Abstract: A piping joint that enables welding without back shielding and without oxidized scaling on the pipe's inner surface. A piping joint has an inner fitting portion formed around the circumference of an end of a first tubular material, and a first bevel is formed on the radial outside of the inner fitting portion around the circumference. An outer fitting portion, fitted to the radial outside of the inner fitting portion, is formed on the end of a second tubular material butt welded to the first tubular material, and a second bevel is formed around the circumference at the end of the outer fitting portion facing the first bevel. The cross-section of the face of the inner fitting portion located on the radial outside, and the cross-section of the face of the outer fitting portion located on the radial inside, are completely round with a constant circumferential curvature.

Abstract: An object is to provide a piping joint structure that enables welding without back shielding, and in which oxidized scale does not occur on the inner surface side of the pipe.

Abstract: A method and apparatus is provided for automating an operation to determine a trace of a tool to be moved, which is used for processing a reference surface of a solid such as an electrode or the like in a numerical controlled discharge machine tool. An origin position is set on the basis of figure information including an origin position mark, which was read from an electrode drawing, a reference surface position is recognized, a processing range is set on the basis of the set origin position and figure information, the number of times of cutting with the tool is calculated on the basis of information regarding the process including the processing range and a cutting amount of the tool, and after that, the trace of the tool to be moved is determined on the basis of the information obtained so far. Since the reference surface position is automatically recognized, it is unnecessary for a human to form a drawing of the reference surface for the electrode drawing.

Abstract: A data preparation device for preparation of data to be used in machining a work is arranged not only to prepare a relief shape by expanding a machining target shape inputted but also to prepare, as an interference critical shape, a shape which is higher than a machining height inputted and to prepare a machining area on the basis of the relief shape and the interference critical shape.