JPH03247525A - Production of cylinder made of quartz glass and equipment therefor - Google Patents

Abstract

PURPOSE:To obtain a cylinder which is free from a microcrack and good in a surface state with good yield in material by heating and softening the tip of a columnar quartz glass rod being rotated around the longsized axis thereof and rotatably drawing this glass rod for a member for punching. CONSTITUTION:A rod 10 made of quartz glass and a dummy cylinder 11 are supported and rotated respectively by the main shaft feed tables 4, 7 placed on the beds 1, 3 of the inlet and outlet sides. The movement of the tables 4, 7 in the right and left directions is restricted as shown in a figure. The end parts of the rod 10 and the cylinder 11 are allowed to abut intactly and concentrically. While the rod 10 and the cylinder 11 are rotated, both are heated to the softening points by a heating furnace 2 and melt-stuck. In this case, a fixation shaft having a coma 13 for punching is inserted into a cylinder 11 and the tip of the coma 13 is engaged with the center of the tip of the rod 10. Then the cylinder 11 is formed from the rod 10 by starting transfer of the tables 4, 7 at the previously set feed velocity while continuing the rotation of the rod 10 and the cylinder 11.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a method and apparatus for manufacturing a quartz glass cylinder.

(Prior Art) Quartz glass tubes have conventionally been used, for example, as members for furnace core tubes and materials for optical fibers in the semiconductor industry.

In order to manufacture this quartz glass tube, conventionally, a solid quartz glass rod is generally manufactured and a hollow cylindrical member (generally called a "cylinder") made of quartz glass is made from this rod. It is cut out by drilling with a core drill, and this intermediate cylinder is heated to, for example, a softening temperature to form a thin-walled tube. An example of a method for forming a cylinder into a tube is the method described in Japanese Utility Model Publication No. 55-35297.

(Problem to be Solved by the Invention) However, according to the conventional method of drilling a solid quartz glass rod to cut out a cylinder, the central part of the quartz glass rod is not used as a cylinder.
In addition to the problem that the yield rate of raw materials for commercialization inevitably decreases, as a result of drilling, countless microcracks occur on the inner surface of the resulting cylinder, and it is difficult to remove these microcracks by grinding. Since oil and grinding debris adhere to the product, acid treatment or the like is required to remove stiffness, resulting in an increase in the number of work steps. There is also the problem that these microcracks cause deterioration of the surface condition of the final product.

The inventors of the present invention have conducted extensive studies in order to solve the problems of conventional methods when producing such quartz cylinders, and
The present invention has been developed in which a quartz glass rod is made into a cylinder without drilling.

An object of the present invention, which was made based on the results of such research and development, is to provide a method and apparatus for manufacturing a quartz glass cylinder that achieves a high material yield and makes effective use of resources.

Another object of the present invention is to prevent the occurrence of microcracks on the inner surface of the cylinder (therefore, it is possible to eliminate the need for a process for removing grinding oil and grinding debris adhering to these microcracks, and to prevent the occurrence of microcracks). An object of the present invention is to provide a method and apparatus for manufacturing a quartz glass cylinder that does not cause deterioration of the surface condition of a final product by preventing this.

Still another object of the present invention is to provide a quartz glass cylinder suitable for producing a final product with less variation in wall thickness when manufacturing quartz glass tubes by equalizing the wall thickness in the circumferential direction of the cylinder. The purpose of this invention is to provide a manufacturing method and apparatus for.

(Means for Solving the Problems) A feature of the method for manufacturing a quartz glass cylinder according to the present invention for realizing the various objects described above is that a cylindrical quartz glass rod is rotated about its long axis. However, the tip of the quartz glass rod is heated and softened, the sharp end of the drilling member is engaged with the center of the rod's tip surface, and the peripheral edge of the tip is rotated and pulled out from the drilling member.

The quartz glass cylinder manufacturing apparatus of the present invention, which is provided to suitably implement such a method, is characterized by: a rotation support means for supporting a cylindrical quartz glass rod while rotating it around its elongated axis; a heating means for heating and softening the tip of the quartz glass; a cylindrical dummy cylinder member concentrically fused to the periphery of the tip surface of the heated and softened quartz glass rod; and rotating the dummy cylinder member around its axis. a cylinder rotating means for rotating the dummy cylinder; a rod-shaped fixed boring means having a sharp end that passes through the cylinder of the dummy cylinder and engages the center of the tip of the quartz glass rod at the heated and softened position; The apparatus includes a moving means for moving the rod and the dummy cylinder member in the drilling direction relative to the fixed drilling means at predetermined speeds.

The fixed perforation means can be constructed, for example, by assembling a piece having a conical sharp tip to the distal end of a fixed rod-like member.

Furthermore, the apparatus of the present invention can be particularly suitably implemented as an industrial apparatus by providing an alignment means for aligning the rod-shaped fixed perforation means inside the cylindrical dummy cylinder member. This is because such centering means allows centering of the quartz glass rod to be processed at the initial stage of the drilling process, which is useful for equalizing the wall thickness of the cylinder. Note that after the drilling process starts, an autonomous alignment action occurs due to the engagement between the drilling member and the tip of the glass rod, so for the purpose of equalizing the wall thickness of the cylinder to be shaped, initial adjustment is not necessary. It is enough to realize your heart.

(Function) The method and apparatus for manufacturing a quartz glass cylinder of the present invention, having the above-described configuration, can produce a cylindrical tube from a rod without using a cutting method.

(Example) The present invention will be described below based on embodiments shown in the drawings.

FIG. 1 is a diagram showing an outline of an example of a quartz glass cylinder manufacturing apparatus for carrying out the present invention. In this figure, 1 indicates an entrance side bed, 3 indicates an exit side bed,
An induction heating type heating furnace 2 is arranged between these.

Reference numeral 4 designates a first spindle feed table which is provided on the entrance side bed so as to be movable in the left-right direction in the figure. Chucking a length of quartz glass rod 10,
The quartz glass rod IO is rotated around 23 in the figure by a rotation drive mechanism (not shown). In order to stabilize the posture of the long quartz glass rod, a support roller 17 is provided on the entrance side bed 1. Note that the position of the support roller 17 in this example can be adjusted in the directions indicated by reference numerals 21 and 22 in the figure.

Further, the first spindle feeding table 4 is fed and moved in the direction of reference numeral 19 in the figure at a predetermined speed by a moving mechanism (not shown).

The quartz glass rod lO supported by the first spindle feeding table 4 and the support roller 17 as described above.
The tip (right end in the figure) is placed inside the heating furnace 2 as shown in the figure, and when a predetermined alternating current is applied to the coil 2a, the heating element (graphite) 12a generates heat, bringing the quartz glass rod to the softening point. It is designed to be heated up to (approximately 2000℃).

On the other hand, another second spindle feeding table 7 is provided above the exit side bed 3, and chucks 8 at both ends thereof are provided.
．． The rotary drive chuck 8 of the heating furnace example, which is one of the parts of 9, includes:
A dummy cylinder 11 made of quartz glass is assembled and supported, and is driven and rotated in the direction of reference numeral 24 in the figure.

The tip of this dummy cylinder 11 made of quartz glass is fitted around the drawing die 12b that is provided integrally with the heating element 12a of the heating furnace 2, and the tip (left end in the figure) is It is designed to be concentrically fused to the tip surface of the quartz glass rod 10 that is the object. The second spindle feeding table 7 is moved in the direction of reference numeral 20 in the figure at a predetermined speed by a moving mechanism (not shown).

16 is a fixed stand fixed on the exit side bed 3;
The fixed shaft 14 supported at one end is fixed to the chuck 9 at the other end rotatably supported by the second main shaft feeding table 7 via a split collar 15, and is passed through the inside of the cylinder 11. A drilling piece (plug) 13 at the tip is provided so as to engage with the tip surface of the quartz glass rod that is the workpiece. The above-mentioned drilling piece 13
Since the quartz glass rod is heated to a softening temperature in the section, it is preferable that the fixed shaft 14 be provided with a double tube structure to provide an appropriate water-cooled structure.

In this example, a steady rest is fitted in the dummy cylinder 11 as explained in FIG. A tool (alignment means) 18 is provided. The fitting and assembling of the steady rest 18 is carried out, for example, by fitting and engaging the two-split collar from the distal end side of the fixed shaft 14.
By assembling the drilling piece 13 to the tip of the hole 4, it can be placed at a predetermined position. Here, when the fixed shaft 14 is cantilevered, the deflection of the tip is theoretically = WJ2"
/3 E I, and if there is this deflection, the piece 13 may not be centered on the rod at the initial stage of drilling the rod, resulting in a portion with inconsistent wall thickness at the end of the cylinder. By assembling the steady rest 18 as described above, there is an advantage that good dimensional accuracy and uniform wall thickness can be obtained.

A case will be described in which a cylinder is manufactured from a rod using the quartz glass cylinder manufacturing apparatus configured as described above.

First, the first spindle feed table 4 on the entrance side bed 1
The ends of the quartz glass rod 10 and the dummy cylinder 11 are abutted against each other in a concentric state, and while the second spindle feeding table 7 on the exit side bed 3 is restrained from moving in the left-right direction in the figure, while rotating. Both are heated in a heating furnace 2 to their softening point and fused together.

In addition, at this time, the fixed shaft having the drilling piece 13 is fitted inside the dummy cylinder 11 in advance, and the drilling piece 13
Engage the sharp end of the rod with the center of the tip of the rod.

Next, after confirming that the rod is heated to the point where it can be pultruded, the first spindle feed table 4 and the second spindle feed table 7 are moved at a predetermined feed rate to move the rod and dummy cylinder. Start moving while continuing rotation. Through this process, the cylinder 11 is molded from the rod 10 in a state similar to so-called pultrusion molding, as shown in FIG. be done.

In FIG. 3, reference numeral 12b indicates a die that determines the outer diameter of the cylinder to be formed. Considering that the die 12b is worn the most in this molding process, this die is attached to the die base 12c. The die body 1 can be inserted into and removed from the die base 12c from the direction opposite to the drilling (extraction) direction shown in FIG.
It is also preferable to provide it divided into 2b and 2b. Since the axial force acting on the die body 12b during molding is only the force in the drilling (pulling) direction, it is sufficient to assemble the die body 12b so that the structure achieves a one-way pullout prevention. Therefore, its replacement is easy.

The quartz glass cylinder formed by the above procedure does not involve grinding a solid rod by drilling as in the conventional method, so virtually all of the material of the quartz glass rod is used to form the cylinder. and has excellent product yield. Furthermore, since it does not involve a grinding method, it has excellent effects such as no microcracks occurring inside the cylinder and no subsequent treatment required.

It goes without saying that the present invention is not limited to the above embodiments, but can be implemented in various modified forms. For example, as shown in FIG. 5, the die body 12b is mechanically separated from the fixed heating element 12a that is integrated with the heating furnace, and the
The rotary flange 29 can be rotatably provided via a bearing 27 assembled to the flange 26 of No. 5, and the rotary flange 29 can also be rotated synchronously with the dummy cylinder 11 by a motor 32 via a chain 31. This has the advantage that relative friction between the workpiece and the die can be significantly reduced. Furthermore, the fixed shaft 14 can be rotated in synchronization with the dummy cylinder II in the circumferential direction, which has the advantage of greatly reducing the relative friction between the fixed part and the rotating part in the inner peripheral part. be.

(Effects of the Invention) As described above, according to the method and apparatus for manufacturing a quartz glass cylinder of the present invention, it is possible to provide a quartz glass cylinder with a high material yield and effective use of resources. There is an effect.

Furthermore, according to the manufacturing method and apparatus of the present invention, the generation of microcracks on the inner surface of the cylinder is avoided (therefore, the process of removing grinding oil and grinding debris adhering to these microcracks can be eliminated). Furthermore, by preventing the occurrence of microcracks, it is possible to provide a quartz glass cylinder that does not cause deterioration of the surface condition of the final product.

Furthermore, according to the manufacturing method and apparatus of the present invention, the quartz glass cylinder is suitable for producing a final product with less variation in wall thickness when manufacturing quartz glass tubes by equalizing the wall thickness in the circumferential direction of the cylinder. It also has the effect of being able to provide

In addition, if the material to be processed is a cylinder member, the device of the present invention can also be used as a tube manufacturing device by applying gas pressure to the inside of the cylinder member (however, no drilling pieces, fixed shafts, etc. are required). There are advantages. Therefore, conversely speaking, the device of the present invention can be used to simultaneously install a quartz glass tube manufacturing device and a quartz glass cylinder manufacturing device without having to specifically install a cylinder manufacturing device, allowing partial changes to be made during use. It has the advantage that it is only necessary to use it. Needless to say, such commonality of equipment brings extremely high utility on an industrial scale.

[Brief explanation of drawings]

Fig. 1 is a diagram showing an outline of the configuration of the quartz glass cylinder manufacturing apparatus according to the present invention - an example; Fig. 2 is an enlarged view of the outlet side bed and the second spindle feeding table; Figure 3 is a further enlarged view of the structure of the pull-out perforation part, Figure 4 is a view showing the structure of another example of the pull-out perforation part, and Figure 5 is a diagram showing the structure of yet another example of the pull-out perforation part. FIG. : Entrance side bed 2: Heating furnace: Outlet side bed: First spindle feed table 6: Chuck second spindle feed table 9: Chuck lO: Quartz glass rod 11: Dummy cylinder 13: Drilling piece 16: Fixed base 18: Steady rest 14: 17: 4 people outside fixed shaft support roller Figure 5

Claims (1)

[Claims] 1. While rotating a cylindrical quartz glass rod about its long axis, the tip of the quartz glass rod is heated and softened, and the sharp end of the drilling member is attached to the center of the rod tip surface. 1. A method for manufacturing a quartz glass cylinder, the method comprising: engaging the quartz glass cylinder, and rotating and pulling out the periphery of the tip with respect to the perforating member. 2. Rotating support means for supporting a cylindrical quartz glass rod while rotating it about its long axis; heating means for heating and softening the tip of the quartz glass; and a peripheral edge of the tip surface of the heated and softened quartz glass rod. a cylindrical dummy cylinder member concentrically fused to the dummy cylinder member, a dummy cylinder rotation means for rotating the dummy cylinder member around its axis, and a heated softening position of the tip of the quartz glass rod passed through the inside of the dummy cylinder. a rod-shaped fixed drilling means with a sharp end that engages with the center of the rod tip surface, and the quartz glass rod and the dummy cylinder member are each moved in the drilling direction with respect to the fixed drilling means at predetermined speeds. A manufacturing device for a quartz glass cylinder, characterized in that it is equipped with a moving means. 3. The apparatus for manufacturing a quartz glass cylinder according to claim 2, wherein the cylindrical dummy cylinder member is provided with an alignment means for aligning the rod-shaped fixed perforation means.