Using an Optical Proximeter to Phase Cylinder Pressure to Crankshaft Position 870478
The use of an optical proximeter to determine dynamic top center in a motored engine is demonstrated. Design criteria are formulated and a data reduction procedure is presented. The method is shown to have an accuracy of Δθ = ± 0.1°. Variations in dynamic top center with engine speed that can be attributed to structural flexing and finite bearing clearances are shown to be less than ± 0.05°. It is also shown that the compression ratio during gas exchange is slightly larger than during compression-expansion.
Other methods of finding top center are discussed and contrasted with optical proximetry. In this context a rational means of examining pressure records is presented and shown to be accurate to within Δθ=±0.3°.
Citation: Ferguson, C., Warner, C., Gottschlich, R., and Wahiduzzaman, S., "Using an Optical Proximeter to Phase Cylinder Pressure to Crankshaft Position," SAE Technical Paper 870478, 1987, https://doi.org/10.4271/870478. Download Citation
Colin R. Ferguson, Cecil F. Warner, Rudy W. Gottschlich, Syed Wahiduzzaman
School of Mechanical Engineering Purdue Univ., Integral Technologies
SAE International Congress and Exposition
Sensors and Actuators-1987-SP-0693, SAE 1987 Transactions-V96-87