US 11,746,394 B2
Method for manufacturing a trunnion for a constant velocity joint, a trunnion manufactured thereby, and a heat treatment device of the trunnion
Jeong Lyul Park, Hwaseong-si (KR); Wonkew Ban, Hwaseong-si (KR); Hyun Ho Yim, Hwaseong-si (KR); Chang-Gu Lee, Hwaseong-si (KR); and Min-Gyu Kim, Suwon-si (KR)
Assigned to HYUNDAI MOTOR COMPANY, Seoul (KR); KIA CORPORATION, Seoul (KR); SEOHAN INDUSTRY CO., LTD., Deoksan-eup (KR); and KOREA FLANGE CO., LTD, Ulsan (KR)
Filed by HYUNDAI MOTOR COMPANY, Seoul (KR); KIA CORPORATION, Seoul (KR); SEOHAN INDUSTRY CO., LTD., Deoksan-eup (KR); and KOREA FLANGE CO., LTD, Ulsan (KR)
Filed on Oct. 4, 2021, as Appl. No. 17/493,484.
Claims priority of application No. 10-2020-0128713 (KR), filed on Oct. 6, 2020.
Prior Publication US 2022/0106660 A1, Apr. 7, 2022
Int. Cl. C21D 9/40 (2006.01); C21D 1/42 (2006.01); F16D 3/205 (2006.01); C21D 1/18 (2006.01); C21D 9/00 (2006.01)
CPC C21D 9/40 (2013.01) [C21D 1/18 (2013.01); C21D 1/42 (2013.01); C21D 9/0062 (2013.01); F16D 3/2055 (2013.01)] 9 Claims
OG exemplary drawing
 
1. A method for manufacturing a trunnion for a constant velocity joint, the trunnion having a plurality of journal units provided on the outside thereof around a hub unit, the method comprising:
a first step of manufacturing the trunnion;
a second step of thermally treating a rounded outer circumferential surface of the journal unit; and
a third step of thermally treating a connection unit disposed between the journal unit and the hub unit and having a diameter smaller than that of the journal unit,
wherein the second step or the third step further includes
a heating step, through a high-frequency induction heating device, of carrying out heating for 1.5 to 2.8 seconds with an output from 64 to 68 kilowatts (KW),
a delaying step of having a time difference from 0.05 to 0.15 seconds, and
a cooling step of carrying out cooling for 4.5 to 5.5 seconds, and
wherein, in the second step or the third step, an input current is from 150 to 159 amperes (A), a positive voltage is from 5.6 to 6.2 kilovolts (KV), and a positive current is from 4.5 to 5.0 A.