Methods and apparatus for controlling a fluid damper
A spring for a suspension is described. The spring includes: a spring chamber divided into at least a primary portion and a secondary portion, and a fluid flow path coupled with and between the primary portion and the secondary portion. The fluid flow path includes a bypass mechanism, wherein the bypass mechanism is configured for automatically providing resistance within the fluid flow path in response to a compressed condition of the suspension.
1. A damper comprising:
a damper body having a longitudinal axis and at least partially defining a fluid chamber containing damping fluid;
a piston rod, a portion of said piston rod movable along the longitudinal axis of, and within, said damper body, wherein during a compression stroke, said portion of said piston rod moves further into said damper body at least partially within a first portion of said fluid chamber;
an enclosed fluid chamber disposed within said damper, said enclosed fluid chamber at least partially bounded by a first movable member separating said first portion of said fluid chamber from said enclosed fluid chamber, said enclosed fluid chamber at least partially bounded by a second movable member;
a gas-filled chamber disposed within said damper, said second movable member separating said enclosed fluid chamber from said gas-filled chamber;
said enclosed fluid chamber having a variable rheology fluid disposed therein, said enclosed fluid chamber at least partially displaceable by said damping fluid wherein movement of said enclosed fluid chamber causes a volume change in said gas-filled chamber; and
a magnet disposed within said enclosed fluid chamber, said magnet configured to provide a magnetic field which affects said variable rheology fluid.
2. The damper of claim 1 , wherein said magnet selectively produces a magnetic field within the enclosed fluid chamber to bring about a change in said rheology fluid.
3. The damper of claim 2 , wherein a portion of said rheology fluid travels through an orifice in said magnet when said enclosed fluid chamber is displaced.
4. The damper of claim 3 , wherein said orifice of said magnet is coated with an abrasion resistant material.
5. The damper of claim 1 wherein said magnet is an electromagnet.
6. The damper of claim 5 wherein said electromagnet is remotely actuatable.
7. The damper of claim 6 further comprising:
a logic/control unit coupled with said electromagnet for controlling operation of said electromagnet.
8. The damper of claim 7 wherein said logic/control unit controls said electromagnet based upon an input provided from a vehicle to which said damper is coupled.
9. The damper of claim 8 wherein said input is selected from the group consisting of: wheel speed, damper piston velocity, and piston rod position.
10. The damper of claim 1 , wherein said first movable member comprises a flexible end-wall permitting said enclosed fluid chamber to be displaced relative to said magnet.
11. The damper of claim 1 , wherein said second movable member comprises a flexible end-wall permitting said enclosed fluid chamber to be displaced relative to said magnet.
12. The damper of claim 1 , wherein said rod includes a valve assembly configured to control flow of said damping fluid.
13. The damper of claim 1 , wherein said variable rheology fluid comprises a magneto-resistive (MR) fluid.
14. The damper of claim 1 , wherein said gas-filled chamber is filled with a pressurized gas.