Denso Corporation

Osamu Fukasawa

Hideki Obayashi

Tomoaki Nakano

Hiroshi Katsurahara

Masahiro Yokoi

Atsushi Koike

Kota Noguchi

A fuel injection control device for an engine executes a split injection constructed by a fixed injection and a variable injection. A required injection amount of the fixed injection is set in a low range. A required injection amount of the variable injection is set in a high range. An injection amount in the high range is larger than that of the low range. The required injection amount of the variable injection is changed within the high range while the required injection amount of the fixed injection is fixed when a load of the engine is varied while the split injection is performed. An injection control characteristic is corrected based on an actual air-fuel ratio detected before the load is varied and an actual air-fuel ratio detected after the load is varied.

Fuel injection control device for engine

An ECU feedback controls a discharge amount of a high-pressure pump in such a manner that a detected fuel pressure is consistent with a target fuel pressure. The ECU determines whether engine shut sown is imminent. When the ECU determines that engine shut down is imminent, the target fuel pressure is established lower than a normal fuel pressure. Since the engine is shut down in a condition where the fuel pressure is decreased, a fuel leakage from a fuel injector is unlikely.

Controller for direct injection engine and controlling method

If a high-pressure pump discharges fuel in an injection waiting period from injection setting to injection start, fuel pressure to occur at injection start time is estimated and a fuel pressure correction coefficient is calculated based on the estimated fuel pressure. If there is no fuel discharge in the injection waiting period, the fuel pressure sensed at the injection setting is regarded as the fuel pressure of the injection start time, and the fuel pressure correction coefficient is calculated based on the sensed fuel pressure. A final injection period is calculated by correcting a basic injection period with the fuel pressure correction coefficient. Thus, fuel pressure correction of the injection period is performed accurately even if actual fuel pressure fluctuates due to the fuel discharge from the high-pressure pump during the injection waiting period.

Controller of in-cylinder injection engine

A startup controller calculates a fuel pressure difference across a discharge stroke of a high-pressure pump at an end of an initial discharge after cranking is started. At the injection setting, the startup controller estimates a fuel pressure increment from an injection setting to an injection start based on the fuel pressure difference. The startup controller adds the fuel pressure increment to a fuel pressure sensed at the injection setting to estimate a fuel pressure at the injection start. The startup controller determines whether to perform or to prohibit the injection based on whether the estimated fuel pressure at the injection start is equal to or higher than an injection permission fuel pressure.

Startup controller for in-cylinder injection internal combustion engine

A fuel pressure control device has a feedback control section for setting a feedback control amount (F/B control amount) in accordance with a deviation between target fuel pressure and actual fuel pressure and a feedforward control section for setting a feedforward control amount (F/F control amount) in accordance with a required fuel injection amount and engine rotation speed. When an engine operation state is an off-idling condition, F/F-F/B combination control for validating the F/F control amount and for setting a control amount of a high-pressure pump by adding the F/F control amount to the F/B control amount is performed. When the engine operation state changes from the off-idling condition to an idling condition, control is switched to F/B single control for invalidating the F/F control amount and for using only the F/B control amount.

Fuel pressure controller for direct injection internal combustion engine

A fuel injection controller of an in-cylinder injection engine determines that a combustion state has deteriorated and executes a split injection for injecting fuel in split amounts into each cylinder in multiple injection events in a cycle of the cylinder if it is determined that a combustion fluctuation is greater than a predetermined determination value during operation of the engine. The fuel injection controller increases a ratio of an injection amount of the first injection event in the split injection and lengthens an injection interval between the injection events as the combustion fluctuation increases. Thus, a wet amount of the injected fuel is reduced to expedite atomization of the injected fuel and to homogenize an in-cylinder mixture gas. As a result, the combustion state is improved.

Fuel injection controller for in-cylinder injection engine

A direct injection engine is provided with valve timing controllers in an intake side and an exhaust side. While the engine is running in a homogeneous combustion mode, a computer determines whether a valve overlap period exists, in which both the intake valve and the exhaust valve are opened. When the valve overlap period exists, the fuel injection timing is established within a valve overlap period to increase a temperature in a cylinder, so that an atomization of the injected fuel is expedited. When no valve overlap exists, the fuel injection timing is established at the vicinity of the valve opening timing of the intake valve, whereby the atomization of the injected fuel is expedited.

Controller for direct injection internal combustion engine

An opening is provided for an exhaust bypass pipe that bypasses an exhaust turbine of an exhaust turbine supercharger. According to the opening, an exhaust gas amount bypassing the exhaust turbine is calculated. An exhaust gas amount supplied to the exhaust turbine is found by subtracting the waste-gate-valve-passing gas amount from an intake air amount (exhaust gas amount) detected by the air flow meter. A rotational speed of the exhaust turbine is calculated from this turbine-supplied gas amount. An estimated boost pressure is calculated from this rotational speed of the exhaust turbine. Consequently, a boost pressure can be accurately estimated without using a boost pressure sensor even under such conditions as to disable detection of boost pressures or degrade the detection accuracy in a system using a conventional boost pressure sensor.

Boost pressure estimation apparatus for internal combustion engine with supercharger

A control mode of an intake valve lift controller is changed between a low-speed mode and a high-speed mode. Based on the control mode, an ignition timing is adjusted. When a knocking is detected by a knock sensor after the control mode is changed from the low-speed mode to the high-speed mode, it is determined that the intake valve lift controller has a malfunction in which the intake valve lift controller is stuck in the low-speed mode. When a combustion stability is lowered to a predetermined level after the control mode is changed from the high-speed mode to the low-speed mode, it is determined that the intake valve lift controller has a malfunction in which the intake valve lift controller is stuck in the high-speed mode.

Growing community of inventors

Nagoya, Japan

Osamu Fukasawa