Manufacturing method of a sandwich panel and the sandwich panel

Abstract

The present invention relates to a method for manufacturing a sandwich panel for automobiles, comprising a plate etching step for etching the surface of a metal plate, a plate press step for forming a pattern of a specific shape on one side of the metal plate etched by the plate etching step, a step of stacking a pair of metal plates, and a step of injecting a plastic resin into the stacked pair of metal plates to perform injection molding. According to the present invention, the bonding performance of the panel can be improved, thereby improving the degree of freedom of shape resulting from press molding.

Description

Technology Field

[0001] The present invention relates to a method for manufacturing a sandwich panel for automobile parts and to the sandwich panel. Background Technology

[0002] There is a need for sandwich panels with excellent durability and various functions for application as automotive parts materials.

[0003] As shown in FIG. 1, a sandwich panel for conventional automotive parts is manufactured by using a bonding film (2) to induce bonding between a metal plate (1), such as steel or aluminum, and a resin (3).

[0004] Therefore, there are limitations to the forming of sandwich panels when applying such a general bonding film structure. Specifically, during press forming of complex shapes, the bonding film layer separates due to peeling or cracking of the bonding film, and there is a high risk of a gap forming between the resin and the metal.

[0005] Therefore, there are limitations to manufacturing for automotive parts due to the limitations of design freedom.

[0006] As such, conventional bonding methods resulted in weak bonding strength between the plates, making bonding impossible after pattern forming and posing a high risk of leakage.

[0007] Furthermore, welding-based joining methods were not suitable for automotive parts because they involve excessive labor and have limitations in the forming area.

[0008] While sandwich panels can be applied in various ways in the field of construction materials, their introduction is limited in the production of parts requiring complex press-forming shapes, such as automotive components, due to interfacial delamination.

[0009] However, if the bonding characteristics of automotive parts can be continuously maintained, applying sandwich panels to simple parts such as roofs, hoods, electronic device boxes for eco-friendly vehicles, and battery cases, as well as to channels formed by air layers or flow paths for improving thermal insulation and NVH (Noise, Vibration and Harshness), has many advantages for automobile manufacturing.

[0010] The matters described in the background technology above are intended to aid in understanding the background of the invention and may include matters that are not prior art already known to those skilled in the art to which this technology belongs. Prior art literature

[0011] Korean Registered Patent Publication No. 10-1262264 The problem to be solved

[0012] The present invention has been devised to solve the aforementioned problems, and the purpose of the present invention is to provide a method for manufacturing an automotive sandwich panel and the sandwich panel said, which can improve the bonding performance of the panel and thereby improve the degree of shape freedom resulting from press forming. means of solving the problem

[0013] A method for manufacturing a sandwich panel for an automobile according to one aspect of the present invention comprises: a plate etching step for etching the surface of a metal plate; a plate pressing step for forming a pattern of a specific shape on one side of the metal plate etched by the plate etching step; a step of stacking a pair of the metal plates; and a step of injection molding by injecting a plastic resin into the stacked pair of metal plates.

[0014] Here, the plate etching step is characterized by immersing the metal plate in an etching solution to perform etching treatment.

[0015] As a result, the metal plate is characterized by having an undercut formed on its surface by the above plate etching step.

[0016] In addition, a void portion having a pattern shape formed by the plate pressing step is formed inside a stacked pair of metal plates, and the injection molding step is characterized by injecting the plastic resin into the void portion.

[0017] In addition, the pattern shape formed on the pair of metal plates is characterized by being identical.

[0018] A sandwich panel for automobiles according to another aspect of the present invention is characterized in that a resin bonding layer is laminated and formed between a pair of metal plates having etched surfaces, and the resin bonding layer is directly bonded to the pair of metal plates.

[0019] In addition, the surface of the metal plate that is bonded to the resin bonding layer is characterized by having an undercut formed therein.

[0020] Next, a sandwich panel for automobiles according to another aspect of the present invention is characterized in that a plurality of voids are formed inside a pair of laminated metal plates with surfaces etched, and at least one of the plurality of voids is filled with plastic resin.

[0021] In addition, the plurality of the above-mentioned cavities are characterized by being spaced apart from each other and formed parallel to one another.

[0022] Here, at least one of the plurality of the above-mentioned cavities is characterized by being in a hollow state.

[0023] Alternatively, the two ends of the hollow cavity are connected to the outside.

[0024] In addition, the plurality of the above-mentioned cavities are formed spaced apart from each other and parallel, and are characterized by being formed by alternating a resin bonding layer filled with the plastic resin and a hollow air layer.

[0025] Furthermore, the plastic resin is filled into the wall surface of the hollow air layer in a manner that surrounds the air layer.

[0026] Next, according to another aspect of the present invention, a sandwich panel for automobiles is characterized in that a void is formed inside a pair of stacked metal plates with surfaces etched, and both ends of the void are connected to the outside.

[0027] In addition, the wall surface of the said cavity is characterized by being filled with the said plastic resin in a manner that surrounds the said cavity. Effects of the invention

[0028] The sandwich panel manufactured by the method of manufacturing a sandwich panel according to the present invention has a bonding strength of 50 to 100% compared to a sandwich panel manufactured by a general bonding film. That is, it exhibits a shear strength of 35 MPa or more.

[0029] In addition, since the bonding is performed using an anchor type, which is a mechanical bond between the resin itself and the metal interface without applying a bonding film, the degree of molding freedom is increased, thereby strengthening the peel strength of the bonding area.

[0030] Therefore, instead of non-formed panels for conventional construction materials, it becomes possible to manufacture automotive parts such as roofs and hoods with increased freedom of forming.

[0031] In the case of blank-type sandwich panels, since it is possible to manufacture panels capable of forming specific patterns, it is possible to produce lightweight panels and panels with specific functionalities.

[0032] Therefore, it can be used as a sandwich plate for rigidity reinforcement, a sandwich plate for NVH optimization, or a cooling system component with a cooling channel formed therein.

[0033] In addition, it can be applied to automotive electronic / electrical components and battery cases, for which demand is increasing, and enables vehicle NVH improvement, fuel efficiency improvement due to thermal insulation when applied to the roof, and vehicle weight reduction through the use of rigidity-reinforcing materials. Brief explanation of the drawing

[0034] Figure 1 schematically illustrates the configuration of a conventional sandwich panel. FIGS. 2 to 4 sequentially illustrate the manufacturing process of the sandwich panel of the present invention. FIG. 5a illustrates the planar shape of a sandwich panel according to the first embodiment of the present invention, and FIG. 5b illustrates the side cross-sectional shape of FIG. 5a. FIG. 6a illustrates the flat cross-sectional shape of a sandwich panel according to a second embodiment of the present invention, and FIG. 6b illustrates the cross-sectional shape when cutting along X1-Y1 of FIG. 6a. FIG. 7a illustrates the flat cross-sectional shape of a sandwich panel according to a third embodiment of the present invention, and FIG. 7b illustrates the cross-sectional shape of FIG. 7a when cut along X2-Y2. FIG. 8a illustrates the flat cross-sectional shape of a sandwich panel according to the fourth embodiment of the present invention, and FIG. 8b illustrates the cross-sectional shape when cutting at X3-Y3 of FIG. 8a. FIG. 9a illustrates the flat cross-sectional shape of a sandwich panel according to the fifth embodiment of the present invention, and FIG. 9b and FIG. 9c illustrate the cross-sectional shape when cutting along X4-Y4 of FIG. 9a. Specific details for implementing the invention

[0035] In order to fully understand the present invention, the operational advantages of the present invention, and the objectives achieved by the implementation of the present invention, reference must be made to the accompanying drawings illustrating preferred embodiments of the present invention and the contents described therein.

[0036] In describing preferred embodiments of the present invention, known technologies or repetitive descriptions that may unnecessarily obscure the essence of the invention will be shortened or omitted.

[0037] FIGS. 2 to 4 sequentially illustrate the manufacturing process of a sandwich panel of the present invention. Hereinafter, a method for manufacturing a sandwich panel for an automobile and a sandwich panel according to an embodiment of the present invention will be described with reference to FIGS. 2 to 4.

[0038] The present invention relates to a method for manufacturing a sandwich panel that exhibits durability suitable for automotive parts by enabling direct bonding between a sheet metal and a resin without the interposition of a bonding film or the like.

[0039] The present invention is for manufacturing a sandwich panel by imparting an undercut or protrusion shape to the resin bonding surface of a metal plate.

[0040] Undercuts can be created by utilizing differences in the degree of corrosion of fine elements within the metal. However, existing metal surface treatment methods such as shot blasting and lasers have limitations in forming undercuts, and the bonding strength during injection bonding is not higher than that of the existing bonding fusion method.

[0041] The present invention undergoes a plate etching step to form an undercut on the surface of a metal plate.

[0042] That is, as shown in FIG. 2, the metal plate (11) is immersed in an etching tank (32) in a continuous roll process by a roll forming device (31) so that an undercut (u) can be formed on the surface of the metal plate (11) by etching.

[0043] Next, a pattern is formed on the etched surface of a metal plate blank (12) as shown in FIG. 3. The pattern formed is intended to form a void, which will be described later, and a specific shape of an intaglio pattern is formed on the etched surface of a pair of metal plates through a plate press step, and the shape of the pattern formed on the pair of metal plates may be the same.

[0044] So, as shown in Fig. 4, a sandwich panel (10) is manufactured by stacking a pair of metal plates so that their pattern surfaces face each other, thereby forming a cavity (20) according to the pattern, and then injecting a plastic resin (30) through an injection port (13) formed in the stacked sandwich panel (10).

[0045] The sandwich panel (10) according to the first embodiment of the present invention is manufactured in this manner, so that a plastic resin is interposed between metal plates made of steel or aluminum as shown in FIG. 5a and FIG. 5b, and it is possible to manufacture it by maintaining a strong bonding force between the metal plates and the resin without a bonding film due to the undercut shape formed on the metal plates.

[0046] The sandwich panel (10) according to the first embodiment of the present invention is characterized by strong bonding properties, in which a plastic resin is filled entirely between metal plates to form a resin bonding layer (21), and in addition to the entire resin bonding layer, various types of cavities can be formed by a plate pressing step.

[0047] The sandwich panel according to the first embodiment of the present invention has excellent bonding strength, making it easy to apply to vehicle bodies or body parts.

[0048] In the following, sandwich panels according to various embodiments implemented with various types of cavities will be described.

[0049] FIG. 6a illustrates the flat cross-sectional shape of a sandwich panel according to a second embodiment of the present invention, and FIG. 6b illustrates the cross-sectional shape when cutting along X1-Y1 of FIG. 6A.

[0050] The sandwich panel (10) according to the second embodiment is characterized by having a cavity formed in a diagonal direction on a planar surface as shown in the illustration, and a resin bonding layer (21) is formed between metal plates by filling the cavity with plastic resin.

[0051] It does not necessarily have to be in a diagonal direction, and multiple cavities are formed spaced apart, like in a city.

[0052] These sandwich panels enable greater rigidity reinforcement, allow bonding strength to be controlled by the panel shape, and the manufactured sandwich panels exhibit improved rigidity compared to the first embodiment (differentiated by pattern type; generally, strength improves by more than 30% when using a unidirectional pattern).

[0053] FIG. 7a illustrates the flat cross-sectional shape of a sandwich panel according to a third embodiment of the present invention, and FIG. 7b illustrates the cross-sectional shape of FIG. 7A when cut along X2-Y2.

[0054] The sandwich panel (10) according to the third embodiment is identical to the second embodiment in that a cavity is formed in a diagonal direction on a planar surface as shown in the illustration.

[0055] However, the multiple spaced-apart cavities are not all resin-filled resin bonding layers (21), and some are formed as empty hollow air layers (22) that are not filled with resin.

[0056] This can further improve NVH and thermal insulation properties compared to the previous embodiments, and the resin bonding layer (21) and the air layer (22) can be formed alternately.

[0057] In other words, the air layer is the largest insulating material on Earth, and by creating a separate air layer to maximize insulation performance, it is possible to improve NVH through rigidity reinforcement.

[0058] Therefore, improving the thermal insulation performance of the roof and headliner results in improved fuel efficiency and enables weight reduction. Additionally, the rigidity of the doors and hood inner panels can be reinforced.

[0059] FIG. 8a illustrates the flat cross-sectional shape of a sandwich panel according to the fourth embodiment of the present invention, and FIG. 8b illustrates the cross-sectional shape when cutting at X3-Y3 of FIG. 8A.

[0060] The sandwich panel (10) according to the fourth embodiment is characterized by having a plurality of cavities of a certain shape formed between the plates as shown in the illustration, and the cavities are formed as empty air layers (22), and a resin bonding layer (21) is formed on the wall surface of the air layer (22) so as to surround the air layer (22).

[0061] These sandwich panels have strong thermal insulation properties.

[0062] In other words, as a case where the air layer is controlled to occupy the maximum possible volume, the air layer can be isolated after blank forming by creating a structure with a hexagonal embossed type that provides a significant rigidity effect, thereby making the thermal insulation performance even better.

[0063] Finally, FIG. 9a illustrates the planar cross-sectional shape of a sandwich panel according to the fifth embodiment of the present invention, and FIG. 9b and FIG. 9c illustrate the cross-sectional shape of FIG. 9A when cut along X4-Y4.

[0064] The sandwich panel (10) according to the fifth embodiment is formed such that the cavity is formed by folding the panel several times as shown in the illustration, and is evenly distributed across the entire area between the panels, and in particular, both ends of the cavity are formed to be open, that is, connected to the outside.

[0065] Therefore, the cavity of the fifth embodiment can form a cooling water channel (23) to allow cooling water to circulate between the plates.

[0066] A configuration such as that of FIG. 9a, that is, a second or third embodiment, may be formed such that a resin bonding layer (21) is formed in some of the cavities and a cooling water channel (23) is formed in some of the cavities. Such a configuration does not correspond to the cross-sectional shape of FIG. 9a, and can be implemented by forming the cooling water channel (23) so that both ends are connected to the outside, and the resin bonding layer (21) is formed separately from the cooling water channel (23).

[0067] Alternatively, a configuration such as Fig. 9b, i.e., as in the fourth embodiment, may be formed as a cooling water channel (23), and a resin bonding layer (21) may be formed on the wall surface of the cooling water channel (23).

[0068] Currently, to implement a cooling system, structures have been manufactured by inserting a separate pipe or preventing leakage through welding. However, in the case of the fifth embodiment of the present invention, by joining both sides of a blank formed by the cooling system through plastic injection, the structure is simple, it can be manufactured as a single integrated unit, and the degree of design freedom is increased.

[0069] As described above, the present invention enables the manufacture of a sandwich panel in which various cavities can be formed between plates by improving bonding properties through the treatment of the plate surface, thereby allowing for free pattern formation.

[0070] Although the present invention has been described above with reference to the illustrated drawings, it is obvious to those skilled in the art that it is not limited to the described embodiments and can be modified and varied in various ways without departing from the spirit and scope of the invention. Accordingly, such modifications or variations should be deemed to fall within the scope of the claims of the present invention, and the scope of rights of the present invention should be interpreted based on the appended claims. Explanation of the symbols

[0071] 10 : Sandwich panel 11: Metal sheet 12: Blank 13: Inlet 20 : Community 21: Resin bonding layer 22 : Air layer 23: Cooling waterway 30: Suzy

Claims

Claim 1 A method for manufacturing a sandwich panel for an automobile, comprising: a plate etching step for etching the surface of a metal plate; a plate pressing step for forming a pattern of a specific shape on one side of the metal plate etched by the plate etching step; a step of stacking a pair of metal plates; and a step of injection molding by injecting a plastic resin into the interior of the stacked pair of metal plates, wherein a void portion having the shape of a pattern formed by the plate pressing step is formed inside the stacked pair of metal plates, and the injection molding step is characterized by injecting the plastic resin into the void portion. Claim 2 A method for manufacturing a sandwich panel for an automobile according to claim 1, wherein the plate etching step is characterized by immersing the metal plate in an etching solution to perform etching treatment. Claim 3 A method for manufacturing a sandwich panel for an automobile according to claim 2, characterized in that an undercut is formed on the surface of the metal plate by the plate etching step. Claim 4 delete Claim 5 A method for manufacturing a sandwich panel for an automobile, wherein, in claim 1, the pattern shape formed on a pair of metal plates is identical. Claim 6 delete Claim 7 delete Claim 8 A sandwich panel for an automobile, characterized in that a plurality of voids are formed inside a pair of laminated metal plates with etched surfaces, and at least one of the plurality of voids is filled with plastic resin. Claim 9 A sandwich panel for an automobile according to claim 8, characterized in that a plurality of the cavities are spaced apart from each other and formed parallel to one another. Claim 10 A sandwich panel for an automobile according to claim 8, characterized in that at least one of the plurality of cavities is in a hollow state. Claim 11 A sandwich panel for an automobile according to claim 10, characterized in that both ends of the hollow cavity are connected to the outside. Claim 12 A sandwich panel for an automobile according to claim 10, characterized in that a plurality of the cavities are spaced apart from each other and formed parallel to each other, and the resin bonding layer filled with the plastic resin and the hollow air layer are formed alternately. Claim 13 A sandwich panel for an automobile according to claim 10, characterized in that the plastic resin is filled in a manner surrounding the air layer on the wall surface of the hollow air layer. Claim 14 A sandwich panel for an automobile, characterized in that a void is formed inside a pair of stacked metal plates with etched surfaces, and both ends of the void are connected to the outside. Claim 15 A sandwich panel for an automobile according to claim 14, characterized in that a plastic resin is filled into the wall surface of the cavity in a manner that surrounds the cavity.

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