Multi-channel online temperature measuring system on the passenger car piston via sensor telemetry at temperatures up to 200°C

Temperature measurement on the piston via the MANNER sensor telemetry has established itself as a key development tool in many well-known companies.

Measurement of structural durability on the piston.

Continuous optimization of the combustion process is required, in order to comply with the legally stipulated emission limits. Technologies used for this purpose, such as the "Common Rail", place ever greater demands on the piston. The requisite increase in the ignition pressure makes it essential to analyze the load on the piston resulting from ignition pressures while the engine is running.

The optimization of the lubrication process in the piston is another important component for effective piston development. Possible friction losses occurring during the piston stroke can only be prevented through optimum design of the piston.

The challenge

It is essential that the piston temperatures and their distribution are measured in various load scenarios without restricting the function of the piston, in order to guarantee the structural durability and to optimize the lubrication process.

The conventional method of online temperature measurement by means of a plunger coil and an NTC as a temperature sensor (Essert method) fails increasingly at high loads. The installation is also extremely time-consuming.

The solution

The 8-channel piston telemetry from MANNER has been an important tool for the development of pistons, verification of the structural durability and optimization of the lubrication process in the piston for many years. However, a new feature is that the piston telemetry can also be used at temperatures up to 200°C, thereby enabling more extensive tests to be carried out.

The system allows multi-channel temperature measurements to be taken online at important points in the piston. It works with rugged thermocouples which withstand the increasing vibration level without any difficulty and are easy to assemble. Another key aspect is the ease of calibration. The sensor telemetry amplifier is also temperature-resistant up to 200°C. It scans the temperature measuring points in the piston at each stroke and transmits the measured values to the stationary evaluation unit. The contactless, battery-free transmission technology, in which the measured values are transmitted spot-like at the bottom dead centre, means that the components are very simple to assemble. The operating time of the system is unlimited thanks to the inductive, maintenance-free patented sensor telemetry transmission technology. The 8-channel temperature measurement amplifier is extremely compact (21 x 12 x 5 mm) and weighs only 3g. Several modules can be cascaded to extend the measuring channels.