Patent ID: 7275626

Claim:
A damper device, comprising: an approximately tubular cylinder; a rotary shaft which is rotatably arranged in the inside of the cylinder and forms wing portions on an outer peripheral portion of an approximately columnar shaft in a state that the wing portions project to an inner wall of the cylinder; two side walls which are formed in a spaced-apart manner between the rotary shaft and the inner wall of the cylinder; an oil chamber which is defined by said two side walls, the rotary shaft and the inner wall of the cylinder and in which a viscous fluid is filled; movement restricting flow passages which restrict the movement of the viscous fluid between front-side oil chambers with respect to a rotational direction of the rotary shaft and rear-side oil chambers with respect to the rotational direction of the rotary shaft which are formed by dividing the oil chamber with the wing portions, the movement restricting flow passages being formed between the inner wall of the cylinder and the wing portions; and selective communication passages which are provided with check valves which selectively restrict the movement of the viscous fluid from the front-side oil chambers to the rear-side oil chambers in response to the rotational direction of the rotary shaft, the selective communication passages being formed between the wing portions and one of the two side walls, and the side walls and the check valves being rotatable along with a rotation of the wing portions, the check valves including valve elements and being arranged in a state that the valve elements, which are brought into and out of contact with the wing portions, are movable in the circumferential direction of the rotary shaft, whereby a rotation resistance force having directivity is applied to the rotary shaft due to the flow resistance which is generated when the viscous fluid moves from the front-side oil chambers to the rear-side oil chambers, the valve elements being constituted by forming valve element portions which are brought into and out of contact with the wing portions on an approximately circular annular ring portion which is loosely fitted on the rotary shaft.