Method of making composite laminate automotive structures

DETAILED DESCRIPTION In one aspect, the present invention provides a hollow laminate beam characterized by its high-stiffness-to-mass ratio.
The beam has an outer portion which is separated from an inner tube by a thin layer of structural foam.
The cavity defined by the beam may be open or closed along its length.
In another aspect, the hollow laminate beam of the present invention is an automotive radiator support beam having an outer metal section and a generally rectangular inner tube, which may be open on one side.
At least three sides of the rectangular inner tube are coated with a structural foam which is disposed between the rectangular inner tube and the outer metal section and in contact therewith.
A metal cap is welded in place to complete the beam and retain the inner tube.
The diameter of any through holes in the inner tube which are in alignment with through-holes in the outer portion are larger than the outer portion through-holes such that the structural foam does not block the through-hole clearances of either metal thicknesses.
In still another aspect, the laminate beam of the present invention is an automotive windshield pillar.
A hollow metal tube is disposed within the pillar and is separated from the outer pillar stampings by a thin layer of structural foam.
In still another aspect, the laminate beam of the present invention is an automotive rocker panel assembly.
The rocker panel assembly comprises mating inner and outer panel sections which form a generally rectangular rocker panel wall structure.
Positioned within the rocker panel wall structure is a closely fitting inner metal tube which defines a cavity.
A thin layer of structural foam is disposed between the rocker panel wall structure and the inner tube structure.
In still another aspect the beam is a motor vehicle drive shaft.
An inner tube is closely received within the outer drive shaft housing, thereby defining an annulus.
A layer of foam is disposed in the annulus.
The present invention also provides a method of increasing the stiffness-to-mass ratio of a beam, wherein the beam defines a cavity