摘要:
In a method for protecting a catalytic converter from overheating, a conventional misfire recognition method is used to determine whether misfires are occurring in a cylinder. If this is the case, an attempt is made to interrupt the fuel supply to the affected cylinder. If this succeeds, the remaining cylinders are supplied with a lean mixture. If it does not succeed, all the cylinders are operated with a rich mixture. The lean setting of the mixture in the case of interrupted fuel supply to the affected cylinder has the effect that after the combustions in the cylinders, no further fuel reaches the catalytic converter which could combust in the catalytic converter with the oxygen induced by the affected cylinder.
摘要:
In order to determine the fuel quantity to be fed into an internal combustion engine during each stroke of the engine, the air mass sucked into each cylinder for combustion during each intake stroke is determined based on an intake-pipe pressure. A current air mass is determined using a measured value for the intake-pipe pressure. Subsequently, during a period in which there is no change in an air intake cross-section for each cylinder, the air mass is determined using a projected intake-pipe pressure, and the fuel quantity to be fed to each cylinder during the current and subsequent intake strokes is determined based on the air mass determinations and a wall film model.
摘要:
The device for determining load in internal combustion engines includes a pressure sensor connected with a combustion chamber of an internal combustion engine which produces an output signal depending on a combustion chamber pressure, a crankshaft angle sensor for detection of a crankshaft angle of the internal combustion engine and a processor for determining a load of the engine from relative values of the output signal of the pressure sensor at predetermined crankshaft angles. The processor includes a device for determining the load from a pressure difference between combustion chamber pressures measured at two different predetermined crankshaft angles (x1, x2) or from two integrated pressure values. The integrated relative pressure values are obtained by integration of a pressure-proportional output signal of the pressure sensor between two different predetermined crankshaft angles.
摘要:
Engine knock sensor signals are amplified, band-pass filtered and rectified and then a sequence of integrated signal peak values are compared with reference signals relating to a typical engine knock signal. If the deviation of the integration values or peak values or their sum over a measurement period differs by less than a predetermined amount from the corresponding reference values, a knock indication is produced. The initial integration or peak value may be given less weight than those that follow. The knock sensor may be an engine block sound sensor, or a combustion chamber light, pressure or iron current sensor. Additional criteria, such as the interval between null transitions or signal maxima or the number of them in a measuring period may be used to inhibit a knock indication in case the main processing should occasionally provide an anomalous knock signal, but this precaution is not sufficiently needed to warrant its inclusion in simplified systems.
摘要:
In a method for adjusting air and fuel masses for a multi-cylinder internal combustion engine with individual injection for each cylinder, the fuel mass for each injection operation is calculated taking into account the probable intake-pipe pressure during the opening time of the inlet valve. After a change of the accelerator pedal, the throttle flap is only adjusted when the fuel masses decisive for the new throttle-flap position have been calculated and substantially ejected. By virtue of the fact that fuel masses to be injected are not calculated taking into account the current air mass flow but taking into account the intake-pipe pressure, which is decisive in the induction operation, and that a change in the actuation of the throttle flap, which would lead to a change in the intake-pipe pressure not taken into account in the calculation of the injection quantity, is only permitted again after a recalculation, an optimum ratio between fuel mass and air mass per charge for the purpose of obtaining a specified value for the air/fuel ratio is always obtained, even in non-steady-state conditions of an internal combustion engine. Apart from the future intake-pipe pressure, account is also taken in the calculation of the fuel mass to be ejected of how much fuel passes into a wall film or is released from the latter.
摘要:
A method and a system for adjusting the lambda value of an air/fuel mixture to be supplied to an internal combustion engine wherein a throttle flap is adjusted in each case in such a manner that lean operation is obtained in a lower load range and a stoichiometric operation (lambda=1) is obtained in an upper load range.
摘要:
To modify engine operation and reduce the tendency of the engine to knock or ping, a knocking signal is generated which is representative of knocking intensity and/or frequency of knocking occurrence, and compared with a permissible knocking signal. The result of the comparison is utilized to change an operating parameter of the engine, for example by injecting a fluid, e.g. water, into the engine, changing charge pressure, for example of a turbocharger or the like. The permissible engine knock signal can be modified in accordance with an engine operating parameter, for example at low temperature, or low speed, the permissible knocking limit can be raised since the damaging effect of knocking at low temperature or low speed is less than under different operating conditions.
摘要:
To measure the irregular running of an internal combustion engine, the following equation, for the running irregularity value (LUW) is applied:LUW=f(T)x.vertline.(T.sub.-- V2-T.sub.-- V1)-(T.sub.-- V3-T.sub.-- V2).vertline.,The values T.sub.-- V1, T.sub.-- V2 and T.sub.-- V3 are combustion time periods, as they are measured at any one time between two fixed segment marks. Different groups of runningirregularity values are formulated, which differ in that combustion time periods are applied in the mentioned equation for different combinations of cylinders. In each group, the running-irregularity values are averaged; and the difference between the minimum and the maximum value of the averaged values is formulated. The difference is evaluated as a variable for the extent of running irregularity.
摘要:
The invention is directed to a method for determining misfires in an internal combustion engine of a motor vehicle. The determination is discontinued after a misfire under specific further conditions for a pregiven number of ignition strokes. When the misfire determination is not discontinued, then a check is made as to whether simple measurement value relationships apply which make a misfire very improbable. If such measurement value relationships are present, then the actual complicated misfire determination is discontinued. It is of special significance to count ignition strokes, which are counted in order to determine the relative frequency of misfires, only then when the above-mentioned conditions are all satisfied which determine as to whether a condition is present at all in which a determination of the misfire is purposeful. In this way, the decisive frequency determination is not influenced by the count of the ignition strokes which are not at all relevant to misfires. The above-mentioned procedure leads to a shortening of the average computation time because of the interruption of the misfire detection in many cases in which specific conditions are satisfied. Furthermore, the reliability of the detection of misfires is increased in that the final determination of misfires takes place only when specific preconditions are satisfied.
摘要:
A known control system for adjusting the lambda value of an internal combustion engine includes a corrective value ROM for transient operation wherein corrective values are stored for correcting the injection times for transient operation. In contrast thereto, the system according to the invention includes a corrective base value ROM 30, an adaptation value RAM 35 and an adaptation unit 34. The values from the corrective base value ROM are not utilized directly for correcting injection times; instead, these values serve as corrective base values which only become adapted corrective values by means of multiplication with adaptation values. The adaptation unit adapts the adaptation values in the adaptation value RAM. For this purpose, the adaptation unit determines the lambda value control deviations during a transient operation. If a control deviation is established, then the adaptation unit supplies a change value which is so dimensioned that an adaptation value, which is present for the monitored transient operation, is so corrected that for the next occurrence of a transient operation having the same initial operating conditions, only a smaller control deviation should occur and in the ideal case no such control deviation should occur. The control system according to the invention makes it possible to obtain very low toxic gas quantities also during a transient operation.