JPS5639334A - 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 respective damping properties on the side of extension at the time when the vehicle is loaded or unloaded. CONSTITUTION:The shock absorber is constituted by providing 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 and used exclusively when the vehicle is unloaded, as well as the 2nd port 11 making the oil in the upper chamber 6 flow toward the lower chamber 7 through the intermediary of the 2nd extension-side damping valve 9 and used exclusively when the vehicle is loaded, and by providing a sleeve 12 opening or closing those ports 10 or 11 selectively corresponding to the relative change in position of a piston 4. Accordingly, the damping property meeting the respective requirements on the occasion that the vehicle is loaded or unloaded can be furnished independently and optionally. Especially, the rate of change in 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 on the occasion that the piston 4 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.