Title:
圧縮コイルばねおよびその製造方法
Document Type and Number:
Japanese Patent JP5361098
Kind Code:
B1
Abstract:
Tensile residual stress due to coiling processing is solved and appropriate compressive residual stress distribution is imparted by forming C-condensed layer at the wire material surface, so that compression coil spring having high durability is produced by using inexpensive wire material in the method for production of the present invention. The coil spring includes steel wire material containing 0.45 to 0.80 weight% of C, 0.15 to 2.50 weight% of Si, 0.3 to 1.0 weight% of Mn and iron and inevitable impurities as the remainder, and having a circle equivalent diameter of 2.5 mm to 10 mm, in which internal hardness at a freely selected cross section of the wire material is in a range of 570 to 700 Hv, C-condensed layer which exceeds average concentration of C contained in the steel wire material exists at surface layer part, and in an approximate maximum principal stress direction generated when a compressive load is loaded on spring of inner diameter side of the coil spring of the wire material, unloaded compressive residual stress at a depth of 0.2 mm and 0.4 mm from surface of the wire material is not less than 200 MPa and not less than 60 MPa, respectively.
Inventors:
Yuichiro Ono
Toru Shiraishi
Yoshiki Ono
Keita Takahashi
Toru Shiraishi
Yoshiki Ono
Keita Takahashi
Application Number:
JP2012202416A
Publication Date:
December 04, 2013
Filing Date:
September 14, 2012
Export Citation:
Assignee:
Nippon Jojo Co., Ltd.
International Classes:
C22C38/00; B21F35/00; B24C1/10; B24C11/00; C21D1/06; C21D7/06; C21D8/06; C21D9/02; C22C38/04; C22C38/54; C23C8/22; F16F1/06
Domestic Patent References:
| JP2012077367A | ||||
| JP2001082518A | ||||
| JP5086418A | ||||
| JP1177318A | ||||
| JP4099126A | ||||
| JP56152921A | ||||
| JP2000326036A | ||||
| JP2008045178A | ||||
| JP5064590B2 |
Attorney, Agent or Firm:
Suenari Mikio