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:
Aug. 21, 2018
Filed:
Jan. 10, 2014
Yamaha Hasudoki Kabushiki Kaisha, Iwata-shi, Shizuoka, JP;
Ei Tsukahara, Shizuoka, JP;
Daijiro Tanaka, Shizuoka, JP;
YAMAHA HATSUDOKI KABUSHIKI KAISHA, Shizuoka, JP;
Abstract
An engine includes a cylinder body, a cylinder head, and an ignition device including spark plugs. The engine also includes an intake device connected to intake ports, an exhaust device connected to exhaust ports, pistons, and a crankshaft connected to the pistons by connecting rods. Explosion intervals of the cylinders are 270°, 180°, 90°, and 180° as crank angles. The engine further includes a discomfort eliminator which, when the engine speed is lower than a predetermined value, makes the indicated mean effective pressure of at least one of two cylinders having an explosion interval of 90° lower than the indicated mean effective pressures of the other cylinders having an explosion interval of not 90°. The engine causes unequal-interval explosions but produces little change in the driving energy per unit time during an operating state in which an occupant is liable to feel torque fluctuations.