Daimler-Benz Ag

Christoph Noller

Hans-Dieter Schuster

Jorg Abthoff

Gunter Loose

Hans-Joachim Langer

Roland Huss

Reiner Kreeb

Ferry Durschmidt

Dieter Schuster

Gottfried Wollenraupt

The invention relates to bearing support of a throttle valve shaft in the housing of an exhaust gas line in which the shaft is rotatably supported on both sides in a bearing sleeve element constructed cup-shaped. The cups themselves are retained by spring force against the housing extending correspondingly conically within these areas. In order to keep small the actuating forces necessary for the rotation of the throttle valve shaft, each bearing sleeve element is retained by itself against the housing by means of a spring supported at the housing and the securing of the shaft against any axial displacement takes place by a separate axial bearing.

Bearing support of a throttle valve shaft in the housing of an exhaust

A self-optimizing control method for optimizing the fuel/air ratio under non-steady conditions in an internal combustion engine is described; in this method, a probe is provided both before and after the catalyst. Control quantities and the time during which the post catalyst probe shows an undesirable fuel/air ratio are stored for certain specified engine-operating conditions in the non-steady range. When the same engine operating condition is repeated, reference is made to the stored control quantities and time and the control quantity is varied in the direction of the correct fuel/air ratio. The time now obtained is compared with the stored time and, if the time has decreased, the new control quantity and the new time are stored. The control values are iteratively corrected by repeating these procedures, when the same engine operating condition reappears, until the time reaches a minimum.

Method for optimizing the air/fuel ratio under non-steady conditions in

A fuel-injected internal combustion engine wherein fuel is injected in dependence upon a quantity or volume of air supplied to the engine. A throttle valve controls the airflow rate with an O.sub.2 probe, arranged in an exhaust manifold, controlling a timing valve through a control device for enabling a timed relief of injection pressure of the fuel. An ignition starter switch is connected to the control device in such a manner that the timing valve is fully open during an operation of the ignition starter switch so as to enable a starting boost. An adjustable timing member is coupled to an operating switch provided in the control device, which operating switch closes automatically after a termination of the starting process. The timing member maintains the timing valve in a fully open position during a specific time span so as to provide for an after-start boost. An additional timing member is adapted to maintain the timing valve in a fully open position during a short time span so as to enable an acceleration enrichment. The control device renders the start boost, after-start boost, and acceleration enrichment ineffective upon the probe reaching its normal operating temperature.

Internal combustion engine

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Waiblingen, Germany

Christoph Noller