METHOD FOR PRODUCING A VEHICLE WHEEL CONSISTING OF SHEET METAL

Abstract

The present invention relates to a method for producing a vehicle wheel consisting of sheet metal.

Claims

1. A method for producing a vehicle wheel consisting of sheet metal, comprising a rim for receiving a tire and a wheel disk attached to the rim in a substance-to-substance, force-fitting and/or form-fitting manner, with an attachment region for releasably attaching to a wheel carrier, comprising the following steps: a) one of cold forming and cold preforming a rim, b) one of cold forming and cold preforming a wheel disk, and c) connecting the wheel disk to the rim in order to form a vehicle wheel, wherein at least one of the rim and the wheel disk comprises a hardenable steel material having a carbon content of at least 0.15% by weight.

2. The method as claimed in claim 1, wherein after step c), the vehicle wheel, in a step d), is first of all partially or completely heated to a temperature above the A.sub.c1 temperature, preferably above the A.sub.c3 temperature, and then the hot vehicle wheel is one of partially hardened in a step e) and completely hardened in a step f).

3. The method as claimed in claim 2, wherein after step f), the completely hardened vehicle wheel is one of partially annealed in a step g) and completely annealed in a step h).

4. The method as claimed in claim 2, wherein after step e), the partially hardened vehicle wheel is annealed in a step i).

5. The method as claimed in claim 1, wherein before step c), the cold formed or cold preformed rim and/or the cold formed or cold preformed wheel disk, in a step j), is first of all completely heated to a temperature above the A.sub.c1 temperature, preferably above the A.sub.c3 temperature, and then at least one of the hot rim and the hot wheel disk is one of partially hardened in a step k) and is completely hardened in a step l).

6. The method as claimed in claim 5, wherein after step l), one of the completely hardened rim and the completely hardened wheel disk is one of partially annealed in a step m) and is completely annealed in a step n).

7. The method as claimed in claim 5, wherein after step k), at least one of the partially hardened rim and the partially hardened wheel disk is annealed in a step o).

8. The method as claimed in claim 6, wherein after step m), n) or o), step c) is carried out.

9. The method as claimed in claim 5, wherein after step k) or l), step c) is carried out.

10. The method as claimed in claim 9, wherein the vehicle wheel is one of partially annealed in a step p) and is completely annealed in a step q).

11. The method as claimed in claim 3, wherein the annealing is carried out at a temperature of at least 200 C. and below 650 C.

12. The method as claimed in claim 11, wherein between the beginning of the annealing process and restoring of the room temperature or downstream of the annealing process, a calibration are carried out, in particular to ensure the dimensional accuracy.

13. The method as claimed in claim 2, wherein the hardening is carried out only in the edge layer of the hardenable steel material.

14. The method as claimed in claim 1 wherein the provided steel material is a tempering steel, in particular of the type C22, C35, C45, C55, C60, 42CrMo4, a manganese-containing steel, in particular of the type 16MnB5, 16MnCr5, 20MnB5, 22MnB5, 30MnB5, 37MnB4, 37MnB5, 40MnB4, a case-hardening steel, an air-hardening steel or a multi-layered steel material composite.

15. The method of claim 1, further comprising using the vehicle wheel for cars, utility vehicles, trucks, special-purpose vehicles, buses, omnibuses, whether with an internal combustion engine and/or an electric drive, or towed units or trailers.

16. The method of claim 1 wherein the hardenable steel material has a carbon content of at least 0.22% by weight.

17. The method of claim 16 wherein the hardenable steel material has a carbon content of at least 0.27% by weight.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0031] The invention will be explained in more detail below with reference to drawings, in which, in detail:

[0032] FIG. 1 shows a sequence of the method according to a first embodiment of the invention,

[0033] FIG. 2 shows a sequence of the method according to a second embodiment of the invention, and

[0034] FIG. 3 shows the essential components of a vehicle wheel in a perspective view.

DESCRIPTION

[0035] FIG. 1 illustrates a sequence of method steps according to a first embodiment of the invention. For the rim (1) to be produced and/or for the wheel disk (2) to be produced, hardenable steel materials having a carbon content of at least 0.15% by weight, in particular of at least 0.22% by weight, preferably of at least 0.27% by weight are provided. The rim (1) and the wheel disk (2) are cold formed or preformed in steps a) and b) by means of compressive forming, tensile forming, tensile-compressive forming, bending forming, shear forming, flow forming, deep drawing or by means of a combination of the production methods mentioned, in particular also in multiple steps on, for example, transfer or progressive presses. In step c), the wheel disk (2) is attached to the rim (1) in a substance-to-substance, force-fitting and/or form-fitting manner in order to form a vehicle wheel (3). Preferably, the wheel disk (2) is attached to the rim at least partially by a joining seam which can be realized as a MIG, MAG, laser, weld or solder seam. The vehicle wheel (3) after its assembly is heated in a step d) first of all partially or completely to a temperature above the A.sub.c1 temperature, preferably above the A.sub.c3 temperature.

[0036] According to a first alternative, after the heating or soaking, the hot vehicle wheel (3) can be partially hardened in a step e), following the arrow I. After step e), the partially hardened vehicle wheel (3) is annealed in a step i), wherein, by means of the heat treatment, a structure in the partially hardened region having preferably a tensile strength of between 800 and 1200 MPa and/or a hardness of between 250 and 370 HV10, preferably of between 850 and 1100 MPa and/or a hardness of between 265 and 340 HV10, particularly preferably of between 900 and 1050 MPa and/or a hardness of between 280 and 330 HV10 is sought, as a result of which optimum operating strength and reliability of the entire vehicle wheel (3) can be ensured.

[0037] According to a second alternative, after the heating or soaking, the hot vehicle wheel (3) can be completely hardened in a step f), following the arrow II. After step f), the completely hardened vehicle wheel (3) can be partially annealed in a step g), following the arrow III, or can be completely annealed in a step h), following the arrow IV. Depending on the design of the vehicle wheel (3), the structure of the completely hardened vehicle wheel can be partially or completely heat-treated, wherein preferably a tensile strength in the annealed region of between 800 and 1200 MPa and/or a hardness of between 250 and 370 HV10, preferably of between 850 and 1100 MPa and/or a hardness of between 265 and 340 HV10, particularly preferably of between 900 and 1050 MPa and/or a hardness of between 280 and 340 HV10 is sought.

[0038] FIG. 2 illustrates a sequence of method steps according to a second embodiment of the invention. For the rim (1) to be produced and/or for the wheel disk (2) to be produced, hardenable steel materials having a carbon content of at least 0.15% by weight, in particular of at least 0.22% by weight, preferably of at least 0.27% by weight are provided. The rim (1) and the wheel disk (2) are cold formed or preformed in steps a) and b) by means of compressive forming, tensile forming, tensile-compressive forming, bending forming, shear forming, flow forming, deep drawing or by means of a combination of the production methods mentioned, in particular also in multiple steps on, for example, transfer or progressive presses. By contrast to the embodiment in FIG. 1, the cold formed or cold preformed rim (1) and/or the cold formed or cold preformed wheel disk (2), in a step j), is first of all partially or completely heated to a temperature above the A.sub.c1 temperature, preferably above the A.sub.c3 temperature. Depending on requirements, step j) can be carried out either only on the cold formed or cold preformed rim (1) or only on the cold formed or cold preformed wheel disk (2) or on both components (1, 2), and is therefore illustrated by dashed lines. For example, only the wheel disk (2) composed of a hardenable steel material, for example of the type C45 or 42CrMo4, is heated, whereas the rim (1) can be composed of a conventional steel material and is not heated. After the heating or soaking, the hot rim (1) and/or the hot wheel disk (2) is subsequently partially hardened in a step k) or completely hardened in a step l).

[0039] After step k), following the arrow V, the partially hardened rim (1) and/or the partially hardened wheel disk (2) is annealed in a step o), wherein, by means of the heat treatment, a structure in the partially hardened region having preferably a tensile strength of between 800 and 1200 MPa and/or a hardness of between 250 and 370 HV10, preferably of between 850 and 1100 MPa and/or a hardness of between 265 and 340 HV10, particularly preferably of between 900 and 1050 MPa and/or a hardness of between 280 and 330 HV10 is sought. The rim (1) and the wheel disk (2) are subsequently connected to each other in order to form a vehicle wheel (3), and step c) is carried out.

[0040] After step l), following arrow VI, the completely hardened rim (1) and/or the completely hardened wheel disk (2) is partially annealed in a step m) or completely annealed in a step n). Depending on the design of the vehicle wheel (3) to be produced, the structure of the completely hardened rim (1) and/or wheel disk (2) can be partially or completely heat-treated, wherein preferably a tensile strength in the annealed region of between 800 and 1200 MPa and/or a hardness of between 250 and 370 HV10, preferably of between 850 and 1100 MPa and/or a hardness of between 265 and 340 HV10, particularly preferably of between 900 and 1050 MPa and/or a hardness of between 280 and 330 HV10 is sought. The rim (1) and the wheel disk (2) are subsequently connected to each other in order to form a vehicle wheel (3), step c).

[0041] Following the arrow VII, after the hardening according to step k) (the partially hardened rim (1) and/or the partially hardened wheel disk (2)) or according to step l) (the completely hardened rim (1) and/or the completely hardened wheel disk (2)), the rim (1) and the wheel disk (2) are connected to each other in order to form a vehicle wheel (3), step c). The vehicle wheel (3) is partially annealed in a step p), following arrow VIII, or is completely annealed in a step q), following the arrow IX, wherein, depending on the design of the vehicle wheel, preferably a tensile strength in the annealed region of between 800 and 1200 MPa and/or a hardness of between 250 and 370 HV10, preferably of between 850 and 1100 MPa and/or a hardness of between 265 and 340 HV10, particularly preferably of between 900 and 1050 MPa and/or a hardness of between 280 and 330 HV10 is sought, in order to be able to ensure optimum operating strength and reliability of the entire vehicle wheel.

[0042] If the vehicle wheel is not intended to be completely hardened and annealed, preferably only the wheel disk is composed of a hardenable steel material, preferably of the types C22, C35, C45, C55, C60, 42CrMo4, 16MnB5, 16MnCr5, 20MnB5, 22MnB5, 30MnB5, 37MnB4, 37MnB5, 40MnB4, or a multi-layered steel material composite, and conventional steel materials, such as, for example, S355, S420MC, S460MC, are used for the rim.

[0043] FIG. 3 shows, in a perspective view, a rim (1), a wheel disk (2) and a vehicle wheel (3) which is composed or formed from a rim (1) and a wheel disk (2) attached to the rim (1) in a substance-to-substance, force-fitting and/or form-fitting manner.