A valve mechanism includes an orifice collar having a hollow portion penetrating in an axial direction, a valve body having a central hole and an opening portion which penetrate in the axial direction and arranged so as to come into contact with an axial end surface of the orifice collar, and a drive valve which is movable in the axial direction and is arranged on an opposite side of the orifice collar with the valve body as a boundary, where the valve body includes spoke valves, each of which includes an outer frame portion, an inner frame portion, and a plurality of spoke portions connecting the outer frame portion 74 and the inner frame portion, and a protective valve which protects the spoke portion when the spoke portion of the spoke valve is deformed.