JP4747283B2 - Overall cutter - Google Patents

Description

  The present invention is a tool used for forming a groove or the like having a complicated shape on a workpiece, for example, when a mounting portion for attaching a turbine blade, a turbine disk, or the like is formed on a turbine. The present invention relates to a general cutter provided with a plurality of outer peripheral cutting blades having a blade shape that is uneven in the radial direction toward the surface.

Conventionally, as a tool for cutting a complicated shape on a workpiece, a plurality of outer peripheral cutting edges extending in the axial direction are provided on the outer periphery of a tool body rotated around an axis, and the axial direction of these outer peripheral cutting edges There has been provided a so-called general cutter in which the shape is complementary to a predetermined shape formed on a workpiece so as to be uneven in the radial direction toward the axial direction (see Patent Document 1).
The general cutter is to transfer the shape of the outer peripheral cutting edge to the workpiece by cutting the outer peripheral cutting edge having a predetermined shape into the workpiece, and the outer peripheral cutting edge has a plurality of curvatures. It is composed of a complicated combination of a curved line and an inclined straight line. Examples of the general cutter include a Christmas cutter (see Patent Document 2) in which the outer shape of the outer cutting edge is formed in a Christmas tree shape, a dovetail cutter, and the like.

  In such a general cutter, the shape of the outer peripheral cutting edge extending in the axial direction is formed in a complicated manner. Depending on the shape of the outer peripheral cutting edge, chip discharge and cutting resistance vary greatly, so chip clogging may occur. There are problems such as local cutting that makes cutting impossible, chips sticking to the surface of the cutting edge, making it difficult to cut, and damage to the processing surface due to chips, and cutting resistance increases. As a result, chattering and vibration of the cutting edge partially occur, and a desired shape cannot be formed with high dimensional accuracy on the workpiece.

  Here, in a cutting tool that rotates two or more cutting blades such as an end mill and a milling cutter, a concave groove called a nick may be formed in the cutting blade in order to reduce cutting resistance and promote chip discharge. With a cutting blade with a nick formed, the cutting contact with the workpiece per cutting blade becomes smaller, so the cutting resistance can be suppressed, and further, the chip is finely divided by the nick to promote chip discharge. Is something that can be done.

By providing the nick as described above on the outer peripheral cutting edge of the overall cutter, it is considered that cutting resistance can be reduced and chip discharge can be promoted, and troubles due to chip clogging and increased cutting resistance can be prevented.
JP 2002-337017 A JP 2001-198722 A

Incidentally, in the case of forming a nick cutting edge it is usually may be formed as concave grooves are recessed in a direction intersecting at right angles against the axial line, when the cutting edge is twisted relative to the axis, the axis perpendicular In many cases, the concave groove is formed so as to extend in the circumferential direction in a direction perpendicular to the cutting edge. However, when such a nick is simply formed on the outer peripheral cutting edge having a complicated shape included in the overall cutter, the following problems occur.

  In the case where the nick is formed so that the groove is recessed in a direction perpendicular to the axis, the outer peripheral cutting edge is in a portion that is uneven in the radial direction, and the nick is formed on the cutting blade inclined with respect to the axis. The bottom surface of the nick and the outer peripheral cutting edge are formed so as to be inclined, and the nick depth differs in the axial direction of the outer peripheral cutting edge. There is a problem in that the machining accuracy is deteriorated due to shortage and vibration or vibration occurs during cutting, and the cutting edge is lost. Such a problem also occurs when a nick is provided on a concave curved or convex curved cutting blade, for example.

  In addition, when the nick is formed so that it intersects at right angles to the cutting edge, the nick depth is uniform with a linear cutting edge, but for example, a nick is formed on a convex curved cutting edge with a large curvature. If this happens, the nick depth will not be uniform, and there will be a part that cuts the cutting edge unnecessarily, and the cutting edge will be lost due to insufficient rigidity of the cutting edge, and vibration and vibration will occur during cutting. There was a problem that accuracy deteriorated.

Further, since the nick depth is not uniform with respect to the blade shape, a portion where the cutting edge is raised is formed between the nick and the outer peripheral cutting edge, and a part of the outer peripheral cutting edge is easily lost. There was a problem. In addition, there is a problem in that the cutting blade wears preferentially at the portion where the cutting blade is raised, and the blade shape collapses.
In addition, when a nick is simply provided on the outer peripheral cutting edge of a general cutter with a complex blade shape, it is necessary to reduce the cutting resistance to prevent the cutting blade from being damaged. As a result, the feed amount and feed speed are excessively reduced, and the processing efficiency is greatly reduced.

  In this way, when a nick is simply attached to an outer peripheral cutting edge having a complicated shape, a number of problems arise, so that it is not possible to stably provide a complete cutter with a nick formed on the outer peripheral cutting edge. Met.

  The present invention has been made in view of the above-described circumstances, and a nick is formed on an outer peripheral cutting edge having a complicated shape to reduce cutting resistance, and the chip is divided to promote chip discharge, and cutting. An object of the present invention is to provide a complete cutter that can be satisfactorily processed and has improved processing efficiency.

A tool body that rotates about an axis is provided, and a plurality of outer peripheral cutting edges are provided on the outer periphery of the tool main body so as to extend in the axial direction. A general cutter that has a shape that is uneven in a radial direction with respect to the axial direction toward the axial direction,
The outer peripheral cutting edge is formed with a groove-shaped nick that is recessed with respect to the blade shape, and the nick includes at least one outer peripheral cutting edge among the plurality of outer peripheral cutting edges, and other outer peripheral cutting edges. The rotation trajectory is arranged so that the bottom surface of the nick follows the rotation trajectory of the outer peripheral cutting blade when the nick is not formed at least in a portion where the blade shape is uneven at the axial direction. And the bottom surface of the nick is formed with a constant depth, and one of the outer peripheral cutting edges has a linear portion extending linearly and a curved portion extending curvedly in the blade shape, and the outer periphery. A plurality of the nicks are formed on the cutting edge, and the width and pitch of the nicks in the curved part of the outer peripheral cutting edge are concave curved parts in the curved part of the outer peripheral cutting edge The width of Nick Characterized in that it is smaller than the fine pitch.

  In the general cutter having the above configuration, a nick having a bottom surface that follows the edge shape of the outer peripheral cutting edge is formed, and the nick depth is constant without depending on the nick formation position. The cutting blade is not cut out in vain. Therefore, the rigidity of the outer peripheral cutting edge can be ensured, and the chipping or the like can be prevented, and the predetermined shape can be formed with high dimensional accuracy on the workpiece by suppressing the blurring and vibration of the outer peripheral cutting edge.

In addition, since the nicks are arranged at different positions in the axial direction between the at least one outer peripheral cutting edge and the other outer peripheral cutting edges, the outer peripheral cutting edge is formed on the workpiece while forming the nicks on the outer peripheral cutting edge. The blade shape of the blade can be transferred. Therefore, the cutting resistance can be kept low by the formation of the nick, and the chip discharge is promoted by dividing the chip, so that the cutting process can be performed satisfactorily.
In addition, since the bottom surface of the nick is formed so as to follow the edge shape of the outer peripheral cutting edge, the portion where the cutting edge is raised is not formed between the nick and the outer peripheral cutting edge, and the outer cutting edge is lost due to cutting resistance. It is possible to prevent the blade shape from collapsing due to partial preferential wear of the cutting blade.

In addition, the cutting resistance is kept low by nicks, and the peripheral cutting edge does not easily break, so there is no need to excessively reduce the rotational speed, feed rate, feed rate, etc. Can be greatly improved.
Moreover, since discharge of chips is promoted, troubles such as chip clogging and adhesion of chips to the cutting blade can be prevented.

  Further, a plurality of the nicks are formed on one outer peripheral cutting edge, and the width in the direction along the blade shape of at least one of the nicks is different from the width of the other nicks, or the pitch between a pair of the nicks By making the size different from the pitch of the other adjacent nicks, it is possible to form a nick that matches the blade shape of the outer peripheral cutting blade, and prevent the blade shape from being greatly collapsed due to the formation of the nick. it can.

  Here, in the case where the outer peripheral cutting edge has a linear portion extending linearly and a curved portion extending in a curved shape in the blade shape, the nick blade shape is aligned between the linear portion and the curved portion. For example, in a curved portion with a small curvature, the width and pitch of the nicks are reduced along the blade shape by making the widths in the different directions different, or making the pitches of the nicks different. Thus, it is possible to easily form a nick having a bottom surface or to increase the width and pitch of the nick and reduce the number of nicks formed in a straight portion. Therefore, the nick can be easily formed, and the manufacturing cost of the total cutter can be reduced.

  As described above, according to the present invention, a nick is formed on the outer peripheral cutting edge having a complicated shape to reduce cutting resistance, and the chip is divided to promote chip discharge, so that cutting can be performed satisfactorily. And a complete cutter with improved machining efficiency can be provided.

A first embodiment of the present invention will be described with reference to the accompanying drawings. 1 to 3 show a Christmas cutter as a general cutter according to the first embodiment of the present invention.
As shown in FIG. 2, the Christmas cutter 10 includes a tool body 11 that is rotated around an axis O, and a plurality of outer peripheral cutting edges 20 that extend in the direction of the axis O are provided on the outer peripheral side of the tool body 11 (this book). In the embodiment, 12 sheets are provided as shown in FIG.

2 and 3, the tool body 11 has a substantially multi-stage columnar shape centering on the axis O, and the rear end side (upper side in FIG. 2) of the tool body 11 is connected to the shank portion 12. Has been.
A cutting edge portion 14 provided with a plurality of outer peripheral cutting edges 20 extending in the direction of the axis O is provided at the tip side (lower side in FIG. 2) of the tool body 11.

  As shown in FIG. 2, the outer shape of the cutting edge portion 14 has a Christmas tree shape as viewed from the side, and has four convex portions 15 that are convex outward in the tool radial direction and directed inward in the tool radial direction. Three concave portions 16 that are concave are provided, and the convex portions 15 and the concave portions 16 are alternately arranged in the direction of the axis O. The outer diameter of the outer peripheral cutting edge 20 in the cross section perpendicular to the axis O of the convex portion 15 and the concave portion 16 is formed such that the diameter gradually decreases as it goes toward the tip end side of the tool body 11.

  The outer peripheral cutting edge 20 provided in the cutting edge portion 14 is formed to be slightly twisted with respect to the axis O, and when the respective outer peripheral cutting edges 20 are viewed from the tool rotation direction, The blade shape is substantially the same shape as the cross section along the axis O of the cutting edge portion 14 (the cross section shown in FIG. 2), and four convex portions 15 and three concave portions 16 are alternately arranged in the axis O direction. ing. That is, each of the outer peripheral cutting edges 20 is provided with four convex cutting edges 21 that are convex toward the outside in the tool radial direction and three concave cutting edges 22 that are concave toward the inside in the tool radial direction. The cutting blades 21 and the concave cutting blades 22 are alternately arranged in the direction of the axis O. Further, the outer peripheral surface of the outer peripheral cutting edge 20 is formed with a relief so as to recede toward the inner side in the tool radial direction as it goes rearward in the tool rotation direction.

  A plurality of chip discharge grooves 17 extending in the direction of the axis O are formed between the outer peripheral cutting edge 20 and the outer peripheral cutting edge 20 (12 in this embodiment, as shown in FIG. 3). 17 is formed to be slightly twisted with respect to the axis O in the same manner as the outer peripheral cutting edge 20. As shown in FIG. 1, the groove bottom of the chip discharge groove 17 is formed in a taper shape that gradually decreases in diameter toward the distal end side of the tool body 11.

  Here, a plurality of nicks 23 are formed on the outer peripheral cutting edge 20 along the shape of the blade in the direction of the axis O, as shown in FIG. The adjacent outer peripheral cutting edges 20 are arranged in a staggered manner so that the formation positions of the nicks 23 in the axial direction are staggered. That is, there are two patterns of outer peripheral cutting edges 20A and 20B depending on the arrangement of the nick 23, and the outer cutting edges 20A and 20B of these two patterns are alternately arranged in the circumferential direction on the cutting edge portion 14. It is.

  Specifically, the bottom surface 23A of the nick 23 follows the blade shape of the outer peripheral cutting edge 20 in the axis O direction. Specifically, the nick 23 extends from the rotation trajectory of the outer peripheral cutting edge 20 to the bottom surface 23A when the nick 23 is not formed. The depth is constant, i.e., parallel to the outer peripheral cutting edge 20 in the straight portion, concave in the concave cutting portion 22, and convex in the convex cutting portion 21. . Further, the bottom surface 23A is formed so as to form a planar shape (second straight line shape) in a direction orthogonal to the axis O (tool rotation direction).

Further, the nick 23 is formed so that the width and the pitch of the nick 23 are different between a straight portion and a curved portion in the shape of the outer peripheral cutting edge 20. Of the blade shapes, the convex cutting edge 21 having a convex curve shape is formed with a nick 23 having a small width and a small pitch, and the nick 23 is formed on a straight portion or a bottom surface portion of the concave cutting blade 22 having a concave curve shape. The width and the pitch are increased.
Furthermore, the connecting portion 23B between the nick 23 and the outer peripheral cutting edge 20 has a concave curve shape that smoothly extends from the bottom surface 23A of the nick 23 to the bottom surface 23A, and then protrudes on the opposite side of the bottom surface 23A of the nick 23. It is formed in a convex curve shape, and the nick 23 and the outer peripheral cutting edge 20 are smoothly connected.

  The thus configured Christmas cutter 10 has a shank portion 12 attached to the end of a spindle of a machine tool or the like, rotated around an axis O, and cut into the material to be cut. The blade shape formed by the cutting blade 20 is transferred to form a multi-stage groove whose cross section is a Christmas tree shape at a time.

  In the Christmas cutter 10 having the above-described configuration, the outer peripheral cutting edge 20 is provided with a nick 23, and the bottom surface 23 </ b> A of the nick 23 conforms to the blade shape of the outer peripheral cutting edge 20, that is, the concave cutting edge 22 is recessed. Since the convex cutting edge 21 is formed in a curved shape in a curved shape, the depth of the nick 23 is made uniform without varying depending on the position where the nick 23 is formed. Accordingly, when forming the nick 23, the outer peripheral cutting edge 20 is not cut out unnecessarily, so that the rigidity of the outer peripheral cutting edge 20 can be ensured to prevent breakage and the like, and occurrence of vibration and vibration of the outer peripheral cutting edge 20. This makes it possible to form a Christmas tree-shaped groove on the workpiece with good dimensional accuracy.

  Further, since the nicks 23 are formed so that the adjacent outer peripheral cutting blades 20 are arranged in a staggered manner, when the Christmas cutter 10 is rotated around the axis O and the rotation trajectories of the outer peripheral cutting blades 20 are superimposed. The blade shape of the outer peripheral cutting edge 20 can be transferred to the workpiece. Therefore, the shape of the outer peripheral cutting edge 20 can be transferred to the workpiece with high dimensional accuracy while forming a nick 23 on the outer peripheral cutting edge 20 to suppress cutting resistance and severing the chip to promote chip discharge. .

  Further, the bottom surface 23A of the nick 23 is formed so as to follow the edge shape of the outer peripheral cutting edge 20, and the connecting portion 23B between the nick 23 and the outer peripheral cutting edge 20 protrudes on the opposite side to the bottom surface 23A of the nick 23. Since the nick 23 and the outer peripheral cutting edge 20 are smoothly connected to each other, a portion where the outer peripheral cutting edge 20 stands upright is not formed between the nick 23 and the outer peripheral cutting edge 20. The strength of the outer peripheral cutting edge 20 can be secured, and the outer peripheral cutting edge 20 can be prevented from being lost due to cutting resistance. Moreover, it is possible to prevent the peripheral cutting edge 20 from being partially preferentially worn and to prevent the shape of the peripheral cutting edge 20 from being broken.

  In addition, the cutting resistance is kept low by the nick 23, and the peripheral cutting blade 20 is not easily damaged, so that it is not necessary to reduce the rotational speed, feed amount, feed speed, etc. of the Christmas cutter 10. The processing efficiency of 10 can be greatly improved. Further, by dividing the chips finely by the nick 23, the discharge from the chip discharge groove 17 is facilitated, and troubles such as chip clogging and welding of the chips to the outer peripheral cutting edge 20 can be prevented.

  Further, since the nick 23 is formed so that the width and the pitch of the nick 23 are different between a straight portion and a curved portion in the shape of the outer peripheral cutting edge 20, the nick 23 is matched to the blade shape of the outer peripheral cutting edge 20. The nick 23 can be formed, and the formation of the nick 23 can prevent the blade shape from greatly collapsing, and the Christmas cutter 10 can reliably transfer the blade shape of the outer peripheral cutting blade 20 to the workpiece. it can. Further, by forming the nick 23 in accordance with the blade shape, it is possible to prevent the peripheral cutting blade 20 from being raised between the outer peripheral cutting blade 20 and the nick 23, and to prevent the outer peripheral cutting blade 20 from being lost. .

  Further, since the nick 23 is arranged so that the width and pitch of the nick 23 are small in the convex cutting blade 21 having a convex curve shape, the nick 23 having the bottom surface 23A along the blade shape is easily formed. be able to. Moreover, since the width | variety and pitch of the nick 23 are arrange | positioned in the bottom face 23A of the concave cutting edge 22 which makes | forms a linear part or a concave curve shape, the location which forms the nick 23 can be reduced. . Therefore, the nick 23 can be easily formed, and the Christmas cutter 10 can be manufactured at a low cost.

Next, a second embodiment of the present invention will be described. FIG. 4 shows a general cutter according to the second embodiment. In addition, the same code | symbol is attached | subjected to the member which is common in 1st Embodiment, and description is abbreviate | omitted.
In the overall cutter 30 according to the second embodiment, the cutting edge portion 14 provided on the tip side (lower side in FIG. 4) of the tool body 11 has a one-step larger diameter on the shank portion 12 side. The large-diameter portion 31, the reduced-diameter portion 32 that gradually decreases in diameter from the large-diameter portion 31 toward the tool tip side, and the constant-diameter portion 33 that has a constant diameter from the reduced-diameter portion 32 toward the tool tip side. And a diameter-expanding portion 34 that gradually increases in diameter from the constant-diameter portion 33 toward the tool tip side, and a convex curved surface portion 35 that is formed on the tool tip side and has an outer periphery convex outward in the tool radial direction.

The cutting edge portion 14 is formed with a plurality of outer peripheral cutting edges 20 extending in the direction of the axis O. The outer peripheral cutting edge 20 includes a first straight cutting edge 41 and a first inclined cutting edge in order from the tool rear end side. A blade 42, a second straight cutting blade 43, a second inclined cutting blade 44, and a convex curve cutting blade 45 are provided.
The outer peripheral cutting edges 20 are formed with nicks 23, and the adjacent outer peripheral cutting edges 20 are staggered alternately. Further, the second straight cutting blade 43 and the second inclined cutting blade 44 are arranged so that the width and pitch of the nick 23 are increased, and the convex curve cutting blade 45 is configured so that the width and pitch of the nick 23 are reduced. Is arranged.

  Also in the general cutter 30 having this configuration, as in the first embodiment, the cutting resistance is reduced by the nick 23 and the chips are finely divided to facilitate the discharge of the chips. Can do. Furthermore, the external shape which the cutting blade part 14 makes can be transcribe | transferred to a to-be-cut material by the rotation locus | trajectory of the some outer periphery cutting blade 20 being piled up.

  Further, in the second straight cutting edge 43 and the second inclined cutting edge 44 that form the linear shape of the outer peripheral cutting edge 20, the nick 23 is formed so as to increase in width and pitch. Since there are few processing parts at the time of forming in 20, it can reduce the manufacturing cost of this total cutter. Moreover, in the convex curve cutting edge 45, since the nicks 23 are arranged so that the width and pitch thereof are small, the nick 23 can be formed in accordance with the shape of the convex curve cutting edge 45, and the nicks 23 and the nicks can be formed. It is possible to prevent a portion where the outer peripheral cutting edge 20 is greatly upright from being formed.

  Further, FIG. 5 shows a dovetail cutter as a general cutter according to the third embodiment. Also in the dovetail cutter 50, the nick 23 is formed in the depth of the nick 23 along the edge shape of the outer peripheral cutting edge 20, similarly to the Christmas cutter 10 which is the first embodiment and the general cutter 30 which is the second embodiment. The cutting resistance is reduced by the nick 23 and the chips are finely divided to facilitate the discharge of the chips, so that cutting can be performed satisfactorily. By rotating the rotation trajectories of the outer peripheral cutting blades 20, the outer shape formed by the cutting blade portions 14 can be transferred to the workpiece.

In the present embodiment, the bottom surface of the nick is formed in a planar shape with respect to the tool rotation direction. However, the present invention is not limited to this, and is curved according to the flank of the outer peripheral cutting edge ( (Backing type).
In addition, the nicks are arranged in a staggered arrangement between adjacent outer peripheral cutting edges, but the present invention is not limited to this. For example, the arrangement of nicks is shifted among the three outer peripheral cutting edges. May be.

  Further, since the blade shape of the general cutter exhibits various shapes in accordance with the groove shape to be formed, it is not limited to those described in the present embodiment, and the general cutter of any shape is also included in the present invention. It becomes the object of. However, a general milling cutter in which the rotation locus of the outer peripheral cutting edge is parallel to the axis, a normal end mill having a constant twist angle, and the like are not included in the general cutter.

FIG. 3 is a partial enlarged view of a part of the outer peripheral cutting edge provided in a plurality of Christmas cutters (total cutters) according to the first embodiment. It is side surface sectional drawing of the Christmas cutter which is 1st Embodiment. It is a front view of the Christmas cutter which is a 1st embodiment. It is a side view of the general cutter which is 2nd Embodiment. It is a side view of the dovetail cutter which is 3rd Embodiment.

Explanation of symbols

10 Christmas cutter (total cutter)
11 Tool body 14 Cutting edge portion 20 Outer peripheral cutting edge 23 Nick 23A Bottom surface of Nick

Claims (1)

A tool body that rotates about an axis is provided, and a plurality of outer peripheral cutting edges are provided on the outer periphery of the tool main body so as to extend in the axial direction. A general cutter that has a shape that is uneven in a radial direction with respect to the axial direction toward the axial direction,
The outer peripheral cutting edge is formed with a groove-shaped nick that is recessed with respect to the blade shape, and the nick includes at least one outer peripheral cutting edge among the plurality of outer peripheral cutting edges, and other outer peripheral cutting edges. The rotation trajectory is arranged so that the bottom surface of the nick follows the rotation trajectory of the outer peripheral cutting blade when the nick is not formed at least in a portion where the blade shape is uneven at the axial direction. The depth from the bottom surface of the nick is made constant,
One of the outer peripheral cutting edges has a linear portion extending linearly and a curved portion extending in a curved shape in the blade shape, and a plurality of the nicks are formed on the outer peripheral cutting blade,
Of the curved portion of the outer peripheral cutting edge, the nick width and pitch of the portion forming the convex curve shape is smaller than the width and pitch of the nick portion of the curved portion of the outer peripheral cutting blade forming the concave curve shape. A complete cutter characterized by

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