Yamaha Hatsudoki Kabushiki Kaisha

Yamaha Motor Company Ltd

Shunji Minami

Hiroshi Kimura

Kazuhiko Nomura

Yasuo Nakao

Satoru Ichikawa

Several embodiments of induction systems for internal combustion engines that improve the charging efficiency, particularly at low speeds are disclosed. Each embodiment employs a plenum chamber upstream of the engine throttle valve and a reed type check valve admits air to the plenum chamber so as to improve charging efficiency at low speeds by maintaining an air flow in the induction system. In accordance with some embodiments, a supercharger is also employed which discharges into the plenum chamber upstream of the throttle valve. This arrangement minimizes pulsation effects from the supercharger being transmitted to the engine intake ports. In addition, the reed type check valve can be employed in many of the embodiments to bypass the supercharger under conditions when the supercharger is not generating any significant boost. The location of the reed type check valve relative to the plenum chamber and throttle valve of the engine minimizes pulsations from being transmitted from the intake ports back to the check valve. In several embodiments an air cleaner housing is formed integrally with the plenum chamber to afford a more compact assembly.

Induction system for internal combustion engines

Several embodiments of induction systems for internal combustion engines that improve the charging efficiency, particularly at low speeds. Each embodiment employs a plenum chamber upstream of the engine throttle valve and a reed type check valve admits air to the plenum chamber so as to improve charging efficiency at low speeds by maintaining an air flow in the induction system. In accordance with some embodiments, a supercharger is also employed which discharges into the plenum chamber upstream of the throttle valve. This arrangement minimizes pulsation effects from the supercharger being transmitted to the engine intake ports. In addition, the reed type check valve can be employed in many of the embodiments to bypass the supercharger under conditions when the supercharger is not generating any significant boost. The location of the reed type check valve relative to the plenum chamber and throttle valve of the engine minimizes pulsations from being transmitted from the intake ports back to the check valve. In several embodiments an air cleaner housing is formed integrally with the plenum chamber to afford a more compact assembly.

Several embodiments of induction systems having forced induction and a regulated fuel pump for delivering fuel to the charge forming device at a pressure that is related to the pressure in the induction system. In some embodiments the pressure is sensed above the level of the fuel in the fuel bowl of the charge forming device, and in others the pressure is sensed in a plenum chamber upstream of the charge forming device inlet. A check valve arrangement is also provided in the fuel line in one embodiment for preventing the backflow of fuel under conditions when the engine is stopped.

Device for supplying fuel to a pressure carburetor

Two embodiments of turbo-charged motorcycle arrangements wherein the turbo-charger is located so as to be protected by the stand of the motorcycle when the stand is in its retracted position.

Engine intake system for motorcycles

A motorcycle construction embodying a turbo-charger that is fed by means of a collector pipe positioned beneath the engine. The turbo-charger is positioned between the engine and the rear wheels and a splash shield extends between the rear wheel and the turbo-charger so as to protect it.

Motorcycle with turbo-charger

A lubricating system for turbo-charger wherein the turbo-charger bearings are located at or below the normal level of oil in the lubricating sump for return of oil from the sump to the turbo-charger bearings when the engine is not running so as to insure cooling of the bearings when the engine is not running.

Lubricating system for turbo-chargers

A multiple bank internal engine for a motorcycle has staggered cylinders which form a recess at one side of one bank of cylinders, and another recess at the opposite ends of another bank of cylinders. Valve actuating mechanisms are accommodated in these recesses so as to minimize the axial length of the engine, and thereby minimizing the width of the envelope occupied by the engine when mounted on a motorcycle.

Growing community of inventors

Fukuroi, Japan

Shunji Minami