Siemens Aktiengesellschaft

Continental Automotive Gmbh

Bayerische Motoren Werke Aktiengesellschaft

Siemens Aktiengesell Schaft

Siemens Aktiengellschaft

Alexander Ketterer

Hong Zhang

Stefan Treinies

Gerd Rösel

Manfred Wier

Oliver Grunwald

Carsten Bruns

Michaela Schneider

Hartmut Pfleger

Michael Krauss

In a method for verifying the tightness of a tank bleeding system with a tank bleeding valve, a stop valve for air-tightly closing the tank bleeding system relative to an atmosphere prevailing outside the motor vehicle, and a bistable pressure switch whose switched condition indicates whether a predefined switching pressure is exceeded or not reached in the tank bleeding system, in order to be able to determine the tightness of the tank bleeding system without using a pressure sensor, the following steps are carried out: waiting until the vehicle speed drops below a certain threshold; opening the tank bleeding valve; closing the tank bleeding valve when a negative pressure has been attained which lies below the switching pressure; measuring the duration from the time an initial pressure lies below the switching pressure until the moment the switching pressure is exceeded again; and assessing the tightness is assessed based on the measured duration.

Method for verifying the tightness of a tank bleeding system without using a pressure sensor

During a first driving cycle, a combustion process is controlled in at least one combustion chamber for the purpose of performing a check on an emission reduction system of an internal combustion engine. During a second driving cycle following the first cycle, a check is performed to establish whether an error in the emission reduction system was detected during the first cycle. An idle time between the first and the second cycles is determined, in the event of an error of the emission reduction system detected during the first cycle. During the second cycle, the combustion process in the at least one combustion chamber is only controlled for the purpose of the check on the emission reduction system, in the event of an error detected in the emission reduction system during the first cycle and in the event of the idle time being longer than a pre-determined repair time.

Method and device for operating an internal combustion engine

The aim of the inventive method is to improve the emission values of an internal combustion engine during idling following a cold start. Said aim is achieved by inferring an adaptive value for the required fuel quantity from a characteristic curve in accordance with the temperature of the internal combustion engine and verifying during continuous lambda regulation whether predetermined adaptation conditions are met. If so, an adaptive value is determined from the parameters of the lambda regulator and the characteristic curve is adjusted according the newly determined adaptive value and the measured temperature of the internal combustion engine.

Method for controlling an internal combustion engine having a lambda regulation

In the present invention lambda control is carried out by using a NOsensor which is arranged in the catalytic converter or downstream of this. At the same time on the basis of the measured NOvalues the operating status is adjusted and the oxygen storage capacity of the catalytic converter is determined for diagnostic purposes.

Method and device for lambda control and for catalytic converter diagnosis in an internal combustion engine

In order to check the functional capability of a three-way catalytic converter of a lambda-controlled internal-combustion engine, the efficiency of the catalytic converter is determined in a conventional way by determining the oxygen storage capability of the catalytic converter. In order to be able to adjust the efficiency with regard to temperature changes, a substitute value for the temperature in the catalytic converter is calculated. Using this substitute value, the efficiency, which has been determined for the catalytic converter, is adjusted for temperature influences. The measure of the functional capability of the catalytic converter thus obtained is accurate even after non-steady-state operating phases of the internal-combustion engine when the catalytic converter is not yet isothermal.

Method of checking the functional capability of a catalytic converter

The catalytic converter of an internal combustion engine is monitored with regard to its conversion capacity. A sensor downstream of the catalytic converter measures the oxygen concentration in the exhaust gas leaving the catalytic converter. A mean value is determined of the oxygen concentration measurement signal, and the area between the measurement signal and the mean value is calculated. The area is then compared with a predetermined comparison value, and a low conversion capacity of the catalytic converter is deduced from the comparison if the area is greater than the comparison value. A corresponding error signal may be stored in memory or immediately output as a warning for the driver of the vehicle.

Method for monitoring catalytic converter efficiency

In a method for checking the conversion capability of a catalytic converter, in particular a precatalytic converter associated with internal combustion engines of motor vehicles, the checking is undertaken through the use of a temperature measurement immediately downstream of the catalytic converter. Initially the temperature at the beginning and at the end of a predetermined idling phase is measured for a predetermined number of idling phases, following an overrun phase in predetermined operating states of a motor vehicle with an internal combustion engine. Then the difference of the temperature measurements for each idling phase is formed. The sum of all of the temperature differences and the sum of the duration of the idling phases are formed and subsequently a quotient of these results is formed. This quotient determines an average gradient. The average gradient determined in this way is compared with a limiting value and the catalytic converter is recognized as defective if the predetermined limiting value is exceeded. The method may be applied to motor vehicles with internal combustion engines.

Growing community of inventors

Pettendorf/Adlersberg, Germany

Alexander Ketterer