The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jan. 22, 2013
Filed:
Aug. 12, 2008
Daisuke Akihisa, Susono, JP;
Daisaku Sawada, Gotenba, JP;
Eiichi Kamiyama, Mishima, JP;
Toyota Jidosha Kabushiki Kaisha, Toyota, JP;
Abstract
A spark ignition internal combustion engine includes a variable expansion ratio mechanism which can alter the mechanical expansion ratio, and an exhaust variable valve mechanism which can alter the timing for opening an exhaust valve. The mechanical expansion ratio and the timing for opening the exhaust valve are set depending on the engine load such that the mechanical expansion ratio increases and the timing for opening the exhaust valve is retarded to the exhaust bottom dead center side as the engine load decreases. By setting the mechanical expansion ratio in such a manner depending on the engine load, thermal efficiency can be enhanced as compared with a case where the mechanical expansion ratio is set to make the actual compression rate constant for example. Consequently, a spark ignition internal combustion engine exhibiting high thermal efficiency is provided.