Abstract: A fuel reformer includes a reforming-fuel injection valve and a fuel reformer catalyst disposed in an EGR pipe and performs a catalyst recovery control when a preset fuel cut execution condition is satisfied. In the catalyst recovery control, a fuel reforming capacity of the fuel reformer catalyst is recovered by stopping an injection of a main fuel and an injection of a reforming-fuel, while supplying additional air to the catalyst by maintaining both of an EGR valve and a throttle valve in a valve open state. Further, in the catalyst recovery control, temperature and a carbon deposit amount of the fuel reformer catalyst are estimated or detected based on which of an opening of the EGR valve and an opening of the throttle valve are adjusted. As a result, fuel reforming capacity is recovered without decreasing a fuel consumption rate improvement effect and a worsening of exhaust emission or drivability.

Abstract: A fuel reformer includes a reforming-fuel injection valve and a fuel reformer catalyst disposed in an EGR pipe and performs a catalyst recovery control when a preset fuel cut execution condition is satisfied. In the catalyst recovery control, a fuel reforming capacity of the fuel reformer catalyst is recovered by stopping an injection of a main fuel and an injection of a reforming-fuel, while supplying additional air to the catalyst by maintaining both of an EGR valve and a throttle valve in a valve open state. Further, in the catalyst recovery control, temperature and a carbon deposit amount of the fuel reformer catalyst are estimated or detected based on which of an opening of the EGR valve and an opening of the throttle valve are adjusted. As a result, fuel reforming capacity is recovered without decreasing a fuel consumption rate improvement effect and a worsening of exhaust emission or drivability.

Abstract: An intake air base amount calculation unit respectively calculates a base air amount Gbase, an intake air temperature correction coefficient Ka and a pulsation correction coefficient Kb, and calculates an intake air base amount Gnb based on these. An internal EGR amount calculation unit calculates an clearance volume EGR amount based on an exhaust valve closing timing EVC, and further calculates a backflow EGR amount based on a valve overlap amount OL, a rotation speed of engine Ne and an intake pipe pressure Pm, and still further calculates an internal EGR amount Gegr by adding the clearance volume EGR amount and the backflow EGR amount. Then, an intake air amount calculation unit calculates an intake air amount of cylinder Gn by subtracting the internal EGR amount Gegr from the intake air base amount Gnb.

Abstract: 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.

Abstract: 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.

Abstract: An intake air base amount calculation unit respectively calculates a base air amount Gbase, an intake air temperature correction coefficient Ka and a pulsation correction coefficient Kb, and calculates an intake air base amount Gnb based on these. An internal EGR amount calculation unit calculates an clearance volume EGR amount based on an exhaust valve closing timing EVC, and further calculates a backflow EGR amount based on a valve overlap amount OL, a rotation speed of engine Ne and an intake pipe pressure Pm, and still further calculates an internal EGR amount Gegr by adding the clearance volume EGR amount and the backflow EGR amount. Then, an intake air amount calculation unit calculates an intake air amount of cylinder Gn by subtracting the internal EGR amount Gegr from the intake air base amount Gnb.

Abstract: 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.

Abstract: 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.

Abstract: An internal combustion engine has a plurality of cylinders and intake passages leading to the cylinders respectively. A plurality of intake control valves block and unblock the intake passages respectively. Drive devices open and close the intake control valves mutually-independently. A detecting device serves to detect a predetermined condition of the engine under which a speed of the engine is required to vary. A control device performs a control of closing the intake control valves mutually-independently by use of the drive devices after the detecting device detects the predetermined condition of the engine.

Abstract: An intake apparatus for an internal combustion engine that has a first intake passage communicating with a combustion chamber of the internal combustion engine; a second intake passage which communicates with the combustion chamber of the internal combustion engine and whose length is greater than a length of the first intake passage; a valve for selectively changing over the communication/shutting off of the combustion chamber of the internal combustion engine with/from between the first or/and second intake passages; and a drive circuit for driving the valve to effect the changing over operation. A controller controls the drive circuit, and an air cleaner device introduces clean air into the combustion chamber of the internal combustion engine.

Abstract: An intake control system includes an intake control valve disposed in a common intake pipe connected to engine cylinders or a plurality of intake control valves disposed in intake pipes connected respectively to the engine cylinders. The intake control valves are openable and closable under the control of an electronic control unit directly or through respective actuators, based on an electric signal indicative of an operating condition of intake valves on engine cylinders.

Abstract: The flow rate of intake air in an engine, engine speed, and automobile speed are detected. The speed-change ratio of a transmission is determined and adjusted in response to a signal which is proportional to the detected intake air flow rate and inversely proportional to the detected engine speed, and in response to the detected automobile speed.

Abstract: In an internal combustion engine, a plurality of engine rotational speeds are detected at predetermined timings for every firing stroke in one cylinder of the engine, and an engine speed variation is calculated as a variation between the square of one of the engine rotational speed and the square of another of the engine rotational speed. A process is performed upon the sequence of the engine speed variations, thus determining an engine combustion state by the processed result.

Abstract: In an apparatus for the feedback control of the air-fuel ratio in an internal combustion engine using the output signal of an air-fuel ratio sensor, a degree of deterioration of the functioning of the air-fuel ratio sensor is detected by using successive measurements of a differential waveform of an output signal of the air-fuel ratio sensor over a predetermined period of time, and an air-fuel ratio feedback control constant is controlled in accordance with the degree of functional deterioration of the air-fuel ratio sensor to correct the air-fuel ratio.

Abstract: A torque detector for detecting a torque applied to a torque transmission shaft which is connected to a load such as a wheel of an automobile. A first rotating body is connected to one end of a driving shaft of an engine coaxially, and an annular second rotating body is disposed around a boss which projects from the center of the first rotating body so as to be coaxial and parallel with the first rotating body. An elastic member connects the inner peripheral portion of the second rotating body to the boss in the radial direction. The angular phase difference between the first and the second rotating bodies which occurs due to the deformation of the elastic member is detected, and torque is calculated from the obtained angular phase difference.

Abstract: In an internal combustion engine, a standard deviation of combustion variations generated for every firing stroke of at least one cylinder is calculated. The misfire limit of the engine is detected by determining whether or not the calculated standard deviation is greater than a reference value. When the calculated standard deviation is greater than the reference value, the controlled air-fuel ratio is decreased, while when the calculated standard deviation is not greater than the reference value, the controlled air-fuel ratio is increased, thereby attaining a lean burn system without a lean mixture sensor.

Abstract: A torque detector, particularly a torque detector for detecting a torque applied to a torque transmission shaft which is connected to a load such as a wheel of an automobile, has a driving member connected to an engine, a driven member connected to a load and driven by the driving member to be rotated, an elastic member for connecting the driving member to the driven member, a transmission for varying the rotating speed ration of the engine to the load, which is provided in the driving member or the driven member, electromagnetic pickups for detecting the angular phase difference between the driving member and the driven member which is produced due to the deformation of the elastic member, a rotating speed ratio counting circuit for detecting the rotating speed ratio of the engine to the load, which is controlled by the transmission, and a microcomputer for calculating engine torque and load driving torque from the rotating speed ratio detected by the rotating speed ratio counting circuit and the angular pha

Abstract: In a method for measuring variations in the output of an internal combustion engine, at least one of signals respectively representing an engine speed, torque, and internal cylinder pressure of the internal combustion engine during the firing strokes of the engine is obtained. A periodical and pulsating change in the obtained signal is detected. A differential value at a portion of the change of the signal having a maximum gradient is then detected. Another method provides measuring variations in the output of the internal combustion engine by calculating the difference between the maximum and minimum values of the change of the obtained signal. Still another method provides measuring variations in the output of the internal combustion engine by correcting the obtained value in accordance with the engine speed. Still another method provides measuring variations in the output of the internal combustion engine by calculating the difference between consecutive changes.

Abstract: A torque variation in an internal combustion engine due to the combustion variations is detected at each predetermined period. An average torque variation to be compared with the detected torque variation is predetermined experimentally based on the engine speed and the intake manifold pressure and is stored in a memory. The number of the detected torque variations which exceed the average torque variation multiplied by a predetermined constant is counted, and if the ratio of the counted number to the total number of the detected torque variations is larger than a predetermined reference value, then the presence of a torque variation is determined.

Abstract: A torque detector, for detecting a torque applied to a torque transmission shaft which is connected to a load of an automobile, comprises an elastic member which is interposed between a driving shaft and the torque transmission shaft so as to be connected thereto, rotating members, each of which is integrally provided with the shafts, have a plurality of teeth or notches in the outer periphery thereof so as to be positioned in each combustion stroke of each piston of an engine of the automobile, electromagnetic pickups for detecting the passing of the teeth or notches and a data processing circuit for calculating torque at a predetermined rotating angle from the angular phase difference between the above two shafts, the torque occurring due to the deformation of the elastic member caused by the increase or decrease of applied torque. The processing means adds the calculated torque in each combustion stroke of each piston and averages the added torque.