Magnetic Abrasive Finishing On The Inner Surface Of The Tube Based On Spiral Magnetic Field

With the development of the mechanical manufacturing field,devices becoming more complex.In order to meet the requirements of the use of complex instruments,the complex elbow is often used as a small and irregular space duty pipe.However,the quality of the inner surface of the bend is difficult to be guaranteed because of the difficult finishing of the traditional processing technology.In this study,magnetic abrasive finishing method is combined with single chip microcomputer to form a controllable electromagnetic field.In order to improve the quality of the inner surface of the curved tube,a special magnetic path is formed by winding a spiral electromagnetic pole.In this paper,electromagnetic field excitation method is used to form the electromagnetic field to analyze the magnetic particle finishing mechanism on the inner surface of the elbow.The force acting on the magnetic abrasive and the critical speed of the spatter of the abrasive particles are investigated.The self-priming phenomenon of abrasive particles is explained from the perspective of their own motion and mutual friction,and the cutting mechanism of abrasive particles is explained.Magnetic abrasive finishing device based on single-chip microcomputer,adopting the Ansoft Maxwell software for simulating magnetic circuit analysis,find out the best magnetic circuit,and explore the hysteresis of magnetic brush in circumferential rotary motion to the influence of the axial feed movement process,syphon and the surface requirement for finishing path,The electric mode and arrangement mode of the electromagnetic pole realize the transition from circumferential rotational motion to axial feeding motion.Combined with the finishing characteristics of the inner surface of the elbow,the magnetic pole is spirally wound along the central axis of the elbow to find the optimal magnetic path and complete the overall design of the polishing device.Spiral magnetic field is used to finish the inner surface of the space-anisotropic faucet.In order to strengthen the magnetic induction intensity in the grinding area,and then enhance the grinding pressure,auxiliary magnetic poles are placed into the tube to improve the surface quality of the workpiece.Box-Behnken experiment is designed by response surface method.The influence of the interaction of magnetic field rotation speed,magnetic abrasive particle size and magnetic induction intensity on the grinding quality is analyzed,and the optimal process parameters were found.The feasibility of the magnetic abrasive finishing method based on single chip microcomputer is verified.In order to solve the problem of precision finishing of inner surface of large curvature bend pipe(for 90 degree elbow),flexible magnetic chain is used to absorb abrasive particles to smooth through the bend,reduce the accumulation of abrasive in the bend of elbow,and improve the non-uniformity of polishing between magnetic poles.Common cross-electro-magnetic pole is used to form cross electrodes coupled grinding magnetic path.The problem of magnetic pole winding interference is solved,which makes the finishing track closer to the wave shape and improves the inner surface quality at the bend of large curvature pipe.The above research work overcomes the shortcomings of using permanent magnet pole to finish the surface of complicated curved pipe.Electromagnetic excitation forms a controllable magnetic field,realizes the non-mechanical axial feed motion along the axis of the curved pipe,avoids the interference between the rotating magnetic pole and the outer wall of the workpiece,improves the finishing efficiency,improves the surface quality of the workpiece.It provides a new method for finishing the inner surface of the elbow.