JPS6038685B2 - Method of manufacturing a mold for forming terminal parts of optical connectors - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing the main mold parts of a molding die for producing a terminal member of an optical fiber connector as a highly accurate plastic molded product.

As shown in FIGS. 1 and 2, the optical fiber connector includes a terminal member 3 provided with a hole 6 into which the optical fiber core 1 is inserted, a microscopic hole 4 into which the optical fiber 2 is inserted, and a sleeve. It is composed of 5.

The terminal member 3 of such a connector has an outer diameter of the part into which the sleeve 5 is inserted with high precision, and an inner diameter of approximately the same diameter as the diameter of the optical fiber strand, with an eccentricity of several rms or less in the center. It has a cylindrical structure with micro-protrusions 4, and the subordinate bolt was manufactured by cutting. In order to reduce the connection loss of optical fibers due to such a connector, it is necessary to reduce the misalignment between both optical fiber wires to be connected to less than a few degrees. The dimensional accuracy of the eccentricity of the hole 4 must also be within a few degrees. Therefore, in the past, they were made one by one by cutting using expensive machine tools, which increased equipment costs and made them expensive because they were not suitable for mass production. Furthermore, since each piece is machined by cutting, the dimensional accuracy varies from piece to piece, making it difficult to stably manufacture highly accurate connector terminal members. In order to reduce the cost, it is possible to make the terminal member by plastic molding, but it is difficult to manufacture a large number of high-precision molds without variations in dimensions, and it is difficult to make a connection with low loss. It has been difficult to manufacture plastic optical connectors.

In view of the above-mentioned points, the present invention makes it possible to easily produce a large number of mold parts with high precision, which are the main parts of a mold for making terminal members of optical connectors from plastic, and with uniform precision. It provides a method by which it can be manufactured, which will be described in detail below.

In order to obtain a plastic terminal member by molding, the third
It can be manufactured by constructing a molding die as shown in the figure.

That is, a hole 17 having the same diameter as the outer dimension of the terminal member to be made is formed, and a hole 17 and a small diameter hole 1 of the wind circle are formed in the bottom wall.
8, a main mold 16 having a cylindrical shape with a bottom, and this mold 16.
a lower mold 22 for housing and supporting the optical fiber core, a round part 20 for forming a hole into which the coated part 1 of the optical fiber core is inserted, and a main mold 16 formed on one end side of this round part 20. The strand part 2 of the optical fiber is inserted into the small diameter hole 18 without any gap.
A mold 1 having a pin portion 21 for forming an insertion hole 4 of
9, a hole is formed to hold this mold 19 and form the other end including the collar portion of the terminal member 3 of the connector, and a sprue 24 for injecting resin and the resin is uniformly poured into the cavity. It is constituted by an upper mold 23 formed with a ring-shaped gate 26 to facilitate insertion and prevent uneven force from being applied to the tip pin portion 21 of the mold 19. The tip of the pin part 21 of the mold 19 is tapered to make it easier to fit into the minute hole 18. In order to reduce the connection loss of the optical fiber, the terminal member of the connector is attached to the sleeve 5 with an accuracy of 1 to 2 mm or less with respect to the required outer diameter of the outer periphery, and a minute outer diameter hole is formed on the outer periphery of the connector. It is necessary to make the corner of No. 4 2 to 3 inches below the skin. Therefore, it is necessary to make the precision of the hole 17 of the main mold 16 and the concentric precision of the minute folding hole 18 with respect to the hole 17 extremely high. Also mold 1
Although the diameter of the pin portion 21 of 9 also needs to be highly accurate, this mold 19 can be easily made with high accuracy by cutting or the like. However, since the main mold 16 is provided with a minute hole 18 at the bottom of the hole 17 that is to form the outer periphery of the terminal village 3, the hole 17 is formed when such a structure is made by direct cutting or the like. On the other hand, it is extremely difficult to machine the hole 18 into the same zero shape with high precision. Furthermore, when mass-producing plastic terminal members, multiple molding machines are used to simultaneously manufacture products with uniform precision, and replacement molds that can be replaced when the mold wears out due to repeated molding must also have the same precision. is necessary. Therefore, as described above, the present invention enables the production of such a main mold 16 with high precision and in large numbers with the same precision. To make a cylindrical body 7 provided with a through hole 8 of minute diameter with an eccentricity of 1 to 2 degrees or less.

This cylindrical body 7 is manufactured by cutting metal or ceramics, and its outer diameter is 1% relative to the diameter of the terminal member to be created.
It can be made with the precision of a mountain surface. Further, the diameter of the microscopic hole 8 is formed to be about one thread larger than the outer diameter of the optical fiber to be used. Next, as shown in FIG. 4B, a master mold 10 is made by inserting and fixing a wire 9 having the same diameter as the micro flanges 8 into the micro flanges 8 of the cylindrical body 7. The wire 9 is made of a strong steel material such as tungsten wire or steel wire so that the protrusion from the small diameter hole 8 is difficult to bend. If the cylindrical body 7 is made of ceramic, the surface is subjected to a conductive treatment such as metal vapor deposition, and then the master mold 10 is made into a Kamesen-taka (a Kamesen-taka) consisting of a box holder 12, a nickel electrode 13, and a power source 14, as shown in FIG. 4c. 1. A fleas mirror layer 15 of sufficient thickness
Forms a frost-like body that grows. The mass mold 10 is removed from the coin body, and the outer periphery is processed to form a main mold 16 which is a flea mold as shown in FIG. 4d. The main mold 16, which is the crab mold created in this way, is the master mold 10.
is transferred with an accuracy of less than 0.1 french, and therefore, the minute diameter hole 18 has an eccentricity of less than 1 to 2 degrees relative to the master mold 10. Furthermore, no matter how many similar tortoise molds are made using the same mass mold 10, it is possible to obtain a faithful copy of the master mold in the same way. Next, we will explain the experimental results of the connection loss of optical fibers connected using plastic terminal members molded using the main mold, which is an open mold, manufactured using the main mold of the present invention and molded using the molding mold incorporating this mold. 2.0±0.001 ribs, micro fleas diameter 0.127±0
．． 001 series, a cylindrical body with a micro-scale hole on the 00.001 side or less is created by cutting ceramics, and a micro-scale hole with a diameter of 0.00 mm is created.
A master mold is formed by inserting and adhesively fixing 126 steel wires on the surface, and depositing gold on the surface.Then, this master mold is placed in a nickel metal tube at a current density of 1 hA' at a temperature of 35 cm.
It was soaked for 20 days under o0 conditions to form a nickel electrodeposition layer with a thickness of approximately 7 layers, and then the master mold was removed and the outer periphery was processed to create a haze mold.

This lightning mold was incorporated into a molding die as the main mold, and the terminal portion was molded by transfer molding of phenol resin. Into each of the pair of terminal members formed in this way, an optical fiber with an outer mold side of 0.125 and a core diameter side of 0.08 is inserted, and connected side by side to a split sleeve made of phosphor bronze. As a result of measuring the splice loss of optical fiber, the average was 0. The value of Mother B was obtained. As described above, according to the present invention, the main mold part of a molding die, which is extremely difficult to directly manufacture with high precision by cutting etc., can be easily manufactured with high precision. It is possible to manufacture many units of the same precision from the mass/event type.

Therefore, by using a molding mold incorporating the main mold part produced thereby, it is possible to mass-produce terminal members of the same high-precision optical connector at a lower cost.

[Brief explanation of drawings]

Fig. 1 is a sectional view showing a state in which optical fibers are connected by an optical connector, Fig. 2 is a perspective sectional view of the terminal portion of the optical connector, and Fig. 3 is a sectional view of the entire mold for forming the terminal member of the optical connector. , FIG. 4 is an explanatory diagram of the manufacturing process of the main mold according to the present invention. 2... Optical fiber wire, 3... Terminal member of optical connector, 4... Optical fiber wire insertion hole, 5... Sleeve, 7... ...Cylindrical body, 8
...Minute flea hole, 9...Wire, 12.
...Denka Zoku, 15...Denka Layer, 16...
... Main mold consisting of electroforming mold, 18 ... Hole, 19 ... Mold, 20 ... Round part, 2
1...Pin part. Figure 1 Figure 3 Figure 2 Figure 4

Claims (1)

[Claims] 1. The diameter of the optical fiber wire, which has an outer periphery that is precisely the same diameter as the outer diameter of the sleeve insertion part of the terminal member of the optical connector to be created, and is inserted and connected to the terminal member with high accuracy and concentricity with respect to the outer periphery. A master mold is created by inserting and fixing a wire having approximately the same diameter as the hole into the micro-diameter hole of a cylindrical body in which a micro-diameter hole with an extremely slightly larger diameter is provided so that the wire protrudes outside of the hole. and perform electroforming by immersing the master mold in an electroforming bath,
An electroformed body is prepared by forming an electroformed layer of a required thickness on the master mold, the master mold is removed from the electroformed body, and after the master mold is removed, the hole formed by the wire is filled with:
A mold having a round bar part for forming a hole into which a coated part of an optical fiber core is inserted, and a pin part for forming a hole into which a strand part of an optical fiber is inserted following the round bar part. A method of manufacturing a mold for forming a terminal member of an optical connector, characterized in that an electroforming mold is obtained into which the pin portion is inserted.