KR100485298B1 - Cutting Insert for Grooving Operations - Google Patents

Abstract

The insert for radial turning of the groove comprises a shank 2 and a cutting head 3, the cutting head 3 having an inwardly inclined top surface 11, 12 forming a bottom and two corresponding surfaces ( 13, 14 and flank sides 15, 16, 17 extending therebetween. The dividing line between the top face and the front flank 17 constitutes the main cutting edge 18, and the dividing line between the top face and the side flank forms the side cutting edges 19, 20. The upper surface is provided with several grooves 21 on each side of each insert centerline CL that are separated from each other and form discrete side cutting edges 19, 20. The groove 21 is preferably V-shaped. The upper part of the insert has two projections 24, 25 arranged on both sides with respect to the centerline CL, with their front ends isolated from each other, the extent of which is defined by a unique upwardly inclined portion and an upper planar portion. Limited. The shapes of the projections 24 and 25 are oval-shaped and converge toward each other when viewed from the front face of the insert and later diverge toward each other.

This shape makes the insert extremely suitable for radial turning operations in grooves.

Description

Cutting insert for grooving operations {Cutting Insert for Grooving Operations}

The present invention relates to a cutting insert for groove forming operations according to the requirements of claim 1. The cutting insert according to the invention is particularly suitable for groove cutting operations of different radii and turning operations of grooves and for profile operations of grooves with small angles, for example for producing grooves for piston rings.

During this process, chip breaking and chip forming operations have a decisive influence on many manufacturing operations. In today's high productivity machines, the demand for good chip removal is very high. Long, uncontrollable chips can easily cause product breakage and cause defects in parts that can be discarded. Therefore, great care is required to control the chip, which greatly affects the design of the tool.

Cutting inserts for turning and dividing grooves are generally clamped in bladed holders for use in confined spaces. Such cutting inserts are disclosed, for example, in US Pat. Nos. 5,375,948 and 5,423, 639.

Cutting inserts, known to date for turning grooves radially, do not always function satisfactorily. Chips are not destroyed sufficiently and chip control is below standard.

1 is a view from above of an insert according to the invention;

Figure 2 is a side view of the insert according to the present invention.

Figure 3 shows the same insert as Figure 2;

4 is an enlarged view of the insert of FIG. 2 seen from above;

5 is a cross-sectional view taken along the line A-A of FIG.

FIG. 6 is a cross-sectional view taken along the line B-B of FIG. 4; FIG.

7 is a cross-sectional view taken along the line C-C of FIG.

It is a first object of the present invention to continuously produce inserts suitable for repeatedly turning grooves radially.

It is a second object of the present invention to produce inserts which are also suitable for profile forming and turning in the longitudinal direction, in particular for forming side profiles of grooves with small angles.

It is a further object of the present invention to produce an insert capable of performing the first cutting in a reliable manner while long, unbroken chips are generally formed.

This and other objects are achieved by developing an insert for turning a groove having the features described in claim 1.

The present invention will be described in detail with reference to the accompanying drawings, but this description does not limit the invention in any sense.

1 shows an insert 1 made of a hard wear resistant material such as cemented carbide and comprising a rear shank 2 and a front cutting head 3. The rear part of the shank 2 has two sides 4, 5 that are substantially parallel to the plane, two obliquely inwardly inclined edge surfaces 6, 7, and a bottom surface 8 formed in a corresponding manner. ) And a rear end face 9 which forms a right angle to the sides 4, 5 and a front shoulder 10 which forms a transition between the shank portion 2 and the cutting head 3, thereby providing a shoulder. The top of (10) forms the highest point h of the insert above the neutral plane P. The bottom surface 8 constitutes a first support surface for supporting the insert with respect to the processing holder body, which is parallel to the neutral plane P of the mating processing tool. The insert is adapted to be fixed to the holder body with respect to the upper surface by an integral clamping arm actuation, whereby the insert is clamped in the working position through the spring force of the arm acting on the insert. Clamping of the insert is disclosed in the Applicant's Swedish patent application No. 991324-2, the contents of which are incorporated herein by reference. The distance t between the sides 4, 5 forms the maximum width of the insert.

The front cutting head 3 has two inclined top surfaces 11 and 12 which are inwardly inclined, two bottom surfaces 13 and 14 which are inclined in a corresponding manner, and top surfaces 11 and 12 respectively. It consists of two longitudinal flanks 15, 16 in the longitudinal direction and an anterior end face 17 between the upper face 11, 12 and the lower face 13, 14, forming an acute angle with respect to. The transition line between the top face 11, 12 and the end face 17 forms a major cutting edge 18, and the transition line between the side faces 15, 16 and the respective top face 11, 12 has a side face. Edges 19 and 20 are formed. Both inclined top surfaces 11, 12 are connected to the upper inclined surface of the shoulder 10 which preferably has a cylindrical half at its rear.

The difference in the insert is that the two sides 15, 16 and the associated side edges 19, 20 extend forward to form an acute angle of 1.5 to 20 ms, preferably 1.5 to 5 ms between them. The upper faces 11, 12 are provided with several mutually separate grooves 21 such that the cutting edges on each side of the longitudinal centerline CL of the insert form a discrete cutting edge. Each groove 21 extends inwardly toward the cutting head in a direction perpendicular to the center line CL. The width and depth of each groove 21 gradually decreases as the center line CL approaches. The groove 21 is preferably smaller than the distance between two adjacent grooves. The maximum depth of the grooves 21 in the plane of the sides 15, 16 is preferably less than the distance between two adjacent grooves. The groove 21 is mainly V-shaped, so that the side walls 22 and 23 of the groove contain an angle of about 65 to 90 degrees in size. The side wall of the groove 21 is mainly flat and the bottom of the groove is curved.

The upper surface at the front end of the insert is formed of two symmetrically positioned projections 24 and 25 on each side of the centerline CL. These protrusions are elliptical. The front portions of these projections converge with respect to each other rearwardly from the main cutting edge 18, and the rear portions diverge against each other. The upper surface of each projection is mainly flat, all of which are limited by the downward slope. The top surface of each protrusion is located at the same height as, or slightly less than, the plane height including the main cutting edge and the side cutting edge as shown in detail in FIG.

By providing these projections 24, 25 slightly isolated from each other, initial chip breakage occurs against them. Increasing the cutting depth and the feed rate change the shear angle on the chip. The shape of the projection is such that the chip breaking function is not adversely affected when the cutting depth is increased. As the depth of cut increases, the interaction between the insert and the workpiece is in three different directions: the main cutting edge 18 and the groove 21 begin to play an active role, contributing to the reduction of the width of the chip. Along the two side cutting edges 19, 20. This helps to avoid the formation of chips that are too thin to handle. The surface 26 which is inclined inwardly and obliquely downward from the main cutting edge 18 and disposed between the nose portions of the two protrusions 24, 25 also contributes to the corrugation of the chip. This surface leads to an upwardly inclined surface 27 disposed between the protrusions 24, 25, wherein the top 28 of the inclined surface 27 is at a level slightly lower than the top of the top surface of the protrusions 24, 25. Is placed.

This shape makes the insert extremely suitable for radial turning of grooves as well as for profiling and longitudinal turning operations.

Claims (13)

In inserts mainly for turning grooves in metal workpieces, A rear shank 2 and a front cutting head 3, The cutting head comprises a top face 11, 12 and a bottom face 5 and flank faces 15, 16, 17 extending between two sides and forming an acute angle with the top face, The transition line between the top face and the front flank face 17 forms the main cutting edge 18 and the top face transition line aligned with the side flank faces 15 and 16 forms the side cut edges 19 and 20. , The two side cutting edges 19, 20 and the associated side flank surfaces 15, 16 extend forward to form an acute angle therebetween, A plurality of grooves (21) separated from each other is characterized in that the insert is formed in the upper surface so as to form discrete lateral cutting edges on each side of the centerline (CL) of the front cutting head. The groove (21) according to claim 1, wherein the groove (21) extends inwardly from inside the insert at right angles to the centerline, the width of the groove (21) is reduced inwardly from within the insert, and the maximum width of the groove (21) is An insert according to claim 1, wherein the insert is smaller than the distance between two adjacent grooves. 2. Insert according to claim 1, characterized in that each groove (21) has a maximum depth in the plane of the side flank surface (15, 16) and the depth of the groove is reduced inwardly inside the insert. 2. Insert according to claim 1, characterized in that the side cutting edges (19, 20) extend in pairs towards the main cutting edge (18), forming an angle between them of 1.5 to 20 degrees. 5. The insert according to claim 4, further comprising two protrusions (24, 25) located at a distance from each other and symmetrically aligned with respect to the center line (CL) of the cutting head. 6. Insert according to claim 5, characterized by a curved surface (26) inclined downward from the main cutting edge (18) connected with the upwardly inclined surface (27) between the projections (24, 25). 7. The cutting head according to any one of the preceding claims, wherein the top surface of the cutting head consists of V-shaped planes (11, 12), both planes inclined downward from each side cutting edge and extending in the longitudinal direction of the cutting head. Inserts, characterized in that. 8. Insert according to claim 7, characterized in that the two downwardly inclined surfaces (11, 12) are connected at the rear with the upwardly inclined surface of the vertical shoulder (10) having a semi-cylindrical shape. 7. Insert according to any one of the preceding claims, characterized in that it is designed to form a mating tool holder and a support surface, characterized by a bottom surface consisting of two bottom surfaces (13, 14) inclined upwardly. . The insert according to any one of the preceding claims, wherein the grooves 21 are substantially V-shaped and the sidewalls 22, 23 of the grooves form an angle in the range of 65 to 90 degrees. sieve. 7. Insert according to any one of the preceding claims, characterized in that the sides (22, 23) of the grooves are substantially flat and the bottom of the grooves is curved. 7. The top surface of claim 1, wherein the top surface is formed with two protrusions 24, 25 which actively contribute to chip shrinkage during chip breaking. And an inclined surface (26) inclined inwardly downward from the main cutting edge (18) located between the parts. The bent upwards of claim 12, wherein the downwardly inclined surface 26 from the main cutting edge 18 changes to a spigot 28 located slightly below the height of the plane that includes the top surfaces of the two protrusions 24, 25. Insert, characterized in that changed to the inclined surface (27).