| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a method of relatively inexpensively manufacturing a lightweight and highly-rigid blade for generation of electricity by wind or water power with metallic material. <P>SOLUTION: First, a hollow metallic girder 5 having a substantially quadrangular transverse section is prepared, and then the hollow metallic girder 5 is installed in a hollow metallic tubular material M4. Both ends of the hollow metallic tubular material M4 receiving the hollow metallic girder 5 therein are sealed by seal means (21, 31) and liquid is filled in the hollow metallic girder 5 and the metallic tubular material M4. By applying press working to the metallic tubular material M4 containing the metallic girder 5 and the liquid therein with press dies (12, 14), the metallic tubular material M4 is formed into an aerofoil shape the transverse section of which is approximate to a streamlined shape, without substantially changing the shape of the transverse section of the metallic girder 5. Thus, it is possible to obtain the aerofoil-shaped blade for generation of electricity by wind or water power, which incorporates the hollow metallic girder 5 therein. <P>COPYRIGHT: (C)2007,JPO&INPIT |
