Abstract:
A sensor is provided, in particular a gas sensor for determining the concentration of a gas component in a measuring gas, which has a sensor element that projects from a housing by a measuring-gas-side end section exposed to the measuring gas, and a sheath tube having gas passageways, which is placed over the measuring-gas-side end section and affixed on the housing. To prevent condensation of water vapor contained in the measuring gas in the measuring space enclosed by the housing and the sheath tube, and thus the production of water droplets that reach the hot sensor element, sheath tube and/or sensor element are/is thermally decoupled from the housing. The thermal decoupling is produced using, for instance, a flange sleeve made of a material having poor thermal conductivity, which separates the sheath tube from the housing by a flange and, via a sleeve section, is inserted in the space between the housing and the measuring-gas-side end section of the sensor element.
Abstract:
A sensor is provided, in particular a gas sensor for determining the concentration of a gas component in a measuring gas, which has a sensor element that projects from a housing by a measuring-gas-side end section exposed to the measuring gas, and a sheath tube having gas passageways, which is placed over the measuring-gas-side end section and affixed on the housing. To prevent condensation of water vapor contained in the measuring gas in the measuring space enclosed by the housing and the sheath tube, and thus the production of water droplets that reach the hot sensor element, sheath tube and/or sensor element are/is thermally decoupled from the housing. The thermal decoupling is produced using, for instance, a flange sleeve made of a material having poor thermal conductivity, which separates the sheath tube from the housing by a flange and, via a sleeve section, is inserted in the space between the housing and the measuring-gas-side end section of the sensor element.
Abstract:
A method and an arrangement control the drive unit of a vehicle. In this method and arrangement, an rpm limiting to a reference rpm takes place when the demand of the driver is withdrawn. The reference rpm is determined at the start of the withdrawal of the driver command.
Abstract:
A method and a device for controlling an output variable of a drive unit in the starting phase is described. A controller is provided, regulating the actual value of at least one output variable to a setpoint variable of this output variable which is specified as a function of time. When at least one condition marking entry into the starting phase exists, the setpoint value of the output variable is initialized with the actual value of the output variable.
Abstract:
Process for controlling the warm-up in an internal combustion engine wherein the combustion chamber pressure is obtained and evaluated, so that, using the evaluation of the combustion chamber pressure signal, the combustion is controlled so that combustion is not completed at the time the exhaust valve opens during warm-up.
Abstract:
The invention is directed to a method for detecting and documenting damage to a catalytic converter in a motor vehicle having a fuel tank and an internal combustion engine wherein combustion misfires can occur when the level of fuel in the tank drops below a critical level. The method includes: detecting the level of fuel in the tank utilizing a fill-level sensor device; utilizing a circuit arrangement to determine when the level in the tank reaches the critical level and switching on a warning lamp to indicate that the critical level has been reached; storing a value corresponding to the critical level and the operating state of the warning lamp in a memory as a first set of data; detecting misfires of the engine and storing information as to the misfires in the memory as a second set of data; and, logically combining the first and second sets of data when the misfires are present at the same time as the critical fill level so that a determination can be made in the context of a later read out of the logically coupled data as to whether the misfires are associated with a level of the fuel corresponding to the critical level.
Abstract:
The invention relates to a method for diagnosing the function of an adjusting device and includes the steps of: driving the adjusting device, detecting the effect of driving the adjusting device on a predetermined variable operatively coupled to the adjusting device; determining the adjusting device to be operable when the effect lies in a first range of possible values; and, determining the adjusting device to be inoperable when the effect lies in a second range of possible values. A third range is defined which separates the first and second ranges from each other. The method is interrupted or repeated when the effect lies in the third range.
Abstract:
An apparatus for checking a tank venting system for leaks that serves to vent a fuel tank of a motor vehicle whose engine has a intake tube. The apparatus has an absorption filter connected to a ventilation line, which can be closed by means of a shutoff valve, and pressure producing devices for the production of an overpressure in the fuel tank. The pressure producing devices are embodied as actuatable by means of the vacuum in the intake tube in order to be able to forego the separate electromechanical drive devices for the pressure producing devices which have been necessary in the prior art.
Abstract:
A method for checking the operability of a tank-venting system in a vehicle having an internal combustion engine, which tank-venting system has a tank with a tank-pressure sensor, an adsorption filter connected to the tank via a tank-connecting line, and a tank-venting valve which is connected to the adsorption filter via a valve line, in which system the adsorption filter has a venting line which can be closed with the aid of a shut-off valve, has the following steps:closing the shut-off valve;opening the tank-venting valve;determining the build-up gradient (p+) of the underpressure building up in the tank;closing the tank-venting valve;determining the decay gradient (p-) of the decaying underpressure in the tank;mathematically combining the build-up and decay gradients in a manner such that the influence of the fill level has as little effect as possible on the evaluation variable (Q) formed by means of the combination; and,comparing the value of the evaluation variable with a threshold value (Q.sub.-- SW) and evaluating the system as non-operative if the value of the evaluation variable and the threshold value fulfill a pregiven relationship.
Abstract:
A method for determining the operability of a tank-venting system on a motor vehicle subjects the signals for the volume flow through the tank-venting valve and the signals for the pressure difference between the tank interior and the ambient to a cross-covariance analysis. The above-mentioned signals are formed by a high pass in advance of forming the cross-covariance function and the maximum or the mean value of the cross-covariance function is formed with respect to the product of the two input variables. A variance measure is formed for the signal of the volume flow through the tank-venting valve and a transfer factor is computed from the variance measure and the mean value or maximum. The tank-venting system is deemed to be operational when the transfer range lies in a pregiven region. An advantage of the method is seen in the independence of the tank-pressure changes which are not caused by volume-flow changes through the tank-venting valve. Here, changes are especially of concern which are caused by the sudden generation of vapor in the tank such as caused by sloshing fuel.