JP5779830B2 - Vertical cutting edge replaceable cutting insert and corner milling cutter - Google Patents

Description

  The present invention relates to a cutting edge exchangeable cutting insert for corner milling, and more particularly to a so-called vertical cutting edge exchangeable cutting insert using a side surface as a rake face and a corner milling cutter using the same.

  As vertical cutting edge exchangeable cutting inserts (hereinafter simply referred to as cutting inserts) for corner milling, for example, those disclosed in the following Patent Documents 1 to 3 are known.

  The cutting insert described in Patent Document 1 and the cutting inserts in FIGS. 1 and 2 of Patent Document 2 are designed to replace a used cutting edge and an unused blade by rotation of 180 °. The sub-cutting blades that have a length that bisects the short side at the short side portion of the side surface that is the same, and that are inclined at the same angle with respect to the long side of the opposing position of the side surface that forms the main cutting edge, are symmetrical Provided.

  Further, the nose R at the front end of the main cutting edge and the nose R at the rear end of the main cutting edge formed between the main cutting edge and the sub cutting edge are made the same size.

  On the other hand, the cutting insert of Patent Document 3 is configured so that the entire short side can be used as a secondary cutting edge (substantially, a part on the main cutting edge side is used as a secondary cutting edge). Further, similarly to the cutting inserts of Patent Documents 1 and 2, the nose R at the front end of the main cutting edge and the nose R at the rear end of the main cutting edge formed between the main cutting edge and the sub cutting edge are made the same size. .

JP-T-2005-528230 Japanese Patent No. 4491404 Special table 2007-520360 gazette

  Since the cutting inserts of Patent Documents 1 and 2 use half of the short side of the side surface as the secondary cutting edge, the length of the secondary cutting edge is limited. In addition, because the short sides divided in half are inclined at the same angle in opposite directions, the angle formed with the main cutting edge is limited, and the tool feed exceeds a certain value, such as exceeding a certain value. There was a problem that the surface roughness of the processed surface deteriorated sometimes.

  The cutting insert of Patent Document 3 can use the entire length of the short side as a secondary cutting edge for Sarae processing. However, if the face angle of the secondary cutting edge is reduced to improve the surface roughness of the processing surface, There is a problem that the perpendicularity of the surface processed by the blade and the sub-cutting blade cannot be secured, and there is a problem that the surface roughness of the machined surface decreases if the perpendicularity is maintained. Was virtually impossible.

  The size of the nose R at the tip of the main cutting edge depends on the size and shape of the workpiece to be processed and is determined by the needs of the user. For this reason, in the conventional cutting insert, the nose R at the rear end of the main cutting edge is also restricted by the nose R at the front end of the main cutting edge and becomes a nose R having a large bending radius.

  As a result, there has been a problem that the level difference (so-called wave height of the feed mark) of the blade-shaped seam of the surface machined into the main cutting edge becomes large when performing digging with a corner milling cutter.

  An object of the present invention is to make a vertical cutting insert for corner milling work capable of maintaining good surface roughness even when the use conditions such as tool feeding are increased.

To solve the above problems, in the present invention, surface rake side of the portrait, the main cutting edge to the long side of the side flank of the main cutting edge on the face or lower surface, cutting the short sides of the side sub-blade ( Sarae blade), a vertical cutting edge replaceable cutting insert that uses part of the end face as a flank for the secondary cutting edge.
A part of the short side of the side surface is configured as the auxiliary cutting edge, and the auxiliary cutting edge is connected to the tip of the main cutting edge through a nose R portion having a bending radius R1 in a side view of the insert,
The end surface includes a first surface serving as a flank surface of the auxiliary cutting edge, and second and third surfaces of inverted triangles disposed on both sides of the first surface. The ridge line that extends in the diagonal direction of the end face and that forms the secondary cutting edge is formed at the intersection with the side face.

  The edge width t of the secondary cutting edge is about 1/3 to 2/3 of the insert thickness T, and the corner angle θ of the corner formed between the main cutting edge and the secondary cutting edge is 85 ° to 95 ° ( A range of 85 ° ≦ θ ≦ 95 ° is appropriate.

  The secondary cutting edge may be either a straight edge or an arc edge, and the radius of the arc in the case of the arc edge is suitably about 200 to 1000 mm.

  Also, the side opposite to the side forming the minor cutting edge on the short side of the side is a bending satisfying the condition of R1 <R2 at the rear end of the main cutting edge that is replaced with the main cutting edge by rotation (rotation of 180 °). It is good to connect via the nose R part of radius R2.

  The bending radius R1 of the nose R portion formed between the tip of the main cutting edge and the sub cutting edge varies depending on the needs of the user, but is generally 0.4 to 6.0 mm. The radius R2 of bending of the nose R portion on the opposite side of the short side is preferably about 5 to 100 times that R1.

  This cutting insert has a seat groove formed on the outer periphery of the cutter body, a rake line on one side, a ridge line at the intersection of the upper surface (or lower surface) and the rake surface as a main cutting edge, and an upper surface (or lower surface) as the main surface. Install the cutting blade so that the flank of the cutting edge, the short side of one side is at the forefront, the auxiliary cutting edge (Sarae blade), and the end face of one side becomes the flank of the auxiliary cutting edge.

  When the upper surface is used as the flank of the main cutting edge, the lower surface is seated on the bottom surface of the seat groove of the cutter body, and the two side surfaces provided on the side surface not involved in cutting and the end surface on the side not involved in cutting are used. A triangular plane is received and supported by the seat side surface of the seat groove. The present invention also provides a corner milling cutter as configured above.

  In the cutting insert of the present invention, the short side of the side surface is asymmetrical and the main cutting edge side of the short side is the sub cutting edge. Therefore, the width of the secondary cutting edge can be freely changed within a preferable numerical range, and the processing conditions fluctuate by making the width wider than the cutting inserts (inserts having the same thickness) of Patent Documents 1 and 2. The degree of freedom in dealing with can be expanded.

  As a result, it is possible to maintain a good surface roughness of the processed surface even when the feed is increased beyond a certain condition.

The perspective view which shows the 1st form of the cutting insert of this invention Plan view of the cutting insert of FIG. Side view of the cutting insert of FIG. End view of the cutting insert of FIG. A perspective view of a corner milling cutter using the cutting insert of FIG. Side view of the corner milling cutter of FIG. Front view of the corner milling cutter of FIG. Sectional drawing which shows the cutting insert support state of FIG. The perspective view which shows the 2nd form of the cutting insert of this invention Side view of the cutting insert of FIG. The perspective view which shows the 3rd form of the cutting insert of this invention Front view of the cutting insert of FIG. Side view of the cutting insert of FIG. End view of the cutting insert of FIG.

  DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of a cutting insert according to the present invention and a corner milling cutter using the cutting insert will be described below with reference to FIGS. 1 to 4 show a first form (no breaker groove) of a cutting insert according to the present invention.

  The cutting insert 1 has a quadrangular basic shape, and the left and right long sides of the side surface 4 formed in a vertically long shape are used as the main cutting edge 6, and a part of both short sides of the side surface 4 is the sub cutting edge. Used as 7 (Sarae blade).

  The long side of the side surface 4 is a ridge line formed at the intersection with the upper surface 2 and the lower surface 3. The short side of the side surface 4 is a ridge line formed at the intersection with the end surface 5.

  The lower surface 3 side has the same configuration as the upper surface 2 side. The configuration of the two opposing side surfaces 4 and 4 and the configuration of the two opposing end surfaces 5 and 5 are the same. Therefore, the description here will be made only on the configuration of the upper surface side and the configuration of one side surface and the end surface.

  The short side of the side surface 4 is an asymmetrical side as shown in FIG. One end side of the short side is connected to the tip of the main cutting edge 6 via the nose R portion 8 having the radius R1, and the one end side is used as the sub cutting edge 7.

  Further, the other end side of the short side of the side surface 4 is connected to the rear end of the main cutting edge 6 on the side whose position is changed by rotation (rotation of 180 °) through a nose R portion 9 having a radius R2. Yes.

  The end surface 5 includes a first surface 5a that forms a ridge line between the side surface 4 and the secondary cutting edge 7, and second and third surfaces 5b and 5c disposed on both sides of the first surface. It is a flat surface.

  The first surface 5 a extends in the diagonal direction of the end surface, and the first surface 5 a constitutes the flank of the auxiliary cutting edge 7. In addition, the second and third surfaces 5b and 5c are inverted triangular surfaces because the first surface 5a extends in the diagonal direction of the end surface.

  The second and third surfaces 5b and 5c are used for axial positioning of the cutting insert with respect to the cutter body. The second and third surfaces 5b and 5c are supported by the seat side surface of the seat groove formed in the cutter body, and the axial load applied to the cutting insert 1 in milling is received at that position. As described above, when the second and third surfaces 5b and 5c are used for positioning of the cutting insert, it is preferable to form each surface as a flat surface, but it may be a curved surface.

  The blade width t of the auxiliary cutting edge 7 shown in FIG. 3 is set to about 1/3 to 2/3 of the insert thickness T. When the blade width t is equal to or less than 1 / 3T, the cutting insert disclosed in the above-mentioned Patent Documents 1 and 2 does not have a significant difference in terms of the degree of freedom in dealing with variations in machining conditions. .

  Moreover, when the blade width t exceeds 2 / 3T, the cutting load of the secondary cutting edge increases and the cutting torque becomes excessive.

  The corner angle θ of the corner formed between the sub cutting edge 7 and the main cutting edge 6 is suitably in the range of 85 ° to 95 ° (85 ° ≦ θ ≦ 95 °). Outside this range, it becomes difficult to maintain the squareness of the corner of the processed surface within a range that is considered preferable.

  In the illustrated cutting insert, the secondary cutting edge 7 is a straight blade, but this may be a convex arcuate blade. In the case of the arcuate blade, the radius of the arc is suitably about 200 to 1000 mm. is there. If it is the arc radius of the range, the generally required machining surface roughness can be secured.

  Bending radii R1 and R2 of the nose R portions 8 and 9 satisfy the relationship of R1 <R2.

  The bending radius R1 of the nose R portion 8 formed between the tip of the main cutting edge 6 and the sub cutting edge 7 may be about 0.4 to 6.0 mm which is generally required. The bending radius R2 of the nose R portion 9 on the rear end side of the main cutting edge is preferably about 5 to 100 times R1.

  An example of the corner milling cutter using the cutting insert 1 according to the first embodiment is shown in FIGS. The illustrated corner milling cutter 20 is provided with a plurality of seat grooves 22 and chip pockets 23 at a predetermined interval in the rotation direction on the outer periphery of the cutter body 21.

  Then, the cutting insert 1 is inserted into each seat groove 22, and the cutting insert 1 is fixed on the seat bottom surface 22 a of the seat groove with a mounting screw 24.

  In the cutting insert 1, the side groove 4 is a rake face, the ridge line at the intersection of the upper face 2 (or lower face 3) and the rake face is the main cutting edge 6, and the upper face 2 (or lower face 3) is the main cut. The flank of the blade, the side that is connected to the tip of the main cutting edge on one short side of the side surface is attached to the auxiliary cutting edge 7, and the end surface 5 that is placed at the foremost side is mounted to face the auxiliary cutting edge 7.

  The side surface 4 on the side not involved in cutting is supported by the seat side surface 22b of the seat groove 22, and the cutting insert is positioned in the cutter rotation direction by the support portion of the seat side surface 22b.

  Further, the second and third surfaces 5b and 5c of the end surface 5 on the side not involved in the cutting are supported by the seat side surfaces 22c and 22d of the seat groove 22, and the support portion of the seat side surfaces 22c and 22d supports the cutting insert 1. Positioning in the cutter axis direction is performed.

  Positioning of the cutting insert 1 in the cutter radial direction is performed by a support portion by the seat bottom surface 22a.

  9 and 10 show a second embodiment of the cutting insert of the present invention. The basic configuration of the second form is the same as that of the first form. This 2nd form provides the breaker groove | channel 10 which processes a chip | tip in the side surface 4 which makes a rake face along the main cutting edge 6, This part differs from a 1st form. Since other configurations are the same as those of the first embodiment, the description thereof is omitted.

  FIGS. 11-14 has shown the 3rd form of the cutting insert of this invention. The basic configuration of the third embodiment is the same as that of the first embodiment. In the third embodiment, a breaker groove 10 is provided on the side surface 4 along the main cutting edge 6.

  Moreover, the position of the sub cutting edge 7 is made the highest, and the main cutting edge 6 is inclined in the direction in which the position decreases as it goes from the front end side connected to the sub cutting edge 7 to the rear end side. For this reason, the rear end of the main cutting edge on the side opposite to the side that becomes the minor cutting edge of the short side of the end face 5 is inclined in the end face view (FIG. 14) and the position is changed by rotation. It is connected to.

  Other configurations are the same as the first embodiment in the third embodiment. Therefore, the description of the same part is omitted here.

DESCRIPTION OF SYMBOLS 1 Cutting insert 2 Upper surface 3 Lower surface 4 Side surface 5 End surface 5a 1st surface 5b 2nd surface 5c 3rd surface 6 Main cutting edge 7 Secondary cutting edge 8 Nose R part 9 of main cutting edge front end of main cutting edge Nose R section 10 Breaker groove 20 Corner milling cutter 21 Cutter body 22 Seat groove 22a Seat bottom face 22b, 22c, 22d Seat side face 23 Chip pocket 24 Mounting screw R1 Bending radius R2 of nose R section at the tip of the main cutting edge After the main cutting edge Bending radius of end nose radius part θ Corner angle t Secondary cutting edge width T Insert thickness

Claims (7)

Long side face (4) is rake face, long side is main cutting edge (6), top face (2) or bottom face (3) is flank face of main cutting edge, short side of side face (4) is minor cutting edge (7) A vertical cutting edge replaceable cutting insert using a part of the end face (5) as a flank of the auxiliary cutting edge (7),
A part of the short side of the side surface (4) is configured as the auxiliary cutting edge (7), and the auxiliary cutting edge (7) has a bending radius R1 at the tip of the main cutting edge (6) in a side view of the insert. Connected through the nose R section (8),
The end surface (5) includes a first surface (5a) serving as a flank surface of the auxiliary cutting edge (7), and second and third surfaces of inverted triangles arranged on both sides of the first surface. (5b, 5c), and the first surface (5a) extends in the diagonal direction of the end surface to form a ridge line that becomes the secondary cutting edge (7) at the intersection with the side surface (4). vertical indexable cutting insert that is. The vertical blade edge replaceable cutting insert according to claim 1, wherein the upper surface (2) has an inclined surface continuous with the nose R portion (9) having a bending radius R2. The vertical blade-tip-replaceable cutting insert according to claim 1 or 2 , wherein a blade width t of the secondary cutting edge (7) is set to 1/3 to 2/3 of an insert thickness T. The claims 1 to 3, the corner of the corner angle theta of which is formed between, and set so as to satisfy the condition of 85 ° ≦ θ ≦ 95 ° between the secondary cutting section (7) and the main cutting (6) The vertical blade-tip-replaceable cutting insert according to any one of the above. The secondary cutting edge (7) is a convex arc blade having a bending radius of 200 to 1000 mm.
Vertical indexable cutting insert according to any one of-claims 4. The secondary cutting edge (7) is connected to the main cutting edge (6) via a nose R portion (8) having a bending radius R1.
The side opposite to the side that forms the minor cutting edge of the short side of the side surface (4) is mainly cut by rotation through a nose R portion (9) having a bending radius R2 larger than R1. vertical indexable cutting insert according to any one of claims 1 to 5 which has Ren'nara the rear end of the main cutting edge side to replace the blade. The cutting insert (1) according to any one of claims 1 to 6, in Zamizo (22) formed on the outer periphery of the cutter body (21), the rake face one side (4), The ridge line at the intersection of the upper surface (2) or the lower surface (3) and the rake face is the main cutting edge (6), the upper surface (2) or the lower surface (3) is the flank of the main cutting edge, and one of the side surfaces (4) The short edge is positioned at the forefront, the secondary cutting edge (7), the first surface (5a) of one end face is mounted in a direction that becomes the flank of the secondary cutting edge (7), and the upper surface (2) The side of the lower surface (3) that does not participate in cutting is the seat bottom (22a) of the seat groove, the side surface (4) that does not participate in cutting is the seat side surface (22b) of the seat groove, and the side that does not participate in cutting. A corner milling cutter configured to support the second and third surfaces (5b, 5c) of the end surface with seat side surfaces (22c, 22d) of the seat groove.

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