Mitsubishi Denki Kabushiki Kaisha

Mitsubishi Jidosha Kogyo Kabushiki Kaisha

Mitsubishi Denki K.k.

Mitsubushi Denki Kabushiki Kaisha

Yoichi Kadota

Ryoji Nishiyama

Hideaki Katashiba

Wataru Fukui

Hirofumi Ohuchi

Hironori Matsumori

Kazutoshi Noma

A fuel control system for a cylinder injection type internal combustion engine which can avoid frequent changeover of engine control mode and ensure a sufficient vacuum level for a brake operating pressure while protecting against degradation combustibility and fuel-consumption performance of the engine without resorting to additional provision of a special circuit or device. The system includes an intake air flow sensor (,) for detecting an intake air quantity (Qa) fed to an internal combustion engine (,) for thereby outputting a corresponding information signal, a crank angle sensor (,) for detecting a rotation speed (rpm) (Ne) of the engine (,) and a crank angle thereof to thereby output a corresponding information signal (SGT), and a pressure sensor (,) for detecting a brake operating pressure (PB). A control unit (,B) of the fuel control system is so designed or programmed as to compare a vacuum level of the brake operating pressure (PB) with a predetermined level (PTH,) corresponding to a permissible upper limit value of the vacuum level to thereby control the engine (,) in a mode conforming to the engine operating state when the vacuum level of the brake operating pressure (PB) is lower than the predetermined level (PTH,), whereas when the vacuum level of the brake operating pressure (PB) becomes equal to or higher than the predetermined level (PTH,), the control unit (,B) controls the engine (,) in a stoichiometric mode to thereby allow the vacuum level of the brake operating pressure (PB) to be sustained lower than the predetermined level (PTH,).

Fuel control system for cylinder injection type internal combustion engine

To control rise of an engine output when performing backward driving with the back gear, the opening degree of a throttle valve for adjusting the air quantity to be taken into the engine is controlled so that it does not increase when the transmission is set to the back gear state.

Engine-output control unit

An exhaust gas recirculation control system for internal combustion engines, comprising an exhaust gas recirculation passage for recirculating a part of an exhaust gas from an internal combustion engine into the engine; an exhaust gas recirculation control valve for controlling a flow rate of the exhaust gas flowing in the exhaust gas recirculation passage; an opening degree controller for controlling an opening degree of the exhaust gas recirculation control valve; an operating condition detector for detecting an operating condition of the engine; means for setting a target exhaust gas recirculation ratio depending on the detected operating condition; a combustion state detector for detecting a combustion state in at least one cylinder of the engine; means for finding an actual exhaust gas recirculation ratio of the engine based on the detected combustion state; and means for controlling the opening degree controller so as to bring the actual exhaust gas recirculation ratio to the target exhaust gas recirculation ratio.

Exhaust gas recirculation control system for internal combustion engines

An inter-cylinder-injection fuel controller for an internal combustion engine which offers fail-safe performance against an increase in the amount of the intake air caused by a trouble in the intake system, and reliably suppresses the engine running speed from abnormally increasing. The fuel controller comprises various sensors 20 for outputting data representing operation conditions of the internal combustion engine, injectors for directly injecting the fuel into the cylinders, and a control unit 89 for operating the amounts F of fuel supplied into the cylinders based upon the operation conditions and for controlling the injectors based upon the amounts of supplying fuel, wherein said various sensors include an amount-of-intaken-air sensor for outputting data that corresponds to the amount Qa of the intaken air, and a crank angle sensor for outputting data .theta. that correspond to the running speed Ne and to the crank angle, and the control unit limits the width of the injection control signals J for the injectors to an upper-limit value that corresponds to the operation conditions.

Inter-cylinder-injection fuel controller for an internal combustion

When the ETV control system runs into trouble, drivability and safety are secured against the system trouble by fixing the step of speed change at a high speed position if the vehicle is running forward or stopping fuel feed to a specific cylinder or cylinders if it is running backward. When the electronic throttle control system runs into trouble, the throttle valve 3 is released from control by stopping power supply to the motor 1, the throttle value 3 is mechanically fixed in a preset position, and the transmission 2 is fixed in a high speed position if the vehicle is running forward, thereby to reduce engine acceleration and the shock to the body due to unnecessary speed change action, or fuel feed to a specific cylinder or cylinders is stopped according to the engine condition if the vehicle is running backward, thereby to reduce the engine output, so that the vehicle be enabled to run smoothly.

Drive by wire fail safe control to fix the vehicle speed at a preset

A fuel control system for a cylinder injection type internal combustion engine which allows the fuel injection mode to make transition from a compression-stroke injection mode for realizing a high air-fuel ratio to the suction-stroke injection mode for realizing a low air-fuel ratio while ensuring stable combustion state without need for additional provision of any especial devices. The system includes an intake air flow sensor for detecting an intake air flow, a crank angle sensor for detecting rotation speed or rpm of the engine and a crank angle, a fuel injector for injecting fuel directly into each of cylinders of the engine, an exhaust gas recirculation system for regulating quantity of exhaust gas recirculated from an exhaust passageway to an intake passageway of the engine, and an electronic control unit for arithmetically determining control quantities for the fuel injector and the exhaust gas recirculation system, respectively, on the basis of detection information derived from the outputs of the intake air flow sensor and the crank angle sensor, respectively. When the fuel injection mode of the internal combustion engine is changed over from the compression-stroke fuel injection mode to the suction-stroke fuel injection mode, the electronic control unit starts to control the exhaust gas recirculation in precedence to any other control required for the suction-stroke fuel injection mode.

Fuel control method and system for cylinder injection type internal

An inter-cylinder-injection fuel controller for an internal combustion engine maintaining stable operation performance at a low cost. The inter-cylinder-injection fuel controller comprises a control unit 8B for controlling the injectors in a mode of the compression stroke injection or in a mode of the intake stroke injection, wherein various sensors 20 include an amount-of-intaken-air sensor and a crank angle sensor, and said control unit includes change-in-the-running-speed suppressing portion 82, 83 for suppressing a change in the running speed caused by a change in the external load in the mode of the compression stroke injection by correcting the amount F of supplying fuel, a rich determining portion 85 for forming a rich signal RC when a target air-to-fuel ratio A/Fo based upon the corrected amount of supplying fuel is on the side more rich than a predetermined lower-limit value .alpha., an air-to-fuel-ratio clipping portion 86 for clipping the controlled air-to-fuel ratio to the lower-limit value in response to the rich signal, an amount-of-deviation operation means for operating the amount of deviation .DELTA.A/F between the lower-limit value and the target air-to-fuel ratio in response to the rich signal, and parameter correction portion 87, 88 for correcting the control parameters toward the direction of increasing the output depending upon the amount of deviation.

A combustion control system includes a waveform shaping device for producing an ON signal from an ion current detected value, a down timing detecting device for detecting down timings of the ON signal, an operating device for converting the down timings into times elapsing from a reference crank angle, mask time section setting device for setting a mask time section corresponding to a combustion period in accordance with a running condition of the internal combustion engine, a selecting device for selecting at least one of said down times detected within the mask section, and a determining device for determining a combustion parameter of said internal combustion engine in accordance with the combustion ending time, whereby the combustion state of each cylinder is detected from the combustion ending time detected by the mask time section to determine the combustion parameter so as to suppress a combustion change. In this configuration, by operating a small quantity of data, an inexpensive and accurate combustion control system for an internal combustion engine can be obtained.

Combustion control system for internal combustion engine

A fuel injection control system for a cylinder injection type internal combustion engine. The system includes an engine control unit (8) for controlling fuel injectors (11) so that fuel injection is forcibly carried out in a suction stroke of the engine immediately before the engine (1) is stopped, wherein the quantity of intake air fed to the internal combustion engine (1) in the suction stroke is forcibly increased. Only the ignition process is validated after the interruption of the fuel supply. By stopping the engine immediately after the suction stroke in which the fuel injection is performed, desirable starting performance of the engine is ensured in the succeeding operation thereof. Enhanced staring performance of the engine can be realized even in the existing engine without incurring high cost and increase in the processing overhead.

Fuel injection control method for cylinder injection type internal

A control device for a cylinder injection type internal-combustion engine restrains the deterioration of combustion in the cylinder injection type internal-combustion engine which implements stratified charge combustion at a delicate fuel injection timing and a delicate ignition timing. The control device is equipped with a combustion state detector for detecting the deterioration of combustion in the internal-combustion engine, and a device for restraining the deterioration of combustion in the internal-combustion engine by gradually changing at least one parameter among the amount of exhaust gas to be recirculated, an ignition timing, and an air-fuel ratio when the combustion state detector has detected the deterioration of combustion in the internal-combustion engine.

Control device for cylinder injection type internal-combustion engine

A fuel control system for a cylinder injection type engine capable of preventing overlap between periods for the fuel injections for a plurality of engine cylinders while reducing burden imposed on injector drivers and allowing the fuel control system to be implemented on a small circuit scale at low cost by limiting fuel injection timings for driving the injectors. The system includes an air flow sensor (2) for outputting information concerning an intake air flow, a crank angle sensor (5) for outputting information concerning rotation speed of the engine (1) and a crank angle, fuel injectors (11A) for injecting fuel directly into individual engine cylinders, and a control unit (8A) for driving the fuel injectors on the basis of the abovementioned information. The control unit (8A) is so arranged as to arithmetically determine a fuel injection quantity and fuel injection timings for driving the fuel injector (11A) at least in one of suction stroke and compression stroke. The control unit (8A) limits a change of fuel injection timing of the injector in a leading direction so that the change in the fuel injection timing does not exceed a predetermined value, and sets the fuel injection timing at a time point corresponding to a lapse of a predetermined time from the preceding fuel injection.

Fuel control system for cylinder injection type internal combustion

When a malfunction determination mode for a fuel-evaporated-gas processing device is employed (step S1), an engine control unit 9A determines whether a malfunction of an O.sub.2 sensor 10 is being checked or not (step S2). When a malfunction of the O.sub.2 sensor 10 is being checked, the determination of a malfunction of the O.sub.2 sensor 10 is executed (step S4) without determining a malfunction of the fuel-evaporated-gas processing device. When the O.sub.2 sensor 10 malfunctions, a processing to be taken when the O.sub.2 sensor 10 malfunctions is executed (step S8) and a warning lamp is turned on (step S9). With this operation reliability in the determination of a malfunction of the fuel-evaporated-gas processing device can be improved without employing a countermeasure such as an increase of the number of determinations and the like.

Malfunction diagnosis device for fuel-evaporated-gas processing device

A self-diagnosis apparatus performs a failure diagnosis of a control unit equipped with a pressure sensor based on an output thereof a pressure sensor. The apparatus performs the failure diagnosis after the elapse of a predetermined period from the time when the output of the pressure sensor has changed by a predetermined quantity.

Self-diagnosis apparatus using a pressure sensor

A misfire detector for an internal combustion engine is provided which, if any of a plurality of modification factors is replaced by a value out of the proper range, can prevent erroneous misfire detection from, continuing. The misfire detector comprises a period measurement unit of signals generated by a crank angle sensor, a modification factor calculating unit for, based on a ratio between the periods of the plurality of signals in a steady operating condition, calculating a plurality of modification factors used to modify errors in period values, a modification factor propriety determining unit for determining whether the plurality of modification factors calculated by the modification factor calculating unit are in the proper range or not, a period variation factor calculating unit for, based on the periods values and the modification factors which have been determined as being proper, calculating each period variation factor used to quantitize variations in the period, and a misfire determining unit for determining the occurrence of a misfire based on the period variation factor calculated by the period variation factor calculating unit.

Misfire detector for internal combustion engine

Malfunction of a purge air control system is checked based on a variation of a fuel tank inner pressure or an air-fuel ratio in response to forced introduction of purge air into an engine. During a mode of checking malfunction of the purge air control system, failure/malfunction checks on other exhaust gas control components/systems, such an ignition system, an O.sub.2 sensor and a fuel supply system, are prohibited.

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Tokyo, Japan

Yoichi Kadota