公开(公告)号：US20240229884A9

公开(公告)日：2024-07-11

申请号：US18399940

申请日：2023-12-29

Applicant: NHK SPRING CO., LTD.

Inventor： Hideki OKADA ,  Yuichiro YAMAUCHI ,  Ryo TANAKA ,  Takeshi SUZUKI ,  Kosuke SHIBAIRI

IPC: F16F1/04 ,  B60G11/14

CPC classification number: F16F1/042 ,  B60G11/14 ,  B60G2204/1244 ,  F16F2226/023

Abstract: According to an embodiment, a coil spring is formed of a wire which is helically wound, and includes an end turn portion and an effective portion, and a surface of the wire in the end turn portion includes an area which is softer than a surface of the wire in the effective portion.

公开(公告)号：US20240133440A1

公开(公告)日：2024-04-25

申请号：US18399940

申请日：2023-12-29

Applicant: NHK SPRING CO., LTD.

Inventor： Hideki OKADA ,  Yuichiro YAMAUCHI ,  Ryo TANAKA ,  Takeshi SUZUKI ,  Kosuke SHIBAIRI

IPC: F16F1/04 ,  B60G11/14

CPC classification number: F16F1/042 ,  B60G11/14 ,  B60G2204/1244 ,  F16F2226/023

Abstract: According to an embodiment, a coil spring is formed of a wire which is helically wound, and includes an end turn portion and an effective portion, and a surface of the wire in the end turn portion includes an area which is softer than a surface of the wire in the effective portion.

公开(公告)号：US20190390727A1

公开(公告)日：2019-12-26

申请号：US16559137

申请日：2019-09-03

Applicant: NHK SPRING CO., LTD.

Inventor： Takeshi SUZUKI ,  Yoshiki ONO ,  Shimpei KUROKAWA ,  Kosuke SHIBAIRI

IPC: F16F1/02 ,  C21D9/02

Abstract: A spring consists of, by mass %, 0.5 to 0.7% of C, 1.0 to 2.0% of Si, 0.1 to 1.0% of Mn, 0.1 to 1.0% of Cr, not more than 0.035% of P, not more than 0.035% of S, and the balance of Fe and inevitable impurities. The spring has a structure including not less than 65% of bainite and 4 to 13% of residual austenite by area ratio in a cross section. The spring has a compressive residual stress layer in a cross section from a surface to a depth of 0.35 mm to D/4, in which D (mm) is a circle-equivalent diameter of the cross section. The spring has a high hardness layer with greater hardness than a center portion by 50 to 500 HV from a surface to a depth of 0.05 to 0.3 mm.