摘要:
A process is proposed for determining the lambda value upstream from the exhaust catalytic converter in which variation in the lambda value (Δλ) from the stoichiometric value is determined on the basis of variation in the charging (ΔOSC) of the oxygen reservoir (7) of the exhaust catalytic converter (6) and variation in the charging (ΔOSC) of the oxygen reservoir (7) is ascertained from the voltage signal (Uλdownstream) of a binary lambda probe (8) associated with the exhaust catalytic converter (6). In accordance with the proposal a control probe upstream from the exhaust catalytic converter can be omitted; this results in cost savings.
摘要:
In a method for the control of the supplied air/fuel ratio of an internal combustion engine (1) with a catalytic converter (5) which is located in the exhaust gas line (2) with an integrated oxygen reservoir (6), it is proposed that the air/fuel ratio be controlled as a function of at least one parameter of the internal combustion engine (1), at least one parameter of the catalytic converter (5), and/or as a function of the type and amount of the exhaust gas emissions which are currently occurring, in order to optimize the relative degree of filling of the oxygen reservoir (6) which is contained in the catalytic converter (5) for favorable conversion of the exhaust gas emissions. According to the proposal, matching to the current conversion demand and the current conversion performance is enabled and thus overall improved exhaust gas conversion is implemented.
摘要:
Four cases are to be distinguished from one another for an exhaust gas line of a motor vehicle with an oxygen storage reservoir and a lambda probe located downstream from at least part of the oxygen storage reservoir, specifically in each case, whether or not the oxygen storage reservoir has sufficient storage capacity and whether or not the lambda probe is fully serviceable. For this purpose, the exhaust gas line is supplied in an alternating sequence with rich and lean exhaust gas, in two different passes the degree of oxygen filling being varied differently. For a minor variation of the degree of oxygen filling, the serviceability of the lambda probe can be deduced on the basis of certain criteria. If the lambda probe is fully serviceable, the sufficiency or insufficiency of the oxygen storage capacity of the oxygen storage reservoir can be deduced for a greater variation of the degree of oxygen filling.
摘要:
During the measurement of the oxygen storage capacity of an oxygen storage system, which is assigned to a catalytic converter, a switchover operation from lean to rich exhaust gas or vice versa is effected. The measurement signals of a lambda probe are recorded; and an integral calculation is carried out over a time interval on the basis of the measurement values. Whereas in the past the start of the time interval was the point in time of the switchover operation, the present invention provides that the start of the second time interval is determined on the basis of the measurement signals of the second lambda probe i.e., the point in time is preferably fixed at the time at which these measurement values reach an extreme value. This design allows the oxygen storage capacity to be measured even if the lambda probe is not fully functioning totally correctly.
摘要:
The invention relates to an exhaust system for an internal combustion engine on a vehicle, comprising an exhaust catalyst and a probe arrangement in the region of the exhaust catalyst as component of a lambda regulation device in which the engine is alternately switched between a lean and rich operating region, depending on the probe signals recorded by the probe device. According to the invention, the probe arrangement is embodied as a single, lambda probe, continuously providing probe signals, arranged downstream of the exhaust catalyst, by means of which, in cooperation with the lambda regulation device, the increase of the oxygen content in the exhaust gas flow over the whole duration of the lean operation phase and the decrease in oxygen content in the exhaust gas flow over the whole duration of the rich operation phase are each recorded in relation to an oxygen content comparison value (U0), whereby in both the lean operation phase and the rich operation phase a switching threshold value (U1, U2; U1′) U2′) dependent on oxygen content is given, which, on reaching said value, the lambda regulation device is switched into the other operating region.
摘要:
The invention relates to a process for operating a nitrogen oxide storage-type catalytic converter of an internal combustion engine, particularly of a motor vehicle, in which the nitrogen oxides which have been produced by the internal combustion engine are stored in the storage catalytic converter in the first operating phase (lean phase) as a storage phase for a specific storage time, and in which, after expiration of the storage time at a specific switching instant for a specific discharge time, switching to the second operating phase as the discharge phase takes place, in which the nitrogen oxides which were stored during the storage time are discharged from the storage catalytic converter, the switching instant in the storage phase being determined as a function of the nitrogen oxide slip as the difference between the nitrogen oxide mass flow which has flowed into the storage catalytic converter and the nitrogen oxide mass flow which has flowed out of the nitrogen oxide storage catalytic converter, each relative to the storage time. As claimed in the invention, to establish the switching instant from the storage phase to the discharge phase, the relative nitrogen oxide slip is determined such that the nitrogen oxide mass flow upstream of the nitrogen oxide storage catalytic converter and the nitrogen oxide mass flow downstream of the nitrogen oxide storage catalytic converter are each integrated over the time interval of the lean phase and the quotient of the integral values are brought into a relative relationship with a definable degree of conversion of the nitrogen oxide which can be derived from the exhaust gas boundary value, such that when this predetermined switching condition is present, switching from the storage phase to the discharge phase is carried out. In this way the fuel consumption can be reduced especially for a new storage catalytic converter using the full storage potential.
摘要:
A process for heating a carbon filter in an exhaust gas system of an internal combustion engine, in particular a diesel engine, with at least one catalytic converter and a carbon filter mounted downstream from the catalytic converter in the direction of flow for accumulating carbon. The catalytic converter mounted upstream from the carbon filter is heated to the extent that the amount of heat from the catalytic converter introduced into the carbon filter heats the carbon filter to the extent that combustion of the carbon is initiated.
摘要:
An offset in the signal of a pre-catalytic converter lambda probe of an exhaust gas system of an internal combustion engine affects a measured oxygen intake storage capacity and a measured oxygen removal storage capacity of an oxygen store with identical magnitude, but with opposite mathematical sign, so that their sum is independent of the offset. The oxygen intake storage capacity and the oxygen removal storage capacity are hereby determined until the output signal of the post-catalytic converter probe exceeds an intermediate threshold value of, for example, 0.45 V for intake and 0.8 V for removal. Exposure of the oxygen store to rich and/or lean exhaust gas is maintained after this threshold value has been crossed to ensure that the oxygen store is indeed sufficiently filled after the oxygen intake storage capacity has been measured, or is sufficiently emptied after the oxygen removal storage capacity has been measured.
摘要:
A gas probe, in particular a lambda probe for the analysis of exhaust gases from a mobile internal combustion engine, includes at least one protective device, at least partly surrounding a sensitive sensor element of the gas probe, which comes into contact with a gas. The at least one protective device includes a gas contact face which at least partly has a hygroscopic surface.
摘要:
An offset in the signal of a pre-catalytic converter lambda probe of an exhaust gas system of an internal combustion engine affects a measured oxygen intake storage capacity and a measured oxygen removal storage capacity of an oxygen store with identical magnitude, but with opposite mathematical sign, so that their sum is independent of the offset. The oxygen intake storage capacity and the oxygen removal storage capacity are hereby determined until the output signal of the post-catalytic converter probe exceeds an intermediate threshold value of, for example, 0.45 V for intake and 0.8 V for removal. Exposure of the oxygen store to rich and/or lean exhaust gas is maintained after this threshold value has been crossed to ensure that the oxygen store is indeed sufficiently filled after the oxygen intake storage capacity has been measured, or is sufficiently emptied after the oxygen removal storage capacity has been measured.