| 摘要 |
<p>A hydraulic shock absorber includes a generally vertical cylinder receiving therein hydraulic liquid, a piston working in the cylinder and partioning the interior thereof into two liquid chambers,an upper and a lower chamber. Two sets of one or more damping force generating check valves are mounted on the piston, one set generating the damping force in the expansion stroke and another set allowing free flow from the lower (2) to the upper (1) chamber in the compression stroke. A piston rod is secured to the piston extending through the end of the cylinder to the outside. Said sets of valves constitute connections between the two liquid chambers (1,2), a liquid reservoir (3) connected to the lower liquid chamber (2) by a third set of check valves generating the damping force in the compression stroke and allowing a return free flow from the reservoir (3) to the lower chamber (2) in the expansion stroke. An improved damping control is achieved by a circuit (10) forming a connection between the two liquid chambers (1, 2), a further circuit (9) connecting the reservoir (3) to the lower liquid chamber (2), each of the two circuits (9, 10) including a controllable first check valve (C1) and second check valve (C2), respectively, that can each take two states of operation under the action of a control means (20), in a first state locking the valve in a closed position cutting off the forward flow (E1 and E2 respectively) through the check valve (C1 and C2 respectively), and in a second state allowing a free forward flow (E1 and E2 respectively) through the check valve (C1 and C2 respectively), whereas the check valve (C1, C2) in the first state as well as in the second state block the reverse flow (D1 and D2 respectively) of both circuits (9, 10).</p> |
