Optimization Design And Experiment Research Of Small Deep Hole Gun Drill Based On GCr15

In recent years,along with the continuous development of machine industry and the implementation of civil military integration policy,deep hole machining technology has been widely applied to civilian product processing.Because of the diversity and specialization of deep hole parts and the demand for accuracy,the requirement for cutting tools is also increasing.In the production process of small deep hole parts,gun drill is the most ideal tool for machining.Using professional small deep hole gun drilling machine,we can produce high precision holes.In order to efficiently complete the small deep hole processing project of the rolling mill GCr15 roller shaft of a steel rolling mill in Shanxi,the main characteristics of the deep hole of the roller shaft are small aperture,large length diameter ratio and thin wall hole,which presents many typical processing difficulties of small deep hole processing.On the basis of the analysis and summary of the structure optimization of the gun drill and the research status of the processing parameters at home and abroad,the mechanism,structure and process parameters optimization of the gun drill used in the machining of the machining roller shaft with small deep hole are studied.The specific contents are as follows:(1)The structure and working mechanism of the gun drill are studied theoretically,the mechanical model of the gun drilling and drilling is deduced,and the width and angle of the cutting edge of the gun drill are optimized according to the machining characteristics of the thin wall hole of the roller shaft,and the theoretical calculation is verified.In view of the problems of high temperature and hard cutting in the cutting area in deep processing,the position of the oil hole is optimized through the rear angle surface of the blade grinding gun,so that the coolant can be cooled efficiently,and the wear of the gun drill is reduced and the quality of the product is improved.(2)In order to further verify the size and influence of all the forces of the optimized gun drill in the eccentric hole of the machining wheel shaft,a three-dimensional model of the gun is created,and the simulation problems of the simulation of the model,such as the modelsimplification of the tool and the workpiece,the mesh division and optimization,the simulation environment,the motion and the boundary and so on,are discussed and discussed.Based on the comparison test,the dynamic process of the eccentric hole of the roller shaft was simulated by using the Deform-3D software.The axial force and torque of the gun drill are obtained in the simulated drilling.The influence of different cutting parameters on the axial force and torque is analyzed and compared,and the influence of the axial force,radial force and torque before and after the gun drill is compared and analyzed.(3)In view of the difficulty problem of chip removal in the semi airtight machining of the gun drill,the fluid domain model of the gun drill is created.The flow field of the gun drill is simulated by the fluid analysis software Fluent(CFD),and the distribution of the fluid field of the gun drill in the two hole oil hole in different positions is obtained.The analysis and comparison are obtained.After optimizing the location of oil holes,the speed loss of coolant is less and the pressure distribution is good.Through the processing experiment,it is found that the optimization of the position of the oil hole improves the problem of the hard cutting of the gun drilling processing system,reduces the wear of the gun drill and improves the quality of the product.(4)Based on the above theoretical simulation research,in view of the eccentric hole of the machining roller shaft,it is easy to deflect or even pass out to the thin wall side,which leads to the low qualification rate of the workpiece and even the scrap.The gun drill after re grinding is used to optimize the taper of the gun,the width and angle of the cutting edge and the auxiliary production with the guide sleeve of the front cone.The optimized parameters are used to carry out the machining test,which not only solved the difficult problem of chip,reduce the tool wear,hole straightness has been greatly to improve,to demonstrate the feasibility of this theory and method.