Upper slewing body and operating machine having the same

Abstract

An upper frame has a bottom plate, a pair of vertical plates that are provided to stand on the bottom plate so as to face each other in a right-left direction, and a left side frame configuring a part of a rim part of the upper frame. An attachment is supported on a support parts provided in front of the slewing bearing in vertical plates. A left vertical plate has a rear curved part, behind the support part, which is curved forming a convex shape directed toward an opposite side of a right vertical plate in a planar view. The upper slewing body further has a first coupling member for coupling the left side frame and the left vertical plate to each other so as to prevent the left vertical plate from being deformed in a direction in which the rear curved part approaches the right vertical plate.

What is claimed is: 
     
         1 . An upper slewing body that is provided on a lower propelling body of an operating machine so as to be able to slew,
 the upper slewing body comprising:
 an upper frame that has a bottom plate that is supported on the lower propelling body via a slewing bearing so as to be able to slew, first and second vertical plates that are provided to stand on the bottom plate so as to face each other in a right-left direction and to extend in a front-back direction, and a side frame fixed to the bottom plate and configuring a part of a rim part of the upper frame, the vertical plates each having a support part located in front of the slewing bearing; and 
 an attachment that is supported on the support parts of the vertical plates so as to be able to rise and fall, 
   wherein the first vertical plate has a curved part, behind the support part, which is curved to form a convex shape directed toward an opposite side of the second vertical plate in a planar view, and   the upper slewing body further comprises a first coupling member for coupling the side frame and the first vertical plate to each other so as to prevent the first vertical plate from being deformed in a direction in which the curved part approaches the second vertical plate.   
     
     
         2 . The upper slewing body according to  claim 1 , wherein
 the side frame is provided at a position opposite to the second vertical plate with respect to the first vertical plate, and   the first coupling member is fixed to and disposed between the side frame and the first vertical plate.   
     
     
         3 . The upper slewing body according to  claim 2 , wherein
 the first vertical plate includes a curved rear part extending rearward from the curved part and a curved front part extending forward from the curved part in a manner that the curved front part comes closer to the second vertical plate toward the front direction, and   the first coupling member is welded to a front end part of the curved rear part so as to be substantially perpendicular to the curved rear part of the first vertical plate.   
     
     
         4 . The upper slewing body according to  claim 3 , further comprising a second coupling member for coupling the curved front part of the first vertical plate and the second vertical plate to each other so as to prevent the first vertical plate from being deformed in a direction in which the curved part approaches the second vertical plate and a direction in which the curved part separates from the second vertical plate. 
     
     
         5 . The upper slewing body according to  claim 1 , wherein
 the side frame is formed from a tubular member that has a circumferential wall provided in a range of the entire circumference around an axis along a longitudinal direction of the side frame, and   the first coupling member is fixed to the circumferential wall of the side frame.   
     
     
         6 . The upper slewing body according to  claim 1 , wherein
 a section in the side frame to which the first coupling member is connected has a greater height than a section in the first vertical plate to which the first coupling member is connected.   
     
     
         7 . The upper slewing body according to  claim 1 , wherein
 the first coupling member is fixed to at least an upper part of the first vertical plate.   
     
     
         8 . An operating machine that has:
 the upper slewing body according to  claim 1 , and   a lower propelling body that supports the upper slewing body via the slewing bearing so as to allow the upper slewing body to slew.