| 摘要 |
PROBLEM TO BE SOLVED: To adjust the rigidity ratio between the X- and Y-axial directions without lowering the durability by constituting a side wall of a pressure receiver chamber of vertical side walls extending from the inner cylinder and a lateral side wall extending from the end of the vertical side walls to an outer cylinder and by forming recessed parts in the external faces of both the side walls with a strut part left in the center. SOLUTION: A side wall 16 of a pressure receiver chamber 18 is constituted of vertical side walls 32 extending from an inner cylinder 10 in the X-axial direction and a lateral side wall 34 extending from the end of the vertical side walls 32 to an outer cylinder 12 in the Z-axial direction and recessed parts 36 recessed in the outside faces of the lateral side wall 34 in the Z-axial direction. A strut part, 37 is left in the center in the Z-axial direction of the lateral side wall 34. The vertical side walls 32 are provided only in a range of the pressure receiver chamber 18 and the both vertical side walls 32 are communicated with each other by the lateral side wall 34 so that the outward swelling in the compression can be prevented. On the other hand, the wall thickness of the lateral side wall 34 is thinned in the recessed part, 36 so as to lower the X-axial rigidity. However, the formation of the recessed part, 36 hardly lowers the Y-axial rigidity. This constitution can appropriately set the rigidity ratio between the X- and Y axes by changing the shape of the recessed part. |
