薄膜热电偶测温螺钉传感器的研制

摘要

针对正常工况下的内燃机活塞表面温度变化迅速的情况，研制了一种便于安装的薄膜热电偶测温螺钉传感器。采用直流脉冲磁控溅射的方法将NiCr／NiSi热电偶薄膜直接溅射沉积在与内燃机活塞同种材料的测温螺钉的端部，热电偶薄膜和测温螺钉之间采用相同的磁控溅射方法制备Al2 O3绝缘薄膜，采用自行研制的薄膜热电偶静、动态标定系统对所研制的测温螺钉进行标定，结果表明所研制的测温螺钉传感器在50～400℃范围内具有良好的线性和热稳定性，其塞贝克系数为41．9μV／K，最大线性误差不超过0．9％。热接点厚度仅为2μm，其响应时间为47．5μs。可以满足曲轴转速为1800 r／min的内燃机活塞表面瞬态温度测试的需求，为内燃机结构的优化改进，新产品的开发提供了有力的保障，为新型传感器技术的进步做出了有益的尝试。%In allusion to the situation that the temperature is changing rapidly on the internal combustion engine piston surface under normal working conditions, a kind of thin-film thermocouple temperature screw sensor was developed for easy installation. The method by DC pulsed magnetron sputtering was used for sputtering the thin film of NiCr/NiSi thermocouple on the end of the screw made of the same material as the internal combustion engine piston for measuring temperature directly.The same method was used for sputtering the insulating film of Al2O3 between the thin film thermocouple and temperature measuring screw.Static and dy-namic calibrations for the thin film thermocouple were carried out by the development system designed by ourselves.It was conclu-ded that the temperature sensor had good linearity and thermal stability within the temperature ranging from 50℃to 400℃.The Seebeck coefficient of the screw sensor was 41.9μV /K, and the maximum linearity error was not more than 0.9%.The thickness of the hot junction was only 2μm, so its response time was 47.5 μs.It can satisfy the test requirements of the surface transient temperature on the internal combustion engine piston, whose crankshaft speed is 1800r/min, which provides strong guarantee in improving the structure of internal combustion engine and developing new production, thus making the beneficial attempt for the progress of the new sensor technology.