Mercedes-benz Aktiengesellschaft

Daimler Chrysler Ag

Daimler-benz Ag

Hartmut Kolb

Wolfgang Woletz

Dieter Scheurenbrand

Manfred Weil

Hans Schroter

Klaus Schust

Hans Schroeter

In a method for testing the tightness of a fuel tank in a motor vehicle, a container that absorbs fuel vapors and is connected by a vent line with a fuel tank and by a scavenging line with an intake manifold of the internal combustion engine of the motor vehicle is provided. The container has a vent line that is connected to the atmosphere, the line being closable by a shutoff valve. In addition, a pressure sensor that detects the system pressure in the fuel tank and a scavenging valve located in the scavenging line, which is opened to feed the fuel vapors stored in container and to develop a vacuum in the tank ventilation system, is provided. The fuel tank is kept at a specific pressure at least approximately during the entire operation of the vehicle and, after a preliminary period that corresponds at least approximately to the time interval during which compensatory processes such as condensation or outgassing of the fuel run to completion, the tightness test is performed at any point in time and in any operating state of the vehicle with the fuel tank sealed pressure-tight.

Method for testing a fuel tank in a motor vehicle for tightness

A deventilating device for motor vehicles is disclosed. The deventilating device allows, in the fuel tank and connected system parts, a limited overpressure which, on the one hand, is safe and, on the other hand, affords the possibility of checking the tightness of the system by on-board means specific to the vehicle.

Motor vehicle fuel supply system with fuel tank deventilating device

A method is provided for monitoring vehicle function components using a diagnostic device taken along in the vehicle. A multiplicity of individual test routines are carried out, respectively, given the presence of start conditions specific to the test routine, in a fixed, cyclic sequence in order to obtain information on the presence or absence of a fault with respect to the relevant function components. Data relating to a first-time execution of a respective test routine is retrievably stored. With the aid of this data, before activation of a test routine pending according to a sequence provided it is determined given the presence of appropriate start conditions whether the test routine has already been performed at least once and whether at least one other activatable test routine exists which has not yet been performed. If no, the pending test routine is activated, otherwise, the test routine not yet performed is activated. This flexibility guarantees the presence of test results for each test routine in an operating time which is as short as possible.

Method for monitoring vehicle function components

In an arrangement for determining leaks in a tank venting system of a motor vehicle which includes a fuel tank, an adsorption filter in communication with the fuel tank, a venting pipe, a regeneration pipe connecting the adsorption filter to the intake manifold of an internal combustion engine, the venting pipe extends to an area adjacent the filler neck of the fuel tank and a test apparatus is provided with a test pipe having a seal sleeve for placement over the tank filler neck and the end of the venting pipe for applying pressure to the tank venting system by means of pumps disposed in the test apparatus and the test apparatus further includes a pressure sensor for determining the pressure in the tank venting system and a control device for controlling application of pressure to the venting system and for the evaluation of the pressure values determined by the pressure sensor for indicating a leak in the venting system.

Arrangement for the stationary leak testing of tank venting systems

The invention relates to a method for checking the operability of a cyclically controlled regeneration valve in a tank venting system of a motor vehicle which utilizes the realization that during operation of the system significant pressure variations are generated in a discharge line arranged between an adsorption filter and the regenerating valve whenever the duty ratio of the regeneration valve is within a certain range. If the regeneration valve is operated at such a duty ratio, the pressure variations in the discharge line are recorded and the extreme pressure valves are determined in an evaluation device for a specified time period after which the difference between the maximum and the minimum pressures is determined and if this difference is below a predetermined threshold, the regeneration valve is indicated as being defective.

Method of checking the operability of a regeneration valve in a tank

In an adjusting device for a throttle flap of an internal combustion engine driving a motor vehicle, wherein further influencing and correcting variables can be introduced via an electric servo-motor into the mechanical transmission device connecting the accelerator pedal and the throttle flap. For this purpose a planetary gear of a transmission device has a rotatable outer gear wheel connected to the accelerator pedal, a sun gear wheel connected to the servo-motor and the planet carrier connected to the throttle flap.

Growing community of inventors

Ludwigsburg, Germany

Hartmut Kolb