JPS5639331A - Shock absorber - Google Patents

Abstract

PURPOSE:To enable automatic change of the damping property of the shock absorber corresponding to the loadage of a vehicle by enabling free setting of the damping property on the side of extension at the time when the vehicle is loaded or unloaded, respectively. CONSTITUTION:The shock absorber is constituted by the 1st port 10 making the oil in an upper chamber 6 flow toward a lower chamber 7 through the intermediary of the 1st extension-side damping valve 8 leading only in one direction, the 2nd port 11 provided along with the former and making the oil in the upper chamber 6 low toward the lower chamber 7 through the valve 8 and the 2nd extension-side damping valve 9, and a sleeve 12 opening or closing selectively the 1st or 2nd ports 10 or 11 according to the relative change in position of a piston 4. Therefore, the damping property meeting the respective requirements under the conditions that a vehicle is loaded or unloaded can be furnished. Especially, the rate of change of the damping force on the extension side at the time when the vehicle is loaded or unloaded can be set extensively and optionally and, therefore, the property of the piston at the time when it operates at a low speed can be improved. In addition, since the type of a leaf valve is adopted for the damping valves 8 and 9, the device can be made compact and the basic length of the absorber can be shortened.