JPS6114783Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a joint for a vacuum pipeline or a joint for a high-temperature, high-pressure gas pipeline, particularly one using metal packing as a sealing member.

As a vacuum tube joint using metal packing as a sealing member, a structure shown in FIG. 1 has been conventionally used. This conventional fitting consists of vacuum line 1,
2 are connected via flanges 3 and 4 welded and fixed to the ends of the respective pipes, and flange 3 has a female spigot part and flange 4 has a male spigot part. Before installing and fitting these socket parts, a metal packing 5 made of, for example, a thin copper plate with a hole drilled in the center is fitted into the inner part of the female socket part, and then the metal packing 5 made of, for example, a thin copper plate is fitted into the inner part of the female socket part. The flanges 3 and 4 are fastened and connected via a fastening bolt 7 so as to be pressed by an annular protrusion 6 having a triangular cross section provided on the end face. The fastening bolt 7 is tightened so that the annular protrusion 6 presses the metal packing 5 with its edge, causing plastic deformation in the vicinity of the pressed surface, and the edge slightly sinks into the metal packing 5. By doing this, the metal packing 5 comes into close contact with the bottom surface of the female pilot part of the flange 3 as well, with the abutting surface along the annular projection 6.
The connection between the vacuum lines 1 and 2 is completely sealed. However, if the connecting part of the vacuum pipes 1 and 2 is installed in a place where it is exposed to a high temperature atmosphere and heated during operation, returns to room temperature when the operation is stopped, and undergoes repeated expansion and contraction, the temperature increases. In order to maintain the vacuum at the connection, the fastening bolt 7 is retightened as necessary. For this purpose, a gap C is provided between the flanges 3 and 4, but if the high vacuum can no longer be maintained by further tightening, the metal packing 5 must be replaced with a new one. .

To do this, it is first necessary to remove the deteriorated metal packing 5, but due to the plastic deformation caused by the above-mentioned retightening, the outer peripheral end surface of the metal packing 5 touches the inner peripheral surface of the female pilot part of the flange 3. Since it is pressed and in close contact, when removing it, make a hole in the shape of a missing circle in a part of the inner circumferential surface of the pilot part, or from the hole, or from the center hole of the metal packing 5. The method used is to hook a hook such as a hook into the patsuking 5 and take it out. This method is not only troublesome, but also often causes scratches on the contact surface, which is important for the seal, during removal, which can cause leaks, which is a problem with conventional vacuum pipe joints. It had been.

This idea was made in order to solve the problems with the conventional vacuum pipe joints mentioned above, and the flange parts having male and female plug parts are tightened together with fastening bolts, and the female plug part In a pipe joint in which a metal packing with a hole in the center is pressed by a concentric annular projection provided on the end face of a male pilot part to seal a pipe connection part, The outer diameter of the male pilot part is made slightly smaller than the inner diameter of the pilot part, and a collar is fitted in the annular gap formed between the male pilot part and the inner and outer peripheral surfaces of the male pilot part, and this collar is provided. The present invention relates to a pipe joint in which the metal packing having an outer diameter that forms an intermediate fit with the inner diameter of the collar is attached to the inner peripheral region of the collar.

Embodiments of this invention will be described below with reference to the drawings. FIG. 2 is a side sectional view of this embodiment. In the figure, components similar to those of the conventional vacuum pipe joint shown in FIG. 1 are designated by the same reference numerals, and description thereof will be omitted.

However, in this embodiment, the flanges 3, 4
The female and male pilot parts are not directly fitted together as shown in FIG. 1, but are fitted through a collar 8.

The collar 8 is loosely fitted into an annular gap formed between the female pilot part of the flange 3 and the male pilot part of the flange 4, and has a height equal to that of the female pilot part. It is set considerably lower than the depth of the part. Therefore, when connecting the vacuum pipes 1 and 2, fit the collar 8 deep into the female plug part of the flange 3, and then attach the metal packing 5.
is placed in the inner peripheral area of the collar 8, the flange 4 is attached, and the flanges 3 and 4 are connected by tightening the fastening bolt 7 in the same manner as in the conventional case. The metal packing 5 is thin (for example, 0.5
mm) using a copper plate or a silver plate of equivalent thickness,
The outer diameter of this metal packing 5 is the inner diameter of the collar 8 in which it is housed, that is, the reference hole.
H ₇ is finished to h ₁₁ , and the fit between both 8 and 5 is an intermediate fit. Also the reference hole
The outer diameter of the male pilot part is finished to _f7 so that the inner peripheral surface of the collar 8, which is finished to _H7 , and the outer peripheral surface of the male pilot part of the flange 4 are a loose fit. ing. In this case, as described above, if there is a risk that the collar 8 placed in the loose state may come up, the male plug of the flange 4 is inserted, although not shown, in order to prevent the metal packing 5 from shifting. For example, a disc spring may be fitted in the part, and the fastening bolt may be tightened while the disc spring prevents the collar 8 from floating up.

When the metal packing 5 deteriorates and needs to be replaced, the fastening bolts 7 are loosened and removed, the flange 4 is removed, and the collar 8 fitted into the female socket of the flange 3 is pulled out. Therefore, it is convenient if the collar 8 is provided with a screw hole into which a small diameter bolt for extraction can be screwed. The metal packing 5 can be removed from the collar 8 while being in close contact with the inner peripheral surface thereof. Outer diameter of packing 5 and collar 8
If the dimensional relationship with the inner diameter of the thin copper plate or thin silver plate is finished as described above, packing 5
When retightening is performed only once, the outer diameter of the packing 5 increases due to the plastic deformation that occurs at that time.
It has been confirmed that it is in close contact with the inner peripheral surface of the collar 8. Next, the collar 8 is fixed in a vise or the like, and the metal packing 5 can be easily removed by pushing it out.

In the embodiment, the case where each flange portion is a single unit has been described, but the present invention can also be applied to a case where, for example, the flange 3 is a part of a flange portion of a vacuum device. In the explanation so far, a joint for a vacuum pipe has been taken as an example, but the same applies to a high-temperature, high-pressure gas pipe.

As is clear from the above description, in the conduit joint according to this invention, it is easy to remove the deteriorated metal packing when replacing the metal packing, and moreover, it is easy to remove the deteriorated metal packing, which is often the cause of leaks in conventional joints. It is possible to completely eliminate the occurrence of scratches on the worn contact surface when removing the metal packing.

[Brief explanation of the drawing]

FIG. 1 is a side sectional view of a conventional vacuum pipe joint, and FIG. 2 is a side sectional view of an embodiment according to this invention. 1, 2... Vacuum pipe line, 3, 4... Flange, 5
...Metal packing, 6...Annular protrusion, 7...
Tightening bolt, 8...color.

Claims (1)

[Scope of utility model registration request] The flange parts that have female and male plug parts are tightened together with fastening bolts, and the metal packing with a hole in the center is placed in the female plug part.
In a pipe joint in which the concentric annular protrusion provided on the end face of the male pilot part is pressed to seal the connection part of the pipe, the outer diameter of the male pilot part is set to the female pilot part. Slightly smaller than the inner diameter of the
A collar is fitted into the annular gap formed between the two pilot parts, and the collar is fitted with an outer diameter that forms an intermediate fit with the inner diameter of the collar in the inner circumferential region of the collar. A conduit joint to which the finished metal packing is attached.