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:
Jul. 15, 2003
Filed:
Mar. 20, 2001
Toshihisa Nemoto, Tougane, JP;
Terutaka Yasuda, Tougane, JP;
Maruyama Mfg. Co., Inc., Tokyo, JP;
Abstract
Apparatuses and methods for reducing hydrocarbons in two-stroke engine exhaust. When a piston is close to top dead center, a groove in the lower end region of the piston confronts an exhaust port and first scavenging ports, respectively, and exhaust gas from the exhaust port is directed to the first scavenging ports. During a scavenging stroke, the first scavenging ports open first to a combustion chamber and exhaust gas is introduced to the combustion chamber, and a second pair of scavenging ports then opens to the combustion chamber and introduces a fuel-containing gas to the combustion chamber. When crankcase pressure reaches 142 Pa or higher, a relief valve opens and maintains the maximum pressure at 142 kPa or lower. Thus, blending in the combustion chamber of the exhaust gas from the first scavenging ports and the fuel-containing gas from the second scavenging ports is suppressed, and short-circuiting of the fuel component to the exhaust port is suppressed.