The demand for five-axis machining centers has been increasing rapidly, as companies seek “intensive processes” and “high accuracy.” However, it is generally more difficult for five-axis machining centers to achieve the same or higher accuracy than three-axis machining centers since it is necessary to have two more rotary feed axes besides the three linear feed ones. Many kinds of five-axis machining centers with various structures have been developed to date; an analysis of the advantages and disadvantages of major five-axis machining center structures was done first. As a result of this analysis, this paper focuses on the “table-on-table type” five-axis machining center. It is capable of accuracy because of its wide range of rotation for the rotary axis and its advantages in the adjustment process of the axis. and this paper proposes a five-axis machining center which has this construction. Furthermore, a new high-speed, highaccuracy, “table-on-table type” of five-axis machining center which uses a direct-drive motor for the rotary axis and a driven center of gravity for the linear axis has been developed based on this concept, and its accuracy has been verified.
The polyurethane resin, the reaction product of 1,4-polybutadiene polyol and isocyanate, is excellent in rubber elasticity.The features of polyurethane resin are its low glass transition temperature and good rubber elasticity property even at low temperature.Moreover, it is excellent in water resistance because of the hydrophobic polybutadiene in its molecular frame.In addition, the insulation property of it is as good as epoxy resin and silicone resin. However, 1,4-polybutadiene polyol is in the form of liquid with high viscosity so that it is unsuitable for potting.Therefore, by the means of mixing ricinoleic polyol of a low viscosity, the workablitiy of 1,4~polybutadiene(Polybutadiene)polyol will be substantially improved without deteriorating other properties.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.