Mounting arrangement of a vehicle wheel made of carbon fiber reinforced plastic

Abstract

Fastening arrangement of a vehicle wheel (1) consisting at least partially of carbon fiber-reinforced plastic at least in the fastening area to a vehicle wheel hub with the interposition of a metal disc (4) and with corrosion protection measures between the fiber-reinforced plastic material or a titanium material bonded thereto or another metal material in the wheel that is corrosion-resistant compared to carbon fiber-reinforced plastic and less noble and thus susceptible to galvanic corrosion metal components of the fastening arrangement also in the area of ​​the wheel bolts (2), by means of which the wheel (1) is screwed to the hub via its screw through holes (3), characterized in thatthat the metal disc (4), which is coated with a corrosion protection layer at least towards the wheel plastic material or the corrosion-resistant metal material, is drawn at least slightly into the screw through-holes (3), and that two-part wheel bolts (2) or, when using threaded bolts that remain in the hub of the vehicle, two-part bolt nuts are provided, in which a head part (2b) intended for tool engagement acts on an annular body (2c) penetrated by the threaded bolt (2a) and at least approximately conically shaped, which, in the assembled state, projects into the screw through-holes (3), which rests on the wheel plastic material or the corrosion-resistant metal material and is coated with a corrosion protection layer at least towards this.

Description

[0001] The invention relates to a fastening arrangement for a vehicle wheel, at least partially made of carbon fiber-reinforced plastic in the fastening area, to a vehicle wheel hub with a metal disc interposed therebetween. It also includes corrosion protection measures between the fiber-reinforced plastic material or a titanium material bonded thereto or another metal material in the wheel that is corrosion-resistant compared to carbon fiber-reinforced plastic and less noble and thus susceptible to galvanic corrosion metal components of the fastening arrangement, including in the area of ​​the wheel bolts, by means of which the wheel is bolted to the hub via its bolt through holes. For the prior art, reference is made, for example, to EP 1 529 969 B1 and WO 2013 / 083443 A1.

[0002] WO 2013 / 083443 A1 discloses a vehicle wheel made of fiber-reinforced plastic, in which a metal disc is provided on the wheel flange to prevent excessive heat input into the plastic material of the wheel during braking. If the metal disc is made of light metal (e.g., cast aluminum) for weight reasons, there should be no direct contact with the hub component, if the hub component is made of carbon fiber-reinforced plastic, to avoid corrosion.

[0003] EP 0 895 875 A1 discloses a vehicle wheel made of a magnesium alloy, in which a corrosion protection layer is provided between the vehicle hub and the wheel flange during assembly. The different metals are therefore unable to perform corrosion-preventing processes. Aluminum, in particular, is proposed.

[0004] WO 2013 / 030 106 A1 discloses a wheel for a motor vehicle in which through holes in the wheel hub are stabilized by a sleeve. The sleeve can be cast into the wheel body, so that the sleeve is positively connected to the wheel body. In addition to the sleeve, an insert can also be provided, which forms a contact surface for mounting the wheel. In this case, it is possible to form the insert and sleeve as one piece with the insert or to construct them separately.

[0005] DE 101 23 854 A1 discloses a wheel fastening arrangement in which a thrust ring with a frustoconical load-bearing surface is provided as a mediating element between a bolt head and a through hole in a wheel body. The thrust ring can be coated for corrosion protection.

[0006] In vehicle construction, lightweight construction is a particularly important issue, especially for so-called unsprung masses. Carbon fiber-reinforced plastics are increasingly being used for this purpose, often in combination with titanium or other metal materials that are more corrosion-resistant than carbon fiber-reinforced plastics. On the other hand, metallic components are still required for strength reasons. For cost-effective reasons, these are made of less noble metal materials that are therefore susceptible to galvanic corrosion. Therefore, appropriate measures must be taken to prevent galvanic contact corrosion between these materials. This contact corrosion is also referred to as galvanocorrosion or electrolytic corrosion, caused by the electrochemical potential between the metal and the carbon of the CFRP material.

[0007] In this sense, it is the object of the present invention to provide a corrosion-resistant fastening arrangement for a vehicle wheel (e.g. of a passenger car) consisting at least partially of carbon fiber reinforced plastic according to the preamble of claim 1.

[0008] The solution to this problem is characterized in that the metal disc, which is coated with a corrosion protection layer at least towards the wheel plastic material, is drawn at least slightly into the screw through holes and that two-part wheel bolts or, when using threaded bolts that remain in the hub of the vehicle, two-part bolt nuts are provided, in which a head part provided for a tool attack acts on an annular body penetrated by the threaded bolt and at least approximately conical in shape and, in the assembled state, protrudes into the screw through holes, which ring body rests on the wheel plastic material or the corrosion-resistant metal material of the wheel and is coated with a corrosion protection layer at least towards this.According to advantageous further developments, the wheel bolts are made of steel and the ring body as well as the metal disc are made of an aluminum alloy, while the corrosion protection layer can be formed from a galvanically insulating coating with a layer thickness in the order of 60 micrometers.

[0009] It has been shown that relatively simple corrosion protection measures, such as those briefly described in the aforementioned WO 2013 / 083443 A1, may not be sufficient. Therefore, a somewhat more complex, yet significantly more reliable measure for preventing contact corrosion is presented here. In particular, the use of a two-part wheel bolt with an integrated so-called ring body, which lies between the wheel and the bolt head, is proposed. Such a two-part bolt is, for example,in EP 1 529 969 B1, also mentioned at the beginning, but in contrast to this known prior art, the annular body according to the present invention, which is at least approximately conically shaped and rests on a corresponding surface of the wheel with its at least approximately conical surface, which also includes a hemispherical surface, projects over a certain distance, practically to a certain extent, into the corresponding screw through-hole. As a corrosion protection measure, this annular body, which does not rotate when the screw is tightened, but rests essentially motionless on the edge of the screw through-hole, in particular because it projects into the through-hole, is provided with an anti-corrosive layer which, because of this non-rotation, cannot be damaged or abraded even if a corresponding screw is used several times.Of course, the present invention can be applied analogously to hubs with threaded bolts remaining therein; here, a corresponding two-piece bolt nut is to be used instead of a two-piece screw.

[0010] The attached single figure shows an embodiment of the present invention in the form of a section with a sectional plane containing the wheel rotation axis A through the so-called hub section of a vehicle wheel, with which the wheel is flanged to a hub (not shown) of a vehicle, e.g. a car, wherein the wheel bolts shown are merely inserted into the bolt through holes of the wheel and are therefore not shown in the final assembled state.

[0011] The reference number 1 designates a wheel of a vehicle, of which only the area near the wheel's axis of rotation A, with which this wheel 1 is flanged to a wheel hub of the vehicle with its right-hand side in the figure, is shown. This wheel 1, or at least its so-called hub section shown in the figure, is made at least partially of carbon fiber reinforced plastic (CFRP) 1a, which is wound around a suitably shaped ring body 1b made of titanium. By means of several wheel bolts 2 arranged in a circular ring with respect to the axis of rotation A as usual, the wheel 1 is fastened to the hub with its right-hand side in the figure resting against the wheel hub (not shown).For these wheel bolts 2, screw through holes 3 are provided in the wheel 1, which in the present case are provided in particular in the titanium ring body 1b, which, away from these screw through holes 3, is wrapped with continuous carbon fibers in a plastic mass, as shown in the half located above the axis of rotation A in the figure.

[0012] To prevent contact corrosion between the wheel 1 and the vehicle wheel hub, which is made of a less noble metal material and thus more susceptible to galvanic corrosion than titanium and carbon, a metal disc 4 is provided on the side of the wheel 1 (here, the right-hand side) with which it rests against the hub. This metal disc 4 is coated with a corrosion protection layer (not shown separately), at least on the side facing the wheel 1, but ideally completely. This metal disc 4 is formed as a deep-drawn part made of an aluminum alloy in such a way that it protrudes significantly into the screw through-holes 3 and, in this case, extends into these through-holes 3, resting against the material of the wheel 1, for at least 30% of the length of these through-holes 3.Thus, at least in the end section of the through holes 3 facing the wheel hub of the vehicle, the metallic wheel bolts 2 located within these through holes 3 and thus also within the annular section 4a of the metal disk 4 projecting into the respective through hole 3 are safely protected from contact corrosion with the material of the wheel 1 (here at this point in particular titanium, but also carbon fiber reinforced plastic, etc.).

[0013] Each wheel bolt 2 is designed as a two-part wheel bolt, with a threaded bolt 2a including a one-piece screw head 2b, to which a tool for tightening or loosening the wheel bolt 2 can be attached as usual, and furthermore with an annular body 2c, which initially forms an independent component and through which the threaded bolt 2a projects. In the pre-assembled state shown in the figure, as well as in the final assembly state, the annular body 2c, which is at least approximately conical on the outside, projects into the screw through-hole 3, which is conically shaped on the side facing the screw head 2b to match the annular body 2c. The side of the annular body 2c facing away from the wheel hub of the vehicle, the left side in the figure, is flat (perpendicular to the wheel rotation axis A) in such a way that the screw head 2b exerts a pressing effect on the annular body 2c when this wheel bolt 2 is tightened.When the wheel bolt 2 is tightened, the bolt head 2b with the threaded bolt 2a rotates relative to the ring body 2c, which rests essentially motionless on the wheel 1 or on the end region of the wall of the bolt through hole 3. While the threaded bolt 2a of the wheel bolt 2 with the bolt head 2b is preferably made of steel, the ring body 2c, which is also metallic and preferably made of an aluminum alloy, is coated with an anti-corrosive layer, so that even in this area where the wheel bolt 2 presses against the wheel 1 or the wheel 1 presses against the wheel hub of the vehicle, the wheel bolt 2 is reliably protected from contact corrosion with the material of the wheel 1.In any case, the corrosion protection layer is not at risk of abrasion where this is absolutely necessary, since the ring body 2c practically does not move relative to the wheel 2 when the wheel bolt 12 is tightened, at least it is not rotated about the axis of the bolt through hole 3.

[0014] As for the corrosion protection layer on the annular body 2c and the metal disk 4, with the fastening arrangement according to the invention, only a relatively small surface area needs to be protected accordingly, with the layer thickness being on the order of 60 micrometers. The essential property of this corrosion protection layer is its electrical non-conductivity, meaning that it acts reliably as an electrical insulator. This corrosion protection layer can be formed, for example, from a hard-anodized GRP material or an AFRP material (= plastic reinforced with glass fibers or amide fibers), or many other known materials.Coming back to the metal disc 4, it can be seen that this is also in an annular centering section Z, via which the wheel 1 is centered as usual on a circular cylindrical ring of the vehicle wheel hub, is drawn into this centering section Z in the direction of the wheel rotation axis A so far that no contact corrosion can occur between the wheel 1 and the wheel hub of the vehicle at this centering section Z either.

Claims

[1] Fastening arrangement of a vehicle wheel (1) consisting at least in the fastening area at least partially of carbon fibre-reinforced plastic to a vehicle wheel hub with the interposition of a metal disc (4) and with corrosion protection measures between the fibre-reinforced plastic material or a titanium material bonded thereto or another metal material in the wheel that is corrosion-resistant compared to carbon fibre-reinforced plastic and less noble and thus susceptible to galvanic corrosion metal components of the fastening arrangement also in the area of ​​the wheel bolts (2), by means of which the wheel (1) is screwed to the hub via its screw through holes (3), characterized byin that the metal disc (4), which is coated with an anti-corrosive layer at least towards the wheel plastic material or the corrosion-resistant metal material, is drawn at least slightly into the screw through-holes (3), and in that two-part wheel bolts (2) or, when using threaded bolts that remain in the hub of the vehicle, two-part bolt nuts are provided, in which a head part (2b) provided for a tool engagement acts on an annular body (2c) penetrated by the threaded bolt (2a), which is at least approximately conical in shape and projects into the screw through-holes (3) in the assembled state, which annular body rests on the wheel plastic material or the corrosion-resistant metal material and is coated with an anti-corrosive layer at least towards this. [2] Fastening arrangement according to claim 1, characterized bythat the actual wheel bolt (2) is made of a steel material and the ring body (2c) and the metal disc (4) are made of an aluminum alloy. [3] Fastening arrangement according to claim 1 or 2, characterized by that the corrosion protection layer is formed from a galvanically insulating coating with a layer thickness in the order of 60 micrometers.

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