Research On Structure Design Of Full-automatic Right-angle Milling Head And Optimization Of Clamping System

The right-angle milling head is the most commonly-installed functional accessory for the gantry boring and milling machine,and it plays a role in expanding the processing scope of the machine tools.The automation and performance of the milling head largely determine the performance and production efficiency of the entire machine tool.At present,the manufacturing technology of full-automatic right-angle milling heads is not advanced in our country.Based on the existing right-angle milling heads,a method combining theoretical calculation and finite element simulation is used to design the entire structure of the fullautomatic right-angle milling head and optimize the clamping system.This improves the automatic performance of milling heads and its working reliability.(1)The entire structure design of the full-automatic right-angle milling head.The overall structure and working principle of the full-automatic right-angle milling head are analyzed,and the transmission process of the spindle drive chain and C-axis drive chain is described.Using the method of theoretical calculation to check the strength of the spiral bevel gears and bearings which are key transmission parts of the right-angle milling head.Driven by the hydraulic oil chamber,the power distribution of the vertical axis and the accurate positioning of the C-axis rotation are realized by means of disengagement and meshing of the spline and gear.The use of water,oil,gas and other media to enable milling heads with the functions of tool cooling,cone-hole blowing,air curtain protection and automatic loosing knife,improves the overall performance of full-automatic milling heads.(2)Structure improvement of clamping system of the full-automatic right-angle milling head.Based on the existing milling head's clamping system,considering the design requirements of the full-automatic right-angle milling head,a spring is installed on the lower end face of the piston plate of the clamping system which provides self-locking function by the elastic force in order to improve the stability and reliability of the milling head.The force of the piston in the improved clamping system is analyzed,and the formula of the clamping oil pressure is deduced by using a theoretical calculation method,which provid guidance for the use of the full-automatic right-angle milling head.It analyzes the problems that may be find during the use of the full-automatic right-angle milling head,and gives the corresponding solutions.(3)Optimization of the structure of the full-automatic right-angle milling head's clamping system.Force analysis is used to solve the force in the clamping state of the milling head.Using this force as a boundary condition,the finite element analysis is performed with Ansys Workbench software on the clamping system.It finds that the steel ball's stress exceeds the steel ball's yield limit in the clamping system installed six steel balls.When the ball number increases to 8,the clamping system can meet the using requirements.(4)Selection of the clamping system's spring and solution of clamping oil pressure.The force condition of the clamping system under the self-locking situation is analyzed.The elasticity coefficient of the spring in the clamping system is calculated by theory and the spring type is selected.Through analysis and calculation,the force of the spring in the clamping state is solved,and the clamping oil pressure needed for the improved clamping system is obtained with the oil pressure formula,which provides a reference for the practical use of the milling head.