US 11,788,162 B2
Manufacturing method of cage and the cage manufactured by the method
Jeong Lyul Park, Hwaseong-si (KR); Won Kew Ban, Hwaseong-si (KR); and Hyo Jin Kim, Hwaseong-si (KR)
Assigned to SEOHAN INDUSTRY CO., LTD., Jincheon-gun (KR); and KOREA FLANGE CO., LTD., Ulsan (KR)
Filed by Seohan Innobility Co., Ltd., Chungcheongbuk-do (KR); and Korea Movenex Co., Ltd., Ulsan (KR)
Filed on Aug. 13, 2021, as Appl. No. 17/401,343.
Claims priority of application No. 10-2020-0103477 (KR), filed on Aug. 18, 2020.
Prior Publication US 2022/0056546 A1, Feb. 24, 2022
Int. Cl. C21D 9/40 (2006.01); F16C 33/44 (2006.01); C21D 1/18 (2006.01)
CPC C21D 9/40 (2013.01) [C21D 1/18 (2013.01); F16C 33/44 (2013.01)] 5 Claims
OG exemplary drawing
 
1. A method of manufacturing a cage for a constant velocity joint, the method comprising:
a cutting operation of forming a structure having an outer shape by cutting a cylindrical pipe;
forming an outer circumference of the cut structure to have a curved surface thereon;
performing a turning operation on a surface of the formed structure;
a punching operation of forming a window in the surface of the structure on which the turning operation is performed;
a broaching operation of processing an edge of the window formed via punching; and
a heat treatment operation of performing a heat treatment to the broached cage,
wherein the heat treatment operation includes:
increasing a temperature of the cage to 880° C. for 100 to 140 minutes;
maintaining the temperature of the cage at 880° C. for 80 to 150 minutes;
cooling the cage to 200 to 270° C.; and
when the slow cooling is completed, performing austempering in a salt bath treatment tank in a range of 200 to 270° C. for 130 to 170 minutes.