JP3925320B2 - Assembly method of molded products - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for assembling a molded product in which a molded part and a metal part are assembled in a press-fit state and fixed together.
[0002]
[Prior art]
The conventional method for assembling a metal part and a molded part is a method in which the dimensional accuracy of the metal part and the molding dimensional accuracy of the molded part are processed with high accuracy, and these are press-fitted and assembled, or the metal part is placed in the mold. It was a method of insert molding.
However, in order to process the dimensional accuracy of the molded part with high accuracy, there is a problem that the precision of the mold and high-precision temperature management from molding to cooling are required, and the molded part becomes expensive.
[0003]
Further, in the case of using the insert molding method by putting a metal part in a mold, holes or grooves are formed in the metal part to form an oil path. For example, the core stator 8 having a linear solenoid structure shown in FIG. In such a metal part, when the resin is injected after being inserted into the mold, the hole 82 and the groove 81 are blocked, and therefore the oil path cannot be secured. A schematic procedure of this insert molding is shown in FIG. That is, the core stator 8 that is a metal part is inserted into the mold 1 and set in FIG. Resin is injected in FIG.3 (b), the coil body 7 which is a molded component is shape | molded, and an assembly | attachment molded product is taken out from the shaping | molding die 1 in FIG.3 (c). In this case, as shown in (b) and (c), the resin blocks the hole 82 and the groove 81 of the core stator 8. Thus, in the case of insert molding, if a metal part has a groove or the like, there is a problem that a resin enters the groove or the like and a space cannot be formed. Usually, in order to secure a space between a metal and a resin, a core or the like is used to prepare a mold, but this may not be possible depending on the shape of the product.
[0004]
[Problems to be solved by the invention]
The present invention has been made in view of the above problems, and the object thereof is to prevent the resin from entering into the groove or the like even in the case of a metal part having a groove or the like. It is to provide a method for assembling a molded product that can be assembled.
[0005]
[Means for Solving the Problems]
The present invention provides a method for assembling a molded product according to each claim as a means for solving the above-mentioned problems.
The method of assembling a molded product according to claim 1 is a method of press-fitting a molded part immediately after cooling in a mold after molding, as soon as it is removed from the mold, and then assembled to a metal part, and then further cooled. When assembling the molded part and the metal part, the diameter of the pin part of the molding die that determines the inner diameter of the molded part and the outer diameter of the metal part to be assembled are the same. after the mold of the fixed mold and the metal part of the holder has the positioning by matching fit, by knocking out the molded part from the stationary mold, Ru Monodea was to assembling the molded parts and metal parts. As a result, the molded parts are higher in temperature and larger than normal metal parts, so they can be easily assembled without pressing the metal parts into the cylindrical part of the molded parts. The size of the part is reduced and the metal part is firmly bonded. In addition, since the molded part is completely cured, a space can be secured without entering the groove of the metal part.
[0006]
According to the assembling method of claim 1 , when the molded part and the metal part are assembled, the molded part is fixed after the fixed mold of the mold and the holder of the metal part are positioned by fitting. Since it is assembled by knocking out from the mold, the molded part can be assembled to the metal part without giving time for cooling or dimensional change immediately after taking out the molded part from the mold.
Furthermore, in said set with method of claim 1, the outer diameter of the metal parts assembled to the diameter of the mold pin portion of which determines the inner diameter of the molded part are the same west, molding immediately after removal from the mold Assembling of the part and the metal part can be facilitated, but when cooled, the dimensions are reduced, and the molded part is firmly fixed to the metal part.
[0007]
The assembling method of claim 2 is such that the temperature at which the molded part is taken out from the mold is approximately 100 ° C. or higher, whereby the molding resin becomes solid and resists knockout from the mold. Even if the strength can be secured and the shrinkage due to subsequent cooling is large, the metal part becomes a cored bar, so that the shrinkage of the molded part is suppressed, and a molded product having a stable size can be obtained.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, a method for assembling a molded product according to an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a diagram illustrating a method for assembling a molded article according to the present invention in accordance with procedures (a), (b), and (c). The mold 1 includes a lower mold 2 that is a fixed mold and an upper mold 3 that is a movable mold. The lower mold 2 is fixed to the equipment by an unillustrated mounting plate or the like. Similarly, the upper mold 3 is also fixed to a movable part (not shown) of the equipment by an unillustrated mounting plate or the like. The lower mold 2 is provided with a knockout pin 4 slidably with respect to the lower mold 2 for knocking out (removing) the molded part 7 after resin molding from the lower mold 2.
[0009]
In FIG. 1A, a bobbin 71 wound in a molding space (cavity) formed by the closed upper mold 3 and lower mold 2 is inserted, and molding is performed from a nozzle (not shown) in this state. The molten resin is injected into the space and insert molding is performed. Thus, the coil body 7 which is a molded part is formed. The mold 1 is held closed until the resin portion of the coil body 7 is hardened. When the temperature of the coil body 7 reaches about 100 ° C. or higher, the upper mold 3 is removed. Generally, the melting point of the resin is about 265 ° C., the resin temperature at the time of molding is about 280 to 300 ° C., and the temperature of the mold is about 50 to 80 ° C. In this case, the temperature for taking out the molded part 7 is preferably about 100 to 252 ° C. If this take-out temperature is close to the melting point of the resin, it is necessary to avoid the resin because it is not sufficiently hardened. In general, the temperature at which a molded part is taken out is 100.degree. C. or less for those whose dimensions need to be stabilized.
[0010]
FIG. 1B shows a view in which the holder 5 holding the core stator 8 which is a metal part is positioned at the position of the removed upper die 3. That is, the lower die 2 is formed with a pin portion 21 that holds the inner diameter of the coil body 7 that is a molding portion, and a positioning recess 22 is formed on the upper surface of the pin portion 21. On the other hand, the holder 5 is provided with a shaft portion 51 for penetrating and holding the core stator 8. Therefore, the holder 5 is positioned with respect to the lower mold 2 by fitting the tip of the shaft portion 51 of the holder 5 into the recess 22 formed on the upper surface of the pin portion 21 of the lower mold 2. That is, the core stator 8 that is a metal part is positioned with respect to the coil body 7 that is a molded part. This state is shown in FIG.
[0011]
FIG.1 (c) has shown the figure which assembled | attached the coil body 7 which is a shaping | molding component to the core stator 8 which is a metal component. The knockout pin 4 is raised, and the coil body 7 is pushed out from the lower mold 2 and assembled to the core stator 8 held by the holder 5 as it is. In this case, by setting the diameter d of the pin portion 21 of the lower mold 2 and the outer diameter D of the core stator 8 to be the same, the assembly can be easily performed without resistance.
[0012]
Next, the core stator 8 assembled with the coil body 7 is taken out from the holder 5 and further cooled. By assembling the coil body to the core stator 8 in this way, the coil body 7 can be assembled to the core stator 8 in a warm state after molding, and the coil body 7 contracts after cooling only by being inserted. The core stator 8 is firmly fixed.
[0013]
When the upper mold 3 is removed, the temperature is slightly lowered by touching the air. However, the temperature of the lower mold 2 is also controlled by a heater (not shown). There is not much influence.
Further, when the molded part 7 is taken out from the lower mold 2, it is cooled by air and the temperature rapidly decreases. Therefore, the molded part 7 is assembled to the metal part 8 using the operation of pushing out from the lower mold 2 with the knockout pin 4. As a result, the assembling time can be reduced to a short time, and the influence of a temperature drop can be prevented. In the present invention, the assembling time could be kept within 1 second.
In addition, when the assembly stops due to an abnormality in the equipment, the temperature of the molded part 7 decreases, the molded part 7 contracts, and the assembly is press-fitted. Because of that, the equipment is burdened, so it is desirable not to assemble for equipment protection.
[0014]
(A '), (b'), and (c ') in FIG. 3 show the general procedure of the method of assembling the molded article of the present invention, and the steps (a), (b), and (c) in the conventional method. It is the figure compared with. That is, in the present invention, the core stator 8 that is a metal part is inserted and assembled into the coil body 7 that is a molded part that has not been completely cooled immediately after being taken out of the mold 1. Therefore, the groove 81 and the hole 82 formed in the core stator 8 are not filled with the molding resin. On the other hand, in the conventional procedures (a), (b), and (c), since the resin is filled with the core stator 8 inserted into the molding die 1, the grooves 81 and the holes 82 of the core stator 8 are made of resin. It will be buried with.
[0015]
As described above, in the present invention, the molded part immediately after cooling in the mold after resin molding can be easily assembled by taking it out from the mold and simultaneously assembling it with the metal part. In addition, after positioning by fitting the lower mold and metal part holder, the molded part is assembled by knocking it out of the lower mold, so the assembly time can be shortened, cooling of the molded part and dimensional change Assembly is possible without giving time. Further, by making the diameter of the pin portion of the mold and the outer diameter of the metal part the same, the assembly of the molded part immediately after removal from the mold can be facilitated. Furthermore, since the temperature at which the molded part is taken out from the mold is approximately 100 ° C. or higher, the resin becomes solid, and it is possible to ensure the strength to withstand knockout of the molded part from the mold. Thus, in the present invention, even a metal part having a groove or the like can prevent the molding resin from entering the groove or the like, and the molded part and the metal part can be assembled in a press-fit state.
[Brief description of the drawings]
FIG. 1 is a diagram illustrating a method for assembling a molded product according to an embodiment of the present invention according to procedures (a), (b), and (c).
FIG. 2 is a longitudinal sectional view of a linear solenoid structure that is a target product of an assembly molded product.
FIG. 3 shows the steps (a), (b), (c) of the method for assembling the molded product of the present invention, and the procedures (a ′), (b ′), (c) of the conventional method for assembling the molded product. It is a figure explaining the outline comparison with ′).
[Explanation of symbols]
1 ... Mold 2 ... Lower mold (fixed mold)
21 ... Pin part 22 ... Recess 3 ... Upper mold (movable type)
4 ... Knockout pin 5 ... Holder 51 ... Shaft portion 7 ... Coil body (molded part)
71 ... Bobbin 8 ... Core stator (metal parts)
81 ... groove 82 ... hole

Claims (2)

After tree butter molding, the molded parts after the mold in the cooling, assembled at the same time the metal component is taken out from the mold, in a subsequent further assembly method of a molded article pressed into metal parts by cooling,
The outer diameter of the metal part to be assembled is the same as the diameter of the pin part of the mold that determines the inner diameter of the molded part,
When assembling the molded part and the metal part, the fixed part of the mold and the holder of the metal part are positioned by fitting, and then the molded part is knocked out of the fixed mold, A method for assembling a molded product, comprising assembling the molded component and the metal component . The method for assembling a molded article according to claim 1 , wherein a temperature at which the molded part is taken out from the mold is approximately 100 ° C or higher.

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