Dual tube lower frame midrail structure

A lower frame rail assembly for a rear-end portion of an automobile, said frame assembly supporting a shock tower assembly and a rear bumper, comprising:

• an interior tubular member having a height dimension and a width dimension;
• an exterior tubular member having height and width dimensions substantially equal to said interior tubular member;
• said interior and exterior tubular members being welded together to form a first longitudinally extending portion with adjacent sidewalls of said tubular members defining a generally vertically oriented internal web;
• said interior and exterior tubular members diverging from said first longitudinally extending portion to form a divergent portion such that a lateral distance spaces said interior tubular member from said exterior tubular member;
• and
• a shock tower support member welded to said interior and exterior tubular members where said tubular members are divergent to provide separate interior and exterior support for said shock tower support member.

An automotive frame corresponding to a rearward portion of an automotive vehicle, comprising:

• first and second laterally spaced lower frame rails, each said lower frame rail being formed from an interior tubular member and an exterior tubular member oriented laterally from one another, said tubular members forming:
• a first longitudinally extending portion wherein said interior and exterior tubular members are welded together along a seam between said tubular members;
• a divergent portion forwardly of said first longitudinally extending portion where said interior and exterior tubular members diverge to define a lateral distance therebetween;
• and
• a second longitudinally extending portion forwardly of said divergent portion where said interior and exterior tubular portions are welded together;
• and
• a plurality of cross frame members interconnecting said first and second lower frame rails between the corresponding said divergent sections.