1　概述小松 PC2 0 0 - 5液压挖掘机的发动机中设有自动预热与预防过热功能。在发动机起动后 ,如果冷却液温度太低 ,可自动提高发动机转速 ,以预热发动机 ,即所谓的自动预热功能。如果发动机在运行中 ,冷却液温度升得太高 ,可自动降低泵负荷和发动机转速 ,以防止发动机过热 ,即 1 Overview Komatsu PC2 0 0 - 5 hydraulic excavator engine with automatic preheat and prevent overheating function. After the engine starts, if the coolant temperature is too low, the engine speed can be automatically increased to warm up the engine, the so-called auto-warming function. If the engine is running, the coolant temperature rises too high to automatically reduce the pump load and engine speed to prevent the engine from overheating, ie