JP4267370B2 - Manufacturing method of composite parts - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for manufacturing a composite part in which a metal part having a surface treatment layer formed by anodizing is bonded to another part, and in particular, a metal in which a metal case is bonded to another part. The present invention relates to a manufacturing method suitable for a case unit.
[0002]
[Prior art]
In recent years, the case of a portable terminal device such as a cellular phone or a portable information terminal is thinner than a plastic case for the purpose of improving portability and protecting electronic components housed in the housing portion of the case. A rigid metal case is provided.
The surface of such a case is subjected to alumite treatment in order to improve corrosion resistance and maintain aesthetics, thereby forming a surface treatment layer. In addition, it is known that a crack will generate | occur | produce when this surface treatment layer is heated more than predetermined temperature (crack generation temperature).
[0003]
As shown in FIG. 3, the housing portion of the case is provided with a fixing member 3 for fixing the electronic component described above to the housing portion 2a. The fixing member 3 is made of resin and is bonded to the bottom surface of the housing portion 2 a of the case 2. For bonding the case 2 and the fixing member 3, an adhesive sheet in which an adhesive is formed in a sheet shape is used.
The adhesive sheet is melted by heating at a melting temperature or higher for a predetermined time, and the melting temperature and the predetermined time depend on the physical properties of the adhesive sheet. That is, for example, in the case of a polyester-based adhesive sheet, the melting temperature is 120 ° C., and the predetermined time is 4 seconds.
In addition, when the adhesive sheet is cooled to a curing temperature or lower from a molten state, the adhesive sheet is cured to obtain a predetermined adhesive force.
[0004]
Conventionally, a metal case unit in which a fixing member 3 is bonded to a metal case 2 is manufactured as follows.
First, an alumite treatment is performed on the case to form a surface treatment layer, and an adhesive sheet is temporarily bonded to the bottom surface of the housing portion of the case. At the time of this temporary bonding, the case is heated for a time shorter than the above-mentioned predetermined time to raise the temperature of the adhesive sheet.
[0005]
Next, as shown in FIG. 4A, the operator places the fixing member 3 on the arrangement portion 21 a of the jig 21, and the case 2 is fixed to the fixing member 3 so that the adhesive sheet 4 contacts the fixing member 3. To be placed on top of each other. Furthermore, when the operator makes the pressing portion 31 provided on the jig 21 contact the case 2, the case 2, the adhesive sheet 4, and the fixing member 3 are clamped by the pressing portion 31 and the arrangement portion 21a. This clamp prevents the relative positions of the case 2 and the fixing member 3 in the thickness direction from greatly deviating.
[0006]
And as shown in FIG.4 (b), while inserting the press part 31 in the hole 22a of the heating horn 22 hold | maintained at temperature lower than the crack generation temperature and higher than the melting temperature of the adhesive sheet 4, By bringing the heating horn 22 into contact with the case 2, the case 2 is heated until the adhesive sheet 4 is melted. For example, when the adhesive sheet 4 is made of a polyester-based adhesive and the case 2 is made of an aluminum alloy, the adhesive sheet 4 is heated with a heating horn 22 at 140 ° C. for 15 seconds. The reason why the temperature of the heating horn 22 is set to 140 ° C. is to prevent the surface treatment layer of the case 2 from cracking, and the reason why the heating is performed for 15 seconds is that the adhesive sheet 4 is heated through the case 2 and the adhesive sheet is heated. This is because it takes 9 seconds for 4 to reach 120 ° C.
[0007]
Further, during the heating, the case 2 is pressed by the heating horn 22 to achieve relative positioning in the thickness direction of the case 2 and the fixing member 3. The pressing force by the heating horn 22 is adjusted by keeping a gap between the heating horn 22 and the jig 21 constant by bringing a stopper 22 b provided on the heating horn 22 into contact with the jig 21.
[0008]
Thereafter, the heating horn 22 is separated from the case 2 and, as shown in FIG. 4C, the pressing portion 31 is inserted into the insertion portion 23a of the cooling horn 23 made of an aluminum alloy and at room temperature, and the cooling is performed. The case 2 is cooled by bringing the horn 23 into contact with the case 2. At this time, since the cooling horn 23 absorbs the heat of the case 2, the temperature of the adhesive sheet 4 is lowered together with the case 2, but the temperature of the cooling horn 23 is increased to be higher than the curing temperature of the adhesive sheet 4. The sheet 4 is not cooled to its curing temperature.
[0009]
Therefore, as shown in FIG. 4D, the case 2 and the fixing member 3 are bonded to each other by separating the cooling horn 23 from the case 2 and lowering the adhesive sheet 4 together with the case 2 to the curing temperature by air cooling. The
Finally, the operator separates the pressing portion 31 from the case 2 and removes the case 2 bonded to the fixing member 3 from the arrangement portion 21a of the jig 21 to complete the manufacture of the metal case unit.
[0010]
In addition to the above, as a method of fixing a metal part such as the case 2 and a resin part such as the fixing member 3 to each other, for example, as shown in Patent Document 1, the metal part is heated by ultrasonic waves. There is also a method of press-fitting while slightly melting the resin part.
[0011]
[Patent Document 1]
Japanese Patent Laid-Open No. 9-33759 (page 3, FIG. 2)
[0012]
[Problems to be solved by the invention]
However, in the manufacturing method of the above metal case unit, the case 2 is heated at a temperature lower than the crack generation temperature so as not to generate cracks in the surface treatment layer, so that the time for melting the adhesive sheet 4 is long. There was a problem of becoming.
Further, since the adhesive sheet 4 melted by the heating of the heating horn 22 is cooled by the cooling horn 23 and further cured by air cooling, the time until the adhesive sheet 4 is cured is increased as a result. was there. From the above, there is a problem that the manufacturing time of the metal case unit becomes long.
[0013]
Moreover, since it was necessary to form the hole parts 22a and 23a which insert the press part 31 in the heating horn 22 and the cooling horn 23, there existed a problem that the cost of the manufacturing apparatus which manufactures a metal case unit became high.
Furthermore, since the operator moved the pressing portion 31 when arranging the case 2 or the like on the arrangement portion 21a and when removing the metal case unit from the arrangement portion 21a, the work is troublesome. was there.
[0014]
Moreover, although the relative positioning of the thickness direction of the case 2 and the fixing member 3 is aimed at by the pressing force of the heating horn 22, the pressing force is released before the adhesive sheet 4 is cured. There was a problem that the relative positional accuracy of the thickness direction of 2 and the fixing member 3 deteriorated.
[0015]
[Means for Solving the Problems]
In order to solve the above-mentioned problems, the invention according to claim 1 is a method in which a first part made of metal is subjected to alumite treatment to form a surface treatment layer, and then is melted by heating and cured with cooling. In the method of manufacturing a composite part in which the second part is fixed to the first part with an adhesive capable of obtaining a predetermined adhesive force, a stable hardness is achieved in which the hardness of the surface treatment layer is stabilized after the alumite treatment. Before heating, the composite part is characterized in that the heating is performed at a temperature higher than the melting temperature of the adhesive and lower than the crack generation temperature at which cracks occur in the surface treatment layer until the adhesive is melted. The manufacturing method is proposed.
[0016]
In addition, the invention according to claim 2 is formed in a sheet shape and a fixing member for fixing a component housed in the case after a surface treatment step of forming a surface treatment layer by performing alumite treatment on a metal case and adhesive sheet consisting of adhesives, and laminating step of superimposing said casing, sequentially thickness direction, melting temperature than the adhesive sheet is melted, and from the crack generation temperature that cracks occur in the surface treatment layer at even lower temperatures, the heating step of the adhesive sheet to heat the casing until melted, and a cooling step of cooling the casing until the adhesive sheet is hardened, the surface treatment layer after the alumite treatment A method of manufacturing a composite part is proposed in which the heating step is performed before the hardness reaches a stable hardness.
The inventors of the present invention have found that the hardness of the surface treatment layer increases with the passage of time after the alumite treatment, and when measured after standing at room temperature, the rate of change in hardness per day is approximately 4 to 5 days. It has been found that it becomes 3% or less, that is, the hardness becomes stable, and the crack generation temperature becomes low as the hardness of the surface treatment layer increases, that is, as the hardness approaches the stable hardness (FIG. 2 ( a) (b)).
[0017]
According to the method for manufacturing a composite part according to the present invention, the surface treatment layer is heated at a hardness lower than the stable hardness, and the surface treatment layer is heated at a temperature higher than the crack occurrence temperature in the stable hardness of the surface treatment layer. However, no cracks are generated in the surface treatment layer. For this reason, the time for melting the adhesive sheet can be shortened.
[0018]
According to a third aspect of the present invention, in the method for manufacturing a metal case unit according to the first or second aspect, the heating step is performed within 72 hours after the alumite treatment. A manufacturing method is proposed.
In addition, the present inventors have found that the elapsed time from the alumite treatment until the hardness of the surface treatment layer becomes the stable hardness is 4 to 5 days, and the hardness between them is about 3 days (72 hours), which is about the stable hardness. It was found that 95%, about 48% at about 48 hours, and about 70% at about 24 hours, respectively. Moreover, the knowledge that crack generation temperature is substantially inversely proportional to the fluctuation | variation of this hardness was acquired (refer FIG. 2 (a) (b)).
[0019]
According to the method for manufacturing a composite part according to the present invention, the case is surely heated before the hardness of the surface treatment layer reaches the stable hardness, so that the time for melting the adhesive sheet is surely shortened. Can do.
[0020]
In addition, the invention according to claim 4 is to form a surface treatment layer by performing alumite treatment on the first metal part, and on the jig, the second part, an adhesive that melts by heating, A heating horn that is placed in sequence with the first component and that is maintained at a temperature higher than a melting temperature at which the adhesive melts and lower than a crack generation temperature at which a crack occurs in the surface treatment layer is provided. After the first component is heated until the adhesive melts, the cooling horn maintained at a temperature equal to or lower than the curing temperature of the adhesive is used instead of the heating horn. By bringing the first part, the adhesive, and the second part between the cooling horn and the jig in the thickness direction by contacting the first part, the adhesion is performed. Cool the first part until the agent is cured We propose a method for manufacturing a composite part, characterized in that.
[0021]
Further, the invention according to claim 5 is to form a surface treatment layer by performing alumite treatment on a metal case, a fixing member for fixing a component housed in the case on a jig, and a sheet shape An adhesive sheet made of the formed adhesive and the case are sequentially stacked and arranged , and are higher than a melting temperature at which the adhesive sheet melts and lower than a crack generation temperature at which a crack occurs in the surface treatment layer. A heating horn maintained at a temperature was brought into contact with the case, and the case was heated until the adhesive sheet melted, and then the temperature was maintained at a temperature equal to or lower than the curing temperature of the adhesive sheet instead of the heating horn. By bringing the cooling horn into contact with the case, the case, the adhesive sheet, and the fixing member are sandwiched in the thickness direction between the cooling horn and the jig. Adhesive sheet is proposed a method for manufacturing a composite part, characterized by cooling the casing until cured.
[0022]
According to the composite component manufacturing method of the present invention, the first component (case) can be pressed by the cooling horn until the adhesive (adhesive sheet) is cured. The relative positional accuracy in the thickness direction with respect to the second component (fixing member) can be improved.
Moreover, since the relative positioning of the first component (case) and the second component (fixing member) can be performed by the cooling horn, the configuration of the composite component manufacturing apparatus is simplified and the manufacturing cost is reduced. Can be achieved.
[0023]
Furthermore, since the relative positioning of the first component (case) and the second component (fixing member) is performed when the first component (case) is cooled, the operator clamps the composite component. Since there is no need, it is only necessary to perform the work of placing the first part (case), the adhesive (adhesive sheet) and the second part (fixing member), and the work of removing the composite part from the jig. The work content of the person becomes easier.
Moreover, since the cooling horn is maintained at a temperature equal to or lower than the curing temperature, the cooling horn can continue to absorb the heat of the first component (case) until the adhesive (adhesive sheet) is cured. Even if it is high, the time until the adhesive (adhesive sheet) is cured can be shortened.
[0024]
The invention according to claim 6 is the method of manufacturing a composite part according to claim 4 or claim 5, wherein the cooling horn is held at a temperature equal to or lower than the curing temperature by a liquid circulating inside. The manufacturing method of the composite part characterized by this is proposed.
According to the method for manufacturing a composite part according to the present invention, the heat absorbed by the cooling horn from the first part (case) is absorbed by the liquid circulating in the interior, so that the cooling horn is surely below the curing temperature. Can be kept at temperature.
[0025]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 shows an embodiment according to the present invention. The case (first component), the fixing member (second component), and the adhesive sheet (adhesive) constituting the metal case unit manufactured by the manufacturing method according to this embodiment are the same as those of the above-described conventional technology. Therefore, the same reference numerals are given and the description thereof is omitted. In this embodiment, the case and the adhesive sheet are made of an aluminum alloy and a polyester adhesive, respectively. Below, the manufacturing method of the metal case unit which concerns on this embodiment is demonstrated.
[0026]
First, an alumite treatment is performed on the case to form a surface treatment layer, and an adhesive sheet is temporarily bonded to the bottom surface of the housing portion after 24 hours have elapsed since the completion of the alumite treatment. In this temporary bonding, for example, the case is heated at 120 ° C. for 3 seconds to heat the adhesive sheet.
Note that the adhesive sheet was temporarily bonded after 24 hours from the alumite treatment, as shown in FIG. 2, because the hardness of the surface treatment layer after the alumite treatment was changed by the present inventors. This is because it has been found that the elapsed time to reach a stable hardness of 3% or less is 4 to 5 days, and that the lower the hardness of the surface treatment layer, the higher the crack generation temperature. This is because.
[0027]
Next, as shown in FIG. 1A, the operator places the fixing member 3 on the arrangement portion 11 a of the jig 11, and attaches the case 2 to the fixing member 3 so that the adhesive sheet 4 contacts the fixing member 3. To be placed on top of each other.
Then, as shown in FIG. 1B, for example, the case 2 is heated by bringing the heating horn 12 maintained at 190 ° C. into contact with the case 2 for 9 seconds, and the adhesive sheet 4 is melted. Here, the temperature of the heating horn 12 is set to 190 ° C., as shown in FIG. 2 (b), so that the temperature is lower than the crack occurrence temperature after 24 hours from the alumite treatment. The reason why the contact time of the heating horn 12 is 9 seconds is that the adhesive sheet 4 is heated through the case 2, and the adhesive sheet 4 is 120 ° C. after the heating horn 12 contacts the case 2. This is because it takes 5 seconds to reach.
[0028]
Thereafter, the heating horn 12 is separated from the case 2 and the cooling horn 13 made of an aluminum alloy is brought into contact with the case 2 as shown in FIG. And the temperature of case 2 and the adhesive sheet 4 falls.
Here, the cooling horn 13 is formed with a flow path for circulating the liquid L1 therein. For this reason, the heat absorbed by the cooling horn 13 is absorbed by the liquid L <b> 1, and the temperature of the cooling horn 13 is maintained below the curing temperature of the adhesive sheet 4. Therefore, the case 2 is cooled to a temperature equal to or lower than the curing temperature of the adhesive sheet 4, and the adhesive sheet 4 is cured and the case 2 and the fixing member 3 are bonded to each other.
[0029]
At the time of this cooling, the case 2 is pressed by the cooling horn 13 so that the case 2 and the fixing member 3 are relatively positioned in the thickness direction. The pressing force by the cooling horn 13 is adjusted by keeping a gap between the cooling horn 13 and the jig 11 constant by bringing a stopper 13 a provided on the cooling horn 13 into contact with the jig 11.
Finally, the cooling horn 13 is separated from the case 2, the operator removes the case 2 bonded to the fixing member 3 from the placement portion 11 a of the jig 11, and the manufacture of the metal case unit is completed.
[0030]
According to the manufacturing method of the metal case unit described above, since the case 2 and the adhesive sheet 4 are heated after 24 hours from the alumite treatment, they can be heated at a temperature higher than the crack generation temperature in the stable hardness of the surface treatment layer. Therefore, the time for melting the adhesive sheet 4 can be shortened, and the manufacturing time of the metal case unit can be reliably shortened.
[0031]
In addition, since the cooling horn 13 is held at a temperature lower than the curing temperature of the adhesive sheet 4 by the liquid L1 circulating inside, the adhesive sheet 4 is cured even if the heating temperature by the heating horn 12 is high. The manufacturing time of the metal case unit can be shortened by shortening the time.
Furthermore, since the case 2 can be pressed by the cooling horn 13 until the adhesive sheet 4 is cured, the relative positional accuracy in the thickness direction between the case 2 and the fixing member 3 can be improved. .
[0032]
Further, the fixing member 3, the adhesive sheet 4, and the case 2 are arranged in the arrangement portion of the jig 11 in order to improve the relative positional accuracy in the thickness direction between the case 2 and the fixing member 3 by the cooling horn 13. After that, it is not necessary to clamp the fixing member 3, the adhesive sheet 4, and the case 2 before the metal case unit is manufactured. For this reason, the configuration of the metal case unit manufacturing apparatus can be simplified to reduce the manufacturing cost, and the work contents of the operator are facilitated.
[0033]
In the above embodiment, the case 2 is formed of an aluminum alloy. However, the present invention is not limited to this, and it is sufficient that the case 2 is formed of a metal capable of at least alumite treatment.
In addition, the adhesive sheet 4 is made of a polyester-based adhesive. However, the adhesive sheet 4 is not limited to this, and may be an adhesive that melts by heating and cures by cooling.
[0034]
Further, the adhesive sheet 4 is temporarily bonded to the case 2 after 24 hours from the alumite treatment. However, the present invention is not limited to this. For example, the adhesive sheet 4 is temporarily bonded immediately after the alumite treatment, and then 24 hours. After the elapse of time, the case 2 and the adhesive sheet 4 may be heated by the heating horn 12.
Although heating of the case 2 and the adhesive sheet 4 by the heating horn 12 is performed after 24 hours have passed from the alumite treatment, it is not limited to this, and may be performed at least within about 72 hours after the alumite treatment. Therefore, this heating may be performed within about 24 hours after the alumite treatment.
[0035]
That is, the hardness of the surface treatment layer increases after the alumite treatment, and as the hardness approaches the stable hardness, the fluctuation rate becomes gentler, and the crack generation temperature decreases as the hardness increases. It is preferable to heat the case 2 and the adhesive sheet 4 as soon as possible after completion. Therefore, if at least about 72 hours, preferably about 48 hours, and more preferably about 24 hours after anodizing according to the change in hardness variation rate, the manufacturing time can be reliably reduced. It is.
[0036]
In addition, the method for bonding the fixing member 3 to the case 2 with the adhesive sheet 4 has been described. However, the present invention is not limited to this, and a method for bonding other components to an alumite-treated metal component with an adhesive. It is possible to apply. However, the adhesive must be solid at room temperature.
As mentioned above, although embodiment of this invention was explained in full detail with reference to drawings, the concrete structure is not restricted to this embodiment, The design change etc. of the range which does not deviate from the summary of this invention are included.
[0037]
【The invention's effect】
As described above, according to the first to third aspects of the present invention, the first component (case) is heated after the alumite treatment and before the hardness of the surface treatment layer reaches the stable hardness. The time for melting the adhesive sheet) can be shortened, and the production time of the composite part can be shortened.
[0038]
According to the invention which concerns on Claim 4, 5, since the cooling horn is hold | maintained at the temperature below the hardening temperature of an adhesive agent (adhesive sheet), the 1st component (case) and the 2nd component (fixing member) The time until the adhesive (adhesive sheet) is cured even when the heating temperature of the first component (case) by the heating horn is high This shortens the manufacturing time of the composite part.
In addition, the second component (fixing member), the adhesive (adhesive sheet), and the first component (case) are arranged in the jig until the composite component is manufactured. Since there is no need to clamp the fixing member), the adhesive (adhesive sheet), and the first part (case) in an overlapped state, the configuration of the composite part manufacturing apparatus is simplified and the manufacturing cost is reduced. And the work contents of the worker are facilitated.
[0039]
According to the invention of claim 6, since the heat absorbed by the cooling horn from the first component (case) is absorbed by the liquid circulating inside, the cooling horn is reliably kept at a temperature equal to or lower than the curing temperature. be able to.
[Brief description of the drawings]
FIG. 1 is an explanatory view showing a method for manufacturing a metal case unit according to an embodiment of the present invention.
2A is a graph showing a change in hardness of an anodized surface layer over time after anodizing, and FIG. 2B is a graph showing a change in crack occurrence temperature of the surface layer.
FIG. 3 is a perspective view showing an example of a conventional metal case unit.
FIG. 4 is an explanatory view showing an example of a conventional method for manufacturing a metal case unit.
[Explanation of symbols]
2 Case (first part)
3 Fixing member (second part)
4 Adhesive sheet (adhesive)
11 Jig 12 Heating horn 13 Cooling horn L1 Liquid

Claims (6)

After the surface treatment step of forming a surface treatment layer by subjecting the first metal part to an alumite treatment, the first component is melted by heating and obtained with a predetermined adhesive force by curing accompanying cooling. In a method for manufacturing a composite part in which a second part is fixed to a part,
Before reaching the stable hardness at which the hardness of the surface treatment layer is stabilized after the alumite treatment, at a temperature higher than the melting temperature of the adhesive and lower than the crack generation temperature at which cracks occur in the surface treatment layer, The method of manufacturing a composite part, wherein the heating is performed until the adhesive melts. After a surface treatment step of forming a surface treatment layer by applying alumite treatment to a metal case, a fixing member for fixing components housed inside the case, and an adhesive sheet made of an adhesive formed in a sheet shape, a lamination step of superimposing sequentially thickness direction, and the case,
A heating step of heating the case until the adhesive sheet melts at a temperature higher than a melting temperature at which the adhesive sheet melts and lower than a crack generation temperature at which a crack occurs in the surface treatment layer;
A cooling step of cooling the case until the adhesive sheet is cured ;
With
A method for producing a composite part, comprising performing the heating step after the alumite treatment and before reaching a stable hardness at which the hardness of the surface treatment layer is stabilized.   The method of manufacturing a composite part according to claim 1 or 2, wherein the heating step is performed within 72 hours after the alumite treatment. An alumite treatment is applied to the first metal part to form a surface treatment layer,
On the jig, the second component, the adhesive that melts by heating, and the first component are sequentially stacked and arranged,
A heating horn held at a temperature higher than a melting temperature at which the adhesive melts and lower than a crack generation temperature at which a crack occurs in the surface treatment layer is brought into contact with the first component, and the adhesive is After heating the first part until it melts,
Instead of the heating horn, the first component is placed between the cooling horn and the jig by bringing a cooling horn maintained at a temperature lower than the curing temperature of the adhesive into contact with the first component. A method of manufacturing a composite part, wherein the first part is cooled until the adhesive is cured in a state where the adhesive and the second part are sandwiched in the thickness direction. Apply alumite treatment to a metal case to form a surface treatment layer,
On the jig, a fixing member for fixing a component housed in the case, an adhesive sheet made of an adhesive formed in a sheet shape, and the case are sequentially stacked and arranged,
A heating horn held at a temperature higher than the melting temperature at which the adhesive sheet melts and lower than the crack generation temperature at which the surface treatment layer is cracked is brought into contact with the case until the adhesive sheet melts. After heating the case,
Instead of the heating horn, the case, the adhesive sheet, and the fixing member are placed between the cooling horn and the jig by bringing a cooling horn held at a temperature lower than the curing temperature of the adhesive sheet into contact with the case. A method of manufacturing a composite part, characterized in that the case is cooled until the adhesive sheet is cured in a state of being sandwiched in the thickness direction.   6. The method of manufacturing a composite part according to claim 4, wherein the cooling horn is maintained at a temperature equal to or lower than the curing temperature by a liquid circulating in the cooling horn.

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