JP5240624B2 - Blade-tip-exchangeable tip and method for manufacturing the same - Google Patents

Description

  The present invention relates to a blade-tip-exchangeable tip and a method for manufacturing the same, and more particularly, to a blade-tip-exchangeable tip having a flank surface composed of a plurality of surfaces and a method for manufacturing the same.

  A blade-tip-exchangeable tip used for cutting is manufactured by compacting and sintering a cemented carbide as disclosed in, for example, Japanese Patent Laid-Open No. 61-288903 (Patent Document 1). . In the case of an unground chip, there is a problem in that a density difference occurs between the upper surface side and the lower surface side during compacting, warping due to this density difference occurs during sintering, and this warping remains as it is. With respect to this problem, in Patent Document 1, a flat portion protruding in the thickness direction of the chip is formed at a corner portion of at least one of the both end surfaces of the chip, and a portion following the flat portion in a direction away from the corner blade is formed. An unground negative slobe tip having an inclined surface having a downward slope is disclosed.

  Further, as another blade tip replaceable tip, for example, in JP-A-2005-324324 (Patent Document 2), a cutting edge or a main cutting edge is formed straight along the entire width of the tip, and the main cutting edge and the surface are formed. A turning insert is disclosed in which the boundary with the cutting edge that finishes is a bending point.

  The user's procedure for using such a blade tip replaceable tip is, for example, as follows. First, a tip is attached to the holder with a specific corner used for cutting facing the tip side of the holder, and fine adjustment is performed to set the tip position of the blade edge to a specified position. At this time, since the size and the amount of deformation are different for each tip, and the tip position of the blade tip is different in units of μm for each corner of the same tip, the tip of the blade tip is set to the same designated position as the corner used for the previous cutting. The position needs to be adjusted again. This blade edge position adjustment amount becomes larger with a tip having a large dimensional tolerance (generally a side flank non-polished tip) or a tip having a large deformation amount. Cutting is performed with the blade-tip-exchangeable tip thus attached. After the tip has been used for cutting until the tip corner life, the tip is removed from the holder. Then, another corner of the same chip or another corner of another chip is attached, and then the fine cutting is performed again to make the cutting edge tip position a designated position, and then cutting is performed.

Japanese Patent Laid-Open No. 61-288903 JP 2005-324324 A

  However, in the blade-tip-exchangeable tips of Patent Documents 1 and 2, a difference occurs in the shape of another corner of the same tip attached to the holder or another corner of another tip. As a result of intensive studies, the present inventor found that the above-mentioned has not been sufficiently reduced.

  In addition, a technique for processing to reduce the difference in the shape of another corner of the same chip attached to the holder or another corner of another chip can be considered, but in processing to obtain a chip with extremely high dimensional accuracy, The sintered compact needs to be polished with a diamond grindstone. However, such a polishing process increases the manufacturing cost. In addition, it is often impossible to polish a portion having a complicated three-dimensional shape. For this reason, it is difficult to realize a chip in which the deviation of the tip position of the blade edge each time the blade edge is replaced.

  The present invention has been made to solve the above problems, and an object of the present invention is to provide a blade-tip-exchangeable tip and a method for manufacturing the same, which can improve the positional accuracy when attached to a holder.

The blade-tip-exchangeable tip according to one aspect of the present invention is connected to a rake face having a polygonal outer periphery and a side sandwiched between a pair of adjacent corners on the outer periphery of the rake face, and intersects the rake face. A flank extending in the direction. The edge that is the intersection of the rake face and the flank face is the cutting edge. The flank is convex and has a first region located in the center of the flank, a second region connected to the first region and located on one side of a set of corners, And a third region that is connected to one region and located on the other side of the set of corners. An opening is provided in the center of the rake face. Extending from a first intersection of an extension line of a portion of the cutting edge that is continuous with the first region and a line segment extending in a direction perpendicular to the extension line from one end of one set of corners of the cutting edge The length from the other end of the pair of corners of the line and the cutting edge to the second intersection with the line segment extending in the direction perpendicular to the extension line is a, and the first region of the cutting edge The length from the end point on the first intersection point side to the first intersection point in the continuous portion is b1, and the length from the second intersection side end point to the second intersection point in the portion connected to the first region of the cutting edge When the height is b2, the conditions of 0.80 ≦ b1 / b2 ≦ 1.20 and 0.32 ≦ (b1 + b2) /a≦0.70 are satisfied. The cutting edge replaceable tip is supported in the first region.

The method of manufacturing a blade-tip-exchangeable tip according to one aspect of the present invention includes a step of preparing a raw material, a step of filling a raw material into a mold, and forming a green compact by compressing the raw material, and a green compact Heating the body to obtain a sintered body. The sintered body includes a rake face whose outer periphery shape is a polygonal shape, and a flank face that extends in a direction intersecting with the rake face that is continuous with a pair of adjacent corners on the outer periphery of the rake face. The side that is the intersection of the rake face and the flank face is a cutting edge, the flank face is convex, and is connected to the first area located in the center of the flank face, the first area, and A second region located on one side of the set of corners and a third region connected to the first region and located on the other side of the set of corners, the center of the rake face Is provided with an opening, an extension line of a portion of the cutting edge that is continuous with the first region, and a line segment extending in a direction perpendicular to the extension line from one end of one set of corners of the cutting edge, From the first point of intersection, from the end point on the other side of the pair of corners of the extension line and the cutting edge The length from the first intersection point to the first intersection point in the portion of the cutting edge that is continuous with the first region is a, the length to the second intersection point with the line segment extending in the direction perpendicular to the long line When b1 is the length from the end point on the second intersection side to the second intersection point in the portion of the cutting edge that is continuous with the first region, b2 is 0.80 ≦ b1 / b2 ≦ 1. 20 and 0.32 ≦ (b1 + b2) /a≦0.70 are satisfied. The sintered body is supported in the first region.

  As a result of diligent research, the inventor has compared the first region having a relatively short distance from the opening provided in the center of the rake face with the second and third regions having a relatively long distance from the opening. It has been found that since the shrinkage due to sintering of the pressed body is small, the strain becomes small. For this reason, when attaching a chip | tip to a holder, the deterioration of the blade-tip position accuracy resulting from a deformation | transformation of a sintered compact can be suppressed by supporting a chip | tip in a 1st area | region. Thus, when attaching a blade-tip-exchangeable chip to the holder, if 0.32> (b1 + b2) / a, the area held in a region having a relatively long distance from the opening becomes too large. For this reason, due to the distortion of this region, the positional accuracy when attaching to the holder cannot be improved. Similarly, when (b1 + b2) / a> 0.70 when attaching the blade-tip-exchangeable tip to the holder, the area of the first region, that is, the area that can be attached to the holder is too small. For this reason, due to the deterioration of stability, it is not possible to improve the positional accuracy when attaching to the holder. In the case of 0.80> b1 / b2 and 1.20 <b1 / b2, the difference between the areas of the second and third regions becomes too large, so the first region is located at a relatively long distance from the opening. Is located. For this reason, since the 1st field also includes a field with big distortion, the position accuracy at the time of attaching to a holder cannot be improved. From the above, by satisfying the conditions of 0.80 ≦ b1 / b2 ≦ 1.20 and 0.32 ≦ (b1 + b2) /a≦0.70, the positional accuracy when attaching to the holder can be improved. it can.

  In the cutting edge replaceable tip according to one aspect of the present invention, preferably, a distance between the extension line and the end point of the cutting edge is d, and the condition of 5 μm ≦ d ≦ 100 μm is satisfied.

  By satisfying the condition of 5 μm ≦ d, the possibility that the corner and the holder come into contact with each other can be further reduced, so that deterioration of the edge position accuracy due to such contact can be further suppressed. By setting d ≦ 100 μm, the chip disposability is well maintained, so that deterioration of the surface roughness of the processed surface can be suppressed.

  In the cutting edge-exchangeable tip according to one aspect of the present invention, at least one of the second region and the third region may be curved. Even if it is such a shape, the blade edge | tip exchange-type chip | tip of this invention can improve the positional accuracy at the time of attaching to a holder.

  In the blade-tip-exchangeable tip according to one aspect of the present invention, at least one of the second region and the third region may be planar. Thereby, it is easier to process the second and third regions than when the second and third regions are curved surfaces.

  In the blade-tip-exchangeable tip according to one aspect of the present invention, the angle of at least one of the set of corners may be 80 ° or less.

  The density of the raw material powder filled in the corners of 80 ° or less tends to be low. However, even with such a shape, the present invention can reduce the influence of distortion near a set of corners. For this reason, even if one set of corners is 80 ° or less, it is possible to improve the positional accuracy when attaching to the holder.

  The blade-tip-exchangeable tip according to one aspect of the present invention further includes another flank formed at a position different from the flank, and the flank and the other flank extend perpendicular to the rake face. It has a shape that is rotationally symmetric about a rotation axis that passes through the center of the rake face.

  Thereby, also about the other flank, it can suppress the deterioration of blade edge position accuracy similarly to the said flank.

The blade-tip-exchangeable tip according to another aspect of the present invention has a hexagonal shape on the outer periphery, a rake face alternately including acute corners and blunt apexes on the outer periphery, and acute corners and obtuse angles on the outer periphery of the rake face. And a flank extending in a direction intersecting with the rake face. The edge that is the intersection of the rake face and the flank face is the cutting edge. The flank is convex and includes a first region located on the apex side and a second region located on the corner side that is continuous with the first region. An opening is provided in the center of the rake face. The length from the intersection of the extended line of the cutting edge connected to the first region and the line segment extending in the direction perpendicular to the extended line from the corner side end point of the cutting edge to the end point on the vertex side of the cutting edge Assuming that a is the length from the end point on the intersection side to the intersection in the portion of the cutting edge that is continuous with the first region, the condition of 0.20 ≦ b / a ≦ 0.70 is satisfied. The cutting edge replaceable tip is supported in the first region.

In another aspect of the present invention, a method for manufacturing a blade-tip-exchangeable tip includes a step of preparing a raw material, a step of filling the raw material into a mold, and forming the green compact by compressing the raw material, and a green compact. Heating the body to obtain a sintered body. The sintered body has a hexagonal shape on the outer periphery, a side sandwiched between a rake face that alternately includes acute corners and obtuse angle vertices on the outer periphery, and acute corners and obtuse angle vertices on the outer periphery of the rake face. And a flank extending in a direction intersecting the rake face, the side that is the intersection of the rake face and the flank face is a cutting edge, the flank face is convex, and is located on the apex side. 1 area and the 2nd area which is connected to the 1st area, and is located in the corner side, the opening is provided in the center of the rake face, and the extension of the part which is connected to the 1st area among cutting edges The length from the intersection of the line and the line segment extending in the direction perpendicular to the extension line from the end point on the corner side of the cutting edge to the end point on the apex side of the cutting edge is a, and is continuous with the first region of the cutting edge. When the length from the end point on the intersection point side to the intersection point in the part is b, 0.20 ≦ The condition that /a≦0.70. The sintered body is supported in the first region.

  As a result of earnest research, the inventor has found that the vicinity of the apex of the obtuse angle is relatively short from the opening provided in the center of the rake face compared to the vicinity of the corner of the acute angle, so the shrinkage due to sintering of the press body is small. And found that the distortion is reduced. For this reason, when attaching a chip | tip to a holder, the deterioration of the blade-tip position accuracy resulting from a deformation | transformation of a sintered compact can be suppressed by supporting a chip | tip in the vertex vicinity of an obtuse angle. Thus, when attaching a blade edge | tip exchange-type chip | tip to a holder, the area hold | maintained in the corner of an acute angle with a large distortion will become too large that it is 0.20> b / a. For this reason, it is not possible to improve the position accuracy when attaching to the holder due to distortion in the vicinity of an acute corner. Similarly, when attaching the blade-tip-exchangeable tip to the holder, if b / a> 0.70, the area that can be attached to the holder is too small. For this reason, due to the deterioration of stability, it is not possible to improve the positional accuracy when attaching to the holder. That is, by satisfying the condition of 0.2 ≦ b / a ≦ 0.7, it is possible to improve the position accuracy when attaching to the holder.

  In the blade tip replaceable tip in another aspect of the present invention, preferably, the condition of 5 μm ≦ d ≦ 100 μm is satisfied, where d is the distance between the extension line and the corner-side end point of the cutting edge.

  By satisfying the condition of 5 μm ≦ d, the possibility that the corner and the holder come into contact with each other can be further reduced, so that deterioration of the edge position accuracy due to such contact can be further suppressed. By setting d ≦ 100 μm, the chip disposability is well maintained, so that deterioration of the surface roughness of the processed surface can be suppressed.

  In the blade-tip-exchangeable tip according to another aspect of the present invention, the second region may be curved. Even if it is such a shape, the blade edge | tip exchange-type chip | tip of this invention can improve the positional accuracy at the time of attaching to a holder.

  In the blade-tip replaceable tip according to another aspect of the present invention, the second region may be planar. Thereby, the processing of the second region is easier than when the second region is a curved surface.

  In the blade-tip-exchangeable tip according to another aspect of the present invention, the acute corner may have an angle of 80 ° or less. The density of the raw material powder filled in the corners of 80 ° or less is likely to be lower than the raw material powder filled in the portion where the apex of the obtuse angle is located. However, even with such a shape, the present invention can reduce the influence of distortion in the vicinity of the acute angle corner. Therefore, even when the acute angle corner is 80 ° or less, the positional accuracy when attaching to the holder is improved. It can be improved.

  In the blade-tip-exchangeable tip according to another aspect of the present invention, the tip is provided with another flank formed at a position facing the flank, and the flank and the other flank are perpendicular to the rake face. It may have a shape that is 120 ° rotationally symmetric about a rotation axis that extends and passes through the center of the rake face.

  Thereby, also about the corner formed in the edge part of another flank, the deterioration of a blade edge position precision can be suppressed similarly to the corner located in the edge part of the said flank.

  In the blade-tip-exchangeable tip in one and other aspects of the present invention, the corner may be a round corner, and the radius of curvature of the corner may be 2.4 mm or less.

  Even in the case where the corner satisfies the above conditions, the present invention can reduce the influence of distortion in the vicinity of the round corner, so that it is possible to improve the position accuracy of attaching to the holder. In particular, the effect of the present invention is remarkable at 1.6 mm or less.

  In the blade-tip replaceable tip in one and other aspects of the present invention, the base material constituting the blade-tip replaceable tip is a WC-based cemented carbide, cermet, high-speed steel, ceramics, or cubic boron nitride sintered body And at least one selected from the group consisting of a diamond sintered body, a silicon nitride sintered body, aluminum oxide, and titanium carbide.

  The present invention is particularly effective for a blade-tip-exchangeable tip produced from these substrates by a sintering method.

  In the blade-tip-exchangeable tip in one and other aspects of the present invention, the flank may be a non-polished surface. Thereby, since a polishing process can be eliminated in the manufacture of the chip, the productivity and economy of the chip can be improved. In addition, the degree of freedom in designing the chip shape can be increased.

  In the blade-tip replaceable tip in one and other aspects of the present invention, the rake face is ground by the blade-tip replaceable tip while the blade-tip replaceable tip is attached to a holder. It may be a negative type shape formed so as to be perpendicular to the grinding surface and inclined toward the traveling direction side of a vertical surface perpendicular to the traveling direction of the holder.

  Even if it is a negative type shape, the blade-tip-exchangeable tip in one and other aspects of the present invention can improve the positional accuracy when attached to the holder.

  In the blade-tip replaceable tip according to one and other aspects of the present invention, an opening may be provided on the rake face. Thereby, a lever lock type can be adopted as a method of holding the chip on the holder.

  In the blade-tip replaceable tip according to one and other aspects of the present invention, the flank may be a surface that is not ground. Thereby, since a grinding process can be eliminated in the manufacture of the chip, it is possible to improve the productivity and economy of the chip. In addition, the degree of freedom in designing the chip shape can be increased.

  As is apparent from the above description, according to the blade tip replaceable tip and the method for manufacturing the blade tip replaceable tip in one aspect of the present invention, when the rake face has a polygonal outer peripheral shape, 0.80. Position accuracy can be obtained by attaching a blade-tip-replaceable tip satisfying the conditions of ≦ b1 / b2 ≦ 1.20 and 0.32 ≦ (b1 + b2) /a≦0.70 to the holder in the first region with small distortion. Can be improved. Further, according to the blade tip replaceable tip and the method of manufacturing the blade tip replaceable tip in another aspect of the present invention, the shape of the outer periphery of the rake face is a hexagonal shape, and an acute corner and an obtuse apex are alternately formed on the outer periphery. When it is included, the positional accuracy can be improved by attaching the blade-tip-exchangeable tip satisfying the condition of 0.20 ≦ b / a ≦ 0.70 to the holder near the apex of the obtuse angle with small distortion.

It is a schematic diagram which shows the structure of the blade-tip-exchangeable tip in Embodiment 1 of the present invention. It is an expansion schematic diagram of the corner vicinity of the blade edge | tip-exchange-type chip | tip in Embodiment 1 of this invention. It is an expansion schematic diagram of the corner vicinity of the blade edge | tip-exchange-type chip | tip in Embodiment 1 of this invention. It is an enlarged schematic diagram of the cutting edge vicinity of the blade-tip-exchangeable tip according to Embodiment 1 of the present invention. It is an enlarged schematic diagram of the cutting edge vicinity of the blade-tip-exchangeable tip according to Embodiment 1 of the present invention. It is an enlarged schematic diagram of the cutting edge vicinity of the blade-tip-exchangeable tip according to Embodiment 1 of the present invention. It is an enlarged schematic diagram of the cutting edge vicinity of the blade-tip-exchangeable tip according to Embodiment 1 of the present invention. It is a schematic diagram which shows the state which attached the blade-tip-exchange-type chip | tip in Embodiment 1 of this invention to the holder. It is a schematic diagram which shows the structure of the blade-tip-exchangeable tip in Embodiment 2 of the present invention. It is a schematic diagram which shows the state which attached the blade-tip-exchange-type chip | tip in Embodiment 2 of this invention to the holder. It is a schematic diagram which shows the structure of the blade-tip-exchangeable tip in Embodiment 3 of the present invention. It is an expansion schematic diagram of the corner vicinity of the blade edge | tip-exchange-type chip | tip in Embodiment 3 of this invention. It is an expansion schematic diagram of the corner vicinity of the blade edge | tip-exchange-type chip | tip in Embodiment 3 of this invention. It is an expansion schematic diagram of the cutting edge vicinity of the blade-tip-exchangeable tip in Embodiment 3 of the present invention. It is an expansion schematic diagram of the cutting edge vicinity of the blade-tip-exchangeable tip in Embodiment 3 of the present invention. It is an expansion schematic diagram of the cutting edge vicinity of the blade-tip-exchangeable tip in Embodiment 3 of the present invention. It is an expansion schematic diagram of the cutting edge vicinity of the blade-tip-exchangeable tip in Embodiment 3 of the present invention. It is a schematic diagram which shows the state which attached the blade-tip-exchange-type chip | tip in Embodiment 3 of this invention to the holder. 6 is a schematic view showing a blade-tip-exchangeable tip of Comparative Example 1. FIG. FIG. 3 is a schematic diagram illustrating a method for measuring a blade-tip-exchangeable tip in Example 1. 6 is a schematic diagram showing a measuring method of a blade edge replaceable tip in Example 2. FIG.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following drawings, the same or corresponding parts are denoted by the same reference numerals, and description thereof will not be repeated.

  With reference to FIGS. 1-7, the structure of the blade-tip-exchange-type chip | tip in one embodiment of this invention is demonstrated. The blade-tip-exchangeable tip 1 a in the present embodiment includes a rake face 10, a flank face 20, and another flank face 30. The rake face 10 is located on the outer periphery and includes a pair of adjacent corners 11a and 11b. The flank 20 is continuous with the side 13 sandwiched between the pair of corners 11a and 11b on the outer periphery of the rake face 10, and extends in a direction intersecting the rake face 10 (a direction orthogonal in the present embodiment). The other flank 30 is formed at a position different from the flank 20 (position facing in the present embodiment). The flank 20 and the other flank 30 have shapes that are perpendicular to the rake face 10 and are rotationally symmetric about a rotation axis that passes through the center of the rake face 10.

  The outer periphery of the rake face 10 is rectangular. Here, the rectangular shape includes a regular polygon, a rhombus, an equilateral non-polygon, a rectangle, and a parallelogram defined in 5.1 of JIS B4120 (1998). The rectangular shape in the present embodiment is a substantially quadrangular shape, for example, a shape having four angles where the angles θa and θb are in the range of 30 ° to 150 °.

  The pair of corners 11a and 11b may be round corners as shown in FIG. 1, and are corners formed by intersecting the straight side 13 and the sides 13a and 13b as shown in FIG. There may be corner corners as shown in FIG. A round corner means that a curve is formed between the sides 13a and 13b forming the corners 11a and 11b and the side 13. The round corner is formed by, for example, R-surface processing. A corner corner means that a straight line is formed between the sides 13 a and 13 b forming the corners 11 a and 11 b and the side 13.

  Note that the angles θa and θb of the corners 11a and 11b mean the angles at which the side 13 and the sides 13a and 13b extend and intersect. The angles θa and θb of at least one of the set of corners 11a and 11b may be 80 ° or less.

  When the corners 11a and 11b are round corners, the radius of curvature of the corner is preferably 2.4 mm or less, and more preferably 1.6 mm or less.

  The other flank 30 side corners of the rake face 10 are the same as the set of corners 11a and 11b on the flank 20 side.

  The other flank 30 may be a surface facing the flank 20, a surface including the side 13 a, or a surface including the side 13 b. There may be a plurality of other flank surfaces 30.

  An opening 14 is provided in the center of the rake face 10. Here, the center is the polygonal center of gravity of the outer periphery of the rake face 10. That is, the opening 14 includes the center of gravity of the rake face. In the present embodiment, the opening 14 penetrates to the surface facing the rake face 10 (in the thickness direction). The opening 14 is provided to attach the blade-tip replaceable tip 1a to a lever lock type holder.

  A side 13 that is a line of intersection between the rake face 10 and the flank 20 is a cutting edge. All of the sides 13 may be cutting edges, and at least one of the corners 11a and 11b may not be cutting edges.

  The flank 20 is convex, and is connected to the first region 21 located at the center of the flank 20 and the first region 21 and one side of the pair of corners 11a and 11b (this embodiment) In this embodiment, the second region 22 is located on the corner 11a side) and is connected to the first region 21 and is located on the other side of the pair of corners 11a and 11b (in the present embodiment, on the corner 11b side). 3rd area | region 23 to be included.

  The first region 21 is a region including a straight line portion including a point located at the shortest distance from the opening (the center of the opening, that is, the center of gravity) of the rake face 10 on the side 13. The second region 22 is an initial point (first inflection point 15a) that is inflected from a portion that is located at the shortest distance from the opening of the rake face 10 on the side 13 and that extends linearly toward the corner 11a. To the corner 11a side. The third region 23 is an initial point (first inflection point 15b) that is inflected from a portion that is located at the shortest distance from the opening of the rake face 10 on the side 13 and that extends linearly toward the corner 11b. To the corner 11b side.

  The second and third regions 22 and 23 may be planar as shown in FIG. 4, or may be curved as shown in FIG. Further, as shown in FIG. 6, a second inflection point 15 c may be provided in the middle of the third region 23. That is, in the third region 23 of FIG. 6, the second inflection point is provided between the first inflection point 15b that is the boundary between the first region 21 and the third region 23, and the corner 11b. 15c is provided. A slope extending from the first inflection point 15b to the second inflection point 15c on the side 13 is different from a slope extending from the second inflection point 15c to the corner 11b. In FIG. 6, the third region 23 includes a plane extending from the first inflection point 15 b to the second inflection point 15 c and a plane extending from the second inflection point 15 c to the corner 11 b. Two or more planes may be included. In addition, as shown in FIG. 7, a first curved surface extending from the first inflection point 15b to the second inflection point 15c and a second curved surface extending from the second inflection point 15c to the corner 11b are provided. In addition, the curvature radii of the first and second curved surfaces may be different. The same applies to the second region 22.

  Moreover, the flank 20 having the first to third regions 21 to 23 may be a non-polished surface or a surface that is not ground.

  Here, with reference to FIG. 4, the parameters of the cutting edge of the blade-tip-exchangeable tip 1a in the embodiment of the present invention will be described. In the present embodiment, the cutting edge is a region excluding the round corners (arc-shaped portions) of the corners 11 a and 11 b on the side 13.

  The extension line 41 of the part connected to the first region 21 (see FIG. 1) of the cutting edge and the end point on one side (corner 11a side in the present embodiment) of one set of corners 11a and 11b of the cutting edge From the first intersection 43 with a line segment 42 extending in a direction perpendicular to the extension line 41 from 16a, the other side of the pair of corners 11a and 11b of the extension line 41 and the cutting edge (in this embodiment, the corner 11b The length from the end point 16b on the side) to the second intersection 45 with the line segment 44 extending in the direction perpendicular to the extension line 41 is defined as a. The length from the end point on the first intersection 43 side (the first inflection point 15a in the present embodiment) to the first intersection 43 in the portion of the cutting edge that is continuous with the first region 21 is defined as b1. In other words, the distance from the end point (first inflection point 15) on the corner 11a side in the first region 21 to the first intersection 43 is b1. The length from the end point on the second intersection 45 side (the first inflection point 15b in the present embodiment) to the second intersection 45 in the portion of the cutting edge that is continuous with the first region 21 is b2. In other words, the distance from the end point (first inflection point 15b) on the corner 11b side in the first region 21 to the second intersection 45 is b. In such a case, the cutting edge replaceable tip satisfies the conditions 0.80 ≦ b1 / b2 ≦ 1.20 and 0.32 ≦ (b1 + b2) /a≦0.70. Further, it is more preferable that the blade-tip-exchangeable tip satisfies the conditions 0.80 ≦ b1 / b2 ≦ 1.20 and 0.32 ≦ (b1 + b2) /a≦0.70.

  When the distance between the extension line 41 and the end points 16a and 16b of the cutting edge is d, the condition of 5 μm ≦ d ≦ 100 μm is preferable, and the condition of 40 μm ≦ d ≦ 80 μm is more preferable. When the distance between the extension line 41 and the end point 16a is different from the distance between the extension line 41 and the end point 16b, the longer distance is preferably within the above range, and both are within the above range. Is more preferable.

  Although the base material which comprises the blade-tip-exchange-type chip 1a is not particularly limited, WC-based cemented carbide, cermet, high-speed steel, ceramics, cubic boron nitride sintered body, diamond sintered body, silicon nitride sintered body, It is preferably at least one selected from the group consisting of aluminum oxide and titanium carbide. A surface coating layer may be formed on the surface of the substrate.

  The cemented carbide includes, for example, tungsten carbide and a binder phase composed of one or more types of iron-based metals, the balance being inevitable impurities, tungsten carbide, and one or more types of iron-based metals. Of the periodic table IVa, Va, IVa group transition metal having a B-1 type crystal structure and a solid solution phase composed of carbon, nitrogen, oxygen or boron, with the balance being an inevitable impurity. It is done. In these cases, the binder phase is, for example, 0.1 to 30% by weight, and the solid solution phase is, for example, 0.01 to 50% by weight. The surface portion of the cemented carbide may have a η phase or free carbon, and may or may not have a layer mainly composed of an iron-based metal or a de-β layer.

  The cermet includes, for example, a binder phase composed of one or more of iron-based metals, a periodic table IVa, Va, IVa group transition metal (mainly titanium) having a B-1 type crystal structure, and carbon, nitrogen, oxygen, or And a solid solution phase composed of boron, with the balance being inevitable impurities. In this case, the binder phase is, for example, 0.1 to 40% by weight, and the solid solution phase is, for example, 0.1 to 95% by weight. There may be a surface hardened layer, a softened layer, or a layer mainly composed of iron-based metal on the surface portion of the cermet.

  Further, in a state where the blade edge replaceable tip 1a is attached to the holder, the rake face 10 is perpendicular to the non-ground surface of the work to be ground by the blade edge replaceable tip 1a, and the progress of the holder is progressed. It may be a negative shape formed so as to be inclined toward the traveling direction side with respect to a vertical plane perpendicular to the direction.

  Then, the manufacturing method of the blade edge | tip replaceable chip | tip 1a in this Embodiment is demonstrated. First, prepare raw materials. The raw material is not particularly limited, but for example, a group consisting of WC-based cemented carbide, cermet, high speed steel, ceramics, cubic boron nitride sintered body, diamond sintered body, silicon nitride sintered body, aluminum oxide and titanium carbide At least one powder selected from.

  Next, a green compact is formed by filling the raw material into a mold and compressing the raw material. In the present embodiment, after the raw material powder is mixed and pulverized, the raw material powder is supplied to a mold on which the convex flank 20 shown in FIG. 1 is formed, and compression molding is performed in that state.

  In addition, when the opening part 14 is not formed in the green compact after compression molding, the opening part 14 is formed in the green compact after compression molding.

  Next, the green compact is heated to obtain a sintered body. The method for obtaining the sintered body is not particularly limited, but for example, liquid phase sintering is adopted.

  Next, cutting edge processing is performed using a brush, barrel, blast, diamond grindstone, laser processing, or the like. Further, polishing may be performed on the rake face 10 or the like. Note that these steps may be omitted.

  Further, even if a surface coating layer is formed on these substrates by a known CVD method, PVD method, sputtering method or a combination thereof, the effect of the present invention is not lost, and after forming the coating layer, a brush, barrel, blast The effect of the present invention is not lost even if a coating layer surface treatment such as partial removal of the coating layer by a diamond grindstone or laser processing or a surface smoothing process is performed.

  Through the above steps, as shown in FIGS. 1 to 7, the rake face 10 whose outer periphery is polygonal and the side 13 sandwiched between a pair of corners 11 a and 11 b adjacent to each other on the outer periphery of the rake face 10. And a flank 20 extending in a direction intersecting the rake face 10, the side 13 that is the intersection of the rake face 10 and the flank 20 is a cutting edge, and the flank 20 is convex. A first region 21 located at the center of the flank 20, a second region 22 connected to the first region 21 and located on one side of the pair of corners 11a, 11b, A third region 23 connected to the region 21 and located on the other side of the pair of corners 11a, 11b. An opening 14 is provided in the center of the rake face 10, and the first of the cutting edges is provided. An extension line 41 of a portion continuous with the region 21; From a first intersection 43 with a line segment 42 extending in a direction perpendicular to the extension line 41 from one end point 16a of one set of corners 11a and 11b of the cutting edge, one set of the extension line 41 and the cutting edge The length from the other end point 16b of the corners 11a, 11b to the second intersection 45 with the line segment 44 extending in the direction perpendicular to the extension line 41 is a, and the first region 21 of the cutting edge The length from the first inflection point 15a that is the end point on the first intersection 43 side in the continuous portion to the first intersection 43 is b1, and the second of the cutting blades in the portion that is continuous with the first region 21. When the length from the first inflection point 15b that is the end point on the intersection 45 side to the second intersection 45 is b2, 0.80 ≦ b1 / b2 ≦ 1.20 and 0.32 ≦ ( b1 + b2) /a≦0.70 to obtain a sintered body satisfying the condition It can be.

  Then, with reference to FIG. 8, the usage method of the blade-tip-exchange-type chip | tip 1a in one embodiment of this invention is demonstrated. In the present embodiment, the blade tip replaceable tip 1a is attached to a holder 50 such as a cutting tool.

  First, the blade tip replaceable chip 1a is attached to the holder 50 so that the specific corner 11a used for cutting faces the open side of the holder 50, and fine adjustment is performed to set the tip position of the blade tip to a specified position. At this time, since the size and the amount of deformation are different for each tip, and the tip position of the blade tip is different in units of μm for each corner of the same tip, the tip of the blade tip is set to the same designated position as the corner used for the previous cutting. Adjust the position. Note that this blade edge position adjustment amount becomes larger with a tip having a large dimensional tolerance (generally a side flank non-polished tip) or a tip having a large deformation amount. Cutting is performed by the blade-tip-exchangeable tip 1a attached in this manner.

  After the tip 1a is used for cutting until the end of the corner 11a of the tip 1a, the tip 1a is removed from the holder 50. Then, another corner of the same chip or another corner of another chip is attached, and then the fine cutting is performed again to make the cutting edge tip position a designated position, and then cutting is performed.

  The inventor found that the first region 21 having a relatively short distance from the opening 14 provided in the center of the rake face 10 in the blade-tip-exchangeable tip 1a is a second having a relatively long distance from the opening 14. And compared with the 3rd field 22 and 23, since shrinkage by sintering of a press object was small, it discovered that distortion became small. Specifically, when the green compact is liquid phase sintered, volume shrinkage of about 50% occurs. At this time, due to non-uniform powder feeding to the mold, temperature distribution in the sintering furnace, gravity, etc., the sintered body does not shrink into a completely similar shape of the green compact. Deformation occurs. For example, a site where there was a lot of powder feeding to the mold, that is, a site where the green compact density was high, a shrinkage amount during sintering was small, a site where there was little powder feeding to the mold, ie a site where the green compact density was low Has a large shrinkage during sintering. As described above, the non-uniformity of the press body density causes non-uniform shrinkage during sintering. As a result, the sintered body is not completely similar to the pressed body, but has a distorted shape. For example, when a complete cube is pressed and then sintered, it becomes a slightly distorted cube. Therefore, in order to obtain a sintered body having the shape as in the present embodiment, the second and third regions 22 and 23 that are relatively long from the opening 14 are relatively far from the opening 14. It has been found that the strain is large due to the large amount of shrinkage because the distance from the center is larger than that of the first region 21 which is short.

  Therefore, as shown in FIG. 8, when the chip 1 a is attached to the holder 50, the distortion caused by the deformation of the press body is supported by supporting the first region 21 with a small distortion by the holding portion 51 of the holder 50. The impact can be reduced. According to the chip 1a of the present embodiment, the relationship between a, b1, and b2 is such that 0.80 ≦ b1 / b2 ≦ 1.20 and 0.32 ≦ (b1 + b2) /a≦0.70. Satisfies. If 0.32> (b1 + b2) / a, the area held by the second and third regions 22 and 23 having a relatively long distance from the opening 14 becomes too large. For this reason, due to the distortion of the second and third regions 22 and 23, the positional accuracy when attaching to the holder 50 cannot be improved. Similarly, when (b1 + b2) / a> 0.70 when attaching the blade-tip-exchangeable tip 1a to the holder 50, the area of the first region 21, that is, the area that can be attached to the holder 50 is small. Too much. For this reason, due to the deterioration of stability, the positional accuracy when attaching to the holder 50 cannot be improved. In the case of 0.80> b1 / b2 and 1.20 <b1 / b2, the difference in area between the second and third regions 22 and 23 becomes too large, so that the distance from the opening 14 is relatively long. The first area 21 is located. For this reason, since the 1st field 21 also includes a field with big distortion, the position accuracy at the time of attaching to holder 50 cannot be improved. That is, by satisfying the conditions of 0.80 ≦ b1 / b2 ≦ 1.20 and 0.32 ≦ (b1 + b2) /a≦0.70, the positional accuracy when attaching to the holder 50 can be improved. it can. Therefore, the blade edge position correction amount can be reduced, and the time required for blade edge position correction when the user replaces the tip can be reduced.

  In addition, the inventor has focused on the distortion of the green compact obtained by compression molding, and has focused on the method of using the distortion. For this reason, even if high dimensional accuracy is not obtained by polishing with a diamond grindstone or the like, the positional accuracy at the time of attaching the blade-tip replaceable tip 1a to the holder 50 can be improved. For this reason, manufacturing cost can be reduced. Furthermore, even if it does not have a complicated three-dimensional shape, it is possible to improve the positional accuracy when attaching the blade-tip replaceable tip 1a to the holder 50. For this reason, since the case where a grinding | polishing process is impossible can be reduced, it can manufacture easily.

  In addition, in order to increase the clamp strength of the blade-tip replaceable tip 1a to the holder 50, a certain contact area between the tip and the holding portion 51 is required. However, in the side non-polished tip, in order to minimize the influence of distortion, it is preferable from the viewpoint of realizing high blade edge position accuracy that only the portion with good linearity is in contact with the holder 50. As a result of investigating the balance between these two characteristic values (clamp strength / cutting edge position accuracy) that are tradeoffs, the numerical range is 0.90 <b1 / b2 <1.10 and 0.45 ≦ (b1 + b2). It was found that /a≦0.60 is particularly preferable. Similarly, in the side polished tip, 0.90 <b1 / b2 <1.10 and 0.45 ≦ (b1 + b2) / in the relationship between the processing accuracy on the holder side and the flatness of the contact portion with the tip. It has been found that it is particularly preferable that the condition of a ≦ 0.60 is satisfied.

  In the blade tip replaceable tip 1a of the present embodiment, preferably, the condition of 5 μm ≦ d ≦ 100 μm is satisfied, where d is the distance between the extension line 41 and the end points 16a and 16b of the cutting edge (see FIG. 4). . Thereby, possibility that the corners 11a and 11b and the holder 50 will contact is suppressed, and the deterioration of the blade edge position accuracy due to such contact can be suppressed. Moreover, since chip disposal property is maintained satisfactorily, deterioration of the surface roughness of the processed surface can be suppressed.

  In general, the larger the cutting edge angle, the higher the cutting resistance and the worse the chip disposal. As the d value increases, the cutting edge position accuracy tends to be improved, but on the other hand, since the cutting edge angle increases in a pseudo manner, phenomena such as an increase in cutting resistance and a deterioration in chip disposal may occur. As a result of investigating the balance between these two characteristic values that are tradeoffs, it was found that the d value is more preferably 40 μm or more and 80 μm or less.

  In the cutting edge replaceable tip 1a of the present embodiment, at least one of the second region 22 and the third region 23 may be curved. Even if it is such a shape, the blade edge | tip replacement | exchange type | mold chip | tip 1a of this Embodiment can improve the positional accuracy at the time of attaching to a holder.

  In the blade tip replaceable tip 1a of the present embodiment, at least one of the second region 22 and the third region 23 may be planar. Processing is easier than when the second and third regions 22 and 23 are curved.

  In the blade edge replaceable chip 1a, the blade edge angles of the pair of corners 11a and 11b may be 80 ° or less. Even if it is such a shape, the blade-tip-exchangeable tip 1a of the present embodiment can improve the positional accuracy when attached to the holder 50.

  The blade-tip-exchangeable tip 1a includes another flank 30 formed at a position different from the flank 20, and the flank 20 and the other flank 30 extend perpendicularly to the rake face 10 and rake. It may have a shape that is rotationally symmetric about a rotation axis that passes through the center of the surface 10. Thereby, also about one set of corners formed in the edge part of the other flank 30, it can suppress the deterioration of a blade edge | tip position accuracy similarly to 1 set of corners 11a and 11b located in the edge part of the said flank 20. .

  In the blade-tip-exchangeable tip 1a of the present embodiment, at least one of the set of corners 11a and 11b may be a round corner, and the radius of curvature of the round corner may be 2.4 mm or less. Even if the pair of corners 11a and 11b satisfy such a condition, in this embodiment, the influence of distortion in the vicinity of the round corner can be reduced, so that the positional accuracy of attaching to the holder can be improved.

  In the blade tip replaceable tip 1a of the present embodiment, the base material is preferably a WC-based cemented carbide, cermet, high speed steel, ceramics, cubic boron nitride sintered body, diamond sintered body, silicon nitride sintered body , At least one selected from the group consisting of aluminum oxide and titanium carbide. This embodiment is particularly effective for a chip manufactured from these materials by a sintering method.

  In the blade tip replaceable tip 1a of the present embodiment, the flank 20 may be a non-polished surface. Thereby, since the polishing step can be eliminated in the manufacture of the chip 1a, the productivity and economics of the chip 1a can be improved. In addition, the degree of freedom in designing the chip shape can be increased.

  In the cutting edge replaceable tip 1a of the present embodiment, the rake face 10 is a non-grinding surface of a work piece to be ground by the cutting edge replaceable chip 1a in a state where the cutting edge replaceable chip 1a is attached to the holder 50. Alternatively, it may be a negative shape formed so as to be perpendicular to the traveling direction of the holder 50 and tilted toward the traveling direction side with respect to a vertical plane perpendicular to the traveling direction of the holder 50. Even if it is such a shape, the blade-tip-exchangeable tip 1a of the present embodiment can improve the positional accuracy when attached to the holder 50.

  In the cutting edge replaceable tip 1a of the present embodiment, the flank 20 may be a surface that is not ground. Thereby, since the grinding process can be eliminated in the manufacture of the chip 1a, the productivity and economy of the chip 1a can be improved. In addition, the degree of freedom in designing the chip shape can be increased.

  The manufacturing method of the blade-tip-exchangeable chip 1a according to the present embodiment includes a step of preparing raw materials, a step of filling a raw material into a mold, and forming a green compact by compressing the raw material, and a green compact. The sintered body is sandwiched between a rake face 10 having a polygonal outer periphery and a pair of corners 11a and 11b adjacent to each other on the outer periphery of the rake face 10. The flank 20 is provided with a flank 20 that extends in a direction intersecting with the rake face 10, the side 13 that is the intersection of the rake face 10 and the flank 20 is a cutting edge, and the flank 20 is convex. A first region 21 located at the center of the flank 20 and a second region 22 connected to the first region 21 and located on one side of the pair of corners 11a and 11b. , Connected to the first region 21 and a set of corners 1a and 11b, the third region 23 located on the other side, and an opening 14 is provided in the center of the rake face 10, and the extension line 41 of the portion of the cutting edge that is continuous with the first region 21 is provided. From the first intersection 43 with the line segment 42 extending in the direction perpendicular to the line segment 44 from one end point 16a of the pair of corners 11a, 11b, the extension line 41 and the cutting edge 1 The length from the other end point 16b of the corners 11a, 11b of the set to the second intersection 45 with the line segment 44 extending in the direction perpendicular to the extension line 41 is a, and the first region of the cutting edges The length from the first intersection 43 side end point (first inflection point 15a) to the first intersection 43 in the portion continuous with 21 is b1, and the cutting blade in the portion continuous with the first region 21 From the end point (first inflection point 15b) on the second intersection 45 side If up to two of the intersections 45 the length was b2, 0.80 ≦ b1 / b2 ≦ 1.20, and satisfies the condition that 0.32 ≦ (b1 + b2) /a≦0.70.

  Thereby, as shown in FIGS. 1-7, the blade-tip-exchange-type chip | tip 1a which can improve the positional accuracy at the time of attaching to the holder 50 can be manufactured.

  In the manufacturing method of the blade-tip-exchangeable tip 1a of the present embodiment, the shape preferably satisfies the conditions of 0.80 ≦ b1 / b2 ≦ 1.20 and 0.32 ≦ (b1 + b2) /a≦0.70. A green compact is formed. Thereby, the blade-tip-exchangeable chip 1a that can improve the positional accuracy when attached to the holder 50 can be manufactured by simplifying the manufacturing process.

(Embodiment 2)
With reference to FIG. 9, the blade-tip-exchangeable tip 1b and the manufacturing method thereof according to Embodiment 2 of the present invention will be described. The cutting edge replaceable tip 1b and the manufacturing method thereof according to the present embodiment are basically provided with the same configuration as the cutting edge replaceable tip 1a and the manufacturing method thereof according to the first embodiment. The difference is that the shape is substantially triangular. The substantially triangular shape means, for example, a shape having three angles θa and θb in the range of 20 ° to 80 °. The other flank 30 in the present embodiment is a surface continuous with the flank 20.

  As shown in FIG. 10, the method of using the blade tip replaceable tip 1b of the present embodiment is basically the same as the method of using the blade tip replaceable tip 1a of the first embodiment shown in FIG. The difference is that a holder 50 that matches the shape of the blade-tip-exchangeable tip 1b of the present embodiment is used.

As described above, in the blade tip replaceable tip 1b and the manufacturing method thereof according to the present embodiment, the shape of the outer periphery of the rake face 10 is substantially triangular. Even if it is such a shape, the positional accuracy at the time of attaching to the holder 50 can be improved.
(Embodiment 3)
With reference to FIGS. 11-17, the blade-tip-exchangeable chip 1c in Embodiment 3 of the present invention will be described. The blade-tip-exchangeable tip 1 c in the present embodiment includes a rake face 10, a flank face 20, and another flank face 30. The rake face 10 includes acute corners 11 and obtuse apexes 12 alternately on the outer periphery. The flank 20 is continuous with a side 13 sandwiched between an acute corner 11 and an obtuse vertex 12 on the outer periphery of the rake face 10 and extends in a direction intersecting the rake face 10 (a direction orthogonal in the present embodiment). The other flank 30 is formed at a position facing the flank 20. The flank 20 and the other flank 30 have a shape that is perpendicular to the rake face 10 and has a rotational symmetry of 120 ° about a rotation axis that passes through the center of the rake face 10.

  The outer periphery of the rake face 10 has a hexagonal shape. Here, the hexagonal shape means a hexagonal shape on the right side as defined in 5.1 of JIS B4120 (1998), for example, a shape having six angles within the range of 30 ° to 150 °. To do. That is, the angle θ1 of the corner 11 is, for example, 30 ° or more and less than 90 °, and the angle θ2 of the vertex 12 is, for example, more than 90 ° and less than 150 °. The angle θ1 of the corner 11 is preferably 80 ° or less.

  The corner 11 and the vertex 12 may be round corners as shown in FIG. 11, or may be corners formed by intersecting the straight side 13 and the side 13a as shown in FIG. Corners may be used as shown in FIG. A round corner means that a curve is formed between the side 13 a forming the corner 11 and the side 13. The round corner is formed by, for example, R-surface processing. A corner corner means that a straight line is formed between the side 13 a forming the corner 11 and the side 13.

  The angle θ1 of the corner 11 means an angle at which the side 13 and the side 13a are extended and intersected. Similarly, the angle θ2 of the vertex 12 means an angle at which the side 13b (see FIG. 11) constituting the outer periphery of the rake face 10 and the side 13 are extended and intersected.

  When the corner 11 is a round corner, the radius of curvature of the corner is preferably 2.4 mm or less.

  The same applies to corners and vertices (on the other flank 30 side) facing the corners 11 and vertices 12 on the rake face 10.

  The rake face 10 is provided with an opening 14. In the present embodiment, the opening 14 is formed at the center of the rake face 10 and penetrates to the face facing the rake face 10 (in the thickness direction). The opening 14 is provided to attach the blade-tip-exchangeable tip 1c to a lever lock type holder.

  A side 13 that is a line of intersection between the rake face 10 and the flank 20 is a cutting edge. All of the sides 13 may be cutting edges, and at least one of the corner 11 and the apex 12 may not be cutting edges.

  The flank 20 is convex, and includes a first region 21 located on the apex 12 side and a second region 22 connected to the first region 21 and located on the corner 11 side. The first region 21 is a region located in a portion extending linearly from the apex 12 side on the side 13. The second region 22 is a region located in a portion extending from the first point (first inflection point 15) inflected from the portion extending linearly from the vertex 12 side on the side 13 to the corner 11 side. That is, the boundary between the first region 21 and the second region 22 is a position where the portion that extends linearly from the apex 12 side toward the corner 11 side on the side 13 (the first inflection point). 15).

  The second region 22 may be planar as shown in FIG. 14 or may be curved as shown in FIG. As shown in FIG. 16, a second inflection point 18 may be provided in the middle of the second region 22. That is, the second region 22 shown in FIG. 16 includes a second inflection between the first inflection point 15 that is the boundary between the first region 21 and the second region 22 and the corner 11. A point 18 is provided. The inclination extending from the first inflection point 15 to the second inflection point 18 on the side 13 is different from the inclination extending from the second inflection point 18 to the corner 11. In FIG. 16, the second region 22 includes a plane extending from the first inflection point 15 to the second inflection point 18 and a plane extending from the second inflection point 18 to the corner 11. Two or more planes may be included. Further, as shown in FIG. 17, a first curved surface extending from the first inflection point 15 to the second inflection point 18 and a second curved surface extending from the second inflection point 18 to the corner 11 are provided. In addition, the curvature radii of the first and second curved surfaces may be different.

  Further, the flank 20 having the first and second regions 21 and 22 may be a non-polished surface or a surface that is not ground.

  Here, with reference to FIG. 14, the parameters of the cutting edge of the blade-tip-exchangeable tip 1c in the embodiment of the present invention will be described. In the present embodiment, the cutting edge is a region excluding the round corner (arc-shaped portion) of the corner 11 and the round vertex (arc-shaped portion) of the vertex 12 on the side 13.

  Cutting is performed from an intersection 46 of an extended line 41 of a portion of the cutting edge continuous with the first region 21 (see FIG. 11) and a line segment 42 extending in a direction perpendicular to the extending line 41 from the corner end point 16 of the cutting edge. The distance to the apex-side end point 17 of the blade is a. Further, the distance from the end point (first inflection point 15) on the intersection point 46 side to the intersection point 46 in the portion continuous with the first region 21 in the cutting edge is defined as b. In other words, the distance from the end point (first inflection point 15) on the vertex 12 side in the second region 22 to the intersection 46 is b. In such a case, the blade-tip-exchangeable tip satisfies the condition of 0.20 ≦ b / a ≦ 0.70, preferably satisfies the condition of 0.35 ≦ b / a ≦ 0.58. More preferably, the condition of 45 ≦ b / a ≦ 0.55 is satisfied.

  When the distance between the extension line 41 and the corner end point 16 of the cutting edge is d, the condition of 5 μm ≦ d ≦ 100 μm is preferable, and the condition of 40 μm ≦ d ≦ 80 μm is more preferable.

  Although the base material which comprises the blade-tip-exchange-type chip | tip 1c is not specifically limited, The base material similar to the blade-tip-exchange-type chip | tip 1a of Embodiment 1 can be used.

  Further, in a state where the blade edge replaceable tip 1c is attached to the holder, the rake face 10 is perpendicular to the non-grinding surface of the work to be ground by the blade edge replaceable chip 1c, and the holder progresses. It may be a negative shape formed so as to be inclined toward the traveling direction side with respect to a vertical plane perpendicular to the direction.

  Then, the manufacturing method of the blade-tip-exchangeable chip 1c in the present embodiment will be described. First, prepare raw materials. The raw material is not particularly limited, but for example, the same raw material as in the first embodiment is prepared.

  Next, a green compact is formed by filling the raw material into a mold and compressing the raw material. In the present embodiment, after the raw material powder is mixed and pulverized, the raw material powder is supplied to a mold in which the convex flank 20 shown in FIG. 11 is formed, and compression molding is performed in that state.

  Next, the green compact is heated to obtain a sintered body. Next, cutting edge processing is performed. Further, polishing may be performed on the rake face 10 or the like. Since these steps are the same as those in the first embodiment, description thereof will not be repeated.

  Through the above steps, as shown in FIGS. 11 to 17, the shape of the outer periphery is a hexagonal shape, and the rake face 10 and the rake face 10 alternately include acute corners 11 and obtuse apexes 12 located on the outer periphery. A flank face 20 extending in a direction intersecting the rake face 10, which is continuous with a side 13 sandwiched between an acute corner 11 and an obtuse apex 12 on the outer periphery of the rim, and at the intersection of the rake face 10 and the flank face 20 A certain side 13 is a cutting edge, the flank 20 is convex, and a first region 21 located on the apex 12 side and a second region located on the corner 11 side are connected to the first region 21. 22, an opening 14 is provided in the center of the rake face, and an extension line 41 of a part of the cutting edge that is continuous with the first region 21, and is perpendicular to the extension line 41 from the corner side end point 16 of the cutting edge. Intersection 46 with a line segment 42 extending in the direction And the distance from the first inflection point 15 which is the end point on the intersection side in the portion of the cutting edge connected to the first region 21 to the intersection 46 is b. In this case, a sintered body that satisfies the condition of 0.20 ≦ b / a ≦ 0.70 can be obtained.

  Then, with reference to FIG. 18, the usage method of the blade-tip-exchange-type chip | tip 1c in one embodiment of this invention is demonstrated. The method of using the blade-tip replaceable tip 1c of the present embodiment is basically the same as the method of using the blade-tip replaceable tip 1a of the first embodiment shown in FIG. 8, but as shown in FIG. The difference is that the holder 50 that matches the shape of the blade-tip-exchangeable tip 1c of the embodiment is used, and that the corner 11 of the blade-tip-exchangeable tip 1c can be attached to face the open side of the holder 50. .

  Next, the effect of the present embodiment will be described with reference to FIGS. The inventor has found that, in the blade-tip-exchangeable tip 1c, the contraction amount increases in the vicinity of the apex 12 of the obtuse angle because the distance from the opening 14 is smaller than the vicinity of the corner 11. Further, the present inventor has found that the vicinity of the apex 12 of the obtuse angle is higher in the density of powder supply to the mold of the raw material powder than the vicinity of the corner 11 of the acute angle, and the stability at the time of compacting is high. It was found that the strain is small because the shrinkage due to the is small.

  Specifically, when the green compact is liquid phase sintered, volume shrinkage of about 50% occurs. At this time, due to non-uniform powder feeding to the mold, temperature distribution in the sintering furnace, gravity, etc., the sintered body does not shrink into a completely similar shape of the green compact. Deformation occurs. For example, a site where there was a lot of powder feeding to the mold, that is, a site where the green compact density was high, a shrinkage amount during sintering was small, a site where there was little powder feeding to the mold, ie a site where the green compact density was low Has a large shrinkage during sintering. As described above, the non-uniformity of the press body density causes non-uniform shrinkage during sintering. As a result, the sintered body is not completely similar to the pressed body, but has a distorted shape. For example, when a complete cube is pressed and then sintered, it becomes a slightly distorted cube. For this reason, in order to obtain a sintered body having a shape as in the present embodiment, the vicinity of the acute corner 11 has a greater distance from the opening 14 than the vicinity of the apex 12 of the obtuse angle, and thus the amount of shrinkage is increased. As a result, it has been found that the distortion is large in the vicinity of the acute corner 11. Further, it has been found that the distortion in the vicinity of the acute corner 11 is larger in the vicinity of the acute corner 11 due to the lower packing density of the raw material powder into the mold than in the vicinity of the apex 12 of the obtuse angle.

  Therefore, as shown in FIG. 18, when the chip 1 c is attached to the holder 50, the first region 21 in the vicinity of the apex 12 having an obtuse angle with small distortion is supported by the holding portion 51 of the holder 50, thereby The influence of distortion resulting from deformation can be reduced. According to the chip 1c of the present embodiment, the relationship between a and b satisfies the condition of 0.20 ≦ b / a ≦ 0.70. When the value of b / a exceeds 0.70, the holding area of the chip 1c to the holder 50 becomes narrow, so that the positional accuracy is deteriorated. In addition, when the value of b / a is less than 0.20, the holding area in a portion with a lot of distortion becomes too wide, and the positional accuracy is deteriorated. That is, by satisfying the condition of 0.20 ≦ b / a ≦ 0.70, it is possible to improve the positional accuracy when attaching the blade-tip replaceable tip 1c to the holder 50. Therefore, the blade edge position correction amount can be reduced, and the time required for blade edge position correction when the user replaces the tip can be reduced.

  In the cutting edge-exchangeable tip 1c of the present embodiment, preferably, the condition of 5 μm ≦ d ≦ 100 μm is satisfied, where d is the distance between the extension line 41 and the corner edge 16 of the cutting edge (see FIG. 14). . Thereby, possibility that the corner 11 and the holder 50 will contact is suppressed, and the deterioration of the blade edge position accuracy due to such contact can be suppressed. Moreover, since chip disposal property is maintained satisfactorily, deterioration of the surface roughness of the processed surface can be suppressed.

  In general, the larger the cutting edge angle, the higher the cutting resistance and the worse the chip disposal. As the d value increases, the cutting edge position accuracy tends to be improved, but on the other hand, since the cutting edge angle increases in a pseudo manner, phenomena such as an increase in cutting resistance and a deterioration in chip disposal may occur. As a result of investigating the balance between these two characteristic values that are tradeoffs, it was found that the d value is more preferably 40 μm or more and 80 μm or less.

  In the cutting edge replaceable tip 1c of the present embodiment, the second region 22 may be curved. Even if it is such a shape, the blade edge | tip replacement | exchange type | mold chip | tip 1c of this Embodiment can improve the positional accuracy at the time of attaching to a holder.

  In the cutting edge replaceable tip 1c of the present embodiment, the second region 22 may be planar. The processing of the second region 22 is easier than when the second region 22 is curved.

  In the above-mentioned blade edge replaceable chip 1c, the edge angle of the corner 11 may be 80 ° or less. Even with such a shape, the blade tip replaceable tip 1c of the present embodiment can improve the positional accuracy when attached to the holder 50.

  The blade-tip-exchangeable tip 1c includes another flank 30 formed at a position facing the flank 20, and the flank 20 and the other flank 30 extend perpendicular to the rake face 10. It may have a shape that is 120 ° rotationally symmetric about a rotation axis that passes through the center of the rake face 10. Thereby, also about the corner formed in the edge part of the other flank 30, the deterioration of blade edge position accuracy can be suppressed similarly to the corner 11 located in the edge part of the said flank 20.

  In the cutting edge-exchangeable tip 1c of the present embodiment, the corner 11 may be a round corner, and the radius of curvature of the corner may be 2.4 mm or less. In this case, even if the corner 11 is a round corner, the corner portion as a whole is an acute corner, and the corner 11 is filled more acutely than the raw material powder filled in the portion where the apex 12 of the obtuse angle is located. The density of the raw material powder tends to be low. However, even if the radius of curvature is 2.4 mm or less, in this embodiment, the influence of distortion in the vicinity of the acute corner 11 can be reduced. For this reason, even if it has a round corner with a curvature radius of 2.4 mm or less, it is possible to improve the positional accuracy of attaching to the holder.

  In the cutting edge replaceable tip 1c of the present embodiment, preferably, the base material is a WC-based cemented carbide, cermet, high-speed steel, ceramics, cubic boron nitride sintered body, diamond sintered body, silicon nitride sintered body , At least one selected from the group consisting of aluminum oxide and titanium carbide. This embodiment is particularly effective for a chip manufactured from these materials by a sintering method.

  In the cutting edge replaceable tip 1c of the present embodiment, the flank 20 may be a non-polished surface. Thereby, since the polishing step can be eliminated in the manufacture of the chip 1c, the productivity and economy of the chip 1c can be improved. In addition, the degree of freedom in designing the chip shape can be increased.

  In the cutting edge replaceable tip 1c of the present embodiment, the rake face 10 is a non-ground surface of the work piece to be ground by the cutting edge replaceable chip 1c in a state where the blade replaceable chip 1c is attached to the holder 50. Alternatively, it may be a negative shape formed so as to be perpendicular to the traveling direction of the holder 50 and tilted toward the traveling direction side with respect to a vertical plane perpendicular to the traveling direction of the holder 50. Even with such a shape, the blade tip replaceable tip 1c of the present embodiment can improve the positional accuracy when attached to the holder 50.

  In the cutting edge replaceable tip 1c of the present embodiment, the flank 20 may be a surface that is not ground. Thereby, since the grinding process can be eliminated in the manufacture of the chip 1c, the productivity and economy of the chip 1c can be improved. In addition, the degree of freedom in designing the chip shape can be increased.

  The manufacturing method of the blade-tip-exchangeable tip 1c according to the present embodiment includes a step of preparing raw materials, a step of filling a raw material into a mold and forming a green compact by compressing the raw material, and a green compact. And a rake face 10 that alternately includes acute corners 11 and obtuse vertices 12 positioned on the outer periphery. A flank 20 that extends in a direction intersecting the rake face 10 and is connected to the side 13 sandwiched between the corner 11 and the apex 12 on the outer periphery of the rake face 10. A certain side 13 is a cutting edge, the flank 20 is convex, and a first region 21 located on the apex 12 side and a second region located on the corner 11 side are connected to the first region 21. 22 at the center of the rake face 10. Of the cutting edge from the intersection 46 of the extension line 41 of the cutting blade continuous with the first region 21 and the line segment 42 extending in a direction perpendicular to the extension line 41 from the corner-side end point 16 of the cutting edge. When the distance to the apex-side end point 17 is a, and the distance from the first inflection point 15 that is the end point on the intersection 46 side in the portion of the cutting edge connected to the first region 21 is b, The condition of 0.20 ≦ b / a ≦ 0.70 is satisfied.

  Thereby, as shown in FIGS. 11-17, the blade-tip-exchange-type chip | tip 1c which can improve the positional accuracy at the time of attaching to the holder 50 can be manufactured.

  In the manufacturing method of the cutting edge replaceable tip 1c of the present embodiment, preferably, a green compact having a shape satisfying the condition of 0.20 ≦ b / a ≦ 0.70 is formed. Thereby, the cutting edge replacement | exchange type | mold chip | tip which can improve the positional accuracy at the time of attaching to the holder 50 can be manufactured by simplifying a manufacturing process.

  In this embodiment, when the rake face has a polygonal outer shape, the conditions of 0.80 ≦ b1 / b2 ≦ 1.20 and 0.32 ≦ (b1 + b2) /a≦0.70 are satisfied. In order to confirm the effect of the present invention by the above, the following tests were conducted.

(Sample preparation)
Ten samples each of Invention Examples 1 to 12 and Comparative Examples 1 to 5 were produced by the following method.

First, it contains WC as a main component, contains 4.0 wt% TiC, 1.8 wt% TaC, 0.9 wt% NbC, and 7.2 wt% Co, with the remainder being inevitable impurities. The raw material powder blended in was pulverized and mixed with a ball mill, and then powdered into a mold for compacting. The green compact thus obtained was sintered at 1420 ° C. for 1 hour. The upper and lower surfaces of the sintered body were ground with a diamond grindstone, and subjected to a blade edge treatment by honing 0.06 mm as viewed from the rake face with a SiC brush. Further, using a known CVD method, TiN (0.3 μm) / MT-TiCN (5.3 μm) / TiBN (1.0 μm) / α-Al ₂ O ₃ (4.0 μm) / TiN (0.3 μm) A coating layer was formed on the sintered body.

  The shape of the sintered body was determined to be the shape of Sumitomo Electric Hardmetal Co., Ltd. SNMG120408N-GU except for the flank, and the flank was determined by adjusting the shape of a predetermined die (mortar). These tips were negative types, the edge angles (θa and θb in FIG. 1) were 90 °, and the rake face 10 was square. The flank was not polished all around (non-polished surface).

  More specifically, in the present invention examples 1, 2, 4 to 6, and 9 to 12, the second and third regions 22 and 23 are single in the same manner as the blade-tip replaceable tip 1a shown in FIG. It was composed of a plane. Further, as shown in FIG. 5, the second region 22 (see FIG. 1) of Example 3 of the present invention has an arc shape with a radius of curvature of about 50 mm. Further, as shown in FIG. 6, the second and third regions 22 and 23 of Example 7 of the present invention are composed of two surfaces, and the center of the second and third regions 22 and 23 (second variation). A line segment extending in parallel with the extension line 41 from the center of the second and third regions 22 and 23, with the surfaces being different from the curved region 15c) on the first region 21 side and the pair of corners 11a and 11b side. The distances between the end points 16a and 16b on the side of the pair of corners 11a and 11b were 7 μm. Further, the second and third regions 22 and 23 of Example 8 of the present invention were formed by arcs having two radii of curvature as shown in FIG. More specifically, the arc on the side close to the first region 21 (each region located from the first inflection points 15a and 15b to the second inflection point 15c) is an arc having a curvature radius of about 80 mm. The arcs on the side close to the set of corners 11a and 11b (regions located from the second inflection point 15c to the set of corners 11a and 11b) are arcs having a curvature radius of about 40 mm, and these two The arc length of the arc was the same.

  In Comparative Example 1, as shown in FIG. 19, the second and third regions described above were not formed, and the flank 120 was constituted by one plane. In Comparative Examples 2 to 5, the configuration of the flank 20 is the same as that of the blade-tip-exchangeable tip 1a shown in FIG. 1, and the second and third regions are configured by a single plane as shown in FIG. It was done. However, in Comparative Examples 2 to 5, the values of (b1 + b2) / a and b1 / b2 described above were set so as to be out of the numerical range defined in the present invention.

  The values of (b1 + b2) / a, b1 / b2, and d of Invention Examples 1 to 12 and Comparative Examples 1 to 5 are described in Table 1 described later.

  Ten samples (chips) as described above were produced for each of Invention Examples 1 to 12 and Comparative Examples 1 to 5. That is, the cutting edge (acute angle corner) used for cutting was 80 cutting edges.

(Test method)
(1) Shape measurement The shape measurement was performed about the sintered compact (chip | tip) which is the sample produced as mentioned above. As a shape measuring method, a chip 1a is arranged as shown in FIG. 20, and a stylus type contour shape measuring machine (CV-4000H stylus needle tip radius 25 μm needle tip correction available) is used as a measuring machine. The shape of 1a was measured. Specifically, the measurement of the contour shape of the chip 1a was performed by scanning the flank of the chip, which is the specimen, with the needle of the measuring instrument in the direction of the arrow in FIG.

(2) Measurement of cutting edge position accuracy in attachment to and removal from holder 1) Attachment of 80 cutting edges with respect to each of the above-described samples using a holder PSSNR2525-43 made by Sumitomo Electric Hardmetal Co., Ltd., 2 The blade edge position was measured using a dial gauge, and 3) the cutting edge was removed, and the difference (called the blade edge adjustment width) between the maximum value and the minimum value of the blade edge position accuracy was measured. Further, the standard deviation of the blade edge position (blade edge adjustment width) was calculated.

(3) Measurement of work time for attachment to and removal from the holder Further, using each of the 80 corners of the present invention example 2 and comparative example 1, the work for adjusting the blade edge position by attaching to the above-described tool was performed 80 times. The time required for was calculated.

(result)
The measurement results of the above-described shape measurement and blade edge position accuracy are shown in Table 1 below.

  As can be seen from Table 1, Invention Examples 1 to 12 satisfying the conditions of 0.80 ≦ b1 / b2 ≦ 1.20 and 0.32 ≦ (b1 + b2) /a≦0.70 satisfy this condition. Compared with Comparative Examples 1 to 5 which are not, the blade edge adjustment width and the standard deviation were small. From these results, it was found that Examples 1 to 12 of the present invention can improve the positional accuracy when attached to the holder. For this reason, it has been found that when the user uses the chips according to Examples 1 to 12 of the present invention, the time required for blade edge adjustment can be reduced.

  Moreover, in the measurement of the working time described above, it was confirmed that the working example 2 of the present invention was about ¼ that of the comparative example 1 and the working time required for the blade edge position adjustment.

  In addition, the inventive example 5 was slightly inferior in the gloss of the processed surface as compared with the inventive examples 1 to 4 and 6 to 12. From this result, it was found that when the distance between the extension line and the end point of the cutting edge is d, the characteristics can be further improved by satisfying the condition of d <95 μm.

  In this embodiment, when the rake face has a polygonal outer shape, the conditions of 0.80 ≦ b1 / b2 ≦ 1.20 and 0.32 ≦ (b1 + b2) /a≦0.70 are satisfied. In order to confirm the effect of the present invention by the above, the following tests were conducted.

(Sample preparation)
Ten samples of Invention Examples 13 to 23 and 10 samples of Comparative Examples 6 to 10 were produced by the following method.

First, WC is the main component, including 1.5 wt% TaC, 0.5 wt% NbC, 0.3 wt% Cr ₃ C ₂ , and 9.8 wt% Co with the balance being inevitable impurities. The raw material powder blended so as to consist of was pulverized and mixed with a ball mill, then fed into a mold and press-molded. The pressed body thus obtained was sintered at 1375 ° C. for 1 hour. The upper and lower surfaces of this sintered body were ground with a diamond grindstone, and subjected to a cutting edge treatment by honing of 0.04 mm as viewed from the rake face with a SiC brush. Furthermore, a coating layer of super multi-layer film (3.2 μm) / TiArCrCN (0.2 μm) in which TiAlCrN and TiSiCrN were laminated with a thickness of 20 nm was formed using a known PVD method.

  The shape other than the flank was the shape of Sumitomo Electric Hardmetal Co., Ltd. TNMG160408N-SU, and the shape of the flank was determined by adjusting the shape of the predetermined mold (mortar) described above. These tips were negative, the cutting edge angles (θa, θb) were 60 °, and the rake face 10 was an equilateral triangle. The values of (b1 + b2) / a, b1 / b2, and d of Examples 13 to 23 of the present invention and Comparative Examples 6 to 10 thus manufactured are described in Table 2 described later. The flank was not polished all around (non-polished surface).

(Test method)
(1) Shape measurement The shape measurement was performed about the sintered compact (chip | tip) which is the sample produced as mentioned above. As a shape measuring method, the chip 1b is arranged on the surface plate 60 as shown in FIG. 21, and the shape of the chip is measured using a laser-type non-contact three-dimensional shape measuring machine (Keyence Corporation KS-1100) as a measuring machine. did. Specifically, laser light was irradiated on the flank face of the chip as the specimen in the direction of arrow 72 in FIG. 21 and the laser light source was scanned in the direction of arrow 71.

(2) Measurement of cutting edge position accuracy in attachment / detachment to / from the holder 1) Attachment of 60 cutting edges with respect to each sample described above using the turning holder PTGNR2525-33 manufactured by Sumitomo Electric Hardmetal Co., Ltd., 2 The blade edge position was measured using a dial gauge, 3) the cutting edge was removed, and the difference between the maximum value and the minimum value of the blade edge position accuracy (named the blade edge adjustment width) was measured. Further, the standard deviation of the blade edge position (blade edge adjustment width) was calculated.

(3) Measurement of work time in attaching / detaching to / from holder Further, using the 60 corners of the present invention example 14 and comparative example 6, the work of adjusting the blade edge position by attaching to the above-described cutting tool was performed 60 times. The time required for was calculated.

(result)
The measurement results of the above-described shape measurement and blade edge position accuracy are shown in Table 2 below.

  As can be seen from Table 2, Invention Examples 13 to 23 satisfying the conditions of 0.80 ≦ b1 / b2 ≦ 1.20 and 0.32 ≦ (b1 + b2) /a≦0.70 satisfy this condition. Compared with the comparative examples 6-10 which do not have, the blade edge | tip adjustment width and the standard deviation were small. From these results, it was found that Examples 13 to 23 of the present invention can improve the positional accuracy when attached to the holder. For this reason, it has been found that when the user uses the chips according to Examples 13 to 23 of the present invention, the time required for blade edge adjustment can be shortened.

  Further, in the measurement of the work time described above, it was also confirmed that the work time required for adjusting the blade edge position was about 1/3 in the inventive example 14 compared to the comparative example 6.

  In addition, the inventive example 17 was slightly inferior in the gloss of the processed surface as compared with the inventive examples 13-16 and 18-23. From this result, it was found that when the distance between the extension line and the end point of the cutting edge is d, the characteristics can be further improved by satisfying the condition of d <95 μm.

  In this embodiment, when the rake face has a polygonal outer shape, the conditions of 0.80 ≦ b1 / b2 ≦ 1.20 and 0.32 ≦ (b1 + b2) /a≦0.70 are satisfied. In order to confirm the effect of the present invention by the above, the following tests were conducted.

(Sample preparation)
Ten samples of the inventive examples 24 and 25 and 10 of the comparative example 11 were prepared by the following method.

  80 wt% composite carbide (consisting of 75 wt% TiCN, 15 wt% WC and 10 wt% NbC), 5.0 wt% WC, 5.0 wt% TiCN, and 3.0 wt% Ni Then, the raw material powder blended so as to consist of 7.0 wt% Co was pulverized and mixed with a ball mill, and then powdered into a mold and press-molded. The press body thus obtained was sintered at 1430 ° C. for 1 hour in a nitrogen atmosphere of 1.0 kPa. The upper and lower surfaces and the side surfaces (entire surface) of the sintered body were ground with a diamond grindstone, and a cutting edge treatment by chamfer honing of 0.1 mm × −20 ° was performed with the diamond grindstone.

  The shape of the sintered body was Sumitomo Electric Hardmetal Co., Ltd. TNGG160404R-UM except for the flank, and the flank was determined by adjusting the shape of a predetermined die (mortar). These chips were negative, the cutting edge angle was 60 °, and the plan shape of the rake face 10 was an equilateral triangle. The rake face and flank face were fully polished. The flank shape was formed using a diamond grindstone during side polishing. The values of (b1 + b2) / a, b1 / b2, and d of Examples 24 and 25 of the present invention and Comparative Example 11 produced in this way are described in Table 3 described later.

(Test method)
(1) Shape measurement The shape measurement method was the same as in Example 1.

(2) Measurement of cutting edge position accuracy in attaching / detaching to / from the holder 1) Attachment of 60 cutting edges for each of the above-mentioned samples using the DTGNR2525M16 turning holder manufactured by Sumitomo Electric Hardmetal Co., Ltd., 2) Dial Measurement of the blade edge position using a gauge, 3) removal of the cutting edge, and measurement of the difference between the maximum value and the minimum value of the blade edge position accuracy (referred to as blade edge adjustment width). Further, the standard deviation of the blade edge position (blade edge adjustment width) was calculated.

(3) Measurement of working time for attachment / detachment to / from holder Further, using the 60 corners of the inventive example 25 and comparative example 11, the work of adjusting the blade edge position by attaching to the cutting tool was performed 60 times. The time required for was calculated.

(result)
Table 3 below shows the measurement results of the shape measurement and the edge position accuracy described above.

  As can be seen from Table 3, Invention Examples 24 and 25 satisfying the conditions of 0.80 ≦ b1 / b2 ≦ 1.20 and 0.32 ≦ (b1 + b2) /a≦0.70 satisfy this condition. Compared with Comparative Example 11 that was not, the blade edge adjustment width and the standard deviation were small. From these results, it was found that Examples 24 and 25 of the present invention can improve the positional accuracy when attached to the holder. Therefore, it has been found that when the user uses the chips according to Examples 24 and 25 of the present invention, the time required for blade edge adjustment can be reduced.

  Furthermore, the inventive example 24 satisfying the conditions of 0.90 <b1 / b2 <1.10 and 0.45 ≦ (b1 + b2) /a≦0.60 is more effective than the inventive example 25 in terms of cutting edge adjustment width and standard. It has been found that the deviation can be further reduced.

  In the measurement of the working time described above, it was also confirmed that the working time required for adjusting the blade edge position was about 3/5 in the inventive example 25 compared to the comparative example 11.

  In this embodiment, when the rake face has a polygonal outer shape, the conditions of 0.80 ≦ b1 / b2 ≦ 1.20 and 0.32 ≦ (b1 + b2) /a≦0.70 are satisfied. In order to confirm the effect of the present invention by the above, the following tests were conducted.

(Sample preparation)
Ten samples each of Invention Examples 25 and 26 and Comparative Example 8 were prepared by the following method.

From a 48 wt% of TiCN, and 10 wt% of TiC, and 2 wt% of TaN, and NbC in 4 wt%, and 14 wt% of WC, and Mo ₂ C in 7 wt%, and 5 wt% of Ni, and 10 wt% of Co The raw material powder blended as described above was pulverized and mixed with a ball mill, and then powdered into a mold and pressed. The pressed body thus obtained was sintered at 1500 ° C. for 1 hour in a nitrogen atmosphere of 0.3 kPa. The upper and lower surfaces of the sintered body were ground with a diamond grindstone, and subjected to a cutting edge treatment by a honing of 0.05 mm as viewed from the rake face with a diamond brush.

  The shape of the sintered body was determined to be TPMT110304N-SU of Sumitomo Electric Hardmetal Co., Ltd. except for the flank, and the flank was determined by adjusting the shape of a predetermined die (mortar). These tips were positive type, and the edge angles (θa, θb in FIG. 9) were 60 °. The values of (b1 + b2) / a, b1 / b2, and d of Examples 26 and 27 of the present invention and Comparative Example 12 produced in this way are described in Table 5 described later. The flank was not polished all around (non-polished surface).

(Test method)
(1) Shape measurement The shape measurement method was the same as in Example 2.

(2) Measurement of cutting edge position accuracy in attaching / detaching to / from the holder 1) Attachment of 30 cutting edges with respect to each sample described above using the turning holder BBPT-212R manufactured by Sumitomo Electric Hardmetal Co., Ltd., 2 The blade edge position was measured using a dial gauge, and 3) the cutting edge was removed, and the difference (called the blade edge adjustment width) between the maximum value and the minimum value of the blade edge position accuracy was measured. Further, the standard deviation of the blade edge position (blade edge adjustment width) was calculated.

(3) Measurement of work time for attachment / detachment to / from holder Further, the work of adjusting the blade edge position by attaching to the above-described cutting tool was performed 60 times using each of the 60 corners of Invention Example 27 and Comparative Example 12. The time required for was calculated.

(result)
Table 4 below shows the measurement results of the shape measurement and the edge position accuracy described above.

  As can be seen from Table 4, Invention Examples 26 and 27 satisfying 0.80 ≦ b1 / b2 ≦ 1.20 and 0.32 ≦ (b1 + b2) /a≦0.70 do not satisfy this condition. Compared to 12, the blade edge adjustment width and standard deviation were smaller. From these results, it was found that Examples 26 and 27 of the present invention can improve the positional accuracy when attached to the holder. For this reason, it has been found that when the user uses the insert according to Examples 26 and 27 of the present invention, the time required for blade edge adjustment can be reduced.

  Furthermore, the inventive example 26 satisfying the conditions of 0.90 <b1 / b2 <1.10 and 0.45 ≦ (b1 + b2) /a≦0.60 is more effective than the inventive example 27 in cutting edge adjustment width and standard. It has been found that the deviation can be further reduced.

  Further, in the measurement of the work time described above, it was confirmed that the work example 27 of the present invention was about 2/3 of the work time required for adjusting the blade edge position as compared with the comparative example 12.

  In this embodiment, when the outer peripheral shape of the rake face is a hexagonal shape and the outer periphery alternately includes acute corners and obtuse angles, the condition of 0.20 ≦ b / a ≦ 0.70 is satisfied. In order to confirm the effect of the present invention by the above, the following tests were conducted.

(Sample preparation)
Ten samples each of Examples 28 and 29 and Comparative Example 13 were prepared by the following method.

A raw material powder containing WC as a main component, 2.0 wt% TaC and 10.0 wt% Co, and the balance composed of inevitable impurities is pulverized and mixed with a ball mill, and then fed into a mold. And press-molded. The press body thus obtained was sintered at 1400 ° C. for 1 hour. The upper and lower surfaces of this sintered body were ground with a diamond grindstone, and subjected to a cutting edge treatment by honing of 0.04 mm as viewed from the rake face with a SiC brush. Further, using a known CVD method, TiN (0.3 μm) / MT-TiCN (4.3 μm) / TiBN (0.6 μm) / α-Al ₂ O ₃ (2.3 μm) / TiC (0.2 μm) After forming a coating layer of / TiN (0.2 μm) on the sintered body, the surface of the coating layer was smoothed using a diamond brush.

  The shape of the sintered body is the model number WNMA080412 (Sumitomo Electric Hardmetal Co., Ltd. AC410K) defined in JIS B4120-1998, except for the flank, and the flank is adjusted by adjusting the shape of a predetermined mold (mortar). Were determined. As shown in FIG. 11, the rake face has a hexagonal outer periphery, and alternately includes acute corners and obtuse apexes on the outer periphery. The edge angle θ1 of the acute corner 11 was 80 °, and the edge angle θ2 of the obtuse vertex 12 was 160 °. The values of b / a and d of Examples 28 and 29 of the present invention and Comparative Example 13 produced in this way are described in Table 3 described later. The flank was not polished all around (non-polished surface).

(Test method)
(1) Shape measurement In the shape measurement method, a cut surface at a point 0.5 mm below a plane parallel to the rake face was embedded and lapped for observation and measurement.

(2) Measurement of cutting edge position accuracy in attaching / detaching to / from the holder 1) Attachment of 60 cutting edges for each of the above-mentioned samples using the DWLNR2525M08 turning holder manufactured by Sumitomo Electric Hardmetal Co., Ltd., 2) Dial Measurement of the blade edge position using a gauge, 3) removal of the cutting edge, and measurement of the difference between the maximum value and the minimum value of the blade edge position accuracy (referred to as blade edge adjustment width). Further, the standard deviation of the blade edge position (blade edge adjustment width) was calculated.

(3) Measurement of work time for attachment / detachment to / from holder Further, 60 corners of the present invention example 28 and comparative example 13 were used, and the work of adjusting the blade edge position by attaching to the above-described tool was performed 60 times. The time required for was calculated.

(result)
The measurement results of the above-described shape measurement and blade edge position accuracy are shown in Table 5 below.

  As can be seen from Table 5, the inventive examples 28 and 29 satisfying the condition of 0.20 ≦ b / a ≦ 0.70 have smaller blade edge adjustment widths and standard deviations than the comparative example 13 that does not satisfy this condition. It was. From these results, it was found that Examples 28 and 29 of the present invention can improve the positional accuracy when attached to the holder. Therefore, it has been found that when the user uses the tip according to Examples 28 and 29 of the present invention, the time required for blade edge adjustment can be shortened.

  Furthermore, the present invention example 28 that satisfies the condition of 0.45 <b / a <0.55 and 40 ≦ d ≦ 80 can further reduce the blade edge adjustment width and the standard deviation than the present invention example 29. I understood.

  Further, in the measurement of the work time described above, it was also confirmed that the work time required for adjusting the blade edge position was about 1/3 in the inventive example 28 compared to the comparative example 13.

  In order to confirm that the effect of the present invention becomes more remarkable when the radius of curvature of the corner is 2.4 mm or less, the following test was performed.

  In this example, a sintered body was produced by the same method as in Example 1, a blade edge treatment and a coating layer were formed, and except for the flank, Sumitomo Electric Hardmetal Co., Ltd. SNMG2507XXN-HU (XX is the curvature of the corner R) A chip having a shape of radius (unit: mm) × 10) was prepared. For example, in the case of SNMG2507XXN-HU, when the radius of curvature of the corner is 2.4 mm, it is SNMG250724N-HU.

  Specifically, the corner radius of curvature is 1.6 mm, 2.4 mm, and 3.2 mm, and each corner has a radius of curvature of 10 chips of the present invention, and each of the comparative example chips. Ten of each were prepared. All three types of chips of the present invention were (b1 + b2) /a=0.50, b1 / b2 = 1.00, and d (μm) = 40, and all chips of the comparative example were (b1 + b2) / a = 0 and d (μm) = 0.

  The blade edge adjustment width and the standard deviation were measured in the same manner as in Example 1 for each of these 10 types of chips.

  As a result, it was found that the cutting edge adjustment width and the standard deviation of the two types of inserts according to the present invention with the corner curvature radius of 2.4 mm or less were improved by 50% or more compared to the comparative insert with the same curvature radius. It was.

  On the other hand, the tip of the example of the present invention having a corner radius of curvature of 3.2 mm improved the edge adjustment width and the standard deviation by 10% or less compared to the tip of the comparative example having the same radius of curvature.

  From these results, it was found that the effect of the present invention that the positional accuracy when attaching to the holder can be improved can be more remarkably achieved by setting the radius of curvature of the corner to 2.4 mm or less.

  It should be understood that the embodiments and examples disclosed herein are illustrative and non-restrictive in every respect. The scope of the present invention is shown not by the above-described embodiment but by the scope of claims, and is intended to include all modifications within the meaning and scope equivalent to the scope of claims.

  The blade tip replaceable tip and the blade tip replaceable tip manufacturing method according to the present invention can reduce the blade position correction amount when the tip is attached to a general holder, and can be used for correcting the blade tip position when the user replaces the tip. The present invention can be applied particularly advantageously to a blade-tip replaceable tip and a method for manufacturing a blade-tip replaceable tip, which are required to reduce the time required.

  1a, 1b, 1c chip, 10 rake face, 11, 11a, 11b, corner, 12 apex, 13, 13a, 13b side, 14, 114 opening, 15, 15a, 15b first inflection part, 15c, 18 2nd inflection point, 16 corner side end point, 16a, 16b end point, 17 apex side end point, 20 flank face, 21 1st area, 22 2nd face area, 30 other flank face, 41 extension line, 42 Line segment, 43 1st intersection, 45 2nd intersection, 46 intersection, 50 holder, 51 holder, 60 surface plate, 71, 72 arrows, θ1, θ2 angles.

Claims (19)

A rake face having a polygonal outer shape,
A flank extending in a direction intersecting with the rake face, connected to a side sandwiched between a pair of adjacent corners on the outer periphery of the rake face,
The side that is the intersection of the rake face and the flank face is a cutting edge;
The flank is convex and has a first region located in the center of the flank and a second region that is continuous with the first region and located on one side of the set of corners. A region, and a third region connected to the first region and located on the other side of the set of corners,
An opening is provided in the center of the rake face,
A first extension line of a part of the cutting edge connected to the first region and a line segment extending in a direction perpendicular to the extension line from one end point of the set of corners of the cutting edge. The length from the intersection of the extension line and the second intersection of the line segment extending in the direction perpendicular to the extension line from the other end of the set of corners of the cutting edge is a,
The length from the end point on the first intersection point side to the first intersection point in the portion continuous with the first region of the cutting edge is b1,
When the length from the end point on the second intersection side to the second intersection point in the portion continuous with the first region of the cutting edge is b2,
0.80 ≦ b1 / b2 ≦ 1.20, and meets the condition of 0.32 ≦ (b1 + b2) /a≦0.70 ,
A blade-tip replaceable tip supported in the first region . When the distance between the extension line and the end point of the cutting edge is d,
The blade-tip replaceable tip according to claim 1, wherein the condition of 5 µm ≤ d ≤ 100 µm is satisfied.   The blade edge replaceable tip according to claim 1 or 2, wherein at least one of the second region and the third region is curved.   The blade edge replaceable tip according to claim 1 or 2, wherein at least one of the second region and the third region is planar.   The blade-tip replaceable tip according to any one of claims 1 to 4, wherein an angle of at least one of the set of corners is 80 ° or less. Further comprising another flank formed at a position different from the flank,
The flank and the other flank have a shape that is perpendicular to the rake face and is rotationally symmetric about a rotation axis that passes through the center of the rake face. The cutting edge-replaceable tip according to claim 1. A rake face having a hexagonal shape on the outer periphery, and alternately including acute corners and obtuse apexes on the outer periphery;
A flank that extends in a direction intersecting with the rake face, connected to a side sandwiched between the corner and the apex at the outer periphery of the rake face,
The side that is the intersection of the rake face and the flank face is a cutting edge;
The flank is convex, and includes a first region located on the apex side and a second region located on the corner side that is continuous with the first region,
An opening is provided in the center of the rake face,
The apex side of the cutting edge from the intersection of the extension line of the cutting edge connected to the first region and the line segment extending from the corner-side end point of the cutting edge in a direction perpendicular to the extension line The length to the end point of
When the length from the end point on the intersection point side to the intersection point in the portion continuous with the first region of the cutting edge is b,
Meet the condition that 0.20 ≦ b / a ≦ 0.70,
A blade-tip replaceable tip supported in the first region . When the distance between the extension line and the end point on the corner side of the cutting edge is d,
The blade-tip replaceable tip according to claim 7, wherein a condition of 5 µm ≤ d ≤ 100 µm is satisfied.   The blade tip replaceable tip according to claim 7 or 8, wherein the second region is curved.   The blade tip replaceable tip according to claim 7 or 8, wherein the second region is planar.   The blade tip replaceable tip according to any one of claims 7 to 10, wherein an angle of the corner is 80 ° or less.   Another flank formed at a position opposite to the flank, the flank and the other flank extending perpendicularly to the rake face and passing through a center of the rake face. The blade-tip-replaceable tip according to any one of claims 7 to 11, which has a shape that is 120 ° rotationally symmetric.   The blade tip replaceable tip according to any one of claims 1 to 12, wherein the corner is a round corner, and a radius of curvature of the corner is 2.4 mm or less.   The base material constituting the blade-tip-exchangeable tip is WC-based cemented carbide, cermet, high speed steel, ceramics, cubic boron nitride sintered body, diamond sintered body, silicon nitride sintered body, aluminum oxide and carbonized The blade-tip replaceable tip according to any one of claims 1 to 13, which is at least one selected from the group consisting of titanium.   The blade tip replaceable tip according to any one of claims 1 to 14, wherein the flank surface is a non-polished surface. With the blade tip replaceable tip attached to a holder,
The rake face is perpendicular to the non-grinding surface of the workpiece to be ground by the blade-tip replaceable tip, and is inclined to the traveling direction side with respect to the vertical surface perpendicular to the traveling direction of the holder. The blade-tip-exchangeable tip according to any one of claims 1 to 15, which has a negative shape formed as described above.   The blade tip replaceable tip according to any one of claims 1 to 16, wherein the flank surface is a surface that is not ground. Preparing the raw materials; and
Forming a green compact by filling the raw material in a mold and compressing the raw material;
Heating the green compact to obtain a sintered body,
The sintered body is
A rake face having a polygonal outer shape,
A flank extending in a direction intersecting with the rake face, connected to a side sandwiched between a pair of adjacent corners on the outer periphery of the rake face,
The side that is the intersection of the rake face and the flank face is a cutting edge;
The flank is convex and has a first region located in the center of the flank and a second region that is continuous with the first region and located on one side of the set of corners. A region, and a third region connected to the first region and located on the other side of the set of corners,
An opening is provided in the center of the rake face,
A first extension line of a part of the cutting edge connected to the first region and a line segment extending in a direction perpendicular to the extension line from one end point of the set of corners of the cutting edge. The length from the intersection of the extension line and the second intersection of the line segment extending in the direction perpendicular to the extension line from the other end of the set of corners of the cutting edge is a,
The length from the end point on the first intersection point side to the first intersection point in the portion continuous with the first region of the cutting edge is b1,
When the length from the end point on the second intersection point side to the second intersection point in the portion continuous with the first region among the cutting edges is b2,
0.80 ≦ b1 / b2 ≦ 1.20, and meets the condition of 0.32 ≦ (b1 + b2) /a≦0.70 ,
The manufacturing method of the blade-tip-exchangeable tip supported in the first region . Preparing the raw materials; and
Forming a green compact by filling the raw material in a mold and compressing the raw material;
Heating the green compact to obtain a sintered body,
The sintered body is
A rake face having a hexagonal shape on the outer periphery, and alternately including acute corners and obtuse apexes on the outer periphery;
A flank that extends in a direction intersecting with the rake face, connected to a side sandwiched between the acute corner and the apex of the obtuse angle on the outer periphery of the rake face,
The side that is the intersection of the rake face and the flank face is a cutting edge;
The flank is convex and includes a first region located on the apex side, and a second region located on the corner side, connected to the first region,
An opening is provided in the center of the rake face,
The apex side of the cutting edge from the intersection of the extension line of the cutting edge connected to the first region and the line segment extending from the corner-side end point of the cutting edge in a direction perpendicular to the extension line The length to the end point of
When the length from the end point on the intersection point side to the intersection point in the portion continuous with the first region of the cutting edge is b,
Meet the condition that 0.20 ≦ b / a ≦ 0.70,
The manufacturing method of the blade-tip-exchangeable tip supported in the first region .

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