METHOD AND DEVICE FOR MANUFACTURING TAPE CORE Russian patent published in 2024 - IPC H01F41/02 H01F27/245 

FIELD: electrical engineering.

SUBSTANCE: in this method of manufacturing a strip core, at least one curved portion (5) of one or more layered grain-oriented electrical steel sheets (1) is formed such that one side (1b) of the steel sheet (1) is placed and restrained on the die (30), and the punch (40) is pressed against the bending portion (1a) of the steel sheet (1) on the other free end side in the thickness direction (T) of the steel sheet. The outer surfaces of the die and punch have an arcuate portion (30a, 40a) having a predetermined curvature, and when the thickness of the steel sheet (1) is T, the bending angles of the arcuate portions (5) areθ (°), the radius of curvature of the arcuate portion (30a) of the die is Rd, and the radius of curvature of the arcuate portion (40a) of the punch is Rp, the relationships of the following equations (1)-(5) are satisfied: 0.02≤T/(2Rd+T)≤ 0.15… (1); 0.5≤ Rd≤3.0… (2); 0.15≤T≤0.30… (3); 2.5≤ Rp/Rd≤10… (4);10°≤θ≤ 90°…(5).

EFFECT: minimizing cracking in curved areas of grain-oriented electrical steel sheets during bending of steel sheets, preventing scratches on the surface of steel sheets or peeling or shedding of the coating on the surface, and improving shape fixation.

6 cl, 9 dwg, 3 tbl