The continuous improvement in engine technology in order to achieve new emission norms have led to an increased amounts of petrol, diesel and soot in the engine oil during engine operation. This dilution causes a fast decrease of the oil properties. Additional, the recommended oil change intervals for automotive engines have continuously been extended over the last few decades. In many cars, this interval is calculated using a set of certain characteristic engine parameters and driving behaviour (oil temperature, engine speed, number of engine ignitions). In order to prevent engine failures as a result of abnormally aged oil, or extreme driving conditions, it is necessary to monitor the oil condition continuously. In this paper a new oil condition sensor for the simultaneous measurement of four physical and electrical parameters by using an oscillating tuning fork developed by Hella in collaboration with Symyx Technologies, is presented. Compared to other described mechanical resonators, such as QCM (quartz crystal microbalance) and SAW (surface acoustic wave) by which it is only possible to analyse a viscosity-density product, this new sensor detects dynamic viscosity, specific density as well as permittivity, independently and unambiguously. The temperature as an additional fourth parameter is detected by a ASIC based sensor. The main focus in the development has been the integration of the micro sensor into an established and highly reliable oil level measurement system with consideration for assembly concerns. Nevertheless, the functionality as a stand alone device can be supported in order to enable an operation as a single oil condition product.The developed sensor enables the measurement of viscosity, density, permittivity and temperature of the engine oil and provides therefore relevant data for sophisticated oil condition algorithms.
Multiparameteric oil condition sensor based on the tuning fork technology for automotive applications
Mehrparameter Ölzustandsensor für Fahrzeuganwendungen basierend auf der Stimmgabeltechnologie
2005
10 Seiten, 7 Bilder, 1 Tabelle, 5 Quellen
Aufsatz (Konferenz)
Englisch
British Library Conference Proceedings | 2005
|Multiparameter oil condition sensor based on the tuning fork principle
Kraftfahrwesen | 2007
|Multiparameter Oil Condition Sensor Based on the Tuning Fork Principle
British Library Conference Proceedings | 2007
|Multiparameter Oil Condition Sensor Based on the Tuning Fork Principle
SAE Technical Papers | 2007
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