KR20210022991A - Different material joint body - Google Patents

Abstract

The present invention relates to a dissimilar material assembly in which plates formed of different materials are firmly bonded using mechanical bonding. The dissimilar material assembly comprises: a first plate formed of a first material; a second plate material formed of a second material different from the first material; a fixture inserted through at least a portion of the first plate and the second plate to mechanically couple the first plate and the second plate; and a molten adhesive layer formed to seal a joint failure or gap between the first plate and the second plate damaged by the fixture, when the fixture combines the first plate and the second plate.

Description

Different material joint body

The present invention relates to a heterogeneous material bonded body, and more particularly, to a heterogeneous material bonded body in which plate materials formed of different materials are firmly bonded using mechanical bonding.

In the automobile industry, in order to improve fuel economy due to environmental problems, weight reduction of the vehicle body is being promoted through the use of aluminum alloys and plastic materials. To this end, in the automotive industry, research on a bonding method that can replace the conventional spot welding for assembling a vehicle body is being made, and recently, a mechanical bonding method using a mechanical fastener such as rivets or screws has been widely used.

Among the mechanical coupling methods, the self-piercing rivet joint method, which is commonly used, is a conventional riveting method in which a rivet joint hole is formed in a joint object such as a steel plate, and a rivet is inserted into the hole, and the head is formed to join the joint object. Unlike this, it is a method of joining the object to be joined by plastically deforming the rivet by pressing the rivet into the object to be joined by hydraulic or pneumatic pressure without processing a hole. In such a self-piercing rivet bonding method, for example, a self-piercing rivet made of a head and a partially hollow cylindrical shank may be used to fasten an object to be joined between the upper and lower plates such as a metal sheet material. For example, in the self-piercing rivet, the shank penetrates the upper plate of the object to be joined by the punch of the setting tool, and it is spread outward by the anvil, and the shank is pressed into the lower plate while the head part supports the upper plate. The upper and lower plates can be joined.

Therefore, in the self-piercing rivet system, when the rivet is pressed through the punch while the object to be joined of the upper and lower plates is placed between the punch and the anvil, the rivet penetrates the upper plate and penetrates into the lower plate, and the tip of the rivet is placed between the punch and the anvil. The object to be joined is integrally joined as it expands and deforms in the radial direction along the forming bone of. As described above, the bonding technique using self-piercing rivets can be used for bonding between parts of dissimilar materials such as aluminum alloys or plastic materials, where spot welding is not easy.

However, such a conventional bonding material of different materials has a problem in that local damage occurs around the hole to be drilled in the process of drilling the bonding material by rivets or screws, and damage such as corrosion occurs at the damaged part. For example, in the case of combining different materials such as a carbon fiber composite material and a metal material, local damage of the carbon fiber composite material may occur around the hole drilled in the process of drilling the carbon fiber composite material by rivets or screws. It leads to galvanic corrosion between the screw and the carbon fiber, and there is a problem that may cause a decrease in the bonding strength and durability of the bonding site.

The present invention is to solve a number of problems including the above problems, and when combining different materials using a mechanical fastener, the damaged part that occurs in the process of drilling rivets or screws is sealed to suppress galvanic corrosion. It is an object of the present invention to provide a bonded body of different materials that can be used. However, these problems are exemplary, and the scope of the present invention is not limited thereby.

According to an embodiment of the present invention, a heterogeneous material conjugate is provided. The dissimilar material bonding body includes: a first plate formed of a first material; A second plate formed of a second material different from the first material; A fixture inserted through at least a portion of the first plate and the second plate to mechanically couple the first plate to the second plate; And a melt-adhesive layer formed to seal the joint breakage or gap between the first plate and the second plate damaged by the fixture when the fixture couples the first plate and the second plate. have.

According to an embodiment of the present invention, the fixture is self-piercing rivets so that when the first plate and the second plate are combined, the first plate and the second plate can be self-piercing. (SPR, Self piercing rivet) or flow drill screw (FDS, Flow drill screw), wherein the melt adhesive layer may be formed by melting and then solidifying a molten insert formed of a thermoplastic resin material.

According to an embodiment of the present invention, the molten insert may be formed in a washer shape, and may be inserted into the leg of the fixture so that it may be formed to be in contact with the lower surface of the head of the fixture.

According to an embodiment of the present invention, the molten insert is formed in a circular plate shape, and between the upper surface of the first plate or between the first plate and the second plate, the fixture is the first It may be formed at a position corresponding to the position where the plate and the second plate are drilled.

According to an embodiment of the present invention, the molten insert may be formed to surround at least a portion of the surface of the fixture so that it may be integrally formed with the fixture.

According to an embodiment of the present invention, the molten insert may be formed of the molten adhesive layer for sealing a joint breakage portion or a gap between the first plate material and the second plate material that are melted and damaged by the fixture, Only the head of the fixture and a peripheral portion thereof inserted through at least a portion of the first plate and the second plate may be heated to a predetermined temperature by a local heating device.

According to an embodiment of the present invention, the molten insert is formed of the thermoplastic resin material having a lower melting temperature than the first plate material formed of the first material, and the predetermined temperature is the melting of the first plate material. It is lower than the temperature, and may be a temperature higher than the melting temperature of the molten insert.

According to an embodiment of the present invention, the first plate may be formed of the first material of a non-metallic material, and the second plate may be formed of the second material of a metallic material.

According to an embodiment of the present invention, the first material is a fiber-reinforced plastic comprising any one of a carbon fiber reinforced plastic (CFRP) and a glass fiber reinforced plastic (GFRP) ( FRP: Fiber Reinforced Plastic) may be a composite material.

According to an embodiment of the present invention, the first plate may be formed of the first material of a metal material, and the second plate may be formed of the second material of a metal material different from the first material. .

According to an embodiment of the present invention, the molten insert may be a thermoplastic resin adhesive including any one of polyvinyl acetate resin, polyvinyl chloride, and polystyrene so that it can be solidified at room temperature and softened when heated.

According to an embodiment of the present invention, the fixture, when drilling the first plate and the second plate, to increase the occurrence of the joint breakage, the first plate and the second plate are perforated. At least one protrusion may be formed to protrude from the surface of the leg.

According to an embodiment of the present invention made as described above, when dissimilar materials are combined using a mechanical fastener, a damaged part generated in the process of drilling a fixture such as a rivet or a screw is sealed to prevent galvanic corrosion between dissimilar materials. Can be suppressed. Accordingly, by improving the corrosion resistance of the bonding portion of the dissimilar material, it is possible to implement a conveying material conjugate capable of improving the bonding strength and durability performance of the dissimilar material. Of course, the scope of the present invention is not limited by these effects.

1 to 4 are cross-sectional views showing step-by-step a bonding process of a dissimilar material assembly according to an embodiment of the present invention.
5 and 6 are cross-sectional views illustrating a combination of a dissimilar material assembly according to other embodiments of the present invention.
7 to 10 are cross-sectional views showing stepwise a bonding process of a dissimilar material assembly according to another embodiment of the present invention.
11 to 14 are cross-sectional views showing stepwise a bonding process of a dissimilar material assembly according to another embodiment of the present invention.

Hereinafter, various exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

The embodiments of the present invention are provided to more completely describe the present invention to those of ordinary skill in the art, and the following examples may be modified in various other forms, and the scope of the present invention is as follows. It is not limited to the examples. Rather, these embodiments are provided to make the present disclosure more faithful and complete, and to completely convey the spirit of the present invention to those skilled in the art. In addition, in the drawings, the thickness or size of each layer is exaggerated for convenience and clarity of description.

Hereinafter, embodiments of the present invention will be described with reference to the drawings schematically showing ideal embodiments of the present invention. In the drawings, for example, depending on manufacturing techniques and/or tolerances, variations of the illustrated shape can be expected. Therefore, the embodiments of the inventive concept should not be construed as being limited to the specific shape of the region shown in the present specification, but should include, for example, a change in shape caused by manufacturing.

1 to 4 are cross-sectional views showing step by step a bonding process of a dissimilar material conjugate according to an embodiment of the present invention, and FIGS. 5 and 6 are cross-sectional views illustrating a combination of a dissimilar material conjugate according to other embodiments of the present invention admit. 7 to 10 are cross-sectional views showing step by step a bonding process of a dissimilar material conjugate according to another embodiment of the present invention, and FIGS. 11 to 14 are a bonding process of a dissimilar material conjugate according to another embodiment of the present invention. These are cross-sectional views showing step by step.

First, as shown in FIG. 1, a fixture 20 is prepared so that the first plate material S1 formed of the first material and the second plate material S2 formed of a second material different from the first material can be combined. I can. More specifically, the fixture 20 is inserted so as to penetrate at least a portion of the first plate material S1 and the second plate material S2 to mechanically couple the first plate material S1 and the second plate material S2. It may be a self-piercing rivet (SPR). In addition, the fixture 20, like a flow drill screw (FDS, flow drill screw), the first plate (S1) and the second plate (S2) self-piercing (Self-piercing) a variety of mechanical fasteners that can be coupled. Can be used.

In addition, after combining the first plate (S1) and the second plate (S2) with the fixture 20, the joint breakage of the first plate (S1) and the second plate (S2) damaged by the fixture (20) or A molten insert 10 formed of a thermoplastic resin material may be prepared so as to form a melt adhesive layer 11 sealing the gap.

For example, as shown in Figure 1, the melt insert 10 is formed in the shape of a washer, the fixture 20 so that it can be formed to be in contact with the lower surface of the head 21 It can be inserted into the leg 22. The molten insert 10 may be a thermoplastic resin adhesive including any one of polyvinyl acetate resin, polyvinyl chloride, and polystyrene so that it can be solidified at room temperature and softened when heated.

Subsequently, as shown in FIG. 2, by riveting the fixture 20, the first plate material S1 made of a non-metal material and the second plate material S2 made of a metal material may be combined. At this time, the first plate (S1) is a fiber reinforced plastic (FRP: Fiber Reinforced Plastic) including any one of a carbon fiber reinforced plastic (CFRP: Carbon Fiber Reinforced Plastic) and a glass fiber reinforced plastic (GFRP: Glass Fiber Reinforced Plastic). ) It can be formed of a non-metallic material that is a composite material. Such plastic-based composite materials rely on excellent mechanical properties, corrosion resistance and excellent moldability of plastics, and are widely used as new structural materials and functional materials based on such excellent properties.

However, the material of the first plate material S1 is not necessarily limited thereto and may be formed of a metal material. In this case, the second plate material S2 may be formed of a metal material different from the first plate material S1.

As such, the first plate material S1 is formed of a non-metallic material or a first material that is a metal material different from the second plate material S2, and is formed of a second material different from the first plate material S1. Since (S2) and the direct coupling by welding cannot be made, it can be mechanically and firmly coupled to the second plate (S2) by using a separate fixture 20, as in the present invention.

Such, the fixture 20, a self-piercing rivet (SPR, Self-piercing rivet) formed of a leg portion 22 formed to be elongated from the head portion 21 and the head portion 21 may be used.

More specifically, as shown in FIG. 2, the leg portion 22 of the fixture 20 penetrates the first plate material S1 and the second plate material S2 by self-perforation, and is opened in a direction away from each other. I can lose. Therefore, as the fixture 20 is press-fitted using hydraulic or pneumatic pressure, the first plate material S1 and the second plate material S2 are directly inserted through the self-perforation, so that the first plate material S1 and the second plate material ( There is no need to pre-process the through hole into which the fixture 20 is to be inserted into the coupling portion of S2).

In addition, while the fastener 20 is plastically deformed in the process of penetrating the first plate (S1) and the second plate (S2) by self-perforation, for example, the leg portion 22 is separated from each other outward. The first plate material S1 and the second plate material S2 may be firmly fixed after being press-fitted while spreading in the direction.

As such, the fixture 20 is a heterogeneous welding process such as arc welding or spot welding, such as a first plate (S1) and a second plate (S2) formed of a first material and a second material that are different from each other. Used for bonding to materials, it is possible to firmly bond dissimilar materials in a mechanical way.

Subsequently, as shown in FIG. 3, the head 21 of the fixture 20 inserted through at least a portion of the riveted and coupled first plate S1 and the second plate S2, and a peripheral portion thereof However, the molten insert 10 can be melted by heating to a predetermined temperature by the local heating device 30.

For example, the local heating device 30 elaborately heats only the head 21 and the peripheral portion of the riveted fixture 20 using a laser beam R to provide a first plate material S1 or a second plate material. Only the molten insert 10 can be effectively melted without deformation of (S2). In addition, the local heating device 30 can locally heat only the head 21 and the surrounding area of the riveted fixture 20 without deforming the first plate material S1 or the second plate material S2. In addition to the above-described laser heating, various heating devices such as lamp heating may be used.

In this case, the molten insert 10 may be formed of a thermoplastic resin material having a lower melting temperature than the first plate material S1 formed of the first material. For example, the molten insert 10 is a thermoplastic resin adhesive containing any one of polyvinyl acetate resin, polyvinyl chloride and polystyrene so that it can be solidified at room temperature and softened when heated by the local heating device 30 In addition, a wide variety of materials capable of sealing joint breakage parts or gaps with a melting temperature lower than that of the first plate material S1 formed of the first material may be used.

Therefore, the local heating device 30 is lower than the melting temperature of the first plate material (S1), and at a predetermined temperature higher than the melting temperature of the molten insert (10), only the head 21 of the fixture 20 and the peripheral portion thereof By heating locally, the molten insert 10 can be melted without damaging the first plate S1.

In this way, when the molten adhesive 10 located between the head 21 of the fixture 20 and the first plate S1 is melted, as shown in FIG. 4, it is melted and the structure of the first plate S1 The melted insert 10 that has penetrated through the space may be solidified again at room temperature to form a melted adhesive layer 11. More specifically, the melt-adhesive layer 11 may be formed by infiltrating into a local damaged area such as a crack generated around the hole to be drilled in the process of drilling the first plate (S1) by the fixture 20. have. Accordingly, the damaged portion that occurs in the process of drilling the fixture 20 can be effectively sealed by the melt-adhesive layer 11.

At this time, a part of the melt-adhesive layer 11 penetrates into a local damage area generated around the hole drilled in the process of drilling the first plate material S1 by the fixture 20 and then hardens to seal the damaged area, Other parts are hardened as they are between the head 21 of the fixture 20 and the first plate S1, thereby improving the bonding force between the fixture 20 and the first plate S1.

In addition, so that the melt-adhesive layer 11 penetrates into the damaged portion of the first plate S1 and is rapidly cured, the head 21 of the riveted fixture 20 and its It may also be possible to shorten the process time by increasing the curing rate of the melt-adhesive layer 11 by locally cooling only the surrounding area.

In addition, the melted insert 10 of the dissimilar material bonded body of the present invention is damaged by the fastener 20 when the fastener 20 combines the first plate material S1 and the second plate material S2, in addition to the above-described shape. The first plate material S1 and the second plate material S2 may be formed in a wide variety of shapes so as to seal a joint break or gap between the first plate material S1 and the second plate material S2.

For example, as shown in FIG. 5, the molten insert 10 may be formed to surround at least a portion of the surface of the fixture 20 so that it may be integrally formed with the fixture 20. In this embodiment, the molten insert 10 is formed to surround only the surface of the head 21 of the fixture 20, but is not limited thereto, and a part of the surface of the head 21 of the fixture 20 It may be formed only or may be formed to surround at least a portion of the surface of the leg 22 of the fixture 20.

In this way, the molten insert 10 is not formed as a separate component, but is formed as a layer surrounding at least a portion of the surface of the fixture 20, so that the molten insert 10 and the fixture 20 are integrally formed. It can be formed as Accordingly, by reducing the process of inserting the molten insert 10 into the fixture 20 when combining different materials, the manufacturing process of the dissimilar material bonded body can be simplified and the ease of handling can be further increased.

In addition, as shown in Fig. 6, the molten insert 10 is formed in a circular plate shape, and on the upper surface of the first plate material S1, the fixture 20 is a first plate material S1 and It may be formed at a position corresponding to the position where the second plate material S2 is drilled.

In addition, as shown in FIG. 7, a molten insert 10 formed in a disk shape may be formed between the first plate material S1 and the second plate material S2. In this case, as shown in FIGS. 8 to 10, after the molten insert 10 melted by the local heating device 30 penetrates between the structures of the first plate material S1 and the second plate material S2, , It is solidified again at room temperature, and the melt adhesive layer 11 may be formed between the first plate material S1 and the second plate material S2.

More specifically, the melt-adhesive layer 11 is a local damage such as a crack generated around the hole drilled in the process of drilling the first plate material S1 and the second plate material S2 by the fixture 20 It can seep into the area and form. Therefore, the damaged portions of the first plate material S1 and the second plate material S2 generated during the drilling process of the fixture 20 are effectively sealed by the melt-adhesive layer 11, and the first plate material S1 and It is possible to further increase the bonding force of the second plate (S2).

In addition, as shown in FIG. 11, when the fixture 20 drills the first plate material S1 and the second plate material S2, the first plate material ( At least one protrusion 22a may be formed to protrude from the surface of the leg 22 of the fixture 20 for drilling S1 and the second plate S2.

For example, as shown in FIG. 12, when the protrusion 22a is formed on the surface of the leg portion 22 of the fixture 20, the fixture 20 drills the first plate material S1 and the second plate material S2. In the process, the joint breakage portion (C) may be caused to be larger.

Subsequently, as shown in FIGS. 13 and 14, when the head 21 and the surrounding portion of the riveted fixture 20 are heated using the local heating device 30, the molten insert 10 ) Penetrates between the tissues of the first plate material S1 and at the same time penetrates and fills the joint breakage portion C. Accordingly, of the melt-adhesive layer 11 formed by solidifying again at room temperature, the melt-adhesive layer 11a formed by penetrating into the joint breakage portion C and solidified acts like a root, and the first plate material S1 and the second plate material It may have the effect of making the bond of (S2) more solid.

Accordingly, a melted adhesive layer that penetrates the joint breakage portion C of the first plate material S1 and the second plate material S2 while the molten molten insert 10 solidifies again at room temperature to seal the bonding breakage portion C. After using the property formed as (11), the fixture 20 induces the first plate (S1) and the second plate (S2) to be enlarged and largely caused when the first plate (S1) and the second plate (S2) are drilled. , The melted insert 10 is melted to fill the joint breakage part C, so that the melted adhesive layer 11 serves as a root to further strengthen the bonding of the first plate material S1 and the second plate material S2. You can induce it.

Therefore, according to various embodiments of the present invention, according to the dissimilar material bonding body, when mechanically bonding dissimilar materials using the fixture 20, the dissimilar materials are sealed by sealing the damaged part occurring in the puncturing process of the fixture 20. The galvanic corrosion of the liver can be effectively suppressed. Accordingly, it is possible to improve the corrosion resistance of the bonding site of the dissimilar material, thereby improving the bonding strength and durability performance of the dissimilar material.

The present invention has been described with reference to the embodiments shown in the drawings, but these are merely exemplary, and those of ordinary skill in the art will appreciate that various modifications and equivalent other embodiments are possible therefrom. Therefore, the true technical protection scope of the present invention should be determined by the technical spirit of the appended claims.

10: molten insert
20: fixture
21: head
22: leg
30: local heating device
R: laser beam
S1: first plate
S2: second plate

Claims (12)

A first plate formed of a first material;
A second plate formed of a second material different from the first material;
A fixture that is inserted through at least a portion of the first plate and the second plate to mechanically couple the first plate to the second plate; And
A melt-adhesive layer formed so as to seal a joint break or gap between the first plate and the second plate damaged by the fixture when the fixture couples the first plate and the second plate;
Containing, heterogeneous material conjugate. The method of claim 1,
The fixture,
When combining the first plate and the second plate, self-piercing rivets (SPR) or flow drill screws (FDS) so that the first plate and the second plate can be self-piercing. , Flow drill screw), including any one of,
The melt adhesive layer,
A dissimilar material bonded body formed by melting and solidifying a molten insert formed of a thermoplastic resin material. The method of claim 2,
The molten insert,
Is formed in a washer (Washer) shape, and inserted into the leg portion of the fixture so as to be formed to be in contact with the lower surface of the head portion of the fixture, the heterogeneous material bonding body. The method of claim 2,
The molten insert,
It is formed in the shape of a circular plate, and at a position corresponding to a position in which the fastener punches the first plate and the second plate on the upper surface of the first plate or between the first plate and the second plate. Formed, heterogeneous material conjugate. The method of claim 2,
The molten insert,
To be formed integrally with the fastener, formed to surround at least a portion of the surface of the fastener, a heterogeneous material bonding body. The method according to any one of claims 3 to 5,
The molten insert,
Pass through at least a portion of the first plate material and the second plate material so that it can be melted and formed as the melt-adhesive layer sealing a joint break or gap between the first plate material and the second plate material damaged by the fixture. Only the head of the inserted fixture and the peripheral portion thereof are heated to a predetermined temperature by a local heating device. The method of claim 6,
The molten insert,
It is formed of the thermoplastic resin material having a lower melting temperature than the first plate formed of the first material,
The predetermined temperature is,
The dissimilar material bonded body, which is a temperature lower than the melting temperature of the first plate material and higher than the melting temperature of the molten insert. The method of claim 1,
The first plate is formed of the first material of a non-metallic material,
The second plate is formed of the second material of a metal material, a heterogeneous material bonding body. The method of claim 8,
The first material,
Fiber Reinforced Plastic (FRP) composite material including any one of Carbon Fiber Reinforced Plastic (CFRP) and Glass Fiber Reinforced Plastic (GFRP), a heterogeneous material bonding body. The method of claim 1,
The first plate is formed of the first material of a metal material,
The second plate is formed of the second material of a metal material different from the first material, a heterogeneous material assembly. The method of claim 2,
The molten insert,
It is a thermoplastic resin adhesive containing any one of polyvinyl acetate resin, polyvinyl chloride, and polystyrene, so that it can be softened when heated and solidified at room temperature. The method of claim 2,
The fixture,
At least one protrusion is formed so as to protrude from the surface of the leg for perforating the first plate and the second plate so as to increase the occurrence of the joint breakage when perforating the first plate and the second plate. , Heterogeneous material conjugate.

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