Design Of High Speed Inner Cooling End Mill For Suppressing Negative Pressure Field In Fluid Field

Carbide cold milling cutters are widely used in the aerospace,automobile manufacturing,shipbuilding and energy,so it is very important to improve many industries in researching for the end mill.At present,with the economic globalization,the manufacturing industry is very competitive,consider at the quality of products,production cycle and other increasingly stringent requirements,the advantages of high-speed cutting gradually highlighted.As the internal cooling cutting greatly increased tool life and improve the workpiece surface quality then the dry cutting which is gradually replaced by internal cooling.With the increasing speed of processing trends,there will be cavitation in the coolant which is surrounding the high-speed internal cooling end,this phenomenon will damage tools and reduce tools life.Based on this,the studies of the fluid field around the high-speed internal cooling end mill shows the shape of the fluid field and give ways to the improvement of the chip pocket of the end mill to reduce the possibility of cavitation of the fluid field under the same processing conditions.Firstly,give the mathematical modeling of the radial section of an existing end mill,and then draw the solid model of end mills on UG 3D modeling software and the fluid field model of high speed inner cooling end mill milling hole.The model of the fluid field is processed by the sliding mesh model and based on this the boundary conditions are determined.The turbulence model is determined as RNG k-epsilon model.The fluid field model is parted off by ANSYS Mesh.The simulation of the fluid field is carried out to obtain the radial section pressure cloud,velocity vector.Figure shows the conclusion that the highest point of pressure is generated at the tip of the rake face and the lowest point of pressure is generated inside the chip flute or at the flank.Secondly,the influence of the rotational speed,the helix angle and the relative position of the tool and the wall of the hole on the fluid field is studied.Then we design simulations in single factor experiment respectively and the different fluid field models are established to obtain the fluid field morphology and the distribution of the pressure at the most point;we also obtain the critical speed of cavitation in the fluid field at room temperature and under normal atmospheric conditions.When the spinning speed is greater than 20000 r / min,there will be cavitation phenomenon in the fluid field.The single helix angle simulation experiment shows that the large helix angle can help to suppress the cavitation.Once more,in design of chip pocket for suppressing cavitation phenomena,the radial section is mathematically modeled according to the five elements,the radius of the base circle,the radius of the chip bottom,the chip flute and transition curve radius,the rake angle in section and the clearance angle in section to draw the end mill model in the single factor variable way.The influence of five elements on the minimum negative pressure in the fluid field is analyzed one by one.We search for optimal solution in the range of last optimal solution,so the final solution will be more and more closer.Carbide cold milling cutters' cutting performance,chipping performance,stiffness,dynamic balance,and other factors are considered by suppressing the cavitation to obtain the radial section of the end mill.Finally,we verify the reliability of the resulting section by comparing the minimum negative pressure of the fluid field at different rotational speeds to achieve the purpose of reducing the possibility of cavitation of the end mills under the same processing conditions.