JPH0349330Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Purpose of the Invention] (Field of Industrial Application) The present invention relates to improvements in bellows used in parts of various devices that require flexibility, sealing performance, etc.

(Prior Art and its Problems) Conventionally, molded bellows, welded bellows, and the like have been widely known as metal bellows. The former molded bellows has folds 4, 4, etc. with a U-shaped cross section as shown in Fig. 2, and is mainly manufactured by hydraulically forming thin-walled circular pipes, so it is excellent in mass production and is economical. However, the peaks 4a, 4a of each of the folds 4, 4...
Because of the concentration of residual stress in the troughs 4b, 4b, . . . , it is not possible to obtain a large displacement per unit length, and this is not suitable for downsizing the device. The latter welded bellows is manufactured by welding the inner circumference and inner circumference and the outer circumference and outer circumference of disc-shaped bellows plates 5, 5, which are formed by punching out a thin plate, as shown in Fig. 3. The welded bellows has the characteristics of having excellent pressure resistance and being able to take a large displacement per unit length.
In 5b..., there is a lot of damage due to the occurrence of pinholes, cracks, and crevices. In addition, in order to compensate for the drawbacks of such welded bellows, the welded parts 5a and 5b are
It is known that a reinforcing ring (not shown) is fitted to the bellows plate (for example, Japanese Utility Model Application Publication No. 55-68749), but since the bellows plate 5 is made of metal, the reinforcing ring fitted thereto is The bellows has a divided shape and does not have any sealing function, and if the bellows is attached to a rotating shaft, the reinforcing ring fitted around the outer periphery may dislodge due to centrifugal force or vibration. There is a risk of it getting lost.

[Structure of the idea]

(Means for Solving the Problems and Their Effects) In order to solve the above-mentioned problems, the jointed bellows of the present invention has a plurality of disc-shaped metal bellows plates arranged in the axial direction. and the outer periphery and the outer periphery are alternately joined by annular joining members, and the joining member has a shape memory in which the shape of the groove for tightening and fitting the inner periphery and the inner periphery or the outer periphery of the bellows plate is memorized. It is characterized by being made of an alloy. In other words, like the welded bellows mentioned above, it has a structure in which bellows plates are joined, so it can expand and contract more per unit length than a molded bellows, and of course has excellent pressure resistance. Since the inner and outer peripheries of each bellows plate are not joined by welding, there is no possibility of damage due to pinholes, cracks, or crevices occurring in these parts. Furthermore, the joining member is press-fitted between the inner periphery and the outer periphery or the outer periphery and the outer periphery of the metal bellows plate by utilizing the temperature-sensitive return effect of the shape memory alloy to the set shape. There is no division in
Sufficient sealing performance between each bellows can be maintained.

(Embodiment) Hereinafter, one embodiment of the jointed bellows of the present invention will be described in detail according to the drawings. FIG. 1 is a half-cut sectional view of the main part showing this embodiment, and in the figure, 1,
1... is a bellows plate formed into a disc shape by punching out a thin metal plate, 2, 2... is a joining member that joins the inner periphery of each bellows plate 1, 1..., and has shape memory. It is made of an alloy and has an annular shape with a substantially U-shaped cross section with a fitting groove 2a on the outer circumferential surface, and 3, 3... are joining members that join the outer periphery of each of the bellows plates 1, 1... ,
Like the joining members 2, 2..., it is made of a shape memory alloy and has an annular shape with a fitting groove 3a on the inner peripheral surface.

A shape memory alloy is an alloy that can memorize a certain shape, and has the property of returning to its original shape when heated after being deformed, for example, at low temperatures. The joining members 2, 2
. . . and 3, 3, . The joining member 2 has a fitting groove 2a in advance.
A shape in which the groove width is slightly smaller than the wall thickness t of two bellows plates 1 is memorized, and after opening the fitting groove 2a and deforming it in the diameter reduction direction, peripheral end 1',
1' and then heating the joining member 2,
Due to the above-mentioned characteristics of the shape memory alloy, the inner circumferential ends 1', 1' of the bellows plates 1, 1 are firmly fitted into the fitting grooves 2a in order to prevent them from returning to their original memorized shape. become. The fitting member 3 on the outer peripheral side joins the bellows plates 1, 1 according to the same principle as the joining member 2 on the inner peripheral side, so a description thereof will be omitted.

This embodiment has the above-mentioned configuration, and is made by joining disk-shaped bellows plates like welded bellows, so it has excellent pressure resistance and elasticity, and since the joining is not done by welding, it is suitable for No damage such as pinholes, cracks, or crevices occurs in the parts.

[Effect of idea]

As explained above, the joint bellows of the present invention is
The continuous pleats are characterized by fitting the inner and outer peripheries of a disc-shaped metal bellows plate with shape memory alloy joining members, and like welded bellows, it has excellent pressure resistance and Since there is no concentration of residual stress like in molded bellows, the amount of expansion and contraction per unit length can be increased, making it possible to reduce the size and weight of the device, and because each bellows plate is not joined by welding. Damage due to pinholes, cracks, etc. is prevented and durability is significantly improved. Furthermore, the joining member is a material in which the inner periphery and the inner periphery, and the outer periphery and the outer periphery of the bellows plates are joined together under pressure by returning to a pre-memorized shape, and although the bellows plate is made of metal, the joining member is Since the joining member itself can be formed into a continuous shape in the circumferential direction, not only does the joining member itself have a sealing function, but it also prevents problems such as deviating from the joining member during rotation.

[Brief explanation of drawings]

FIG. 1 is a half-cut sectional view of a main part showing an embodiment of a joined bellows according to the present invention, FIG. 2 is a half-cut sectional view of a main part showing an example of a conventional molded bellows, and FIG.
The figure is a half-cut sectional view of essential parts showing an example of the welded bellows. 1... Bellows plate, 2, 3... Joining member, 2a, 3a... Joining groove.

Claims (1)

[Scope of utility model registration request] The inner periphery and the outer periphery and the outer periphery and the outer periphery of a plurality of disk-shaped metal bellows plates arranged in the axial direction are alternately joined using annular joining members, and the joining members are connected to the bellows plates. A jointed bellows characterized by being made of a shape memory alloy that has a memorized groove shape for tightening and fitting the inner periphery to the inner periphery or the outer periphery to the outer periphery.