US20130229005A1

US20130229005A1 - Vehicle Cross-Member Assembly with Adhesive Reservoirs

Info

Publication number: US20130229005A1
Application number: US13/682,483
Authority: US
Inventors: John Martin Knittel; Xiaoming Chen; Sanjay Mehta; Michael M. Azzouz; Eric William Barrett; Mark Wlotkowski
Original assignee: Ford Global Technologies LLC
Current assignee: Ford Global Technologies LLC
Priority date: 2011-07-28
Filing date: 2012-11-20
Publication date: 2013-09-05
Also published as: US20130026796A1; DE102012216495A1; US20130026793A1; CN103010305A; US20130026794A1; DE102012214558A1; US9108678B2; US8915530B2

Abstract

A method of manufacturing a vehicle cross-member assembly includes: adding adhesive to an adhesive reservoir in an interconnecting member composed of a first material; overlapping a first rail composed of a second material with the interconnecting member; and welding the interconnecting member to a second rail in a position perpendicular with respect to the second rail. The second rail is composed of a different material than the first rail.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation and claims the benefit of U.S. patent application Ser. No. 13/221,142 titled “Vehicle Support Frames with Interlocking Features for Joining Members of Dissimilar Materials” filed Aug. 30, 2011, U.S. patent application Ser. No. 13/239,592 titled “Vehicle Support Frames with Interlocking Features for Joining Members of Dissimilar Materials” filed Sep. 22, 2011, and U.S. patent application Ser. No. 13/545,584 titled “Vehicle Support Frames with Interlocking Features for Joining Members of Dissimilar Materials” filed Jul. 10, 2012, which are hereby incorporated by reference in their entirety.

TECHNICAL FIELD

The present disclosure relates to vehicle support frames with rails having dissimilar materials and methods for manufacturing the same.

BACKGROUND

Conventional vehicle support frames can be composed of different materials including, for example, steel, aluminum and reinforced polymer composites. Vehicle manufacturers attempt to strike a balance between weight reduction and structural rigidity. It is desirable to design lightweight vehicle frames for full-sized light trucks. Aluminum structural members can be designed to achieve up to a 50% weight reduction while still meeting performance targets. Joining aluminum members to steel frame rails presents challenges as the two materials, when welded, have limited structural integrity.
One existing reference teaches the use of an overlapping configuration for the rails of dissimilar materials. A first and second structural member sandwiches one end of a third structural member and adhesive is applied therebetween. The second structural member is thereafter welded to the first structural member. U.S. Patent Publication No. 2009/0188206, titled “System and Method for Joining Dissimilar Materials” teaches an overlapping configuration with a surface weld on the second structural member. Still, it is desirable to have a vehicle cross-member assembly as opposed to a collinear assembly; it is also desirable to improve this design by providing a point of access for spot weld fixtures or other weld fixtures that require a clamped fitting.
Therefore, it is desirable to have improved interconnecting techniques for joining two structural members composed of dissimilar materials.

SUMMARY

The present disclosure addresses one or more of the above-mentioned issues. Other features and/or advantages will become apparent from the description which follows.
One exemplary embodiment of the present disclosure relates to a method of manufacturing a vehicle cross-member assembly, includes: adding adhesive to an adhesive reservoir in an interconnecting member composed of a first material; overlapping a first rail composed of a second material with the interconnecting member; and welding the interconnecting member to a second rail in a position perpendicular with respect to the second rail. The second rail is composed of a different material than the first rail.
Another exemplary embodiment of the present disclosure relates to a method of manufacturing a vehicle cross-member assembly, the method including: adding adhesive to an adhesive reservoir in a first rail composed of a first material; overlapping an interconnecting member composed of a second material with the first rail; and welding the interconnecting member to the second rail in a position perpendicular to the second rail. The second rail is composed of a different material than the first rail.
Another exemplary embodiment of the present disclosure relates to a vehicle cross-member assembly, having: a first rail composed of a first material; a second rail, perpendicularly positioned with respect to the first rail, composed of a second material; and an interconnecting member composed of the second material having adhesive in reservoirs formed thereon to join the interconnecting member and the first rail. The interconnecting member is welded to the second rail.
Yet another exemplary embodiment of the present disclosure relates to a vehicle cross-member assembly, having: a first rail composed of a first material having adhesive in reservoirs formed thereon; a second rail, perpendicularly positioned with respect to the first rail, composed of a second material; and an interconnecting member composed of the second material. The interconnecting member is welded to the second rail.
One advantage of the present disclosure is that it provides improved interconnecting techniques for joining two structural members composed of dissimilar materials.
Another advantage of the present disclosure is that it teaches the manufacture and use of light-weight vehicle structural frames that can be utilized with vehicles of different sizes, including full-sized truck frames. The weight reduction for the disclosed frame assemblies compared to contemporary structural frames can be as great as 50%. Fuel efficiency and performance can be enhanced by the use of the disclosed frame assemblies.
Another advantage of the present disclosure is that it teaches joining techniques for structural members having dissimilar material composition and a closed-section configuration. Structural members can be positioned at any angle with respect to each other.
Joining vehicle frame assembly rails composed of dissimilar materials will be explained in greater detail below by way of example with reference to the figures, in which the same reference numbers are used in the figures for identical or essentially identical elements. The above features and advantages and other features and advantages of the present teachings are readily apparent from the following detailed description of the best modes for carrying out the invention when taken in connection with the accompanying drawings. In the figures:

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a top perspective view of a vehicle support frame assembly.

FIG. 2 is a partial perspective view of the vehicle support frame assembly of FIG. 1 at circle 2.

FIG. 3 is a perspective view of the interconnecting member of FIG. 2.

FIG. 4 is a perspective view illustrating application of adhesive in reservoirs formed in the interconnecting member of FIG. 3.

FIG. 5 is a perspective view illustrating the assembly of the interconnecting member and cross rail of FIG. 2.

FIG. 6 is a perspective view of a die for forming recesses in a cross rail.

FIG. 7 is a partial perspective view of another exemplary vehicle support frame assembly with adhesive outside of the interconnecting member.

FIG. 8 is a partial perspective view the vehicle support frame assembly of FIG. 7 from the inside of the cross rail.

FIG. 9 is a perspective view illustrating application of adhesive outside of an interconnecting in another exemplary vehicle support frame assembly.

FIG. 10 is a partial perspective view of the vehicle support frame assembly of FIG. 9 illustrating application of adhesive inside of the cross rail at the corners.

FIG. 11 is a partial perspective view of the interconnecting member of FIG. 9.

FIG. 12 is a perspective view of another exemplary embodiment of an interconnecting member and rail with adhesive outside of the interconnecting member.

FIG. 13 is a partial perspective view the vehicle support frame assembly of FIG. 12 from the inside of the cross rail.

FIG. 14 is a cross-sectional view the vehicle support frame assembly of FIG. 12 at line 14-14.

FIG. 15 is an assembly view of another exemplary vehicle support frame assembly.

FIG. 16 is a perspective view of the interconnecting member for use with the vehicle support frame assembly of FIG. 15.

FIG. 17 is as perspective view of another exemplary interconnecting member for use with a vehicle support frame assembly.

DETAILED DESCRIPTION

Referring to the drawings, wherein like characters represent examples of the same or corresponding parts throughout the several views, there are shown vehicle support frames having joined structural members composed of different materials. Particularly, lighter weight aluminum structural members are joined to steel side rails in most embodiments. The aluminum and steel members are joined through an interconnecting member juxtaposed between them. The disclosed interconnecting members mitigate several challenges incumbent with joining dissimilar materials by teaching an interconnecting member having multiple portions. Each portion can be composed of a different material. Once attached to each other the portions form as a link or bridge between rails attached to a portion of the interconnecting member. In some embodiments, the rails are attached to the interconnecting member via MIG welding.
The teachings herein are applicable to any type of vehicle frame including frames for pickup trucks, vans, minivans, sports utility vehicles, sedans, coupes, commercial vehicles, and all utility vehicles.
Referring now to FIG. 1, there is shown therein a vehicle cross-member assembly (or support frame) 10. The illustrated cross-member assembly 10 is configured for use in a pickup truck. Cross-member assembly 10 (as shown) is taken from the rear section of the truck frame, which supports the truck bed (not shown). Assembly 10 is a support frame. Side rail assemblies 20 and 30 extend longitudinally with respect to the assembly 10 and the vehicle. In the shown embodiment, side rail assemblies 20, 30 can be composed of different materials. Rails 20, 30 can be formed via any standard forming process, e.g., stampings, hydro-forming, or roll forming. The rearward ends of the rails 20, 30 are interconnected through a rearward steel cross-member 40. Attached to cross-member 40 is a tow hitch 50. Each end of the rails is fitted with a side bracket 60 for interconnecting cross-member 40 with the rails and for connecting the rails 20, 30 to other vehicle structure (e.g., the truck bed, rear fascia or bumper, etc.). At the frontward end of the cross-member assembly 10, shown in FIG. 1, there is another steel cross-member 70 intersecting each side rail 20, 30. As shown, rails 20, 30 are welded to cross-member 70.
Rails 90, 100 (as shown in FIG. 1) are positioned perpendicularly with respect to rails 20, 30. Rails 90, 100 are a part of a spare tire support frame 75. Rails 90, 100 are fitted with an interconnecting member 80, as discussed hereinbelow. Rails 90, 100 are mechanically interlocked with interconnecting member 80. As discussed below, in this embodiment, adhesive is used to attach the interconnecting member to rails.
Now with reference to FIG. 2 there is shown a partial perspective view of the cross-member assembly 10 of FIG. 1 at circle 2. The assembly 10 has rails 20 and 100 composed of different materials. The material used for side rail 20 is not weld compatible with the material used for the rail 100. In this embodiment, the side rail 20 is composed of steel and the cross rail 100 is made of aluminum.
Shown in FIG. 2 is an intersection of the side rail 20, interconnecting member 80 and rail 100. Interconnecting member (or “ICM”) 80 passes through side rail 20 at a 90 degree angle or perpendicularly. ICM 80 is welded to side rail. Interconnecting member 80 is a steel tube in the illustrated embodiment of FIG. 2.
As shown in FIG. 3, the interconnecting member 80 has a series of oblong recesses or reservoirs 110 formed via crimping on an outer surface of the interconnecting member. Reservoirs are configured to hold adhesive 120 therein, as shown in FIG. 4. Different types of adhesives can be used including e.g., resins or two-way epoxies. Rail 100 also includes a series of crimps 130 (as shown in FIG. 2) formed on the outer surface of rail 100. Crimps 130 are located at the same longitudinal position as reservoirs 110 when the interconnecting member 80 is assembled with the rail 100 to form an interlock between the two members. In the illustrated embodiment, rail 100 includes eight crimps 130.
The support frame assembly of FIGS. 2-3 is manufactured using a method of manufacture as described hereinbelow. The method includes the steps of: (1) adding adhesive to an adhesive reservoir in an interconnecting member, as shown and discussed with respect to FIG. 4; (2) overlapping the cross-member and the interconnecting member, e.g., as shown in FIG. 5; (3) performing a second crimping; and (4) welding the interconnecting member to a side rail, in a position perpendicular with respect to the second rail, as shown in FIG. 2.
With respect to the first step, adding adhesive to an adhesive reservoir in the interconnecting member, this step is shown in FIG. 4. In FIG. 4 an operator, O, is shown holding the interconnecting member 80 in one hand and an adhesive applicator 140 in the other hand. Adhesive 120 is inserted in the reservoirs 110. In this embodiment, adhesive 120 is applied to fill the reservoirs 110. Less or more adhesive can be used.
Once the adhesive is applied, the operator moves to the next step, as shown in FIG. 5. The rail 100 and interconnecting member 80 are positioned in an overlapping configuration, as shown in FIG. 5. In this embodiment, ICM 80 is inserted in the rail 100 with a spatial gap of approximately 0.5 mm between the inner surface of rail and the outer surface of ICM on each side. In other embodiments, the spatial gap between rail and ICM can be greater or less than 0.5 mm. In other embodiments, ICM 80 and rail 100 can overlap in different configurations. E.g., in one embodiment, rail 100 is inserted in the ICM 80.
After ICM 80 and rail 100 are placed in an overlapping configuration, pressure is applied to the rail and/or ICM, as shown in FIG. 6. This is part of a two-step crimping process—(i) forming reservoirs in the ICM and then (ii) crimping the cross member with compatible crimps. In FIG. 6, there is a stamp press 150 having a mandrel 160 configured to form crimps 130 in the rail 100 and/or ICM 80. Crimps 130 in the rail 100 are formed to match crimps or reservoirs 110 on ICM 80. Crimps 130 act as a secondary mechanical interlock between rail 100 and interconnecting member 80 in this embodiment. The press 150 is configured to evenly distribute the adhesive between the rail 100 and ICM 80. In this embodiment, the press 150 is configured to apply pressure to the cross rail 100 and ICM 80 so as to cause adhesive to ooze out of the reservoirs of the ICM. Adhesive is spread between the outer surface of the ICM and the inner surface of the rail 100 to form a joint between the two members. Rail 100 has four sets of two crimps 130 formed on each side of the outer surface of rail. Rail 100 and ICM 80 are rotated in 90 degree iterations between each press.
The finished assembly of the ICM 80 and rail 100 is shown in FIG. 7-8. After, the pressing process, adhesive 120 seeps out of one end of the rail 100 and one end of the ICM 80. As shown in FIG. 7, adhesive 120 is squeezed in the crimping process. Adhesive 120 seeped out of the end of rail 100 to overflow on the outside of the ICM and rail, thereby forming a barrier between the cross rail 100 and ICM 80 joint and the surrounding environment. FIG. 8 is a cross-section in the rail 100 taken from the inside the rail looking toward the side rail 20 (of FIG. 2). As shown in FIG. 8, adhesive 120 is squeezed in the crimping process so as to seep out of an end of ICM 80. Adhesive 120 that seeps out of end of the ICM 80 overflows on the inside of the rail, thereby forming a barrier between the rail and ICM joint and the surrounding environment on an inside surface as well.
Another exemplary support frame assembly 200 is partially shown and discussed with respect to FIGS. 9-14. Shown is a method of manufacturing the support frame assembly 200, which is a vehicle cross-member assembly. The method includes the steps of: (1) adding adhesive to an adhesive reservoir in an interconnecting member, as shown and discussed with respect to FIG. 9-11; (2) overlapping the cross rail and the interconnecting member, e.g., as shown in FIG. 12; (3) crimping the overlapped ICM and rail; and (4) welding the interconnecting member to a side rail in a position perpendicular to the second rail, as shown in FIG. 2.
With respect to the first step, adding adhesive to an adhesive reservoir in the interconnecting member, this step is shown in FIG. 9. An adhesive applicator 210 includes a tip 220 marked at “M” for filling each reservoir 230 in an interconnecting member 240 to a desired level. In FIG. 9, an operator, I, is shown with the adhesive applicator 210 in one hand. ICM 240 includes at least three adhesive reservoirs 230 on each surface in this configuration. Adhesive 250 is inserted in the reservoirs. Adhesive 250 is also applied at a midpoint (280), 360 degrees around an outer surface of interconnecting member 240. The ICM 240 with adhesive 250 is also illustrated in FIG. 11.
In this embodiment, additional adhesive 250 is applied to the inner walls of rail 270, as shown in FIG. 10. Adhesive 250 is longitudinally applied along corners 290 of cross rail 270, as shown in FIG. 10. FIG. 10 is a cross-section view of the rail 270 pre-assembly with ICM 240.
Once the adhesive 250 is applied, the operator moves to the next step, as shown in FIG. 12. The rail 270 and interconnecting member 240 are positioned in an overlapping configuration, as shown in FIG. 12. In this embodiment, ICM 240 is inserted in the rail 270. After ICM 240 and rail 270 are placed in an overlapping configuration, pressure is applied to the rail 270 and ICM 240. The press is configured to evenly distribute the adhesive between the rail and ICM by squeezing the adhesive out of the reservoirs and to create matching crimps between the rail and ICM for interlocking the two parts. Rail 270 has four sets of three crimps 260 formed on each side of the outer surface of rail. In this embodiment, the adhesive used is an epoxy (e.g., a two-part epoxy). Alternative one-part epoxies or other adhesives can also be used.
ICM 240 includes an optional reservoir 230—as exposed in FIGS. 9 and 11—that can be filled with adhesive or left unfilled (e.g., as shown in FIG. 9). Reservoir 230 can be filled, for example, for more overlapping or stronger joints. In those embodiments, ICM 240 is inserted farther into cross rail 270 and three reservoirs on each side of the rail are filled to link ICM and cross rail. The use of optional reservoirs allows for commonality of parts for the cross rails and ICMs between different vehicle platforms.
After, the pressing process, adhesive 250 seeps out of one end of the rail 270 and one end of the ICM 240. As shown in FIG. 13, adhesive 250 is squeezed in a crimping process so as to seep out of an end of ICM 240. Adhesive 250 that seeps out of the ends of rail and ICM forms a barrier between the rail 270 and ICM 240 joint and the surrounding environment on the inside surface and outside surface as well. Different types of adhesives can be used to create barriers of different kinds. In the illustrated embodiment of FIG. 13 a less viscous adhesive is used than in the embodiment of FIG. 8, for example, thus a thicker barrier is formed by the overflow of adhesive on the exterior of the ICM and in the interior of the rail.
FIG. 14 illustrates a cross-section in the support frame assembly 200 of FIG. 12 at line 14-14 shown therein. As shown, adhesive 250 is completely filled between the ICM 240 and rail 270 at all four corners through the overlap length. Rail 270 is journaled onto the ICM 240. Adhesive 250 is evenly distributed at the shown cross-section and the entire overlap as well.
Now with reference to FIGS. 15-16 there is shown another exemplary embodiment of a support frame assembly 500. FIGS. 15-16 show partial perspective views of the support frame 500. The support frame (or support frame assembly) 500 has rails 510, 520 composed of different materials. The material used for side rail 510 is not weld compatible with the material used for the cross-member. In this embodiment, the side rail 510 is composed of steel and the rail 520 is made of aluminum. Shown is an interconnecting member 530 formed with the side rail 510. Interconnecting 530 is casted with side rail 510 in this embodiment. In other embodiments ICM 530 is, e.g., welded to rail 510. Interconnecting member 530 is a steel tube. As shown in FIGS. 15 and 16, the rail 520 has a series of recesses or reservoirs 540 formed on the outer surface of the rail 520. Reservoirs 540 are oblong in shape and configured to hold adhesive therein. Different types of adhesives can be used including e.g., resins or two-way epoxies.
The support frame assembly of FIGS. 15-16 is manufactured using a method of manufacture as described hereinbelow. A method of manufacturing a vehicle cross-member assembly includes: adding adhesive to an adhesive reservoir in a rail; overlapping an interconnecting member with the rail by inserting the rail inside of the interconnecting member; performing a second crimping to distribute the adhesive and create the interlock between the two members; and, if needed, welding the interconnecting member to a side rail in a position perpendicular to the side rail, the side rail composed of a different material than the cross-member rail.
In another embodiment, as shown in FIG. 17, an interconnecting member fits inside of the rail 550. The interconnecting member can include a series of complementary reservoirs formed on the outer surface of interconnecting member, e.g., 230, as shown in FIG. 9. A second crimping is performed on the rail 550 after the assembly to form protrusions. Complementary reservoirs and protrusions are located at the same positions to create mechanical interlocks between the two members. The interlock can also be created by a single step crimping on the interconnector-rail assembly without pre-existing protrusions.
Reservoirs can be any combination of recesses, protrusions, or a recess with protrusion and so forth. Reservoirs can be formed using known forming procedures (e.g., stamping, hydroforming, or die casting). Additionally, any of the aforementioned assembly or forming process steps can be executed by an operator, automated machine or a combination of the two.
Those familiar with the art to which this invention relates will recognize various alternative designs and embodiments for practicing the invention within the scope of the appended claims.

Claims

We claim:

1. A method of manufacturing a vehicle cross-member assembly, comprising:

overlapping a first rail composed of a first material with an interconnecting member; and

welding the interconnecting member to a second rail in a position perpendicular with respect to the second rail;

wherein the second rail is composed of a different material than the first rail.

2. The method of claim 1, further comprising:

adding adhesive to an adhesive reservoir in the interconnecting member composed of a second material.

3. The method of claim 2, further comprising:

forming the adhesive reservoir in the interconnecting member.

4. The method of claim 3, wherein the forming the adhesive reservoir includes forming an oblong recess or protrusion in the interconnecting member.

5. The method of claim 2, further comprising:

applying pressure to the interconnecting member or first rail so as to distribute adhesive therebetween.

6. The method of claim 5, further comprising:

crimping the first rail.

7. The method of claim 5, wherein applying pressure to the interconnecting member or first rail includes oozing adhesive out of one end of the interconnecting member and one end of the first rail so as to create a protective barrier of adhesive.

8. A method of manufacturing a vehicle cross-member assembly, comprising:

adding adhesive to an adhesive reservoir in a first rail composed of a first material;

overlapping an interconnecting member composed of a second material with the first rail; and

welding the interconnecting member to the second rail in a position perpendicular to the second rail;

9. The method of claim 8, further comprising:

forming the adhesive reservoir in the first rail.

10. The method of claim 9, wherein the forming the adhesive reservoir includes forming an oblong recess or protrusion in the first rail.

11. The method of claim 8, further comprising:

12. The method of claim 11, further comprising:

crimping the interconnecting member.

13. The method of claim 11, wherein applying pressure to the interconnecting member or first rail includes oozing adhesive out of one end of the interconnecting member and one end of the first rail so as to create a protective barrier of adhesive.

14. A vehicle cross-member assembly, comprising:

a first rail composed of a first material;

a second rail, perpendicularly positioned with respect to the first rail, composed of a second material; and

an interconnecting member composed of the second material having adhesive in reservoirs formed thereon to join the interconnecting member and the first rail;

wherein the interconnecting member is welded to the second rail.

15. The vehicle assembly of claim 14, wherein the reservoir is a protrusion or recess.

16. The vehicle assembly of claim 14, wherein an inner corner of the first rail includes adhesive included therein.

17. A vehicle cross-member assembly, comprising:

a first rail composed of a first material having adhesive in reservoirs formed thereon;

an interconnecting member composed of the second material;

wherein the interconnecting member is welded to the second rail.

18. The vehicle assembly of claim 17, wherein the reservoir is a protrusion or recess.

19. The vehicle assembly of claim 17, wherein an inner corner of the interconnecting member includes adhesive included therein.