GB2331477A

GB2331477A - Connecting elongate metallic members

Info

Publication number: GB2331477A
Application number: GB9724589A
Authority: GB
Inventors: James Neville Randle; Martin Jarrett; Andrew Rogers
Original assignee: Luxfer Group Ltd
Current assignee: Luxfer Group Ltd
Priority date: 1997-11-20
Filing date: 1997-11-20
Publication date: 1999-05-26
Anticipated expiration: 2017-11-20
Also published as: GB9724589D0; GB2331477B; GB2331477A9

Abstract

A method for connecting elongate metallic members and a connection and/or structure using the method in which a first elongate member (1) has an internal channel (WXYZ) into which a second elongate member (10) is inserted, the second member being inserted at least partly into the first member and indenting the first member into the second member in the channel region, the second member being secured relative to the first member.

Description

2331477 CONNECTING ELONGATE METALLIC MEMBERS The present invention relates

to a method f or connecting elongate metallic members and also to elongate metallic members adapted for connection. It is particularly useful in, but not limited to, use in vehicles.

Aluminium extrusions and castings are known to be used in the manufacture of internal structures in motor vehicles, see, for example, European patent application EP-A-0234800, European patent application EP-A-0043228, and German patent application DE-A-3811427. Specifically, aluminium extrusions and castings have been used in a number of automotive chassis and space-frames, as well as being used extensively in the construction of commercial vehicles and public service vehicles.

Aluminium extrusions or castings are often used in vehicles as elongate members. In the past, amongst other methods, aluminium castings have been used as fasteners or nodes to connect extrusions. Alternatively, notched extrusions have been joined and strengthened with plates. Even conventional welding has been used such as Metal Inert Gas (MIG) welding, Tungsten Inert Gas (TIG) welding. The problems of joining aluminium extrusions or castings are significant, particularly in non-uniform regions such as at the corners of windscreens and doors.

None of the known methods is ideal, due to problems of poor positional accuracy and lack of strength in the resulting joints. For example, distortion, and damage to heat treated materials, is caused by welding. Furthermore, where adhesive is used, poor adhesion occurs due to the squeezing out of adhesive during the assembly of parts designed to mate very closely.

1 is The present invention relates to a method of connecting to a first elongate metallic member, a second elongate metallic member, the first member comprising an internal longitudinal channel, the first member being configured so as to prevent lateral insertion of the second member, the second member being insertable longitudinally into the first member with there being play towards and away from the channel, and the second member comprising at least a portion configured to fit into the channel, the method comprising the steps of inserting the second member at least partway into the first member, pressing the second member into the channel, and securing the second member in position relative to the first member.

The connection is highly reliable and the members can be connected quickly. This has particular advantages of providing strong connections, and providing local stiffening to parts of a vehicle that may be particularly highly loaded, such as the A-pillars of an automotive spaceframe, whilst allowing for time-efficient massproduction.

Preferably, the first member comprises a pair of side walls joined by a transverse wall to define the channel, the play being towards and away from the transverse wall.

Preferably the side walls of the first member provide channel side surfaces which diverge away from the transverse wall and are in the range of 50 to 4511, and preferably less than 200, from parallel.

Preferably, the first member is hollow and preferably said transverse wall is the shorter of a pair of opposed walls between which there is the play.

Preferably the second member is hollow, and preferably comprises a further pair of opposed walls, one wall of which is shorter, joined by a further pair of side walls.

Preferably, the members are at least approximately quadrilateral in crosssectional shape. Preferably each member is of uniform cross section along its length. Preferably each member has four walls that are straight, curved or otherwise shaped with parallel, tapering or curved surfaces.

Preferably the members are trapezoidal in cross sectional shape with opposed walls being parallel.

Preferably the members are made of a light metal or light metal alloy, preferably aluminium or aluminium alloys, e.g. Sxxx, 6xxx and 7xxx series alloys. The members are preferably extrusions or castings or a combination of both. Castings can have non uniform cross sections along their lengths.

The method of connecting preferably comprises securing by adhering at least one wall defining the channel to at least one corresponding surface of the second member using adhesive. Preferably adhesive is applied to a corresponding surface or surfaces of the second member bef ore it is inserted into the first member, preferably with gaps f or the adhesive between the channel and the corresponding surf aces of the second member. When inserted to a predetermined longitudinal position, the second member is preferably then pressed into the channel.

The method of connecting preferably comprises the step of deforming the longer wall of the pair of opposed walls of the first member, for example by pressing it inwards, 1 I i 1 is preferably using a tool, so that it abuts the second member so as to hold it in the channel, for example until the adhesive sets. Preferably this pressing results in an indented second member, the indent acting to hold the first member in position in the channel. Preferably the longer wall of each of at least one, and preferably both, members has a relatively thin part for ease of deformation, and preferably when deformed the first member holds the second member in longitudinal position also.

The present invention also relates to a corresponding method of connecting each of a plurality of second elongate metallic members to corresponding first elongate metallic members. Each of the second members have preferably been fixed to other of the second members by welding, for example, to form one or more nodes.

The present invention also relates to a structure comprising a second elongate metallic member and a first elongate metallic member, the first member comprising an internal longitudinal channel, the first member being configured so as to prevent lateral insertion of the second member, the second member having been inserted longitudinally at least partway into the first member with play towards and away from the chann6l, the second member comprising at least a portion configured to fit into the channel, the second member having been pressed into the channel and having been secured in its position relative to the first member.

The structure is preferably for load bearing use in vehicle, such as an automobile.

a The present invention also relates to a frame comprising a plurality of second elongate metallic members and corresponding first elongate metallic members. Each of the second members have preferably been fixed to other of the second members by welding to form one or more nodes.

The frame is preferably for load bearing use in a vehicle, such as an automobile.

The present invention also relates to apparatus comprising a second elongate metallic member and a first elongate metallic member, the first member comprising an internal longitudinal channel, the first member being configured so as to prevent lateral insertion of the second member, the second member being insertable longitudinally at least partway into the first member with play towards and away from the channel, the second member comprising at least a portion configured to fit into the channel so that the second member is adapted to be pressed into the channel.

Preferred embodiments of the present invention will now be described by way of example and with reference to the drawings, in which:

Figure 1 is a cross sectional view through first and second hollow extrusions in an intermediate position during assembly according to a first embodiment, Figure 2 is a cross sectional view according to the first embodiment showing the extrusions in unjoined configuration, Figure 2a is a cross sectional view according to the first embodiment showing the extrusions in the joined m is configuration (corresponding to Section A-A shown in Figure 3), Figure 3 is a schematic diagonal view of part of a frame including four joined pairs of extrusions according to the first embodiment.

Figure 4 is a cross sectional view through first and second hollow extrusions according to a second embodiment, Figure 5 is a cross sectional view through a first and second hollow extrusion according to a third embodiment, and Figure 6 is a cross sectional view through a first and second hollow extrusion according to a fourth embodiment.

As shown in Figure 1, a first extrusion 1 comprises a pair of parallel opposed walls 2, 4, one opposed wall (top wall) 2 being shorter than the other opposed wall (bottom wall) 4. The top wall 2 has an inner top face W, and the bottom wall 4 has an inner bottom face X. The opposed walls 2, 4 are joined by side walls 6, 8 which have respective inner faces Y, Z which are out of parallel by between 50 and 250. The first extrusion 1 has a uniform cross section.

The second extrusion 10 (also known as a nodal extrusion) comprises a pair of parallel opposed walls 12, 14, of which one 12 is shorter, joined by side walls 16, 18. These side walls 16, 18 have respective external faces A, B which are out of parallel by between 50 and 250.

In this embodiment, the faces A, B are out of parallel by the same angle as the corresponding inner surfaces Y, Z of the side 6, a of the first extrusion 1. The second extrusion 10 has a uniform cross section.

Before connecting the first extrusion 1 and second extrusion 10 both are pre-treated using pre-treatments such as chromium based pre-treatments as described in European patent application EP-A-0127343. Non-chromium pretreatments can also be used. Pre-treatment is to ensure that subsequently applied as discussed below adhesive bonds well to the extrusions 1, 10.

For connection, adhesive is applied to its faces A, B and its external top face C. The second extrusion 10 is then slid partway into the end of the first extrusion 1 to a degree of overlap by the first extrusion sufficient to enable a strong join. The separation of the opposed walls of the first extrusion (i.e. between inner top face W and inner bottom face X) is greater than that of the external top face C and bottom face D of the second extrusion. There is thus some "play" between the two extrusions, as can be seen by a comparison of Figure 2 and Figure 2a.

As shown in Figure 2, the second extrusion 10 is slid into the first extrusion 1 along its inner bottom face X after adhesive (not shown) has been applied to its top face C and the external faces A, B of its side walls 16, 18. There is thus no contact at this stage between the respective side walls 6, 16, 8, 18 and the respective top walls 2, 12 of the two extrusions 1, 10. In consequence, adhesive is not wiped from those surfaces during insertion. The adhesive is a cold cure adhesive such as epoxy resin. Alternatively, the adhesive can be a heat-curable adhesive and/or an acrylic resin. The adhesive is preferably a load-bearing adhesive.

Once the extrusions are in a desired relative longitudinal position, pressure is applied against the external face D of the bottom wall 14 of the second extrusion lo so as to bring its top face C and external faces A, B of its side walls 16, 18 into contact with the corresponding internal faces X, Y, Z of the first extrusion, as shown in Figure 2a. As shown in Figures 2 and 2a the top wall 2 and side walls 6, 8 of the first extrusion define a channel 20 into which the second extrusion fits, and because of the adhesive a strong adhesive bond is obtained. The pressure can be applied by use of a tool (not shown) to indent the bottom wall 4 which is relatively thin, of the first extrusion 1 so as to cause it to bend and press on the bottom wall 14 of the second extrusion 10. Alternatively the pressure can be applied by piercing the bottom wall 4 of the first extrusion 1 and passing the head of a pressing tool (not shown) through each hole. In this embodiment, the pressure is only applied until the adhesive is set.

In an alternative embodiment, a rivet, self-tapping screw or other fastener (not shown) from the top wall 12 of the second extrusion 10 through the top wall 2 of the first extrusion 1 is used to pull the faces C and W together. In other embodiments, such mechanical fasteners can be applied to any surfaces causing the second member to be pressed into the channel of the first member.

The joined first and second extrusions also has a stiffening function. The extrusions can either be straight in their longitudinal direction or with a continuous uniform radius where one is inserted inside the other.

is As shown in Figure 3, a frame, for example, an aluminium space frame for use in a vehicle is constructed from a number of first and second extrusions. Second extrusions 10 are welded together to form nodes, for example using known MIG and TIG methods. The preferred welding method is friction welding because it results in a weld having a strength close, if not equal, to the strength of a second extrusion 10 as such.

Four second extrusions 10 are shown welded together (around a nodal Point 22) in Figure 3, however, a different number of second extrusions can be selected for welding together. The welded second extrusions are then pressed into a selected configuration, for example to fit a selected vehicle type and a cap shaped plate 24 formed by pressing, die casting, conventional casting or another suitable method is fitted over the welds after the first extrusions have been fitted. The overlap of first and second extrusions is not only to connect them but also provides increased stiffness to the frame.

Other embodiments of the invention are shown in Figures 4, 5, and 6.

In the embodiment shown in Figure 4, the first extrusion It and second extrusion 10f have respective side walls 61, 8f, 161, 181 including outward bends, and are otherwise similar. The separation of opposed walls 121, 141 of the second extrusion 101 is greater than in the first embodiment. In the otherwise similar embodiment shown in Figure 5, only the first extrusion ill includes outward bends in its side walls 611, 811. In these two embodiments (shown in Figures 4 and 5), the side wall portions 6a', 8a', 6all, 8all of the first extrusions 11, ill adjacent their respective bottom walls 41, 411 are parallel and act as guides preventing relative transverse movement of the second extrusion 101, 1011 during sliding. For example, in the Figure 4 embodiment, the side walls 61, 8f of first extrusion 1f have inner faces E, F below their bends; and the side walls 161, 181 of the second extrusion 101 have outer faces G, H below their bends, the first extrusion being dimensioned so that faces E, F contact faces G, H so that relative lateral movement is prevented. In other embodiments, other surfaces perform this guiding function.

In the event that greater tensile strength is required, as shown in Figure 6, a rod or cable (not shown) can be inserted through the hole 28 running through a predominantly solid second extrusion 10110 and tightened at some remote point. The additional tensile strength can be required when used in buildings, bridges, and bus and railway carriage structures.

In other embodiments, the extrusions are replaced by castings. Castings can have non uniform cross sections along their lengths.

Claims

CLAIMS is 1. A method of connecting a first elongate metallic member to a

second elongate metallic member, the f irst member comprising an internal longitudinal channel, the f irst member being conf igured so as to prevent lateral insertion of the second member, the second member being insertable longitudinally into the first member with there being play towards and away from the channel, and the second member comprising at least a portion configured to f it into the channel, the method comprising the steps of inserting the second member at least part way into the f irst member, indenting the f irst member into the second member in the channel region, and securing the second member in position relative to the first member.
2. Connection between a f irst elongate metallic member and a second elongate metallic member, the f irst member comprising an internal longitudinal channel, the first member being configured so as to prevent lateral insertion of the second member, the second member being insertable longitudinally into the first member with there being play towards and away f rom the channel, and the second member comprising at least a portion conf igured to f it into the channel, the members being secured by an indentation between the first and second members.
3. A method or connection according to any one of the preceding claims wherein the first member comprises a pair of side walls joined by a transverse wall to def ine the channel, the play being towards and away from the transverse wall.
4. A method or connection according to claim 3 wherein the side walls of the first member provide channel side surfaces which diverge away from the transverse wall and are in the range of 50 to 450 and preferably less than 200 from parallel.
5. A method or connection according to any one of the preceding claims wherein the first member is hollow and preferably said transverse wall is the shorter of a pair of opposed walls between which there is play.
6. A method or connection according any one of the preceding claims wherein the second member is hollow and preferably comprises a further pair of opposed walls, one wall of which is shorter, joined by a further pair of side walls.
7. A method or connection according to any one of the preceding claims wherein the members are at least substantially quadrilateral in cross-section or shape.
8. A method or connection according to any one of the preceding claims wherein each member is of uniform crosssection along its length.
9. A method or connection according to any one of claims 1 to 6 wherein each member has four walls that are straight, curved or otherwise shaped with parallel, tapering or curved surfaces.
10. A method or connection according to any one of claims 1 to 6 wherein the members are trapezoidal in crosssectional shape with opposed walls being parallel.
A method or connection according to any one of the preceding claims wherein the members are made of a light metal or light metal alloy, preferably aluminium or aluminium alloys.
12. A method according to claim I and any preceding claim dependent thereon wherein securing the second member in position relative to the first member comprises securing by adhering at least one wall defining the channel to at least one corresponding surface of the second member, using adhesive.
13. A method according to claim 12 wherein the adhesive is applied to a corresponding surface or surfaces of the second member before it is inserted into the first member, preferably with gaps for the adhesive between the channel and the corresponding surfaces of the second member.
14. A method according to claim 12 or 13 comprising the step of deforming a longer wall of a pair of opposed walls of the first member so that it abuts the second member.
15. A structure including the connection of claim 2 and any claims dependent thereon.
16. The structure of claim 15 incorporated in an automobile.
17. An automobile including the structure of claim 16.
18. A method of connecting a first elongate metallic member to a second elongate metallic member substantially as described with reference to one or more of the accompanying drawings.
19. A connection or structure substantially as described with reference to one or more of the accompanying drawings.