Title:
PISTON RING AND MANUFACTURING METHOD THEREFOR
Document Type and Number:
WIPO Patent Application WO/2022/209023
Kind Code:
A1
Abstract:
A piston ring manufacturing method according to the present disclosure includes the following steps. (A) A step in which an arc current is supplied to a cathode configured from a carbon material having a density of at least 1.70 g/cm3, thereby ionizing the carbon material. (B) A step in which a bias voltage is applied in an environment having substantially no hydrogen atoms, thereby forming a DLC film on the surface of a base material for a piston ring. After step (A) is carried out continuously, step (A) is paused, and then step (A) is resumed, and by repeating this process, a DLC film which has an extinction coefficient of 0.1-0.4 measured using light having a wavelength of 550 nm, and has a nanoindentation hardness of 16-26 GPa is formed.
Inventors:
SHINOHARA AKIO (JP)
Application Number:
PCT/JP2021/045155
Publication Date:
October 06, 2022
Filing Date:
December 08, 2021
Export Citation:
Assignee:
KK RIKEN (JP)
International Classes:
F02F5/00; F16J9/26
Domestic Patent References:
| WO2016021671A1 | 2016-02-11 |
Foreign References:
| JP2014062326A | 2014-04-10 | |||
| JP2002285328A | 2002-10-03 | |||
| JP2020200803A | 2020-12-17 |
Other References:
See also references of EP 4095375A4
Attorney, Agent or Firm:
HASEGAWA Yoshiki et al. (JP)
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