Abstract: In order to provide a sealing assembly for a fuel cell stack comprising a plurality of fuel cell units, which are arranged consecutively in a stacking direction, wherein each of the fuel cell units comprises a housing with at least one housing part made of a metallic material, which also has an adequate electrical insulation effect and an adequate mechanical strength at a high operating temperature of the fuel cell stack, it is proposed that the sealing assembly comprises at least one intermediate element made of a metallic material, wherein the intermediate element is soldered to a housing part of a first fuel cell unit at at least one location by means of a metal solder and is secured to a housing part of a second fuel cell unit at at least another location, wherein the intermediate element and/or the housing part of the first fuel cell unit is provided with a coating made of a ceramic material.

Abstract: In order to provide a sealing assembly for a fuel cell stack comprising a plurality of fuel cell units, which are arranged consecutively in a stacking direction, wherein each of the fuel cell units comprises a housing with at least one housing part made of a metallic material, which also has an adequate electrical insulation effect and an adequate mechanical strength at a high operating temperature of the fuel cell stack, it is proposed that the sealing assembly comprises at least one intermediate element made of a metallic material, wherein the intermediate element is soldered to a housing part of a first fuel cell unit at at least one location by means of a metal solder and is secured to a housing part of a second fuel cell unit at at least another location, wherein the intermediate element and/or the housing part of the first fuel cell unit is provided with a coating made of a ceramic material.

Abstract: In a fuel cell stack having a plurality of fuel cell units, which are arranged consecutively in a stacking direction, wherein each of the fuel cell units comprises a housing with at least one housing part made of a metallic material, which has an adequate electrical insulation effect and an adequate mechanical strength at a high operating temperature of the fuel cell stack, a sealing assembly is provided and comprises at least one intermediate element made of a metallic material, wherein the intermediate element is soldered to a housing part of a first fuel cell unit at at least one location by a metal solder and is secured to a housing part of a second fuel cell unit at at least another location, wherein the intermediate element and/or the housing part of the first fuel cell unit is provided with a coating made of a ceramic material.

Abstract: In order to provide a sealing assembly for a fuel cell stack comprising a plurality of fuel cell units, which are arranged consecutively in a stacking direction, wherein each of the fuel cell units comprises a housing with at least one housing part made of a metallic material, which also has an adequate electrical insulation effect and an adequate mechanical strength at a high operating temperature of the fuel cell stack, it is proposed that the sealing assembly comprises at least one intermediate element made of a metallic material, wherein the intermediate element is soldered to a housing part of a first fuel cell unit at least one location by means of a metal solder and is secured to a housing part of a second fuel cell unit at least another location, wherein the intermediate element and/or the housing part of the first fuel cell unit is provided with a coating made of a ceramic material.

Abstract: In order to provide a sealing assembly for a fuel cell stack comprising a plurality of fuel cell units, which are arranged consecutively in a stacking direction, wherein each of the fuel cell units comprises a housing with at least one housing part made of a metallic material, which also has an adequate electrical insulation effect and an adequate mechanical strength at a high operating temperature of the fuel cell stack, it is proposed that the sealing assembly comprises at least one intermediate element made of a metallic material, wherein the intermediate element is soldered to a housing part of a first fuel cell unit at at least one location by means of a metal solder and is secured to a housing part of a second fuel cell unit at at least another location, wherein the intermediate element and/or the housing part of the first fuel cell unit is provided with a coating made of a ceramic material.

Abstract: Pulsations which falsify an output signal of an air mass meter occur at low and medium rotational speeds in a unit that supplies air to an internal combustion engine. A method for adjusting the load of the internal combustion engine limits an opening angle of an electromotively adjustable throttle valve to a rotational speed-dependent opening value which includes an opening base value that is between a lower and an upper limit value. In the case of the lower limit value, the full load of the engine is reached. In the case of the upper limit value, pulsations of the air in an intake duct upstream of the throttle valve do not yet occur.

Abstract: During lean operation of the internal combustion engine, preferably in relatively long-lasting overrunning shutoff phases, the output voltage of the sensor signal is regulated to a predetermined desired value via the heating control unit. If within the diagnosis period, fewer than a predeterminable number of monitoring results are within a tolerance range located around the desired value, then the heating circuit is classified as defective.

Abstract: The invention relates, in particular, to the checking of the conversion of a precatalyzer associated with internal combustion engines. The checking being carried out during the overrunning of the motor vehicle given a sufficiently long idling phase. The following criteria being evaluated singly or in combination to determine if the catalyzer is operative. The first criteria checked is the difference between the temperature downstream and upstream of the catalyzer (FIG. 2). The second criteria checked is if the temperature downstream of the catalyzer is in a predetermined range (FIG. 3). The third criteria checked is if the temperature downstream and upstream of the catalyzer exhibits a minimum difference (FIG. 4). The fourth criteria checked is if the magnitude of the temperature gradient for the temperature upstream of the catalyzer is significantly greater than the magnitude of the temperature gradient of the temperature downstream from the catalyzer.

Abstract: In a diagnostic method for recognizing combustion misfiring in an internal-combustion engine, a map of characteristics, in which characteristic numbers dependent on load and on rotational speed are filed, is provided. One or more different diagnostic methods are selected by a diagnostic device depending on the respective characteristic number and allow as reliable information as possible of combustion misfiring for the respective load and rotational-speed range.

Abstract: A method for adapting a starting injection timing to a pressure of ambient air includes storing in memory a correction factor representing an ambient air pressure when an engine is turned off. A value for a starting injection timing is modified with the correction factor, upon a starting process.

Abstract: A method for monitoring functional capability of a tank venting system for a motor vehicle, includes evacuation of the tank venting system through the use of negative pressure or vacuum prevailing in the suction tube of an internal combustion engine and assessing the system based on negative pressure buildup and negative pressure letup gradients. Additionally, besides other abnormal termination criteria, the dynamics of pressure changes are also monitored and the method is immediately discontinued, if pressure fluctuations are ascertained which exceed a predetermined measure.

Abstract: A method for detecting bad stretches of road includes ascertaining a tripping variable representing acceleration of at least one wheel of a vehicle. A bad stretch of road is detected if the amount of the tripping variable exceeds a predeterminable limit value. The tripping variable is dependent on at least two segment times that the wheel needs to pass through associated angle segments.

Abstract: A method and an apparatus are provided for adapting air values from a substitute performance graph to currently prevailing variables of state of ambient air. The air values are used for controlling mixture preparation if pulsations of air occur in an intake tube of an internal combustion engine instead of using measured values supplied by an air meter. The air values are adapted by multiplying the air values by an adaptation factor. In one embodiment the adaptation factor is calculated by dividing a measured value supplied by the air meter in the intake tube of the internal combustion engine by an air value taken from the substitute performance graph and subjecting the adaptation factor to sliding averaging, at times when no pulsations are present; and using a lambda-control-average value as the adaptation factor and subjecting the adaptation factor to sliding averaging, at times when pulsations are present.

Abstract: The method and associated apparatus ascertain an air value which is used in the mixture preparation in the event of pulsations of air in the intake tube of an internal combustion engine. During each intake stroke of a cylinder of the engine, a maximum value and a minimum value of an air flow are ascertained from measured values furnished by an air flow rate meter. A differential value is formed from a magnitude of the two extreme values. And the differential value is compared with a predeterminable threshold value. For air/fuel mixture is prepared on the basis of the air value. If certain conditions apply, the processor switches over from the measured values furnished by the air flow rate meter to predetermined substitute values from a substitute performance graph.

Abstract: A method for detecting combustion misfires in internal combustion engines includes calculating a non-concentricity value from fluctuations in angular speed of a crankshaft, and dropping the non-concentricity value below a negative non-concentricity limit value if a combustion misfire is present. If the non-concentricity value drops below the non-concentricity limit value, a value for a stretch of bad road is calculated from successively calculated non-concentricity values, and the value for a stretch of bad road is dropped below or made of equal magnitude to a positive limit value for a stretch of bad road, if a stretch of bad road is present. The previously indicated combustion misfire is not confirmed if the value for a stretch of bad road drops below or is of equal magnitude to the limit value for a stretch of bad road. However, the previously indicated combustion misfire is confirmed if the value for a stretch of bad road exceeds the limit value for a stretch of bad road.

Abstract: A method for recognizing stretches of rough or bad road includes recognizing tank pressure values at successive evaluation instants. A change in tank pressure is ascertained from successive tank pressure values. A stretch of rough or bad road is recognized if the change exceeds a limit value.

Abstract: The speed for each cylinder of an internal combustion engine is detected at two crankshaft positions (z1, z2) of a cylinder and an irregular combustion is recognized when the gradient of the speed curve falls below limit value GW.

Abstract: A method for detecting combustion misfires includes calculating engine roughness values from fluctuations in crankshaft rpm, comparing the values with threshold values, and forming cylinder groups having an increased likelihood of misfiring. During a period of observation, each engine roughness value calculated for each cylinder is separately compared with a first threshold value and with a second threshold value being reduced in comparison with the first threshold value, a first counting sum associated with the cylinder is formed if the first threshold value is exceeded, and a second counting sum associated with the cylinder is formed if the second threshold value is exceeded.

Abstract: A method for suppressing vibration in the drive train of a motor vehicle includes detecting an rpm of a vehicle engine; deriving an rpm gradient from the rpm and evaluating the rpm gradient; and reducing torque of the engine by varying an ignition angle if impermissible vibration is detected, wherein the torque reduction is controlled as a function of an upper and a lower limit value for the rpm gradient. The ignition angle is retarded if the rpm gradient drops below the lower limit value; switching back to an initial performance graph takes place if the rpm gradient exceeds the upper limit value; and the upper and the lower limit values are predetermined as a function of the engine rpm.

Abstract: A method is provided for recognizing erratic combustion in a multicylinder internal combustion engine by using a time measuring device to measure successive time periods which a crankshaft needs to rotate through predetermined angles during operating strokes of successive cylinders. The method includes determining a static component by using a calculating device to subtract a time period of the next cylinder in an ignition order from the time period of a cylinder to be examined. The static component is multiplied with a standardizing factor by using the calculating device. A dynamic component is determined by using the calculating device to subtract a time period of a next cylinder in the ignition order from a time period of a preceding cylinder in the ignition order, and a dynamic component is negated.