EP3898045A1

EP3898045A1 - Cutting tool

Info

Publication number: EP3898045A1
Application number: EP19804623.7A
Authority: EP
Inventors: Quanliang ZHAO; Jose AGUSTIN-PAYA; Robert MILITELLO
Original assignee: ZCC Cutting Tools Europe GmbH
Current assignee: ZCC Cutting Tools Europe GmbH
Priority date: 2018-12-20
Filing date: 2019-10-30
Publication date: 2021-10-27
Also published as: US20220072623A1; CN113056341A; DE102018133164A1; WO2020125845A1

Abstract

The invention relates to a cutting tool for machining, in particular for a peeling-like machining process, comprising a chip-forming depression which runs along the cutting edge and in which elevated chip-forming elements are formed. According to the invention, the elevated chip-forming elements have an elongated contour with a length which is greater than the width, in plan view, such that the chip-forming elements have a rising flank and a falling flank. The rising flank, which is longer by comparison, is defined by a rising angle (α) of 3° to 20°, preferably 5° to 10°, and a falling angle (ß) of 25° to 45°, preferably 27° to 35°, and the transition between the rising flank and the falling flank is rounded, the radius (R) of said rounded section ranging between 0.05 mm and 1 mm, preferably between 0.25 mm and 0.4 mm.

Description

Cutting tool

The invention relates to a cutting tool for machining operations, in particular for peeling-like machining operations, with a chip-forming trough running along the cutting edge, in which raised recesses are formed

Spanformelemente are arranged.

Machining includes the machining of metals such as Steel, cast iron, but also non-ferrous metals and plastics understood.

The present invention is basically suitable for cutting tools for turning, milling or grooving and in particular for peeling processing.

In chip inserts, chip guiding or chip shaping elements have the task of shaping and guiding the chip detached from the workpiece, with particular care being taken to ensure that the workpiece is not damaged by the chip formed, as is e.g. can happen with so-called tangled chips. The chip should also be guided and broken in such a way that the friction caused by the chip flow is limited to such an extent that excessive heating of the cutting insert and in particular of the cutting edge is avoided, since this would lead to faster tool wear. With certain workpieces such as aluminum or plastic, there is also a risk of the chip sticking to the chip surface if the heat is high.

The special case of a cutting tool for peeling

Machining is described in DE 197 25 341 B4. The

Cutting tool has main and secondary cutting edges arranged side by side, which together form an obtuse angle. Along these cutting edges is a chip breaker with a rising flank facing the cutting edge

provided that viewed in plan view at least two by adjacent

Indentations should have laterally limited projections. As in In general, peeling tools have a secondary cutting edge that is significantly longer than the main cutting edge. When rotating peeling

Target surface roughness of the workpiece from 4 pm to 8 pm.

Another suitable for peel-like machining

Indexable insert is described in EP 0 117400 B1. This

The insert is nine-cornered and has three unequal main and minor cutting edges on the bottom and top, resulting in the shape of an equilateral triangle with symmetrically angled tips. The

The ratio of the length of the main cutting edges to the length of the secondary cutting edges should be between 1: 1, 5 to 1: 3. A chip-forming groove is provided along each main cutting edge and runs approximately parallel to the main cutting edge. In areas close to the cutting edge, the chip groove merges into a rising flank, which ends with an upper flank.

EP 0611 334 B4 describes a polygonal "cutting insert with a rake face" !, which has a central crusher that protrudes from the plane defined by the set avoiding edges and runs out towards a cutting corner area in the form of at least one longitudinal rib, preferably two longitudinal ribs. which are arranged symmetrically to a cutting corner angle bisecting and whose longitudinal axes have a common intersection in the area of the chip breaker.

In addition, chip breakers on chip faces are known from the prior art which run essentially parallel to the minor cutting edge. Such

Chip breaker steps lift the chip that is running away from the workpiece, but there is insufficient chip guidance so that the chip that runs off is uncontrollable. DE 19725 341 therefore proposes chip breakers with two laterally limited projections. EP 0278083 A1 proposes a cutting insert in which an area with a rake angle of more than 30 ”adjoins the chamfer on the rake surface at right angles to the cutting edge the rake angle becomes smaller with increasing distance from the chamfer will, in the chip face regions of the cutting body lying between the cutting surfaces, chip ribs extending in the chip discharge direction and with side spacing next to one another should be arranged protruding from the chip face, between which there are further elevations with run-up ramps. In the corner area there are three degree elevations arranged side by side, the two outer ones with their longitudinal axes running parallel to the chip ribs adjacent to them.

EP 0 143 758 A1 relates to a cutting insert with elongated ribs which are trapezoidal in cross section and run parallel to the cutting edge. These ribs are interrupted by hollows.

In order to cope with different feeds and depths of cut and to keep the frictional force of the chip as low as possible, the

EP 0674 559 B1 proposes a cutting insert with at least one chip-guiding groove with raised chip-shaping elements in the form of longitudinal ribs which are at least partially bridged over the chip-guiding groove and which are provided with chip-guiding elements which are transverse to the axis of the longitudinal rib.

It is an object of the present invention to further develop a cutting tool of the type mentioned at the outset, in which the friction of the chip running off is minimized and the cutting forces are kept low and the chip steering is improved with the lowest possible cutting resistance.

This object is achieved by a cutting tool according to claim 1.

According to the invention, the raised chip-forming elements provided in the chip-forming trough (chip-forming groove) have - viewed in a plan view - an elongated contour with a greater length than their width. Furthermore, the

Chipform elements have a rising flank and a falling flank, the comparatively longer rising flank being characterized by a rising angle from 3 "to 20 °, preferably 5 * to 10" and the falling flank by an angle between 25 ° to 45 ", preferably 27" to 35 "is defined, the transition from the Rising edge to the falling edge is rounded and the radius of this

Rounding is between 0.05 mm and 1 mm, preferably between 0.25 mm and 0.4 mm.

Developments of this cutting insert are described in the subclaims. This measure ensures that, on the one hand, in the area of the rising flanks in connection with the maximum elevation of the raised

Chip-forming element ensures a safe chip guidance, on the other hand high friction of the chip running off is avoided because the chip only partially contacts the chip faces in the falling flanks. This effect is particularly pronounced when the raised chip elements viewed in the top view in the area of their boundary line, which is shown by the

adjacent rising and falling flanks is defined, has a greater width than in the adjacent areas.

The chip-forming elements are preferably arranged at a distance from one another, in particular at a distance of 0.4 mm to 0.6 mm with a respective length of 4 mm to 10 mm defined by their longitudinal axis. Furthermore, the chip-forming elements are preferably lined up on a line which runs parallel to the cutting edge, the orientation of the chip-forming elements being inclined by 10 "to 20", preferably 15 ", in relation to the chip removal direction. The angle of rise α and the angle β of the falling edge are formed by the connecting line between the base of the rising or falling flank in the area of the groove and the upper vertex on the apex line and the connecting line between the two base points of the rising and falling flank parallel to the cutting edge in the groove Chip shaping elements are oriented towards the active cutting edge so that the cut incoming chip is guided in the direction of the longitudinal axis of the chip shaping elements. In a cross-sectional view, the chip elements can have a concave, convex or even partially rectilinear shape perpendicular to their longitudinal axis, the concave design being preferred.

As an alternative to chip form elements arranged separately next to one another within a chip form groove, it is possible to line up the chip form elements like fish scales, the chip form elements each being in their

Viewed in the longitudinal direction, they overlap by 10% to 30%. This

Fish scale structure has particular advantages with turning or milling tools.

In addition to the overlap in the longitudinal direction, it is also possible to use chip-forming elements which additionally overlap laterally, the degree of overlap measured vertically to the longitudinal axis being a maximum of 20%, preferably a maximum of 10%.

According to a further embodiment of the invention - particularly in the area of a cutting corner - the arrangement and design of the chip-forming elements

axially symmetrical to the cutting edge angle bisector.

Finally, at a distance from the cutting edge and viewed in the direction of chip flow, behind the chip mold trough there can be a flank that rises to a central raised plateau, from which further preferably semi-rib-shaped further chip mold elements extend in the direction of the cutting edge, which protrude into the space between the above-mentioned raised chip mold elements .

A chamfer can be provided to stabilize the cutting edge.

Within the scope of the present invention and also those configurations are detected in which individual raised chip-forming elements protrude into the cutting edge and break through this to form a focal cutting edge elevation. By this measure gives the cutting edge a non-linear configuration with adjacent slight increases.

Embodiments of the invention are shown in the drawings. Show it:

1 is a perspective view of a peeling tool,

2 is a plan view of the peeling tool of FIG. 1,

Fig. 3 is a detailed view of a chip groove with raised

Chip form elements,

4 shows a single view of a chip-forming element in a chip-forming groove, FIG. 5 shows a section along line A-A in FIG. 4,

Fig. 6 is a chip forming groove with raised arranged offset to each other

Chip form elements,

Fig. 7 shows another embodiment of a chip groove with a

Chip-forming element that penetrates the cutting edge,

Fig. 8 shows a corner area of a cutting tool for turning with two

cutting edges tapering at an acute angle,

Fig. 9 is a detailed view of a chip groove with raised

Chip form elements in a fish scale-like arrangement,

Fig. 10 is a detailed view of a rhombic cutting insert

fish scales lined up

Chipform elements and

Fig. 11 is a detailed view of a cutting corner of a rhombic

Cutting insert with differently raised chip form elements and a rising flank to a middle plateau.

In principle, the present invention can be applied to all basic cutting insert shapes known from the prior art, for example triangular, square, rhombic or even approximately rectangular

Cutting inserts, such as those used in particular for peeling, in which a relatively long secondary cutting edge, which enclose an obtuse angle of less than 180 °, adjoins a short main cutting edge. In principle, the invention can also be used in lancing inserts, which are not shown in the present case.

If so-called indexable inserts are used, they can have a positive or negative contour. If the contour is positive, the top and bottom sides are designed as rake faces with correspondingly adjacent cutting edges

1 and 2 show a cutting tool (as an exchangeable cutting insert) for peeling processing. Such cutting inserts are characterized by a relatively short main cutting edge 10 in conjunction with a long secondary cutting edge 11, the main cutting edge and the secondary cutting edge including «not obtuse angles. The middle rake face plateau 12 is designed as a support and rake face in so-called indexable inserts. In the case of the cutting inserts according to FIGS. 1 and 2, there are four usable main and secondary cutting edges.

As is known in principle, a chip-forming guide 14 or chip-forming groove can directly adjoin the cutting edge or a chamfer 13. Within this chip-forming groove 14 are individual raised chip-forming elements 15 (here five row-shaped raised chip-forming elements 15 are provided, each of which has a relatively flat rising flank with a rising angle of preferably 5 ° to 10 ° compared to an imaginary horizontal plane. These rising angles! A, 5 is, in any case, exaggerated for clarity, is smaller than the angle β of the falling flank, which can be, for example, 30 °. Both in the longitudinal sectional view AA and in a view transverse to this sectional plane, the chip-forming element 15 is preferably convex The rise angle o and the angle β of the falling flank is formed by the connecting line between the base point of the rising or falling plane in the region of the groove 14 and the upper vertex at the apex line 153 and the connecting line running parallel to the cutting edge in the groove 14 never between the two base points of the rising and the falling edge. At the upper apex line 153, which defines the transition between the rising flank 151 and the falling flank 152, the chip form element has a radius R between 0.25 mm and 0.4 mm. The

When viewed from the cutting edge 10 or the chamfer 13, the chip forming groove 14 is formed by a falling part, as a result of which a rake angle of

for example, 10 ° to 15 °. At this sloping part, which in the

When viewed in cross-section, it can run in a straight line or also concavely curved, a rising part adjoins a chip recess minimum up to an edge 141 which delimits a central chip face plateau 12.

The angle of rise to this rake face plateau can be the same size or larger than the angle of the falling flank. This chip form groove, which is known in principle according to the prior art, serves to bend the chip and to break it as short as possible.

FIG. 3 shows part of a chip shaping guide 14 with three raised chip shaping elements 15 arranged next to one another. The distance between the chip form elements is, for example, 0.5 mm; the respective length l of each

Chip form elements is approx. 5 mm. The chip-forming elements can, as shown in FIGS. 2 and 3, each have the same contour and be lined up along a common line, or alternatively, as indicated in FIG. 6, offset from one another, i.e. with a different distance from the cutting edge. Furthermore, the raised chip-forming elements 15 can also be arranged rotated by 180 °, so that, as shown in FIG. 6, two falling flanks face each other.

In another embodiment shown in FIG. 7, the extremely concave chip-forming element 16 is arranged in such a way that it breaks through the chamfer 13 or the cutting edge 10, which results in a local elevation of the cutting edge. 8, the tip cutting corner 17 of a rhombic cutting insert is shown, in which the rake formation is axisymmetric to the

Cutting edge bisector 18 is configured. there are two raised ones in the chip mold recess adjoining the cutting edge or the chamfer

Chip-shaped elements 15 are arranged, in which the respective «! face shorter and steeper falling flanks.

A different design of the rake face of the cutting tool with overlapping raised chip shape elements can be seen in FIG. 9. The chip form elements 19 there have a relatively significantly longer rising flank and, in contrast, a very short falling flank which falls onto the rising flank of the raised chip form element located behind it. This results in a zigzag-shaped contour when viewed in the direction of chip removal.

In addition, the chip-forming elements 19 lying parallel to the cutting edge but at the same distance from the cutting edge overlap, as a result of which parallel to the

Cutting edge 10 results in an approximately undulating course, which causes the outgoing chip on the one hand good steering, on the other hand one

experiences the least possible friction when guided over the chip-forming elements 19. The overlap areas marked with the reference symbols Üi and Üz are 10% to 30% (Üi) or a maximum of 20%

In the embodiment shown in FIG. 10, a rhombic cutting insert with a cutting corner 17 is also selected, in which the cutting edges 20, 21 converge. In the sloping chip recess 14 and in each case parallel to the cutting edge 20, 21 in an overlapping manner

Chip mold elements 22 arranged one behind the other.

The combination of the raised chip-shaped elements according to the invention in

11 shows the connection with already known chip-forming elements. In the example there and in a chip-forming trough 14, individual raised chip-forming elements 23, each of the same design, are arranged, which are approximately the chip-forming elements can correspond, which is shown in Figs. 1 to 5. In the one chosen there

In the exemplary embodiment, the longitudinal axis of these chip-forming elements 23 is oriented approximately perpendicular to the cutting edge; a maximum of 10 * to 15 * angle to the cutting edge perpendicular should be selected.

The chip breaker 24 shown in FIG. 11 drops, for example, at an angle of approximately 20 * into the chip-forming trough 14, the chip breaker 24

Cutting edge 10 clearly protrudes. From this chip breaker survey, respective longitudinal ribs 25 protrude, the orientation and contour of which in principle

DE 41 36417 A1 has been described. These ribs 25 each extend into areas between the raised chip elements 23 according to the present invention.

Claims

speech

1. Cutting tool for machining operations, especially for

peeling-like machining, with a chip-forming trough running along the cutting edge, in which chip-shaped elements that have been formed are arranged,

characterized,

that the raised chip-forming elements (15, 16, 19, 22, 23) have - viewed in a plan view - an elongated contour with a length (I) greater than their width,

that the chip form elements have a rising flank (151) and a falling flank (152), the comparatively longer rising flank (151) being characterized by a rising angle (a) of 3 "to 20 °, preferably 5 ^e to 10" and a falling angle ( β) is defined between 25 ° to 45 ^e , preferably 27 ”to 35 °,

that the transition from the rising flank (151) between the falling flank (152) is rounded and the radius (R) of this rounding is between 0.05 mm and 1 mm, preferably between 0.25 mm and 0.4 mm.

2. Cutting insert according to claim 1, characterized in that the

Elevated chip-form elements (15, 16) viewed in plan view in the area of their upper apex line (153), which are defined by the adjoining

Rising and falling edges are defined to have the greatest width.

3. Cutting insert according to one of claims 1 or 2, characterized in that the chip-forming elements (15) are spaced apart, preferably a distance (a) of 0.4 mm to 0.6 mm with a respective length defined by their longitudinal axis (I ) from 4 mm to 10 mm.

4. Cutting insert according to one of claims 1 tos 3, characterized in that the chip-forming elements (15) are lined up in a line parallel to the cutting edge (10, 11) and the orientation thereof is inclined to the chip flow direction by 10 ° to 20 °, preferably 15 * is.

5. Cutting insert according to one of claims 1 tos 4, characterized in that the chip-forming elements (15, 16, 19, 22, 23) so active

Cutting edge (10, 11) are aligned so that the cut

incoming chip is guided in the direction of the longitudinal axis of the chip form elements.

6. Cutting insert according to one of claims 1 tos 5, characterized in that the chip-forming elements (15, 16) in a cross-sectional view, i.e.

have a concave, convex or partially straight shape honed perpendicular to the longitudinal axis.

7. Cutting insert according to one of claims 1 tos 6, characterized in that at least individual raised chip-forming elements (16) into the

The cutting edge (10) protrude and form a local one

Break through the cutting edge elevation.

8. Cutting insert according to one of claims 1, 2, 4 to 7, characterized

characterized in that the chip form elements (19, 22) merge into each other and are lined up like fish scales, whereby

preferably the degree of overlap (Ch) viewed in its longitudinal direction is 10% to 30%.

9. Cutting insert according to one of claims 1, 2 or 4 to 8, characterized

characterized in that the chip form elements overlap laterally, the degree of overlap (Üz) measured vertically to the longitudinal axis being a maximum of 20%, preferably a maximum of 10%.

10. Cutting insert according to one of claims 1 tos 6, characterized in that in particular in the region of a cutting corner (17) the arrangement and design of the chip-shaped elements (15) axially symmetrical to

Cutting corner angle bisector (18) is formed.

11. Cutting insert according to one of claims 1 tos 10, characterized in that a flank rising to a central raised plateau (24) is provided in the edge to the cutting edge and in the direction of chip flow viewed behind the chip mold cavity, of which preferably

half-rib-shaped further chip-shaped elements (25) in the direction of

Extend the cutting edge, which protrude into the space between two adjacent raised chip-forming elements (23).

12 cutting insert according to one of claims 1 tos 11, characterized in that before the chamfer (13) adjoins the cutting edge.