JPH017723Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an internal CVD rotary joint for connecting a reaction tube such as a quartz tube and a gas phase piping for supplying gas phase raw materials into the reaction tube.

In the internal CVD method, as shown in Fig. 1, a reaction tube 2 such as a quartz tube is rotatably held in a chuck 1 of a glass lathe, and while the reaction tube 2 is being rotated, a gas phase is introduced from a gas phase pipe 3 into the chuck 1 of a glass lathe. Supply raw materials and reactor tube 2
The base material is produced by oxidizing the raw material inside the chamber, depositing glass powder on the inner peripheral wall, and heating the powder with a burner 4 to vitrify it.

By the way, in this internal CVD method, the fixed gas phase pipe 3 and the rotating reaction tube 2 are connected via the rotary joint 5.

Conventionally, this type of rotary joint is
A spherical joint as shown in FIG. 2 is used.

In other words, the convex spherical part 6a provided at the tip of the rotary pipe 6 connected to the reaction tube 5 is rotatably connected to the concave spherical part 7a provided at the tip of the fixed pipe 7 connected to the gas phase pipe 3. The reaction tube 2 and the gas phase pipe 3 are connected by fitting together.

At this joint, the fitting surfaces of the spherical parts 6a and 7a are polished to prevent leakage of the gas phase raw material as much as possible.

However, in spite of this, such conventional spherical joints tend to have insufficient airtightness, and leakage of gas phase raw materials often occurs.

The present invention aims to solve the above problem by providing a plurality of airtight retaining parts in the leakage passage between the rotating pipe and the stationary pipe.This will be explained with reference to the embodiment shown in the drawings. A first pipe 1 connected to a reaction tube 2 as shown in FIG.
A large-diameter portion 10a whose inner diameter is larger than that of other portions is formed at the tip of the 0. At the boundary between the large-diameter portion 10a and the small-diameter portion 10b, there is a A step portion 10c based on the structure is formed.

A second pipe 11 connected to the other gas phase system piping 3
An annular projection 12 is formed on the outer periphery of the first pipe 10 in the longitudinal direction, and the tip of the pipe 11, that is, the portion between the end surface 11a of the pipe 11 and the annular projection 12 has a larger diameter than the first pipe 10. The inner end surface 12a of the annular projection 12, which is inserted into the portion 10a and faces toward the distal end of the second pipe 11, is in contact with the end surface of the first pipe 10, and the second pipe 1
The tip end surface of No. 1 is in contact with the stepped portion 10c.

Further, in the gap between the large diameter portion 10a and the first pipe 11, a sealing member 13 formed of a pair of O-rings is provided.
a, 13b are provided, and these seal members 13a, 13b are adapted to be able to come into sliding contact with both the inner circumferential surface of the large diameter portion 10a and the outer circumferential surface of the second pipe 11.

Furthermore, a cap nut 1 is attached to the base end side of the second pipe 11.
4 is installed.

A through hole 14a is formed in the ceiling surface of this cap nut 14, and the inner diameter of the hole 14a is equal to the annular projection 1.
2 and is equal to or larger than the outer diameter of the first pipe 11.

To attach this cap nut 14 to the second pipe 11, insert the proximal end of the pipe 11 into the through hole 14a, and insert the threaded part 14c formed on the inner periphery of the attachment part 14b of the nut 14 into the first pipe 11. The nut 14 may be screwed onto a threaded portion 10d formed on the outer periphery of the annular projection 12, and the nut 14 may be rotated until the ceiling surface contacts the outer end surface 12b of the annular projection 12.

That is, the annular projection 12 and the cap nut 14 constitute a connecting portion A for connecting the first pipe 10 and the second pipe 11.

However, the connecting portion A is not limited to the above-mentioned configuration, and may be one in which the annular projection 12 and the cap nut 14 are integrated.

Furthermore, one end of a flexible pipe 15 having flexibility is attached to the base end of the second pipe 11, and the other end of the same pipe 15 is adapted to be attached to the gas phase pipe 3.

The material for the first pipe 10, the second pipe 11, and the cap nut 14 is preferably a fluororesin having corrosion resistance. In particular, a fluororesin having low frictional resistance is advantageous for both the pipes 10 and 11.

Further, the seal members 13a and 13b are preferably made of rubber such as Viton, and the flexible pipe 15 is preferably a tube made of FRP.

In the above-described embodiment, the first pipe 10 was a rotating pipe and the second pipe 11 was a fixed pipe (non-rotating pipe), but as it is obvious, these two pipes 10 and 11 are configured to rotate relative to each other. The second pipe 11 is a rotating pipe, the first pipe 10 is a fixed pipe, the second pipe 11 is a reaction tube 2,
The first pipes 10 may be connected to the gas phase pipes 3, respectively.

As described above, the rotary joint of the present invention has a first pipe, a second pipe, and a connecting part for connecting these first and second pipes, and the end of the first pipe is on the outside, These pipe ends are fitted so that they can rotate relative to each other so that the second pipe end is on the inside, and the connecting part is an annular projection that is provided on the outer periphery of the second pipe and can freely come into contact with the end surface of the first pipe. and an attachment part that can be freely attached to the outer circumference of the first pipe and applies a connecting force to the second pipe via an annular protrusion. A sealing member is provided that can slide on the inner peripheral surface of the first pipe and the outer peripheral surface of the second pipe, and a flexible pipe is attached to the end of the second pipe, so that either one of the two pipes can freely rotate. Since the other pipe is fixed, one of the two pipes is connected to the gas phase system piping, and the other is connected to the reaction tube, the leak path for gas phase raw materials is reduced compared to the conventional example. There are many airtight areas that block the air, so the airtightness is good.

Further, since the second pipe includes a flexible pipe, even if there is an axis misalignment between the second pipe and its connection partner, they can be connected without difficulty via the flexible pipe.

[Brief explanation of the drawing]

Figure 1 is a schematic diagram showing the general internal CVD method.
FIG. 2 is a sectional view showing a conventional rotary joint, and FIG. 3 is a sectional view showing a rotary joint according to the present invention. 2... Reaction tube, 3... Gas phase system piping, 10... First pipe, 11... Second pipe, 12... Annular projection, 13a, 13b... Seal member, 15... Flexible pipe, A ...Connection part.

Claims (1)

[Scope of Claim for Utility Model Registration] (1) An internal CVD method rotary joint for connecting a rotatably held reaction tube and a gas phase system piping for supplying gas phase raw materials into the reaction tube. At the point, the first pipe, the second pipe,
and a connecting part for connecting these first and second pipes, and these pipe ends are fitted so that they can rotate relative to each other so that the end of the first pipe is on the outside and the end of the second pipe is on the inside. The connecting portion includes an annular projection that is provided on the outer periphery of the second pipe and that can freely come into contact with the end surface of the first pipe, and a connecting portion that can be freely attached to the outer periphery of the first pipe and that connects to the second pipe via the annular projection. It consists of a mounting part that provides connection force,
Further, a sealing member is provided in the gap between the first pipe and the second pipe, and is slidable on the inner circumferential surface of the first pipe and the outer circumferential surface of the second pipe, and at the end of the second pipe. A flexible pipe is attached, one of the two pipes is rotatably provided, the other is fixed, one of the two pipes is connected to the gas phase pipe, and the other is connected to the reaction pipe. Internal CVD rotary joint connected to. (2) A large-diameter portion is provided on the mating end side of the first pipe into which the second pipe is inserted, and the end surface of the second pipe comes into contact with the stepped portion between the large-diameter portion and the small-diameter portion. The rotary joint for internal CVD method according to claim 1 of the utility model registration claim, which is flexible. (3) The connecting part consists of an annular protrusion formed on the outer periphery of the second pipe and a cap nut, and the cap nut has an outer diameter smaller than the annular protrusion and equal to or equal to the outer diameter of the second pipe. The rotary joint for internal CVD method according to claim 1 or 2, which is provided with a through hole having a diameter larger than that.