JP2632118B2 - Bellows - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a curved rectangular
The present invention relates to a bellows having a structure in which two side plates and two spindle-shaped end plates are combined. With this structure, the bellows can be replaced without cutting the piping or the like that has a sealing property and a relative displacement allowance and cuts the inside. This bellows is not particularly limited, but is useful for maintaining the airtightness of a portion where a pipe, a rod, or the like penetrates a container wall in a technical field related to nuclear power.

[0002]

2. Description of the Related Art For example, when pipes or rods penetrate a reactor containment vessel wall, it is necessary to have a hermetic structure so as to keep the inside and outside of the vessel wall airtight. In such a case, the pipes thermally expand and contract due to the temperature of the fluid flowing through the pipes and the like, and thus displacement occurs depending on the use condition. Therefore, in the prior art, a bellows as shown in FIGS. 3 and 4 is used in order to allow relative displacement between the pipe and the wall and to maintain the sealing performance.

The bellows 10 has a very general shape in which a large number of folds are formed (alternately, peaks and valleys) over the entire circumference of a cylindrical body. In this structure, the other end 16 is connected to the wall 18. Since the displacement of the pipe 14 in the axial direction is absorbed by the expansion and contraction deformation of the bellows 10, the inside and outside thereof are kept airtight at the wall surface 18 as a boundary.

[0004]

As described above, the bellows is made of a thin metal material or the like so that it can be easily expanded and contracted, and because it repeatedly expands and contracts, it is damaged by contact with other equipment and fatigue. easy. However, when the bellows having the conventional structure needs to be replaced due to breakage or the like, the replacement work is very troublesome. The reason is that, under the condition that the bellows cannot be attached from the axial direction of the pipe, the pipe has to be cut once to mount the new bellows. Therefore, there is a need to increase the number of pipe connection lines and to take measures to maintain the atmosphere inside the pipe, resulting in a problem of an increase in man-hours.

As a countermeasure, there is a method of mounting a bellows divided vertically and performing vertical seam welding.
It is actually difficult to weld on the corrugated line after molding,
Hard to achieve.

An object of the present invention is to solve the above-mentioned problems and to provide a bellows having a structure which can be easily replaced without cutting a pipe or the like penetrating therethrough.

[0007]

According to the present invention which can achieve the above object, two curved rectangular side plates, each having a fold-like portion except for a peripheral portion, are opposed to each other so as to form a space inside. This is a bellows in which spindle-shaped end plates are combined at both ends thereof, ridge portions are joined, and a tubular body is attached to each of the end plates. Here, the folds formed on the side plates have a shape in which the height of the peaks and valleys gradually decreases as approaching the ridgeline portion connecting the side plates, and the folds are in a plane perpendicular to the bellows central axis. It is preferable to form a plurality of them in parallel so as to be positioned at the same position.

[0008]

When an axial displacement occurs in a pipe or the like penetrating the inside, the bellows are deformed according to the displacement amount and absorb the displacement. At this time, no excessive stress is generated at the joint.
When replacing the bellows, the old bellows can be removed by cutting it at the ridgeline portion, and the new bellows can be joined at the ridgeline portion, so that the internal piping and the like can be remounted without cutting.

[0009]

1 is a partially cutaway perspective view showing an embodiment of the bellows according to the present invention. The bellows 20 has a structure in which two curved rectangular side plates 22 each having a fold portion formed in a central portion excluding a peripheral portion and two spindle-shaped end plates 24a and 24b are combined. The side plate 22 has a shape in which a cylindrical bellows having a large radius of curvature is cut into a rectangle along a generatrix as a whole. However, the folds 26 have a shape in which the height of the peaks and valleys gradually decreases as approaching the generatrix, and a plurality of the folds 26 are formed in parallel so as to be located in a plane perpendicular to the central axis of the bellows. At the center of the end plates 24a and 24b, a hole through which the pipe passes is formed. These side plates 22 and end plates 24a and 24b are made of a material having some flexibility such as a thin stainless steel plate and having excellent corrosion resistance.

The two side plates 22 are symmetrically arranged such that their concave surfaces face each other, and two end plates 2 are provided at both ends thereof.
4a and 24b are arranged and combined so as to form a space inside, and the ridge portions 30 and 32 are welded. For welding, lip welding, which can be easily separated and re-welded, is optimal. Further, connection cylinders 34 and 36 are welded to the hole edges of the end plates 24a and 24b, respectively. In use, the pipe 40 is welded to one connecting cylinder 34 and the other connecting cylinder 3 is welded.
6 is welded to the containment wall of the reactor.

FIG. 2 shows the operation of the bellows of this embodiment. When a relative displacement in the axial direction occurs between the connecting cylinder 34 to which the pipe 40 is welded and the connecting cylinder 36 to be welded to the container wall, the bellows 20 moves the side plate 22 and the end plate 24a,
24b is deformed, and the ridge portion is slightly bent as shown by the imaginary line to absorb the displacement. As a result, the inside and outside sealing properties are maintained.

The bellows replacement operation may be performed as follows. First, the old side plate is removed by cutting the ridge portions 30 and 32. Then, it is completed by applying a new side plate and re-welding. These operations are easy because the cut and welded portions are straight or gently arcuate.

Although the end plate and the connecting cylinder may be formed separately and joined by welding, they may be formed integrally. It is also possible to directly connect a pipe, a rod, or the like to the end plate without interposing a connecting cylinder.

[0014]

As described above, according to the present invention, two curved rectangular side plates having folds and two spindle-shaped end plates are combined so as to form a space inside, and the ridge portion is formed. , The bellows can be replaced by cutting and joining at the ridge line without cutting a pipe or the like penetrating the inside. Therefore, it is possible to avoid an increase in welding lines on pipes and rods every time the bellows is replaced. There is no possibility that the atmosphere inside the pipe is contaminated, and no countermeasures are required. Ancillary work such as cutting and rewelding of piping and rods can be omitted, and an increase in man-hours can be avoided. And the like.

[Brief description of the drawings]

FIG. 1 is a partially cutaway perspective view showing one embodiment of a bellows according to the present invention.

FIG. 2 is an explanatory diagram of the operation.

FIG. 3 is an explanatory view showing an example of a bellows having a conventional structure.

FIG. 4 is a sectional view thereof.

[Explanation of symbols]

 Reference Signs List 20 Bellows 22 Side plate 24a, 24b End plate 26 Fold 30, 32 Ridge portion 34, 36 Connecting cylinder

Claims (2)

(57) [Claims] 1. Two curved rectangular side plates having a pleated portion except for a peripheral portion are disposed so as to face each other so as to form a space therein, and spindle-shaped end plates are respectively provided at both ends thereof. A bellows which is combined with each ridge line portion and attached to each end plate. 2. The fold portion formed on the side plate has a shape in which the height of the peak and the valley gradually decreases as approaching the ridge portion connecting the side plates, and the fold is perpendicular to the central axis of the bellows. 2. The bellows according to claim 1, wherein a plurality of the bellows are provided in parallel so as to be formed in a plane.