SU752522A1 - Method of manufacturing rectangular strip-type magnetic cores - Google Patents

Description

(54) METHOD OF MANUFACTURING RECTANGULAR TAPE MAGNETIC WIRES

one

The invention relates to the technology of manufacturing tape magnetic circuits, widely used in electrical and radio devices.

A known method of manufacturing flexible cores is that the prepared tape is cut into segments of different lengths with a certain cutoff step. A set of such plates per half core is assembled into a trapezoidal bag, which is a blank for subsequent bending. The bending of the bag is performed on the press using a punch and die, and the bag acquires the necessary form 1.

The disadvantages of this method are the complexity of the technology, low productivity and a significant deterioration of the magnetic properties of the material due to cold deformation of the tape during stamping and bending.

A method of manufacturing cores is also known, including winding a tape on the original mandrel, removing the wound ring blank from the original mandrel, laying it in the second mandrel, making the ring blank final.

forms in the second mandrel, fixation of the obtained core and annealing 2.

This method allows uniform winding of cores and is distinguished by higher productivity.

However, the magnetic properties of the material are significantly deteriorated by cold deformation and are not sufficiently restored when the core is annealed in a fixed state together with the mandrel. Closest to the present invention is a method of winding a steel magnetic core, according to which a ribbon of silicon electrical steel is wound on an annular mandrel, then removed from the mandrel and inserted into the annular billet two forming elements having

 the shape of rectangular parallelepipeds, in which from the outer side facing the inner surface of the core, rounded radii of small size are made. Forming elements are moved apart

20 from the inside. Then, from the outer sides, the core is compressed by two forming elements, as a result of which the core acquires a rectangular shape. The radius of curvature of each inner corner of the core is made smaller than the rounding radius of the similar angles of the inner anchor for annealing. Then, the inner forming elements are removed, the annealing mandrel is inserted under pressure, and annealing is carried out 3.

However, during cold forming of the billet, the magnetic properties of the core deteriorate and are not fully restored during annealing, which affects the quality of the manufactured magnetic cores. In addition, the installation under pressure of the mandrel for annealing reduces the performance of a known method.

The purpose of the invention is to increase the productivity and quality of the manufactured magnetic baud.

The goal is achieved by the fact that before forming the billet is heated to 900-950 ° C.

FIG. Figure 1 shows schematically an annular billet in a stretcher; in fig. 2 — stretching the ring blank; in fig. 3 - an annular billet in a device for compression; in fig. 4 - compression ring blanks.

A tape of electrical steel is wound on a cylindrical mandrel to obtain a predetermined outer diameter of the ring billet. The ends of the tape on the ring billet are fixed by spot welding.

Next, remove the ring from the mandrel blanks and individually placed them in the oven, heated to 900-950 ° C, and heated for 4-5 minutes. The heated blanks are removed from the furnace and placed in a device for changing shape. Part of the cores are made by stretching the ring blanks in a different grip, the other part by squeezing them on a press.

In the manufacture of cores by stretching, the heated annular billet 1 (Fig. 1) is placed on the movable jaws 2 of the expanding vice and by the force P is stretched to obtain a rectangular core (Fig. 2). In the manufacture of cores by squeezing, the heated annular billet 1 (Fig. 3) is put on the inner core of the W-shaped mandrel 3 mounted on the press with punches 4. After the pressure P is applied, the circular billet is molded

rectangular core 5 (Fig. 4) with the help of the bounding walls of the mandrel 3 and the punches 4.

Then all the obtained rectangular cores are placed in a vacuum oven.

and annealed without adaptation in the same vessel at 880 ° C with an exposure time of 2.5 hours. The cooling after annealing is carried out at a rate of 50 ° C / h to 600 ° C and further along with the furnace. The technical and economic effect of the proposed method is to reduce

electromagnetic losses in the cores, which leads to a decrease in their dimensions, weight and material savings. With the same dimensions, the quality of the cores is improved.

Along with an increase in the quality of cores, the use of the proposed method leads to a significant increase in labor productivity. Heating and stretching (compression) of ring blanks take 6-8 minutes, therefore, labor productivity

This method is mainly determined by winding and annealing.

The use of the proposed method also leads to a simplification of the tooling and an increase in its service life, since in this method it is not subjected

heating at high temperature.

Claims (3)

1. Bal N. R. K. Transformers for radio electronics. L., Sudpromgiz, 1971, p. 88-103. 2. US patent number 2.288,855, cl. 29-605,1940. 3. For Japan Japan No. 50-23724, cl. H 01 F 3/04, 1975. . / fig one P Phi1.d FIG.