Yamaha Hatsudoki Kabushiki Kaisha

Yamaha Motor Corporation

Yoshihiko Moriya

Yu Motoyama

Takeshi Ito

Hisatoshi Kinoshita

Michihisa Nakamura

Masaki Torigoshi

Ryusuke Kato

Toshihiko Takahashi

Takafumi Fukuda

Miyoshi Ishibashi

Nobuhiko Matsunaga

Akihiko Ohokubo

Takeru Ibara

Yuh Motoyama

Masahiko Ito

An exhaust system includes a first exhaust pipe group, a first catalyst device, and a second exhaust pipe group. A first coupling pipe of the first exhaust pipe group includes spaces in communication with respective first exhaust pipes. A second coupling pipe of the second exhaust pipe group includes spaces in communication with respective second exhaust pipes. The first exhaust pipe group and the second exhaust pipe group are joined such that the respective spaces are opposed to one another, with the first catalyst device interposed therebetween.

Exhaust system, and engine device and vehicle with the same

A direct cylinder injected engine in several different embodiments which are specifically illustrated as two-cycle engines but which can also be used in four-cycle engines. The fuel injector is positioned so as to minimize escape of fuel from the exhaust port in the two-cycle engine applications. In addition, multiple or extended spark plug firing is accomplished under difficult running conditions and wherein fuel vaporization may be incomplete. This will ensure complete combustion. Various control routines and strategies are disclosed that control the number or time of injection depending upon such factors as engine speed, load, speed variation, air fuel ratio variations and pressure variations.

Ignition control system for engine

A number of embodiments of exhaust temperature sensors that cooperate with an exhaust control for maintaining optimum engine performance by controlling the exhaust temperature to maintain the desired pulse back effect on the exhaust system.

Engine control and wall temperature sensor

An exhaust port controlling arrangement for an internal combustion engine having both main and auxiliary exhaust ports. A main control valve cooperates with the main exhaust port for varying the timing at which the exhaust port opens in response to engine speed. An on/off auxiliary control valve is positioned in a passage leading from the auxiliary exhaust port for opening and closing the flow through the auxiliary exhaust passage in response to an engine condition. Means retard the opening of the main exhaust port upon opening of the auxiliary exhaust ports to improve the power and torque curves of the engine.

Exhaust timing control device for two-cycle engine

An improved method of operating a direct cylinder-injected engine wherein adequate fuel and scavenging can be achieved at mid and high-mid range by injecting the fuel in two increments. Various control strategies are disclosed, and they all particularly lend themselves for use with two-cycle crankcase compression engines.

Engine control system

A fuel injection system for an engine having a reed type valve in the induction system. The injection system is designed and controlled so that the fuel that is injected is injected substantially entirely before the reed type valve is closed. The time of closing of the reed type valve is determined either by measuring the pressure differential or by recording data indicative of the valve closing in response to various engine running conditions such as speed and/or load.

Fuel injection control

A fuel/air injector for a crankcase compression two-cycle internal combustion engine and control strategy therefore wherein under a first load range of the engine which is generally a low speed, low load range, fuel is supplied to the fuel/air injector at a time which does not precede the opening of the injector valve and then as the load and speed of the engine increase, the timing of opening of the injector valve is advanced until a certain condition is reached and thereafter the opening of the injector valve is held constant and the timing of fuel supply is advanced so that fuel supply precedes the opening of the injector valve.

Air fuel injector and control

A solenoid valve device and specifically a solenoid operated injection valve wherein the bouncing of the valve element upon closing is dampened. This is done by providing an inertial mass which is slidable relative to the stem portion of the valve element and contacts fixed abutments on the stem portion of the valve element to limit the relative movement in each direction. In addition, a cushioning arrangement is interposed between the inertial mass and the abutment for cushioning the stopping of the inertial mass.

Solenoid valve device

Two embodiments of fuel injection systems for two cycle crankcase compression internal combustion engines that employ two fuel injectors. One fuel injector injects into the combustion chamber while another injects into the induction system of the engine. A simplified regulating system is incorporated so that the first injector receives fuel under a higher pressure than the second injector.

Growing community of inventors

Iwata, Japan

Yoshihiko Moriya