Title:
INTERNAL-COMBUSTION ENGINE PISTON, AND METHOD FOR CONTROLLING COOLING OF INTERNAL-COMBUSTION ENGINE PISTON
Document Type and Number:
WIPO Patent Application WO/2018/198786
Kind Code:
A1
Abstract:
The objective of the present invention is to provide a novel internal-combustion engine piston with which it is possible to achieve both an improvement in thermal efficiency and a reduction in harmful components of exhaust gas, and with which the occurrence of abnormal combustion such as knocking and pre-ignition can be suppressed. A cooling passage 200 is formed in a piston, and on the surface of a piston top face are provided a first heat shielding layer 101 made from a material having a lower thermal conductivity and volumetric specific heat than those of a piston base material, and a second heat shielding layer 102 made from a material having a lower thermal conductivity and volumetric specific heat than those of the first heat shielding layer 101, wherein a first distance between the first heat shielding layer 101 and the cooling passage 200 is set to be less than a second distance between the second heat shielding layer 102 and the cooling passage 200. Cooling losses can be reduced by means of the second heat shielding layer, and harmful components of exhaust gas can be reduced by promoting vaporization of fuel attached to the piston, by means of the first heat shielding layer. Further, since the first distance is less than the second distance, the temperature of the first heat shielding layer does not rise excessively, and therefore the occurrence of knocking and pre-ignition can be suppressed.
Inventors:
SUKEGAWA YOSHIHIRO (JP)
TAKAHASHI NORIKAZU (JP)
TAKAHASHI NORIKAZU (JP)
Application Number:
PCT/JP2018/015347
Publication Date:
November 01, 2018
Filing Date:
April 12, 2018
Export Citation:
Assignee:
HITACHI AUTOMOTIVE SYSTEMS LTD (JP)
International Classes:
F02F3/10; C23C24/08; F01P3/10; F01P7/14; F01P7/16; F02F3/00; F02F3/22; F16J1/01; F16J1/09
Foreign References:
| JP2013067823A | 2013-04-18 | |||
| JPH0565850A | 1993-03-19 | |||
| JP2004285944A | 2004-10-14 | |||
| JP2013164028A | 2013-08-22 | |||
| JP2013024143A | 2013-02-04 | |||
| JP2008038757A | 2008-02-21 | |||
| JP2013024142A | 2013-02-04 | |||
| JP2011220207A | 2011-11-04 |
Attorney, Agent or Firm:
POLAIRE I.P.C. (JP)
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