SU721244A1 - Method of manufacturing end-type cutting tools - Google Patents

Description

The invention relates to the processing of metals by pressure and can be used in tool manufacturing in the manufacture of end cutting tools by extrusion. A known method of manufacturing end cutting tools includes end welding of plate and fast cutting steel blanks and subsequent extrusion of the welded semi-finished product 1. The disadvantage of this method is the low quality of the products due to the formation of defects at the front end of the tool. There is also known a method of manufacturing end cutting tools, such as milling cutters, which can improve the quality of products, including welding on the ends of a billet of ductile steel and a billet of high-speed steel and subsequent direct pressing of the resulting welded semi-finished product without a press residue, and obtained from a high-speed steel part of the semi-finished product (2). The disadvantages of this method are low productivity and in a number of cases the accuracy of the products is low. In addition, for the manufacture of right-handed and left-handed screw tools, differential arrays are required, which is inconvenient to operate and reduces productivity. The aim of the invention is to increase the productivity and accuracy of the products. The goal is achieved by the fact that, before pressing to the free end, high-speed steel billets are additionally welded with one more billet of plastic steel, after extrusion, the semi-finished product is cut across into two halves. Thus, in one working stroke of the press, two products are obtained, and in the case of extrusion of a semifinished product through a screw matrix, one of the tools, for example cutters, after cutting the extruded semi-finished product, has a right-sided screw profile and the other is left-sided. FIG. A flowchart of the process is shown (Fig. 1a shows the start

the deformation of the welded semi-finished product; 16 — intermediate extrusion step); in fig. Figures 2 and 3 respectively show the blanks of the working parts of the right-hand and left-side cutters obtained by cutting an extruded screw profile.

The manufacture of the working part of the cutter is made in the following sequence.

To the ends of the workpiece 1 of high-speed steel (see Fig.1) weld the workpiece 2 and 3 of. plastic, for example, carbon steel.

The semi-finished product welded from blanks 1-3 is heated in an inductor up to t 1150 - 1180 ° С. The heated welded semi-finished product is placed in the container 4, an intermediate plate 5 is installed on it. Next, the initial welded semi-finished product is squeezed out by the die 7 in one stroke of the press through the die 7, thus starting the deformation from the section made of plastic carbon steel. Carbon steel, filling the cavity of the matrix 7 at the initial extrusion, creates the necessary backing of a non-plastic high-speed steel when the last one enters the screw cavity. As a result, the possibility of formation of defects along the entire length of the cutting shaft of the filler is excluded even for small ) the radii of the top of the tooth. The ductile carbon steel is deformed without cracking, and the profile section extruded from it is used during the manufacture of the tail, butt section of the tool. An extruded screw profile is then cut, producing blanks of both right-handed (see FIG. 2) and left-handed (see FIG.) Tools.

The method was tested under production conditions at hot hydrodynamic extrusion without a press residue of 12 mm billet workpieces with a working part 1 of steel P 18 and a connecting part 2 or 3 of steel 45 (see Fig. 2 and 3). In tests, the effectiveness of a known method was compared.

The results of comparative tests showed that the application of the proposed method provides:

reduction of allowance for subsequent machining 3-5 times; savings of high-speed steel by 20-25%; improving the quality of cutting tools; reducing the number required to extrude dies in 2 times; reduction of labor costs for extrusion of one milling cutter 1.2-1.8 times.

Claims (2)

1. Severdenko V.P. et al. Hot hydrodynamic extrusion of cutting tools Minsk, Science and Technology, 1974, pp. 422-243, table. 33. 2. USSR author's certificate in application N 2590919/27, cl. B 21 K 5/04, 03/17/78.