JP2004188585A - Throw-away tip and cutting tool using it - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain an excellent finishing surface roughness of a cut material from the beginning stage of machining, and at the same time to realize a lifetime extension of a tip in a throw-away tip. <P>SOLUTION: In the throw-away tip constituted by integrally forming a base portion for fixing a holder and a protruding portion provided with a cutting edge near its tip, by forming the cutting edge 8 of the tip and a rake face contiguous to it in the tip region of the protruding portion, by making a part of the cutting edge 8 of the tip overhang laterally from the circumferential face of the protruding portion, a plurality of roughly circular arched cutting edges with the different radius of curvature and an escaping portion 13 in the rear are disposed in series with the cutting edge 8 of the tip in the crossover ridge-line of the rake face 9 and a flank in a portion overhanging laterally from the circumferetaial face of the protruding portion, that of a second roughly circular arched cutting edge 12 which is also contiguous to a first roughly circular arched cutting edge is larger than the radius of curvature of the first roughly circular arched cutting edge 11 contiguous to the cutting edge of the tip and the arithmetic average roughness (Ra) of the flank of the second roughly circular arched cutting edge is made equal or smaller than that of the flank of the first roughly circular arched cutting edge. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

  The present invention relates to a throw-away insert used for processing various components and a cutting tool using the same.

  Conventionally, cutting tools for processing various parts include a throw-away type in which a throw-away tip is freely attached to the tip of a holder as shown in FIG. 13 and a cutting edge in a tip of the holder as shown in FIG. A brazing type or the like in which a brazing is fixed.

  Of these, the brazing type requires a lot of time and labor to braze the cutting edge portion, and the cost is high. Therefore, the throw-away type is often used at present. However, since the throw-away type as shown in FIG. 13 has a limit in the minimum processing diameter due to its structure, it is generally used for large-diameter processing of automobile parts and the like, and is generally used for OA equipment parts, electronic parts and the like. For small-diameter machining, a throw-away tip in which a rod-shaped base serving as a mounting portion for a sleeve type holder as shown in FIG. 15 and a protruding portion having a cutting edge at the tip are integrally formed, and FIG. A throw-away tip is used in which a flat base serving as a mounting portion to a holder as shown and a protruding portion having a cutting edge at the tip are integrally formed (for example, see Patent Document 1).

In particular, the latter indexable insert is mounted on the holder at the base of the flat plate, so that the chip has a large restraining force and is unlikely to generate chatter vibration. It is widely used for precision processing of required OA equipment parts and electronic parts as described above.
JP-A-11-277309

However, in the conventional indexable inserts as shown in FIGS. 16 and 17, the finished surface roughness of the work material is not stable at the initial stage of machining and shows a relatively large value. The roughness tended to stabilize and settle at a relatively small value. As shown in FIG. 18, at the stage of processing the initial poor finished surface roughness of the workpiece, i.e. the processing step d ₂ is large, there is a problem that would result out many defective products.

  The present invention has been made in order to solve the above-described problems of the prior art. In addition to obtaining a good work surface finish from the initial stage of machining, it is possible to increase the non-defective rate of the work material. It is another object of the present invention to provide a throw-away chip that can extend the life of the chip.

  In order to solve the above-mentioned problems, the present inventor has repeatedly examined the above-mentioned problems, and as a result, as a result of repeating the processing, the surface roughness gradually becomes stable as the processing is repeated, and a relatively small value is settled. It was found that the cutting edge, which had a small nose R shape, was gradually worn by repeated processing to become a relatively large R shape close to a straight line, and that the worn portion played a role of performing a saray on the machined surface. .

  That is, the indexable insert according to claim 1 is formed integrally with a holder fixing base and a protruding portion provided with a cutting edge near the front end thereof, and a work material is formed at a front end portion of the protruding portion. In a throwaway tip, which forms a tip cutting edge and a rake face continuous with the tip cutting edge for processing, and furthermore, at least a part of the tip cutting edge projects laterally from the peripheral surface of the protruding portion, A plurality of substantially arc-shaped cutting blades having different radii of curvature, at the intersection ridge line of the rake face and the flank of a portion protruding laterally from the peripheral surface of the protrusion, continuing to the tip cutting blade, A rear escape portion that connects the substantially arc-shaped cutting edge and the peripheral surface of the protruding portion is disposed, and the first substantially arc-shaped cutting edge is determined based on a radius of curvature of the first substantially arc-shaped cutting blade that is continuous with the leading edge cutting edge. A second substantially arcuate cutting edge further larger than that of the second substantially arcuate cutting edge The arithmetic mean roughness of the flank face (Ra) is characterized by small equivalent to that or than that of the flank of the first substantially arcuate cutting edge.

  According to such a configuration, the first substantially arcuate cutting edge has a smaller substantially arcuate curvature than the second substantially arcuate cutting edge, so that the first substantially arcuate cutting edge cuts into a work material. The cutting force at the time can be reduced. In addition, the second substantially arcuate cutting edge has a substantially arcuate curvature greater than that of the first substantially arcuate cutting edge, so that the second substantially arcuate cutting edge can finish the work surface of the workpiece with the second substantially arcuate cutting edge. Since the step caused by the stitch in the cross section of the processed part of the work material becomes smaller, it becomes smoother, that is, the finished surface roughness becomes smaller, so the finished surface roughness of the work material is stable at a small value from the initial stage of processing Can be made. Here, the fact that the finished surface roughness of the work material is stabilized at a good value from the initial stage of processing means that the non-defective rate of the work material to be processed is improved. As a result, the life of the chip is improved. In addition, since the surface shape of the flank of the second substantially arc-shaped cutting edge for performing the finish machining of the work material is transferred to the processed finished surface of the work material, the arithmetic operation on the flank of the second substantially arc-shaped cutting blade is performed. By making the average roughness (Ra) equal to or smaller than that of the first substantially arc-shaped cutting edge, the surface roughness of the transfer side is improved, and as a result, the finish of the workpiece to be transferred is finished. Surface roughness can be reduced.

  The indexable insert according to claim 2 is characterized in that the flank of the second substantially circular cutting edge has an arithmetic mean roughness (Ra) of 0.1 μm or less.

  According to this configuration, the surface shape of the flank surface of the second substantially arc-shaped cutting edge is directly transferred to the finished surface of the work material. Therefore, by defining as described above, the finished surface roughness can be reduced. It can be good.

  In addition, in the throw-away tip according to claim 3, both ends of the second substantially arc-shaped cutting blade are arranged such that an end of the rear escape portion closer to an end of the first substantially arc-shaped cutting blade than the protruding portion. It is characterized by being arranged close to

  According to this configuration, by arranging the second substantially arcuate cutting edge as described above, only the second substantially arcuate cutting edge and its flank face are applied to the finished surface of the work material, and the rear side Since the relief portion is prevented from hitting the finished surface of the work material, the finished surface roughness of the work material can be kept good.

  Further, the indexable insert according to claim 4 is characterized in that it is used for internal diameter processing, and the above-described configuration can reduce the cutting resistance at the time of cutting and reduce the work material even in small-diameter internal diameter processing in which the maximum processing diameter is limited. Of the finished surface can be kept good.

  In the cutting tool according to the fifth aspect, by mounting the above-mentioned throw-away tip, it is possible to perform cutting such that the cutting resistance at the time of cutting is small and the finished surface roughness of the work material is good.

  According to a sixth aspect of the present invention, there is provided a throwaway tip in which a base for fixing a holder and a protruding portion provided with a cutting edge near its distal end are integrally formed, and a work material is formed at a distal end portion of the protruding portion. In a throwaway tip, which forms a tip cutting edge and a rake face continuous with the tip cutting edge for processing, and furthermore, at least a part of the tip cutting edge projects laterally from the peripheral surface of the protruding portion, At the intersection ridge line of the rake face and the flank face of the portion protruding laterally from the peripheral surface of the protrusion, continuous with the tip cutting edge, a substantially arc-shaped cutting edge, a straight cutting edge, A rear flank connecting the linear cutting blade and the peripheral surface of the protruding portion is disposed, and an arithmetic mean roughness (Ra) of the flank of the linear cutting blade is a flank of the substantially arc-shaped cutting blade. It is characterized by being equal to or smaller than that of.

  According to such a configuration, when the workpiece is cut into the workpiece by the substantially arc-shaped cutting blade and the processing surface of the workpiece is finished by the linear cutting blade, a finished surface generated by a feed stitch in a cross section of a processed portion of the workpiece. Since the step is smaller, the surface roughness becomes smoother, that is, the finished surface roughness becomes smaller, so that the finished surface roughness of the work material can be stabilized at a small value from the initial stage of machining. Also, since the surface shape of the flank of the linear cutting edge for finishing the work material is transferred to the finished surface of the work material, the arithmetic average roughness (Ra) on the flank of the linear cutting blade is obtained. Is made equal to or smaller than that of the above-described substantially arc-shaped cutting blade, the surface roughness on the transfer side is improved. As a result, the finished surface roughness of the work material on the side to be transferred can be reduced. .

  Further, the throwaway tip according to claim 7 is characterized in that the flank of the linear cutting edge has an arithmetic average roughness (Ra) of 0.1 μm or less.

  According to this configuration, the surface shape of the flank of the linear cutting edge portion is directly transferred to the finished surface of the work material. You can do it.

  In addition, in the indexable insert according to claim 8, both ends of the straight cutting edge are arranged such that an end on the rear escape portion side is closer to the protruding portion than an end on the substantially arcuate cutting edge side. It is characterized by being.

  According to this configuration, by arranging the linear cutting blades as described above, only the linear cutting blades and the flank thereof are applied to the finished surface of the work material, and the rear flank is formed by the rear flank. Since it is possible to prevent the finished surface of the work material from being hit, the finished surface roughness of the work material can be favorably maintained.

  In addition, the indexable insert according to claim 9 is characterized in that it is used for internal diameter machining, and the above-described configuration can reduce the cutting resistance at the time of cutting and reduce the work material even in small-diameter internal diameter machining in which the maximum machining diameter is limited. Of the finished surface can be kept good.

  In the cutting tool according to the tenth aspect, by mounting the above-mentioned indexable insert, it is possible to perform cutting such that the cutting resistance at the time of cutting is small and the finished surface roughness of the work material is good.

  According to the indexable insert of the present invention, the radius of curvature of the first substantially arcuate cutting edge that is continuous with the tip cutting edge is larger than that of the second substantially arcuate cutting edge that is further continued with the first substantially arcuate cutting edge. This makes it possible to reduce the cutting resistance when cutting into the work material with the first substantially arcuate cutting edge, and the second substantially arcuate cutting edge has a substantially arcuate shape with respect to the first substantially arcuate cutting edge. Due to the large curvature, when finishing the machined surface of the work material with the second substantially arcuate cutting edge, a step generated by a feed groove in the finished surface of the work material is reduced, so that the finished surface is smoother, that is, the finished surface is roughened. Since the degree is small, the finished surface roughness of the work material can be stabilized at a small value from the initial stage of processing. Furthermore, since the surface shape of the flank of the second substantially arc-shaped cutting edge for performing the finish machining of the work material is transferred to the finished surface of the work material, the flank of the second substantially arc-shaped cutting blade is By making the arithmetic average roughness (Ra) equal to or smaller than that of the first substantially arcuate cutting edge, the surface roughness on the side to be transferred is improved, and as a result, the work material on the side to be transferred is Finished surface roughness can be reduced.

  Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

  1 to 7 show one embodiment of the present invention. FIG. 1 is a plan view of a throw-away tip 1 according to the embodiment, FIG. 2 is a side view, FIG. 3 is an enlarged view of a portion A in FIG. 4 is an enlarged side view of a portion A in FIG. 1, FIG. 5 is a schematic sectional view of a processed portion, FIG. 6 is a plan view of a holder with the throw-away tip 1 of the present embodiment mounted on the holder, and FIG. It is a schematic diagram which shows that a surface shape is transferred to a processing finish surface.

  In FIGS. 1, 2 and 6, the throw-away tip 1 according to the present embodiment is obtained by projecting a projecting portion 4 along one side surface 3 integrally with a flat plate base 2 for fixing a holder. A screw hole 5 for fixing a chip screw, which penetrates to the bottom surface, is formed in the center of the holder 2 and is attached to the holder 7 by a screw 6 for fixing the chip.

  1 and 2, a tip cutting edge 8 and a rake face 9 continuous with the tip cutting edge 8 are formed at a tip end portion of the protruding portion 4 for processing a work material. According to the present invention, as shown in FIGS. 3 and 4, in the throw-away tip 1 in which a part of the projection is laterally protruded from the peripheral surface of the protruding portion 4, A plurality of substantially arc-shaped cutting blades 11 and 12 having different radii of curvature and a rear flank portion 13 are provided on the protruding portion at the intersection of the rake face 9 and the flank 10, continuing to the tip cutting edge 8. And are arranged. Here, as shown in FIG. 5, there is a case where a relief groove 24 is formed at an intersection of a processing surface and a processing end wall surface. Such a processing is performed by cutting a cutting edge in a radial direction of a work material. Therefore, in order to prevent interference other than the cutting edge portion with the work material, the shape is such that only the vicinity of the substantially arc-shaped cutting edge is laterally projected from the projecting portion.

Further, a first substantially arcuate cutting edge 11 continuing to the tip cutting edge 8 cuts into the work material, and a second substantially arcuate cutting edge 12 further continuing to the first substantially arcuate cutting edge 11 is used for finishing machining. As a blade, perform the finished surface. Here, according to the present invention, since the radius of curvature of the first substantially arcuate cutting edge 11 is larger than that of the second substantially arcuate cutting edge 12, as shown in FIG. since the level difference d ₁ of the finished surface 16 caused by the feed-th in the cross section is reduced, the second finishing surface of a substantially arcuate cutting edge 12 is more smooth, i.e. so the finished surface roughness is decreased, the processing initial From the stage, the finished surface roughness of the work material can be stabilized at a small value. Here, the fact that the finished surface roughness of the work material is stabilized at a good value from the initial stage of processing means that the non-defective product rate of the work material to be processed is improved. As a result, the life of the chip is improved.

  Further, the width w of the second substantially arcuate cutting blade 12 along the axial direction of the projection 4 is preferably in the range of 0.01 mm to 0.1 mm. If it exceeds 0.1 mm, the rate of contact of the second substantially arcuate cutting edge 12 with the work material increases, so that the cutting resistance increases and chattering vibrations easily occur, which is not preferable. In order to obtain the above-mentioned effect when the distance is smaller than 0.01 mm, the feed rate is set to 0.001 mm / rev. Is required, and the processing efficiency is reduced, which is not preferable.

  As shown in FIG. 4, the arithmetic mean roughness (Ra) of the flank 15 of the second substantially circular cutting edge 12 is equal to or smaller than that of the flank 14 of the first substantially circular cutting edge 11. It is formed so that it becomes. This is because, as shown in FIG. 7, the surface shape of the flank 15 of the second substantially arc-shaped cutting blade 12 serving as the finishing cutting edge is transferred to the finished surface of the work material 17, 2. It is important that the surface roughness of the flank 15 of the substantially arc-shaped cutting edge portion 12 is smaller in order to increase the finished surface roughness. In particular, it is preferable that the arithmetic mean roughness (Ra) of the flank 15 of the second substantially arcuate cutting edge 12 is 0.1 μm or less. Incidentally, the arithmetic mean roughness (Ra) of the flank of the conventional chip shown in FIG. 14 is in the range of 0.3 μm to 0.4 μm, and by defining this as described above, the finished surface roughness of the work material is obtained. The degree can be improved to less than half the value. Here, since the finished surface roughness of the work material is caused by the surface roughness of the flank 15 of the second substantially arc-shaped cutting edge 12 for performing the finishing, the first substantially arc-shaped cutting edge of the cut portion is used. The surface roughness of the flank 14 of the cutting edge 11 is not related to the surface roughness of the finished surface 16. Note that the arithmetic mean roughness (Ra) of the flank not involved in cutting at a distance of 0.4 mm or more from the second substantially arc-shaped cutting edge 12 (intersecting ridge) is not necessarily the flank 14 of the first substantially arc-shaped cutting edge 11. Even if it is not the same or smaller, it does not affect the finished surface roughness.

  As shown in FIG. 5, both ends of the second substantially arcuate cutting edge 12 are such that the end on the rear escape portion 13 side protrudes from the end on the first substantially arcuate cutting edge 11 side. It is arranged so as to be close to the part 4. This is because only the second arcuate cutting edge 12 and its flank 15 are applied to the finished surface 16 of the work material, and the rear flank 13 is prevented from hitting the finished surface 16 of the work material. The finished surface roughness of the cut material can be kept good.

  FIG. 8 is an enlarged view of a cutting edge of a type in which the straight cutting edge 22 is a finishing cutting edge as another embodiment of the present invention. The step of the finished surface formed by the feed groove in the cross section of the processed portion can be reduced by maintaining the angular relationship in an appropriate range even if the finishing cutting edge is configured by the straight cutting edge 22, so that the second substantially circular shape is used. An effect similar to that of the arcuate cutting edge 12 can be obtained.

  FIGS. 9 and 10 show plan views of a throw-away tip provided with a rod-shaped base 26 as another embodiment of the present invention. The tip of the projection 4 formed integrally with the rod-shaped base 26 is provided with a cutting edge 8 having the same configuration as the throw-away tip provided with the above-mentioned flat base 2 to reduce the surface roughness of the work material. It can be kept good.

Further, FIGS. 11 and 12 show, as another embodiment of the present invention, indexable inserts 27 and 28 having cutting edges for pulling. A tip cutting edge 8 is provided on the holder fixing base side, a first substantially arcuate cutting edge 11 (substantially arcuate cutting edge 21), a second substantially arcuate cutting edge 12 (straight cutting edge 22), and a rear end. By arranging the side reliefs 13 (23), it is possible to reduce the cutting resistance due to the cut into the work material and to keep the finished surface roughness of the work material favorable even in the drawing process. Although the embodiment has been exemplified, it is needless to say that the present invention is not limited to the above-described embodiment, and can be arbitrary without departing from the object of the invention.

FIG. 2 is a plan view of a throw-away tip (flat base type) of the present invention. It is a side view of the throw away tip of FIG. It is the A section enlarged view of FIG. It is a side view of the A section expansion of FIG. FIG. 2 is a schematic sectional view of a processed portion of the indexable insert of FIG. 1. It is a holder top view when the throw away tip of this invention is fixed to the holder main body. It is a mimetic diagram showing that the surface shape of the flank of the throw away tip of the present invention is transferred to the processed finish surface. FIG. 6 is an enlarged view of a cutting edge in another embodiment of the present invention. FIG. 9 is a plan view of a throw-away tip (rod-type base type) according to another embodiment of the present invention. FIG. 9 is a plan view of a throw-away tip (rod-type base type) according to another embodiment of the present invention. FIG. 9 is a plan view of a throw-away insert (a flat base type for drawing) according to another embodiment of the present invention. FIG. 7 is a plan view of a throw-away insert (a rod-shaped base for drawing) according to another embodiment of the present invention. It is a holder top view of the conventional throw-away type inside diameter machining tool. It is a holder top view of the conventional brazing type inside diameter machining tool. It is principal part sectional drawing of the conventional integrated type inside diameter machining tool. It is a top view of the conventional throw away type holder. It is the B section enlarged view of FIG. It is a section schematic diagram of the processing part in the conventional throw away type cutting tool.

Explanation of reference numerals

1: Indexable insert (flat base type)
2: Flat base 3: Side surface 4: Projecting portion 5: Screw hole 6: Tip fixing screw 7: Holder body 8, 20: Tip cutting edge 9: Rake surface 10: Flank surface 11: First substantially arcuate cutting edge 12: second substantially arcuate cutting edge 13, 23: rear flank portion 14: flank surface of first substantially arcuate cutting edge 15: flank surface of second substantially arcuate cutting edge 16: finished surface 17 of work material : Work material 18: Wear surface 19: Shape transfer edge 21: Substantially arc-shaped cutting edge 22: Straight cutting edge 24: Sliding grooves 25 a, 25 b: Indexable insert (rod base type)
26: rod-shaped base 27: indexable insert (flat base for drawing)
28: Indexable insert (bar base type for pulling)
31: Holder main body 32: Indexable tip 33: Flat base 34: Projecting portion 35: Tip cutting edge 36: Substantially circular cutting edge 37: Rear flank 38: Rake surface 39: Work material 40: Slack groove w : Widths d1 and d2 of second substantially arcuate cutting blades: Steps generated by feed stitches in the cross section of the work material

Claims (10)

A holder fixing base and a protruding portion having a cutting edge in the vicinity of a front end thereof are integrally formed, and a front cutting edge and a front cutting edge are formed at a front end portion of the protruding portion for processing a work material. A rake face that is continuous with the cutting edge, and furthermore, at least a part of the tip cutting edge projects laterally beyond the peripheral surface of the protruding portion. At the intersection of the rake face and the flank of the projected portion, a plurality of substantially arc-shaped cutting edges having different radii of curvature, the plurality of substantially arc-shaped cutting edges, and the periphery of the protruding portion are continuous with the tip cutting edge. A rear escape portion connecting the first and second surfaces is disposed, and a second substantially arc-shaped portion further connected to the first substantially arc-shaped cutting edge from a radius of curvature of the first substantially arc-shaped cutting edge continuous to the tip cutting edge. The arithmetic mean roughness (Ra) of the flank of the second substantially arc-shaped cutting edge is larger than that of the first substantially arc-shaped cutting edge. Indexable insert, wherein the arcuate cutting edge of the small equivalent to that or than that of the flank. The indexable insert according to claim 1, wherein an arithmetic mean roughness (Ra) of a flank surface of the second substantially arcuate cutting edge is 0.1 µm or less. Both ends of the second substantially arc-shaped cutting blade are arranged such that an end on the rear clearance side is closer to the protruding portion than an end on the first substantially arc-shaped cutting blade. The throw-away tip according to claim 1 or 2, wherein The indexable insert according to any one of claims 1 to 3, wherein the indexable insert is for internal diameter machining. A cutting tool comprising the holder with the indexable insert according to any one of claims 1 to 4. A holder fixing base and a protruding portion having a cutting edge in the vicinity of a front end thereof are integrally formed, and a front cutting edge and a front cutting edge are formed at a front end portion of the protruding portion for processing a work material. A rake face that is continuous with the cutting edge, and furthermore, at least a part of the tip cutting edge projects laterally beyond the peripheral surface of the protruding portion. A substantially arcuate cutting edge, a straight cutting edge, a straight cutting edge, and the peripheral surface of the protruding portion are provided at the intersection of the rake face and the flank of the projected portion at the intersection of the leading edge cutting edge. And a rear flank connecting the flank of the straight cutting edge and the arithmetic mean roughness (Ra) of the flank of the straight cutting edge is equal to or smaller than that of the flank of the substantially circular cutting edge. Features a throwaway tip. The indexable insert according to claim 6, wherein the flank of the straight cutting edge has an arithmetic mean roughness (Ra) of 0.1 µm or less. 7. The linear cutting blade according to claim 6, wherein both end portions of the straight cutting edge are arranged such that an end portion on the rear clearance portion side is closer to the protruding portion than an end portion on the substantially arcuate cutting edge side. Or the throw-away tip according to 7. The indexable insert according to any one of claims 6 to 8, wherein the indexable insert is for internal diameter machining. A cutting tool comprising the indexable insert according to any one of claims 6 to 9 mounted on a holder.

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