Nissan Motor Company Limited

Yoshimi Nunome

Makoto Kobayashi

Hideaki Mizuno

Yoshiaki Tanaka

Katsuya Moteki

Kenshi Ushijima

Yusuke Sato

Kazuhiro Fujikane

A vibration reducing device that reduces the vibration of a control object includes a digital controller. A vibration state detection device detects the vibration of the control object and generates an analog signal of the vibration of the control object. An input-side bandpass filter has a passband that is narrower than a frequency range from a Nyquist frequency to a sampling frequency of the digital controller, and that contains no frequencies that are an integer multiple of the Nyquist frequency of the digital controller. The input-side bandpass filter allows a part of the analog signal that falls within the passband from the analog signal generated by the vibration state detection device to pass. An A/D conversion device converts the analog signal that has passed through the input-side bandpass filter into a digital signal. A D/A conversion device converts a digital feedback control signal, determined by the digital controller on the basis of the digital signal converted by the A/D conversion device, into an analog feedback control signal. An actuator applies vibration to the control object on the basis of the analog feedback control signal converted by the D/A conversion device.

Vibration reducing device

A piston-crank mechanism links crankpins of a crankshaft with piston pins of pistons by using a plurality of links. The piston-crank mechanism allows an upward inertia force produced near a top dead center of each piston to be smaller than a downward inertia force produced near a bottom dead center of the piston in order to reduce secondary vibration occurring during operation. In a four-cycle inline four-cylinder internal combustion engine, a total force of inertia forces exerted from adjacent cylinders to each of second and fourth crankshaft bearings becomes a downward force, which reinforces a downward force produced in response to combustion pressure. These second and fourth crankshaft bearings have a rigidity higher than the remaining crankshaft bearings.

Internal combustion engine

A crankshaft mechanism is disclosed that takes advantage of component makeup and orientation to cancel out inertial force. A crankshaft of the crankshaft mechanism includes at least one counterweight that is arranged in combination with the rest of the mechanism to cancel out the inertial force particularly at a timing in front of a bottom dead center of a piston where the inertial force becomes a maximum.

Crankshaft of piston crank mechanism

Growing community of inventors

Yokosuka, Japan

Yoshimi Nunome