The Study On Storage Piston Temperature Measurement System Based On Microcontroller

The problems caused by thermal load are more and more prominent with the constant strengthen of the engine. Especially the pistons direct contact with the gas, under great thermal and mechanical load, which leads to serious problem such as ablation, cracking and distortion. Counter measure can be developed from learning about engine piston temperature distribution. Storage- measuring is one of varied piston temperature measurement methods. It can be used for multi- loading measurement when ensure the reliability and precision at the same time.In this paper, the system was developed from the former storage piston temperature measuring equipment. The new system had reduced the volume of the device to expand the application range; reduced the number of components of the device to improve the reliability; unified the clock signal to solve the data missing problem of the former device. The new system included power supply, the main control MCU, real time clock, temperature trigger switch, cold junction compensation, A/D converter, memory, serial communication port and so on function module. The energy conservation design such as unified power supply and temperature trigger switch extended the working time of the device, and the large-capacity memory chip also provided a guarantee for long-term measurements.The newly developed storage temperature measuring system was installed on the engine test bench and the piston temperature measurement experiment was carried out to verify the reliability of the system and the fastening devices. At the same time, thermal plugs were installed close to the measuring points of thermocouples of the storage- measuring method. As one of most widely used and be generally accepted methods of temperature measurement, the thermal plugs verif ied the result of the new system.Only the storage temperature measuring system was installed on the Dongfeng Cummins 6BT turbocharged diesel engine. And the piston temperatures had been measured at five engine speeds, namely 1300rpm?1500rpm?1700rpm?2000rpm and 2200 rpm when the torque was constant at about 430N?m to analysis the piston temperature varied with engine speed. The results indicate that the highest temperature of the piston is on the top surface at any speed, the temperature reaches 283 ? at 2200 rpm on the exhaust side.