JP3930306B2 - Metal tube manufacturing method - Google Patents

Description

[0001]
[Industrial application fields]
The present invention relates to a method of manufacturing a metal tube. More specifically, for example, a metal tube generally referred to as a ferrule such as an optical fiber connector or device has a true circular cross section and a diameter of 0.125 mmφ. The present invention relates to a method of manufacturing a component or the like that connects a core by accurately aligning the positions of cores at the center of the optical fiber by supporting an optical fiber having a thickness of 5 mm through a cylindrical tube.
[0002]
[Prior art]
Conventionally, in the case of a ferrule for an optical fiber, for example, it has a shape as shown in FIGS. 1 (a) and 1 (b), and a material using zirconia ceramics occupies the mainstream, and FIG. 1 (a). 1 is a single core type ferrule 1 having a cylindrical shape with a thickness of about 2.5 mmφ and a length of about 10 mm, and a round hole 2 having a diameter of about 0.1255 mmφ in the center. Is a two-core type.
[0003]
On the other hand, in the Japanese Patent Application No. 10-375372, the inventor electrocasts one or a plurality of metal or plastic wires as a mother die, removes the wires, and performs machining. A metal ferrule manufactured by a method such as nickel is proposed.
[0004]
In this patent, for example, electroforming is carried out with a schematic apparatus as shown in FIG. 2, for example. In FIG. 2, the electroforming liquid 3, the positive electrode 4, the holding jig 5, the air stirring nozzle 6, a spring 7, a negative electrode 8, and a line 9.
[0005]
In the SUS, a positive electrode 4 in which nickel spheres are placed in a cylindrical titanium basket in an electroforming solution 3 mainly composed of heated nickel sulfamate is arranged at four corners with a holding jig 5 as a center. A holding jig 5 having a minus electrode 8 fixed to a state where the wire 9 such as a wire is pulled by a spring 7 is set at the center, and a direct current is applied while a small amount of air is blown out from the air stirring nozzle 6 and stirred. A method has been proposed in which a rod having a predetermined thickness is formed by casting, a center line is removed, and then a metal tube having a predetermined dimension is manufactured by machining.
[0006]
In this patent, a method for drawing a line has been proposed, but there are occasional things that do not come off at this time.
[0007]
[Problems to be solved by the invention]
In view of the above, the present invention provides a method of manufacturing a metal tube such as a ferrule for an optical fiber in which one or a plurality of metal wires are used as a matrix, and the wires are removed after electroforming. The problem is to improve productivity by improving line pull-out.
[0008]
[Means for Solving the Problems]
Line pull-out is the most important factor in yield rate and machining efficiency for improving productivity, and has been the main research theme of the inventor for many years. -Treated SUS wire has been used, but when these metal wires are used, the higher the tensile strength, the better the disconnection rate. However, as a result of recent research, it has been found that there is a metal wire with a remarkably good pulling rate even with a low tensile strength, and the present invention has been achieved by intensively pursuing the cause.
[0009]
That is, in the case of a conventional tempered SUS wire, the tensile strength is about 2400 N / mm ² and the elongation is about 0 to 2%, but the average value of the measured value of the drop-out rate is about 95% with a length of 25 mm. The length of 50 mm is about 80%, and the length of 100 mm is about 50%. However, it is desirable to remove in a longer state in terms of machining productivity, and the length is about 100 mm or more. As a result of studying at a rate of 90% or more, it has been clarified that a metal wire having a high elongation rate and a relatively high tensile strength has a particularly good pulling rate, a high elongation rate, and a tensile strength. Adopted means of using relatively high metal wire.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
More specifically, FIG. 3 is a configuration diagram of an electroforming apparatus showing an embodiment of the present invention. The electroforming liquid 3 differs depending on the material of the target electroformed metal, for example, nickel. Alternatively, an electroformed metal such as an alloy thereof, iron or an alloy thereof, copper or an alloy thereof, cobalt or an alloy thereof, a tungsten alloy, or a fine particle-dispersed metal can be employed. Nickel sulfamate, nickel chloride, nickel sulfate, sulfamic acid first An aqueous solution mainly composed of an aqueous solution of iron, ferrous borofluoride, copper pyrophosphate, copper sulfate, copper borofluoride, copper silicofluoride, copper copper fluoride, copper alkanol sulfonate, cobalt sulfate, sodium tungstate, or the like, or In these liquids, silicon carbide, tungsten carbide, boron carbide, zirconium oxide, silicon nitride, alumina, diamond What fine powder liquid were dispersed is used. Of these, a bath mainly composed of nickel sulfamate is particularly suitable in terms of easiness of electroforming, various physical properties such as hardness, chemical stability, and ease of welding. The electroforming liquid is filtered at a high speed with a filter having a filtration accuracy of about 0.1 to 5 μm, heated and controlled to an appropriate temperature range of about 50 ± 2 ° C., and sometimes activated carbon treatment is performed. To remove organic impurities.
[0011]
The positive electrode 4 differs depending on the target electroformed metal, and is selected from nickel, iron, copper, cobalt, etc., and a plate-like or spherical one is used as appropriate. In the case of using a spherical one, it can be used by placing it in a titanium basket and covering it with a polyester cloth bag. The positive electrode 4 is arranged at the center of the circular jig fixing structure 15 so as to be positioned at equal intervals with all of the holding jigs 5 so that the electroforming speed is constant and the electroforming speed is almost equal. Although it is desirable from the end of casting, the position of the plus electrode 4 is not limited to this position. For example, the plus electrode 4 may be arranged at a plurality of locations along the outer wall of the electroforming tank 10, The fixture fixing structure 15 is not necessarily circular, and may be elliptical, for example.
[0012]
Stirring such as air, propeller, ultrasonic wave, and supervibration can be employed for stirring, but it is also possible to omit stirring by increasing the rotation speed of the holding jig and adding a pit inhibitor.
[0013]
Further, in FIG. 3, it is configured that one integrating ammeter 13 is used for one holding jig 5, and a small rectifier is used for each holding jig 5. Although it is desirable because it is easy to perform management, it is not necessarily limited to this, and many holding jigs 5 may be energized with one large rectifier.
[0014]
FIG. 4 is a schematic side view showing details of the vicinity of the holding jig 5 according to one embodiment of the present invention. The jig fixing structure 15, the holding rod 16, the free rotating portion 17, and the belt receiving device 18, belt 12, electrical insulating portion 19, negative electrode spring 20, connecting portion 21, holding jig 5, spring 7, wire 9, and clip 22. 16 is welded, is rotated idly by the free rotating portion 17, the rotation of the belt 12 is transmitted to the belt receiving wheel 18 and rotated, and the holding jig 5 is rotated 10 to 1000 rpm via the electric insulating portion 19 and the connecting portion 21. The holding jig 5 is held in a state in which the wire 9 is pulled by the clip 22 and the spring 7, and the electroforming liquid surface 23 is positioned as shown in FIG. Therefore, a negative current is applied only to the lower side of the electrical insulation part 19 Cast a may be performed.
[0015]
In the present invention, a metal wire having a high elongation rate and a relatively high tensile strength is used as the wire 9, but a wire having an elongation rate of about 10 percent or more and a tensile strength of about 500 N / mm ² or more is used. With a length of 100 mm, a drop rate of about 90% or more can be obtained. Desirably, by using a wire having an elongation of about 20 percent or more and a tensile strength of about 1000 N / mm ² or more, the drop rate is reduced. Further, the removal rate of about 90% or more was obtained with a length of about 200 mm.
[0016]
In the present invention, any metal wire can be used as long as it meets such conditions, but it is appropriately selected from iron alloy wire, copper alloy wire, titanium alloy wire, aluminum alloy wire, nickel alloy wire, tungsten alloy wire, etc. Can be, but it has two types of iron alloy wire with good corrosion resistance such as annealed SUS wire, phosphor bronze wire, beryllium copper alloy wire, nickel-titanium shape memory alloy wire, cover wire, invar wire, aluminum bronze Alloy wire is highly suitable. Among them, phosphor bronze wire, beryllium copper alloy wire, nickel-titanium shape memory alloy wire (martensitic), aluminum bronze type 2 alloy wire have good electrical conductivity, so uniform electrodeposition This is a particularly desirable metal wire from the viewpoint of properties.
[0017]
Electroforming is carried out with the apparatus as described above. In the electroforming, a direct current is applied at a current density of about 4 to 10 A / dm ² for a predetermined time and is grown in a rod shape to a predetermined thickness. First, start with a low current, gradually increase the current, and when the accumulated current amount reaches a predetermined deposition amount (thickness) for each holding jig 5, the current from the rectifier is automatically It is desirable to have a configuration that cuts off
[0018]
【The invention's effect】
The present invention has the following effects by the method described above. One or a plurality of metal wires 9 are used as a mother die, and after electroforming, the wires 9 are pulled out. In the manufacture of various metal tubes such as ferrules and devices for optical fibers, the metal wires 9 extend. By adopting a means that uses a metal wire with a high rate and a relatively high tensile strength, the wire pull-out rate is remarkably improved, and as a result, the yield rate and the working efficiency of machining are improved. Can significantly increase the performance.
[Brief description of the drawings]
FIG. 1 is an enlarged sectional view and a side view of a ferrule according to a conventional method.
FIG. 2 is a schematic configuration diagram of an electroforming apparatus according to a conventional method.
FIG. 3 is a schematic plan view showing an embodiment of an electroforming apparatus according to a conventional method.
FIG. 4 is a side view showing a schematic configuration in the vicinity of a holding jig of the rotary electroforming apparatus according to the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Ferrule 2 True circular hole 3 Electroforming liquid 4 Positive electrode 5 Holding jig 6 Air stirring nozzle 7 Spring 8 Negative electrode 9 Wire 10 Electroforming tank 11 Holding jig rotation driving motor 12 Belt 13 Accumulated ammeter 14 Pulley 15 Jig fixing structure 16 Holding rod 17 Free rotating part 18 Belt receiving 19 Electric insulation part 20 Negative electrode spring 21 Connecting part 22 Clip 23 Electroforming liquid surface

Claims (6)

In a method of manufacturing a metal tube in which one or a plurality of metal wires are used as a mother die and electroformed, and then drawn out, the elongation is 20% or more and the tensile strength is 1000 N / mm ² or more. Use the line
A method for manufacturing a metal tube. The method of manufacturing a metal tube according to claim 1, wherein the metal tube is a ferrule used for an optical fiber connector. The method of manufacturing a metal tube according to claim 2, wherein the material of the wire is beryllium-copper alloy, phosphor bronze alloy, nickel-titanium shape memory alloy, or aluminum bronze alloy. The method of manufacturing a metal tube according to claim 2, wherein the material of the wire is an iron alloy, a Kovar wire, or an Invar wire. The method for producing a metal tube according to claim 3 or 4, wherein the electroforming liquid used for the electroforming is mainly composed of nickel sulfamate. In the electroforming, a direct current is passed through the wire so that the current gradually increases within a current density range of 4 to 10 A / dm ^{2, and} the amount of current flowing through the wire becomes a predetermined integrated current amount. 6. The method of manufacturing a metal tube according to claim 5, wherein the direct current flowing through the wire is stopped when the value is reached.

Images