Flame grinding device and method for flame grinding the end of quartz glass tube

Abstract

The present invention provides a flame polishing device for flame polishing the end of a cylindrical quartz glass tube, comprising: a stationary table for horizontally placing the quartz glass tube; and a burner for flame polishing, which can be arranged on an extension line of the circumference of the end of the quartz glass tube and opposite to the circumference of the end of the quartz glass tube, wherein the burner is configured to move around along the circumference of the end of the quartz glass tube. Thus, a flame polishing device is provided, which can uniformly flame polish the end of the quartz glass tube as a processing object.

Description

Technical Field

[0001] The invention relates to a flame grinding device and a method for flame grinding the end of a quartz glass tube. Background Art

[0002] As a method for polishing glass, there is flame polishing (flame polishing, also referred to as "FP"), which is a method of polishing glass using flame. For example, flame polishing is used when polishing the cut surface of the end of a glass tube.

[0003] As for general glass tubes produced in large quantities, a method is generally known in which a plurality of products are continuously transported while rolling on rollers and are subjected to flame polishing treatment by contacting the products with flames generated by a fixed burner from below. However, in this method in which the products are transported while being physically rotated, there is a concern that the products may be damaged.

[0004] Regarding this problem, a method of utilizing a volatile lubricant has been considered (see Patent Document 1). However, the method described in Patent Document 1 not only fails to eliminate the cause of the damage itself, but also generates the cost of using a lubricant, and also generates a new concern that the lubricant will remain in the product. In addition, it is easy to think that the appropriate amount and chemical composition of the lubricant must be considered according to the composition and size of the product, which is considered to increase the burden.

[0005] Therefore, in order to minimize the occurrence of damage in glass tubes, quartz glass tubes have been flame-polished manually one by one by bringing the flame generated by a hand-held burner into contact with the stationary quartz glass tubes. This manual operation has the disadvantages of (1) requiring skilled skills to flame-polish all the target quartz glass tubes evenly and appropriately; and (2) manual flame polishing is time-consuming.

[0006] Prior art literature

[0007] Patent Literature

[0008] Patent Document 1: Japanese Patent Application Publication No. 2015-137206 Summary of the invention

[0009] 1. Technical issues to be resolved

[0010] The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a flame polishing device and a flame polishing method capable of uniformly flame polishing the end portion of a quartz glass tube to be processed.

[0011] (II) Technical solution

[0012] The present invention is made to solve the above-mentioned problem and provides a flame polishing device for flame polishing the end of a cylindrical quartz glass tube, characterized in that it comprises: a stationary table for horizontally placing the quartz glass tube; and a burner for flame polishing, which can be arranged at a position opposite to the circumference of the end of the quartz glass tube on an extension line of the circumference of the end of the quartz glass tube, wherein the burner is configured to move in a circle along the circumference of the end of the quartz glass tube.

[0013] If it is such a flame grinding device, the end of the quartz glass tube as the processing object can be uniformly flame-grinded. In addition, since the flame grinding process can be automatically performed by the device, there is no need for an operator with skilled skills.

[0014] In the flame polishing device of the present invention, preferably, the burner is configured to be able to change the speed of the orbiting movement according to the angular position on the circumference of the orbiting movement.

[0015] This flame grinding device can reduce unevenness (uneven heating) in flame grinding at the end of the quartz glass tube by changing the speed of the circumferential movement according to the angular position on the circumference.

[0016] In addition, preferably, the stationary table can station a plurality of the quartz glass tubes, and the flame polishing device has a plurality of the burners, which can be respectively arranged at positions opposite to the circumferences of the respective ends of the plurality of quartz glass tubes stationary on the stationary table on extension lines of the circumferences of the respective ends, and the plurality of burners are respectively configured to simultaneously move in a circular motion along the circumferences of the ends of the plurality of quartz glass tubes.

[0017] If a flame polishing device configured in this manner is provided that can flame polish a plurality of quartz glass tubes simultaneously, the work can be accelerated and productivity can be improved.

[0018] In addition, preferably, the mechanism for causing the burner to move in a circular motion includes vibration-proof rubber.

[0019] In this way, the mechanism for causing the burner to move in a circular motion is provided with the vibration-proof rubber, so that the mechanism can be operated smoothly and the flame polishing process can be performed stably.

[0020] In addition, preferably, the mechanism for causing the burner to perform orbital movement is configured so that the radius of the orbital movement of the burner can be changed by changing the mounting position of an attachment.

[0021] By forming a mechanism for causing the burner to move around in this way, the radius of the burner's movement around can be easily changed. Thus, even when flame polishing the end of a quartz glass tube with different tube diameters, the radius of the burner's movement around can be easily adjusted.

[0022] In addition, preferably, the stationary table is configured to be movable forward and backward in a direction approaching the burner and in a direction away from the burner, and is configured to be rotatable in a horizontal plane.

[0023] By configuring the stationary table to be movable forward and backward, the distance between the burner and the end of the quartz glass tube can be easily adjusted. In addition, by configuring the stationary table to be rotatable in a horizontal plane, a flame polishing device that can quickly process both end surfaces of the quartz glass tube can be made.

[0024] In addition, preferably, the burner is configured to be movable forward and backward in a direction approaching the stationary table and in a direction away from the stationary table.

[0025] By making the burner movable forward and backward in this manner, the distance between the burner and the end of the quartz glass tube can be easily adjusted.

[0026] In addition, preferably, the stationary table is formed with a groove for stationary placement of the quartz glass tube.

[0027] By providing a stationary table having such grooves, the quartz glass tube can be stationary more stably.

[0028] In addition, preferably, the stationary table allows the quartz glass tube to remain stationary without being fastened.

[0029] In this way, in a flame polishing apparatus including a stationary table capable of stationary quartz glass tube without fastening, it is possible to prevent the quartz glass tube from being damaged by fastening.

[0030] In addition, the present invention provides a method for flame polishing an end portion of a quartz glass tube, wherein the method flame polishes an end portion of a cylindrical quartz glass tube, and is characterized in that the method comprises the following steps: placing the quartz glass tube horizontally still; arranging a burner for flame polishing at a position opposite to the circumference of the end portion of the quartz glass tube on an extension line of the circumference of the end portion of the quartz glass tube; and while the burner is moved in a circular motion along the circumference of the end portion of the quartz glass tube by mechanical control, a flame from the burner is brought into contact with the end portion of the quartz glass tube, thereby flame polishing the end portion of the quartz glass tube.

[0031] If be such flame grinding method that makes burner move around by mechanical control, then can evenly carry out flame grinding process to the end of the quartz glass tube as processing object.In addition, owing to can automatically carry out flame grinding process by mechanical control, therefore do not need to have skilled operator.

[0032] Furthermore, in the method for flame polishing the end of a quartz glass tube of the present invention, preferably, when the burner is moved in a circumferential direction along the circumference of the end of the quartz glass tube, the speed of the circumferential movement of the burner is set to be faster in an upper section including the highest point of the circumference and in a lower section including the lowest point than in a middle section between the upper section and the lower section.

[0033] In this way, by changing the speed of the orbiting movement according to the angular position on the circumference of the orbiting movement of the burner, it is possible to reduce the unevenness of the flame grinding at the end of the quartz glass tube.

[0034] In this case, preferably, the upper interval is set to occupy a range of more than 30° and less than 90° of the circumference in the upper part of the circle, the lower interval is set to occupy a range of more than 10° and less than 30° of the circumference in the lower part of the circle, and the speed of the orbital movement of the burner in the upper interval and the lower interval is set to more than 1.2 times and less than 1.6 times the speed of the orbital movement of the burner in the middle interval.

[0035] In this case, it is further preferred that the upper interval is set to occupy a range of more than 50° and less than 70° of the circumference in the upper part of the circle, the lower interval is set to occupy a range of more than 15° and less than 25° of the circumference in the lower part of the circle, and the speed of the orbital movement of the burner in the upper interval and the lower interval is set to more than 1.4 times and less than 1.5 times the speed of the orbital movement of the burner in the middle interval.

[0036] By changing the speed of the circumferential movement in this way, it is possible to more effectively reduce the unevenness of the flame polishing at the end of the quartz glass tube.

[0037] In addition, preferably, in the step of placing the quartz glass tubes at rest, a plurality of the quartz glass tubes are placed at rest, and in the step of configuring the burners, the plurality of burners are respectively configured to be opposite to the circumference of the end portions of the plurality of quartz glass tubes on extension lines of the circumferences of the end portions of the plurality of quartz glass tubes, and in the step of flame-polishing the end portions of the quartz glass tubes, the ends of the plurality of quartz glass tubes are flame-polished simultaneously by causing the plurality of burners to move simultaneously in a circular motion along the respective circumferences of the end portions of the plurality of quartz glass tubes.

[0038] By simultaneously performing the flame polishing process on a plurality of quartz glass tubes in this manner, the work can be accelerated and the productivity can be significantly improved.

[0039] In addition, preferably, the step of leaving the quartz glass tube at rest is performed without fastening the quartz glass tube.

[0040] By leaving the quartz glass tube at rest without fastening in this manner, it is possible to prevent the quartz glass tube from being damaged by fastening.

[0041] (III) Beneficial effects

[0042] According to the flame polishing device and the method for flame polishing the end of a quartz glass tube of the present invention, the end of the quartz glass tube to be processed can be flame polished uniformly. In addition, since the flame polishing process can be performed automatically, a skilled operator is not required. In addition, since a plurality of quartz glass tubes can be processed simultaneously, productivity can be significantly improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 This is a schematic diagram showing an example of the structure of the flame polishing device of the present invention.

[0044] Figure 2 This is an enlarged view showing an example of a state in which the end portion of a quartz glass tube is heated by a burner in the flame polishing device of the present invention.

[0045] Figure 3 This is a schematic cross-sectional view showing a state in which a burner moves around the end of a quartz glass tube.

[0046] Figure 4 This is an example of the structure of the flame polishing device of the present invention, and is a schematic plan view showing a part of the structure of the flame polishing device capable of flame polishing a plurality of quartz glass tubes simultaneously using a plurality of burners.

[0047] Figure 5 This is a schematic cross-sectional view showing an example of a stationary table that can be used in the flame polishing device of the present invention.

[0048] Figure 6 This is a flowchart showing the outline of the method of flame polishing the end of a quartz glass tube according to the present invention. DETAILED DESCRIPTION

[0049] The flame polishing device of the present invention flame polishes the end of a cylindrical quartz glass tube, and is characterized in that it comprises: a stationary table, which horizontally stabilizes the quartz glass tube; and a burner for flame polishing, which can be arranged at a position opposite to the circumference of the end of the quartz glass tube on an extension line of the circumference of the end of the quartz glass tube, wherein the burner is configured to move in a circle along the circumference of the end of the quartz glass tube.

[0050] Hereinafter, the present invention will be described in more detail with reference to the accompanying drawings.

[0051] Figure 1 Schematic diagram of a flame polishing device 100 of the present invention is shown. The flame polishing device 100 of the present invention comprises a stationary table 11 and a burner 21 for flame polishing. The stationary table 11 is a table for horizontally placing a cylindrical quartz glass tube 91. The burner 21 is configured to be arranged at a position opposite to the circumference of the end 92 of the quartz glass tube 91 on an extension line of the circumference of the end 92 of the quartz glass tube 91. Figure 1 The front end of the burner 21 is positioned at the lowest position facing the circumference of the end 92 of the quartz glass tube 91, and the flame 22 is brought into contact with the end 92 of the quartz glass tube 91. The quartz glass tube 91 also has another end 93 on the opposite side.

[0052] In the present invention, the burner 21 is further configured to perform orbital movement along the circumference of the end portion 92 of the quartz glass tube 91. The orbital movement of the burner 21 can be realized by a burner orbital movement mechanism 24. Figure 2 and Figure 3 Displays the burner's orbital movement. Figure 2 This is an enlarged view showing an example of a state in which the end portion 92 of the quartz glass tube 91 is heated by the burner 21 . Figure 2 The burner 21 is shown to be arranged on an extension line of the uppermost part of the circumference of the end 92 of the quartz glass tube 91 and to face the uppermost part. Figure 2 As shown, the molten portion in the end portion 92 of the quartz glass tube 91 is the uppermost portion of the end portion 92. The burner 21 is further configured as shown in FIG. Figure 2 The direction of the orbital movement is not limited to Figure 2 The direction of the arrow symbol shown can also be the opposite direction of the circular movement.

[0053] Figure 3 The burner is shown moving around relative to the end of the quartz glass tube. Figure 3 The end 92 of the quartz glass tube 91 is shown in FIG. Figure 1 and Figure 2The burner 21 is a diagram obtained by observing the end 92 of the quartz glass tube 91 from the burner 21 side. The burner 21 moves around along the circumference of the end 92 of the quartz glass tube 91. Figure 3 The burner 21 shown by the middle dotted line moves in a circle in the circumferential direction 31 at a position opposite to the circumference of the end 92 of the quartz glass tube 91 on the extension line of the circumference of the end 92 of the quartz glass tube 91. The diameter of the circumference of the burner 21 that performs this circular movement corresponds to the diameter of the quartz glass tube 91 (particularly, the middle of the outer diameter and the inner diameter at the end 92 of the quartz glass tube 91).

[0054] In the flame polishing device 100 of the present invention, preferably, the burner 21 is configured to be able to change the speed of the orbital movement according to the angular position on the circumference of the orbital movement. Figure 3 As shown, the moving range of the burner 21 is divided into an upper range 32, a lower range 34, and a middle range 33 and 35 according to the angular position on the circumference. The upper range 32 is a range including the highest point of the circumference, and the lower range 34 is a range including the lowest point of the circumference. The middle ranges 33 and 35 are located between the upper range 32 and the lower range 34. In the description of the present invention, for the sake of convenience, the middle ranges 33 and 35 are described as the first middle range 33 moving from the upper range 32 to the lower range 34, and the second middle range 35 moving from the lower range 34 to the upper range 32. Figure 3 In the case of the illustrated circumferential direction 31, the burner 21 circumferentially moves in the order of the upper section 32, the first middle section 33, the lower section 34, the second middle section 35, and the upper section 32. However, flame grinding can be started from any section.

[0055] This flame grinding device changes the speed of the circumferential movement according to the angular position, thereby being able to reduce unevenness of flame grinding (uneven heating) at the end of the quartz glass tube.

[0056] In addition, the flame polishing device 100 of the present invention can be configured to be capable of simultaneously performing flame polishing on the end portions 92 of a plurality of quartz glass tubes 91. Figure 4 The method of the flame grinding device will be described. Figure 4 2 is a schematic top view showing a part of the structure of a flame polishing device capable of simultaneously performing flame polishing on the end portions 92 of a plurality of quartz glass tubes 91 using a plurality of burners 21. Figure 4 As shown, the stationary table 11 is a platform on which a plurality of quartz glass tubes 91 can be stationary. The flame polishing device 100 includes a plurality of burners 21 . Figure 4, an example of flame polishing the ends 92 of eight quartz glass tubes 91 simultaneously using eight burners 21 is shown. The plurality of burners 21 are configured to be respectively arranged on the extension lines of the circumferences of the ends 92 of the plurality of quartz glass tubes 91 placed on the stationary table 11 and at positions opposite to the circumferences of the respective ends 92. The plurality of burners 21 are configured to be respectively moved around simultaneously along the circumferences of the ends 92 of the plurality of quartz glass tubes 91. Flames 22 are respectively generated from the plurality of burners 21, and each flame 22 is respectively brought into contact with the ends 92 of the plurality of quartz glass tubes 91. Thus, flame polishing treatment can be performed simultaneously on the plurality of quartz glass tubes 91. If a flame polishing device configured in this way and capable of flame polishing treatment on the plurality of quartz glass tubes simultaneously is used, the operation can be accelerated.

[0057] In the flame polishing device 100 of the present invention, it is preferable that the mechanism for causing the burner 21 to move in a circular motion includes a vibration-proof rubber. Figure 1 and Figure 4 In the burner circling movement mechanism 24, a vibration-proof rubber 26 is mounted on the shaft 25. Thus, the burner circling movement mechanism 24 is provided with the vibration-proof rubber 26, so that the burner 21 can be smoothly moved by eliminating the shaking, and the flame polishing process can be stably performed.

[0058] In the flame polishing device 100 of the present invention, the mechanism for orbiting the burner (burner orbiting mechanism 24) may be configured to change the radius of the orbiting movement of the burner 21 by changing the attachment mounting position. Figure 4 The structure is shown. The burner orbiting mechanism 24 has an accessory mounting portion 27. The accessory mounting portion 27 is configured to mount accessories in a manner that the radius of the orbiting movement is different. By configuring the burner orbiting mechanism 24 in this way, the radius of the orbiting movement of the burner 21 can be easily changed. Thus, even when flame polishing is performed on the end 92 of the quartz glass tube 91 with different tube diameters, the radius of the orbiting movement of the burner 21 can be easily adjusted using the same device.

[0059] In addition, in the flame polishing device 100 of the present invention, the stationary table 11 can be constructed so that it can move forward and backward in a direction approaching the burner 2 and in a direction away from the burner 21 by making the stationary table 11 slide on a track, for example. By constructing the stationary table 11 so that it can move forward and backward in this way, the distance between the burner 21 and the end 92 of the quartz glass tube 91 can be easily adjusted. In addition, the stationary table 11 can be constructed so that it can rotate in a horizontal plane by making the stationary table 11 into a turntable, for example. By constructing the stationary table 11 so that it can rotate in a horizontal plane in this way, a flame polishing device can be made that can quickly process the two end portions 92, 93 of the quartz glass tube 91 on the stationary table 11. That is, it is possible to Figure 1 After the end 92 of the quartz glass tube 91 shown is flame-polished, the stationary table 11 is rotated in a horizontal plane to flame-polish the other end 93 .

[0060] The forward and backward movement and the rotation in the horizontal plane of the stationary table 11 can be achieved by Figure 1 The static table shown is realized by moving the rotating mechanism 15. This method can be called a sliding turntable method.

[0061] Similar to the forward and backward movement of the stationary table 11, the burner 21 may be configured to be able to move forward and backward in a direction approaching the stationary table 11 and in a direction away from the stationary table 11. Figure 1 This is realized by the burner forward and backward moving mechanism 29 shown. By making the burner 21 movable forward and backward in this way, the distance between the burner 21 and the end 92 of the quartz glass tube 91 can be easily adjusted, and the workability is very high.

[0062] In addition, in the flame grinding device 100 of the present invention, Figure 5 As shown, the stationary table 11 can be made into a member having a groove 13. In this groove 13, the quartz glass tube 91 can be stationary. Figure 5 An example in which eight grooves 13 are formed is shown, which is equivalent to Figure 4 The number of grooves 13 can be appropriately changed according to the number of quartz glass tubes 91 to be flame-polished. By forming the stationary table 11 with such grooves 13, the side of the quartz glass tube 91 will not be damaged and the quartz glass tube 91 can be stationary more stably.

[0063] In addition, in the flame polishing device 100 of the present invention, it is preferred that the stationary table 11 stationarily holds the quartz glass tube 91 without fixing. Not fixing means that when the quartz glass tube 91 is placed on the stationary table 11, it is not fixed except by the action of gravity. For example, pressing a fixing member from above the quartz glass tube 91, or fixing the quartz glass tube 91 to the stationary table 11 with a rope or a belt is fixing. For a flame polishing device having a stationary table 11 that can hold the quartz glass tube 91 without fixing, it is possible to prevent damage to the quartz glass tube caused by fixing. The stationary table 11 having the above-mentioned groove 13 can stably hold the quartz glass tube 91 even without fixing.

[0064] Next, refer to Figure 6 The method for flame polishing the end of a quartz glass tube of the present invention is described. The present invention is a method for flame polishing the end of a cylindrical quartz glass tube. The method comprises the steps of placing the quartz glass tube horizontally ( Figure 6 Step S1); the step of arranging the burner for flame grinding on the extension line of the circumference of the end of the quartz glass tube and the circumference of the end of the quartz glass tube at a position opposite to the circumference of the end of the quartz glass tube ( Figure 6 and, while mechanically controlling the burner to move around the circumference of the end of the quartz glass tube, the flame from the burner contacts the end of the quartz glass tube, thereby flame-polishing the end of the quartz glass tube ( Figure 6 Step S3).

[0065] This method of the present invention can be used Figure 1 First, in step S1, the quartz glass tube 91 is horizontally placed on the stationary table 11 of the flame grinding device 100. Figure 5 As shown in FIG. 1 , if a groove 13 is formed on the stationary table 11, the quartz glass tube 91 can be stationary more stably. The step of stationary the quartz glass tube 91 is preferably performed without fastening the quartz glass tube 91. For example, Figure 5 In the stationary table 11 having the groove 13 shown above, the quartz glass tube 91 can be stably stationed even without fastening, so it is preferable to use such a stationary table 11 to station the quartz glass tube 91. In this way, by stationing the quartz glass tube 91 without fastening, damage to the quartz glass tube 91 due to fastening can be prevented.

[0066] Next, in step S2, the burner 21 for flame polishing is arranged at a position opposite to the circumference of the end 92 of the quartz glass tube 91 on the extension line of the circumference of the end 92 of the quartz glass tube 91. In this arrangement step, fine adjustment can be performed using the stationary table moving and rotating mechanism 15 and the burner forward and backward moving mechanism 29 provided in the flame polishing device 100. The alignment can be performed manually by the operator, or the movement of the stationary table moving and rotating mechanism 15 and the burner forward and backward moving mechanism 29 can be pre-programmed to be performed automatically. In addition, it is also possible to perform fine adjustment manually by the operator after the rough movement is automatically performed.

[0067] Next, in step S3, while the burner 21 is mechanically controlled to move in a circular motion along the circumference of the end 92 of the quartz glass tube 91, the flame 22 is brought into contact with the end 92 of the quartz glass tube 91 from the burner 21. Thus, the end 92 of the quartz glass tube 91 is flame-polished. In this flame-polishing step, the burner circular motion mechanism 24 automatically moves the burner 21 in a circular motion by mechanical control.

[0068] If the flame polishing method is used in which the burner 21 is moved around by mechanical control, the end 92 of the quartz glass tube 91 to be processed can be uniformly flame polished. In addition, since the flame polishing can be automatically performed by mechanical control, even an operator without skilled skills can perform the operation.

[0069] In the flame polishing method of the present invention, a plurality of quartz glass tubes 91 can be flame polished at the same time. Figure 1 , Figure 4 First, in the above step S1 (the step of leaving the quartz glass tube to stand), as shown in FIG. Figure 4 The plurality of quartz glass tubes 91 are left stationary as shown. In addition, in the above step S2 (the step of arranging the burners), the plurality of burners 21 are arranged so as to be opposed to the circumference of the end portions 92 of the plurality of quartz glass tubes 91 on the extension lines of the circumferences of the end portions 92 of the plurality of quartz glass tubes 91. In addition, in the above step S3 (the step of flame-polishing the end portions of the quartz glass tubes), the end portions 92 of the plurality of quartz glass tubes 91 are flame-polished simultaneously by causing the plurality of burners 21 to move around simultaneously along the circumferences of the end portions 92 of the plurality of quartz glass tubes 91.

[0070] By simultaneously performing the flame polishing process on a plurality of quartz glass tubes 91 in this manner, the work can be accelerated, and the productivity of the quartz glass tubes 91 can be significantly improved.

[0071] After the end 92 on one side of the quartz glass tube 91 is flame-polished, the end 93 on the other side is usually flame-polished. Figure 1 The flame polishing device 100 having the stationary table moving and rotating mechanism 15 and the stationary table 11 of the sliding turntable type shown in the figure can easily perform flame polishing of both ends. In the case of the stationary table 11 of the sliding turntable type, after the above steps S1 to S3 are performed in the flame polishing of the end 92 on one side, in the flame polishing of the end 93 on the other side, since step S1 has already been performed, steps S2 and S3 can be performed on the end 93 on the other side of the quartz glass tube 91 by simply rotating the stationary table 11.

[0072] In the flame polishing method of the present invention, the above steps S1 to S3 are sufficient, but other steps can be appropriately added. For example, before the flame polishing step S3, the end 92 of the quartz glass tube 91 can be preheated by the burner 21. In the preheating step, there is no need to move the burner 21 around. The preheating can be performed multiple times and is not limited to once. For example, the end 92 of the quartz glass tube 91 can be preheated once by the burner 21, and the end 93 on the other side can be preheated once. After that, the flame polishing step S3 can be performed after the burner configuration step S2 of the end 92 is performed and the secondary preheating of the end 92 is further performed. In this case, after the flame polishing step S3 of the end 92 is performed, the burner configuration step S2 of the end 93, the secondary preheating of the end 93, and the flame polishing step S3 can be performed.

[0073] In the flame polishing method of the present invention, preferably, in the above step S3, when the burner 21 is moved around the circumference of the end 92 of the quartz glass tube 91, the speed of the moving around of the burner 21 is set to: Figure 3 The speed in the upper section 32 including the highest point of the circumference and the lower section 34 including the lowest point is faster than in the middle sections 33 and 35 located between the upper section 32 and the lower section 34. The change in the speed of the circumferential movement can be achieved in the following manner, that is, the burner 21 is configured to be able to change the speed of the circumferential movement according to the angular position on the circumference of the circumferential movement as described above. In addition, the change in the speed of the circumferential movement can be performed by pre-programmed mechanical control. By changing the speed of the circumferential movement according to the angular position on the circumference of the circumferential movement of the burner 21 in this way, the unevenness of the flame polishing in the end 92 of the quartz glass tube 91 can be reduced.

[0074] This is considered to be because: due to the nature of the burner flame, the flame 22 generated by the burner 21 tends to be wider above the central axis of the burner 21 (that is, the central axis of the flame 22) than below and in the lateral direction. Accordingly, the upper section 32 and the lower section 34 tend to be relatively strongly affected by the heating caused by the flame 22. In addition, with respect to this tendency, the upper section 32 tends to be larger than the lower section 34. Therefore, it is preferred that the speed of the circumferential movement of the burner 21 is set to be faster in the upper section 32 and the lower section 34 than in the middle sections 33 and 35. Furthermore, with respect to the length of the section that makes the speed of the circumferential movement faster, it is preferred that the upper section 32 be longer than the lower section 34.

[0075] In this case, it is preferred that the upper section 32 is set to occupy a range of 30° to 90° of the circumference at the upper part of the circumference, and the lower section 34 is set to occupy a range of 10° to 30° of the circumference at the lower part of the circumference. It is further preferred that the speed of the orbital movement of the burner 21 in the upper section 32 and the lower section 34 is set to be 1.2 times to 1.6 times the speed of the orbital movement of the burner 21 in the middle sections 33 and 35.

[0076] In this case, it is further preferred that the upper section 32 is set to occupy a range of 50° to 70° of the circumference at the upper part of the circumference, and the lower section 34 is set to occupy a range of 15° to 25° of the circumference at the lower part of the circumference. It is further preferred that the speed of the orbital movement of the burner 21 in the upper section 32 and the lower section 34 is set to be 1.4 times to 1.5 times the speed of the orbital movement of the burner in the middle sections 33 and 35.

[0077] By changing the speed of the circumferential movement in this way, it is possible to more effectively reduce the unevenness of the flame polishing at the end portion 92 of the quartz glass tube 91 .

[0078] In addition, the angle ranges of the upper section 32, the lower section 34, and the middle sections 33 and 35 and the speed of the orbital movement of each section can be adjusted appropriately. For example, although the appropriate angle ranges and orbital movement speeds may vary depending on the diameter of the quartz glass tube 91, room temperature, etc., they can be adjusted appropriately by those skilled in the art. In addition, the angle ranges and orbital movement speeds can be easily changed by changing the program of mechanical control.

[0079] Example

[0080] Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples, but the present invention is not limited to these Examples.

[0081] [Example 1]

[0082] use Figure 1 and Figure 4 The flame polishing device 100 shown performs flame polishing of the end 92 of the quartz glass tube 91. For the flame polishing device 100, a polishing device having a vibration-proof rubber 26 is used. The flame polishing device 100 having a burner forward and backward moving mechanism 29 and a stationary table moving and rotating mechanism 15 is used to adjust the distance between the burner 21 and the stationary table 11, but the stationary table 11 is not rotated, and only the end 92 on one side of the quartz glass tube 91 is flame polished. In addition, the quartz glass tube 91 to be stationary on the stationary table 11 is set to one. The quartz glass tube 91 is not fixed, but is stationary on the stationary table 11 horizontally. As the stationary table 11, a stationary table having a groove 13 is used. Next, the burner 21 for flame polishing is arranged at a position opposite to the circumference of the quartz glass tube 91 on the circumference extension line of the quartz glass tube 91, and the burner 21 is rotated along the circumferential position of the end 92 of the quartz glass tube 91, thereby irradiating the end 92 of the quartz glass tube 91 with the flame 22. The rotating speed of the burner 21 is kept constant. A plurality of quartz glass tubes are not processed simultaneously but are processed one by one.

[0083] The number of turns was 15. In addition, the LPG supply amount supplied to one burner 21 was set to 2.8 L / min, and the oxygen supply amount was set to 13.3 L / min. The distance between the burner 21 and the end 92 of the quartz glass tube 91 (the irradiation distance of the flame 22) was set to 35 mm. These conditions of the number of turns, gas supply amount, and irradiation distance are common to Examples 2 to 7 and Comparative Examples 1 to 3 described later.

[0084] [Example 2]

[0085] The flame polishing of the end 92 of the quartz glass tube 91 was performed by the same method as in Example 1 except that the rotation speed of the burner 21 was controlled according to the irradiation position of the flame 22. The rotation speed at this time was set to be faster in the upper section 32 and the lower section 34 of the circumference of the end of the quartz glass tube 91 than in the other sections (middle sections 33 and 35). Specifically, the rotation speed was set to 18.6 revolutions / minute in the range of 60° in the upper section 32 and 20° in the lower section 34, and the rotation speed was set to 13.0 revolutions / minute in the middle sections 33 and 35 (the rotation speed in the upper section 32 and the lower section 34 was about 1.4 times that of the middle sections 33 and 35).

[0086] [Example 3]

[0087] The flame polishing of the end 92 of the quartz glass tube 91 was performed in the same manner as in Example 2 except that the rotation speed of the burner 21 was changed. Specifically, the rotation speed was set to 16.8 revolutions / minute in the range of 30° in the upper section 32 and 10° in the lower section 34, and the rotation speed was set to 14.0 revolutions / minute in the middle sections 33 and 35 (the rotation speed in the upper section 32 and the lower section 34 was about 1.2 times that of the middle sections 33 and 35).

[0088] [Example 4]

[0089] The flame polishing of the end 92 of the quartz glass tube 91 was performed in the same manner as in Example 2 except that the rotation speed of the burner 21 was changed. Specifically, the rotation speed was set to 19.1 revolutions / minute in the range of 90° in the upper section 32 and 30° in the lower section 34, and the rotation speed was set to 11.9 revolutions / minute in the middle sections 33 and 35 (the rotation speed in the upper section 32 and the lower section 34 was about 1.6 times that of the middle sections 33 and 35).

[0090] [Example 5]

[0091] The flame polishing of the end 92 of the quartz glass tube 91 is performed by the same method as in Example 2 except that the flame polishing treatment is performed simultaneously on the plurality of (eight) quartz glass tubes 91. In this case, the flame polishing of the plurality of quartz glass tubes 91 is performed by arranging a plurality of combinations of quartz glass tubes and burners in parallel in the long axis direction of the quartz glass tubes so as to simultaneously process the ends of the plurality of quartz glass tubes.

[0092] [Example 6]

[0093] The flame polishing of the ends 92 and 93 of the quartz glass tube 91 was performed in the same manner as in Example 5, except that the flame polishing of the ends 92 and 93 of the quartz glass tube 91 was performed by rotating the stationary table 11 using the stationary table moving and rotating mechanism 15 .

[0094] [Example 7]

[0095] The flame polishing process of the end portion 92 of the quartz glass tube 91 was performed in the same manner as in Example 1 except that the flame polishing device 100 without the vibration-proof rubber 26 was used.

[0096] [Comparative Example 1]

[0097] The quartz glass tube was placed still on a jig, and flame polishing of the quartz glass tube was performed manually using a hand-held burner.

[0098] [Comparative Example 2]

[0099] The quartz glass tube is rotated around a fixed rotation axis, and a burner is fixed and arranged at a position opposite to the upper end of the quartz glass tube on the upper end extension line of the quartz glass tube, thereby flame polishing the quartz glass tube. The rotation of the quartz glass tube at this time is performed by preparing two heat-resistant carbon rollers that can be connected to a motor via a shaft and a gear and rotated, arranging them in a manner such that their rotation axes are parallel and horizontal, placing the quartz glass tube on the two carbon rollers, and driving the motor to rotate the carbon rollers.

[0100] [Comparative Example 3]

[0101] The flame polishing of the end of the quartz glass tube was performed in the same manner as in Comparative Example 2, except that a non-volatile lubricant was supplied to the carbonaceous roller. Furthermore, since the processing site used flame, a volatile lubricant could not be used.

[0102] [Evaluation Methods of Examples and Comparative Examples]

[0103] The quality of the quartz glass tubes produced in the respective Examples and Comparative Examples, the operation of the apparatus, the amount of processing, and the load of post-processing were evaluated as follows.

[0104] Quality evaluation:

[0105] The presence or absence of scratches on the surface of the quartz glass tube and the flame polishing state of the end were visually inspected and evaluated. The evaluation results were as follows.

[0106] The quartz glass tube is broken or cannot be flame-polished

[0107] bad

[0108] · The quartz glass tube is slightly damaged or the heating is uneven due to flame grinding

[0109] Better

[0110] The quartz glass tube does not cause damage and the heating unevenness of flame grinding is small

[0111] good

[0112] ·Quartz glass tubes are not damaged and almost free of uneven heating due to flame grinding

[0113] Very good

[0114] Evaluation of device action:

[0115] The operator evaluated the degree of the shaking state of the device during the operation. The evaluation results were as follows.

[0116] ·Device does not work properly

[0117] It is better if the device moves but produces slight shaking

[0118] The device moves without obvious shaking

[0119] Evaluation of processing volume:

[0120] The processing volume per unit time was evaluated. The evaluation results are as follows.

[0121] · Same as flame grinding by manual work

[0122] · Same to twice as good as flame polishing by manual labor

[0123] · More than twice the level of flame polishing performed by manual labor, especially good

[0124] Post-processing load:

[0125] The load of post-treatment was evaluated. The evaluation results are as follows.

[0126] ・Poor increase in post-processing load compared to flame grinding performed by manual work

[0127] ・The post-processing load is about the same as that of flame grinding performed manually

[0128] good

[0129] Post-processing includes cleaning by immersing the quartz glass tube in an approximately 2% aqueous hydrogen fluoride solution (hydrofluoric acid), followed by washing with pure water and drying, repairing when damage occurs, and processing necessary after flame polishing in order to manufacture other products.

[0130] The flame polishing conditions and evaluation results of each of the quartz glass tubes produced in Examples 1 to 7 and Comparative Examples 1 to 3 are summarized and shown in Table 1 below.

[0131] [Table 1]

[0132]

[0133] As can be seen from Table 1, in Examples 1 to 7, the flame polishing process can be performed more stably than the flame polishing process performed manually in Comparative Example 1. In Comparative Example 1, the quality of the quartz glass tube varies, especially due to human factors. In addition, even a skilled craftsman may fail.

[0134] In addition, the state of the end of the quartz glass tube obtained by flame polishing is also good by changing the rotation speed according to the angular position on the circumference, especially as in Examples 2 to 6. In addition, by simultaneously performing flame polishing on a plurality of quartz glass tubes as in Examples 5 and 6, the processing volume can be significantly increased.

[0135] In addition, the comparison between Example 1 and Example 7 confirmed that the flame polishing device 100 has the effect obtained by the vibration-proof rubber 26. This is because the vibration-proof rubber 26 can suppress the occurrence of vibration caused by the "play" of the mechanism.

[0136] In addition, the quartz glass tube was damaged in Comparative Example 2. Furthermore, due to the damage, the damage was enlarged by the hydrofluoric acid cleaning in the post-process, and the burden of the post-process was increased.

[0137] In Comparative Example 3, the problem of damage is not solved, and the need to wipe off the lubricant further increases the burden of post-processing.

[0138] The present invention is not limited to the above-mentioned embodiments. The above-mentioned embodiments are for illustrative purposes only, and any solution having substantially the same structure and producing the same function and effect as the technical concept described in the claims of the present invention is included in the technical scope of the present invention.

Claims

1. A flame grinding device for flame grinding the end of a cylindrical quartz glass tube, characterized in that: have: a stationary table for horizontally stationary the quartz glass tube; and, A burner for flame polishing can be arranged on an extension line of the circumference of the end of the quartz glass tube and at a position opposite to the circumference of the end of the quartz glass tube. The burner is configured to perform a circumferential movement along the circumference of the end of the quartz glass tube, and is configured to be able to change the speed of the circumferential movement according to the angular position on the circumference of the circumferential movement, and the speed of the circumferential movement of the burner is set to be faster in an upper section that includes the highest point of the circumference and occupies a range of 30° to 90° of the circumference and in a lower section that includes the lowest point and occupies a range of 10° to 30° of the circumference than in a middle section between the upper section and the lower section, and the mechanism for causing the burner to perform a circumferential movement is configured to be able to change the radius of the circumferential movement of the burner by changing the installation position of the accessory.

2. The flame grinding device according to claim 1, characterized in that: The stationary table can stationary a plurality of the quartz glass tubes. The flame polishing device comprises a plurality of the burners. The plurality of burners can be arranged at positions opposite to the circumferences of the respective ends of the plurality of quartz glass tubes stationary on the stationary table, on the extension lines of the circumferences of the respective ends. The plurality of burners are respectively configured to simultaneously perform circumferential movement along the circumferences of the ends of the plurality of quartz glass tubes.

3. The flame grinding device according to claim 1, characterized in that: The mechanism for causing the burner to perform a circular movement includes a vibration-proof rubber.

4. The flame grinding device according to claim 1, characterized in that: The stationary table is configured to be movable forward and backward in a direction approaching the burner and in a direction away from the burner, and is configured to be rotatable in a horizontal plane.

5. The flame grinding device according to claim 1, characterized in that: The burner is configured to be movable forward and backward in a direction approaching the stationary table and in a direction away from the stationary table.

6. The flame grinding device according to claim 1, characterized in that: The stationary table is formed with a groove for stationary placement of the quartz glass tube.

7. The flame grinding device according to any one of claims 1 to 6, characterized in that: The stationary table allows the quartz glass tube to remain stationary without being fastened.

8. A method for flame grinding a quartz glass tube, wherein the end of a cylindrical quartz glass tube is flame ground, characterized in that: The following steps are involved: The quartz glass tube is placed horizontally and still; Arrange a burner for flame polishing at a position opposite to the circumference of the end of the quartz glass tube on an extension line of the circumference of the end of the quartz glass tube; as well as The burner is mechanically controlled to move in a circular motion along the circumference of the end portion of the quartz glass tube, and the speed of the circular motion of the burner is set to be faster in an upper section including the highest point of the circumference and occupying a range of 30° to 90° of the circumference and in a lower section including the lowest point and occupying a range of 10° to 30° of the circumference than in a middle section between the upper section and the lower section, while the flame from the burner contacts the end portion of the quartz glass tube, thereby flame polishing the end portion of the quartz glass tube.

9. The method for flame grinding a quartz glass tube according to claim 8, characterized in that: The speed of the orbital movement of the burner in the upper section and the lower section is set to be 1.2 times or more and 1.6 times or less of the speed of the orbital movement of the burner in the middle section.

10. The method for flame grinding a quartz glass tube according to claim 9, characterized in that: The upper section is set to occupy a range of not less than 50° and not more than 70° of the circumference at the upper part of the circumference, The lower section is set to occupy a range of not less than 15° and not more than 25° of the circumference at the lower part of the circumference, The speed of the orbital movement of the burner in the upper section and the lower section is set to be 1.4 times or more and 1.5 times or less of the speed of the orbital movement of the burner in the middle section.

11. The method for flame grinding a quartz glass tube according to claim 8, characterized in that: In the step of leaving the quartz glass tubes to stand, a plurality of the quartz glass tubes are left to stand. In the step of arranging the burners, the plurality of burners are respectively arranged to be opposite to the circumference of the end portions of the plurality of quartz glass tubes on the extension lines of the circumferences of the end portions of the plurality of quartz glass tubes, Furthermore, in the step of flame-polishing the ends of the quartz glass tubes, the ends of the quartz glass tubes are flame-polished simultaneously by causing the plurality of burners to simultaneously move around along the circumferences of the ends of the plurality of quartz glass tubes.

12. The method for flame grinding a quartz glass tube according to any one of claims 8 to 11, characterized in that: The step of leaving the quartz glass tube at rest is performed without fastening the quartz glass tube.

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