JP4345974B2 - Quartz glass tube having a plurality of linear holes, method for manufacturing the same, and apparatus for manufacturing the same - Google Patents

Description

The present invention relates to a method and apparatus for manufacturing a quartz glass tube having a plurality of linear holes.

  An optical fiber is widely used mainly in the communication field, and the optical fiber is usually manufactured by drawing a base material called an optical fiber preform.

  Common optical fiber preforms (base materials before drawing) are mainly MCVD (Modified Chemical Vapor Deposition Method), VAD (Vapor phase Axial Deposition Method), and OVD methods. (Outside Vapor Phase Deposition Method). An optical fiber having a predetermined aperture can be obtained by thinly drawing the optical fiber preform.

  Currently, in order to further increase the speed and capacity of optical communication, in the optical communication system, the number of wavelength multiplexing is increasing and the wavelength region is being expanded. In a wavelength division multiplexing (WDM) optical transmission system, various WDM transmission optical components are used. We are also researching a large-capacity transmission system using ultra-wideband.

  As one of the WDM transmission optical components, a special polarization maintaining optical fiber having a hole in a cross section is used. In addition, a special holey fiber having a hole in the cross section is required even in a large-capacity transmission system using ultra-wideband.

  Such a special optical fiber may require two or more holes in the cross section instead of only one.

  The shape of the optical fiber inherits the shape and quality of the optical fiber preform, which is the base material before drawing, so that in order to manufacture a special optical fiber having a plurality of holes in the cross section, an optical fiber preform is used. At the reforming stage, it is necessary to form an optical fiber preform having a plurality of linear holes so as to correspond to the shape of the holes required for the special optical fiber after drawing.

  In order to form such an optical fiber preform having a plurality of linear voids, after the optical fiber preform is once manufactured by the MCVD method, the VAD method or the OVD method, a new linear void is formed. It is necessary to make a hole.

  As a method for forming a new linear hole in an optical fiber preform, there is a cold cutting process using a drill. At this time, only a circular hole can be obtained. Further, cracks may occur in the optical fiber preform, or the surface properties of the opened hole portion surface may become rough. Furthermore, since cutting oil and cutting debris adhere to the air holes, its optical characteristics may be impaired when used for special fibers such as the above-mentioned polarization maintaining optical fiber and holey fiber. Since the cut portion becomes cutting waste, the yield decreases.

  Alternatively, the core rod material to be the core portion of the optical fiber is manufactured by the above-described MCVD method, VAD method, or OVD method, and this core rod material is inserted into the separately prepared quartz glass tube material to be the optical fiber cladding portion. There is also a method of obtaining a preform for an optical fiber by combining with a quartz glass tube by a rod in collapse method. However, even in this method, it is necessary to make a hole in the quartz glass tube material used as a cladding portion of the optical fiber in advance. There is.

  Patent Document 1 describes a rod-in collapse method that eliminates the need for drilling. Here, the cross-sectional shape of the inner surface of the pipe is pressed by pressing a perforated part (plug) having a non-circular and point-shaped cross-sectional shape such as a polygon or a star shape against the end surface of a heat-softened linear quartz glass material. Manufactures quartz glass tubes that are non-circular and point object shapes such as polygons and stars. Then, a quartz glass tube having a non-circular and point-shaped cross section is used as a cladding tube material, and a core rod material having a circular cross section is inserted therein, and an optical fiber preform is formed by a rod-in collapse method. is there. Here, a gap portion formed between the circular cross section of the core rod material and the noncircular and point-targeted tube inner surface of the clad tube material becomes a hole.

JP2003-221253A

  However, in this method, the plurality of holes to be formed are arranged in an annular shape near the center of the quartz glass material, and the cross-sectional shapes of the individual holes to be formed must all be the same. I don't get it. Further, when the number of holes increases or the cross-sectional shape of the holes becomes complicated, the shape of the perforated part (plug) becomes complicated and a large load is applied to the plug, and as a result, the plug is easily damaged. Furthermore, since these holes are not completely independent of each other, deformation may occur when an optical fiber preform is manufactured by the rod-in collapse method, and the shape as intended. May not be obtained.

An object of the present invention is to provide a method and apparatus for manufacturing a quartz glass tube having a plurality of linear pores of the cross-sectional shape of arbitrary.

Furthermore, in the current trend of higher speed and larger capacity of optical communication, the cross-sectional shape of the optical fiber will be required not only in the vicinity of the core but also in the overall shape design including the outer contour. A further object of the present invention is to provide a method and an apparatus for producing a quartz glass tube having a plurality of linear holes having a non-circular outer contour and an arbitrary cross-sectional shape.

A manufacturing method and manufacturing apparatus for a quartz glass tube having a plurality of linear holes according to the present invention are shown in the following (1) to ( 12 ). These may be referred to as the present invention (1) to the present invention ( 12 ), respectively. The present invention (1) to the present invention ( 12 ) may be collectively referred to as the present invention.

(1) the end face of one end portion of the wire-like quartz glass material, have a plurality of elongate perforations, the position adjusting jig for holding the positional relationship between the elongated perforations in the elongated perforations A plug is provided , and a die is installed on the outer periphery of one end, and the linear quartz glass material and the plug are provided with a rotation of the axis center relative to the die while the linear quartz glass is provided. A plurality of linear holes, characterized by being heated and softened sequentially from one end of the material and moved along the axial direction, and the heated and softened portion is press-fitted into a space formed by a plug and a die. A method for producing a quartz glass tube having

(2) to the end surface of one end portion of the wire-like quartz glass material, have a plurality of elongate perforations, the position adjusting jig for holding the positional relationship between the elongated perforations in the elongated perforations A plug is provided , and a die is installed on the outer periphery of one end, and while rotating the linear quartz glass material, it is heated and softened sequentially from one end of the linear quartz glass material in the axial direction. This is a method of manufacturing a quartz glass tube that is moved along and press-fitted into the space formed by the plug and the die, and the plug and the die are synchronized with the rotation of the linear quartz glass material. And a method for producing a quartz glass tube having a plurality of linear holes.

( 3 ) A plurality of the plugs according to ( 1 ) or ( 2 ) above, wherein a composite plug comprising a base and a plurality of long perforated parts each having a base end fixed to the base is used. A method for producing a quartz glass tube having a linear hole.

( 4 ) A quartz glass having a plurality of linear voids according to any one of ( 1 ) to ( 3 ) above, wherein a quartz glass blank is used as the linear quartz glass material. A method of manufacturing a tube.

( 5 ) The linear quartz glass tube and / or the quartz glass tube formed after the press-fitting when the heat-softened portion of the linear quartz glass tube is press-fitted into the space formed by the plug and the die. The method for producing a quartz glass tube according to ( 4 ) above, wherein the inside of the pores is reduced to less than atmospheric pressure.

( 6 ) A quartz glass tube having a plurality of linear holes according to any one of ( 1 ) to ( 3 ) above, wherein a quartz glass rod is used as the linear quartz glass material. Manufacturing method.

( 7 ) When the heat softened portion of the linear quartz glass rod is press-fitted into the space formed by the plug and the die, the inside of the pores of the quartz glass tube formed after the press-fitting is reduced to less than atmospheric pressure. A method for producing a quartz glass tube having a plurality of linear holes as described in ( 6 ) above.

( 8 ) A plurality of the plugs according to any one of ( 1 ) to ( 7 ) above, wherein a composite plug having a circular or non-circular cross-sectional shape of the long perforated portion of the plug is used. A method for producing a quartz glass tube having linear holes.

( 9 ) A means for moving the linear quartz glass material in the axial direction, a heating means for heating the linear quartz glass material, and a space for press-fitting the heat-softened linear quartz glass material. an apparatus for producing a quartz glass tube having a die and a plug, the plug is Ri Do a plurality of elongated perforations, position adjustment for holding the positional relationship between the elongated perforations between its elongated perforations A quartz glass tube having a plurality of linear holes, wherein a jig is provided, and a means for synchronously rotating a linear quartz glass material and a plug with respect to a die is provided . Manufacturing equipment.

( 10 ) Production of a quartz glass tube having a plurality of linear holes as described in ( 9 ) above, wherein the plug is held in a rotatable state about the axis of the quartz glass tube apparatus.

( 11 ) A means for moving the linear quartz glass material in the axial direction, a heating means for heating the linear quartz glass material, and a space for press-fitting the heat-softened linear quartz glass material. an apparatus for producing a quartz glass tube having a die and a plug, the plug is Ri Do a plurality of elongated perforations, position adjustment for holding the positional relationship between the elongated perforations between its elongated perforations An apparatus for producing a quartz glass tube having a plurality of linear holes, characterized in that it is provided with a jig and has means for synchronously rotating a linear quartz glass material, a plug and a die. .

( 12 ) A quartz glass tube having a plurality of linear holes as described in ( 11 ) above, wherein the plug and the die are held so as to be rotatable around the axis center of the quartz glass tube. Manufacturing equipment.

  According to the present invention, a plurality of linear vacancies that are independent from each other, and each of the linear vacancies is formed integrally with a quartz glass tube. It is possible to provide a quartz glass tube having the following linear holes. In addition, according to the present invention, a quartz glass tube having a plurality of linear holes having an arbitrary cross-sectional shape can be manufactured with high dimensional accuracy, and a quartz glass tube having excellent surface properties of the linear holes can be manufactured. can do. Furthermore, according to the present invention, it is possible to provide a quartz glass tube having a plurality of linear holes having a non-circular outer contour and an arbitrary cross-sectional shape, with excellent dimensional accuracy and excellent surface properties. Things can be manufactured.

  In order to manufacture a quartz glass tube having a plurality of linear holes according to the present invention, a linear quartz glass material is first prepared.

  Then, a plug having a plurality of long perforated portions is installed on the end surface of one end portion of the quartz glass material, and a die is installed on the outer periphery of the one end portion, and the linear quartz glass material and the plug are attached to the die. While rotating relative to the center of the shaft, heat and soften sequentially from one end of the linear quartz glass material and move it along the axial direction, and press-fitting it into the space formed by the plug and die. Thus, a quartz glass tube having linear holes corresponding to a plurality of long perforated portions is manufactured. When manufacturing a quartz glass tube with a non-circular cross-section, the linear quartz glass material is pressed into the plug and die while rotating in synchronization with the rotation of the linear quartz glass material. To manufacture a quartz glass tube.

  The inner diameter of the die is set to a dimension corresponding to the outer diameter of the quartz glass tube to be molded. Since the outer diameter of the quartz glass material is formed by the inner diameter of the molding die during the press-fitting of the heat-softening portion, by expanding or reducing the diameter of the quartz glass material or keeping the same diameter, It can be formed into a quartz glass tube having various outer diameters.

  The present invention will be described below with reference to the drawings.

  FIG. 1 shows an embodiment of manufacturing a quartz glass tube having three linear holes.

  Here, a quartz glass base tube is used as the linear quartz glass material 1. A dummy cylinder 5 is attached to one end and the other end of the linear quartz glass material by welding, and is gripped by an output side chuck 10 and an input side chuck 11 that can rotate and move horizontally.

  A heater 15 is installed between the entrance side chuck 11 and the exit side chuck 10. The linear quartz glass material 1 moves together with the entrance chuck 11 from the left to the right, is heated and softened sequentially from one end by the heater 15 and moves along the axial direction, and the heat softened portion has three lengths. It is press-fitted into the space formed by the plug having the perforated portion 16 and the die 21 and fed.

  This plug is a composite plug having three long perforated portions 16, and the base ends of the three long perforated portions 16 are all fixed to the base portion 17 of the plug. Is held by a mandrel 22. The cross-sectional shape of the long perforated portion corresponds to the cross-sectional shape of a plurality of linear holes in the formed quartz glass tube.

  Here, the composite plug is provided with a position adjusting jig 18 for maintaining the shape and positional relationship of the intended linear holes. When the position adjusting jig is provided, it is preferable to provide the position adjusting jig because there is no possibility that the long perforated part is bent by its own weight. When installing the position adjustment jig, it is preferable to install it at a position about 50 to 100 mm away from the distal end of the long perforated part in the proximal direction. When installed near the base end of the long perforated part, it is difficult to obtain the effect of preventing bending. Conversely, when installed near the front end of the long perforated part, the heat softened part of the linear quartz glass material is the long perforated part. This is because the position adjusting jig may interfere when press-fitting into the.

  In addition, since the position adjusting jig is intended to maintain the shape and positional relationship of the formed linear holes, the function only needs to be maintained at the start of press-fitting. If the positional relationship between the long perforated parts is maintained at the start of press-fitting, the positional relationship is maintained by the holes formed by press-fitting. Therefore, the position adjusting jig is pushed by the quartz glass material that is press-fitted after heat softening and moves toward the base of the composite plug.

  Note that the position adjusting jig is not limited to one place. You may install in several places according to the length of a long perforated part. Further, a dummy cylinder in which a plurality of target linear holes are previously drilled may be welded to the front end portion of the quartz glass material. By doing so, the composite plug can be accurately press-fitted into the quartz glass material while maintaining the positional relationship of the long perforated portions without using a position adjusting jig.

  The linear quartz glass material is press-fitted after heat softening, and the inside thereof is moved in the right direction while being drilled by the three long drilling portions 16, and the outer contour of the cross-sectional shape is formed by the die 21. While being processed, it moves in the right direction of the drawing. In this way, the linear quartz glass material is heated and softened sequentially, and is pressed into a space formed by the plug having the three long perforated portions 16 and the die 21 and fed into the three pieces. A quartz glass tube having linear vacancies is sequentially formed, and is molded while the shape having three linear vacancies is maintained up to the other end of the linear quartz glass material.

  The ratio of the moving speed of the inlet side chuck and the moving speed of the outlet side chuck is the ratio of the cross-sectional area of the linear quartz glass material and the cross-sectional area of the quartz glass tube having the linear holes formed by molding. Is set to the inverse of. In addition, it is desirable that the rotational speed of the entrance side chuck and the rotational speed of the exit side chuck have no speed difference because the positional relationship between the linear holes is maintained as set.

During this molding process, a plug having a linear quartz glass material and three long perforated portions 16 is
Around the central axis in the horizontal direction, the die 21 is rotated synchronously. This is to make the heating state in the circumferential direction of the linear quartz glass material uniform and improve the dimensional accuracy of the outer diameter of the formed quartz glass tube. If the rotational speed is slow, the soaking effect is insufficient. If the rotational speed is too fast, the contact frequency with the die increases, the wear of the die increases, and the surface properties of the molded quartz glass tube 30 are also impaired. The rotation speed is preferably 1 to 10 rpm. More preferred is 2-7 rpm.

  Furthermore, when manufacturing the quartz glass tube, the inside of the linear quartz glass base tube, which is a quartz glass material, and / or the inside of the pores of the quartz glass tube formed after press-fitting is reduced to less than atmospheric pressure. ,preferable. When the inside of a linear quartz glass tube or the inside of a quartz glass tube hole formed after press-fitting is reduced to less than atmospheric pressure, the shape and position of the linear hole in the quartz glass tube after molding are It is because it is easy to be kept on the street.

  A method of depressurizing the interior of a linear quartz glass tube or the inside of a hole in a quartz glass tube formed after press-fitting to below atmospheric pressure will be described with reference to FIG. When manufacturing a quartz glass tube having a plurality of linear holes from a linear quartz glass elementary tube, holders 41 for blocking the entry of outside air are installed at both ends of the tube being molded. On the side of the linear quartz glass tube, the inside of the quartz glass tube is evacuated using a vacuum pump (not shown). Then, on the side of the quartz glass tube having a plurality of linear holes after forming, the mandrel that holds the plug base is hollow, and a small hole 43 that can be exhausted is provided on the side surface of the mandrel. It exhausts using a vacuum pump (not shown).

  Such pressure reduction treatment may be performed either on the side of the linear quartz glass tube or on the side of the quartz glass tube having a plurality of linear holes after molding (plug side). It is preferable to do this. The pressure reduction treatment is effective even slightly, but if the pressure is excessively reduced, contact with the plug becomes intense and scratches may occur on the inner surface, so the internal pressure is preferably 100000 Pa or less. In order to improve the dimensional accuracy by reducing the pressure, it is particularly preferable to set the pressure to 30000 to 60000 Pa on the raw tube side and 1000 to 10,000 Pa on the plug side.

  In particular, the pressure reduction treatment from the plug side improves the accuracy of forming a plurality of linear holes in the quartz glass tube after the forming process. This is because, on the inner surface of the heat-softened quartz glass, a plurality of holes are continuously formed in the longitudinal direction along the radial portions of the plurality of long perforated portions constituting the plug. Seem. Note that if the pressure is excessively reduced, the contact between the multiple long perforated portions constituting the plug and the quartz glass becomes intense, and the long perforated portions are damaged or the inner surface of the pores of the quartz glass tube is damaged. There is a risk of

  Up to this point, the method of using a quartz glass tube as the linear quartz glass material has been described. However, instead of using the quartz glass tube, a quartz glass rod may be used as the linear quartz glass material. . Even when the quartz glass material is a quartz glass rod, the principle remains unchanged. However, in the case of performing the decompression process below the atmospheric pressure, only the decompression process is performed from the side (plug side) of the quartz glass tube having a plurality of linear holes after the forming process.

  The shape of the inner contour of the cross-sectional shape of the die is designed to be the outer contour of the target cross-sectional shape of the quartz glass tube, and is circular or non-circular.

  FIG. 2 is a schematic view illustrating a die that can be used in the manufacturing apparatus of the present invention. The die shown in FIG. 2 can be used to manufacture a quartz glass tube having a square outer cross section. As described above, when a die having a non-circular cross section is used, the die 21 is rotated in synchronization with the rotation of the quartz glass material 1 in FIG. Thereby, since the glass material is press-fitted into the space formed by the die and the plug, a quartz glass tube having a non-circular outer contour in cross-sectional shape can be manufactured.

  At this time, the die 21 may be forcibly rotated using a driving device, but is held in a rotatable state, and the quartz glass material is rotated by the frictional force between the outer surface of the quartz glass material and the inner surface of the die. It is desirable to rotate in synchronization with. When a die having a circular cross-sectional inner contour is used, the die may be rotated in synchronization with the rotation of the quartz glass material or may be fixed.

  The shape and size of the inner contour of the cross-sectional shape of the die may be set in accordance with the shape and size of the outer contour of the cross-sectional shape of the quartz glass tube to be manufactured, and is not limited to the shape shown in FIG. In other words, in accordance with the outer contour of the cross-sectional shape of the quartz glass tube to be manufactured, a die whose inner contour is circular, or a die whose inner contour is non-circular such as an ellipse, polygon, star, etc. Use it.

  Next, FIG. 3 shows the composite plug and the position adjusting jig 18 at the time of molding. The composite plug is composed of three long perforated portions 16 and a plug base portion 17 for fixing the base ends thereof. The cross-sectional shape of each long perforated portion in FIG. 3 is circular, and the cross-sectional shape of this long perforated portion corresponds to the cross-sectional shape of a plurality of linear holes in the quartz glass tube after molding.

  Therefore, the cross-sectional shape of the plurality of linear holes in the target quartz glass tube after molding is determined by the cross-sectional shape of the long perforated portion 16 constituting the plug. In FIGS. 1 and 3, the plug having a long perforated portion having a circular cross-sectional shape is used, but the cross-sectional shape is not limited to a circular shape. Here, the number of linear holes is three, but is not limited to three, and may be two or four or more.

  FIG. 4 shows various cross-sectional shapes of a plurality of linear holes in the formed quartz glass tube. Thus, the cross-sectional shape of the linear hole is not limited to a circle, but may be an ellipse, a triangle, a quadrangle, a pentagon, or a polygon, and a daruma or star. And you may form a some linear void | hole combining them suitably. The outer contour of the cross-sectional shape of the quartz glass tube may be circular as shown in FIG. 4, but may be non-circular as shown below.

  FIG. 5 shows a cross-sectional shape of a quartz glass tube having a non-circular outer contour. Thus, the outer contour of the cross-sectional shape of the quartz glass tube may be a non-circular shape such as a square, other polygons, or an ellipse. Further, the cross-sectional shape of the linear holes may be circular or non-circular or a combination thereof.

  In order to manufacture such a quartz glass tube having a linear hole having a cross-sectional shape, a plug having a plurality of long perforated portions having a corresponding cross-sectional shape may be used.

  Note that the cross-sectional shape of the tip of the long perforated part that constitutes the plug retains the shape and positional relationship of the holes formed after drilling so that the formed holes do not deform immediately after drilling. It is necessary to ensure a sufficient length (for example, a length up to the exit side position of the die). It is not always necessary to have the same cross-sectional shape over the entire length from the distal end portion to the proximal end portion, but it is preferable to use a plug having long perforated portions having the same cross-sectional shape with the same diameter from the distal end to the proximal end. Further, the shape of the tip of the long perforated part may be designed in consideration of the dimensional accuracy of the formed linear hole, such as a hemispherical shape, the load on the plug when drilling the linear hole, and the like.

  The quartz glass material constituting the quartz glass material is not limited to synthetic quartz glass manufactured by the VAD method or the like, but can be applied to other quartz glass such as natural quartz glass using quartz powder as a raw material.

  The temperature of the raw material at the time of processing cannot be determined unconditionally because the softening point varies greatly depending on the OH group concentration and Cl concentration. It is preferable to heat the quartz glass material at the highest temperature immediately before the dice, and when it is slightly lower than that, it is formed in contact with the long perforated portions constituting the die and the plug.

  The set temperature of the heating furnace is about 2000 to 2700 ° C. Therefore, as the material of the long perforated portion constituting the die or the plug, an oxide of alumina oxide, a metal such as tungsten or molypden, graphite, or the like is preferable. Graphite is most preferable in terms of strength and purity at high temperatures. The molding process is preferably performed in an inert atmosphere to prevent oxidation of the quartz glass material.

A quartz glass tube as a linear quartz glass material was manufactured using a synthetic quartz glass ingot obtained from SiO ₂ obtained by hydrolyzing high-purity SiCl ₄ with an oxyhydrogen flame.

  Then, using the manufacturing apparatus shown in FIG. 1, a quartz glass tube having the cross-sectional shape (two circular holes) shown in FIG. Molded.

  A quartz glass tube (outer diameter 160 mm, inner diameter 50 mm, length 1300 mm), a die having an inner diameter of 150 mm, and a composite type plug with a structure corresponding to the cross-sectional shape shown in FIG. Shape: Both are circular, diameter is 20mm), heating temperature is 2300 ° C, rotation speed is 5rpm, quartz glass tube internal pressure is 50000Pa, pressure on the side of the quartz glass tube after molding (plug side) Was set to 1000 Pa, the feeding speed of the quartz glass tube was set to 16.70 mm / min, and the drawing speed of the quartz glass tube after forming was set to 17.78 mm / min to form linear holes.

  As a result, a quartz glass tube (outer diameter 149.78 mm, length 1360 mm) having two circular holes was obtained. When the weight was measured and the yield was calculated, it was 98.3%.

  Next, in order to confirm whether or not the target cross-sectional shape was obtained, the sample was sampled about 100 mm in length, and the shape and positional relationship of the linear holes were confirmed.

  Two linear holes were observed, and the diameter of the holes was measured with calipers to be 20.02 mm and 20.03 mm, respectively. Further, when the difference between the major axis and the minor axis of the hole was determined, the difference was 0.01 mm, and it was confirmed that the circular shape was maintained.

Similarly, a quartz glass rod as a linear quartz glass material was manufactured using a synthetic quartz glass ingot obtained from SiO ₂ obtained by hydrolyzing high-purity SiCl ₄ with an oxyhydrogen flame.

  Then, using the manufacturing apparatus shown in FIG. 1, as described below, the cross-sectional shape shown in FIG. 7 (one circular hole and four square holes is obtained from this linear quartz glass rod. A quartz glass tube having

  A quartz glass rod (outer diameter: 145 mm, length: 1400 mm), molding die having an inner diameter of 160 mm, composite type plug having a structure corresponding to the cross-sectional shape shown in FIG. 7 (number of long perforated portions: 5, plug cross-sectional shape: One is circular and the diameter is 20 mm, the other four are square and 15 mm × 15 mm), the heating temperature is 2350 ° C., the rotation speed is 7 rpm, and the side of the quartz glass tube after molding (plug side) The internal pressure was set to 1500 Pa, the feeding speed of the quartz glass rod was set to 18.35 mm / min, and the drawing speed of the quartz glass tube after forming was set to 16.04 mm / min to form linear holes.

  As a result, a quartz glass tube (outer diameter 159.86 mm, length 1220 mm) having one circular hole and four square holes was obtained. When the weight was measured and the yield was calculated, it was 99.7%.

  Next, in order to confirm whether or not the target cross-sectional shape was obtained, the sample was sampled about 100 mm in length, and the shape and positional relationship of the linear holes were confirmed.

  Five linear vacancies were observed, and the diameter of the vacancies was measured with calipers. The circular portion was 20.03 mm, and when the difference between the major axis and the minor axis of the circular portion was determined, the difference was 0. .01 mm, and it was confirmed that the circular shape was maintained. The four square portions were 15.01 to 15.03 mm, but the difference between the major axis and the minor axis was 0.01 mm or less, and it was confirmed that the target shape was maintained. It was.

Similarly, a quartz glass rod as a linear quartz glass material was manufactured using a synthetic quartz glass ingot obtained from SiO ₂ obtained by hydrolyzing high-purity SiCl ₄ with an oxyhydrogen flame.

  Then, using the manufacturing apparatus shown in FIG. 1, the linear quartz glass rod has the cross-sectional shape (outer contour: square, two rectangular holes) shown in FIG. 8 as described below. A quartz glass tube was formed.

  A quartz glass rod (outer diameter: 100 mm, length: 2000 mm), a die having a structure corresponding to the cross-sectional shape shown in FIG. 8 (length of one side: 120 mm) and a composite plug (number of long perforated portions: 2, plug cross section) (Shape: 15 mm × 40 mm), the heating temperature is 2350 ° C., the rotation speed is 3 rpm, the internal pressure on the side of the quartz glass tube after molding (plug side) is 1000 Pa, and the feeding speed of the quartz glass rod is 28. A linear hole was formed by setting the drawing speed of the quartz glass tube after molding to 94 mm / min to 17.22 mm / min.

  As a result, a quartz glass tube (length: 1150 mm) having a square cross-sectional outer contour and two rectangular holes was obtained.

  Next, in order to confirm whether the target cross-sectional shape was obtained, about 30 mm in length was sampled, and the shape and positional relationship of the linear holes were confirmed.

  The lengths of one side of the outer contour of the cross-sectional shape were 119.91 mm and 119.89 mm, respectively. In addition, two linear holes were observed, and the dimension of the holes was measured with calipers. The long side of one rectangle was 40.06 mm, the short side was 15.03 mm, and the long side of the other rectangle was 40. 0.08 mm and the short side was 15.06 mm. In both cases, it was confirmed that the target shape was maintained.

Similarly, a quartz glass tube as a linear quartz glass material was manufactured using a synthetic quartz glass ingot obtained from SiO ₂ obtained by hydrolyzing high-purity SiCl ₄ with an oxyhydrogen flame.

  Then, using the manufacturing apparatus shown in FIG. 1, as described below, from the linear quartz glass tube, the cross-sectional shape shown in FIG. 9 (outer contour: oval, one circle and four ellipses) A quartz glass tube having holes having a shape was formed.

  A quartz glass tube (outer diameter: 100 mm, inner diameter: 60 mm, length: 2000 mm), a die (long diameter: 120 mm, short diameter: 100 mm ellipse) having a structure corresponding to the cross-sectional shape shown in FIG. Number of: 5; 1 is a circle with a diameter of 15 mm; 4 is an ellipse with a major axis of 30 mm and a minor axis of 15 mm; the heating temperature is 2300 ° C., the rotation speed is 5 rpm, and the internal pressure of the quartz glass blank is 55000 Pa, The internal pressure on the quartz glass tube side (plug side) after molding is 30000 Pa, the feeding speed of the quartz glass rod is 45.21 mm / min, and the drawing speed of the quartz glass tube after molding is 29.03 mm / min. Set to form a linear void.

  As a result, a quartz glass tube (length 1250 mm) having an oval cross-sectional outer shape and one circular hole and four oval holes was obtained.

  Next, in order to confirm whether the target cross-sectional shape was obtained, about 30 mm in length was sampled, and the shape and positional relationship of the linear holes were confirmed.

  The elliptical shape of the outer contour of the cross-sectional shape had a major axis of 119.93 mm and a minor axis of 99.94 mm. In addition, five linear holes were observed, and the size of the holes was measured with a caliper, and one circle was a perfect circle having a diameter of 15.03 mm. The four ellipses had a major axis of 30.03 to 30.09 mm and a minor axis of 15.02 to 15.06 mm. In both cases, it was confirmed that the target shape was maintained.

  According to the present invention, a plurality of linear vacancies that are independent from each other, and each of the linear vacancies is formed integrally with a quartz glass tube. It is possible to provide a quartz glass tube having the following linear holes. In addition, according to the present invention, a quartz glass tube having a plurality of linear holes having an arbitrary cross-sectional shape can be manufactured with high dimensional accuracy, and a quartz glass tube having excellent surface properties of the linear holes can be manufactured. can do. Furthermore, according to the present invention, it is possible to provide a quartz glass tube having a plurality of linear holes having a non-circular outer contour and an arbitrary cross-sectional shape, with excellent dimensional accuracy and excellent surface properties. Things can be manufactured.

It is the schematic diagram which showed the aspect of manufacture of the quartz glass tube | pipe which has three linear void | holes. It is the schematic diagram which illustrated the dice | dies which can be used for the manufacturing apparatus of this invention. It is the schematic diagram which showed the composite plug and the position adjustment jig at the time of a shaping | molding process. It is the schematic diagram which showed the various cross-sectional shape of the several linear hole in the quartz glass tube after shaping | molding. It is the schematic diagram which showed the cross-sectional shape of the quartz glass tube whose cross-sectional outer contour is non-circular. It is the schematic diagram which showed the cross-sectional shape (The outer contour is circular. Two circular holes) of the quartz glass tube of Example 1. It is the schematic diagram which showed the cross-sectional shape (The outer contour is circular. One circular hole and four square holes) of the quartz glass tube of Example 2. It is the schematic diagram which showed the cross-sectional shape (The outer outline is a square. Two rectangular holes) of the quartz glass tube of Example 3. It is the schematic diagram which showed the cross-sectional shape (Outer outline is an ellipse. One circular hole and four oval holes) of the quartz glass tube of Example 4.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Quartz glass material 5 Dummy cylinder 10 Outlet chuck 11 Inlet chuck 15 Heater 16 Plug long hole part 17 Plug base part 18 Position adjustment jig 21 Die 22 Mandrel 30 Molded quartz glass tube 41 Holder 43 Small hole

Claims (12)

The end face of one end portion of the linear quartz glass material, have a plurality of elongate perforations, the position adjustment jig is provided for holding the positional relationship between the elongated perforations in the elongated perforations The plug and the die on the outer periphery of one end are respectively installed, and the linear quartz glass material and the plug are provided with one end of the linear quartz glass material while the plug is rotated about the axis center relative to the die. A quartz having a plurality of linear holes, wherein the quartz is heat-softened sequentially and moved along the axial direction, and the heat-softened portion is press-fitted into a space formed by a plug and a die. Manufacturing method of glass tube. The end face of one end portion of the linear quartz glass material, have a plurality of elongate perforations, the position adjustment jig is provided for holding the positional relationship between the elongated perforations in the elongated perforations move and has plugs and the die to the outer periphery of one end portion, respectively installed, while providing rotation to linear quartz glass material, in the axial direction by sequentially softened from linear quartz glass blank at one end And a method of manufacturing a quartz glass tube in which the heat softened portion is press-fitted into a space formed by a plug and a die, and the plug and the die rotate in synchronization with the rotation of the linear quartz glass material. A method for producing a quartz glass tube having a plurality of linear holes. 3. A plurality of linear holes according to claim 1 or 2 , wherein a composite plug comprising a base portion and a plurality of long perforated portions each having a base end fixed to the base portion is used. A method for producing a quartz glass tube having As linear quartz glass blank, characterized by using quartz glass mother tube, method for manufacturing a silica glass tube having a plurality of linear pores according to any one of claims 1 to 3. When the heat-softened portion of the linear quartz glass tube is press-fitted into the space formed by the plug and the die, the linear quartz glass tube and / or the hole of the quartz glass tube formed after the press-fitting The method for producing a quartz glass tube according to claim 4 , wherein the inside of the tube is depressurized to less than atmospheric pressure. As linear quartz glass blank, characterized by using a quartz glass rod, the method for manufacturing a silica glass tube having a plurality of linear pores according to any one of claims 1 to 3. When the heat-softened portion of the linear quartz glass rod is press-fitted into the space formed by the plug and the die, the inside of the holes of the quartz glass tube formed after the press-fitting is reduced to less than atmospheric pressure. The method for producing a quartz glass tube having a plurality of linear holes according to claim 6 . Sectional shape of the elongated perforations of the plug is characterized by using a composite plug is circular or non-circular shape, a plurality of linear pores according to any one of claims 1 to 7 A method for producing a quartz glass tube. A means for moving the linear quartz glass material in the axial direction, a heating means for heating the linear quartz glass material, and a die and a plug for forming a space for press-fitting the heat-softened linear quartz glass material an apparatus for producing a quartz glass tube having bets, plug Ri Do a plurality of elongated perforations, the position adjusting jig for holding the positional relationship between the elongated perforations in the elongated perforations is provided, and wherein the one having the means for synchronously rotating the linear quartz glass blank and plug relative to the die apparatus for producing a quartz glass tube having a plurality of linear pores. 10. The apparatus for producing a quartz glass tube having a plurality of linear holes according to claim 9 , wherein the plug is held so as to be rotatable around the axial center of the quartz glass tube. A means for moving the linear quartz glass material in the axial direction, a heating means for heating the linear quartz glass material, and a die and a plug for forming a space for press-fitting the heat-softened linear quartz glass material an apparatus for producing a quartz glass tube having bets, plug Ri Do a plurality of elongated perforations, the position adjusting jig for holding the positional relationship between the elongated perforations in the elongated perforations is provided, and linear quartz glass blank, and characterized in that comprising means for synchronously rotating the plug and die apparatus for producing a quartz glass tube having a plurality of linear pores. 12. The apparatus for producing a quartz glass tube having a plurality of linear holes according to claim 11 , wherein the plug and the die are held so as to be rotatable around an axis center of the quartz glass tube.

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