Variable rate bound stoppers and variable rate suspension systems containing variable rate bound stoppers
AssigneeToyota Motor Engineering & Manufacturing North America, Inc.
InventorAria Kashani
Life of this patent
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Abstract
A variable rate bound stopper includes a bound stopper in the form of an elastomer member. The elastomer member has an aperture such that the bound stopper is configured to be positioned over and disposed around a piston rod of a shock absorber. A shape memory alloy (SMA) coil formed from an SMA wire extends around at least a portion of the elastomer member. The SMA coil has a relaxed state and an activated state. The SMA coil constrains the elastomer member from deforming radially outward and alters an intrinsic spring rate of the bound stopper when in the activated state.
Claims20
A variable rate bound stopper comprising:
- a bound stopper comprising an elastomer member with an aperture, the bound stopper configured to be positioned over and disposed around a piston rod of a shock absorber;
- a shape memory alloy (SMA) coil formed from an SMA wire extending around at least a portion of the elastomer member, the SMA coil comprising a relaxed state and an activated state, wherein:
- the SMA coil constrains the elastomer member from deforming radially outward in both the relaxed state and the activated state thereby altering an intrinsic spring rate of the bound stopper in both the relaxed state and the activated state.
A shock absorber comprising:
- a cylinder and a piston rod extending from the cylinder;
- a bound stopper comprising an elastomer member positioned onto and disposed around the piston rod;
- and
- at least two shape memory alloy (SMA) coils extending around at least a portion of the elastomer member, wherein:
- each of the at least two SMA coils comprise a relaxed state and an activated state;
- each of the at least two SMA coils constrain the elastomer member from deforming radially outward when in the activated state;
- an intrinsic spring rate of the bound stopper is altered when the at least two SMA wires are in the activated state;
- wherein the bound stopper has a first spring rate when one of the at least two SMA coils is in the activated state and constrains the elastomer member;
- and
- the bound stopper has a second spring rate when another of the at least two SMA coils is in the activated state and constrains the elastomer member.
A variable rate vehicle suspension system comprising:
- a cylinder and a piston rod extending from the cylinder;
- a bound stopper comprising an elastomer member with an aperture, wherein the piston rod extends through the aperture such that the bound stopper is disposed around the piston rod;
- at least two shape memory alloy (SMA) coils extending around at least a portion of the elastomer member;
- and
- a vehicle stability control (VSC) electronic control unit (ECU) and an electrical power source in communication with each of the at least two SMA coils, the VSC ECU configured to activate the electrical power source and the electrical power source configured to provide an activation electric current to each of the at least two SMA coils when the electrical power source is activated, wherein:
- each of the at least two SMA coils comprise a relaxed state and an activated state;
- each of the at least two SMA coils constrain the elastomer member from deforming radially outward when in the activated state;
- an intrinsic spring rate of the bound stopper is altered when the at least two SMA wires are in the activated state;
- wherein the bound stopper has a first spring rate when one of the at least two SMA coils is in the activated state and constrains the elastomer member;
- and
- the bound stopper has a second spring rate when another of the at least two SMA coils is in the activated state and constrains the elastomer member.
Dependencies are inferred from the claim text.