RU2317875C1 - Cutting instrument - Google Patents

Abstract

FIELD: the invention refers to the field of processing materials by cutting.

SUBSTANCE: the instrument has a holder and located on it a cutting plate. For increasing technological characteristics the cutting plate is fulfilled in the shape of a three-edged pyramid or a truncated pyramid or a prism with a three-cornered foundation having flat or/and fashioned surfaces. At that the maximal thickness of the cutting plate is defined depending of the height of the holder. The cutting plate is mounted due to welding or is formed by welding deposition.

EFFECT: increases technological characteristics of the cutting plate.

2 dwg

Description

The invention relates to the production and design of cutting tools, in particular to the design of the cutting plate of cutters, mills, etc.

Known designs of the working part of the cutting tool, which have a cutting plate in the form of a prism, which are mounted on the holder by soldering, gluing and mechanical fastening (Handbook of the designer-toolmaker. Under the general editorship of V.I. Barannikov. - M .: Engineering, 1994 - 560 C.), the distinguishing features of which are the shape of the cutting insert in the form of a regular prism with flat faces and the methods of its installation: mechanical fastening, soldering, gluing.

The disadvantages of the known methods of mounting the insert include:

- insufficient strength of attachment of the cutting insert at high temperatures that occur during cutting;

- significant thickness of the cutting part (from 5 mm) in order to bring the zone of its connection with the holder from the region of high temperatures;

- the presence of a step in the holder for mounting the plate, as a result of this, a dangerous section arises that weakens the holder and reduces its strength;

- increased wear of the insert due to significant heating.

The closest is the design of the working part of the cutting tool, characterized in that the cutting plate is formed by welding (Smirnov F.F. Surfacing of the cutting tool with high-speed steel. / In the book. "Cast and deposited cutting tool. Design and production" - M .: Mashgiz, 1951, p. 289-304 .; Zubkov N.S., Tyutyaev V.A., Zubkova E.N. Production of a deposited metal-cutting tool.- Tver: Publishing House of the Tver State Technical University, 1998 - 124 pp. ; Patent RU No. 2078668 C1, class 6 В23Р 15/30, В23K 9/4, Tyutyaev V.A., Zubkova E.N. Method for manufacturing a cutting tool. publ. 10.05.1997.), the shape of which seeks to copy the shape and dimensions of the cutting inserts for cutters with prismatic inserts.

The essential features of this tool are the shape and dimensions of the cutting insert and the methods used to mount the insert on the holder.

The technical result of the proposed design of the cutting part is to create a tool with higher wear resistance of the working part, as well as the strength and rigidity of the holder.

The problem to which the invention is directed, is to increase the technological properties of the cutting tool.

The solution to this problem was achieved by changing the shape of the cutting insert (see Fig. 1), which has the shape of a trihedral pyramid (Fig. 1b, c) or a truncated pyramid or prism with a triangular base (Fig. 1d, e), which are flat (Fig. 1b, d, e) and (or) shaped surfaces (Fig.1c).

A distinctive feature of this design is that the cutting insert must have a maximum thickness s = (0.05-0.16) H, where H is the height of the tool holder, which is approximately 1.5-2 times less than with the tool, with mounted prismatic plate for which s = (0.18-0.25) H (on p. 286 in the book: Toolmaker's Handbook / I.A. Ordinartsev, G.V. Filippov, A.N. Shevchenko and others; under the general editorship of I.A.Ordinartsev. - L .: Engineering, Leningrad., 1987. - 846 p.). This improves the heat transfer from the cutting insert to the tool holder (a lower layer thickness with lower thermal conductivity is achieved). Strong adhesion to the toolholder at high temperatures is ensured by the use of welding for mounting the cutting insert (diffusion, embossed or other) or the formation of the cutting insert using surfacing that slightly melts the substrate (up to 5%) (laser powder, laser microplasma, plasma powder and other similar) so as not to distort the shape of the cutting insert and the shape of the holder.

Thus, the proposed cutting tool provides: greater wear resistance due to improved heat removal from the cutting edge to the body of the cutter during free cooling and when cooling with liquid circulating through the internal holes in the holder; saving material of the insert due to the smaller thickness of the insert; Improving the strength and rigidity of the tool holder due to the absence of a dangerous section.

A brief description of the drawings. Figure 1 presents the design options of the cutting part, where: a), d) is a traditional design; b), c), e), e) - the proposed design; b) - in the form of a trihedral pyramid with straight faces; c) - in the form of a trihedral pyramid with straight and shaped faces; d) - in the form of a prism with a triangular base; f) - in the form of a truncated pyramid with a triangular base; 1 - cutting insert; 2 - holder (case); s is the thickness of the insert, H is the height of the tool holder.

Figure 2 shows the wear curves of the cutters along the rear face, where: I - wear curves of the cutters with a maximum thickness of the cutting layer of more than 3 mm and base cutters (solid forged and with a soldered cutting plate with a thickness of 5 mm); II - wear curves of cutters with a minimum thickness of the cutting layer of 1.5-1.8 mm; III - wear curves of incisors with an optimal thickness of the cutting layer of 2.2-2.5 mm.

The proposed design has been tested in a production environment. Plasma-powder surfacing of tool holders made of steel 45 by high-speed steel P6M5 was carried out. Surfacing was carried out without penetration of the substrate on the inclined surface of the bevel (10 °). By processing on a grinding machine, the edges of the cutters are formed in such a way as to obtain cutting inserts in the form of trihedral pyramids. The maximum thickness of the cutting layer (figb, size s) was in the range of 1.5-3.5 mm Then the deposited tool was subjected to double tempering at a temperature of 560 ° C for one hour. Tests of cutters were carried out when turning a shaft made of steel 45 with a keyway without cooling according to the regime, feed - 0.57 mm / rev, cutting depth - 1 mm, cutting speed - 40-80 m / min. The hardness of the deposited and base cutters (with P6M5 cutting inserts 5 mm thick and solid forged from P6M5 steel, heat-treated using traditional technology — quenching and triple tempering at 560 ° C for one hour) was the same and amounted to 61-63HRC. Figure 2 shows the wear curves of the tested incisors along the rear face. Cutters with a cutting plate with a maximum thickness of more than 3 mm had a resistance similar to the base cutters made by traditional technology (group of wear curves I, Fig.2). Cutters with a cutting plate with a thickness of 2.2-2.5 mm had a maximum wear resistance, 2-3.5 times higher than the wear resistance of the base cutters (group of wear curves III, figure 2). Cutters with a thin plate (1.5-1.8 mm) showed intermediate wear resistance located between cutters with an optimal thickness (2.2 mm) of the cutting insert and base cutters with a plate thickness of 5 mm and a forged cutter (wear curve group II, fig. .2).

Distinctive features of this cutting tool are:

- the shape of the cutting insert in the form of a trihedral pyramid, or a truncated trihedral pyramid, or a prism with a triangular base with flat and (or) shaped faces;

- the thickness of the cutting layer s = (0.05-0.16) H, where H is the height of the tool holder;

- mounting of the cutting insert is carried out by welding or by forming it by surfacing, which does not distort the given shape of the cutting insert itself and the holder.

The advantages of this design are:

- greater wear resistance by increasing the efficiency of heat removal to the holder with free cooling and when cooling with liquid circulating through the internal holes in the holder;

- improving the strength and rigidity of the tool holder;

- saving material of the insert;

The inventive design fully fulfills the goal. The claimed technical solution is not known in the Russian Federation and abroad and meets the requirements of the criterion of "novelty." The claimed technical solution does not obviously follow from the existing level of technology and meets the requirements of the criterion of "inventive step". The technical solution can be implemented in industry and meets the requirements of the criterion of "industrial applicability".

Claims (1)

A cutting tool comprising a holder and a cutting insert placed on it, characterized in that the cutting insert is made in the form of a trihedral pyramid, or a truncated pyramid, or a prism with a triangular base, which have flat and / or shaped faces, with a maximum thickness of the cutting plate s is s = (0.05-0.16) H, where H is the height of the holder, and the cutting plate on the holder is mounted by welding or formed by surfacing.

Images