| 摘要 |
PROBLEM TO BE SOLVED: To decide a characteristic of the force, which is to be generated by an actuator, on the basis of the only spring constant of a plate spring without lowering the durability of a seal member. SOLUTION: In this device, a peripheral part of a partitioning wall forming member 11A is formed with a rib part 11d, which is projected from a top surface side of the member 11A and connected in the circumferential direction, so as to enlarge the area of the peripheral surface of the partitioning wall forming member 11A. Outer diameter of the partitioning wall forming member 11A is enlarged, and a cross dimension (a) of a clearance between the peripheral surface of the partitioning wall forming member 11A and an upper spacer 5. Thickness of a seal member 16 is increased and the volume thereof is secured so that the seal member 16 is fixed between the peripheral surface of the rib 11d and the upper spacer 5, and a spring constant of the seal member 16 in the thickness direction (vertical direction) is reduced, and a spring constant thereof in the cross direction (horizontal direction) is increased so that the seal member is form soft in the thickness direction and hard in the cross direction. Spring constant of the seal member 16 in the thickness, direction is set sufficiently smaller in comparison with a spring constant of a plate spring 13 in the same direction. |
