JP2005315314A - Joint structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a joint structure for connecting a quartz pipe and another pipe or quartz pipes to each other, properly coping with tapering or other deformation due to an etching phenomenon on the outer peripheral surface of the end part of the quartz pipe to prevent liquid leakage. <P>SOLUTION: This joint structure connects the quartz pipe and another pipe or the quartz pipes to each other. The joint structure includes: a joint body provided with a first step part formed on the inner peripheral surface to allow one end of the quartz pipe to be inserted; a fastening nut fitted to the outer peripheral surface of the quartz pipe and engaged with the end part of the joint body; a stopping means interposed between the fastening nut and the outer peripheral surface of the quartz pipe; and a first sealing means interposed between the joint body and the outer peripheral surface of the quartz pipe. The first sealing means is constructed by two or more stacked packing pieces having V-shaped section and first and second pressing adaptors clamping the packing pieces. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a joint structure for connecting quartz tubes to each other or a quartz tube and a resin pipe used in a manufacturing process of a semiconductor, a liquid crystal or the like.

  Conventionally, as the joint structure as described above, for example, there is a structure as shown in FIG. That is, the end portion of the quartz rod 3 is inserted into the one end side connection portion 2a of the joint body 2, and the tightening nut 4 and the one end side connection portion 2a of the joint body 2 that are fitted on the outer peripheral surface of the quartz rod 3 are connected to the quartz body. A taper surface 6b formed on an end portion of the tightening ring 6 and an end portion of the joint body 2 and a first end side connection portion 2a; 10a, the diameter of the tightening ring 6 is reduced and deformed in the direction in which it is crimped and fixed on the outer peripheral surface of the quartz rod 3, and the retaining ring 6 is retained in the circumferential groove formed on the outer peripheral surface of the quartz rod 3. The ring 5 is fitted and fixed, and the retaining ring 5 is held between the opposing surfaces of the tightening nut 4 and the tightening ring 6 inserted on the quartz rod 3.

  By the way, for example, when the liquid feeding is a liquid that chemically acts on Si in quartz, such as an aqueous solution of potassium hydroxide or an (ammonia + hydrogen peroxide) solution, the end of the quartz tube is caused by the solution leached from the end of the quartz tube. The outer peripheral surface of the glass tube is gradually eroded with time, so-called etching phenomenon occurs, and the end of the quartz tube becomes tapered. However, in the above prior art, the tightening ring 6 and the inner peripheral surface of the joint main body 2 cannot follow the tapering phenomenon of the outer peripheral surface of the quartz tube, resulting in poor sealing and liquid leakage.

Although effective techniques for solving the above problems have not yet been realized, related patent documents include the following.
JP 61-105391 A JP-A-5-87287

  The problem to be solved by the present invention is to prevent liquid leakage caused by tapering or other deformations caused by etching phenomenon on the outer peripheral surface of the end of the quartz tube in the joint structure connecting the quartz tube and another pipe or the quartz tube.

  The present invention relates to a joint structure for connecting a quartz tube and another pipe or quartz tube to each other, a joint body having a first step portion into which one end of the quartz tube is inserted and formed on the inner peripheral surface, and an outer peripheral surface of the quartz tube. A fastening nut that is inserted and screwed into an end of the joint body, a retaining means that is interposed between the fastening nut and the outer peripheral surface of the quartz tube, and between the joint body and the outer peripheral surface of the quartz tube. The first sealing means is provided, and the first sealing means is composed of a plurality of laminated cross-section V-shaped packings and first and second pressing adapters for clamping them, thereby solving the above-mentioned problem. It is something to try.

Further, in the above joint structure, the retaining means includes a groove portion carved on the outer peripheral surface of the quartz tube and a ring fitted in the groove portion and engaged with a fastening nut, and the first seal means is the joint body. Between the second stepped portion recessed in the inner peripheral surface of the first stepped portion and the outer peripheral surface of the quartz tube, and the first and second holding adapters are respectively inserted into the quartz tube and inserted into the outer periphery thereof. The packing group is formed by an annular body that is in close contact with the surface and is locked to the ring, and an abutting surface of the second stepped portion, and the packing group is connected to the joint body and the quartz tube by pressing of the holding adapter by tightening the fastening nut. There is a case in which a tight seal is provided between the outer peripheral surface and the outer peripheral surface.

Further, in the above joint structure, each packing of the packing group according to the first seal means is formed so that the inclination angle of the valley portion is smaller than the inclination angle of the peak portion in the V-shaped cross section thereof. The expansion of each packing in the inner and outer diameter directions due to the pressing of the adapter may be amplified to ensure a strong sealing property between the joint body and the outer peripheral surface of the quartz tube.

Still further, in any one of the joint structures described above, a second seal means is interposed between the end surface portion of the tip of the quartz tube and the abutting surface of the first step portion, and the second seal means is the end surface of the quartz tube. A groove portion formed in the portion and an annular protrusion formed on the abutting surface of the first step portion and in close contact with the groove portion.

In the present invention, even if deformation such as tapering due to an etching phenomenon occurs on the outer peripheral surface of the quartz tube end, the first seal means having the above configuration is formed between the inner peripheral surface of the joint body and the outer peripheral surface of the quartz tube facing the inner peripheral surface. By always tightly sealing the gap, the liquid leakage seen in the above prior art does not occur. That is, even if the outer peripheral surface of the quartz tube is deformed, such as a taper, the plurality of cross-section V-shaped packings in the first sealing means are constantly clamped by the holding adapter and are inflated and urged toward the outer diameter of the inner diameter. Therefore, the packing can ensure a firm and firm sealing performance following the taper and other deformations.

The joint structure that connects the quartz tube and other pipes or the quartz tube is a joint body that has a first step portion into which one end of the quartz tube is fitted and formed on the inner circumferential surface, and is fitted on the outer circumferential surface of the quartz tube. A fastening nut screwed into an end of the joint body, a retaining means interposed between the fastening nut and the outer peripheral surface of the quartz tube, and interposed between the joint body and the outer peripheral surface of the quartz tube. The first sealing means comprises a plurality of cross-sectional V-shaped packings and first and second pressing adapters that clamp them. The retaining means comprises a groove formed on the outer peripheral surface of the quartz tube and a split ring fitted in the groove and engaged with a fastening nut, and the first sealing means is the first step of the joint body. Between the second stepped portion recessed in the inner peripheral surface and the outer peripheral surface of the quartz tube, and the first and second holding adapters are respectively inserted into the quartz tube and are in close contact with the outer peripheral surface. An annular body that is locked to the ring and an abutting surface of the second stepped portion, and the packing group is disposed between the joint body and the outer peripheral surface of the quartz tube by pressing the holding adapter by tightening the fastening nut. Make sure to seal tightly.

  The joint body, the fastening nut, and the rings are made of a resin material having excellent chemical resistance, heat resistance, and pressure resistance such as PTFE and PFA. The packing having a V-shaped cross section is assembled by sandwiching an adapter (male, female) using a so-called normal V packing. The packing may be rubber or cloth rubber, but may be made of fluororesin or the like depending on the type of solution.

Further, each packing of the packing group according to the first sealing means is formed so that the inclination angle of the valley portion is smaller than the inclination angle of the peak portion in the V-shaped cross section, and when the pressing adapter is pressed, The trough part widens the crest part to amplify the expansion force in the inner and outer diameter directions of each packing to ensure a strong sealing property between the joint body and the outer peripheral surface of the quartz tube.

Further, a second sealing means is interposed between the end surface portion of the tip of the quartz tube and the abutting surface of the first step portion, and the second sealing means is formed with a groove formed on the end surface portion of the quartz tube and the first step. Better sealing effect if it is made up of an annular protrusion made of a flexible material that is formed on the abutting surface of the portion and is in close contact with the groove to prevent leakage to the outer peripheral surface of the quartz tube However, the formation of the groove on the end face of the quartz tube is not easy to process, and even if the liquid feed leaks, the first sealing means can ensure the sealing performance, so the second sealing means is Usually not always required.

FIG. 1 is a cross-sectional view of an essential part showing one embodiment of a joint structure according to the present invention.
In the figure, reference numeral 11 denotes a joint structure, and a quartz tube and a resin (PFA) tube are connected by the joint structure 11. Reference numeral 12 denotes a joint body, and an end portion of the quartz tube 13 is fitted and inserted into a first step portion 14 formed in an annular shape on the inner peripheral surface of the joint body 12 at one end side of the joint body 12. It is firmly fixed by each element.

A second step 15 is further provided around the inner peripheral surface of the first step 14. The second step portion 15 is provided with a first sealing means, and is interposed between the inner peripheral surface of the joint body 12 and the outer peripheral surface of the quartz tube 13 for various liquid feeding fluids flowing between the quartz tube and the joint body. It is sealed.
The first sealing means is composed of a plurality of laminated cross-section V-shaped packings and first and second pressing adapters that clamp them. That is, 16 is a plurality of cross-section V-shaped packings that are annularly inserted into the outer peripheral surface of the quartz tube 13, and the annular first holding adapter (female) 17 and the first holding adapter 17 that is inserted into the outer peripheral surface of the quartz tube 13. 2 Pressed by a second holding adapter (male) composed of the abutting surface of the stepped portion 15, and pressed against the outer peripheral surface of the quartz tube 13 and the inner peripheral surface of the second stepped portion 15, so that the both are completely cut off. It will be sealed. Each packing 16 and the first pressing adapter 17 are made of rubber or cloth-filled rubber.

Reference numeral 18 denotes an annular ring fitted into an annular groove formed on the outer peripheral surface of the quartz tube 13, and the groove and the ring 18 constitute a means for preventing the disconnection. The body 12 is prevented from coming off.
Reference numeral 19 denotes a fastening nut that is fitted to the outer peripheral surface of the quartz tube 13 and screwed into the joint body 12. The ring 18 of the above-mentioned prevention means comes into contact with the back surface of the fastening nut 19, thereby preventing the fastening nut 19 and the joint body 12 screwed to the fastening nut 19 from falling off the quartz tube 13. In FIG. 1, reference numeral 20 denotes a fastening nut that connects a resin (PFA) tube 21 to the joint body 12.

  FIG. 2 is a partially cutaway perspective view showing a detailed configuration of the first sealing means. The crests of the V-shaped packing 16 are opposed to the troughs of the first holding adapter (female) 17 that is inserted into the quartz tube 13 in the form of an annular body, and the plurality of packings 16 are sequentially connected to each other. The valley of the packing at the rearmost part is fitted and supported on the abutment surface of the second step part 15 as the second pressing adapter (male) and the ridge part formed here, The joint body 12 is screwed by the rotation of the fastening nut 19 to press the first and second holding adapters to clamp the packing, thereby functioning the first sealing means.

  FIG. 3 is a cross-sectional view showing one embodiment of the V-shaped packing of the first sealing means. In this embodiment, the crest portions 16a and the trough portions 16b of the V-shaped packings 16 and 16 are formed with different inclination angles. That is, as shown in the figure, the inclination angle of the peak portion 16a is set to be larger than the inclination angle of the valley portion 16b, so that the valley portion 16b is expanded by the peak portion 16a when the packing is pressed in the adjacent packings 16 and 16. Is done. Such expansion of the valley portion 16b is caused by the packing 16 in the second step portion 15 of FIG. 1 in the direction of the outer peripheral surface of the quartz tube 13 and the inner peripheral surface of the joint body 12 (the inner peripheral surface of the second step portion). Therefore, even if the outer peripheral surface of the quartz tube 13 is deformed, the packing firmly contacts the outer peripheral surface, so that a good sealing property can be secured. This point will be further described with reference to FIG.

  FIG. 4 is a partially cutaway cross-sectional view showing the corresponding state of the first sealing means when an etching phenomenon occurs on the outer peripheral surface of the end portion of the quartz tube 13 due to the liquid feeding (potassium hydroxide aqueous solution or the like) and the diameter is reduced. It is. The end of the quartz tube 13 subjected to the experiment is deformed into a tapered shape by the action of liquid feeding, and the diameter of the end has been reduced from the original 19.5 mm to 18.5 mm. Even in such a situation, the first sealing means appropriately copes with ensuring a desired sealing property. That is, since the packings 16 and 16 clamped by the first holding adapter 17 and the like expand inward and outward in the radial direction of the quartz tube 13 as described above, it is possible to firmly seal the outer peripheral surface of the reduced quartz tube 13. Become.

FIG. 5 is a partially cutaway cross-sectional view showing another embodiment according to the joint structure of the present application. Although this embodiment is provided with the second sealing means, other configurations are the same as the embodiment shown in FIG.
In this embodiment, a second sealing means is interposed between the end surface portion of the tip of the quartz tube 13 and the abutting surface of the first step portion 14. That is, the second sealing means includes an annular groove portion 22 formed on the end surface portion of the quartz tube 13 and an annular protrusion portion 23 formed on the abutting surface of the first step portion 14 and in close contact with the annular groove portion 22. It is configured. When the fastening nut 19 is rotated, the joint body 12 is screwed and the engagement between the emotion groove 22 and the annular protrusion 23 is strengthened, and the sealing performance is further enhanced in combination with the action of the first sealing means. Can be expected.

It is principal part sectional drawing which shows one Example of the joint structure which concerns on this invention. FIG. 5 is a partially cutaway perspective view showing a detailed configuration of the first sealing means. It is sectional drawing which shows one Example of the V-shaped packing of a 1st sealing means. FIG. 7 is a partially cutaway cross-sectional view showing a corresponding state of the first sealing means when an etching phenomenon occurs. It is a partially cutaway sectional view showing another embodiment according to the joint structure of the present application. It is a perspective view which concerns on a prior art example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 Joint structure 12 Joint main body 13 Quartz tube 14 1st level | step difference part 15 2nd level | step difference part 16 Cross-section V-shaped packing 17 1st holding | suppressing adapter 18 Retaining means 19 Fastening nut

Claims (4)

A joint structure for connecting a quartz tube and another pipe or quartz tube, and a fitting body in which a first step portion into which one end of the quartz tube is inserted is formed on the inner peripheral surface, and an outer peripheral surface of the quartz tube. A fastening nut screwed into an end of the joint body, a retaining means interposed between the fastening nut and the outer peripheral surface of the quartz tube, and an interposed member between the joint body and the outer peripheral surface of the quartz tube. A joint structure characterized in that the first seal means comprises a plurality of laminated V-shaped packings and first and second pressing adapters that sandwich them. 2. The joint structure according to claim 1, wherein the retaining means is constituted by a groove formed on an outer peripheral surface of a quartz tube and a ring fitted into the groove and engaged with a fastening nut, and the first sealing means is the joint body. Between the second stepped portion recessed in the inner peripheral surface of the first stepped portion and the outer peripheral surface of the quartz tube, and the first and second holding adapters are respectively inserted into the quartz tube and inserted into the outer periphery thereof. The packing group is formed by an annular body that is in close contact with the surface and is locked to the ring, and an abutting surface of the second stepped portion, and the packing group is connected to the joint body and the quartz tube by pressing of the holding adapter by tightening the fastening nut. A joint structure characterized by tightly sealing between the outer peripheral surface. 3. The joint structure according to claim 2, wherein each packing of the packing group according to the first sealing means is formed so that an inclination angle of a valley portion is smaller than an inclination angle of a peak portion in a V-shaped cross section. A joint structure characterized by amplifying expansion in the inner and outer diameter directions of each packing due to the pressing of the adapter to ensure a strong sealing property between the joint body and the outer peripheral surface of the quartz tube. 4. The joint structure according to claim 1, wherein a second sealing means is interposed between an end face portion of the tip of the quartz tube and a butting surface of the first step portion, and the second sealing means is the quartz tube. A joint structure comprising: a groove formed on an end surface portion; and an annular protrusion formed on the abutting surface of the first step portion and in close contact with the groove.

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