JP2005153101A - Throw-away tip - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a throw-away tip for remarkably improving chipping resistance of a cutting edge. <P>SOLUTION: In this throw-away tip 1, cutting edges 5, 7 are formed in a crossing edge part of a rake surface 3 and a flank 4. Grinding is applied to at least either the rake surface 3 or the flank 4, 6 facing on the cutting edges 5, 7, and a cutting edge vicinity grinding trace 8 marked by grinding from a plurality of directions is formed in the vicinity of the cutting edges at the ground part. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a throw-away tip in which a cutting blade is polished.

  Conventionally, the cutting edge portion has been polished, and as a specific technique, for example, as described in Patent Document 1, while pressing the cutting edge ridge line in the radial direction of the grindstone side surface, There are known a method of processing and a method of pressing a cutting edge ridge line parallel to the rotation direction of the side surface of the grindstone.

  Further, a method is used in which the cutting edge portion of the sintered throw-away tip is polished to increase the dimensional accuracy of the cutting edge ridge line and to increase the sharpness of the cutting edge ridge line. In such processing, the grindstone is set so that the side surface of the grindstone has a predetermined angle with respect to the cutting edge ridgeline, and the grindstone is pressed in the lateral direction while pressing the thickness surface of the grindstone against the rake face or flank face following the cutting edge ridgeline. Polishing is performed while scanning.

A polishing flaw extending in the polished direction is seen in the vicinity of the edge of the cutting edge thus polished, and it is known that the cutting performance changes depending on the direction of the polishing flaw as in Patent Document 1.
Japanese Patent Laid-Open No. 3-202207

  However, in the throw-away tip in which the abrasive scratches remain in one direction as described above, depending on the cutting conditions, a strong impact may be locally applied in the direction of the abrasive scratches. Had the problem of abnormally frequent defects.

  In addition, when processing to sharpen the cutting edge ridge line, if the grinding is performed so that the grinding stone is scratched in one direction, minute chipping occurs on the cutting edge ridge line, resulting in the cutting edge ridge line There was a problem that sharpness was impaired.

  The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide a throw-away tip that can improve the sharpness of the cutting edge ridge line and can remarkably improve the chipping resistance at the cutting edge ridge line. is there.

  As a result of studying the above problems, the present inventors formed a cutting edge at the intersection ridge portion between the rake face and the flank face, and polished at least one of the rake face or the flank face toward the cutting edge. In addition, the sharpness of the cutting edge ridge line can be improved and the cutting edge can be improved by using a throw-away tip having a configuration in which there are polishing marks in the vicinity of the cutting edge polished from a plurality of directions in the vicinity of the cutting edge of the polished portion. It was found that chipping resistance at the ridgeline can be improved.

  Here, according to the present invention, in the vicinity of the cutting edge of the rake face, there is a polishing mark in the vicinity of the cutting edge, and a central polishing mark polished from one direction on the central side of the polishing mark in the vicinity of the cutting edge. Existence is desirable in that the chip discharge direction can be made constant in the chip discharge property and a stable chip discharge property can be secured.

  Further, according to the throw-away tip of the present invention, there is a polishing mark portion near the cutting edge on the rake face, the polishing mark near the cutting edge forms a breaker groove, and from the cutting edge of the breaker groove to the groove bottom portion. The inclination angle of the groove can be smaller than the rising angle from the groove bottom toward the center surface. With such a shape of the breaker groove, the chips can be reliably drawn into the breaker groove, and the chips can be reliably removed. Can be discharged after being curled or divided, and stable chip discharge is obtained.

  Further, the arithmetic average surface roughness (Ra) of the polishing mark portion in the vicinity of the cutting edge is 0.01 to 0.1 μm, so that the welding resistance is excellent and the chips can be surely drawn into the breaker groove. At the same time, it is desirable in terms of enhancing the impact resistance and fracture resistance in the vicinity of the cutting edge.

  According to the throw-away tip of the present invention, a cutting edge is formed at a crossing ridge portion between the rake face and the flank face, and at least the rake face toward the cutting edge is polished, and the polished portion By using a throw-away tip with a configuration in which there are polishing marks in the vicinity of the cutting edge in the vicinity of the cutting edge, the sharpness of the cutting edge can be improved and chipping resistance in the cutting edge can be improved. .

  One embodiment of the throw-away tip (hereinafter simply referred to as a tip) of the present invention will be described with reference to FIG.

  According to FIG. 1, the tip 1 has a substantially flat plate shape with a substantially triangular shape, and three cutting edges are formed at three corners, and a rake face 3 and a front flank 4 of the tip 1 are formed. The main cutting edge 5 is formed on the intersection ridge between the rake face 3 and the auxiliary cutting edge 7 on the intersection ridge between the rake face 3 and the side clearance face 6.

  According to the present invention, the cutting edges (the main cutting edge 5 and the auxiliary cutting edge 7) formed at the intersecting ridge portion between the rake face 3 and the flank face (the front flank face 4 and the side flank face 6) are polished. The cutting edge ridgeline is a major feature of the throwaway tip 1 having a configuration in which there are polishing edges 8 near the cutting edge polished in a plurality of directions near the cutting edge of the polished portion. The sharpness of the cutting edge and the chipping resistance at the edge of the cutting edge can be improved. In FIG. 1, the cutting edge vicinity polishing mark 8 is formed on the rake face 3.

  Here, according to the present invention, there is a cutting edge vicinity polishing mark 8 in the vicinity of the cutting edge of the rake face 3, and a center side polishing mark 10 polished from one direction exists in the center side of the cutting edge vicinity polishing mark 8. This is desirable in that the chip discharge direction can be made constant in the chip discharge property and a stable chip discharge property can be secured.

Further, according to the throw-away tip 1 of this embodiment, the portion 8 near the cutting edge of the rake face 3 forms a breaker groove, and as shown in FIG. 2, the cutting edge of the breaker groove (the main cutting edge 5). ) is the inclination angle alpha ₁ to the groove bottom portion 11 may be a shape smaller than the rising angle alpha ₂ directed from the groove bottom 11 at the center plane, according to breakers groove of this shape, the chip breaker groove While being able to pull in reliably, a chip can be reliably curled or cut and discharged, and a stable chip discharge property can be obtained.

  Furthermore, when the arithmetic mean surface roughness (Ra) of the polishing mark 8 portion near the cutting edge is 0.01 to 0.1 μm, the welding resistance can be improved, and chips can be surely drawn into the breaker groove. It is desirable in terms of improving the impact resistance in the vicinity of the cutting edge.

  On the other hand, in the present invention, the base material 2 can be applied to any of cemented carbide, cermet, or ceramic, but is most preferably applicable to cemented carbide in terms of hardness and workability.

On the other hand, according to the present invention, TiC, TiCN, TiN, (TiM) N (where M is at least one selected from the group of Al, Si, Zr and Cr), Al ₂ O ₃ by CVD or PVD. At least one layer selected from the group consisting of diamond (including PCD and DLC) and cBN, or a multilayer coating of these may be formed, among which a coating layer formed by a CVD method in terms of adhesion strength It is desirable.

  Next, a method for manufacturing the above-described chip 1 of the present invention will be described.

  First, the substantially flat base material 2 is produced, and the portion of the base material 2 forming the main cutting edge 5 is processed using a grindstone having the form shown in FIG.

  Here, in the case of polishing, as shown in FIG. 3, which is a schematic diagram of an example of the representative polishing method of the present invention shown in FIG. 3, the side direction of the grindstone and the traveling direction of the grindstone are particularly 2. It is important to process with an angle difference θ of not less than °, and further 5 to 15 °, thereby improving the sharpness of the cutting edge ridge line and improving chipping resistance at the cutting edge ridge line.

  That is, as shown in FIG. 4 which is a schematic diagram of a conventional polishing method, when the side surface direction of the grindstone and the traveling direction of the grindstone are parallel, minute chipping is likely to occur on the cutting edge ridge line, Polishing marks in one direction are generated in the polishing portion, and the chipping resistance tends to be remarkably lowered depending on the cutting conditions.

  According to the present invention, when the breaker groove is formed with the grindstone tilted, the conventional method forms an arc portion in the thickness direction of the grindstone and transfers the arc shape to the rake face of the chip 1. Although the breaker groove was formed, according to the present invention, the breaker groove can be formed by tilting the grindstone while the thickness direction of the grindstone is flat, and the shape of the breaker groove can be changed depending on the inclination of the grindstone. The desired shape can be controlled. Furthermore, according to this method, when the grindstone is set in the polishing apparatus, the grindstone can be fixed at the tip position by grinding the grindstone once by attaching it to the apparatus. That is, in the conventional grindstone in which the position of the tip of the grindstone cannot be adjusted by dressing, when the grindstone is rotated due to a slight misalignment when the grindstone is set in the apparatus, the tip position of the grindstone is shaken, and Although unevenness occurred in the way of contact, according to the above configuration of the present invention, since the positional accuracy of the tip of the grindstone is high, the shake of the way of contact between the grindstone and the polishing surface of the chip 1 is reduced, and the chip 1 There is also a merit that no extra impact is applied. Further, this effect makes it possible to smooth the surface roughness of the breaker portion to 0.01 to 0.1 μm in terms of arithmetic average surface roughness (Ra).

  A # 1000 grade metal bond grindstone is placed on the surface of a T43 type shaped chip base material made of a cemented carbide obtained by bonding WC particles with an average particle diameter of 1.5 μm with Co, and the side surface and the sliding surface ( The angle formed by the imaginary plane of the rake face is 15 °, the angle difference between the direction of the grinding wheel side face and the scanning direction of the grinding wheel is 8 °, and the cutting direction of the grinding wheel and the secondary cutting edge (secondary cutting edge 7 in FIG. 1) The grindstone was scanned in the direction perpendicular to the edge of the blade. In the processing, after the grindstone was mounted on the polishing apparatus, the position of the grindstone tip was adjusted by dressing.

  When the polished surface after processing was observed with a microscope, it became a polishing mark in the vicinity of the cutting edge with polishing marks from multiple directions, and the surface was sharply shining, and the edge of the cutting edge was sharp without any microchipping. It was in a good state. Moreover, it confirmed that the center side grinding | polishing trace grind | polished from one direction existed in the center side of the cutting edge vicinity grinding | polishing trace. Furthermore, the arithmetic average surface roughness (Ra) of the portion near the cutting edge was measured and found to be 0.051 μm.

  When a cutting test was performed under the following conditions using the obtained throw-away tip, 300 pieces could be machined and chip discharge was stable.

Cutting conditions Cutting speed: 150 m / min
Cutting depth: 3mm
Feed: 0.1mm / rev
Work material: S45C
Cutting state: wet (Comparative Example 1)
With respect to the throw-away tip of Example 1, an arc shape having a curvature radius r = 4.5 mm is formed in the thickness direction of the grindstone, and the direction of the grindstone is changed between the grindstone side surface and the sliding surface (imaginary plane of the rake face). A chip having a conventional polishing breaker was produced in the same manner as in Example 1 except that the angle formed was 15 ° and the scanning was performed in a direction where the angle difference between the direction of the grindstone side surface and the scanning direction of the grindstone was 0 °. When the polished surface after processing was observed with a microscope, it was a conventional processed surface with polishing marks from one direction, and microchipping occurred at the edge of the cutting edge. Furthermore, the arithmetic average surface roughness (Ra) of the polished portion near the cutting edge was measured and found to be 0.175 μm.

  When a cutting test was performed under the following conditions using the obtained throw-away tip, defects were generated when 200 pieces were processed. In addition, a slight dimensional shift of the grindstone is generated during polishing, and an impact may be applied to the chip surface during polishing.

It is a schematic sectional drawing which shows an example of the throw away tip of this invention. It is a conceptual diagram for demonstrating the shape of a breaker groove | channel about other examples of the throw away tip of this invention. It is a conceptual diagram for demonstrating the grinding | polishing process of the throw away tip of this invention. It is a conceptual diagram for demonstrating the grinding | polishing process of the conventional throw away tip.

Explanation of symbols

1: Throw away tip (chip)
2: Base material 3: Rake face 4: Front relief face 5: Main cutting edge 6: Side relief face 7: Sub cutting edge 8: Polishing mark in the vicinity of the cutting edge 10: Central polishing mark 11: Groove bottom

Claims (4)

A cutting edge is formed at the intersecting ridge part of the rake face and the flank face, and at least the rake face toward the cutting edge is polished and polished in a plurality of directions near the cutting edge of the polished part. A throw-away tip characterized by the presence of polishing marks near the blade. 2. The vicinity of the cutting edge near the cutting edge of the rake face is present, and the center side polishing mark polished from one direction is present on the center side of the polishing edge near the cutting edge. The throw-away tip described. There is a polishing mark near the cutting edge on the rake face, the polishing mark part near the cutting edge forms a breaker groove, and an inclination angle from the cutting edge of the breaker groove to the groove bottom is directed from the groove bottom to the center surface. The throw-away tip according to claim 1 or 2, wherein the throw-away tip is smaller than a rising angle. The throw-away tip according to any one of claims 1 to 3, wherein an arithmetic average surface roughness (Ra) of the polishing mark portion near the cutting edge is 0.01 to 0.1 µm.

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