Papers by Keyword: Finishing Characteristics

Abstract: This paper describes an internal finishing process for thick non-ferromagnetic tube (10~20 mm in thickness) by the application of a magnetic field-assisted machining process using a magnetic machining jig (permanent magnet tool). In this study, a new automatic inner surface finishing system was developed, and to achieve smooth surface roughness and high form accuracy, a multiple-stage machining which contains of rough machining and precision finishing was carried out. Especially, in order to improve the form accuracy the rough processing time was made longer compared with the research in the past. The experiments were performed for a thick SUS304 stainless steel tube 10 mm in thickness. The results showed that surface-roughness and form accuracy were able to be improved greatly, the initial surface roughness of 4.9μm Ra can be improved to 0.01 μm Ra and the roundness of inside tube can be improved from 206 μm to13μm.

Abstract: Pyramidal structured lapping film, which has minute pyramidal structures formed by abrasive grains and adhesives on polyester films, is newly developed finishing tool[1,2]. It is said that the tool has eminent grinding characteristics, mainly, good finished surface quality because chips generated during grinding process can escape into spaces between pyramidal structures, and high grinding efficiency because new abrasive grains come out from inside of the pyramidal structures during grinding process. However, finishing characteristics of this grinding tool have not yet been fully explained.　In this research, the grinding experiments were conducted, focusing on the efficiency of grinding. The grinding forces were measured to examine the state of the surface of the tool. In addition, to improve the grinding efficiency using this tool, a method for changing the grinding load continuously while processing was used. This method was intended to enhance the effective chip generation and new abrasive grain emergence. As a result, stock removal of the workpiece was increased more than when the grinding load was kept constant. Moreover, using scanning electron microscope, this new grinding tool surface was observed, and its effectiveness was examined.

Abstract: This paper describes a new efficient internal finishing process for a thick tubing (10~30mm in thickness), by the application of a magnetic field-assisted machining process using a magnet tool. Because a stronger magnetic force can be generated than conventional magnetic abrasives, it makes the internal finishing of thick non-ferromagnetic tubing possible. Moreover, in order to obtain a high-quality surface, this process method was developed using magnetic particles magnetically attracted on the magnet surface. This paper characterizes the processing principle and advantages of this process. Then, the mechanism of this finishing process was examined by a plane model experiment. It was clarified that the magnetism and shape of a magnetic particle influence realization possibility of this processing method, and it also influence the finishing characteristics.

Abstract: This paper examines a new magnetic field assisted machining process using a magnetic machining jig. By using this process, a high efficiency and high quality internal finishing process can be achieved, and it was clarified that it was very effective to finish the internal surface of a thick tube (5~30mm in thickness). In this study, the experiments performed on the SUS304 stainless steel tubes (10mm in thickness) examine the applicability of improving the internal surface roughness and the roundness of inside tube, and it also examine the effects of a rotational speed of the magnetic machining jig. The results showed that this processing method enables improve the internal surface roughness and the roundness of inside tube. It is clarified that the roundness of inside tube is highly dependent on the rotational speed of magnetic machining jig, and the roundness can be improved rapidly at a higher rotational speed with the magnetic machining jig.