Method of manufacturing a vehicle frame member with a subframe attachment mount

A method of providing a subframe mount in an automotive frame member including a pair of laterally disposed hydroformed tubular members, each of which having an inner wall and an outer wall, said tubular members being welded together such that said inner walls are positioned adjacent one another to define an internal web in said automotive frame member, comprising the steps of:

• forming a semi-cylindrical vertically oriented depression in said inner wall of each said tubular member, said semi-cylindrical depressions defining a cylindrical pocket within said internal web having an inlet therein accessible from externally of said frame member;
• creating a first opening in said outer wall of one of said tubular members, said opening being located opposite of said depression, and a second opening in said inner wall into said depression, said first and second openings being aligned;
• establishing a slot in said inner and outer walls of each said tubular member, said slots in said one tubular member being adjacent said first and second openings, respectively;
• affixing a cylindrical mounting member to a mounting plate;
• and
• positioning said cylindrical mounting member and said mounting plate through said first and second openings and said slots to locate said cylindrical mounting member within said cylindrical pocket.

A method of forming an automotive frame member with a subframe mount, comprising:

• hydroforming a first tubular member with a semi-cylindrical depression in a first vertically oriented wall with a first opening in a second vertically oriented wall opposite said semi-cylindrical depression, with a second opening in said first wall into said semi-cylindrical depression, said first and second openings being aligned, and with a slot passing through each of said first and second walls adjacent said first and second openings, respectively;
• hydroforming a second tubular member with a semi-cylindrical depression in a first vertically oriented wall with a slot passing through each of said first wall into said semi-circular depression and a second vertically oriented wall in alignment with said slot in said first wall of said second tubular member;
• securing said first and second tubular members together such that said semi-circular depressions therein are opposed to form a cylindrical pocket, said first walls of said first and second tubular members forming an internal web for said automotive frame member, said slots in said first and second tubular members being aligned;
• affixing a cylindrical mounting member to a mounting plate to define a subframe mount;
• and
• positioning said cylindrical mounting member and said mounting plate through said first and second openings and said slots to locate said cylindrical mounting member within said cylindrical pocket.