| Magnetic grinding technology is an emerging technology, which is based on electromagnetic basis, magnetic rotor grinder driven by magnetic force is used for grinding on the workpiece. This technique is mainly applied to the inner surface of the long, non-magnetic material pipe grinding. Currently, the technology can carry on an effective processing for long stainless steel tube surface, and the inner surface roughness is reduced to about 0.4μm, But there are also some problems, mainly in the following aspects:1) In the long process of grinding, honing stone has a large amount of wear, and some have not even reached the processing requirements, it has been worn into the waste, only stop processing, affecting the stability and efficiency of the magnetic grinding system seriously, thereby affecting the inner surface quality of the tube;2) The rotor abrasive only can grind for the particular workpiece diameter, it is poor of adjusting performance, limiting the range of application, at the same time, the structure of honing stone is not conducive to grinding debris and heat emissions;To solve the above problems, the main contents of this paper are as follows:First,This article described common abrasives, the preparation and selection principles of abrasives, analyzed and researched the amount of wear in the grinding honing process, the results showed that abrasive hardness was the key factor in honing wear large impact. Research internships to Zhengzhou Research institute for Abrasives&Grinding Co. Ltd, Developed a grit size of 160#, at a concentration of 120%, bronze binder steel-CBN honing stone successfully.Second,On the basis of preliminary studies, the structure of rotor abrasive was optimized and designed. Simple structure, good adjustable rotor abrasive was devised. Used Ansoft software for the entire magnetic grinding system finite element analysis, the simulation results showed that magnetic field generated by the rotor abrasive and electromagnetic field generator could generate effective coupling, and overcome the drag torque generated by the grinding process effectively, then the workpiece inner surface was processed effectively.Finally,In order to verify the practical application performance of new rotor abrasive, and explore the best grinding parameters, the paper conducted three experiments grinding, as follows:1) The amount of wear of honing stone comparative experiment. Selected microcrystalline corundum honing stone and steel-CBN honing stone to grind 0Cr18Ni9 stainless steel tube respectively. Experimental data showed: under the same conditions, the amount of wear steel-CBN honing stone was only 1/50 of the microcrystalline corundum honing stone, improved the stability of the processing greatly, it was able to continuous processing for a long time.2) Explore the impact of The rotation frequency of the rotor abrasive to the workpiece surface quality. The rotational frequency of the rotor abrasives was separately set to 5Hz, 7Hz, 10 Hz, 12 Hz. Experimental data showed: Under the other certained conditions, the rotation frequency of the rotor abrasive for the best inner surface quality was 10 Hz.3) Processing trip for a workpiece surface quality of experimental inquiry. Combined with previously obtained optimal parameters, machining time was set for 1-6 trip(trip length is 1000 mm). The experimental data showed: stainless steel tube processed four trip could meet roughness requirement, the roughness requirement was 0.2 μm.The new rotor abrasives can effectively meet the processing requirements of the workpiece for inner diameter ?62~?68(experiment with only inner diameter is ?68 stainless steel pipe as an example), solved the limitations for grinding specific size workpiece. At the same time, through analysis and experiment showed that: The steel-CBN honing stone could solve the problem of honing stone wear volume effectively, and reduce the stainless steel tube surface roughness by 1.64 μm to about 0.2 μm. |
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