Robert Boschgmbh

Dieter Lederer

Gholamabas Esteghlal

Karl-Bernhard Lederle

Martin Streib

Michael Pfeil

Thorsten Fritz

Sujay Sirur

A device for determining the mass flow via a tank venting valve for an internal combustion engine including an intake manifold and a throttle valve, the intake manifold being connected to the tank venting valve and an exhaust gas recirculation system, one measuring transducer each being assigned to the throttle valve and the tank venting valve, and a sensor for the mass flow via the exhaust gas recirculation system being assigned to the exhaust gas recirculation system. In order to be able to determine the mass flow via the tank venting valve with improved accuracy it is provided in such a device that a mass flow normalizer is assigned to the measuring transducers and to the sensor for the mass flow via the exhaust gas recirculation system; the mass flow normalizer picks up, sums, and normalizes the signals of the measuring transducers and the sensor assigned to the mass flows via the throttle valve, via the tank venting valve, and via the exhaust gas recirculation system; a convertor is assigned to the mass flow normalizer; the convertor calculates a virtual throttle valve angle from which an allocator determines the mass flow via the tank venting valve.

Method and device for determining the mass flow rate passing through the air-bleed valve of an internal combustion engine tank

In a method for testing the functional reliability of a fuel-tank venting valve which is provided in a tank system of a motor vehicle in particular, is connected to an intake manifold and is triggerable by a control unit, a pressure source is provided for testing the tank system for leaks by using excess pressure or a vacuum, and the test of the functional reliability of the fuel-tank venting valve is performed on the basis of at least one performance quantity of the pressure source. In order to achieve a short diagnostic time and a high degree of diagnostic certainty, the fuel-tank venting valve is triggered to open or close, and a certain change in pressure is implemented. The at least one performance quantity of the pressure source is detected, and a properly opening and closing fuel-tank venting valve is determined from the performance quantity thus detected.

Method and control unit for function diagnosis of a fuel-tank venting valve of a fuel tank system in a motor vehicle in particular

A method for checking the operativeness of a tank-ventilation valve of a tank-ventilation system of a motor vehicle is characterized by the following steps: the tank-ventilation valve is triggered in a stepped manner in a preselectable working point; the intake-manifold pressure (p) is measured and modeled in the process; the measured intake-manifold pressure (p) is compared to the modeled intake-manifold pressure and an operative tank-ventilation valve assumed if a correlation within preselected limits is given; otherwise, a defective tank-ventilation valve is assumed.

Method for checking the operativeness of a tank-ventilation valve of a tank-ventilation system

A method checks the operability of a tank-venting system for a motor vehicle having an internal combustion engine. The tank-venting system includes a fuel tank (), an adsorption filter () and a filter line () connecting the adsorption filter to the fuel tank. The adsorption filter () has a venting line () and a switchover/check valve () is provided for closing off the venting line (). The system includes a tank-venting valve () and a valve line () connecting the tank-venting valve to the adsorption filter. In the method, an overpressure relative to atmospheric pressure is introduced into the tank-venting system utilizing a drivable pressure source (). An operating characteristic variable of the pressure source is detected while introducing the overpressure to determine the pressure course. A conclusion is drawn as to the presence of a leak from the pressure course. The overpressure is reduced by opening the tank-venting valve () and simultaneously closing said switchover/check valve ().

Tank-venting system in a motor vehicle and method for checking the operability of the tank-venting system

A method is introduced for testing the operability of a tank vent valve between an internal combustion engine and a fuel vapor reservoir, in which the stored fuel vapor is supplied from the fuel vapor storage to the internal combustion engine when the tank vent valve is open, and in which the fuel vapor supply represents a first energy flow to the internal combustion engine, and in which air also flows to the internal combustion engine via a throttle valve, and, in which a second energy flow is assigned to this air, and in which an arrangement is provided which holds the sum of the two energy flows at a predefined value, and in which the tank vent valve is controlled in an opening manner, and in which a change in the energy flow delta E through the throttle valve, resulting from the opening control, is determined, and is compared to a predetermined threshold, and in which and a small change in the energy flow, which does not exceed the threshold value (threshold), is evaluated as a fault.

Method for the diagnosis a tank ventilation valve

An arrangement for correcting a signal (S) is suggested which contains a signal evaluation (), which determines a characteristic variable of the input signal (US) of a controller () and/or the actuating variable (fr) of the controller () and/or at least one determined corrective signal (ora, fra) and/or at least one of their mean values (form) and compares the characteristic variable to at least one threshold value (SC1, SC2, SC3) and, when reaching or passing through at least one threshold value (SC1, SC2, SC3), an output signal (A) is made available at the end of the determination of the corrective signal (ora, fra).

Signal correcting device

In order to reduce the influence of the elasticity of components of a vessel () and/or of an outgassing of a liquid fluid (), which is disposed in the vessel () or a condensation of a gas disposed in the vessel or of a gas mixture () on an underpressure or an overpressure in the vessel, a gas mass flow is controlled to obtain a constant underpressure or overpressure in the vessel. In this way, a leak of the vessel can be detected with great reliability and the size of the leak can be computed with great accuracy. The vessel is especially a vessel of a tank system and tank-venting system of a motor vehicle having an internal combustion engine. In the event that a gas mass flow adjusts, which is constant in average, and which is greater than a pregivable limit value, a conclusion is drawn as to the presence of a leak. The size of the leak is computed from a signal characterizing the constant gas mass flow.

Method and arrangement for checking the tightness of a vessel

Method for controlling a tank venting valve between an internal combustion engine and a fuel vapor storage unit, with the stored fuel vapor being supplied from the fuel vapor storage unit to the internal combustion engine when the tank venting valve is open. A distinction is made between active and inactive tank venting phases, and the purge rate is preset during active tank venting by a purge rate setting means as a function of operating parameters of the engine and/or the tank venting system. If the duration of the inactive tank venting phase exceeds a minimum duration, the purge rate in the subsequent active tank venting phase is temporarily limited to a value below the rate preset by the purge rate setting means.

Method and electronic control unit for controlling the regeneration of a fuel vapor accumulator in internal combustion engines

A method and an electronic control device for diagnosing the mixture formation in internal combustion engines including tank ventilation. The diagnosis is linked to the mixture adaptation and is performed only with active lambda control and, therefore, especially not in operating modes of the internal combustion engine in which lambda is merely controlled. In the method, outside of active lambda control, an indication of a mixture or probe fault is recognized in that, given active tank ventilation and non-active mixture adaptation, a fault suspicion is formed when a measurement for the influence of the tank ventilation on the mixture composition, the measurement is formed assuming an intact system, takes on implausible values. If this suspicion exists, the mixture adaptation is requested to verify the suspicion, if appropriate.

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Ludwigsburg, Germany

Dieter Lederer