The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Aug. 27, 1996
Filed:
Sep. 30, 1994
Gerhard Hotzel, Stuttgart, DE;
Harald Neumann, Vaihingen, DE;
Walter Strassner, Schorndorf, DE;
Johann Riegel, Bietigheim-Bissingen, DE;
Robert Bosch GmbH, Stuttgart, DE;
Abstract
The invention is directed to an arrangement for detecting the oxygen content in the exhaust gas of an internal combustion engine. The arrangement includes a concentration measuring cell operating pursuant to the Nernst principle. The concentration measuring cell has a measuring electrode, a solid electrolyte and a reference electrode and a series circuit which includes a direct voltage source and a series resistor. The series circuit connects the measuring electrode to the reference electrode. The measuring electrode communicates with the exhaust gas of the internal combustion engine and is connected to the reference electrode via the solid electrolyte. The reference electrode communicates with the reference gas volume. The reference gas volume is partitioned from the exhaust gas and from the ambient air so that a particle exchange between the reference gas volume and the exhaust gas as well as between the reference gas volume and the ambient air is at least made more difficult. The output voltage of the concentration measuring cell defines a measure for the difference of the oxygen concentrations in the exhaust gas of the engine and the reference gas volume. The output voltage of the direct voltage source and/or the value of the series resistance is so pregiven that an electric current Ip is always so directed that oxygen is transported from the exhaust gas to the reference gas volume independently of the output voltage of the concentration measuring cell. The current Ip flows in a current circuit including direct voltage source, series resistance and concentration measuring cell.