Honda Giken Kogyo Kabushiki Kaisha

Honda Giken Kogyo K.k.

Ngk Insulators, Inc.

Takashi Komatsuda

Yuichi Shimasaki

Hiroaki Kato

Takuya Aoki

Akihisa Saito

Toshikazu Oketani

Tetsu Teshirogi

Takayoshi Nakayama

Hideo Furumoto

Seiji Matsumoto

Yukio Miyashita

Seiji Hatcho

Hiroaki Muramatsu

Hiroshi Hashimoto

Kazuo Ishii

Shinichi Takahashi

Shigeharu Hashimoto

Seiji Kato

Tadato Ito

Hiroshi Ohno

Toshiaki Ichitani

Hiromu Nakamura

Hajime Uto

Koichi Fujimori

Kaoru Aoki

Kazuhiro Furuhashi

Hideo Kaiho

Tatsumi Yamada

Kouichi Fujimori

Tsutomu Yamasaki

Takuya Takagi

Seiji Haccho

In a cylinder head of an internal combustion engine, communicating passageways &prime; for coolant are provided between combustion chambers and pass-through holes to at positions which overlap straight lines L L connecting centers C C of the exhaust port openings with centers C to C of the pass-through holes to and straight lines L L connecting centers C C of the intake port openings with centers C to c of the pass-through holes to when a mating surface of the cylinder head with the cylinder block is viewed from the bottom. When peripheries of the exhaust port openings and intake port openings thermally expand, the suppression of thermal expansion by the bolts at fastening portions is alleviated by the communicating passageways

Cylinder head for an internal combustion engine

An exhaust manifold M is comprised of a plurality of inner exhaust pipe shells secured to an upper flange, and a plurality of outer exhaust pipe shells secured to the upper flange to individually cover the inner exhaust pipe shells, wherein a downstream end of each of the corresponding inner exhaust pipe shells slidably contacts an annular bead bulging from an outer peripheral surface of the downstream end of the outer exhaust pipe shells. An inner collecting pipe shell communicates with the plurality of inner exhaust pipe shells and is secured at its upstream end to the plurality of outer exhaust pipe shells, and an outer collecting pipe shell which is secured at its upstream end to the plurality of outer exhaust pipe shells covers the inner collecting pipe shell. A downstream end of the inner collecting pipe shell slidably contacts an annular mesh member interposed therebetween. Sliding portions for absorbing a difference in the axial thermal elongation between inner and outer double walls are provided separately at the downstream end of an exhaust single pipe and the downstream end of an exhaust collecting pipe. Thus, the sliding stroke in each of the sliding portions can be set to a small value, and the absorption of the thermal elongation can be carried out smoothly.

Heat-insulation type exhaust manifold

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.

Electrode structure and electric heater comprising the same

A heat-insulating, light and vibration-proof exhaust manifold for a multi-cylinder internal combustion engine is provided. The exhaust manifold comprises an upper stream flange, a lower stream flange, four manifold pipes at an upper stream, a manifold chamber (gathering section) at a lower stream and a manifold case of a plate metal covering the manifold pipes and the manifold chamber. The manifold pipes have upper stream ends to be connected to exhaust ports of the internal combustion engine through the upper stream flange and lower stream ends gathering in the manifold chamber. Upper stream ends of the manifold pipes and the manifold case are welded to the upper stream flange, and lower stream ends of the manifold chamber and the manifold case are welded to the lower stream flange. The manifold pipe and the manifold chamber can slide relatively at a slide portion which is maintained by pressing the manifold chamber and the manifold case against the manifold pipe.

Exhaust manifold of a multi-cylinder internal combustion engine

A failure detection system detects a failure occurring in an exhaust secondary air supply system of an internal combustion engine, and has a catalytic converter installed in an exhaust pipe of an exhaust system of the engine for reducing pollutants from exhaust gases emitted from the engine, a conduit connected, at one end, to the exhaust pipe at a location upstream of the catalytic converter and an air pump connected to an opposite end of the conduit for supplying compressed air in the conduit. The conduit is closed by the a valve which opens in response to the negative pressure and a second valve which opens in response to the conduit pressure. In the system a first prescribed level and the second prescribed level are set and two pressure switches are provided for generating output at the levels. A failure occurring in the air pump and the valve is detected based on operation of the air pump and the output of the pressure detectors. Alternatively, the failure is detected by changing the timing of the termination of the air pump and closing of the second valve while using one switch and the second prescribed level. The system is simple in configuration.

Failure detection system of exhaust secondary air supply system of

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.

Exhaust gas-purifying system for internal combustion engines

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.

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.

Idle speed control system of internal combustion engine

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.

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.

Failure detection system of electrically heated catalytic converter of

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.

Exhaust system ambient temperature detection system for internal

An air pump abnormality-detecting system for an internal combustion engine. The engine has a catalyst arranged in the exhaust system of the engine, a passage extending from the exhaust system at a location upstream of the catalyst, and an electrically driven air pump arranged across the passage, for supplying secondary air into the exhaust system. A current sensor detects electric current flowing through the air pump, and a voltage sensor detects voltage applied to the air pump. An abnormality of the air pump is detected by comparing an output from the current sensor obtained during operation of the air pump, with predetermined abnormality-detecting reference values. At least one of the output from the current sensor or the predetermined abnormality-detecting reference values is corrected in response to an output from the voltage sensor.

Air pump abnormality-detecting system for internal combustion engines

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.

Current supply control system of electrically heated catalytic converter

An exhaust gas-purifying device for an internal combustion engine has an adsorbing device arranged in an exhaust passage of the engine for adsorbing unburnt fuel components in exhaust gases from the engine, a catalytic converter arranged in same at a location downstream of the adsorbing device for purifying the exhaust gases, and a heater for electrically heating the catalytic converter. The temperature of the adsorbing device is detected. The heater is controlled to be operated at least on condition that the temperature of the adsorbing device is above a predetermined value. In another form of the invention, the temperature of the catalytic converter is detected. A rate of a rise of the temperature of the catalytic converter is determined. A deterioration state of the adsorbing device is determined based on the rate of the rise of the temperature of the catalytic converter.

Exhaust gas-purifying device for internal combustion engines

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.

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Wako, Japan

Takashi Komatsuda