JPH11129102A - Manufacture of throw-away chip and throw-away chip - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacturing method of throw-away chips, which allows easy and precise machining, and the throw-away chips. SOLUTION: A thickest center 2 is formed at the center of a chip 1 to be protruded stepwise to the main A-surface side. A cutting edge 5 is formed at three places on the top of the chip 1 to be thinner stepwise from the center 2, the cutting edge 5 having a thinner portion 6 mainly at its center and a thicker portion 7 than the thinner portion 6. The thicker portion 7 has an uprise area 9 uprising from the thinner portion 6 via a step difference 8 to the main A-surface side to be a height of the uprise area thicker than the thinner portion 6. The surface on the main A-surface side of the thicker portion 7, or the surface of the uprise area 9, is ground to be a ground surface while the surface on the main A-surface of the thinner portion 6 is not ground to be a fired surface as it remains fired.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a throw-away insert used for, for example, grooving or parting off, and a method of manufacturing the same.

[0002]

2. Description of the Related Art Conventionally, a generally triangular throw-away tip (hereinafter simply referred to as a tip) as shown in FIG. Are known.

As shown in FIG. 18B, this type of chip has a blade edge thickness corresponding to a groove width or the like (reference thickness of chip (tip reference thickness: thickest portion at the center)).
There is a case where the thickness is reduced by a step on one main surface, or a case where the thickness is reduced by a step on both main surfaces as shown in FIG.

For manufacturing a chip having the above-described structure, for example, the following methods are known. For example, as shown in FIG. 19A, a WC-Co alloy powder is sintered into a substantially triangular prism shape, and then at least one main surface side of three tops is ground and removed in a step shape ( (Broken line portion), a method of completing a chip having a desired size.

Similarly, as shown in FIG. 19 (a), at least one principal surface of three apexes is applied to a substantially triangular green compact formed by solidifying powder before sintering. A method of grinding and removing, then sintering, and finally grinding for finishing to complete chips of desired dimensions.

Further, as shown in FIG. 19 (b), the material is pressed using a biaxial press, then sintered, and
Alternatively, a method of producing chips having desired dimensions by finish grinding.

[0007]

However, even the above techniques are not always sufficient, and further improvement has been demanded. In other words, in the above-mentioned technology, there is a problem that the grinding process is not easy because many portions are removed by grinding after sintering, and the substantially triangular material is very hardened after sintering.

[0008] Further, the above technique has a problem that it is difficult to obtain accuracy. Further, although the portion to be removed by grinding after sintering is smaller than that described above, after sintering, the entire surface (upper surface, side surface, lower surface) of the convex portion is finish-ground to secure a predetermined dimensional accuracy. Therefore, there is also a problem that the grinding process is not easy.

Further, in the above technique, since the compression ratio of the thick portion and the thin portion does not become the same, when sintering,
Distortion, warpage, cracks, and the like are liable to occur, and production was not possible particularly when the step was large. In the case of chips having different levels of steps, different dies must be used.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and has as its object to provide a throw-away insert which is easy to process even with a large step and has high accuracy, and a method for manufacturing the same. I do.

[0011]

The invention described in the claims of this specification is as follows. (Claim 1) In a method for manufacturing a throw-away insert in which a thickness of a cutting edge portion provided in a plate shape and provided in an outer peripheral direction thereof is set smaller than a reference thickness of the insert, a shape corresponding to the throw-away insert is provided. In order to produce a powder compact, a press molding machine is used in which at least one of an upper press punch and a lower press punch is divided into a plurality corresponding to portions having different thicknesses of the powder compact to be obtained. The punched material (hereinafter referred to as a divided punch) compresses the material powder filled in the cavity of the press die with different strokes depending on the thickness of each corresponding part of the powder compact to be obtained. A method for manufacturing a throw-away tip, comprising sintering a powder compact. (Claim 2) The method for manufacturing a throw-away chip according to claim 1, wherein the press molding machine is provided with a press control mechanism for driving each of the divided punches independently of each other. (Claim 3) The powder in the cavity is 0.75 to 4 t / cm ² irrespective of the thickness of each part of the powder compact to be obtained.
3. The method of manufacturing a throw-away tip according to claim 1, wherein the insert is compressed and molded at a substantially constant pressure set in the range of. (Claim 4) The filling depth of the material powder in the cavity is adjusted according to the thickness of each corresponding part of the powder compact to be obtained so that the compression ratio of the material powder in each part is substantially equal to each other, 4. The method of manufacturing a throw-away chip according to claim 3, wherein the material powder is compressed by the divided punches with strokes different from each other in accordance with a filling depth corresponding to each part. (Claim 5) The method according to claim 4, wherein the compression ratio is adjusted in the range of 2 to 4. (Claim 6) By changing the filling amount of the material powder into the cavity, a throw-away chip having substantially the same outer shape in plan view and different thicknesses is manufactured. A method for producing a throw-away tip according to any one of the above. (Claim 7) A throw manufactured by the manufacturing method according to any one of claims 1 to 6, characterized in that the throw is a grooving or parting-off tip having a cutting edge portion thinner than a central portion. Away tip. (Claim 8) The indexable insert according to claim 7, wherein a protruding portion is provided on one or both main surfaces at a tip end side of the thin portion forming the cutting edge portion. (Claim 9) A pair of a rake face and a flank formed adjacent to each other in the circumferential direction is formed on the outer peripheral surface thereof as a whole substantially in a plate shape, or a plurality of pairs are formed along the circumferential direction. It has a chip body in which a cutting edge in the thickness direction is formed at the intersection of the rake face and the flank forming a pair, and the thickness of the cutting edge portion is the thickness of the thickest portion formed in the center portion of the chip. It is set smaller than the chip reference thickness defined as the thickness,
Further, when a protruding portion is provided on one or both main surfaces at the distal end side of the thin portion forming the cutting edge portion, and a powder compact having a shape corresponding to the chip body is considered, the powder compact is The outer peripheral surface of the chip body and, consequently, the outer peripheral surface of the powder compact are relative to the die hole inner surface of the press die in one of the directions corresponding to the pressing direction, so that the die is obtained by die pressing in the thickness direction. A throw-away tip characterized in that it can be released from the die hole by sliding it into the die. (Claim 10) The indexable insert according to claim 8 or 9, wherein a surface on one or both main surfaces of the raised portion is a ground surface. (Claim 11) The indexable insert according to any one of claims 8 to 10, wherein, of the thin portions forming the cutting edge portion, the surface on the main surface side excluding the raised portion is a sintered skin surface. (Claim 12) The surface roughness of one or both main surfaces of the raised portion is 0.05 to 0.4 μmRa, and of the thin portion forming the cutting edge portion, of the main surface side excluding the raised portion. The throw-away tip according to any one of claims 8 to 11, wherein the surface roughness is 0.2 to 1 µmRa. (Claim 13) The indexable insert according to any one of claims 8 to 12, wherein the raised portion is for adjusting a grooving width.

[0012]

According to the first aspect of the present invention, when manufacturing a throw-away insert in which the thickness of the plate-shaped cutting edge portion provided in the outer peripheral direction is set smaller than the reference thickness of the insert, In order to produce a powder compact having a shape corresponding to the throw-away tip, at least one of the upper press punch and the lower press punch is divided into a plurality of parts corresponding to portions having different thicknesses of the powder compact to be obtained. Use a punch press machine. Then, by these divided punches, the material powder filled in the cavity of the press die is compressed by a stroke different from each other according to the thickness of each corresponding part of the powder molded body to be obtained, to obtain a powder molded body. Sinter the body.

Thus, even in the case of a throwaway chip having a large unevenness, such as a step on the main surface side, a simple shape of the throwaway chip can be obtained by simply pressing and then sintering. The indexable insert manufactured in this way has sufficient dimensional accuracy. However, even if the dimensional accuracy is further increased by grinding, the grinding area (volume) is smaller than in the past, Less time is needed. Therefore, there is little reduction in the number of grinding wheels to be ground.

For example, in the case of a throw-away insert having a shape as shown in FIG. 18A, as shown in FIG. 18B, the thickness of the cutting edge corresponding to the groove width or the like is equal to the reference thickness of the insert (the thickest portion). (E.g., formed at the center of the chip), the thickness of one of the main surfaces is thinner due to a step, or, as shown in FIG. Some have become. In this case, when the powder compact is manufactured using a die press machine, as shown in FIG.
When the thick portion and the thin portion are formed at once by 01 and 402, the thick portion and the thin portion are compressed by the same press stroke despite the difference in the powder filling depth between the thick portion and the thin portion. This causes a difference in the compression ratio between the two parts. Therefore, the apparent density of the obtained powder compact becomes non-uniform, for example, low density in a thick portion and high density in a thin portion. When such a molded body is fired, the shrinkage of the high-density portion is small, and the shrinkage of the low-density portion is large, so that the obtained throw-away chip is likely to be strained, warped, or cracked. If the step is large, manufacturing itself may not be possible. In the case of chips having different levels of steps, different dies must be used.

Therefore, in the method according to the first aspect, at least one of the upper press punch and the lower press punch is divided into a plurality of parts corresponding to the portions having different thicknesses, for example, into a split mold, and the divided punches are formed. The powder in the cavity is compressed with different strokes according to the thickness of each corresponding part of the powder compact to be obtained by the (divided punch). More specifically, the thick part having a large powder filling depth and the thin part having a small filling depth are separately pressed by a separate press punch, and the former is pressed with a large compression stroke so that the density is not insufficient. Press with a small compression stroke so that the density is not too high.

Thus, even when a thick part and a thin part are formed on the molded body, the density of the molded body can be made substantially uniform,
Even in the case of a throwaway chip with large irregularities, such as a step on the main surface side, simply press the density of the powder compact as it is and then sinter it to obtain a good shape throwaway tip. Become. Needless to say, it is desirable to provide a difference in the amount of powder to be compressed between the thin portion and the thick portion in order to obtain a compact having a uniform density. In this case, in the die hole, for example, among the divided lower press punches, the one that is responsible for pressing the thick part is located below the one that is also responsible for pressing the thin part, so that the powder in the die hole is It is effective to make the filling depth larger in the former than in the latter. If the press used has a press control mechanism that drives each split punch independently of each other,
Press stroke control of each split punch can be performed easily and accurately (claim 2).

Specifically, the powder in the cavity is 0.75 to 4 irrespective of the thickness of each part of the powder compact to be obtained.
Compress at almost constant pressure set in the range of t / cm ²
Molding is convenient for obtaining a molded body having a uniform density, soundness, and easy handling (claim 3). Pressure is 0.
If it is less than 75 t / cm ² , the strength of the molded body may be insufficient, and cracks and chips may easily occur during handling after molding. On the other hand, if the pressure exceeds 4 t / cm ² , an excessive force is applied to the press punch or press die, which may cause a problem of shortening the service life. The above pressure is
More preferably, it is better to adjust within the range of 1 to ² t / cm ² .

In order to make the pressure at the time of molding substantially constant irrespective of the thickness of each part of the powder compact, the material powder in the cavity depends on the thickness of the corresponding part of the powder compact to be obtained. It is desirable to adjust the filling depth so that the compression ratio of the material powder in each part is substantially equal to each other, and to compress the material powder with different strokes according to the filling depth corresponding to each part by the divided punch ( Claim 4). In this case, the compression ratio is preferably adjusted in a range of 2 to 4 (claim 5). When the compression ratio is less than 2, the pressure at the time of molding becomes insufficient, and the strength of the molded body becomes insufficient, so that cracks or chips may easily occur during handling after molding. On the other hand, if the compression ratio exceeds 4, an excessive force is applied to the press punch or the press die, which may cause a problem of shortening the service life. The compression ratio is appropriately adjusted to an optimum value according to the material and properties of the powder (for example, bulk density, flowability, particle size distribution, etc.).

The indexable insert has an outer peripheral surface,
A pair of a rake face and a flank formed adjacent to each other in the circumferential direction can be formed as one set or a plurality of sets along the circumferential direction, and a thickness is set at an intersection of the rake face and the flank forming the pair. It can be configured as having a tip body in which a directional cutting blade is formed. In this case, the thickness of the cutting edge portion is set smaller than the tip reference thickness defined as the thickness of the thickest portion formed at the center of the tip.

In order to enable the above-described press forming in the thickness direction of the throw-away chip, the outer peripheral surface of the chip body and, consequently, the outer peripheral surface of the powder compact must be pressed in the pressing direction with respect to the inner surface of the die hole of the press die. It is necessary to have a shape that can be released from the die hole by relatively sliding in one of the directions corresponding to (9). Such an outer peripheral surface shape more specifically satisfies the following conditions. In the following, with reference to the schematic diagram of FIG. 4, the chip body 1a has an arbitrary cross section S parallel to the thickness direction.
, When a reference line O parallel to the thickness direction is virtually set through the midpoint M of the maximum width Wmax of the cross section in a direction orthogonal to the thickness direction, a cross-sectional outline representing the outer peripheral surface of the chip 1 The form of the portion (P1 to P3) must be one of the following.

The sectional outline portion is substantially parallel to the reference line O: the outline portion P1 in FIG. 4A corresponds to this. With reference to the drawing, the powder molded body PC has such a shape of the cross-sectional outline, so that, for example, the upper punch 101 is retracted and the lower punch 102
Is relatively raised with respect to the die 100, and this can be released from the die hole 100a.

In the sectional outline portion, the distance L from the reference line O monotonically decreases from one side of the reference line O to the other side: The outline portion P2 shown in FIG. Corresponds to. This is a case where a die taper is provided in the die hole 100a. In this case, if the powder compact PC is slid relative to the die 100 in a direction in which the above L increases, the powder compact PC can be released.

In the cross-sectional outline portion, there is a maximum point U in the middle where the distance L from the reference line O is maximum, and the maximum point U
The distance L from the reference line O monotonically decreases as both the side parts Pa and Pb move away from the maximum point U: FIG.
The outline part P3 in (a) corresponds to this. For example, even when a protrusion B is formed in a direction perpendicular to the pressing direction from the outer peripheral surface of the powder compact PC, if the protrusion does not have two or more local maximums, the inner surface of the die hole 100a may be formed. Molding is possible by combination with the tip surface of the punch 101 (or 102), and if the punch 101 is retracted, release from the die hole 100a can be performed without any problem. Similarly, by retracting the upper punch 101 and raising the lower punch 102 relatively to the die 100, the powder compact PC can be released from the die hole 100a.

The press molding machine used for the press molding is as follows:
A cavity is formed by the inner surface of the die hole of the press die and each punch surface of the press punch inserted into the die hole from above and below, and the upper and lower press punches are relatively close to each other, and the material powder filled in the cavity is removed. By press molding, a die press device for producing a powder compact to be a throw-away chip can be obtained. The material powder in the cavity is compressed by the upper and lower press punches in the thickness direction of the powder compact to be formed.

Further, if pressing in the thickness direction becomes possible,
As described in claim 6, by changing the filling amount of the material powder into the cavity, the throw-away chips having substantially the same outer shape in plan view and different thicknesses are formed with the same die and the same die. There is also the advantage that it can be manufactured with a set of punches. This eliminates the need to prepare a large number of expensive die and punch sets when manufacturing chips of various thicknesses, which is very economical. In addition, if the compression stroke of each divided punch is changed independently together with the powder filling amount, it is possible to freely change the thickness ratio between the thick portion and the thin portion formed on the molded body. Become. For example, like the throwaway tip of claim 8 described below,
When a cutting edge portion thinner than the center portion is formed, the compression stroke of the punch corresponding to the center portion is fixed, and the compression stroke of the punch corresponding to the cutting portion is changed, so that the thickness of the center portion is reduced. It is also possible to change only the thickness of the cutting edge portion while keeping the constant.

The invention of claim 7 is an example of a throw-away tip manufactured by the manufacturing method of claim 1, which has a cutting edge portion thinner than the center portion, and performs processing with this cutting edge portion. A grooving tip or a parting-off tip. In the invention of claim 8, since a protruding portion protruding toward one or both main surfaces is provided on the tip side of the cutting edge portion of the throwaway tip, by grinding the surface of the protruding portion, It is possible to adjust the thickness of the cutting edge portion.

In the case where the thickness of the cutting edge portion (actually in contact with the workpiece) on the tip side is adjusted, according to the constitutions of claims 8 and 9 of the present invention, the tip side on which the raised portion is formed is provided. Since only the surface needs to be ground, the number of parts to be ground is small, and hence the processing is easy and the cost can be reduced.
Moreover, since the grinding area is reduced, the grinding resistance is reduced, so that the deflection of the grinding machine and the jig is reduced.
From that point, the dimensional accuracy is improved. The protruding portion can be formed by forming at least one of the main surfaces of the cutting edge portion into a stepped shape such that the cutting edge portion becomes thicker on the tip end side. This makes it difficult for the grinding area to fluctuate when grinding the protruding portion, thereby stabilizing the grinding resistance and enabling more precise processing.

In the tenth aspect of the present invention, the surface on one or both main surfaces of the raised portion is a ground surface. In other words, since the thickness of the tip side of the cutting edge portion is adjusted by grinding the surface of the raised portion, high dimensional accuracy can be secured.

In the eleventh aspect of the present invention, the surface on the main surface side of the thin portion of the cutting edge portion is a sintered skin surface. In other words, according to the present invention, the surface of the thin portion is not ground and remains as fired. Since the thin portion does not directly contact the workpiece, it is not necessary to increase the dimensional accuracy, thereby reducing the manufacturing cost.

The surface roughness of one or both of the main surfaces of the raised portion can be in the range of 0.05 to 0.4 μm Ra, for example, when the surface is finished by ordinary grinding. In the thin portion forming the cutting edge portion, the roughness of the surface on the main surface side excluding the protruding portion is, for example, in the range of 0.2 to 1 μmRa when the surface is a sintered skin surface. (Claim 12).

According to the thirteenth aspect of the present invention, since the raised portion is used for adjusting the grooving width, the surface of the raised portion is ground and its height is adjusted, so that the thickness at the tip end side of the cutting edge portion is increased. That is, the grooving width can be adjusted. Also,
When the surface of the raised portion is ground, the raised portion is a part of the cutting edge portion and has a small area.

The height of the bulge (the bulge from the thin part)
Before grinding, 0.1 to 1.0 mm can be adopted. Within this range, the groove width can be suitably adjusted by grinding to reduce the height. In addition, since the height is moderate, the strength is sufficient, and breakage or the like hardly occurs during use. The height of the raised portion after grinding is 0.05 to 0.5.
mm.

[0033]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The embodiments of the present invention will be described below with reference to some embodiments shown in the drawings. (Embodiment 1) FIGS. 1A and 1B show a throw-away chip 1 according to an embodiment of the present invention. The chip 1
For example, it is used for grooving, and has a chip body 1a formed in a substantially triangular plate shape as a whole.
On the outer peripheral surface of the chip main body 1a, a total of three pairs of a rake face 302 and a flank 303 formed adjacently in the circumferential direction are formed corresponding to each vertex position of the triangle. The cutting edge 301 in the thickness direction is formed at the intersection of the rake face 302 and the flank face 303 forming the same.

As shown in FIG. 2, in the center of the chip 1,
The thickest central part 2 (reference thickness: 4 to 5 mm, for example)
Are provided on one main surface side (hereinafter referred to as main A surface) so as to protrude in a step shape. Further, at the three apexes of the triangular tip 1, a cutting edge portion 5 that is thinned in a step shape from the central portion 2 is formed, and this cutting edge portion 5 is mainly a thin portion at the center side. 6 and a thick portion 7 on the distal end side that is thicker than the thin portion 6. That is, the thick portion 7
Is provided with a raised portion 9 that protrudes from the thin portion 6 to the main A surface side via the step 8, and is thicker than the thin portion 6 by the height of the raised portion 9. In addition, the cutting blade 301 is formed at the leading edge of the thick portion 7.

The thickness of the thin part 6 is, for example, about 2.5 mm, and the thickness of the thickest part of the thick part 7 is, for example, 3.0 m.
m. The thick portion 7 is provided in a radial direction from the top of the chip 1 in a width of, for example, about 1.5 mm (width on the upper surface of the step). Also, in FIG.
The height of the raised portion 9, that is, the height of the step 8, which is the difference between the thick portion 7 and the thin portion 6, is, for example, approximately 0.5 mm. The thickness is increased.

The surface on the main A side of the thick portion 7, that is, the surface of the raised portion 9 is ground and has a center line average line roughness specified by JIS of 0.05 to 0.4 μm Ra (for example, 0 to 0.4 μm Ra). .
Although the ground surface is about 2 μm Ra), the surface on the main A side of the thin-walled portion 6 is not ground, so that it has a baked surface (sintered surface) as it is when baked. The roughness is, for example, 0.2 to 1 μmRa. However, the baked surface may be subjected to a surface treatment such as blasting or coating, and in this specification, the baked surface subjected to such surface treatment is also referred to as a sintered surface. I do. On the other hand, the main surface opposite to the main A surface of the chip 1 (hereinafter, referred to as the main B surface) is a flat surface having no irregularities unlike the main A surface side, and has a thickness of 0.05 to 0.4 μm Ra ( For example, 0.2 μmR
(about a). In addition, the corner portion (corner portion) of the thick portion 7 is rounded so as to conform to the groove bottom shape.

When the above chip 1 is used, FIG.
As shown in FIG. 1A, the chip 1 is attached to a steel chip holder (hereinafter, simply referred to as a holder) 11 (the chip 1 is thereby attached).
Constitutes a tool unit together with the tip holder 11). That is, the chip 1 is fitted into the substantially triangular concave mounting portion 12 provided at the tip of the holder 11 so as to support the outer peripheral surface of the chip 1. Then, the chip 1 is fixed to the holder 11 by sandwiching the side support surface 1 q of the chip 1 on the upper surface side with the locking member 15 and fixing the locking member 15 with the screw 13. Note that a screw insertion hole 4 is formed in the center of the main surface in the thickness direction so that the chip 1 can be attached by screwing. As shown in FIG. 1, the central portion 1p of the main surface is flat, and the concave mounting portion 1 of the holder 11 in FIG.
2 is a principal-surface-side reference surface for positioning the chip 1 on the holder 11 in the thickness direction when the chip 1 is mounted on the holder 2.

When the chip 1 is mounted on the holder 11, the chip 1 is not deviated from the holder 11. That is, a taper is formed on the side support surface 1q of the chip 1 so that the outer diameter of the chip 1 increases toward the main surface side facing the holder 11 over the entire circumference, while the mounting portion 12 is formed on the outer side thereof. Since the taper whose diameter becomes narrower is formed, when the chip 1 is fitted into the mounting portion 12 and pressed down from above, the chip 1 is pressed to the main A surface side, thereby preventing falling off.

Then, with this chip 1 fixed,
For example, as shown in FIG.
When grooving is performed on 6, the chip 1 is pressed together with the holder 11 in the direction of arrow A to perform cutting. In this embodiment, the holder 11 is formed, for example, in the shape of a rectangular bar having a rectangular cross section.

The above-mentioned indexable insert 1 is made of a metal-ceramic composite material such as cemented carbide or cermet, and is manufactured by a powder metallurgy technique. Specifically, a material powder is formed by die pressing in the thickness direction to form a powder compact, which is formed at 1400 to 1600 ° C.
And then, if necessary, subjecting the outer surface to processing such as polishing.

Here, in order for the powder compact PC to be obtained by die pressing in the thickness direction, the powder compact PC after pressing must be placed on one side of the die hole inner surface corresponding to the pressing direction. It must have an outer peripheral surface shape that can be released from the die hole by relatively sliding in the direction. Accordingly, the shape of the outer peripheral surface of the throw-away tip 1 obtained by firing the powder compact PC is as follows:
Regardless of the cross section in the thickness direction, any one of the following three conditions must be met without exception (see FIG. 4).

The cross-sectional outline is substantially parallel to the reference line O. In FIG. 4A, the outline part P1 appearing on the right side of the cross section S corresponds to this. The distance L from the reference line O to the cross-sectional outline portion monotonically decreases from one side of the reference line O to the other side. In FIG. 4 (b), the outline part P2 appearing on the right side of the cross section S corresponds to this. For example, when the inner surface of the die hole has a taper. There is a maximum point U where the distance L from the reference line O is the largest in the middle of the cross-sectional outline, and both side portions P of the maximum point U
The distance L from the reference line O monotonically decreases as both a and Pb move away from the maximum point U. In FIG. 4A, the outline P3 shown on the left side of the cross section S corresponds to this. Specifically, the protrusion B is provided at the middle portion in the thickness direction of the side surface.
Is formed.

Hereinafter, a method for manufacturing the chip 1 will be described. First, the material powder of the chip 1 is a metal powder of a metal-ceramic composite material such as a cemented carbide or a cermet as described above. For example, when a WC-Co-based cemented carbide is used, WC 80 to 95 weight is used. Parts (eg, 94 parts by weight) and C
A powder obtained by adding about 2% by weight of a paraffin resin as a binder to 5 to 10 parts by weight of o (for example, 6 parts by weight) and granulating by a spray drying method or the like can be used.

Then, the material powder is filled in a die press. As shown in FIG. 5 (a) (FIG. 5 schematically illustrates a die part with emphasis on a characteristic portion), this die press apparatus has a pair of upper and lower splitters corresponding to the central portion 2 of the chip 1 (FIG. 1). Dies (divided punches) 221 and 222, and a pair of upper and lower split dies (divided punches) 223 and 224 corresponding to the cutting blade portion 5 are provided. The portion corresponding to the raised portion 9 is included in the split mold 223 on the upper side. Here, the upper mold 2
21 and 223 use the upper press punch and the lower split molds 222 and 2
24 constitutes a lower press punch.

The upper molds 221 and 223 are mounted on mold plates 221a and 223a, respectively, and these mold plates 221a and 223a are driven by motors 241 and 242 via a drive shaft such as a screw shaft (not shown). As a result, they are driven up and down independently of each other. On the other hand, the lower split molds 222 and 224 also
22a and 224a, these mold plates 2
The motors 22a and 224a are driven by motors 251 and 252 via a drive shaft such as a screw shaft (not shown), so that the motors 22a and 224a are vertically driven independently. Here, the motors 241 and 242 and the motors 251 and 252 and the drive shafts (not shown) driven by them constitute a press control mechanism (the press control mechanism is omitted in FIGS. 5B and 5C). Is drawn).

First, as shown in FIG.
The above-described material powder P is filled in the die hole 232 (cavity) of the press die 231 having a taper corresponding to the taper shape of the side support surface 1q. At this time, upper and lower split dies 221 to 224 corresponding to the central portion 2 and the cutting blade portion 5
In, the distance between the upper and lower split dies 221 to 224 is set according to the thickness of each part. The height of the filled material powder P is substantially flush with the surface of the die plate 231 due to the operation of a not-shown abrasion feeder or the like.

Next, as shown in FIG. 5B, the drive shaft of the die press device is connected to the motors 241, 242 and 25.
Driven in the vertical direction by 1,252, split molds 221,22
The split dies 221 to 224 are moved while keeping the interval between the two dies and the interval between the split dies 223 and 224 constant.
Then, as shown in FIG.
222 and the upper and lower split dies 223 and 224 are relatively approached in the axial direction and stopped at a desired chip 1 shape position,
Next, as shown in FIG.
And the lower split dies 222 and 224 are brought close to each other and pressed at a predetermined pressure. As a result, the total compression stroke of the split dies 221 and 222 that press the thick central portion is larger than the full compression stroke of the split dies 223 and 224 that also press the thin cutting edge portion. As a result, a compact PC having a substantially uniform density regardless of the wall thickness can be obtained.
For example, after the upper split molds 221 and 223 are retracted, the molded body PC is taken out by being pushed up by the lower split molds 222 and 224, sintered at a predetermined temperature, and in a predetermined tolerance range (thickness direction). For example, a chip material (blank) within ± 0.05 mm and an outer peripheral direction of ± 0.1 mm, for example.

The pressing pressure on the main surface of the molded body PC is substantially the same at both large and small portions, specifically, 0.5 to ⁴ t / cm ² (preferably 1 to 4 t / cm ² ).
２2 t / cm ² ) is preferably set. In this case, the state of FIG.
The compression ratio of the powder between the state (c) and the state (c) is set to about 2 to 4. The compression stroke of each of the split dies 221 and 222 or the split dies 223 and 224 is adjusted so that the conditions of the press pressure and the powder compression ratio are satisfied.

Next, this chip material is ground. Specifically, the center A surface side of the central portion 2 and the thick portion 7 of the chip material, the tip side of the thick portion 7 and the entire main B surface side are ground (for example, 0.2 μm Ra). Smooth the surface and provide the desired high precision dimensions. Furthermore, the thick portion 7
The tip 1 is subjected to a rounding process or the like to complete the chip 1.

The tip 1 of the present embodiment manufactured in this manner has a structure in which the cutting edge portion 5 is provided with the protruding portion 9, so that its size (thickness of the thick portion 7) is adjusted according to the grooving width. For example, when finishing with high precision, there is an advantage that the amount of grinding is smaller than that of a conventional chip, and the processing is easy. In other words, as shown in FIG. 6A, when the raised portion is not formed on the cutting edge portion 5, almost the entire surface of the cutting edge portion 5 on the main A surface side (lateral flank side) (see FIG. 6A). Although the hatched portion has to be ground, as shown in FIG. 6B, by forming the raised portion 9, only the surface of the raised portion 9 (the hatched portion in FIG. 6) needs to be cut. There is. The protruding portion 9 is formed by providing a step 8 on the main A surface side of the cutting blade portion 5 so as to be thick at the tip end side. Thereby, when grinding the raised portion 9, the grinding area is less likely to fluctuate, and as a result, the grinding resistance is stabilized, and processing with higher precision is possible.

When the above-described chip 1 of this embodiment is manufactured, as shown in FIG. 5, even if the chip 1 has irregularities such as large steps, a plurality of split dies 221 corresponding to the irregularities are formed.
２224 and press sintering with a multi-axial press, so that its manufacture is easy. In particular, since the split molds 221 to 224 corresponding to the unevenness are moved and pressed, the uneven shape can be formed satisfactorily. Also, since the surface 6a on the main A surface side of the thin portion 6 and the main B surface of the chip 1 are substantially parallel, the pressing pressure in the thin portion 6 becomes uniform, and warpage and distortion are suppressed. is there. In addition,
In the thick portion 7 before the grinding process, similarly to the thin portion 6, the surface on the main A side and the main B surface of the chip 1 may be parallel.

In this embodiment, the surface of the raised portion 9 is ground in order to ensure high dimensional accuracy. However, if the dimensional accuracy is not so required, the grinding of the surface of the raised portion 9 is omitted. Is also good. In this case, the surface of the raised portion 9 also becomes a sintered surface. Further, in the present embodiment, the thickness of the thin portion 6 is constant, but the thickness may be gradually changed (for example, increased) toward the distal end side as shown in FIG. 7, for example.

The powder compact for producing the chip 1 is produced by die pressing in the thickness direction.
As shown in FIGS. 8A and 8B, by changing the filling amount of the material powder into the die hole 100a (cavity) of the die 100, the outer shape in plan view is substantially the same, and the thickness is large. A molded body PC (in other words, a chip) different from each other is placed in the same die 100 and punches 101 and 1.
02 can be manufactured. In addition, if the compression stroke of each divided punch is changed independently together with the powder filling amount, it is possible to freely change the thickness ratio between the thick portion and the thin portion formed on the molded body. Become. For example, in FIG. 10 of Example 2 described later, the compression stroke of the split dies 236 and 237 forming the central portion 2 (center portion: FIG. 9) is fixed, and the split die 238 corresponding to the cutting edge portion 9 (FIG. 9). , 239
, It is possible to change only the thickness of the cutting edge portion 9 while keeping the thickness of the central portion 2 constant.

(Embodiment 2) Next, Embodiment 2 will be described, but the description of the same parts as in Embodiment 1 will be omitted or simplified.

In this embodiment, as shown in FIG. 9, a substantially triangular chip 32 having a cutting portion 31 having no protruding portion is produced by using a die press. Hereinafter, the manufacturing method will be briefly described. First, chip 32
Are the same as those in the first embodiment.
As shown in FIG. 10 (FIG. 10 schematically shows a characteristic portion with emphasis on a characteristic portion, and a press control mechanism portion is omitted) as shown in FIG. A pair of upper and lower split dies 236 and 23 corresponding to 9)
7. A pair of upper and lower split dies 238 and 239 corresponding to the thin cutting edge portion 31 (FIG. 9). Hereinafter, the manufacturing procedure will be described.

First, as shown in FIG.
The above-mentioned material powder P is filled in the die hole 242 of 41. At this time, the upper and lower split dies 236 to 239 corresponding to the central portion 33 and the cutting edge portion 31 (FIG. 9) are arranged at intervals of the upper and lower split dies 236 to 239 according to the thickness of each part. . That is, the interval between the upper and lower split dies 238 and 239 corresponding to the thin cutting edge portion 31 is narrow, and the interval between the upper and lower split dies 236 and 237 corresponding to the central portion 33 is wide. That is, the filling depth of the powder is small in the former,
It is larger in the latter.

Next, as shown in FIG. 10B, each of the split dies 236 to 239 is fixed while keeping the interval between the upper and lower split dies 236 and 237 and the corner between the upper and lower split dies 38 and 39 constant. Move. Then, as shown in FIG. 10C, the upper and lower split dies 236 and 237 and the upper and lower split dies 238 and 239 are moved closer to each other and stopped at a desired chip 32 shape position. Press. When the pressing is completed, the molded body PC is taken out and fired to produce a chip material. The obtained chip material has a central part 33 and a cutting edge part 3.
The main A surface side, the front end side of the cutting blade portion 31, and the entire main B surface side are ground to complete the chip 32 in FIG.

(Embodiment 3) Next, Embodiment 3 will be described. The description of the same parts as in Embodiment 1 will be omitted or simplified. As shown in FIG. 11, a substantially triangular chip 5 having a thick central portion 51 and a thin cutting edge portion 52 having no protruding portion is used in this embodiment, as shown in FIG.
3 is produced. Hereinafter, the manufacturing method will be briefly described. First, materials for manufacturing the chip 53 are as follows.
This is the same as the second embodiment.

The die press for pressing this powder is as follows:
As shown in FIG. 12, the split mold 255 has a flat upper surface.
And a split die 256 corresponding to the lower central portion 51 and a split die 257 corresponding to the cutting blade portion 52 (the press control mechanism is omitted). Hereinafter, the manufacturing procedure will be described in order. First, as shown in FIG. 12A, the above-described material powder P is filled in the die hole 262 of the die 261. At this time, the split dies 255 to 257 are arranged according to the thickness of the central portion 51 of the tip 53 and the thickness of the cutting edge portion 52.

Next, as shown in FIG. 12B, the upper and lower mold halves 255 to 257 are moved so as to approach each other to gradually compress the material powder and stop at a desired shape of the chip 53. To press. When the pressing is completed, the molded body PC is taken out and fired to produce a chip material. The chip material is ground to form chips 53. In this embodiment, there is an advantage that the same effects as those of the second and third embodiments can be obtained while using the split dies 256 and 257 only for the lower punch.

(Embodiment 4) Next, Embodiment 4 will be described, but the description of the same parts as in Embodiment 1 will be omitted or simplified. FIG. 13A shows a chip according to this embodiment.
As shown in (b), the chip 71 has a substantially triangular shape.
On both main surface sides, there is a step from the central portion 72 to the cutting edge portion 75. Further, as shown in FIG. 13C, the cutting edge portion 75 includes a thin portion 73 and a thick portion 74 on the distal end side.
, And has raised portions 76 and 77 on both main surface sides of the thick portion 74. The surfaces on the main surfaces of the raised portions 76 and 77 are ground surfaces, and the surfaces on both main surfaces of the thin portion 73 are burnt surfaces.

The chip 71 has a large step on one main surface side, but has a small step on the other main surface side. Therefore, as shown schematically in FIG. 14, the larger step is on the lower side. Then, it can be manufactured by a die press apparatus in which one split mold 281 is arranged at the top of the figure and two split molds 282 and 283 are arranged below (the press control mechanism is omitted).

It is needless to say that the present invention is not limited to the above-described embodiment, and can be implemented in various modes without departing from the gist of the present invention. For example, in the above Examples 1 to 4, the case where a substantially triangular chip was manufactured using a cemented carbide was described.
The present invention can be similarly applied to super hard tool materials such as cermets and ceramics. The throw-away away chip 1 of the present invention may be formed in a parallelogram shape as shown in FIGS. 15A and 15B, for example, or may be formed in FIGS. 16A and 16B.
And a trapezoidal shape as shown in FIG. 17 or a plate shape having various plane shapes.

[Brief description of the drawings]

FIG. 1 is a plan view and a side view of a chip according to a first embodiment.

FIG. 2 is a side view, a plan view, and a front view showing a cutting blade portion of the chip of FIG. 1 in an enlarged manner.

3A and 3B show a method of using the chip of Example 1, wherein FIG. 3A is a perspective view showing a state where the chip is mounted on a holder, and FIG.
FIG. 4 is an explanatory diagram showing a processing state.

FIG. 4 is an explanatory diagram of an outer peripheral surface shape pattern of the throw-away tip of the present invention.

FIG. 5 is an explanatory diagram showing a procedure for manufacturing the chip of the first embodiment.

FIG. 6 is an explanatory view showing the cutting position of the insert of Example 2 in comparison with the insert of the conventional example.

FIG. 7 is a conceptual diagram showing a modified example of the chip of the first embodiment.

FIG. 8 is an explanatory view showing a method of manufacturing chips having different thicknesses by changing a powder filling amount.

FIG. 9 is a plan view of a chip according to a second embodiment.

FIG. 10 is an explanatory diagram showing a procedure for manufacturing the chip of the second embodiment.

FIG. 11 is an explanatory view showing the shape of a chip according to a third embodiment.

FIG. 12 is an explanatory view showing the procedure for manufacturing the chip of the third embodiment.

FIG. 13 is a plan view, a side view, and an explanatory view showing an enlarged main part of a chip according to a fourth embodiment.

FIG. 14 is an explanatory view illustrating a method for manufacturing a chip of Example 4;

FIG. 15 is a plan view and a side view showing a modified example of the chip of the present invention.

FIG. 16 is a plan view and a side view showing another modified example of the chip of the present invention.

FIG. 17 is a plan view showing still another modified example of the chip of the present invention.

FIG. 18 is an explanatory view of a thin portion formed on a chip.

FIG. 19 is another explanatory diagram of the related art.

[Explanation of symbols]

1, 32, 53, 71 Throwaway tips (tips) 2, 33, 51, 72 Central portion 5, 31, 52, 75 Cutting edge portion 6, 73 Thin portion 7, 74 Thick portion 8, 35 Step 9, 76 , 77 Raised portion 231 Press die 232 Die hole (cavity) 241, 242 Motor (press control mechanism) 251, 252 Motor (press control mechanism) 301 Cutting blade 302 Rake surface 303 Relief surface

Claims (13)

[Claims] 1. A method for manufacturing a throw-away insert, wherein the thickness of a cutting edge portion provided in a plate shape and provided in an outer peripheral direction thereof is set smaller than a reference thickness of the insert, wherein a shape corresponding to the throw-away insert is provided. In order to make a powder compact, a press molding machine in which at least one of an upper press punch and a lower press punch is divided into a plurality corresponding to portions having different thicknesses of the powder compact to be obtained is used. The material powder filled in the cavity of the press die is compressed at different strokes depending on the thickness of each corresponding part of the powder compact to be obtained by the divided punch (hereinafter, referred to as a divided punch). A method for producing a throw-away chip, comprising forming a compact and sintering the powder compact. 2. The method according to claim 1, wherein the press molding machine includes a press control mechanism for driving the respective divided punches independently of each other. 3. The powder in the cavity has a thickness of 0.75 to 4 t, irrespective of the thickness of each part of the powder compact to be obtained.
^3. The method for producing a throw-away tip according to claim 1, wherein the tip is compressed and molded at a substantially constant pressure set in the range of / cm ² . 4. The material powder in the cavity, depending on the thickness of each corresponding part of the powder compact to be obtained,
The filling depth is adjusted so that the compression ratios of the material powders of the respective parts are substantially equal to each other, and the material powder is compressed by the divided punches at different strokes according to the filling depths corresponding to the respective parts. Item 3. The method for producing a throwaway tip according to Item 3. 5. The method according to claim 4, wherein the compression ratio is adjusted in a range of 2 to 4. 6. A method of manufacturing a throw-away chip having substantially the same outer shape in plan view and different thicknesses by changing a filling amount of the material powder into the cavity. The method for producing a throwaway tip according to any one of the above. 7. A throw manufactured by the manufacturing method according to claim 1, which has a cutting edge portion thinner than a central portion, and is a grooving or parting-off tip. Away tip. 8. The indexable insert according to claim 7, wherein a protruding portion is provided on one or both main surfaces of the thin portion forming the cutting edge portion. 9. A pair of a rake face and a flank formed adjacent to each other in the circumferential direction is formed on the outer peripheral surface thereof as a whole in a substantially plate shape, or a plurality of pairs are formed along the circumferential direction. A chip body in which a cutting edge in the thickness direction is formed at an intersection of the rake face and the flank forming the pair, and the thickness of the cutting edge portion is the thickest formed in the center portion of the chip. The tip is defined to be smaller than the tip reference thickness defined as the thickness of the portion, and furthermore, at the tip side of the thin portion forming the cutting edge portion, a ridge is provided on one or both main surfaces, When considering a powder compact having a shape corresponding to the chip body, the outer peripheral surface of the chip body, and thus the outer peripheral surface of the powder compact, so that the powder compact is obtained by die pressing in the thickness direction. Is pressed against the inner surface of the die hole of the press die. By relatively slid in either direction corresponding to the pressing direction, the cutting insert, characterized in that a shape that can be released from the die hole. 10. The indexable insert according to claim 8, wherein a surface on one or both main surfaces of the raised portion is a ground surface. 11. The indexable insert according to claim 8, wherein, of the thin portions forming the cutting edge portion, the surface on the main surface side excluding the raised portion is a sintered skin surface. . 12. The surface roughness of one or both main surfaces of the raised portion is 0.05 to 0.4 μm Ra, and the thin portion forming the cutting edge portion, excluding the raised portion, The throw-away tip according to any one of claims 8 to 11, wherein the roughness of the main surface is 0.2 to 1 µmRa. 13. The indexable insert according to claim 8, wherein the raised portion is for adjusting a grooving width.