Abstract: The idling speed of an internal combustion engine is controlled by controlling the position of a control valve disposed in the intake system of the engine to control the amount of intake air fed to the engine. A desired idling speed is determined according to the operating condition of the engine and the control valve is moved to a temporary target position which is expected to be suitable to obtain the desired idling speed. Then feedback control is carried out to converge the actual idling speed to the desired idling speed. When the actual idling speed is finally equalized to the desired idling speed, the actual position of the control valve at that moment is detected and memorized to be adopted as the temporary target position for the same operating condition in later control of the idling speed.

Abstract: An internal combustion engine is provided with an exhaust gas recirculating passage for communicating the intake passage and the exhaust passage thereof. The recirculating passage is provided with a valve for controlling the amount of recirculated exhaust gas. A fundamental air-fuel ratio control value for regulating the air-fuel ratio of the intake gas to a predetermined value is corrected by an operating condition correction value according to the operating condition of the engine. The operating condition correction value is successively changed to an optimal value by comparing the actually obtained air-fuel ratio with a predetermined value. The operating condition correction value for correcting the fundamental air-fuel ratio control value when the exhaust gas recirculation is carried out is changed independently from the same for correcting the fundamental air-fuel ratio correction value when the exhaust gas recirculation is not carried out.

Abstract: An exhaust gas purifying apparatus, for use in an automobile multi-cylinder engine of the type which has exhaust port ducts leading from engine cylinders and through which exhaust gases are emitted subsequent to combustion of an air-fuel mixture, the exhaust gas purifying apparatus having a reducing catalyst unit and an oxidizing catalyst unit disposed in a main exhaust manifold which is corrected on one side, to a first group of the exhaust port ducts and, on the other side to the atmosphere, an auxiliary exhaust manifold is connected, on one side to a second group of the exhaust port ducts and on the other side to a portion of the main exhaust manifold which is downstream from the reducing catalyst unit and upstream of the oxidizing catalyst unit.

Abstract: For use in an automobile multi-cylinder engine having exhaust ports leading from engine cylinders and through which exhaust gases are emitted, an exhaust gas purifying apparatus comprising a reducing catalyst unit and an oxidizing catalyst unit disposed in a main exhaust manifold communicated through exhaust ducts to a first group of the exhaust ports and, on the other hand, to the atmosphere, an auxiliary exhaust manifold communicated to a second group of the exhaust port and, on the other hand, to a portion of the main exhaust manifold at a position intermediately between the reducing and oxidizing catalyst units, a secondary air supply passage extending from a source of secondary air to the auxiliary exhaust manifold, and an additional secondary air supply passage extending from the secondary air source to any one of the collecting ducts communicated to the exhaust ports of the first group.

Abstract: For use in an automobile multi-cylinder engine having exhaust port ducts leading from engine cylinders and through which exhaust gases are emitted subsequent to combustion of air-fuel mixture, an exhaust gas purifying apparatus which has a reducing catalyst unit and an oxidizing catalyst unit disposed in a main exhaust manifold connected on one hand to a first group of the exhaust port ducts and on the other hand to the atmosphere, and an auxiliary exhaust manifold connected on one hand to a second group of the exhaust port ducts and on the other hand to a portion of the main exhaust manifold at a position downstream of the reducing catalyst unit and upstream of the oxidizing catalyst unit. The apparatus further has a pressure operated valve disposed in a secondary air supply passage for introducing secondary air into the auxiliary exhaust manifold by the utilization of a pulsating flow of the exhaust gases through the auxiliary exhaust manifold.

Abstract: An exhuast gas purifying apparatus for use in an automobile multi-cylinder engine of the type which has exhaust ports communicating with engine cylinders and through which exhaust gases are emitted subsequent to combustion of an air-fuel mixture. The exhaust gas purifying apparatus comprising a reducing catalyst unit and a three-way catalyst unit which are disposed in a main exhaust manifold which is connected at one end to a first group of the exhaust ports and at the other end to the atmosphere, and an auxiliary exhaust manifold connected at one end to a second group of the exhaust ports and at the other end to a portion of the main exhaust manifold at a location downstream of the reducing catalyst unit and upstream from the three-way catalyst unit. A pressure operated valve is disposed in a secondary air supply passage for introducing a secondary air into the auxiliary exhaust manifold by the utilization of the pulsating flow of the exhaust gases through the auxiliary exhaust manifold.

Abstract: A process for preparing a chlorinated polymer or copolymer of vinyl chloride which comprises varying the amount of ultraviolet rays irradiated to a unit amount of the polymer or copolymer to control the reaction rate within the range from 0.75-0.25 mole/hour/kilogram of the polymer or copolymer until the rate of substitution of chlorine attains at least 1.6 moles/kilogram of the polymer or copolymer, the polymer or copolymer being chlorinated in an aqueous suspension under irradiation of ultraviolet rays. The polymers so produced have excellent thermal stability and excellent processability.