Face to rim connection for a composite wheel

Abstract

A connection (110) between a rim portion (102) and a face portion (104) of a composite wheel (100). The rim portion (102) comprises a first set of fibers (122). The face portion (104) comprises a second set of fibers (124). The connection (110) comprises a transition zone (120) in which the first set of fibers (122) and the second set of fibers (124) are arranged in a layered structure. Each layer (125A, 125B, 125C) of the layer structure includes a first section (127) including an arrangement of the first set of fibers (122), and a first connection end (128), and a second section (129) including an arrangement of the second set of fibers (124), and a second connection end (130). The first connection end (128) is arranged adjacent to or abutting the second connection end (130) forming a layer joint (132A, 132B, 132C). The layer joint (132A, 32B, 132C) of each adjoining layer (125A, 125B, 125C) is spaced apart in a stepped configuration.

Claims

1. A connection between a rim portion of a composite wheel including a first set of fibres and a face portion of the composite wheel including a second set of fibres, the connection comprising: a transition zone in which the first set of fibres and the second set of fibres are arranged in a layered structure, wherein each layer of the layer structure includes: a first section including an arrangement of the first set of fibres having a first connection end, and a second section including an arrangement of the second set of fibres having a second connection end, wherein the first connection end being arranged adjacent to or abutting the second connection end forming a layer joint, the layer joint of each adjoining layer being spaced apart in a stepped configuration.

2. The connection according to claim 1, wherein the layer joint of each layer is respectfully laterally spaced apart from the layer joint of each adjoining layer.

3. The connection according to claim 1, wherein the stepped configuration comprises a linear stepped arrangement.

4. The connection according to claim 1, wherein the layer structure comprises a plurality of stacked layers.

5. The connection according to claim 4, wherein each layer of the layer structure comprises a coplanar arrangement of the first section and the second section.

6. The connection according to claim 1, wherein the transition zone is spaced away from a position where the rim portion meets the face portion of the composite wheel.

7. The connection according to claim 1, wherein the composite wheel is formed about a central wheel axis, where the face portion includes the second set of fibres substantially radially aligned relative to the central wheel axis and the rim portion formed from the first set of fibres substantially axially aligned relative to the central wheel axis, and wherein the connection is formed from the second set of fibres extending from the face portion substantially axially aligned relative to the central wheel axis and the first set of fibres extending from the rim portion substantially axially aligned relative to the central wheel axis.

8. The connection according to claim 7, wherein the rim portion includes an edge flange portion which extends at an angle relative to the central wheel axis and the first set of fibres of the connection extend from the edge flange portion.

9. The connection according to claim 1, wherein at least some of the first set of fibres from the transition zone extend into the rim portion and at least some of the second set of fibres of the transition zone extend into the face portion of the composite wheel.

10. The connection according to claim 9, wherein at least a portion of the second set of fibres in the transition zone include a first set of second fibres which extend into a front portion of the face portion and a second set of second fibres which extend into a rear portion of the face portion of the composite wheel.

11. The connection according to claim 1, wherein each layer in the transition zone comprises oriented fibres that are either unidirectional fibres or biaxial fibres.

12. The connection according to claim 1, wherein the first set of fibres and the second set of fibres comprise carbon fibre fibres.

13. The connection according to claim 1, wherein the first set of fibres and the second set of fibres are provided as at least one fabric sheet.

14. The connection according to claim 1, wherein one or each of the first section and second section are formed from tailored fibre preform having a desired shape and fibre orientation.

15. The connection according to claim 1, further comprising at least one capping layer substantially extending over the stepped configuration of the layer joints.

16. The connection according to claim 1, further comprising a matrix material enveloping the first set of fibres and second set of fibres.

17. A method of connecting a rim portion and a face portion of a composite wheel, the rim portion of the composite wheel having a first set of fibres and the face portion of the composite wheel having a second set of fibres, the method comprising: providing in a first layer a first section including an arrangement of the first set of fibres having a first connection end and a second section including an arrangement of the second set of fibres having a second connection end, wherein the first connection end being arranged adjacent to or abutting the second connection end forming a first layer joint; providing at least one further layer over the first layer, the further layer having a further first section including an arrangement of a further first set of fibres having a further first connection end and a further second section including an arrangement of a further second set of fibres having a second connection end, wherein the further first connection end of the further layer being arranged adjacent to or abutting the further second connection end of the further layer forming a second layer joint; and wherein the layer joint of each adjoining layer is spaced apart in a stepped configuration.

18. The method of claim 17 further comprising connecting the rim portion and the face portion of the composite wheel using a connection between the rim portion and the face portion.

19. The method of claim 17, further comprising: providing a matrix material in contact with each of the layers of the connection; and curing the connection.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The present invention will now be described with reference to the figures of the accompanying drawings, which illustrate particular preferred embodiments of the present invention, wherein:

(2) FIG. 1 is a perspective view of a composite wheel including a connection between a face portion and rim portion thereof according to one embodiment of the present invention.

(3) FIG. 2 is a more detailed view of the rim to face connection region of the composite wheel shown in FIG. 1.

(4) FIG. 3 provides a schematic representation of the structural reinforcement components for the connection between the rim portion and the face portion of the composite wheel shown in FIGS. 1 and 2.

DETAILED DESCRIPTION

(5) Referring firstly to FIG. 1, there is shown a perspective view of a composite wheel 100 which includes the connection 110 of the present invention. The illustrated composite wheel 100 has been developed by the Applicant as being formed as a one-piece body. The general process of manufacture of the composite wheel 100 is described in International Patent Publication WO2010/024495A1, the contents of which are to be understood to be incorporated into this specification by this reference.

(6) The illustrated composite wheel 100 includes two main sections: A). a rim portion 102 comprises an annulus structure onto which a tyre (not illustrated) is mounted; and B). a face portion 104 comprising a circular hub 106 and a series of spokes 108. The hub 106 includes five fastening apertures 107 configured to received fastening bolts (not illustrated) used to fix the wheel to a wheel mount of a vehicle. The spokes 108 comprise elongate arms connected to the hub 106 at one end and the rim portion 102 at another end.

(7) As described in International Patent Publication WO2010/024495A1, the creation of such a one-piece composite wheel 100 necessitates use of a separate rim portion mold (not illustrated) and face portion mold (not illustrated). In use, the rim portion 102 is formed by laying up a first set of fibres typically embodied in a reinforcement fabric seated in the rim portion mold, and the face portion 104 is formed by separately laying up a second set of fibres, typically embodied in a reinforcement fabric seated in the face portion mold. The face portion mold includes an inner bucket mold and an outer cylindrical mold. The reinforcement fabric from the rim portion mold and face portion mold are then assembled together in a combined mold, with the separate portions being Interconnected at a connection point 110. A final molding process is then undertaken in which matrix material, such as a resin can be injected and/or infused into the reinforcement of the overall wheel form to produce a molded single piece wheel 100.

(8) A mechanically efficient connection between the rim portion 102 and face portion 104, and in particular each spoke to rim connection 110 is important to provide stiffness and strength to the wheel 100. In this respect, lateral, vertical and torsional loads are transmitted through a tyre to the rim portion 106 of the wheel 100. These loads transmit bending and torsional stresses through the spokes 108 that need to be resolved efficiently at each spoke to rim connection 110.

(9) The spoke to rim connection 110 of the present invention is formed through the interconnection of the rim reinforcement and face reinforcement of the rim portion 102 and face portion 104 of the composite wheel 100. This connection 110 is shown in more detail in FIGS. 2 and 3.

(10) Referring firstly to FIG. 2, there is shown a more detailed view of the spoke to rim connection 110 of the composite wheel 100 shown in FIG. 1. Externally, the connection region 110 is orientated with the outer surface 114 of the rim portion 102 and is configured to blend into that configuration.

(11) Referring now to FIG. 3, there is shown a schematic representation of the structural reinforcement components for the connection 110 between the rim portion 102 and the face portion 104 of the composite wheel 100 shown in FIGS. 1 and 2. The illustrated connection 110 is formed in a transition zone 120 between the rim portion 102 and face portion 104 of the wheel 100. In the transition zone 120, a section of first fibres 122 from the rim portion 102 are interconnected with a section of second fibres 124 from the face portion 104 of the composite wheel 100. The fibres 122, 124 of the transition zone 120 are formed on top of and aligned with the reinforcement fibres 122 of the rim portion 102. The reinforcement fibres 122 of the rim portion 102 are illustrated in FIG. 3 as being held against a mold face 126A of the rim tool 126 of the rim portion 102. The fibres 122, 124 of the transition zone 120 laterally attach to the face mold portion 104. The reinforcement fibres 124 of the face portion 104 are illustrated in FIG. 3 as being held against a mold face 126D of the face tool 126C.

(12) The illustrated transition zone 120 includes coplanar layers 125A, 125B and 125C of the first set of fibres 122 and the second set of fibres 124 arranged in a stacked layered structure. The illustrated representation has three layers 125A, 125B and 125C. However, it should be appreciated that the number of layers may vary considerably dependent on the design of the connection and the size and type of composite members. In some cases only a few, for example 2, 3, 4, 6 or 10 layers are used whereas in other cases a higher number, for example 20, 30, 50, 100 or more layers are needed to obtain the desired quality and properties of connection.

(13) The second set of fibres 124 comprise fibres or sheets which extend into the structure of the face portion 104. In the illustrated arrangement, the second set of fibres 124 include a first set of fibres 124A which extend to a front portion of the face portion 104 and a second set of fibres 124B which extend to a rear portion of the face portion 104. For example, where the face portion comprises one or more spokes (not illustrated in FIG. 3), the first set of fibres 124A would extend to a front portion of the spokes and a second set of fibres 124B which extend to a rear portion of the spokes. Similarly, where the face portion comprises a disc configuration (not illustrated in FIG. 3), the first set of fibres 124A would extend to a front portion of the disc and a second set of fibres 124B which extend to a rear portion of the disc. This arrangement creates a strong fibre tie (and thus connection) between the face portion 104 and the connection 110.

(14) Similarly, the first set of fibres 122 extend into the structure of the rim portion 102 in order to create a strong fibre tie (and thus connection) between the rim portion 102 and the connection 110.

(15) In each layer of the transition zone 120, the reinforcement lay-up of the face portion 104 and the reinforcement lay-up of the rim portion 102 are matched. In this respect, each layer 125A, 125B and 125C includes a first section 127 comprising an arrangement of the first set of fibres 122 having a first connection end 128, and a second section 129 comprising an arrangement of the second set of fibres 124 having a second connection end 130. The first connection end 128 is arranged adjacent to or abutting the second connection end 130 forming respective layer joints 132A, 132B, 132C. The layer joints 132A, 132B, 132C of each adjoining layer 125A, 125B, 125C are spaced apart in a stepped configuration. This results in the upper and lower layers 125A, 125B, 125C of the layered structure bridging the intermediary layer joint 125A, 125B, 125C, thereby interconnecting the respective fibre reinforcement of the first section 127 and the second section 129 of the intermediary layer 125A, 125B, 125C. The stepped structure also ensures that the layer joint 132A, 132B, 132C of one layer 125A, 125B, 125C is aligned with another proximate layer joint 132A, 132B, 132C.

(16) In the illustrated embodiment, the stepped configuration of the layer joints 132A, 132B, 132C comprises a linear stepped arrangement. Furthermore, the layer joints 132A, 132B, 132C of each adjoining layer 125A, 125B, 125C are preferably spaced apart with substantially the same lateral spacing. However, it should be appreciated that the particular step configuration and/or step spacing may be varied to suit particular configurations of strength requirements.

(17) In the illustrated embodiment, the first set of fibres 122 from the rim portion 102 of the composite wheel 100 and the second set of fibres 124 from the face portion 104 of the composite wheel 100 comprise carbon fibres. However, it should be appreciated that a wide variety of fibres may be used in the present invention, including but not limited to carbon fibres, glass fibres, aramid fibres, synthetic fibres, bio fibres, mineral fibres, metal fibres, boron fibres or any combination of these.

(18) In the illustrated embodiment, the layers 125A, 125B, 125C of the transition zone 120 and connection 110 are laid substantially parallel to a surface of the rim portion. However, it should be appreciated that the fibres 122, 124 may be provided in any desirable orientation in the transition zone 120. However, the fibres 122, 124 are preferably oriented to reduce the stress between the transition zone and the rim portion 102 and face portion 104 and/or reduce the stress between the rim portion 102 and face portion 104 as well as to strengthen areas of the final structure which will be exposed to a higher stress during service. The orientation of fibres 122, 124 therefore may or may not be the same in all of the layers 125A, 125B, 125C.

(19) As shown in FIG. 3, the transition zone 120 is spaced away from the position/point 101 where the rim portion 102 meets the face portion 102 of the composite wheel 100. The arrangement allows for the connection 110 between the rim portion 102 and face portion 104 to be made at a position which is spaced away from the point 101 at which the structure of the face portion 104 meets the structure of the rim portion 102. This is advantageous since that location 101 is an area where the stresses in the structure are high during certain operational loading conditions.

(20) Again, the fibres 122, 124 may be provided in any suitable form including in prepregs, semi-pregs, woven or non-woven fabrics, mats, pre-forms, pre-consolidated pre-forms, individual or groups of fibres, tows, tow-pregs, or the like. During lay-up of a connection 110, a matrix material, such as a resin need not be comprised in the layers comprising fibres or between the layers comprising fibres. However, the matrix material should form a continuous matrix after the curing.

(21) The illustrated connection 110 can therefore be achieved in various ways:

(22) In a first embodiment, the first set of fibres 122 and the second set of fibres 124 are provided as multi-axial fabric sheets or plys (not illustrated). Each ply can be cut to shape so as to fit in a specific location. The fabric, which could be either stitched together or woven, would contain fibres running in the most appropriate directions as discussed above.

(23) In a second embodiment, the connection 110 and transition zone 120 thereof may be prepared as a pre-form (not illustrated). In such an embodiment, each of the first section 127 and second section 129 are formed into a tailored fibre preform having a desired shape and fibre orientation. For example, a tailored fibre preform may be created by laying down tow and stitching or binding the tow to form the desired shape and fibre orientation.

(24) In some embodiments, the connection ends 128 and 130 of the first section 127 and second section 129 could be stitched, woven or otherwise joined together. In other embodiments, the connection ends 128 and 130 of the first section 127 and second section 129 may be only interconnected by the adjoining layers 125A, 125B, 125C and matrix material such as resin or metal impregnated therein.

(25) A final capping layer 135 is added on the inside surface 114 of the rim portion 102 to cover the layer joint 132A, 132B, 132C structure once the face portion 104 and rim portion 102 reinforcement are assembled and the connection 110 layers 125A, 125B, 125C are laid. The capping layer 135 provides a final layer of reinforcement over the layer joint 132A proximate the inside surface 114 of the rim portion 102, and provides a finishing layer preferably matching the inside surface 114 of the rim portion 102. In the illustrated embodiment, the capping layer 135 comprises a layer of the first set of fibres 122 to match the inside surface 114 of the rim portion 102

(26) The illustrated composite wheel 100 (FIG. 1) is intended to be formed as a unitary body. This involves simultaneous injection and/or impregnation of a matrix material, which in the exemplary embodiment is a resin, into all parts including the rim portion 102, face portion 104 and connection 110 and then curing of each of the portions of the composite wheel 100. The resin used is preferably epoxy-based. However, it should be understood that any suitable resin can be used for example unsaturated polyester, polyurethane, polyvinyl ester, epoxy, thermoplastics, similar chemical compounds or combinations thereof. A variety of resin delivery systems can be used including, but not limited to Resin Infusion and/or Resin Transfer Molding and/or Vacuum Assisted Resin Transfer Molding.

(27) It should be appreciated that in other embodiments, a metal base matrix material may be used to form a metal composite matrix composite wheel 100.

(28) In constructing a composite wheel illustrated in FIG. 1, the wheel includes three main mould faces. Firstly, a face mould, which is generally radially orientated relative to the axis of rotation of the wheel X-X. Secondly, an inner bucket mould face, which forms the inside face of the wheel 140 (FIG. 2). The inner bucket mould face includes a front face forming the back mould wall of the face portion which is radially orientated relative to the axis of rotation of the wheel X-X and side walls forming the back mould wall of the rim portion that are axially aligned to the axis of rotation of the wheel X-X. Thirdly, the rim moulds are substantially axially aligned to the axis of rotation of the wheel X-X.

(29) In use, the rim portion 102 and face portion 104 are laid up with reinforcement and then the connection 110 is laid up with reinforcement. To facilitate this layup, the connection 110 is preferably located in a position between the rim portion 102 and face portion 104 that does not substantially hamper the layup procedure of rim portion 102 and face portion 104.

(30) As shown in FIGS. 2 and 3, in some embodiments the connection 110 can be formed at a location 150 in the composite wheel 100 in which the direction of draft in the part changes. At this location 150, the direction or draft of the geometry between the rim portion 102 and face portion 104 changes. It should however be appreciated that the connection 110 could be located at any suitable position between the rim portion 102 and face portion 104, with the flexibility of fibres being utilised to orientate the connection 110 and at the selected location.

(31) In the illustrated embodiments, the second fibres 124 of the connection 110 extending from the face portion 104 are axially aligned relative to the wheel axis X-X. The second fibres 124 extend substantially perpendicularly from joint position 141 on face portion 104 of the composite wheel 100. These second fibres 124 are therefore aligned around 90° relative to the radial alignment of the face portion 104 of the wheel. The first fibres 122 of the connection 110 extending from the rim portion 102 are axially aligned relative to the wheel axis X-X. These first fibres 122 extend laterally (at an angle of between 80 to 90°) from an edge of a flange portion 142 of the rim portion 102. This location places the second fibres 124 of the connection 110 above the hard section of the face portion mould face. The compliance of the fibres (and fabric thereof) enable these second fibres to be moved out of the way during assembly and then assembled in position aligned with, and adjacent to the lay-up of the rim portion 102 once the face portion 104 and rim portion 102 have been assembled.

(32) In use, the connection 110 of the present invention can be assembled using the following steps: A. providing in a first layer 125C, a first section comprising an arrangement of the first set of fibres having a first connection end, and a second section comprising an arrangement of the second set of fibres having an second connection end, the first connection end being arranged adjacent to or abutting the second connection end forming a layer joint; B. providing further layers 125B, 125A over the first layer 125C having a similar configuration as the first layer 125C. However, the layer joint 132A, 132B, 132C of each adjoining layer 124A, 125B, 125C are arranged to be spaced apart in a stepped configuration; and C. providing a final capping layer 135 on the inside surface 114 of the rim portion 102 to cover the layer joint 132A, 132B, 132C structure.

(33) It should be understood that in practice layers 125A, 125B and 125C can be included in the rim mould lay-up whereas the layers 124 are included in the face mould lay-up. The connection 110 of the present invention is created when the rim mould and face mould are assembled. The final capping layer 135 (or close out ply) 135 is added after the rim mould and face mould sections have been assembled together.

(34) After forming the connection, a resin is injected and/or impregnated into the reinforcement of each of the rim portion 102, the face portion 104 and connection of the wheel and then allowed to cure.

(35) Those skilled in the art will appreciate that the invention described herein is susceptible to variations and modifications other than those specifically described. It is understood that the invention includes all such variations and modifications which fall within the spirit and scope of the present invention.

(36) Where the terms “comprise”, “comprises”, “comprised” or “comprising” are used in this specification (including the claims) they are to be interpreted as specifying the presence of the stated features, integers, steps or components, but not precluding the presence of one or more other feature, integer, step, component or group thereof.