DE102015105086A1 - Manufacturing method for a composite panel - Google Patents

Abstract

A manufacturing method for a composite panel (1) comprises: bonding an outer panel (20) to an inner panel (30) by applying an adhesive (40) to an outer edge (21) of the outer panel (20); Applying a coating by means of electrolytic plating on a surface (22) of the outer panel (20) of the composite panel (1) in which the outer panel (20) is connected to the inner panel (30); and firing a coating film (50) formed by the plating coating on the surface (22) of the outer panel (20) onto the outer panel (20). The adhesive (40) used herein is a room-temperature curing adhesive that does not flow at the time of firing.

Description

BACKGROUND OF THE INVENTION

1. Field of the invention

The present invention relates to a manufacturing method of a composite panel in which an outer panel of a metallic material is bonded to an inner panel of a material having a coefficient of linear expansion different from the coefficient of linear expansion of the metallic material.

2. Description of the Related Art

In recent years, a panel such as a hood for an automobile has been manufactured as a composite panel in which an outer panel made of a metallic material has been bonded to an inner panel made of a material different from the metallic material , An aluminum alloy or steel sheet made of a high-tensile steel is used as the metallic material for the outer panel, and a metallic material other than the outer panel or a fiber-reinforced plastic is used as the material for the inner panel.

The outer panel and the inner panel are made of different materials so that their coefficients of linear expansion are different from each other. Due to the coefficients of linear expansion may occur due to a shear stress (a thermal load) acting on adhesive surfaces, a release of the adhesive. In this regard, the Japanese laid-open application proposes JP 2007-118852 A a manufacturing method for a composite panel in which an outer panel is adhesively attached to an inner panel, and a bracket is adhesively attached to the inner panel and outer panel to cover at least a part of an outer edge side of the inner panel from the outer edge of the outer panel ,

Even if, due to the shear stress (thermal stress) caused on the adhesive surfaces due to a difference between the expansion coefficients of the outer panel and the inner panel peeling of the adhesive, it is possible to avoid with the clip that the outer panel from the inner panel detaches.

However, in general, the adhesive bonding the outer panel to the inner panel is applied at a time when the outer panel and the inner panel are assembled, and thereafter the adhesive is cured at a time when a coating film is deposited by a coating by electrodeposition. is baked on the outer panel by electroplating. Accordingly, when the coating film is baked, the outer panel is stretched in the region of elastic deformation due to the heat of firing, and the outer edge of the outer panel is restricted in such a stretched state by the cured adhesive from the inner panel.

Accordingly, after baking of the coating film due to the cured adhesive, the outer edge of the outer panel is prevented from contracting by the inner panel upon cooling (when left to cool), so that the deformation of the outer panel is maintained at the time of firing. This can affect the appearance of the exterior panel.

SUMMARY OF THE INVENTION

The present invention provides a manufacturing method of a composite panel, which manufacturing method can avoid deformation of an outer panel at room temperature even when coating / firing is performed on a surface of the outer panel in a state in which outer edges of the outer panel and an inner panel are adhesively bonded together are.

A manufacturing method for a composite panel according to one aspect of the invention comprises: bonding an outer panel made of a metallic material to an inner panel made of a material having a coefficient of linear expansion different from the coefficient of linear expansion of the metallic material by applying a Adhesive on an outer edge the outer panel or an outer edge of the inner panel and curing the adhesive; Performing a plating coating on a surface of the outer panel of the composite panel in which the outer panel is connected to the inner panel; and baking a coating film formed on the surface of the outer panel by electroplating coating on the outer panel, wherein the adhesive is a room temperature curing adhesive that does not flow at the time of firing.

According to one aspect of the present invention, the room-temperature-curing adhesive is used when the outer panel is bonded to the inner panel during bonding, so that the outer panel is bonded to the inner panel by curing the adhesive without heat acting on the outer panel and the inner panel , whereby the composite panel is formed.

The composite panel thus obtained is subjected to a plating coating at the time of coating, and when the coating film is baked in the outer panel upon firing, thermal stress is temporarily applied to the outer panel due to differential thermal expansion between the outer panel and the inner panel.

However, the glue does not flow during firing, so that the adhesive is retained in the cured state. Even if the outer panel is cooled to room temperature after firing and thus the outer panel contracts, the thermal stress acting on the outer panel is removed. As a result, the outer panel returns to its original shape, so that the appearance of its coating surface is not affected.

Thus, in the composite panel after firing, a shearing stress caused due to the thermal stress hardly affects the adhesive surfaces of the outer panel and the inner panel at room temperature, so that it is possible to reliably secure the adhesion of the outer panel and the inner panel via the adhesive.

In particular, when the adhesive is applied to seal inside surfaces of the outer panel and the inner panel, the sealing property can be ensured. This makes it possible to resist corrosion of the metallic material outer panel.

It should be noted that the "room temperature curing adhesive" is an adhesive that cures only by natural drying without heating to glue two elements together. A room-temperature curing two-component adhesive is commonly known as a room-temperature curing adhesive.

The metallic material of the outer panel may be an aluminum alloy and the material of the inner panel may be a fiber reinforced plastic. A coefficient of linear expansion of the aluminum alloy is significantly greater than a coefficient of linear expansion of the fiber-reinforced plastic. Therefore, when the aluminum alloy is used for the outer panel and the fiber-reinforced plastic for the inner panel, a difference in thermal expansion between them during firing is larger than combinations of other materials. However, the adhesive is maintained in the cured state as described above, so that it is possible to restrict the deformation of the outer panel after firing. It is thereby possible to sufficiently obtain a shape property originally having the aluminum alloy outer panel, the molding property being a molding property based on a coating gloss.

At the time of bonding, a seaming process may be performed so that the adhesive is applied to the outer edge of the outer panel and the outer edge of the outer panel is folded toward the outer edge of the inner panel.

The adhesive is arranged in the folding process between the outer edge of the outer panel and the outer edge of the inner panel. This makes it possible to avoid overflowing of the adhesive. Further, even if the adhesive is peeled off at the time of firing, the inner panel is not detached from the outer panel because the outer edge of the inner panel is received in the folded portion (outer edge) of the outer panel.

The adhesive may be a two-component epoxy adhesive. This makes it possible to reduce the surface deviation, which is an offset amount of the composite panel after firing.

According to one aspect of the present invention, it is possible to restrict deformation of the outer panel at room temperature even in a case where firing / coating is performed on a surface of the outer panel in a state where outer edges of the outer panel and an inner panel overlap with each other an adhesive are connected.

BRIEF DESCRIPTION OF THE DRAWING

The features and advantages as well as the technical and economic significance of exemplary embodiments of the present invention will be described below with reference to the accompanying drawings, in which like numerals denote like elements; this shows:

1 a view showing each step of the method for producing a composite panel according to an embodiment of the present invention;

2 a schematic perspective view showing an outer panel and an inner panel;

3 a schematic perspective view showing the composite panel, wherein the outer panel is connected to the inner panel;

4 a schematic sectional view showing a folded structure of the outer edges of the outer panel and the inner panel; and

5 a schematic perspective view for describing the galvanization coating, which is performed on the surface of the outer panel of the composite panel, in which the outer panel is connected to the inner panel.

DETAILED DESCRIPTION OF EMBODIMENTS

Hereinafter, an embodiment of the present invention will be described with reference to the drawings. 1 FIG. 14 is a view for illustrating each step of manufacturing a composite panel according to an embodiment of the present invention and FIG 2 FIG. 12 is a schematic perspective view illustrating an outer panel and an inner panel. FIG. 3 is a schematic perspective view of the composite panel in which the outer panel is connected to the inner panel, and 4 shows a schematic sectional view showing a folded structure of the outer edges of the outer panel and the inner panel. 5 FIG. 12 is a schematic perspective view for describing the electrodeposition coating on the surface of the outer panel of the composite panel. FIG.

First, an outer panel (a hood top) 20 and an interior panel (a hood inside) 30 prepared. The outer panel 20 is an aluminum alloy panel that is a metallic material, and is a panel that fits into the in 2 shown shape is press-formed. A coating by means of electrolytic deposition or the galvanization coating becomes on a surface of the outer panel 20 performed after the outer panel 20 with the inner panel 30 was connected. In the present embodiment, as for the weight saving in the panel, as the metal material for the outer panel 20 The aluminum alloy used, however, for example, a steel sheet can be used.

The interior panel 30 consists of a material with a coefficient of linear expansion that differs from the linear expansion coefficient of the metallic material. Examples of the material include a metal material different from that of the outer panel 20 differs, a plastic material, a fiber-reinforced plastic and the like. Here, the fiber-reinforced plastic, which is a material of low weight and high strength, is preferred.

The fiber-reinforced plastic comprises a plastic that is reinforced by a reinforcing fiber. The reinforcing fiber may be, for example, a fiber such as a glass fiber, a carbon fiber, an aramid fiber, an aluminum fiber, a boron fiber, a steel fiber, a PBO fiber or a high-strength polyethylene fiber.

The plastic may be a thermosetting resin or a thermoplastic resin, and examples thereof include an epoxy resin, a phenolic resin, a melamine resin, a carbamide resin, a silicone resin A maleimide resin, a vinyl ester resin, an unsaturated polyester resin, an unsaturated polyethylene resin, a polyurethane resin, a cyanate resin and a polyimide resin.

In the present embodiment, the resin with such a reinforcing fiber in an in 2 shown form brought. To reduce costs, there is the inner panel 30 of an SMC molding compound (C-SMC) in which carbon is the reinforcing fiber in a thermosetting resin.

First, in S11 of 1 , an adhesive on an outer edge 21 of the outer panel 20 So prepared, applied, and the interior panel 30 gets on the outer panel 20 applied, as in 2 shown. The adhesive used here is a room temperature-curing adhesive which does not flow in the step (a firing step) described below for firing a coating film.

Such an adhesive may be a two-component epoxy adhesive and is preferably a two-component epoxy adhesive comprising a bisphenol A epoxy resin, a bisphenol F epoxy resin, a novolak epoxy resin or the like as a base component, and an amine, a polyamine or a Merkaptanhärtemittel includes. The two-component epoxy resin may be a solvent-free resin, an organic solvent-containing resin, or a water-based resin.

Then, in S12 of 1 , a folding process with respect to the outer edge 21 of the outer panel 20 and the outer edge 31 of the interior panel 30 executed as in 3 is shown. More precisely, the outer edge 21 of the outer panel 20 towards the outer edge 31 of the interior panel 30 folded. Here, as in 4 shown is the outer edge 21 of the outer panel 20 arranged so that they outer edge 31 of the interior panel 30 surrounds, and an adhesive 40 is between the outer edge 21 of the outer panel 20 and the outer edge 31 of the interior panel 30 applied.

Then, in S13 of 1 , the adhesive 40 dried. In the present embodiment, the room-temperature curing adhesive becomes an adhesive 40 used so that it is possible the outer panel 20 and the interior panel 30 by curing the adhesive without heating the outer panel 20 and the interior panel 30 to connect (connection step). This will be a composite panel 1 receive.

Then, in S14 of 1 , a galvanizing coating on a surface 22 of the outer panel 20 of the composite panel 1 executed, in which the outer panel 20 with the inner panel 30 connected is. This is a coating film 50 on the surface of the outer panel 20 educated.

In the galvanization-coating step, the resin coating film becomes 50 on the surface of the outer panel 20 not hardened. In this regard, in S15 of 1 that on the surface 22 of the outer panel 20 coating film formed by the plating coating 50 on the outer panel 20 burned (the firing step). More specifically, the composite panel 1 heated to a predetermined temperature for a given time to the coating film 50 cure. In this case, the coating film adheres 50 on the surface of the outer panel 20 at. In the present embodiment, the adhesive that does not flow in the firing step becomes the adhesive 40 used so the glue 40 remains in the cured state at the time of the burning step.

Thus, in the present embodiment, when the outer panel 20 with the inner panel 30 in the bonding step, the room-temperature curing adhesive becomes 40 used. Accordingly, a composite panel (hood) 1 be formed such that the outer panel 20 with the inner panel 30 by curing the adhesive 40 is formed without heat on the outer panel 20 and interior panel 30 must act.

The composite panel thus obtained 1 is then subjected to the plating step of the galvanization coating and a thermal load acts due to a thermal expansion difference between the outer panel 20 and the interior panel 30 temporarily on the outer panel 20 when the coating film 50 in the burning step on the surface 22 of the outer panel 20 is burned.

However, during the firing step, the adhesive flows 40 not, so the glue 40 in its place, at which the glue 40 is applied, remains, and the adhesive 40 held in a state in which the adhesive 40 adhered to an adhesive surface. Accordingly, even if the outer panel 20 after the firing step cools to room temperature and the outer panel 20 is contracting on the outside panel 20 acting thermal load removed. This returns the outer panel 20 back to its original shape, so that the appearance of its coating surface is not affected.

Moreover, after the firing step at room temperature, hardly any shear stress caused by the thermal stress acts on the adhesive 40 , the outside panel 20 with the inner panel 30 bonded. This allows the adhesion between the outer panel 20 and the interior panel 30 with the glue 40 to ensure reliable.

In addition, in the present embodiment, an aluminum alloy for the outer panel 20 used, and a fiber-reinforced plastic (especially a carbon fiber reinforced plastic) is used for the inner panel 30 used. In this case, a difference in thermal expansion between the two is greater in the firing step than in other combinations of materials. However, as described above, at the time of bonding, the adhesive remains in the cured state, thereby making it possible to deform the outer panel 20 to avoid after the firing step. This makes it possible to suitably form a shape characteristic of the outer panel 20 aluminum alloy originally has to achieve, wherein the molding property is a molding property based on the coating gloss.

In addition, the folding process on the outer panel 20 executed. Thus, even if the adhesive dissolves due to a shearing force in the firing step, the inner panel does not fall off the outer panel since the outer edge of the inner panel 30 is received in the folded part (the outer edge) of the outer panel.

Hereinafter, examples of the present invention will be described.

(Example 1) An outer panel (outer hood) made of an aluminum alloy ( JIS: 6000s Series aluminum alloy) with an in 2 and an inner panel made of carbon fiber reinforced plastic (C-SMC) and an adhesive which is a two-component epoxy adhesive (a product of LORD Far East Incorporated: Fusor320 / 310BBlack, with a basic component and a curing agent in the ratio of 1: 1) are prepared.

Then, the two-component epoxy adhesive is applied to an outer edge of the outer panel, and a folding process is performed to fold the outer edge of the outer panel toward the outer edge of the inner panel, as in FIG 4 is shown. Thereafter, the two-component epoxy adhesive is cured at 30 ° C (room temperature) for 70 minutes. Then, a plating coating is performed on a surface of the outer panel, and a coating film formed by the plating coating on the surface of the outer panel is baked at a temperature of 180 ° C for a heating time of 20 minutes.

Images of an entire surface of a composite panel before and after firing are taken, and a displacement of the outer panel of the composite panel after firing is measured based on the composite panel before firing. A result thereof is shown in Table 1. (A) to (F) of Table 1 show the shift amount of the respective measurement points 3 , [Table 1] Displacement amount at each measuring point (mm) (A) (B) (C) (D) (E) (F) example 1 -2.5 7.5 -2.5 0.0 -2.5 -7.5 Example 2 -3.0 6.0 -2.5 0.0 -3.0 -6.0 Example 3 -3.0 7.5 -3.0 1.0 -3.0 -7.5 Comparative Example 1 -2.5 2.5 -2.5 15.0 -5.0 -5.0

(Example 2) A composite panel is produced in the same manner as in Example 1. The difference from Example 1 is as follows: an adhesive which is a two-part epoxy adhesive (a product of LORD Far East Incorporated: Fusor320 / 322, with a base component and a hardener in the ratio of 1: 1) is used as an adhesive. Then, similar to Example 1, images of the total area of the composite panel are taken before and after firing, and based on the composite panel before firing, a displacement of the outer panel of the composite panel after firing is measured. The result thereof is shown in Table 1.

(Example 3) A composite panel is produced in the same manner as in Example 1. The difference from Example 1 is as follows: An adhesive which is a two-component epoxy adhesive (a product of LORD Far East Incorporated: Fusor390 / 391, with a base component and a curing agent in the ratio of 1: 1) is used as an adhesive. Similar to Example 1, images of the total area of the composite panel are taken before and after firing, and based on the composite panel before firing, a displacement of the outer panel of the composite panel after firing is measured. The result thereof is shown in Table 1.

(Comparative Example) A composite panel is produced in the same manner as in Example 1. The difference from Example 1 is that a one-component epoxy adhesive is used as the adhesive and a coating film applied to the surface of the outer panel by the galvanizing coating is baked, and the adhesive is baked at a temperature of 180 ° C and a heating time of 40 minutes , Similar to Example 1, images of the entire surface of the composite panel are taken before and after firing, and based on the composite panel before firing, a displacement of the outer panel of the composite panel after firing is measured. One result of this is in 1 shown.

<Result 1 and Consideration 1> In the case of the composite panels of Examples 1 to 3, the adhesive is preliminarily cured by drying in the bonding step, so that the outer panel, which is elastically deformed by the expansion in the firing step, returns to its original shape after cooling. Accordingly, the shift amount as the surface deviation at the point (D) is smaller than that in the comparative example. Besides, in the composite panel of the comparative example, the adhesive is cured at a time when the outer panel is elastically deformed due to the expansion in the firing step. As a result, the deformation is maintained, so that the amount of shift as the surface deviation at the point (D) is larger than in the examples 1 to 3.

(Reference Examples 1 to 3) An aluminum alloy plate (JIS: 6000 series aluminum alloy) of 25 mm × 70 mm × 0.9 mm, which corresponds to an outer panel, and a carbon fiber reinforced plastic plate (C-SMC) of 25 mm × 70 mm × 2, 0 mm, which corresponds to a Innenpaneel be prepared. The adhesives according to Examples 1 to 3 are prepared as adhesives for Reference Examples 1 to 3.

The thus prepared aluminum alloy plate is degreased by isopropyl alcohol (IPA), and the carbon fiber reinforced plastic plate is degreased by dry wiping. Then, these plates are dipped in rust preventive oil (a product of Sugimura Chemical Industrial Co., Ltd., PRETON 303PX2) and allowed to stand for 24 hours or more.

Each of the adhesives is applied to the aluminum alloy plate and the carbon fiber reinforced plastic plate after immersion to obtain an adhesive thickness of 0.25 mm and an adhesion area of 25 mm × 12.5 mm, and each of the adhesives is heated at 30 ° C (room temperature ) cured for 70 minutes. Then, a heating or heating process corresponding to the firing step is carried out at a heating temperature of 180 ° C for a heating temperature of 20 minutes.

In order to perform a three-dimensional measurement, in each test described above, test pieces or samples are prepared from the composite panels in which the aluminum alloy plate is bonded to the carbon fiber reinforced plastic plate by each of the adhesives of Reference Examples 1 to 3.

More specifically, a shear strength test ( JISK6850 ) under the condition of an elastic load rate of 5 mm / min, a jaw distance of 90 mm and a test temperature of 25 ° C, to measure a shear strength between the aluminum alloy plate and the carbon fiber reinforced plastic plate. The result thereof is shown in Table 2. Table 2 shows an average shear strength measured three times for each of Reference Examples 1 to 3.

In addition, a cross peel test is performed at an elastic load rate of 5 mm / min. At a test temperature of 25 ° C to measure the breaking strength between the aluminum alloy plate and the carbon fiber reinforced plastic plate. The result of this is shown in Table 2. Table 2 shows an average of the breaking strength measured three times for each of Reference Examples 1 to 3.

Further, breakage behavior of the aluminum alloy plate is observed in each of the tests. A result of this is shown in Table 2. Note that in Table 2, AF represents an interface error, CF represents an adhesion cohesion error, TCF represents a thin film adhesion cohesion failure, and corresponding values shown below each show a range of values. [Table 2] Shear Strength Test tensile Strength (MPa) Break behave Strength (N / 25 mm) Break behave Reference Example 1 13.6 AF 0% CF 95% TCF 5% 476 AF 0% CF 100% TCF 0% Reference Example 2 11.1 AF 0% CF 98% TCF 2% 446 AF 0% CF 100% TCF 5% Reference Example 3 7.1 AF 50% CF 50% TCF 5% 352 AF 95% CF 5% TCF 0%

<Result 2 and Consideration 2> It is clear from the result of Reference Examples 1 to 3 that when the adhesives of Reference Examples 1 and 2 are used, a fracture behavior of the adhesion cohesion failure is large, so that it is considered that the Aluminum alloy plate and carbon fiber reinforced plastic plate are in a particularly good adhesive state.

In the above, the embodiment of the present invention has been described, however, the present invention is not limited to the above embodiment, and various changes can be made without departing from the spirit of the present invention described in the claims.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been 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.

Cited patent literature

• JP 2007-118852 A [0003]

Cited non-patent literature

• JIS: 6000er [0045]
• JISK6850 [0056]

Claims (4)

Manufacturing method for a composite panel ( 1 characterized in that it comprises: connecting an outer panel ( 20 ), which consists of a metallic material, with an inner panel ( 30 ), which consists of a material having a coefficient of linear expansion, which differs from the coefficient of linear expansion of the metallic material, by applying an adhesive ( 40 ) on an outer edge ( 21 ) of the outer panel ( 20 ) or an outer edge ( 31 ) of the inner panel ( 30 ) and curing of the adhesive ( 40 ); Performing a plating coating on a surface ( 22 ) of the outer panel ( 20 ) of the composite panel ( 1 ), in which the outer panel ( 20 ) with the inner panel ( 30 ) connected is; and firing a coating film ( 50 ) caused by the electroplating coating on the surface ( 22 ) of the outer panel ( 20 ) was formed on the outer panel ( 20 ), the adhesive ( 40 ) is a room-temperature curing adhesive that does not flow at the time of firing. Manufacturing method for a composite panel ( 1 ) according to claim 1, wherein: the metallic material of the outer panel ( 20 ) is an aluminum alloy; and the material of the inner panel ( 30 ) is a fiber reinforced plastic. Manufacturing method for a composite panel ( 1 ) according to claim 1 or 2, wherein: at the time of joining, a folding process is carried out so that the adhesive ( 40 ) on the outer edge ( 21 ) of the outer panel ( 20 ) is applied, and the outer edge ( 21 ) of the outer panel ( 20 ) towards the outer edge ( 31 ) of the inner panel ( 30 ) is folded. Manufacturing method for a composite panel ( 1 ) according to any one of claims 1 to 3, wherein: the adhesive ( 40 ) is a two-component epoxy adhesive.

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