection bit 22 having another configuration configured as described above is fixed to the board surface 11 of the cutter face 1 by welding via a base material 221. Then, when the cutter face 1 is rotated, the soft tip 222A disposed on the side of the tip 222 comes into contact with the ground to excavate the ground. That is, the outer peripheral protection bit 22 has high wear resistance due to the hard tip 222B, and the impact resistance is improved because the soft tip 222A cushions the impact applied to the hard tip 222B. As a result, the life of the outer periphery protection bit 22 can be extended, and long distance excavation can be performed without replacing the outer periphery protection bit 22 on the way.

  Further, the outer peripheral protection bit 22 described above has a bonding material 223 made of a material that is similar to the cemented carbide of the soft tip 222A and is softer than the soft tip 222A, interposed between the tip 222 and the base material 221. It is brazed. That is, the base material 221 has a large thermal expansion, and the soft tip 222A and the hard tip 222B have a small thermal expansion. However, since the bonding material 223 relaxes the stress strain between them, the chip 222 (particularly the hard tip 222B) is cracked. It is possible to prevent the situation that occurs. As a result, the outer periphery protection bit 22 having the above-described configuration can be easily manufactured.

  Further, the outer peripheral protection bit 22 described above is provided with a hardfacing overlay 224 at a portion of the base material 221 exposed to the outside. The hardfacing 224 acts as a wear stop for the base material 221. As a result, the life of the outer periphery protection bit 22 can be extended, and long distance excavation can be performed without replacing the outer periphery protection bit 22 on the way. Further, the outer peripheral protection bit 22 described above is made of a material equivalent to the hard tip 222B or the cemented carbide alloy of the hard tip 222B through a bonding material 223 in a part of the portion exposed at the bit tip portion of the base material 221. It is arranged. The hard tip 222B (including a material equivalent to the cemented carbide of the hard tip 222B) acts as a wear stop for the base material 221. As a result, the life of the outer periphery protection bit 22 can be extended, and long distance excavation can be performed without replacing the outer periphery protection bit 22 on the way.

  Although not explicitly shown in the figure, in the above-described outer peripheral protection bit 22, the soft tip 222A and the hard tip 222B are divided into a plurality from the bit leading end to the bit base end and fixed by brazing. It is good. As a result, even if some of the divided soft tips 222A and hard tips 222B are lost during excavation, the other soft tips 222A and hard tips 222B that are split are prevented from being lost together. Therefore, long-distance excavation can be performed without exchanging the outer periphery protection bit 22 on the way. In addition, when the soft tip 222A and the hard tip 222B are divided, it is preferable to divide them in a stepwise manner from the bit leading end to the bit base end. Thereby, the situation where both the soft tip 222A and the hard tip 222B are lost can be prevented.

  In addition, although not shown in the drawing, in the outer peripheral protection bit 22 described above, a part of the portion that is exposed to the bit tip portion of the base material 221 at the center is opened upward in FIGS. 11 and 14. A material equivalent to the soft tip 222A or the cemented carbide of the soft tip 222A may be disposed in the notch 221A. In this case, brazing may be performed without interposing the bonding material 223 between the soft tip 222A (including a material equivalent to the cemented carbide of the soft tip 222A) and the base material 221. The soft tip 222A (including a material equivalent to the cemented carbide of the soft tip 222A) arranged in this way also acts as a wear stop for the base material 221. As a result, the life of the outer periphery protection bit 22 can be extended, and long distance excavation can be performed without replacing the outer periphery protection bit 22 on the way.

  Next, the first embodiment of the main bit 23 will be described. 16 is a side view showing Embodiment 1 of the main bit which is a cutter bit according to the present invention, and FIG. 17 is a plan view of the main bit shown in FIG.

  As shown in FIGS. 16 and 17, the main bit 23 has a tip 232 made of cemented carbide disposed on the tip of a base material 231 made of steel. The chip 232 includes a soft chip 232A and a hard chip 232B.

  The soft tip 232A is made of a cemented carbide made of a relatively soft material. The material of the soft tip 232A in the present embodiment is JIS: E5, which has a hardness of 86 to 87HRA. The soft tip 232A is provided with a through hole 232Aa penetrating from the upper side to the lower side in FIG. In this embodiment, the through-hole 232Aa is formed in a circular opening shape, and a plurality of (three places) are provided. The opening shape of the through hole 232Aa is not limited to a circular shape.

  The hard tip 232B is made of a cemented carbide that is harder than the soft tip 232A. The material of the hard chip 232B in the present embodiment is JIS: E4 to E1 having a hardness of 87 to 92HRA, and preferably JIS: E2 having a hardness of 89 to 91HRA. The hard tip 232B is formed in a rod shape so as to be inserted into the through hole 232Aa of the soft tip 232A in accordance with the opening shape. That is, the hard chip 232B is formed in a cylindrical shape in the present embodiment.

  In the chip 232, the soft chip 232A and the hard chip 232B are fixed to each other by brazing. As shown in FIG. 16, the chip 232 is arranged with respect to a notch 231A cut out in a substantially L shape that opens upward and toward the tip when viewed from the side.

  A bonding material 233 is interposed between the chip 232 and the base material 231. The bonding material 233 is made of a material similar to the cemented carbide of the soft tip 232A and softer than the soft tip 232A. The material of the bonding material 233 in the present embodiment is a cemented carbide which is softer than the soft tip 232A and harder than the base material 231. The bonding material 233 is interposed between the soft tip 232A and the hard tip 232B and the base material 231, and is used for mutual fixation by brazing.

  Note that the soft tip 232A may be divided into a plurality of sides as shown in FIG. 17, and may be fixed by brazing.

  The main bit 23 configured in this manner is fixed to the board surface 11 of the cutter face 1 by bolting the base end of the base material 231 on the side opposite to the side on which the chip 232 is provided, although not explicitly shown in the drawing. When the cutter face 1 is rotated, the tip of the tip 232 (the upper end in FIG. 16), which is the soft tip 232A side, comes into contact with the ground to excavate the ground. That is, the main bit 23 has high wear resistance due to the hard tip 232B, and the impact resistance is improved because the soft tip 232A cushions the impact applied to the hard tip 232B. As a result, the life of the main bit 23 can be extended, and long-distance excavation can be performed without exchanging the main bit 23 halfway.

  Further, the main bit 23 described above has a bonding material 233 made of a material that is similar to the cemented carbide of the soft tip 232A and is softer than the soft tip 232A, interposed between the tip 232 and the base material 231. It is brazed. That is, the base material 231 has a large thermal expansion, and the soft chip 232A and the hard chip 232B have a small thermal expansion. However, since the bonding material 233 relaxes the stress strain between them, the chip 232 (particularly the hard chip 232B) is cracked. It is possible to prevent the situation that occurs. As a result, the manufacture of the main bit 23 having the above configuration is facilitated.

  The main bit 23 described above is provided by dividing the flexible chip 232A into a plurality of pieces. As a result, even if some of the divided soft tips 232A are lost during excavation, the other soft tips 232A that are divided are prevented from being lost together, so that the life of the main bit 23 can be extended. It becomes possible to perform long-distance excavation without exchanging 23 on the way.

  Next, a second embodiment of the main bit 23 will be described. 18 is a side view showing Embodiment 2 of the main bit which is a cutter bit according to the present invention, and FIG. 19 is a plan view of the main bit shown in FIG. In the second embodiment of the main bit 23, the same reference numerals are given to the same parts as those of the first embodiment of the main bit 23 described above.

  As shown in FIGS. 18 and 19, the main bit 23 has a tip 232 made of cemented carbide disposed on the tip of a base material 231 made of steel. The chip 232 includes a soft chip 232A and a hard chip 232B.

  The soft tip 232A is made of a cemented carbide made of a relatively soft material. The material of the soft tip 232A in the present embodiment is JIS: E5, which has a hardness of 86 to 87HRA.

  The hard tip 232B is made of a cemented carbide that is harder than the soft tip 232A. The material of the hard chip 232B in the present embodiment is JIS: E4 to E1 having a hardness of 87 to 92HRA, and preferably JIS: E2 having a hardness of 89 to 91HRA.

  The chip 232 is disposed with respect to a notch 231A cut out in a substantially L shape that opens upward and toward the tip in FIG. Then, the soft tip 232A is arranged on the most distal side (outer side), the hard tip 232B is stacked inside the soft tip 232A, and the soft tip 232A is further stacked inside the hard tip 232B, and the soft tip 232A is used as the hard tip. It is arranged in a form sandwiching 232B. In this case, the soft tip 232A and the hard tip 232B are fixed to each other by brazing.

  A bonding material 233 is interposed between the chip 232 and the base material 231. The bonding material 233 is made of a material similar to the cemented carbide of the soft tip 232A and softer than the soft tip 232A. The material of the bonding material 233 in the present embodiment is a cemented carbide which is softer than the soft tip 232A and harder than the base material 231. The bonding material 233 is interposed between the soft tip 232A and the hard tip 232B and the base material 231, and is used for mutual fixation by brazing.

  Note that the laminated soft chip 232A and hard chip 232B may be divided into a plurality of sides as shown in FIG. 19, and may be fixed by brazing. Furthermore, the laminated soft chip 232A and hard chip 232B may be divided into a plurality of parts as shown in FIG. 18 and fixed by brazing.

  The main bit 23 configured in this manner is fixed to the board surface 11 of the cutter face 1 by bolting the base end of the base material 231 on the side opposite to the side on which the chip 232 is provided, although not explicitly shown in the drawing. When the cutter face 1 rotates, the tip of the tip 232 (the upper end of FIG. 18), the soft tip 232A side, comes into contact with the ground to excavate the ground. That is, the main bit 23 has high wear resistance due to the hard tip 232B, and the impact resistance is improved because the soft tip 232A cushions the impact applied to the hard tip 232B. As a result, the life of the main bit 23 can be extended, and long-distance excavation can be performed without exchanging the main bit 23 halfway.

  Further, the main bit 23 described above has a bonding material 233 made of a material that is similar to the cemented carbide of the soft tip 232A and is softer than the soft tip 232A, interposed between the tip 232 and the base material 231. It is brazed. That is, the base material 231 has a large thermal expansion, and the soft chip 232A and the hard chip 232B have a small thermal expansion. However, since the bonding material 233 relaxes the stress strain between them, the chip 232 (particularly the hard chip 232B) is cracked. It is possible to prevent the situation that occurs. As a result, the manufacture of the main bit 23 having the above configuration is facilitated.

  The main bit 23 described above is provided by dividing the laminated soft chip 232A and hard chip 232B into a plurality of parts. As a result, even if a part of the soft tip 232A or the hard tip 232B divided at the time of excavation is lost, the other soft tip 232A or the hard tip 232B that is divided is prevented from being lost together. Therefore, long-distance excavation can be performed without exchanging the main bit 23 halfway.

  Next, a third embodiment of the main bit 23 will be described. 20 is a front view of the main bit as a cutter bit according to the third embodiment of the present invention as viewed from the tip, FIG. 21 is a side view of the main bit shown in FIG. 20, and FIG. 22 is a view of the main bit shown in FIG. It is a top view. In the third embodiment of the main bit 23, the same reference numerals are given to the same portions of the main bit 23 as those of the first embodiment.

  As shown in FIGS. 20 to 22, the main bit 23 is provided with a tip 232 made of cemented carbide at the tip of a base material 231 made of steel. The chip 232 includes a soft chip 232A and a hard chip 232B.

  The soft tip 232A is made of a cemented carbide made of a relatively soft material. The material of the soft tip 232A in the present embodiment is JIS: E5, which has a hardness of 86 to 87HRA. The soft tip 232A is provided with a through hole 232Aa penetrating from the distal end to the proximal end in FIG. In this embodiment, the through-hole 232Aa is formed in a circular opening shape, and a plurality of (three places) are provided. The opening shape of the through hole 232Aa is not limited to a circular shape.

  The hard tip 232B is made of a cemented carbide that is harder than the soft tip 232A. The material of the hard chip 232B in the present embodiment is JIS: E4 to E1 having a hardness of 87 to 92HRA, and preferably JIS: E2 having a hardness of 89 to 91HRA. The hard tip 232B is formed in a rod shape so as to be inserted into the through hole 232Aa of the soft tip 232A in accordance with the opening shape. That is, the hard chip 232B is formed in a cylindrical shape in the present embodiment.

  In the chip 232, the soft chip 232A and the hard chip 232B are fixed to each other by brazing. As shown in FIG. 21, the chip 232 is arranged with respect to a notch 231A cut out in a substantially L shape that opens upward and toward the tip when viewed from the side.

  A bonding material 233 is interposed between the chip 232 and the base material 231. The bonding material 233 is made of a material similar to the cemented carbide of the soft tip 232A and softer than the soft tip 232A. The material of the bonding material 233 in the present embodiment is a cemented carbide which is softer than the soft tip 232A and harder than the base material 231. The bonding material 233 is interposed between the soft tip 232A and the hard tip 232B and the base material 231, and is used for mutual fixation by brazing.

  The main bit 23 configured in this manner is fixed to the board surface 11 of the cutter face 1 by bolting the base end of the base material 231 on the side opposite to the side on which the chip 232 is provided, although not explicitly shown in the drawing. When the cutter face 1 is rotated, the tip of the tip 232 (the upper end in FIG. 16), which is the soft tip 232A side, comes into contact with the ground to excavate the ground. That is, the main bit 23 has high wear resistance due to the hard tip 232B, and the impact resistance is improved because the soft tip 232A cushions the impact applied to the hard tip 232B. As a result, the life of the main bit 23 can be extended, and long-distance excavation can be performed without exchanging the main bit 23 halfway.

  Further, the main bit 23 described above has a bonding material 233 made of a material that is similar to the cemented carbide of the soft tip 232A and is softer than the soft tip 232A, interposed between the tip 232 and the base material 231. It is brazed. That is, the base material 231 has a large thermal expansion, and the soft chip 232A and the hard chip 232B have a small thermal expansion. However, since the bonding material 233 relaxes the stress strain between them, the chip 232 (particularly the hard chip 232B) is cracked. It is possible to prevent the situation that occurs. As a result, the manufacture of the main bit 23 having the above configuration is facilitated.

  Next, a fourth embodiment of the main bit 23 will be described. FIG. 23 is a front view of a main bit as a cutter bit according to a fourth embodiment of the present invention as viewed from the tip, FIG. 24 is a side view of the main bit shown in FIG. 23, and FIG. 25 is a view of the main bit shown in FIG. It is a top view. In the fourth embodiment of the main bit 23, the same reference numerals are given to the same portions of the main bit 23 as those of the first embodiment.

  As shown in FIGS. 23 to 25, the main bit 23 is provided with a tip 232 made of cemented carbide at the tip of a base material 231 made of steel. The chip 232 includes a soft chip 232A and a hard chip 232B.

  The soft tip 232A is made of a cemented carbide made of a relatively soft material. The material of the soft tip 232A in the present embodiment is JIS: E5, which has a hardness of 86 to 87HRA.

  The hard tip 232B is made of a cemented carbide that is harder than the soft tip 232A. The material of the hard chip 232B in the present embodiment is JIS: E4 to E1 having a hardness of 87 to 92HRA, and preferably JIS: E2 having a hardness of 89 to 91HRA.

  The chip 232 is disposed with respect to a notch 231A cut out in a substantially L shape that opens upward and toward the tip of FIG. The soft chip 232A is disposed on the uppermost side (outer side), the hard chip 232B is stacked on the lower side (inner side) of the soft chip 232A, and the soft chip 232A is stacked on the lower side (inner side) of the hard chip 232B. Thus, the hard chip 232B is sandwiched between the soft chips 232A. In this case, the soft tip 232A and the hard tip 232B are fixed to each other by brazing.

  A bonding material 233 is interposed between the chip 232 and the base material 231. The bonding material 233 is made of a material similar to the cemented carbide of the soft tip 232A and softer than the soft tip 232A. The material of the bonding material 233 in the present embodiment is a cemented carbide which is softer than the soft tip 232A and harder than the base material 231. The bonding material 233 is interposed between the soft tip 232A and the hard tip 232B and the base material 231, and is used for mutual fixation by brazing.

  The laminated soft chip 232A and hard chip 232B may be divided into a plurality of sides as shown in FIG. 25, and may be fixed by brazing. Furthermore, the laminated soft chip 232A and hard chip 232B may be divided into a plurality of pieces in the distal direction as shown in FIG. 24, and may be fixed by brazing.

  The main bit 23 configured in this manner is fixed to the board surface 11 of the cutter face 1 by bolting the base end of the base material 231 on the side opposite to the side on which the chip 232 is provided, although not explicitly shown in the drawing. When the cutter face 1 is rotated, the tip of the tip 232 (the upper end in FIG. 23), the soft tip 232A side, comes into contact with the ground to excavate the ground. That is, the main bit 23 has high wear resistance due to the hard tip 232B, and the impact resistance is improved because the soft tip 232A cushions the impact applied to the hard tip 232B. As a result, the life of the main bit 23 can be extended, and long-distance excavation can be performed without exchanging the main bit 23 halfway.

  Further, the main bit 23 described above has a bonding material 233 made of a material that is similar to the cemented carbide of the soft tip 232A and is softer than the soft tip 232A, interposed between the tip 232 and the base material 231. It is brazed. That is, the base material 231 has a large thermal expansion, and the soft chip 232A and the hard chip 232B have a small thermal expansion. However, since the bonding material 233 relaxes the stress strain between them, the chip 232 (particularly the hard chip 232B) is cracked. It is possible to prevent the situation that occurs. As a result, the manufacture of the main bit 23 having the above configuration is facilitated.

  The main bit 23 described above is provided by dividing the laminated soft chip 232A and hard chip 232B into a plurality of parts. As a result, even if a part of the soft tip 232A or the hard tip 232B divided at the time of excavation is lost, the other soft tip 232A or the hard tip 232B that is divided is prevented from being lost together. Therefore, long-distance excavation can be performed without exchanging the main bit 23 halfway.

  FIG. 26 is a plan view showing a preceding bit which is a general conventional cutter bit, and FIG. 27 is a front view of the preceding bit shown in FIG. 26 and FIG. 27, the tip 102 mainly made of a JIS: E5 (or E3) cemented carbide is fixed to both ends of a base material 101 made of steel by brazing. is there. The chip 102 has a width W of 20 mm to 40 mm, a height T of 20 mm to 60 mm, and a thickness H of 10 mm to 30 mm. Based on this leading bit 100, for example, when trying to design a long-life cutter bit for long-distance excavation that excavates 10 km without replacement, for example, for a cutter bit that excavates 2 km without replacement, the size of the chip 102 is , Width W is double, height T is 3 to 10 times, and thickness H is 2 to 3 times. That is, the design is difficult because the height T is too high. However, in the above-described cutter bit (for example, the preceding bit 21) according to the present invention, the soft tip 212A made of E5 and the hard tip 212B made of E4 to E1 (preferably E2) are used in combination, and each tip The joining material 213 was interposed between 212A and 212B and the base material 211 and brazed. As a result, a long-life excavation long-life cutter bit (for example, the leading bit 21) having high wear resistance and impact resistance is obtained, and the height H of the tip 212 is set to 2 with respect to the general tip 102. It becomes possible to design with about twice the size.

  As described above, the above-described cutter bit can achieve a long life, and can eliminate the need for replacement during long-distance excavation. Further, since the mechanical life of the exchanging machine with the cutter bit for replacement becomes unnecessary due to the long life, the construction of the excavator can be simplified and the cost can be reduced. Furthermore, long-distance excavation can be performed even with an excavator having a medium diameter (cutter face diameter of about 5 m to 7 m) that cannot accommodate a mechanical exchange device.

  Although not clearly shown in the figure, the center bit 24, which is a cutter bit, can have the same configuration as the preceding bit 21, the outer periphery protection bit 22, or the main bit 23 described above.

  In each of the embodiments described above, JIS: E5, which is a hardness of 86 to 87 HRA, is applied as the material of the soft chips 212A, 222A, and 232A, and the material of the hard chips 212B, 222B, and 232B is a hard material of 87 to 92HRA. Although JIS: E4 to E1 (preferably JIS: E2 having a hardness of 89 to 91 HRA) is applied, it is not limited to this. For example, the material of the soft chips 212A, 222A, and 232A is JIS: E4 having a hardness of 87 to 88HRA, and the material of the hard chips 212B, 222B, and 232B is JIS: E3 to E1 having a hardness of 88 to 92HRA. (Preferably JIS: E2) may be applied. Further, JIS: E3 having a hardness of 88 to 89 HRA is applied as the material of the flexible chips 212A, 222A and 232A, and JIS: E2 to E1 having a hardness of 89 to 92HRA as the material of the hard chips 212B, 222B and 232B. (Preferably JIS: E2) may be applied. Further, the material of the soft tips 212A, 222A, 232A may be 84 to 89 HRA, and the material of the hard tips 212B, 222B, 232B may be 85 to 92 HRA.

  Further, in each of the above-described embodiments, the chips 212 and 222 in which the flexible chips 212A, 222A, and 232A, the hard chips 212B, 222B, and 232B, and the bonding materials 213, 223, and 233 are bonded in advance by brazing or diffusion bonding. , 232 may be brazed to the base materials 211, 221, 231. In this way, stress distortion between the chips 212, 222, 232 and the base materials 211, 221, 231 is relieved, so that the chips 212, 222, 232 (particularly the hard chips 212B, 222B, 232B) are produced during the manufacturing process. ) Can be prevented from cracking. As a result, the long-life cutter bits (21, 22, 23) having the above-described configuration can be easily manufactured.

It is the figure which looked at the cutter face to which the cutter bit concerning the present invention is applied from the board side. It is a front view showing Embodiment 1 of a preceding bit which is a cutter bit concerning the present invention. FIG. 3 is a plan view of a preceding bit shown in FIG. 2. FIG. 3 is a side view of the preceding bit shown in FIG. 2. It is II sectional drawing in FIG. It is sectional drawing which shows the other example of the preceding bit shown in FIG. It is a front view which shows Embodiment 2 of the preceding bit which is a cutter bit which concerns on this invention. It is a top view of the preceding bit shown in FIG. FIG. 8 is a side view of the preceding bit shown in FIG. 7. It is II-II sectional drawing in FIG. It is a front view which shows embodiment of the outer periphery protection bit which is a cutter bit which concerns on this invention. It is a top view of the outer periphery protection bit shown in FIG. It is a side view of the outer periphery protection bit shown in FIG. It is III-III sectional drawing in FIG. It is IV-IV sectional drawing in FIG. It is a side view which shows Embodiment 1 of the main bit which is a cutter bit which concerns on this invention. It is a top view of the main bit shown in FIG. It is a side view which shows Embodiment 2 of the main bit which is a cutter bit which concerns on this invention. It is a top view of the main bit shown in FIG. It is the front view seen from the tip which shows Embodiment 3 of the main bit which is a cutter bit concerning the present invention. It is a side view of the main bit shown in FIG. It is a top view of the main bit shown in FIG. It is the front view seen from the tip which shows Embodiment 4 of the main bit which is a cutter bit concerning the present invention. It is a side view of the main bit shown in FIG. It is a top view of the main bit shown in FIG. It is a top view which shows the leading bit which is a general conventional cutter bit. It is a front view of the preceding bit shown in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Cutter face 11 Board surface 12 Opening part 21 Leading bit 211 Base material 211A Notch 212 Tip 212A Soft tip 212Aa Through-hole 212B Hard tip 213 Joining material 213A Reinforcement part 214 Hardening 22 Peripheral protection bit 221 Base material 221A Notch 222 Tip 222 Chip 222B Hard chip 223 Bonding material 224 Hardening 23 Main bit 23A Cutter bit 23B Trim bit 231 Base material 231A Notch 232 Chip 232A Soft chip 232Aa Through hole 232B Hard chip 233 Bonding material 24 Center bit

Claims (7)

In a cutter bit used in an excavator, a chip made of cemented carbide is brazed to a base material made of steel,
A chip composed of a soft tip made of a cemented carbide of a relatively soft material and a hard tip made of a cemented carbide of a material harder than the soft tip;
Made of a material flexible than the flexible tip and the material is approximated to the flexible tip, and a bonding material to be subjected to mutual brazing interposed at least between the rigid tip and the base material, the soft tip A cutter bit , wherein the hard tip is inserted and disposed in a provided through hole, and the joining material is interposed between the soft tip and the hard tip and the base material .   The cutter bit according to claim 1, wherein the hardness of the soft tip is 84 to 89HRA, and the hardness of the hard tip is 85 to 92HRA.   The cutter bit according to claim 1, wherein the soft tip has a hardness of 86 to 87HRA, and the hard tip has a hardness of 87 to 91HRA. It is provided in the bonding material by a material equivalent to the material of the bonding material, and a reinforcing portion is provided to be inserted into a part of a through hole of the flexible chip and a recess provided in the base material. The cutter bit according to claim 1. The cutter bit according to any one of claims 1 to 4, wherein the soft tip is divided and arranged . The cutter bit according to claim 1, wherein the hard tip is divided and arranged . A material made of a cemented carbide that is harder and softer than the base material, or a material that is softer than a cemented carbide of a soft material is disposed at a portion where the base material is exposed. The cutter bit according to any one of claims 1 to 6 .

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