Butt jointed closed section hollow structural element

Abstract

A method is provided which forms a closed section hollow structural element by performing the following steps which include press forming an upper sheet metal component configured with two primary parallel downstanding interface flanges; press forming a lower sheet metal component configured with two primary parallel upstanding interface flanges; complementarily trimming the downstanding interface flanges and the upstanding interface flanges using five-axis laser cutting; and butt welding the interface flanges of the upper and lower sheet metal components to one another to form a continuous hollow structural element of variable cross section.

Claims

1. A method of forming a vehicular suspension subframe comprising: forming four closed section hollow structural elements of variable cross section, wherein the forming of each of the four closed section hollow structural elements comprises: press forming an upper sheet metal component with a generally open section and configured with two primary parallel downstanding interface flanges; press forming a lower sheet metal component with a generally open section and configured with two primary parallel upstanding interface flanges; complementarily trimming edges of the downstanding interface flanges and the upstanding interface flanges using five-axis laser cutting, while the upper and lower sheet metal components are held in a dimensional compliance in a fixture and in engagement with spacer blocks while maintaining the upper and lower sheet metal components at a predetermined distance during the complementarily trimming; removing the spacer blocks subsequent to performing the complementary trimming; butt welding the downstanding interface flanges and the upstanding interface flanges of the upper and lower sheet metal components to one another, while continuing to rigidly hold the upper and lower sheet metal components in the fixture, to form each of the four continuous closed section hollow structural elements of variable cross section; and securing the four closed section hollow elements of variable cross section with each other to create the vehicular suspension subframe.

2. The method of forming the vehicular suspension subframe as defined in claim 1, wherein the butt welding the downstanding interface flanges and the upstanding interface flanges of the upper and lower sheet metal components comprises a continuous laser butt weld.

3. The method of forming the vehicular suspension subframe as defined in claim 1, which further comprises subsequent to the removing of the spacer blanks, moving the upper sheet metal component and the lower sheet metal component into contact with each other while continuing to rigidly hold them in the fixture, and during the butt welding, structurally attaching the upper and lower metal sheet components along an interface by a butt weld.

4. A method of forming a continuous closed section hollow structural element of variable cross section comprising: press forming an upper sheet metal component with a generally open section and configured with two primary parallel downstanding interface flanges; press forming a lower sheet metal component with a generally open section and configured with two primary parallel upstanding interface flanges; complementarily trimming edges of the downstanding interface flanges and the upstanding interface flanges using five-axis laser cutting, while the upper and lower sheet metal components are held in a dimensional compliance in a fixture and in engagement with spacer blocks and maintaining the upper and lower sheet metal components at a predetermined distance during the complementarily trimming; removing the spacer blocks subsequent to performing the complementary trimming; and butt welding the downstanding interface flanges and the upstanding interface flanges of the upper and lower sheet metal components to one another, while maintaining the upper and lower sheet metal components in the fixture, to form the continuous closed section hollow structural element of variable cross section.

5. The method of forming the continuous closed section hollow structural element as defined in claim 4, wherein the upper and lower sheet metal members are clamped to one another by a first fixture member and a second fixture member of the fixture during the butt welding and with the spacer blocks removed.

6. The method of forming the continuous closed section hollow structural element as defined in claim 4, wherein the continuous closed section hollow structural element of variable cross section has a length, a width and a height, the length greater than the width and the height, wherein the butt welding creates a butt welding joint between the downstanding interface flanges and the upstanding interface flanges, and the butt welding joint extending along the length when the continuous closed section hollow structural element is formed.

7. A method of forming a closed section hollow structural vehicular suspension arm of variable cross section comprising: press forming an upper sheet metal component with a generally open section and configured with two primary parallel downstanding interface flanges; press forming a lower sheet metal component with a generally open section and configured with two primary parallel upstanding interface flanges; complementarily trimming edges of the downstanding interface flanges and the upstanding interface flanges using five-axis laser cutting, while the upper and lower sheet metal components are held in a dimensional compliance in a fixture and in engagement with spacer blocks while maintaining the upper and lower sheet metal components at a predetermined distance during the complementarily trimming; removing the spacer blocks subsequent to performing the complementary trimming; and butt welding the downstanding interface flanges and the upstanding interface flanges of the upper and lower sheet metal components to one another, while continuing to rigidly hold the upper and lower sheet metal components in the fixture, to form the continuous closed section hollow structural vehicular suspension arm of variable cross section.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 is a perspective view of the inventive closed section hollow element;

(2) FIG. 2 is an expanded perspective view of the inventive closed section hollow element;

(3) FIG. 3 is a perspective view of the components of the inventive closed section hollow element partially installed in the purpose built fixture;

(4) FIG. 4 is a perspective view of the purpose built fixture with the components of the inventive closed section hollow element fully installed and trimmed;

(5) FIG. 5 is a perspective view of the purpose built fixture with the components of the inventive closed section hollow element fully installed during laser welding;

(6) FIG. 6 is a perspective view of an application of the inventive closed section hollow element;

(7) FIG. 7 is a perspective view of a further application of the inventive closed section hollow element;

(8) FIG. 8 is a perspective view of another application of the inventive closed section hollow element.

DETAILED DESCRIPTION

(9) Referring to FIGS. 1 and 2, a closed section hollow element (1) is substantially constructed from an upper sheet metal stamped component (10) and a lower sheet metal stamped component (20). Both of the sheet metal stamped components are manufactured by press forming a flat sheet of steel, aluminum or other suitable metal or alloy into a required open section shape which is dictated by the final application's structural and packaging requirements. The upper sheet metal stamped component (10) is configured with two primarily parallel downstanding interface flanges (12)(14). As shown in the non-limiting example of FIGS. 1 and 2, the lower sheet metal stamped component (20) is configured with two primarily parallel upstanding interface flanges (22)(24). The downstanding interface flanges (12)(14) of the upper sheet metal component (10) are five-axes laser trimmed after press forming to create highly accurate interface edges (16)(18). The upstanding interface flanges (22)(24) of the lower sheet metal component (20) are five-axes laser trimmed after press forming to create highly accurate interface edges (26)(28). The interface edges (16)(18)(26)(28) are complementarily trimmed via a five-axes laser during a single operation while the upper sheet metal stamped component (10) and a lower sheet metal stamped component (20) are rigidly held in dimensional compliance by a purpose built fixture. In this manner the interface edges (26)(28) of the upstanding interface flanges (22)(24) and the interface edges (16)(18) of the downstanding interface flanges (12)(14) are configured to tightly match with a zero gap. This zero gap interface (also referred to as interface) facilitates a high quality non-linear weld (30) that structurally attaches the upper sheet metal stamped component (10) and the lower sheet metal stamped component (20) so as to create a continuous hollow structural element (1) having a variable cross section.

(10) FIG. 3 illustrates a non-limiting example of a purpose built fixture (40) configured to rigidly hold the upper sheet metal stamped component (10) and lower sheet metal stamped component (20) with the sheet metal stamped components shown prior to installation in the purpose built fixture (40) held at a pre-determined distance by the spacer blocks (42). FIG. 4 illustrates the purpose built fixture (40) with the upper sheet metal stamped component (10) and lower sheet metal stamped component (20) fully installed in the fixture (40) and the interface edges (16)(18)(26)(28) having been complementarily trimmed via a five-axes laser. The scrap material (50)(52) that contains inaccurate formed edges (54)(56) is shown detached from the interface flanges (12)(14)(22)(24).

(11) FIG. 5 illustrates the purpose built fixture (40) with the spacer blocks retracted (42) and the upper sheet metal stamped component (10) and lower sheet metal stamped component (20) brought into contact with each other along their previously laser trimmed interface edges (16)(18)(26)(28) creating a zero gap condition. A laser beam (60) is illustrated completing a welded butt joint (30) by butt welding along the entire zero gap interface so as to create a continuous hollow structural element (1) of a variable cross section.

(12) FIG. 6 illustrates a non-limiting example of a vehicular suspension arm (70) configured as a closed section hollow element of a variable cross section constructed using the manufacturing technique previously described.

(13) FIG. 7 illustrates a non-limiting example of a vehicular motor compartment rail (72) configured as a closed section hollow element of a variable cross section constructed using the manufacturing technique previously described.

(14) FIG. 8 illustrates a non-limiting example of a vehicular suspension subframe (74) configured from four closed section hollow elements of variable cross section constructed using the manufacturing technique previously described.