Application Of Extrusion Dressing Technology In Ultra-High Speed Grinding Wheel

High-speed and ultra-high-speed grinding technology can not only greatly improve the processing efficiency,but also obtain good surface roughness and accuracy.However,because of the high speed and ultra-high speed grinding speed,the grinding force of grinding wheels is relatively large,and the grinding wheels are basically made of super-hard abrasive grinding wheels.Compared with dressing at normal speed,dressing of super-high speed grinding wheel is more difficult because of its high dressing speed,high grinding force and high temperature.Therefore,it is one of the important factors for the development of ultra-high speed grinding technology to study and solve the difficult dressing problem of ultra-high speed grinding wheel.At present,there is little research on dressing technology of super high speed grinding wheel at home and abroad.Most of the dressing methods used are traditional dressing methods of ordinary speed grinding.There are many problems such as low dressing efficiency,easy tool wear,complex device and poor precision.Therefore,it is necessary to carry out research in order to find a better technology suitable for super high speed grinding wheel dressing.Aiming at the difficult dressing problem of ultra-high speed grinding wheels,this paper puts forward a scheme of dressing ultra-high speed grinding wheels by extrusion dressing method,and carries out a series of research work for this purpose,and achieves corresponding results.The details are as follows:1 Study on Extrusion Grinding and Dressing Mechanism of Ultra-high Speed Grinding WheelUnder high speed operation,the diamond surface of the grinding wheel is restrained by free abrasive to grind the super-high speed grinding wheel.By destroying the bonding agent bridge on the surface of the super-high speed grinding wheel,the abrasive grains fall off and the required shape of the grinding wheel is quickly dressed;Then the shape and contour of the super high speed grinding wheel can be precisely grinded by micro-grinding with diamond extrusion grinding wheel pair;Through theoretical analysis and experimental study,the morphology of grinding wheel after extrusion and grinding dressing was observed under micro-condition,and the mechanism characteristics of extrusion and grinding dressing were revealed.2 Study on mechanical properties of extrusion-grinding dressingAccording to the analysis of extrusion and grinding dressing force in the process of extrusion and grinding dressing,the mathematical model of extrusion and grinding dressing force is established;Combining the mathematical model of extrusion grinding force and the empirical formula of grinding force,the formula of extrusion grinding dressing force is deduced.The data and deduced formulas of extrusion and grinding dressing force are validated by experimental research.The formula of extrusion and grinding force is simulated by MATLAB software,and the effect of extrusion and grinding dressing force on the efficiency of extrusion and grinding dressing is analyzed.3 Development of diamond extrusion wheel and design and manufacture of extrusion,grinding and dressing deviceIn this paper,diamond roller is used as extrusion and grinding dressing tool,and its manufacturing method,processing accuracy and shape requirements have an impact on the effect of extrusion and grinding dressing.In order to improve dressing efficiency,diamond extrusion wheels are manufactured by electroplating method,which is divided into external electroplating method and internal electroplating method.In this paper,the relative manufacturing technology is studied.The abrasive grain arrangement of diamond extrusion grinding wheel is in order of conventional blade arrangement.Diamond particle size is 18/20,30/35,70/80,etc.Its processing and manufacturing accuracy can reach 0.003mm~0.005 mm,the extrusion and grinding dressing device is composed of a precision drive spindle and a feed precision sliding table with force feedback.The feed device is designed with a force feedback system to control the clearance of extrusion and grinding dressing.The automatic control system is designed and developed,which can set and control the force of extrusion and grinding dressing and adjust the parameters of extrusion and grinding dressing.4 Experimental study on the basic technological rules of extrusion-grinding dressingExtrusion and grinding dressing experiments mainly studied the effects of free abrasive and non-free abrasive,dressing speed difference,feed speed and grinding wheel type on extrusion and grinding dressing efficiency.Based on the principle of single variable,the extrusion and grinding dressing tests are carried out,and the results are as follows:the efficiency of dressing with free abrasive is high;The dressing efficiency decreases with the increase of dressing speed difference,when the dressing speed ratio q = 0.6,the dressing efficiency is higher;The dressing efficiency of extrusion grinding decreases with the increase of feed speed,and the dressing efficiency is the highest when feed speed ap=0.5um/s;Ceramic bonded diamond grinding wheel is easy to dress,high dressing efficiency and good grinding performance.