DE102021208711A1 - Process for the production of a motor vehicle structural component from a basic profile body with an AlSi coating and a plastic reinforcement element to be bonded, as well as a basic profile body - Google Patents

Abstract

The invention relates to a method for producing a motor vehicle structural component with a metallic profile base body (16) which is provided with an AlSi coating (40) at least in some areas on its surface, and with a plastic reinforcing element (18) designed as a planar element, which one of its main surfaces is to be glued to the profile base body (16) over its entire surface, whereby in a first process step an adhesive area at least partially provided with the AlSi coating (40) extends at least in shape and size over the main surface of the reinforcing element to be glued (18) extends, is removed in order to produce an adhesive surface (K), and in a second method step the reinforcing element (18) is arranged with its main surface together with an adhesive (24) on the adhesive surface (K) in order to close the bond generate.

Description

Process for the production of a motor vehicle structural component from a basic profile body with an AlSi coating and a plastic reinforcement element to be bonded, as well as a basic profile body

The invention relates to a method for producing a motor vehicle structural component with a metal profile base body which is provided with an AlSi coating at least in some areas, and a plastic reinforcing element to be bonded thereto. The reinforcement element to be bonded is, in particular, a reinforcement element made of a fiber-reinforced plastic.

Furthermore, the invention relates to a profile base body with at least partial AlSi coating, which is prepared for gluing to a plastic reinforcement element.

The invention relates in particular to a method for producing motor vehicle structural components in the form of an A, B, C or D pillar or a roof element of a motor vehicle body. In this respect, reference is also made to motor vehicles with at least one such motor vehicle structural component.

In particular, reference is made to a method for producing motor vehicle structural components in the form of a B-pillar. Furthermore, the invention relates in particular to profile bases which, due to the process, are provided with an AISi coating before being connected to a plastic reinforcement element, at least in an adhesive area, i.e. in an area in which the profile base body after the application of the AlSi -Coating to be connected by gluing with the reinforcing element made of plastic. In particular, the invention relates to profile base bodies that are completely provided with an AISi coating.

The invention also refers specifically to motor vehicle structural components with a profile base body and at least one reinforcement element designed as a surface element, which is to be fixed with one of its main surfaces adhesively relative to the profile base body. In this context, a surface element means an element which essentially extends over a length and a width and whose thickness is rather small compared to the length and the width. Accordingly, such elements have a front and a back with - in comparison to the other sides - relatively large main surfaces, i.e. the two main surfaces are significantly larger than the other surfaces.

Out of U.S. 2008/0156425 A1 discloses a method for producing a motor vehicle structural component, in particular a B-pillar, which is formed from a metal profile base body and a fiber-reinforced plastic reinforcement element bonded thereto. In this document, reference is made neither to an AISi coating in connection with the profile body nor to the treatment of such a coating.

Out of US 2017/0008568 A1 a motor vehicle structural component in the form of a B-pillar of a motor vehicle body and a method for producing such a motor vehicle structural component are known. The motor vehicle structural component is formed from a metal profile base body and a fiber-reinforced plastic reinforcement element bonded thereto. In this document, too, reference is made neither to an AISi coating in connection with the profile base body nor to a treatment of such a coating in connection with the arrangement of the reinforcement element.

Out of US 2019/0092976 A1 discloses a motor vehicle structural component in the form of an A-pillar of a motor vehicle body, which consists of a profile base body provided with an AlSi coating and a plastic reinforcing element bonded thereto. It is disclosed that in the area where the reinforcing element is to be arranged, either the AlSi coating should be omitted or a coating previously applied there should be removed mechanically by grinding or chemically. In the areas without the AlSi coating, an adhesive is then applied with an adhesive thickness that is at least as large and usually larger than the AlSi coating in the exemplary embodiments shown, in order to then adhesively bond the reinforcing element to the profile base body. In all of the exemplary embodiments, the reinforcing element has a shorter or longer length than the area without the AISi coating. The exemplary embodiments all relate to flat adhesive surfaces. The gluing of a reinforcing element designed as a surface element to one of its main surfaces is not disclosed.

The invention is based on the object of providing a method for producing a motor vehicle structural component which is to be bonded with one of its main surfaces to the profile base body over its entire surface, by means of which a motor vehicle structural component with a high connection quality is produced. In this case, the motor vehicle structural component on a metallic profile body, which at least partially with a AISi coating is provided. Furthermore, the motor vehicle structural component has a reinforcing element made of plastic and designed as a planar element. In addition to the method, a profile base body for a motor vehicle structural component as described above is also to be made available, which is prepared for the gluing of a plastic reinforcing element designed as a surface element in order to achieve a high connection quality.

In particular, the method should also be applicable to motor vehicle structural components whose reinforcing element to be bonded has at least one curved surface in the area of the main surface to be bonded, which is to be bonded over its entire surface to a likewise curved surface of the profile base body.

The object is achieved according to the invention with the features of the independent claims. Further practical embodiments and advantages of the invention are described in connection with the dependent claims.

The method according to the invention serves to produce a motor vehicle structural component with a metallic profile base body and with a plastic reinforcing element designed as a surface element. The profile base body is provided with an AISi coating at least in some areas on its surface. One of the main surfaces of the reinforcement element should be fully bonded to the profile body. In a first step of the method according to the invention, an adhesive area provided with the AISi coating--at least in regions--which extends in shape and size at least over the main surface of the reinforcing element to be bonded is removed in order to produce an adhesive surface. This means that preferably an area adapted in shape and size to the main surface of the reinforcement element to be bonded—if it was provided with an AISi coating—is at least largely freed from the AISi coating by removing it. In this context, removal as far as possible means that the AISi coating extends over significantly less than 50 percent after removal in the area of the adhesive surface. At least 70 percent, at least 80 percent or at least 90 percent of the adhesive surface is preferably free of an AISi coating, so that the base material of the profile base body is on the surface in this area. The adhesive surface can preferably be recognized by a continuous peripheral line in which the AISi coating has been completely removed. The AISi coating is at least largely removed within this peripheral line, which in terms of shape and size corresponds at least to the main surface of the reinforcing element to be bonded. In a second method step, the reinforcing element is arranged with its main surface together with an adhesive on the adhesive surface in order to create the bond. With the method according to the invention, a high-quality connection between the profile base body and the reinforcement element can be achieved, in particular because a large-area adhesive connection between one of the main surfaces of the reinforcement element is produced largely or completely independently of the AISi coating directly with the base material of the profile base body. The AlSi coating can be removed in a suitable manner, in particular by a mechanical or chemical removal method.

In a preferred embodiment of the method according to the invention, the removal according to the first method step is carried out using at least one laser beam. Removal using a laser beam enables the AlSi coating to be removed with particular precision, on the one hand in relation to the shape of the area treated by the laser beam to obtain the adhesive surface, but on the other hand also in relation to achieving a precise depth.

Reference is made in particular to the use of a pulsed laser beam. The use of a pulsed laser beam is particularly suitable for removing relatively thin AlSi coatings (e.g. in the range of 1-1000 µm).

As can already be seen from the wording "at least one laser beam", the removal can also be carried out using two or more laser beams, in particular in order to shorten the overall processing time required.

Regardless of the type of process with which the AISi coating is removed, it is advantageous if the removal takes place in layers. However, it is also advantageous in connection with a layer-by-layer removal if this is done by means of a laser beam, since the removal by means of a laser beam, particularly if a pulsed laser beam with advantageous settings is selected, enables continuous observation of the surface of the adhesive surface. In this way, only as much material as necessary can be removed easily and cost-effectively, which is advantageous in particular given that the AlSi layer thicknesses have tolerances and it is accordingly essential when the AlSi layer is removed mechanically or chemically is more difficult or practically impossible to ablate as precisely as with a laser beam. The other methods are in any case much more time-consuming and in practice are likely to be associated with less precision.

In a further practical embodiment of the method according to the invention, it is checked during the removal whether the AlSi layer has been removed to a specified extent and the removal is ended as soon as the AlSi layer has been removed to a specified extent. Such a check can be carried out by an operator who, for example, recognizes when the AISi coating has been completely or largely removed from a surface with an increasing metallic luster during the removal and its changing degree of gloss. The check is preferably carried out by means of a monitoring device, in particular by means of a camera or some other optical monitoring device. In particular, this has a comparison module in which reference values are stored for a desired minimum quality of the removal of the AlSi layer or the base material of the profile base body that appears underneath. As soon as the values determined with the monitoring device are within a specified target range, the removal can then be ended. Monitoring can be carried out in a particularly time-efficient manner in connection with removal using a laser beam, because the surface of the base body—in contrast to mechanical or chemical removal—remains largely free of dissolved particles during the removal, especially if these evaporate immediately or are removed in some other way.

Alternatively or in addition, reference is made to the possibility of checking using a laser beam for distance measurement. For example, by measuring the difference in distance between a processed and an unprocessed surface, the depth of the removal can be measured exactly and the measured value can be used for exclusive or additional verification. For example, if it is known that an AlSi layer has a thickness of 50 µm +/- 5 µm, when measuring a depth of 55 µm it can be assumed that the AlSi layer has been completely removed. Furthermore - in the case of a plausibility check - if the degree of gloss is (possibly) sufficient, but the measured value for the depth is below the tolerance, further material can be removed to be on the safe side.

It is possible to carry out the removal layer by layer until an adhesive surface with a certain surface quality is created. Then, after the adhesive area has been removed, the adhesive surface has a specific, predetermined surface structure, in particular a smooth and step-free surface or a surface with another, predetermined surface.

It is also possible to divide the bond surface into surface segments and monitor the surface finish by segment, stopping removal in a segment as soon as that segment has the desired surface finish. In this case, small steps between individual segments can and will occur in practice. However, only as much material as necessary is removed in each segment and the profile base body is only reduced in its material thickness as much as necessary. As a result, an overall higher quality of connection between the profile base body and the reinforcing element can be achieved, particularly if the AlSi layer has greater fluctuations in thickness.

In a further practical embodiment of a method according to the invention, in particular during or after the removal of the AISi coating, upwardly projecting adhesive structures are formed or arranged in the area of the adhesive surface. In particular, in this way, stamp-like adhesive structures, consisting in particular of the AISi coating, can be formed, by means of which the later connection between the adhesive and the reinforcing element is further improved, especially if the adhesive structures have barbs protruding radially outwards, which connect with the hardened dovetail adhesive. It is also possible to form the adhesive structures from the base material of the basic profile body if the AISi coating is first completely removed and then the structures are formed by partial removal. This can be carried out very precisely with a pulsed laser beam in particular.

It is further preferred if the adhesive surface for producing the bond is completely provided with adhesive, since in this way, on the one hand, corrosion of the profile base body is counteracted and, on the other hand, the available surfaces are used completely to produce a high-strength adhesive connection. Adhesive can also be provided completely by applying the adhesive in a suitable quantity and manner in such a way that when the reinforcing element is later pressed on it is ensured that the adhesive is distributed completely in the space between the profile base body and the reinforcing element.

The invention also relates to a profile body for a motor vehicle structural component, the at least one reinforcing element made of art material, which is designed as a surface element and is glued to one of its main surfaces with the profile base body. The profile base body is provided with an AlSi coating at least in some areas on its surface. Furthermore, the AISi coating is at least predominantly removed in the area of an adhesive surface, which extends in shape and size at least over the main surface of the reinforcement element, which faces the profile base body during adhesive bonding. Reference is hereby once again made to the understanding of the term “predominantly remote” that has already been explained above. The AlSi coating is preferably completely removed in the area of the adhesive surface. For the reasons already explained above, a profile base body according to the invention enables a high-strength adhesive connection, in particular on a motor vehicle structural component in the form of a B-pillar, which is usually an elongated component whose height is much greater than the length and thickness. A reinforcement element for such a B-pillar preferably also has such a shape, but can only extend over part of the height and part of the length.

In a practical embodiment of a profile base body according to the invention, upwardly projecting adhesive structures are provided, i.e. formed and/or arranged, on the adhesive surface in the AISi coating and/or in the material of the profile base body. The associated advantages have already been referred to above in connection with the method.

If adhesive structures have radially protruding barbs and/or points on the upper side, the quality of the connection can be further increased, in particular because the surface of the adhesive surface is enlarged and/or additional interlocking between the adhesive and profile base body is achieved.

In a further practical embodiment, the adhesive surface extends over at least one curved surface area, preferably over two or more curved surface areas, and/or the basic profile body is a hot-formed component. Such a design is found in particular on a B-pillar of motor vehicles. In particular, reference is made in this context to U-shaped profile base bodies which are to be bonded to likewise U-shaped reinforcement elements to form a loadable and in particular rigid and torsion-resistant motor vehicle structural component.

• 1 ein Kraftfahrzeug mit gestrichelt gekennzeichneter Hervorhebung einer B-Säule in einer Seitenansicht,
• 2 die B-Säule des Kraftfahrzeuges aus 1 im endmontierten Zustand in einer isometrischen Darstellung,
• 3 die B-Säule aus 2 mit allen Einzelelementen in einer Explosionsdarstellung,
• 4 eine schematische Darstellung einer Bearbeitungsvorrichtung zum Entfernen einer AISi-Beschichtung mittels eines gepulsten Laserstahls,
• 5 eine erste Ausführungsform mit einer in der Klebefläche ausgebildeten, nach oben ragenden Haftstruktur,
• 6 eine weitere Ausführungsform mit einer in der Klebefläche ausgebildeten, nach oben ragenden Haftstruktur,
• 7 eine weitere Ausführungsform mit einer in der Klebefläche ausgebildeten, nach oben ragenden Haftstruktur,
• 8 eine weitere Ausführungsform mit einer in der Klebefläche ausgebildeten, nach oben ragenden Haftstruktur und
• 9 eine weitere Ausführungsform mit einer in der Klebefläche ausgebildeten, nach oben ragenden Haftstruktur.

Further practical embodiments of the invention are described below in connection with the drawings. Show it:

• 1 a motor vehicle with a B-pillar highlighted in dashed lines in a side view,
• 2 the B-pillar of the motor vehicle 1 in the final assembled state in an isometric representation,
• 3 the B-pillar 2 with all individual elements in an exploded view,
• 4 a schematic representation of a processing device for removing an AISi coating by means of a pulsed laser beam,
• 5 a first embodiment with an upwardly projecting adhesive structure formed in the adhesive surface,
• 6 a further embodiment with an upwardly projecting adhesive structure formed in the adhesive surface,
• 7 a further embodiment with an upwardly projecting adhesive structure formed in the adhesive surface,
• 8th a further embodiment with an upwardly projecting adhesive structure formed in the adhesive surface and
• 9 another embodiment with an upwardly projecting adhesive structure formed in the adhesive surface.

1 shows a motor vehicle 10 in a side view. The B-pillar 14, which is a motor vehicle structural element within the meaning of the invention, is located in the area 12 marked with dashed lines. The largest external dimension of the B-pillar 14 is the height, which essentially extends in the vertical direction of the vehicle (z-direction). The length extending in the vehicle longitudinal direction (x-direction) and the width extending in the vehicle transverse direction (y-direction) are significantly smaller than the height. The height of the B-pillar 14 of a motor vehicle 10 is usually greater than 300 mm, usually greater than 500 mm. The height is mostly less than 1000 mm.

The B-pillar 14 extends upwards substantially over the height of the adjacent front side window 26 and the rear side window 28 to a roof element 30.

As in the 2 and 3 is clearly visible, the B-pillar 14 is formed in the embodiment shown essentially from a metal profile base body 16 and a fiber-reinforced reinforcement element 18. Das Reinforcement element 18 is made of fiber-reinforced plastic, in particular glass fiber-reinforced plastic (GRP). It extends over more than 50 percent of the height of the profile body 16 and thus over a large part of the height. The reinforcement element 18 can also be referred to as an FRP patch or GRP patch.

The largest dimension of the reinforcement element 18 is the height extending in the vehicle vertical direction (z-direction), the second largest dimension is the length extending in the vehicle longitudinal direction (x-direction). The thickness extending in the transverse direction of the vehicle (y-direction) is significantly smaller than the length and the height. As a result, the reinforcement member 18 has a front major surface V and a rear major surface R which are substantially larger than all other surfaces.

Before carrying out the method according to the invention, the profile base body 16 is completely covered with an AlSi coating (in the 1 until 3 not shown). According to a first method step, the AlSi coating is then removed in a bonding area (not shown) in order to produce a bonding surface K. The shape and size of the adhesive surface K is in 3 is represented by the dashed line 20. The shape and size of the adhesive surface K is adapted here to the rear main surface R in order to prepare for full-surface bonding. For gluing - as in 3 visualized - a suitable adhesive 24 is arranged between the adhesive surface K and the rear main surface R, in particular by applying the adhesive 24 to the adhesive surface K and/or to the reinforcement element 18 and then positioning the reinforcement element 18 opposite the adhesive surface K and holding it in this position until the adhesive 24 has hardened.

In this embodiment, a clamping plate 32 is provided to fix the top end 34 of the reinforcement element 18 in relation to the profile base body 16 .

4 shows a schematically illustrated processing device 36, which is particularly suitable for carrying out the method according to the invention. A pulsed laser beam 38--visualized here with dashed lines--is directed with the processing device 36 in the direction of the profile base body 16 with an AISi coating 40 applied to its surface such that individual particles 42 of the AISi coating 40 are blasted off. The particles 42 blown off are conveyed away by means of process gas, which is visualized by arrows 44 and is directed via a nozzle 46 in the direction of the laser impact area. In this way, by controlling the laser beam 38, the AlSi coating 40 can be completely and precisely removed layer by layer in very small increments, as shown in FIG 4 visualized in the work area 48 .

In the 5 until 9 Various geometric design options for adhesive structures 50 are shown.

In the embodiments according to 5 until 8th the adhesion structures 50 are worked out of the material of the AISi coating 40 by the AlSi coating 40 not being removed or only being partially removed in the area of the adhesion structures 50 .

The adhesive structures 50 in the in 5 embodiment shown in cross section as plateaus each having two peaks 52 .

In the embodiment according to 6 mushroom-head-like adhesive structures 50 are formed with radially protruding barbs 54 formed on the upper side.

In the embodiment according to 7 Adhesive structures 50 each having two individual tips 52 are formed.

In the embodiment according to 8th C-shaped adhesion structures 50 are formed with radially protruding barbs 54 formed on the upper side.

The embodiment according to 9 differs from the embodiments according to the 5 until 8th that the adhesive structures 50 are formed in the material of the profile base body 16. In this embodiment, radially protruding barbs 54 are also provided on the upper side. These are formed by adhesion structures 50 with a trapezoidal cross section, it being possible for the upper corners of the trapezoidal adhesion structures 50 to be rounded in order to reduce stresses in the region of discontinuous upper corners.

The features of the invention disclosed in the present description, in the drawings and in the claims can be essential both individually and in any combination for the realization of the invention in its various embodiments. The invention can be varied within the scope of the claims and taking into account the knowledge of the person skilled in the art.

In that regard, particular reference is made to the fact that the adhesive structures 50 according to the 5 until 8th in the one shown and in other suitable ones Shapes can also be fully or partially formed in the profile base body 16. Conversely, the adhesive structures 50 in 9 shown embodiment can also be formed in the AlSi coating 40.

Reference List

10

motor vehicle

12

marked area

14

B pillar

16

Profile body

18

reinforcement element

20

body contact surface

22

reinforcement element contact surface

24

adhesive

26

front side window

28

rear side window

30

roof element

32

clamping plate

34

top end

36

processing device

38

laser beam

40

AlSi coating

42

particles

44

Arrow (visualization of a process gas)

46

jet

48

Workspace

50

adhesive structure

52

Top

54

barb

V

front main surface

R

back main surface

K

adhesive surface

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

• US20080156425A1 [0007]
• US20170008568A1[0008]
• US20190092976A1 [0009]

Claims (10)

Method for producing a motor vehicle structural component with a metallic profile base body (16) which is provided with an AlSi coating (40) at least in some areas on its surface, and with a plastic reinforcing element (18) designed as a surface element, which has one of its main surfaces is to be glued to the profile base body (16) over its entire surface, in a first method step an adhesive area which is at least partially provided with the AlSi coating (40) and which extends at least in shape and size over the main surface of the reinforcing element (18) to be glued , is removed in order to produce an adhesive surface (K), and in a second method step the reinforcing element (18) is arranged with its main surface together with an adhesive (24) on the adhesive surface (K) in order to produce the bond. Method according to the preceding claim, characterized in that the removal according to the first step of the method is carried out using at least one laser beam (38). Method according to one of the preceding claims, characterized in that the removal takes place in layers. Method according to one of the preceding claims, characterized in that during the removal it is checked whether the AlSi coating (40) has been removed to a predetermined extent and the removal is terminated as soon as the AlSi coating (40) has been removed to a predetermined extent is. Method according to one of the preceding claims, characterized in that upwardly projecting adhesive structures (50) are formed or arranged in the area of the adhesive surface (K). Method according to one of the preceding claims, characterized in that the adhesive surface (K) is completely provided with adhesive (24) to produce the bond. Profile base body for a motor vehicle structural component, which has at least one reinforcing element (18) made of plastic, which is designed as a surface element and is glued to one of its main surfaces with the profile base body (16), the profile base body (16) being attached at least in regions its surface is provided with an AISi coating (40), characterized in that the AlSi coating (40) in the area of an adhesive surface (K), which extends in shape and size at least over the main surface of the reinforcing element (18), the facing the profile base body (16) during gluing, is at least largely removed. Profile base body according to the preceding claim, characterized in that upwardly projecting adhesive structures (50) are provided on the adhesive surface (K) in the AISi coating (40) and/or in the material of the profile base body (16). Profile base body according to the preceding claim, characterized in that the adhesive structures (50) have barbs (54) and/or points (52) protruding radially on the upper side. Profile base body according to one of the three preceding claims, characterized in that the adhesive surface (K) extends over at least one curved surface area and/or the profile base body (18) is a hot-formed component.

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