JP2007021621A - Tip and milling tool - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a tip and a milling tool, achieving reduced cutting resistance and long life of a cutting edge. <P>SOLUTION: This tip 1 is shaped substantially like a square plate, and provided with a major cutting edge 6 and a minor cutting edge 5 formed on the ridge parts of a cutting face 2 opposite to a seating surface 2 with a corner edge 7 interposed between them. The major cutting edge 6 has a descending part 6a inclined to gradually decrease in distance to the seating surface 3 at least in the direction of separating from the corner edge 7, and further a first flank 16a of the major cutting edge connected to the major cutting edge 6 has a smaller clearance angle than a second flank 16b of the major cutting edge formed adjacent to the lower area of the first flank 16a of the major cutting edge. In a side view of the tip 1, the first flank 16a of the major cutting edge is formed so that the width in the direction of thickness of the tip 1 is largest at one end intersecting the minor cutting edge 5 and gradually decreased toward the other end intersecting the adjacent corner part. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

The present invention relates to a chip for cutting metal or the like and a rolling tool using this chip, such as a face mill and an end mill having an approach angle exceeding 0 °, and more particularly to a rolling tool and a chip having an approach angle of 45 °.

This type of chip is shown in FIG. The insert shown in FIG. 9 is used with a face mill (a rolling tool), has a cutting edge 15 formed between a cutting rake face 12 and a flank face 13, and between the flank face 13 and the bottom face. The cutting edge 15 has an axial rake angle (axial rake angle) Y1 and Y2 with respect to the rotation axis of the rolling tool and is continuous with each other. With first and second cutting edge elements 15a, 15b, Y1 being significantly larger than Y2, Y1 being substantially in the range of 4 ° to 30 °, and Y2 being substantially in the range of ± 15 °. The cutting edge has a projection of length a on the rotation axis, while the first cutting element has a projection of length a1 in the range of 0.6a to 0.9a on the rotation axis The intersection line between the plane passing through the rotation axis of the rolling tool and the surface milled by the cutting edge 15 The flank 13 and the cutting edge elements 15a and 16b are positioned and formed such that the flank is substantially perpendicular (see Patent Document 1, for example).

JP-A-5-253730

The conventional tip has an effect of reducing the back force of the cutting resistance of the cutting tool, but the cutting edge near the intersection of the auxiliary cutting edge 14 and the cutting edge 15 located on the tool tip side becomes sharp. Therefore, the strength is reduced. When the rake angle in the axial direction is increased, the clearance angle of the cutting edge 15 in the insert is secured on the tool rear end side of the clearance surface 13 formed on the cutting edge 15 side in order to ensure a clearance with the work material. Must be increased, and the cutting edge of the cutting edge 15 becomes sharp. For this reason, there is a problem in that the strength in the vicinity of the intersecting portion is reduced, and chipping and defects are likely to occur.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a chip and a turning tool that can reduce cutting resistance and extend the life of a cutting edge.

In order to solve the above problems, the present invention has a substantially square plate shape, the upper surface facing the flat seating surface is a rake face, and the ridge portion of the rake face is formed at each corner portion. A main cutting edge and a secondary cutting edge are formed with the corner blade interposed therebetween, and the corner blade flank and the main cutting edge flank are respectively formed on the side surfaces extending from the corner blade, the main cutting edge and the sub cutting edge toward the seating surface. In the tip formed with the surface and the auxiliary cutting edge flank, the main cutting edge has a downward inclined portion that is inclined so that the distance from the seating surface gradually decreases as the distance from the corner blade increases. The main cutting edge flank comprises a main cutting edge first flank formed on the main cutting edge side and a main cutting edge second flank formed on the seating surface side, The clearance angle of the first flank face is the clearance angle of the second flank face of the main cutting edge. In the side view of the tip, the main cutting blade first flank has the largest width in the tip thickness direction at one end where it intersects with the corner blade, and intersects with another adjacent corner blade. It is a chip characterized in that it is formed so as to gradually become smaller as it approaches the other end, and to become the smallest at the other end.

According to the chip of the present invention configured as described above, the main cutting edge has at least a downward inclined portion that is inclined so that the distance from the seating surface gradually decreases as the distance from the corner blade increases. Therefore, in the cutting tool equipped with the insert, the back force acting in the axial direction of the cutting resistance is reduced, cutting with a low-rigidity machine tool, so-called multi-blade equipped with a relatively large number of inserts. In cutting with a turning tool, chatter vibration of the tool is suppressed, and highly efficient and highly accurate machining becomes possible. By setting the length of the downward inclined portion in the main cutting edge direction to be in the range of 50% to 90% of the total length of the main cutting edge, the above-described effect can be reliably obtained. When the length of the descending inclined portion in the main cutting edge direction is less than 50% of the total length of the main cutting edge, the effect of reducing the cutting resistance cannot be obtained. Since the inclination of the upward inclined portion to be made becomes abrupt, the chip dischargeability may be deteriorated.

Further, the first flank of the main cutting edge connected to the main cutting edge has a smaller flank angle than the second flank of the main cutting edge, so that the cutting edge of the main cutting edge is prevented from being sharpened and chipped or chipped. Is prevented. Further, the main cutting edge first flank extending in the main cutting edge direction in a side view as viewed from the direction orthogonal to the chip thickness direction has one end intersecting the corresponding auxiliary cutting edge flank and the main cutting edge. The width in the chip thickness direction of the first flank of the blade takes a maximum value at the one end, gradually decreases with increasing distance from the one end in the main cutting edge direction, and is minimum at the other end that intersects the adjacent corner. Since the effect of increasing the strength of the main cutting edge by the main cutting edge first flank increases the closer to the intersection of the main cutting edge and the corner blade, the intersection is formed. The fracture resistance in the vicinity of the part is greatly improved. The maximum value of the width of the main cutting edge first flank is preferably in the range of 10% to 50% of the maximum distance between the main cutting edge and the seating surface in the chip thickness direction. This is because if it is less than 10%, the effect of increasing the strength of the main cutting edge may not be obtained, and if it exceeds 50%, the clearance between the main cutting edge first flank and the work material cannot be secured. The width of the first cutting edge flank gradually decreases from the tool front end area of the main cutting edge to the tool rear end area, and the main cutting edge with a large flank angle is formed below the main cutting edge first flank. Since the blade second flank is formed, an appropriate clearance is ensured between the main cutting blade first flank and the main cutting blade second flank and the work material over the entire main cutting edge. As a result, cutting resistance and flank wear are increased. Further, at least one corner blade flank connected to the corner blade has a clearance angle equal to the main cutting blade first flank at one end connected to the main cutting blade first flank and is connected to the auxiliary cutting blade flank. When the clearance angle gradually increases toward the end and the clearance angle is equal to the secondary cutting edge clearance at the other end, the edge strength of the corner blade near the intersection with the main cutting edge is Increased and extremely high fracture resistance is obtained.

When the angle formed between the descending inclined portion of the main cutting edge and the seating surface is less than 2 ° in a side view as viewed from the direction perpendicular to the thickness direction of the chip, the effect of reducing cutting resistance, particularly back force, can be obtained. If the angle exceeds 15 °, the length of the main cutting edge that comes into contact with the work material increases and cutting resistance, in particular, the main component force and the feed component force, may increase. A range of 15 ° is suitable.

The main cutting edge first flank faces such that the ridgeline that appears when cutting along a plane parallel to the seating surface is inclined at a slight angle in the range of 0.3 ° to 2.0 ° with respect to the corresponding ridgeline of the seating surface. Is formed. Then, the main cutting edge first flank is formed so that its width in the chip thickness direction gradually becomes narrower as it goes away from the intersection with the sub cutting edge. Correspondingly, the tip seat provided on the tool body of the turning tool has an angle formed by the support wall surface for abutting and supporting the side surface of the tip and the tool axis when viewed from the direction orthogonal to the seat surface. The angle is 0 ° to 44.7 °, the approach angle of the tip mounted on the tip seat is 45 °, and the secondary cutting edge is perpendicular to the tool axis.

If the clearance angle of the first flank of the main cutting edge is less than 3 °, the clearance with the work material may not be ensured and cutting resistance may increase. If the clearance angle exceeds 20 °, the main cutting edge and the main cutting edge Since there is a possibility that the effect of increasing the strength of the blade and the intersecting portion may not be obtained, the range is 3 ° to 20 °.

Furthermore, if the clearance angle of the second flank of the main cutting edge is less than 10 °, the clearance with the work material may be insufficient and cutting resistance may increase. If the clearance angle exceeds 30 °, the strength of the main cutting edge will increase. Since the strength of the entire chip including the above cannot be ensured, the range is 10 ° to 30 °.

When a positive rake angle in the range of 10 ° to 30 ° is given to at least the rake face connected to the main cutting edge, the cutting resistance is further reduced due to a synergistic effect with the downward inclined portion provided on the main cutting edge. .

The flat land surface formed along the edge of the rake face on the inner edge of the rake face prevents a reduction in the strength of the edge of the edge and prevents chipping and chipping more effectively. To do. If the land surface width is less than 0.05 mm, the effect of increasing the strength of the cutting edge is difficult to obtain, and if it exceeds 0.30 mm, the sharpness may be reduced and the cutting resistance may be increased. If the angle between the land surface and the flank is too small, the effect of increasing the strength of the cutting edge is difficult to obtain, and if it is too large, the cutting resistance may increase. Therefore, the land surface and the main cutting blade first flank The angle between the land surface and the auxiliary cutting edge clearance surface is in the range of 60 ° to 80 °.

The cutting edge strength is also increased by honing provided over the entire edge of the rake face. The cross-sectional shape of the honing in the orthogonal cross section of the side ridge portion is a curved shape smoothly connected to the rake face and the flank face, or a single arc shape. In the case of curved honing, the rake face side is wider than the flank face width, the rake face side width is in the range of 0.04 mm to 0.10 mm, and the flank face side width is 0. The range is 02 mm to 0.05 mm. If either the width on the rake face side or the width on the flank face is below the lower limit, the strength of the cutting edge may be insufficient, and if either one exceeds the upper limit, the cutting resistance increases or the machining surface There is a risk of deterioration of surface roughness. In the case of arc-shaped honing, the radius of curvature of the arc is in the range of 0.02 mm to 0.08 mm. If the lower limit is not reached, the strength of the cutting edge may be insufficient, and if the upper limit is exceeded, the cutting resistance may increase or the surface roughness of the machined surface may deteriorate.

In order to increase the flatness and surface roughness of the machined surface finished by the secondary cutting edge, the secondary cutting edge has a ridge line shape in a plan view as viewed from the chip thickness direction, which is a straight line or an arc that protrudes outward. . Furthermore, the angle formed between the auxiliary cutting edge and the main cutting edge intersecting with the auxiliary cutting edge is approximately 45 °, and the insert can be applied to a rolling tool having an approach angle of 45 °.

In a cutting tool in which one or a plurality of inserts are mounted on the outer periphery of a tip of a substantially cylindrical tool body that is rotated around an axis, the insert is a tip having the above-described configuration. The axial rake angle of the main cutting edge located on the outer peripheral side of the tool is positive. Here, the auxiliary cutting edge located on the tool front end side is substantially perpendicular to the axis of the tool body.

FIGS. 1-8 is a figure which shows one Embodiment of the face milling which is a chip | tip with which this invention is applied, and a cutting tool equipped with this chip | tip. FIG. 1 is a plan view seen from the thickness direction of the chip. FIG. 2 is a side view of the chip shown in FIG. FIG. 3 is a rear view of the chip shown in FIG. FIG. 4 is an enlarged view of an end surface taken along line S1-S1 in FIG. FIG. 5 is a front view of the face mill as seen from the tool tip side. 6 is a side view seen from a direction orthogonal to the axis of the face mill shown in FIG. FIG. 7 is a partial cross-sectional side view of the face mill shown in FIG. FIG. 8 is an enlarged view of a portion E in FIG.

First, the chip 1 has a substantially square plate shape as shown in FIGS. 1 and 2, the upper surface thereof is a rake surface 2, and the lower surface is substantially orthogonal to the thickness direction of the chip 1. The seating surface 3 is a flat surface, and the side surface between these upper and lower surfaces is a flank. A mounting hole 4 penetrating the upper and lower surfaces is formed in the approximate center of the upper surface. The mounting hole 4 is for inserting a clamp screw 109 for attaching the chip 1 to the tool body 101 of the face mill 100. Corner edges 7 are formed at four corner portions A, B, C, D on the side ridges of the upper surface that becomes the rake face 2, and the main cutting edge 6 and the auxiliary cutting edge 5 are sandwiched between the corner cutting edges 7. Is formed. The main cutting edge 6 extends between two adjacent corner portions A, B, C, D. The corner blade 7 is formed in a straight line connecting the main cutting edge 6 and the auxiliary cutting edge 7 or a curved line that smoothly connects both as in this embodiment. Further, at least the cutting edge of the chip 1 is made of a hard material such as cemented carbide, cermet, or ceramic, or a superhard material such as a diamond sintered body or a cubic boron nitride sintered body.

In FIG. 2, the main cutting edge 6 has one end portion intersecting with the corresponding corner blade 7 and the other end portion intersecting with the adjacent corner portion being located at the same height, and the main cutting edge 6 in the direction of the main cutting edge 6. A descending inclined portion 6a is formed so as to gradually decrease the distance from the seating surface 3 as the distance from the one end portion increases. An inclination angle formed by the downward inclined portion 6a and the seating surface 3 is in a range of 2 ° to 15 °. Then, an inclination angle in the range of 3 ° to 20 ° is set so that the distance from the seating surface 3 gradually increases after passing through the lowest point 6b at which the distance from the seating surface 3 is minimized in the vicinity of the other end. An ascending inclined portion 6c is formed up to the other end portion. The length of the downward inclined portion 6a in the direction of the main cutting edge 6 is in the range of 50% to 90% of the entire length of the main cutting edge 6.

As can be understood from FIGS. 2 to 4, the flank 16 of the main cutting edge is formed on the flat main cutting edge first flank 16 a formed on the main cutting edge 6 side and on the seating surface 3 side. It is comprised from the flat main cutting edge 2nd flank 16b. The main cutting edge first flank 16a has an angle with respect to the normal of the seating surface 3, that is, the flank angle θ6a is in the range of 3 ° to 20 °, while the main cutting edge second flank 16b has a relief angle θ6b of 10 °. It is set as the range of degrees-30 degrees. And in the cross section cut | disconnected by the plane orthogonal to the main cutting edge 6, the said main cutting blade 1st flank 16a and the said main cutting blade 2nd flank 16b cross | intersect the obtuse angle. On the other hand, the clearance angle of the auxiliary cutting edge flank 15 extending from the auxiliary cutting edge 5 to the seating surface 3 is in the range of 15 ° to 35 °.

Further, in the side view of FIG. 2, the main cutting edge first flank 16 a connected to the main cutting edge 6 has a maximum width in the thickness direction of the tip 1 at one end portion intersecting the corresponding corner blade flank 17. It takes a value and gradually decreases as it moves away from the one end in the direction of the main cutting edge 6, and is formed to take a minimum value at the other end that intersects the adjacent corner. In relation to this, the main cutting edge first flank 16 a has a ridge line that appears when it is cut in a plane parallel to the seating surface 3, with respect to the ridge line of the corresponding seating surface 3. It is formed so as to be inclined at an angle in the range of 0 °. The corner blade first flank 17a formed on the corner blade 7 side of the corner blade flank 17 has a flank angle at one end intersecting the main cutting blade first flank 16a with the relief of the main blade flank 16a. The clearance angle at the other end that is equal to the angle θ6a and intersects the secondary cutting edge flank 15 is made equal to the clearance angle θ5 of the secondary cutting edge flank 15, and as it goes from the one end to the other end. The clearance angle is formed so as to gradually increase. On the other hand, the corner blade second flank 17b formed on the seating surface 3 side is interposed between the main cutting blade second flank 16b and the auxiliary cutting blade flank 15 and has a substantially constant clearance angle over the entire surface. It is said that.

As shown to (a) of FIG. 4, the substantially flat land surface 10 is formed in the inner area | region connected to the side ridge part of the rake face 2 along the said side ridge part. The land surface 10 is formed on at least the main cutting edge 6 and is preferably formed over the entire edge of the rake face. The width W1 of the land surface 10 is in the range of 0.05 mm to 0.30 mm, and the angle formed between the land surface 10 and the main cutting edge first flank 16a is in the range of 70 ° to 87 °. At the same time, the angle formed between the land surface 10 and the auxiliary cutting edge relief surface 15 is in the range of 60 ° to 80 °.

The inner region connected to the land surface 10 is from a flat surface inclined so as to gradually approach the seating surface 3 as it goes inward from the land surface 10 as illustrated in FIGS. 4 (a) and 4 (b). A rake face 2a to which a positive rake angle α is provided is formed. As shown in FIG. 5, the rake angle α is in the range of 10 ° to 30 °. When the rake face 2 is inclined with a curved surface, the inclination angle formed by the tangent at the intersection with the land surface 10 is the rake angle α, and the rake angle α is in the range of 10 ° to 30 °. . The rake face 2 a to which the positive rake angle α is given may be connected to a cutting edge formed on the side ridge portion without using the land face 10. On the inner side of the rake face 2a to which a positive rake angle is given, a flat surface 2b is formed which surrounds the mounting hole 4 at the center of the rake face 2 and is parallel to the seating face 3.

A honing 11 having substantially the same shape is formed on the entire side edge. The honing 11 is a cross-section cut along a plane orthogonal to the side ridge, and has an arc shape that smoothly contacts either the rake face 2 or the land face 10 and the flank faces 15, 16a, 17a (see FIG. 4). (See (a)) or a curved shape (see (b) of FIG. 4) employed in the present embodiment. In the honing 11 having a circular cross section, the radius of curvature r1 of the circular arc is in the range of 0.03 mm to 0.10 mm. In the honing 11 having a curved cross section, the curve smoothly connects an arc that smoothly connects to either the rake face 2 or the land surface 10 and an arc that smoothly connects to the flank faces 15, 16 a, and 17 a. The rake face side width W2 is in the range of 0.04 mm to 0.10 mm, the flank face side width W3 is in the range of 0.02 mm to 0.05 mm, and the flank face 15 , 16a, and 17a have a radius of curvature r2 of a circular arc smoothly connected to 0.015 mm to 0.040 mm.

In a plan view as viewed from the chip thickness direction, the auxiliary cutting edge 5 is formed linearly as in the present embodiment, or is formed in a curved shape slightly protruding outward. The sub cutting edge 5 has an angle of 45 ° with the main cutting edge first flank 16a of the corresponding main cutting edge 6. The auxiliary cutting edge flank 15 extending from the auxiliary cutting edge 5 toward the seating surface 3 is formed of a flat surface or a curved surface corresponding to the planar view shape of the auxiliary cutting edge 5.

In the face mill (rolling tool) 100 to which the chip 1 described above is mounted, the tool body 101 has a substantially cylindrical shape as shown in FIGS. 5 to 7, and the front end surface along the tool axis CL. An attachment hole 104 that penetrates through 102 and the rear end surface 103 is formed. In the tool body 101, the rear end face 103 is brought into close contact with the main spindle or arbor end face of a machine tool (not shown), and a fixing bolt (not shown) is fixed in a state where a shaft protruding from the end face is inserted into the mounting hole 104. It is attached to the main shaft of the machine tool by means and is rotatable around the axis.

Five tip seats 105 are cut out at substantially equal intervals in the circumferential direction on the outer periphery of the tip of the tool body 101. A floor plate 106 for seating the chip 1 is attached to the seating surface 105a of the chip seat 105 with a hexagon socket bolt (not shown). In the hexagon socket head cap screw, a female screw hole is formed along its axis to which a clamp screw 109 for fixing the chip 1 is screwed. Support wall surfaces 105b and 105c for positioning the chip are formed on the two wall surfaces rising from the seat surface 105a. Further, a tip pocket 107 is formed in a region in front of the tool rotation direction K connected to each tip seat 105, and cutting oil supplied from the outside of the tool body 101 circulates on the wall surface of the tip pocket 107. In addition, a fluid supply hole 108 for spraying near the cutting point is opened.

The tip 1 abuts the seating surface 3 against a seating surface 106a which is one end surface of the floor plate 106, and the two main cutting edge second flank 16b facing the tool rear end side are supported by the support wall surfaces 105b and 105c of the tip seat 105. The clamp screw 109, which is placed so as to be in contact with each other and inserted through the mounting hole 4 of the chip 1, is fixed to the tool body 101 by screwing into a female screw hole provided in a hexagon socket head cap screw for fixing the base plate. . The main cutting edge second flank 16b is inclined at a slight angle in the range of 0.3 ° to 2.0 ° with respect to the ridgeline of the seating surface 3 in a cross section cut along a plane parallel to the seating surface 3. Is formed. Correspondingly, the angle δa formed between the support wall surface 105b and the tool axis CL is an angle in the range of 43.0 ° to 44.7 ° when viewed from the direction orthogonal to the seat surface 105a. Therefore, the approach angle δ, which is an angle formed between the main cutting edge 6 of the chip 1 mounted on the chip seat 105 and the tool axis CL, is about 45 °, and the auxiliary cutting edge 5 and the tool axis The angle formed with the heart CL is approximately 90 °.

In FIG. 6, the tip 1 is mounted on the tool body 101 with a positive axial rake angle AR1. The axial rake angle AR1 is in the range of 10 ° to 30 °. Further, the axial rake angle AR2 in the downward inclined portion 6a of the main cutting edge 6 of the tip 1 is such that the inclination of the downward inclined portion 6a (in the range of 2 ° to 15 ° with respect to the seating surface 3) is the axial rake angle AR1. Joining makes me even more positive.

The operation and effect of the chip 1 and the face mill 100 of the present embodiment having the above-described configuration will be described below. First, since the main cutting edge 6 of the tip 1 has the downward inclined portion 6a inclined so that the distance from the seating surface 3 gradually decreases as the distance from the corner blade 7 increases, The axial rake angle AR2 is more positive than the axial rake angle AR1 in the tool body 101 of the face mill 100. As a result, the back force of the cutting force is greatly reduced, and cutting with a low-rigidity machine tool or cutting with a so-called multi-blade turning tool with a relatively large number of inserts is high. Efficient and highly accurate machining is possible. In order to enhance the above effect, the length of the downward inclined portion 6a in the direction of the main cutting edge 6 is set to be in a range of 50% to 90% of the entire length of the main cutting edge 6. This is because when the length of the descending inclined portion 6a is less than 50% of the entire length of the main cutting edge 6, the effect of reducing the cutting resistance cannot be obtained, and when exceeding 90%, the descending inclined portion 6a is connected to the descending inclined portion 6a. This is because the slope of the ascending inclined portion 6b to be provided becomes steep and the chip dischargeability may be deteriorated. Furthermore, if the angle formed between the downward inclined portion 6a and the seating surface 3 in a side view of the tip 1 is less than 2 °, there is a possibility that the effect of reducing cutting resistance, particularly back force, may not be obtained. If it exceeds, the length of the main cutting edge 6 in contact with the work material becomes large, and the cutting resistance, especially the main component force and the feed component force may be increased, so the range is 2 ° to 15 °. Yes.

Furthermore, according to the tip 1 of the present embodiment, the main cutting edge first flank 16a has a clearance angle smaller than that of the main cutting edge second flank 16b. Prevents sharpening and prevents chipping and chipping. Further, in the direction of the main cutting edge 6, the width of the main cutting edge first flank 16 a gradually increases in the tip thickness direction as it approaches the one end that intersects the corner blade flank 17 a, and is the largest at the one end. Therefore, in the vicinity of the intersection between the main cutting edge 6 and the corner edge 7, the strength of the cutting edge becomes extremely high, so that the chipping resistance is greatly improved and the life of the chip 1 is extended. Furthermore, the main cutting edge first flank 16a gradually narrows away from the one end and is formed to have a minimum value at the other end that intersects the adjacent corner. Since the proper clearance is ensured between the main cutting edge first flank 16a and the main cutting edge second flank 16b and the work material from the tool to the rear end of the tool, cutting resistance and flank wear The increase of is suppressed. Furthermore, the corner blade first flank 17a has a flank angle at the intersection with the main cutting blade first flank 16a equal to the flank angle θ6a of the main cutting blade first flank 16a. Since the clearance angle gradually increases toward the intersecting portion, the edge strength in the vicinity of the intersecting portion with the main cutting edge 6 also increases in the corner blade 7, so that the chipping resistance is greatly improved and the length of the tip 1 is increased. Longer life is expected.

Furthermore, the main cutting edge second flank 16b that is in contact with and supported by the support wall surfaces 105b and 105c of the chip seat 105 is separated from the main cutting edge 6 by the main cutting edge first flank 16a formed in the upper region thereof. Because they are separated, damage to the main cutting edge is less likely to occur. Therefore, when using all four corners of the chip 1, the chip 1 is accurately positioned and firmly fixed to the chip seat 105.

The main cutting edge first flank 16 a has a slight ridge line that appears when it is cut in a plane parallel to the seating surface 3 with respect to the corresponding ridge line of the seating surface 3 in a range of 0.3 ° to 2.0 °. As a result, the width of the main cutting edge first flank 16a in the tip thickness direction gradually narrows as the distance from the auxiliary cutting edge 5 increases.

In order to improve the fracture resistance of the main cutting edge 6 and the intersection of the main cutting edge 6 and the corner blade 7, the clearance angle θ6a of the main cutting edge first flank 16a is in the range of 3 ° to 20 °. . If the angle is less than 3 °, the clearance with the work material cannot be ensured and the cutting resistance may increase. If the angle exceeds 20 °, the strength of the main cutting edge 7 and the strength of the main cutting edge 6 and the corner blade 7 is increased. This is because the effect of increasing the value cannot be obtained.

When the clearance angle θ6b is 10 ° or more, the main cutting edge second flank 16b ensures clearance with the work material, and when it is 30 ° or less, the fracture resistance of the main cutting edge 6 is ensured. .

At least a rake angle α in the range of 10 ° to 30 ° is given to the rake face 2 connected to at least the main cutting edge 6, and this rake angle α is a synergistic effect with the downward inclined portion 6 a provided on the main cutting edge 6. This further reduces cutting resistance. If the rake angle α is less than 10 °, the effect of reducing the cutting resistance cannot be obtained, and if it exceeds 30 °, the chipping resistance of the cutting edge may be reduced.

The flat land surface 10 formed along the side ridge portion in the inner region continuous to the side ridge portion of the rake face 2 prevents a reduction in strength of the edge of the side ridge portion, and escapes connected to the side ridge portion. The effect of preventing chipping and chipping is further enhanced by cooperation with the surface. If the width W1 of the land surface 10 is less than 0.05 mm, the effect of increasing the strength of the cutting edge is difficult to obtain, and if it exceeds 0.30 mm, the sharpness may be reduced and the cutting resistance may be increased. If the angle between the land surface 10 and the flank is too small, it is difficult to obtain the effect of increasing the strength of the cutting edge. If it is too large, the cutting resistance may increase. The angle formed by 16a is in the range of 70 ° to 87 °, and the angle formed by the land surface 10 and the auxiliary cutting edge relief surface 15 is in the range of 60 ° to 80 °.

The cutting edge strength is also increased by the honing 11 provided over the entire edge of the rake face 2. In the orthogonal cross-section of the side ridge portion, the cross-sectional shape of the honing 11 is a curved line smoothly connected to either the rake face 2 or the land face 10 and the flank face, or a single arc shape. In the case of curved honing, the width W2 on the rake face side is wider than the width W3 on the flank face side, the width W2 on the rake face side is in the range of 0.04 mm to 0.10 mm, and the width on the flank face side The reason why W3 is in the range of 0.02 mm to 0.05 mm is that the strength of the cutting edge may be insufficient if either the rake face width W2 or the flank face width W3 falls below the lower limit. This is because if either one exceeds the upper limit, the cutting resistance may increase or the surface roughness of the machined surface may deteriorate. In the arcuate cross-section honing, the radius of curvature of the arc is in the range of 0.02 mm to 0.08 mm because the cutting edge strength may be insufficient if the lower limit value is exceeded, and the cutting resistance increases if the upper limit value is exceeded. This is because the surface roughness of the machined surface may be deteriorated.

The shape of the auxiliary cutting edge 5 in a plan view as viewed from the thickness direction of the chip 1 is a linear shape or an arc shape protruding outward, and the auxiliary cutting edge 5 is formed on the tool axis CL in the face mill 100 of the present embodiment. On the other hand, the flatness of the processed surface is good because it is substantially perpendicular. In particular, it is preferable that the shape of the sub-cutting blade 5 in a plan view is an arc shape. In this case, the surface of the processed surface has a corrugated shape connecting the arcs, and the appearance quality is improved.

The shape of the corner blade 7 in plan view is linear as shown in FIG. 8 (a), and the angle β formed with the auxiliary cutting edge 5 is in the range of 160 ° to 178 °. It is possible to prevent burrs of work materials that are easily connected to each other and to prevent chipping of work materials that are likely to break up chips such as cast iron. This is because when the corner blade 7 comes off from the work material, the region to be cut out has a triangular shape with a wide base and a low height when viewed from the tool rotation direction, and the reaction force of the cutting resistance received from the corner blade 7 is This is because it acts toward the bottom side of the triangular shape, and flashing due to plastic deformation near the bottom side of the triangular shape and crack chipping due to dropping off are suppressed. Further, since the cut thickness of the corner blade 7 is very small, the amount remaining as a flash or a chip is very small. In addition, since the cutting thickness is very small, chipping or chipping of the corner blade 7 is unlikely to occur, and the sharpness is maintained, thereby suppressing flash or crack chipping. In addition, in order to prevent the chipping and the defect | deletion in the bending part which the corner blade 7 and the main cutting edge 6 cross | intersect, the said bending part may be made into circular arc shape as shown in FIG.8 (b). If the angle β formed by the corner blade 7 and the sub-cutting blade 5 is less than 160 °, it is difficult to obtain the effect of suppressing flashing and chipping, and if it exceeds 178 °, it becomes difficult to form the corner blade 7. The length of the corner blade 7 is preferably in the range of 0.3 mm to 1.0 mm because the effect of suppressing burrs and chipping is high and the cutting resistance is not increased.

The embodiments of the present invention have been described with reference to the drawings. However, these are merely embodiments, and the approach angle δ is not limited to 45 °, but is larger than 0 °, for example, the approach angle δ is 15 °. Applicable to face milling such as 30 °. Needless to say, other embodiments can be implemented in various modifications and improvements based on the knowledge of those skilled in the art.

It is a top view seen from the thickness direction of the chip. It is a side view of the chip | tip shown in FIG. It is a rear view of the chip | tip shown in FIG. It is the S1-S1 line cutting part end surface enlarged view in FIG. It is a front view of the front milling machine seen from the tool front end side. It is the side view seen from the direction orthogonal to the axial center of the face mill shown in FIG. It is a partial cross section side view of the front milling machine shown in FIG. It is the E section enlarged view in FIG. It is a perspective view of the chip | tip used for the conventional rolling tool.

Explanation of symbols

1 Tip 2 Rake face 2a Rake face with rake angle 3 Seating face 5 Sub cutting edge 6 Main cutting edge 6a Down sloping part 6b Up sloping part 7 Corner blade 10 Land surface 11 Honing 15 Sub cutting edge flank 16a Main cutting Blade first flank 16b Main cutting blade second flank 17a Corner blade first flank 17b Corner blade second flank 100 Front milling (rolling tool)
101 Tool body 105 Insert seat AR1 Axial rake angle AR2 at tool body Axial rake angle α at rake angle of main cutting edge α Rake angle δ Approach angle

Claims (17)

It has a substantially square plate shape, and the upper surface facing the flat seating surface is a rake face, and the side edge of this rake face has a main cutting edge and a minor cutting edge sandwiched between the corner blades formed at each corner. A blade is formed, and a corner blade flank surface, a main cutting blade flank surface, and a sub cutting blade flank surface are formed on side surfaces extending from the corner blade, the main cutting blade, and the sub cutting blade toward the seating surface, respectively. In the chip,
The main cutting edge has a downward inclined portion that is inclined so that the distance from the seating surface gradually decreases as the distance from the corner blade increases.
The main cutting edge flank consists of a main cutting edge first flank formed on the main cutting edge side and a main cutting edge second flank formed on the seating surface side,
The clearance angle of the first flank of the main cutting edge is smaller than the clearance angle of the second flank of the main cutting edge,
In the side view of the tip, the first flank of the main cutting edge has the largest width in the tip thickness direction at one end intersecting with the corner blade, and the other end intersecting with another adjacent corner blade. A chip characterized by being formed so as to gradually become smaller as it approaches the position and to become smallest at the other end portion. 2. The chip according to claim 1, wherein when the chip is viewed from the side, an angle formed by the descending inclined portion and the seating surface is in a range of 2 ° to 15 °. A ridge line that appears when the main cutting edge first flank is cut along a plane parallel to the seating surface is inclined in a range of 0.3 ° to 2.0 ° with respect to a corresponding ridge line of the seating surface. The chip according to claim 1, wherein the chip is a chip. The clearance angle of the first flank of the main cutting edge is in the range of 3 ° to 20 °, and the clearance angle of the second flank of the main cutting edge is in the range of 10 ° to 30 °. The chip according to any one of claims 1 to 3. The rake face continuous to at least the main cutting edge is provided with a positive rake angle, and the rake angle is in the range of 10 ° to 30 °. The chip described. 6. The chip according to claim 1, wherein a flat land surface extending inward from the side ridge portion is formed along the side ridge portion of the rake face. The chip according to claim 6, wherein the land surface has a width of 0.05 mm to 0.30 mm. The angle formed by the land surface and the first cutting edge flank is in the range of 70 ° to 87 °, and the angle formed by the land surface and the auxiliary cutting blade flank is in the range of 60 ° to 80 °. The chip according to claim 6, wherein the chip is provided. The chip according to any one of claims 1 to 8, wherein a honing having substantially the same shape is formed in the side ridge portion of the rake face over the entire side ridge portion. 10. The honing has a cross section orthogonal to the side ridge portion, and has an arc shape or a curved shape that smoothly contacts either the rake face or the land face and the flank face. Chips. The honing cross-sectional shape is a curve that smoothly connects an arc that touches the rake face and an arc that touches the flank face, and the rake face side is wider than the flank face side, and the rake face side 11. The chip according to claim 9, wherein the width of the chip is in the range of 0.04 mm to 0.10 mm, and the width on the flank side is 0.02 mm to 0.05 mm. The honing cross-sectional shape is a single arc shape smoothly connected to both the rake face and the flank face, and the radius of curvature of the arc is in the range of 0.02 mm to 0.08 mm. The chip according to claim 9 or 10, characterized in that The tip according to any one of claims 1 to 12, wherein the auxiliary cutting edge is linear or arcuate when viewed from a direction perpendicular to the rake face. The tip according to any one of claims 1 to 13, wherein an angle formed by the sub cutting edge and the main cutting edge is approximately 45 °. One or a plurality of tip seats are formed at substantially equal intervals in the circumferential direction on the outer periphery of the tip of the substantially cylindrical tool body that is rotated around the axis, and the tip is mounted on the tip seat. In the cutting tool,
The tip is the tip according to any one of claims 1 to 14, and the axial rake angle of the main cutting edge located on the tool outer peripheral side of the tip is positive. The cutting tool according to claim 15, wherein in the tip mounted on the tool body, the auxiliary cutting edge located on the tool tip side is substantially perpendicular to the axis of the tool body. The tip seat includes a seat surface and at least one support wall surface that rises from the seat surface,
The tip has a main cutting edge second flank formed on a side surface of the main cutting edge, the seating surface of which is in contact with the seating surface and opposed to the main cutting edge that is at least provided for cutting and located on the outer peripheral side of the tool. In contact with the support wall surface, mounted on the tool body,
Furthermore, an angle formed by the support wall surface and the axis of the tool body is in a range of 43.0 ° to 44.7 ° when viewed from a direction perpendicular to the seating surface of the chip seat. Item 15. A turning tool according to Item 15 or 16.

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