Yamaha Hatsudoki Kabushiki Kaisha

Denso Corporation

Yoh Aramaki

Hisatoshi Kinoshita

Yuta Shimizu

Kazuteru Iwamoto

Ryota Nakashima

Yoshihiko Nonogaki

Minoru Hotta

Nobuyuki Kawashima

Ryo Tomii

Makoto Wakimura

Shunichi Akama

Satoshi Shiokawa

Haruhiko Fujita

A straddled vehicle, including: an engine, which includes a combustion chamber; a three-way catalyst, which is configured to purify exhaust gas exhausted from the combustion chamber; an upstream oxygen sensor, which is provided upstream of the three-way catalyst in a flow direction of the exhaust gas, and is configured to detect an oxygen concentration in the exhaust gas; a downstream oxygen sensor, which is provided downstream of the three-way catalyst in the flow direction of the exhaust gas, and is configured to detect the oxygen concentration in the exhaust gas; and a controller, which includes a processor, and a non-transitory storage medium containing program instructions, execution of which by the processor causes the controller to execute a detachment determination process of determining whether the three-way catalyst is detached at least based on a signal input as a signal of the downstream oxygen sensor.

Straddled vehicle

An object is to provide a misfire detection device and a vehicle with an enhanced detection reliability. A misfire detection device includes: a rotation speed acquisition unit configured to acquire a rotation speed of a rotator rotated by a four-stroke engine; a misfire determination unit configured to determine the presence or absence of a misfire in the four-stroke engine based on the rotation speed of the rotator acquired by the rotation speed acquisition unit; and a periodic fluctuation detection unit configured to detect a periodic fluctuation contained in a rotation fluctuation of the four-stroke engine based on a rotation speed acquired by the rotation speed acquisition unit, the periodic fluctuation being repeated on a circulation cycle of at least one element of a wrapping transmission element or a plurality of transmission wheels, the periodic fluctuation having a plurality of extreme values within the circulation cycle of the one element.

Misfire detection device and vehicle

Growing community of inventors

Iwata, Japan

Yoh Aramaki