Abstract: An exhaust purifying system for an automobile engine including an exhaust system for the emission of exhaust gases to the atmosphere through a catalytic converter. The system comprises a temperature detector for detecting a signal indicative of the temperature of the catalyst, a total engine operating hour detector for detecting a signal indicative of the total operating hour over which the engine has been operated, a spark timing control for retarding the spark timing when the temperature detector detects that the catalyst temperature is lower than a predetermined value, and a retard time corrector for increasing the amount of control to be performed by the spark timing control with increase within a predetermined range detected by the total engine operating hour detector.

Abstract: An internal combustion engine including a combustion chamber, an intake system having an intake valve and an intake passage leading through the intake valve to the combustion chamber for providing a supply of intake gas to the combustion chamber. A valve timing control device is provided for governing opening and closing timings of the intake valve so that the intake valve is closed at a controlled timing in the compression stroke, whereby a controlled amount of the intake gas is returned from the combustion chamber to the intake passage in the compression stroke to thereby control the effective charge to the combustion chamber.

Abstract: A two rotor type rotary piston engine including a casing comprised of a pair of rotor housings connected together with an intermediate housing interposed therebetween and side housings attached to the outer sides of the rotor housings to define rotor cavities. A substantially triangular rotor is disposed in each rotor cavity. The intake system includes a light load intake port formed in the intermediate housing so as to open to each rotor cavity, a medium load and heavy load intake ports formed in each side housing. The light load and medium load intake ports are formed so that they are opened to a working chamber after the chamber is disconnected from the exhaust port and closed substantially simultaneously. The heavy load intake port is associated with a control valve which is closed under light and medium load operations.

Abstract: A rotary piston engine including a casing comprised of a rotor housing and a pair of side housings attached to the opposite sides of the rotor housing to define a rotor cavity. A substantially triangular rotor is disposed in the rotor cavity. The intake system includes a light load intake port formed in one of the side housings so as to open to the rotor cavity, a medium load and heavy load intake ports formed in the other side housing. The light load and medium load intake ports are formed so that they are opened to a working chamber after the chamber is disconnected from the exhaust port and closed substantially simultaneously. The heavy load intake port is associated with a control valve which is closed under light and medium load operations.