Abstract: The air introducing means comprising air pump for introducing air into exhaust pipe and heating device for heating the introduced air are provided. Both an air pump for introducing air into exhaust pipe and a heating device for heating the introduced air are provided. Heating device is connected to the control unit which causes it to stop heating when the temperature of the water for cooling engine exceeds a preset temperature. Idle rotation regulator for keeping the rotational speed of the engine at a level higher than the idling speed is also provided. Further provided is a control unit that actuates the idle rotation regulator when the engine is brought to idling while the heating device performs heating. If the rotational speed of the engine is increased while it is running at idle, more power is generated by dynamo to make up for the power consumption by the heating device.

Abstract: In an apparatus for controlling the introduction of air into an exhaust pipe of an internal combustion engine in which air is introduced from the intake side to the exhaust side to improve the efficiency of purifying exhaust gases, to prevent a decline in the purification efficiency of a catalyst in a state in which the exhaust gas temperature immediately after starting is low. A control valve 11 is provided in an air introducing pipe 9 for introducing air from the intake side to the exhaust side, and the control valve 11 is set in a shut-off state during starting or during starting and a predetermined time duration immediately after starting.

Abstract: A secondary air control apparatus constituted by an exhaust gas purifier 32 of an engine 21, a feed quantity control valve 29 for feeding secondary air, a secondary air heating device 31, and a controller 35 for controlling the feed quantity of secondary air and the secondary air heating device 31. The quantity of secondary air to be fed is set in accordance with the operation conditions of an engine, and the secondary air to be fed is modulated in quantity and heated, so that it is possible to utilize the purifying effect of a catalyst efficiently.

Abstract: In an apparatus for controlling the introduction of air into an exhaust pipe of an internal combustion engine in which air is introduced from the intake side to the exhaust side to improve the efficiency of purifying exhaust gases, to prevent a decline in the purification efficiency of a catalyst in a state in which the exhaust gas temperature immediately after starting is low. A control valve 11 is provided in an air introducing pipe 9 for introducing air from the intake side to the exhaust side, and the control valve 11 is set in a shut-off state during starting or during starting and a predetermined time duration immediately after starting.

Abstract: Exhaust gas cleaner system for an automotive internal combustion engine includes an air introduction pipe 8 for introducing secondary air, heated initially by a heater 23, to the catalytic converter unit 7 mounted on the exhaust pipe 3. The ignition timings of the engine is retarded at least during the time when the secondary air is heated by the heater 23. Preferably, the number of ignition timings are counted by a counter modulo 5, for example, in the case of a four-cylinder engine, and the ignition timings are retarded when the counter content is 3 or 4, such that the ignition timings of the cylinders are retarded intermittently. Alternatively, the retardation of the ignition timings may be terminated before the introduction of the heated secondary air is terminated.Where two first and second catalytic converter units 7a and 7b are provided, secondary air distributed by a change-over valve 10a is heated separately by heaters 23b and 23c.

Abstract: Windbreak cover is provided on the periphery of both heater and the air introducing pipe through which heated air is permitted to flow. The windbreak cover blocks the wind from blowing against the heater and the air introducing pipe while the vehicle is running. Since neither the heater nor the air introducing pipe is cooled with the wind that blows while the vehicle is running, the temperature of the heated air that is introduced into the exhaust pipe will not drop even when the vehicle is running. As a result, the temperature of the air being introduced can be maintained at a predetermined level, thus permitting the exhaust gas to be purified in consistent manner.

Abstract: In an exhaust gas purification system for an internal combustion engine including a catalytic converter disposed in an exhaust pipe, an apparatus for controlling an amount and temperature of fresh air fed into the exhaust pipe so that optimal purification efficiency of the catalytic converter can realized. The apparatus includes an air pump for taking in fresh air, a control valve for controlling air flow, a heater for heating the air and the controller for controlling the pump, the valve and the hater in dependence on engine operation states so that nitrogen oxides, carbon monoxide and hydrocarbon contained in the exhaust gas can be removed to a maximum through reduction and oxidation reactions. An abnormality detecting device detects occurrence of abnormality in the air feeding control apparatus for ensuring fail-safe operation thereof.

Abstract: In an exhaust gas purification system for an internal combustion engine including a catalytic converter disposed in an exhaust pipe, an apparatus for controlling an amount and temperature of fresh air fed into the exhaust pipe so that optimal purification efficiency of the catalytic converter can realized. The apparatus includes an air pump for taking in fresh air, a control valve for controlling air flow, a heater for heating the air and the controller for controlling the pump, the valve and the hater in dependence on engine operation states so that nitrogen oxides, carbon monoxide and hydrocarbon contained in the exhaust gas can be removed to a maximum through reduction and oxidation reactions. An abnormality detecting device detects occurrence of abnormality in the air feeding control apparatus for ensuring fail-safe operation thereof.

Abstract: In an apparatus for controlling the introduction of air into an exhaust pipe of an internal combustion engine in which air is introduced from the intake side to the exhaust side to improve the efficiency of purifying exhaust gases, to prevent a decline in the purification efficiency of a catalyst in a state in which the exhaust gas temperature immediately after starting is low. A control valve 11 is provided in an air introducing pipe 9 for introducing air from the intake side to the exhaust side, and the control valve 11 is set in a shut-off state during starting or during starting and a predetermined time duration immediately after starting.

Abstract: An apparatus for introducing fresh air into an exhaust pipe of an internal combustion engine for purification of exhaust gas includes an air introducing means disposed between an intake pipe and an exhaust pipe of an internal combustion engine for introducing a fresh air into the exhaust pipe and hence to a catalytic converter, and a heater for heating the fresh air introduced through the air introducing means, wherein the heated air is fed to an catalytic converter via the exhaust pipe. Conversion of noxious components contained in the exhaust gas into harmless components is attained with the enhanced efficiency owing to heating of the fresh air by the heating means.

Abstract: Exhaust gas cleaner system for an automotive internal combustion engine includes an air introduction pipe 8 for introducing secondary air, heated initially by a heater 23, to the catalytic converter unit 7 mounted on the exhaust pipe 3. The ignition timings of the engine is retarded at least during the time when the secondary air is heated by the heater 23. Preferably, the number of ignition timings are counted by a counter modulo 5, for example, in the case of a four-cylinder engine, and the ignition timings are retarded when the counter content is 3 or 4, such that the ignition timings of the cylinders are retarded intermittently. Alternatively, the retardation of the ignition timings may be terminated before the introduction of the heated secondary air is terminated.Where two first and second catalytic converter units 7a and 7b are provided, secondary air distributed by a change-over valve 10a is heated separately by heaters 23b and 23c.

Abstract: In an internal combustion engine equipped with an intake pipe and an exhaust gas purification/discharge system including an exhaust pipe and a catalytic converter installed in the pipe for purification of engine exhaust gas, an apparatus for controlling introduction of air to the exhaust gas purification/discharge system comprises an air feed pipe having one inlet port and an outlet port connected to the exhaust pipe at a position upstream of the catalytic converter, a valve installed in the air feed pipe at a position downstream of the inlet port, and a computerized controller operatively connected to the valve for controlling the valve such that the air introduction to the exhaust gas purification/discharge system is optimized for exhaust gas purification effected by the catalytic converter.

Abstract: The air introducing means comprising air pump for introducing air into exhaust pipe and heating device for heating the introduced air are provided. Both an air pump for introducing air into exhaust pipe and a heating device for heating the introduced air are provided. Heating device is connected to the control unit which causes it to stop heating when the temperature of the water for cooling engine exceeds a preset temperature. Idle rotation regulator for keeping the rotational speed of the engine at a level higher than the idling speed is also provided. Further provided is a control unit that actuates the idle rotation regulator when the engine is brought to idling while the heating device performs heating. If the rotational speed of the engine is increased while it is running at idle, more power is generated by dynamo to make up for the power consumption by the heating device.

Abstract: A secondary air introduction apparatus introduces secondary air into an exhaust system of an internal combustion engine so as to clean exhaust gases emitted from the engine through the aid of a catalyst which is disposed in the exhaust system. The apparatus has a heating device which heats the secondary air which is to be introduced into the exhaust system, thereby elevating the temperature of the exhaust gases when the noxious components in the exhaust gases react with the oxygen in the secondary air, thereby improving the cleaning efficiency. In one form of the apparatus, the heating device is fixed to a part of the exhaust system such as a catalyst case connected in the exhaust pipe. The apparatus may have a controller which, upon detecting occurrence of any abnormality through detection of the temperature of the secondary air heated by the heating device, operates to activate a warning device or stop the operation of the whole apparatus.

Abstract: A misfiring detecting apparatus for an internal combustion engine avoids misidentification of misfiring in the engine in certain operating conditions thereof, thus providing for improved misfiring determination. Angular velocities of a crankshaft of the engine are detected at two crank positions both after top dead center of the engine or respectively before and after thereof. The occurrence of misfiring in the engine is determined on the basis of a deviation between the angular velocities thus detected. Misfiring determination is disabled if the rotational speed of the engine is greater than a predetermined value, or if an engine load is less than a predetermined value, or if the engine is in an engine starting period.

Abstract: A knock suppressing apparatus for an internal combustion engine includes an amplifier that amplifies the output signal of a knock sensor for sensing engine vibrations. A vibration level signal and a threshold signal are generated based on the amplifier output signals, and knocking is detected by comparing the vibration level signal and the threshold signal. The gain of the amplifier is varied in accordance with an operating condition indicative of the noise level of the engine so as to maintain the vibration level signal and the threshold signal within prescribed ranges suitable for knock determination. In one form of the invention, when the amplifier gain is varied, the threshold signal is also varied at substantially the same time and by substantially the same percentage as the amplifier gain.

Abstract: A knock suppression apparatus and method for a multi-cylinder internal combustion engine can perform knock determination for each cylinder, and selectively prevent such knock suppression control from being reflected or performed on a cylinder for which knock determination is determined to be erroneous due to the influences of noise, thereby avoiding resultant reduction in the engine control efficiency. A plurality of knock sensors are provided each of which senses vibrations of a corresponding cylinder to generate a corresponding output signal. A knock determiner generates a knock determining signal if it is determined, based on the output signals of the knock sensors, that there is knocking in a cylinder. A controller controls engine operating parameters in a direction to suppress knocking in the cylinder based on the knock determining signal.

Abstract: An improved knock suppression apparatus and method for an internal combustion engine is able to determine whether knocking is taking place in each of the engine cylinders through a microcomputer, reduce the load on the hardware components employed and simplify the arrangement thereof to a substantial extent. To this end, it is determined whether knocking is taking place in each cylinder. It is further determined whether such knock determination is incorrect due to noise. If the knock determination is correct, then the knocking cylinder alone is subject to knock control such as ignition timing retarding control so as to suppress the knocking. On the other hand, if incorrect, the knock control on the cylinder is suppressed.

Abstract: A knocking suppression apparatus for a multi-cylinder engine has a knock sensor mounted on a bracket which is secured to the engine in at least two locations. Engine vibrations are transmitted from the engine to the knock sensor by the bracket. The knock sensor generates an electrical signal, on the basis of which a knocking suppression circuit controls an engine operating parameter, such as the ignition timing, so as to suppress knocking.