Design And Analysis Of Glass Mould Press Structure

With the rapid development of unmanned aerial vehicles,intelligent pilots,security monitoring,digital cameras,aerospace and other fields,the demand for optical lenses is increasing.Aspherical glass lens can correct the spherical aberration of the focusing system and increase the effective focusing,so it has wide practical value.Aspherical glass lens molding technology is a high-precision optical component molding method,its characteristics are:high precision molding,low cost,energy conservation and environmental protection,suitable for mass production.At present,the technology still has the problems of low yield and high stress of finished products,so the market has a great demand for high precision glass moulder and high quality aspherical lens.Therefore,it is necessary to study the structure design and molding process of the molding press.In order to improve the machining efficiency and yield,this paper analyzes the working principle and technology of aspherical glass lens molding technology,designs the mechanical structure of the seven-station glass molding press and draws the three-dimensional model of the overall structure.The whole structure is fixed by the lower mold,and the upper mold is moved down to complete the mold pressing.In addition,this article has made the key design and analysis for some mechanical structure:use positioning module to make upper and lower mold center alignment is good,as the elevator and motor combining power transmission way,using infrared heating system and infrared tube reasonable layout,design the powered by electric putter move mould device,so as to promote the intelligent moulding equipment and automation.For finished products stress is large,the problem such as the filling is not full and in the actual detection of glass mold production of high-temperature airtight environment the inconvenience precast body and mould parameters such as displacement,equivalent stress changes of disadvantage,this paper analyzes the viscoelastic and establish the model of moulded glass material,thermodynamic properties such as elastic modulus,heat capacity and the mechanism of heat transfer and friction in the process of moulding.Using simulation software MSC.Marc two-dimensional axisymmetric model is established,based on the generalized Maxwell model for aspheric lens of glass moulding process in finite element analysis,choose D-ZK3 glass material,mold material selection WC,explore the overall situation of the change of the equivalent stress,displacement and prefabricated body center of upper and lower equivalent stress,the change rule of the moulding process visualization.In this paper,the effects of die pressing rate,die pressing temperature and friction factor on the equivalent stress of aspherical glass lens and die as well as the effect of friction on the prefabricated body shift are studied in the process of die pressing,which can provide valuable reference for the setting of technological parameters of actual die pressing production and the improvement of die life.Through research shows that the glass on the edge of the precast body equivalent stress is greater than the center,the center under the center of the surface of the equivalent stress is greater than the surface,the equivalent stress of aspheric lens and mold with the mold temperature is reduced,with the rising of moulded rate and friction coefficient decreases,and the equivalent stress of mold in the process of moulding is greater than the precast body,the friction factor of large precast body full of cavity.By means of orthogonal test,it is found that the molding temperature and rate are the main factors affecting the equivalent stress of the glass preform.According to the practical application,the suitable die pressing process parameters were obtained:the temperature was 580 ℃,the rate was 0.1mm/s,and the friction factor was 0.2.