Yamaha Hatsudoki Kabushiki Kaisha

Seigo Takahashi

Kazuteru Iwamoto

Hidetoshi Ishigami

Yuki Yamaguchi

Yuuji Araki

Daiki Ito

Takahiro Masuda

Koji Takahashi

A motorcycle includes a CPU (Central Processing Unit) of an ECU (Electronic Control Unit) that drives a fuel heating device when a fuel heating condition is satisfied and the result of a fuel heating prohibition determination process indicates that heating is permitted. On the other hand, the CPU does not drive the fuel heating device when the fuel heating condition is not satisfied or when the result of the fuel heating prohibition determination process indicates that heating is prohibited. In the fuel heating prohibition determination process, the CPU determines a tilted state of the motorcycle, and prohibits or permits heating of fuel in a fuel pipe by the fuel heating device based on a detection result of the tilted state.

Motorcycle

A variable valve device, which is capable of automatically canceling a deviation in the relationship between the rotation angle of a control shaft and the lift degree generated because of the disassembling and assembling of an engine, includes a target lift degree calculator that calculates a target lift degree, a motor driver that drives a brushless DC motor that rotates the control shaft until the lift degree reaches the target lift degree, and an automatic deviation canceller that automatically cancels the deviation. More specifically, the magnetic pole pulse pattern of the motor before the engine starts is obtained and it is determined whether the pattern match magnetic pole pulse pattern stored before the engine stops. If they do not match, an idle lift degree is set, the idle lift degree is changed so that the engine speed is within the tolerance range of an idle engine speed, the rotation angle for the idle portion is subtracted from the obtained angle of the control shaft and a reference angle is updated by the difference.

Variable valve device for engine

A variable valve device, which is capable of controlling a fuel injection amount or the like if a control shaft sensor has a failure, uses a brushless DC motor to rotate the control shaft, detects the rotation angle of the motor using its magnetic pole sensors, and calculates an estimated rotation angle of the control shaft based on the rotation angle. The variable valve device further determines that the control shaft sensor has a failure if the difference between the actual rotation angle of the control shaft detected by the control shaft sensor and the calculated estimated rotation angle exceeds a prescribed value and controls the fuel injection amount, fuel injection timing and ignition timing of the engine based on the calculated estimated rotation angle.

Growing community of inventors

Shizuoka, Japan

Seigo Takahashi