Process and apparatus for testing thermal fatigue of cylinder heads of internal combustion engines

摘要

In the present invention, there is disclosed an apparatus for testing thermal fatigue in internal combustion engine cylinder heads (C) comprising a cylinder head (C) support (14) having at least one cylinder head (C) area adapted to be exposed to combustion under normal engine operating conditions, and at least one burner (11) that is arranged to direct a flame at said area. The testing apparatus comprises at least one thermal flux sensor (171) placed in the cylinder head (C) at the same level as the heated zone to check that the heat flux created by the flame corresponds with a require accuracy to a predetermined value. When calibrating the invented apparatus for testing thermal fatigue in internal combustion engine cylinder heads (C) provided with burners (11) temperature sensors are placed in instrumented cylinder head (C) wherein the sensors are placed in vicinity of at least one area intended for exposure to combustion effects in the engine. Subsequently, temperature sensors are used while the cylinder head (C) is treated in engine testing apparatus and a temperature map for that area is determined under normal stable operating conditions, and said temperature map is then stored into a computer memory. A thermal flux sensor (171) is placed in an instrumented cylinder head (C) area and the cylinder head (C) is then arranged in a temperature fatigue test stand. Subsequently, a thermal flux delivered by each burner (11) is adjusted to create a temperature map being closest to that one stored in the computer memory, and after processing the measured value of the thermal flux is then stored as a required value. When making thermal fatigue tests, the cylinder head (C) is first placed in a test apparatus and then adjustment to the required value is carried out by alternating phases of thermal flux heating and phases of cooling for a predetermined period.