Wheel rim with a deep dish

Abstract

Wheel rim (2) with a drop center (4) arranged between an outer rim shoulder (7) and an inner rim shoulder (8), which are spaced apart from each other in the axial direction and each terminate at the axially outer and inner edges into a rim flange (9, 10) and each is bounded axially on the outer side by an outer rim hump (5) and axially on the inner side by an inner rim hump (6), wherein the drop center (4) has a uniform thickness throughout and is offset radially inwards relative to both humps (5, 6) and has a radially inner, low profile section (11) and at least one radially outwards offset, raised profile section (12) relative to this, wherein at least the transition from the raised profile section (12) to the inner rim hump (6) has a steep wall section (14),which has an angle of inclination between 45 degrees and 90 degrees relative to the axial direction of the wheel rim (2), characterized in that the raised section (12) has an inclination of 2 to 4 degrees relative to the axial direction of the wheel rim (2) in the direction of the inner hump (6) of the rim.

Description

[0001] The present invention relates to a wheel rim with a drop center, in particular for a motor vehicle, according to the preamble of claim 1. The present invention also relates to a wheel rim with a drop center, in particular for a motor vehicle, according to the preamble of claim 4.

[0002] DE 10 2009 016 211 A1, which is closest to the invention, shows a steel wheel with a rim and a wheel disc that are bonded together. The rim can have a drop center, within which a fastening area is offset radially inward to enable connection to the wheel disc. A hump can be seen axially on the inside and outside of the drop center.

[0003] DE 10 2006 056 229 A1 shows a vehicle wheel rim with a shoulder on the inside and outside of the rim base, which transitions into an inner flange and an outer flange, respectively. The inner flange and the associated shoulder section form a T-shaped cross-section, with the inner flange having a radially outwardly extending section and a radially inwardly extending section.

[0004] DE 60 2004 012 697 T2 shows a sheet metal rim whose profile comprises axially inner and outer hook sections, as well as adjacent sections that form a seat. In some designs, this is followed by an outer boss and an inner boss. Between the bosses are a connecting section and a radially inwardly offset, groove-shaped section. The inner flank of the groove-shaped section has a special curvature.

[0005] JP 2006-327331 A discloses a wheel having a rim portion for supporting a bead portion of a tire and a disc portion for connecting the rim portion and an axle. The wheel includes a first larger-diameter bottom surface formed in an inner portion in the vehicle transverse direction adjacent to the disc portion, and a second smaller-diameter bottom surface formed in an outer portion in the vehicle transverse direction adjacent to the disc portion, which is offset at the position closer to the inner side in the diametric direction of the wheel than the first bottom surface.

[0006] EP 2 459 391 B1 discloses a motor vehicle wheel with a rim having an outer flange, an inner flange, and a rim well connecting the two flanges for holding a tire between the outer flange and the inner flange. This rim well has a drop-center section, wherein the drop-center section or at least a part thereof is arranged adjacent to the tire seat associated with the inner flange. The rim well is asymmetrical in cross-section, wherein the drop-center section represents the deepest part of the rim well. The rim well deepens from the tire seat associated with the outer flange towards the deepest part of the drop-center section.

[0007] From WO 02 / 020 286 A1 a vehicle wheel, in particular for a motor vehicle, e.g., a passenger car, is known, with - a wheel disc for attachment to a rotary axis, - a rim having a wall connected to the wheel disc with an outer side facing away from the wheel disc, and - an airborne sound-absorbing fiber material arranged on the outside of the rim, wherein the fiber material has a carrier layer lying on the outside of the rim, which has an underside facing the outside of the rim and an outside facing away from this, from which the fibers protrude, and wherein the carrier layer is held on the outside of the rim, wherein the carrier layer of the fiber material is arranged within a region of the wall of the rim which is recessed relative to adjacent parts of the peripheral surface of the outside and which has a bottom surface to which the carrier layer is attached.

[0008] The wheel rim serves, as is well known, to accommodate and hold a tire. The wheel rim is usually connected to a wheel flange via several spokes, for example, in the case of a light alloy wheel, or to a wheel disc. The wheel flange or disc serves to attach the wheel to the vehicle's hub via wheel bolts. During use, the wheels are subjected to increasing and decreasing dynamic bending and torsional forces, which are the basis for their respective dimensions. Achieving low weight and maintaining the desired NVH (noise, vibration, harshness) properties also play a key role.

[0009] Regarding the wheel rim's drop center, the wheel stiffness increases the deeper, i.e., the further radially inward, the drop center is positioned on the wheel rim. Conversely, a shallow drop center leads to a decrease in wheel stiffness and thus to a lowering of the wheel's natural frequency, which in turn results in less favorable NVH properties. A lower wheel natural frequency causes the generation of louder noise perceived by the vehicle's occupants, which is undesirable. Accordingly, to achieve good NVH properties, the highest possible natural frequency or stiffness of the wheel is desired.

[0010] In general, the depth of a drop center is directly limited by the spatial extent of a brake caliper located in the interior space surrounded by the inside of the vehicle wheel, which is part of a conventional motor vehicle braking system. In particular, the maximum possible depth of the wheel rim drop center is determined by the height of the brake caliper. However, an increase in the braking performance of a motor vehicle braking system generally involves an increase in the size of the brake caliper, as material is usually added to the caliper to increase its rigidity. A shallower drop center, on the other hand, leads to poorer NVH properties, as already explained above.

[0011] Against this background, the present invention is based on the object of creating a wheel rim with a drop center, particularly for a motor vehicle, that exhibits high rigidity and good NVH properties while simultaneously providing sufficient space for accommodating a large brake caliper to achieve high braking performance of the motor vehicle. Furthermore, the wheel rim should be lightweight and cost-effective to manufacture.

[0012] This object is achieved by a wheel rim having the features of claim 1.

[0013] A wheel rim is shown with a drop center arranged between an outer rim shoulder and an inner rim shoulder, which are spaced apart from one another in the axial direction and each taper into a rim flange at the axially outer and inner edges, and are each delimited axially on the outer side by a rim hump and axially on the inner side by a rim hump, wherein the drop center as a whole is designed with a uniform thickness and is offset radially inwardly relative to both humps and has a radially inner, low profile section and at least one raised profile section offset radially outwardly relative to the latter, wherein at least the transition from the raised profile section to the rim-inner hump has a steep wall section which has an angle of inclination of between 45 degrees and 90 degrees relative to the axial direction of the wheel rim,wherein the raised section has an inclination of 2 to 4 degrees relative to the axial direction of the wheel rim, increasing in the direction of the rim's inner hump.

[0014] However, the problem can also be solved with a wheel rim having the features of claim 4.

[0015] For this purpose, a wheel rim is shown with a drop center arranged between an outer rim shoulder and an inner rim shoulder, which are spaced apart from one another in the axial direction and each taper into a rim flange at the axially outer and inner edges, and are each delimited axially on the outer side by a rim hump and axially on the inner side by a rim hump, wherein the drop center as a whole is designed with a uniform thickness and is offset radially inwardly relative to both humps and has a radially inner, low profile section and at least one raised profile section offset radially outwardly relative to this, wherein at least the transition from the raised profile section to the rim-inner hump has a steep wall section which has an angle of inclination of between 45 degrees and 90 degrees relative to the axial direction of the wheel rim,wherein a transition between the low profile section and the raised profile section is designed as a flat ramp which has an angle of inclination of between 2 and 10 degrees relative to the axial direction of the wheel rim.

[0016] Further particularly advantageous embodiments of the invention are disclosed in the respective subclaims.

[0017] It should be noted that the features listed individually in the following description can be combined with one another in any technically reasonable manner and demonstrate further embodiments of the invention. The description further characterizes and specifies the invention, particularly in conjunction with the figures.

[0018] As mentioned above, a wheel rim comprises a drop center arranged between an outer rim shoulder and an inner rim shoulder. The “inner” side of the wheel rim facing the vehicle when the wheel rim is mounted on a vehicle. Accordingly, “outer” refers to the side of the wheel rim facing away from the vehicle. The outer and inner rim shoulders are spaced apart from one another in the axial direction. They each taper into a rim flange at the axially outer and inner edges, respectively, and are each delimited on the axial inside and outside by an outer rim hump and an inner rim hump, i.e. a bulge in the outer and inner rim shoulders. As already mentioned, the drop center as a whole, i.e. along its entire axial course, is offset radially inward relative to both humps.It further has a low, radially inner section and at least one raised section offset radially outwards relative to the latter. Both the low and the raised section of the drop center are positioned as deep as possible in the wheel rim relative to the humps that axially define the drop center in order to give the wheel rim the desired high rigidity and thus good NVH properties. At the same time, however, the section that is raised relative to the low section provides sufficient space for a stiff, larger, and in particular higher, brake caliper whose height is limited at the top by the wheel rim, which can be used to achieve greater braking performance for the motor vehicle. The relatively deep profile of the drop center, which extends along the entire axial direction of the wheel rim, ensures a stiff design of the wheel rim and therefore a high natural frequency of the wheel rim.of an entire wheel, of which the wheel rim according to the invention is a component. The weight of the wheel rim according to the invention is essentially unchanged compared to a conventional wheel rim with a conventional drop center.

[0019] At least the transition from the raised section to the rim-inner hump has a steep wall section. The steep wall section has an inclination angle of between 45 degrees and 90 degrees, more preferably between approximately 60 degrees and approximately 85 degrees, and even more preferably between approximately 70 degrees and approximately 80 degrees, relative to the axial direction of the wheel rim. Similarly, the transition from the low section of the drop center to the rim-outer hump preferably also has a steep wall section. This can be between approximately 45 degrees and approximately 90 degrees, more preferably between approximately 60 degrees and approximately 85 degrees, and even more preferably between approximately 70 degrees and approximately 80 degrees.The respective steep wall sections connecting the drop center with the corresponding humps and in particular the rim-inner steep wall section, which forms the transition from the raised section of the drop center to the rim-inner hump, further improve the rigidity of the wheel rim, so that the natural frequency of the wheel rim according to the invention can be increased again.

[0020] As described above, the raised section has an inclination of 2 to 4 degrees, preferably approximately 3 degrees, relative to the axial direction of the wheel rim, rising toward the inner hump of the rim. The raised section of the drop center, which is inclined in the axial direction of the wheel rim, provides even more installation space for the brake caliper, which is located below the wheel rim when the wheel rim is mounted on the vehicle, while simultaneously keeping the drop center as low as possible.

[0021] According to a further advantageous embodiment of the invention, a transition between the low profile section and the raised profile section is designed as a steep step. The steep step preferably has an inclination angle of between approximately 45 degrees and approximately 90 degrees, more preferably between approximately 50 degrees and approximately 80 degrees, and even more preferably between approximately 60 degrees and approximately 70 degrees, relative to the axial direction of the wheel rim. This steep step also further improves the rigidity of the wheel rim, so that the natural frequency of the wheel rim according to the invention can be increased even further.

[0022] As mentioned above, the transition between the low profile section and the raised profile section is designed as a flat ramp. The flat ramp has an inclination angle of between 2 and 10 degrees relative to the axial direction of the wheel rim, preferably between approximately 4 and 6 degrees, and more preferably approximately 5 degrees. The flat ramp allows for a deeper axial profile of the raised profile section of the drop center over a larger axial section, thereby further increasing the rigidity of the wheel rim.

[0023] In a further preferred embodiment, the wheel rim is a light metal alloy wheel rim which, together with a wheel flange which is connected to the wheel rim via a plurality of wheel spokes, forms a light metal alloy wheel.

[0024] Further features and advantages of the invention will become apparent from the following description of non-limiting embodiments of the invention, which are explained in more detail below with reference to the drawings. In this drawing, schematically show: Fig. 1 a partial sectional side view of a wheel with a wheel rim according to the invention according to a first embodiment, Fig. 2 a detailed view of an axial profile of the wheel rim from Fig. 1 and Fig. 3 a detailed view of an axial profile of a wheel rim according to the invention according to a second embodiment.

[0025] In the different figures, parts that are equivalent in terms of their function are always provided with the same reference symbols, so that they are usually only described once.

[0026] Fig. 1 shows a partial sectional side view of a wheel 1 with a wheel rim 2 according to the invention according to a first embodiment. Fig. The wheel 1 shown in Figure 1 is shown mounted on a motor vehicle (not shown). Fig. 1 In addition to the wheel 1 and the wheel rim 2, a brake caliper 3 can also be seen.

[0027] How Fig. 1, the wheel rim 2 has a drop center 4. The drop center 4 extends in the axial direction of the wheel rim 2 between two humps 5 and 6 which are spaced apart from one another in the axial direction, of which hump 5 is arranged on the outer side of the rim and hump 6 on the inner side of the rim. An outer rim shoulder 7 adjoins the outer rim hump 5 in an axially outward direction. Similarly, an inner rim shoulder 8 adjoins the inner rim hump 6 in an axially inward direction. The outer rim shoulder 7 tapers at its axially outer edge into an outer rim flange 9. The inner rim shoulder 8 likewise tapers at its axially inner edge into an inner rim flange 10.

[0028] In the Fig. 1 that the drop center 4 in its entirety, i.e. in its entire axial extent, is offset radially inwards with respect to both humps 5 and 6 and has a constant thickness. Furthermore, the drop center 4 in its entirety is also offset radially inwards with respect to both rim shoulders 7 and 8. In order to achieve the deepest possible drop center 4 for high rigidity of the wheel rim, the drop center 4 further has a radially inner, low extending section 11 and, relative to this, a raised extending section 12 offset radially outwards. The drop center 4 formed by the two extending sections 11 and 12 is offset radially inwards with respect to the two humps 5 and 6, in particular, to such an extent that both the low extending section 11 and the raised extending section 12 have a respective steep wall section 13 on the outer side of the rim and a respective steep wall section 14 on the inner side of the rim.14 into the respective hump 5 or 6. At least the rim-inner steep wall section 14 has an angle of inclination of between approximately 45 degrees and approximately 90 degrees, preferably between approximately 60 degrees and approximately 85 degrees, and even more preferably between approximately 70 degrees and approximately 80 degrees, relative to the axial direction of the wheel rim 2. Fig. In the embodiment of the wheel rim 2 shown in Figure 1, the outer rim wall section 13 also has such an inclination relative to the axial direction of the wheel rim 2. The wall sections 13 and 14, and especially the inner rim wall section 14, contribute to increasing the rigidity of the wheel rim 2.

[0029] Furthermore, both sections 11 and 12 are selected in their entire axial course with respect to the brake calliper 3 such that a minimum distance 15, preferably about 5 mm, always remains between the brake calliper 3 and the deep base 4 of the wheel rim 2. As in Fig. 1, the transition between the low profile section 11 and the raised profile section 12 in the illustrated embodiment of the wheel rim 2 is designed as a steep step 16 in order to achieve optimal adaptation to the outer surface of the brake caliper 3 and at the same time to achieve maximum rigidity and thus a high natural frequency of the wheel rim 2. Accordingly, the raised profile section 12, in contrast to the low profile section 11, further has an inclination rising from the outer to the inner side of the rim relative to the axial direction of the illustrated wheel rim 2, which inclination is 2 to 4 degrees, preferably approximately 3 degrees. The steep step 16 has an angle of inclination of between approximately 45 degrees and approximately 90 degrees, preferably between approximately 50 degrees and approximately 80 degrees, and even more preferably between approximately 60 degrees and approximately 70 degrees, relative to the axial direction of the wheel rim 2.

[0030] Fig. 2 shows a detailed view of an axial profile of the wheel rim 2 Fig. 1.

[0031] Fig. Figure 3 shows a detailed view of an axial profile of a wheel rim 17 according to the invention according to a second embodiment. The essential difference between the wheel rim 17 and the wheel rim 2 lies in the design of the drop center. The wheel rim 17 has a drop center 18, the lowest section 11 of which essentially corresponds to that of the wheel rim 2 of Fig. 2. Instead of the Fig. 2, the wheel rim 17 has a flat ramp 19. The flat ramp 19, which has an angle of inclination of between about 2 and about 10 degrees, preferably between about 4 and 6 degrees and more preferably about 5 degrees, relative to the axial direction of the wheel rim 17, forms the transition between the low profile section 11 of the drop center 18 and a raised profile section 20 of the drop center 18. In contrast to the raised profile section 12 of the Fig. 2, the raised section 20 of the wheel rim 17 has essentially no inclination relative to the axial direction of the wheel rim 17. This design of the deep base 18 allows for a Fig. 1 and Fig. 2 shown wheel rim 2 again a slightly stiffer design of the wheel rim 17 and thus a slightly higher natural frequency and better NVH properties of the wheel rim 17, since the rim inner steep wall section 14 in Fig. 3 compared to the rim inner steep wall section 14 in Fig. 2 is again slightly extended in the radial direction of the wheel rim 17.

[0032] The wheel rims according to the invention described above are not limited to the embodiments disclosed herein, but also include other embodiments with similar effects. For example, the drop center can also have more than one raised section relative to the radially innermost, lowest section. An exemplary embodiment configured in this way could have a stepped ascending profile from the lowest section.

[0033] In a preferred embodiment, the wheel rim according to the invention is used as a light metal alloy wheel rim of a light metal alloy wheel on a motor vehicle. List of reference symbols: 1 wheel 2 wheel rims 3 brake caliper 4 low bed 5 Rim outer hump 6 Rim inner hump 7 Outer rim shoulder 8 Inner rim shoulder 9 Outer rim flange 10 Rim inner rim flange 11 Low gradient section of 4 12 Elevated section of 4 13 Outer rim steep wall section 14 Rim inner steep wall section 15 Minimum distance between 3 and 4 16 steep steps 17 Wheel rim 18 low bed 19 Flat ramp 20 Elevated section of 18

Claims

[1] Wheel rim (2) with a drop center (4) arranged between an outer rim shoulder (7) and an inner rim shoulder (8), which are spaced apart from one another in the axial direction and each terminate at the axially outer and inner edges into a rim flange (9, 10) and are each delimited axially on the outer side by a rim-outer hump (5) and axially on the inner side by a rim-inner hump (6), wherein the drop center (4) is designed as a whole with a constant thickness and is offset radially inwardly relative to both humps (5, 6) and has a radially inner, low profile section (11) and, relative to the latter, at least one raised profile section (12) offset radially outwardly, wherein at least the transition from the raised profile section (12) to the rim-inner hump (6) has a steep wall section (14),which has an angle of inclination of between 45 degrees and 90 degrees relative to the axial direction of the wheel rim (2), characterized by that the raised section (12) has an inclination of 2 to 4 degrees relative to the axial direction of the wheel rim (2) increasing in the direction of the rim inner hump (6). [2] Wheel rim (2) according to claim 1, characterized by that a transition between the low section (11) and the raised section (12) is designed as a steep step (16). [3] Wheel rim (2) according to claim 2, characterized by that the steep step (16) has an angle of inclination of between 45 degrees and 90 degrees, preferably between 50 degrees and 80 degrees and more preferably between 60 degrees and 70 degrees, relative to the axial direction of the wheel rim (2). [4] Wheel rim (17) with a deep well (18) arranged between an outer rim shoulder (7) and an inner rim shoulder (8), which are spaced apart from one another in the axial direction and each run into a rim flange (9, 10) at the axially outer and inner edges, and are each delimited axially on the outer side by a rim-outer hump (5) and axially on the inner side by a rim-inner hump (6), wherein the deep well (18) is designed in its entirety with a constant thickness and is offset radially inwardly relative to both humps (5, 6) and has a radially inner, low profile section (11) and, relative to the latter, at least one raised profile section (20) offset radially outwardly, wherein at least the transition from the raised profile section (20) to the rim-inner hump (6) has a steep wall section (14),which has an angle of inclination of between 45 degrees and 90 degrees relative to the axial direction of the wheel rim (17), characterized by that a transition between the low profile section (11) and the raised profile section (20) is designed as a flat ramp (19) which has an angle of inclination of between 2 and 10 degrees with respect to the axial direction of the wheel rim (17). [5] Wheel rim (17) according to claim 4, characterized by that the flat ramp (19) has an angle of inclination of between 4 and 6 degrees, preferably 5 degrees, relative to the axial direction of the wheel rim (17). [6] Wheel rim (17) according to claim 4 or 5, characterized by that the raised section (20) has no inclination relative to the axial direction of the wheel rim (17). [7] Wheel rim (2, 17) according to one of the preceding claims, characterized bythat the steep wall section (14) has an angle of inclination between 60 degrees and 85 degrees, more preferably between 70 degrees and 80 degrees, relative to the axial direction of the wheel rim (2, 17). [8] Wheel rim (2, 17) according to one of the preceding claims, characterized by that the wheel rim (2, 17) is a light metal alloy wheel rim.

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