| With the continuous expansion of the application range of screw pumps,the requirements for the machining accuracy of important components of screw pumps are becoming higher and higher.As the core component of the screw pump,the screw’s accuracy plays a decisive role in the performance of the host.However,the screw profile is more complicated,which increases the processing difficulty.Generally,the forming tool is used to process the screw,due to the high cost of the forming tool and the complicated calculation of the surface profile of the tool,it not only increases the processing cost but also reduces the processing efficiency.In view of the current status of screw processing at home and abroad,this paper proposes to use the disk milling cutter enveloping milling method to process the three-screw pump driven screw.By fitting the section curve of the screw pump,disk milling cutter geometric parameters,milling process parameters,cutting trajectory and interference problems are analysis,it lays the theoretical and technical foundation for actual processing.Firstly,the spiral surface equation is established,the screw section curve is fitted according to the cross-sectional value data of the three-screw pump,fitting error is analyzed;On this basis,the solid model of the driven screw is established,and the change rule of the curvature of the screw surface of the screw is analyzed,which provides a theoretical basis for later tool interference analysis.Secondly,a simplified model is established based on the disk milling cutter entity,and the meshing state is analyzed according to the cutter tip arc milling revolution equation and the cutter double-cone surface revolution equation to determine the disk milling cutter arc cutting trajectory,the tool machining inclination angle and the tool effectiveness cutting radius are determined;The tool line spacing value of the concave and convex surfaces of the screw is determined according to the given equal residual height and the tool line spacing mathematical model.By reasonably arranging parameters such as line spacing and step length,the tool trajectory is determined.Finally,the principle of CNC machining is analyzed,and the CNC machining program is written according to the trajectory of the tool position,and the simulation tool is used to verify the interference state of the trajectory of the tool.After processing,whether the residual material on the screw surface meets the processing accuracy requirements isanalyzed through simulation processing,NC machining program code is output.Milling is performed on a CNC machine tool,and the accuracy of the screw section curve fitting,tool trajectory and CNC program are verified. |
