Honda Motor Co., Ltd.

Takashi Konomoto

Toru Sekiguchi

Katsuji Wada

Toshifumi Yoshida

Taku Hirota

Norio Suzuki

Hiroki Ishikawa

Junichi Hatano

Masahiro Fujii

Atsuhiro Miyauchi

Tomoko Morita

An abnormality determination device of an internal combustion engine in which a breather line connects an intake-air path positioned upstream from a forced-induction system and a crankcase includes an intake-air flow rate sensor that detects an intake air flow rate in the intake-air path, a pressure sensor that detects a pressure of the breather line, and an abnormality determination unit that determines abnormality of the breather line. The abnormality determination unit estimates an intake air resistance of the intake-air path from the pressure when the engine is under low load conditions under which the intake air flow rate is less than a predetermined value and the pressure when the engine is under high load conditions under which the intake air flow rate is the predetermined value or greater and determines abnormality of the breather line when the intake air resistance is less than a threshold.

Abnormality determination device of internal combustion engine

In a failure determination device for an internal combustion engine equipped with a supercharger, the failure determination device determining a failure of a breather pipe that is connected between a crankcase and an intake passage at a position on an upstream side of the supercharger, the breather pipe is constituted by a double pipe including an inner pipe and an outer pipe, a communication passage communicates an enclosed space between the inner pipe and the outer pipe of the breather pipe with a portion of the intake passage on a downstream side of the supercharger. When the detected breather outer-pipe gauge pressure is higher than or equal to a determination threshold that is set in accordance with detected intake gauge pressure, the failure determination device determines that the breather pipe is failed.

Failure determination device for internal combustion engine

An abnormality assessment device includes an on-off valve that shuts an intake path on an upstream side of a connection portion of a breather line with respect to the intake path and an abnormality assessment element that assesses abnormality of the breather line. The abnormality assessment element assesses abnormality of the breather line based on a difference between an intake flow rate that is detected by an intake flow rate sensor and a target intake flow rate in a case where the on-off valve is closed.

Abnormality assessment device of internal combustion engine

An abnormality determination apparatus for an internal combustion engine in which an intake passage upstream of a supercharger and a crankcase are connected by a breather line includes: an intake flow rate detection unit that detects an intake flow rate in the intake passage; and an abnormality determination unit that determines abnormality of the breather line. The abnormality determination unit accumulates a value calculated from a rotation second-order component of a fluctuation waveform of the intake flow rate over a predetermined period of time and determines the abnormality of the breather line when the accumulated value is less than a predetermined threshold.

Abnormality determination apparatus for internal combustion engine

An abnormality determination apparatus for an internal combustion engine in which an intake passage upstream of a supercharger and a crankcase are connected by a breather line includes: an intake flow rate detection unit that detects an intake flow rate in the intake passage; and an abnormality determination unit that determines abnormality of the breather line. The abnormality determination unit calculates a rotation second-order component of a fluctuation waveform of the intake flow rate, accumulates a first number of times for which the rotation second-order component exceeds an upper threshold and a second number of times for which the rotation second-order component falls below a lower threshold, and determines the abnormality of the breather line by comparing an accumulated value of the first number of times and the second number of times with the number of revolutions of a crank.

An abnormality determination apparatus for an internal combustion engine in which an intake passage upstream of a supercharger and a crankcase are connected by a breather line includes: an intake flow rate detection unit that detects an intake flow rate in the intake passage; and an abnormality determination unit that determines abnormality of the breather line. The abnormality determination unit accumulates a time for which a rotation second-order component of a fluctuation waveform of the intake flow rate is equal to or more than a threshold over a predetermined period of time and determines the abnormality of the breather line when the accumulated value is less than a predetermined accumulation threshold.

An internal combustion engine includes on-off valves that configure a closed space by closing an internal space of a breather line, a pump that depressurizes or pressurizes the closed space, a pressure sensor that detects a pressure of the closed space, and an abnormality assessment element that assesses abnormality of the breather line. The abnormality assessment element assesses abnormality of the breather line based on a pressure change of the closed space in a case where the closed space is depressurized or pressurized by the pump.

Provided is a connection state determination device. The connection state determination device for the breather pipe determines the connection state of a breather pipe in an internal combustion engine having a supercharger, and the breather pipe is connected between an engine body including a crank case and an intake passage on the upstream side of a compressor of the supercharger, and communicates the crank case and the intake passage. The connection state determination device includes a pipe internal pressure sensor that detects the pressure inside the breather pipe, a pulsation waveform obtaining part for obtaining pulsation due to the variation of pressure inside the breather pipe as a pulsation waveform based on the detected pressure, and a connection state determination part that determines the connection state of the breather pipe based on the pulsation waveform.

Connection state determination device for breather pipe

An exhaust emission control device for an internal combustion engine, which is capable of properly regenerating a NOx catalyst, while properly controlling NOx catalyst temperature and ensuring excellent drivability. As a regeneration operation, the exhaust emission control device feedback-controls a detected reducing condition of exhaust gases to a predetermined reducing condition, by controlling the amount of main fuel injected by main injection or feedback-controls the same to the predetermined reducing condition by controlling the amount of auxiliary fuel injected by auxiliary injection. The device determines whether the regeneration operation should be executed in a catalyst temperature control mode for controlling the NOx catalyst temperature. If, as a result of the determination, the regeneration operation should be executed in the catalyst temperature control mode, the device selects the feedback control of the main fuel amount, and otherwise selects the feedback control of the auxiliary fuel amount.

Exhaust emission control device and method for internal combustion engine, and engine control unit

An exhaust emission control device for an internal combustion engine which is capable of supplying a just enough amount of reducing agent to a NOx catalyst while causing the consumption amount of reducing agent dependent on the degradation degree of an upstream catalyst to be reflected thereon. A NOx catalyst is disposed at a location downstream of a catalyst having an oxidation function for purifying exhaust gases, for trapping NOx contained in exhaust gases in an oxidizing atmosphere, and reducing the trapped NOx in a reducing atmosphere to thereby purify the trapped NOx. Exhaust gases flowing into the NOx catalyst are controlled to the reducing atmosphere, by supplying reducing agent to an upstream side of the catalyst. The degradation degree of the catalyst is estimated, and a time period over which the reduction control should be executed is corrected according to the estimated degradation degree.

The present invention provides a fuel control for an internal-combustion engine having an exhaust gas purifying device that is disposed in an exhaust system of the engine. A reducing agent is supplied to the exhaust gas purifying device by injecting fuel in an expansion stroke or an exhaust stroke of the engine. An intake air amount supplied to the engine is controllable. The fuel control includes decreasing the intake air amount supplied to the engine during the fuel injection for the supply of the reducing agent. The fuel control also includes advancing an injection timing of the fuel injection for the supply of the reducing agent when an actual intake air amount is less than a desired intake air amount or when an actual boost pressure is higher than a desired boost pressure. The advancement of the injection timing improves the combustibility of engine while decreasing the HC exhaust amount.

Fuel control of an internal-combustion engine

A control system for an internal combustion engine, which is capable of properly setting fuel injection timing according to the actual degree of delay of the amount of fresh air to be supplied to cylinders of the engine, thereby making it possible to positively suppress torque variation, when the control system has switched an air-fuel ratio mode between a lean mode and a rich mode. The control system controls the air-fuel ratio of a mixture by switching the air-fuel ratio mode. In the lean mode, the control system sets a target fresh air amount for the lean mode, and in the rich mode, it sets a target fresh air amount for the rich mode. Upon switching the air-fuel ratio mode, the control system corrects the fuel injection timing according to the difference between the target fresh air amount for the lean mode or the rich mode and the detected fresh air amount.

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Wako, Japan

Takashi Konomoto