Damper device

A damper device comprising:

• a cylinder having a cylindrical shape and closed at both ends;
• a piston provided on a shaft end of a piston rod that pierces through one end of the cylinder, and disposed without a gap in the cylinder so as to be freely reciprocated in an axial direction of the cylinder;
• a free piston provided between the other end of the cylinder and the piston, and disposed without a gap in the cylinder so as to be freely reciprocated in the axial direction of the cylinder;
• a partition wall fixed to the cylinder between the piston and the free piston and partitioning inside of the cylinder into spaces in the axial direction of the cylinder;
• a partition wall orifice composed of an orifice that pierces through the partition wall;
• a piston orifice composed of an orifice that pierces through the piston;
• a viscous fluid filled into a liquid chamber that is formed between the free piston and the one end of the cylinder in the cylinder;
• a compressible gas filled into a gas chamber that is formed between the free piston and the other end of the cylinder in the cylinder;
• a partition wall-side flow variable structure configured to regulate a flow rate of the viscous fluid passing through the partition wall orifice;
• a piston-side flow variable structure configured to regulate a flow rate of the viscous fluid passing through the piston orifice;
• and
• a control unit configured to control the partition wall-side flow variable structure and the piston-side flow variable structure,
• wherein the control unit controls the partition wall-side flow variable structure and the piston-side flow variable structure so as to allow the flow rate of the viscous fluid passing through the piston orifice to become larger than the flow rate of the viscous fluid passing through the partition wall orifice.