JPH06241362A - Fluid pipe joint - Google Patents

Abstract

PURPOSE:To maintain a specified sealing force even if gaskets are deformed or shrunk slightly so as to a chiere the maintenance by simply adding a simple structure. CONSTITUTION:Springs 28 are located on the outside of both flanges 21 respectively and a spring pressurizing member 26 is arranged on the further outside of the springs. Then the spring pressurizing members on both sides are held by a clamp member 29 so as to tighten the flanges in axial direction through the springs.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is for fluid piping intended for use in semiconductor manufacturing equipment, vacuum equipment, pharmaceutical manufacturing machines, food machinery, and other fields where high sealing performance is required for fluid piping paths. Regarding fittings.

[0002]

2. Description of the Related Art Conventionally, as a fluid pipe joint used in such a field, a gasket is interposed between flanges of pipes to be connected, and both flanges are joined from the outside by a tightening member. What you do is common. Conventional examples are shown in FIGS. 4, 5, and 6, respectively.

In the conventional example shown in FIG. 4, a disk-shaped metal gasket 4 is interposed between ring-shaped convex portions 3 provided on the opposing surfaces of the flanges 2 of both pipes 1 to be connected, and both flanges 2 are connected.
Male and female screw members 5 and 6 are arranged on the outer side of, and the metal gasket 4 is sandwiched by both ring-shaped convex portions 3 by screwing these screw members 5 and 6 and bringing them closer to each other.

In the conventional example shown in FIG. 5, a rubber O-ring 8 is arranged as a gasket in a ring groove 7 provided in the flange 2 of one of the tubular bodies 1, and male and female screws outside the both flanges 2 are arranged. The members 5 and 6 are screwed together and brought close to each other, so that the O-ring 8 is brought into pressure contact with the facing surface of the flange 2 of the other tubular body 1.

In the conventional example shown in FIG. 6, the convex portions 10a on both sides of the rubber gasket 10 are fitted into the ring grooves 9 provided on the facing surfaces of the flanges 2 of the two tubular bodies 1, and both flanges 2
Is clamped from the outside by the clamp band 11.

[0006]

However, in any of these prior art examples, when the gasket is pressed against the facing surface of the flange, the male and female screw members and the clamp band that apply axial pressure to the flange are pressed against the gasket. After that, only the restraining action of restraining the movement is performed, and only the elasticity of the gasket itself serves as the sealing force.

Therefore, if the gasket is permanently deformed or contracted due to the influence of high temperature or chemicals, the sealing force is impaired and the fluid leaks. For example, in the case of the metal gasket 4 of FIG. 4, although the tensile stress of the screw tightening acts as a sealing force, if the gasket itself is permanently deformed, the stopper position of the screw portion is displaced, and as a result, the tensile stress due to the screw tightening is generated. It is lost and leaks occur. Moreover, it is difficult to reuse the metal gasket once deformed. Also,
In the case of a metal gasket, leakage may occur depending on the degree of tightening torque of the screw part.

Therefore, in view of the above problems, the object of the present invention can be achieved even if the gasket is deformed or contracted to some extent, and the predetermined sealing force can be maintained, and further, it can be achieved only by adding a simple structure. To do so.

[0009]

In the joint for fluid piping according to the present invention, a spring is interposed between the flange of both pipes to be connected and the tightening member, and the flange is tightened in the axial direction through the spring. Let As one form thereof, as shown in FIG. 1, springs are respectively arranged on the outer sides of both flanges, and spring pressure members are arranged on the outer sides thereof, and the flanges are clamped by clamping the spring pressure members on both sides. Axial tightening is conceivable. Also, as another form,
As shown in FIG. 2 or FIG. 3, it is possible to dispose male and female screw members on the outside of both flanges, screw these screw members close to each other, and press the spring on the flange with the screw members to tighten them. Conceivable.

[0010]

In the case of the present invention, the tightening force of the spring pressing member or the screw member is applied to both flanges via the springs, and the gaskets are sandwiched by these flanges while receiving the elasticity of the springs. Even if it contracts, the sealing force is maintained by the spring load.

[0011]

Embodiments of the present invention will now be described in detail with reference to the drawings. FIG. 1 shows a first embodiment of the present invention. Two tubes 20
A flange 21 is integrally provided at each of the connection ends of
These are symmetrically opposed. A ring-shaped groove 23 having a V-shaped cross section is provided on the opposing surfaces of these flanges 21 to securely hold the gasket 22 therebetween, and
2 is clamped by the ring-shaped seat portions 24 of both flanges 21 remaining on the inner circumference of the groove 23, and the groove 2
The edge 25 remaining on the outer periphery of the wire 3 restrains the movement in the radial direction.

A cap-shaped spring pressing member 26 covering the flanges 21 is arranged outside each of the flanges 21 with the ferrules 27 thereof symmetrically opposed to each other. Between the two, two leaf springs 28 in a ring shape are overlapped and arranged obliquely, and the leaf springs 28 in each set are covered with the respective spring pressure members 26 together with the flange 21.

A clamp band 29, which is divided into two in the circumferential direction, is fitted on the outer side of the ferrules 27 of both spring pressing members 26. And the clamp band 29
Are tightened by a screw mechanism (not shown) to bring the two ferrules 27 closer to each other, so that the two spring pressing members 26 simultaneously press the two sets of leaf springs 28 toward the flanges 21. As a result, the gasket 22 is pressed from both sides via the two sets of leaf springs 28. In this case, the leaf spring 28
Is compressed between the spring pressure member 26 and the flange 21, and tightening becomes impossible when the ferrules 27 hit each other, and a prescribed spring load is applied to the gasket 22.

Therefore, the gasket 22 has the flange 21.
Since a prescribed spring load is applied to seal between the two seats 24, even if the gasket 22 is permanently deformed or contracted by heat, chemicals, etc., the spring load is slightly reduced and leakage does not occur. I can't reach it.

As the material of the parts of the structure shown in FIG. 1, the gasket 22 may be rubber, resin such as polytetrafluoroethylene, or metal such as stainless steel.
8 is so-called spring steel, and other parts are preferably stainless steel. In FIG. 1, reference numeral 30 is a spring pressure member 26.
A retaining ring fixed to the outer periphery of the tubular body 20 to prevent separation between the two, and this retaining ring may be omitted.

Next, FIG. 2 shows an example of fastening using male and female screw members 31 and 32. In this case, the male and female screw members 31 and 32 are formed in a cap shape to serve also as the spring pressing member in the example of FIG. 1, and only one set of leaf springs 28 is provided between the female screw member 31 and the flange 21 on one side. It is arranged. Then, when the male and female screw members 31 and 32 are screwed together and brought close to each other, the flange 21 on one side is closed by the leaf spring 28.
The flange 21 on the opposite side is directly pressed by the male screw member 32, while being pressed by the female screw member 31 via the. The leaf spring 28 includes a male screw member 32 and a female screw member 3.
It is doubly covered by the screwed portion with 1.

FIG. 3 also shows an example in which the male and female screw members 31 and 32 are used for fastening, but this is slightly different from FIG. That is, in the example of FIG. 2, the leaf spring 28 is doubly covered with the screwed portion of the male screw member 32 and the female screw member 31, but in the example of FIG. Is.

In each of the embodiments shown in FIGS. 1, 2 and 3, the flange 21 is provided with the ring-shaped groove 23, which is used to secure the seat portion 24 for sealing with the gasket 22. It is for convenience and may be omitted. The same applies to the edge 25 that restrains the gasket 22.

In order to confirm the effect of the present invention, a prototype having the structure shown in FIG. 1 was made and tested. In this case, the diameter of the tubular body 20 is 1/2 inch, the material of the gasket 22 is stainless steel, the spring load is about 500 kgf when tightened, and water at 10 ° C and steam at 150 ° C are alternately introduced 10 times each, and helium is introduced. The leak amount was measured with a leak detector, but it was below the minimum sensitivity. For the same gasket, 1
The desorption was performed 0 times, and the leak amount was measured each time.
All were below the minimum sensitivity.

When the same experiment was performed on the conventional structure of FIG. 4, although no leak due to the thermal cycle of water and water vapor was detected, a clear leak was detected at the fifth time in the gasket desorption test, and After the second time, the gasket could not be sealed unless a torque equal to or higher than the first tightening torque was applied.

[0021]

As described above, according to the present invention, the tightening force by the spring pressure member or the screw member is applied to both flanges via the springs, and the gaskets are sandwiched while giving elasticity of the springs. Even if it is permanently deformed or contracted, the sealing force can be maintained by the spring load to prevent the occurrence of leakage, and it can be realized with a simple structure.

[Brief description of drawings]

FIG. 1 is a sectional view of a first embodiment of the present invention.

FIG. 2 is a sectional view of a second embodiment.

FIG. 3 is a sectional view of a third embodiment.

FIG. 4 is a sectional view of a conventional example using a metal gasket.

FIG. 5 is a sectional view of a conventional example using an O-ring.

FIG. 6 is a cross-sectional view of a conventional example using a gasket having a convex portion.

[Explanation of symbols]

 20 pipe body 21 flange 22 gasket 26 spring pressure member 28 leaf spring 29 clamp band 31 female screw member 32 male screw member

Claims (4)

[Claims] 1. A fluid pipe joint in which a gasket is interposed between the flanges of both pipes to be connected, and both flanges are clamped from the outside by a tightening member to join them, and between the flange and the tightening member. A joint for fluid piping, characterized in that a spring is interposed between and a flange is tightened in the axial direction via the spring. 2. A spring is disposed outside each of the two flanges, and a spring pressure member is disposed outside the respective flanges, and the flanges are tightened in the axial direction by sandwiching the spring pressure members on both sides with a clamp member. The fluid pipe joint according to claim 1, wherein the joint is a fluid pipe joint. 3. Male and female screw members are arranged on the outer sides of the both flanges, and these screw members are screwed together so as to be close to each other, and the spring is pressed against the flanges by the screw members to tighten them. The joint for fluid piping according to claim 1. 4. The joint for fluid piping according to claim 1, wherein the spring is a ring-shaped leaf spring.