The influence of temperature on precision parts in CNC machining
Posted by Admin
1. In the essential machining process, due to the impact of various heat sources, cutting heat, ambient temperature, thermal radiation, etc., the temperature changes of machine tools, tools, and processed workpieces will cause thermal deformation, which affects the relationship between the workpiece and the tool. The relative displacement between the two forms a machining deviation, which affects the machining accuracy of cnc machined parts. The linear expansion coefficient of the steel material is 0.000012/℃, and the steel material with a length of 100mm stretches 1.2μm when the temperature rises by 1℃. In addition to temperature changes directly affecting the expansion and contraction of the workpiece, it also affects the accuracy of machine tools.
2. In precision machining, higher requirements are put forward for workpiece machining accuracy and accuracy stability. According to statistics from related materials, in precision machining, due to thermal deformation, machining deviations account for 40%-70% of the total machining deviations. Therefore, in high-precision precision machining, in order to prevent the workpiece from swelling due to temperature changes, the reference temperature of the environment is usually strictly regulated, and the deviation boundary of the temperature change is established. The constant temperature processing of 20℃±0.1℃ and 20±0.01℃ still occurs.
3. Under normal circumstances, in order to prevent the workpiece from expanding due to temperature changes during processing and measurement, the indoor reference temperature is usually strictly regulated, and the deviation boundary for temperature changes is established, but the requirements for the relative humidity of the air do not have the accuracy requirements for textile testing. .