WO2002047842A1

WO2002047842A1 - Process for manufacturing a tire rim plate

Info

Publication number: WO2002047842A1
Application number: PCT/IB2001/002337
Authority: WO
Inventors: Visino Marin
Original assignee: Attrezzeria M.V. Di Marin Visino E C. S.N.C.
Priority date: 2000-12-11
Filing date: 2001-12-06
Publication date: 2002-06-20
Also published as: ITMN20000055A1; AU2002220965A1; ITMN20000055A0

Abstract

A process for manufacturing a disc (10) for aluminium-alloy tire rim for vehicle wheels, comprising a step of cold-forging a rolled disc, providing radial ribs (6), and a subsequent step of producing circular holes (11) for the passage of cylindrical elements.

Description

PROCESS FOR MANUFACTURING A TIRE RIM PLATE

Technical field The present invention relates to a process for manufacturing a disc for aluminum-alloy tire rim for vehicle wheels, and to the disc obtained thereby. Background art

It is known that vehicle wheels comprise a metallic tire rim suitable to be fixed detachably to a hub provided at the ends of the axles of said vehicles. Such tire rim comprises an annular channel for supporting the tire and a disc which is associated with said annular channel and has, at its center, means for coupling to the hub. Disclosure of the invention

Aluminum-alloy tire rims are known, but they are manufactured with processes that are not entirely satisfactory; accordingly, the aim of the present invention is to provide a process for manufacturing the disc of an aluminum-alloy tire rim having optimized characteristics.

This aim is achieved by a process for manufacturing a disc for aluminum- alloy tire rim for vehicle wheels, according to the invention, characterized in that it comprises a step of cold-forging a rolled disc, providing radial ribs, and a subsequent step of producing circular holes for the passage of cylindrical elements. Brief description of the drawings

Further characteristics and advantages will become better apparent from the description of some preferred but not exclusive embodiments of the invention, illustrated only by way of non-limitative example in the accompanying drawings, wherein: Figure 1 is a view of the initial disc;

Figure 2 is a sectional view, taken along the line II-II of Figure 1; Figure 3 is a view of the disc after the first step of the process; Figure 4 is a sectional view, taken along the line IV-IV of Figure 3;

Figure 5 is a view of the disc after the second step of the process;

Figure 6 is a sectional view, taken along the line VI-VI of Figure 5;

Figures 7 and 8 are respectively a top view and a bottom view of the finished disc, obtained after the third step of the process;

Figure 9 is a view of the manner of coupling the disc to the annular channel so as to form the tire rim;

Figure 10 is a view of a semifinished disc according to a second embodiment thereof; Figure 11 is a sectional view, taken along the line XI-XI of Figure 10;

Figure 12 is an exploded view of a semifinished disc according to a third embodiment thereof;

Figure 13 is a view of the semifinished disc of Figure 12. Ways of carrying out the invention With reference to the figures, the reference numeral 1 designates, in

Figures 1 to 4, a flat disc made of rolled aluminum alloy, which is meant to be subjected, during a first step of the process, to blanking so as to produce uniformly distributed radial openings 2, which are visible in Figures 3 and 4 and are shaped substantially like an isosceles triangle with notches 3a and 3b at the ends of the base which allow, during the subsequent step described hereinafter, to fold a tongue at said base in order to constitute a reference in the assembly of the disc to the annular channel of the tire rim.

The radial openings can of course have a different shape and be for example teardrop-shaped. The second step of the process consists in cold-forging the disc obtained after blanking, obtaining the semifinished part designated by the reference numeral 4 and shown in Figures 5 and 6, which comprises highly raised radial ribs 5 and 6 in the spaces between the radial openings 2; said ribs extend from the central well 7, which has a substantially flat bottom provided with ridges 8 and studs 9, and end so as to overlap, to a significant extent, the peripheral band 4, so as to obtain a great overall strengthening of the structure of the disc.

During this second cold-forging step, the formation of the radial ribs 5 and 6 is facilitated by the presence of the radial openings 2, which allow easy migration of the material so as to follow the impressions of the die.

It is during this second step that one might obtain, where required, the previously mentioned folding of the tongues at the bases of the openings 2 between the notches 3a and 3b; as an alternative, it might be possible to provide a different type of reference in the assembly of the disc with the annular channel of the rim, such as a circumferential protrusion.

The third step of the process, which leads to the finished disc shown in Figures 7 and 8 and designated by the reference numeral 10, consists in providing, by means of a blanking die or a drilling unit, circular holes 11 at the peripheral band 4a for the passage of cylindrical elements, for example bolts, which are suitable to fix the finished disc 10 to the annular channel of the rim, as will become better apparent hereinafter, and circular holes at the bottom of the well 7; the holes comprise circular holes 12, on the studs 9, for the passage of the screws for fixing the disc to the hub, and the central hole 13 for accommodating a pin for centering on the hub. Figure 9 is an exploded view of the manner of coupling the resulting disc

10 to the annular channel 14, so as to form the tire rim of a wheel, and clearly shows that the mutual locking of the disc 10 and of the channel 14 is provided by means of bolts inserted in the holes 11 of the disc and in the holes 14a provided in the circumferential protrusion 14b of the annular channel 14.

A second embodiment of the invention is shown in Figures 10 and 11, which illustrate the semifinished part 15, which is obtained by directly subjecting to the cold-forging step the disc 1, shown in Figures 1 and 2; therefore, between the radial ribs 16 and 17 there are no openings 2 but there is instead a continuity of material, as in the region 18. The forging step that leads to the semifinished part 15 is of course followed by a drilling step to obtain holes such as the ones described earlier with reference to Figures 7 and 8.

A further embodiment of the invention is illustrated with reference to Figures 12 and 13, which show the semifinished part 19 obtained by cold- forging a disc 1, which is visible in Figures 1 and 2, obtaining radial ribs 20 and 21 that extend from the central well 22, whose side wall is provided with impressions 23.

The reference numeral 24 further designates an element for reinforcing the bottom of the central well 22, where the stresses due to the fixing of the disc to the hub connected to the axle of a vehicle are concentrated; such element is constituted by a steel disk with a raised edge, suitable to be associated with the semifinished part 19 by means of a press, with intense mutual adhesion by means of the impressions 25 on the raised edge and by means of impressions that mate with the ridges provided on the bottom of the well.

The element 24 is provided beforehand with a central hole 26 and with holes 27, and it is thus possible to provide, without any problem, the drilling of the semifinished part shown in Figure 13, which is constituted by the assembled elements 19 and 24, so as to obtain the finished disc.

As an alternative to the steel disk 24, an element for reinforcing the bottom of the well might be provided by means of a simple aluminum alloy disk; its fixing by means of a press is followed by drilling in order to obtain the holes as described earlier. It should also be added that a reinforcement element of the described type can of course be applied to a disc such as the one shown in Figures 7 and 8, provided with radial openings 2.

The described invention is susceptible of numerous modifications and variations, all of which are within the scope of the inventive concept; thus, for example, the initial disc, instead of being flat as in the case of the disc 1, may have a raised portion in its central region.

The disclosures in Italian Patent Application No. MN00A000055, from which this application claims priority, are incorporated herein by reference.

Claims

1. A process for manufacturing a disc for aluminum-alloy tire rim for vehicle wheels, characterized in that it comprises a step of cold-forging a rolled disc, providing radial ribs, and a subsequent step of producing circular holes for the passage of cylindrical elements.

2. The process according to claim 1, characterized in that the rolled disc is flat.

3. The process according to claim 1, characterized in that the rolled disc has a raised portion in its central region.

4. The process according to one or more of the preceding claims, characterized in that it comprises a step of cold forging a rolled disc, obtaining highly raised radial ribs that extend from a central well with a substantially flat bottom, and a subsequent step of producing circular holes for the passage of cylindrical elements.

5. The process according to one or more of the preceding claims, characterized in that it comprises a first step of blanking a rolled disc, obtaining uniformly distributed radial openings; a second step of cold- forging said disc, obtaining, in the spaces between said radial openings, said highly raised radial ribs that extend from a central well with a substantially flat bottom and end so as to overlap a peripheral band; a third step of providing circular holes for the passage of cylindrical elements such as the elements for fixing to the hub and to the annular channel of the tire rim, and the pin for centering on said hub.

6. The process according to one or more of the preceding claims, characterized in that it comprises, after the step of cold forging and obtaining highly raised radial ribs that extend from a central well with a substantially flat bottom, a step of applying, by means of a press, a reinforcement element at the bottom of said well.

7. The process according to claim 6, characterized in that the reinforcement element is constituted by a steel disk with a raised rim, suitable to move into contact with the side wall of the well and provided with circular holes at the holes with which the bottom of the well is to be provided, a subsequent step of producing said holes being provided.

8. The process according to claim 7, characterized in that the side wall of the well is provided with impressions suitable to improve the stable adhesion of the reinforcement element.

9. The process according to claim 6, characterized in that the reinforcement element is constituted by a disk made of aluminum alloy, a subsequent step of producing circular holes being provided.

10. A disc for aluminum-alloy tire rim for vehicle wheels, obtained with the process according to one or more of the preceding claims, characterized in that it comprises a plurality of radial ribs and circular holes for the passage of cylindrical elements.

11. The disc for aluminum-alloy tire rim for vehicle wheels, obtained with the process according to one or more of the preceding claims, characterized in that it comprises a plurality of highly raised radial ribs that extend from a central well with a substantially flat bottom, said circular holes being provided at a peripheral band for the passage of elements for fixing to an annular channel of the tire rim, a central hole for accommodating a pin for centering on the hub and circular holes for the passage of screws for fixing to said hub being provided at said bottom of the well.

12. The disc according to one or more of the preceding claims, characterized by the presence of openings interposed between the radial ribs that extend from the central recess and end so as to overlap the peripheral band.

13. The disc according to one or more of the preceding claims, characterized in that the openings interposed between the radial ribs are shaped substantially like an isosceles triangle with notches at the ends of the base, said notches being suitable to allow the folding of a tongue at said base in order to constitute a reference in the assembly of the disc to the annular channel of the tire rim.

14. The disc according to one or more of the preceding claims, characterized in that the openings interposed between the radial ribs are substantially teardrop-shaped.

15. The disc according to one or more of the preceding claims, characterized in that it provides for continuity of material between the radial ribs.

16. The disc according to one or more of the preceding claims, characterized in that it comprises a reinforcement element at the bottom of the central well.

17. The disc according to one or more of the preceding claims, characterized in that the reinforcement element provided at the bottom of the central recess is constituted by a steel disk with a raised rim, which adheres to the side wall of said well.

18. The disc according to one or more of the preceding claims, characterized in that the reinforcement element that is present at the bottom of the central well is constituted by a disk made of aluminum alloy.

19. The disc according to one or more of the preceding claims, characterized in that it comprises a circumferential protrusion that is suitable to constitute a reference in the assembly of the disc to the annular channel of the tire rim, obtained during the cold forging step.