高压共轨柴油机ECU热测试分析

柴油机电控单元(Electronic Control Unit,ECU)的集成化和小型化发展及其恶劣的工作环境导致元器件存在高温失效的危险.基于ECU负载模拟器和快速温度变化试验箱,搭建ECU热测试平台,模拟柴油机的不同运行工况和环境条件,研究ECU热负荷状态.研究表明,柴油机转速和扭矩的大小影响元器件的热损耗,75%的元器件在柴油机额定功率点温度最高,但喷油器电磁阀驱动模块元器件在柴油机最大扭矩点温度最高且受柴油机运行工况影响最突出.环境温度的改变影响元器件与环境之间的综合热阻,引起元器件与环境的温差随环境温度上升呈先减小后增加的变化趋势.当环境温度达到105℃时,ECU内部分元器件温度达到汽车电子元器件的许用温度125℃,需改善元器件换热条件.

Thermal test and analysis for ECU of common-rail diesel engine

The integration and miniaturization of diesel engine ECU as well as poor working condi-tions are likely to result in the failure of ECU's components.In order to study the thermal load of ECU,thermal test and analysis of diesel engine ECU under different operation modes and envi-ronment temperatures are performed through the ECU thermal test system.It's found out that the rotational speed and the torque of diesel engine will affect the power loss of ECU's compo-nents.About 75％ of components'temperature reaches maximum when diesel engine operates at rated power,but the temperature of components in injector solenoid valve drive module reaches maximum under maximum torque condition and are significantly affected by the operation condi-tions of diesel engine.The environment temperature affects heat transfer so that the temperature difference between ECU's components and environment decreases first and then increases with the increase of environment temperature.As environment temperature up to 105 ℃,temperature of ECU components is closed to 125 ℃ which is permissible temperature and the improvement of cooling condition for components is required.