Honda Giken Kogyo Kabushiki Kaisha

Akira Murakami

Shigeo Hidai

Seiichi Hosogai

Atsushi Izumiura

Atsushi Kato

Eisaku Gosho

Manabu Niki

Katsunori Nakamura

Kotaro Miyashita

Shigeru Aoki

Kazuhiro Ueda

Akira Hashimoto

Toshikatsu Takanohashi

Toshiyuki Nishida

Yuichiro Tanabe

Nobuo Arai

Ryuichi Noseyama

Kenichiro Ishibashi

Yoshikazu Ohshima

Mistuo Hashizume

Hirohisa Kitaura

An abnormality detecting apparatus for an intake system of an internal combustion engine, which detects an abnormality of the intake system, is disclosed. The intake system has a throttle valve, a bypass passage bypassing the throttle valve, and an idling control valve for controlling the amount of air supplied through the bypass passage to the engine. A total intake air amount supplied to the engine is calculated. An amount of intake air supplied through the bypass passage is calculated based on a valve opening control quantity for the idling control valve. A parameter indicative of a leak air amount of the intake system is calculated according to the result of a comparison between the calculated total intake air amount and the amount of intake air supplied through the bypass passage. It is determined that the intake system is abnormal when the parameter indicative of the leak air amount is greater than a determination threshold in an engine operating condition where the throttle valve is substantially fully closed.

Abnormality detection apparatus for intake system of internal combustion engine

An exhaust emission control system for an internal combustion engine, having a nitrogen oxide removing device provided in an exhaust system of the internal combustion engine for absorbing nitrogen oxides contained in exhaust gases in an exhaust lean condition. The exhaust emission control system includes first and second oxygen concentration sensors respectively provided upstream and downstream of the nitrogen oxide removing device for detecting an oxygen concentration in the exhaust gases. The air-fuel ratio of an air-fuel mixture to be supplied to the engine is changed from a lean region to a rich region with respect to a stoichiometric ratio. An amount of reducing components flowing into the nitrogen oxide removing device from the time when an output value from the first oxygen concentration sensor has changed to a value indicative of a rich air-fuel ratio after enrichment of the air-fuel ratio is calculated. Deterioration of the nitrogen oxide removing device is determined according to the calculated amount of reducing components and an output value from the second oxygen concentration sensor.

Exhaust emission control system for internal combustion engine

An oxygen concentration sensor abnormality-detecting system is provided for an internal combustion engine having first and second oxygen concentration sensors arranged in the exhaust system upstream and downstream of a catalytic converter therein. An ECU determines that the first oxygen concentration sensor is functioning abnormally if an output from the first oxygen concentration sensor does not change when an output from the second oxygen concentration sensor changes.

Oxygen concentration sensor abnormality-detecting system for internal combustion engines

A system for detecting failure of a fuel pressure sensor in an internal combustion engine, including an injector (32) provided at an intake system of the engine downstream of a throttle valve (38), a fuel supply passage (16) connected to a fuel supply source (fuel tank 12) for supplying fuel to the injector (32), pressure regulator (28) provided in the fuel supply passage (16) and operating to maintain a difference between the fuel pressure (PF2A) and the manifold absolute pressure at a constant value, a fuel pressure sensor (PF2 sensor 54) for detecting the fuel pressure (PF2A) in the fuel supply passage (16) downstream of the pressure regulator, and a manifold absolute pressure sensor (62) for detecting the manifold absolute pressure (PBA) downstream of the throttle valve (38). In the system, an index indicative of a ratio (.DELTA.PF2A) of the fuel pressure (PF2A) fluctuation relative to the manifold absolute pressure (PBA) fluctuation is compared to reference values (#PF2L, #PF2H) which define a range. Sensor failure is discriminated when the index (.DELTA.PF2A) is found to have remained outside of the range for a predetermined maximum time (tmP2STK). The system enables rapid and accurate detection of fuel pressure sensor abnormality (failure).

System for detecting failure of fuel pressure sensor

An air-fuel ratio control system for an internal combustion engine includes an ECU which cuts off fuel supply to the engine at deceleration thereof, measures a fuel cut-off period over which the fuel cut-off means cuts off fuel supply to the engine, and enriches the air-fuel ratio of a mixture supplied to the engine to a degree dependent upon the measured fuel cut-off period, at the restart of fuel supply to the engine immediately after termination of cutting-off of fuel supply to the engine. When a second cutting-off of fuel supply to the engine is carried out within a predetermined time period after the restart of fuel supply to the engine immediately after termination of a first cutting-off of fuel supply to the engine, the ECU sets the degree of enriching the air-fuel ratio of the mixture supplied to the engine according to the sum of a first fuel cut-off period over which the first cutting-off of fuel supply to the engine lasted and a second fuel cut-off period over which the second cutting-off of fuel supply to the engine lasted.

Air-fuel ratio control system for internal combustion engines

Supply of fuel is stopped when fuel pressure sensed by a pressure sensor provided upstream of a regulator is at a predetermined value or less to avoid abnormal combustion caused by improper adjustment of air/fuel ratio. Even slight variation of the fuel pressure is sensed by monitoring the fuel pressure in an interval after closing a fuel shut-off valve once opened to re-opening of it. In addition, an abnormal state in the fuel system is detected by comparing an accumulated value of amount of injected fuel and an estimated value of fuel consumption in the tank. Furthermore, the peak current value of the fuel injection valve is controlled so that, when the engine at a low temperature is started, lift load of the injection valve is larger than sticking force of the injection valve, thereby preventing such situation where the injection valve is frozen so that it cannot supply fuel to the engine. In this case, the engine can be smoothly started by simultaneously controlling the valve open time. Furthermore, the temperature of the regulator is properly maintained so that optimum function can be exhibited by controlling the flow rate of cooling water flowing through a water passage provided in the regulator for regulating the fuel gas pressure.

Gas fuel supply system for vehicle

Growing community of inventors

Wako, Japan

Akira Murakami