Yamaha Hatsudoki Kabushiki Kaisha

Morihiro Oishi

Takashi Mizokawa

Hisashi Kazuta

Takasi Mizokawa

A boat propulsion unit includes an electric motor, a potentiometer arranged to detect the rotating angle of a throttle grip, a first stop mode sensor, a second stop mode sensor, and a controller including a CPU, and a disconnection and short detecting circuit. If the voltage signal fed by the disconnection and short detecting circuit is out of the specified range, the CPU detects the operation mode designated by the throttle grip based on the switching of the outputs from the first stop mode sensor and the second stop mode sensor. Then, the electric motor is driven in the forward operation mode and with the specified output power when the forward operation mode is designated, whereas, the electric motor is driven in the reverse operation mode and with the specified output power when the reverse operation mode is designated. Using this arrangement, the boat propulsion unit can obtain a minimum required boat operation as intended by the boat operator even when an abnormality has occurred in the controls.

Boat propulsion unit

A boat propulsion apparatus is constructed such that an operation mode can be switched to a reverse mode and an amount of an output can be set by an easy operation without a complicated structure and further in which a main body of the propulsion apparatus can be locked to a hull. The boat propulsion apparatus is provided with a main body and a locking mechanism. The main body of the propulsion apparatus is provided with an electric motor, a throttle grip, a potentiometer arranged to detect an indication by the throttle grip, a first controller arranged to control an operation mode and an output of the electric motor depending on an output of the potentiometer, and second controller arranged to control the locking mechanism depending on an indication provided by the throttle grip. According to an operation for turning the throttle grip to a reverse mode area, the controller switches the electric motor to the reverse mode, and the second controller operates the locking mechanism to lock the main body of the propulsion apparatus to a hull.

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Shizuoka, Japan

Morihiro Oishi