Method for manufacturing an aluminium truck platform assembly, vehicle and reinforcement assembly

Abstract

Method for manufacturing an aluminium wagon platform assembly comprising the following: Extrusion of an aluminium tube (46); Extrusion of an aluminium reinforcement beam (34) with a channel (29) having an inner surface; Friction welding of the aluminium tube (46) onto the inner surface of the aluminium reinforcement carrier (34); Roll forming of a crossbeam (24); Forming a hole (54) in the crossbeam (24); and Inserting the aluminium tube (46) through the hole (54) in the crossbeam (24) while simultaneously nesting the crossbeam (24) against the inner surface of the channel (29).

Description

TECHNICAL AREA

[0001] The present invention relates to a method for manufacturing an aluminium truck platform assembly, a vehicle and a reinforcement arrangement for an aluminium truck platform of a vehicle. BACKGROUND

[0002] Pickup trucks are motor vehicles with an open rear cargo bed, often referred to as a truck bed. Pickup trucks are popular primarily because the bed allows the vehicle to be used in many different ways, including hauling various types of cargo and towing different types of trailers. Traditionally, the majority of pickup truck body structures were formed from steel alloys. Building on years of experience, pickup truck designers have learned how to design steel body components to withstand a wide variety of demanding pickup truck applications. The current legal and economic environment has increased the importance of making pickup trucks more fuel-efficient while maintaining or improving functionality and durability.One way to reduce a vehicle's fuel consumption is to reduce the weight of the vehicle structure, especially when it is unloaded.

[0003] Aluminum alloys typically have a higher strength-to-weight ratio than steel alloys. Consequently, replacing steel with aluminum offers the potential for weight reduction. However, the modulus of elasticity of aluminum is generally lower than that of steel. Furthermore, manufacturing techniques and joining methods that work well for steel parts may not be suitable for the same part made of aluminum. Because of these and other differences, a simple material substitution does not necessarily produce an acceptable design.

[0004] Aluminum alloys are generally identified by a four-digit number, the first digit of which typically indicates the major alloying element. When describing a series of aluminum alloys based on the major alloying element, the first number may be followed by three x's (uppercase or lowercase) or three zeros. For example, the major alloying element in 6xxx (or 6000) series aluminum alloys is magnesium and silicon, while the major alloying element in the 5xxx series is magnesium, and in the 7xxx series, it is zinc. Additional numbers, represented by the letter "x" (or by zeros) in the series designation, define the exact aluminum alloy. For example, an aluminum alloy 6061 has a composition of 0.4 - 0.8% silicon, 0 - 0.7% iron, 0.15 - 0.4% copper, 0 - 0.15% manganese, 0.8 - 1.2% magnesium, 0.04 - 0.35% chromium, 0 - 0.25% zinc and 0 - 0.15% titanium.Different alloys offer different compromises regarding strength, hardness, machinability and other properties.

[0005] Furthermore, five different temper designations can be used for aluminum alloys: F – as manufactured, O – annealed, H – work-hardened, T – heat-treated, and W – as quenched (between solution annealing and artificial or natural aging). A single- or double-digit number may follow the temper designation for further description. For example, aluminum with a temper designation T6 has been solution annealed and artificially aged, but not cold-worked after solution annealing (or in such a way that the cold working is not apparent in the material properties).

[0006] US Patent 2012 / 0313399 A1 describes a method for manufacturing a superstructure on a vehicle frame, comprising an aluminum tube and an aluminum reinforcing beam with a channel and an inner surface, wherein the tube is welded to the inner surface of the reinforcing beam, and a cross member is roll-formed, with a hole formed in the cross member. DE 38 02 300 C1 discloses a friction welding method for tubes on plates. DE 11 2011 103 467 T5, JP H08-244652 A, and JP 2001-247 051 A describe the mounting of flatbeds.

[0007] The object of the invention is to improve the durability of aluminium flatbed truck assemblies and corresponding vehicles. SUMMARY

[0008] To solve the aforementioned problem, a method according to claim 1, a vehicle according to claim 6, and a reinforcement arrangement according to claim 14 are proposed. Advantageous embodiments of the invention are specified in the dependent claims and the following description.

[0009] According to one embodiment, a method for manufacturing an aluminum truck bed assembly is provided. The method comprises extruding an aluminum tube and extruding an aluminum reinforcing beam with a channel having an inner surface. The aluminum tube is friction-welded to the inner surface of the aluminum reinforcing beam. A cross member is roll-formed, and a hole is formed in the cross member. The method further comprises inserting the aluminum tube through the hole in the cross member while simultaneously interlocking the cross member against the inner surface of the channel. The aluminum reinforcing beam holds the cross member and a frame rail of the vehicle in a spatial relationship.

[0010] The process may also include punching an aluminum truck bed, joining the aluminum tube or cross member to the aluminum truck bed, and inserting a fastener through the aluminum truck bed, the aluminum tube, the cross member, and the aluminum reinforcement beam to be attached to the frame rail of a vehicle.

[0011] In another embodiment, a vehicle comprises a pair of longitudinal frame rails and an aluminum truck bed arranged over the frame rails. A transverse cross member is arranged between the aluminum truck bed and the frame rails and contacts the aluminum truck bed. A spacer is arranged between them and contacts the cross member and one of the frame rails. An aluminum tube is friction-welded to the spacer and contacts the aluminum truck bed.

[0012] The crossbeam can include a base and a pair of opposing side walls extending from the base towards the aluminum truck bed. The spacer can include a base that contacts the base of the crossbeam and one of the frame rails, thus dividing the two. The aluminum tube can include a hollow interior dimensioned to accommodate a mounting bracket or fastener that indirectly connects the aluminum truck bed to the frame rails, leaving a space between them.

[0013] In another embodiment, a reinforcement arrangement is provided for a truck bed. A crossbeam has a surface that defines an opening through it and an elongated channel. An extruded aluminum reinforcement beam is attached to the crossbeam outside the channel. The aluminum reinforcement beam is positioned between the crossbeam and a frame rail of the truck. An extruded tubular beam is friction-welded to the aluminum reinforcement beam and extends through the opening into the channel. BRIEF DESCRIPTION OF THE DRAWINGS Fig. Figure 1 is a perspective view of a pickup truck with an aluminum truck bed according to an embodiment of the present invention. Fig. Figure 2 is a bottom view of the aluminium truck platform with several reinforcement arrangements attached to it according to one embodiment. Fig. Figure 3 is a perspective view of a crossbeam and a pair of aluminium reinforcement beams of the reinforcement arrangement for attachment to the lower surface of the aluminium truck bed according to one embodiment. Fig. 4 is a cross-section taken along line 3-3 of the reinforcement arrangement of Fig. 3. Fig. Figure 5 is a perspective side view of the reinforcement arrangement attached under the aluminium truck bed and above the frame rails of the pickup truck according to one embodiment. Fig. Figure 6 is a perspective view of a tubular support for friction welding onto a crossbeam of the reinforcement arrangement according to one embodiment. DETAILED DESCRIPTION

[0014] Embodiments of the present invention are described here. It is understood, however, that the disclosed embodiments are merely examples and that other embodiments may take different and alternative forms. The figures are not necessarily to scale; some features may be exaggerated or minimized to show details of particular components. The specific structural and functional details disclosed here should therefore not be interpreted as limiting, but merely as a representative basis for teaching a person skilled in the art how to apply the embodiments in various ways.It is obvious to the average person skilled in the art that various features illustrated and described with reference to any one of the figures can be combined with features illustrated in one or more other figures to create embodiments not explicitly illustrated or described. The combinations of illustrated features provide representative embodiments for typical applications. However, various combinations and modifications of the features that comply with the teachings of this invention may be desirable for specific applications or implementations.

[0015] Fig. Figure 1 represents a pickup truck 10, which has many structural elements made of aluminum. The pickup truck 10 includes a cargo bed or an aluminum truck bed 12, which is located behind a passenger compartment 14 of the pickup truck 10. The aluminum truck bed 12 is shown with an open and exposed top, although other embodiments exist in which the aluminum truck bed 12 is covered. A tailgate 16 is hinged to its underside to allow access to the upper surface of the aluminum truck bed 12. When open, the tailgate 16 and the upper surface of the aluminum truck bed 12 can be coplanar to provide a flat loading area.

[0016] Many of the components of the pickup truck 10 can be made of aluminum. The aluminum truck bed 12 is no exception and can be made of 6000 series aluminum. When such a material selection is made for the aluminum truck bed 12, additional reinforcing structures can be provided to support the strength and rigidity of the aluminum truck bed 12. These reinforcing structures, as described below, can also be made of 6000 series aluminum. Certain designs of these reinforcing structures provide the pickup truck 10 with a strength comparable to that of typical pickup trucks constructed primarily of steel.

[0017] Fig. Figure 2 shows the underside 20, or the lower surface, of the aluminum truck bed 12. The aluminum truck bed 12 has a length L extending along the length of the pickup truck 10 and a width W. As also shown in Figure 2, the aluminum truck bed 12 has a length L extending along the length of the pickup truck 10 and a width W. Fig. As can be seen in Figure 1, the aluminum truck bed 12 can include a series of longitudinal grooves 22 to increase structural stiffness. Even with these grooves 22, the aluminum truck bed 12 can still be described as essentially flat, since most of the upper surface of the aluminum truck bed 12 is indeed flat.

[0018] Under the underside 20 of the aluminium truck platform 12 are several reinforcement arrangements, some of which are isolated in Fig. Figure 3 shows that each of the reinforcement assemblies comprises a crossbeam 24 extending transversely across the grooves 22 and along the width of the aluminum truck bed 12. Each crossbeam 24 includes a generally horizontal (parallel to the aluminum truck bed 12) base 26. A pair of opposing sidewalls 28 extends from the base 26 at relatively obtuse angles (e.g., between 91 and 110 degrees) to the base 26. These opposing sidewalls 28 also extend along the length of the crossbeam 24, forming a channel 29 within the concave or inner surface of the crossbeam 24'. A pair of flanges 30 is set off from and parallel to the base 26, with each flange extending from a corresponding sidewall. The flanges provide engagement surfaces for the reinforcement assembly to engage with the underside 20 of the aluminum truck bed 12.

[0019] The crossbeams 24 can be manufactured from 6000 series roll-formed aluminum. Roll forming is an efficient process for producing a pressed component in which the component's shape is constant and free from any waviness or abrupt changes in geometry. A roll-formed crossbeam 24 provides a longitudinal, one-piece support beam that adequately supports the aluminum truck bed 12.

[0020] Referring to the Fig. 2-5 Several spacers or aluminum reinforcement beams 34 are provided on the outer surface of each of the crossbeams 24. The aluminum reinforcement beams 34 each comprise a base 36 that engages with an associated crossbeam 24. The side walls 38 of the aluminum reinforcement beams 34 also extend from the base 36 at angles similar to those of the side walls 28 that extend from the base 26 of the crossbeam. A channel is defined by the base 36 and the side walls 38. The base 36 and the side walls 38 are designed to engage with and contact the base 26 and the side walls 28 of the crossbeam 24.

[0021] To enhance the strength of a one-piece roll-formed crossbeam 24, the aluminum reinforcement beam 34 can be made of 6000 series extruded aluminum. In an extrusion process, aluminum in a malleable state can be "pressed" through a die, such as the die of the aluminum reinforcement beam, and cut or snapped to length. When the aluminum reinforcement beam 34 is positioned below the crossbeam 24 and opposite the aluminum truck bed 12, it acts as a spacer to create a clearance zone for components located beneath the aluminum truck bed 12. This eliminates the need to create local recesses in the aluminum truck bed 12 or the crossbeams 24, enabling roll forming due to a consistent shape (as described above).

[0022] The base 36 of the aluminum reinforcement beam 34 can be extruded and dimensioned to provide adequate clearance under the aluminum truck bed 12 for the given vehicle system clearance requirements. The base 36 can be thicker than the side walls 38, not only to assist in supporting the crossbeam 24 relative to its sides, but also to provide clearance under the crossbeam 24. The base 36 and the side walls 38 provide additional strength to the crossbeam 24, preventing its collapse under heavy loads while maintaining clearance between the aluminum truck bed 12 and the components below.

[0023] A typical pickup truck 10 comprises a pair of frame rails arranged beneath the aluminum truck bed 12 and extending along the length L of the aluminum truck bed 12. Referring to Fig. Figure 5 shows the crossbeam 24 and the support beam as part of a reinforcement arrangement 42 between the aluminum truck bed 12 and one or more frame rails 44 of the pickup truck 10. Instead of a direct connection between the aluminum truck bed 12 and the frame rails 44, the reinforcement arrangement 42 can provide a space between the underside 20 of the aluminum truck bed 12 and the frame rails 44. In particular, the flanges 30 of the crossbeam 24 contact the underside of the aluminum truck bed 12, while the base 36 of the support beam contacts one of the frame rails 44.

[0024] To secure the reinforcement assembly 42 between the aluminum truck bed 12 and the frame rails 44, a crumple tube or extruded aluminum tube 46 is provided on each support beam. Each aluminum tube 46 can be friction-welded to an upper surface of the base 36 of the aluminum reinforcement beam 34. For example, in one embodiment, an end face 48 of the aluminum tube 46 can be friction-welded to the base 36, with the length of the aluminum tube 46 extending between the side walls 38. Several annularly recessed surface features 50 are provided on the outer surface of the aluminum tube 46 to facilitate the flow of aluminum during friction welding. The surface features 50 are shown as rounded ribs that are regularly and annularly recessed and extend along the length of the aluminum tube 46.The surface features 50 can assume any other shape capable of providing additional material on the outer surface of the aluminum tube to facilitate friction welding. In further embodiments, the surface features 50 comprise one or more longitudinal grooves formed in the outer surface of the aluminum tube 46. In still further embodiments, a series of alternating grooves and ribs is formed on the outer surface.

[0025] The extruded aluminum tube 46, which is friction-welded to the extruded aluminum reinforcement beam 34, provides additional support under the aluminum truck bed 12 and maintains a spatial relationship between the aluminum truck bed 12, the aluminum reinforcement beam 34, and the frame rails 44. The aluminum tube 46 further prevents the crossbeam 24 and its support components from collapsing under heavy loads.

[0026] An exemplary method for manufacturing and assembling the reinforcement assembly 42 is now described. Several of the 6000 series aluminum crossbeams 24 are formed by roll forming, including the base 26, the side walls 28, and the flanges 30 described above. At least two spacer holes 52 are punched, cut, or otherwise formed at widely spaced positions in the crossbeam 24 to be subsequently aligned with the frame rails 44 transverse to the crossbeam. The aluminum reinforcement beams 34, with the base 36 and the side walls 38 as described above, are formed by extrusion of 6000 series aluminum such that the aluminum reinforcement beams 34 include channels. The aluminum tubes 46 with surface features 50 are also formed from extruded 6000 series aluminum.The aluminum tube 46 can be extruded such that a hole 54 is present through its central axis. Each aluminum tube 46 is friction-welded to the inner surface within the channel of the individual aluminum reinforcement carriers 34. A hole (not shown) in the aluminum reinforcement carrier 34 can also be formed and aligned with the hole 54 of the aluminum tube 46.

[0027] After welding, one of the aluminum tubes 46 is inserted through a spacer hole 52 in one of the crossbeams 24. Due to the similar shapes of the bases and side walls, the aluminum reinforcement beam 34 can be pressed so that its inner surface interlocks with the outer surface of the crossbeam 24. This aligns the aluminum reinforcement beam 34 and the aluminum tube 46 from one crossbeam 24 onto one of the frame rails 44. The process can be repeated to interlock two aluminum reinforcement beams 34 with each of the crossbeams 24 at positions to be attached to the frame rails 44 (explained below). Each aluminum reinforcement beam 34 maintains a spatial relationship between the crossbeam 24 and the frame rail 44, while simultaneously indirectly connecting the two. A fastener (e.g., bolt, screw, etc.) is used to secure the aluminum reinforcement beam 34 to the frame rail 44.The reinforcement assembly 42 can then be screwed or inserted into the aluminum platform 12 through the hole 54 of the aluminum tube 46, through the aluminum reinforcement beam 34, and into the frame rail 44. This secures the reinforcement assembly 42 between the aluminum platform 12 and the frame rail 44 in an aluminum platform assembly.

[0028] As already mentioned, and as is best done in Fig. As can be seen in Figure 2, the reinforcement arrangement 42 comprises a roll-formed crossbeam 24 with a pair of offset extruded support beams. Each support beam is aligned with a corresponding frame rail under the aluminum wagon platform 12 and extends along the length L of the aluminum wagon platform 12. In other words, several support beams, attached to different crossbeams 24, are aligned along a single frame rail. In the figure shown in Fig.In the embodiment shown in Figure 2, three crossbeams 24 are provided, each of which has a pair of support beams. Half of the support beams are linearly oriented for attachment to one frame rail, while the other half are linearly oriented for attachment to another frame rail. Other embodiments are conceivable in which more or fewer than the number of crossbeams and / or support beams are provided.

[0029] While the embodiments described above relate to a pickup truck 10, it is understood that the structural features of the present invention can be used in other vehicles, for example SUVs (Sports Utility Vehicles), vans, etc.

[0030] Although exemplary embodiments are described above, it is not intended that these embodiments describe all possible forms encompassed by the claims. The terms used in the description serve to describe, not to limit, the invention, and it is understood that various modifications can be made without departing from the concept and scope of the invention. As previously described, the features of different embodiments can be combined to form further embodiments of the invention that may not be explicitly described or illustrated.While various embodiments may have been described as offering advantages or being preferable to other embodiments or implementations of the prior art with respect to one or more desired properties, the average person skilled in the art understands that compromises are made between one or more features or properties in order to achieve the desired overall system characteristics, which depend on the specific application and implementation. These features may include, but are not limited to, cost, strength, durability, life-cycle costs, marketability, appearance, packaging, size, ease of maintenance, weight, manufacturability, ease of assembly, etc.Embodiments that are described as less desirable than other embodiments or implementations of the prior art with respect to one or more properties are therefore not outside the scope of protection of the invention and may be desirable for certain applications.

Claims

[1] A method of manufacturing an aluminum truck bed assembly comprising: Extrusion of an aluminium tube (46); Extruding an aluminum reinforcement beam (34) having a channel (29) with an inner surface; Friction welding the aluminum tube (46) to the inner surface of the aluminum reinforcement beam (34); Roll forming a cross member (24); Forming a hole (54) in the cross member (24); and Inserting the aluminum tube (46) through the hole (54) in the cross member (24) while nesting the cross member (24) against the inner surface of the channel (29). [2] The method of claim 1, further comprising stamping an aluminum truck bed (12) and connecting the aluminum tube (46) or cross member (24) to the aluminum truck bed (12). [3] The method of claim 2, further comprising inserting a fastener through the aluminum truck bed (12), the aluminum tube (46), the cross member (24) and the aluminum reinforcement beam (34) for attachment to a frame rail (44) of a vehicle. [4] The method of claim 1, wherein the step of extruding the aluminum tube (46) further comprises forming the aluminum to include a plurality of annular stepped surface features (50) on an outer surface of the aluminum tube (46) to facilitate friction welding. [5] The method of claim 4, wherein the surface features (50) are ribs extending along a length of the aluminum tube (46). [6] Vehicle comprising: a pair of longitudinally aligned frame rails (44); an aluminum truck bed (12) disposed over the frame rails (44); a transversely extending cross member (24) contacting the aluminum truck bed (12) and disposed between the aluminum truck bed (12) and the frame rails (44); a spacer disposed between and contacting the cross member (24) and one of the frame rails (44); and an aluminum tube (46) friction welded to the spacer and in contact with the aluminum truck bed (12). [7] A vehicle according to claim 6, wherein the spacer indirectly connects the cross member (24) to one of the frame rails (44). [8] The vehicle of claim 6, wherein the cross member (24) includes a base (36) and a pair of opposed side walls (38) extending from the base (36) toward the aluminum truck bed (12). [9] The vehicle of claim 8, wherein the spacer comprises a base (36) contacting the base (36) of the cross member (24) and one of the frame rails (44). [10] The vehicle of claim 6, wherein the aluminum tube (46) includes a plurality of annular stepped surface features (50) on an outer surface of the aluminum tube (46). [11] The vehicle of claim 10, wherein the surface features (50) are ribs extending along a length of the aluminum tube (46). [12] The vehicle of claim 6, wherein the aluminum tube (46) includes a hollow interior dimensioned to receive a fastener that indirectly connects the aluminum truck bed (12) to the frame rails (44) with a space therebetween. [13] The vehicle of claim 6, further comprising the spacer in the form of a friction welded extruded aluminum spacer and the aluminum tube (46). [14] Reinforcing arrangement for an aluminum truck bed (12) of a vehicle, comprising: a cross member (24) having a surface defining an opening therethrough and an elongated channel (29); an extruded aluminum reinforcement beam (34) secured to the cross member (24) outside the channel (29), the aluminum reinforcement beam (34) being disposed between the cross member (24) and a frame rail (44) of the vehicle; and an extruded tubular support friction welded to the aluminum reinforcement support (34) and disposed through the opening and into the channel (29). [15] The reinforcement assembly of claim 14, wherein the extruded tubular beam engages the aluminum truck bed (12) of the vehicle at an end of the extruded tubular beam opposite the frame rails (44). [16] The reinforcement assembly of claim 14, wherein the extruded tubular support comprises surface features (50) on an outer surface of the extruded tubular support. [17] The reinforcement assembly of claim 16, wherein the surface features (50) are ribs extending along a length of the extruded tubular beam. [18] The reinforcement assembly of claim 14, further comprising a fastener extending through the extruded tubular beam, the opening in the cross member (24), the extruded aluminum reinforcement beam (34) and the frame rails (44).

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