An exhaust gas purifying device for an engine comprises a catalyst arranged in the exhaust passage for purifying the exhaust gas, the catalyst having an oxidizing ability. An amount of sulfate adsorbed in the catalyst is obtained. When the adsorbed sulfate amount becomes larger than a predetermined amount, a reducing agent is fed to the catalyst temporarily to desorb the adsorbed sulfate from the catalyst and reduce the sulfate. At this time, the amount of the reducing agent is set to make the air-fuel ratio of the exhaust gas flowing into the catalyst rich.

Exhaust gas purifying device for engine

An exhaust manifold comprising a plurality of exhaust pipes and a merging portion applies exhaust gas from each cylinder uniformly to an oxygen sensor in a merging portion at low speed thereby improving the durability of the oxygen sensor. A downstream forward end of each exhaust pipe of the exhaust manifold, when connected to an inlet wall of a merging case having the oxygen sensor mounted on a side thereof, is formed in the shape of a bell mouth for leading the exhaust gas to the oxygen sensor. Each exhaust pipe is fixedly welded to the merging case at a position upstream of the forward end of the bell mouth. An angle formed by lines perpendicular to tangential lines at starting and ending points of a curved portion of the bell mouth at the forward end of the exhaust pipe is set in the range of 45° to 75°. As a result, the bell mouth spreads over the whole interior of the merging case and reduces a flow rate of the exhaust gas, and part of the exhaust gas flows toward the oxygen sensor. The oxygen sensor is thus more evenly exposed to the exhaust gas and has increased durability.

Exhaust manifold, for internal combustion engine, for improving durability of oxygen sensor at merging portion of exhaust manifold

To provide a motorcycle exhaust system, which is less susceptible to the elevated temperature of the exhaust gases and vibrations induced by the motorcycle combustion engine (E) and in which the sectional area of the exhaust passage can be properly adjusted independence on the operating condition of the motorcycle combustion engine (E), the motorcycle exhaust system includes a motorcycle combustion engine (E) mounted at a location generally intermediate between front and rear wheels (3 and 9), an exhaust passage fluidly connected at one end with an exhaust port of the motorcycle combustion engine (E), a silencer (17) fluidly connected with the opposite end of the exhaust passage and supported by the motorcycle frame structure (FR) at a location generally above the rear wheel (9); and an exhaust control valve (24) disposed in an inlet of the silencer (17) for variably adjusting the sectional area of the exhaust passage.

Motorcycle exhaust system

In an exhaust system, a first oxygen sensor (S1) is attached to an exhaust pipe (101) connected to a standard cylinder in which the amount of injected fuel is the closest to the average of the amounts of fuel injected in a plurality of cylinders. A controller calculates the air-fuel ratio of the standard cylinder based on the value detected by the first oxygen sensor (S1). Then, based on the difference between the calculated air-fuel ratio of the standard cylinder and a predetermined target air-fuel ratio, the amount of correction to the amount of fuel injected in the standard cylinder is determined such that the air-fuel ratio of the standard cylinder is equal to the target air-fuel ratio. Furthermore, based on the amount of correction to the amount of fuel injected in the standard cylinder, the amounts of correction of the other cylinders are determined.

Exhaust system, and engine device and vehicle with the same

An engine control system that is configured to be attached to the intake port or intake manifold of a reciprocating engine. The system can be designed to allow installation as original equipment or as a retrofit unit. In either case, the system provides the engine with a dual ignition and electronically controlled fuel-injection. The system includes a master control unit (MCU) that utilizes a firmware operated microprocessor. The MCU is connected to a plurality of sensors that sense critical system parameters that determine the engine settings. All system parameters are user-controlled by three system command switches that are located on a control display unit (CDU). The CDU is attached to the MCU by an electrical cable and is positioned on the vehicle to provide easy accessibility.

Self-contained sequential-throttle-body-injection engine control system

A motorcycle having an exhaust system with a sensor in the exhaust system for engine control. The sensor is located so that it will be protected by the exhaust device into which it protrudes and by other portions of the motorcycle. The exhaust system includes a plurality of exhaust pipes and the exhaust device and one of these exhaust pipes is readily removable from a unitary assembly comprised of the remaining exhaust pipes and exhaust device so that an adjacent component of the motorcycle can be easily serviced.

Gekka Ryoichi

Papers

Oxygen sensor layout