| 摘要 |
PURPOSE:To obtain a light and rigid structure without damaging property of material of a machine tool body by welding a reinforcing member being different from the machine tool body material in mechanism property to structure members such as bed, column, etc., of the machine tool monolithically. CONSTITUTION:A cross girder 5 of a gantry type boring machine is made of casting material, and provided with partition walls vertically and horizontally to increase its rigidity. A sliding face 11 is formed in front of the cross girder 5. Maximum bending moment is generated in the central part of the cross girder 5, compressive stresses are generated on the upper face 12, and tensile stresses and generated on the underside 13. Thus, in order for the underside 13 to withstand the tensile stresses, a reinforcing member 14 made of I-beam is welded to the underside. For this welding, the reinforcing member 14 is previously buried in a mold, and a molten cast metal is then poured into the mold. By melting heat of the molten cast metal, only the portion adjacent to the surface of the reinforcing member 14, the components of cast iron metal and steel are fused as a unit, and both the metals are welded. When the cast iron and steel are cooled, both metals are firmly welded to form a welded junction 15. |
