JP2008168400A - Throw-away tip and manufacturing method thereof - Google Patents

Abstract

The present invention provides a throw-away tip and a method for manufacturing the same that can suppress displacement with respect to a holder.
A throw-away tip 1 is a clamp-on type throw-away tip in which a main body 1a is pressed by a clamp 5b and fixed to a shank 5. This throw-away tip 1 is a solid type in which a cutting edge portion 1b is formed integrally with an edge portion of the main body 1a. A rough surface region 1e having a surface roughness larger than 1f is formed.
[Selection] Figure 1

Description

  The present invention relates to a clamp-on type throw-away tip in which a main body is pressed by a clamp and fixed to a holder, and a manufacturing method thereof.

Conventionally, the cutting tool of the following patent document 1 is known as a tool in which a throwaway tip (blade tip replaceable tip) is used. In this cutting tool, a throw-away tip is fixed to a seating surface of a holder with a screw. In this document, it is proposed that the surface roughness of the seating surface of the holder with which the throw-away tip abuts is kept small, thereby suppressing the deflection of the throw-away tip and improving the processing accuracy.
Japanese Patent Laid-Open No. 2003-231006

  However, in this cutting tool, since the friction between the back surface of the throw-away tip and the holder seat surface is small, the tip may be displaced with respect to the holder during use. Then, an object of this invention is to provide the throw away tip which can suppress the shift | offset | difference with respect to a holder, and its manufacturing method.

  The throw-away tip of the present invention is a clamp-on type throw-away tip in which the main body is pressed by a clamp and fixed to a holder, and is a solid type in which the cutting edge is integrally formed on the edge of the main body. The clamp contact portion that contacts the clamp is characterized in that the surface roughness is larger than the rake face of the cutting edge portion.

  This throw-away tip has a larger surface roughness of the clamp contact part of the main body than the rake face of the cutting edge part, so that when mounted on the holder, the clamp and the clamp contact part have relatively large friction. Contact. Therefore, the holding stability of the throw-away tip with respect to the clamp and the holder is improved, and the deviation with respect to the holder is suppressed.

  In addition, the throw-away tip of the present invention is a clamp-on type throw-away tip in which the main body is pressed by a clamp and fixed to the holder. The thickness is 0.8 μm or more.

  In this throw-away tip, since the surface roughness of the clamp contact portion of the main body is an arithmetic average roughness of 0.8 μm or more, the clamp and the clamp contact portion are relatively large when mounted on the holder. Contact with friction. Therefore, the holding stability of the throw-away tip with respect to the clamp and the holder is improved, and the deviation with respect to the holder is suppressed.

  The method of manufacturing the throw-away tip of the present invention is a method of manufacturing a clamp-on type throw-away tip in which the main body is pressed by the clamp and fixed to the holder. A roughening step for roughening is provided.

  According to this manufacturing method, the surface of the clamp contact portion of the throw-away tip is roughened by the roughening step, so when the throw-away tip is mounted on the holder, the clamp and the clamp contact portion Contact with relatively large friction. Therefore, in the throw-away tip by this manufacturing method, the holding stability with respect to the clamp and the holder is improved, and the deviation with respect to the holder is suppressed.

  According to the throw-away tip and the manufacturing method thereof of the present invention, it is possible to suppress the displacement of the throw-away tip with respect to the holder.

  Hereinafter, preferred embodiments of the throw-away tip according to the present invention will be described in detail with reference to the drawings.

(First embodiment)
A throw-away tip 1 shown in FIGS. 1 and 2 is used by being attached to the tip of a shank (holder) 5 in a lathe tool 3 for lathe. The cutting tool 3 employs a so-called clamp-on method, and has a structure in which the chip 1 is pressed by a clamp 5 b and fixed to the shank 5. That is, a mounting seat surface 5a that contacts the lower surface of the chip 1 to be mounted is formed at the tip of the shank 5, and the clamp 5b that holds down the chip 1 is bolted. When the bolt 5c is tightened, the tip 5d of the clamp 5b is strongly pressed near the center of the upper surface 1c of the main body 1a, and the tip 1 is firmly sandwiched between the mounting seat surface 5a and the clamp tip 5d and fixed. Is done.

  This chip 1 is made of PCD (diamond sintered body), and is called a solid type having a structure in which a cutting edge portion 1b is integrally formed on an upper surface edge portion of a main body 1a. The chip 1 has a substantially equilateral triangular prism shape, and the upper surface 1c extending in a planar shape is provided at the peripheral edge and has a relatively small surface roughness (arithmetic average roughness of about 0.01 μm) and a polishing surface region 1d. A rough surface region 1e which is provided inside the surface region 1d and has a relatively large surface roughness (arithmetic average roughness of 0.8 μm or more). A part of the polished surface region 1d constitutes a rake surface 1f of the cutting edge portion 1b.

  A method for manufacturing such a chip 1 will be described. First, after sintering the regular triangular prism PCD block, the entire upper surface 1c forming the regular triangle is polished to an arithmetic average roughness of about 0.01 μm, and a part of the side surface of the triangular prism is polished as a flank of the cutting edge portion 1b. The cutting edge 1b is formed at the edge of the upper surface 1c. In addition, it is also possible to prepare the commercial item by which the cutting edge part 1b by which the above process was already performed was formed here. Next, using a YAG laser processing machine, the region other than the peripheral portion of the upper surface 1c is XY-scanned with the laser beam to roughen the region so that the arithmetic average roughness becomes 0.8 μm or more (roughening). Process). By this roughening step, the surface of the region other than the peripheral portion of the upper surface 1c is roughened, and the rough surface region 1e is formed. Further, the peripheral edge portion of the upper surface 1c which is not roughened in this roughening step and remains as a polished surface constitutes the polishing surface region 1d. When the chip 1 thus processed is mounted on the shank 5, the tip 5d of the clamp 5b has a positional relationship such that it abuts a part (clamp contact portion) of the rough surface area 1e of the main body 1a. .

  For comparison, when the surface roughness of a conventional commercially available throwaway tip made of cemented carbide was measured, the arithmetic average roughness was about 0.01 μm over the entire top surface. Therefore, when a conventional chip is used, the tip 5d of the clamp 5b comes into contact with a surface having an arithmetic average roughness of about 0.01 μm.

  On the other hand, according to the structure of the throw-away tip 1, as described above, the surface of the rough surface region 1d with which the tip 5d of the clamp 5b contacts is roughened to an arithmetic average roughness of 0.8 μm or more. The friction of contact between the tip 5d of the clamp 5b and the rough surface region 1d increases. Accordingly, the holding stability of the chip 1 with respect to the clamp 5b and the shank 5 is improved, and the displacement of the chip 1 with respect to the shank 5 is suppressed even during use of the cutting tool 3. Further, when the chip 1 is used, no special configuration is required for the shank 5, so that the chip 1 can be mounted on a conventional shank, and the above-described effects can be obtained.

  Further, in this chip 1, since the upper surface 1c is roughened except for the peripheral portion and the peripheral portion is left as a polished surface region 1c with a small surface roughness, the rake surface 1f of the cutting edge portion 1b is smooth. Thus, the cutting performance of the cutting edge portion 1b can be maintained. In the manufacturing process described above, the entire upper surface 1c is first polished to form the rake face 1f, and then the roughening process is performed so as to leave the polished surface region 1d at the peripheral edge. According to this processing order, conversely, processing is easier than polishing the peripheral portion of the upper surface 1c roughened as a whole to form the rake face 1f. Further, since the upper surface 1c of the chip 1 to be roughened is planar, for example, a general-purpose device such as a YAG laser processing machine is used and the upper surface 1c is scanned by a simple method such as planar scanning of laser light. Roughening can be performed.

Subsequently, a test conducted by the present inventors will be described. The inventors manufactured the above-described throw-away tip 1 by the above-described manufacturing method. The top surface 1c of the chip 1 forms an equilateral triangle with a side of 9.6 mm, and surrounds the rough surface region 1e and a rough surface region 1e formed at the center of the top surface 1c and forming a regular triangle with a side of 6.2 mm. And a polishing surface region 1d having a width of 1.0 mm. Next, the surface roughness of the rough surface region 1e of the manufactured chip 1 was measured. Here, using a stylus type surface roughness meter (trade name: Surfcom 590A, manufactured by Tokyo Seimitsu Co., Ltd.) having a stylus tip diameter of 0.1 μm, the rough surface area 1e is scanned along six scanning lines. The arithmetic average roughness Ra, the maximum height Rmax, and the ten-point average roughness Rz were measured. The scanning lines 1 to 3 extend in a direction orthogonal to one side of the equilateral triangle on the upper surface 1c, and the scanning lines 4 to 6 are lines extending in a direction orthogonal to the scanning lines 1 to 3. The measurement results are as shown in Table 1 below.

  As shown in Table 1, it was confirmed that the arithmetic average roughness Ra of the rough surface region 1e of the chip 1 was 0.8 μm or more. Further, the arithmetic average roughness Ra of the polished surface region 1d of the chip 1 was measured by the same measuring method, and it was confirmed that it was about 0.01 μm. When such a chip 1 was mounted on the shank 5 and a turning test was performed using a lathe, the chip 1 was not displaced. Further, the rake face 1f of the cutting edge portion 1b was sufficiently smooth, and there was no problem in the cutting performance of the cutting edge portion 1b.

(Second Embodiment)
The throw-away tip 21 shown in FIGS. 3A and 3B is a so-called ultra-high pressure sintered body brazing type tip. The chip 21 includes a main body 21a in which a counterbore portion 21s is formed, and an ultra-high pressure sintered body 21t fixed to the counterbore portion 31s by brazing. The ultra-high pressure sintered body 21t is made of PCD or PCBN (CBN sintered body), and a cutting edge portion 21b is formed at the edge. Then, the upper surface 21c of the main body 21a was roughened to an arithmetic average roughness of 0.8 μm or more using a YAG laser processing machine or the like in the same manner as the rough surface region 1e (see FIG. 1) of the chip 1 described above. A rough surface region 21e is formed.

  When the tip 21 is attached to the shank 5 (see FIG. 1), the tip 5d of the clamp 5b is in a positional relationship such that it abuts a part of the rough surface region 21e. Such a chip 21 also has the same effects as the chip 1 of the first embodiment described above. In this embodiment, the description of the same or equivalent configuration as that of the above-described embodiment is omitted.

(Third embodiment)
The throw-away tip 31 shown in FIGS. 4 (a) and 4 (b) is a so-called ultra-high pressure sintered body brazing type tip, which is used by being mounted on a milling cutter (holder) compatible with a blade-tip replaceable tip. is there. The chip 31 includes a main body 31a on which a spot facing portion 31s is formed, and an ultra-high pressure sintered body 31t fixed to the spot facing portion 31s by brazing. The ultra-high pressure sintered body 31t is made of PCD or PCBN, and a cutting edge portion 31b is formed at the edge. The upper surface 31c of the main body 31a of the chip 31 is roughened to an arithmetic average roughness of 0.8 μm or more using a YAG laser processing machine or the like in the same manner as the rough surface area 1e (see FIG. 1) of the chip 1 described above. The rough surface area 31e thus formed is formed.

  When the tip 31 is mounted on a milling cutter (not shown), a positional relationship is established such that a clamp that holds the tip 31 contacts the rough surface region 31e. Such a chip 31 also has the same effects as the chip 1 of the first embodiment described above. In this embodiment, the description of the same or equivalent configuration as in each of the above-described embodiments is omitted.

  The present invention is not limited to the embodiment described above. For example, the material of the throw-away chip is not limited to PCD, and may be cemented carbide (tungsten carbide alloy), ceramic, cermet, or PCBN. Further, it is only necessary that the surface of the chip has a roughened region in the portion that contacts the clamp, and the roughened region on the chip surface may be appropriately determined according to the shape of the clamp of the holder. . The throw-away tip surface is not limited to laser processing, and may be roughened by grinding, electric discharge processing, or blast processing.

It is an exploded perspective view showing one embodiment of a cutting tool to which a throw away tip according to the present invention is applied. FIG. 2 is an enlarged cross-sectional view showing the vicinity of the tip of the shank in the tool of FIG. 1. (A) is a perspective view which shows 2nd Embodiment of the throw away tip which concerns on this invention, (b) is the top view. (A) is a perspective view which shows 3rd Embodiment of the throw away tip which concerns on this invention, (b) is the top view.

Explanation of symbols

  1, 21, 31 ... throw-away tip, 1 a, 21 a, 31 a ... main body, 1 b, 2 b, 3 b ... cutting edge part, 1 e, 21 e, 31 e ... rough surface area (clamp contact part), 1 f ... of cutting edge part Rake face, 3 ... Shank (holder), 5b ... Clamp.

Claims (3)

In the clamp-on type throw-away tip where the main body is pressed by the clamp and fixed to the holder,
The cutting blade is a solid type formed integrally with the edge of the main body,
A throw-away tip, wherein a clamp contact portion of the main body that contacts the clamp has a surface roughness larger than a rake face of the cutting edge portion. In the clamp-on type throw-away tip where the main body is pressed by the clamp and fixed to the holder,
The throw-away tip according to claim 1, wherein a surface roughness of a clamp contact portion that contacts the clamp of the main body is an arithmetic average roughness of 0.8 μm or more. In the manufacturing method of the throw-on tip of the clamp-on method in which the main body is pressed by the clamp and fixed to the holder,
A method of manufacturing a throw-away tip, comprising a roughening step of roughening a surface of a clamp contact portion that contacts the clamp of the main body.

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