JP2006062070A - Throw-away insert and cutting tool using it - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a throw-away insert and a cutting tool capable of making a grooving work of small inside diameter and assuring excellent economy and an excellent processing stability. <P>SOLUTION: The throw-away insert 1 is equipped with a base 4 consisting of a flat plate having approximately a quadrangular shape and a first projection part 6a and a second projection part 6b formed on the base 4 in a single piece therewith and overhung from the two ends of two adjoining side faces 5 of the base 4 approximately in the perpendicular direction to each other, wherein the first main side face 11a adjacent to the first side flank 14a as the side face of the first projection part 6a is inclined in such a way as given a relief angle α from the oversurface 2 toward the undersurface 3 while the second main side face 11b adjacent to the second side flank 14b as the side face of the second projection part 6b is inclined in such a way as given a relief angle α from the undersurface 3 toward the oversurface 2. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a throw-away insert and a cutting tool used for grooving in turning, in particular, grooving with a small inner diameter.

  Various shapes are known and put into practical use as a throw-away insert used for grooving. For example, in Patent Document 1, a clamp hole penetrating the upper and lower surfaces is provided in the center of the insert body in an insert body having a substantially rectangular flat plate shape having a plurality of side surfaces between the upper and lower surfaces. A throwaway insert using two corners having a pair of long cutting blades protruding in the horizontal direction and rotationally symmetric is described (see FIG. 6A). The throw-away insert described in Patent Document 1 is configured to enable deep grooving while ensuring cutting edge strength, so the entire length T of the insert is long, and is particularly used for grooving with a small inner diameter. In some cases, the opposite corner interferes. As a countermeasure against the interference at the opposite corner that occurs during grooving with such a small inner diameter, it is conceivable to reduce the length t of the long cutting edge of the insert, but in that case the grooving depth is reduced. It is too practical. Further, Patent Document 2 describes a throw-away insert specialized for grooving with a small diameter and a single corner specification (see FIG. 6B). However, such a one-corner configuration is not preferable because the cost per corner of the cutting edge increases.

Therefore, in Patent Document 3, as a configuration capable of grooving with a small inner diameter with a two-corner specification, two projecting portions having cutting edges at the tips from the side surfaces of a substantially rectangular flat plate-like insert body are arranged in a substantially perpendicular direction. It has been proposed that each projecting portion is configured to be rotationally symmetric with respect to a bisector of an angle formed by each other (see FIG. 7A). According to the shape described in Patent Document 3, two corners can be used, which is economical, and in addition, grooving with a small inner diameter can be performed without interference of the opposite corners.
JP-A-10-156604 Japanese translation of PCT publication No. 2002-512564 US Pat. No. 4,607,888

  However, in the configuration described in Patent Document 3, the side surface (side surface restrained by the holder) of the insert is formed at right angles to the lower surface (upper surface) as shown in FIG. As shown in FIG. 7 (c), the cutting load (cutting force) F generated during the grooving process is received by the clamp screw that fixes the insert rather than the constraining side surface. In addition, since this insert is used for grooving with a small inner diameter, the diameter of the clamp screw inevitably becomes smaller as the size of the insert and the tip diameter of the holder become smaller. Therefore, the above-described cutting load F is concentrated on the thin clamp screw, and as a result, the clamp screw is likely to break.

  An object of the present invention is to solve the above-mentioned problems, and to provide a throw-away insert and a cutting tool that are capable of grooving with a small inner diameter and are excellent in economy and processing stability.

  A throw-away insert according to the present invention for solving the above-mentioned problems is formed from a polygonal flat plate-like substrate having an upper surface, a lower surface and a plurality of side surfaces, and a part of the side surface of the substrate formed integrally with the substrate. Two projecting portions that are extended, and among these projecting portions, the first projecting portion is provided on the upper surface side adjacent to the first front flank and the first front flank. A first front cutting edge formed of an intersecting ridge line with the first rake face is formed, and the second projecting portion is provided on the lower surface side adjacent to the second front flank face and the second front flank face. A second front cutting edge having a crossing ridge line with the second rake face formed is formed, and in a throwaway insert in which a clamp hole penetrating from the upper surface to the lower surface is formed in a substantially central portion, The first main side surface that is adjacent to the first side clearance surface is the lower surface side from the upper surface side. The second main side surface adjacent to the second lateral clearance surface, which is the side surface of the second protrusion, is inclined toward the upper surface side from the lower surface side. It is inclined to be attached.

  According to such a configuration, the first main side surface and the second main side surface are inclined so that clearance angles are provided, so that when the first front cutting edge is used, the second main side surface is inclined. Since the side surface is inclined and arranged in an inversely tapered manner, the cutting load during grooving can be received by the second main side surface, so the load on the clamp screw is reduced. On the other hand, when using the second front cutting edge, it is possible to receive a cutting load during processing on the first main side surface, so that the load applied to the clamp screw is reduced. Thereby, breakage of the clamp screw can be prevented and stable grooving can be performed over a long period of time.

  In the throw-away insert of the present invention, for example, the base has a substantially rectangular flat plate shape having an upper surface, a lower surface, and four side surfaces, and the two projecting portions are formed from the end portions of two adjacent side surfaces. The form currently extended in the direction in which a corner | angular becomes a substantially right angle can be illustrated.

  Further, the clearance angle of the first main side surface and the second main side surface being 2 ° to 15 ° can effectively receive the cutting load during grooving at the main side surface and is applied to the clamp screw. It is desirable in that the load can be further reduced.

  Furthermore, when at least a part of the first main side surface or the second main side surface abuts against the holder side restraint surface, the throwaway insert and the holder are reliably restrained by surface contact, and the mounting stability is improved. This is desirable.

  Further, in a state where the throwaway insert is mounted on a substantially rod-shaped holder, a corner portion on the first side flank side of the first front cutting edge when the first front cutting edge is used is The corner portion on the second lateral flank side of the second front cutting edge is located on the most distal side in the axial direction of the holder. It is preferably designed to be located. Thereby, the first main side surface and the second main side surface can be grooved at the inner end without interfering with the inner end of the work piece during cutting.

  Since the angle formed by the extending direction of the first protruding portion and the extending direction of the second protruding portion in the present invention is 60 ° to 90 °, the thickness on the restraining surface side of the holder is not reduced. This is desirable in that the rigidity of the holder can be maintained.

  In the present invention, an angle formed between the first main side surface and a sub-side surface adjacent to the first main side surface via the first protruding portion, and the second main side surface and the second protruding portion are interposed. In view of obtaining a stable restraining force, the angle between the second side surface and the sub-side surface adjacent to the second side surface is preferably 45 ° to 90 °.

  Furthermore, in the present invention, the chip breaker is provided on the first rake face and the second rake face, so that the chips can be finely divided or the discharge direction can be controlled. It is desirable in that it can prevent entanglement.

  The cutting tool of this invention is equipped with said throw away insert, It is characterized by the above-mentioned.

  According to the throw-away insert of the present invention, the first main side surface adjacent to the first lateral clearance surface that is the side surface of the first protrusion is inclined so that the clearance angle is given from the upper surface side to the lower surface side. And the second main side surface adjacent to the second lateral clearance surface, which is the side surface of the second protrusion, is inclined so as to have a clearance angle from the lower surface side toward the upper surface side. When the cutting edge is used, the second main side inclined in a reverse taper shape receives the cutting load during grooving, and conversely, when the second front cutting edge is used, the first main side is cut. Since the load applied to the clamp screw can be reduced by receiving the load, the breakage of the clamp screw can be prevented as a result, and stable grooving can be performed over a long period of time.

  Hereinafter, a throw-away insert according to an embodiment of the present invention will be described in detail with reference to the drawings. FIG. 1 (a) is a plan view showing a throw-away insert (hereinafter abbreviated as an insert) 1 according to this embodiment, and FIG. 1 (b) is a side view of the insert 1 of FIG. 1 (a) viewed from the x direction. FIG. 1C is a side view of the insert 1 of FIG. 1A viewed from the y direction (an arrow view in the y direction). FIG. 2 is a conceptual diagram showing a state in which a cutting load is applied in a state where the insert 1 of FIG.

  As shown in FIG. 1, the insert 1 according to the present embodiment includes a substantially rectangular flat plate-like base body 4 having an upper surface 2, a lower surface 3 and four side surfaces, and is formed integrally with the base body 4 and adjacent to the base body 4. Two projecting parts (first projecting part 6a and second projecting part 6b) projecting (extending) from each end of the two side surfaces 5a and 5b in a substantially perpendicular direction.

  The 1st protrusion part 6a and the 2nd protrusion part 6b are extended in the direction where the angle | corner which a mutual makes becomes a substantially right angle. Here, the extending direction of the first protruding portion 6a refers to the direction of the intersecting ridge line between the upper surface 2, the first main side surface 11a, and the first lateral relief surface 14a, and the extending direction of the second protruding portion 6b is The direction of the intersecting ridge line between the upper surface 2 and the second main side surface 11b and the second side flank 14b. Therefore, the angle formed by the extending direction of the first projecting portion 6a and the extending direction of the second projecting portion 6b is the intersection ridgeline between the upper surface 2 and the first main side surface 11a, and the upper surface 2 and the second main side surface 11b. It can be represented by an angle β formed between the intersecting ridge lines.

  The first projecting portion 6a has a first front consisting of a cross ridge line between a first front flank 7a on the tip side and a first rake face 8a provided on the upper surface 2 side adjacent to the first front flank 7a. A cutting edge 9a is formed. The second projecting portion 6b includes a second front flank formed by a crossed ridge line between a second front flank 7b on the tip side and a second rake face 8b provided on the lower surface 3 side adjacent to the second front flank 7b. A cutting edge 9b is formed. A clamp hole 10 penetrating from the upper surface 2 to the lower surface 3 is formed at a substantially central portion of the base 4.

  The insert 1 is designed to be rotationally symmetric about a line parallel to the bisector A of the angle β formed by the extending direction of the first protruding portion 6a and the extending direction of the second protruding portion 6b. Has been. As a result, the insert becomes a two-corner specification, which is economical, and grooving can be performed on a work material having a small inner diameter.

  Here, in the insert 1 in the present embodiment, the first main side surface 11a adjacent to the first side flank 14a which is the side surface of the first protrusion 6a has a flank angle α from the upper surface 2 side toward the lower surface 3 side. The second main side surface 11b that is inclined so as to be attached and is adjacent to the second lateral clearance surface 14b that is the side surface of the second protrusion 6b has a clearance angle α from the lower surface 3 side toward the upper surface 2 side. The main feature is that it is inclined to be attached. Here, the clearance angle α in the present embodiment is an angle formed between the first main side surface 11 a and the surface V perpendicular to the lower surface 3 and an angle formed between the second main side surface 11 b and the surface V perpendicular to the lower surface 3. That means.

  With such a configuration, as shown in FIG. 2, when the first front cutting edge 9 a is used, the second main side surface 11 b is inclined in a reverse taper shape and is restrained by the holder 13. That is, since the angle formed by the second main side surface 11b and the lower surface 3 is an acute angle, the cutting load F during grooving can be received mainly by the second main side surface 11b, so the load on the clamp screw 12 is reduced. Is done. On the other hand, when the second front cutting edge 9b is used, the first main side surface 11a is inclined in a reverse taper shape and restrained by the holder 13, so that the cutting load F during grooving can be received by the first main side surface 11a. As a result, breakage of the clamp screw 12 can be prevented as a result, and stable grooving can be performed over a long period of time.

  Further, the clearance angle α on the first main side surface 11a and the second main side surface 11b is 2 ° to 15 °, so that the main side surface portion can effectively receive the cutting load during grooving, and the clamp This is desirable in that the load applied to the screw 12 can be further reduced.

  Furthermore, when at least a part of the first main side surface 11a or the second main side surface 11b is brought into contact with the restraining surface on the holder 13 side, the insert 1 and the holder 13 can be reliably constrained by surface contact. This is desirable in terms of improving the mounting stability. In addition, when the 1st main side surface 11a or the 2nd main side surface 11b is made to contact | abut with the holder 13 side restraint surface, the ratio with which the 1st main side surface 11a or the 2nd main side surface 11b and the holder 13 contact is the 1st main side. It is desirable that it is 20 area% or more, especially 30 area% or more with respect to the entire surface of the side surface 11a or the second main side surface 11b.

  Further, as shown in FIG. 1 (a), the angle γ formed between the second main side surface 11b and the sub side surface 5b adjacent to the first main side surface 11b via the first protrusion 6b is 45 ° to 90 °. Preferably there is. Similarly, the angle formed between the first main side surface 11a and the sub-side surface 5a adjacent to the first main side surface 11a via the first protrusion 6a is preferably 45 ° to 90 °. As a result, the opening angle of the constraining surface, that is, the angle formed by the first main side surface 11a and the sub side surface 5a and the angle formed by the second main side surface 11b and the sub side surface 5b become a right angle or an acute angle. And can be restrained.

  Furthermore, the 1st main side surface 11a (2nd main side surface 11b) is with respect to the 1st side flank 14a (2nd side flank 14b) of the adjacent 1st protrusion part 6a (2nd protrusion part 6b). Since the first main side surface 11a and the second main side surface 11b do not interfere with the back end surface in the inner diameter portion of the work material, they are grooved on the back end surface. Is possible. By the way, if the main side and the side clearance surface are on the same plane, the machining process at the time of manufacturing the insert requires only one process, so there is no cost error and no dimensional error will occur. .

  Further, the width L of the sub-side surfaces 5a and 5b is 1 mm or more, so that a contact area with the holder 13 can be ensured and an appropriate restraining force can be obtained. In addition, the upper limit of this width L is not specifically limited, What is necessary is just to set suitably according to the magnitude | size of the insert 1, the magnitude | size of a protrusion part, etc.

  In the insert 1, the first rake face 8a (second rake face 8b) is formed in a groove shape that is parallel to the first front cutting edge 9a (second front cutting edge 9b) and forms a gently curved surface. This plays the role of a chip breaker. This configuration makes it easy to control the chip discharge direction, and as a result, biting of the chips and entanglement of the chips with the holder 13 can be prevented.

  FIG. 3 is a plan view showing a state in which an insert 1a according to another embodiment of the present invention is mounted on a substantially rod-shaped holder 13. As shown in FIG. As shown in FIG. 3, the angle β formed between the projecting directions of the two projecting portions (the first projecting portion 6 a and the second projecting portion 6 b) in the insert 1 a is 60 ° to 90 °, preferably 65 ° to 75 °. Since the thickness w can be increased without reducing the thickness w on the restraining surface 13a side of the holder 13, the rigidity of the holder 13 can be maintained, and the holder 13 can be damaged or being cut. Chatter vibration can be suppressed. In addition, when the angle β formed by the overhanging directions is within the above range, in addition to ensuring a sufficient restraining area of the side surface 5b, the area of the upper surface 2 and the lower surface 3 of the base body 4 is ensured and sufficient clamping holes are provided. Since it can form in a magnitude | size, the intensity | strength of the clamp screw 12 is securable. Further, the second projecting portion 6 b does not project toward the outer side (back) 13 b side of the holder 13.

  Further, in the state where the insert 1 a is mounted on the holder 13, the corner portion 91 a on the first side flank 14 a side of the first front cutting edge 9 a when the first front cutting edge 9 a is used is the axial direction D of the holder 13. It is preferable that it is located in the forefront side. Similarly, when the second front cutting edge 9b is used, the corner portion 91b on the second side flank side 14b of the second front cutting edge 9b is designed to be positioned on the most distal side in the axial direction D of the holder 13. It is preferable. Accordingly, the first main side surface 11a and the second main side surface 11b can be grooved on the back end surface without interfering with the back end surface in the inner diameter portion of the work material during cutting.

  FIG. 4 is a plan view showing an insert 1b according to still another embodiment of the present invention. As shown in FIG. 4, if the protruding chip breaker 15 is provided on the first rake face 8a, the chip discharge direction can be controlled and the chips can be finely divided. In particular, when grooving with a small inner diameter, the space inside the inner diameter of the work material is narrow, and if the chips extend to the back side of the machining hole, the chips may bite during cutting and cause chipping of the insert. Cutting becomes unstable. Therefore, by providing the protruding chip breaker 15, the chips can be finely divided, and the discharge direction of the chips can be controlled so as to be surely discharged to the processing hole opening side. It becomes possible. A similar chip breaker is also provided on the second rake face 8b.

  FIG. 5 (a) is a plan view showing an insert 1c according to still another embodiment of the present invention, and FIG. 5 (b) is a side view of the insert 1c of FIG. 5 (a) seen from the x direction. FIG. 5 (c) is a side view of the insert 1c of FIG. 5 (a) viewed from the y direction. As shown in FIGS. 5 (a) to 5 (c), the insert 1c includes a base 4 on a substantially triangular flat plate having an upper surface 2, a lower surface 3, and three side surfaces 11a, 11b, 5c, and an integral with the base 4. And two projecting portions 6 a and 6 b extending from both ends of the sub-side surface 5 c of the base body 4. Other parts are denoted by the same reference numerals as those in FIGS. 1A to 1C, and description thereof is omitted.

  As mentioned above, although embodiment of this invention was illustrated, this invention is not limited to said each embodiment, It cannot be overemphasized that it can be set as arbitrary forms, unless it deviates from the objective of invention.

(a) is a plan view showing a throw-away insert according to an embodiment of the present invention, (b) is a side view of the insert of (a) seen from the x direction, (c) is of (a) It is the side view which looked at the insert from the y direction. It is a conceptual diagram which shows a mode that the cutting load is applied in the state which mounted | wore the holder of the insert of FIG. It is a top view which shows the state which mounted | wore the holder with the insert concerning other embodiment of this invention. It is a top view which shows the insert concerning other embodiment of this invention. (a) is a plan view showing an insert according to yet another embodiment of the present invention, (b) is a side view of the insert of (a) seen from the x direction, (c) is (a) It is the side view which looked at insert of y) from the y direction. (a) And (b) is a top view which shows the conventional insert for grooving. (A) is a plan view showing a conventional grooving insert, (b) is a side view of the insert of (a) as seen from the z direction, and (c) is the insert of (a) as a holder. It is a conceptual diagram which shows a mode that the cutting load in the mounted state is applied.

Explanation of symbols

1: throwaway insert 2: upper surface 3: lower surface 4: base 5a: first sub-side surface 5b: second sub-side surface 5c: sub-side surface 6a: first projecting portion 6b: second projecting portion 7a: first front relief surface 7b : Second front flank 8a: first rake face 8b: second rake face 9a: first front cutting edge 9b: second front cutting edge 10: clamp hole 11a: first main side face 11b: second main side face 12: Clamp screw 13: Holder 14a: First lateral flank 14b: Second lateral flank 15: Protruding chip breaker F: Cutting load (cutting force)
t: Length of the long cutting edge portion of the insert T: Total length of the insert L: Width of the sub-side surface α: Relief angle β: Overhang angle γ between the protruding portions γ: Angle formed between the main side surface and the sub-side surface w: Wall thickness of the holder

Claims (9)

A polygonal flat base having an upper surface, a lower surface and a plurality of side surfaces, and two protrusions integrally formed with the base and extending from a part of the side surfaces of the base. The first projecting portion includes a first front cut formed by an intersection ridge line between a first front flank on the tip side and a first rake face provided on the upper surface side adjacent to the first front flank. A blade is formed, and the second protrusion includes a second front flank formed by a crossed ridge line between a second front flank on the tip side and a second rake face provided on the lower surface side adjacent to the second front flank. In the throw-away insert in which a cutting blade is formed and a clamp hole penetrating from the upper surface to the lower surface is formed in the substantially central portion,
The first main side surface adjacent to the first lateral clearance surface, which is the side surface of the first protrusion, is inclined so as to have a clearance angle from the upper surface side toward the lower surface side, and the second protrusion portion A throwaway insert, wherein a second main side surface adjacent to a second side flank which is a side surface of the first side flank is inclined so as to have a clearance angle from the lower surface side toward the upper surface side.   The base has a substantially rectangular flat plate shape having an upper surface, a lower surface, and four side surfaces, and the two projecting portions extend from the end portions of the two adjacent side surfaces in a direction in which the angle formed between them is approximately a right angle. The throw-away insert according to claim 1, wherein the throw-away insert is provided.   The throwaway insert according to claim 1 or 2, wherein a clearance angle between the first main side surface and the second main side surface is 2 ° to 15 °.   The throwaway insert according to any one of claims 1 to 3, wherein at least a part of the first main side surface and the second main side surface is in contact with the holder-side restraining surface.   In a state where the throwaway insert is mounted on a substantially rod-shaped holder, the corner portion on the first side flank side of the first front cutting edge when the first front cutting edge is used is the axial direction of the holder When the second front cutting edge is used, a corner portion on the second side clearance surface side of the second front cutting edge is located on the most distal side in the axial direction of the holder. The throw away insert according to any one of claims 1 to 4. The throw-away insert according to any one of claims 1 to 5, wherein an angle formed by an extending direction of the first protruding portion and an extending direction of the second protruding portion is 60 ° to 90 °. An angle formed between the first main side surface and a sub-side surface adjacent to the first main side surface via the first projecting portion, and the second main side surface and the second main side surface via the second projecting portion. The throwaway insert according to any one of claims 1 to 6, wherein an angle formed between adjacent sub-side surfaces is 45 ° to 90 °. The throw-away insert according to any one of claims 1 to 7, further comprising a chip breaker on the first rake face and the second rake face. The cutting tool provided with the throw away insert in any one of Claims 1-8.

Images