DE102020127784A1 - Process for the surface treatment of a component and motor vehicle - Google Patents

Abstract

Method for surface treatment of a component, such as a chassis component of a motor vehicle, comprising the steps: - providing a component; - processing the component to produce a coating on the component; - processing the component in such a way that the coating at least partially melts or melts; - relocating , in particular pivoting and/or rotating, of the coated component.

Description

The present invention relates to a method for the surface treatment of a component, such as a chassis component of a motor vehicle, and a motor vehicle.

The focus here is on methods for surface treatment to create corrosion protection. A method for this that is customary in the motor vehicle sector is, for example, hot-dip dip methods, such as hot-dip galvanizing. In these coating processes, a workpiece made of a higher melting point metal or alloy is immersed in a molten bath of a lower melting point metal or alloy. As the workpiece is lifted out of the molten bath, the liquid metal adheres to the workpiece and forms a solid metallic coating as it cools. When pulling the components out of the melt, defects such as noses ("zinc tips") or thickening can form, especially on the edges and corners of the component. There is also often the problem that smaller holes or recesses in the workpiece fill up with the melt and "block". Manual rework is often not economically feasible. the WO 2017/162342 A1 proposes in this context a stripping device in terms of system, which is designed in such a way that all components are guided past the stripping device for stripping liquid zinc after they have been submerged. However, such an approach requires a high design effort and is relatively inflexible when the component geometry changes. In addition, this approach reaches its limits when it comes to complicated component geometries.

It is therefore an object of the present invention to optimize the known surface treatments, such as in particular hot-dip processes.

This object is achieved by a method according to claim 1 and by a motor vehicle according to claim 10. Further advantages and features emerge from the subclaims and the description and the attached figures.

• - Bereitstellen eines Bauteils;
• - Bearbeiten, insbesondere Beschichten, des Bauteils zum Erzeugen einer zumindest abschnitts- oder bereichsweisen Beschichtung auf dem Bauteil;
• - Bearbeiten oder Behandeln des Bauteils derart, dass die Beschichtung zumindest teilweise schmilzt oder anschmilzt;
• - Verlagern, insbesondere Schwenken, Kippen und/oder Rotieren, des beschichteten Bauteils.

Mit Vorteil erfolgt die Beseitigung etwaiger Fehlstellen nicht manuell oder mechanisch mittels Verwendung von Werkzeugen oder Vorrichtungen, sondern thermisch durch Umschmelzen, Anschmelzen bzw. Aufschmelzen der Beschichtung in Kombination mit einem Bewegen oder Verlagern des Bauteils. Bei den vorgenannten Fehlstellen kann es sich beispielsweise um Aufdickungen, Nasen oder zugelaufene Öffnungen in oder an dem Bauteil handeln. Durch das zumindest teilweise Anschmelzen oder (Auf-)Schmelzen der Beschichtung gelangt diese in den flüssigen Aggregatszustand und kann sich neu verteilen. Die Bewegungsrichtung ergibt sich dabei mit Vorteil allein durch die Schwerkraft in Kombination mit der Neuausrichtung des Bauteils mittels bevorzugt Schwenken, Kippen und/oder Rotieren. Anders als bei der manuellen Nacharbeit, bei der eine Fehlstelle zunächst explizit erkannt werden muss, damit sie nachbearbeitet werden kann, erfolgt bei dem vorgeschlagenen Ansatz oftmals eine automatische Oberflächenoptimierung. Durch Erwärmen des Bauteils sowie die Verlagerung können sich auch automatisch Fehlstellen zurückbilden, die vielleicht unentdeckt geblieben sind, da sie an schwer zugänglichen Stellen liegen.According to the invention, a method for the surface treatment of a component, such as a chassis or structural component of a motor vehicle, comprises the steps:

• - Providing a component;
• - Processing, in particular coating, the component to produce an at least sectional or regional coating on the component;
• - Editing or treating the component in such a way that the coating at least partially melts or melts;
• - Displacement, in particular pivoting, tilting and/or rotating, of the coated component.

Advantageously, any defects are not eliminated manually or mechanically using tools or devices, but rather thermally by remelting, melting or fusing the coating in combination with moving or shifting the component. The aforementioned defects can be, for example, thickened areas, lugs or closed openings in or on the component. Due to the at least partial melting or (over-)melting of the coating, it becomes liquid and can be redistributed. The direction of movement advantageously results solely from gravity in combination with the realignment of the component by preferably pivoting, tilting and/or rotating. In contrast to manual rework, in which a defect must first be explicitly recognized so that it can be reworked, the proposed approach often involves automatic surface optimization. By heating the component and by relocating it, flaws that may have gone undetected because they are in hard-to-reach places can also automatically recede.

According to a preferred embodiment, the component is displaced in order to distribute the coating before the coating is melted on or begins to melt. The component can be shifted into a first position, for example rotated by 180°. According to one embodiment, the shifting takes place step-by-step or step-by-step. The component can be shifted accordingly in several positions. According to one embodiment, a renewed partial or partial melting can take place after each stage. This can be advantageous if the component geometry is very complicated.

According to one embodiment, the component is displaced when the coating has melted or melted on or after heating. By relocating the component, it is possible to have a targeted influence on a “redistribution” of the coating, at least in certain areas.

• - Beschichten des Bauteils mittels Schmelztauchen.

Das Schmelztauchen ist ein Beschichtungsverfahren, bei welchem ein Bauteil oder Werkstück aus einem höherschmelzenden Metall oder einer Legierung vollständig in ein schmelzflüssiges Bad eines niedrigerschmelzenden Metalls oder einer Legierung eingetaucht wird. Gemäß einer bevorzugten Ausführungsform erfolgt das Bearbeiten des Bauteils bzw. das Beschichten des Bauteils mittels eines Feuerverzinkungsverfahrens. Beim Feuerverzinken wird ein metallischer Überzug durch Eintauchen des Bauteils oder Werkstücks in geschmolzenes Zink aufgebracht. Gemäß einer bevorzugten Ausführungsform ist ein Beschichtungswerkstoff vorliegend eine Zinkaluminiumlegierung, insbesondere ZnAI5.According to a preferred embodiment, the method comprises the step:

• - Coating of the component by hot dipping.

Hot dipping is a coating process in which a component or workpiece of a higher melting point metal or alloy is completely immersed in a molten bath of a lower melting point metal or alloy. According to a preferred embodiment, the component is processed or the component is coated by means of a hot-dip galvanizing process. In hot-dip galvanizing, a metallic coating is applied by immersing the component or workpiece in molten zinc. According to a preferred embodiment, a coating material is a zinc-aluminum alloy, in particular ZnAl5.

However, the proposed approach is not limited to hot dip processes. Rather, the method can be used for all types of coatings that are suitable for being at least partially liquefied, that is, in particular, are capable of returning to the liquid state of aggregation.

In this case, the layer or coating does not have to change completely into the liquid state of aggregation in relation to its thickness, but at least at the edge area or at least to the extent that the defects can be compensated for. The actual implementation here depends on the materials used, in particular with regard to the coating, as well as on the component geometry and/or a wall thickness of the coating.

• - Erwärmen des Bauteils bzw. vollumfängliches Auf- oder Einbringen von Wärme zum Anschmelzen, Aufschmelzen oder Umschmelzen der Beschichtung.

Gemäß einer Ausführungsform werden die Bauteile einzeln in geeignet geformte Induktionsspulen eingebracht. Alternativ kann ein Induktionstunnel durchfahren werden. Gemäß einer Ausführungsform werden zum Schmelzen der Beschichtung auch (Durchlauf-)Öfen verwendet. Bei den vorgenannten Verfahren erfolgt zweckmäßigerweise ein Erwärmen des gesamten Bauteils.According to one embodiment, the method comprises the step:

• - Heating of the component or full application or introduction of heat to melt, melt or remelt the coating.

According to one embodiment, the components are placed individually in suitably shaped induction coils. Alternatively, an induction tunnel can be driven through. According to one embodiment, (continuous) furnaces are also used to melt the coating. In the aforementioned methods, the entire component is expediently heated.

• - Lokales Auf- oder Einbringen von Wärme.

Dieser Ansatz kann Vorteile bringen, wenn die bekannten Problemstellen oder Fehlstellen gut lokalisierbar sind und sich eine Erwärmung des kompletten Bauteils nicht lohnen würde. Auch hier kann mit Induktionsspulen gearbeitet werden. Alternativ werden geeignete Heizelemente oder Heizstrahler verwendet, welche geeignet sind, lokal das Bauteil derart zu erwärmen, dass die Beschichtung zumindest teil- oder bereichsweise in den flüssigen Aggregatszustand übergeht.According to one embodiment, the method comprises the step:

• - Local application or introduction of heat.

This approach can be advantageous if the known problem areas or defects are easy to localize and heating the entire component would not be worthwhile. Induction coils can also be used here. Alternatively, suitable heating elements or radiant heaters are used, which are suitable for locally heating the component in such a way that the coating changes to the liquid aggregate state at least partially or in certain areas.

• - Anschmelzen der Beschichtung unmittelbar nach dem Aufbringen der Beschichtung.

Es hat sich als vorteilhaft erwiesen, wenn die Beseitigung der Fehlstellen unmittelbar nach dem Anbringen der Beschichtung erfolgt. Insbesondere beim Schmelztauchen, und insbesondere bevorzugt beim Feuerverzinken, hat es sich als vorteilhaft erwiesen, die noch heißen Bauteile zu nehmen und deren Beschichtung zum Beseitigen der Fehlstellen anzuschmelzen, umzuschmelzen oder aufzuschmelzen.According to one embodiment, the method comprises the step:

• - Melting of the coating immediately after application of the coating.

It has proven to be advantageous if the defects are eliminated immediately after the coating has been applied. Particularly in the case of hot-dip dipping, and particularly preferably in the case of hot-dip galvanizing, it has proven to be advantageous to take the still hot components and to melt, remelt or melt their coating to eliminate the defects.

• - Entnehmen des Bauteils einer Beschichtungsanlage, insbesondere Austauchen des Bauteils aus einem Schmelzbad;
• - Zumindest bereichs- oder abschnittsweises Erwärmen des Bauteils, bevorzugt unmittelbar nach dem Austauchen.

Gemäß einer Ausführungsform erfolgt das Verlagern als Zwischenschritt vor dem Erwärmen des Bauteils, alternativ auch danach. Dabei ist der Ausdruck „unmittelbar“ dahingehend zu verstehen, dass das Bauteil als solches bevorzugt nicht vollständig abgekühlt oder zumindest nur wenig abgekühlt ist.Accordingly, according to one embodiment, the method comprises the steps:

• - Removing the component from a coating system, in particular exchanging the component from a molten bath;
• - Heating of the component at least in certain areas or sections, preferably immediately after the immersion.

According to one embodiment, the shifting takes place as an intermediate step before the component is heated, alternatively also afterwards. The expression “immediately” is to be understood to mean that the component as such is preferably not completely cooled or at least has cooled only slightly.

Appropriately, the component properties must not be changed by the heat input to melt the coating. This can be achieved by a suitable choice of temperature during melting and/or by the course over time. The heat is expediently introduced over a very short period of time in the range of a few seconds. At this point, the actual procedure is to be designed on a case-by-case basis, since it depends, among other things, on the choice of heating medium, the maximum temperature of the heating source and the distance between the heating source and the component, etc.

• - Schwenken, Kippen und/oder Rotieren in mehreren Schritten bzw. intervallweise.

Es hat sich herausgestellt, dass es vorteilhaft sein kann, wenn das Bauteil um einen bestimmten Winkel gedreht oder geschwenkt wird, um dann in dieser Lage oder Position zumindest einige Sekunden zu ruhen. Die Beschichtung hat in dieser Ruhephase „Zeit“, sich neu zu verteilen. Je nach Bauteilgeometrie kann aber auch ein kontinuierliches Schwenken und/oder Rotieren vorteilhaft sein.According to one embodiment, the method comprises the step:

• - Pan, tilt and/or rotate in several steps or at intervals.

It has been found that it can be advantageous if the component is rotated or pivoted through a specific angle and then rests in this location or position for at least a few seconds. The coating has in this rest phase "Time" to redistribute. However, depending on the component geometry, continuous pivoting and/or rotating can also be advantageous.

The shifting, in particular the pivoting, tilting and/or rotating, these expressions being to be understood in particular as examples, preferably does not take place in an undirected or random manner, but is based on the type of defect and in particular on its position. After or during heating, the component is expediently oriented in such a way that the material of a thickened area or "nose" can "flow back" into the respective surface.

• - Dreidimensionales Verlagern, insbesondere Schwenken, Kippen und/oder Rotieren um zumindest eine Dreh- oder Rotationsachse.

Die dreidimensionale Bewegung/Verlagerung im Raum ermöglicht eine flexible Beseitigung von Fehlstellen auch bei komplexen Bauteilgeometrien.According to one embodiment, the method comprises the step:

• - Three-dimensional shifting, in particular pivoting, tilting and/or rotating about at least one axis of rotation or rotation.

The three-dimensional movement/displacement in space enables a flexible elimination of defects, even with complex component geometries.

• - Maschinelles Schwenken, Kippen und/oder Rotieren des Bauteils.

Zweckmäßigerweise wird ein Handhabungsgerät, wie beispielsweise ein Industrieroboter, zum Schwenken, Kippen und/oder Rotieren verwendet. Gemäß einer Ausführungsform wird die vorgenannte Handhabungseinrichtung bereits beim Beschichtungsprozess verwendet. Alternativ kann für den Beschichtungsprozess auch ein anderes Handhabungsgerät, wie beispielsweise ein anderer Industrieroboter bzw. grundsätzlich ein anderes Konzept, verwendet werden.According to a preferred embodiment, the method comprises the step:

• - Mechanical panning, tilting and/or rotating of the component.

A handling device, such as an industrial robot, is expediently used for pivoting, tilting and/or rotating. According to one embodiment, the aforementioned handling device is already used during the coating process. Alternatively, a different handling device, such as a different industrial robot or a fundamentally different concept, can also be used for the coating process.

The handling device or the handling device can be designed to grip the component directly. Alternatively, the component can be arranged in a suitable supporting structure, which is acted upon by the handling device. According to one embodiment, this can already have been used during the coating of the component.

• - Ein- oder Aufbringen der Wärme und Schwenken/Kippen/Rotieren gleichzeitig.

Mit Vorteil kann dadurch die Taktzeit des Prozesses verkürzt werden.According to one embodiment, the method comprises the step:

• - Applying or applying the heat and pan/tilt/rotate at the same time.

This can advantageously shorten the cycle time of the process.

• - Beaufschlagen der angeschmolzenen Beschichtung mit einem Fluidstrom, insbesondere mit Druckluft.

Insbesondere zugelaufene Öffnungen können beispielsweise mittels Druck- oder Pressluft freigeblasen werden.According to one embodiment, the method comprises the step:

• - Subjecting the partially melted coating to a fluid flow, in particular compressed air.

In particular, closed openings can be blown free, for example, by means of compressed air.

According to one embodiment, the fluid flow, such as in particular the aforementioned compressed air flow, is temperature-controlled in such a way that the blowing free and the partial or partial melting can take place in one operation.

According to preferred embodiments, the aforementioned components are chassis or structural components of motor vehicles, such as axle supports of passenger cars. After emergence from the melt, such as the ZnAI5 melt, the components are, preferably while still hot, individually "dipped" into suitably shaped induction coils or driven through appropriate induction tunnels. This advantageously takes place quickly and possibly locally at a temperature above the melting temperature of the coating or the coating material. The components are turned and/or rotated, for example by 180°. As a result, thickening dissolves and zinc tips run into the surface. Clogged openings are free again or can be blown free with the help of compressed air. As a result, the coating quality can be significantly increased while costs are significantly reduced at the same time, especially if existing system technology, which is required for the coating process anyway, is used for the relocation.

According to a preferred embodiment, the layer or coating is in particular an anti-corrosion layer, in particular a zinc layer. According to a preferred embodiment, a component material is a steel material, with the method not being limited to this material.

The invention further relates to a motor vehicle comprising at least one component produced or surface-treated according to the invention.

• 1: eine schematische Ansicht eines Bauteils vor einer Beschichtung;
• 2: eine schematische Ansicht einer Ausführungsform eines Bauteils nach einer Beschichtung sowie eine Auswahl von Verfahrensschritten einer Ausführungsform des erfindungsgemäßen Verfahrens.

Further advantages and features emerge from the following description of an embodiment of the method with reference to the attached figures. Show it:

• 1 : a schematic view of a component before coating;
• 2 1: a schematic view of an embodiment of a component after coating and a selection of method steps of an embodiment of the method according to the invention.

1 shows a component 10 before a coating process in a schematic, perspective view. This is, for example, a component made of sheet steel. An opening 12 can be seen in a front sheet metal section of the component 10 .

2 shows that from the 1 known component 10 after a surface treatment, in this case, for example, after hot-dip galvanizing. After emerging from the molten bath, two defects have formed, for example a thickening 14 on the upper component section 11 and a defect 16 in the area of the opening 12, cf 1 . In the present case, this is closed by the coating material.

The basic idea of the method according to the invention is that, preferably immediately after emerging from the hot-dip bath, the component 10 is heated at least in certain areas in such a way that the coating is melted on, partially melted or re-melted. Here, or immediately adjacent to this heating process, the component is rotated, tilted and/or pivoted, shown schematically via method steps s1 and s2. In reality it is often better to move the component 10 before heating. In process step s2, the "thickening" has already receded. If necessary, the temperature input and the pivoting, tilting and/or rotating can be supplemented by directing a fluid flow onto the component, for example compressed air. Here, for example, the opening 12 can also be blown free or the closed opening 16 can be uncovered, see method step s3. Here, too, the component 10 can be moved at the same time or not. As a result, after carrying out the method steps, there is a component 10 in which all defects have been eliminated, even without manual reworking.

Reference List

10

component

11

upper component section11

12

opening

14

defect, thickening

16

void, closed opening

s1, s2, s3

process steps

QUOTES INCLUDED IN DESCRIPTION

This list of documents cited 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 2017/162342 A1 [0002]

Claims (10)

Method for the surface treatment of a component, such as a chassis component of a motor vehicle, comprising the steps: - Providing a component (10); - Processing the component (10) to produce a coating on the component (10); - Editing the component (10) such that the coating at least partially melts or melts; - Displacement, in particular pivoting and/or rotating, of the coated component (10). procedure after claim 1 , wherein the displacement of the component (10) takes place before the coating is melted on or begins to melt. procedure after claim 1 or 2 , comprising the step: - Coating of the component (10) by hot dipping. Method according to one of the preceding claims, comprising the step: - Full application or introduction of heat. Method according to one of the preceding claims, comprising the step: - Local application or introduction of heat. Method according to one of the preceding claims, comprising the step: - Melting of the coating (10) immediately after the application of the coating. Method according to one of the preceding claims, comprising the step: - Three-dimensional displacement of the component (10). Method according to one of the preceding claims, comprising the step: - Applying or applying the heat and panning/rotating at the same time. Method according to one of the preceding claims, comprising the step: - Applying a fluid stream, in particular compressed air, to the melted coating. Motor vehicle, comprising at least one component, produced by a method according to one of the preceding claims.

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