Helical compression spring and method for manufacturing same
Number of patents in Portfolio can not be more than 2000
United States of America Patent
Stats
-
Sep 5, 2017
Grant Date -
Sep 10, 2015
app pub date -
Sep 5, 2013
filing date -
Sep 14, 2012
priority date (Note) -
In Force
status (Latency Note)
Importance
Abstract
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 min from surface of the wire material is not less than 200 MPa and not less than 60 MPa, respectively.
First Claim
Other Claims data not available
Family
International Classification(s)
- 2013 Application Filing Year
- C23C Class
- 2155 Applications Filed
- 1819 Patents Issued To-Date
- 84.41 % Issued To-Date
Cited Art Landscape
Patent Citation Ranking
- 2 Citation Count
- C23C Class
- 27.20 % this patent is cited more than
- 8 Age
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|---|---|---|---|---|
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