GB2187148A

GB2187148A - Frame construction

Info

Publication number: GB2187148A
Application number: GB08603235A
Authority: GB
Inventors: John Philip Hancock
Original assignee: British Alcan Aluminium Ltd
Current assignee: British Alcan Aluminium Ltd
Priority date: 1986-02-10
Filing date: 1986-02-10
Publication date: 1987-09-03
Also published as: WO1987004679A1; EP0234800A1; US4958844A; ATE56925T1; GB8603235D0; JPH01502418A; DE3765135D1; CA1305738C; AU7021887A; ES2018540B3; GB2187148B; EP0234800B1; AU602331B2

Abstract

A load-bearing structural member (5-6) comprising at least two hollow extrusions 12-13 of light metal alloy each formed with two surfaces mated together with a layer of adhesive therebetween by relative linear movement of the extrusions in a single direction, the surfaces on one of the extrusions being formed on limbs (29) projecting therefrom and the angle between the mating surfaces and said direction being within the range 5 DEG to 150 DEG , the surfaces on the other extrusion terminating in shoulders (21) to be approached by the tips of the limbs (29) and means to ensure that the layer of adhesive always extends between the shoulders 21 and the tips (74).

Description

GB 2 187 148 A

SPECIFICATION to the accompanying drawings inwhich:

Figure 1 is a side elevational view of part of a veh Frame construction iclechassis, Figure 2 is a pia n view of th e ch assis of Fig u re 1, This i nventi on rel ates to a f ra me constructio n su ch 70 Figure 3 is a part section on the line 111-111 of Figure 1 as a vehicle chassis. to an enlarged scale, Conventionally vehicle chassis for commercial Figure4is a view of part of Figure 3 to a further vehicles are generally steel 1adderframe" con- enlarged scale, and structions which are torsionally very flexible and reli- Figure 5is a section on the line V-V of Figure 3to ance is placed upon this flexibility to contribute to 75 the same scale as Figure 4.

the vehicle suspension. It has never proved commer- Referring to Figures 1 and 2 these show the rear cially satisfactoryto make such a chassis of light end of a vehicle chassis 1 for a commercial vehicle metal alloys such as aluminium alloys largely be- having a body 2 and two pairs of wheels such as3 causefatique problems generated at all thejoints and 4. The chassis comprises side rails 5 and 6joined have been difficuitto overcome. Nevertheless there 80 bycross-members 7. Outriggers 8 are carried bythe is considerable pressureto make use of light metal chassisto support a floor 9 andthevehicle body2.

and particularly aluminium alloys both in viewof Appropriate cross members 7 carry parts 10 of the theirgreater corrosion resistance and alsoto save transmission system of the vehicle and different weight. cross members support suspension elements, indi- In recentyears important developments have 85 cated generally at 11, forthewheels 3 and 4.

taken place in suspension systems particularly pneu- Referring nowto Figures 3,4and 5the chassis 1 is matically operated systems, and these have now substantially wholly of aluminium alloy and the side reached a point of design where it is beneficial to use rails 5 and 6 comprise three hollow extrusions; a a much more torsionally stiff chassis structure. central extrusion 12 and identical top and bottom ex- Thus a vehicle chassis can now be as rigid as it is 90 trusions 13 and 14.

possible to make it commensurate with other design The central extrusion 12 is rectangular in cross constraints and it is an object of the present inven- section with side walls 15 and 16 and top and bottom tion to provide such a chassis that can be of light walls 17 and 18. Outwardly of its end walls the extru metal such as of aluminium alloys. sion 12 has upper and lower pairs of inwardlycurved According to one aspect of the present invention 95 limbs 19 and 20. These limbs are set inwardly of the there is provided a frame construction such as a veh- side walls to provide shoulders 21.

icie chassis having at least two spaced apart side The top and bottom extrusions 13 and 14 are of rails each comprising at ieasttwo hollow extrusions box like formation having sidewalls 22 and 23 and of light metal alloy formed with closely mating sur- end walls 24 and 25. The walls 25 are extended to faces bonded togetherwith an adhesive, at least one 100 provide flanges 26. Each side wall 22 and each end of the members being formed with at least one extru- wall 25 is formed with a re-entrant slot 27; 28 to rece ded formation for receiving fasteners to be secured ive fasteners in conventional manner. The walls 22 to other parts of the vehicle. and 23 are extended beyond thewalls 24to provide Preferably each side member has three hollow ex- limbs 29 having internal surfaces 30 which closely trusions; a central symmetrical extrusion and a pair 105 embracethe outer surfaces of the limbs 19. The outer of identical top and bottom extrusions bonded to op- surfaces 31 of the limbs 29 are aligned with the outer posite ends of the central extrusion. The extruded surfaces of the walls 15 and 16 of the central extru formations may be re-entrant slots and are prefer- sion 12. Thethree extrusions are bonded together ablyformed only in thetop and bottom extrusions. with a toughened single part epoxy adhesive such as The side rails may be linked by spaced apartcross 110 that sold underthe Registered Trade Mark"Perma members of.stiff boxformation extending between band" astype ESP1 10. ftwill be understood that by brackets bonded to the side rails. The walls of the providing the slots 27 and 28 other items, as will be boxformation are preferably internally stiffened by described, may be secured tothe railswithoutthe their flexible tapes stuckto the walls of the boxat stress-raising problems associated with hole dril predetermined high stress locations. 115 ling.

According to another aspect of the invention there The cross members 7 are of mixed mechanical and is provided a frame construction such as a vehicle bonded construction and are carried by heavy cast chassis comprising a pair of spaced apart side rails of brackets such as 32 at each end thereof. The brackets light metal alloy joined by a plurality of spaced apart 32 have a base 33, side walls 34, end walls 35 and box structures, each box structure having a pairof 120 internal reinforcements 36. The brackets are secured brackets bonded to the side rails and comprising top to the rails by binding their bases 33 to the walls 23, and bottom walls secured to the brackets and side 15 and 23 of the top, central and bottom extrusions walls of sheet material reinforced at predetermined 13,12 and 14. Rivetted connections (not shown) may high stress locations with theirflexible tapes stuck also be provided since drilling the walls 23 and 15 thereto. Preferablythe upper and lower surfaces of 125 does not significantly reduce the stress efficiency of the side rails are joined by sheet material between the rails.

the box structuresto provide a monocoque construc- Opposed brackets 32 arejoined attheir upper and tion. lower ends by "top hat" extrusions 37 and 38 (Figure The above and other aspects of the invention will 5) each having a base 39 and upstanding walls 40 now be described byway of example with reference 130 disposed inwardly of the side edges of the base. As 2 GB 2 187 148 A 2 shown in Figure3the lowerextrusion 38 has itswalls

Claims

cut and the base 39 is bentto provide a central part CLAIMS

41 and inclined ends 42. The extrusions 37 and 38 are secured to the brackets 32 by bolts 43 passing 1. Aframe construction such as a vehicle chassis through the walls 40. These bolts also pass through 70 having at least two spaced apart side rails each com sleeves 44 having their ends extending into recesses prising at least:two hollow extrusions of light metal (not shown) in the walls 34 to reduce stress in the alloy formed with closely mating surfaces, bonded cast brackets 32. The cross members 7 are provided together with an adhesive, at least one of the mem with side wal Is 45 comprising sheets 46 held by the bers being formed with at least one extruded form- bolts 43 and by additional bolts such as 47 in the 75 ation for receiving fasteners to be secured to other brackets 32. parts of the vehicle.

As shown only in Figure 3 the internal surfaces of
2. A frame construction according to claim 1 in the sheets 46 are reinforced byflexible tapes of which each side member has three hollow ex woven plastics material 48 stuckto these internal trusions; a central symmetrical extrusion and a pair surfaces. Thetapes are shown in a generally lattice 80 of identical top and bottom extrusions bonded to op formation between additional bolts 49 securing the posite ends of the central extrusion.

sheets 46to the walls 40 of the extrusions 37 and 38.
3. A frame construction according to claim 1 or However, in practice these tapes may be differently claim 2 in which the extruded formations are re shaped and differently disposed depending upon the entrant slots and are formed only in the top and stress patterns shown to develop in the cross membottom extrusions.

bers 7 by a suitable computer programme. Between
4. A frame construction according to anyone of each cross member 7 the chassis is enclosed by their the preceding claims in which the side rails are linked sheets 50 which are secured attheir side edges to the by spaced apart cross members of stiff boxform rails 5 and 6 by extruded strips 51 held by bolts such ation extending between brackets bonded to the side as 52 engaged in the slots 28. The sheets 50 are also 90 rails.

bonded to the bases 39 of the extrusions 38.
5. Aframe construction according to claim 4in The arrangementso far described thus provides a which the walls of the boxformation are internally very stiff chassis of monocoque construction having stiffened by theirflexible tapes stuckto the walls of clean surfaces. The interior of the chassis, between the box at predetermined high stress locations.

the cross members 7 may be used to contain items 95
6. Aframe construction comprising a pair of spa such as fuel tanks, air reservoirs and spare wheels so ced apart side rails of light metal alloyjoined by a that the vehicle has a physically and aerodynamic- plurality of spaced apart box structures, each box ally clean underside. structure having a pair of brackets bonded to the side Pairs of floor support cross members 53 of -Crails and comprising top and bottom walls secured shape having upper and lowerflanges 54 and 55 100 to the brackets and side walls of sheet material re joined by wal Is 56 are arranged backto back with the inforced at predetermined high stress locations with walls 56 spaced apart across the upper extrusions 37. theirf lexible tapes stuckthereto.

The cross members 53 extend beyond the rails 5and
7. Aframe construction according to claim 6 in 6 and are secured thereto by clamps 57 held by bolts which the upper and lower surfaces of the.side rails (not shown) in the slots 28 and engaged over prot- 105 are joined by sheet material between the box struc rusions 58 on the flanges 54. The outriggers 8 are tures to provide a monocoque construction.

formed of two sheets of material extending between
8. Aframe construction substantially as herein and secured to the cross members 53 and formed described with reference to Figure 1, Figure 2, Figure with flanges 59 secured by bolts 60 in the slots 27. 3, Figure 4 and Figure 5 of the accompanying The floor planks 9 are conventionally secured to the 110 drawings.

cross members 53. It will be understood thatthis floor construction further contributes to the stiffness of the chassis. Printed for Her Majesty's Stationery Office by Croy n Printing Company (UK) Ltd,7187, D8991685.

The forward end of the chassis (not shown) has an Pu bl isohed by The Patent Office, 25 Southampton Buildings, London, WC2A 1 AY, additional structure alongside and underneath it to from which copies maybe obtained, integrate with the front suspension mounting assembly and assist in accepting braking loads. This structure would also be designed to compensate for loss of strength to the chassis at the points where the monocoque skins 50 are discontinued around the rear of the engine and gearbox. Large f lat plates are attached across the outer faces of the structure on each side, extending above itto the full chassis depth and bolted to the side rails 5 and 6 via the-T-siots 27.

These plates may, in fact, be plate-like assemblies built up from several laminations of thinner plate and having the central areas of some layers removed to save weight. Also, to avoid a forming operation, a suitably designed flange section could be attached to the plate structure to stiffen the edge.