RU1836198C - Circular rotating cutter - Google Patents

Abstract

Usage: in metalworking, in particular in a cutting tool. SUMMARY OF THE INVENTION: a cutting insert used in a circular rotary cutter having a cylindrical holder and a side cutting edge defined between a cutting main rear surface and a side rear rear end and a side base edge defined between a side rear end and a base surface, wherein a side rear end contains the first and second constituent lateral rear end surfaces intersecting along an intersection line extending along the lateral rear end from the first position adjacent to the front end ohm of the insert and positioned in an intermediate position to the second position crossing the cutting edge and adjacent to the rear cond of the insert, the component end surfaces being essentially flat and arranged at an angle to one another so that the lateral rear corner of the insert defines the relative to the cylindrical holder in the region of the front end is equal to the lateral rear corner of the insert in the region of the rear end. 1 s.p. f-ly, 9 ill.

Description

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WITH

The invention is used in metalworking, in particular in a cutting tool.

An object of the invention is to increase tool life.

In FIG. 1 is a schematic side view of a simplified cutter showing the installation of a cutting insert in accordance with the invention on it: FIG. 2 is a plan from under a cutting insert made in accordance with the invention; in Fig.3 is a plan from above of the cutting insert shown in Fig.2; Fig. 4 is a side view of the cutting insert shown in Figs. 2 and 3: Figs. 5 and 6 are, respectively, a cross section of one side of the cutting insert shown in Fig. 4. taken respectively along lines IX-IX and XX; Figures 7-9 are respectively the cross-sections of the milling cutter and the cutting insert shown in Fig. 1, along lines l-l, II-H and Ill-Ill superimposed on the corresponding circular cutting path.

As seen in FIG. 1,2 and 3, insert 1 is mounted on a seat 2 formed in a recess 3 located within holder 4.

The insert 1 is located at an axial rear angle a relative to the longitudinal axis of the tool holder, as can be seen in FIGS. 2 and 3, and is formed with an upper main rear surface 5, a lower base surface 6, front and rear end surfaces 7 and 8 and side ends 9 and

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10. The side cutting edges 11 and 12 are respectively defined between the side ends 9 and 10 and the upper rear surface. The lateral ends end respectively at the base surface b at the edges 13 and 14 of the base. The front and rear cutting edges 15 and 16 are defined respectively between the front and rear end surfaces 7 and 8 and the upper rear surface 5. A central hole 17 is made in the insert 1 for screw clamping of the insert T to the tool holder 4.

Side end 9 contains the first and. the second constituent embossed end surfaces 18 and 19 that intersect along the intersection line 20 extending along the side embossed end 9 from the first position 21, adjacent to the front end determined by the position of the insert at the front end to the second position 22 with the intersection of the cutting edge 11 is adjacent to the rear end of the insert. These constituent embossed end surfaces of 18 m 19 are flat and are angled to one another.

Similarly, the lateral end face 10 is formed with component embossed end surfaces that intersect along the intersection line, with the inclination directions of the intersection lines being opposite.

Figure 5 shows the correspondingly different slopes of the components of the embossed end surfaces along the IV-IV section line, Fig. B along the VV- section line passing through position 22, the intersection line 20 intersecting the cutting edge 11 is shown, and the inclination is shown a uniform embossed end surface, this inclination being equal to the inclination of the component of the embossed end surface along its entire length.

Figs. 3 and 5 are given to explain a method for determining the position of a constituent embossed end surface 18.

FIGS. 7, 8 and 9 are corresponding sections of a part of the insert 1 of the police I-, MM and Ill-Ill in FIG. 1, shown respectively superimposed on the circular paths, following which the corresponding points on the cutting edge lying on the corresponding cross lines x.

As can be seen in ng) ig. 7, a trailing angle be defined between the constituent rear end surface 18 and the tangent 23 to the circular path 24 at point 25. In this region, the height ha of the constituent rear end surface 18 is at its maximum. Similarly, as can be seen from Fig and drawings,

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twenty

25

thirty

35

40

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fifty

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which relate to an intermediate point 26 along the cutting edge, a trailing angle is defined between the constituent rear end surface 18 and the tangent 27. The height HB of the constituent rear end surface 18 in this region is less than ha. Finally, at a point 28 at the trailing end of the cutting edge 11, a trailing angle is defined between the single end surface 18 and the tangent 29, and the constituent end surface 18 will no longer appear in this area.

The rake angle of the component of the rear end surface 18 at the front end of the insert 1 is selected so that it is equal to the rear angle of the single rear end surface at the rear end of the insert and the cutting edge of the front end is suitably reinforced, which allows it to resist significant cutting force exerted on the front end. You may notice that while beats uv, Us at the intermediate point of the cutting edge is less than any of the angles beats or uv. However, it has been found that selecting a trailing angle in the leading parts of the cutting edge that are subjected to cutting forces such that it is equal to the trailing corner in the trailing end of the cutting edge is effective in reinforcing the most sensitive parts of the cutting edge, extending thereby the life of the cutter.

In addition, it is clear from Figs. 7-9 that by creating the upper component of the rear end surface 18, it is possible to make an insert with a relatively large radial main trailing angle (i.e., a large positive cutting edge) without dangerous, at the same time, weakening of the cutting edge at the front end subjected to the highest stresses and cutting forces.

When determining the parameters that determine the design of the rear end and component surfaces so that the described results are obtained, it is necessary to keep in mind the following given coefficients:

(I) Target average diameter DA cut

(II) Specified axial major rear angle Oo.

(III) The minimum clearance angle defined by the wear characteristics of the insert and the material of the part.

Based on these coefficients, the optimum clearance angle is determined, which is the actual clearance angle of the trailing end of the insert (in this case whiskers).

i In a specific example: DA 40 mm; f 75 °; .

If now, as can be seen in FIG. 2, the base 6, the front and rear ends 7 and 8 and the constituent side main rear surfaces 18 and 19 are supported in a substantially symmetrical shape, the upper main rear surface 5, the cutting edges 11 and 12 and the constituents the rear end surfaces 18 and 19 are deliberately twisted with respect to the base b so that, as shown in FIG. 3, the dashed line 30, corresponding to the imaginary initial boundary of the base b, is shifted to the broken line 31. Similarly, as shown f and FIG. 5, broken line 32, corresponding to obrazhaemoy source side rear surface of the insert, moves parallel to the surface of the component 19 and the end surface of the component is now parallel to the end surface 18 ..

By keeping the initial symmetrical arrangement of the base and the lower components of the end surfaces of the insert, the insert can be quickly clamped with a bull stop into the usual clamping surfaces of a conventional tool holder.

Furthermore, while the invention has been specifically described with reference to a double-end insert having a pair of side cutting edges and front and rear cutting edges, it is equally applicable to a single-end cutting insert.

Claims (2)

1. A circular rotary milling cutter comprising a cylindrical holder with at least one the circumference of a removable cutting insert with a side cutting edge formed by the front and side rear surfaces and a side base edge formed by the base and side rear surfaces, characterized in that, in order to increase durability, the lateral rear surface is made in the form of two flat surfaces located at an angle to one another, while the intersection line said Planes is positioned at an angle to the cutting edge along the rear surface until it intersects with the cutting edge at the rear end of the insert, the lateral rear corners of the insert relative to the cylindrical holder in the region of the front and rear ends of the insert are essentially equal. 2. The insert according to claim 1, with the exception that it is provided with an opposed first second side cutting edge formed by corresponding similar surfaces as the first edge, and the lateral rear surface of the second edge is made similarly the lateral rear surface of the first edge in the form of two flat surfaces whose intersection line has a direction opposite to the direction of the intersection line of similar lateral planes the rear surface of the first edge. fa2. / Jifzi yz ° - ../ -I. att fioch -J 8 fig-3 sg if and Wffiffls- fiz $  6 FIG. 9