| 摘要 |
<p>A revolving frame (11) is composed of a center frame (12) and a tail frame (30). The center frame (12) is composed of a front bottom plate (13) and left and right front vertical plates (14, 17) erected on the front bottom plate (13) and having front part sides being left and right bracket portions (14A, 17A) performing pin-connection between a lower boom (5A) of a working mechanism (5) and a boom cylinder (5E). The tail frame (30) is composed of left and right I-section beams (31, 32) and a rear bottom plate (33) connecting each I-section beam (31, 32) to each other. A height dimension (A) between boom pin through holes (15A, 18A) provided in the bracket portions (14A, 17A) is set smaller than a height dimension (B) of the front end of an upper flange portion (31B, 32B) of the I-section beam (31, 32).</p> |
