Papers by Author: Yoshimi Takeuchi

Abstract: Recently, in accordance with the technical development and miniaturization of the information equipments, the demand of optic elements with high precision and miniaturization is increased. The mold is used in the manufacture of the optic elements. Thus, it is needed to machine the mold with high efficiency and high precision. As the material of mold, hard material including cemented carbide and ceramics is used. However, it is a problem of the occurrence of severe tool wear when hard material is machined. To solve this problem, the cutting point swivel machining by using the diamond tool with special chamfer was proposed, which has the ability to suppress tool wear and to realize ultraprecise machining. It is confirmed that the cutting point swivel machining has the ability to suppress tool wear by the microgrooving experiment of SiC. This study aims at investigating the effect of the cutting point swivel machining, and making clear the relationship between tool rotation speed and tool wear. As a result, it is known that the actual cutting direction can be changed by using the cutting point swivel machining, and that the chipping of tool becomes conspicuous with increasing tool rotation speed.

Abstract: This study deals with 5-axis control tool path generation to create microshapes dexterously and efficiently, while maintaining quality. Concerning 5-axis control machining, the use of ball end mills is generally employed. However, this method needs a lot of time to obtain high quality surface. To solve this problem, a side cutting edge of the ball end mill is positively utilized with its parallel to the ruled surface. Therefore, a new CAM system is developed to detect the surface to be machined with the side cutting edge, and to generate collision-free tool paths between the tool and the work piece. The effectiveness of the developed CAM system is experimentally confirmed by creating a tiny Möbius ring.

Abstract: Ultraprecision machine tools can be expert power together with a CAD/CAM system in generating tool paths. However, CAM systems generally focus on generating NC data. Consequently, operators have to perform process planning by considering the features of machine tools, cutting tools and workpieces. Above all, the setting error may cause interference between the cutting tool and the workpiece, and result in low machining accuracy. Therefore, this study deals with the development of a CAPP/CAM system in ultra-precision micromachining to assist operators in relation to settings. The developed system determines the number of the used control axes of the machine tool, and calculates the required setting accuracy, while preventing tool interference and maintaining the shape error within the tolerance. From the simulation result, it is found that the CAPP/CAM system is effective in producing micro parts easily and accurately.

Abstract: In recent years, ultraprecision micromachining technology draws wide attention. In particular, multi-axis control ultraprecision machine tools are playing an important role in producing complicated microparts made of a variety of materials. In addition, CAM software is also an essential element to control these machine tools. The paper deals not only with the current state of multi-axis control ultraprecision machine tools but also with the manufacture of two workpieces consisting of complicated shapes by means of micromilling.

Abstract: Recently, in accordance with the technical development and miniaturization of the information equipments, the demand of optic elements with high precision and miniaturization is increased. The die is used for manufacturing the optic elements. Thus, it is needed to machine the die with high efficiency and high precision. As the material of die, hard material including cemented carbide and ceramics is used. However, when hard material is machined, there is a problem that severe tool wear occurs, and worn tool shape is transferred into the surface so that precision machining cannot be realized. In this study, a method, called cutting point swivel machining, is proposed to suppress tool wear by using the tool with special chamfer and all parts of tool tip. The effect of tool wear suppression is verified by the machining of SiC. Then, the relation between the suppression of tool wear and tool rotation period is verified.