JP2011173734A - Extended tube for spinning machine and spinning machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an extended tube for a spinning machine improving the airtightness of the extended tube for annealing installed under a heating furnace, and the fiber cutting performance under the heating furnace, controlling the dimension of the optical fiber with high accuracy and certainly preventing defects such as scratch, and the spinning machine. <P>SOLUTION: In the spinning machine, the optical fiber 14 is passed downward from the heating furnace 10 through a first extended tube 24 communicating with the lower part of the heating furnace 10, a bellows extended tube 26 surrounding the periphery of the first extended tube 24 for annealing and having a bendable and flexible bellows type body 26a and a second extended tube for annealing which communicates with the lower part of the first extended tube 24 for annealing, and annealed, wherein the lower part of the first extended tube 24 for annealing is inserted into an upper end part opening of the second extended tube 28 to be movable back and forth and the upper end of the bellows extended tube 26 is detachably fixed to the lower part of an adaptor 30 and the lower end is detachably fixed to the upper end of the second extended tube 28 for annealing. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an extension pipe for a spinning machine and a spinning machine used for manufacturing an optical fiber, and more particularly to an extension pipe for slow cooling installed under a heating furnace and a spinning machine provided with the extension pipe.

  As shown in FIG. 5A, an optical fiber spinning machine conventionally used inserts an optical fiber preform 12 into the heating furnace 10 from above, and heats the preform 12 with the heat of the heater 10a. Then, the optical fiber 14 is continuously manufactured by taking out the tip 14a of the optical fiber 14 that has been melted and drawn out of the melted base material 12 with a take-up machine (not shown). A heat insulating material 10c is loaded in the outer wall portion 10b of the heating furnace 10 so that the heat generated by the heater 10a does not escape.

  Below the heating furnace 10, there is provided an extension tube 16 for slow cooling that gradually cools by passing a high-temperature optical fiber 14 after melting, and is gradually added by blowing gas or air into the extension tube 16. It is cooled (Japanese Patent Application Laid-Open No. 2004-155610 (Patent Document 1), Japanese Patent Application Laid-Open No. 10-194770 (Patent Document 2)).

  In this type of slow cooling extension pipe 16, flanges 16b and 16c are formed at the upper and lower ends of the pipe body 16a. The adapter 18 is fixed by screwing an upper portion 18a (formed with a male screw) into a screw portion 10d (formed with a female screw) at the lower portion of the heating furnace 10. And the female screw hole similar to the said screw part 10d is formed in the lower part of the adapter 18. FIG. Sealing between the lower surface of the heating furnace 10 and the adapter 18 and between the adapter 18 and the flange of the slow cooling extension pipe 16 is performed by an O (O) ring or the like.

  As shown in FIG. 5 (b), the flange 16b at the upper end of the slow cooling extension pipe 16 is formed with a male screw 16d on the outer periphery of the cylindrical portion protruding upward.

  The slow cooling extension pipe is fitted to the adapter 18 (the heating furnace 10) by screwing and fixing the male screw 16d protruding in a cylindrical shape of the upper end flange 16b from below into the female screw hole below the adapter 18. 16 is connected and fixed.

  In this way, the slow cooling extension pipe 16 is fixed by screwing the male screw 16d of the flange 16b into the lower part of the adapter 18, so that when the slow cooling extension pipe 16 is bent, the bending is corrected. The slow cooling extension tube 16 needs to be centered (position adjustment, etc.). However, centering is difficult due to the following problems.

That is, in order to center the slow cooling extension tube 16, for example, as shown in FIG. 5, the screw 22a from the four sides in the X and Y directions along the horizontal direction of the free end of the slow cooling extension tube 16 on the non-fixed side is provided. An aligning jig 22 that is pressed by 22a... Is provided. (C) of FIG. 5 is an alignment jig viewed from the vertical direction. The frames indicated by reference numerals 22b and 22b are positioned so as to sandwich the extension pipe 16 for cooling, and are screwed into the frames 22b and 22b. The screws 22a, 22a ... are brought into contact with the slow cooling extension pipe 16. Reference numeral 22c denotes a base to which the alignment jig 22 is attached.
At the time of alignment, the free end of the slow cooling extension tube 16 is appropriately shaken in the X and Y directions and bent by turning the screws 22a, 22a... If the bending of the slow cooling extension pipe 16 is large, the heating furnace 10, the adapter 18, the male threaded portion 16d of the flange 16b, etc. There is a possibility that the seal portion provided at an appropriate position of the screw portion is distorted and the inside of the heating furnace 10 and the slow cooling extension pipe 16 becomes poor and the internal gas leaks.

As a cause of bending of the installed extension pipe 16 for slow cooling,
(1) The case where the screw portion 10d at the bottom of the heating furnace 10 is not formed along the vertical direction.
(2) The slow cooling extension pipe 16 is manufactured by welding the flanges 16b and 16c to the pipe body 16a. At this time, the flanges 16b and 16c are bent (distorted) with respect to the pipe body 16a. There are cases.

  Further, since the slow cooling extension pipe 16 is connected to the adapter 18 by screwing (fixing), the slow cooling extension pipe 16 is removed from the adapter 18 to make a space, and an optical fiber near the lower portion of the heating furnace 10. There is also a problem to be solved that 14 cannot be cut and becomes an obstacle to improving workability.

  On the other hand, as described in Patent Document 1 and Patent Document 2, the slow cooling extension tube 16 is not suitable for the optical fiber in order to prevent the generation of silica (SiC) on its surface and to improve the dimensional accuracy. The optical fiber is slowly cooled by drawing in an active gas and blowing an inert gas into the slow cooling extension tube.

  The inventor has devised a bellows as a structure in which the slow cooling extension tube 16 can be easily removed from the lower part of the heating furnace 10 (unknown). However, since the bellows structure has an internal concavo-convex portion, the concavo-convex portion may disturb the flow of inert gas around the optical fiber and affect the control of the fiber diameter.

  In addition, when silica is deposited on the uneven portion of the bellows, the deposited silica may adhere to the optical fiber, and the optical fiber may be damaged, resulting in problems such as disconnection.

JP 2004-155610 A JP-A-10-194770

  In view of such a situation, the present invention provides a fiber under a heating furnace that is obtained by simply removing the airtightness of the slow cooling extension pipe installed under the heating furnace from the heating furnace and the adapter and the slow cooling extension pipe. Provided are an extension tube for a spinning machine and a spinning machine that can improve cutability, control the dimensions of an optical fiber with high accuracy, and reliably prevent defects such as scratches on the optical fiber.

  The present invention relates to an extension tube for a spinning machine and a spinning machine.

The present invention provides an optical fiber which is provided with a hollow slow cooling extension tube at the lower part of a heating furnace for heating an optical fiber preform, and gradually cools the optical fiber drawn downward from the heating furnace through the hollow. In the spinning machine
The slow cooling extension pipe has a first slow cooling extension pipe communicating with the lower part of the heating furnace, and a bellows having a bellows-shaped body that can be bent and stretched around the first slow cooling extension pipe It is an extension pipe for a spinning machine having an extension pipe and a second slow cooling extension pipe communicating with the lower part of the first slow cooling extension pipe.
In the present invention, a hollow adapter is provided at the lower part of the heating furnace, and the upper end of the first slow cooling extension pipe is detachably fixed to the lower part of the adapter so that the adapter and the first slow cooling extension pipe are attached. And the second slow cooling extension pipe are communicated with each other, and the lower part of the first slow cooling extension pipe is preferably inserted into the upper end opening of the second slow cooling extension pipe so as to be movable back and forth. It is.
In the present invention, it is preferable that the bellows extension pipe has an upper end detachably fixed to the lower part of the adapter and a lower end fixed detachably to the upper end of the second slow cooling extension pipe.

In the present invention, the adapter is provided with a flange at the lower end,
The bellows extension pipe is provided with flanges at the upper and lower ends of a bellows-shaped main body,
The second extension tube for slow cooling is provided with a flange at least at the upper end of the tubular main body,
The upper flange of the bellows extension pipe is screwed with a separate screw to the lower part of the adapter fixed to the lower part of the heating furnace,
It is preferable that the flange at the upper end of the second slow cooling extension pipe is screwed to the flange at the lower end of the bellows extension pipe with a separate screw.

Further, in the present invention, a cylindrical screw portion that communicates with the hollow opening at the lower end of the adapter and has a male screw formed around it is formed to project downward, and the first extension tube for slow cooling is formed at the upper end. A flange is formed,
The flange at the upper end is abutted against the lower end of the cylindrical screw portion at the lower end of the adapter, and the cylindrical female screw body is screwed into the male screw at the protruding portion so as to wrap around the flange at the upper end. It is preferable that the upper end of the tube is fixed to the adapter.

  In the present invention, it is preferable that the second slow cooling extension pipe is provided with an extension pipe bracket that supports the main body from the side and is movable for centering.

  The present invention is an optical fiber spinning machine using the slow cooling extension pipe.

According to the extension pipe for a spinning machine and the spinning machine of the present invention, the extension pipe for slow cooling includes a first extension pipe for slow cooling communicating with the lower part of the heating furnace, and a periphery of the first extension pipe for slow cooling. And a second slow cooling extension pipe communicating with the lower part of the first slow cooling extension pipe, so that the slow cooling extension pipe is provided. When centering the bellows, the bellows of the bellows extension tube can be flexibly bent.
In the present invention, the upper end of the first slow cooling extension pipe is detachably fixed to the lower part of a hollow adapter provided in the lower part of the heating furnace, and the adapter, the first slow cooling extension pipe, and the second slow cooling are fixed. In addition, the lower part of the first slow cooling extension pipe is inserted into the upper end opening of the second slow cooling extension pipe so as to be able to move forward and backward. The position of the extension pipes can be adjusted.
Moreover, it is preferable that the upper end of the bellows extension pipe is detachably fixed to the lower part of the adapter and the lower end is detachably fixed to the upper end of the second slow cooling extension pipe.

  Further, when the first slow cooling extension pipe and the second slow cooling extension pipe are centered by the bellows extension pipe, the adapter provided at the lower part of the heating furnace and the slow cooling extension pipe itself are twisted. Since there is no such thing, it is possible to reliably prevent a decrease in airtightness.

  Further, when the optical five is pulled out from the base material heated in the heating furnace, the optical fiber can be pulled out from the first slow cooling extension tube through the second slow cooling extension tube, and the optical fiber is exposed in the bellows. Therefore, silica or the like is not deposited on the inner surface of the bellows having irregularities.

  Further, since the lower part of the first slow cooling extension pipe is inserted into the upper end opening of the second slow cooling extension pipe so as to be able to advance and retract, the centering or the bellows extension pipe may be deformed. Even if a position change occurs in the second slow cooling extension tube, it can cope with good airtightness.

  In addition, since the first slow cooling extension tube can be attached to and detached from the adapter, when it is necessary to cut the optical fiber, the bellows extension tube and the first slow cooling extension tube are removed from the lower part of the adapter, and the bellows extension tube However, since the bellows-like main body can be expanded and contracted, the bellows can be shrunk to easily make a space in the lower part of the heating furnace, and the optical fiber can be exposed to be cut and easily handled.

  In the present invention, the adapter is provided with a flange at the lower end, the bellows extension tube is provided with a flange at the upper end and the lower end of the bellows-shaped main body, and the second slow cooling extension tube is at least of the tubular main body. Assuming that a flange is provided at the upper end, a flange at the upper end of the bellows extension pipe is screwed to the lower part of the adapter fixed to the lower part of the heating furnace with a separate screw, and the second flange is connected to the flange at the lower end of the bellows extension pipe. By connecting the flange at the upper end of the slow cooling extension pipe with a separate screw, the bellows extension pipe can be easily removed by removing the screw.

  Further, in the present invention, a cylindrical threaded portion that communicates with the hollow opening at the lower end of the adapter and has a male screw formed around it is formed to project downward, and the first slow cooling extension tube has a flange at the upper end. The upper end flange is abutted against the lower end of the cylindrical screw portion at the lower end of the adapter, the upper end flange is wrapped around, and the cylindrical female screw body is screwed into the male screw of the protruding portion, so that the first By fixing the upper end of the slow cooling extension pipe to the adapter, the first female slow cooling extension pipe can be removed from the adapter with a simple operation by turning the cylindrical female screw body and removing it from the cylindrical screw portion. Can do.

  Further, in the present invention, the second slow cooling extension pipe can be supported and centered by providing an extension pipe bracket that supports the main body from the side and is movable for centering. .

1 is an overall explanatory view of a spinning machine provided with a slow cooling extension pipe according to an embodiment of the present invention. It is explanatory drawing of the extension pipe | tube for slow cooling of FIG. 1, and its periphery. It is longitudinal cross-sectional explanatory drawing from the heating furnace lower part of the extension pipe for slow cooling of FIG. FIG. 2 is a detailed longitudinal sectional view of the vicinity of the first slow cooling extension pipe of the slow cooling extension pipe of FIG. 1. (A) is an overall explanatory view of a spinning machine provided with a conventional spinning machine extension pipe (slow cooling extension pipe), (b) is an explanatory view around the adapter, and (c) is an alignment for the slow cooling extension pipe. It is explanatory drawing which the jig crossed.

  Embodiments of the present invention will be described below with reference to the accompanying drawings.

  FIG. 1 is an overall explanatory view of a spinning machine provided with a slow cooling extension pipe according to the embodiment, FIG. 2 is an explanatory view of the slow cooling extension pipe of FIG. 1 and its surroundings, and FIG. FIG. 4 is a detailed longitudinal sectional view of the vicinity of the first slow cooling extension tube of the slow cooling extension tube of FIG. 1. In the figure, the same reference numerals as those in FIG.

  As shown in FIGS. 1 to 4, the optical fiber spinning machine according to the embodiment includes a hollow slow cooling extension pipe (first slow cooling extension pipe) at the bottom of the heating furnace 10 that heats the optical fiber preform 12. 24, a bellows extension pipe 26, and a second slow cooling extension pipe 28), and the optical fiber 14 drawn downward from the heating furnace 10 is passed through the hollow of the slow cooling extension pipe and gradually cooled. To do.

  The slow cooling extension pipe includes a first slow cooling extension pipe 24 that communicates with the lower part of the heating furnace 10 and a bellows-shaped body that can be bent and stretched around the first slow cooling extension pipe 24. A bellows extension pipe 26 having 26a, and a second slow cooling extension pipe 28 communicating with the lower part of the first slow cooling extension pipe 24.

  A hollow adapter 30 is provided in the lower part of the heating furnace 10, and the upper end of the first slow cooling extension pipe 24 is detachably fixed to the lower part of the adapter 30 so that the adapter 30 and the first slow cooling extension pipe 24 are fixed. And the second slow cooling extension pipe 28 are communicated with each other, and the lower part of the first slow cooling extension pipe 24 is inserted into the upper end opening of the second slow cooling extension pipe 28 so as to be able to advance and retract. ing.

  The bellows extension pipe 26 has an upper end detachably fixed to the lower part of the adapter 30 and a lower end fixed detachably to the upper end of the second slow cooling extension pipe 28.

  Here, the adapter 30 is provided with flanges 30b and 30c at the upper and lower ends of a tubular main body 30a.

  The bellows extension pipe 26 is provided with flanges 26b and 26c at the upper and lower ends of a bellows-shaped main body 26a.

  The second slow cooling extension pipe 28 is provided with flanges 28b and 28c at the upper and lower ends of a tubular main body 28a.

  The flange 26b at the upper end of the bellows extension pipe 26 is abutted against the lower flange 30c of the adapter 30 fixed to the lower part of the heating furnace 10, and they are screwed together by a separate screw 32 (preferably a bolt with a hole or a hexagonal bolt). The flange at the lower end of the bellows extension pipe 26 is screwed to the flange at the upper end of the second slow cooling extension pipe 28 by a separate screw 34 (preferably a bolt with a hole or a hexagon bolt).

  The screw 32 is threaded downward from the lower flange 26 c (through hole) of the adapter 30 to the flange 26 b (female screw hole) of the bellows extension pipe 26 and screwed.

  Similarly, the flange 26b at the lower end of the bellows extension pipe 26 is brought into contact with the flange 28b at the upper end of the second slow cooling extension pipe 28 so that the two (flange 26c and flange 28b) are separated from each other by screws 34 (holes). Screw or hexagon head bolt is preferred). The screw 34 is threaded downward from the flange 26c (through hole) of the bellows extension pipe 26 to the flange 28b (internal thread hole) of the second slow cooling extension pipe 28 and screwed.

  The adapter 30 is provided with flanges 30b and 30c at the upper and lower ends of a tubular main body 30a. A cylindrical portion 30d having a male screw formed on the outer periphery from the upper portion of the upper flange 30b is formed to project upward. The cylindrical portion 30d is screwed into the screw portion 10d at the lower part of the heating furnace 10, and the upper end flange 30b is brought into contact with the lower part of the heating furnace 10 and attached.

  As shown in FIGS. 3 to 4, the adapter 30 is formed with a cylindrical threaded portion 30 e that communicates with the hollow opening at the lower end thereof and has a male screw formed around it, and projects downward. Further, the first slow cooling extension pipe 24 has a flange 24b formed at the upper end of the main body 24a.

  The flange 24b at the upper end of the first slow cooling extension tube 24 is abutted against the lower end of the cylindrical screw portion 30e at the lower end of the adapter 30, and the cylindrical female screw body 36 such as a nut is wrapped around the flange 24b at the upper end. The upper end of the first slow cooling extension tube 24 is fixed to the adapter 30 by screwing into a male screw of the screw portion 30e. Reference numeral 38 denotes a sealing O (O) ring.

  Further, the second slow cooling extension pipe 28 is provided with an extension pipe bracket 40 which supports the main body 28a from the side and is movable for centering.

  The optical fiber spinning machine according to the embodiment uses the first slow cooling extension pipe 24, the second slow cooling extension pipe 28, and the bellows extension pipe 26 of the slow cooling extension pipe.

  The adapter 30, the first slow cooling extension pipe 24, the second slow cooling extension pipe 28, and the bellows extension pipe 26 are all made of stainless steel (SUS) for durability at high temperatures. preferable. The screws 32 and 34 are also preferably made of SUS material as necessary.

  The extension pipe bracket 40 includes a support jig 40a that supports the main body 28a of the second slow cooling extension pipe 28 and a driver 40b that drives the support jig 40a left and right. ing. The extension pipe bracket 40 is preferably made of aluminum. In addition, the driving mechanism of the driving body 40b can be set as appropriate, and the illustration thereof is omitted.

  As shown in FIG. 2, the support jig 40a has a cylindrical shape, and the second slow cooling extension pipe 28a 28a is provided in the space in the center in the radial direction of the lids 40c and 40c at the upper and lower ends, respectively. The second slow cooling extension tube 28a 28a is sandwiched from the outer periphery by a plurality of (four in the embodiment) screws 40c1, 40c1,... Screwed into the lid portions 40c, 40c in the inner diameter direction. It is fixed so that it can be adjusted. That is, the fixing position of the second slow cooling extension pipe 28a 28a can be adjusted by inserting and removing the plurality of screws 40c1, 40c1,.

  According to the spinning machine and the extension pipe for the spinning machine according to the embodiment, the flange 24b at the upper end of the first slow cooling extension pipe 24 can be attached to and detached from the lower part of the hollow adapter 30 provided at the lower part of the heating furnace 10. The adapter 30 is fixedly connected to the first slow cooling extension tube 24 and the second slow cooling extension tube 28, and the lower portion of the cylindrical main body 24a of the first slow cooling extension tube 24 is The bellows extension pipe 26 is detachably fixed to the lower part of the adapter 30 and the lower end of the second slow cooling extension pipe 28 is removably inserted into the upper end opening of the second slow cooling extension pipe 28. Since the slow cooling extension pipe 28 is detachably fixed to the upper end of the slow cooling extension pipe 28, the bellows of the bellows extension pipe 26 can be flexibly bent when the slow cooling extension pipe is centered.

  Further, when the first slow cooling extension pipe 24 and the second slow cooling extension pipe 28 are centered by the bellows of the bellows extension pipe 26, the adapter 30 or the slow cooling adapter provided in the lower part of the heating furnace 10 can be easily swung. Since the extension tube itself is not distorted, it is possible to reliably prevent a decrease in hermeticity.

  Further, when the optical five 14 is pulled out from the base material 12 heated in the heating furnace 10, the optical fiber 14 can be pulled out from the first slow cooling extension pipe 24 through the second slow cooling extension pipe 28, and the bellows. Since the optical fiber 14 is not exposed in the main body 26a, silica or the like is not deposited on the uneven inner surface of the bellows main body 26a.

  Further, the lower part of the cylindrical main body 24a of the first slow cooling extension pipe 24 is inserted into the upper end opening of the second slow cooling extension pipe 28 so as to be movable back and forth. Even if the bellows extension pipe 26 is deformed or the second slow extension pipe 28 is changed in position, it is possible to cope with airtightness.

  Further, since the first slow cooling extension tube 24 can be attached to and detached from the adapter 30, when the optical fiber 14 needs to be cut, the bellows extension tube 26 and the first slow cooling extension tube 24 are connected to the lower part of the adapter 30. Since the bellows-like main body 26a can be expanded and contracted, the bellows-like main body 26a is shrunk so that a space can be easily opened in the lower part of the heating furnace 10 and the optical fiber 14 is exposed. Easy to cut and easy to handle.

  The adapter 30 is provided with a flange 30c at the lower end, the bellows extension pipe 26 is provided with flanges 26b and 26c at the upper and lower ends of a bellows-shaped body 26a, and the second slow cooling extension pipe 28 is tubular. The flange 28b is provided at least at the upper end of the main body 28a, and the flange 26b at the upper end of the bellows extension pipe 26 is screwed to the lower portion of the adapter 30 fixed to the lower portion of the heating furnace 10 with a separate screw 32. A flange 28b at the upper end of the second slow cooling extension tube 28 is screwed to a flange 26c at the lower end of the bellows extension tube 26 by a separate screw 34. If the screw 32 is removed, the bellows extension tube 26 can be easily removed from the adapter 30 to free up space.

  Further, a cylindrical screw portion 30e that communicates with the hollow opening at the lower end of the adapter 30 and has a male screw formed around it is formed to project downward, and the first slow cooling extension tube 24 has a flange 24b at the upper end. The upper end flange 24b is abutted against the lower end of the cylindrical screw portion 30e at the lower end of the adapter 30, and the cylindrical female screw body 36 is wrapped around the upper end flange 24b to be the male screw of the cylindrical screw portion 30e. By screwing and fixing the upper end of the first slow cooling extension tube 24 to the adapter 30, the cylindrical female screw body 36 can be turned and removed from the cylindrical screw portion 30e with a simple operation. One slow cooling extension tube 24 can be removed from the adapter 30.

  In addition, the second slow cooling extension pipe 28 is provided with the extension pipe bracket 40 that supports the main body from the side and is movable for centering, so that the support and centering can be performed.

  The extension tube for a spinning machine and the spinning machine according to the present invention have the airtightness of the extension tube for slow cooling installed under the heating furnace and the fiber cutting property under the heating furnace by simply removing the extension tube for slow cooling. It can be used to improve the size of the optical fiber with high accuracy and reliably prevent defects such as scratches on the optical fiber.

DESCRIPTION OF SYMBOLS 10 Heating furnace 10a Heater 10b Outer wall part 10c Heat insulating material 10d Screw part 12 Optical fiber preform 14 Optical fiber 14a Optical fiber tip 24 First slow cooling extension pipe 24a First slow cooling extension pipe main body 24b First The flange 24c at the upper end of the slow cooling extension pipe 26c The flange 26 at the lower end of the first slow cooling extension pipe 26 The bellows extension pipe 26a The bellows-shaped main body 26b The flange 26c at the upper end of the bellows extension pipe The flange 28 at the lower end of the bellows extension pipe The slow cooling extension tube 28a The second slow cooling extension tube main body 28b The upper flange 28c of the second slow cooling extension tube The second slow cooling extension pipe lower flange 30 Adapter 30a The adapter main body 30b The adapter Upper end flange 30c Adapter lower end flange 30d Adapter upper end cylindrical portion 30e Adapter lower end cylindrical screw portion 32 Screw 34 Screw G 36 Cylindrical female screw body 38 O-ring 40 Extension pipe bracket 40a Support jig 40b Driver

Claims (7)

An optical fiber spinning machine in which a hollow slow cooling extension tube is provided at a lower part of a heating furnace for heating an optical fiber preform, and an optical fiber drawn downward from the heating furnace is gradually cooled through the hollow ,
The slow cooling extension pipe has a first slow cooling extension pipe communicating with the lower part of the heating furnace, and a bellows having a bellows-shaped body that can be bent and stretched around the first slow cooling extension pipe An extension tube for a spinning machine, comprising: an extension tube; and a second extension tube for slow cooling communicating with a lower portion of the first extension tube for slow cooling.   A hollow adapter is provided in the lower part of the heating furnace, and an upper end of the first slow cooling extension pipe is detachably fixed to the lower part of the adapter so that the adapter, the first slow cooling extension pipe, and the second slow cooling are fixed. The extension pipe for communication is communicated, and the lower part of the first extension pipe for slow cooling is inserted into the upper end opening of the second extension pipe for slow cooling so as to be movable back and forth. An extension tube for a spinning machine as described.   The spinning machine according to claim 2, wherein the bellows extension pipe has an upper end detachably fixed to the lower part of the adapter and a lower end fixed to the upper end of the second slow cooling extension pipe. For extension tube. The adapter is provided with a flange at the lower end,
The bellows extension pipe is provided with flanges at the upper and lower ends of a bellows-shaped main body,
The second extension tube for slow cooling is provided with a flange at least at the upper end of the tubular main body,
The upper flange of the bellows extension pipe is screwed with a separate screw to the lower part of the adapter fixed to the lower part of the heating furnace,
4. An extension pipe for a spinning machine according to claim 2, wherein the flange at the upper end of the second slow cooling extension pipe is screwed to the flange at the lower end of the bellows extension pipe with a separate screw. A cylindrical threaded portion that communicates with the hollow opening at the lower end of the adapter and has a male screw formed around it is formed to project downward, and the first extension tube for slow cooling has a flange formed at the upper end,
The flange at the upper end is abutted against the lower end of the cylindrical screw portion at the lower end of the adapter, and the cylindrical female screw body is screwed into the male screw at the protruding portion so as to wrap around the flange at the upper end. 5. An extension pipe for a spinning machine according to claim 1, wherein an upper end of the pipe is fixed to the adapter.   The extension tube bracket for supporting the main body from the side and making it movable for centering is provided on the second extension tube for slow cooling. Extension tube for spinning machines.   An optical fiber spinning machine using the extension pipe for a spinning machine according to claim 1.

Images