KR100427444B1 - Upper chamber switching apparatus for an optical fiber drawing furnace - Google Patents

Abstract

The present invention relates to an upper chamber opening and closing device for an optical fiber melting furnace. It is connected to the driving means installed on the outside to block the discharge to form two blocking means that operate to open and close the opening of the chamber is blocked by a double, so the discharge of the internal gas and the inflow of external air is blocked when replacing the fiber base material It is possible to replace the optical fiber base material in the state, to maintain the internal atmosphere as much as possible, the graphite resistance heating plate is also prevent the oxidation is extended life is the upper chamber opening and closing device for the optical fiber melting furnace that can improve the optical fiber quality and productivity.

Description

Upper chamber switching apparatus for an optical fiber drawing furnace}

The present invention relates to an upper chamber opening and closing apparatus for an optical fiber melting furnace, in order to block external air from flowing into the melting furnace when the optical fiber base material is introduced into the optical fiber edge furnace, so that only the optical fiber base material is introduced through the blocking device. The upper chamber opening and closing device for the optical fiber melting furnace to prevent the change in the atmosphere of the fiber can be produced continuously high quality optical fiber.

The optical fiber base material (preform) is an intermediate material in the manufacture of optical fibers, and is generally formed in the same structure as the optical fiber and melted with a high temperature to manufacture the optical fiber.

In other words, the structure is formed in the same manner as the optical fiber, and the central core is formed in the form of a double cylinder surrounded by a cladding around it.

The optical fiber finished with the optical fiber base material is generally covered with a protective exposure on the outside to protect the inside. The entire size except the protective coating has a diameter of 100 to several hundred μm (1 μm is 1/1000 mm). Since the refractive index is higher than the refractive index of the cladding, the light is focused on the core portion so that the light can proceed without exiting well.

Such an optical fiber base material is generally subjected to a flame hydrolysis reaction in an inside (MCVD method) or outside (OVD method (outside vapor phase deposition)) while rotating an appropriate mounting table (graphite, fraud rod or high purity quartz tube) in the axial direction. Thus, the silicon oxide layer synthesized with germanium, boron, phosphorus, etc. is fabricated as an optical fiber base material while being deposited by dozens of times.

In addition, a vapor phase axial deposition (VAD) method for growing a base material directly on the end of a quartz rod is also used.

The completed optical fiber base material is edged to a predetermined diameter through the optical fiber cutting device as shown in Figure 1 which is a view schematically showing the configuration of a general optical fiber cutting device.

That is, the optical fiber cutting line 10 of FIG. 1 melts and heats the injected optical fiber base material 1 to a constant temperature, and then applies tension to radiate the optical fiber 2 to form an optical fiber 2 having a predetermined diameter ( 11), a cooling device 12 for cooling the optical fiber 2 drawn out of the melting furnace 11, a coating device 13 for coating a protective material on the optical fiber 2 passed through the cooling device 12 and It consists of a curing device 14 for curing the protective material by passing through the optical fiber 2 coated with the protective material.

That is, as shown in the configuration of the conventional optical fiber edge melting furnace of Figure 2, the melting furnace 11 is a heating means (11a) formed inward to heat the input optical fiber base material 1, and the melting furnace ( 11) An Ar gas supply part 11b for supplying Ar gas to the inside was formed.

Here, the optical fiber base material 1 is heated to a predetermined temperature by heating means 11a, such as a graphite heating plate, which is introduced into the melting furnace 11 and formed therein, and at one side of the melting furnace 11, an Ar gas supply part 11b. To form Ar gas into the melting furnace 11 to prevent oxidation in the Ar gas atmosphere.

Radiation is made so that the optical fiber base material 2 having a constant diameter is formed in the heated optical fiber base material 1, and the optical fiber 2 radiated from the melting furnace 11 is still at a high temperature and passes through the cooling device 12. To cool.

In addition, since the optical fiber 2 is weak to humidity and abrasion, the protective material is directly coated through the coating device 13 immediately after cooling. At this time, the protective material is mainly used KYNAR (Polyvinylidene Fluoride: PVDF), epoxy, UV curing resin.

The protective material coated on the optical fiber 2 is cured by a curing furnace of the curing device 14 while passing through the curing device 14.

The optical fiber 2 coated up to the protective material is wound into the spool 15 to be commercialized.

In addition, although not shown in the drawing during the process of the optical fiber 2, a measuring instrument capable of measuring the diameter of the optical fiber, such as a laser micrometer, is arranged to continuously measure the diameter of the optical fiber 2 from radiation.

However, the quality of the optical fiber during the entire manufacturing process is the melting furnace for melting the base material, although the operation is performed while the upper part of the melting furnace is blocked, conventionally shielding the inflow of external air during the replacement of the optical fiber base material. Without it, the fiber base material was exchanged with the upper part of the melting furnace completely open.

Thus, when the upper part of the melting furnace is opened and opened, the internal gas of high temperature rises and escapes due to the density difference, and instead, the external air descends into the melting furnace by the pressure difference and flows in. The external air flowing in from the outside has a big difference in temperature with the gas inside, which causes a big change in the temperature inside the melting furnace.In particular, the graphite heating plate reacts with the carbon of the graphite heating plate installed inside the melting furnace where oxygen in the outside air reaches 2000 ℃. Particles separated from the graphite heating plate generated in this process are oxidized to the optical fiber base material, causing optical fiber breakage, and thus affecting the optical fiber, which is a big problem in the quality of the optical fiber.

In addition, the graphite heating plate has a problem that the life of the graphite heating plate is shortened because oxidation proceeds every time the optical fiber base material is replaced.

That is, these problems were problems that hinder the improvement of production efficiency and quality in the manufacture of high precision optical fiber.

The present invention has been made to solve the above problems, an object of the present invention is to prevent the outside air flow into the interior of the furnace for the optical fiber edge line to maintain the atmosphere inside the furnace, in particular oxidation of the graphite heating plate To prevent lifespan and to extend the life of the graphite heating plate, and to reduce the adhesion of particles to the optical fiber base material to reduce the breakage of the optical fiber to improve productivity and manufacture high quality optical fiber In providing a chamber opening and closing device.

1 is a view schematically showing the configuration of a general optical fiber cutting apparatus.

2 is a configuration diagram showing the configuration of a conventional melting furnace for optical fiber edge lines.

3 is a block diagram of the upper chamber opening and closing apparatus for the optical fiber melting furnace according to the present invention.

Figures 4a to 4f is an operation example of the upper chamber opening and closing apparatus for the optical fiber melting furnace of the present invention.

-Explanation of symbols for the main parts of the drawings-

1: Optical fiber base material 2: Optical fiber

10: optical fiber edge device 11: melting furnace

11a: heating means 11b: Ar gas supply portion

12 cooling device 13 coating device

14 curing device 20 chamber

21 cooling means 31 first blocking means

32: second blocking means 33: heat insulating material

40: driving means

The present invention for realizing the above object is installed on the upper end of the optical fiber melting furnace to melt the optical fiber base material to be radiated into the optical fiber and the upper and lower chambers are respectively opened, and installed on the upper of the chamber outside It is connected to the installed drive means provides an upper chamber opening and closing device for the optical fiber melting furnace characterized in that the blocking means for opening and closing the opening of the chamber is formed.

The blocking means is formed by the first blocking means formed on the upper end of the chamber and the second blocking means formed on the lower end of the chamber.

An insulating material is formed on the lower surface of the second blocking means, and the driving means is an electric motor.

A heat radiation member is formed on an outer surface of the chamber, and the heat radiation member is a heat radiation fin or a heat radiation piece.

Hereinafter, exemplary embodiments of the present invention will be described with reference to the accompanying drawings. In addition, the present embodiment is not intended to limit the scope of the present invention, but is presented by way of example only and the same parts as in the conventional configuration using the same reference numerals and names.

First, the upper chamber opening and closing apparatus for the optical fiber melting furnace of the present invention is installed on the melting furnace 11 upper portion of the optical fiber cutting line 10 shown in FIG. Therefore, the injected optical fiber base material 1 is introduced into the melting furnace 11 through the upper chamber opening and closing apparatus for the optical fiber melting furnace of the present invention, heated to a constant temperature in the melting furnace 11 and melted, and radiated by tension. To become an optical fiber 2 having a predetermined diameter, and the optical fiber 2 drawn out of the melting furnace 11 is cooled while passing through the cooling device 12, and the protective material is coated while passing through the coating device 13 again. The protective material is cured while passing through the curing device 14 to manufacture the optical fiber 2.

Figure 3 is a block diagram of the upper chamber opening and closing device for the optical fiber melting furnace according to the present invention, Figure 4 is an operation example of the upper chamber opening and closing device for the optical fiber melting furnace of the present invention.

The upper chamber opening and closing apparatus for the optical fiber melting furnace of the present invention is installed on the upper end of the optical fiber melting furnace 11 for melting the optical fiber base material 1 to be radiated into the optical fiber 2, the upper and lower chambers respectively opened 20 And the optical fiber base material 1 flowing into the optical fiber melting furnace 11 and connected to the driving means 40 installed in the chamber 20 to block the inflow of external air and the discharge of the internal gas. And a blocking means operable to open and close the opening of the chamber 20.

The blocking means is formed of the first blocking means 31 formed on the upper end of the chamber 20 and the second blocking means 32 formed on the lower end of the chamber 20 to configure the double blocking.

The lower surface of the second blocking means 32 is formed with a heat insulating material 33, so as to shield the high temperature heat conducted in the melting furnace 11 of the lower side.

In addition, the drive means 40 provided outside the chamber 20 is preferably formed of an electric motor such as a stepping motor (stepping motor) to be able to precisely control.

However, the driving means 40 may be formed in a configuration that can manually open and close the blocking means 31, 32 so that the operator can directly input the optical fiber base material 1. That is, the blocking means 31 It is also possible to configure the 32 to be operated by the rotation of the handle through the gear portion.

When the optical fiber base material 1 is introduced, which drive means 40 is used, the blocking means 31 and 32 are opened and closed to the extent that only the optical fiber base material 1 can pass therethrough.

In particular, it is preferable to form the cooling means 21 on the outer surface of the chamber 20. Although the cooling means may be provided with separate cooling devices, it is most preferable to form a heat radiating member so as to radiate heat conducted in the melting furnace 11.

The heat radiation member forms a heat radiation fin or a heat radiation piece.

In addition, the material of the chamber 20 is also formed to withstand the heat conducted in the melting furnace of the lower by using a material having excellent durability at high temperatures and excellent thermal conductivity.

Operation of the upper chamber opening and closing apparatus for the optical fiber melting furnace of the present invention described above will be described with reference to FIG.

First, the inside of the melting furnace 11 is replaced by a graphite heating plate which is a heating means 11a. It is heated to such an extent that Ar gas is continuously supplied through the Ar gas supply part 11b.

In this case, in order to supply the optical fiber base material 1 into the melting furnace 11, first, the first blocking means 31 formed at the upper end of the chamber 20 is driven by the driving means 40 for the first blocking means 31. The optical fiber base material 1 is opened and closed so that the optical fiber base material 1 can pass. This can be opened and closed by checking the degree of the opening while the operator checks directly, and although not shown in the figure above, the measuring device for measuring the diameter of the optical fiber base material, such as a laser micrometer By measuring the diameter of the optical fiber base material introduced into the first blocking means 31 in real time, and controlling the driving means 40 through a separate control unit according to the result of measuring the diameter of the optical fiber base material 1. ) Is opened and closed.

Accordingly, as shown in FIGS. 4A to 4C, the first blocking means 31 is opened and closed according to the degree of entry of the optical fiber base material 1 and the diameter of the optical fiber base material 1 so that only the optical fiber base material 1 chamber 20 ) Is entered, and outside air cannot enter. On the other hand, the air in the chamber 20 is slightly discharged as the optical fiber base material 1 enters, but the room for the introduction of external air by the air in the discharged chamber 20 is further reduced.

In addition, when the optical fiber base material 1 is continuously lowered, it reaches the second blocking means 32 formed at the lower end of the chamber 20. The second blocking means 32 is also similar to the first blocking means 31. The driving means 40 for the second blocking means 32 is opened and closed to the extent that the optical fiber base material 1 can pass therethrough. It can be opened and closed by checking the degree of the opening while the operator checks directly, and the measuring device that can measure the diameter of the optical fiber base material, such as a laser micrometer, although not shown in the figure above the second blocking means 32 In this case, the diameter of the optical fiber base material to pass through the second blocking means 32 is measured in real time, and the driving means 40 is controlled through a separate control unit to control the driving means 40 according to the measurement result of the diameter of the optical fiber base material 1. 32) to open and close.

Accordingly, as shown in FIGS. 4D to 4F, the second blocking means 32 is opened and closed according to the degree of entry of the optical fiber base material 1 and the diameter of the optical fiber base material 1 so that only the optical fiber base material 1 is second blocked. Passing through the means 32 will enter into the furnace 11 while descending.

At this time, the Ar gas is continuously supplied to the inside of the melting furnace 11 through the Ar gas supply part 11b, so that the pressure inside the melting furnace 11 is higher than the outside, so that the gas inside the melting furnace 11 is discharged to the chamber 20 and the air in the chamber 20 is discharged. Does not flow into the furnace 11. Therefore, the atmosphere in the melting furnace 11 can be maintained as much as possible.

Therefore, double blocking is made by the first blocking means 31 and the second blocking means 32, so that only the optical fiber base material 1 flowing into the optical fiber melting furnace passes and the inflow of external air and the discharge of the internal gas are blocked. The atmosphere inside is maintained to prevent oxidation of the graphite heating plate, which is the heating means 11b formed inside the melting furnace.

In addition, a heat insulating material 33 is formed on the lower surface of the second blocking means 32 to prevent the heat of the melting furnace 11 from being conducted, thereby protecting the blocking means 31 and 32 and the chamber 20. On the outer surface of the (20) is formed a heat radiation fin or a heat radiation piece to radiate the heat of the chamber 20 in an air-cooled manner to prevent the temperature rise of the chamber 20.

As described above, the present invention forms a shielding means to double the optical fiber base material to replace the optical fiber base material while preventing the rising of the internal gas due to the pressure difference while the upper part of the melting furnace is opened when the upper part of the melting furnace is opened. It is possible to prevent the oxygen in the incoming air from reacting with the carbon of the graphite resistance heating plate located on the wall of the furnace in a high temperature environment, thereby reducing the generation of oxide particles generated in the graphite resistance heating plate, thereby improving the quality of the optical fiber. There is an advantage to this. In addition, since the oxidation of the graphite heating plate is prevented, there is an advantage of extending the life of the graphite heating plate. Therefore, since the degradation of the optical fiber quality is prevented by the replacement of the optical fiber base material, the productivity is improved as well as the optical fiber quality is improved.

Claims (7)

A chamber installed at the upper end of the optical fiber melting furnace which melts the optical fiber base material to be radiated into the optical fiber, and the upper and lower chambers are respectively opened; The upper chamber opening and closing device for the optical fiber melting furnace, characterized in that formed in the upper portion of the chamber and connected to the drive means installed outside to open and close the opening of the chamber. The upper chamber opening and closing apparatus for an optical fiber melting furnace according to claim 1, wherein the driving means provided outside the chamber is an electric motor. The upper chamber opening and closing apparatus for an optical fiber melting furnace according to claim 1, wherein the blocking means is formed of a first blocking means formed at an upper end of the chamber and a second blocking means formed at a lower end of the chamber. 4. The upper chamber opening and closing apparatus for an optical fiber melting furnace according to claim 3, wherein an insulating material is formed on a lower surface of the second blocking means. The upper chamber opening and closing apparatus for an optical fiber melting furnace according to any one of claims 1 to 3, wherein a cooling means is formed on an outer surface of the chamber. 6. The upper chamber opening and closing apparatus for an optical fiber melting furnace according to claim 5, wherein the cooling means is a heat radiation member. 7. The upper chamber opening and closing device for an optical fiber melting furnace according to claim 6, wherein the heat dissipation member is a heat dissipation fin or a heat dissipation piece.