LU83970A1 - CUTTING INSERT FOR SHELLING OR SHAFT TURNING - Google Patents

Description

- 1 -. Cutting insert for peeling or shaft turning

The invention relates to a cutting insert for peeling or shaft turning, which has a plurality of blades arranged one behind the other.

The peeling of bars, pipes or, for example, wire is widely used. That is why operators of peeling machines and manufacturers of tools for such machines strive to constantly improve the working conditions in order to be able to manufacture cost-effective and high-quality products. Particular attention is paid to the design of the cutting edge geometry or the cutting element, which is usually a cutting insert made of high-speed steel or hard metal or a combination of these two materials. Depending on the purpose, the cutting insert has one or more cutting edges.

A cutting tool for peeling or shaft turning is known in which the cutting insert is designed as an elongated octagon (DE-PS 1,800,195). With this cutting insert, very good results are achieved with regard to the surface quality of the peeled material.

To achieve a very high depth of cut with large feeds, it is known to design the cutting insert so that it has a first main cutting edge and a secondary cutting edge (DE-QS 28 25 748).

9 _ 2 _

The invention has for its object to provide a cutting insert with which close tolerances and a high surface quality of the machined material can be achieved with high cutting performance.

The object is achieved in that a first main cutting edge, an adjoining ^ first secondary cutting edge, a second main cutting edge following this and a second secondary cutting edge are arranged such that two independent chips are present during machining.

According to an embodiment of the invention, the length of the a / first minor cutting edge is determined by the relationship a = - max 2, where Ln is the section from the beginning of the first minor cutting edge to the end of the second minor cutting edge.

Another embodiment of the invention is that the distance b between the first and the second minor cutting edge by the relationship

b = 0.1 to 0.5 + K

is determined, where K is the solidified zone known per se. of the respective pre-processed material.

The advantages which can be achieved with the invention consist, in particular, in that pre-peeling and finishing peeling with simultaneous good glowing and guiding properties is possible with a single cutting insert. This results in tight tolerances and a high surface quality of the workpiece to be machined with a good service life of the cutting insert.

- 3 _

The invention is described in more detail with reference to the drawings. Show it

Ί, 2 and 3 a cutting insert according to the invention in three views,

4 details of the new cutting insert,

Fig. 5 shows a cutting insert according to the invention with a workpiece to be machined and

6 shows a known schematic representation for the factor K.

It can be seen from FIGS. 1 to 5 that the new cutting insert 9 / produces two separate chips. The first main cutting edge 1 has the task of pre-peeling.

The subsequent secondary cutting edge 2 preferably has a length a which is at most half the length Ln (FIG. 4). With such a design, feeds s = -Tp- x f are possible, the factor f being between 0.7 and 0.9. The workpiece 7 to be machined in FIG. 5 is pre-smoothed and guided by the first secondary cutting edge 2.

The second main cutting edge 3 is used for finishing. This is followed by the second secondary cutting edge 4, with which the workpiece 7 is smoothed to ensure tight tolerances and to achieve a high surface quality.

Between the first secondary cutting edge 2 and the second secondary cutting edge 4 there should be a distance b = 0, 'i to 0.5 -t- K (FIG. 4). K stands door the solidified zone of the respective pre-processed material and can be determined in a manner known per se. Fiq. G shows: such a representation. In this example, the solidified zone K is in the range of 0 to 0.4 mm; the hardness in this hardened area is significantly higher than the hardness in the unsolidified area of the material.

i i i j t \ - 4 -

J

(! The first secondary cutting edge 2 is expediently selected at an angle of 0 ° to 15 °, preferably 0 ° to 5 ° to the axis 8 a of the workpiece 7 (FIG. 5). As indicated in FIG. 5 at 10; the first secondary cutting edge 2 may be designed to spring back against the second main cutting edge 3.

] -. The second main cutting edge 3 does not necessarily run parallel to the first main cutting edge 1, but the angle ^; - be smaller than 90 ° in Fig. 4 and the second secondary cutting; de 4 can be arranged parallel to the axis 8 of the workpiece 7.

The angle ^, in FIG. 5, the inlet angle of the first main cutting edge 1, is preferably selected according to the depth of cut and the material to be machined, preferably 15 ° + _ 10 °, in extreme cases it can also be selected up to 35 °.

λ

The surfaces 5 in Fig. 1, 2 and 3 serve as holding and clamping surfaces in known clamping tools. With the help of the bore 6 and a correspondingly designed device, the cutting insert 9 can also be attached.

Other, common types of fastening are also possible.

The main materials used for the cutting insert are hard metal and high-speed steel or a combination of these two materials. However, all other cutting materials, such as ceramics, are also conceivable.

Claims (3)

1. Cutting insert for peeling or turning, which has a plurality of cutting edges arranged one behind the other, characterized in that a first main cutting edge (1), an adjoining first secondary cutting edge (2), a second main cutting edge (3) following this and a second secondary cutting edge (4) are arranged so that two independent chips are available during machining. 2. Cutting insert according to claim 1, characterized in that the length (a) of the first secondary cutting edge (2) by the relationship a _LD. max 2 is determined, where Ln is the section from the ticginn of the first minor cutting edge (2) to the endo of the second minor cutting edge (4). u «. - 2 - 3. Cutting insert according to claim 1, characterized in that the distance (b) between the first (2) and the second secondary cutting edge (4) is determined by the relationship b = 0.1 to 0.5 + K, where K is the known solidified zone of the respective preprocessed material.