GB2491846A

GB2491846A - Automobile chassis

Info

Publication number: GB2491846A
Application number: GB201109890A
Authority: GB
Inventors: John Francis Owen
Original assignee: ACEDES HOLDINGS LLC
Current assignee: ACEDES HOLDINGS LLC
Priority date: 2011-06-13
Filing date: 2011-06-13
Publication date: 2012-12-19
Also published as: GB201109890D0; CN202608893U

Abstract

A chassis structure comprises a multiplicity of cylindrical pivot members 1 which are arranged in parallel spaced relation to form nodes of the chassis. Joint members 2, 3 are located on each pivot member 1 and have a cylindrical sleeve 4 dimensioned to receive and form a sliding fit with the pivot member 1. The joint members have one or more attachment projections 5, 6, 7, 8, 9. Braces 10 extend between the projections of a pair of joint members, and each brace comprises an elongate body having sockets 12 at opposite ends. The sockets are dimensioned to receive a projection. One or more main section members 13 are provided, each having an elongate body with two or more sockets 14, 15 at each end. The sockets are dimensioned to receive a projection. The joints are bonded to respective sleeves, braces and optional main section members by a curable adhesive composition.

Description

AUTOMOBILE CHASSIS

This invention relates to an automobile chassis, particularly but not exclusively for electrically powered vehicles.

Most vehicle chassis structures are formed in a monocoque body structure wherein the chassis is integral with the body and formed by steel or aluminium pressings welded together to form a single structure. This method requires a high level of investment in tooling and machinery and is suitable only for high volume production. Space frame chassis structures are also used for low volume products, for example sports or racing cars. In space frame chassis constructions, a separate assembly is formed by welding together tubular steel or aluminium members to form a single structure. This requires the use of complicated jigs to ensure dimensional stability.

According to a first aspect of the present invention, a chassis structure comprises a multiplicity of cylindrical pivot members arranged in parallel spaced relation to form nodes of the chassis; two or more joint members located on each pivot member, each joint member including a cylindrical sleeve dimensioned to receive and form a sliding fit with a pivot member; each joint including one or more attachment projections; a multiplicity of braces, each brace extending between projections of a pair of joint members, each brace comprising an elongate body having sockets at opposite ends, each socket being dimensioned to receive a projection; one or more optional main section members each comprising an elongate body having two or more sockets at each end, each socket being dimensioned to receive a projection; the joints being bonded to respective sleeves, braces and optional main section members by a curable adhesive composition.

In preferred embodiments each pivot member comprises a hollow cylindrical member arranged to extend vertically in use. Use of a hollow cylindrical construction confers the advantage that the pivot member may be mounted upon a support member during assembly of the chassis. Alternatively the pivot member may be unsupported during assembly.

In preferred embodiments the joint member comprises a cylindrical sleeve with one or more projections extending radially from the sleeve.

In preferred embodiments the joint may have one, two or three projections extending from the sleeve in a common radial plane.

In preferred embodiments each main section comprises an elongate body with two or more sockets at each of opposite ends thereof The pivot members, joint members, braces and any main section members are preferably composed of a magnesium-containing alloy. Preferred magnesium alloys may be selected from the group consisting of: magnesiumlaluminiumlzinc alloys and magnesium/zinc/manganese alloys optionally containing one or more of zirconium, silicon, copper, nickel, iron or calcium.

Further elements may be present. Preferred alloys consist of magnesiumlaluminiumlzinc or magnesium/zinc/manganese alloys together with minor amounts of zirconium, copper, silicon, nickel, iron and calcium.

The pivot members, joint members and main section members are preferably shaped with a constant cross section so that they may be formed by extrusion.

Use of magnesium containing alloys provides a lightweight but strong construction which may provide dimensional accuracy during extrusion.

Particularly suitable alloys may be selected from the group consisting of: (i) Mg Al 2.5-3.5 Mn0,21*0 Zn0614, optionally including: Si0*1 Cm.os La004 plus Ni (50 ppm) and Fe (50 ppm); (ii) Mg Al5,872 Mn0 15050 Zn0,41,5, optionally including: Sio,i Cn0,05 La004 plus Ni (50 ppm) and Fe (50 ppm); (iii) Mg Al789.2 Mn012..0,50 Zn0,20,8, optionally including: Si0,1 Cn005 La004 plus Ni (50 ppm) and Fe (50 ppm) (iv) Mg Zn4 662 Zn 0.45; iF (v) Mg Al243,6 Mn0,05o4 Zn05..15, optionally including: Sio.i Cn0.05 Fe005 and Ni (50 ppm); (vi) Mg Al7 892 Mn0 1204 Zn0 515, optionally including: Si0.1 Cn005 Fe005 and Ni (50 ppm); (vii) Mg Zn4 862 Zn 0.45-0.8; (viii) Mg Al01 Mn0 061 6 Zn17523, optionally including: Si0.1 Cn005 Fe006 and Ni (50 ppm); Use of compounds (iii) or (vi) is particularly preferred to provide an optimum compromise between strength and dimensional accuracy during extrusion.

The invention finds particular application in manufacture of electrically powered cars, for example small sized town cars Use of magnesium alloy confers the advantage that the chassis is lighter than a corresponding aluminium construction. The chassis is also fUlly recycleable. A high damping capacity and high strength to weight ratio are also provided. The preferred magnesium alloys are easy and safe to machine, easily deformable at moderate temperatures. The alloy also confers high electromagnetic interference, good thermal and electrical conductivity and good radio frequency interference properties.

Preferred alloys have the following properties:-Property Alloy (vi) Alloy (iii) Density at 20°C g/cm3 L83 1.78 Liquidus Temperature °C 610 645 Solidus Temperature °C 490 570 Incipient Melting Temperature °C 427 565 Ignition Temperature °C 542 546 Specific Heat 20 -100°C I 1,076 1,040 37kg. °K Coefficient of Linear Thermal Expansion 27.2 26 at 20 -200°C pmIm.°K Latent Heat of Fusion kj/kg 280 339 Thermal Conductivity at 20°C 59.2 125 (Btu!ft.h°F) Electrical Resistivity at 20°C nQ/m 122 61 Poisson's Ratio 0.35 0.35 HardnessHB/RE 80-88 55-66 Tensile Yield Strength MPa 250 -275 160-175 Tensile Strength MPa 345 -380 230 -260 Elongation to Break % in 50mm 6 -7 11 -12 Compressive Yield Strength MPa 195 -240 93 Shear Strength MPa 150 -165 130 Ultimate Bearing Strength MPa 469 385 Bearing Yield Strength MPa 331 229 Modulus of Elasticity GPa 46-49 44 -48 The adhesive for joining braces to the joints may comprise any adhesive suitable for providing high strength bonds to metallic substrates. Acrylate or methacrylate adhesives may be used. A preferred adhesive is ReAct TM 730 manufactured by Hemon Manufacturing Inc. A preferred adhesive for joining a pivot member or main section to a joint may comprise a two component methacrylate adhesive adapted for bonding metal substrates. A preferred adhesive is Fusion Bond TM 371 manufactured by Hernon Manufacturing Inc. The preferred adhesives do not require surface preparation and bond well to dirty or oily surfaces, providing excellent gap fills and fast curing times. The pivot members, joint members braces and main sections may be dimensional to provide a gap of 0.3 to 0.8mm, preferably 0.5mm to accommodate the adhesive.

According to a second aspect of the present invention there is provided a kit for assembly into a car chassis comprising: a multiplicity of cylindrical tubular pivot members; a multiplicity of joint members, each joint member including a cylindrical sleeve adapted to receive a pivot member, and each joint including one or more attachment projections; a multiplicity of braces, each brace having sockets at opposite ends, each socket being dimensioned to receive a projection; one or more main section members, each comprising an elongate body having two or more sockets at opposite ends, each socket being dimensioned to receive a projection.

The kit may further comprise a quantity of one or more of metal bonding curable adhesives.

A chassis in accordance with the present invention confers the advantage that the assembly is self-jigging. A jig is not necessary to assemble the components as is required with a space-frame chassis.

According to a third aspect of the present invention there is provided a method of assembly of an automobile chassis comprising the steps of:-arranging a plurality of cylindrical pivot members each in a vertically extending parallel spaced relation; sliding one or more joint members into engagement with a pivot member, each joint member comprising a cylindrical sleeve dimensioned to form a slidable engagement with the pivot member, each joint member including one or more attachment projections; engaging a plurality of braces or main section members to attachment projections of adjacent joint members, each brace comprising an elongate body having sockets at opposite ends, each socket being dimensioned to receive a projection; each optional main section member comprising an elongate body having a plurality of sockets at each end, each socket being dimensioned to receive a projection; the method including the steps of applying an adhesive composition to surfaces of the pivot members, projections or sockets; arranging the pivot members, joint members, braces and optional main section members to form a chassis assembly; and curing the adhesive to form a chassis structure.

The chassis structure may comprise a complete vehicle chassis or a part of a complete vehicle chassis.

The invention is further described by means of example but not in any limitative sense with reference to the accompanying drawings, of which: Figure 1 is a perspective view of a joint assembly in accordance with this invention; Figure 2 is a perspective view of a typical chassis assembly for an electric city car in accordance with this invention; Figure 3 is a perspective view of a typical rolling chassis assembly for an electric city car in accordance with this invention; Figure 4 shows the cross section of a main section extrusion; Figure 5 is the cross section of a brace extrusion; Figure 6 is the cross section of a pivot member extrusion; Figure 7 is the cross section of a 90° joint extrusion; Figure 8 is the cross section of a 110° joint extrusion; Figure 9 is the cross section of a Tjoint extrusion; Figure 10 is the cross section of an end joint extrusion; and Figure 11 shows a partially assembled vehicle structure.

Figure 1 shows a joint assembly in accordance with this invention. A cylindrical pivot member (1) arranged in an upright orientation has two joint members (2,3) slidably inserted onto the outer cylindrical surface of the pivot member (1).

The lower joint member comprises a cylindrical sleeve (4) and two radially extending rectangular section attachment members (5,6). The upper joint member (3) has three radially extending rectangular section attachment members (7,8,9) extending radially at predetermined angles as described below.

A square section tubular brace an elongate body (10) and rectangular or square sockets (11,12) at opposite ends thereof The dimensions of the sockets (11 and 12) are selected to allow the attachment (5) to be inserted providing a suitable gap to receive an adhesive composition (not shown).

A main section member comprises an elongate rectangular body (13) having two rectangular or square sockets (14, 15) dimensioned and separated by a suitable distance to receive the attachment members (6,8) of the lower and upper joint members (2, 3). A suitable clearance is provided between the attachment member (8) and socket (14) to allow a quantity of adhesive to be disposed between the components to allow them to be bonded together.

Figure 2 shows a chassis assembly comprising joints as shown in Figure 1. A plurality of vertically extending tubular pivot members (20, 21, 22, 23, etc) have joint members e.g. (24, 25, 26, 27, 28) slidably engaged on the cylindrical outer surfaces. Braces (29, 30, 31, etc) extend between adjacent pivot members e.g. (20, 21) and joints e.g. (28). The lower chassis body is composed of main section members (32, 33, 34, etc) each being connected at opposite ends to pivot members by means of two joint members e.g. (24, 25).

During assembly of the chassis a first pivot member e.g. (20) is arranged vertically and the joint members (24, 25, 26, 27, 28) are slidably inserted onto the cylindrical pivot member (20).

Respective quantities of adhesive are applied to one or both of the contacting surfaces using a conventional applicator. A second pivot member e.g. (21) is provided with joint members in the same way. Main section members e.g. (32, 33) are inserted between adjacent pivot members to form the main structure of the chassis. Braces e.g. (30, 31) are engaged between respective pivot members to form the upper chassis, adhesive being applied between the joints as they are assembled.

The uncured chassis structure is then aligned using a jig before the resin is allowed to cure either at ambient temperature or in an oven as convenient.

S

Figure 3 shows a rolling chassis assembly suitable for use in manufacture of an electric powered city car. Main section members (40, 41, 42 etc) arc secured together by joints (46, 47, 48, etc) mounted on vertically extending pivot members (43, 44, 45). Wheel assemblies (49) are secured to the main section members to provide a rolling chassis structure.

Figures 4 to 10 show cross sectional views of extruded components for use in this invention.

Figure 4 shows a main section extrusion comprising an outer skin (50) cross braces (51) and upper (52) and lower (53) square section sockets dimensioned to recieve attachments of the joint members; Figure 5 shows a cross sectional view of a square section brace member and; Figure 6 shows a cross sectional view of a joint extrusion; Figure 7 is the cross sectional view of an extrusion forming a joint member. A cylindrical sleeve (54) having a cylindrical bore (55) integrally formed with square section attachment members (56, 57) formed with hollow central portions (58, 59) and closed end portions (60, 61); Figure 8 shows a cross sectional view of a 1100 joint extrusion; Figure 9 shows a cross sectional view of a T-joint extrusion and; Figure 10 shows an end joint extrusion; Figure 11 shows a partially assembled vehicle structure including a chassis in accordance with this invention.

Claims

CLAIMS1. A chassis structure comprising a multiplicity of cylindrical pivot members arranged in parallel spaced relation to form nodes of the chassis; two or more joint members located on each pivot member, each joint member including a cylindrical sleeve dimensioned to receive and form a sliding fit with a pivot member; each joint including one or more attachment projections; a multiplicity of braces, each brace extending between projections of a pair of joint members, each brace comprising an elongate body having sockets at opposite ends, each socket being dimensioned to receive a projection; one or more optional main section members each comprising an elongate body having two or more sockets at each end, each socket being dimensioned to receive a projection; the joints being bonded to respective pivot members and sockets by a curable adhesive composition.
2. A chassis structure as claimed in claim 1 where each pivot member comprises a hollow cylindrical member.
3. A chassis structure as claimed in claim 2 wherein the pivot members are arranged to extend vertically in use.
4. A chassis structure as claimed in any preceding claim wherein the joint member comprises a cylindrical sleeve with one or more projections extending radially from the sleeve.
5. A chassis structure as claimed in claim 4 wherein the joint has one, two or three projections extending from the sleeve in a common radial plane.
6. A chassis structure as claimed in any preceding claim wherein each main section comprises an elongate body with two or more sockets at each of the opposite ends thereof.
7. A chassis structure as claimed in any preceding claim wherein the pivot members, joint members and braces and any main section members are composed of a magnesium containing alloy.
8. A chassis structure as claimed in claim 7 wherein the alloy is selected from the group consisting of: magnesiumlaluminiumlzinc alloys and magnesiumlzinc/manganese alloys.
9. A chassis structure as claimed in claim 8 further containing one or more of zirconium, silicon, copper, nickel, iron and calcium.
10. A chassis structure as claimed in any preceding claim wherein the adhesive is an acrylate or methacrylate adhesive.
11. A kit for assembly into a car chassis comprising: a multiplicity of cylindrical tubular pivot members arranged in parallel spaced relation; a multiplicity of joint members, each joint member including a cylindrical sleeve adapted to receive a pivot member, and each joint including one or more attachment projections; a multiplicity of braces, each brace having sockets at opposite ends, each socket being dimensioned to receive a projection; one or more main section members, each comprising an elongate body having two or more sockets at opposite ends, each socket being dimensioned to receive a projection.
12. A kit is claimed in claim 11 further comprising a quantity of one or more metal bonding curable adhesives.
13. A method of assembly of an automobile chassis comprising the steps of:-arranging a plurality of cylindrical pivot members in vertically extending parallel spaced relation; sliding one or more joint members into engagement with a pivot member, each joint member comprising a cylindrical sleeve dimensioned to form a slidable slidable engagement with the pivot member, each joint member including one or more attachment projections; engaging a plurality of braces or main section members to attachment projections of adjacent joint members, each brace comprising an elongate body having sockets at opposite ends, each socket being dimensioned to receive a projection; each optional main section member comprising an elongate body having a plurality of sockets at each end, each socket being dimensioned to receive a projection; the method including the steps of applying an adhesive composition to surfaces of the pivot members, projections or sockets; arranging the pivot members, joint members, braces and optional main section members to form a chassis assembly; and curing the adhesive to form a chassis structure.
14. A chassis structure as claimed in claim 9 comprising magnesiumlaluminiumlzine or magnesiunilzinc/manganese alloy together with minor amounts of zirconium, copper, silicon, nickel, iron and calcium.