US 12,440,879 B2
Wire drawing method and wire drawing device
Younjeong Hong, Tokyo (JP); and Chengting Hsieh, Tokyo (JP)
Assigned to HITACHI, LTD., Tokyo (JP)
Appl. No. 18/021,700
Filed by HITACHI, LTD., Tokyo (JP)
PCT Filed Sep. 28, 2021, PCT No. PCT/JP2021/035534
§ 371(c)(1), (2) Date Feb. 16, 2023,
PCT Pub. No. WO2022/085375, PCT Pub. Date Apr. 28, 2022.
Claims priority of application No. 2020-177502 (JP), filed on Oct. 22, 2020; and application No. 2021-116021 (JP), filed on Jul. 13, 2021.
Prior Publication US 2023/0330731 A1, Oct. 19, 2023
Int. Cl. B21C 23/08 (2006.01)
CPC B21C 23/08 (2013.01) 8 Claims
OG exemplary drawing
 
1. A wire drawing method comprising:
preparing a first wire rod by surrounding a first rod with a first pipe having a first longitudinal length and a second pipe having a second longitudinal length different from the first longitudinal length;
creating a second wire rod that includes the first pipe having a third longitudinal length and the second pipe having a fourth longitudinal length different from the third longitudinal length, by reducing a cross-sectional diameter of the first wire rod through wire drawing; and
setting a first difference between the third longitudinal length and the fourth longitudinal length in the second wire rod to be smaller than a second difference between the first longitudinal length and the second longitudinal length in the first wire rod.