Piston Temperature Measurement during Engine Warm-up and Application for Analysis of Piston Behavior 2019-32-0548
In recent years, internal-combustion engines have been required to satisfy various performance standards against emission regulations and fuel-efficiency targets. To this end, accurate measurement of piston temperature under various engine operating conditions is important.
Some studies reported the use of wireless methods to confirm the reliability of the measurement system at the highest engine speed and create a piston temperature map under all operating conditions. However, previous case studies only considered relatively large displacement engines, and the advantage of wireless methods—a high degree of freedom for design—was not used. In terms of engine operating conditions, few cases focus on the piston to cylinder wall clearance during engine warm-up conditions. Thus, wireless methods are still space to use their features.
In this study, we develop and implement a telemetry-type method for a motorcycle engine, which has smaller displacement and is therefore more restrictive relative to measurement system design than past case studies. The temperature distribution in the entire piston is measured, considering the temperature distribution of a cylinder bore wall surface during the period between a cold start and the completion of the warm-up. Temperature measurement data are continuously obtained under transient operating conditions. In addition, the measurement results are input to a model that simulates piston behavior to improve the calculation results of piston slap noise.