Cylinder device

A cylinder device, comprising:

• a guide member configured to be fixed in a circumferential direction and an axial direction;
• a piston member configured to be fixed in the circumferential direction and displaced in the axial direction;
• a piston rod configured to be displaced in the circumferential direction and the axial direction;
• and
• a conversion mechanism configured to convert a portion of a displacement in the axial direction of the piston member into a displacement in the circumferential direction, and to transmit the displacement in the circumferential direction to the piston rod,
• wherein the conversion mechanism is disposed at a portion in which the guide member, the piston member, and the piston rod overlap in a radial direction, and
• the conversion mechanism includes:
• a displacement switching groove provided in either one of the guide member or the piston member, and including an axially directed part configured to extend in the axial direction, and a circumferentially directed part configured to extend in the circumferential direction, the axially directed part and the circumferentially directed part being connected in an L-shape;
• a helical groove provided in another one of the guide member or the piston member, disposed so as to overlap the displacement switching groove in the radial direction, and inclined with respect to the axial direction;
• and
• a link pin supported by the piston rod, and configured to extend in the radial direction, to be inserted into the displacement switching groove and the helical groove, and to move along the displacement switching groove and the helical groove.