JP2007144572A - Cutting insert for grooving, cutting tool for grooving, and cutting method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cutting insert for grooving capable of machining a groove bottom of a material to be cut to be flat and have low resistance with excellent chip discharging property. <P>SOLUTION: This cutting insert has a base part 2 to be mounted on a tool holder and a cutting part 3 projecting from the base part 2. The cutting part 3 has a front flank 4 disposed on the projecting direction front side of the cutting part 3, a recessed breaker surface 5 disposed to stretch over the base part 2 on an upper side of the cutting part 3 adjacently to the front flank 4, and a linear front cutting edge 6 formed as an intersecting ridge of the front flank 4 and the breaker surface 5. The breaker surface 5 has a rake face 7 adjacent to the front cutting edge 6 and a rising face 9 connected to an upper face 8 of the base part 2 continuous to the rake face 7. A recessed groove 10 extended from the rising face 9 to the upper face 8 of the base part 2 is provided, and a groove width W of the recessed groove 10 is made maximum in an intersecting ridge line of the rising face 9 and the upper face 8 of the base part 2. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a cutting insert for grooving used as a tool for cutting such as grooving of metal parts.

  2. Description of the Related Art Conventionally, as a cutting insert used for cutting such as grooving of metal parts, a configuration in which a pair of protrusions is provided on both the left and right sides in the vicinity of the front cutting edge of the rake face is known. In such a grooving cutting insert, the chip generated by the front cutting edge hits the projections on both the left and right sides, so that the cross section of the chip is generated from the flat shape with the front cutting edge generated, and the center in the width direction is below It is transformed into a shape that is narrowed down to a convex shape and discharged. Here, the chip whose cross-section is narrowed as described above has higher rigidity and narrower width than the chip having a flat cross-section by the amount of deformation. For this reason, the chips are curled and discharged, and are easily divided in the middle of the curl, so that there is no problem of entanglement with the work material or the tool holder.

  However, when grooving is performed with a cutting insert having protrusions on the rake face in this way, chips always continue to hit the protrusions on both sides, resulting in a higher cutting resistance than the case without protrusions. However, there is a problem that the life of the cutting insert is reduced.

Therefore, as a cutting insert for solving such a problem, Patent Document 1 or Patent Document 2 discloses a cutting insert having a concave groove extending from the front cutting edge to the rear of the rising surface through the rake face. In this cutting insert, due to the configuration in which the substantially central portion of the front cutting edge is recessed by the concave groove, the chip cross-sectional shape generated by the front cutting edge is deformed into a shape that is squeezed down to a convex shape. It is described that an effect that cutting resistance is small can be obtained with respect to those in which chip treatment is performed by bringing chips into contact with and deforming the protrusion provided on the rake face.
JP 2001-212704 A JP 2002-254216 A

  However, in the configuration proposed in Patent Document 1 or Patent Document 2, since the substantially central portion of the front cutting edge is recessed by the concave groove as described above, the cutting edge shape is the shape of the work material. It is transferred to the bottom of the groove, and the substantially central part of the bottom of the groove becomes an uneven surface that is raised in a convex shape, and a new finishing process with another tool is necessary to remove the raised part. There was a problem that. In addition, since a large concave groove is formed in the central portion from the front cutting edge of the cutting insert to the rake face, there is a problem that the thickness of the portion is reduced and the cutting edge strength is reduced.

  The present invention has been made to solve such problems of the prior art, and in grooving, the groove bottom of the work material can be processed flat and with low resistance, and chip dischargeability is also good. It aims at providing the cutting insert for grooving.

  In order to solve the above problems, a cutting insert for grooving according to the present invention is a grooving cutting insert having a base for mounting on a tool holder, and a cutting part protruding from the base, The cutting portion includes a front clearance surface disposed on the front side in the protruding direction of the cutting portion, and a concave breaker surface disposed on the upper side of the cutting portion and straddling the base portion adjacent to the front clearance surface. A straight front cutting edge formed as a cross ridge between the front flank and the breaker surface, the breaker surface being a rake face adjacent to the front cutting edge, and the rake face. A rising surface continuously connected to the upper surface of the base portion, and has a concave groove extending from the rising surface to the upper surface of the base portion, and the concave portion at the intersecting ridge line between the rising surface and the upper surface of the base portion. The groove width W is maximized It is characterized in.

  According to this configuration, in the grooving process, the chips generated by the front cutting edge flow rearward along the rake face, and when reaching the rising surface, the chips are narrowed down into a convex shape by the concave groove. As a result, the width of the chip becomes smaller than the groove width of the machined workpiece, so that the chip is reliably discharged outside without remaining in the groove of the workpiece. In addition, it is not a configuration in which chips are processed by abutting and deforming chips on the rake face, but the chips are deformed by a concave groove provided on the rising surface behind the breaker surface. Since it is the structure which performs a process, the cutting resistance at the time of grooving can be reduced, and the lifetime of a cutting insert can also be extended. Furthermore, since the front cutting edge is linear, the groove bottom surface can be processed into a flat shape.

  Moreover, the groove width W of the concave groove is smaller than the blade width D of the front cutting edge, so that the chip narrowing effect can be remarkably performed, and the cutting insert by the formation of the concave groove, particularly in the vicinity of the rake face. This is desirable in that the strength reduction can be minimized.

  Furthermore, if the relationship between the groove width W and the blade width D is 0.5 ≦ (W / D) ≦ 0.75, both the chip narrowing effect and the suppression effect on the strength reduction of the cutting insert are enhanced. It is desirable in that it can be.

  In addition, the groove is line-symmetrical with respect to the vertical bisector of the front cutting edge, so that chips are discharged in a direction perpendicular to the front cutting edge without being biased left and right. Therefore, it is desirable in that it does not cause a problem that chips are applied to the groove wall surface of the machined work material to damage the wall surface.

  Further, according to the grooving cutting tool formed by mounting the grooving cutting insert on the tool holder, as described above, the chip is formed in a convex shape downward by the concave groove on the rising surface of the cutting insert. Since it is deformed so as to be squeezed, the width of the chip becomes smaller than the groove width of the machined workpiece, and the chip is reliably discharged outside without remaining in the groove of the workpiece. Furthermore, the bottom surface of the groove can be flattened by a single grooving process with a straight front cutting edge, and chip processing is performed by abutting and deforming chips on the projection provided on the rake face. Instead of the configuration, the chip is processed by deforming the chips with a concave groove provided on the rising surface behind the breaker surface, so that the cutting resistance during grooving can be reduced and the life of the cutting insert can be reduced. Can be extended.

  Also, an attaching step for constructing a grooving cutting tool by attaching the cutting insert to the tool holder, a proximity step for bringing the grooving cutting tool closer to the work material, and rotating the work material. However, a cutting process for grooving the work material by applying the front cutting edge to the outer peripheral surface of the work material, and a retreating process for retracting the grooving cutting tool from the work material are provided. According to the cutting method of the work material, as described above, the groove width of the machined work material is changed because the chips are deformed so as to be squeezed into a convex shape downward by the groove on the rising surface of the cutting insert. Therefore, the width of the chip becomes smaller than that, and the chip is surely discharged outside without remaining in the groove of the work material. Furthermore, the bottom surface of the groove can be flattened by a single grooving process with a straight front cutting edge, and chip processing is performed by abutting and deforming chips on the projection provided on the rake face. Instead of the configuration, the chip is processed by deforming the chips with a concave groove provided on the rising surface behind the breaker surface, so that the cutting resistance during grooving can be reduced and the life of the cutting insert can be reduced. Can be extended.

  According to the grooving cutting insert of the present invention, in the grooving process, the chips generated by the front cutting edge flow backward along the rake face, and the chips are lowered by the concave groove when reaching the rising surface. It is narrowed down to a convex shape. As a result, the width of the chip becomes smaller than the groove width of the machined workpiece, so that the chip is reliably discharged outside without remaining in the groove of the workpiece. Furthermore, the bottom surface of the groove can be flattened by a single grooving process with a straight front cutting edge, and the chip is processed by abutting and deforming the chip on the projection provided on the rake face. It is not a configuration, but the chip is processed by deforming the chips with a concave groove provided on the rising surface behind the breaker surface, so the cutting resistance during grooving can be reduced and the life of the cutting insert can be reduced. Can be extended.

  Embodiments of the present invention will be described below with reference to the accompanying drawings.

  1 to 5 show an embodiment of the present invention. FIG. 1 is a top view of a cutting insert for grooving according to the first embodiment of the present invention, FIG. c) Side view, FIG. 2 is a top view of the main part of the grooving cutting insert of FIG. 1, (b) Side view of the main part, and FIG. 3 is a cut using the grooving cutting insert of the present invention. FIG. 4 is a schematic view showing the shape of chips generated when grooving is performed by the grooving cutting insert of the present invention, and FIG. 5 is a grooving according to another embodiment of the present invention. It is a cutting insert for processing, Comprising: It is a perspective view which shows (a) 2nd embodiment, (b) 3rd embodiment, (c) 4th embodiment, respectively.

  First, in FIG. 1, a grooving cutting insert (hereinafter simply referred to as an insert) 1a according to a first embodiment of the present invention is a substantially triangular flat plate for mounting on a tool holder 13 (see FIG. 3). It has a base part 2 and a cutting part 3 provided with a cutting edge for projecting in three directions from the base part 2 and for grooving a work material. Further, the cutting part 3 is disposed so as to straddle the base 2 on the upper side of the cutting part 3 adjacent to the front flank 4 disposed on the front side in the protruding direction of the cutting part 3. And a straight front cutting edge 6 formed as an intersecting ridge between the front flank 4 and the breaker surface 5, and the front cutting edge 6 has a substantially triangular flat plate shape. The base 2 is disposed in parallel with the thickness direction. Further, the breaker surface 5 includes a rake surface 7 adjacent to the front cutting edge 6 and a rising surface 9 that is continuous with the rake surface 7 and is connected to the upper surface 8 of the base 2. The groove 10 has a groove 10 extending toward the upper surface 8, and the groove width W of the groove 10 is maximum at the intersecting ridge line between the rising surface 9 and the base upper surface 8.

  According to such a configuration, as shown in FIG. 3, when grooving is performed on the peripheral surface of the work material 11, the chips 12 generated by the front cutting edge 6 flow backward along the rake face 7. When the rising surface 9 is reached, there is no contact between the chip 12 and the insert 1a in the groove 10, so that the portion of the chip 12 along the groove 10 is in the groove 10 as shown in FIG. Deforms into a convex shape protruding to As a result, since the width of the chip 12 is smaller than the groove width of the machined work material 11, the chip 12 is not left in the groove of the work material 10, and the chip discharge performance is improved. In addition, instead of the conventional configuration in which chips are disposed by abutting and deforming chips on the rake face provided on the rake face, the groove 10 provided on the rising surface 9 behind the breaker surface 5 is not provided. Therefore, since the chip processing is performed by deforming the chip 12, the cutting resistance during grooving can be reduced, and the life of the cutting insert can be extended.

  As shown in FIG. 2, when the groove width W of the concave groove 10 is smaller than the blade width D of the front cutting edge 6, the chips 12 generated by the front cutting edge 6 are along the rake face 7. When it flows backward and reaches the rising surface 9, the portion corresponding to the groove 10 does not interfere with each other, and the portions on both sides interfere with each other, so that the chip narrowing effect that the chips 12 are squeezed into a convex shape is remarkable. In addition, the strength reduction of the insert 1 itself due to the formation of the concave groove 10 can be suppressed to the minimum necessary.

  The optimum relationship between the groove width W and the blade width D in order to further enhance the chip narrowing effect and the strength reduction suppressing effect is 0.5 ≦ (W / D) ≦ 0.75. When W / D is smaller than 0.5, the effect of narrowing down the chips is insufficient, and the chips tend to remain in the processed grooves of the work material. Conversely, if W / D is greater than 0.75, chips will not remain in the groove, but the chips will be somewhat difficult to divide, and the thickness of the insert will be reduced by the increase in the width of the groove. Insert strength will decrease.

  Further, the concave groove 10 has a substantially line-symmetric shape with respect to the vertical bisector of the front cutting edge 6 so that the discharge of the chips 12 is not biased left and right, and in a direction perpendicular to the front cutting edge 6. Since it will be discharged | emitted stably, it is desirable at the point which does not produce the malfunction that the chip 12 hits the groove | channel wall surface of the processed workpiece 11, and damages a wall surface.

  Moreover, as shown in FIG. 3, according to the grooving cutting tool 14 (hereinafter abbreviated as tool 14) formed by attaching the insert 1a to the tool holder 13, chips generated by the front cutting edge are scooped. The chips flow backward along the surface, and the chips are deformed by the grooves when reaching the rising surface. As shown in FIG. 4, the vicinity of the center in the width direction of the chip cross section is narrowed into a convex shape in the grooves. As a result, the chip width is smaller than the groove width of the machined work material, so that the chip discharge performance is improved without the chip remaining in the groove of the work material. In addition, it is not a configuration in which chips are processed by abutting and deforming chips on the rake face, but the chips are deformed by a concave groove provided on the rising surface behind the breaker surface. Since it is the structure which performs a process, the cutting resistance at the time of grooving can be reduced, and the lifetime of a cutting insert can also be extended.

  Further, as shown in FIG. 2, a chamfered cutting edge 15 is formed in the vicinity of the boundary between the rake face 7 and the rising face 9 so that the width between them increases as the distance from the front cutting edge 6 increases. Then, chamfering can be performed on the edge portions on both sides of the processed groove portion at the same time as the groove processing is performed on the work material, and the number of processing steps can be reduced. Incidentally, it is desirable that the chamfering cutting edge 15 is disposed as a part of the contour line of the rake face having a positive rake angle because the cutting resistance during the chamfering process can be reduced.

  Moreover, if it is the structure which the ditch | groove 10 extended long in the direction which leaves | separates from the front cutting edge 6 on the base upper surface 8 like the insert 1a, the low carbon steel etc. which are hard to cut and are easy to extend comparatively etc. Even when the workpiece is made of a work material, it is desirable that the chips extending without being curled small flow along the recessed grooves 10, so that the cross-section of the chips is narrowed in the meantime, so that the chip is easily broken.

  As mentioned above, although 1st embodiment of this invention was illustrated, this invention is not limited to embodiment mentioned above, It cannot be overemphasized that it can be made arbitrary, unless it deviates from the objective of invention. . For example, as in the second embodiment of the present invention shown in FIG. 5 (a), the base has a substantially rectangular flat plate shape, and the front cutting edge is arranged in parallel to the main surface of the flat base portion. Alternatively, as in the third embodiment of the present invention shown in FIG. 5B, the shape of the base may be a substantially triangular flat plate. Further, as in the fourth embodiment of the present invention shown in FIG. 5C, the shape of the base is a substantially rectangular flat plate, and the two front cutting edges are arranged so as to correspond to the two main surfaces, respectively. The provided structure may be sufficient. The insert can be mounted on the tool holder by inserting a screw member (not shown) into the clamp hole in the center of the insert and directly fixing it to the tool holder, or a separate clamp member such as a presser fitting ( (Not shown) may be provided on the tool holder and fixed so as to be pressed from the upper surface of the insert by the clamp member.

  Sample No. 1 according to the first embodiment of the present invention described above. 2-10 inserts were made with various dimensions shown in Table 1. In addition, as a comparative example, an insert that does not have a groove is designated as sample No. 1 was produced. The blade width of the front cutting edge was unified at 4 mm.

  About the obtained sample insert, the outer diameter grooving process was performed on the following conditions, and the chip disposal state was compared.

<Processing conditions>
Machining form Outside diameter grooving work material SCM415
Cutting speed V = 150m / min
Feed 0.2mm / rev
Cutting state The wet results are shown in Table 1.

  As is apparent from the results in Table 1, according to the present invention, sample No. 1 having a concave groove extending from the rising surface to the upper surface of the base portion. In 2 to 10 inserts, the chips were narrowed down in the width direction, and good chip dischargeability was obtained. In particular, Sample No. No. 4 in which the blade width D of the front cutting edge and the groove width W of the concave groove satisfy 0.5 ≦ (W / D) ≦ 0.75. In the inserts of 4 to 6, the chips were reliably divided into short pieces, and no chips remained on the work material, and extremely good chip discharge performance was exhibited.

  On the other hand, sample No. which is not provided with a concave groove as a comparative example. In the insert of 1, since the chips are not narrowed in the width direction, chips having the same width as the processed groove width of the work material are generated, and the chips remain in a state of being clogged in the grooves of the work material. This resulted in more defects.

It is (a) top view, (b) front view, (c) side view of the cutting insert for grooving according to the first embodiment of the present invention. It is the (a) principal part top view and (b) principal part side view of the cutting insert for grooving of FIG. It is the schematic which shows the mode of cutting using the cutting insert for grooving of this invention. It is the schematic which shows the shape of the chip | tip produced | generated when grooving with the cutting insert for grooving of this invention. It is the cutting insert for grooving processing by other embodiment of this invention, Comprising: It is a perspective view which shows (a) 2nd embodiment, (b) 3rd embodiment, (c) 4th embodiment, respectively. is there.

Explanation of symbols

1a Cutting insert for grooving (first embodiment)
1b Cutting insert for grooving (second embodiment)
1c Cutting insert for grooving (third embodiment)
1d Cutting insert for grooving (fourth embodiment)
2 Base part 3 Cutting part 4 Front relief surface 5 Breaker surface 6 Front cutting edge 7 Rake face 8 Base upper surface 9 Rising face 10 Groove 11 Workpiece material 12 Chip 13 Tool holder 14 Grooving cutting tool 15 Chamfer cutting edge W Concave Groove width D Groove width of front cutting edge

Claims (6)

A cutting insert for grooving having a base for mounting on a tool holder and a cutting part protruding from the base,
The cutting portion includes a front flank disposed on the front side in the protruding direction of the cutting portion, and a concave breaker surface disposed across the base on the upper side of the cutting portion adjacent to the front flank. And a straight front cutting edge formed as an intersection ridge between the front flank and the breaker surface,
The breaker surface has a rake surface adjacent to the front cutting edge, and a rising surface connected to the upper surface of the base portion continuously from the rake surface,
Groove cutting having a groove extending from the rising surface to the upper surface of the base, and having a maximum groove width W at the intersecting ridge line between the rising surface and the upper surface of the base. insert. The groove insert W for grooving according to claim 1, wherein a groove width W of the concave groove is smaller than a blade width D of the front cutting edge. The grooving cutting insert according to claim 2, wherein the relationship between the groove width W and the blade width D is 0.5 ≦ (W / D) ≦ 0.75. The grooving cutting insert according to any one of claims 1 to 3, wherein the concave groove has a line-symmetric shape with respect to a vertical bisector of the front cutting edge. A grooving cutting tool comprising the tool holder mounted with the grooving cutting insert according to any one of claims 1 to 4. A method for cutting a work material using the grooving cutting insert according to any one of claims 1 to 4,
An attachment step of mounting the cutting insert on the tool holder to constitute a cutting tool for grooving,
A proximity step of bringing the cutting tool for grooving close to the work material;
A cutting process in which the front cutting edge is applied to the outer peripheral surface of the work material while rotating the work material, and grooving the work material,
A retracting step of retracting the grooving cutting tool from the work material;
A cutting method for a work material, comprising:

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