摘要:
A method of and an apparatus for controlling boost pressure in a turbocharged internal combustion engine. A turbine disposed in the engine exhaust passage is driven by exhaust gas and in turn drives a compressor disposed in the engine air intake passage, thus boosts the engine combustion chamber by delivering pressurized air thereto. The boost pressure is reduced when the actual ignition timing becomes more retarded than a reference ignition timing. The reference ignition timing is varied in proportion to an engine speed and/or an intake air pressure. Since the decision whether or not to reduce the boost pressure is based on the ignition timing actually being applied to the engine, no risk of damage to the engine arises and unnecessary reduction of engine output can be reliably prevented, enabling the engine to operate with optimum performance.
摘要:
A control system for ignition timing and boost pressure in an internal combustion engine equipped with a turbocharger. The system has a device for detecting knocking in the respective cylinders and the result of the detection by this a device is used as the basis for calculating the ignition timing for each cylinder. When the mean ignition timing calculated from the ignition timings for all cylinders exceeds a prescribed reference value, the boost pressure is reduced. Alternatively, the boost pressure is immediately reduced when the most retarded of the ignition timings exceeds the prescribed value in the direction of retardation, irrespective of whether or not the average value exceeds the prescribed value. As a result, reduction of engine output can be minimized while precluding damage to the engine.
摘要:
An apparatus for controlling ignition timing in an internal combustion engine determines the amount of adjustment of ignition timing for preventing knocking with reference to the engine operating state. The amount of adjustment of the ignition timing carried out upon the detection of knocking is varied depending on the engine speed. Specifically, it is made large in the low speed region where the interval between successive firings is relatively long, thus increasing the speed with which knocking can be prevented and enhancing the protection of the engine from damage in this operating region. Also, rapid acceleration and other transient engine operating states are detected and a transient state adjustment is calculated separately of the adjustment amount for knocking prevention. The transient state adjustment is added to the knocking prevention adjustment and the result is used for retarding the ignition timing, whereby knocking can be effectively prevented during rapid acceleration. Further, after knocking has been prevented, the ignition timing is advanced with consideration given to reference knocking occurrence frequencies set independently for different engine operating conditions. Thus, the knocking occurrence frequency can be maintained at a fixed level irrespective of the engine operating condition, whereby the engine output can be optimized.
摘要:
A method of and an apparatus for controlling ignition timing in an internal combustion engine, which determines the ignition timing on the basis of the engine speed and load state, discriminates whether or not knocking has occurred on the basis of the output of a knocking detection circuit, retards the so-determined ignition timing by a predetermined amount when knocking occurs, and advances the ignition timing by a predetermined amount after knocking has been avoided. The maximum amount of retardation and advancement carried out upon occurrence of knocking is varied depending on one or more engine operating conditions, enabling the ignition timing to be controlled to near MBT and the engine output to be the maximum possible. The said engine operating condition or conditions include an engine speed in the case of compensation in the direction of ignition retardation and include an engine speed and a load state in the case of compensation in the direction of ignition advance.
摘要:
A method of and an apparatus for controlling ignition timing in an internal combustion engine. When the ignition timing has been retarded for preventing knocking and the engine operation thereafter moves into a region of operation where knocking control is unnecessary with the retardation of the ignition timing still in effect, the ignition timing is slightly advanced once per predetermined number of firings. Since the ignition timing is gradually restored, engine output hunting is prevented. The advancement of the ignition timing is determined whether or not a prescribed wait period has passed. The period varies depending on an engine speed.
摘要:
A device for detecting and measuring the concentration of a gas in a mixture of gas such as oxygen in the exhaust gas of an internal combustion engine and circuits for using that measurement to control the air-fuel ratio supplied to the engine. The detecting device has two separate gas residence chamber with different diffusion resistance openings for each chamber and separate pairs of electrodes for each chamber whereby the measurement can be separately made in each chamber. The particular chamber selected for measurement may be done on the basis of whether the air-fuel ratio is lean or rich whereby a substantially linear reading results for all ratios or on the basis of the transition-state or steady-state operating condition of the engine to provide either more rapid or more accurate readings. Further, by using the cells from both chambers to compare their readings and standards, the actual readings can be corrected for abnormalties that may occur after a period of use or to indicate the detector has become defective.
摘要:
A method of engine air/fuel ratio control using an oxygen concentration sensor producing a concentration-proportional output, in which a compensation value is computed for compensating a basic value such as a basic fuel injection time interval, and in which a deviation of an air/fuel ratio detected using the oxygen concentration sensor from a target air/fuel ratio is measured the compensation value is computed and updated only under the condition that the deviation is below a predetermined value, with the compensation value being determined in accordance with the amount of deviation.
摘要:
A system of abnormality detection for an oxygen concentration sensor employed to sense the oxygen concentration in engine exhaust gas for obtaining data to control the air/fuel ratio of a fuel mixture supplied to the engine. In which, the oxygen concentration sensor includes a sensor cell element, an oxygen pump element each formed of a pair of electrodes which sandwich a solid electrolytic member, and a heater element for heating the solid electrolytic member. The system functions to detect an abnormality of the heater element on the basis of the value of a voltage developed between the electrodes of the sensor cell element and an air/fuel ratio compensation value that is derived by sensing the exhaust gas oxygen concentration.
摘要:
A system of abnormality detection for an oxygen concentration sensor employed to sense the oxygen concentration in engine exhaust gas, and to obtain data to control the air/fuel ratio of a fuel mixture supplied to the engine. The oxygen concentration sensor including a sensor cell element and an oxygen pump element. The system serves to detect an abnormality such as an open-circuit or a short-circuit in electrode connecting leads of the sensor cell element on the basis of a value of voltage developed between the electrodes of the sensor cell element and of a value of current which flows between the electrodes of the oxygen pump element.
摘要:
A method for controlling an oxygen concentration sensor mounted on an engine, including oxygen ion conductive solid electrolyte members operative as an oxygen pump element and a sensor cell element respectively, a source of pump current to be supplied to the oxygen pump element, and a heater element for heating the oxygen pump element and the sensor cell element. The method includes an operation for detecting an engine temperature of a time immediately before the start of the supply of a drive current of the heater element, and a control operation for starting the supply of the pump current after an elapse of a time period determined in response to the engine temperature from the start of the supply of the drive current of the heater element.