摘要:
An electrode structure includes: a metallic electrode; a case for accommodating and holding the electrode, and one end of a lead wire connecting to the electrode; and an insulating member interposed between the electrode and the case in order to ensure insulation between the electrode and the case, in which structure a waterproof member is interposed between the case and the lead wire in order to prevent the incoming of water from between the case and the lead wire, and an electric heater havinging the above electrode structure. An electrode structure of an electric heater, includes: a first electrode; a second electrode of a cylinder shape, having a base portion connected with the first electrode and a top end portion connected with a lead wire; an insulating member having a thermal resistance, pierced by the second electrode; an elastic insulator having a thermal resistance, covering at least a portion of the second electrode; a case for accommodating and holding the second electrode, having a predetermined length L; and a rubber sealing member attached to the top end of the case. The electrode structure is preferably used by connecting to a conductive substance accommodated in a metallic housing, to apply electricity to the conductive substance. The conductive substance is preferably a metallic honeycomb structure. The given length L mentioned above is preferably L.gtoreq.40 mm.
摘要:
An exhaust gas-purifying system for an internal combustion engine includes an alternator driven by the engine. A regulator controls voltage generated by the alternator. An electrically-heated catalyzer is arranged in the exhaust system of the engine and connected to the alternator to be electrically heated by electric power generated by the alternator. An ECU controls the regulator to control the voltage generated by the alternator and supplied to the electrically-heated catalyzer, according to operating conditions of the engine detected by sensors such as an engine coolant temperature sensor and an intake air temperature sensor.
摘要:
A system and method for detecting a failure occurring in an exhaust secondary air supply system of an internal combustion engine. A conduit is connected to the exhaust pipe to supply secondary air to the exhaust pipe to promote oxidization of the emissions in the exhaust gases. A valve is provided in the conduit for opening/closing it. The failure of the valve is detected by operating the air pump to supply the air in the conduit, while closing the conduit by the valve. The air/fuel ratio is detected by an oxygen sensor installed downstream of the conduit to be compared with a desired air/fuel ratio. If the detected air/fuel ratio is leaner than a desired air/fuel ratio, the air flows to the exhaust pipe so that the valve is considered to be stuck to open. Alternatively, a pump current is detected and is compared with a reference value indicative of the current at no air flow. If the detected current is less than the reference value, the valve is considered to be in failure. Moreover, the movement of a valve member is sensed to detect whether the valve is stuck to close.
摘要:
An exhaust gas-purifying system is provided for an internal combustion engine for use in a vehicle having an alternator driven by the engine to generate electric power. An electrically-heated catalyzer is arranged in the exhaust system of the engine and connected to the alternator to be electrically heated thereby. A changeover switch is provided for selectively switching the destination of electric power generated by the alternator to the electrically-heated catalyzer and to the electrical equipment. An ECU controls the electric power generated by the alternator, depending upon a direction in which the changeover switch has been switched. The ECU detects abnormality of the changeover switch, and when the abnormality is detected, the electric power generated by the alternator is changed to a value smaller than a value assumed when the changeover switch is normal.
摘要:
A system for detecting the ambient temperature of an exhaust system of an internal combustion engine, where an oxygen sensor (O.sub.2 sensor) is installed for detecting oxygen content in exhaust gases generated by the engine. The oxygen sensor has a detection element and a heater for heating the detection element when supplied with current. The exhaust system is further provided with a catalytic converter which similarly has a heater for heating the catalyst for promoting the activation thereof. The electric resistance of the sensor heater is detected and based on the detected resistance, the ambient temperature of the exhaust system is detected or estimated in accordance with characteristics preestablished with respect to the electric resistance of the heater. With the arrangement, it becomes possible to detect the ambient temperature of the exhaust system without using a temperature sensor. The detected ambient temperature is used for controlling the current supply to the heater of the catalytic converter.
摘要:
A current control system of an electrically heated catalytic converter installed in the exhaust system of an internal combustion engine. In the engine, fuel metering is controlled by correcting a basic quantity of fuel injection by correction factors. The correction factors are grouped into the factors for increasing the fuel injection quantity at engine warmup and other factors. Therefore, the total value of the factors for increasing the fuel injection quantity at engine warmup are compared with a predetermined value, and if the total value exceeds the predetermined value, the current supply to the heater is inhibited. Alternatively, the cranking time is compared with a predetermined value and if it exceeds the predetermined value, the current supply is inhibited. Since the quantity of fuel injection is increased in these situations, unburned emissions will accordingly be increase. With the arrangement, the exhaust temperature is prevented from rising excessively and the catalytic converter is prevented from being degraded or damaged.
摘要:
An adsorber temperature-estimating device for an internal combustion engine comprises an adsorber arranged in the exhaust passage, for adsorbing an unburnt gas component present in exhaust gases emitted from the engine. Operating parameter sensors detect operating parameters of the engine, and an ECU estimates the temperature of the adsorber, based on the detected operating parameters. An exhaust gas-purifying system for the engine comprises the adsorber, a catalytic converter arranged in the exhaust passage at a location downstream of the adsorbing means, for purifying exhaust gases, and a secondary air supply pump for supplying secondary air to the exhaust passage at a location upstream of the catalytic converter. The ECU controls an amount of secondary air to be supplied to the exhaust passage, based on the estimated temperature calculated by the adsorber temperature-estimating device.
摘要:
A system for controlling an idle speed of an internal combustion engine having an electrically heated catalytic converter which is heated up when current is supplied from an alternator driven by the engine. In the engine idle control, a basic value of a desired idle engine speed is determined with respect to the engine coolant temperature in the same manner as the prior art. However, an augmentative correction amount of the desired idle engine speed is determined with respect to the exhaust system ambient temperature. More specifically, the desired idle engine speed is increased in response to the heating of the catalytic converter so as to prevent the alternator from generating electric power insufficient for heating up the catalytic converter.
摘要:
A system for detecting a failure of an electrically heated catalytic converter installed in an exhaust system of the engine for reducing pollutants from exhaust gases emitted from the engine, the catalytic converter having a heater which is connected with the power source to be supplied with current. A parameter such as electric power consumption indicative of an electric resistance of the heater of the catalytic converter. If the parameter is out of a range defined by reference values, it is determined hat a failure has occurred in the heater of the catalytic converter. In the system, reference values at a specific condition based on a correction coefficient obtained on the ratio between the parameter designed before manufacturing and that measured after manufacturing.
摘要:
An exhaust gas-purifying system for an internal combustion engine includes an alternator driven by the engine. A regulator controls voltage generated by the alternator. An electrically-heated catalyzer is arranged in the exhaust system of the engine and connected to the alternator to be electrically heated by electric power generated by the alternator. An ECU controls the regulator to control the voltage generated by the alternator and supplied to the electrically-heated catalyzer, according to a degree of aging of the electrically-heated catalyzer.