JPH08109998A - Vacuum double bellows pipe - Google Patents

Abstract

PURPOSE: To reduce the lateral oscillation of a pipe by suppressing the deformation in the radial direction of a bellows part which is interposed to absorb the difference of the extension/contraction quantity due to the temperature difference between the inside and outside pipes. CONSTITUTION: As for a vacuum double bellows pipe 14, an extension part 17 set along the inside diameter surface of a bellows part 15 is installed on an outer pipe 12 having the bellows part 15, and the deformation of the bellows part 15 can be suppressed by the extension part 17.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vacuum double bellows pipe.

[0002]

2. Description of the Related Art In a vacuum double pipe, in order to absorb a difference in expansion / contraction amount due to a temperature difference between an inner pipe and an outer pipe, a bellows portion has been conventionally provided in a part of the inner and outer pipes.

FIG. 7 shows an example thereof. In this case, the inner pipe 1 is covered with the outer pipe 2, and the bellows pipe 3 is welded to one end of the outer pipe 2 so that the end portion of the bellows pipe 3 and The ends of the outer pipe 2 are welded to each other through the annular end plates 4 and 5, and the vacuum chamber 6 is provided in the space between the outer pipe 2 and the bellows pipe 3 and the inner pipe 1. is there.

[0004]

In the vacuum double bellows pipe as described above, the bellows pipe 3 has a function of absorbing a difference in expansion / contraction amount due to a temperature difference between the inner pipe 1 and the outer pipe 2. However, due to the presence of the bellows pipe 3, there is a problem that the outer pipe 2 lacks stability and lateral shake (deformation in the radial direction) is likely to occur. When the outer pipe 2 shakes laterally, the outer pipe 2 comes into contact with the inner pipe 1 and causes a decrease in heat retention performance as a vacuum double pipe. In addition, lateral vibration also causes cracks. Furthermore, it may cause abnormal noise due to resonance.

When the bellows pipe 3 is connected to a part of the inner pipe 1, the same problem as described above occurs for the inner pipe 1.

Therefore, an object of the present invention is to solve the above-mentioned problems in a vacuum double bellows pipe, to reduce the lateral runout of a pipe having a bellows portion, and to stabilize the pipe.

[0007]

In order to achieve the above object, the present invention provides a vacuum between an inner pipe and an outer pipe, and a vacuum provided by providing a bellows part in a part of one of the above pipes. In the double bellows pipe, one of the inner and outer pipes having the bellows portion is provided with an extension along the inner diameter surface of the bellows portion.

[0008]

In the vacuum double bellows pipe having the above-mentioned structure, when the bellows portion is deformed in the radial direction, the deformation is suppressed by the extension portion of the pipe existing on the inner diameter surface of the pipe, and the pipe connected to the bellows portion is suppressed. Lateral shake is reduced.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In the first embodiment shown in FIG. 1, an inner pipe 11 is covered with an outer pipe 12, and an annular end plate 1 is provided at one end thereof.
It is integrally welded to the inner pipe 11 via 3. The bellows pipe 14 has a slightly larger diameter than the outer pipe 12, its bellows portion 15 is covered on the outer peripheral surface of the outer pipe 12 on the free end side, and the tip of the bellows portion 15 is welded to the outer diameter surface of the outer pipe 12.
The portion of the outer pipe 12 inserted from the welded portion 16 over the entire length of the bellows portion 15 is the extension portion 1 in the claims.
Make up 7.

The bellows pipe 14 side of the pipe portion 18 is welded to the inner pipe 11 via the annular end plate 13. The space between the outer pipe 12 and the bellows pipe 14 and the inner pipe 11 is evacuated to form a vacuum chamber 21.

The end portions of the pipe portion 18 and the outer pipe 12 may be directly welded to the inner pipe 11 without the annular end plate 13 as shown in FIG. Alternatively, as shown in FIG. 3, an annular projection 28 is provided on the inner pipe 11 so that the outer pipe 12
And the pipe portion 18 directly to the annular projection 28 of the inner pipe 11.
It may be welded to. 2 and 3, the number of welded parts is reduced and the end plate is not required, so that the cost can be reduced.

The second embodiment shown in FIG. 4 is the outer pipe 12
The bellows portion 15 is integrally provided in the middle, and the pipe portion 22 on one end side of the bellows portion 15 is the pipe portion 2 on the other end side.
The diameter is slightly larger than 3, and the ends of the large-diameter pipe portion 22 and the small-diameter pipe portion 23 are welded to the inner pipe 11 via the annular end plates 13 and 13.

One end of the pipe forming the extension 17 is welded to the inner diameter surface of the small-diameter pipe portion 23, and the extension 1
7 extends along the inner diameter surface of the bellows portion 15 and extends over the entire length thereof.

The third embodiment shown in FIG. 5 is a left outer pipe 2
4 and the right outer pipe 25 constitute an outer pipe, the ends of the two are opposed to each other with a slight gap, and the ends on the opposite side are provided with inner ends through annular end plates 13 and 13. It is welded to the pipe 11.

One end of the bellows pipe 14 is welded to the outer diameter surface of the left outer pipe 24, and the other end of the bellows pipe 14 is covered with the right outer pipe 25 and welded to the outer diameter surface thereof. An extension portion 17 along the inner diameter surface of the bellows portion 15 is formed between the welded portion 16 of the right outer pipe 25 and the end portion facing the left outer pipe 24.

The fourth embodiment shown in FIG. 6 is a large diameter inner pipe 2
6 and the small diameter inner pipe 27 constitute an inner pipe, and the bellows portion 15 is provided at the end of the large diameter inner pipe 26, and the bellows portion 15 is covered on the end of the small diameter inner pipe 27, and the outer diameter surface thereof is provided. We are welding. An extension 17 extending from the weld 16 to the end of the small diameter inner pipe 27 along the inner diameter surface of the bellows portion 15.
Is configured.

One end of the outer pipe 12 is welded to the outer diameter surface of the large-diameter inner pipe 26 via the annular end plate 13. The other end of the outer pipe 12 is welded to the outer diameter surface of the small-diameter inner pipe 27 via the annular end plate 13.

Also in the second, third and fourth embodiments described above, as shown in FIGS. 2 and 3 of the first embodiment, the outer pipe or the like is directly connected to the inner pipe 11 without providing the end plate. 26, 2
Of course, it can be welded to 7.

In any of the above embodiments, the fluid passing through the inner pipe is transferred while being insulated from the outside by the vacuum chamber 21 existing outside the inner pipe. When a deforming force in the radial direction is applied to the bellows part 15, the force is received by the extension part 17 existing inside, so that a certain amount of deformation is suppressed.

[0020]

Since the present invention is as described above, the presence of the bellows portion absorbs the difference in expansion / contraction amount due to the temperature difference between the inner and outer pipes, and the extension portion is provided along the inner diameter surface of the bellows portion. , Suppress the deformation of the bellows in the radial direction,
There is an effect of suppressing lateral vibration of the pipe provided with the bellows portion.

[Brief description of drawings]

FIG. 1 is a sectional view of a first embodiment.

FIG. 2 is a sectional view of a modification example of the above.

FIG. 3 is a sectional view of another modification example of the above.

FIG. 4 is a sectional view of the second embodiment.

FIG. 5 is a sectional view of the third embodiment.

FIG. 6 is a sectional view of a fourth embodiment.

FIG. 7 is a sectional view of a conventional example.

[Explanation of symbols]

 11 Inner pipe 12 Outer pipe 13 End plate 14 Bellows pipe 15 Bellows portion 16 Welded portion 17 Extension portion 18 Pipe portion 21 Vacuum chamber 22 Large diameter pipe portion 23 Small diameter pipe portion 24 Left outer pipe 25 Right outer pipe 26 Large diameter inner pipe 27 Small diameter inner pipe 28 protrusion

Claims (1)

[Claims] 1. A vacuum is provided between the inner pipe and the outer pipe,
In a vacuum double bellows pipe in which a bellows portion is provided in a part of one of the above-mentioned pipes, an extension portion along an inner diameter surface of the bellows portion is provided in either one of the inner and outer pipes provided with the bellows portion. A vacuum double bellows pipe that is characterized.