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活塞的热疲劳性能对柴油发动机的全寿命至关重要。由于能量有限和可控性差等缺点,现有实验系统均不能满意地进行活塞热负荷模拟实验。为此,提出并建立了一套激光诱发活塞热负荷的实验系统。该系统通过对激光束的空间整形,使之投射到活塞表面后诱发的温度场分布满足特定要求。基于PROFIBUS-DP现场总线技术实现了系统集成和实验过程的全反馈控制。针对活塞的典型热负荷条件,即高周热疲劳和热冲击分别进行实验,以模拟正常工作循环和“启动-停车”等热负荷或转速突变工况。通过设置加热-冷却周期或上限-下限温度,可以获得相应的热负荷模拟实验效果。研究结果表明,采用经光束整形的激光进行活塞热负荷模拟实验具有周期短、可控性好等优点。
The thermal fatigue performance of the piston is crucial to the life of the diesel engine. Due to the limited energy and poor controllability, the existing experimental system can not satisfactorily carry out the piston thermal load simulation experiment. To this end, a laser-induced experimental system of piston heat load is proposed and established. The system through the laser beam spatial shaping, so that it projected onto the surface of the piston induced temperature distribution to meet specific requirements. Based on PROFIBUS-DP fieldbus technology, the system integration and experimental feedback control are realized. Typical heat load conditions for the piston, that is, high thermal fatigue and thermal shock were tested separately to simulate normal duty cycle and “sudden start-stop” or other heat load or speed mutation conditions. By setting the heating - cooling cycle or the upper limit - the lower limit temperature, you can get the corresponding simulation results of thermal load. The results show that the simulation of the piston thermal load using the laser beam shaping has the advantages of short cycle and good controllability.