DE102005056460A1 - Assembling a component with metal and plastic parts, e.g. for vehicle chassis items, involves covering the joint region with a melt adhesive coating - Google Patents

Abstract

A component consisting of a metal part (3) and plastic parts (4, 7), e.g. ribs (4) for a structurally stiffened region (5), has a continuous coating of plastic (9, 13) applied in the joint region. The plastic can be a melt adhesive placed by injection molding, or it can be applied by a nozzle or by a continuous lacquering process to sheet metal in coil form. Alternatively the coating can be applied after shaping the metal part. An independent claim is included for hybrid components made in this way. The thickness of the plastic layer is between 20 micrometer and 1 millimeter.

Description

The The invention relates to a method for producing a hybrid component according to the preamble of Patent claim 1 and a hybrid component according to claim 13.

Hybrid components which consist of two or more components are in the last Time in industrial practice more and more used. they offer the advantage, the properties of different materials to be able to connect to one another in one component. This can be the weight of the component can be reduced and costs can be saved without sacrificing component requirements have to. Particularly interesting are hybrid components, which consist of a metal component consist, which is reinforced by a plastic component. Metals offer stiffness and cost considerations a cheap one Construction component while the plastic component in addition to the weight reduction the possibility offers to integrate functions in the component. These hybrid components are usually made by placing the metal component in an injection mold is inserted and partially encapsulated with molten plastic or injected behind. The plastic part covers the metal component only partially and serves as a reinforcing structure.

From the generic DE 103 03 368 A1 a method for producing such a hybrid component is known. The hybrid component consists of at least two individual components, a metal component and a plastic part, which covers at least a portion of the metal component. The metal component is given a coating before the application of the plastic.

at The encapsulation of the metal component shown in this document Plastic creates a positive connection between metal and plastic, the metal component is made of plastic like a staple enclosed. A disadvantage of such a purely positive connection between plastic and metal is that the connection is not tight is so that moisture between metal component and plastic coating penetrate and can cause corrosion. This problem can, as in the generic method, be met with that the metal parts before the Um- or Hinterspritzen with coated with a dip coating to prevent corrosion should. However, this has the disadvantage that the components thereby their Lose weldability and thus can not be used in the shell. Conversely, the metal component without coating first overmoulded, then welded and subsequently, e.g. by dip coating, with a corrosion protection Provided coating, so the component in the area of encapsulation without Corrosion protection, because the dip coating does not separate there. Such components can therefore can only be used in areas that are not critical in terms of corrosion technology are.

From the DE 41 09 397 A1 Furthermore, a hybrid component is known in which a component made of metal is coated with plastic. In this case, a layer of an adhesive is provided between metal component and plastic. In this case, however, a pure casing of the metal component is provided, in contrast to the hybrid component described below, in which the plastic forms a reinforcement of the metal component.

Of the Invention is based on the object, a method for manufacturing a hybrid component and a hybrid component with a plastic component as reinforcement to propose the metal component, which from a corrosion point of view is tight and yet the desired Having stiffness. Furthermore, the hybrid component should be preferred be used in automotive body, so for example welded, his.

The Output is solved by the features of claims 1 and 13.

After that a method is proposed in which between the subarea the metal component and the reinforcing Plastic a cohesive Connection is provided. Through this cohesive connection can in Comparison to the generic positive connection significantly higher Forces over that transferred entire component so that the rigidity of the component increases. Therefore can depend on the given stiffness requirements, the sheet thickness is reduced and weight saved (claim 1).

advantageously, the metal component is encapsulated with the plastic in the form of a plastic melt or injected behind. This is a cost effective and industrially widespread method for producing a Hybrid component (claim 2).

In an advantageous embodiment, the cohesive connection is effected by an adhesive layer of a heat-activatable material applied to the metal component before the application of the plastic. This allows a very simple and efficient process management, since the heat energy for activating the adhesive layer is provided by the fact that the metal component is molded with molten plastic. Furthermore, as already known methods, for example from the field of bonding of metal components, for the Her position of this hybrid component are used (claim 3).

It is cheap, when the adhesive layer after a forming operation on the finished molded Metal component is applied. In this way, for example coated the edges of the finished component and thus efficient protected against corrosion be (claim 4).

alternative is the adhesive layer before a forming process for producing the Metal component applied to a metal sheet. When applying the adhesive layer on a sheet or a coil can the sheets are still stored as long as desired after coating and only then be further processed, so that a shift of the Coating process can take place within the production chain. In this way, the application of the adhesive layer in the production process shifted to the front, and can be used for example in the automotive industry be carried out directly at the supplier during manufacture of the sheets. In this way, the production is streamlined at the car manufacturer (Claim 5).

advantageously, the adhesive layer is applied by means of an adhesive nozzle. This procedure is proven and cost-effective (Claim 6).

In the case, that the adhesive layer is already applied to the undeformed metal sheet A ribbon coating process can be used with the advantages a fast procedure (Claim 7).

In In an advantageous embodiment, the adhesive layer can then only be applied to one side of the sheet. Alternatively, the Adhesive layer applied on both sides. For example, one-sided coated sheet metal still welded or otherwise in the shell to be used (claims 8 and 9).

Next the provision of an adhesive layer on the metal component can be a plastic can be used, which has good adhesive properties and therefore without intermediate adhesive layer directly to the metal component creates a material bond. So can on the procedural step of the Applying an additional Adhesive layer are omitted (claim 10).

advantageously, can the cohesive connection be achieved by the use of a plastic, which contains microencapsulated adhesive components that are heat-activated. So can when injecting the metal component, the heat of the plastic melt directly for curing the Adhesives are used, with the advantages of the above Dispensing with an adhesive layer (claim 11).

alternative for the procedure of the rear or overmolding can in an advantageous Design the metal component with a separately manufactured plastic component be connected in the solid state, wherein the cohesive connection by a prior to bonding applied to the plastic component Adhesive layer is achieved. Due to the separate production of the plastic component If necessary, the process chain can be flexibly changed (claim 12).

Farther a hybrid component is proposed, which is represented by one of the above Process is prepared (claim 13).

Further Embodiments and advantages of the invention will become apparent from the description out.

In The drawings, the invention with reference to several embodiments explained in more detail.

It demonstrate:

1 a hybrid component produced according to the invention,

2 an alternative embodiment of a hybrid component,

3 a further embodiment of a hybrid component,

4 an exemplary sequence of a method for producing a hybrid component and

5 an alternative sequence of a method for producing a hybrid component.

Hereinafter, a method of manufacturing a hybrid component will be described 1 and a hybrid component produced in this way 1 described in detail.

The aim is the production of a hybrid component 1 , which consists of a metal component 3 and a plastic part 7 is composed. This should have compared to a component made of a single material, in particular a pure metal component, improved rigidity and improved corrosion protection. The metal component 3 can be z. B. be a profile, which is produced for example by deep drawing or roll forming. The plastic component 7 is a rib structure, for example 4 , which reinforce the metal component 3 serves and simultaneously contributes to weight loss. In the hybrid component described here 1 it is therefore not a plastic 7 coated metal component. Rather, the plastic fulfills the important function of struktu strengthening the hybrid component 1 , The hybrid component 1 is used in the bodyshell, so it must be workable, for example by a welding process.

1 shows a hybrid component 1 in a side view, which consists of a metal component 3 and a plastic 7 composed, here by way of example in the form of two ribs 4 , which is a subarea 5 of the metal component 3 cover, on the metal component 3 is arranged.

Between metal component 3 and plastic 7 is a material connection 9 intended. This is produced in this embodiment as follows:
Before the connection between metal component 3 and plastic 7 is prepared, becomes an adhesive layer 13 for later cohesive connection of metal and plastic 7 intended. In this embodiment, the adhesive layer becomes 13 one-sided on the surface of the metal component 3 applied.

When applying the adhesive layer 13 Here, a distinction is made between several basic procedures: first, an adhesive layer 13 on an already manufactured, so for example, already produced by deep drawing metal component 3 , are applied. Alternatively, the adhesive layer 13 already before the forming process on the sheet 15 be applied, from which then by forming the metal component 3 will be produced.

The adhesive layer 13 initially fulfills the task of good adhesion of the plastic 7 on the metal component 3 to enable. Furthermore, the adhesive layer 13 fulfill the additional task of the metal component 3 or the sheet metal 15 to protect against corrosion. Both functions can either be in a single adhesive layer 13 integrated or realized in two superimposed layers. This application is called a two-layer system. This consists of a corrosion protection coating and an additional adhesive layer, while a single-layer system consists for example of an adhesive or a plastic with an additional anti-corrosion function.

Single-layer or two-layer systems can be applied using customary application methods, for example by means of an adhesive nozzle. Alternatively, they can also, especially if they are before forming on the sheet 15 or applied to a coil, in the form of a coating by spraying or in the form of a coil coating or a printing process on the sheet 15 be applied.

Following the application of the adhesive layer 13 be plastic 7 and metal part 3 connected with each other. This connection takes place here, for example, by the fact that the plastic 7 in the form of a plastic melt to the metal component 3 is injected. In this case, the heat generated during injection molding of the molten plastic material is used to the adhesive layer 13 to activate and in this way the desired material connection between metal component 3 and plastic 7 to achieve.

The adhesive layer 13 fulfills a dual function in this embodiment: On the one hand, it provides the necessary material connection between metal component 3 and plastic 7 On the other hand, it provides corrosion protection of the metal component 3 , This is particularly interesting if the sheet metal structure is not to be enclosed in all areas of plastic.

2 shows a sectional view of another embodiment of a hybrid component 1 , Here is the plastic 7 again in the molten state, as a plastic melt to the metal component 3 splashed around, or the metal component is plastic 7 back-molded. As will be further appreciated, the metal component is 3 before the encapsulation already with an adhesive layer 13 , from both sides, has been coated. The resulting hybrid component 1 now indicates in addition to the in 2 illustrated positive connection between plastic 7 and metal component 3 still an adhesion on.

So if you want to produce a component with a defined stiffness, compared to a pure metal component or a conventionally produced hybrid component, the sheet thickness can be reduced and thus saved weight. In addition, a purely positive connection has the disadvantage that the connection is not tight, so that moisture can penetrate and cause corrosion. The hybrid component produced in this way 1 can also be further processed in the shell, it can for example be welded there and / or provided with a paint coating.

If the component to be produced is now a closed profile, which is relatively difficult to coat, a so-called coil coating primer can be used to coat the sheet before it is shaped as an adhesive layer. These primers are significantly more elastic than conventional paint coatings and can therefore be deformed and mechanically joined. Furthermore, they can be applied in Bandlackierverfahren example only on one side, which is not possible or only with great effort in a dip coating. In this way, the uncoated side thus further processed in the shell, for example, be welded. Due to the flexible coating, the metal component 3 at the Spritzgie ßen hold higher holding forces, without the occurring deformations lead to the detachment of the coating. As a result, the process is less sensitive to overspraying, which increases process reliability.

3 shows a further sectional view of another embodiment of a hybrid component 1 During manufacture. In contrast to the embodiments according to 1 and 2 becomes the plastic 7 not here in the molten state on the metal component 3 sprayed on, but as previously manufactured, for example, molded, solid plastic component 21 completely connected to the metal component. In this case, the adhesive layer 13 , like in the 3 shown on the metal component 3 or alternatively on the plastic component 21 be provided, for example, be applied by a glue nozzle.

4 shows an exemplary sequence of the method for producing the hybrid component 1 , First, a coil in the form of a metal sheet 15 produced. This is then viewed with a ribbon coating incl. Corrosion and adhesion promoter coating, which corresponds to the coil coating primer described above. This painting can also be done on one side. In the third step, a blank is made from the coil or sheet metal 15 , This blank is then transformed by a forming process, such as deep drawing, to a metal component 3 reshaped. Then be plastic 7 and metal component 3 glued together. In this case, the activation of the adhesive must be done by an additional measure.

Should pre-coated coils are used, so the adhesive layers must certain Meet requirements for transport and storage. In particular, the Do not stick metal layers together in a coil. Farther must have protection against aging as well as some UV resistance be given. Depending on the further processing, the used Adhesive layers thermoformable be and may do not lead to sticking in the thermoforming tool.

Alternatively, in 5 another approach to making the hybrid component 1 shown. After the coil has been produced, first the blank is cut, then the finished metal component is finished 3 , Subsequently, the adhesive layer 13 on the finished metal component 3 applied, which in the last step at the desired locations with plastic 7 is overmoulded.

The procedure is also for with plastic 7 overmoulded edges, as in 2 shown, suitable, where it additionally provides corrosion protection. In areas not overmolded by plastic, the corrosion protection is achieved by a subsequent cathodic dip-coating.

After processing the hybrid components 1 in shell, which can be done conventionally by welding, as shown above, the body goes through, as is usual today, the dip coating. Here, a sealing of the bare areas and the open cut edges.

The application of the adhesive layer 13 on the metal component 3 , ie the adhesive coating or the alternative plastic coating, can either only locally at the later contact zones between plastic part and metal component 3 done, or she is completely on the metal component 3 carried out. Should complicated geometries for the plastic 7 be provided, for example, a rib profile, a full-surface order may be advantageous for reasons of time or cost savings. This can be done, for example, in coil coating systems in which coils can be coated at up to 200 meters per minute. In this way, position tolerances of the plastic coating to the adhesive layer used with the result of insufficient adhesion can be avoided. This also has the advantage that the hybrid component 1 can be glued to the body structure in the shell without additional effort. Furthermore, the coating at the locations where the bond is not needed, protect the metal from corrosion. There are many serially available adhesives which have the desired anti-corrosive properties.

The adhesive layer 13 pointing to the metal part or the finished plastic part 21 is applied, may consist of a thermoplastic hot melt adhesive, which after the order by a re-melting, either - as mentioned above - by the heat of the plastic melt or in the cathodic oven or in a suitably heated joining station, the cohesive connection 9 manufactures. The chemical composition of the adhesive depends on the plastic to be joined. The thickness of the adhesive layer, which may range from 20 microns to 1 millimeter, depends on the material used and the process.

To a hybrid component 1 to use in the bodyshell, the plastics used must 7 and coatings KTL-suitable, that is, the plastic used 7 must have a melting point above the KTL stoving temperature (about 160-210 ° C), low distortion and be chemically innert in the KTL bath. The connection between metal component and plastic must not come loose and allow no great deformation due to residual stresses or creep deformations under its own weight or mechanical load.

For larger component tolerances can for the adhesive layer 13 also expandable systems based on EVA (ethyl vinyl acetate) or EPDM (ethylene-propylene-diene rubber) are used, which have up to five or ten times the volume increase with heat. The desired expandability depends on the desired stiffness of the hybrid component. Expandable materials adhere to bare metal and prevent corrosion with the side effect of improving the damping properties of the hybrid component 1 ,

Next the adhesive technique shown above can, for. Belly a welding process for producing the cohesive Connection can be used. In particular, frictional, Ultrasonic or laser welding for Connection of the plastic component to the metal component.

Notwithstanding the in 1 or 2 illustrated application of the adhesive layer 13 on the metal component 3 The adhesive function can also be in the plastic 7 or the plastic component 21 to get integrated.

It can on the one hand, the finished plastic part 21 as indicated above, with an adhesive layer 13 be coated. On the other hand, a plastic 7 be used with good adhesive properties, which then around the metal component 3 is splashed around. Optionally, in addition, the metal component 3 be coated on one side or on both sides with a corrosion protection, which possibly additionally as a primer for the adhesive or plastic 7 serves.

Another way of integrating the adhesive function in the plastic 7 is where in to the metal component 3 molded plastic 7 to provide a microencapsulated adhesive. A hardener is embedded in tiny plastic capsules, is released when the plastic melts, and initiates the adhesion reaction.

alternative to the aforementioned methods are other methods for generating the cohesive Connection possible, For example, the RTM (Resin Transfer Molding) or the RIM (Reaction Injection molding), which resins based on EP (epoxy resin) can be used which have a good adhesion and corrosion protection effect.

Claims (13)

Method for producing a hybrid component ( 1 ) of at least two individual components made of different materials, comprising at least one metal component ( 3 ), to which at least one subarea ( 5 ) a plastic ( 7 ) for structural reinforcement of the metal component ( 3 ), characterized in that between the portion ( 5 ) of the metal component ( 3 ) and the plastic applied thereto ( 7 ) a cohesive connection ( 9 ) is provided. Method according to claim 1, characterized in that the metal component ( 3 ) with the plastic ( 7 ) is injection-molded or back-injected in the form of a plastic melt. Method according to claim 1 or 2, characterized in that the cohesive connection ( 9 ) by a prior to the application of the plastic ( 7 ) on the metal component ( 3 ) applied adhesive layer ( 13 ) is made of a heat-activatable material. Method according to claim 3, characterized in that the adhesive layer ( 13 ) after a forming process on the finished shaped metal component ( 3 ) is applied. Method according to claim 3, characterized in that the adhesive layer ( 13 ) before a forming process for producing the metal component ( 3 ) on a metal sheet ( 15 ) is applied. Method according to claim 4 or 5, characterized in that the adhesive layer ( 13 ) is applied by means of an adhesive nozzle. Method according to claim 5, characterized in that the adhesive layer ( 13 ) with a tape coating process on the sheet ( 15 ) is applied. Method according to claim 7, characterized in that the adhesive layer ( 13 ) only on one side of the sheet ( 15 ) is applied. Method according to claim 7, characterized in that the adhesive layer ( 13 ) on both sides of the sheet ( 15 ) is applied. A method according to claim 2, characterized in that the material connection (7) by the use of a plastic ( 9 ), which has good adhesive properties. Method according to claim 2, characterized in that the cohesive connection ( 9 ) by the use of a plastic ( 9 ) containing microencapsulated adhesive components that are heat activated. Method according to claim 1, characterized in that the metal component ( 3 ) with a separately manufactured plastic component ( 21 ), wherein the cohesive connection ( 9 ) by a prior to the connection to the plastic component ( 21 ) on brought adhesive layer ( 13 ) is achieved. Hybrid component ( 1 ) of at least two individual components ( 3 . 9 ) made of different materials, characterized in that it is produced by a method according to one of claims 1 to 12.