KR20160117665A - Method for fabricating metal-plastic combination using electric discharge machining - Google Patents

Method for fabricating metal-plastic combination using electric discharge machining Download PDF

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Publication number
KR20160117665A
KR20160117665A KR1020150044041A KR20150044041A KR20160117665A KR 20160117665 A KR20160117665 A KR 20160117665A KR 1020150044041 A KR1020150044041 A KR 1020150044041A KR 20150044041 A KR20150044041 A KR 20150044041A KR 20160117665 A KR20160117665 A KR 20160117665A
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South Korea
Prior art keywords
metal member
plastic
metal
fine grooves
primer
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Application number
KR1020150044041A
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Korean (ko)
Inventor
김학권
강선영
김민기
박순
윤병휘
김종선
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재영솔루텍 주식회사
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Priority to KR1020150044041A priority Critical patent/KR20160117665A/en
Publication of KR20160117665A publication Critical patent/KR20160117665A/en

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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C45/00—Injection moulding, i.e. forcing the required volume of moulding material through a nozzle into a closed mould; Apparatus therefor
    • B29C45/14—Injection moulding, i.e. forcing the required volume of moulding material through a nozzle into a closed mould; Apparatus therefor incorporating preformed parts or layers, e.g. injection moulding around inserts or for coating articles
    • B29C45/14467—Joining articles or parts of a single article
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23H—WORKING OF METAL BY THE ACTION OF A HIGH CONCENTRATION OF ELECTRIC CURRENT ON A WORKPIECE USING AN ELECTRODE WHICH TAKES THE PLACE OF A TOOL; SUCH WORKING COMBINED WITH OTHER FORMS OF WORKING OF METAL
    • B23H9/00—Machining specially adapted for treating particular metal objects or for obtaining special effects or results on metal objects
    • B23H9/008—Surface roughening or texturing

Abstract

Disclosed is a method of manufacturing a metal-plastic bonded body in which a bonding force between a metal and a plastic is enhanced by applying electro discharge machining to the surface of a metal. The disclosed method of manufacturing a metal-plastic bonded body includes a discharge machining step of forming a plurality of fine grooves having a depth deeper than an inner diameter on a surface of a metal member by electro discharge machining the surface of the metal member, And a plastic bonding step of forming a plastic member integrally bonded to the surface of the member.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a method of manufacturing a metal-

TECHNICAL FIELD The present invention relates to a method of manufacturing a metal-plastic joined body in which a metal and a plastic member are rigidly bonded to each other using electric discharge machining.

A metal-plastic combination body in which a metal member and a plastic member are firmly joined together is used in many fields of industry. For example, these metal-plastic assemblies are also used in parts of aircraft or housings of secondary batteries. The metal-plastic combined body is mainly manufactured by a method of bonding a metal member and a plastic member with an adhesive, and a method of molding a plastic member bonded to a metal member by performing insert molding while inserting the metal member into the metal mold .

The surface treatment process of the metal member is carried out in order to enhance the bonding force between the metal member and the plastic member regardless of the method of joining with the adhesive or the insert injection method and the surface treatment process of the metal member is easy, , Efforts are being made to improve the bonding strength so as to have a strengthening effect.

Korean Patent Registration No. 10-0922281

The present invention provides a method of manufacturing a metal-plastic bonded body in which a bonding force between a metal and a plastic is enhanced by applying electro discharge machining to the surface of a metal.

Further, according to the present invention, the surface of the portion of the metal to be bonded to the plastic is processed by electrical discharge machining, so that the metal surface treatment can be performed easily, quickly, and at a reduced cost, And a method for producing the metal-plastic combination which is not induced.

According to the present invention, there is provided an electric discharge machining method comprising: a discharge machining step of electro-discharging a surface of a metal member to form a plurality of fine grooves having a depth deeper than an inner diameter on the surface; And a plastic bonding step of forming a plastic member bonded to the metal-plastic bonding member.

The plastic bonding step may include an insert molding step of disposing the metal member having the plurality of fine grooves formed therein in the mold, injecting and curing the melted liquid resin, and molding the plastic member bonded to the metal member .

The plastic bonding step may include a primer applying step of applying a liquid primer for increasing the bonding force between the metal and the plastic on the surface of the metal member on which the plurality of fine grooves are formed before the insert injection step, And a primer curing step of curing the liquid primer to form a primer layer.

The primer may be formed by mixing a urethane resin and an epoxy resin.

The liquid resin may be selected from the group consisting of polypropylene (PP), polyphenylene sulfide (PPS), polyamide, polycarbonate (PC), acrylonitrile butadiene styrene (ABS) , Polybutylene terephthalate (PBT), and the like.

The plastic bonding step may include an adhesive applying step of applying an adhesive to the surface of the metal member having the plurality of fine grooves formed thereon and a step of attaching the plastic member to the surface of the metal member coated with the adhesive and curing the adhesive, And an adhesive curing step of forming an adhesive layer connecting the member and the plastic member.

The step of discharging comprises the steps of immersing the metal member in the insulating liquid, disposing the working electrode in the insulating liquid so as to face the surface of the metal member, and disposing the working electrode on the negative (-) and negative And connecting the metal member to the positive electrode of the power source to cause a discharge between the metal member and the working electrode.

The machining electrode can move parallel to the surface of the metal member so that fine grooves are sequentially formed at a plurality of points on the surface of the metal member.

The metal member may include iron (Fe) as a material.

The inner diameter of the plurality of fine grooves may be 50 to 800 탆, and the plurality of fine grooves may be continuous.

According to the present invention, electrical discharge machining is applied to a metal surface to form a large number of fine grooves having narrow and deep surface roughness. The portion filled and filled in the fine grooves serves as a hook for preventing the separation of the plastic member and the metal member, so that the bonding force between the plastic member and the metal member is enhanced.

In addition, it is possible to reduce the working time of the fine grooves by making the machining electrode wider in correspondence with the surface area of the metal member and to perform the surface machining, to facilitate the machining, to form the fine grooves along the specific pattern on the surface of the metal member easy. In addition, there is no emission of environmental pollutants as compared with the case where fine grooves are formed by etching.

1 is a block diagram illustrating a method of manufacturing a metal-plastic bonded body according to a first embodiment of the present invention.
FIGS. 2 to 4 sequentially illustrate the method of manufacturing the metal-plastic bonded body of FIG.
5 is a block diagram illustrating a method of fabricating a metal-plastic bonded body according to a second embodiment of the present invention.
6 is a cross-sectional view illustrating an example of a metal-plastic bonding body manufactured by the method of manufacturing a metal-plastic bonding body according to a second embodiment of the present invention.

Hereinafter, a method of manufacturing a metal-plastic bonded body according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings. The terminology used herein is a term used to properly express the preferred embodiment of the present invention, which may vary depending on the intention of the user or operator or the custom of the field to which the present invention belongs. Therefore, the definitions of these terms should be based on the contents throughout this specification.

FIG. 1 is a block diagram showing a method of manufacturing a metal-plastic bonded body according to a first embodiment of the present invention, and FIGS. 2 to 4 sequentially show a method of manufacturing the metal-plastic bonded body of FIG. Referring to FIG. 1, the metal-plastic bonded body manufacturing method according to the first embodiment of the present invention includes a metal surface cleaning step S11, an electrical discharge machining step S12, a primer applying step S13, a primer hardening step S14 , And an insert molding step S15. Here, the metal member may be a metal member containing iron (Fe) as a main material such as steel, carbon steel, and stainless steel.

The metal surface cleaning step S11 is a step of removing impurities on the surface of the metal member prior to the electrical discharge machining step S12, for example, a degreasing step. In the degreasing step, a degreasing solution is applied to the surface of the metal member to remove oil on the surface of the metal member. For example, a method in which the metal member is immersed so as to be completely immersed in the degreasing solution and then taken out is applicable. A degreasing liquid can be prepared by mixing the degreasing agent and water in an appropriate ratio. The metal member taken out of the degreasing liquid is washed with water. Through the degreasing step, the surface coating of the metal member and the oil component are removed.

1 and 2, the electric discharge machining step S12 is a step of electrodischarge machining the surface of the metal member 11 to deposit the metal member 11 on the surface of the metal member 11 at a depth (DE) Is a step of forming a large number of fine grooves 14. The electric discharge machining is a process of machining the surface of the metal member 11 by causing a discharge between the machining electrode 35 and the workpiece, that is, the metal member 11. The machining is carried out by high frequency discharge of the machining electrode 35 charged with negative , And the surface of the metal member (11) facing the machining electrode (35) is eroded and removed.

The electrical discharge machining step S12 includes the steps of immersing the metal member 11 in the insulating liquid 34 filled in the water tank 33 and immersing the working electrode 35 having the flat bottom surface in the insulating liquid 34, Placing the machining electrode 35 in contact with the negative electrode (-) of the power source 31 and connecting the metal member 11 to the positive electrode (-) of the power source 31 +) So as to cause a discharge between the metal member 11 and the machining electrode 35. The insulating liquid 34 may be, for example, oil such as kerosene.

The magnitude of the impact applied to the surface of the metal member 11 due to discharge when a discharge occurs between the flat bottom surface of the machining electrode 35 and the surface of the metal member 11 is small at each point on the surface of the metal member 11 A large number of weak points are relatively weak on the surface of the metal member 11 and a large number of fine grooves 14 having a narrow inner diameter HD and a deep DE are formed continuously on the surface of the metal member 11 do. The inner diameter (HD) of the plurality of fine grooves (14) is 50 to 800 탆 and the depth (DE) of the fine grooves (14) is larger than the inner diameter (HD). Further, due to the impact of discharge, the inner side surface 15 of the fine groove 14 is not smooth and rough. That is, the surface roughness is large.

The machining electrode 35 is finely movable up and down and horizontally by a servo control feed mechanism 39. The distance between the machining electrode 35 and the surface of the metal member 11 can be adjusted by moving in the vertical direction. The working electrode 35 can move to another point on the surface of the metal member 11 while keeping the distance from the surface of the metal member 11 as the work electrode 35 moves in the horizontal direction. The processing electrode 35 is displaced to the surface of the metal member 11 to cause discharge and the process of moving the machining electrode 35 in the horizontal direction and causing the discharge again is repeatedly carried out, The fine grooves 14 can be sequentially formed at a plurality of points on the substrate. The fine grooves 14 are formed on the entire surface of the metal member 11 even if the total moving distance of the machining electrode 35 is reduced as the area of the lower surface of the machining electrode 35 facing the surface of the metal member 11 is larger So that the machining time can be reduced. When the machining electrode 35 moves parallel to the surface of the metal member 11 while discharging it on the surface of the metal member 11, a specific pattern in which a plurality of fine grooves 14 are gathered on the surface of the metal member 11 in accordance with the movement locus .

The primer coating step S13, the primer hardening step S14 and the insert injection step S15 are the same as in the first embodiment except that the plastic member 19 integrally joined to the surface of the metal member 11 on which the plurality of fine grooves 14 are formed 4) of a plastic bonding step. Referring to FIGS. 1 and 3 together, the primer application step S13 is a step of applying a liquid primer (or a primer) for increasing the bonding force between the metal and the plastic on the surface of the metal member 11 having a plurality of fine grooves 14 formed by electrical discharge machining primer. In addition, a paint or an adhesive may be used after applying a small amount of an adhesion initiation initiator to an object so that different kinds of objects can be easily and firmly adhered to each other when the paints are applied to an object or other kinds of objects are adhered to each other. The adhesive reaction initiator used in a small amount is referred to as a primer or a pretreatment agent.

The primer applied to the surface of the metal member 11 is formed by mixing a urethane resin and an epoxy resin. The urethane-based resin and the epoxy-based resin have excellent adhesion to metals and excellent heat resistance, thereby enhancing the heat resistance of the primer.

The primer can be applied to the surface of the metal member 11 by a method such as dipping, spraying, painting, silk screen printing, for example. Through the primer applying step S13, a plurality of fine grooves 14 are filled with the primer.

The primer curing step (S14) is a step of curing the liquid primer applied to the surface of the metal member (11) to form the primer layer (18). If the primer is not cured, the liquid primer may flow into the mold when the metal member 11 is placed in the mold in the insert injection step S15, so that the mold may be contaminated. Therefore, in the primer curing step (S14), there is no need to completely harden the primer, and so-called semi-curing is sufficient to harden the surface of the metal member 11 so as not to flow down.

As a method of curing the primer, thermal curing for heating the metal member 11 or UV curing for irradiating the metal member 11 with ultraviolet ray may be applied. When the primer is irradiated with ultraviolet light, the UV curing is applied when a curing UV resin is included. The thickness PT of the primer layer 18 formed by the primer curing step S14 is 5 to 20 占 퐉. If the thickness (PT) of the primer layer 18 is too thin, the effect of strengthening the adhesion between the metal and the plastic may not be exhibited. Conversely, if the thickness (PT) of the primer layer 18 is too thick, the manufacturing cost of the metal-plastic bonded body becomes large.

1 and 4 together, the insert injection step S15 is a step in which a plurality of fine grooves 14 are formed, a metal member 11 having a primer layer 18 formed thereon is placed in a mold, And injecting and curing the resin in the form of a liquid, thereby molding the plastic member 19 bonded to the metal member 11. The metal-plastic joint injection mold has a lower core 42 and an upper core 45 which are in close contact with or spaced from each other. The metal member 11 having the primer layer 18 formed thereon is interposed at the interface between the lower core 42 and the upper core 45. When the lower core 42 and the upper core 45 are in close contact with each other, A cavity 48 for forming a member 19 is formed.

When the molten liquid resin is injected into the mold through a sprue bush (not shown) in a state where the lower core 42 and the upper core 45 are in close contact with each other, the surface of the metal member 11 on which the primer layer 18 is formed is filled. When the liquid resin at the high temperature contacts the primer layer 18, the primer layer 18 is melted again and mixed with the liquid resin. Therefore, when the liquid resin is cured to form the plastic member 19, The bonding force of the portion to which the plastic member 19 is bonded is strengthened.

The molten primer mixes the liquid resin so that the liquid resin fills the fine grooves 14 and hardens so that the mating surfaces of the metal member 11 and the plastic member 19 are fastened to each other like a hook, 11 and the joining face of the plastic member 19 is increased, the joining force between the metal member 11 and the plastic member 19 becomes stronger.

When the liquid resin is hardened and the plastic member 19 is formed, the upper core 45 and the lower core 42 are separated and the integrally formed metal-plastic joined body is taken out from the mold.

The liquid resin to be injected and injected into the cavity 48 in the insert injection step S15 may be selected from the group consisting of polypropylene (PP), polyphenylene sulfide (PPS), polyamide, polycarbonate polycarbonate, acrylonitrile butadiene styrene (ABS), or polybutylene terephthalate (PBT). Alternatively, it may be a resin obtained by mixing a plurality of kinds of synthetic resins selected from the above-mentioned synthetic resins.

The primer coating step S13 and the primer curing step S14 may be omitted since they are not essential steps prior to the insert injection step S15 and the method of manufacturing a metal- Only the insert injection step may be provided.

FIG. 5 is a block diagram illustrating a method of manufacturing a metal-plastic bonded body according to a second embodiment of the present invention. FIG. 6 is a cross- Sectional view showing an example of a joined body. 5 and 6, a method of manufacturing a metal-plastic bonded body according to a second embodiment of the present invention includes a metal surface cleaning step S21, an electrical discharge machining step S22, an adhesive applying step S23, And a curing step S24.

The metal surface cleaning step S21 is a step of removing impurities on the surface of the metal member 31 prior to the electrical discharge machining step S22 and the electrical discharge machining step S22 is a step of discharging the surface of the metal member 21, (24) on the surface of the substrate (21). Since the metal surface cleaning step S21 and the discharge machining step S22 are the same as the metal surface cleaning step S11 and the discharge machining step S12 described in the first embodiment of the present invention, It is omitted.

The adhesive application step S23 and the adhesive curing step S24 are the same as the other examples of the plastic bonding step of forming the plastic member 29 integrally bonded to the surface of the metal member 21 on which the fine grooves 24 are formed to be.

The adhesive application step S23 is a step of applying an adhesive to the surface of the metal member 21 on which a plurality of fine grooves 24 are formed by electrical discharge machining. The applied adhesive fills the plurality of fine grooves 24. The adhesive curing step S24 is a step of adhering the plastic member 29 to the surface of the metal member 21 to which the adhesive is applied and curing the adhesive to form an adhesive layer 28 for connecting the metal member 21 and the plastic member 29 ). Depending on the kind of adhesive, the adhesive curing method may be thermosetting or UV curing. UV curing is applied when the adhesive contains a UV resin that hardens when exposed to ultraviolet light.

The plastic member 29 can be molded by injection injection of a liquid resin into a cavity of a mold (not shown) and curing. The liquid resin to be injection-injected into the cavity may be, for example, polypropylene (PP), polyphenylene sulfide (PPS), polyamide, polycarbonate (PC), acrylonitrile butadiene styrene Acrylonitrile butadiene styrene (ABS), or polybutylene terephthalate (PBT). Alternatively, it may be a resin obtained by mixing a plurality of kinds of synthetic resins selected from the above-mentioned synthetic resins.

Since the adhesive fills and hardens the plurality of fine grooves 24, the adhesive layer 28 is hardly coupled and separated in the plurality of fine grooves 24 as if it is hooked. Further, as compared with the case where the surface of the metal member is smooth, the bonding area between the adhesive and the metal member 21 is increased due to the plurality of fine grooves 24. Therefore, the bonding force between the metal member 21 and the plastic member 29 via the adhesive layer 28 is further strengthened.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it will be understood by those skilled in the art that various changes and modifications may be made without departing from the scope of the present invention. Therefore, the true scope of protection of the present invention should be defined only by the appended claims.

11, 21: metal member 14, 24: fine groove
18: primer layer 19, 29: plastic member
28: adhesive layer 35: working electrode
42: lower core 45: upper core

Claims (10)

An electrodeposition step of electrodischarge machining the surface of the metal member to form a plurality of fine grooves having a depth larger than the inner diameter on the surface; And a plastic bonding step of forming a plastic member integrally bonded to the surface of the metal member having the plurality of fine grooves. The method according to claim 1,
The plastic bonding step may include an insert molding step of disposing the metal member having the plurality of fine grooves formed therein in the mold, injecting and curing the melted liquid resin, and molding the plastic member bonded to the metal member Wherein the metal-plastic bonding body is formed of a metal. 3. The method of claim 2,
The plastic bonding step may include a primer applying step of applying a liquid primer for increasing the bonding force between the metal and the plastic on the surface of the metal member on which the plurality of fine grooves are formed, prior to the insert injection step; And a primer curing step of curing the applied liquid primer to form a primer layer. ≪ Desc / Clms Page number 20 > The method of claim 3,
Wherein the primer is formed by mixing a urethane-based resin and an epoxy-based resin. 3. The method of claim 2,
The liquid resin may be selected from the group consisting of polypropylene (PP), polyphenylene sulfide (PPS), polyamide, polycarbonate (PC), acrylonitrile butadiene styrene (ABS) , And polybutylene terephthalate (PBT). The method of claim 1, The method according to claim 1,
Wherein the plastic bonding step comprises: an adhesive applying step of applying an adhesive to a surface of the metal member on which the plurality of fine grooves are formed; And an adhesive curing step of attaching a plastic member to a surface of the metal member coated with the adhesive and curing the adhesive to form an adhesive layer connecting the metal member and the plastic member, - Process for the production of plastic assemblies. The method according to claim 1,
The step of discharging comprises the steps of immersing the metal member in the insulating liquid, disposing the working electrode in the insulating liquid so as to face the surface of the metal member, and disposing the working electrode on the negative (- And connecting the metal member to the positive electrode of the power source to cause a discharge between the metal member and the working electrode. 8. The method of claim 7,
Wherein the machining electrode moves parallel to the surface of the metal member so that fine grooves are sequentially formed at a plurality of points on the surface of the metal member. The method according to claim 1,
Wherein the metal member comprises iron (Fe) as a material. The method according to claim 1,
Wherein the plurality of fine grooves have an inner diameter of 50 to 800 탆, and the plurality of fine grooves are continuous.
KR1020150044041A 2015-03-30 2015-03-30 Method for fabricating metal-plastic combination using electric discharge machining KR20160117665A (en)

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Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR100922281B1 (en) 2006-02-28 2009-10-15 최진문 Method for Adhesion between Plastic resin and Metal film

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR100922281B1 (en) 2006-02-28 2009-10-15 최진문 Method for Adhesion between Plastic resin and Metal film

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