The Research And Development Of The CNC System Of High Efficient Precision Universal Gantry Rail Grinder

Rail grinding machine is a kind of large and precision equipment, which is characterized by structure complicated, frequently operated and high precision and quality of workpieces. Because of the grinding wheel’s "self-sharpening", as well as chip and crushed grain of blocking the grinding wheel, the grinding wheel needs to adjust position again and again so as to compensate the deviation and set tool during the procedure.The existing grinding wheel’s dressing and cutting mainly through the artificial perception of operators, which results in a highly concentrated spirit.highly intensity labor and work pressure for the tool operators when operating the machine, that would lead to low work efficiency, long production cycle and high cost of processing. Research on high efficiency precision universal gantry rail grinder and its control technology is of great significancy in realizing the automatic grinding, reducing labor intensity and ensuring machine accuracy.This subject aimed to achieve customizable circular grinding process, do research and development for the high precision universal gantry rail grinder and efficient numerical control system for a company, main research and development work were reflected as the following aspects:(1) The development level of rail grinder and the main existing problems of CNC gantry rail grinding machine at home and abroad were described summarized in this dissertation, as well as the type and characteristics of open CNC system.(2) On the basis of the analysis of the mechanical equipment, common rail type, structure characteristics and process requirements, according to the machine tool automatic renovation, compensation and grinding requirement, a overall scheme of the machine was formulated.3D model of the gantry rail grinding machine was established by CERO software, and the structure of the machine for some part were redesigned, such as universal grinding wheel dressing with five shaft structure to complete the grinding wheel dressing.(3) According to requirements of the universal grinding machine with multi-axis and multi-channel control, the grinding machine’s hardware system on the basis of "NC embedding PC" was established. The motion control of the system module, servo drive module, servo motor as well as the grating ruler were calculated and selected.(4) The gantry rail grinding machine’s PC software was designed and developed on VC6.0 platform, using the method of modular programming. There were manual module, automatic module, parameter setting module, diagnosis module and the automatic programming system module in the designed software. For grinding wheel dressing, the problem of automatic compensating and automatic processing were solved by establishing the parameters mathematical model of grinding wheel and dresser. Based on the gantry rail grinding machine for grinding wheel dresser of finishing processes, the parameterize expression of grinding wheel dresser’s trajectory was figured out. On the basis of the combination with grinding wheel database, processing customized, the method of realizing universal rail grinder’s wheel dressing and grinding process automation was put forward.(5) In terms of improving the rail’s orientation precision, the convex curve and the interpolation model of the guide rail were established. By using linear approximation method and the numerical analysis method, the curve tangent point and node coordinates was obtained by the software programming. Then, Helen formula was applied to analyze and verify whether the obtained node meet the accuracy requirement or not by examples. At last, the approximation results of the theoretical ions curve and linear were simulated in Matlab software.In this dissertation, the structure of grinding wheel dresser based on the gantry rail grinder is innovated, modular programming was adopted in PC software in order to subsequent function extension expediently and enhance the system’s versatility. Research results can provide technical support for the CNC system of the high efficient precision universal gantry rail grinder.