PURPOSE: To easily manufacture lattice members and a joint member, to make it possible to easily cope with variations in a joint angle, etc., and to facilitate the control of welding and the control of degree of accuracy.
CONSTITUTION: The end 11a of a lattice member 11 of a round pipe is at a right angle to the central axis thereof, and a joint member 12 is formed as a hollow body. The hollow body is formed in the shape of a circle in a plan view, and formed in the shape including a drum type cutting off the upper side and lower side of a spherical body in a font view, an opening 11b of the end of the lattice member 11 is fitted to a spherical surface 12a around the joint member 12, and the end surface of the end 11a of the lattice member 11 and the spherical surface 12a of the joint member 12 make an acute angle so as to face them to each other. The end surface of the end 11a of the lattice member is welded to the spherical surface 12a of the joint member, and the lattice member 11 is connected to the joint member 12. Accordingly, even if an angle, a position, etc., against the joint member of the lattice member are varied, the central axis of the lattice member passes through the center of the spherical surface of the joint member, so that the same lattice member and joint member can be used.
SOGA YUTAKA
MIZUTANI NAOKI
OKAMURA KIYOSHI
MARUOKA YOSHIOMI
