| 摘要 |
PURPOSE:To maintain the tightness of the lower face of the external peripheral wall of a piston head to the external peripheral flange of a piston rod even by gas pressure or thermal expansion force by fastening them with an external peripheral bolt so as to remove a certain gap which is defined while they are in the unloaded state. CONSTITUTION:An internal wall 1a which is formed on a piston head 1 and a piston rod 2 are fastened with an internal peripheral bolt 3 at the internal peripheral fitting faces A thereof. The lower face of the external peripheral wall 1b of the piston head 1 and the external peripheral flange 2a of the piston rod 2 have a certain gap (corresponding to a thermal deformation of the piston head 1) therebetween while umloaded. Under the condition, if both are fastened with the external peripheral bolt 4 until the piston rod 2 and the external peripheral fitting face B of the piston head are closely fit to each other, the fastening may be maintained by gas pressure and thermal expansion force because the piston head 1 is supported by both the internal and external peripheral wall faces even while a piston is cold. |
