JP2004209790A - Thin-walled insert-formed article, thin-walled cored formed article, forming method, and forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To continuously produce a largve number of thin-walled cored formed articles prevented from the filling failure of a material resin and the eccentricity of a hole. <P>SOLUTION: A large number of the thin-walled cored formed articles are produced by successively performing a process (I) wherein an electrically conductive material continuing so as to be inserted into the cavity of a die is provided between the partition surfaces of the die, a process (II) wherein a resin is charged in the cavity while passing electric current through the electrically conductive material to heat the material to obtain an insert-molded article having the electrically conductive material incorporated therein, a process (III) wherein the die is opened not only to take out the insert-article to the outside of the die but also to move the continuing electrically conductive material to provide the rear part of a part where the insert-formed article is provided between the partition surfaces in the same way as the process (I) and a process (IV) wherein the elctrically conductive material is extracted from the thin-walled insert-formed article to form the hole. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
According to the present invention, after providing a continuous conductive material on a partition surface of a mold cavity, a resin is filled while heating the conductive material to obtain a thin insert molded product, and the conductive material is extracted to obtain a thin holed molded product. According to the present invention, it is possible to prevent poor resin filling and eccentricity of pores, and particularly to molded articles having thin pores, which can be used for optical fiber connectors.
[0002]
[Prior art]
A connector for an optical fiber usually has a portion in which a small-diameter hole for inserting an optical fiber is formed along the central axis, a portion in which a large-diameter hole for inserting the optical fiber is formed along the central axis, and a flange portion. The small-diameter hole and the large-diameter hole are connected via a tapered diameter portion. The connection of a pair of optical fibers is performed by inserting each ferrule into which they have been inserted and joined and inserting them from both ends of the sleeve and abutting the ends of the ferrules, whereby each optical fiber is aligned with its axis line aligned. The tips are butted and connected. Therefore, high dimensional accuracy of the hole is required for the connector for the optical fiber. Conventionally, optical fiber connectors have been manufactured by filling a resin into a mold cavity in which a columnar core pin has been set to produce a molded product, and then extracting the core pin from the molded product to form pores. I've been.
[0003]
However, when the diameter of a columnar pin generally used as a core in a plastic molding die is about φ1 mm or less and the length is 3 mm or more, various failures due to pin breakage or bending are likely to occur due to resin pressure. Therefore, for example, due to the bending of the pin, the position of the hole of the molded product is deviated from the original position and the product cannot be assembled, the product does not function, or the broken pin remains in the molded product. There was a defect that stopped functioning as a product.
[0004]
As a countermeasure, a long wire made of special material is stretched in a state inserted into the cavity of the mold, and after injecting and filling the material resin into the cavity, the wire is pulled to be thinly deformed and pulled out from the molded product. There is a molding method by the method (for example, refer to Patent Document 1).
On the other hand, in a thin-walled molded product, when the thickness is about 0.2 mm or less and the length is about 10 mm or more, poor filling tends to occur due to insufficient fluidity of the material resin. As a countermeasure, there is a method of injecting and filling the material resin at a high speed, a method of injecting and filling by increasing the mold temperature to around the melting point or the softening point of the resin, and the like. In the case of a molded product, only a flow length of up to about 30 mm can be obtained.
Furthermore, if the molded product has a thin cylindrical shape, there is a problem such as breakage or bending of the pin or cutting of the wire, and high-speed injection cannot be performed. For example, if the thickness is 0.2 mm, the material resin is filled only up to about 10 mm. I can't.
[0005]
On the other hand, using a wire as a hoop material, by preventing external force from acting on the hoop material during hoop molding, it is possible to prevent the plurality of hoop materials from being out of balance, secure the function as a molded product, and achieve stable molding. A mold clamping device for an injection molding machine is disclosed (for example, see Patent Document 2).
[0006]
[Patent Document 1]
JP 2001-239550 A (Claim 1, Paragraph 0006, Paragraph 0011)
[Patent Document 2]
JP-A-11-309765 (Claim 1, paragraph 0004, paragraph 0005)
[0007]
[Problems to be solved by the invention]
An object of the present invention is to provide a manufacturing method, an apparatus, and a molded product that prevent incomplete filling of a material resin and eccentricity of a hole. To provide technologies that can be used.
[0008]
[Means for Solving the Problems]
The present inventors have proposed a molding method in which a continuous wire or the like is stretched while being inserted into a cavity of a mold, and a step of sequentially injecting and filling a material resin into the cavity and a step of intermittently moving the wire are performed. In the above, it has been found that, by injecting and filling the material resin in a state where the wire is energized to generate heat near the melting point of the material resin, it is possible to prevent the occurrence of defective filling and eccentricity, thereby completing the present invention.
[0009]
That is, a first aspect of the present invention is that a conductive material (4) continuous between partition surfaces (2, 2 ') of a mold (1, 1') so as to be inserted into a cavity (3) of the mold is provided. Providing step (I),
Next, a step of filling the resin (5) in the cavity (3) while energizing the conductive material (4) to heat the conductive material (4) to obtain a thin insert molded product (6) containing the conductive material ( II),
Next, the mold (1, 1 ') is opened, the thin insert molded product (6) is taken out of the mold, and the continuous conductive material (4) is moved, so that the thin insert molded product (6) is moved. Step (III) of providing the rear part of the part provided with the parentheses) between the partition surfaces (2, 2 ′) in the same manner as in the step (I).
And a method for producing a thin insert molded product.
A second aspect of the present invention provides the method for producing a thin insert molded product according to the first aspect of the present invention, wherein the material of the conductive material (4) is metal or carbon.
A third aspect of the present invention provides the method for producing a thin insert molded product according to the first or second aspect of the present invention, wherein the thickness of the resin is from 0.1 to 3.0 mm.
A fourth aspect of the present invention is that, after the step (III) according to the first aspect of the present invention, a step (IV) of extracting the conductive material (4) from the thin insert molded product (6) to form a hole (7).
And a method for producing a thin-hole-formed product.
A fifth aspect of the present invention is a method of extracting a conductive material (4) from a thin insert molded product (6),
(I) a method of applying a release agent to the conductive material (4),
(Ii) A method of providing a flange portion (8) at the end of a molded product and receiving a reaction force when the conductive material (4) is pulled out by the flange portion (8), or (iii) a method of combining these methods The method for producing a thin-hole-formed article according to the fourth aspect is provided.
A sixth aspect of the present invention is the fourth or the fourth aspect of the present invention, wherein the thickness of the resin is 0.1 to 3.0 mm, and the fixed hole diameter portion having the hole diameter φ of 0.1 to 2.0 mm is 0.5 mm or more. 5. A method for producing a molded product having a thin walled hole according to item 5.
According to a seventh aspect of the present invention, a tapered ferrule which can be pulled out at one end is fitted into a part of the conductive material (4), the conductive material with a ferrule (4) is pulled out, and one end of the hole (7) is expanded. A method for producing a thin-hole-formed product according to the fourth or fifth aspect of the present invention, wherein the tapered hole (17) is formed.
An eighth aspect of the present invention is a tapered hole (17) in which a flange (8) is integrally provided at an end of a molded product having a thin-walled hole, and one end of a hole (7) extends outward in the flange (8). ') Is further provided by the finishing step (V), the method for producing a thin-hole-formed product according to any one of the fourth to seventh aspects of the present invention.
According to a ninth aspect of the present invention, there is provided a thin-walled insert molded product obtained by the manufacturing method according to any one of the first to third aspects of the present invention.
According to a tenth aspect of the present invention, there is provided a thin-walled hole-formed product obtained by the method according to any one of the fourth to eighth aspects of the present invention.
According to an eleventh aspect of the present invention, there is provided a thin-walled molded product according to the tenth aspect of the present invention, which is used for an optical fiber connector.
A twelfth aspect of the present invention is a molding apparatus used in the manufacturing method according to any one of the first to eighth aspects of the present invention,
An insulating material (12) for electrically insulating the conductive material (4) from the mold (1, 1 ') and electrodes (16, 16') for supplying a current to the conductive material (4) are provided. Power supply controller (11) for energizing the mold apparatus (10) and conductive material (4)
The present invention provides a molding apparatus having:
[0010]
BEST MODE FOR CARRYING OUT THE INVENTION
A method for manufacturing a thin insert molded product according to the present invention will be described below with reference to the drawings. FIG. 1 is a diagram showing an example of the relationship between a mold and a conductive material according to the present invention, wherein FIG. 1 (a) is a longitudinal sectional view and FIG. 1 (b) is a side view. A conductive material 4 such as a wire is stretched between the partition surfaces 2 and 2 ′ of the opened upper mold 1 (for example, a fixed mold) and the lower mold 1 ′ (for example, a movable mold). Thereafter, the upper mold 1 and the lower mold 1 'are closed to form the cavity 3. A portion where the conductive material 4 is in contact with each mold is covered with an electrical insulating material 12, and electrodes 16 and 16 ′ are provided at both ends of the mold via the electrical insulating material 12. 4 is energized. A voltage and a current necessary for heating the conductive material 4 to a predetermined temperature are supplied from the power supply controller 11 (not shown) to the electrodes 16 and 16 '. After heating the conductive material 4 to a predetermined temperature, the resin 5 is filled from the resin gate 15 to obtain a thin insert molded product 6 into which the conductive material 4 is inserted. When the thin-walled insert 6 is very small, the heating time may be very short.
[0011]
FIG. 2 is a diagram showing an example of the relationship between supply of a conductive material to a molding die apparatus according to the present invention, energization of the conductive material during resin filling, and take-up or winding of the obtained thin insert molded product. .
In FIG. 2, the continuous conductive material 4 wound around the conductive material supply drum 13 passes between the molds 1 and 1 'as described above, and flows between the drum 14 (which may be a winding drum). Is stretched with a predetermined tension. Therefore, even if the resin 5 is filled from the cavity 15, the thin insert molded product 6 can be obtained without the conductive material 4 being deformed or eccentric.
After the thin insert molded product 6 is cooled and solidified, the molds 1 and 1 'are opened, and for example, after the lower mold 1' moves and is taken out of the mold by the ejection pin 21 (see FIG. 4), The conductive material 4 is wound around the drum 14 by a predetermined length, and the continuous conductive material 4 is moved and newly stretched in the mold. By repeatedly performing the above steps, a large number of thin-walled insert molded products 6 in which the continuous conductive material 4 is inserted can be obtained.
As described above, the conductive material may be stretched by applying tension to the conductive material supply drum 13 and the drum 14 or by another method of pulling the conductive material 4. For example, instead of the drum 14, a method of grasping and pulling a conductive material portion having no thin-walled insert molded product, or a multi-stage roll feeding of a conductive material portion having no thin-walled insert molded product by rotating a notch roll. However, a method in which the cutout portion is adapted to a thin-walled insert molded product may be used.
[0012]
FIG. 4 shows an example of an apparatus for manufacturing a thin insert molded product. In FIG. 4, reference numeral 20 denotes an injection molding machine, which is connected to the resin gate 15. Although there is no particular limitation on the injection molding machine, a vertical molding machine is often used at the time of hoop molding. Reference numeral 21 denotes a protruding pin, by which the thin insert molded product 6 is protruded from the mold.
[0013]
Resins The types of the resin (5) used in the present invention include thermoplastic resins, thermosetting resins, crystalline resins, non-crystalline resins, biodegradable resins, non-biodegradable resins, synthetic resins, and natural resins. Any type of resin, such as resin making, general-purpose resin, engineering resin, and polymer alloy, may be used.
General-purpose thermoplastic resins include polyolefins such as polyethylene (PE), polypropylene (PP), poly-4-methyl-pentene-1, and polycyclic olefin, polystyrene (PS), AS resin, ABS resin, polyvinyl chloride (PVC). ), Polyacrylonitrile (PAN), (meth) acrylic resin, cellulosic resin, elastomer and the like.
As the engineering resin, various aliphatic polyamides or aromatic polyamides (PA) such as nylon 6, 6, 6, 12, and 6, 12, polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polyethylene na Aromatic polyester resin such as phthalate (PEN), polycarbonate (PC), polyacetal, polyphenylene ether (PPO), polyphenylene sulfide (PPS), polysulfone (PSu), polyimide (PI), liquid crystal polyester, liquid crystal polyamide, fluorine resin And the like.
Examples of the thermosetting resin include phenol resin, epoxy resin, polyurethane, rubber, unsaturated polyester, urea / melamine resin, and silicone resin.
[0014]
Additives, etc. The above resin (5) may be mixed with resin additives, fillers, reinforcing materials, and the like, if necessary. Examples of the reinforcing material include glass fibers, carbon fibers, carbon nanotubes, carbon nanoparticles, graphite, glass flakes, mica, amorphous silica, glass beads, and glass balloons.
[0015]
Conductive material 4
The material of the conductive material 4 is not particularly limited as long as the material can easily flow the heated resin by heating the conductive material 4 to a desired temperature. Carbon and the like. There is no limitation on the shape of the conductive material 4, and examples thereof include a linear shape, a rod shape, a plate shape, an L-shaped plate shape, and a shape that can be pulled out from the thin insert molded product 6 by drawing the conductive material 4 to obtain a molded product having a thin hole. Are preferable, and a wire having a high roundness is more preferable.
[0016]
Method of Energizing To energize the conductive material 4, a method of providing the electrodes 16 and 16 ′ in a part of the mold as shown in FIG. 1 or a method of providing the electrodes 16 and 16 ′ outside the mold may be used. In the method of providing the electrodes outside the mold, the structure of the mold is simplified, the electrodes 16 and 16 ′ are provided at predetermined positions of the conductive material 4, a method of making direct contact, a method of clipping, a non-contact method Power is supplied by a method such as power supply.
The power supply controller 11 used to energize the conductive material 4 is used in accordance with the above-described energization method, and applies a voltage and flows a current so that the conductive material 4 is heated to a desired temperature. The heating period is preferably from after the conductive material 4 is stretched to the mold to before cooling of the molded article in the mold starts.
[0017]
Method for Manufacturing Thin-Walled Hole-Molded Product The conductive material 4 is extracted from the thin-walled insert-molded product 6 obtained as described above, and a thin-walled-hole formed product 9 can be obtained. To extract the conductive material 4 from the thin insert molded product 6, even if the conductive material 4 is cut on both sides of the thin insert molded product 6, the conductive material 4 is extracted from the thin insert molded product 6 without cutting the conductive material 4. Alternatively, if not cut, the conductive material 4 can be reused.
As a method of extracting the conductive material 4 from the thin insert molded product 6, for example,
(I) a method of applying a release agent to the conductive material 4,
(Ii) a method in which a flange 8 is provided at an end of a molded product, and a reaction force when the conductive material 4 is pulled out is received by the flange 8;
And the like, and these may be used in combination.
Examples of the release agent include fluorine, silicon, and molybdenum.
[0018]
In the present invention, the conductive material 4 may be extracted from the thin insert molded product 6, or the conductive material 4 may be extracted from the resin portion of the thin insert molded product 6 without actually extracting the conductive material 4 (that is, it corresponds to the molded product 9 having a thin hole). It may be in a state of sliding relative to.
[0019]
Shape of Thin-Walled Hole-Molded Product In the thin-walled hole-formed product 9 of the present invention, the conductive material 4 having a uniform diameter is extracted from the insert-formed product 6 to form the hole 7, and therefore, usually, as shown in FIG. , A columnar hole 7 is formed. If the conductive material 4 is cylindrical, the hole 7 is also cylindrical. If the conductive material 4 is rectangular, the hole 7 is also rectangular.
FIG. 3B shows an example of a molded product having a thin-walled hole having a tapered hole 17 in which one end of a cylindrical hole extends outward. The tapered hole 17 may be formed by boring the end of the thin-hole-formed product shown in FIG. 3 (a), but a tapered ferrule that is pulled out to one end side of a part of the conductive material 4 is formed. And the conductive material 4 with a ferrule may be pulled out, and a tapered hole 17 may be formed together with the hole 7 to facilitate insertion of the optical fiber.
FIG. 3C shows an example of a molded product having a thin-walled hole in which a flange portion 8 is integrally provided at an end portion by molding. By providing the flange portion 8, the conductive material 4 can be easily pulled out by gripping the flange portion 8 or hooking the flange surface. It should be noted that the outer diameter of the molded product having a thin hole may be different on both sides of the flange portion 8. Furthermore, the resin gate 15 may face the flange portion 8 to facilitate the removal of the runner.
FIG. 3D shows an example in which the flange portion 8 of the thin-walled hole-formed product provided with the flange portion 8 of FIG. 3C is bored to form a tapered hole 17.
FIG. 3E has a tapered hole 17 at the flange 8 at the other end, and a hole having a larger diameter than the hole 7 is formed at the opposite end, and the large diameter hole and the hole 7 are tapered. They are connected by holes. The large-diameter hole and the tapered hole can be provided in the resin molding step by forming the ferrule into a shape corresponding to the large-diameter hole and the tapered hole, as in FIG. 3B. . By forming the tapered hole 17 or the large-diameter hole 7 ′ at both ends, it becomes easy to insert the optical fiber from both ends, and it becomes easy to join the optical fibers from both ends in the middle of the hole 7.
FIG. 3F shows another example of a molded product having a thin hole. The flange portion 8 may be provided not at the end portion but at the middle of the molded product 9 having a thin hole.
[0020]
In the present invention, since the conductive material 4 is heated by supplying current when filling the resin, the flow of the resin cooled by contact with the mold can be overcome, and a thin-walled molded product can be obtained. In addition, by heating the conductive material 4, it is difficult for the position of the conductive material 4 to be displaced when the resin is filled, so that it is possible to obtain a thin-walled molded product with little eccentricity of holes and high accuracy.
According to the present invention, the thickness of the resin is 0.1 to 3.0 mm, preferably 0.3 to 1.0 mm, and the hole diameter φ is 0.1 to 2.0 mm, preferably 0.1 to 0. It is 8 mm, and it is possible to produce a thin-walled molded article having a fixed hole diameter portion of 0.5 mm or more, preferably 1.0 or more, particularly preferably 2.0 mm or more.
When the large-diameter hole 7 'is provided, its diameter is 2.5 to 3.5 mm, preferably 2.7 to 3.0 mm.
[0021]
The molded product with a thin hole according to the present invention is used for an optical fiber connector or the like.
[0022]
【Example】
Hereinafter, the present invention will be described specifically with reference to Examples, but the present invention is not limited thereto.
[0023]
[Example 1]
Vectra A460 (Liquid Crystal Polymer, manufactured by Polyplastics Co., Ltd.) is used as the resin, and a long stainless steel wire of 0.125 mm in diameter is used as the conductive material. After installation, the steel wire is energized and heated to a temperature not lower than the melting temperature of the resin, while the resin is injected and filled to form an insert molded product. After cooling, the steel wire is pulled out, and the shape shown in FIG. Thus, an optical fiber connector having a resin thickness of 0.6 mm, a hole diameter of 0.125 mm, and a length of a pore diameter portion of 5.0 mm was molded.
[0024]
【The invention's effect】
According to the present invention, a conductive material for forming a hole in an insert molded product is placed in a cavity by applying tension thereto, and injection molding is performed while the conductive material is energized to generate heat, and each time the insert molded product is wound. With this method, defective filling can be eliminated, and the occurrence of defective products due to the position of the hole of the molded product deviating from the original position or the broken product of the pin can be prevented.
[Brief description of the drawings]
FIG. 1 is a diagram showing an example of a relationship between a mold and a conductive material according to the present invention.
FIG. 2 is a diagram showing an example of a relationship between supply of a conductive material to a molding die apparatus according to the present invention and taking-off of a thin insert molded product obtained.
FIG. 3 is a cross-sectional view of an example of a molded product having a thin hole according to the present invention.
FIG. 4 is a view showing one example of a manufacturing apparatus for a thin insert molded product according to the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1, 1 'Mold 2, 2' Partition surface 3 Cavity 4 Conductive material 5 Resin 6 Thin insert molded product 7 Hole 7 'Large-diameter hole 8 Flange part 9 Thin molded product with thin hole 10 Molding device 11 Power controller 12 Insulation Material 13 Conductive material supply drum 14 Drum 15 Resin gate 16 Electrode 17, 17 'Tapered hole 20 Injection molding machine 21 Projection pin

Claims (12)

A step (I) of providing a continuous conductive material (4) between the partition surfaces (2, 2 ′) of the mold (1, 1 ′) so as to pass through the cavity (3) of the mold;
Next, a step of filling the resin (5) in the cavity (3) while energizing the conductive material (4) to heat the conductive material (4) to obtain a thin insert molded product (6) containing the conductive material ( II),
Next, the mold (1, 1 ') is opened, the thin insert molded product (6) is taken out of the mold, and the continuous conductive material (4) is moved, so that the thin insert molded product (6) is moved. Step (III) of providing the rear part of the part provided with the parentheses) between the partition surfaces (2, 2 ′) in the same manner as in the step (I).
A method for producing a thin insert molded product. The method according to claim 1, wherein the material of the conductive material (4) is metal or carbon. The method for producing a thin insert molded product according to claim 1 or 2, wherein the resin has a thickness of 0.1 to 3.0 mm. The step (IV) of extracting the conductive material (4) from the thin-walled insert molding (6) after the step (III) according to claim 1 to form a hole (7).
A method for producing a molded product having a thin-walled hole. The method of extracting the conductive material (4) from the thin insert molded product (6)
(I) a method of applying a release agent to the conductive material (4),
(Ii) A method in which a flange portion (8) is provided at an end portion of the molded product, and a reaction force when the conductive material (4) is pulled out is received by the flange portion (8), or (iii) a combination method thereof. 5. The method for producing a molded product having a thin hole according to item 4. The molded product having a thin-walled hole according to claim 4 or 5, wherein the resin has a wall thickness of 0.1 to 3.0 mm, and a fixed hole diameter portion having a hole diameter φ of 0.1 to 2.0 mm is 0.5 mm or more. Manufacturing method. A part of the conductive material (4) is fitted with a tapered ferrule that can be pulled out on one end side, the conductive material (4) with a ferrule is removed, and a tapered hole (17) in which one end of the hole (7) extends outward. The method for producing a thin-hole-formed article according to claim 4 or 5, which is formed. A flange portion (8) is integrally provided at an end of the thin-hole-formed product by molding, and a tapered hole (17 ′) in which one end of the hole (7) extends outward is further formed on the flange portion (8). The method for producing a molded product having a thin-walled hole according to any one of claims 4 to 7, which is formed in the step (V). A thin insert molded product obtained by the manufacturing method according to claim 1. A thin-walled hole-formed product obtained by the production method according to any one of claims 4 to 8. The thin-walled hole-formed product according to claim 10, which is used for an optical fiber connector. A molding apparatus used in the manufacturing method according to any one of claims 1 to 8,
An insulating material (12) for electrically insulating the conductive material (4) from the mold (1, 1 ') and electrodes (16, 16') for supplying a current to the conductive material (4) are provided. Power supply controller (11) for energizing the mold apparatus (10) and conductive material (4)
Molding apparatus having

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