Research On The Influence Of Geometrical Parameters On The Thermal Deformation Of Mechanical Parts

The research involved in this paper is funded by NSFC: Basic Theory and Application Research on Thermal Error of Complex and Regular Mechanical Parts(No. 50475069). Temperature influence on performance and accuracy of mechanical apparatus and instrument is the inevitable physical phenomenon With the improving accuracy of mechanical apparatus and instruments, the influence of temperature increases proportionally. So it is not only important theoretically but also notable in practical to research basic theory and application technology of mechanical parts' thermal error, take effective measures to reduce the temperature influence.With a high-accuracy thermal deformation experimental devices employed to controll and measure temperature, detect geometric parameters by mechanical, optical, electrical equipments, the thermal deformation laws for the geometric parameters influence of cylinder and precision flat between 0～60℃can be studied experimentally. And the conclusion can drawn that any dimension thermal deformation of precise parts is not only related to its dimension, coefficient of thermal expansion and temperature change, but also related to geometrical parameters. And the geometrical parameters influence on thermal deformation of precise parts is significant..The law of the cylinder and precision flat's temperature distribution in the working circumstance is preliminarily explored and discussed, and the temperature distribution regularity is deduced with the change of time, which can improve the further research on mechanical components' thermal deformation in uniform temperature field theoretically and experimentally.The improvement to the system of measuring temperature is done on the base of original experimental device of thermal deformation. The improved high-accuracy temperature measuring system can directly measure the surface temperature of the parts and the origin device only measuring space temperature in constant temperature cabinet. High-accuracy temperature measurement system is mainly composed of chip microcomputer STC89C516RD+ and temperature sensors, and A-class thin film industrial platinum resistance Pt100 is adopted as temperature sensitive elements to obtain high precision in this system. MAX1402 is used to signal acquisition and A/D convertor, MAX7219 is used as 8-digit LED display driver. The accuracy of the thermometer is very high with sensor nonlinear compensation technique, based on least square method and linear interpolation through software.