Abstract: In a homogeneous charge compression-ignited internal-combustion engine, based on information regarding the operational state of the engine, a combustion mode switching discriminator selects a homogeneous charge compression-ignited combustion mode if engine operating conditions allow homogeneous charge compression-ignited combustion. If not, the combustion mode switching discriminator selects a spark-ignited combustion mode. Immediately after switching from spark-ignited combustion to homogeneous charge compression-ignited combustion, a combustion mode switching corrector outputs switching correction values for operating quantities for homogeneous charge compression-ignited combustion. The correction values are used to adjust the operating quantities for homogeneous charge compression-ignited combustion, and new operating quantities obtained from the adjustments are output as control quantities from a combustion mode selector.

Abstract: An engine that re-circulates its exhaust gas suffers decreased accuracy in estimating an EGR rate real-time especially while the operating state of the engine is in a transitional state, which often results in torque fluctuations and deteriorated exhaust gas. A sensor for directly detecting an EGR flow rate is disposed in an EGR path. An EGR rate and in-cylinder oxygen concentration are calculated from the output value of that sensor. In addition, when this EGR rate calculation method is used, the calculation is properly switched between a steady operation state characterized by a low load and small rotational fluctuations and a transitional operating state including the acceleration and deceleration. This makes it possible to correctly estimate the EGR rate and the in-cylinder oxygen concentration under a wide range of engine operation conditions, and thereby to avoid the fluctuation of torque and the deterioration of exhaust gas.

Abstract: The present invention prevents an EGR sensor installed in an engine's EGR path from being soiled by soiling substances in exhaust. A catalyst is positioned upstream of the EGR sensor to purify the soiling substances in EGR gas. The status of the EGR sensor is properly controlled in accordance with the conditions of the catalyst. This ensures the EGR sensor is less likely to be affected by the soiling substances in the exhaust under any circumstances of the EGR path and allows the EGR sensor to avoid a decrease in the accuracy of EGR gas detection. An alternative configuration may be employed such that the EGR gas recirculates from the downstream side of a catalyst installed in a main exhaust path.

Abstract: An engine controller capable of reducing torque fluctuation and the like in change between spark ignition combustion and homogeneous charge compression ignition combustion is provided. Spark ignition burning mode or homogeneous charge compression ignition burning mode is selectively set as burning mode according to the operating state of an engine. In spark ignition burning mode, a spark plug is used. In homogeneous charge compression ignition burning mode, fuel is burned utilizing pressure rise in a combustion chamber in conjunction with the ascent of a piston. The burning mode is changed between these modes. In transition for change between the spark ignition burning mode and the homogeneous charge compression ignition burning mode, the following measure is taken: a period during which the lift amount and/or the valve opening period (IVevent) of an intake valve is made smaller than a set value for the homogeneous charge compression ignition burning mode is provided.

Abstract: In an in-cylinder injection type spark ignition internal combustion engine in which the intake air amount is controlled by use of an intake valve or an exhaust valve, which is provided with mainly a variable valve mechanism, instable combustion during a low-load operation is avoided without an increase in pumping loss (without a decrease in the thermal efficiency). In the in-cylinder injection type spark ignition internal combustion engine, during low-load operation, on the basis of the cooling water temperature of the engine the opening and closing timing of the intake valve is controlled in a retard angle manner and the opening and closing timing of the exhaust valve is controlled in an advance angle manner. Furthermore, the fuel injection timing is controlled in a retard angle manner on the basis of the retard angle amount of the intake valve opening and closing timing.

Abstract: There is provided a thermal type flow meter capable of accurately detecting a flow rate even when a fluid temperature varies rapidly or when the fluid temperature is high. A probe includes: a first main heating resistor; a second main heating resistor set at a temperature different from that of the first main heating resistor; and a sub-heating resistor for heating lead wires of the two main heating resistors. A CPU of a sensor control circuit finds a fluid temperature by using the two main heating resistors, and finds a fluid flow rate by using at least one of the two main heating resistors.

Abstract: In a homogeneous charge compression-ignited internal-combustion engine, based on information regarding the operational state of the engine, a combustion mode switching discriminator selects a homogeneous charge compression-ignited combustion mode if engine operating conditions allow homogeneous charge compression-ignited combustion. If not, the combustion mode switching discriminator selects a spark-ignited combustion mode. Immediately after switching from spark-ignited combustion to homogeneous charge compression-ignited combustion, a combustion mode switching corrector outputs switching correction values for operating quantities for homogeneous charge compression-ignited combustion. The correction values are used to adjust the operating quantities for homogeneous charge compression-ignited combustion, and new operating quantities obtained from the adjustments are output as control quantities from a combustion mode selector.

Abstract: A high-accuracy EGR sensor is provided. A recirculation system is provided which controls the flow rate of EGR by use of the sensor. A thermal gas flowmeter includes a heating resistor disposed in a flow of gas to be measured for detecting the flow rate of the gas, and an external circuit electrically connected to the heating resistor for outputting a signal according to the flow rate of the gas to be measured using the heating resistor. The heating resistor is controlled to be heated at a temperature equal to or higher than a vapor film forming temperature for forming a vapor film.

Abstract: A conventional technique performs valve close control of an EGR valve after an EGR-gas back flow is detected. Therefore, the conventional technique has a subject that, if an EGR-gas flow direction changes from forward flow to back flow, a back flow condition will last not only for a response delay time of a detector but also for the judgment time by calculation processing and the actuation time of the EGR control valve.

Abstract: Disclosed herein is a control apparatus for a spark-ignition engine that is capable of avoiding knocking at the time of high-load operation. With this control apparatus, a residual-gas suction unit or the like is not used, an exhaust gas does not deteriorate due to injection in a compression stroke, and a thermal efficiency also does not decrease. An engine control apparatus (ECU) 20 is used for the control of a direct-injection type spark-ignition engine. During the high-load operation of the spark-ignition engine, the ECU 20 injects fuel a plurality of times. In addition, the ECU performs first fuel injection toward internal EGR that exists in a combustion chamber of the spark-ignition engine.

Abstract: An engine that re-circulates its exhaust gas suffers decreased accuracy in estimating an EGR rate real-time especially while the operating state of the engine is in a transitional state, which often results in torque fluctuations and deteriorated exhaust gas. A sensor for directly detecting an EGR flow rate is disposed in an EGR path. An EGR rate and in-cylinder oxygen concentration are calculated from the output value of that sensor. In addition, when this EGR rate calculation method is used, the calculation is properly switched between a steady operation state characterized by a low load and small rotational fluctuations and a transitional operating state including the acceleration and deceleration. This makes it possible to correctly estimate the EGR rate and the in-cylinder oxygen concentration under a wide range of engine operation conditions, and thereby to avoid the fluctuation of torque and the deterioration of exhaust gas.

Abstract: A control apparatus of an engine having a compression ignition combustion mode and a spark ignition combustion mode selects the spark ignition combustion mode when operation conditions fall within a spark ignition operation area set in a spark ignition operation area/compression ignition operation area setting map memory part and selects the compression ignition combustion mode when the operation conditions fall within a switching stable area set in the memory part upon operation by the spark ignition combustion mode. The control apparatus controls to continue the compression ignition combustion mode as long as the operation conditions fall within a compression ignition operation area set in the memory part upon operation by the compression ignition combustion mode.

Abstract: In an engine controller capable of carrying out spark ignition type combustion and compressed self-ignition type combustion, in order to suppress operation performance deterioration and exhaust performance deterioration at the time of switching a combustion mode from the compressed self-ignition type combustion to the spark ignition type combustion, intake pipe pressure downstream a throttle is quickly reduced by making the throttle opening degree smaller than a target throttle opening degree of the spark ignition type combustion immediately after switching for a certain period during the combustion mode is switched from the compressed self-ignition type combustion to the spark ignition type combustion. As a result, responsiveness of an intake amount at the time of switching the combustion mode from the compressed self-ignition type combustion to the spark ignition type combustion is enhanced, and combustion switching without exhaust deterioration and torque variation is realized.

Abstract: An engine controller controls an actuator for selectively executing spark-ignited combustion and compression-ignited combustion of an internal combustion engine in accordance with an engine operational state. The controller is comprises of a deterioration recognition section for recognizing a deterioration state of the engine or the actuator during the spark-ignited combustion. The engine controller is configured to change at least one of a switching condition between the spark-ignited combustion and compression-ignited combustion and an operational condition for the compression-ignited combustion, during the spark-ignited combustion, in accordance with the deterioration state of the engine or the actuator recognized by the deterioration recognition section.

Abstract: The present invention prevents an EGR sensor installed in an engine's EGR path from being soiled by soiling substances in exhaust. A catalyst is positioned upstream of the EGR sensor to purify the soiling substances in EGR gas. The status of the EGR sensor is properly controlled in accordance with the conditions of the catalyst. This ensures the EGR sensor is less likely to be affected by the soiling substances in the exhaust under any circumstances of the EGR path and allows the EGR sensor to avoid a decrease in the accuracy of EGR gas detection. An alternative configuration may be employed such that the EGR gas recirculates from the downstream side of a catalyst installed in a main exhaust path.

Abstract: A controller of an internal combustion engine capable of spark ignition combustion and compression ignition combustion which restrains the degradation of operation performance and exhaust performance at the time of combustion type switching. The controller includes control means for performing combined combustion which leads to ignition combustion by a pressure rise by spark ignition combustion through adjustment of an internal cylinder temperature and a combustion speed at the end of compression, wherein the combined combustion is performed in the process of combustion type switching between spark ignition combustion and compression ignition combustion based on a result of determination of whether or not combustion type switching is possible, thus implementing a smooth combustion type switching.

Abstract: The controller includes combustion mode switching means for decreasing an exhaust gas temperature in the spark ignition combustion immediately before the combustion mode switching based on an estimated exhaust gas temperature immediately before the combustion mode switching, or for decreasing an EGR amount in the HCCI combustion immediately after the combustion mode switching.

Abstract: An engine controller controls an actuator for selectively executing spark-ignited combustion and compression-ignited combustion of an internal combustion engine in accordance with an engine operational state. The controller is comprises of a deterioration recognition section for recognizing a deterioration state of the engine or the actuator during the spark-ignited combustion. The engine controller is configured to change at least one of a switching condition between the spark-ignited combustion and compression-ignited combustion and an operational condition for the compression-ignited combustion, during the spark-ignited combustion, in accordance with the deterioration state of the engine or the actuator recognized by the deterioration recognition section.

Abstract: There is provided an engine control unit to ensure operational performance and safety performance of a vehicle by carrying out switchover of combustion according to an operating condition of a vehicle (automobile). A vehicle peripheral condition such as vehicular gap, etc., a traveling geographical state, a condition that ensures vehicle stability, etc. are acquired, and switchover of combustion, for example, switchover between compression ignition combustion and spark ignition combustion is effected correspondingly.

Abstract: An engine controller controls an actuator for selectively executing spark-ignited combustion and compression-ignited combustion of an internal combustion engine in accordance with an engine operational state. The controller is comprises of a deterioration recognition section for recognizing a deterioration state of the engine or the actuator during the spark-ignited combustion. The engine controller is configured to change at least one of a switching condition between the spark-ignited combustion and compression-ignited combustion and an operational condition for the compression-ignited combustion, during the spark-ignited combustion, in accordance with the deterioration state of the engine or the actuator recognized by the deterioration recognition section.