SHOCK ABSORBER

To provide a shock absorber which can inhibit occurrence of noise without causing increase in the weight of a vehicle and grasp vibration of an unsprung member without difficult installation work.SOLUTION: A shock absorber 1 includes: a shock absorber body 2 having a cylinder 6 which is connected to a wheel (an unsprung member) W of a vehicle V, and a rod 8 which gets into/out from the cylinder 6 to move relative to the cylinder 6 and is connected to a vehicle body (a sprung member) B of the vehicle V; a solenoid valve (a damping force adjuster) 3 which can adjust a damping force generated during expansion/contraction of the shock absorber body 2 according to an amount of a supplied electric current; and an electric current control unit 5 which is attached to the cylinder 6 and supplies an electric current to the solenoid valve (the damping force adjuster) 3 based on a control command received from an ECU (a control device) 4 mounted on the vehicle V. The electric current control unit 5 includes an unsprung acceleration sensor 5c.SELECTED DRAWING: Figure 3 【課題】車両の重量の増加を招かず、ノイズの発生を抑制できるとともに、面倒な設置作業を伴わずにばね下部材の振動を把握できる緩衝器を提供する。【解決手段】緩衝器１は、車両Ｖの車輪（ばね下部材）Ｗに連結されるシリンダ６とシリンダ６内に出入りしてシリンダ６に対して相対移動可能であって車両Ｖの車体（ばね上部材）Ｂに連結されるロッド８とを有する緩衝器本体２と、供給される電流量に応じて緩衝器本体２の伸縮時に発生する減衰力を調整可能なソレノイドバルブ（減衰力調整装置）３と、シリンダ６に取り付けられて、車両Ｖに搭載されるＥＣＵ（制御装置）４から受け取る制御指令に基づいてソレノイドバルブ（減衰力調整装置）３に電流供給する電流制御ユニット５とを備え、電流制御ユニット５は、ばね下加速度センサ５ｃを備えている。【選択図】図３