Yamaha Hatsudoki Kabushiki Kaisha

Kazutoshi Ishioka

Toshio Unno

Takeharu Noguchi

Naoki Sekiguchi

A speed change ratio controller, which controls a speed change ratio of the continuously variable transmission, normally exercises map control according to a predetermined speed change ratio map so that a V-N characteristic curve prescribed by a vehicle speed (V) and an engine rotational frequency (N) falls in a range of a predetermined region of speed change. When an accelerator opening degree exceeds a predetermined range and a vehicle load exceeds a predetermined range a target speed change ratio is corrected so that the V-N characteristic curve gets out of the predetermined region of speed change. After the V-N characteristic curve gets out of the region of speed change, the necessity of continuation of acceleration or deceleration is determined on the basis of a predetermined condition such as returning of an accelerator grip, and when the continuation is unnecessary, normal map control is automatically restored.

Controller of continuously variable transmission and vehicle provided with the same

To prevent engine speed from increasing during low-speed operation, a transmission includes a change-gear mechanism, a centrifugal clutch, a control unit and a secondary sheave rotation sensor. The change-gear mechanism has an input shaft, an output shaft and an actuator for changing a change-gear ratio between the input and output shafts. The centrifugal clutch is connected to the output shaft. The control unit controls the actuator. The secondary sheave rotation sensor detects and outputs a rotational speed of the output shaft to the control unit. The control unit controls the actuator based on a target change-gear ratio obtained by dividing a target rotational speed of the input shaft by the rotational speed of the output shaft.

Transmission, power unit having the same, vehicle, controller for transmission, and method of controlling transmission

A continuously-variable-transmission control device having high control response and stability, reduced processing load on a control device and V-belt wear recognition. The width of the V-belt is calculated on the basis of a position of the primary sheave, a length of the V-belt, a distance between the sheaves, an angle of the sheave, and a change gear ratio during idling, and the calculated belt width is stored. The control device performs a feed-forward control on the starter in which it corrects the target position of the primary sheave on the basis of the belt width, and then controls the sheave position so as to reach the corrected target position. When the calculated belt width becomes equal to or smaller than a predetermined threshold, the control device issues an alarm that alerts the driver to replace the V-belt.

Continuously-variable-transmission control device and straddle-type vehicle

A motorcycle has a transmission including a transmission mechanism and an electronic control unit (ECU). The transmission mechanism includes a crankshaft as an input shaft, a driven shaft as an output shaft and an electric motor. The electric motor changes continuously the transmission ratio between the crankshaft and the driven shaft. The ECU estimates the heat value of the motor from a rate of change in the transmission ratio. When the estimate heat value reaches or exceeds a specified value the electric motor is restricted or stopped.

Control apparatus for transmission mechanism, transmission, vehicle provided therewith, method of controlling the transmission mechanism, and method of estimating heat value of electric motor in the transmission mechanism

Growing community of inventors

Shizuoka, Japan

Kazutoshi Ishioka