Patents by Inventor Daisuke HAMANAKA

Daisuke HAMANAKA has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 12673359
    Abstract: In a rack bar and a steering device using the same, an endmost tooth bottom for reducing a stress exerted on a first forging die during die forging of a rack tooth molding part is formed on the endmost side of a plurality of tooth bottoms. Specifically, the endmost tooth bottom is formed so that a depth thereof is less than a depth of an ordinary tooth bottom by a difference. This reduces an amount of flow of a material of the rack bar during formation of the endmost tooth bottom by an amount commensurate with the difference. As a result, the stress exerted on the first forging die can be reduced, and occurrence of heat checking in the first forging die can be suppressed.
    Type: Grant
    Filed: July 7, 2022
    Date of Patent: July 7, 2026
    Assignee: HITACHI ASTEMO, LTD.
    Inventors: Shinichi Yamanaka, Daisuke Hamanaka, Norihiro Kimura, Keisuke Kitamura
  • Publication number: 20240375170
    Abstract: In a rack bar and a steering device using the same, an endmost tooth bottom for reducing a stress exerted on a first forging die during die forging of a rack tooth molding part is formed on the endmost side of a plurality of tooth bottoms. Specifically, the endmost tooth bottom is formed so that a depth thereof is less than a depth of an ordinary tooth bottom by a difference. This reduces an amount of flow of a material of the rack bar during formation of the endmost tooth bottom by an amount commensurate with the difference. As a result, the stress exerted on the first forging die can be reduced, and occurrence of heat checking in the first forging die can be suppressed.
    Type: Application
    Filed: July 7, 2022
    Publication date: November 14, 2024
    Applicant: HITACHI ASTEMO, LTD.
    Inventors: Shinichi YAMANAKA, Daisuke HAMANAKA, Norihiro KIMURA, Keisuke KITAMURA