Patent ID: 11933382
Assignee: SOMIC MANAGEMENT HOLDINGS INC.
Field: Mechanical elements (Mechanical engineering)
Classification: CPC F | IPC F

Claim 2:
3. A volume change compensation device connected to a hydraulic fluid housing portion which liquid-tightly houses hydraulic fluid including liquid to compensate for a change in a volume of the hydraulic fluid, the volume change compensation device comprising:
a body tube formed in a tubular shape and having a first opening which communicates with the hydraulic fluid housing portion, the body tube housing part of the hydraulic fluid;
an inner cylinder piston formed in a cylindrical shape with a bottom portion and an opened end that is positioned opposite the bottom portion, the inner cylinder piston being slidably provided in the body tube along an axis direction in a state in which the part of the hydraulic fluid is housed;
an inner cylinder inner small piston slidably provided along the axis direction in the inner cylinder piston;
an inner cylinder piston pressing elastic body provided in the body tube, the inner cylinder piston pressing elastic body being positioned away from the first opening farther than the inner cylinder piston and elastically pressing the inner cylinder piston toward the first opening; and
a fixing tool configured to fix the inner cylinder inner small piston to the bottom portion of the inner cylinder piston,
wherein the inner cylinder piston is arranged in such an orientation that the opened end of the inner cylinder piston is closer to the first opening of the body tube than the bottom portion, and
an air hole for an air flow into the inner cylinder piston is formed at the bottom portion of the inner cylinder piston.