Damper device

A damper device configured to be attached between a pair of members that are configured to approach and separate from each other, and applying a braking force when the pair of members approach or separate from each other, the damper device comprising:

• a cylinder having a cylindrical shape having an internal space, an opening at one end portion, and a vent hole and a valve seat at another end portion, the vent hole communicating with the internal space;
• and
• a piston configured to reciprocate in the cylinder, wherein
• an elastically deformable valve body is provided at the other end portion of the cylinder and abuts against the valve seat before and when the piston moves in a damper braking direction, and at least a part of the valve body separates from the valve seat when the piston moves in a return direction opposite to the damper braking direction,
• the valve seat surrounds the vent hole and protrudes in a direction opposite to the internal space, and is formed with a vent groove that extends from an outer periphery of the valve seat toward the vent hole and communicates with the vent hole,
• a part of the valve seat that faces the valve body is configured to serve as an inclined surface whose protrusion amount gradually decreases from a side of the outer periphery of the valve seat toward the vent hole,
• the vent groove includes a first groove that extends from an outer periphery of the inclined surface toward the vent hole such that a depth thereof with respect to the inclined surface gradually decreases, and
• when the piston moves in the damper braking direction, the valve body comes into contact with the inclined surface and is elastically deformed along the inclined surface, and a contact area with the inclined surface widens.