JP2023088051A - Cutter bit and manufacturing method of cutter bit - Google Patents

Abstract

To provide a cutter bit allowing its manufacturing to be performed in a relatively simple manner and having wear resistance and a manufacturing method of the cutter bit.SOLUTION: A cutter bit 1 is provided with a base member 2 fixed on an excavation machine and a blade member 3 fixed on the base member 2, where a plurality of hard chips 4, 4, ... are embedded along an outer surface of the base member 2. A manufacturing method of the cutter bit 1 comprises the steps of: placing the plurality of hard chips 4, 4, ... along an inner surface of a casting mold; forming the base member 2 through injecting melted metal in a mold; and fixing the blade member 3 at a tip of the base member 2.SELECTED DRAWING: Figure 1

Description

The present invention relates to a cutter bit used in an underground excavator and a method for manufacturing the cutter bit.

Tunnel construction using the shield tunneling method, jacking method, TBM, etc. will be carried out using a tunnel excavator equipped with a cutter bit. The cutter bit is required to have strength and wear resistance so that it does not fall off while maintaining a predetermined angle of the carbide tip as a blade material. On the other hand, the base material that holds the blade material may be worn away as the ground is cut, or may fall off the excavator. If the cutter bit falls off or wears out, it is necessary to interrupt the excavation work to replace or install the cutter bit. Therefore, in some cases, the wear resistance is improved to extend the life of the cutter bit.
For example, Patent Document 1 discloses a cutter bit in which a hard tip made of a cemented carbide and a soft tip made of a softer cemented carbide than the hard tip are fixed to each other. In the cutter bit of Patent Document 1, the soft tip abuts on the ground to excavate the ground, so that the soft tip absorbs the impact applied to the hard tip, and the hard tip ensures high wear resistance. However, if the cutter bit is made of a high-strength material like the cutter bit of Patent Document 1, the cost of the cutter bit increases.
Further, Patent Document 2 discloses a cutter bit in which build-up welding is applied to the outer surface of a base material to which a blade is fixed. According to the cutter bit of Patent Document 2, the wear of the base material is suppressed by build-up welding, and the risk of wear and flaking of the cutter bit can be reduced. However, it takes time and effort to build up and weld the outer surface of the base material.

JP 2006-241681 A JP 2013-087426 A

An object of the present invention is to propose a cutter bit that can be manufactured relatively easily and has wear resistance, and a method for manufacturing this cutter bit.

In order to solve such problems, the cutter bit of the present invention includes a base material fixed to an excavator and a blade fixed to the base material, and a cutting edge along the outer surface of the base material. Multiple hard chips are embedded.
This cutter bit manufacturing method includes the steps of arranging a plurality of hard tips along the inner surface of a mold, injecting molten metal into the mold to form a base material, and a step of fixing the
The hard tip of such a cutter bit suppresses the wear of the base material, so that the life of the cutter bit can be extended.
In addition, since the hard tip is embedded when forming the base material (injecting the melted metal into the mold), there is little labor involved in manufacturing.

In addition, it is preferable that a through hole is formed in each of the hard tips. If a through-hole is formed in the hard tip, a plurality of hard tips can be arranged using a mounting member (for example, a bar or an anchor) inserted through the through-hole, and the metal melted in the mold ( It is possible to prevent the hard tip from moving and being unevenly arranged when injecting the casting material. It should be noted that it is desirable to use a material such as molybdenum or tungsten, which has a higher melting point than the cast-in material (for example, SS material) that constitutes the base material, for the mounting member. Also, the mounting member can be made of a material such as stainless steel.
Further, by inserting the same bar material into the plurality of through-holes, the plurality of hard tips can be arranged side by side in a row. Furthermore, by arranging a plurality of rows of the plurality of hard chips arranged side by side, the hard chips can be arranged in a plane.
If the hard tip is a cermet tip used in a cutting tool or the like, the material cost can be reduced, and waste materials can be effectively used.

INDUSTRIAL APPLICABILITY According to the cutter bit and the method for manufacturing the cutter bit of the present invention, the cutter bit can be manufactured relatively easily and at low cost, and has wear resistance and can have a long service life.

1 is a cross-sectional view showing a cutter bit according to an embodiment of the present invention; FIG. FIG. 4 is a perspective view showing an example of a hard tip; FIG. 4 is an exploded perspective view schematically showing a cutter bit; 4 is a flow chart showing a method for manufacturing a cutter bit; (a) is a cross-sectional view showing a mold forming process, (b) is a cross-sectional view showing a chip placement process, and (c) is a plan view showing the placement of hard chips. (a) is a sectional view showing a cutter bit according to another embodiment, and (b) is a sectional view showing a cutter bit according to another embodiment.

In this embodiment, a cutter bit 1 that is fixed to a cutter head of a shield machine and performs cutting of ground will be described. A cutter bit 1 is shown in FIG. The cutter bit 1 includes a base material 2 and a blade member 3 brazed to the base material 2, as shown in FIG. In this embodiment, silver solder is used as the brazing material for brazing.

The base material 2 is a member that is fixed to an excavator (cutter head) and supports the blade material 3, and is a so-called shank material. The base material 2 holds the blade material 3 at a predetermined angle and prevents it from falling off. The base material 2 of the present embodiment is made of a material having a coefficient of expansion larger than that of the blade material 3 and sufficient rigidity and strength as a structural member. In this embodiment, SS material, SKC material, or the like is used as the material forming the base material 2, but the material forming the base material 2 is not limited.
The base material 2 is formed with a concave portion 21 opening on the tip side thereof. In this specification, the front end of the base material 2 refers to the corner between the front surface 22 and the rear surface 23 of the base material 2 . The concave portion 21 is a missing portion formed at the tip of the base material 2 . The blade material 3 is directly fixed (brazed) to the base material 2 .

The front surface 22 of the base material 2 is the front surface of the cutter bit 1 in the traveling direction, and as shown in FIG. The back surface 23 of the base material 2 is a surface facing the natural ground (cutting surface), and is inclined away from the bottom surface 25 toward the tip (blade material 3) side. The corner where the extended surface of the back surface 23 and the extended surface of the front surface 22 intersect becomes an acute angle. In the present embodiment, the back surface 23 is formed with a break point, but the back surface 23 may be a flat surface (a flat surface without a break point).
A rear surface 24 of the base material 2 is a surface on the rear side of the cutter bit 1 in the advancing direction, and a bottom surface 25 is a surface that contacts a cutter head (not shown). The rear surface 24 and the bottom surface 25 of the base material 2 of this embodiment intersect at right angles. Note that the rear surface 24 and the bottom surface 25 do not necessarily have to be perpendicular. Moreover, the shape of the base material 2 is not limited.

A plurality of hard chips 4 , 4 , . . . are embedded in the base material 2 . The hard tip 4 is arranged along the outer surface (surface other than the bottom surface) of the base material 2 . That is, a plurality of hard chips 4, 4, . . . are embedded facing front surface 22, rear surface 23, rear surface 24 and side surfaces.
The hard tip 4 of this embodiment is a cermet tip containing titanium carbide or titanium carbonitride as a main component, and is reused from a cutting tool or the like. A hard tip 4 is shown in FIG.
As shown in FIG. 2, each hard tip 4 has a central portion formed with a through hole 41 for attachment to a cutting tool or the like. FIG. 3 shows an installation example of the hard tip 4. As shown in FIG. In this embodiment, as shown in FIG. 3, a plurality of rows of hard tips 4, 4, . By arranging a plurality of rows in parallel along the outer surface of , the hard tips 4 are arranged in a plane.

The blade member 3 is composed of a carbide tip having a rectangular cross section, and is arranged along the front surface 22 and the back surface 23 of the base member 2 as shown in FIG. The blade material 3 of this embodiment has a front surface 31 and a rear surface 32 exposed at the tip of the base material 2, and a bottom surface 33 and a rear surface 34 that are brazed to the recess 21 (base material 2). The intersection of the front surface 31 and the back surface 32 of the blade member 3 forms an acute angle. On the other hand, the intersection of the front surface 31 and the bottom surface 33 and the intersection of the bottom surface 33 and the rear surface 34 of the blade member 3 are at right angles, and the intersection of the rear surface 32 and the rear surface 34 are at an obtuse angle.

A method for manufacturing the cutter bit 1 of this embodiment will be described below. FIG. 4 shows a method of manufacturing the cutter bit 1. As shown in FIG. As shown in FIG. 4, the method of manufacturing the cutter bit 1 includes a mold forming step S1, a chip placement step S2, a base material forming step S3, and a blade fixing step S4. FIG. 5 shows a construction situation of the cutter bit 1. FIG.
The mold forming step S1 is a step of forming the mold 6. As shown in FIG. The casting mold 6 of this embodiment is a sand mold, and is formed by hardening sand while having a cavity 61 corresponding to the shape of the base material 2, as shown in FIG. 5(a). The upper surface of the cavity 61 is open (opening 62).

In the chip placement step S2, a plurality of hard chips 4, 4, . . . A plurality of hard chips 4, 4, . . . At this time, it is desirable to arrange the hard tips 4 without gaps so that the surface of the base material 2 facing the outer surface is aligned.
In this embodiment, as shown in FIG. 5(c), the plurality of hard tips 4, 4, . . . are arranged in parallel along the front surface, rear surface, rear surface, and side surface of the base material 2 in a planar manner. That is, a plurality of hard chips 4, 4, . In addition, the mounting member 5 arranged at the opening of the mold and the mounting members 5 arranged on the front surface, the rear surface, and both side surfaces of the mold are connected, and the opposite surfaces of the mold (the front surface and the rear surface of the base material 2) The hard tips 4, 4, . . . are arranged in a box shape by connecting the mounting members 5 arranged on the opposite sides with a connecting member 51 horizontally spanned between the facing surfaces. For the mounting member 5 and the connecting member 51, a material such as molybdenum or tungsten having a melting point higher than that of the stuffing material (for example, SS material) constituting the base material 2 is used, so that the stuffing material is injected into the mold. prevent it from melting when Stainless steel or the like may be used for the mounting member 5 .

In the base material forming step S3, the base material 2 is formed by injecting a casting material (melted metal) into the mold 6 (cavity 61). After the casting material injected into the mold 6 is solidified, the base material 2 is taken out from the mold 6 .
In the blade fixing step S4, the blade 3 is fixed to the tip of the base material 2. As shown in FIG. The blade material 3 is brazed to the concave portion 21 of the base material 2 .

As described above, according to the cutter bit 1 of the present embodiment, since the hard tip 4 is disposed facing the outer surface of the base material 2, the wear of the base material 2 is suppressed, and the life of the cutting ability is extended. be able to. Therefore, the frequency of replacement of the cutter bit 1 can be reduced, and labor can be reduced.
Since the hard tip 4 is arranged in a plane, the base material 2 is prevented from being partially worn.
In addition, since the hard tip 4 is embedded when forming the base material 2, there is little trouble in manufacturing. Since one surface of the plurality of hard tips 4, 4, . . . Further, by arranging the hard tips 4 without gaps, the wear resistance of the base material 2 is further improved.
Further, since the hard tip 4 is positioned by the mounting member 5, it is possible to prevent the hard tip 4 from being arranged in a biased position when the casting material is injected.
Moreover, since the mounting member 5 passing through the hard tip 4 and the connecting member 51 connecting the mounting members 5 are embedded in the base material 2 , the hard tip 4 is prevented from slipping out of the base material 2 . Therefore, the effect of suppressing wear of the base material 2 by the hard tip 4 is maintained for a long period of time, and as a result, the life of the cutter bit 1 can be extended.
By using a used cermet tip for the hard tip 4, reduction in material cost and effective utilization of waste materials are realized. Further, since a used cermet tip can be used as the hard tip 4 without being processed, labor required for processing can be omitted.

Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and each component can be modified as appropriate without departing from the scope of the present invention.
In the above-described embodiment, a case where the cutter bit 1 is used in a shield machine has been described, but the excavator that uses the cutter bit 1 is not limited. may
The method of fixing the blade material 3 to the base material 2 is not limited to brazing. Also, the brazing material used for brazing is not limited to silver brazing.
In the above-described embodiment, used cermet chips are reused as the hard tips 4, but the hard tips 4 may be made of a new material. Moreover, the material of the hard tip 4 is not limited.
The configuration of the mounting member 5 used when installing the hard tip 4 in the mold is not limited. For example, as shown in FIG. 6(a), an anchor 52 (J hook, L hook, etc.) may be used as the mounting member 5. FIG. At this time, if the anchors 52 are connected to each other, the hard tip 4 can be prevented from slipping out. Also, as shown in FIG. 6(b), if one end portions of a plurality of anchors 52 are tied together, the work of arranging the hard tip 4 becomes easier. In this case, it is preferable to connect the anchors 52 to each other via the connecting member 51 at the intermediate portion of each anchor 52 .

Reference Signs List 1 cutter bit 2 base material 21 recess 22 front surface 23 rear surface 24 rear surface 25 bottom surface 3 blade material 31 front surface 32 rear surface 33 rear surface 34 bottom surface 4 hard tip 41 through hole 5 mounting member 51 connecting member 6 mold 61 cavity 62 opening

Claims (8)

a base material secured to the excavator;
a cutter bit fixed to the base material,
A cutter bit characterized by having a plurality of hard tips embedded along the outer surface of the base material. 2. The cutter bit according to claim 1, wherein a through hole is formed in each of said hard tips. 3. The cutter bit according to claim 2, wherein a plurality of said hard tips are arranged in a row by inserting the same bar into said through-holes of said plurality of hard tips. 4. The cutter bit according to claim 3, wherein the plurality of rows of hard tips arranged side by side are arranged in rows. 3. The cutter bit according to claim 2, wherein said hard tip is arranged at a predetermined position by an anchor locked in said through hole. A cutter bit according to any one of claims 1 to 5, characterized in that said hard tip is a cermet tip. placing a plurality of hard tips along an inner surface of the mold;
injecting molten metal into the mold to form a base material;
A method for manufacturing a cutter bit, comprising the step of fixing a blade material to the tip of the base material. A through hole is formed in each of the hard tips,
8. The method of manufacturing a cutter bit according to claim 7, wherein a plurality of said hard tips are arranged using a mounting member inserted through said through hole.

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