内燃机活塞表面瞬态温度传感器的研制

摘要

针对内燃机活塞表面温度变化迅速的特点,研制了一种瞬态温度传感器用于测量活塞表面温度。采用直流脉冲磁控溅射的方法将 NiCr 薄膜直接溅射沉积在高温烧结后嵌有 NiCr、NiSi 丝的陶瓷元件端面,NiCr 薄膜外侧溅射 Si3 N4保护膜。传感器外壁选用带螺纹的304不锈钢作为铠装套筒。采用自行研制的薄膜热电偶静动态标定系统对所研制的瞬态温度传感器进行标定,结果表明：所研制的传感器在50~400℃范围内具有良好的线性和热稳定性,其塞贝克系数在39~41μV/K 之间,非线性误差小于0.34%,重复性好；热接点薄膜厚度为355 nm 时,传感器的响应时间为41.7μs,且响应时间随着薄膜厚度的增大而增加；该瞬态温度传感器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。%According to the internal combustion engine piston surface temperature rapidly changing situations,this paper developed a transient temperature sensor for measuring the piston surface tem-perature.By using a DC pulse magnetron sputtering method sputtering deposited NiCr film directly on end face of ceramic element which was sintered in the high-temperature and embedded with NiCr,NiSi wire,sputtering Si3 N4 protective film on the sensor’s outside of NiCr film.The sensors’outer wall used threaded 304 stainless steel as armored sleeve.To calibrate the designed transient temperature sensor by using self-developed thin-film thermocouple static and dynamic calibration system,the re-sults show:that the developed sensor has good linearity and thermal stability in the range of 50~400 ℃.Its Seebeck coefficient is between 39 μV/K to 41 μV / K,the nonlinear error is less than 0.34%,good repeatability.The thickness of hot junction thin film is as 355 nm,the sensor’s response time is as 41.7 μs,and the response time increases with the film thickness increases.The transient temperature sensor can meet the crankshaft speed to 1800 r/min of an internal combustion engine pis-ton surface transient temperature testing requirements.