JP2000301579A - Method and apparatus for manufacturing injection molding having fine long hole - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a deformation of a fine-diameter core pin and to assure a dimensional accuracy of a portion having a fine long hole therein by gradually filling molten resin in a lengthwise direction of the pin by utilizing a moving plate. SOLUTION: Molds 41, 31 are opened. A slide block 32 is placed at a starting position. A second slide block 39 is moved to approach a moving dowel 34 to a clamp piece 37. An end of a fine-diameter core pin 33 is fixedly held, and the molds 41, 31 are closed. Molten resin is injection molded from a gate G. The plate 35 and the dowel 34 are slowly moved against a force of a spring in response to a charging resin amount. Then, generated gas when the resin is filled is externally drawn from a gap or the like between a pinhole P of the plate 35 and the pin 33, while the plate 35 is moved from a starting point of a cavity C1 to an ending point from a portion formed with a portion having a fine long hole therein. After the filling is completed, the molds are opened. Thus, a pressure to the pin 33 is lowered to prevent its deformation, and fine holes of high accuracy can be assured.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and apparatus for manufacturing a connector ferrule used for connecting an injection-molded product having a fine elongated hole, for example, an optical fiber.

[0002]

2. Description of the Related Art As an example of a connector ferrule used for connecting an optical fiber to an injection-molded product having a portion having a fine elongated hole therein, Japanese Patent Publication No. 6-54364.
What is described in the issue is known. FIG. 4
This will be described with reference to FIG.

[0003] A pair of guide pin insertion holes (13) and (13) for receiving a guide pin and a tip of one or more optical fibers are provided at the tip of a small ferrule body (11) having a box shape as a whole. Small slot for inserting optical fiber (14)
A recess (12) for pouring an adhesive is formed at the center of the surface of the ferrule main body, and an opening (15) for drawing out the main line side of the optical fiber is formed at the rear end. The recess (12) and the opening (15) are in communication. Further, the fine optical fiber insertion hole (14) communicates with the bottom of the recess (12). In addition, at the bottom of the concave portion (12), one or more grooves are provided for convenient placement of one or more optical fibers.
(16) is provided. On the other hand, the guide pin insertion hole (1
3) and (13) need not be communicated with the recess (12) and are formed only on the left and right meat portions of the ferrule body (11). When an optical fiber is attached to this connector, a plurality of optical fibers are inserted from the opening (15) as shown in FIG. 4, and the tip of each optical fiber is inserted into the minute slot (14). Is done.

A conventional method of manufacturing the connector ferrule will be described with reference to FIGS.
One of the injection molds (21) to be fixed, the other movable mold (22) which is detachably moved with respect to the mold (21), and the pair of molds (21) and (22). The cavity of the product is formed by the slide block (25) sliding on the separation surface between the two.

[0005] The shape of the slide block (25) is extremely thin at the tip with an outer diameter substantially equal to the outer diameter of the optical fiber.
For example, one or more small-diameter core pins (26) having an outer diameter of 0.125 mm are provided, and a thick portion and a lid (27) at which the opening (15) of the ferrule body (11) is to be formed at the rear end are provided. I have it. Furthermore, at the time of injection molding of the product, a pair of upper and lower clamp means (2) for holding and fixing the distal end of the small-diameter core pin (26).
3) and (24) are fixed inside the pair of molds (21) and (22), respectively. Then, a molten epoxy-based thermosetting resin or a thermoplastic resin (29) such as PPS is injected from a gate (not shown) into the cavity, and after the resin is hardened, the small-diameter core pin (26) is injected. ) Is slid together with the slide block (25) in the direction of the arrow to pull out the core pin, and then the movable mold (22) is moved to take out the product.

[0006]

The small diameter core pin (26) is bent and deformed in proportion to the pressure of the molten resin at the time of injection molding. Usually, the pressure of the molten resin exceeds 150 MPa, so that not only the bending of the small-diameter core pin (26) but also the gap between the molds (21) and (22), the small-diameter core pin and the clamping means. The molten resin flows into the gap (28) between (23) and (24), and burrs are generated. In addition, small diameter core pin (2
When bending deformation occurs in 6), it becomes difficult to secure the dimensional accuracy of the optical fiber insertion fine hole (14) formed by the small diameter core pin, and fatigue fracture of the small diameter core pin occurs. There are drawbacks such as the need for maintenance. An object of the present invention is to provide a method of manufacturing an injection-molded article having a portion having a fine elongated hole therein, which resolves these disadvantages, and an apparatus for manufacturing the same.

[0007]

SUMMARY OF THE INVENTION According to the present invention, the length of a small-diameter core pin is adjusted by using a moving plate so that the pressure of molten resin does not instantaneously apply to the entire length of the small-diameter core pin during injection molding. A method and apparatus for manufacturing an injection-molded article provided with a portion having a fine elongated hole therein so that a molten resin can be gradually filled in a vertical direction.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS By providing a moving plate in a cavity for controlling a rapid flow of a molten resin while preventing deformation of a small diameter core pin for forming a portion having a fine elongated hole therein. An injection product having a small-diameter core pin with deformation prevention and high-precision fine holes can be obtained.

[0009]

(Embodiment 1) An example of the present invention will be described with reference to FIGS. The other movable mold (3), which is detachably opposed to one of the fixed injection molds (41)
1) is installed. At least one small-diameter core pin (33) serving as a core for forming the fine elongated hole (14) between the pair of molds, for example, the outer diameter of the optical fiber is 0.
A slide block (32) in which a core pin having an outer diameter substantially equal to 125 mm is protruded at the tip is formed with a groove (3) in which the mold (31) is formed.
It is slidably mounted on 1A). When it is necessary to form a through hole having a relatively large inner diameter in the injection molded product, a thick rigid second core pin (33A) for this purpose is also protruded.

The cavities (C1) and (C1) are formed by the opposing surfaces of the molds (41) and (31) and the slide block (32).
(C2) is formed. Here, the cavity (C1) is a portion that forms a portion having a fine elongated hole therein,
(C2) is a portion that forms a portion having no minute long hole therein. Further, on the facing surface of the molds (41), (31),
Clamp means is constituted by one clamp piece (42) protruding from the mold (41) side and the other clamp piece (37) protruding from the other mold (31) side. The tip of the small-diameter core pin (33) is temporarily held during injection molding. In this case, at least one clamp piece has a groove (37) for receiving the tip of the small-diameter core pin (33).
A) For example, V-shaped grooves are engraved according to the number of small-diameter core pins, and a minute groove for providing a gas release function described later is provided between the groove and the small-diameter core pins. Gap is formed. Further, a moving plate (35) moving inside the cavity (C1) and a moving piece (34) moving outside the cavity are arranged before and after the clamp means, and both are integrally connected. This moving plate (35) has a cavity
It is configured to be slidable along the vicinity of the inner wall of the cavity with a size and accuracy such that the molten resin filled in (C1) does not flow out of the cavity (C1).

A pin hole (P) for slidably receiving the small-diameter core pin (33) is formed at the center of the moving plate (35). Slidably receiving through holes having a relatively large inner diameter are also formed. A second slide block (39) is slidably mounted between the opposing surfaces of the molds (41) and (31) outside the cavity, and the movable piece is placed on the second slide block (39).
(34) is slidably disposed relative to the second slide block (39). An urging means (36), for example, a spring means such as a spring coil, a leaf spring, or a disc spring is provided between the second slide block (39) and the moving piece (34). Therefore the moving plate (35) in the cavity
When moving toward the outside of the cavity, the moving plate (35)
The moving piece (34) integrally connected with the moving piece also moves in the same direction, and as a result, the moving piece (34) presses the urging means (36). The urging means (36) and the second slide block (39) can be replaced with a hydraulic device or a pneumatic device.

After the injection molding, when the engagement between the molds (41) and (31) is released, the moving piece (34) and the second slide block (39) are separated from each other by the energy stored in the spring means. However, the second slide block is a locking part at the rear end of the mold (31).
(31B), and the movable piece (34) is configured to be locked by a projection (39A) protruding from the distal end of the second slide block itself. During molding, the mold (41)
In the case where a small gap is generated between the two dies due to some unexpected cause, for example, the pressure of the injected resin between the core pin (33) and the clamp means of the core pin (33), It is expected that a gap will be generated and the function of the clamp means will be reduced. In this case, as shown in FIG. 12, a clamp piece (42) protruding from one of the molds (41)
Is configured to be movable with respect to the mold (41) via urging means (42A) such as a coil spring, a plate spring, and a disc spring.
Even if there is a small gap between (1) and (31), the clamp piece
Since the biasing means (42A) protrudes and moves by the urging means (42A) so as to compensate for the minute gap, the above-mentioned fear is eliminated. here
(42B) is a fixing member fixed to the mold (41).

Next, a method of manufacturing a product using the above-described apparatus will be described. At the initial position in FIG. 1, a pair of dies (41) and (31) are
(32) is moved to the start position and the second slide block (39) is moved to move the moving piece (34) close to the clamp piece (37). Close). At this time, the tip of the small diameter core pin (33) is held and fixed by the clamp means. Then the mold gate
The molten resin is injected and filled from (G). At this time, the moving plate (35) and the moving piece (34) move slowly against the urging force of the spring means according to the amount of resin to be filled. The gas generated at the time of filling the resin while this moving plate moves from the starting point of the cavity (C1), that is, a portion forming a portion having a fine elongated hole therein, to the end point is a pinhole (P) of the moving plate (35).
And the gap between the small-diameter core pin (33) and the gap between the clamping means and the small-diameter core pin (33). In this way, after the filling of the resin is completed, the mold is released, the slide block (32) is retracted in the direction of the arrow, the small-diameter core pin (33) is removed from the molded product, and the product is then molded. Discharged from At this time, the second slide block (39) and the moving piece (34) return to the initial position by the spring back of the spring means.

(Embodiment 2) Another embodiment of the present invention will be described with reference to FIGS. Other injection molded articles having a portion having a fine slot therein, for example, another connector ferrule (60) for connecting an optical fiber has a fine slot (63) for receiving a tip portion of the optical fiber. Tip (6
1) and a base (62) with a somewhat finer slot (64) for receiving the mains side of the optical fiber as coated. This ferrule is manufactured with the device shown in FIG. A small-diameter core pin (33) is integrally protruded from the center of one of the molds (41), and the core pin (33) is provided with the fine elongated hole (63).
And a portion (33C) for forming a portion having a somewhat fine elongated hole (64). The periphery of the part where the part (33C) is fixed to the mold forms a substantially cylindrical space part, and this space part is the base part.
A cavity (C2) for forming (62) is formed. On the other hand, the other mold (31) is provided with a cavity (C1) that forms the tip (61) of the ferrule continuously with the cavity (C2). The exit of the cavity (C1) is provided with a clamping means (30) for clamping the tip of the small-diameter core pin (33).
A) and (30B) are attached to the mold (31) so that they can be opened and closed freely.

A movable plate (35) that slides inside the cavity (C1) is mounted at the entrance of the cavity (C1) with the clamping means (30A) and (30B) interposed therebetween. The moving plate (35) has a pinhole formed so that the small-diameter core pin (33) can be inserted and slidable to each other, and the molten plate filled in the cavity (C1). It is configured to be slidable along the vicinity of the inner wall of the cavity (C1) with a size and accuracy such that the resin does not flow out of the moving plate (35). In addition, cavity (C1)
At the exit of the moving piece (34) is mounted movably in the internal groove of the mold (31), and the moving plate (35) and the moving piece (34)
And are connected integrally. For this reason, both move integrally. An urging means (36) for urging the moving piece (34), for example, a spring means such as a spring coil, a plate spring, and a disc spring is mounted in the internal groove of the mold (31).

Next, a method of manufacturing a product using the above-described apparatus will be described. From the initial position in FIG. 9, one of the pair of molds (41) and (31) is moved to bring them into close contact with each other, and the small-diameter core pin (33) is passed through the pinhole of the moving plate (35). The tip of the small diameter core pin (33) is held by the clamp means (30A) and (30B). Next, when the molten resin is filled from the gate (G) of the mold (41), the cavity of the mold (41) is filled.
Flow into (C2) base of ferrule around core pin (33)
(62) is formed. Subsequently, the molten resin slowly flows into the cavity (C1) while moving the moving plate (35) against the spring force of the spring means, and flows around the small-diameter core pin (33) at the tip of the ferrule (33). 61). Next, one mold is separated, and the small-diameter core pin (33) is extracted. At this time, the moving plate (35) and the moving piece (34) return to the initial position by the urging means (36). Thereafter, the product is removed from the mold.

[0017]

The present invention has the following effects. By using the moving plate (moving piece), the gas generated when filling the molten resin into the cavity by injection molding can escape well, so that the injection molding can be performed at an extremely low pressure,
In addition, since low-speed molding can be performed by the urging means, pressure acting on the small-diameter core pin is reduced, and deformation of the small-diameter core pin can be prevented. For this reason, highly accurate micropores can be obtained.

Also, since molding can be performed at a low pressure, burrs are less generated. Further, since the filling property of the resin is improved, gates of various shapes can be adopted.

Since the movable plate is arranged at the tip of the molded product and is formed so as to be movable, the "chamfering" or "spotting" of the molded product is performed by variously selecting the shape of the portion where the movable plate contacts the molded product. Etc. can be performed automatically.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram showing an example of the method of the present invention in chronological order.

FIG. 2 is a perspective view showing a main part of the apparatus of the present invention.

FIG. 3 is a perspective view showing a main part of the apparatus of the present invention.

FIG. 4 is an explanatory view showing an example of a product manufactured by the present invention.

FIG. 5 is a front view of an example of a product manufactured according to the present invention.

FIG. 6 is a longitudinal sectional view of an example of a product manufactured according to the present invention.

FIG. 7 is a perspective view showing another example of a product manufactured by the present invention.

8 is a longitudinal sectional view in FIG.

FIG. 9 is an explanatory diagram showing another example of the method of the present invention in chronological order.

FIG. 10 is an explanatory view showing a conventional manufacturing method.

FIG. 11 is a view taken in the direction of the arrow ZZ in FIG.

FIG. 12 is an explanatory view showing another example of the clamping means of the device shown in FIGS. 2 and 3;

[Explanation of symbols]

 31 Movable mold 41 Mold 35 Moving plate 33 Small diameter core pin 36 Biasing means 32 Slide block 37, 42 Clamp piece 34 Moving piece

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Kosei Ishibashi 1-5-1, Kiba, Koto-ku, Tokyo Inside Kyoei Line Materials Co., Ltd. (72) Masahiro Shibata 1-5-1, Kiba, Koto-ku, Tokyo No. Kyoei Line Material Co., Ltd. (72) Inventor Minoru Nakamura 1-5-1, Kiba, Koto-ku, Tokyo Kyoei Line Material Co., Ltd.

Claims (9)

[Claims] An injection mold (41) and one of said molds (41).
In the cavity space formed between the other movable mold (31) which is separable from the other, a small-diameter core pin (33) for forming a fine elongated hole (14) is provided in the space. After the molten resin is injected into the cavity to fill the outside of the small-diameter core pin (33) with the molten resin, the small-diameter core pin is pulled out and a fine elongated hole is formed therein. A method for manufacturing an injection-molded article to be formed, wherein a moving plate (35) moving along and close to an inner wall of a cavity forming a portion having the fine elongated hole therein comprises the small-diameter core pin. The movable plate is slidably mounted on the small-diameter core pin while the tip of the small-diameter core pin is fixed to the mold, and then the movable plate is pressed with the molten resin pressure. The moving plate is pressed against the pressure of the molten resin filled in the cavity through the urging means (36) for urging the moving plate. Is moved from the start point to the end point of the cavity. 2. The urging means when the mold is released.
2. The method according to claim 1, wherein the movable plate is returned to the original position by the method (36). 3. An injection-molded article having a fine elongated hole is a connector ferrule used for connecting an optical fiber. 3. The injection molded article having a fine elongated hole according to claim 1, wherein Manufacturing method for injection molded products. 4. An injection mold (41) and one of said molds (41).
A slide block having at least one small-diameter core pin (33) for forming a fine elongated hole (14) between the movable mold (31) and the other movable mold (31) which can move freely. 32) is slidably mounted, a cavity for filling the molten resin is formed by the facing surfaces of these molds and the slide block, and after the molten resin is injected into the cavity, the slide block is retracted. An apparatus for producing an injection-molded article having a part having a fine elongated hole therein configured to pull out a small-diameter core pin by pulling out the small-diameter core pin. (33)
Clamp pieces (37), (42) for temporarily holding the tip of the small-diameter core pin with a small gap when the slide block is moved to the molten resin filling position.
Is provided inside the mold, and the clamping means is provided at an end of a cavity (C1) forming a portion having a fine elongated hole therein, and the cavity side of the clamping means is provided from a starting point of the cavity (C1). A moving plate (35) which moves along the inner wall of the cavity to the end point and has a pinhole for penetrating the small-diameter core pin is slidably mounted, and is provided on the other side of the clamping means. A moving piece (34) integrally connected to the moving plate (35) is slidably mounted on the mold, and the moving piece (34) is attached to the mold via biasing means (36). An apparatus for producing an injection-molded article having a portion having a fine elongated hole therein, which is characterized by being mounted. 5. A second slide block (39) is slidably mounted between the pair of molds, and the movable piece (34) is further slidable with respect to the second slide block (39). And a spring means is provided between the second slide block and the moving piece for urging the two in a direction away from each other, and the second slide block is fixed between the molds while filling the resin. The moving piece together with the moving plate compresses the spring means and retreats, and after the resin is filled, the second slide block and the moving piece are separated by the spring means when the mold is released. 5. An apparatus for producing an injection-molded article having a portion having a fine elongated hole therein according to claim 4. 6. An injection-molded article having a portion having a fine elongated hole therein according to claim 4, wherein at least one of the clamp means is configured to be movable with respect to the mold via a biasing means. manufacturing device. 7. An injection mold (41) and one of said molds (41).
In the cavity space formed between the other movable mold (31) which is separable from the other, a small-diameter core pin (33) for forming a fine elongated hole (14) is provided in the space. After the molten resin is injected into the cavity to fill the outside of the small-diameter core pin (33) with the molten resin, the small-diameter core pin is pulled out to form a fine elongated hole therein. An apparatus for manufacturing an injection-molded article having a portion having a small-diameter core pin (33) for forming a fine elongated hole therein toward a cavity of the other mold in one mold. At least one projection is provided, and the other mold cavity is provided with a clamp means for fixing and holding the tip of the small-diameter core pin at the time of filling the molten resin. Movement with a pinhole through which the small-diameter core pin penetrates (35) is mounted slidably, said moving plate on the other side (3
A moving piece (34) integrally connected to the mold (5) is slidably mounted on the mold, and the moving piece (34) is urged by the urging means (3
An apparatus for manufacturing an injection-molded article having a portion having a fine elongated hole therein, which is mounted on a mold through (6). 8. The apparatus according to claim 4, wherein said urging means is a spring means.
An apparatus for producing an injection-molded article comprising a portion having a fine elongated hole therein according to claim 7. 9. The apparatus according to claim 4, wherein said biasing means is a hydraulic or pneumatic control device.