DE102020110242A1 - Method for producing a hybrid component - Google Patents

Abstract

The invention relates to a method for producing a hybrid component (21), consisting at least of a sheet metal part (1), a long or continuous fiber-reinforced semi-finished plastic product (23) which is coated on the sheet metal part (1) with an adhesion promoter layer (55) in between, and an injection molding structure (25) made of short fiber-reinforced plastic, which is applied to the plastic semi-finished product (23), the method comprising a thermoforming process in which the long or continuous fiber-reinforced plastic semi-finished product (23) is pressed onto the sheet metal part (1) in a malleable state is or is draped into it, and has an injection molding process in which the injection molding structure (25) is applied to the semi-finished plastic product (23). According to the invention, the thermoforming process and the injection molding process take place functionally independently of one another in a thermoforming tool (61) and in an injection molding tool (63).

Description

The invention relates to a method for producing a hybrid component according to the preamble of claim 1, a process arrangement for performing the method according to claim 14 and a hybrid component according to claim 15.

Adhesion-promoting systems that enable the connection between two or more joining partners usually require an activation temperature. This must be exceeded in the joining process in order to achieve sufficient bond strength. The joining partners (e.g. plastics or plastic melts) require sufficient dimensional stability for safe handling. This is mostly achieved by falling below a demolding temperature. The thermal management of the process is therefore subject to cyclically changing temperature control. The use of a temperature control system that performs the temperature change by supplying or removing heat from one and the same tool or tool part has proven to be uneconomical in practical application due to the long times for the temperature change. The profitability of a variothermal process therefore depends largely on the time it takes to change the process temperatures. This is the fundamental problem, especially for the use of adhesion promoters and adhesion promoting layers.

• Hybrid-Plus-Technik: Bei der Hybrid-Plus-Technik wird ein verzinktes Stahlblech im Vorfeld mittels des Coil Coating-Verfahrens mit einem Haftvermittler und alternativ mit einer zusätzlichen Kunststoffkoppelschicht versehen. Das zu fertigende Bauteil wird einem herkömmlichen Spritzgießprozess überführt. Die Energie zur Aktivierung des Haftvermittlers oder der Haftvermittlerschicht wird durch die Wärmeenergie der Kunststoffschmelze bezogen. Die Kunststoffapplikation kühlt im Anschluss im Werkzeug ab und bildet einen festen Verbund zum Stahlblech. Bei der Hybrid-Plus-Technik wird die Kunststoffschmelze als Energieträger zur Aktivierung des Haftvermittlers genutzt. Die in der Kunststoffschmelze gespeicherte Energie ist allerdings nur ausreichend, um Haftvermittler mit niedrigen Aktivierungstemperaturen zu aktiveren. Insbesondere der Durchlauf durch die kathodische Tauchlackierung für Karosseriebauteile ist nicht unbedingt möglich. Des Weiteren kann es bei hochgefüllten Kunststoffen dazu kommen, dass die Haftvermittlerschicht durch die abrasive Wirkung des Füllstoffes mechanisch abgetrennt wird und sich vor der Schmelzfront sammelt. Eine Haftungswirkung ist dann nur noch bedingt gegeben.

The following methods are known for producing a hybrid component:

• Hybrid-Plus technology: With the Hybrid-Plus technology, a galvanized steel sheet is provided in advance with an adhesion promoter and, alternatively, with an additional plastic coupling layer using the coil coating process. The component to be manufactured is transferred to a conventional injection molding process. The energy for activating the adhesion promoter or the adhesion promoter layer is obtained from the thermal energy of the plastic melt. The plastic application then cools down in the tool and forms a solid bond with the sheet steel. With the hybrid plus technology, the plastic melt is used as an energy carrier to activate the adhesion promoter. However, the energy stored in the plastic melt is only sufficient to activate adhesion promoters with low activation temperatures. In particular, the passage through the cathodic dip painting for body parts is not necessarily possible. Furthermore, with highly filled plastics it can happen that the adhesion promoter layer is mechanically separated by the abrasive effect of the filler and collects in front of the melt front. A liability effect is then only given to a limited extent.

Intrinsic resin transfer molding technology (intrinsic RTM): In the intrinsic RTM process, metal sheets are joined with fiber-reinforced plastics. The joining surface of the metal is pretreated in advance. This can be cleaning with acetone or structuring of the surface, e.g. by laser pre-treatment. The fiber reinforced plastics are prepared as a prepreg. For this purpose, dry fiber layers are stacked on top of one another and provided with a plastic powder that acts as an adhesive in the intermediate layers. The sheet metal and the prepreg are placed and joined together in a heated press, whereby the plastic powder melts under pressure and heat and enables the connection to the sheet metal and the embedding of the fibers. The intrinsic RTM requires a lot of effort for the preparation of the partners to be joined. In particular, the draping of the dry semi-finished fiber products is an essential additional work step that is not required when processing pre-impregnated semi-finished products. Furthermore, the application of adhesion promoters and the structure as a stack are disadvantageous, since this represents an increased effort for the handling system.

Polymer-Injection-Forming (PIF): Polymer-Injection-Forming is a modification of the Resin-Transfer-Molding-Process (RTM). The extension of the RTM process to the PIF process consists in the fact that the shaping device is first used to reshape the sheet metal component of the component. A mostly hardening molding compound (resin-hardener system) is then injected. The injection pressure ensures that the sheet metal is further deformed. The connection is made with bonding systems or without additional coupling layers. This process can mainly be used for the connection of thermosetting plastics to metals. The disadvantage of the PIF is that it can only be used with thermosetting resin-hardener systems or other easy-flowing compounds. A transferability to thermoplastics is not given.

Thermosetting prepreg pressing: In the case of thermosetting prepreg pressing, semi-finished products in the form of layered structures made of sheet metal and fiber-reinforced plastics with unreacted resin hardening systems are produced in advance of component production. These are placed in a temperature-controlled tool, which reshapes the stacked semi-finished product and provides the necessary activation energy for curing. The variety of shapes in thermoset prepreg pressing is severely limited because it is a pure forming process, whereas economic processes in particular represent the combination of several joining, original and forming processes.

3D hybrid technology: In 3D hybrid technology, pre-formed sheet metal semi-finished products are placed in the upper half of a two-part forming tool. A preheated extrusion compound and a glass fiber reinforced organic sheet are placed on the lower mold. During the pressing process, the organic sheet is formed into the semi-finished sheet metal and the extrusion compound forms stiffening ribs. The adhesion of the organic sheet to the metallic sheet is achieved by a previously applied adhesive film or laser structuring. The disadvantage of the 3D hybrid technology lies in the use of extrusion masses and the associated increased effort for handling as well as the susceptibility to errors for inaccurate positioning of the molten extrusion mass.

3D hybrid technology with thermoplastic injection molding: The 3D hybrid technology with thermoplastic injection molding replaces the extrusion molding approach with an injection molding step to form stiffening ribs. For this purpose, the cavity is filled in a cascade by means of a hot runner injection. The disadvantage of the 3D hybrid technology with thermoplastic injection molding lies in the tool design with only one cavity. The mold temperature must represent a compromise between the fastest possible cooling after injection, good mold filling and activation of the adhesion promoter system. As a result, the selection of available injection molding granulates is very limited and must fall on higher-temperature-resistant types. Furthermore, the adhesion promoter used must first be applied manually to the semi-finished sheet metal product in a laborious manner under temperature and vacuum.

From the DE 10 2017 010 437 A1 a device for the hot forming of thermoplastic semi-finished products into molded parts is known. From the WO 2019/215020 A a hybrid steel-plastic semi-finished product is known.

The object of the invention is to provide a method for producing a hybrid component in which the production effort, the component effort and the process duration are reduced compared to the prior art.

The object is achieved by the features of claim 1, claim 14 or claim 15. Preferred developments of the invention are disclosed in the subclaims.

The invention is based on a hybrid component that consists of at least one sheet metal part, a semi-finished plastic product reinforced with long or continuous fibers, which is coated on the sheet metal part with an intermediate layer of adhesion promoter, and an injection-molded structure made of short fiber-reinforced plastic which is applied to the semi-finished plastic product.

The adhesion promoter layer can be coated on the sheet metal part in advance. The sheet metal part can already be preformed. However, used sheets do not necessarily have to have already been formed, but can also be formed integrated in the process. The form of the plastic application is also arbitrary. This can involve the application of flat, unidirectional or multidirectional reinforced long or continuous fiber systems (nonwovens, knitted fabrics, knitted fabrics, woven fabrics, tangled nonwovens) embedded in a plastic matrix. Alternatively or in combination with this, plastic structures (ribs, functional elements) can be applied by casting processes based on shapeless substances (granulates, powder) or liquids (resins, reactive precursors of polymers).

A method for producing such a hybrid component can have a thermoforming process and an injection molding process. In the thermoforming process, a semi-finished plastic product reinforced with long or continuous fibers is pressed or draped into the sheet metal part in a malleable state, namely to form the semi-finished plastic product coated on the sheet metal part. In the subsequent injection molding process, the injection molding structure is applied to the semi-finished plastic product. Draping generally describes the “nestling” of the fiber-reinforced plastic semi-finished product against the contour given by the sheet metal. This contour can be three-dimensional but also two-dimensional.

The matrix of the plastic semifinished product can, for example, be a thermoplastic. However, the invention is not limited to a thermoplastic semi-finished product. Rather, thermosetting prepregs can be used instead. The fibers are embedded in a mixture of a resin and a hardener, which has not yet reacted and is only caused to react, e.g. by applying heat, and thus to form the thermosetting plastic. These prepregs are not necessarily hot during handling.

The injection molding structure can be a thermoplastic melt (thermoplastics or thermoplastic elastomers) or a resin-hardener mixture (for the production of elastomers or thermosets after a crosslinking reaction).

The invention is based on the fact that when the thermoforming process and the injection molding process are carried out in a common tool or tool stage - that is, the sheet metal part remains unchanged in the same tool cavity during both thermoforming and injection molding - is associated with time-consuming heating and cooling processes. Such heating and cooling processes are necessary in order to set the thermoforming process temperature and the injection molding process temperature, respectively.

Against this background, according to the characterizing part of claim 1, in a departure from the prior art, the thermoforming process and the injection molding process are no longer carried out in a common tool. Rather, the thermoforming process and the injection molding process take place functionally independently of one another in a thermoforming tool (or thermoforming tool stage) and an injection molding tool (or injection molding tool stage) that is separate therefrom.

The approach of the invention is generally that - in contrast to the prior art - a component passes through two or more individual tools or tool parts. The tools or tool parts are tempered in such a way that the required process temperature is adapted to the processing step in question. The process temperatures per tool are preferably not changing, but are set permanently, i. H. isothermal. The time for a temperature change no longer depends on the duration of the heat exchange, but only on the transfer duration from the previous to the next tool or tool part. The result is a significant reduction in the cycle time and thus an increase in the economic efficiency of the process. The process can also be carried out in such a way that a component first goes through all tool stages. Alternatively, each tool stage can be used at any time in the process.

The invention describes a process for the production of hybrid components in a tool that is divided at least several times, but at least twice, which makes it possible to specifically adapt process-relevant parameters such as temperature or pressure to the respective process step to be mapped. Here it is possible, for example, to combine a thermoforming process of a continuous fiber-reinforced semi-finished plastic product with an injection molding process, whereby different temperature profiles of the individual process steps are required. When thermoforming a continuous fiber-reinforced plastic semi-finished product, a high temperature (100 - 300 ° C) of the sheet metal semi-finished product may be necessary in order to guarantee a resilient material connection between the sheet metal semi-finished product and the molded continuous fiber-reinforced plastic semi-finished product. In a possible subsequent process step, ribs can be applied to the molded-in semi-finished product. A lower temperature (60 - 140 ° C) is desirable here in order to enable the plastic ribs to cool down economically and in a stable manner. On the one hand, the cooling process should take place as quickly as possible, but not too quickly, in order to avoid component defects such as sink marks, vacuoles or blowholes (in order to be able to put sufficient pressure on the component). For this purpose, two mold halves are set up at different temperatures. After the first process step, the semi-finished product is removed at a high temperature and cooled in the second tool stage. In particular, this enables component manufacture to meet requirements and the quality of the components and their mechanical properties can be significantly increased. In addition, the process enables the economical production of hybrid components in short cycle times as well as the processing of high-melting adhesion promoters or adhesion promoter layers together with standard thermoplastics for injection molding. Due to the possibility of realizing rapid temperature changes, the process for variothermal applications that require both high and low temperatures makes more economic sense than known processes in which the temperature change depends on the efficiency of the heat exchange.

By combining similar process steps from different processes in one tool or tool part, synergy effects can be used and process steps can be saved, which in turn reduces the cycle time. Furthermore, by separating the tool parts, process parameters can be optimally set with regard to the process step to be mapped by the tool part. This enables time- and resource-efficient production to be realized. Due to the possibility of simultaneous production with all tool parts, the number of components produced per unit of time is significantly increased compared to continuous production.

The process can be used for the production of all components in multi-material construction. In particular, the invention is of interest for high-volume productions with a tight budget per component. Due to the flexibility, the process can be used for isothermal as well as variothermal applications, for one-component or multi-component injection molding and for pure forming processes exclusively with metals or in combination with other formable or formable materials.

The main innovation of the process is the modular structure of the process structure, with as few dependencies as possible Process steps exist among each other. This means that the individual step can be optimally adapted to the technical production requirements.

In the state of the art, the aim is usually to combine as many process steps as possible into one manufacturing operation and thereby shorten manufacturing times. The simultaneous, cycle time-reducing mode of operation achieved in this way is achieved in the present invention in that the process steps are deliberately divided into several processing stations, which also all run simultaneously. As a result, the cycle time remains at least the same and can also be reduced due to the reduced dependencies through optimized parameter settings.

Aspects of the invention are described in detail below: Thus, in a technical implementation, the thermoforming tool can have a die and a stamp. A temperature control system can preferably be assigned to the thermoforming tool. To prepare for the thermoforming process, the sheet metal part can first be placed in the thermoforming tool. Subsequently, in a pressing process, the punch can press the flat semi-finished plastic product in a malleable state onto the sheet metal part and thereby drape it into the sheet metal contour. The plastic semifinished product can optionally be preheated separately from the thermoforming tool in a heating device until its malleable state is reached.

A perfect bond strength between the sheet metal part and the plastic semi-finished product is of the utmost importance for the hybrid component. The adhesion promoter layer required for this can preferably be thermally activated as soon as an activation temperature is exceeded. With regard to a simple process control, the thermoforming tool can be heated during the thermoforming process to a process temperature which is higher than the activation temperature of the adhesion promoter layer. In this way, a firm connection of the semi-finished plastic product to the sheet metal part is guaranteed.

The flat plastic semi-finished product is preheated, if necessary, in a heating device separate from the thermoforming tool to a processing temperature or melting temperature at which the plastic matrix of the semi-finished product can be processed or is molten. With regard to reliable adhesion of the semi-finished plastic product to the sheet metal part, an adhesion promoter layer that can be activated at a high temperature has proven to be particularly advantageous. For example, the activation temperature of the adhesion promoter layer can be 220 ° C, while the melting temperature of the plastic matrix of the plastic semifinished product can be 260 ° C.

The necessity of the relatively high mold temperatures (up to 260 ° C) compared to the prior art is due to the fact that the activation temperature of the adhesion promoter or the adhesion promoter layer is much higher than the temperatures of the adhesion promoters available on the market up to now. As a result, the component also qualifies for use at elevated temperatures (e.g. when overbaking the cathodic dip painting in bodywork; 190 ° C), because the bond would only loosen again after the activation temperature was exceeded.

With the aid of the temperature-controlled thermoforming tool, according to the invention, temperature control is made possible in which, on the one hand, the adhesion promoter layer can be kept above its activation temperature for a sufficiently long time. On the other hand, demouldability can also be guaranteed by deliberately falling below the demolding temperature. An essential aspect of the invention is that the halves of the tool step or the individual tool have different temperatures for the thermoforming step (one half well above the activation temperature of the adhesion promoter (or the adhesion promoter layer), the other half below the demolding temperature). As a result, when the tool is closed, thermal equalization processes can take place, which allow the temperatures required to activate the adhesion promoter on the sheet metal to be exceeded long enough, but a demolding temperature is still reached after an economically sensible time. An isothermal process control of the mold halves can significantly increase the stability of the thermoforming step, because the return of the equalization processes, i.e. the formation of a homogeneous temperature distribution over the respective mold half, takes place more quickly than with variothermal approaches and a safe, known initial state is set after each use can.

After the thermoforming process has taken place, the composite component consisting of sheet metal part and semi-finished plastic product is cooled down to a demolding temperature that is below the melting temperature or the processing temperature of the plastic and / or the activation temperature of the adhesion promoter. When the demolding temperature has been reached, the composite component can be inserted into the mold cavity of the injection molding tool or the injection molding tool step by means of a transfer unit in order to start the injection molding process. In the injection molding process, depending on the approach, a thermoplastic melt (thermoplastic or thermoplastic elastomer) or a resin-hardener mixture (to produce elastomers or thermosets after crosslinking reaction) is heated in an injection unit until a processable state is reached and then under pressure into the mold cavity of the injection molding - Injected into the tool. This creates an injection-molded structure on the draped-in, long or continuous fiber-reinforced semi-finished plastic product.

The injection molding tool or the injection molding tool stage is also heated isothermally using the temperature control technologies customary for the injection molding process and, depending on the type of material used, the customary temperatures. The injection molding temperature level is significantly lower than the thermoforming temperature level.

In a specific technical implementation, the hybrid component can, for example, be built into a vehicle body as a body pillar in a body shop. The body shop is followed by a KTL process in which the vehicle body is wetted with KTL paint in an immersion bath and the vehicle body, which is wetted with KTL paint, is then heated in a KTL oven to a KTL temperature in which the KTL Lacquer hardens. With regard to a stable connection between the plastic semi-finished product and the injection-molded structure on the plastic semi-finished product, it is relevant that the activation temperature of the adhesion promoter layer and the melting temperatures of the plastic semi-finished product and the injection-molded structure are higher than the KTL temperature.

In a preferred embodiment, the hybrid component can have at least one metal insert, which can preferably be integrated in the hybrid component as follows: In a first thermoforming step, the long or continuous fiber-reinforced plastic semi-finished product can be pressed onto the sheet metal part. In a second partial thermoforming step, the metal insert can be pressed into the plasticized plastic matrix of the semi-finished plastic product. The two sub-steps can be carried out with a common hot press stroke of the thermoforming stamp. A solid integration of the metal insert in the hybrid component is of particular importance. The metal insert can therefore also be encapsulated with the injection-molded structure on the edge side. This results in a circumferential border which, together with the semi-finished plastic product, encompasses the edge of the metal insert.

An exemplary embodiment of the invention is described below with reference to the accompanying figures.

• 1 in einer perspektivischen Teilansicht eine A-Säule in einer angedeuteten Einbaulage in einer Fahrzeugkarosserie;
• 2 eine Schnittansicht entlang einer Schnittebene A aus der 1;
• 3 die Anlagenskizze einer Prozessanordnung zur Durchführung des erfindungsgemäßen Verfahrens;
• 4 bis 7 jeweils Ansichten, anhand derer eine Prozessabfolge zur Herstellung eines Hybridbauteils veranschaulicht ist.

Show it:

• 1 in a perspective partial view an A-pillar in an indicated installation position in a vehicle body;
• 2 a sectional view along a sectional plane A from FIG 1 ;
• 3 the system sketch of a process arrangement for carrying out the method according to the invention;
• 4th until 7th in each case views, on the basis of which a process sequence for the production of a hybrid component is illustrated.

In the 1 an A-pillar installed in a vehicle body is indicated in a schematic representation. The A-pillar is designed as a hollow profile beam with an outer sheet metal part 1 and an inner sheet metal part 3 executed. At an upper column node 5 the A-pillar runs an upper body side member 7th , a side frame part delimiting the windshield of the vehicle 9 as well as a transverse assembly 11 together. At the lower column node 13th the A-pillar closes a side sill towards the rear in the vehicle's longitudinal direction x 15th at. In addition, the outer sheet metal part 1 the A-pillar has an upper screw-on base 17th as well as a lower screw-on base 19th for screwing the upper and lower door hinges, not shown, of the front door of the vehicle.

According to the 2 is the sheet metal part on the outside of the vehicle 1 Part of a hybrid component 21 . The hybrid component 21 points next to the outer sheet metal part 1 a long fiber reinforced thermoplastic semi-finished product 23 , an injection molding structure 25th Made of short fiber reinforced, thermoplastic material and a metal insert 39 on. In the 2 is the metal insert 39 an example of an upper hinge reinforcement for the upper screw-on base 17th in order to achieve a stable screw connection of the upper door hinge of the vehicle door.

Based on 2 becomes the material structure of the hybrid component 21 described: Accordingly, the plastic is a semi-finished product 23 in a thermoforming process described later with the interposition of an adhesion promoter layer 55 ( 4th ) into the inside of the outer sheet metal part 1 pressed in. The outer sheet metal part 1 is U-shaped in cross section, with an outer profile base in the transverse direction of the vehicle x 27 as well as with front and rear profile walls raised towards the inside of the vehicle 29 , 31 . From the profile walls 29 , 31 are each edge flanges 33 bevelled. According to the 2 covers the semi-finished plastic product 23 the inside of the outer sheet metal part 1 almost completely.

The Indian 2 Metal inlay shown 39 is in a form-fitting connection with the semi-finished plastic product in the thermoforming process described later 23 brought. In the 3 is the metal insert 39 for example at the edge with the short fiber reinforced, thermoplastic plastic material of the rib structure 25th encapsulated. The rib structure 25th therefore forms a circumferential border 60 together with the semi-finished plastic product 23 the edge of the metal insert 39 encompasses. The metal insert 39 is not in direct contact with the outer sheet metal part 1 , but rather with the intermediate layer of the semi-finished plastic product 23 spaced therefrom.

In the 2 is the outer sheet metal part 1 in flange connection with the inner sheet metal part 3 shown in which the edge flanges of the sheet metal parts 1 , 3 at a joining plane F. are welded to each other. Between an upper edge 49 the rib structure 25th and the inner sheet metal part 3 there is a free space in the 2 by means of a sealing element 51 closed is.

In the 3 is the system sketch of a process arrangement for the production of the hybrid component 21 described. As a result, the thermoforming process and the injection molding process are functionally independent of each other in a thermoforming tool 61 and in an injection mold 63 take place. The thermoforming tool 61 has a die as the tool halves 65 and a stamp 67 on that by means of a temperature control system 69 are heatable. In the thermoforming tool 61 is a component assembly described later 71 generated from the sheet metal part 1 , the semi-finished plastic product 23 and the metal inserts. This is done by means of a transfer unit 73 in a mold cavity 75 transferred that of tool halves 77 , 79 of the injection mold 63 is limited to perform the injection molding process. The injection molding tool or the injection molding tool stage 63 is also isothermal with a temperature control system customary for the injection molding process 70 and depending on the type of material used, the usual temperatures can be heated. The injection molding temperature level is significantly lower than the thermoforming temperature level.

The following are based on the 4th until 7th the process steps for manufacturing the hybrid component 21 described. The ones in the 4th until 7th Tool geometries indicated are to be understood as purely exemplary. To prepare for the thermoforming process, the 4th the preformed sheet metal part 1 into the die 65 inserted. The preformed sheet metal part 1 is in the 4th with an indicated adhesion promoter layer 55 coated (takes place in a preprocessing process not shown). In addition, the long or continuous fiber-reinforced thermoplastic semi-finished product is used 23 possibly heated in a heating device (not shown) to a plasticized hot state in which the plastic matrix of the plastic semifinished product 23 is molten.

In addition, the pre-formed sheet metal part is made before the start of the thermoforming process 1 by means of the die 65 heated to the adhesive layer applied thereon 55 to be heated above their activation temperature. Then the punch presses 67 with one joining force in one joining direction I. ( 4th ) the metal insert 39 with intermediate arrangement of the semi-finished plastic product 23 with a hot press hub (in a one-shot process) into the sheet metal part 1 , creating a component composite 71 ( 5 ) results in which the sheet metal part 1 with the semi-finished plastic product 23 is coated and the metal insert 39 in a form-fitting connection with the semi-finished plastic product 23 is.

With the help of the temperature control system 69 is in the die 65 and in the stamp 67 of the thermoforming tool 61 each allows a temperature control in which on the one hand the adhesion promoter layer 55 can be kept above their activation temperature for a sufficiently long time. On the other hand, demouldability can also be guaranteed by deliberately falling below the demolding temperature. An example of this is the temperature of the die in the thermoforming process 65 are at 260 ° C to 280 ° C. In contrast, the temperature of the stamp 67 be at 140 ° C to 160 ° C.

The composite component created in the thermoforming process 71 ( 5 ) is in the thermoforming tool 61 Cooled down to a demolding temperature which is below the thermoplastic melting temperature. When the demolding temperature is reached, the component composite is 71 by means of the transfer unit 73 into the mold cavity 75 ( 3 ) of the injection mold 63 inserted to prepare for the injection molding process. In the injection molding process ( 6th ) is (with the mold cavity closed 75 ) a molten, thermoplastic and short fiber reinforced injection molding compound into the mold cavity 75 injected under pressure and heat. This forms on the semi-finished plastic product 23 sprayed-on rib structure 25th ( 7th ). In the rib structure 25th is the already mentioned surrounding border 60 integrated with both the metal insert 39 as well as with the semi-finished plastic product 23 is in material connection.

In the thermoforming process, according to the invention, the process temperature can be kept isothermally at a temperature level which in one half of the tool / tool step is significantly higher than the melting temperature of the thermoplastic matrix of the semifinished plastic product 23 and the other half is below the demolding temperature. This activates the adhesion promoter layer that can be activated at high temperature 55 guaranteed. In contrast, the injection molding process temperature in the injection molding tool 63 be kept at a temperature level that essentially corresponds to the mold temperature recommended for processing the plastic used, i.e. is significantly lower than the thermoforming Temperature level. By providing the two separate thermoforming and injection molding tools 61 , 63 time-consuming temperature control processes for heating up and cooling down can be avoided. Rather, the two tools 61 , 63 isothermally kept at the respective temperature level, and that heating and cooling processes are required. This reduces the process time in the manufacture of the hybrid component 21 .

List of reference symbols

1

outer sheet metal part

3

inner sheet metal part

5

upper column node

7th

upper body side member

9

Frame side part

11

Transverse assembly

13th

lower column node

15th

Sill

17th

upper screw-on base

19th

lower screw-on base

21

Hybrid component

23

Semi-finished plastic products

25th

Injection molding structure

27

outer profile base

29, 31

Profile walls

33

Edge flanges

39

Metal inlay

49

Top edge

51

Sealing element

55

Adhesion promoter layer

60

all-round edging

61

Thermoforming tool

63

Injection molding tool

65

die

67

rubber stamp

69

Temperature control system

70

Temperature control system

71

Component composite

73

Transfer unit

75

Mold cavity

77, 79

Mold halves of the injection molding tool

I.

Joining direction

F.

Joining plane

P.

Process direction

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

• DE 102017010437 A1 [0009]
• WO 2019/215020 A [0009]

Claims (15)

A method for producing a hybrid component (21), consisting of at least one sheet metal part (1), a long or continuous fiber-reinforced semi-finished plastic product (23) which is coated on the sheet metal part (1) with an adhesion promoter layer (55) in between, and an injection-molded structure (25) made of short fiber reinforced plastic, which is applied to the plastic semifinished product (23), the method comprising a thermoforming process in which the long or continuous fiber reinforced plastic semifinished product (23) is pressed onto or in the sheet metal part (1) in a malleable state is draped in, and has an injection molding process in which the injection molding structure (25) is applied to the semi-finished plastic product (23), characterized in that the thermoforming process and the injection molding process functionally independent of one another in a thermoforming tool (61) and in an injection molding -Tool (63) done. Procedure according to Claim 1 , characterized in that the sheet metal part (1) is coated beforehand with the adhesion promoter layer (55) before the thermoforming process is carried out. Procedure according to Claim 1 or 2 , characterized in that the plastic semifinished product (23) consists of a thermoplastic material, or that the plastic semifinished product (23) consists of thermoplastic elastomers, or that thermoset prepregs are used for the plastic semifinished product (23). Method according to one of the preceding claims, characterized in that in the injection molding process, depending on the approach, a thermoplastic melt (i.e. thermoplastics or thermoplastic elastomers) or a resin-hardener mixture (to produce elastomers or thermosets after crosslinking reaction) is used, and in particular the Thermoplastic melt or the resin-hardener mixture is heated in an injection unit until a processable state is reached and then injected under pressure into the mold cavity of the injection molding tool, whereby the injection molding structure (25) forms on the semi-finished plastic product (23). Method according to one of the preceding claims, characterized in that the thermoforming tool (61) has tool halves, for example a die (65) and a punch (67), and / or that the thermoforming tool (61) has a temperature control system (69) is assigned, by means of which the sheet metal part (1) can be heated, and / or that in preparation for the thermoforming process, the sheet metal part (1) is inserted into the thermoforming tool (61) and then the punch (67) in a pressing process Semi-finished plastic product (23) in the malleable state is pressed onto or draped into the sheet metal part (1). Procedure according to Claim 5 , characterized in that the halves (65, 67) of the thermoforming tool (61) have different temperatures for the thermoforming step, and that in particular one half is well above the activation temperature of the adhesion promoter layer (55), while the other half is below the demolding temperature, so that when the mold (61) is closed, thermal equalization processes take place which, on the one hand, allow the temperatures required to activate the adhesion promoter layer (55) on the sheet metal to be exceeded long enough, but, on the other hand, a demolding temperature is reached after an economically sensible time, and / or that the stability of the thermoforming step can be increased by an isothermal process control of the tool halves (65, 67). Method according to one of the preceding claims, characterized in that the adhesion promoter layer (55) can be activated thermally, namely when an activation temperature is exceeded, and that the process temperature preferably runs isothermally during the thermoforming process, and / or that the thermoforming process temperature is greater than the Activation temperature of the adhesion promoter layer (55). Method according to one of the preceding claims, characterized in that, before the thermoforming process is carried out, the semifinished plastic product (23) is preheated to a melting temperature at which the plastic matrix of the semifinished plastic product (23) is molten, and in particular the adhesion promoter layer (55) has a high activation temperature which is greater than or equal to the processing temperature of the plastic semifinished product (23), and / or that in particular the thermoforming process temperature is at a preferably isothermal temperature level that is significantly higher than the processing temperature of the plastic matrix of the plastic semifinished product (23). Method according to one of the preceding claims, characterized in that after the thermoforming process the composite component (71) made of sheet metal part (1) and semi-finished plastic product (23) is cooled down to a demolding temperature, and that when the demolding temperature is reached, the composite component (71) is cooled by means of a transfer unit (73) is inserted into the mold cavity (75) of the injection molding tool (63). Method according to one of the preceding claims, characterized in that the injection molding tool or the injection molding Tool stage (63) is also preferably heated isothermally with the temperature control technologies (70) customary for the injection molding process and, depending on the type of material used, customary temperatures, and / or that the injection molding temperature level is significantly lower than the thermoforming temperature level. Method according to one of the preceding claims, characterized in that the hybrid component (21) is installed in the body in a vehicle body, and that after the body is built a KTL process follows in which the vehicle body is wetted with KTL paint in an immersion bath and then the vehicle body wetted with KTL paint is heated in a KTL furnace to a KTL temperature at which the KTL paint hardens, and that in particular the activation temperature of the bonding agent layer (55) and the processing temperature of the semi-finished plastic product (23) as well as the injection molding -Structure (25) is greater than the KTL temperature, and / or that the plastic matrix of the plastic semifinished product (23) and the injection molding structure (25) are essentially the same material with approximately the same processing temperatures. Method according to one of the preceding claims, characterized in that the hybrid component (21) has at least one metal insert (39), and that in particular in a first thermoforming substep, the semi-finished plastic product (23) is pressed onto the sheet metal part (1) and in In a second thermoforming sub-step, the metal insert (39) is pressed onto the still malleable plastic matrix of the semi-finished plastic product (23), and that in particular the two sub-steps take place in a common pressing stroke of the thermoforming stamp (67). Procedure according to Claim 12 , characterized in that the edge of the metal insert (39) is encapsulated with the injection-molded structure (25), to be precise with the formation of a circumferential border (60) which, together with the semi-finished plastic product (23), forms the edge of the metal insert ( 39) encompasses. Process arrangement for carrying out a method according to one of the preceding claims. Hybrid component which is produced by a method according to one of the preceding claims.

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