Yamaha Hatsudoki Kabushiki Kaisha

Kimitake Otome

Junichi Kaku

Hidetoshi Kageyama

Osamu Tamura

The present invention is an injection system including an injection device. The injection device includes a pumping chamber and an electrically operated device associated with the pumping chamber which, when energized, is capable of providing a rapid increase in localized fluid pressure in said pumping chamber without reciprocating a piston in a cylinder bore. A discharge port associated with the pumping chamber permits discharging of fluid displaced by the localized pressure increase. The injection system includes a circuit providing an energizing voltage to the electrically operated device, and a control for changing at least one characteristic of the energizing voltage selected from the group consisting of: the peak energizing voltage, the rate at which said energizing voltage increases, the rate at which said energizing voltage decreases, the duration of energization, and the frequency of energization.

Fuel injection system

A fuel injection system is provided with an interior pumping chamber (94) which is connected to a fuel inlet (98). A pumping element (90) is provided with piezoelectric elements (124) which are interspaced between electrodes (126, 128). The pumping element (90) is electrically connected to an ECU (58). Activation of the piezoelectric elements causes pumping element (90) to expand and thereby impart pressure from a pressure surface (112) which extends into the pumping chamber (94). Fuel in the pressure chamber, as a result of the piezoelectric elements is pushed from the pressure chamber and through an injection valve (116). The applicants are reminded that formal drawings are now required. Further, as noted in the Office Action of Dec. 16, 1999, in FIG. 2, numeral 124 should be changed to indicate mounting plate 121. On drawing sheet 6, FIG. 6a and FIG. 6b should be indicated.

A number of embodiments of two cycle crankcase compression internal combustion engines having at least two cylinders in a common bank in side-by-side relationship. Each embodiment incorporates a main Schnurle type scavenging system that includes a pair of main scavenge passages on opposite sides of the exhaust passage that terminate in main scavenge ports that are disposed in proximity to and on opposite sides of the exhaust port. A transversely extending supplemental scavenge passage is provided for delivering a charge to the combustion chamber to somewhat restrict the scavenging flow so as to prevent fuel from passing out of the exhaust port. Fuel is injected into proximity with this supplemental scavenge passage. This facilitates stratification of the fuel charge. The ports are rotated from normal around the cylinder bore axis in many embodiments to provide a more compact construction. Even in those embodiments where this is not done, the fuel injectors are mounted so that they can be easily accessed from outside of the engine body. Various applications for the engine such as a motorcycle, personal watercraft and outboard motor are depicted.

Porting arrangement for two cycle engine

Scavenge system for two cycle engines

A number of embodiments of two-cycle engines employing Schnurle-type scavenging. In addition and in some embodiments, a ramble port is also incorporated so as to introduce a tumble charge into the combustion chamber and reduce the likelihood of fresh charge from exiting from the exhaust port. This tumble charge may be utilized to achieve stratification, and the fuel charge may be delivered to the combustion chamber through the tumble port or in proximity to it. Various arrangements are shown for controlling the amount of scavenge flow to improve stratification and fuel vaporization.

Scavenge control for engine

A number of embodiments of two-cycle engines employing Schnurle-type scavenging. In addition, a tumble port is also incorporated so as to introduce a tumble charge into the combustion chamber and reduce the likelihood of fresh charge from exiting from the exhaust port. This tumble charge may be utilized to achieve stratification, and the fuel charge may be delivered to the combustion chamber through the tumble port or in proximity to it. Also, arrangements are shown for controlling the amount of tumble flow.

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Iwata, Japan

Kimitake Otome