| 摘要 |
PROBLEM TO BE SOLVED: To suppress the increase in the number of parts and number of assembly processes by integrating a piston body consisting of the resin material with a piston stem to easily improve the accuracy. SOLUTION: In a servo piston 16, a piston body 17 mainly consisting of the resin material is integrated with a piston stem 18 to be erected in the axial direction from the piston body 17 along its sliding direction. Fitting grooves 4b, 4a to which large and small D rings 4d, 4c are fitted are formed on the outer circumferential surface of the piston body 17. Left and right screw parts 20, 21 are spirally formed on the outer circumferential surface of the piston stem at a piston body fixing part 19 of the piston stem 18, and the strength in the shearing direction is increased to prevent detachment of the piston stem 18 from the piston body 17. Integration of the piston body 17 dispenses with the machining with excellent accuracy of an outer peripheral edge part. |
