| 摘要 |
PROBLEM TO BE SOLVED: To provide a low-cost bend by enabling mass-production within the severe range for allowable errors by forming two rectangular holes for connecting as to form a double side corner respectively on an inner surface to change the direction and on a stepwise transition face on the outer surface to change the direction. SOLUTION: The bend C is composed of a hexagon block having two orthogonal connecting faces F1 and F2 between which an internal guide tunnel is formed by machining. Actually, this tunnel is composed of two orthogonal hole parts A1 and A2 having rectangular cross sections respectively formed from the faces F1 and F2. These two orthogonal hole parts A1 and A2 are joined on the inner side to change the direction, form the linear double side corner having an apex point S and form a transition plane P to cut a corner section almost at 45 deg. formed from a flight of steps G while facing toward the apex point S on the outer side to change the direction. These steps G are linearly formed. |
