The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Mar. 10, 2020
Filed:
Dec. 23, 2018
Nhk Spring Co., Ltd., Yokohama-shi, Kanagawa, JP;
Akira Tange, Yokohama, JP;
Hideki Okada, Yokohama, JP;
NHK SPRING CO., LTD., Yokohama-Shi, Kanagawa, JP;
Abstract
A method of manufacturing a suspension coil spring includes forming first shot peening indentations on a surface of a wire by projecting first shots toward the wire and forming a compressive residual stress portion to which a compressive residual stress is imparted from the surface of the wire to a first depth, and projecting ball shots as second shots toward a lower end turn portion by an ultrasonic apparatus. A size of each ball shot is larger than a size of each first shot. The method includes forming second shot peening indentations on a surface of the lower end turn portion, and a deep residual stress portion in the lower end turn portion, a compressive residual stress of the deep residual stress portion imparted from the surface of the wire to a second depth that is deeper than the first depth.