Vehicle wheel disc, a vehicle wheel including such a wheel disc, and methods for manufacturing such a wheel disc and vehicle wheel

Abstract

The wheel disc includes a hub disposed at a center of the wheel disc and defining a wheel axis. The wheel disc further includes an outer periphery and a transition portion extending radially between the hub and the outer periphery. The transition portion has a leading surface and a trailing surface, the leading surface having a relatively smooth profile and the trailing surface defining a plurality of concentric ring-shaped curvatures, whereby the transition portion varies in thickness between the leading surface and the trailing surface.

Description

[Technical field]

[0001]

[0001] The present invention relates generally to vehicle wheel discs and vehicle wheels, and more particularly to improved wheel discs, vehicle wheels including such wheel discs, and methods of manufacturing such wheel discs and vehicle wheels. [Background technology]

[0002]

[0002] An automobile wheel may be formed by joining multiple components. For example, a wheel may be constructed of two formed steel pieces joined together, such as by welding. One known conventional wheel includes a generally planar or circular wheel disc welded to the outer periphery of an annular outer rim. The outer rim has an annular shape suitable for receiving and supporting a tire. The wheel disc includes a central hub portion that serves as the wheel mounting portion of the wheel for coupling to an axle by a number of lug bolts and lug nuts.

[0003] It is known to manufacture wheel discs by a flow forming or flow turning process. In the flow forming process, a flow forming machine is used to form a circular steel blank into a wheel disc of the desired shape. For example, the steel blank may be clamped at a center region or a hub region. The material of the disc extending radially outward from the hub is pressed and stretched by flow forming while the blank is rotated against a rotating chuck and / or other tool to obtain the desired contour. Conventional wheel discs made by flow forming or flow turning generally have uniform surfaces on the inside and outside of the wheel disc. This results in a wheel disc that can withstand the loads that arise during operation of the vehicle on which the wheel is mounted. Although such flow forming processes result in wheel discs with sufficient rigidity, it is desirable to manufacture wheel discs in which the material usage of the wheel disc can be optimized to reduce the overall mass of the wheel disc. Summary of the Invention

[0004] The present invention relates to an improved wheel disc, a vehicle wheel including such a wheel disc, and methods of manufacturing such a wheel disc and vehicle wheel, as shown and / or described herein.

[0005]

[0005] According to one embodiment, the wheel disc is configured for use in a full face fabricated vehicle wheel and may include one or more of the following features, elements, or advantages, individually and / or in combination: the wheel disc includes a hub disposed at a center of the wheel disc and defining a wheel axis. The wheel disc further includes an outer periphery and a transition portion extending radially between the hub and the outer periphery. The transition portion has a leading surface and a trailing surface, the leading surface having a relatively smooth profile and the trailing surface defining a plurality of concentric ring-shaped curvatures, whereby the transition portion varies in thickness between the leading surface and the trailing surface.

[0006] According to this embodiment, the concentric ring-shaped curvature includes an undulation formed on the rear surface of the transition portion.

[0007] According to this embodiment, the undulations are formed as alternating convex and concave ring-shaped curves concentric with the wheel axis.

[0008] According to this embodiment, a plurality of ventilation holes are formed in the transition portion.

[0009] According to this embodiment, the transition is subdivided into a number of concentric segments.

[0009]

[0010] According to this embodiment, the transition portion is divided into first, second, third, fourth, and fifth consecutive segments extending radially outward from the wheel axis.

[0010]

[0011] According to this embodiment, the first segment includes 0-3 ring-shaped bends, the second segment includes 0-2 ring-shaped bends, the third segment includes 1-20 ring-shaped bends, the fourth segment includes 0-2 ring-shaped bends, and the fifth segment includes 0-3 ring-shaped bends.

[0011]

[0012] According to this embodiment, the first segment is thinned by up to 40% of the thickness of the hub, the second segment is thinned by up to 40% of the thickness of the hub, the third segment is thinned by up to 60% of the thickness of the hub, the fourth segment is thinned by up to 40% of the thickness of the hub, and / or the fifth segment is thinned by up to 60% of the thickness of the hub.

[0012]

[0013] According to this embodiment, the concentric segments include undulations formed as alternating convex and concave ring-shaped curves concentric with the wheel axis on the rear surfaces of the first, second, third and fourth segments.

[0013]

[0014] According to this embodiment, the first segment is adjacent the outer edge of the hub.

[0015] According to this embodiment, the front surface of the first segment has a frustoconical shape inclined at a first angle relative to the wheel axis.

[0014]

[0016] According to this embodiment, the front surface of the third segment has a frustoconical shape inclined at a second angle relative to the wheel axis.

[0015]

[0017] According to this embodiment, the third segment has a vent formed therein, and the third segment has a radial length that is between about 50 percent and about 70 percent of the radial length of the transition portion.

[0016]

[0018] According to this embodiment, the first angle is different from the second angle.

[0019] According to this embodiment, the second segment joins the first and third segments with a curvature that smoothly matches the first and third segments.

[0017]

[0020] According to this embodiment, the rear surface of the fifth segment is generally planar and perpendicular to the wheel axis.

[0018]

[0021] According to this embodiment, the fourth segment joins the third and fifth segments with a curvature that smoothly mates with the third and fifth segments.

[0019]

[0022] According to this embodiment, the rear surface of the fifth segment does not have a concentric ring-shaped curvature formed thereon.

[0023] According to this embodiment, the rear surface of the fifth segment has a relatively smooth profile.

[0020]

[0024] According to this embodiment, the wheel disc is manufactured in a flow forming process by flow forming a metal blank upon elongation of a preformed peripheral region adjacent the clamped hub.

[0025] According to this embodiment, the metal blank is a steel blank.

[0021]

[0026] According to this embodiment, the wheel disc is a steel wheel disc.

[0027] According to this embodiment, the wheel disc is an aluminum, magnesium, titanium or alloys thereof, carbon fiber, and / or composite wheel disc.

[0022]

[0028] According to another embodiment, a steel wheel disc is configured for use in a full face fabricated vehicle wheel and may comprise one or more of the following features, elements or advantages, individually and / or in combination: the steel wheel disc may comprise a hub located at the center of the wheel disc and defining a wheel axis, an outer periphery, and a transition portion extending radially between the hub and the outer periphery and having a plurality of ventilation holes, the transition portion having a leading surface and a trailing surface, the leading surface having a relatively smooth profile and the trailing surface having at least one concentric ring-shaped curvature, thereby varying the thickness of the transition portion between the leading surface and the trailing surface.

[0023]

[0029] According to this embodiment, the transition section includes 1-20 ring-shaped bends, and the transition section is thinned by up to 60% of the thickness of the hub.

[0024]

[0030] According to another embodiment, a method of manufacturing a vehicle wheel disc configured for use in a full face fabricated vehicle wheel may include one or more of the following steps, features, elements, or advantages, individually and / or in combination: (a) providing a metal preform, (b) placing the preform on a mandrel of a flow forming machine, and (c) flow forming the preform against the mandrel by a rolling tool to form a wheel disc having a hub located at the center of the wheel disc and defining a wheel axis, an outer periphery, and a transition extending radially between the hub and the outer periphery, the wheel disc having a leading surface and a trailing surface, the leading surface having a relatively smooth profile and the trailing surface being formed with a plurality of concentric ring-shaped curvatures, thereby creating a transition of varying thickness between the leading surface and the trailing surface created during flow forming by displacement of the rolling tool.

[0025]

[0031] The various aspects of this invention will become apparent to those skilled in the art from the following detailed description of the preferred embodiment, when read in light of the accompanying drawings. [Brief description of the drawings]

[0026] [Figure 1]

[0032] FIG. 1 is a front view of an embodiment of a vehicle wheel according to the present invention; [Diagram 2]

[0033] FIG. 2 is a cross-sectional view of the wheel taken along line 2-2 of FIG. 1. [Diagram 3]

[0034] FIG. 2 is a front perspective view of the wheel of FIG. 1. [Figure 4]

[0035] FIG. 2 is a rear perspective view of the wheel of FIG. 1. [Diagram 5]

[0036] 2 is an enlarged cross-sectional view of a portion of the wheel disc of the wheel of FIG. 1 showing details of the profile of the rear surface of the wheel disc. [Figure 6]

[0037] 2 is an enlarged cross-sectional view of a portion of the wheel disc of the wheel of FIG. 1 showing profile details and dimensional features of the example rear surface of the wheel disc; [Figure 7]

[0038] 6 is a view similar to FIG. 5 showing another embodiment of a wheel disc according to the present invention. [Figure 8]

[0039] FIG. 8 is a cross-sectional view showing a blank that can be used to manufacture the wheel disc shown in FIGS. 1 to 7. [Figure 9]

[0040] FIG. 2 is a schematic diagram of a flow forming machine illustrating the process of flow forming a wheel disc preform. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0027]

[0041] 1-4, there is shown a "full face" vehicle wheel, generally designated 10. The vehicle wheel 10 generally includes an inner "full face" wheel disc, generally designated 12, and an annular outer "partial" wheel rim 14. Although the present invention is illustrated and described in connection with the particular vehicle wheel construction disclosed herein, it will be recognized that the present invention may be used with other types of "full face" vehicle wheel constructions.

[0028]

[0042] In a preferred embodiment (and as illustrated herein), the wheel disc 12 and the wheel rim 14 are manufactured separately and then joined by any suitable means, such as welding, to form the fabricated full face vehicle wheel 10. In a preferred embodiment, the wheel disc 12 and the wheel rim 14 are made of steel and then secured together, such as by a weld 16 (shown in FIG. 2 ), to form the wheel 10. Of course, the wheel disc 12 and / or the wheel rim 14 may be made of any suitable material, such as, for example, aluminum, magnesium, titanium or alloys thereof, carbon fiber, and / or composite materials, and / or may be secured together by any suitable means, as desired.

[0029]

[0043] The wheel disc 12 and wheel rim 14 in combination define a wheel axis W of the wheel 10. The wheel rim 14 may have any suitable annular shape for receiving and supporting a tire (not shown). The wheel rim 14 preferably has a continuous annular shape relative to the wheel axis W for receiving a vehicle tire (not shown) thereon. It should be appreciated that the wheel rim 14 may have any desired diameter and / or shape. In a preferred embodiment, the wheel rim 14 has an outer diameter or wheel diameter within the range of about 405 millimeters (about 16 inches) to about 560 millimeters (about 22 inches).

[0030]

[0044] In the preferred embodiment (and as illustrated herein), the steel wheel rim 14 is formed by a rolling and forming process to obtain a desired annular shape, as shown in Figures 1-4. The wheel rim 14 includes a leading peripheral edge 20 and a trailing peripheral edge 22. The wheel rim 14 further includes a generally tubular or cylindrical center wall 24 extending between edges 20 and 22. The center wall 24 can have any suitable shape for receiving a tire and for providing rigidity to the annular shaped outer rim 14. Thus, the center wall 24 is preferably not completely tubular or cylindrical, but includes a curve or bend therein.

[0031]

[0045] As best shown in FIG. 2, the rear edge 22 of the wheel rim 14 defines a bent lip 26 for contacting and sealing against the tire wall when the tire is mounted on the completed wheel 10. The front edge 20 is formed to provide a joint weld edge with the rear of the wheel disc 12. It should be noted that, as best shown in FIG. 2, in the illustrated embodiment, the outer periphery of the wheel disc 12 defines a bent lip 28 for contacting and sealing against the tire wall when the tire is mounted on the wheel 10. Of course, the tire wheel disc 12 and wheel rim 14 could alternatively be formed such that the bent lip 28 is instead formed on the wheel rim 14. In this case, the outer periphery of the wheel disc would have a smaller diameter and would be welded to the inner wall of the center wall 24.

[0032]

[0046] When the wheel 10 is formed by joining the wheel disc 12 to the outer rim 14, the wheel 10 defines a centerline C or center plane that is approximately equally spaced axially from the rolled lips 26 and 28 of the wheel 10, as shown in FIG. 2. The wheel 10 includes circular bead seats 30 and 32 where the tire contacts and seals with the wheel 10. The bead seats 30 and 32 may be located generally adjacent the rolled lips 28 and 26, respectively. The dashed lines generally indicated by BS generally represent the bead seats or inner diameter portions of the tire that are mounted on the wheel 10. The "rim width", as it is known in the art, may be determined as the axial distance between the bead seats 30 and 32. The diameter of the wheel is generally the radial diameter of the bead seats 30 and 32.

[0033]

[0047] Wheel disc 12 is generally comprised of or defined by three portions: a central hub generally designated 40, an outer periphery 42, and an annular transition generally designated 44. Hub 40 is preferably circular and generally defined as the central portion of wheel disc 12 and serves as the wheel mounting portion or central mounting portion of wheel 10. Note that outer periphery 42 includes a rolled lip 28. Transition portion 44 is generally annular or ring shaped and extends radially between hub 40 and outer periphery 42. Transition portion 44 generally surrounds hub 40. As will be described in more detail below, transition portion 44 is preferably subdivided into a number of segments that transition into or adjacent to each other or into hub 40 and periphery 42.

[0034]

[0048] In a preferred embodiment, the wheel disc 12 is preferably manufactured from a single steel blank which is shaped by suitable means to form the wheel disc 12. The blank may first be provided as a smooth, flat, annular or ring-shaped steel disc blank B (shown in FIG. 8) which is then preferably shaped into the final wheel disc shape by flow forming. Alternatively, the blank B may be formed by any suitable means, such as stamping and / or flow forming, into a wheel disc "preform" having a particular partially shaped wheel disc shape (such as preform 48 shown in FIG. 9) before being shaped into the final wheel disc shape, preferably by flow forming.

[0035]

[0049] It is known to manufacture wheel discs by flow forming or flow turning processes. However, as will be explained in more detail below, the present invention relates to the manufacture of wheel discs 12 by a flow forming process in which the thickness of the transition 44 varies. In the flow forming process, a flow forming machine is preferably used to shape the wheel disc preform into the desired shape of the wheel disc 12. For example, FIG. 9 shows a schematic flow forming machine, generally designated 46, having a mandrel 47 that receives a wheel disc preform 48. The mandrel 47 may have a profile surface 47a that corresponds to the desired profile shape of the final formed wheel disc. The wheel disc preform 48 may be clamped at a central region, such as the hub 40. The material of the wheel disc preform extending radially outward from the hub 40 is pressed and stretched by flow forming while rotating rollers 49 (or other tooling) against the wheel disc preform mounted on the mandrel 47 (or other tooling) to obtain the desired profile. It should be noted that the mandrel 47 and rollers 49 are depicted very diagrammatically and generally. Thus, the cross-sectional profile of transition portion 44 can be produced such that the thickness of transition portion 44 varies as desired. This differs from conventional wheel discs made by flow forming or flow turning, which have a generally uniform surface on the inside and outside of the wheel disc.

[0036]

[0050] In the illustrated embodiment, the hub 40 has a front side or surface 50, as seen in Figures 1, 2, 3, 5, and 6, and a rear side or surface 52, as seen in Figures 2, 4, 5, and 6. The front surface 50 is located on the outside of the wheel 10 when the wheel 10 is mounted on a vehicle. The rear surface 52 is located on the inside of the wheel 10 when the wheel 10 is mounted on a vehicle. The hub 40 serves as the wheel mounting or center mounting portion of the wheel 10 for connection to an axle (not shown) by a number of lug bolts (not shown) and lug nuts (not shown).

[0037]

[0051] The hub 40 includes a circular outer edge, generally indicated at 54, which generally defines the edge of the hub 40 that joins or connects with the transition section 44 of the wheel disc. The hub 40 has a diameter H D (See FIGS. 5 and 6.) Although the hub 40 has a plurality of openings formed therein, as will be discussed in more detail below, the hub 40 has a relatively constant thickness H between the front surface 50 and the rear surface 52. t (See FIG. 5). In fact, the thickness H t may correspond to the thickness of the initial blank from which the wheel disc 12 is formed. Of course, the hub 40 may be formed with varying thicknesses, if desired. In a preferred embodiment, the thickness H t In a more preferred embodiment, the thickness H t is in the range of about 3.5 mm to about 6.8 mm.

[0038]

[0052] The hub 40 includes a centrally located pilot opening or hub hole 56. The hub hole 56 extends along the wheel axis W. The hub hole 56 may receive a portion of an axle and / or may receive a protective / decorative cap (not shown). The hub hole 56 may have any suitable diameter. The hub hole 56 may be formed by a stamping process performed on a blank.

[0039]

[0053] A plurality of lug bolt receiving holes 58 are formed in the hub 40 and are circumferentially spaced about the hub bore 56 and the wheel axis W. In the illustrated embodiment, the hub 40 includes five lug bolt receiving holes 58. Alternatively, the number and / or location of the lug bolt receiving holes 58 may be other than as illustrated, as desired. The lug bolt receiving holes 58 receive lug bolts (not shown) for securing the vehicle wheel 10 to an associated vehicle axle with lug nuts (not shown). The lug bolt receiving holes 58 may also be used to secure a blank for a flow forming machine during manufacture of the wheel disc 12.

[0040]

[0054] The details of the transition section 44 will now be discussed. The transition section 44 defines a front side or surface 60, as seen in Figures 1, 2, 3, 5, and 6, and a rear side or surface 62, as seen in Figures 2, 4, 5, and 6. The front surface 60 is located on the outside of the wheel 10 when the wheel 10 is mounted on the vehicle. The rear surface 62 is located on the inside of the wheel 10 when the wheel 10 is mounted on the vehicle. As mentioned above, it is preferred to form the transition section 44 with a varying thickness between the front surface 60 and the rear surface 62 for the most part. Such a varying thickness can optimize the material usage of the wheel disc 12, thereby reducing the overall mass of the wheel disc 12.

[0041]

[0055] In a preferred embodiment, the varying thickness is created by forming a plurality of circular wave or ring shaped undulations or undulating "dimples" generally designated 64 (see FIG. 4) in the rear surface of the transition section 44, as best seen in FIGs. 4, 5, and 6. These undulations 64 may be formed as alternating convex and concave ring shaped curves concentric with the wheel axis W, as discussed below.

[0042]

[0056] The transition portion 44 preferably has a plurality of vent holes formed therethrough. In the illustrated embodiment, the transition portion 44 includes a set of five large vent holes 70 and a set of five smaller outer vent holes 72. The vent holes 70 and 72 not only vent a wheel brake (not shown) located adjacent the wheel 10 when the wheel 10 is mounted on a vehicle, but also reduce material in the transition portion 44, thereby reducing the overall mass of the wheel disc 12. The number of vent holes 70 and 72 in the illustrated embodiment corresponds to the five-bolt hole pattern of the lug bolt receiving holes 58 for an aesthetically pleasing appearance.

[0043]

[0057] Vents 70 are preferably spaced equidistant from one another circumferentially about transition portion 44 about wheel axis W. Similarly, vents 72 are preferably spaced equidistant from one another circumferentially about transition portion 44 about wheel axis W, but are offset from vents 70. Of course, it should be understood that transition portion 44 may have any suitable shape and have any number of vents located at any suitable positions within transition portion 44.

[0044]

[0058] 1, in the illustrated embodiment of the wheel disc 12, the vent holes 70 each have a generally trapezoidal shape with rounded corners. Each of the vent holes 70 are similar in shape and size. The vent holes 70 extend relatively far in the radial direction, as shown in cross section in FIG. 2, thereby removing a significant amount of material. Referring back to FIG. 1, the vent hole 70 has an inner wall 74, an outer wall 76, and a pair of angled walls 78. The inner wall 74 has an overall width 70a. The outer wall 76 has an overall width 70b. The vent hole 70 has an overall radial length 70c. As can be appreciated, the shape, number, and / or location of the vent holes 70 can be other than that shown and described, if desired.

[0045]

[0059] In a preferred embodiment, the width 70a of the inner wall 74 may be in the range of about 30 millimeters to about 120 millimeters. In a more preferred embodiment, the width 70a of the inner wall 74 may be in the range of about 30 millimeters to about 100 millimeters. Accordingly, in a preferred embodiment, the width 70b of the outer wall 76 may be in the range of about 50 millimeters to about 150 millimeters. In a more preferred embodiment, the width 70b of the outer wall 76 may be in the range of about 80 millimeters to about 130 millimeters. In a preferred embodiment, the radial length 70c may be in the range of about 50 millimeters to about 160 millimeters. In a more preferred embodiment, the radial length 70c may be in the range of about 50 millimeters to about 150 millimeters.

[0046]

[0060] In the illustrated embodiment of the wheel disc 12, the vents 72 each have a generally triangular shape with rounded corners. Each of the vents 72 are similar in shape and size. The vents 72 have an outer wall 80 and a pair of angled walls 82. The vents 72 have an overall width 72a. The vents 72 have an overall radial length 72b. In a preferred embodiment, the width 72a may range from about 30 millimeters to about 100 millimeters. In a more preferred embodiment, the width 72a may range from about 30 millimeters to about 90 millimeters. Thus, in a preferred embodiment, the length 72b may range from about 30 millimeters to about 90 millimeters. In a more preferred embodiment, the length 72b may range from about 40 millimeters to about 85 millimeters.

[0047]

[0061] When the vent holes 70 and 72 are formed, a relatively significant portion of material is removed from the transition portion 44. The design of the wheel disc 12, and in particular the design of the transition portion 44, is preferably designed such that the presence of the vent holes 70 and 72 is taken into consideration when designing the contours 64 of the rear surface 62 of the transition portion 44. Thus, the amount of material removed from the area of ​​the vent holes 70 and 72 determines the design aspect and shape of the contours 64. Of course, other factors such as the weight target of the wheel 10, the design intent of the wheel 10, and the performance intent of the wheel 10 should also be considered. The vent holes 70 and 72 may be formed by any suitable method, such as punching, stamping, or cutting operations.

[0048]

[0062] Stress levels at critical points within the wheel disc 12 should be known and considered when determining the shape of the trailing surface 62 of the transition region 44. Thus, the shape of the vent holes 70 and 72 can affect optimal results to achieve performance requirements. The design implications of the desired thickness difference of the relief 64 formed in the trailing surface 62 of the transition region 44 generally correlate to the location from the vent holes 70 and 72 and the amount of material removal.

[0049]

[0063] Also, it should be understood that the views of the wheel disc 12 shown in cross section in Figures 5 and 6 are without section lines to aid in clarity and understanding of the views of Figures 5 and 6. Finally, the details in the drawings of Figures 5 and 6 (as well as other figures) are not necessarily to scale and may have exaggerated dimensions to aid in clarity and understanding of the drawings.

[0050]

[0064] For ease of explanation, the transition portion 44 is subdivided into a number of concentric radial or annular segments. In the illustrated embodiment as shown in Figures 5 and 6, there are generally five segments generally designated A, B, C, D, and E. The segments A, B, C, D, and E are separated from one another at transition points 100, 102, 104, 106, 108, and 110. The transition points 100, 102, 104, 106, and 108 are radially spaced from one another and relate to a radial dimension or distance relative to the wheel axis W. The segments A, B, C, D, and E generally transition into one another or into the outer periphery 42 of the hub 40 or wheel disc 12. Each of the segments A, B, C, D, and E generally includes an inner end located closer to the wheel axis W and an outer end located further from the wheel axis W. More specifically, segment A extends between transition point 100 and transition point 102 .

[0051]

[0065] Transition point 100 generally corresponds to the outer edge of circular outer edge 54 of hub 40. Curved segment B extends between transition points 102 and 104. Segment C extends between transition points 104 and 106. In a preferred embodiment, vents 70 and 72 are formed in segment C. Curved segment D extends between transition points 106 and 108. Segment E extends between transition points 108 and 110. Transition point 110 is generally located adjacent to outer periphery 42 of wheel disc 12.

[0052]

[0066] As seen in FIG. 5, the transition points 100, 102, 104, 106, 108, and 110 generally correspond to the change in curvature of the front surface 60 of the transition section 44. In the preferred embodiment of the wheel disc 12, the front surface 60 of the transition section 44 can be described as "smooth" (without undulations) such that the change in the profile of the front surface 60 is linear without curvature, forming a linear frustoconical shape, or includes a single smooth curvature between two segments having frustoconical shapes with different inclinations (angles) relative to the wheel axis W, thereby connecting the two frustoconical inclinations. The term smooth as used herein can generally refer to a surface that is a generally uniform and regular surface without appreciable protrusions, lumps, or depressions. Of course, a smooth surface may also be curved, such as the front surface 60 of the curved segments B and D of the ring shape. Conversely, the rear surface 62 of the transition section 44 is preferably formed with an undulating curve of concentric rings, as discussed below.

[0053]

[0067] The front surface 60 between transition points 100 and 102 is relatively straight (as shown in cross section) or has no curvature and forms a generally straight frusto-conical shape about the wheel axis W. The inner end of segment A connects with the circular outer edge 54 of the hub 40. The outer end of segment A connects with the inner end of segment B. Like segment A, the front surface 60 of segment C between transition points 104 and 106 is relatively straight and has no curvature and forms a generally straight frusto-conical shape about the wheel axis W. However, the inclination of segment C with respect to the wheel axis W is different than the inclination of segment A. Segment B (between transition points 102 and 104) joins segments A and C with a curvature that smoothly matches both segments A and C. Similarly, curved segment D (between transition points 106 and 108) smoothly merges with the sloped frustoconical front surface 60 of segments C and E (between transition points 108 and 110). Note that front surface 60 of segment E may be perpendicular to the wheel axis W.

[0054]

[0068] As shown in Figure 6, the conical front surface 60 of segment A is inclined at an angle S1 relative to the wheel axis W. In the illustrated embodiment, the angle S1 is about 43 degrees relative to the wheel axis W. In a preferred embodiment, the angle S1 may be in the range of about 15 degrees to about 60 degrees. In a more preferred embodiment, the angle S1 may be in the range of about 20 degrees to about 45 degrees.

[0055]

[0069] The conical front surface 60 of segment C is inclined at an angle S2 from 90 degrees from the wheel axis, as shown in Figure 6. In the illustrated embodiment, the angle S2 is about 16 degrees. Thus, the angle S2 is about 74 degrees (90-16) from the wheel axis W. In a preferred embodiment, the angle S2 may be in the range of about 45 degrees to about 85 degrees. In a more preferred embodiment, the angle S2 may be in the range of about 50 degrees to about 70 degrees.

[0056]

[0070] Wheel 10 can be manufactured in any size suitable for mounting a tire. Conventional vehicle tire sizes generally range from about 16 inches (about 406 mm) to about 22 inches (about 560 mm), for example. With reference to Figures 5 and 6, for ease of explanation, the illustrated embodiment of wheel disc 12 pertains to a wheel 10 having a "wheel diameter" (conventionally understood as the diameter of bead seats 30 and 32) of 22 inches or about 560 mm. The outermost diameter W of the illustrated embodiment is D Note that the rear surface 62 of segment E is at a depth D approximately 600 mm from the rear surface 52 of the hub 40 in the axial direction. d It is just a few meters away.

[0057]

[0071] In the illustrated embodiment, the depth D d is about 89 millimeters. In a preferred embodiment, the depth D d may range from about 25 millimeters to about 120 millimeters. In a more preferred embodiment, the depth D d may range from about 30 millimeters to about 110 millimeters. dThe dimensions of, the slopes S1 and S2, and the dimensions of segments A, B, C, D, and E are generally determined by the requirement to accommodate adjacent brake calipers (not shown) in those segments when wheel 10 is mounted on a vehicle.

[0058]

[0072] As mentioned above, the transition portion 44 may be formed in any suitable size and shape. With reference to the illustrated embodiment of FIG. 5, the transition portion 44 is spaced apart from the wheel axis W by an outer radius T. O and inner radius T I The radial length or distance of the transition portion 44 is dimensionally defined by the radial length T T (T O -T I In a preferred embodiment, the radial length T T In a more preferred embodiment, the radial length T T may range from about 120 millimeters to about 200 millimeters.

[0059]

[0073] As shown in FIG. 5, segment A has a radial length T1. Segment B has a radial length T2. Segment C has a radial length T3. Segment D has a radial length T4. Segment E has a radial length T5. In the illustrated embodiment, radial length T1 is radial length T T The radial length T2 is about 8% of the radial length T T The radial length T3 is about 6% of the radial length T T The radial length T4 is approximately 61% of the radial length T T The radial length T5 is about 6% of the radial length T T In a preferred embodiment, the radial length T1 is about 19% of the radial length T T The radial length T2 may be in the range of about 5% to about 30% of the radial length T T The radial length T3 may be in the range of about 5% to about 30% of the radial length T TThe radial length T4 may be in the range of about 60% to about 80% of the radial length T T The radial length T5 may be in the range of about 5% to about 15% of the radial length T T The range may be about 10% to about 30% of the above.

[0060]

[0074] As previously mentioned, the rear surface 62 of the transition section 44 is preferably formed with a plurality of concentric rings of undulating depressions 64. As shown in FIG. 5, the rear surface 62 of the transition section 44 has radii R1-R2. 11 The curved line 64 is formed by alternating concave and convex undulations of radii R1 to R 11 Note that the radius lengths and center point coordinates have different lengths relative to each other. Details of the dimensions of the radius lengths and center point coordinates are described in more detail below with respect to FIG.

[0061]

[0075] As shown in FIG. 5, the rear surface 62 of segment A is formed with a concave ring-shaped curve corresponding to radius R1. The term concave as used herein refers to the curvature formed in the rear surface 62 toward the front surface 60, which reduces the thickness of the transition 44 in that region. A convex curvature refers to the curvature formed in the rear surface 62 away from the front surface 60, which increases the thickness of the transition 44 in that region. Radius R2 corresponds to the convex ring-shaped curvature extending between segments A and B. Radius R3 corresponds to the concave ring-shaped curvature formed in segment B.

[0062]

[0076] The rear surface 62 of segment C has a radius R4 to R 10 Segment C thus includes a total of seven different curvatures in the illustrated embodiment. Segment D includes alternating convex and concave ring-shaped curvatures corresponding to radius R 11In the embodiment shown, the rear surface 62 of segment E has no curvature formed therein, and preferably the rear surface 62 of segment E is planar, perpendicular to the wheel axis W. Of course, segment E may be formed with a single curvature or multiple curvatures, as desired.

[0063]

[0077] As can be appreciated, depending on the particular size of the vehicle wheel (which can typically range from 16 inches to 22 inches), segments A-E may have any combination of the following numbers of ring-shaped bends in accordance with the present invention: Segment A may include 0-3 ring-shaped bends. Segment B may include 0-2 ring-shaped bends. Segment C may include 1-20 ring-shaped bends. Segment D may include 0-2 ring-shaped bends. Segment E may include 0-3 ring-shaped bends.

[0064]

[0078] Alternatively, one or more of segments A-E may be other than as shown and described. For example, as shown in the embodiment illustrated in FIG. 7, and using like reference numerals with "'" added to indicate corresponding and / or similar parts or structures, wheel disc 12' may include a plurality of ring-shaped curvatures (radii R4'-R5') in segment C' only, with the number of such ring-shaped curvatures ranging from 1 to 20. 10 ') can be provided.

[0065]

[0079] The blank or wheel disc preform used to form the wheel disc 12 has a thickness H of the hub 40. t During the formation of the contoured recess 64 in the rear surface 62 of the transition portion 44, the thicknesses of the segments A, B, C, D, and E may be reduced. In a preferred embodiment, segment A is formed with a constant thickness corresponding to the thickness H of the hub 40. t In a preferred embodiment, segment B is thinner than the thickness H of hub 40. tIn a preferred embodiment, the segments C are thinner than the thickness H of the hub 40. t In a preferred embodiment, the segment D is thinner than the thickness H of the hub 40. t In a preferred embodiment, the segment E is thinner than the thickness H of the hub 40. t It is thinned by up to 60%.

[0066]

[0080] As shown in FIG. 6, the curvature of the undulating depression 64 is determined by the corresponding center points CP1 to CP 11 Different radius dimensions R1 to R 11 The dimensions of the radius and center point generally correspond to the dimensions of the tool that forms the rear surface 62 of the transition portion 44 when formed by a flow forming machine as described above.

[0067]

[0081] With reference to Figure 6, the wheel disc 12 shown is for a wheel 10 having a "wheel diameter" of 22 inches or approximately 560 mm. The following table shows the concave and convex radii R1-R2 for a wheel sized as in the illustrated embodiment of Figure 6. 11 6. Note that the X and Y coordinates originate from the wheel axis W at the rear surface 52 of the hub 40, as shown by X=0 and Y=0 in FIG. 6. The X axis is generally along the same plane as the rear surface 52 of the hub 40. The negative sign (-) on the X coordinate refers to a center point coordinate located above or outside the wheel 10. [Table 1] As can be understood, the specific numbers, ranges, dimensions, and / or percentages disclosed herein can be other than those shown and described, if desired.

[0068]

[0082] The principles and modes of operation of this invention have been explained and illustrated in its preferred embodiments. However, it must be understood that the invention may be practiced otherwise than as specifically explained and illustrated without departing from its spirit or scope.

Claims

1. 1. A wheel disc configured for use in a full face fabricated vehicle wheel, comprising: a hub disposed at a center of the wheel disc and defining a wheel axis; An outer periphery; a radially extending transition between the hub and the outer periphery, the transition having a leading surface and a trailing surface, the leading surface having a relatively smooth profile and the trailing surface defining a plurality of concentric ring-shaped curvatures thereby providing a transition having a varying thickness between the leading surface and the trailing surface; A wheel disc comprising:

2. The wheel disc of claim 1 , wherein said concentric ring-shaped curvature includes an undulation formed in said trailing surface of said transition portion.

3. 3. The wheel disc of claim 2, wherein said undulations are formed as alternating convex and concave ring-shaped curves concentric with said wheel axis.

4. The wheel disc of claim 1 wherein a plurality of vent holes are formed in said transition portion.

5. The wheel disc of claim 1 , wherein said transition portion is subdivided into a plurality of concentric segments.

6. 6. The wheel disc of claim 5, wherein said transition portion is divided into first, second, third, fourth, and fifth contiguous segments extending radially outward from said wheel axis.

7. 7. The wheel disc of claim 6, wherein the first segment includes 0-3 ring shaped bends, the second segment includes 0-2 ring shaped bends, the third segment includes 1-20 ring shaped bends, the fourth segment includes 0-2 ring shaped bends, and the fifth segment includes 0-3 ring shaped bends.

8. 7. The wheel disc of claim 6, wherein the first segment is thinned by up to 40% of the thickness of the hub, the second segment is thinned by up to 40% of the thickness of the hub, the third segment is thinned by up to 60% of the thickness of the hub, the fourth segment is thinned by up to 40% of the thickness of the hub, and / or the fifth segment is thinned by up to 60% of the thickness of the hub.

9. 7. The wheel disc of claim 6, wherein said concentric segments include undulations formed as alternating convex and concave ring-shaped curves concentric with said wheel axis on a rear surface of said first, second, third, and fourth segments.

10. The wheel disc of claim 6 wherein said first segment is adjacent an outer edge of said hub.

11. 7. The wheel disc of claim 6, wherein said first segment leading surface has a frustoconical shape inclined at a first angle relative to said wheel axis.

12. 12. The wheel disc of claim 11, wherein said third segment leading surface has a frustoconical shape inclined at a second angle relative to said wheel axis.

13. 13. The wheel disc of claim 12, wherein said third segment has a vent hole formed therein, said third segment having a radial length between about 50 percent and about 70 percent of a radial length of said transition portion.

14. The wheel disc of claim 12 wherein said first angle is different from said second angle.

15. 13. The wheel disc of claim 12, wherein said second segment joins said first segment and said third segment with a curvature that smoothly mates with said first segment and said third segment.

16. 16. The wheel disc of claim 15, wherein said fifth segment rear surface is generally planar and perpendicular to said wheel axis.

17. 17. The wheel disc of claim 16, wherein said fourth segment joins said third segment and said fifth segment with a curvature that mates smoothly with said third segment and said fifth segment.

18. 17. The wheel disc of claim 16, wherein said trailing surface of said fifth segment is free of concentric ring-shaped curvatures.

19. 20. The wheel disc of claim 18, wherein said trailing surface of said fifth segment has a relatively smooth profile.

20. 10. The wheel disc of claim 1, manufactured in a flow forming process by flow forming a metal blank upon expansion of a preformed peripheral area adjacent said clamped hub.

21. 21. The wheel disc of claim 20, wherein said metal blank is a steel blank.

22. The wheel disc of claim 1 , wherein said wheel disc is a steel wheel disc.

23. 10. The wheel disc of claim 1, wherein the wheel disc is an aluminum, magnesium, titanium or alloys thereof, carbon fiber, and / or composite wheel disc.

24. 10. A full face fabricated vehicle wheel having a wheel rim configured to be secured to a wheel disc according to claim 1, wherein said wheel disc is a steel wheel disc.

25. 10. The method of forming a wheel disc as recited in claim 1, wherein said wheel disc is a steel wheel disc and is formed into a final desired shape by a flow forming process.

26. 10. A method for molding a full face fabricated vehicle wheel having a wheel rim configured to be secured to a wheel disc as claimed in claim 1, wherein said wheel disc is a steel wheel disc.

27. 1. A steel wheel disc configured for use in a full face fabricated vehicle wheel, comprising: a hub disposed at a center of the wheel disc and defining a wheel axis; An outer periphery; a transition portion extending radially between the hub and the outer periphery, the transition portion having a plurality of vent holes, the transition portion having a leading surface and a trailing surface, the leading surface having a relatively smooth profile and the trailing surface having at least one concentric ring-shaped curvature, thereby varying in thickness between the leading surface and the trailing surface; Steel wheel disc.

28. 28. The steel wheel disc of claim 27, wherein said transition portion includes 1 to 20 ring shaped bends, said transition portion being reduced in thickness by up to 60% of said hub thickness.

29. 1. A method of manufacturing a vehicle wheel disc, comprising the steps of: (a) providing a metal preform; (b) placing the preform on a mandrel of a flow forming machine; (c) flow forming the preform against the mandrel with a rolling tool; a hub disposed at a center of the wheel disc and defining a wheel axis; An outer periphery; a radially extending transition between the hub and the outer periphery, the transition having a front surface and a rear surface, the front surface having a relatively smooth profile and the rear surface being formed with a plurality of concentric ring-shaped curvatures, whereby a transition thickness between the front surface and the rear surface is created during flow forming by displacement of the rolling tool; forming a wheel disc having a The method includes:

30. 30. The method of claim 29, including forming a plurality of vent holes in the transition portion, such as by a punching, stamping, or cutting operation.

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