| 摘要 |
<P>PROBLEM TO BE SOLVED: To enhance workability during formation of a plurality of kinds of revolving frame. <P>SOLUTION: When forming a plurality of kinds of revolving frame 11, 41, and 71 constituting upper revolving bodies 3, 33, and 63 having different turning radiuses, a curvature radius of arc parts 20A, 24A, and 24B provided in the revolving frame 11, a curvature radius of arc parts 50A, 54A, and 54C provided in the revolving frame 41, and a curvature radius of arc parts 80A, 84A, and 84C provided in the revolving frame 71 are set to the same value as the turning radius R1 of an upper revolving body 3. Thus, the arc parts 20A, 24A, 24B of the revolving frame 11, the arc parts 50A, 54A, 54C of the revolving frame 41, and the arc parts 80A, 84A, 84C of the revolving frame 71 can be formed using only a common arc part molding die 27, and the workability can be enhanced when forming these different kinds of revolving frame 11, 41, 71. <P>COPYRIGHT: (C)2012,JPO&INPIT |
