Linear load limiter apparatus and method
First Claim
1. A method for optimizing the interaction between an airbag, a seat belt, and a seat belt load limiter in a vehicle impact, the method comprising:
- determining a desired total restraint force profile, the desired total restraint force profile describing a desired total restraint force exerted on a vehicle occupant for each of a plurality of values of an impact-related variable;
determining an airbag force profile, the airbag force profile describing the force exerted by the airbag on the occupant for each of the plurality of values of the impact-related variable; and
determining a desired seat belt force profile describing a desired seat belt force exerted on the occupant for each of the plurality of values of the impact-related variable, the step of determining the desired seat belt force profile including, for each of the plurality of values of the impact-related variable, subtracting the corresponding airbag force from the corresponding desired total restraint force.
13 Assignments
0 Petitions
Accused Products
Abstract
A method for coordinating the restraint forces provided by a seat belt load limiter and a vehicle airbag is provided. The method includes determining a desired total restraint force profile, determining the airbag force profile, and determining a desired seat belt force profile from the desired total restraint force profile and the airbag profile. The method preferably includes determining a load-limiting force profile sufficient to substantially achieve the desired seat belt force profile, and determining the profile of a load limiter system variable sufficient to substantially achieve the load-limiting force profile. A load limiter is also provided that is characterized by a variable load-limiting force. The load-limiter includes a tube characterized by a tube wall thickness, and a deformation apparatus slidably engaged in the tube for linear translation therein. The deformation apparatus is configured to plastically deform the tube during linear translation to generate a load-limiting force. The tube wall thickness varies over the length of the tube such that the load-limiting force varies during linear translation of the piston.
-
Citations
8 Claims
-
1. A method for optimizing the interaction between an airbag, a seat belt, and a seat belt load limiter in a vehicle impact, the method comprising:
-
determining a desired total restraint force profile, the desired total restraint force profile describing a desired total restraint force exerted on a vehicle occupant for each of a plurality of values of an impact-related variable; determining an airbag force profile, the airbag force profile describing the force exerted by the airbag on the occupant for each of the plurality of values of the impact-related variable; and determining a desired seat belt force profile describing a desired seat belt force exerted on the occupant for each of the plurality of values of the impact-related variable, the step of determining the desired seat belt force profile including, for each of the plurality of values of the impact-related variable, subtracting the corresponding airbag force from the corresponding desired total restraint force. - View Dependent Claims (2, 3, 4, 5, 6, 7)
-
-
8. A method for designing a load-limiter apparatus, the method comprising:
-
determining a desired load-limiting force magnitude (F) for the load-limiter apparatus, the load-limiter apparatus having a tube characterized by a tube wall thickness (t) and comprised of a material having a yield strength (σ
0);
a piston supported in the tube for linear translation within the tube;
at least one ramp on the piston; and
a quantity (n) of rolling elements having radius (r) located between said at least one ramp and said tube;
wherein the load limiting force is attributable to, during the energy absorbing stroke of the piston, each of the quantity of rolling elements plastically deforming the tube by plowing a groove therein at a penetration depth (p), and friction between the tube and the quantity of rolling elements, the tube and the quantity of rolling elements having a coefficient of friction (μ
); andselecting the value of at least one of the yield strength, quantity of rolling elements, radius of rolling elements, penetration depth, rube wall thickness, and coefficient of friction such that the relationship
-
Specification