JP2012241459A - Cutter bit for one-way digging - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cutter bit for one-way digging which has improved excavation performance and workability by reducing exchange frequency of a cutter bit and which is optimal for a fully whirling boring machine that must perform underground obstacle removal work, bedrock construction, or the like.SOLUTION: A cutter bit 10 for one-way digging which is installed in the lower end peripheral edge of a casing tube whirling in one direction, through a holder comprises a bit body 11 having a plurality of chip attachment parts 11c in the cutting direction, and a plurality of chips 12a and 12b to be respectively attached to the respective chip attachment parts. In the cutter bit 10, each chip is formed in a mass and a step d is created so that at least the height of the chip 12b at the back side in the cutting direction is higher than the height of the chip 12a at the most front side in the cutting direction, while the chip at the most front side is made to have a rake angle of obtuse angle.

Description

  The present invention relates to a cutter bit (casing bit) for one-way excavation suitable for use in an all-swivel boring machine used in a casing method.

  In general, in the all-slewing boring machine used in the casing method, as shown in FIG. 6, various cutter bits 102 are spaced apart at predetermined intervals in the circumferential direction at the lower edge of the first tube 101 in the casing tube 100. It is well known that it is detachably attached via the holder 103 (see Patent Document 1).

  As shown in FIG. 7, the holder 103 has a holder main body 103a welded to the lower end of the first tube 101, and the inner and outer surfaces of the center lower portion (in the attached state) of the holder main body 103a are cut into a square to obtain a cutter mounting portion 103b. Is formed. A bolt insertion hole 103c is formed at the center of the cutter mounting portion 103b.

  As shown in FIG. 8, the cutter bit 102 includes a bit body 104 and a chip 105. The bit body 104 has a chip holding portion 104a that is positioned in a lower portion (in an attached state) and holds the chip 105, and It has a bifurcated mounting portion 104b that is located at the upper portion (in the mounting state) and is fitted to the cutter mounting portion 103b of the holder 103 and is bolted. The bifurcated mounting portion 104b has a tapered hole 104c for bolt connection on one side and a screw hole 104d on the other side.

  Further, as shown in FIG. 8A, the cutter bit 102 is an outer blade whose trapezoidal horizontal cross-sectional shape at the tip of the cutter portion is positioned near the outer periphery of the tube, and (b) of FIG. As shown in FIG. 8 (c), the horizontal cross section at the tip of the cutter unit is a trapezoidal shape with a horizontal cross-sectional shape at the tip of the cutter unit and the cutting edge is positioned closer to the inner periphery of the tube. There are various types used as a center blade whose shape is a knife type and whose blade edge is located at the center of the tube.

JP 2005-29979 A Japanese Patent No. 4485706

  However, in the conventional cutter bit 102 described above, the chip 105 is a single plate and has a sharp rake angle, so that it is made of a cemented carbide having excellent wear resistance and impact resistance. Even if it is formed, the replacement frequency of the cutter bit has increased in the casing construction method in recent years due to the fact that the chip 105 is worn quickly and easily lost in underground obstruction removal work and bedrock construction, which are particularly demanding. There was a problem that excavation efficiency and workability deteriorated.

  Further, Patent Document 2 discloses a casing bit in which a plurality of rod-shaped chips are implanted. However, in this casing bit as well, in addition to being rod-shaped, a bidirectional excavation bit (the number of chips used is limited). Therefore, the replacement frequency of the cutter bit is increased due to wear and breakage, and it is not suitable for underground obstruction removal work or bedrock construction.

  Therefore, the present invention improves the excavation efficiency and workability by reducing the replacement frequency of the cutter bit, and is optimal for one-way excavation to be used for all-spinning boring machines that require ground obstruction removal work or rock work. The purpose is to provide a cutter bit.

A cutter bit for unidirectional excavation according to the present invention for achieving such an object is as follows:
In the unidirectional excavation cutter bit that is detachably attached to the lower end periphery of the casing tube that turns in one direction via a holder,
A bit body having a plurality of chip mounting portions in the cutting direction;
A plurality of chips each mounted on each chip mounting part;
With
Each of the chips is formed in a lump shape, and is disposed with a step so that at least the height of the tip at the rear of the cutting direction is higher than the height of the tip at the forefront of the cutting direction, and an obtuse rake angle is formed on the foremost tip. It is characterized by having it.

Also,
The cutter bit is characterized in that the cutter section has a horizontal cross-sectional shape and is used as a center blade.

Also,
The cutter bit is characterized in that the cutter has a trapezoidal horizontal cross-sectional shape and is used as an outer cutter or an inner cutter.

  According to the cutter bit for unidirectional excavation according to the present invention, the excavation efficiency and workability can be improved, and the removal of underground obstacles can be achieved because the excavation performance of the cutter bit can be maintained for a long time by extending the life of the chip and making it plural. It is most suitable for all-spinning boring machines that require construction and bedrock construction.

BRIEF DESCRIPTION OF THE DRAWINGS It is structure explanatory drawing of the cutter bit used as a center blade which shows Example 1 of this invention, The figure (a) is a side view, The figure (b) is a top view, The figure (c) is a rear view. It is structure explanatory drawing of the cutter bit used as an outer blade which shows Example 2 of this invention, The figure (a) is a side view, The figure (b) is a top view, The figure (c) is a rear view. FIG. 4 is a structural explanatory view of a cutter bit that is also used as an inner blade, in which FIG. (A) is a side view, (b) is a plan view, and (c) is a rear view. It is an arrangement view of a cutter bit showing an example of use of a center blade. It is an arrangement view of a cutter bit showing an example of use of an outer blade and an inner blade. It is explanatory drawing which shows the attachment state to the casing tube of the conventional cutter bit. It is structure explanatory drawing of a holder. FIG. 4A is an explanatory diagram of various cutter bits. FIG. 1A is a cutter bit used as an outer blade, FIG. 1B is a cutter bit used as an inner blade, and FIG. 1C is a cutter bit used as a center blade. is there.

  Hereinafter, the cutter bit for one-way excavation concerning the present invention is explained in detail using an example using a drawing.

  FIG. 1 is an explanatory view of the structure of a cutter bit used as a center blade showing Embodiment 1 of the present invention, where FIG. 1 (a) is a side view, FIG. 1 (b) is a plan view, and FIG. 1 (c) is a rear view. FIG. 4 is a layout diagram of cutter bits showing an example of use of the center blade.

  1 is attached to the periphery of the lower end of the first tube 101 (see FIG. 6) via the holder 103 (see FIG. 6) in the casing tube 100 (see FIG. 6) of the all-swivel boring machine used in the casing method. A cutter bit for one-way excavation.

  This cutter bit 10 is composed of a bit body 11 and two relatively large chips 12a and 12b. The bit body 11 is located at the upper part (in the attached state) and is attached to a cutter mounting portion 103b (see FIG. 7) and a chip holding part 11b for holding the chips 12a and 12b located in the lower part (in the attached state).

  Two chip-shaped chip mounting parts 11c are formed in the chip holding part 11b along the cutting direction, and the two chips 12a and 12b are respectively mounted by brazing on these chip mounting parts 11c. The two tips 12a and 12b are arranged with a step d so that the height of the tip 12b at the rear in the cutting direction is higher than the height of the tip 12a at the forefront in the cutting direction, and the obtuse angle to the frontmost tip 12a. It has a rake angle.

  The bifurcated mounting portion 11a is formed with a taper hole 11d for bolt connection on one side and a screw hole 11e on the other side.

  As shown in FIG. 1B, the cutter bit 10 is used as a center blade in which the horizontal sectional shape of the cutter portion is a knife type and the blade tip portion is located at the center of the tube. Moreover, the hatching in FIG. 1 shows a hardening build-up process.

  Since it is configured in this way, in addition to unidirectional excavation, a plurality of relatively large lump chips 12a and 12b are used in length and thickness, and the plurality of chips 12a and 12b have a height higher than the tip 12a at the forefront in the cutting direction. Since the step d is provided so that the height of the tip 12b at the rear in the cutting direction is increased, and the tip 12a at the forefront is provided with an obtuse rake angle, the cutter bit is improved by extending the life of the tip and making it plural. The long-term maintenance of excavation performance can be achieved.

  As a result, the excavation efficiency and workability are improved by reducing the replacement frequency of the cutter bit, and it is optimal for use in all-swivel boring machines that require ground obstruction removal work, bedrock construction, and the like.

  FIG. 4 shows an example of use of the cutter bit 10 of this embodiment. This is because a conventional cutter bit 102 as an outer cutter and a cutter bit 102 as an inner cutter are arranged between a plurality of cutter bits 10 of this embodiment as center cutters arranged at predetermined intervals (11 in the illustrated example). This is an example in which one piece is arranged and excavated in one direction. In FIG. 4, reference numeral 103 denotes a holder.

  FIG. 2 is an explanatory view of the structure of a cutter bit used as an outer blade showing Embodiment 2 of the present invention. FIG. 2 (a) is a side view, FIG. 2 (b) is a plan view, and FIG. 2 (c) is a rear view. 3 is an explanatory view of the structure of a cutter bit that is also used as an inner blade. FIG. 3 (a) is a side view, FIG. 3 (b) is a plan view, FIG. 3 (c) is a rear view, and FIG. FIG. 6 is a layout diagram of cutter bits showing an example of use of an inner blade.

  2, 20 is attached to the periphery of the lower end of the first tube 101 (see FIG. 6) through the holder 103 (see FIG. 6) in the casing tube 100 (see FIG. 6) of the all-round boring machine used in the casing method. A cutter bit for one-way excavation.

  The cutter bit 20 is composed of a bit body 21 and three relatively large chips 22a, 22b, and 22c. The bit body 21 is located in the upper part (in the mounted state) and is attached to the cutter mounting portion 103b of the holder 103. It has a bifurcated mounting portion 21a that is fitted and bolted (see FIG. 7), and a chip holding portion 21b that holds the chips 22a, 22b, and 22c located in the lower portion (in the mounted state).

  Three chip-shaped chip mounting parts 21c are formed in the chip holding part 21b along the cutting direction, and the three chips 22a, 22b, 22c are respectively mounted by brazing on these chip mounting parts 21c. . The three tips 22a, 22b and 22c are arranged with a step d so that at least the height of the tip 22b immediately behind the tip 22a is higher than the height of the tip 22a at the forefront in the cutting direction, and the foremost tip. An obtuse rake angle is given to 22a. In the illustrated example, the tip 22b immediately behind the tip 22a at the forefront in the cutting direction and the tip 22c behind the tip 22b have the same height, but they may also be provided with a step. Needless to say.

  The bifurcated mounting portion 21a has a tapered hole 21d for bolt connection on one side and a screw hole 21e on the other side.

  As shown in FIG. 2B, the cutter bit 20 is used as an outer cutter in which the cutter section has a trapezoidal horizontal cross-sectional shape and the cutting edge is positioned on the tube outer peripheral side. Moreover, the hatching in FIG. 2 shows a hardening build-up process.

  On the other hand, reference numeral 30 in FIG. 3 denotes a lower end periphery of the first tube 101 (see FIG. 6) in the casing tube 100 (see FIG. 6) of the all-swivel boring machine used in the casing method via a holder 103 (see FIG. 6). It is a cutter bit for one-way excavation to be attached.

  The cutter bit 30 is composed of a bit body 31 and three relatively large chips 32a, 32b, and 32c. The bit body 31 is located in the upper part (in the attached state) and is attached to the cutter mounting portion 103b of the holder 103. It has a bifurcated mounting portion 31a that is fitted to (see FIG. 7) and is bolt-coupled, and a chip holding portion 31b that is positioned below (in the mounted state) and holds the chips 32a, 32b, and 32c.

  Three chip-shaped chip mounting parts 31c are formed in the chip holding part 31b along the cutting direction, and the three chips 32a, 32b, 32c are respectively mounted by brazing on these chip mounting parts 31c. . The three tips 32a, 32b, and 32c are arranged with a step d so that at least the height of the tip 32b immediately behind the tip 32a is higher than the height of the tip 32a that is the foremost in the cutting direction, and the foremost tip. An obtuse rake angle is given to 32a. In the illustrated example, the tip 32b immediately behind the tip 32a at the forefront of the cutting direction and the tip 32c behind the tip 32b have the same height, but in these cases, a step may be provided. Needless to say.

  The bifurcated mounting portion 31a has a tapered hole 31d for bolt connection on one side and a screw hole 31e on the other side.

  As shown in FIG. 3B, the cutter bit 30 is used as an inner blade whose trapezoidal horizontal cross-sectional shape of the cutter portion is located on the inner peripheral side of the tube. Moreover, the hatching in FIG. 3 shows a hardening build-up process.

  Also in these cutter bits 20 and 30, it is possible to maintain the excavation performance of the cutter bit for a long time by extending the life of the chip and increasing the number of chips. .

  FIG. 5 shows an example of using the cutter bits 20 and 30 of this embodiment. This is an example in which two cutter bits 20 serving as outer blades are disposed between two cutter bits 30 serving as inner blades arranged at predetermined intervals (11 in the illustrated example) and excavated in one direction. In FIG. 5, reference numeral 103 denotes a holder.

  Needless to say, the present invention is not limited to the above embodiments, and various modifications such as changing the number and shape of chips are possible without departing from the scope of the present invention.

  The cutter bit for unidirectional excavation according to the present invention can be effectively applied to a casing bit of an all-swivel boring machine in which underground obstruction removal work, rock work, or the like is required.

10 Cutter bit used as center blade 11 Bit body 11c Bit mounting portion 12a, 12b Tip 20 Cutter bit used as outer blade 21 Bit body 21c Bit mounting portion 22a, 22b, 22c Tip 30 Cutter bit used as inner blade 31 Bit Main body 31c Bit mounting portion 32a, 32b, 32c Tip 100 Casing tube 103 Holder d Step

Claims (3)

In the unidirectional excavation cutter bit that is detachably attached to the lower end periphery of the casing tube that turns in one direction via a holder,
A bit body having a plurality of chip mounting portions in the cutting direction;
A plurality of chips each mounted on each chip mounting part;
With
Each of the chips is formed in a lump shape, and is disposed with a step so that at least the height of the tip at the rear of the cutting direction is higher than the height of the tip at the forefront of the cutting direction, and an obtuse rake angle is formed on the foremost tip. One-way excavation cutter bit characterized by having it.   The cutter bit for unidirectional excavation according to claim 1, wherein the cutter bit has a knife-shaped horizontal cross-sectional shape and is used as a center blade.   2. The cutter bit for unidirectional excavation according to claim 1, wherein the cutter bit has a trapezoidal horizontal cross-sectional shape and is used as an outer cutter or an inner cutter.

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