Internally reinforced hydroformed assembly and method of making same

Abstract

An internally reinforced hydroformed assembly and method of making same includes a hydroformed tubular member and a reinforcement disposed within the hydroformed tubular member prior to hydroforming. The internally reinforced hydroformed assembly and method of making same also includes at least one weld to secure the reinforcement to an interior surface of the hydroformed tubular member.

Description

TECHNICAL FIELD

The present invention relates generally to hydroformed assemblies and, more particularly, to an internally reinforced hydroformed assembly and method of making same for automotive structures.

BACKGROUND OF THE INVENTION

It is known to hydroform tubular components or members. Hydroformed tubular members are becoming increasingly popular in automotive body structural applications. During vehicle body manufacturing, many of the hydroformed tubular members are used in vehicle body and chassis applications. However, vehicle strength, stiffness, and/or impactworthiness often necessitate the need for local areas of structural reinforcement to meet their design goals.

Vehicle structure often requires boxed tubular members such as beams for strength, stiffness, and impactworthiness. Generally, there are two types of boxed beams, either stamped or hydroformed. Hydroforming is a cost effective process to produce a boxed beam and offers an advantage over stamped boxed beams for quality and benefit for cost and stiffness. A hydroformed beam only requires one weld along the length of the beam to close the section compared with stamped boxed beams that require two welds, which adds cost, mass, and increased welding.

One method for reinforcing a hydroformed tubular member is to provide an exterior reinforcement after the hydroformed tubular member such as a hydroformed beam has been formed. However, exterior reinforcements on hydroformed beams can create packaging problems and costly design tear-ups. Another method is to add internal reinforcements after the hydroformed beam has been formed. For example, after the hydroformed beam has been formed, processes are added to cut open an access window, load and position metal reinforcements, and weld the reinforcement in place. After the reinforcements are added, a metal cover is positioned over the access hole and welded around the perimeter. However, adding internal reinforcements to hydroformed tubular members after the hydroformed tubular member has been formed is cost prohibitive compared to stamped box constructions.

As a result, it is desirable to provide a new internally reinforced hydroformed tubular member. It is also desirable to provide a hydroformed tubular member that is locally and internally reinforced prior to the hydroforming process. It is further desirable to provide a method of locally and internally reinforcing a hydroformed tubular member. Therefore, there is a need in the art to provide a new reinforced hydroformed assembly and method of making same that meets these desires.

SUMMARY OF THE INVENTION

It is, therefore, one object of the present invention to provide a new internally reinforced hydroformed assembly.

It is another object of the present invention to provide a new method of making an internally reinforced hydroformed assembly.

To achieve the foregoing objects, the present invention is an internally reinforced hydroformed assembly including a hydroformed tubular member and a reinforcement disposed within the hydroformed tubular member prior to hydroforming. The internally reinforced hydroformed assembly also includes at least one weld to secure the reinforcement to an interior surface of the hydroformed tubular member.

Also, the present invention is a method of making an internally reinforced hydroformed assembly. The method includes the steps of providing a reinforcement and providing a channel shaped member with the reinforcement disposed therein. The method also includes the steps of forming the channel shaped member into a tubular member with the reinforcement internally therein. The method further includes the steps of hydroforming the tubular member and reinforcement together to form a locally and internally reinforced hydroformed tubular member.

One advantage of the present invention is that an internally reinforced hydroformed assembly is provided for a vehicle to locally and internally reinforce a hydroformed tubular member. Another advantage of the present invention is that a method of making an internally reinforced hydroformed assembly is provided to form a locally and internally reinforced hydroformed tubular member. Yet another advantage of the present invention is that the assembly and method adds an internal reinforcement prior to the hydroforming process for the tubular member to capture the packaging benefits of internal reinforcement without incurring the additional cost of post hydroform reinforcement processing. Still another advantage of the present invention is that the assembly and method improves hydroform structural performance and part quality. A further advantage of the present invention is that the assembly and method reduces manufacturing costs. Yet a further advantage of the present invention is that the assembly and method adds design flexibility to locally and internally reinforce hydroformed tubular members for crashworthiness, strength, and/or stiffness improvements.

Other objects, features, and advantages of the present invention will be readily appreciated, as the same becomes better understood, after reading the subsequent description taken in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a fragmentary elevational view of an internally reinforced hydroformed assembly, according to the present invention.

FIG. 2 is a fragmentary elevational view of another embodiment, according to the present invention, of the internally reinforced hydroformed assembly of FIG. 1.

FIG. 3 is a fragmentary elevational view of yet another embodiment, according to the present invention, of the internally reinforced hydroformed assembly of FIG. 1.

FIG. 4 is a fragmentary elevational view of a reinforcement for the internally reinforced hydroformed assembly, according to the present invention.

FIG. 5 is a fragmentary elevational view of another embodiment of a reinforcement for the internally reinforced hydroformed assembly, according to the present invention.

FIG. 6 is a fragmentary elevational view of yet another embodiment of a reinforcement for the internally reinforced hydroformed assembly, according to the present invention.

FIG. 7 is a fragmentary elevational view of still another embodiment, according to the present invention, of the internally reinforced hydroformed assembly of FIG. 1.

FIG. 8 is a fragmentary elevational view of a further embodiment, according to the present invention, of the internally reinforced hydroformed assembly of FIG. 1.

FIGS. 9A and 9B are fragmentary elevational views illustrating a first step of a method, according to the present invention, of making an internally reinforced hydroformed assembly.

FIG. 10 is a fragmentary elevational view illustrating a second step of the method of making an internally reinforced hydroformed assembly.

FIG. 11 is a fragmentary elevational view illustrating a third step of the method of making an internally reinforced hydroformed assembly.

FIG. 12 is a fragmentary elevational view illustrating a fourth step of the method of making an internally reinforced hydroformed assembly.

FIG. 13 is a fragmentary elevational view illustrating a second step of another embodiment, according to the present invention, of the method of making an internally reinforced hydroformed assembly.

FIG. 14 is a fragmentary elevational view illustrating a third and fourth step of the method of making an internally reinforced hydroformed assembly of FIG. 13.

FIG. 15 is a fragmentary elevational view illustrating a fifth step of the method of making an internally reinforced hydroformed assembly of FIG. 13.

FIG. 16 is a fragmentary elevational view of yet a further embodiment, according to the present invention, of the internally reinforced hydroformed assembly of FIG. 1.

DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring to the drawings and in particular FIG. 1, one embodiment of an internally reinforced hydroformed assembly 10, according to the present invention, is shown for assembly in automotive structures (not shown) of a vehicle (not shown). The internally reinforced hydroformed assembly 10 includes at least one tubular component or member 12 and a reinforcement 14 disposed within the tubular member 12. The tubular member 12 and reinforcement 14 are made of a metal material. In one embodiment, the tubular member 12 has a generally rectangular cross-sectional shape and extends axially and the reinforcement 14 has a generally “L” cross-sectional shape and extends axially. The reinforcement 14 is disposed within the tubular member 12 and is joined to an interior side of the tubular member 12 to overlap a portion of the tubular member 12 by a suitable fastening mechanism such as welds 16. In the embodiment illustrated, the reinforcement 14 overlaps a corner of the tubular member 12. It should be appreciated that the reinforcement 14 is called a “metal double up” because it adds a double metal thickness in an area that is locally reinforced. It should also be appreciated that the tubular member 12 is similar to a boxed beam.

Referring to FIG. 2, another embodiment, according to the present invention, of the internally reinforced hydroformed assembly 10 is shown. Like parts of the internally reinforced hydroformed assembly 10 have like reference numerals increased by one hundred (100). In this embodiment, the internally reinforced hydroformed assembly 110 includes the tubular member 112 and the reinforcement 114. In the embodiment illustrated, the reinforcement 114 has a generally “C” cross-sectional shape and extends axially. The reinforcement 114 is disposed within the tubular member 112 and is joined to an interior side of the tubular member 112 to overlap a portion of the tubular member 112 by a suitable fastening mechanism such as welds 116. In the embodiment illustrated, the reinforcement 114 is located along one side and overlaps two corners of the tubular member 112. It should be appreciated that the reinforcement 114 is called a “metal double up” because it adds a double metal thickness in an area that is locally reinforced.

Referring to FIG. 3, yet another embodiment, according to the present invention, of the internally reinforced hydroformed assembly 10 is shown. Like parts of the internally reinforced hydroformed assembly 10 have like reference numerals increased by two hundred (200). In this embodiment, the internally reinforced hydroformed assembly 210 includes the tubular member 212 and the reinforcement 214. In the embodiment illustrated, the reinforcement 214 has a generally rectangular cross-sectional shape and extends axially. The reinforcement 214 is disposed within the tubular member 212 and is joined to an interior side of the tubular member 212 to overlap a portion of the tubular member 212 by a suitable fastening mechanism such as welds 216. In the embodiment illustrated, the reinforcement 214 overlaps the full or entire interior perimeter of the tubular member 212. It should be appreciated that the reinforcement 214 is called a “metal double up” because it adds a double metal thickness in an area that is locally reinforced.

Referring to FIG. 4, another embodiment of the reinforcement 14 is shown. Like parts of the reinforcement 14 have like reference numerals increased by three hundred (300). In this embodiment, the reinforcement 314 is a generally flat or planar plate that extends axially. In the embodiment illustrated, the reinforcement 314 is generally rectangular in cross-sectional shape. It should be appreciated that the reinforcement 314 is called a “bulkhead” because it has a shape that traverses a section to locally reinforce it from section distortion and “oil canning” under load.

Referring to FIG. 5, the reinforcement 114 is shown. In this embodiment, the reinforcement 114 has a generally “C” cross-sectional shape and extends axially. It should be appreciated that the reinforcement 114 is called a “bulkhead” because it has a shape that traverses a section to locally reinforce it from section distortion and “oil canning” under load.

Referring to FIG. 6, yet another embodiment of the reinforcement 14 is shown. Like parts of the reinforcement 14 have like reference numerals increased by four hundred (400). In this embodiment, the reinforcement 414 has a generally flanged “C” or top hat cross-sectional shape and extends axially. It should be appreciated that the reinforcement 414 is called a “bulkhead” because it has a shape that traverses a section to locally reinforce it from section distortion and “oil canning” under load.

Referring to FIG. 7, still another embodiment, according to the present invention, of the internally reinforced hydroformed assembly 10 is shown. Like parts of the internally reinforced hydroformed assembly 10 have like reference numerals increased by five hundred (500). In this embodiment, the internally reinforced hydroformed assembly 510 includes the tubular member 512 and reinforcement 514. The reinforcement 514 has a generally “C” cross-sectional shape and extends axially. The reinforcement 514 is disposed within the tubular member 512 and joined to one interior side of the tubular member 512 by a suitable fastening mechanism such as welds 516. The tubular member 512 may have the opposed interior side with at least one, preferably a plurality of slots 517 extending therethrough. The reinforcement 514 is joined to the opposed interior side by a suitable fastening mechanism such as welds 516. In the embodiment illustrated, the internally reinforced hydroformed assembly 510 may include another tubular member such as a bracket 518 disposed against and joined to the tubular member 512 opposite the reinforcements 514 by a suitable fastening mechanism such as welds 516.

Referring to FIG. 8, still another embodiment, according to the present invention, of the internally reinforced hydroformed assembly 10 is shown. Like parts of the internally reinforced hydroformed assembly 10 have like reference numerals increased by six hundred (600). In this embodiment, the internally reinforced hydroformed assembly 610 includes the tubular member 612 and the reinforcement 614. In this embodiment, the reinforcement 614 has a generally flanged “C” or top hat cross-sectional shape and extends axially. The reinforcement 614 has a base wall 614a and a pair of opposed side walls 614b extending generally perpendicular to the base wall 614a. The reinforcement 614 also has a flange wall 614c extending generally perpendicular to each of the side walls 614b. The reinforcement 614 is disposed within the tubular member 612. The flange walls 614c are joined to one interior side of the tubular member 612 by a suitable fastening mechanism such as welds 616. The tubular member 612 may have the opposed interior side with at least one, preferably a plurality of slots 517 extending therethrough. The base wall 614a of the reinforcement 614 is joined to the opposed interior side by a suitable fastening mechanism such as welds 616. In the embodiment illustrated, the internally reinforced hydroformed assembly 610 may include another tubular member such as a bracket 618 disposed against and joined to the tubular member 612 opposite the side walls 614b of the reinforcement 614 by a suitable fastening mechanism such as welds 616.

Referring to FIGS. 9A through 12, one embodiment of a method, according to the present invention, of making an internally reinforced hydroformed assembly 10 is shown for assembly in automotive structures (not shown) of a vehicle (not shown). The method adds the reinforcement to the tubular member prior to hydroforming. The method is used to double up metal internally within the hydroform.

The method includes the step of providing a tubular member 712. The tubular member 712 is made of a metal material. In one embodiment, the tubular member 712 has a generally rectangular cross-sectional shape and extends axially.

The method also includes the step of providing a reinforcement 714. The method includes the step of forming the reinforcement 714. The method includes the step of forming a planar shaped member by trimming a flat or planar blank 720 from a coil 722 of metal material as illustrated in FIGS. 9A and 9B. The method includes the step of joining the reinforcement to a surface of the planar shaped member by welding a flat or planar reinforcement 714 to a surface of the blank 720 to produce welds 716 therebetween as illustrated in FIG. 10. It should be appreciated that the welds 716 may be stitch, spot, laser, and/or continuous. It should also be appreciated that the location of the reinforcement 714 is usually determined from product impactworthiness, stiffness, and/or strength requirements.

The method further includes the step of providing a channel shaped member 724 with the reinforcement 714 disposed therein. The method includes the step of forming the blank 720 and welded reinforcement 714 into a channel shaped member 724 with a die form operation as illustrated in FIG. 11. The blank and welded reinforcement is placed in a die set, generally indicated at 726, comprised of an upper die half 728 and a lower die half 730. The upper die half 728 includes projection portion 732 and the lower die half 730 includes a cavity portion 734 for receiving the blank 720 and welded reinforcement 714 and the projection portion 732. The upper die half 728 and lower die half 730 are progressively closed so that the blank 720 and welded reinforcement 714 is progressively deformed into the cavity portion 734 of the die set 726.

The method includes the step of forming the channel shaped member 724 into a tubular member 812 with the reinforcement 714 internally therein with a die form operation as illustrated in FIG. 12. The channel shaped member 724 is placed in a die set, generally indicated at 736, comprised of an upper die half 738 and a lower die half 740. The upper die half 738 includes a cavity portion 742 and the lower die half 740 includes a cavity portion 744 for receiving the channel shaped member 724. The upper die half 738 and lower die half 740 are progressively closed so that the channel shaped member 724 is progressively deformed into the cavity portions 742, 744 of the die set 736. It should be appreciated that a second die form is used to complete the tube shape so it can be welded into a tube to be hydroformed. It should also be appreciated that the application of the metal double up reinforcement can be used in a straight or curved hydroformed section.

The method further includes the step of welding the tubular member 712 and hydroforming the tubular member 712 and reinforcement 714 together to form a locally and internally reinforced hydroformed tubular member. The welding occurs along an interface 746 between the ends of the tubular member. After welding is complete, the tubular member 712 and reinforcement are placed in a die set (not shown) comprised of an upper die half (not shown) and a lower die half (not shown). The upper die half includes a tubular forming cavity portion for the tubular member 712. Likewise, the lower die half includes a tubular forming cavity portion for the tubular member 712.

The ends of the tubular member 712 are sealed and hydraulic fluid is pumped into the tubular member 712 under pressure. The upper die half and lower die half are progressively closed so that the tubular member 712 is progressively deformed and the pressurized fluid captured therein expands the walls of the tubular member 712 into the cavity portions of the die set.

The die halves are fully closed upon one another with the tubular member 712 being tightly clamped between the die halves. During this closing of the die halves, a relatively constant hydraulic pressure may be maintained within the tubular member 712 by incorporating a pressure relief valve (not shown) into the seal enclosing the ends thereof so that hydraulic fluid may be forced from the tubular member 712 as it collapses.

Once the die is closed, the tubular member 712 is then expanded to a final cross-sectional profile by increasing the hydraulic pressure sufficient to exceed the yield limit of the tubular member 712 so that the tubular member 712 is forced into conformity with the tubular forming cavity portions of the die halves. The die halves are then opened to permit removal of the finished tubular member from the die halves.

Referring to FIGS. 13 through 16, another embodiment, according to the present invention, of the method is shown. Like parts of the method have like reference numerals increased by one hundred (100). In this embodiment, the method is used to internally reinforce the tubular member 812 with a bulkhead reinforcement 814 prior to hydroforming.

The method includes the step of providing a tubular member 812. The tubular member 812 is made of a metal material. In one embodiment, the tubular member 812 has a generally rectangular cross-sectional shape and extends axially.

The method also includes the step of forming a planar shaped member. The method includes the step of trimming a flat blank from a coil of metal material as illustrated in FIGS. 9A and 9B to form the planar shaped member.

The method further includes the step of forming the planar shaped member into a channel shaped member 824 with a die form operation as illustrated in FIG. 13. The planar shaped member is placed in a die set, generally indicated at 826, comprised of an upper die half 828 and a lower die half 830. The upper die half 828 includes projection portion 832 and the lower die half 830 includes a cavity portion 834 for receiving the planar shaped member, and the projection portion 832. The upper die half 828 and lower die half 830 are progressively closed so that the planar shaped member is progressively deformed into the cavity portion 834 of the die set 826. It should be appreciated that the planar shaped member is formed into a channel shaped member 824 and its bottom surface will locally match the final bulkhead reinforcement shape.

The method includes the step of forming the reinforcement 814, preferably to a bulkhead shape. In this embodiment, the reinforcement 814 has a generally flanged “C” or top hat cross-sectional shape and extends axially. The reinforcement 814 has a base wall 814a and a pair of opposed side walls 814b extending generally perpendicular to the base wall 814a. The reinforcement 814 also has a flange wall 814c extending generally perpendicular to each of the side walls 814b.

The method includes the step of positioning the reinforcement 814 in the channel shaped member 824. The method also includes the step of joining the reinforcement 814 to an interior surface of the channel shaped member 824 by welding the reinforcement 814 to the channel shaped member 824. The flange walls 814c are joined to an interior surface of the channel shaped member 824 by a suitable fastening mechanism such as welds 816. It should be appreciated that the welds 816 may be stitch, spot, laser, and/or continuous.

The method includes the step of forming the channel shaped member 824 into a tubular member 812 with the reinforcement 814 internally therein with a die form operation as illustrated in FIG. 14. The channel shaped member 824 is placed in a die set, generally indicated at 836, comprised of an upper die half 838 and a lower die half 840. The upper die half 838 includes a cavity portion 842 and the lower die half 840 includes a cavity portion 844 for receiving the channel shaped member 824. The upper die half 838 and lower die half 840 are progressively closed so that the channel shaped member 824 is progressively deformed into the cavity portions 842, 844 of the die set 836. It should be appreciated that a second die form is used to complete the tube shape so it can be welded into a tube to be hydroformed. It should also be appreciated that the application of the bulkhead reinforcement 814 is for locally straight sections within the tubular member 812.

The method further includes the step of welding the tubular member 812 and hydroforming the tubular member 812 and reinforcement 814 together to form a locally and internally reinforced hydroformed tubular member. The welding occurs along an interface 846 between the ends of the tubular member 812 and may include welding the base wall 814a to an interior surface of the tubular member 812. After welding is complete, the tubular member 812 and reinforcement 814 are placed in a die set, generally indicated at 848, comprised of an upper die half 850 and a lower die half 852. The upper die half 850 includes a tubular forming cavity portion (not shown) for the tubular member 812. Likewise, the lower die half 852 includes a tubular forming cavity portion (not shown) for the tubular member 812.

The ends of the tubular member 812 are sealed and hydraulic fluid is pumped into the tubular member 812 under pressure. The upper die half 850 and lower die half 852 are progressively closed so that the tubular member 812 is progressively deformed and the pressurized fluid captured therein expands the walls of the tubular member 812 into the cavity portions of the die set 848.

The die halves 850, 852 are fully closed upon one another with the tubular member 812 being tightly clamped between the die halves 850, 852. During this closing of the die halves 850, 852, a relatively constant hydraulic pressure may be maintained within the tubular member 812 by incorporating a pressure relief valve (not shown) into the seal enclosing the ends thereof so that hydraulic fluid may be forced from the tubular member 812 as it collapses.

Once the die set 848 is closed, the tubular member 812 is then expanded to a final cross-sectional profile by increasing the hydraulic pressure sufficient to exceed the yield limit of the tubular member 812 so that the tubular member 812 is forced into conformity with the tubular forming cavity portions of the die halves 850, 852. The die halves 850, 852 are then opened to permit removal of the finished tubular member from the die halves 850, 852.

The present invention has been described in an illustrative manner. It is to be understood that the terminology, which has been used, is intended to be in the nature of words of description rather than of limitation.

Many modifications and variations of the present invention are possible in light of the above teachings. Therefore, within the scope of the appended claims, the present invention may be practiced other than as specifically described.

Claims

1. An internally reinforced hydroformed assembly comprising:

a hydroformed tubular member;

a reinforcement disposed within said hydroformed tubular member prior to hydroforming; and

at least one weld to secure said reinforcement to an interior surface of said hydroformed tubular member.

2. An internally reinforced hydroformed assembly as set forth in claim 1 wherein said reinforcement has a generally planar cross-sectional shape.

3. An internally reinforced hydroformed assembly as set forth in claim 1 wherein said reinforcement has a generally “L” cross-sectional shape.

4. An internally reinforced hydroformed assembly as set forth in claim 1 wherein said reinforcement has a generally “C” cross-sectional shape.

5. An internally reinforced hydroformed assembly as set forth in claim 1 wherein said reinforcement has a generally top hat cross-sectional shape.

6. An internally reinforced hydroformed assembly as set forth in claim 1 wherein said reinforcement has a generally rectangular cross-sectional shape.

7. An internally reinforced hydroformed assembly as set forth in claim 1 wherein said reinforcement comprises a pair of planar plates spaced axially, said at least one weld comprising a plurality of welds to join one end of said plates to an interior surface of said tubular member and another end of said plates to an opposed interior surface of said tubular member.

8. An internally reinforced hydroformed assembly as set forth in claim 1 wherein said reinforcement comprises a base wall, a pair of opposed side walls extending generally perpendicular from said base wall, and a pair of flange walls, one of said flange walls extending generally perpendicular from one of said side walls, said at least one weld comprising a plurality of welds to join said base wall to an interior surface of said tubular member and said flange walls to an opposed interior surface of said tubular member.

9. An internally reinforced hydroformed assembly as set forth in claim 1 wherein said reinforcement overlaps at least one interior corner of said tubular member.

10. An internally reinforced hydroformed assembly as set forth in claim 1 wherein said reinforcement overlaps substantially the entire interior surface of said tubular member.

11. An internally reinforced hydroformed assembly as set forth in claim 1 including a bracket disposed against an exterior surface of said tubular member opposite said reinforcement.

12. A method of making an internally reinforced hydroformed assembly, said method comprising the steps of:

providing a reinforcement;

providing a channel shaped member with the reinforcement disposed therein;

forming the channel shaped member into a tubular member with the reinforcement internally therein; and

hydroforming the tubular member and reinforcement together to form a locally and internally reinforced hydroformed tubular member.

13. A method as set forth in claim 12 wherein said step of providing a reinforcement comprises forming the reinforcement into a cross-sectional shape from at least one of a group comprising planar, L, C, rectangular, and top hat.

14. A method as set forth in claim 12 including the step of forming a planar shaped member.

15. A method as set forth in claim 14 including the step of joining the reinforcement to a surface of the planar shaped member.

16. A method as set forth in claim 15 wherein said step of providing a channel shaped member with the reinforcement disposed therein comprises forming the planar shaped member with the reinforcement into a channel shaped member.

17. A method as set forth in claim 14 wherein said step of providing a channel shaped member with the reinforcement disposed therein comprises forming the planar shaped member into a channel shaped member.

18. A method as set forth in claim 17 wherein said step of providing a channel shaped member with the reinforcement disposed therein further comprises positioning the reinforcement in the channel shaped member.

19. A method as set forth in claim 12 including the step of welding the reinforcement to an interior surface of the tubular member prior to hydroforming.

20. A method as set forth in claim 12 including the step of welding an interface between ends of the tubular member prior to hydroforming.

21. A method of making an internally reinforced hydroformed assembly, said method comprising the steps of:

forming a reinforcement;

forming a planar shaped member;

joining the reinforcement to a surface of the planar shaped member;

forming the planar shaped member with the reinforcement into a channel shaped member;

forming the channel shaped member into a tubular member with the reinforcement internally therein; and

hydroforming the tubular member and reinforcement together to form a locally and internally reinforced hydroformed tubular member.

22. A method of making an internally reinforced hydroformed assembly, said method comprising the steps of:

forming a reinforcement;

forming a channel shaped member;

positioning the reinforcement in the channel shaped member;

joining the reinforcement to an interior surface of the channel shaped member;

forming the channel shaped member into a tubular member with the reinforcement internally therein; and

hydroforming the tubular member and reinforcement together to form a locally and internally reinforced hydroformed tubular member.