SHOCK ABSORBER

To provide a shock absorber that can change only the damping force during extension or contraction even if comprising a needle valve.SOLUTION: A shock absorber D comprises: a cylinder 1; a piston 2 that is inserted into the cylinder 1 so as to be movable in an axial direction; a piston rod 3 that is inserted into the cylinder 1 and connected to the piston 2; a shock absorber body DB having a plurality of working chambers R2, 4 filled with liquid; a first path P1 and a bypass path PB that allow communication between the working chambers R2, 4; a damping valve 5 that is provided in the first path P1, and applies resistance to a flow of liquid from one working chamber R2 to another working chamber 4; a check valve 6 that is provided in the bypass path PB, and allows only a flow of liquid from the one working chamber R2 to the other working chamber 4; and a needle valve 7 that is provided in series with the check valve 6 in the bypass path PB, and capable of changing the area of a flow path.SELECTED DRAWING: Figure 4 【課題】ニードルバルブを備えていても伸長時或いは収縮時の減衰力のみを変更可能な緩衝器を提供する。【解決手段】本発明の緩衝器Ｄは、シリンダ１と、シリンダ１内に軸方向移動可能に挿入されるピストン２と、シリンダ１内に挿入されるとともにピストン２に連結されるピストンロッド３と、液体が充填される複数の作動室Ｒ２，４とを有する緩衝器本体ＤＢと、作動室Ｒ２，４同士を連通する第１通路Ｐ１およびバイパス路ＰＢと、第１通路Ｐ１に設けられて一方の作動室Ｒ２から他方の作動室４へ向かう液体の流れに抵抗を与える減衰バルブ５と、バイパス路ＰＢに設けられて一方の作動室Ｒ２から他方の作動室４へ向かう液体の流れのみを許容するチェックバルブ６と、バイパス路ＰＢにチェックバルブ６と直列に設けられて流路面積を変更可能なニードルバルブ７とを備えている。【選択図】 図４