WO2019201635A1

WO2019201635A1 - Method and tool for producing a vehicle wheel

Info

Publication number: WO2019201635A1
Application number: PCT/EP2019/058752
Authority: WO
Inventors: David Pieronek; Jörg GORSCHLÜTER
Original assignee: Thyssenkrupp Steel Europe Ag; Thyssenkrupp Ag
Priority date: 2018-04-17
Filing date: 2019-04-08
Publication date: 2019-10-24
Also published as: DE102018205773A1

Abstract

The present invention relates to a method and a multi-part tool (10) for the production of a wheel (1) for a vehicle having a rim (2) for receiving a tyre and a wheel disc (3) integrally, frictionally and/or interlockingly connected to the rim (2) having a connection area (3.1) for detachable mounting on a wheel carrier. The invention further discloses an alternative and a multi-part tool (10) for producing a wheel (1) for a vehicle.

Description

Method and tool for producing a vehicle wheel

The invention relates to a method and a multi-part tool for producing a wheel for a vehicle with a rim for receiving a tire and to the rim material, force and / or form-fitting tethered wheel with a connection area for releasable mounting to a wheel ,

Technical background

Vehicle wheels or motor vehicle wheels are safety components and must therefore be able to absorb the high mechanical and dynamic cyclical loads during ferry operation. Conventional "steel wheels" in sheet metal construction usually consist of a wheel disc (wheel disc), which ensures the connection to the wheel hub and a rim (rim tape), which receives the tire. Nowadays, the wheel components are manufactured on step presses in several steps (up to eleven stages) by cold forming (deep drawing, pressure rolling, profiling). In the past, only microalloyed steels (structural steel, fine grained steel) and dual-phase steels with a strength of 400 to 600 MPa have been used. The joining technique used is preferably an MAG weld in combination with a press connection (deep-bed rim).

The weight of the vehicle wheels has a disproportionate effect as a rotationally moving mass on the energy consumption of the vehicles as well as on the unsprung masses. Therefore, in general, the lowest possible vehicle wheel weight should be aimed at ideally high rigidity. Especially for commercial vehicles with several wheels and a single weight of approx. 36 to 40 kg, a significant reduction in weight also has a positive effect on the transport load. Compared to conventionally produced vehicle wheels, further lightweight construction potential can be exploited with steel if, on the one hand, material with a higher strength or fatigue strength is used to safely accommodate the operating loads and, on the other hand, geometric adjustments, such as stampings to compensate for stiffness losses due to lower material thicknesses can be implemented. With increasing material strength, however, the cold workability of conventional steels (carbon steel) generally decreases, which is almost exhausted even in today's wheeled dishes. Thus lightweight construction with cold-workable and higher-strength steels based on today's production concepts for wheels is reaching its technical limits. In addition to the weight of the wheels, the design also plays a significant role in passenger vehicles. The design freedom and attractiveness of known steel wheels is therefore also severely limited by conventional construction methods and materials.

In addition to the so-called cold forming, so-called hot forming in vehicle / body construction is also used, among others also known under indirect or direct hot forming. Through the use of hot forming, the requirement for high formability and simultaneously high strength of the final molded components can be met. Corresponding forming processes, which take place involving a preceding heat treatment of the workpiece, for example in a separate oven, are well known from the prior art, in particular the hot forming and press hardening of sheet steel. However, the use of hot forming for significantly cyclic loaded steel sheet components such as Wishbones, wheels, axle beams, not yet established in automotive vehicle construction.

As state of the art for sheet metal hot forming of passenger car wheels or the corresponding Radschüsseln, which may be at least partially press hardened, reference is made to the publications DE 10 2007 019 485 A1, DE 10 2013 1 14 245 B3 and DE 10 2014 108 901 B3 , The focus of these publications is essentially on the local mechanical component properties of the wheel disc after hot forming or press hardening, as well as corresponding method steps or devices for the production of wheel shells for standard steel wheels.

An at least partially curing of a rim on the assembled wheel is disclosed in the publication US 2004/0041458 A1, with the aim of increasing the resistance of the wheel in the event of a curb impact or a sudden load. In a standard wheel for passenger vehicles, the mass is predominantly concentrated in the rim (> approx. 60%), so that an increase in the material strength in the rim not only has a positive effect on the resistance under sudden load, but with a corresponding design It may also make it possible to reduce the weight of the rim, which is particularly desirable for commercial vehicle wheels. The local hardening of the wheel according to the proposed method of US 2004/0041458 A1 is unfavorable insofar as the procedure would lead to enormous component distortion, which has an unfavorable effect on the dimensional accuracy and the concentricity of the wheel.

A standard-compliant rim is rotationally symmetrical and / or annular and has in particular about the axis of rotation of the wheel undercut geometry areas on the rim Horn and the rim shoulder (Hump, valve seat), so that the production by direct Warme- is technically difficult to implement. In addition, due to the complex geometry of the rim, it can be assumed that hot working with the known tool components (punch, blank holder, die) is not expedient.

Summary of the invention

The invention is therefore based on the object to provide a suitable method and a corresponding tool for the production of hot-formed or press-hardened rims and thus also wheels made of sheet steel, which a high weight reduction, dimensional stability, durability and safety, especially at acceptable production costs guarantee.

This object is achieved by a method having the features of patent claim 1 and alternatively by a method having the features of patent claim 2.

According to a first teaching, the invention relates to a method for producing a wheel for a vehicle with a rim for receiving a tire and to the rim material, force and / or form-fitting tethered wheel with a connection area for detachable mounting to a wheel comprising the steps:

Providing a rotationally symmetrical and / or tubular and / or near-net shape preform of a rim,

Providing a wheel dish,

- connecting the wheel disc to the preform of the rim,

- At least partial or complete heating of the preform of the rim and optionally the tethered wheel to a temperature of at least A _Ci , preferably to a temperature of at least A _C 3, in particular based on the steel material of the rim, and then at least partially hot forming with at least partially Presshär wherein the at least partially hot forming is carried out with at least partial press hardening in a multi-part tool, the multi-part tool having at least one inner die, at least one upper die and at least two outer dies, the outer dies each having an effective surface at least in regions sen, which at least partially correspond to the final geometry of the outer contour of the rim of the rim, wherein the warm preform of the rim between the outer dies is arranged and the warm preform of the rim by acting on the outer surface of the effective areas on the Au screen outer rim of the preform into the final geometry of the outer contour of the Rim of the wheel transferred, at least partially hot-formed and at least partially press-hardened.

According to the invention, an already prefabricated, assembled wheel comprising a preform of the rim with a connected Radschüssel, in particular comprising a frictional and / or material connection, at least partially or completely to a temperature of at least A _Ci , preferably to a temperature of at least A _C3 the steel material of the rim, heated or heated and then at least partially thermoformed in a multi-part tool at least the warm preform of the rim and at least partially press-hardened. As a result of the at least partial press hardening, in particular due to the tool contact, a hardened structure arises at least partially in the rim of the wheel, by means of which a high dimensional stability can be achieved by avoiding springback. As a result, the dimensional accuracy of the overall wheel in the multipart tool can be improved so that costly reworking, for example, to compensate for concentricity deviations, can be reduced or completely avoided. The at least partially produced hardened structure in the rim, when appropriately carried out, leads to a higher operating strength of the rim, which enables a significant weight reduction of the overall wheel.

According to one embodiment of the method, the inner die and / or the upper die each have an active surface, which act on the visible side and / or back of the Radschüssel the arranged between the outer dies, warm preform with tethered Radschüs- sel, the wheel bowl optionally at least partially warm deformed and at least partially press-hardened. This results in a hardness structure at least partially in the wheel bowl of the wheel, which can contribute to the further improvement of the wheel, since the at least partially produced hardness structure in the wheel bowl leads to a higher operational stability of the wheel bowl, which carries a further Weight reduction of the total wheel allows.

According to one embodiment of the method, the active surfaces at least partially have the end geometry of the connection region on the wheel disc and the connection region can be hot-formed at least in regions in the multi-part tool. The final shape of the wheel disc can also be taken into account in the multi-part tool, which can be saved by advance in the manufacturing steps, in particular substantially the near-net shape geometry or final geometry of the wheel. In addition, the operational stability of the connection, especially of a possible welded joint, can be Partly influenced, for example, possible softening in the heat-affected zone (HAZ) and thus metallurgical notches can be reduced, which has a positive effect on the durability and stability of the overall wheel.

According to one embodiment of the method, the inner die and / or the upper die are designed such that they each have a further active surface, which are provided at least partially circumferentially around the active surface for the wheel disc and at least partially the final geometry of the inner contour of the rim Rades correspond, wherein the warm preform of the rim by the action of the further active surfaces of the Innenge- sen and / or Obergesenks on the inner contour of the preform of the rim at least partially converted into the final geometry of the inner contour of the rim of the wheel, at least partially hot-formed and at least partially press cured. In particular, the further active surfaces in the multi-part tool can serve as a kind of counter bearing, in particular if the active surfaces of the outer dies act on the outer contour of the preform of the rim or rim of the wheel and thereby the preform of the rim respectively the rim between them and, by at least partial press hardening, a certain dimensional stability in the rim can be set. As a result, the dimensional accuracy of the overall wheel can be improved, so that complex reworking, for example for compensating the runout deviations, can be reduced or completely avoided.

According to an alternative to the first teaching, the invention relates to a method for producing a wheel for a vehicle with a rim for receiving a tire and to the rim material, force and / or form-fitting tethered wheel with a connection area for releasable mounting on a wheel carrier, comprising the steps:

Providing a wheel dish,

at least partially or completely heating the preform of the rim to a temperature of at least A _Ci , preferably to a temperature of at least A _C3 , in particular based on the steel material of the rim, and then at least partially hot forming with at least partial press hardening, wherein the at least partially hot forming is carried out with at least partial press hardening in a multi-part tool, wherein the multi-part tool has at least one inner die, at least one upper die and at least two outer dies, wherein the outer dies each at least partially have an active surface which at least partially the final geometry of Outer contour of the rim of the wheel correspond to the warm preform the rim is arranged between the outer dies and the preform of the rim is transferred to the outer contour of the preform of the rim in the final geometry of the outer contour of the rim of the wheel by action of the active surfaces of the outer dies, at least partially hot-formed and at least partially press-hardened,

- Tying the wheel rim to the preform of the rim, in particular in a multi-part tool, during at least partially hot forming with at least partial press hardening or tying the wheel bowl to the rim of the wheel after at least partially hot forming with at least partial press hardening.

According to the invention, a preform of the rim in the not yet prefabricated, assembled, ie in not yet connected with a wheel dish state, at least partially or completely to a temperature of at least A _Ci , preferably to a temperature of at least A _C3 , heated or heated and then hot-formed at least in some areas in a multi-part mold and at least partially press-hardened. By at least partial press hardening, in particular by the tool contact, a hardened structure arises at least partially in the rim of the wheel, by means of which a high dimensional stability can be achieved by avoiding springback. The resulting hardness structure leads, with appropriate implementation to a higher operating strength of the rim, which allows a significant weight reduction of the overall wheel.

According to one embodiment of the alternative method, the wheel disc is heated to a temperature of at least A _Ci , preferably to a temperature of at least A _C3 , before it is inserted into the multi-part tool and then brought into contact with the warm preform of the rim or before being brought into contact with the warm preform of the rim which is already disposed in the multi-part tool. An at least partially hot forming with at least partial press hardening can therefore be carried out in addition to the at least partially hot forming with at least partial press hardening of the warm preform of the rim and the wheel in the multi-part tool, the hardness structure produced with appropriate implementation to a higher operating strength of the wheel, which allows a significant weight reduction. In addition, the processing effort in the multipart tool can reduce the production costs.

Alternatively, the wheel dish can also be inserted into the multipart tool in the cold state and then brought into contact with the warm preform of the rim or brought into contact with the warm preform of the rim, which is already in the multi-part mold. gene tool is arranged. The wheel disc may already be optionally hot-formed and at least partially hardened, at least in some areas. A cold forming by spin forming or pressing is conceivable. As a result, at least partial press hardening of the wheel disc in the multi-part tool can be dispensed with, as a result of which the tool has to be made less complex.

According to one embodiment of the alternative method, after the at least partially hot forming and at least partial press hardening the wheel disc is connected at least non-positively and / or positively to the rim. The wheel disc, whether hot or cold, is brought into contact with the rim's warm preform, where the preform of the rim has a larger diameter compared to the cold state due to thermal expansion, cooling the warm preform of the rim a thermal shrinking onto the wheel disc, whereby at least one press connection (force and / or positive connection) between wheel disc and rim can be provided particularly efficiently by the process. As a result, the manufacturing effort of the overall wheel can be significantly optimized. In addition, residual stresses during thermal process control can be reduced, which would otherwise adversely affect the operating strength of the wheel.

According to a further embodiment of the alternative method, in order to increase the operating strength of the wheel and for secure connection between the wheel disc and the rim, an additional material connection can take place in a downstream process step, in particular by means of welding, in order to also ensure a security against rotation of the wheel components. Afford. Alternatively, in the course of hot-forming the rim, local stampings or locally geometric shapes can be introduced into the area between the wheel rim and the rim in order to achieve an additional form fit, which makes a subsequent thermal joining process unnecessary for achieving a security against twisting ,

According to one embodiment, a hardenable steel material having a carbon content of at least 0.07 wt.%, In particular of at least 0.10 wt.%, Preferably of at least 0.15 wt., Is preferably used for the rim and optionally for the wheel disc. %, more preferably at least 0.22% by weight.

The inventors' vibration strength studies have shown that hardenable steel materials having a predominantly martensitic and / or bainitic structure, such as Manganese-boron, tempering and air- or oil-hardening steels, compared to the conventionally used dual-phase and microalloyed steels have a significantly increased cyclic bending strength and thus in principle further lightweight by sheet thickness reduction, in particular the motor vehicle rim, enable. The steel material provided may be case hardening steel or tempered steel, in particular grades C10, C15, C22, C35, C45, 42CrMo4, a manganese-containing steel, in particular grade 8MnCrB3,16MnB5, 16MnCr5, 22MnB5, 37MnB5, an air-hardening steel, an oil-hardening steel or a multi-layered steel composite material, for example with three steel layers, of which at least one of the layers is curable.

At the temperature A _Ci , the microstructure begins to convert to austenite and, in particular, is completely austenitic when the temperature A is exceeded. Preferably, the preform of the rim and / or wheel bowl is heated to a temperature of at least A, so that there is a substantially austenitic structure in the entire component. A _Ci and A are characteristic values which are dependent on the composition (alloy constituents) of the steel material used and can be taken from so-called ZTA or ZTU diagrams. The at least partial press-hardening preferably takes place in a tool in which the at least partially hot forming is carried out, where the tool is actively cooled in at least one region in which the press-hardening is to be implemented, so that a rapid cooling by contact with the Tool part, in particular with the tool surface / -wirkfläche is effected to austenite in a hard structure, which in particular predominantly martensite and / or bainite may have to convert, (M _f martensite finish). The required cooling rates can also be taken from the ZTU diagrams, depending on the target structure.

Under at least partially hot forming is in particular a molding of the preform of the rim and optionally the wheel in the desired final geometry (desired geometry) of the rim and wheel, in other words in the desired final geometry of the wheel, and / or a calibration to improve the dimensional accuracy or compliance with Toleran - to understand zen. In combination with at least partial press hardening, a final component with final mechanical properties and at least partially predominantly marttensitic and / or bainitic microstructure of the rim or of the wheel is provided. If necessary, the rim or the wheel can also be completely press hardened. A predominantly martensitic and / or bainitic structure presupposes a minimum proportion of the structural phase individually or in combination of 50%. The rotationally symmetrical and / or tubular and / or near-net shape preform of the rim is produced in particular from a flat sheet metal blank made of a hardenable steel material. By means of cold forming, for example by means of rotationally moved tool components, for example by means of spin forming, profiling, etc., a preform of the rim can preferably be provided with a rim well and / or hump and / or rim shoulder and / or rim flange which is close to the final contour. Under outer contour of the preform of the rim or the rim of the wheel is at least partially the outer geometry of the rim flange, in particular sections of the outer geometry of the rim flange and / or the rim shoulder, preferably in sections, the outer geometry of the rim flange, the rim shoulder and / or the Humps The outer geometry of the rim flange, the rim shoulder, the hump and / or the rim well, which is no longer visible, in particular, in the state of use of a mounted tire, is particularly preferred. Under inner contour of the preform of the rim or the rim of the wheel is at least partially the inner geometry of the rim flange, in particular sections the inner geometry of the rim flange and / or the rim shoulder, preferably in sections the inner geometry of the rim flange, the rim shoulder and / or of the hump, particularly preferably in sections, the inner geometry of the rim flange, the rim shoulder, the hump and / or the rim well, which is at least partially visible in use, in particular, and is in direct contact with the wheel disc, to understand.

In particular, the wheel dish can be cold-formed or end-formed cold-formed near the final contour or else it can already be hot-formed at least in regions and optionally at least partially press-hardened. In the vehicle-mounted state, the visible side of the wheel disc corresponds to the side facing away from the vehicle and the rear side corresponds to the side of the wheel disc facing the vehicle which is not visible to the vehicle when mounted on the vehicle.

According to one embodiment, the wheel disc preferably has a material thickness of up to 6 mm for the production of a wheel for passenger vehicles preferably or a thickness of more than 6 mm, in particular more than 8 mm for the production of a wheel for commercial vehicles, which by the higher wheel loads are justified. In particular deviations from the aforementioned material thicknesses are conceivable in further embodiments depending on the design and vehicle type. According to one embodiment, the rim preferably has a material thickness up to a maximum of 3 mm for the production of a wheel for passenger vehicles or in particular a material thickness of more than 3 mm for the production of a wheel for commercial vehicles, which are justified by the higher wheel loads. In particular, deviations from the aforementioned material thicknesses are conceivable in further embodiments depending on the design and vehicle type.

According to one embodiment, the at least partially press-hardening of the preform of the rim and optionally the wheel disc is additionally assisted by the use of a fluid which is brought into direct contact with the warm preform of the rim and optionally warm wheel disc. As a result, for example, areas on the wheel which, owing to their geometry, for example with undercut geometry, can not experience tool contact for at least partial press hardening, can additionally be brought into contact with a fluid in order to cool them and thus also to set a hardened structure at least partially in areas not in contact with the tool. In addition, the higher heat transfer when using a cooling by means of a fluid just the hardenability of components with higher material thicknesses can be improved.

According to a second teaching, the invention relates to a multi-part tool for producing a wheel for a vehicle with a rim for receiving a tire and to the rim material, force and / or form-fitting tethered wheel with a connection area for releasable mounting to a Radträger, with at least one inner die, at least one upper die and at least two outer dies, wherein the outer dies each at least partially have an active surface which at least partially correspond to the final geometry of the outer contour of the rim of the wheel, with a warm preform the rim between the By lowering the outer surfaces of the outer rim of the rim, the warm preform of the rim can be converted into the final geometry of the outer contour of the rim of the wheel, at least partially hot-formed and at least partially press-hardened at least z white outer dies are translationally movable and in the contracted state, the rim of the wheel along its outer contour at least partially, in particular substantially completely can accommodate.

According to the invention, as a result of the at least two translationally movable outer dies of the multi-part tool, the rim of the wheel along its outer contour in the contracted state at least partially, in particular substantially completely, so that at least the warm preform of the rim in the multi-part tool at least at least partially thermoformed and at least partially press-hardened, where at least partially in the rim of the wheel by the at least partial press hardening, a hardened structure is formed by which a high dimensional stability can be achieved by avoiding springback.

The number of outer dies is therefore not reduced to two. Depending on the size and application of the wheel, it is also possible for three, four or more than four outer dies to be provided, which are each translationally movable and an effective face designed correspondingly to the outer contour of the rim for at least partially receiving the rim or the wheel enable. Translationally movable means that the outer valley can preferably be moved radially in the direction of the rim or the wheel, and in particular the axis of rotation of the rim or of the wheel corresponds to the central point in the tool, in particular for the movable embodiment of the outer dies.

To avoid repetition, reference is made to the advantageous embodiments of the method for producing a wheel for vehicles.

According to one embodiment of the tool, the inner die and / or the upper die are translationally movable, particularly preferably in the axial direction of the wheel. Preferably, they are coaxially movable with each other, wherein the axis of rotation of the rim and the axes of the inner and Obergesenks are congruent, in particular the inner die or the upper die can be rigid, whereby the tool can be fitted with less movable components and simpler. In particular, it is thereby possible that the tool at least partially, in particular substantially completely absorbs the wheel in the contracted state, so that a component distortion can be substantially prevented.

According to one embodiment of the tool, the inner die and / or the upper die each have an active surface, which acts on the visible side and / or back of the Radschüs- sel arranged between the outer dies, warm preform of the rim with attached Radschüssel, which optionally optionally at least partially thermoforming the wheel disc and at least partially press-hardening it, and in particular the active surfaces at least partially correspond to the final geometry of the connection area on the wheel disc. As a result, in particular also the at least partially hot forming with at least partial press hardening of the wheel disc next to the rim in the multipart Implemented tool and thereby reducing the manufacturing cost and rework and the dimensional accuracy of the overall wheel can be increased.

According to one embodiment of the tool, the inner die and / or the upper die are formed such that they each have a further active surface, which are at least partially circumferentially provided around the active surface for the wheel and at least partially the end geometry of the inner contour of the rim Rades correspond, so that sufficient hardening and dimensional stability can be made possible by the two-sided tool contact.

Brief description of the drawings

In the following the invention will be explained in more detail with reference to drawings. The same parts are always provided with the same reference numerals. In detail show:

1 to 4 a process sequence of a method for producing a wheel at different times using the example of a multi-part tool in perspective view according to a first embodiment of the invention,

5 and 6 a process sequence of a method for producing a wheel at different times using the example of a multi-part tool in a perspective view according to a second embodiment of the invention,

7 to 10 a process sequence of a method for producing a wheel at different times using the example of a multi-part tool in a perspective view according to a third embodiment of the invention,

1 to 14 a process sequence of a method for producing a wheel at different times using the example of a multi-part tool in a perspective view according to a fourth embodiment of the invention and

Fig. 15 is a perspective view of an assembled wheel. Description of the Preferred Embodiments

The wheel (1) for a vehicle comprises a rim (2) for receiving a tire (not shown) and a wheel bowl (3) connected to the rim (2) in a material, force and / or form-locking manner with a connection region (3.1). for detachable mounting to a wheel carrier, not shown, FIG. 15. Particularly preferably, the connection of the wheel disc (3) to the rim (2) takes place by means of an interference fit (force and / or form fit) in combination with a thermal joining method ( Material connection) such as a MAG or laser welding. The wheel (1) can be designed for a passenger vehicle, with a material thickness of up to 3 mm being preferred for the rim (2) and preferably a material thickness of up to 6 mm for the wheel disc (3), or in particular for a commercial vehicle are designed, wherein for the rim (2) preferably a material thickness of more than 3 mm and for the wheel disc (3) preferably a material thickness is provided with more than 6 mm.

A rotationally symmetrical and / or tubular and / or near-net shape preform of the rim (2 ') and a wheel disc (3') are provided (not shown). The rotationally symmetrical and / or tubular and / or near-net shape preform of the rim (2 ') is produced in particular from a flat sheet metal blank made of a hardenable steel material by means of cold forming, for example by profiling from a hardenable steel material and preferably has an at least near net shape rim base and / or hump and / or rim shoulder and / or rim flange and receiving area of a valve (not shown). The wheel dish (3 ') can also be produced from a hardenable steel material, in particular by means of cold forming, near the end geometry (not shown). In a further step, the wheel disc (3 ') is connected to the preform of the rim (2') in a material, force and / or form-fitting manner (not shown) and can be used as an already prefabricated, assembled wheel (1 '). be further processed. Particularly preferably, the connection is made by a press fit in combination with a thermal joining method such as. a MAG or laser welding.

The preform of the rim (2 ') with the connected wheel bowl (3') is heated by suitable means, for example in a continuous furnace, at least partially or completely to a temperature of at least A _Ci , preferably at least A _C 3 warms, with the warm preform of the rim (2 ') or the warm prefabricated wheel (T) then at least partially thermoformed and at least partially press hardened tet is. The connected wheel disc (3 ') can optionally also be heated at least partially, in particular actively.

Other means of heating, whether radiative, conductive, inductive, alone or in combination, may also be used.

FIGS. 1 to 4 show a process sequence of a method for producing a wheel (1) at different times using the example of a multi-part tool (10) in a perspective view according to a first embodiment of the invention. The at least partially hot forming with at least partial press hardening is carried out in a multi-part tool (10), wherein the multi-part tool (10) at least one inner die (1 1), at least one upper die (12) and at least two outer valley (13 ) having. The outer dies (13) each have, at least in regions, an active surface (13.1) which at least partially corresponds to the final geometry of the outer contour (2.2) of the rim (2) of the wheel (1).

The prefabricated wheel (1 ') is provided for at least partially hot forming and at least partially press-hardening (FIG. 1). The prefabricated wheel (1 ') with the warm preform of the rim (2') is arranged between the outer dies (13) in the tool (10), in particular inserted in the opened tool (10), wherein in particular the inside - Drop (1 1) is designed such that it can accommodate the prefabricated wheel (1 ') (Figure 2). In the course of the upper die (12) in the direction of the inner die (1 1) moves translationally, symbolized by the arrow shown, wherein the inner die (1 1) and / or the upper die (12) each have an active surface (1 1 .1, 12.1 ), which act on the visible side (3.2 ') and / or back (3.3') of the wheel disc (3 ') to at least one fixation of the prefabricated wheel (1') but also a tool contact (1 1, 12), in particular at least in some areas with the wheel dish (3 ') and also at least in some areas with the inner contour (2.3') of the preform of the rim (2 '), so that at least one cooling is carried out in sections in the wheel dish (3') and also in sections on the inner contour (2.3 ') of the preform of the rim (2') is effected and associated therewith an at least partially forming a hardness structure is initialized (Figure 3). In the production of a commercial vehicle wheel, it is particularly preferable to provide contact in the contact area or in the system area (3.1) to be generated, since the highest material thickness is present in the contact area (3.1) and then the corresponding tool holding time is also determined. In this embodiment, the upper die (12) are translationally movable and the inner die (1 1) is rigid. In a further embodiment, which is not shown, the inner die (1 1) can also be translato- Risch movably executed or the upper die (12) rigid and only the inner die (1 1) be made translationally movable. If the active surfaces (1.1.1, 12.1) on the inner die (11) and on the upper die (12) have, for example, at least in part the final geometry of the connection region, the wheel bowl (3 ') can be in the warm state of the attachment. bonding area (3.1) in the multi-part mold (10) at least partially hot-formed and optionally at least partially press-hardened.

The inner die (11) can be designed, for example, segmented in order to reduce the shrinking of the wheel disc (3) and / or the rim (2) in order to achieve a smooth process sequence without component damage.

Finally, the two outer dies (13) are moved translationally in the direction of the preform of the rim (2 '), symbolized by the illustrated arrows, so that in the combined state, the rim (2) of the wheel (1) along its outer contour (2.2 ) of the rim (2) at least partially, in particular substantially completely can accommodate. In this case, the preform of the rim (2 ') by the action of the active surfaces (13.1) of the outer dies (13) on the outer contour (2.2') of the preform of the rim (2 ') in the final geometry of the outer contour

(2.2) the rim (2) of the wheel (1) transferred, hot-formed at least in some areas and at least partially press-hardened (Figure 4). The inner die (1 1) and / or the upper die (12) are formed such that they each have a further active surface (1 1.2, 12.2), which at least partially circumferentially around the active surface (1 1.1, 12.1) for the Radschüs- sel (3 ') are provided and at least partially the final geometry of the inner contour

(2.3) correspond to the rim (2) of the wheel (1), wherein the warm preform of the rim (2 ') by the action of further active surfaces (1 1 .2, 12.2) of the inner die (1 1) and / or upper die (12 ) on the inner contour (2.3 ') of the preform of the rim (2') at least partially transferred to the final geometry of the inner contour (2.3) of the rim (2) of the wheel (1), at least partially hot-formed and at least partially press-hardened. In particular, the further active surfaces (1 1.2, 12.2) in the multi-part tool can serve as a kind of counter bearing, in particular if the active surfaces (13.1) of the outer dies (13) act on the outer contour (2.2 ') of the preform of the rim (2'). ) or the rim (2) of the wheel (1) and thereby accommodate the rim (2) between them and a certain dimensional accuracy in the rim (2) can be adjusted by two-sided tool contact and at least partial press hardening.

By the at least partial press hardening, in particular by the tool contact (1 1, 12, 13), arises at least partially in the rim (2) and optionally at least partially in the Radschüssel (3) of the wheel (1) a hardness structure through which a high dimensional stability by avoiding springback and durability can be achieved. The outer valley (13) is designed to be transparent in FIG. 4, so that it can be shown that the wheel (1) is at least partially, preferably substantially completely, accommodated when the tool (10) is moved together.

The tool (10) is after a predetermined time, in particular after reaching a temperature, in particular when all conversion processes (bainite and / or martensite) are substantially completed and the desired structure in the wheel (1) is set, in particular after reaching the M _f temperature, again opened and the assembled wheel (1) can be removed and in particular further steps are supplied, such as a blast treatment of the surface for the eventual removal of a resulting scale on the wheel (1) and / or a cathodic Dipcoating (KTL) for setting a given corrosion protection.

FIGS. 5 and 6 show a process sequence of a method for producing a wheel (1) at different times using the example of a multi-part tool (10) in perspective view according to a second embodiment according to the invention, where in the process sequence essentially the process sequence according to FIG The first embodiment according to the invention with the difference corresponds to the fact that, instead of two now four outer counters (13) in the tool (10) translationally movable, symbolized by the arrows, are provided. The four outer dies (13) each enclose one quarter of the outer contour (2.2) of the rim (2) of the wheel (1). Thus, a better force distribution and surface pressure can be achieved. The tool (10) is after a predetermined time, in particular after reaching a temperature, in particular when all conversion processes (Bai nit and / or martensite) are substantially completed and the desired structure in the wheel (1) is set, in particular after reaching the m _r temperature, reopened and the assembled wheel (1) can be removed.

FIGS. 7 to 10 show a process sequence of a method for producing a wheel (1) at different times using the example of a multi-part tool (10) in perspective view according to a third embodiment according to the invention. The configuration of the tool (10) in FIGS. 7 to 10 essentially corresponds to the configuration of the tool (10) in FIGS. 5 and 6 or in FIGS. 1 to 4. In contrast to the two aforementioned exemplary embodiments, a not yet prefabricated or operable wheel (1 ') can alternatively be made available, wherein initially a preform of the rim (2') and a wheel disc (3 ') are provided separately from each other, and a connection of the wheel disc (3 ') during the at least partially hot forming with at least partial press hardening to the preform of the rim (2') and / or after the at least partially hot forming with at least partial press hardening of the wheel disc (3) to the rim (2 ) of the wheel (1) takes place in a separate step (not shown).

The preform of the rim (2 ') is heated or heated by suitable means, for example in a through-flow furnace, at least partially or completely to a temperature of at least A _Ci , preferably at least A _C 3. The warm preform of the rim (2 ') is arranged between the outer dies (13) in the tool (10), in particular inserted into the opened tool (10), wherein in particular the inner die (1 1) is designed such that it can accommodate the warm preform of the rim (2 ') (Figure 7). Furthermore, a wheel dish (3, 3 ') in the cold state, which in particular cold formed close to the final shape or final formed or even already optionally correspondingly optionally at least partially thermoformed and may be at least partially press hardened, or alternatively in the warm state, wherein it is by means of suitable means, for example in a continuous furnace, to a temperature of at least a _Ci, preferably at least _C 3 a, at least partially or entirely heated or warmed, is provided.

The cold or warm wheel bowl (3, 3 ') is inserted into the opened tool (10), in which already the warm preform of the rim (2') is located and on the active surface (1 1 .1) of the inner die (1 1 ), wherein the geometry of the inner die (1 1) is adapted to the rim (2, 2 ') such that the wheel disc (3, 3') can be placed inside the preform (2 '), wherein the warm preform of the rim (2 ') is dimensioned larger due to its thermal expansion compared to the cold state, d. that the diameter of the warm preform of the rim (2 ') is larger in comparison to the cold preform of the rim (2') or rim (2) and thereby the wheel disc (3, 3 ') within the warm preform ( 2 ') can be arranged (Figure 8).

In the further course, the upper die (12) is moved in a translatory manner in the direction of the inner die (11), symbolized by the illustrated arrow, wherein the upper die (12) also has an active surface (12.1) which faces the visible side (3.2 ') and the active surface (1 1.1) of the inner die (1 1) on the back (3.3') of the wheel disc (3, 3 ') act to at least to cause a fixation of the wheel dish (3, 3 '). If a warm wheel disc (3 ') is used, heat is dissipated by the tool contact (1 1, 12), so that at least cooling down in sections in the wheel disc (3') and, associated therewith, forming at least a portion Hardness structure can be initialized (Figure 9). The Wirkflä chen (1 1 .1, 12.1) on the inner die (1 1) and on the upper die (12) vorzugswei- se on the final geometry of the connection region (3.1) of the wheel disc (3), so that at least the connection area (3.1) the wheel bowl (3 ') in the hot state in the multi-part tool (10) at least partially thermoformed and optionally at least partially press-hardened.

Finally, the four outer dies (13) are moved translationally in the direction of the preform of the rim (2 '), symbolized by the illustrated arrows, so that in the collapsed state the rim (2) of the wheel (1) along its outer contour (2.2 ) can at least partially, in particular substantially completely absorb. In this case, the preform of the rim (2 ') by the action of the active surfaces (13.1) of the outer dies (13) on the outer contour (2.2') of the preform of the rim (2 ') in the final geometry of the outer contour (2.2) of the rim (2) of the wheel (1) transferred, at least partially thermoformed and at least partially press-hardened (Figure 10). The inner die (1 1) and / or the upper die (12) are formed such that they each have a further effective surface (1 1.2, 12.2) which at least partially circumferentially around the active surface (1 1.1, 12.1) for the wheel disc (3 ') are provided and correspond at least in sections to the final geometry of the inner contour (2.3) of the rim (2) of the wheel (1), wherein the warm preform of the rim (2') by acting on the further active surfaces (1 1.2 , 12.2) of the inner die (1 1) and / or upper die (12) on the inner contour (2.3 ') of the preform of the rim (2') at least partially into the Endgeome- industry of the inner contour (2.3) of the rim (2) of the wheel (1), at least partially thermoformed and at least partially press-cured. As a result of the at least partial removal of heat from the warm preform of the rim (2 ') into the outer dies (13), inner dies (11) and upper dies (12) and with a thermal shrinkage associated with them, this becomes within the preform of the rim (2 ') and rim (2) arranged Radschüssel (3, 3') non-positively and / or positively connected to the rim (2) by shrinking the rim (2). The tool (10) is after a predetermined time, in particular after reaching a temperature, in particular when all conversion processes (bainite and / or martensite) are essentially completed and the desired structure in the wheel (1) is set, ins - Specially after reaching the M _r temperature, reopened and the assembled wheel (1) can be removed and fed in particular further steps, such as a further joining step, preferably by welding to an additional To close the existing press fit between the wheel disc (3) and rim (2) and / or a cathodic dip coating (KTL) for setting a predetermined corrosion protection.

FIGS. 11 to 14 show a process sequence of a method for producing a wheel (1) at different times using the example of a multi-part tool (10) in a perspective view according to a fourth embodiment according to the invention.

In contrast to the third exemplary embodiment in FIGS. 7 to 10, in this embodiment, the inner die (11) is designed to be movable at the top, translationally movable, and the upper die (12) is rigidly formed in the tool (10). Furthermore, the wheel disc (3, 3 '), irrespective of whether it is in the hot or cold state, is inserted into the opened tool (10) and placed on the active surface (12.1) of the upper die (12) (FIG ).

The preform of the rim (2 ') is heated or heated by suitable means, for example in a through-flow furnace, at least partially or completely to a temperature of at least A _Ci , preferably at least A _C 3. The warm preform of the rim (2 ') is arranged between the outer dies (13) in the tool (10), in particular in the opened tool (10) inserted, in which already the warm or cold wheel bowl (3, 3') is located , The geometry of the upper die (12) is adapted to the rim (2, 2 ') in such a way that the warm preform of the rim (2') is as it were pushed over between the outer dies (13) and over the wheel bowl (3, 3 ') can be so that the warm preform of the rim (2 '), the Radschüssel (3, 3') within the preform of the rim (2 ') can take, the warm preform of the rim (2') due to their thermal expansion in comparison is dimensioned larger to the cold state, that is, that the diameter of the warm preform of the rim (2 ') in comparison to the cold preform of the rim (2') or rim (2) is greater and thereby the wheel disc (3, 3 ' ) can be provided within the warm preform of the rim (2 ') (Figure 12).

In the further course, the inner die (11) is moved in a translatory manner in the direction of the upper die (12), symbolized by the illustrated arrow, wherein the inner die (11) also has an effective face (1.1.1) which faces the rear (3.3 ') and the active surface (12.1) of the upper die (12) act on the visible side (3.2') of the wheel disc (3, 3 ') to effect at least one fixation of the wheel disc (3, 3'). If a warm wheel disc (3 ') is used, heat is dissipated by the tool contact (1 1, 12), so that at least one cooling down is carried out in sections in the wheel disc (3') and at least one sectional formation of a hardness structure is initialized (FIG. 13). The active surfaces (11.1, 12.1) on the inner die (11) and on the upper die (12) preferably have at least partially the final geometry of the connection region (3.1) of the wheel disc (3), so that at least on the wheel disc (3 ') in the hot state of the connection region (3.1) in the multi-part tool (10) at least partially thermoformed and optionally at least partially press-hardened.

Finally, the four outer dies (13) are moved translationally in the direction of the preform of the rim (2 '), symbolized by the illustrated arrows, so that in the collapsed state the rim (2) of the wheel (1) along its outer contour (2.2 ), at least in some areas, for example, can absorb them substantially completely (FIG. 14), cf. also embodiment according to FIG. 10. The tool (10) is essentially completed after a predetermined time, in particular after reaching a temperature, in particular when all conversion processes (bainite and / or martensite) have been completed and the desired structure in the wheel (1). is set, in particular after reaching the M _r temperature, reopened and the assembled wheel (1) are removed.

Both wheels (1) for passenger vehicles and for commercial vehicles can be produced with the method and tool (10) according to the invention. The individual features shown in the respective exemplary embodiments can also be combined with one another or with one another. The rim (2) of the wheel (1) can be completely or only partially press-hardened, for example only areas such as, for example, the rim flange, the rim shoulder, the hump and / or the rim well. The wheel dish (3) of the wheel (1) can either be completely press-hardened, partially or not at all. Preferably, at least partially, in particular the connection region (3.1), the wheel disc (3) is completely press-hardened in a wheel (1) for passenger vehicles and / or the middle region with the ventilation holes in a wheel (1) for commercial vehicles.

The tool (10) can furthermore also have means (not shown) for active and / or passive cooling of the individual tool components (11, 12, 13) in order to produce a mass without any appreciable disruption, for example due to tool components to be heated. to ensure. Translationally movable means that the outside Ke (13) radially in the direction of the rim (2, 2 ') respectively of the wheel (1) and are movable away, in particular the axis of rotation (A) of the rim (2, 2') respectively of the wheel (1) the central Point in the tool in particular for the movable execution of the outer Gesenk (13) corresponds. In addition, a fluid can additionally be used, in particular if, for example, no tool contact can take place in regions, for example by means of undercut geometries on the wheels (1), so that this area can additionally be acted upon by a fluid in order to produce a certain cooling effect, so that also in these areas a hardness structure can be formed. Also conceivable is the use of Tai- lored Products, in particular materials with adjusted thicknesses or semi-finished products with adapted geometry, for example, press-rolled blanks, tailored welded blanks, tailored rolled blanks, etc.

The manufactured wheels (1) are used in passenger vehicles, commercial vehicles, trucks, special vehicles, buses, buses, agricultural machinery, agricultural vehicles, military vehicles, whether with an internal combustion engine and / or electric drive, trailer, semi-trailer or trailers.

Claims

claims

1. A method for producing a wheel (1) for a vehicle with a rim (2) for receiving a tire and to the rim (2) material, force and / or form-fitting connected wheel disc (3) a connection area (3.1) for detachable mounting to a wheel carrier, comprising the steps:

Providing a rotationally symmetrical and / or tubular and / or endconverted preform of a rim (2 '),

Providing a wheel dish (3 '),

Bonding the wheel disc (3 ') to the preform of the rim (2'),

- At least partial or complete heating of the preform of the rim (2 ') and optionally the tethered wheel bowl (3') to a temperature of at least A _Ci and then at least partially hot forming with at least partial press hardening, wherein the at least partially hot forming with at least partial press hardening is carried out in a multipart tool (10), the multipiece tool (10) having at least one inner die (11), at least one upper die (12) and at least two outer dies (13), the outer dies (13) each have an active surface (13.1) which at least partially corresponds to the final geometry of the outer contour (2.2) of the rim (2) of the wheel (1), wherein the warm preform of the rim (2 ') is arranged between the outer dies (13). net and the preform of the rim (2 ') by the action of the effective surfaces (13.1) of the outer die (13) on the outer contour (2.2') of the preform of the rim (2 ') in the En Geometry of the outer contour (2.2) of the rim (2) of the wheel (1) transferred, at least partially hot-formed and at least partially press-hardened.

2. A method for producing a wheel (1) for a vehicle with a rim (2) for receiving a tire and to the rim (2) material, force and / or form-fitting connected wheel bowl (3) a connection area (3.1) for detachable mounting to a wheel carrier, comprising the steps:

Providing a wheel dish (3, 3 '),

at least partially or completely heating the preform of the rim (2 ') to a temperature of at least A _Ci and then at least partially hot forming with at least partial press hardening, wherein the at least partially hot forming with at least partial press hardening in a multi-part Tool (10) is performed, wherein the multi-part tool (10) at least one inner die (11), at least one upper die (12) and at least two outer counters (13), wherein the outer dies (13) each have an effective surface (13.1) which at least partially correspond to the final geometry of the outer contour (2.2) of the rim (2) of the wheel (1), wherein the warm preform of the rim (2 ') is arranged between the outer dies (13) and the preform of the rim (2). 2 ') by the action of the active surfaces (13.1) of the outer dies (13) on the outer contour (2.2') of the preform (2 ') in the final geometry of the outer contour (2.2) of the rim (2) of the wheel (1) transferred, at least partially hot formed and at least partially press hardened,

Bonding the wheel disc (3, 3 ') to the preform of the rim (2') during the at least partial hot forming with at least partial press hardening and / or bonding the wheel disc (3) to the rim (2) after the at least partially hot forming with at least partial press hardening.

3. The method of claim 1, wherein the inner die (11) and / or the upper die (12) each have an active surface (11.1, 12.1), which on the visible side (3.2 ') and / or back (3.3') of the wheel ( 3 ') of the between the outer dies (13) arranged, warm preform of the rim (2') with tethered wheel bowl (3 ') act, the wheel disc (3') optionally at least partially thermoformed and at least partially press-hardened.

4. The method according to claim 3, wherein the active surfaces (1 1.1, 12.1) at least partially have the final geometry of the connection region (3.1) on the Radschüssel (3) and the connection region (3.1) in the multi-part tool (10) at least partially thermoformed and optional at least partially press cured.

5. The method of claim 3 or 4, wherein the inner die (11) and / or the upper die (12) are formed such that they each have a further active surface (1 1.2, 12.2), which at least partially circumferentially around the active surface (1 1.1, 12.1) are provided for the wheel disc (3 ') and at least partially correspond to the final geometry of the inner contour (2.3) of the rim (2) of the wheel (1), wherein the warm preform of the rim (2') by the action of further active surfaces (11.2, 12.2) of the inner die (11) and / or upper die (12) on the inner contour (2.3 ') of the preform of the rim (2') at least in sections into the final geometry of the inner contour (2.3) the rim (2) of the wheel (2) transferred, at least partially hot-formed and at least partially press-hardened.

6. The method of claim 2, wherein the wheel disc (3 ') is heated to a temperature of at least A _Ci , before being inserted into the multi-part tool (10) and then with the warm preform of the rim (2') in contact is brought or in contact with the warm preform of the rim (2 '), which is already arranged in the multi-part tool (10).

7. The method of claim 2, wherein the wheel dish (3) prior to insertion into the multi-part tool (10) and then bring into contact with the warm preform of the rim (2 ') or before bringing into contact with the warm preform of Rim (2 '), which is already arranged in the multi-part tool (10), optionally at least partially thermoformed and at least partially cured.

8. The method according to any one of claims 6 or 7, wherein after the at least regionally hot forming and at least partially press hardening the wheel disc (3) at least in non-positive and / or positive manner in a subsequent process step on the rim (2) is connected.

9. The method according to claim 8, wherein the wheel disc (3) is additionally bonded cohesively to the rim (2).

10. The method according to any one of the preceding claims, wherein for the rim (2 ') and optionally for the wheel dish (3'), a curable steel material having a carbon content of at least 0.07 wt .-%, in particular of at least 0 10% by weight, preferably at least 0.15% by weight.

1 1. The method according to any one of the preceding claims, wherein the wheel disc (3) a material thickness up to a maximum of 6 mm for the production of a wheel (1) for passenger vehicles or a material thickness of more than 6 mm for the production of a wheel (1) for commercial vehicles.

12. The method according to any one of the preceding claims, wherein the at least partially press-hardening of the preform of the rim (2 ') and optionally the Radschüssel (3') additionally by using a fluid, which in direct contact with the warm preform of the rim (2 ') and optional warm wheel dish (3 ') is supported.

13. Multi-part tool (10) for producing a wheel (1) for a vehicle with a rim (2) for receiving a tire and to the rim (2) material, force and / or form-fitting connected wheel disc (3) a connection region (3.1) for releasably mounting to a wheel carrier, with at least one inner die (1 1), at least one upper die (12) and at least two outer dies (13), wherein the outer dies (13) each at least partially an effective surface (13.1 ), which at least partially correspond to the final geometry of the outer contour (2.2) of the rim (2) of the wheel (1), wherein a warm preform of the rim (2 ') can be arranged between the outer dies (13), wherein Acting on the outer contour (2.2) of the preform of the rim (2 ') the warm preform of the rim (2') into the final geometry of the outer contour (2.2) of the rim (2) of the wheel (1) transferred, at least partially warm u be shaped and at least partially press-hardened, wherein the at least two outer dies (13) are translationally movable and in the contracted state, the rim (2) of the wheel (1) along its outer contour (2.2) at least partially, in particular substantially completely be able to record.

14. Tool according to claim 13, wherein the inner die (1 1) and / or the upper die (12) are translationally movable.

15. Tool according to claim 13 or 14, wherein the inner die (1 1) and / or the upper sink (12) each have an active surface (1 1.1, 12.1), which on the visible side (3.2 ') and / or back ( 3.3 ') of the wheel disc (3') between the Außengesen- ken (13) arranged, warm preform of the rim (2 ') act with tailed Radschüs- sel (3'), the Radschüssel (3 ') optionally at least partially warm umfor - Men and at least partially press-harden, in particular the active surfaces (1 1.1, 12.1) at least partially correspond to the final geometry of the connection region (3.1) on the Rad bowl (3).

16. Tool according to one of claims 13 to 15, wherein the inner die (1 1) and / or the upper die (12) are formed such that they each have a further active surface (1 1.2, 12.2), which at least partially circumferentially around the Active surface (1 1.1, 12.1) for the wheel disc (3 ') are provided and at least partially correspond to the final geometry of the inner contour (2.3) of the rim (2) of the wheel (1).

17. Tool according to one of claims 13 to 16, wherein the tool (10) in the contracted state, the wheel (1) at least partially, in particular substantially completely receives.

18. Use of a wheel (1) produced according to one of Claims 1 to 12 in passenger vehicles, commercial vehicles, lorries, special vehicles, buses, buses, agricultural machines, agricultural vehicles, military vehicles, whether with internal combustion engine and / or electric drive, Trailers, semi-trailers or trailers.