Abstract: A device for controlling the heating of a catalyst arranged in the exhaust passage of an engine. When the engine is started, the catalyst is rapidly heated by the heater, and the time for which the power is supplied to the heater is increased as the degree of deterioration of the catalyst becomes greater, to thus increase the temperature of the catalyst to the activation temperature thereof when the power supply to the heater is stopped regardless of whether the catalyst is new or has deteriorated.

Abstract: An exhaust emission control apparatus includes an absorbent provided in an upstream portion of an exhaust passage of an engine to absorb hydrocarbon in exhaust gas passed through the exhaust passage at a temperature lower than a predetermined first temperature, the hydrocarbon being desorbed from the absorbent at a temperature higher than the first temperature, a catalytic converter provided in a downstream portion of the exhaust passage to purify hydrocarbon in the exhaust gas when a catalyst of the catalytic converter is active, the catalyst of the catalytic converter being activated at a temperature higher than a predetermined second temperature, the second temperature being higher than the first temperature, and a heating part for heating the catalytic converter to a temperature higher than the second temperature when the engine is in a prescribed starting condition and the absorbent is at a temperature higher than the first temperature, so that the hydrocarbon desorbed from the absorbent in the exhaust p

Abstract: A device for controlling the heating of a catalyst arranged in the exhaust passage of an engine. When the engine is started, the catalyst is rapidly heated by the heater, and the time for which the power is supplied to the heater is increased as the degree of deterioration of the catalyst becomes greater, to thus increase the temperature of the catalyst to the activation temperature thereof when the power supply to the heater is stopped regardless of whether the catalyst is new or has deteriorated.

Abstract: A device for controlling the heating of a catalyzer arranged in the exhaust passage of an engine. When the engine is started, the catalyzer is rapidy heated by the heater, and the time for which the power is supplied to the heater is increased as the catalyzer use period becomes longer, to thus increase the temperature of the catalyzer to the activation temperature thereof when the power supply to the heater is stopped regardless of whether the catalyzer is new or has deteriorated.

Abstract: An exhaust gas recirculation system for an internal combustion engine of the back pressure control type which includes a chamber space which is positioned at a middle portion of an exhaust gas recirculation passage and upstream of an exhaust gas recirculation control valve and downstream of an orifice and which is maintained substantially at atmospheric pressure, wherein the orifice is adapted to provide effective opening area which is variable between a substantial partial opening and full opening in accordance with engine temperature.

Abstract: An EGR/ignition timing control system for an internal combustion engine having a vacuum advancer and an EGR system, wherein the control system includes a vacuum valve which is operated at the same critical vacuum as an EGR valve of the EGR system so as to trap, in cooperation with a check valve, the maximum vacuum supplied to the vacuum advancer as long as the EGR valve is opened and is effecting exhaust gas recirculation.

Abstract: An EGR/ignition timing control system for an internal combustion engine having a vacuum advancer and an EGR system, wherein the control system includes a vacuum switch which is operated at the same critical vacuum as an EGR valve of the EGR system and a solenoid valve which is operated by the vacuum switch so as to trap, in cooperation with a check valve, the maximum vacuum supplied to the vacuum advancer as long as the EGR valve is open and is effecting exhaust gas recirculation.

Abstract: Disclosed is an internal combustion engine with an exhaust gas recirculating system. The engine has a movable shroud. The shroud is positioned near the rear surface of the valve head of the intake valve so as to obstruct a part of the mixture stream flowing through the valve opening of the intake valve for creating the swirl motion of the mixture in the combustion chamber when the amount of the recirculated exhaust gas is larger than a predetermined level. The shroud is retracted to a position where the shroud does not obstruct the mixture stream flowing in the intake port of the engine when the amount of the recirculated exhaust gas is smaller than said predetermined level.