JP6449581B2 - Cutting insert and throwaway cutter - Google Patents

Description

  The present invention relates to a cutting insert attached to a throw-away cutter, and a throw-away cutter.

  2. Description of the Related Art A throw-away cutter such as a face mill or an end mill (hereinafter simply abbreviated as a cutter) equipped with a cutting insert (hereinafter simply abbreviated as an insert) is known (for example, Patent Document 1). ). Such a cutter is required to be cut while being rotated at a high speed in order to increase the processing efficiency. The insert attached to the cutter is provided with a main cutting edge that first cuts the work material and a sub cutting edge that cuts the cut surface again after cutting with the main cutting edge.

JP 2011-110635 A

  However, in the cutting insert of Patent Document 1, the rake face has a substantially square shape and four cutting edges. However, the area of the rake face is large, and in order to ensure a predetermined cutting edge length, the insert must be enlarged. I must. For this reason, the weight of the insert is increased, and the weight of the insert is required to rotate the cutter at high speed. Further, in order to rotate the cutter at a high speed, it is necessary to increase the binding force of the insert to the cutter.

  Accordingly, an object of the present invention is to provide a cutting insert that is lightweight and has a high restraining force when mounted on a cutter, and a throw-away cutter mounted with the cutting insert.

The cutting insert of the present invention is
A rake face, a seating face facing the rake face, and a side face located between the rake face and the seating face, the rake face comprising three short ridge lines and the respective short ridge lines. Three long ridge lines located between the long ridge lines, w1, the distance from the center of the cutting insert at the midpoint of the long ridge line, the virtual straight line L1 connecting both ends of the long ridge line, When the distance from the center to the intersection with the line extending to the midpoint of the long ridge line is w2, w1 / w2 is a convex arc having 1.1 to 1.8, and each of the long ridge lines A perpendicular line passing through the center passes through the center of the cutting insert, and the side surface extends between one long ridge line and the seating surface, along the flank surface along the one long ridge line, and along the flank surface, It is depressed toward the center on the seating surface side from the flank. The difference portion has respectively three and restraining surface consisting of a plane located between the stepped portion of the seating surface, between the seating surface from one short edge line leading to the one long edge line, the flank , Intersecting the stepped portion and the constraining surface, and having three outer peripheral surfaces each extending from the short ridge line to the seating surface, and an intersection point x and an intersection point y between the constraining surface and the outer peripheral surface located on the stepped portion side The distance between the intersection point x and the one long ridge line is different from the distance between the intersection point y and the one long ridge line in plan view . When the short ridge line, the outer peripheral surface, the one long ridge line, the flank surface, the stepped portion, the restraint surface, and the relationship of the distance are set as one set, the three sets are rotationally symmetric with respect to the center. Is located.

Indexable cutter of the present invention, the insert pocket provided at the tip outer periphery of the cutter body, the cutting insert is mounted, in plan view, the distance W4 between the boundary line at the end of the previous Sulfur butterfly ridge It is attached so that the shorter one of the distances is located on the tip side.

The cutting insert of the present invention is light in weight because the area of the rake face with respect to the length of the cutting edge of the insert is narrow, and the thickness of the insert is made thinner on the restraint surface on the seating surface side than the stepped portion. In addition, the insert has a shape in which the distance to the long ridge line at both ends of the boundary line with the stepped portion of the constraining surface is different in a plan view. It can function as a cutting edge and can be arranged to efficiently receive the resistance of the main cutting edge that is most likely to receive cutting resistance. Therefore, the binding force of the insert can be increased. Therefore, the throw-away cutter of the present invention can rotate at high speed and has good cutting efficiency.

It is a perspective view which shows an example of the cutting insert of this invention. It is a top view of the cutting insert of FIG. It is the side view which looked at the cutting insert of FIG. 2 from the Z direction. It is VV sectional drawing which shows the state which screwed the screw into the screw hole in the cutting insert of FIG. It is a partially cutaway side view about an example of the throw-away cutter equipped with the cutting insert of FIGS. It is a principal part enlarged view which shows arrangement | positioning of the long ridgeline of the throwaway cutter of FIG.

  An example of the cutting insert (insert) and the throw-away cutter (cutter) of the present invention will be described with reference to the drawings.

The insert 1 of FIGS. 1-4 has a plate shape, and has a rake face 2 and a seating face 3 as main faces. The rake face 2 has a rotationally symmetric shape with respect to the center O. At the end of the rake face 2, there are alternately three convex curved long ridge lines 5 (5a, 5b, 5c) and three short ridge lines 6 (6a, 6b, 6c). In the present embodiment, the convex curved long ridge line 5 is an arc, and the distance w1 from the center O at the center p of the long ridge line 5 and the center O of the virtual straight line L1 passing through both ends r and s of the long ridge line 5 are. The ratio (w1 / w2) to the distance w2 is 1.1 to 1.8. A particularly desirable range of the ratio (w1 / w2) is 1.1 to 1.3. The short ridge line 6 is a straight line, but may be a curve having a radius of curvature that is twice or more larger than that of the long ridge line 5. The long ridge line 5 and the short ridge line 6 are smoothly connected in a curved shape.

  The side surface of the insert 1 includes a flank 7 extending from each of the long ridge lines 5 (5a, 5b, 5c), a step 8 extending from the flank 7 to the center O side, and the step 8 to the seating surface 3 side. And a constraining surface 9 composed of a flat surface extending in the direction. In the present embodiment, the ratio (t1 / w3) of the chord length w3 (not shown) between the ends r and s of the long ridge line 5 to the side surface thickness t1 is 0.2 to 0.5, The thickness t1 is smaller than that of a normal insert defined by the ISO standard. Thereby, the insert 1 is reduced in weight. A particularly desirable range of the ratio (t1 / w3) is 0.3 to 0.4.

  According to this embodiment, the distances w4 and w5 to the long ridge line 5 at both ends x and y of the boundary line L2 on the stepped portion 8 side of the restraint surface 9 are different in plan view. The distances w4 and w5 to the long ridge line 5 at both ends x and y are the distance between x and y and the point intersecting the long ridge line 5 on a straight line that passes through both ends x and y and is orthogonal to the boundary line L2. It is a width, in other words, a width between a point where a line perpendicular to the boundary line L2 from both ends x and y of the boundary line L2 intersects the long ridge line 5 and both ends x and y. As a result, when the insert 1 is attached to the cutter 30, the long ridge line 5 functions as the main cutting edge 20 and the auxiliary cutting edge 21, and the resistance of the main cutting edge 20 to which the cutting resistance is most likely applied is restrained by the cutter 30. The part can be received efficiently, and the insert 1 can be arranged so as not to loosen. Therefore, the binding force of the insert 1 can be increased, and the cutter 30 can be rotated at a high speed, and the cutting efficiency is good. 2 and 6 is a virtual line representing a virtual machining surface for machining the work material.

The flank 7 extends along the long ridge line 5 from the long ridge line 5 toward the seating surface 3 and is inclined at a flank angle α of 5 to 20 ° with respect to the direction perpendicular to the rake face 2. Yes. The restraint surface 9 is
The angle β between the stepped portion 8 and the seating surface 3 and perpendicular to the seating surface 3 is 0 to 10 °. The angle β is preferably 0 ° from the viewpoint of increasing the binding force of the insert 1. The ratio (t2 / t1) between the thickness t2 of the seating surface 3 and the stepped portion 8 and the thickness t1 of the side surface is 0.4 to 0.9. If it is this range, while the long ridgeline 5 used as a cutting blade maintains the rigidity which does not lack at the time of cutting, the restraint force of the insert 1 in the restraint surface 9 can be maintained. A particularly desirable range of the ratio (t2 / t1) is 0.5 to 0.7.

  The step portion 8 and the constraining surface 9 are smoothly connected in a curved shape. Further, the constraining surface 9 and the seating surface 3 are connected by a C-plane (inclined surface). In FIG. A boundary line L3 that is an edge of the seating surface 3 exists on the side close to O). The constraining surface 9 and the seating surface 3 may be smoothly connected by an R surface (curved surface).

  In the position which cross | intersects the short ridgeline 6 of a side surface, it has the outer peripheral surface 12 extended from the short ridgeline 6 to the seating surface 3. FIG. Thus, the rigidity that the long ridge line 5 serving as a cutting edge is not chipped at the time of cutting can be maintained. In this embodiment, the outer peripheral surface 12 is a flat surface, but it may be a curved surface. Further, the angle γ formed by the outer peripheral surface 12 and the rake face 2 is the same as the clearance angle α, but the angle γ may be smaller than the clearance angle α.

  The insert 1 has a screw hole 14 penetrating from the center of the rake face 2 including the center O to the seating surface 8. Then, as shown in FIG. 4, the wall surface of the screw hole 14 that contacts the screw head 17 of the screw 16 when the screw 16 is inserted into the screw hole 14 expands toward the rake face 2, and against the screw head 17. This is a convex curved surface 18 that comes into contact with the convex surface. As a result, when the screw 16 is brought into contact with the convex curved surface 18 and the screw 16 is decentered in the direction away from the main cutting edge 20 and tightened, the insert 1 moves toward the constraining surface 33 of the cutter 30 shown in FIG. There exists an effect | action pulled in and the insert 1 is restrained more firmly.

  In this embodiment, as shown in FIG. 5, the insert 1 is inserted into the insert pocket 32 provided at the outer periphery of the front end of the cutter body 31 in a plan view, and the constraining surface 9 and the step 8 at the end of the long ridge 5. Is attached so that the width r4 having a smaller width w4 with the boundary line L2 is located on the tip Z side.

  Here, FIG. 2 shows the same orientation as the insert 1 arranged in FIG. In this embodiment, as shown in FIG. 2, the step portions 8 of the three restraint surfaces 9 corresponding to the three long ridge lines 5 (the first long ridge line 5a, the second long ridge line 5b, and the third long ridge line 5c) In the boundary line 10 (the first boundary line 10a, the second boundary line 10b, and the third boundary line 10c), the first boundary line 9a and the second boundary line 9b are the center of the main cutting edge 20c of the third long ridge line 5c. It is line symmetric with respect to the perpendicular L4 passing through u. Thereby, since it can be arranged to receive the resistance of the main cutting edge 20 efficiently, the binding force of the insert 1 can be increased. Therefore, the cutter 30 has a high binding force of the insert 1, can be rotated at a high speed, and has a high cutting efficiency.

  As shown in FIG. 6 which is an enlarged view of the main part of FIG. 2 and FIG. 5, the insert 1 is the main cutting edge 20 with the leading edge q of the long ridge 5 as a boundary, and the outer periphery side of the cutter 30 (see FIG. 6 on the right side from q. Further, the shorter one becomes the secondary cutting edge 21 with the leading edge q of the long ridge line 5 as a boundary, and is arranged on the center side of the cutter 30 (left side from q in FIG. 6).

The cutter body 31 rotates around the central axis O ′. The insert 1 has an axial rake angle (not shown. In FIG. 5, the angle at which the top of the insert 1 is inclined to the back side of the paper) is 1 ° to 10 °, and a radial rake angle (not shown. In FIG. The angle is set so that the angle of the right side tilts to the back side of the paper surface is -1 ° to -10 °. Also, the cutter 30
Has a clamp member 35 and the insert 1 is firmly restrained by both the screw 16 and the clamp member 35.

  As mentioned above, although 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 summary of this invention.

1 Insert (cutting insert)
2 Rake face 3 Seating face 5 (5a, 5b, 5c) Long ridge line 6 (6a, 6b, 6c) Short ridge line 7 Relief face 8 Stepped portion 9 Constraining surface 10 (10a, 10b, 10c) Boundary line 12 Outer peripheral surface 14 Screw hole 16 Screw 17 Screw head 18 Convex surface 20 Main cutting edge 21 Sub cutting edge 30 Slowway cutter (cutter)
31 Cutter body 32 Insert pocket 33 Restraint surface 35 Clamp member O Center p Long edge line center q Long edge line leading edge r, s Long edge line both ends u Main cutting edge center Z Tip O 'Center axis w1 Long edge line center O Distance w2 from the center O of the virtual straight line L1 Distance w3 r from the center O, distances w4, w5 between s, width L1 between the long edge line and the boundary line L2 at the s, virtual straight line L2 passing through both ends r and s, step on the constraining surface Boundary line L3 on the flank side Boundary line L4 on the flank side of the stepped portion α Normal line passing through the center of the main cutting edge α Flank angle of the flank surface γ Angle with respect to the direction perpendicular to the seating surface γ On the rake surface of the outer peripheral surface Angle with vertical direction

Claims (7)

Rake face,
A seating surface facing the rake surface;
A cutting insert comprising: a side surface located between the rake surface and the seating surface ;
The rake face is
Having three short ridge lines and three long ridge lines located between the respective short ridge lines;
The long ridge line is a distance from the center of the cutting insert at the middle point of the long ridge line w1, a virtual straight line L1 connecting both ends of the long ridge line, and a line extending from the center to the middle point of the long ridge line When the distance to the intersection is w2, w1 / w2 is a convex arc with 1.1 to 1.8,
A perpendicular passing through the center of each long ridge line passes through the center of the cutting insert,
The side surface
Between the one long ridge line and the seating surface, a flank surface along the one long ridge line, and a step portion along the flank surface and recessed toward the center on the seating surface side from the flank surface And three restraint surfaces each consisting of a plane located between the stepped portion and the seating surface,
Between one short edge line leading to the one long edge line of the seating surface, the flank, with intersecting said stepped portion and the restraint surface having the three respective outer peripheral surface over the seating surface from the short ridge ,
The two connecting virtual straight line intersection x and the intersection y between the restraining surface and the outer peripheral surface located in front Symbol stepped portion side and the boundary line L2, in a plan view, to the one long edge line and the intersection point x The distance is different from the distance to the intersection y and the one long ridge line,
When the one short ridge line, the outer peripheral surface, the one long ridge line, the flank, the stepped portion, the restraint surface, and the distance are set as one set, three sets are Cutting inserts that are positioned rotationally symmetrically.   The cutting insert according to claim 1, wherein the short ridge line is a straight line.   The cutting insert according to claim 1 or 2, wherein the side surface on the short ridge line side is a flat surface extending from the short ridge line to the seating surface, and is inclined by 5 to 20 ° with respect to a direction perpendicular to the rake face. A screw hole is present at the center of the rake face including the center, and a wall surface of the screw hole that the screw head of the screw contacts when the screw is inserted into the screw hole expands toward the rake face. The cutting insert according to any one of claims 1 to 3, wherein the cutting insert is a convex curved surface that comes into convex contact with the screw head. A throw-away cutter in which the cutting insert according to any one of claims 1 to 4 is attached to an insert pocket provided at a tip outer peripheral portion of a cutter body, wherein the cutting insert is placed in the insert pocket of the cutter body. in plan view, indexable cutter mounted so that the distance the distance W4 is shorter is positioned at the front end side of said boundary line at the end of the previous Sulfur butterfly ridge.   The throw-away cutter according to claim 5, wherein the cutting insert is attached so that the longer one becomes the main cutting edge and the shorter one becomes the sub-cutting edge, with the leading edge of the long ridge line as a boundary. The three long ridge lines are defined as a first long ridge line, a second long ridge line, and a third long ridge line, and correspondingly , a boundary line with the step portion of the three constraining surfaces present on the side surface, When the first boundary line , the second boundary line, and the third boundary line are used, the first boundary line and the second boundary line are perpendicular to the center of the main cutting edge of the third long ridge line in plan view. The throw-away cutter according to claim 6, wherein the cutting insert is attached to the insert pocket so as to be line-symmetric with respect to the insert pocket.

Images