DE102020205203A1 - Process for the production of a vehicle wheel and a correspondingly produced vehicle wheel - Google Patents

Abstract

The invention relates to a method for producing a vehicle wheel from sheet steel with a high aesthetic appearance and individual styling features, the method comprising the following steps: providing a first component made from sheet steel, which in the assembled state of the vehicle wheel corresponds to a wheel rim, and a second component made from stainless steel Sheet steel which, in the assembled state of the vehicle wheel, corresponds to a wheel disk or part of a wheel disk; Joining the first and second components to produce an assembled vehicle wheel. The invention further relates to a vehicle wheel comprising a wheel rim with a wheel disk or part of a wheel disk connected to the wheel rim.

Description

Technical Field

• - Bereitstellen eines ersten Bauteils aus Stahlblech, welches im zusammengebauten Zustand des Fahrzeugrads einer Radfelge entspricht, und eines zweiten Bauteils aus nichtrostendem Stahlblech, welches im zusammengebauten Zustand des Fahrzeugrads einer Radschüssel oder Teil einer Radschüssel entspricht;
• - Verbinden des ersten und des zweiten Bauteils um ein zusammengebautes Fahrzeugrad zu erzeugen. Des Weiteren betrifft die Erfindung ein Fahrzeugrad umfassend eine Radfelge mit einer an die Radfelge angebundenen Radschüssel oder Teil einer Radschüssel.

The invention relates to a method for producing a vehicle wheel from sheet steel, the method comprising the following steps:

• - Providing a first component made of sheet steel, which corresponds to a wheel rim in the assembled state of the vehicle wheel, and a second component made of stainless steel sheet, which corresponds to a wheel disk or part of a wheel disk when the vehicle wheel is assembled;
• Joining the first and second components to produce an assembled vehicle wheel. The invention further relates to a vehicle wheel comprising a wheel rim with a wheel disk or part of a wheel disk connected to the wheel rim.

Technical Background (Background Art)

Vehicle wheels are safety components and must therefore be able to withstand high mechanical and dynamic alternating loads during operation. From the WO 2004/103733 A1 it is known to produce vehicle wheels from two steel components. These conventional “steel vehicle wheels” in sheet metal construction consist of a wheel disc, which ensures the connection to the wheel hub, and a wheel rim (rim tape), which holds the tire. Nowadays, the wheel components are exclusively manufactured by cold forming in a multi-stage process (deep drawing, spinning, profiling). In addition to the durability, rigidity and weight of the wheels, the design plays the most important role in passenger cars. Further developments of the construction methods or joining connections (see Semi- / Full-Face Wheels - see US 6,382,735 B2 ) have led to an improvement in the appearance of steel wheels, but the possible styling attractiveness and design flexibility can still be improved, especially in comparison to the appearance of vehicle wheels made of aluminum alloys, which are manufactured using the casting or forging process.

In addition, the development costs as well as the investment in tools for the realization of different wheel disc design variants made of sheet steel are enormous, so that different and individual designs with smaller quantities have not been possible / cannot be implemented up to now.

Multi-part motor vehicle wheels are known from the prior art, in particular with the focus on dividing a wheel into a support structure and optically upgrading it with an additional design element or connecting it to form a structure. The disclosure documents DE 10 2013 107 394 A1 as DE 10 2017 222 562 A1 propose, for example, multi-part motor vehicle wheels made of sheet steel, in which the wheel disc consists of two components in order to further increase the aesthetic appearance and design flexibility. Finally, the Offenlegungsschrift suggests DE 10 2013 101 421 A1 a multi-part motor vehicle wheel, in which a wheel disc is designed as a support structure and is connected to several design elements made of sheet steel. These multi-part motor vehicle wheels made of sheet steel increase the appearance and design flexibility, but only allow individualization to a limited extent.

With regard to the state of the art, there is a need for optimization, in particular in the provision of an aesthetic appearance and individualization of the vehicle wheels comprising a wheel rim with a single or multi-part wheel disc or a wheel spider connected to the wheel rim, in particular in comparison with the appearance of vehicle wheels made of aluminum alloys, which are cast - or forging processes are made.

Summary of Invention

The invention is therefore based on the object of providing a method for producing a vehicle wheel with which a vehicle wheel can be produced not only with an attractive appearance in terms of geometry but also in terms of effects and to specify a corresponding vehicle wheel.

This object is achieved by a method with the features of claim 1. This object is achieved by a vehicle wheel with the features of claim 9.

According to the invention it is provided that at least one pretreatment and at least one aftertreatment is carried out on at least one surface of the second component before and / or after the connection.

The inventor has found that by performing at least one surface of the second component, in particular the wheel disk or part of the wheel disk, for example in the case of a multi-part design, before and / or after the connection to the first component, at least one pretreatment and at least one post-treatment the wheel disk or part of the wheel disk already made of the stainless steel sheet can be used to further improve the appearance, In particular, a vehicle wheel made of sheet steel with a high aesthetic appearance and individual styling features can be produced. The at least one surface of the wheel disk or part of the wheel disk relates to the visible surface of the vehicle wheel in the mounted state, that is, it is the side facing away from a vehicle-mounted wheel carrier.

The wheel disk or part of the wheel disk can be individually connected to the wheel rim, classically in the drop center of the wheel rim or as a so-called semi-face or full-face variant. As part of a wheel disk is to be understood that the wheel disk can be designed in several parts, for example a front, visible and a rear wheel disk, not visible or only partially visible in the assembled state, or a base carrier as a wheel disk with one or more other connected in the visible area Share. At least the part of the wheel disk, if the wheel disk is not made in one piece, consists of a stainless steel sheet in the visible area in the assembled state of the vehicle wheel. The second component does not necessarily have to be bowl-shaped with a circumferential ring or flange (bowl lobes); a star-shaped construction with or without a circumferential ring or flange is also possible. A wheel spider can thus also be understood as a wheel disc within the meaning of the invention.

Depending on the design of the vehicle wheel, the connection between the wheel disk or part of the wheel disk with the wheel rim can be made with a material, non-positive and / or positive fit and the vehicle wheel is assembled from at least two components. In a preferred embodiment, the vehicle wheel consists of a wheel rim and a wheel disc to ensure operational stability and one or more additional components made of stainless steel sheet, which increase the design-related appearance and design flexibility of the vehicle wheel and enable customization.

A stainless steel sheet has a Cr content of at least 10.5% by weight, with iron (Fe) as the remainder and unavoidable impurities being included in addition to other possible constituents, depending on the desired alloy.

Any suitable steel material can be used as the steel sheet for the wheel rim. In particular, the steel materials already conventionally used can be used, preferably with a tensile strength Rm of at least 400 MPa, preferably of the quality S 420 MC or S 460 MC. The wheel rim can be press-rolled and / or hardened at least in certain areas, for example press-hardened.

Further advantageous configurations and developments emerge from the following description. One or more features from the claims, the description and also the drawing can be combined with one or more other features from them to form further embodiments of the invention. One or more features from the independent claims can also be linked by one or more other features.

According to one embodiment of the method according to the invention, the pretreatment comprises at least one chemical, thermal or mechanical method step for cleaning and / or processing the surface of the second component.

In particular after the second component has been connected to the first component, the surface of the second component may have contamination in the visible area, be it from handling during the connection and / or from the connection itself, for example during welding in the form of weld spatter, scale and / or Formation of temper colors or the like. The mechanical or chemical process removes impurities or contamination on the surface of the second component, so that the high chromium content of the stainless steel sheet on the cleaned surface can form a complete, impervious, corrosion-proof passive layer of chromium oxide on the cleaned surface. As a mechanical method for cleaning, grinding and / or blasting can be carried out. A matt, in particular non-directionally oriented surface can be produced by means of jets. A matt surface is a non-glossy, light diffusely reflecting surface. Pickling can be used as a chemical method of cleaning. Pickling removes not only the contamination, but also any metal oxides that may have formed on the surface. In connection with the pickling, passivation, for example with nitric acid, can preferably be connected in order to preferably accelerate the formation of the protective chromium oxide layer.

A local thermal treatment with concentrated energy input on the surface can improve the appearance and individualization of the vehicle wheel. The thermal treatment of the surface can preferably be carried out with a laser beam. A laser engraving can produce targeted material removal in the base material and / or a coating, if present, and thus a modified surface structure or texture or topography. This can create a novel Surface design as well as customization can be achieved according to customer requirements.

According to one embodiment of the method according to the invention, the thermal treatment of the surface includes a targeted tempering treatment in the base material in order to be able to bring about a color change / change in the edge layer near the surface. In this case, a further oxide layer with a black color can essentially be produced.

According to a further embodiment of the method according to the invention, the thermal treatment includes a targeted change in the microstructure in the area close to the surface, whereby the radiation reflection and absorption under light can be changed and a marking or color effect can thus be achieved.

According to a further embodiment of the method according to the invention, the thermal treatment of the surface comprises a targeted joining process of the base material and an additional material, such as a powder coating, in order to be able to bring about a desired surface structure and / or marking.

According to one embodiment of the method according to the invention, the aftertreatment comprises at least one chemical, thermal or mechanical method step for conditioning the surface of the second component. Possible chemical processes, for example, remove impurities or contamination on the surface of the second component, so that the high chromium content of the stainless steel sheet on the cleaned surface can form a complete, impervious, corrosion-proof passive layer of chromium oxide on the cleaned surface. Alternative or additional coatings or coating systems are also possible. An electrochemical removal process in the form of electropolishing can be carried out as a chemical process for conditioning. A reflective surface can be produced by means of electropolishing, in particular by reducing the micro-roughness of the surface, which enables no or poor adhesion of dirt and / or impurities in later use. The electropolishing takes place in particular in an electrolysis cell, preferably using direct current in sulfuric or orthophosphoric acid between, for example, 2 and 20 minutes.Depending on the nature of the surface in the ready state before electropolishing, a reduction in roughness Ra of 60% and more is possible, i.e. that a surface with a roughness Ra up to 1 µm, in particular up to 0.8 µm, preferably up to 0.6 µm can be set. The determination of the roughness Ra is known from the relevant regulations. Alternatively, electrolytic coloring can be carried out as a chemical process for conditioning. By means of electrolytic coloring, interference effects can be generated on the surface. Alternatively or additionally, electrolytic coloring can be carried out as a chemical process for conditioning. Examples of implementation can be found in the following sources, for example: DBU final report-AZ-33037 “Chromium-free coloring of stainless steel components” or MB 976 “Colored stainless steel”. Texturing can be carried out as a mechanical method for conditioning. By means of texturing, for example by embossing the surface and thus setting a structured topography, in particular in connection with a locally differently thick chromium oxide layer. Alternatively or additionally, engraving and / or milling can be carried out as a mechanical method for conditioning with a specific design. The different layer thicknesses can produce interference effects on the surface, in particular in combination with electrolytic coloring, these interference effects can even be intensified in terms of color. Alternatively, etching can be carried out as a chemical process for conditioning. Etching, for example as a photochemical process, can roughen the surface, which can lead to a matt appearance. Brushing can also be carried out as a mechanical process as an alternative or in addition to conditioning.

Alternatively, the pretreatment can include at least one chemical, thermal or mechanical process step for conditioning the surface of the second component and the post-treatment at least one chemical, thermal or mechanical process step for cleaning and / or processing the surface of the second component.

According to one embodiment of the method according to the invention, at least one final treatment is carried out on at least the second component after the at least one pretreatment and the at least one post-treatment. In particular, stone chips and / or other abrasive effects can damage the passive chromium oxide layer during subsequent use, which means that corrosion protection can no longer be ensured. The final treatment preferably comprises at least one chemical process step. As a chemical process step, a clear lacquer can be applied as a coating, which on the one hand protects the chromium oxide layer from premature damage or additionally protects it and on the other hand is made transparent in order to cover the surface produced in the course of the aftertreatment on the second Not to adversely affect the component or to visibly maintain the set conditioning.

According to one embodiment of the method according to the invention, the second component consists of a CrNi steel sheet. By adding Ni with at least 2.5% by weight, the stainless steel sheet can be made more resistant to corrosion. In addition, the addition of Ni can also increase the tensile strength and the yield point, which in turn can have a positive effect on the design of the second component or the wheel disk or part of the wheel disk with higher tensile strength by reducing the thickness while maintaining the same performance, in particular reducing weight. The second component is preferably made of a steel material with the material number 1.4301, which corresponds to AISI 304 or the EN material designation X5CrNi18-10. Alternatively and particularly preferably, the second component consists of a steel material with the material number 1.4404, which corresponds to AISI 316 L or the EN material designation X2CrNiMo17-12-2.

According to a second aspect, the invention relates to a vehicle wheel comprising a wheel rim made of sheet steel with a wheel disk connected to the wheel rim or part of a wheel disk made of stainless steel sheet. According to the invention, a surface of the wheel disk or part of the wheel disk has a locally modified surface structure and is provided with a transparent coating. The locally changed surface structure is the result of the pre-treatment and / or post-treatment carried out, which lead to a specific surface structure. A layer of clear varnish is preferably applied as a transparent coating, which protects the surface of the wheel disk or part of the wheel disk, especially in the visible side facing away from the wheel carrier in the assembled state, from premature damage, and the chromium oxide layer formed in the course of production and that in the course of post-treatment generated surface or the visual appearance is retained and not adversely affected.

According to one embodiment of the vehicle wheel according to the invention, the wheel disk or part of the wheel disk can have locally different colors.

In order to avoid repetition, reference is made to the explanations relating to the method according to the invention.

Figure list

• 1: Frontansicht einer Ausführung eines erfindungsgemäßen Fahrzeugrads mit zweiteiliger Radschüssel und Lasergravur.

The invention is explained in more detail below with reference to drawings. The same parts are always provided with the same reference numerals. In detail shows:

• 1 : Front view of an embodiment of a vehicle wheel according to the invention with a two-part wheel disc and laser engraving.

Description of the Preferred Embodiments (Best Mode for Carrying out the Invention)

In one embodiment, a first component was provided as a wheel rim made of sheet steel of grade S 420 MC and a second component was designed as a two-part wheel disc, cf. 1 , whereby the visible or external sheet steel component was made of a stainless steel sheet of quality 1.4301 and the steel sheet component arranged behind it or internal sheet steel component made of a 22MnB5 with a press-hardened microstructure. The wheel rim and the inner sheet steel component were pressed together in the rim shoulder and firmly bonded (semi-full-face variant). The visible or external sheet steel component of the two-part wheel disk (part of the wheel disk) was processed locally on the surface with a laser. As a result, an engraving, symbolized by black triangles between the ventilation holes, was created and the external sheet steel component (part of the wheel disc) was individualized. The engraving, not shown here, can also contain logos, lettering, etc., whereby the individualization can be increased. After the thermal processing (pretreatment), an aftertreatment was carried out to clean the surface and / or processed areas. After the pretreatment or after the treatment, a continuous passive chromium oxide layer formed on the surface of the outer part of the wheel disc. Then the outer part of the wheel disc was assembled with the already connected wheel rim and the inner sheet steel component. In a final step or as a final treatment, the outer part of the wheel disk was partially painted using clear lacquer, so that a transparent coating was applied to at least the cleaned and conditioned surface of the wheel disk in the visible area to protect the chrome oxide layer and maintain the visual appearance. This made it possible to improve the appearance and individualization of the vehicle wheel.

In a further exemplary embodiment, not shown, a first component was made as a wheel rim from a steel sheet of grade S 460 MC and a second component as a one-piece wheel disc made from a stainless steel sheet Quality 1.4404 provided. The wheel rim and wheel dish were made classically. The wheel disc was connected in the drop center of the wheel rim by means of a press fit and material connection (welding) in order to produce a vehicle wheel. Other designs and connections, for example as a semi or full face variant, are also conceivable. The vehicle wheel was pickled in at least one pretreatment step in an electrolytic bath so that at least the visible surface of the wheel disc, in this case the vehicle wheel completely, was chemically cleaned of impurities and / or contamination, and then in at least one post-treatment step in a further electrolytic bath was electropolished so that at least the visible surface of the wheel disk, in this case the vehicle wheel completely, was electrochemically conditioned by reducing the micro-roughness in particular of the visible surface of the wheel disk so that a reflective surface could be produced. After the pretreatment or after the treatment, a continuous passive chromium oxide layer formed on the surface of the wheel disc. In a final step or in the final treatment step, the entire vehicle wheel was painted using clear varnish, so that a transparent coating was applied at least to the cleaned and conditioned surface of the wheel disc in the visible area to protect the chrome oxide layer and maintain the visual appearance. Samples were taken from the generated vehicle wheel or from the wheel disc and, using micrographs and relevant evaluation methods, a chromium oxide layer was shown and a roughness Ra of less than 0.8 µm was determined.

The features described can all be combined with one another as far as technically possible.

QUOTES INCLUDED IN THE DESCRIPTION

This list of the documents listed by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent literature cited

• WO 2004/103733 A1 [0002]
• US 6382735 B2 [0002]
• DE 102013107394 A1 [0004]
• DE 102017222562 A1 [0004]
• DE 102013101421 A1 [0004]

Claims (12)

A method for producing a vehicle wheel from sheet steel, the method comprising the following steps: providing a first component made of sheet steel, which in the assembled state of the vehicle wheel corresponds to a wheel rim, and a second component made of stainless steel sheet, which in the assembled state of the vehicle wheel of a wheel disc or corresponds to a part of the wheel disc; - Connecting the first and the second component to produce an assembled vehicle wheel, characterized in that at least one pretreatment and at least one post-treatment is carried out before and / or after the connection on at least one surface of the second component. Procedure according to Claim 1 , wherein the pretreatment comprises at least one chemical, thermal or mechanical process step for cleaning and / or processing the surface of the second component. Procedure according to Claim 1 , wherein the aftertreatment comprises at least one chemical, thermal or mechanical method step for conditioning the surface of the second component. Procedure according to Claim 1 , wherein the pretreatment comprises at least one chemical, thermal or mechanical process step for conditioning the surface of the second component and the post-treatment comprises at least one chemical, thermal or mechanical process step for cleaning and / or processing the surface of the second component. Method according to one of the preceding claims, wherein at least one final treatment is carried out on at least the second component after the at least one pretreatment and the at least one post-treatment. Procedure according to Claim 5 , wherein the final treatment comprises at least one chemical process step. Method according to one of the preceding claims, wherein the second component consists of a CrNi steel sheet. Method according to a Claim 7 , whereby the second component consists of a steel material with the material number 1.4301. Method according to a Claim 7 , whereby the second component consists of a steel material with the material number 1.4404. Vehicle wheel comprising a wheel rim made of sheet steel with a wheel disk or part of a wheel disk made of stainless steel sheet connected to the wheel rim, characterized in that a surface of the wheel disk or part of the wheel disk has a locally modified surface structure and is provided with a transparent coating. Vehicle wheel after Claim 10 , whereby the wheel disk or part of the wheel disk consists of a steel material with the material number 1.4301 or 1.4404. Vehicle wheel after Claim 11 , wherein the wheel disk or part of the wheel disk can have locally different colors.

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