JP2000003648A - Bellows - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a bellows capable of relaxing stress concentration arising in its end part on the side of a container wall of an apparatus without enlarging the frame of the bellows, and improving a service life. SOLUTION: In a bellows 4 having an end part fixed to a movable lever 2 put through a container wall 1 and making rocking motion, and the other end fixed to the container wall 1, the spring constant of the end part of the bellows 4 fixed to the container 1 is adapted to be larger than the other portions. To set up such a spring constant, the height H of crests on the end part of the bellows 4 on the container wall side is adapted smaller than the height of crests on the other portions.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure of a bellows used for sealing a lever portion provided through a wall of an equipment container.

[0002]

2. Description of the Related Art In general, bellows are often used as one method of transmitting a driving force without damaging two different spaces such as between vacuum and atmosphere. For example, in a vacuum valve (vacuum circuit breaker), a movable rod is moved up and down with respect to a fixed rod by an operation mechanism provided outside the vacuum valve container, and an electrode provided at each rod end is brought into and out of contact with the rod. In this case, a bellows is used for the movable rod to seal the inside and outside of the vacuum valve.

[0003]

In the mechanism formed as described above, there is no particular problem when the bellows expands and contracts only in its axial direction.
In the case where the movable electrode and the fixed electrode come into contact with or separate from each other by the lever swinging about the main shaft as in a vacuum valve disclosed in Japanese Patent No. 43727, the bellows repeatedly bends and deforms. Therefore, stress concentrates in the vicinity of the bellows joint, especially in the vicinity of the fixed part on the container wall side, and during many years of operation, cracks may occur in this part and the hermetic seal of both spaces may be broken. .

In this case, of course, if the diameter of the bellows is increased to some extent, the stress concentration will be eased. However, increasing the size of the bellows means increasing the size of the equipment in which the bellows is used. It is not a reasonable solution.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object of the present invention is to reduce stress concentration at the bellows end without increasing the size of the bellows,
An object of the present invention is to provide a bellows capable of improving the life.

[0006]

The present invention basically provides a bellows having one end fixed to a movable lever that penetrates and swings a container wall and the other end fixed to the container wall. The intended purpose is achieved by forming the spring constant at the end of the bellows on the container wall side larger than the spring constant at other parts.

[0007] Further, as a suitable example of the present invention, in a bellows having one end fixed to a movable lever penetrating and swinging through a container wall and the other end fixed to the container wall, an end of the bellows on the container wall side is provided. Is proposed so that the peak height at is smaller than the peak height at other portions.

In this case, the height of the bellows is
It is also proposed that the container wall is formed so as to change continuously from the end on the container wall side to the other end.

That is, in the bellows formed as described above, the spring constant at the end of the bellows on the container wall side is formed to be larger than that of the other parts. The stresses generated at the ends are dispersed, so that the stress collection is alleviated and the service life can be improved without increasing the size of the bellows.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the illustrated embodiments. FIG. 1 is a cross-sectional view showing a bellows and a peripheral structure in which the bellows is used. Reference numeral 1 denotes a container wall of a device such as a vacuum valve, and both sides of the side wall are formed to be separate spaces (vacuum-atmosphere). Reference numeral 2 denotes a movable lever provided through the wall of the equipment container to operate a device inside the container from outside the container.

The movable lever 2 is provided so as to penetrate the container wall 1 and is formed so as to swing about a main shaft 3 provided outside the container. A bellows 4 is provided on the container wall 1 and the movable lever 2 to seal the inside and outside of the container at the movable lever penetrating portion of the equipment container. That is, the bellows 4 has one end fixed to the movable lever 2 and the other end fixed to the container wall 1.

In this case, the bellows 4 is formed as follows. The peak height H of the bellows 4 at the end on the container wall side is formed smaller than the peak height of the other portions. In other words, the spring constant of the end on the container wall side is formed larger than that of the other portions.

With such a bellows, the end on the container wall side has a structure that is harder than the other parts. Therefore, even if the bellows is bent, the stress at the end of the bellows is dispersed to other parts. This alleviates stress concentration.

Next, when this bellows is compared with a conventional bellows, when the main shaft 3 is located outside the bellows 4 as shown in FIG. A composite operation of “shift operation” is performed. As shown in FIG. 3, the stress generated in the bellows 4 is large at the bellows end, and is particularly concentrated on the fixed portion S1 with the container wall 1. The horizontal axis of the graph represents the position between both ends A-A 'of the bellows, and the horizontal axis of the graph represents the stress generated in the bellows 4 at the peaks and valleys. Also, depending on conditions such as the rotation angle,
There is a portion S2 where the peaks come into contact with each other, which may further promote stress concentration.

On the other hand, in the bellows 4 of the present invention, the peak height H of the end S1 on the container wall side is formed to be smaller than the peak height of the other portion, so that the stress is reduced as shown in FIG. It is dispersed at the center in the bellows expansion and contraction direction. Further, contact between the peaks in the portion S2 can be prevented.

Further, in this case, the peak height of the bellows 4 is
When formed to change continuously from the end on the container wall side, the stress can be uniformly distributed in the direction of expansion and contraction,
It becomes a longer life bellows.

In the above description, the peak height of the bellows is changed in order to increase the spring constant at the end of the bellows. However, in order to change this spring constant, the pitch of the peaks or the bellows may be changed. Various changes may be considered, such as changing the plate thickness.

Further, the present invention can be applied to a case where the main shaft 3 is arranged inside the bellows. When the main shaft 3 is installed inside the bellows as shown in FIG. 5, the bellows 4 performs a pure "square bending operation", so that the stress concentration at the end is reduced as compared with the case where the main shaft 3 exists outside the bellows. . However, when the peaks contact each other in the portion S2, stress concentration occurs in this portion, and the durability decreases. This problem can be solved by reducing the peak height at the bellows end to avoid contact between the peaks as in the present invention.

In the above description, the case where the bellows is applied to a vacuum device has been described. However, it is needless to say that the bellows can be used for a gas container or a liquid container.

[0020]

As described above, according to the present invention, it is possible to obtain a bellows which can reduce the stress concentration at the end of the bellows without increasing the physical size of the bellows and can improve the life. .

[Brief description of the drawings]

FIG. 1 is a side sectional view showing one embodiment of a bellows of the present invention.

FIG. 2 is a side sectional view showing a conventional bellows.

FIG. 3 is a characteristic diagram showing stress acting on a conventional bellows.

FIG. 4 is a characteristic diagram showing stress acting on a bellows according to an embodiment of the present invention.

FIG. 5 is a side sectional view illustrating the operation of a bellows according to another embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Container wall, 2 ... Movable lever, 3 ... Main shaft, 4 ... Bellows, S ... Part, H ... Mountain height.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Ayumu Morita 7-2-1, Omika-cho, Hitachi City, Ibaraki Prefecture Inside Power & Electricity Development Division, Hitachi, Ltd. (72) Inventor Toru Tanimizu 1-1-1, Kokubu Plant, Hitachi, Ltd. (72) Inventor Toshio Horikoshi 1-3-1, Uchisaiwaicho, Chiyoda-ku, Tokyo Tokyo Electric Power Company (72) Inventor Zenji Yomimoto Uchiyukicho, Chiyoda-ku, Tokyo 1-3-1 Tokyo Electric Power Company (72) Inventor Takanori Hashimoto 74-1 Minaminakajori, Tsubata-cho, Kawakita-gun, Ishikawa Prefecture Inside Kuze Bellows Industrial Co., Ltd.

Claims (3)

[Claims] 1. A bellows having one end fixed to a movable lever that penetrates and swings through a container wall and the other end fixed to the container wall. A bellows characterized in that the bellows is formed so as to be larger than a spring constant in a portion. 2. A bellows, one end of which is fixed to a movable lever which penetrates and swings through a container wall and the other end of which is fixed to a container. A bellows characterized in that the bellows is formed to be smaller than the peak height of the bellows. 3. The bellows according to claim 2, wherein the peak height of the bellows is continuously changed from the end on the container wall side toward the other end.