Yamaha Hatsudoki Kabushiki Kaisha

Kazuhiko Nomura

Shunji Minami

Yasuo Nakao

Nobuyuki Kanno

Toshiyuki Sato

Hisashi Kazuta

Hiroshi Kimura

Atsushi Kanda

Satoru Ichikawa

Masaharu Naito

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.

In a motorcycle having a main frame, a seat support on the frame, and a seat mounted to the seat support. The seat support is at least partially separable from the main frame so as to provide ready access to stored items or for maintenance and repair of motorcycle elements beneath the seat. The seat support is made separable by separable fasteners, or by hinges or pivot pins. The seat support can also serve as the mount for a rear fender. It can be made in a monocoque configuration for improved rigidity, and even for storage such as for a fuel tank.

Motorcycle fuel system with flow from a main tank through a lower

A motor cycle includes a frame, a front and rear wheel, and an engine mounted to the frame which has at least two exhaust pipes. A muffler is mounted to the frame beneath the engine, and both exhaust pipes discharge into the muffler. At least one tailpipe exhausts from the muffler. The silencing volume of the muffler can enable a shorter-than-usual tailpipe to be used, which need not interfere with access to the rear wheel axle.

Motorcycle engine exhaust system

A motorcycle includes a frame that mounts an engine and a fuel tank. The fuel tank is mounted above the engine. Air intake conduitry includes an upwardly extending intake pipe, an upwardly extending connecting pipe, and a connecting box immediately beneath the fuel tank, atop the intake and connecting pipers, which serves to connect them so as to provide an air intake conduit from the atmosphere to the engine. In a V-type engine, the pipes and box are disposed in the angle between the cylinders. In multi-bank engines, which utilize a pair of intake pipes, the connecting pipe, and also an air cleaner, can be disposed between them. When the fuel tank includes a pair of draped sides to form a saddle-like tank, the connecting box can be disposed between the draped sides.

Air intake conduitry for a motorcycle

A vehicle which uses 'blended' fuel, i.e., fuel and lubricating oil combined, is provided with a fuel tank and an oil tank. A measuring device receives a predetermined amount of oil, and when an actuation occurs, usually associated with a fuel-filling operation, the measured amount of oil is discharged into the fuel tank where it blends with the fuel. The actuation may, for example, be derived from the opening and/or closing of a fuel tank closure, or from the insertion of a fuel filler nozzle into the tank.

Oil supply means for tanks containing blended fuel and oil

A hydraulic shock absorber which comprises a piston rod inserted into a cylinder assembly; a piston fixed to the inner end of the piston rod to divide the internal space of the cylinder assembly into first and second oil chambers; and passage means designed to attain communication between both chambers and provided with an opening-variable orifice whose opening area automatically varies with the temperature of damping oil, wherein the damping property of said shock absorber is always kept constant independently of changes in the temperature of damping oil.

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Iwata, Japan

Kazuhiko Nomura