P18.40-2503-79
Example illustration of engine 282 |
1 | Engine oil fill level sensor |
Overview
This document contains information on:
General
Function requirements
Function
General
The engine oil fill level sensor measures distance between the sensor on the oil pan floor and the oil surface using ultrasound and thus continuously determines the engine oil fill level.
Function requirements
Vehicle is located on level surface
Function
A piezo ceramic emits an ultrasound signal. The sound moves upward in the measuring tube system; it is then reflected in the oil surface, moves back downward and is detected by a sensor next to the piezo ceramic. The sensor measures the time between sending out and receiving the ultrasound and calculates the distance to the surface from this. Because the temperature affects the speed of the sound, the oil temperature is measured by an internal sensor and is taken into account in the running time calculation. The oil level in the oil pan is derived from this overall calculation.
The oil inlet to the measuring tube system is separated by a meander structure, a labyrinthine structure, from the oil pan. This structure prevents the intake of oil foam into the measure system, which impairs the measurement.
This measurement is repeated continually so that the oil level can be determined even in the case of a sporty driving profile. Depending on the driving profile, the lateral and longitudinal accelerations affect the measurement, which accordingly takes longer as a result.