JPS626376Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a joint, particularly a joint suitable for cryogenic fluids.

In recent years, due to the research and development of cryogenic technology using liquid helium, reliable couplings for cryogenic fluids have been desired. However, since conventional couplings for ultra-low temperature fluids use metal O-rings made of stainless steel, etc., once tightened, the pedestal contact surface deforms and the
When it is installed for the first time, the new O-ring and the abutment surface do not align, causing leakage, so it has the disadvantage that it cannot be used repeatedly. In addition, no sufficient countermeasures were taken against low-temperature shrinkage, resulting in the disadvantage that gaps would form at low temperatures and leaks would occur.

Therefore, an object of the present invention is to provide a joint for cryogenic fluids that eliminates the above-mentioned drawbacks.According to the present invention, the slopes on one of the end faces of the adjacent stainless steel joint parts are at an angle of 60° to 100° from each other in the cross section. Protrusions that are substantially orthogonal to each other and project in the axial direction are provided in an annular shape, and an annular groove corresponding to the protrusions is provided on the other end surface,
An annular packing made of a thin plate of a malleable, soft metal such as aluminum or copper that is resistant to ultra-low temperatures and has a higher shrinkage rate than the joint material is sandwiched between the end faces,
A joint for ultra-low temperature liquid is provided, characterized in that both end faces are press-sealed in the axial direction by a fastening means without sliding the end faces and the packing.

An embodiment of the cryogenic fluid coupling according to the present invention will be described below with reference to the accompanying drawings. The cryogenic fluid coupling 10 according to the present invention includes a male coupling part 20 located on the right side in FIG. It mainly consists of a packing 40 and a cap nut 50 that tightens both joints 20 and 30 in the axial direction.

The male joint part 20 is made of stainless steel and, as shown in FIG. 1, consists of a pipe part 21 that projects to the right and a male fitting part 22 that has a larger outer diameter than the pipe. The inner end surface 23 of this male fitting part 22 has a second
As shown in the figure, an annular protrusion 24 with a chevron-shaped cross section protrudes in the axial direction, and a slope 25 of the protrusion 24
intersect with each other at an angle of 60° to 110°.

Cap nut 5 through which the pipe portion 21 of the male joint portion 20 passes
0 consists of a sleeve 52 that extends in the axial direction and has a female thread 51 cut on its inner surface, and an end 54 that extends from the sleeve 52 perpendicular to the tube axis and radially inward and has a through hole 53. The outer periphery of the cap nut 50 is constituted by a hexagonal surface 55, and can be easily rotated with a tool to tighten both end faces of the male joint part 20 and female part 30, which will be described later. Joint male part 20
On the outer periphery of the tube portion 21 and between the male fitting portion 22 of the male joint portion 21 and the inner end surface 56 of the cap nut 50,
A washer 57 having a rectangular cross section is fitted.

Joint female part 30 located on the left in FIG.
is made of stainless steel, protrudes to the right, and has the same inner and outer diameter as the tube portion 21 of the male joint 20.
A nut part 33, which is formed integrally with the pipe part 31 on the right side of the pipe part 31 and whose outer periphery is constituted by a hexagonal surface 32, and a sleeve 34 extending rightward from this nut part 33 are integrally provided. It is being A female thread 51 of a cap nut 50 is attached to the outer periphery of this sleeve 34.
The internal diameter of the sleeve is slightly larger than the outer diameter of the male fitting part 22 so that a fitting hole 36 into which the male fitting part 22 of the female joint part 20 is fitted is formed inside. It's getting bigger. The bottom end surface 37 of the fitting hole 36 is provided with a V-shaped groove 38 corresponding to the chevron-shaped protrusion 24 provided on the end surface 23 of the male fitting portion 22, as shown in detail in FIG.

Between the bottom end surface 37 of the fitting hole 36 and the end surface 23 of the male fitting part 22, there is a thickness of about 0.2 to 0.4 mm, preferably
0.3mm malleable, soft, ultra-low temperature resistant metal,
For example, it is made of a thin plate of aluminum, copper, etc. An annular gasket 40 is clamped.

To connect this joint 10, the undeformed flat annular packing 40 is held between the end faces 37 and 23, and the sleeve 52 of the cap nut 50 is inserted.
The female thread 51 is screwed onto the male thread 35 on the sleeve 34 of the female joint part 30. In this way Fukuronatsu 5
0 toward the female joint part 30 side, the male joint part 20
Since the end face 23 of the fitting hole 36 is pressed against the end face 37 of the fitting hole 36 of the female joint part 30, the packing 40 is plastically deformed into the shape shown in FIG. 2, sealing the gap between the end faces 23 and 37. wear it. In this way, the male joint part 20 and the female joint part 30 are connected in a sealed state to form a conduit for a cryogenic fluid such as liquid helium.

In addition to the screw type coupling of the embodiment, various known coupling fastening means can be used as the fastening means, but depending on the purpose, one having strength and structure that can withstand ultra-low temperatures is preferable.

The structure and operation of the cryogenic fluid coupling according to the present invention are as described above, and the following points can be mentioned as effects of the present invention. In other words, at low temperatures, the packing 40 has a larger shrinkage rate than the joint,
The difference in radial shrinkage between the two not only ensures a seal at the protruding edge of the end face, but it is also compact in size and easy to handle. In addition, the flow path of the joint has the same diameter as the pipe, resulting in less pressure loss, and by changing the inner diameter of the packing, it can be used not only as a simple joint but also as an orifice or a blind joint. Naturally, it can be used many times, and has a pressure resistance of 15 to 20 kg/cm ² and a maximum of 30 kg/cm ² .

[Brief explanation of the drawing]

FIG. 1 is a diagram showing a low-temperature fluid joint according to the present invention, in which the upper half is a longitudinal sectional view and the lower half is a side view. FIG. 2 is a partially enlarged view showing the vicinity of the annular packing shown in FIG. 1. 20...male joint part, 24...annular protrusion, 30...
...Female joint part, 38...V-shaped groove, 40...Puttlekin, 50...Cap nut.

Claims (1)

[Scope of utility model registration request] One of the adjacent end faces of the stainless steel joint is provided with an annular protruding ridge that is approximately orthogonal to each other at an angle of 60° to 100° in cross section and projects in the axial direction, and an annular recess corresponding to the axially protruding ridge is provided on the other end face. A groove is provided, and an annular packing made of a thin plate of malleable, soft metal such as aluminum or copper that is resistant to ultra-low temperatures and has a higher shrinkage rate than the joint material is sandwiched between the end faces, and the end face and the packing are slid together. 1. A coupling for ultra-low temperature fluid, characterized in that both end faces are press-sealed in the axial direction by a fastening means without causing any tension.