JP5453701B2 - Replaceable tip and throw-away cutter - Google Patents

Description

  The present invention relates to a blade tip replaceable tip used as a cutting edge of a front milling cutter, and more specifically, a sintered tip having a polygonal shape as a basic shape, and improved support stability by a sintering pan during sintering. The present invention relates to a cutting edge replaceable tip and a throw-away cutter using the tip.

  As a conventional example of a blade cutter replaceable tip for milling cutter, for example, there is one disclosed in Patent Document 1 below. In addition, Patent Documents 2 and 3 below disclose blade edge replaceable tips in which measures for suppressing warping and distortion during sintering are taken.

Japanese Patent Laid-Open No. 08-57709 JP 09-66405 A Japanese Patent Publication No. 1-38602

  The blade-tip-exchangeable tip disclosed in Patent Document 1 is a double-sided use type that uses both the upper and lower surfaces as a scooping surface, and is a flat holding surface with a position higher than the blade edge at the center of the upper and lower surfaces (tip when used) It is a surface to be seated on the seat bottom surface and is also called a central land portion.

  In this replaceable tip of Patent Document 1, a powder compact is placed on a heat-resistant sintering dish made of carbon or the like with one of the upper and lower surfaces facing down, and in this state, it is placed in a sintering furnace together with the sintering dish. A method of introducing and sintering is employed. However, in this method of directly supporting the holding surface with the sintering dish, the heating condition between the contact part and the non-contact part with the sintering dish is different, and the chip is likely to warp during sintering. The resulting foreign matter may adhere to the holding surface.

  If the seating stability during use deteriorates due to this, problems such as blade runout occur during cutting. Therefore, in order not to adversely affect the cutting performance, the holding surface is finished and polished after sintering to ensure accuracy. However, this method inevitably increases the cost of the chip due to an increase in the number of processes.

  On the other hand, the chip of Patent Document 2 has three or more protrusions arranged on the upper and lower surfaces in a uniform arrangement, and the protrusions are received by a sintering pan and sintered. According to this method, the holding surface is lifted from the support surface of the sintering pan during sintering. Therefore, almost the entire surface of the chip surface is heated on average to suppress warping during sintering, but the protrusions provided on the upper and lower surfaces of the chip are minute hemispherical protrusions that make point contact with the support surface. Therefore, it is difficult to improve the support stability by the sintering dish.

  In some milling chips, the upper surface and the lower surface are configured as a common surface so that both surfaces can be used, and the position of the cutting edge is higher than the position of the holding surface. In the chip of this form, when the protrusion of Patent Document 2 is provided, it is necessary to increase the height of the protrusion as the holding surface is lowered than the cutting edge, and it becomes difficult to ensure the strength of the protrusion.

  In addition, since the protrusion is installed on the holding surface, the chip seat formed on the cutter body needs to be a special-shaped seat that avoids interference with the protrusion, and the workability of the chip seat is improved. Deterioration is unavoidable.

  Furthermore, the chip disclosed in Patent Document 3 forms a flat portion protruding in the thickness direction of the chip at the corner portion, and the ridge line portions of the upper and lower surfaces between the flat portions are concave inclined surfaces, and is sintered. The chip can be supported by the flat part. However, this chip cannot give a positive rake angle to the cutting edge of the corner part or attach a chip breaker because the corner part is flattened, and the cutting function is sacrificed.

  This invention makes it possible to float almost the entire area of the chip from the sintering dish when it is placed on the sintering dish with the upper surface or the lower surface facing down without sacrificing the cutting function of the chip. It is an object to be able to suppress distortion without providing support protrusions.

In order to solve the above-described problems, in the present invention, a cutting edge formed by intersecting ridges of the upper and lower surfaces and the side surface is provided, and a flat holding surface whose position is lower than that of the cutting edge is provided at the center of the upper and lower surfaces. The tip has a polygonal basic shape with a replaceable blade tip.
Between the main cutting edge extending from one of the adjacent corners to the other of the cutting edge, the Sarae blade disposed at each corner portion of the chip, and one main edge of the Sarae blade and the main cutting edge on the side involved in the cutting A second R portion interposed between the first R portion interposed between the other end of the Sarae blade and the main cutting edge on the side not involved in cutting, respectively.
The second R portion had the maximum height among the cutting edges, and a flat land was given to the second R portion.

  The second R portion may have a radius of curvature larger than that of the first R portion, or may be the same as the radius of curvature of the first R portion.

  This blade-tip-exchangeable tip is configured such that the upper surface and the lower surface are formed as a common surface, and the lower surface is widened between the first R portion on the upper surface and the second R portion on the lower surface. What connected between the R part and the 1st R part of the lower surface by the side surface whose upper side is wide respectively is preferable. The common surface referred to here is a surface on which the same surface as before the inversion is reproduced when the chip is inverted (inverted).

  The Sarae blade is preferably inclined in a direction in which the position gradually decreases from the second R portion side toward the first R portion side.

  The main cutting edge is inclined in a direction in which the amount of depression in the chip thickness direction of the blade gradually increases from both ends of the blade toward the longitudinal center or from one end of the blade to the other end. Is also preferable.

  The present invention also provides a throw-away cutter that is configured by detachably mounting the above-described blade tip replaceable tip of the present invention on a tip seat formed on the outer periphery of the tip of the cutter body.

  In the blade tip replaceable tip according to the present invention, the second R portion connected to the other end of the Sarah blade is located at the highest position on the top surface of the tip (the place where the bottom position on the bottom surface of the tip is lowest). is there. A flat land is given to the second R portion. The second R portion to which the flat land is applied is in each corner portion of the chip, and therefore, the chip during sintering can be supported with the flat land as a support surface.

  Since the support at this time is performed by receiving the flat land of the second R portion having the lowest position on the lower surface side with the sintering dish, the holding surface on the lower surface side surrounded by the cutting blade is lifted from the sintering dish. Therefore, almost the entire surface of the chip is heated on average during sintering, and warpage and distortion during sintering are suppressed.

  As described above, according to the present invention, the position of the second R portion connected to the other end of the Sarah blade is made highest (lowest on the lower surface side), and a flat land is given to the second R portion, so that Since the chip can be supported by the flat land during sintering, it is possible to suppress deformation and distortion during sintering of the chip whose holding surface is lower than the cutting edge without providing protrusions on the top and bottom surfaces. This prevents the problem of securing the strength of the projection accompanying the installation of the projection and the problem of deterioration of the workability of the chip seat formed on the cutter body.

  In addition, since a flat land is applied to the second R portion connected to the other end of the Sarah blade and the flat land is used as a chip support surface during sintering, a positive rake angle is provided to the cutting edge of the corner portion. In addition, it is possible to form a breaker groove along the cutting edge without sacrificing the cutting function of the cutting edge of the corner portion.

  Furthermore, when the radius of curvature of the second R portion is larger than the radius of curvature of the first R portion, the flat land area is secured to some extent, the flat land is in surface contact with the sintering pan, and the upper and lower surfaces Therefore, the support stability of the chip by the sintering pan is higher than the support by the protrusions of Patent Document 2, and a better effect can be obtained with respect to deformation and strain suppression during sintering.

  Further, since the radius of curvature of the second R portion is made larger than the radius of curvature of the first R portion, the removal of the feed mark at the time of cutting by the Sarah blade is performed by the second R portion and the first R portion. Since the remaining amount is reduced as compared with the case where the curvature radii are equal (comparison when the cutter feed amount is considered to be the same), the processing accuracy when used for cutting is also improved.

  The operation and effect of the configuration preferred in the above will be described in the section of the embodiment for carrying out the invention.

The perspective view which shows an example of the blade-tip-exchangeable tip of this invention FIG. 1 is an enlarged plan view of the blade-tip replaceable tip of FIG. Side view of the blade tip replaceable tip of FIG. 1 is a side view showing the corner portion of the chip of FIG. 1 as viewed in the direction of arrow A in FIG. 4 is an enlarged side view showing a part of FIG. Sectional view along line XX in FIG. Sectional drawing along the YY line of FIG. Explanatory drawing of the cutting function of the 2nd R section Partially cutaway side view showing an example of a throw-away cutter using the blade tip replaceable tip of the present invention An enlarged plan view of a blade-tip-exchangeable tip having the same radius of curvature of the first R portion and the second R portion of the corner Side view of a replaceable blade tip with the main cutting edge tilted in the same direction from one end to the other

  Embodiments of a blade tip replaceable tip and a throw-away cutter according to the present invention will be described below with reference to FIGS. 1 to 7 is a tip for a double-sided use type front milling cutter having a basic shape of a square, and is manufactured by sintering. The four corners of the upper surface 2 and the lower surface 3 are respectively used for cutting by rotation by tip rotation of 90 ° with the axis as a fulcrum.

  The upper surface 2 and the lower surface 3 are configured as a common surface. When the entire surface is turned over, the upper surface becomes the lower surface and the lower surface becomes the upper surface. A flat holding surface 5 that is supported by the seat bottom surface of the chip seat formed on the cutter body is formed at the center of these surfaces. The holding surface 5 provided so as to surround the central attachment hole 6 is lower than the cutting edge 7.

  The cutting edge 7 has a main cutting edge 7a located between the corners and a Sarah blade (sub cutting edge) 7b arranged at the corner. Further, the first R portion 7c is placed between the Sarae blade 7b and the main cutting edge 7a on the side involved in cutting (the main cutting edge on the right end in FIG. 3), and the main cutting on the side not involved in the cutting with the Sarae blade 7b. A second R portion 7d is disposed between each blade 7a (the main cutting blade at the left end in FIG. 3).

  The main cutting edge 7a is configured as a blade that forms a straight line in a plan view of the chip 1 (see FIG. 2) and whose position is lower than that of the Sarah blade 7b in a side view of the chip 1 (see FIG. 3).

Further, as shown in FIG. 5, the Sarae blade 7 b is connected to the first R portion 7 c from the position of the second R portion 7 d.
The blade gradually lowers as it goes to the side, and the first R portion 7c is connected to the lowest position. The first R portion 7c of the illustrated chip has no height displacement, but the position on the main cutting edge 7a side may be lowered.

  Thereby, the position of the second R portion 7d is the highest in the upper surface 2 (the lowest in the lower surface 3). In the chip of FIG. 1, the radius of curvature r2 shown in FIG. 2 of the second R portion 7d is made larger than the radius of curvature r1 of the first R portion 7c, and the side surface 4 is formed on the second R portion 7d. A flat land 8 that intersects at an angle of 90 ° is given (see FIG. 6). As shown in FIG. 10, the radius of curvature r2 of the second R portion 7d and the radius of curvature of the first R portion 7c are provided. r1 may be set equal.

As described above, the upper surface 2 and the lower surface 3 are configured as a common surface in which the same surface as before the inversion is reproduced when the chip is inverted, and as shown in FIG. The second R portion 7d on the lower surface is positioned directly below the first R portion 7c, and the first R portion 7c on the lower surface is positioned directly below the second R portion 7d on the upper surface. Therefore, in the first R portion 7c and the second lower side between the R portion 7d of the lower surface 3 is wide sides of the upper surface 2 (expressed for convenience 4 _-1) The second R of the upper surface 2 The above-described arrangement is made possible by connecting the portion 7d and the first R portion 7c of the lower surface 3 with side surfaces (also denoted as _4-2 ) whose upper side is wider.

Note that the main cutting edge 7a, the Sarae blade 7b, and the first R portion 7c may be provided with a land 9 for reinforcing the blade edge shown in FIG. The blade-strengthening land 9 is, for example, a land that intersects the side surface at an angle of 90 ° or a negative land that intersects the side surface at an obtuse angle. At this time, as shown in FIGS. 1 and 2, the land 9 is formed on the entire circumference of the cutting edge 7, the rake face 10 is continuous with the land 9, and the flat land 8 is connected to the land 9 of the second R portion 7 d. Form.

  The illustrated chip 1 is provided with a rake face 10 that is inclined in a direction that forms an acute angle with respect to the side face 4 between the cutting edge 7 and the holding face 5. The rake face 10 improves the sharpness by making the rake angle of the cutting edge 7 positive, and smoothes out chips.

  In the chip 1 of the present invention configured as described above, the second R portion 7d is located at the uppermost portion (lowermost portion of the lower surface 3) in the upper surface 2, and the second corner portion of the chip is second. The chip 1 can be supported by the sintering plate in a state in which the upper and lower surfaces 2 and 3 are parallel to the supporting surface sf (see FIG. 3) of the sintering plate, with the flat land 8 applied to the R portion 7d. it can.

  In the state where the flat land 8 supports, as shown in FIG. 3, the holding surface 5 at the center of the lower surface is lifted from the support surface sf of the sintering dish. Further, the positions of the main cutting edge 7a, the Sarah blade 7b, and the first R portion 7c are made lower than those of the second R portion 7d. A gap formed between the holding surface of the lower surface is opened to the outside.

  For this reason, almost the entire surface of the surface of the chip 1 is heated on average during sintering, and warpage and distortion of the chip due to non-uniform heating are suppressed.

  In the chip of the present invention, the flat land 8 is in surface contact with the sintering dish. For this reason, the support stability is increased as compared with the protrusions of Patent Document 2 described above, which also contributes to the suppression of deformation and distortion during sintering, and the seating stability of the holding surface 5 is improved. Helps to increase without polishing finish.

  By making the radius of curvature of the second R portion larger than the radius of curvature of the first R portion, the area of the flat land 8 is expanded, and the support stability of the chip during sintering is ensured. Further, when the radius of curvature of the second R portion is increased, as shown in FIG. 8, the remaining amount of the feed mark M left between the locus of the first R portion 7c and the locus of the second R portion 7d is increased. Since the radius of curvature of the R portion of 2 is smaller than that when the radius is small, the processing accuracy of the surface cut into the chip is also improved.

  In the illustrated tip 1, the main cutting edge 7a is inclined in a direction in which the position gradually decreases from both ends of the blade toward the center in the longitudinal direction (direction in which the amount of sagging in the tip thickness direction gradually increases) It is not necessary to cause a step that causes a decrease in strength or the like in the boundary between the R portion 7c and the main cutting edge 7a or in the middle of the main cutting edge 7a. However, the shape of the main cutting edge 7a is not limited to this, and as shown in FIG. 11, the position of the blade is inclined gradually downward from the one end to the other end side as shown in FIG. It may be a shape.

  The Sarae blade 7b is preferably a cutting blade that forms a straight line in the plan view of the chip in terms of processing accuracy, but may be a curved blade that approximates a straight line.

  Further, a tip having a basic shape in the positive direction can use four corners on one side and is excellent in economic efficiency, but the present invention can also be applied to a tip having a basic shape of a triangle.

  FIG. 9 shows an example of a throw-away cutter using the chip 1 of the present invention. The illustrated throw-away cutter 20 is a front milling cutter, and is configured by mounting the tip 1 of the present invention on the outer periphery of the front end of a cutter body (main body) 21. The cutter body 21 is provided with a chip seat 22 and a chip pocket 23 along the chip seat 22 with a predetermined interval in the circumferential direction, and is formed at a circumferential interval on the outer periphery of the tip of the cutter body. The chip 1 is fixed to each chip seat 22 by a clamp screw 24 and is detachably mounted.

  The present invention can also be applied to a chip having a basic shape of a polygon other than a square, such as a triangle or a parallelogram. In addition, the above explanation has been made by taking a tip for a face milling cutter as an example. For example, a tip provided with a Sarah blade 7b at each corner portion of a tip having a triangular shape is also used for turning. can do.

DESCRIPTION OF SYMBOLS 1 Cutting edge replaceable chip 2 Upper surface 3 Lower surface 4 Side surface 4 _-1 Side surface 4 connecting the first R portion on the upper surface and the second R portion on the lower surface _-2 The second R portion on the upper surface and the first R on the lower surface Side surface 5 Holding surface 6 Mounting surface 7 Mounting hole 7 Cutting edge 7a Main cutting edge 7b Sarae blade 7c First R section 7d Second R section 8 Flat land 9 Land for reinforcing the blade edge 10 Rake face 20 Throw away type cutter 21 Cutter body 22 Chip seat 23 Chip pocket 24 Clamp screw sf Support surface r1 of sintering pan Curvature radius r2 of first R section Curvature radius of second R section

Claims (7)

It has a cutting edge (7) formed by the intersecting ridges of the upper and lower surfaces (2, 3) and the side surface (4), and further has a flat holding surface (5) whose position is lower than that of the cutting edge (7). the lower surface (2, 3) and closed in a central portion said cutting edge (7) the holding surface (5) to the rake face (10) basic shape, which is formed is sintered indexable polygons from A chip,
The cutting edge (7) includes a main cutting edge (7a) extending from one of the adjacent corners to the other, a Sarae blade (7b) disposed at a corner portion of the chip, and one end of the Sarae blade (7b) and cutting. The first R portion (7c) interposed between the main cutting edge (7a) on the side involved in the cutting, the other end of the Sarah blade (7b) and the main cutting edge (7a) on the side not involved in the cutting 2nd R part (7d) interposed between each is included,
A land (9) is formed on the entire periphery of the cutting edge (7), and the rake face (10) is formed so as to continue to the land (9).
The second R portion (7d) has the highest height among the cutting edges, and the cutting edge provided with a flat land (8) on the land (9) of the second R portion (7d). Replaceable tip.   The cutting edge exchangeable tip according to claim 1, wherein a radius of curvature (r2) of the second R portion (7d) is set larger than a radius of curvature (r1) of the first R portion (7c). The upper surface (2) and the lower surface (3) are configured as a common surface, and a space between the first R portion (7c) of the upper surface (2) and the second R portion (7d) of the lower surface (3). A side surface (4 _-1 ) whose lower side is wide and a side surface whose upper side is wide between the second R portion (7d) of the upper surface (2) and the first R portion (7c) of the lower surface (3) The blade-tip-exchangeable tip according to claim 1 or 2, connected by ( _4-2 ).   The blade edge replacement according to claim 1 or 2, wherein the Sarae blade (7b) is inclined in a direction in which the position gradually decreases from the second R portion (7d) side toward the first R portion (7c) side. Formula chip.   The blade edge replacement according to any one of claims 1 to 4, wherein the main cutting edge (7a) is inclined in a direction in which the amount of depression in the chip thickness direction of the blade gradually increases from both ends of the blade toward the center in the longitudinal direction. Formula chip.   The blade tip exchange type according to any one of claims 1 to 4, wherein the main cutting edge (7a) is inclined in a direction in which the amount of depression in the chip thickness direction of the blade gradually increases from one end to the other end of the blade. Chip.   A throw-away type comprising a blade tip replaceable tip (1) according to any one of claims 1 to 6 detachably mounted on a tip seat (22) formed on the outer periphery of the tip of the cutter body (21). Cutter.

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