Patent Application
20120211318
An embodiment relates generally to real time damping devices within a vehicle.
Vehicles utilize damping devices to control or smooth movement between two members of a vehicle that may produce an oscillation. These damping devices typically are piston-type devices that include two fluid filled chambers that control motion or oscillation by transferring fluid between chambers utilizing hydraulic gates and valves. Damping is often controlled by regulating a resistance of the fluid flow between the piston chambers. Typically such piston-type devices utilize flow channels having a set size to transfer the flow of fluid out of the primary chamber. However, having flow channels of a fixed size will result in a same damping response for smoothing movement between two vehicle components, and therefore, cannot provide an effective real-time damping that adjusts to the particular vehicle conditions. Magnetorheological (MR) fluid may be used to variably control the flow of fluid out of the pressure chamber; however, with additional cost and design complexity.
An advantage of an embodiment is a real-time variable control of the flow of fluid between a first chamber and a second chamber of a damping module by variably controlling a position of a damper in a damping assembly that couples two vehicle members. The variable control of the damper is controlled utilizing magnetic shape memory elements regulated by an electromagnetic field. The position of the damper may be regulated in real time to variably control the flow of fluid through an opening of a flow channel between the first chamber and the second chamber thereby controlling the relative movement or oscillation between two vehicle members. Another advantage of magnetic shape memory elements is the quick response time that allows for enhanced control of fluid flowing through the opening of the flow channel.
An embodiment contemplates a real-time continuous damping module. A cylindrical tubular member contains a fluid. The cylindrical tubular member includes a first chamber and a second chamber for receiving and storing fluid. A pressurizing device is configured to pressurize fluid in the first chamber. A flow channel is configured to allow fluid to flow between the first chamber and second chamber when the pressurizing device exerts a pressure on the fluid within the first chamber. A variable damper assembly is configured to control a flow of fluid through the flow channel. The variable damper assembly includes a damper configured to variably obstruct an opening of the flow channel. A magnetic shape memory element is configured to variably control a position of the damper within the opening of the flow channel. The magnetic shape memory element exhibits changes in shape when exposed to a magnetic field. An electromagnetic device is configured to generate the magnetic field across the magnetic shape memory element. The electromagnetic device regulates the magnetic field for variably controlling the position of the damper within the flow channel by changing the shape of the magnetic shape memory element.
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The real-time continuous damping module 10 includes a cylindrical tubular member 12 containing a fluid 14. The cylindrical tubular member 12 may be a single-tube construction or may be a twin-tube construction where the two tubes slide axially relative to one another. The cylindrical tubular member 12 includes a first chamber 16 and a second chamber 18 for retaining the fluid 14. The fluid 14 is pressurized in the first chamber 16 and is forced to the second chamber 18 that functions as a reservoir. The transition of the fluid from the first chamber 16 to the second chamber 18 affects the stiffness or compression force between the two vehicle components. By variably regulating the amount of fluid that is able to flow out of the first chamber 16 to the second chamber 18 when the first chamber is pressurized, the damping between the two components may be variably controlled.
A variable damper assembly 20 is disposed within the cylindrical tubular member 12 for controlling a flow of fluid through a flow channel 21 between the first chamber 16 and the second chamber 18. More than one flow channel may be incorporated within the variable damper assembly 20. The variable damper assembly 20 may be incorporated as part of a pressurizing device acting on the first chamber 16, such as a piston, or may be separate from the pressurizing device.
A magnetic shape memory element 24 is configured to act on the damper 22 to control a position of the damper 22 relative to the opening of the flow channel 21. The magnetic shape memory element 24 exhibits changes in its shape when exposed to a magnetic field for variably displacing the damper 22 over the opening of the flow channel 21.
The variable damper assembly 20 further includes an electromagnetic device 26 that is configured for generating a magnetic field across the magnetic shape memory element 24. The electromagnetic device 26 includes a core 28, such as a ferromagnetic core, and a coil 30 wound around the core 28 for generating the magnetic field. The strength of the magnetic field depends on the current supplied to the coil 30, in addition to the cross-section area of the core 28, and the number of turns and the cross-section area of the wire of the coil 30. Varying the strength of the magnetic field generated by the electromagnetic device 26 will vary the expansion of the magnetic shape memory element 24.
While certain embodiments of the present invention have been described in detail, those familiar with the art to which this invention relates will recognize various alternative designs and embodiments for practicing the invention as defined by the following claims.
