| 摘要 |
PURPOSE:To prevent a guide bush from being dropped from a housing and improve the durability of the guide bush by providing expanded inner diameter section at both ends in the axial direction of a housing hole at the open end of a cylinder. CONSTITUTION:The hole 14a of a housing 14 has a cylindrical shape at the center area 20 in the axial direction and has expanded inner diameter sections 21 at both ends in the axial direction. A guide bush 15 fixed to the inner periphery of a back metal 15a is fitted to the inner wall surface of this hole 14a. This device is constituted by entering the guide bush 15 by pressure in the axial direction of the inner wall surface of the hole 14a and caulking both ends of the guide bush 15 to the expanded inner diameter sections of the hole 14a. Thereby, the escape load of the guide bush 15 is increased and its durability is improved. |
