Shock absorber having bidirectional valve and flow restricting passage parallel to the valve

A shock absorber comprising:

• a cylinder body;
• a piston received in said cylinder body and cooperating with said cylinder body to define two chambers on opposite sides of said piston, one and the other of said two chambers respectively functioning as a high-pressure chamber and a low-pressure chamber in which a pressure of a working fluid is lower than that in said high-pressure chamber;
• a piston rod fixed to said piston;
• a damping force control device including (i) a hard valve which permits a flow of said working fluid from said high-pressure chamber toward said low-pressure chamber when a difference between the pressures in the high-pressure and low-pressure chambers is larger than a predetermined threshold, (ii) a soft valve which permits the flow of the working fluid from said high-pressure chamber toward said low-pressure chamber when said difference is not larger than said threshold, and (iii) a variable flow restrictor device for controlling a cross sectional area of flow of the working fluid through a hard-valve by-passing passage formed in parallel with said hard valve;
• both of said hard valve and said soft valve permitting a flow of said working fluid therethrough from said high-pressure chamber toward said low-pressure chamber during both elongation and contraction of an assembly consisting of said cylinder body and said piston rod;
• and
• said hard and soft valves being disposed in respective two axially opposite portions of said piston which partially define said two chambers, respectively, said piston having an intermediate fluid passage connecting said hard and soft valves, said hard-valve by-passing passage being open at one of opposite ends thereof to one of said two chambers which is located on the side of said hard valve, and at the other end thereof to said intermediate fluid passage.

A shock absorber comprising:

• a cylinder body;
• a piston received in said cylinder body and cooperating with said cylinder body to define two chambers on opposite sides of said piston, one and the other of said two chambers respectively functioning as a high-pressure chamber and a low-pressure chamber in which a pressure of a working fluid is lower than that in said high-pressure chamber;
• a piston rod fixed to said piston;
• a damping force control device including (i) a hard valve which permits a flow of said working fluid from said high-pressure chamber toward said low-pressure chamber when a difference between the pressures in the high-pressure and low-pressure chambers is larger than a predetermined threshold, (ii) a soft valve which permits the flow of the working fluid from said high-pressure chamber toward said low-pressure chamber when said difference is not larger than said threshold, and (iii) a flow restricting hard-valve by-passing passage which has a function of restricting a flow of the working fluid therethrough and which is disposed in parallel with said hard valve;
• and
• at least one of said hard valve and said soft valve permitting a flow of said working fluid therethrough from said high-pressure chamber toward said low-pressure chamber during both elongation and contraction of an assembly consisting of said cylinder body and said piston rod.

A shock absorber comprising:

• a cylinder body;
• a piston received in said cylinder body and cooperating with said cylinder body to define two chambers on opposite sides of said piston, one and the other of said two chambers respectively functioning as a high-pressure chamber and a low-pressure chamber in which a pressure of a working fluid is lower than that in said high-pressure chamber;
• a piston rod fixed to said piston;
• a damping force control device including (i) a hard valve which permits a flow of said working fluid from said high-pressure chamber toward said low-pressure chamber when a difference between the pressures in the high-pressure and low-pressure chambers is larger than a predetermined threshold, (ii) a soft valve which permits the flow of the working fluid from said high-pressure chamber toward said low-pressure chamber when said difference is not larger than said threshold, and (iii) a flow restricting hard-valve by-passing passage which has a function of restricting a flow of the working fluid therethrough and which is disposed in parallel with said hard valve;
• and
• both of said hard valve and said soft valve permitting a flow of said working fluid therethrough from said high-pressure chamber toward said low-pressure chamber during both elongation and contraction of an assembly consisting of said cylinder body and said piston rod, said hard and soft valves being disposed in respective two axially opposite portions of said piston which partially define said two chambers, respectively;
• and
• said piston having an intermediate fluid passage connecting said hard and soft valves, said flow restricting hard-valve by-passing passage being open at one of opposite ends thereof to one of said two chambers which is located on the side of said hard valve, and at the other end thereof to said intermediate fluid passage.

A shock absorber comprising:

• a cylinder body;
• a piston received in said cylinder body and cooperating with said cylinder body to define two chambers on opposite sides of said piston, one and the other of said two chambers respectively functioning as a high-pressure chamber and a low-pressure chamber in which a pressure of a working fluid is lower than that in said high-pressure chamber;
• a piston rod fixed to said piston;
• a damping force control device including (i) a hard valve which permits a flow of said working fluid from said high-pressure chamber toward said low-pressure chamber when a difference between the pressures in the high-pressure and low-pressure chambers is larger than a predetermined threshold, (ii) a soft valve which permits the flow of the working fluid from said high-pressure chamber toward said low-pressure chamber when said difference is not larger than said threshold, (iii) a flow restricting soft-valve by-passing passage which has a function of restricting a flow of the working fluid therethrough and which is disposed in parallel with said soft valve, and (iv) a variable flow restrictor device for controlling a cross sectional area of flow of the fluid through said flow restricting soft-valve by-passing passage.

A shock absorber comprising:

• a cylinder body;
• a piston received in said cylinder body and cooperating with said cylinder body to define two chambers on opposite sides of said piston, one and the other of said two chambers respectively functioning as a high-pressure chamber and a low-pressure chamber in which a pressure of a working fluid is lower than that in said high-pressure chamber;
• a piston rod fixed to said piston;
• a damping force control device including (i) a hard valve which permits a flow of said working fluid from said high-pressure chamber toward said low-pressure chamber when a difference between the pressures in the high-pressure and low-pressure chambers is larger than a predetermined threshold, (ii) a soft valve which permits the flow of the working fluid from said high-pressure chamber toward said low-pressure chamber when said difference is not larger than said threshold, and (iii) at least one of (a) a first variable flow restrictor device for controlling a cross sectional area of flow of the fluid through a soft-valve by-passing passage which is disposed in parallel with said soft valve, and (b) a second variable flow restrictor device for controlling a cross sectional area of flow of the fluid through a hard-valve by-passing passage which is disposed in parallel with said hard valve;
• and
• at least one of said hard valve and said soft valve permitting a flow of said working fluid therethrough from said high-pressure chamber toward said low-pressure chamber during both elongation and contraction of an assembly consisting of said cylinder body and said piston rod.

A shock absorber;

• comprising:
• a cylinder body;
• a piston received in said cylinder body and cooperating with said cylinder body to define two chambers on opposite sides thereof, one and the other of said two chambers respectfully functioning as a high-pressure chamber and a low-pressure chamber in which a pressure of a working fluid is lower than that in said high-pressure chamber;
• a piston rod fixed to said piston;
• a valve device which permits a flow of said working fluid from said high-pressure chamber toward said low-pressure chamber;
• and wherein said valve device includes two leaf valves superposed on each other and consisting of a first leaf valve and a second leaf valve which has two portions, and wherein said first and second leaf valves are arranged such that said first leaf valve is superposed on one of said two portions of said second leaf valve and is not superposed on the other of said two portions of said second leaf valve, and such that the number of said leaf valves to be flexed concurrently changes depending upon an operating state of the shock absorber, and such that both of said first and second leaf valves are flexed with substantially no separation thereof from each other, for thereby permitting said flow of said working fluid when two of the leaf valves are flexed and such that said second leaf valve is flexed while said first leaf valve is displaced as a result of the flexure of said second leaf valve which serves as a flexing fulcrum for supporting said first leaf valve when said second leaf valve is flexed, for thereby permitting said flow of said working fluid when one of the leaf valves is flexed.