Damper device

A damper device, comprising:

• a cylinder unit including an internal space having a contacting inner wall surface;
• a piston unit having a piston head that has an outer circumferential portion that slides on the contacting inner wall surface of the cylinder unit and that divides the internal space of the cylinder unit into a first gas chamber and a second gas chamber, a rod that extends from an end of the piston head on a side of the second gas chamber, and a hole with a bottom that opens on the piston head on a side of the first gas chamber and that extends through an inside of the rod toward the side of the second gas chamber;
• and
• a guide shaft having a base portion that is fixed on the cylinder unit on a side of the first gas chamber, a shaft portion that extends from the base portion toward a side of the piston unit, coaxial with a sliding center axis of the piston unit, and a tip portion that is provided on a tip of the shaft portion and that has an outer peripheral surface that slides on an inner wall surface of the hole with the bottom of the piston unit, wherein
• in the piston unit, the hole with the bottom is guided along the outer peripheral surface of the guide shaft, and the outer circumferential portion is guided on the contacting inner wall surface of the cylinder unit, to move along the sliding center axis, such that the first gas chamber and the second gas chamber act as a damper with respect to a movement of the piston unit.