JP3289234B2 - Flare nut - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a flare nut for connecting a small-diameter pipe connected to a pressurized container to an external device such as a union connector.

[0002]

2. Description of the Related Art When a small diameter pipe connected to a conventional pressurized container is connected to a union connector by a flare nut, the flare nut communicates with the container. The container is pressurized after the flare nut is connected to the union connector and a leak test is performed on the connection.

[0003]

As described above, the union connector cannot be connected to the container while the container is being pressurized as described above, and the connection requires complicated operations such as decompression and pressurization of the container. An object of the present invention is to enable connection with an external device while maintaining the internal pressure of a container.

[0004]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a screw fitting which is attached to a tip of a pipe having an internal pressure and which is formed inside a tip opening to which an external device is connected, and which is connected to the pipe side from the end of the screw. A flare nut having a tapered first sealing surface in close contact with a tapered sealing surface at the tip of the external device, wherein the flare nut has an outer diameter larger than the inner diameter of the tapered sealing surface tip of the external device, and A cylindrical plug having a hollow portion communicating with the external device side end opening and the outer peripheral surface opening is inserted into the flare nut, and the inner diameter is substantially equal to the outer diameter of the plug so that the plug can be inserted. Having an inner diameter substantially equal to the outer diameter of the plug so that the plug can be inserted, and having the outer peripheral surface opening exposed when the connection of the external device is completed. A second extending from the minimum diameter portion to the pipe side; The inside surface of the flare nut includes an inner surface that is larger than the outer diameter of the stopper and an inner diameter that is larger than the outer diameter of the pipe and that extends from the end of the second seal surface on the side of the pipe to the connection with the pipe. Is achieved. The above object is to fit a spacer made of an annular elastic material to the top of the external device side of the plug, and to form a step having an inner diameter smaller than the outer diameter of the spacer from the fitting portion toward the pipe side. This is achieved by forming on the second sealing surface of the flare nut. According to the above configuration, since the plug is inserted into the flare nut, the internal pressure applied to the pipe before the connection of the external device is caused by the close contact between the plug and the second sealing surface of the flare nut and the opening on the outer peripheral surface of the hollow portion of the plug. And the second sealing surface. When the external device is engaged with the screw part of the flare nut to connect the external device, the plug is pushed out in the pipe direction by the external device, and the outer peripheral opening of the hollow portion passes through the second sealing surface to enlarge the inner diameter. When it reaches the part, the close contact state is released, and the piping and the external device communicate with each other through the hollow part of the plug. In addition, by fitting a spacer made of an annular elastic material to the top of the stopper on the side of the external device, the inner surface of the spacer and the flare nut are in close contact with each other to improve the sealing property, and the top of the stopper in contact with the external device is crushed. To prevent

[0005]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to the drawings. First, the configuration of the embodiment of the present invention will be described. FIG. 1 is a longitudinal sectional view showing the overall configuration of the embodiment of the present invention. FIG. 2 is a perspective view showing the structure of the stopper according to the embodiment of the present invention. As shown in FIG. 1, a flare nut 3 is attached to a tip of a pipe 2 connected to a pressurized container 1. A plug 10 is slidably inserted into the flare nut 3. On the inner surface of the flare nut 3, a screw portion 6 that engages with a screw portion of the external device 4, a first seal surface 7 that comes into contact with a tapered seal surface at the tip of the external device 4, and the pipe 2 side from the first seal surface 7. The second sealing surface 8 is in contact with the outer peripheral surface 12 of the plug 10 shown in FIG.
An inner diameter enlarged portion 9 having an inner diameter larger than the outer diameter of 0 and smaller than the outer diameter of the pipe 2 is formed.

As shown in FIG. 2, the stopper 10 is cylindrical and has an outer diameter larger than the inner diameter of the tip of the tapered sealing surface of the external device 4, and the top surface 11 is flat and has a bottom surface 16 opposite to the top surface 11.
Has a chamfered edge. The plug 10 has an inverted T-shaped hollow portion 13 formed therein, and the top opening 11 on the top surface 11 and the outer opening 15 on the outer peripheral surface 12 communicate with each other through the hollow portion 13. Since the outer diameter of the tip of the tapered sealing surface of the external device 4 that comes into contact with the top surface 11 of the plug 10 does not always match the outer diameter of the plug 10 due to mutual manufacturing errors or the like, the outer diameter of the distal end of the external device 4 when connection is completed. Is larger than the outer diameter of the stopper 10, the top surface 11 of the stopper 10 shifts to the external device 4 side, and the external device 4
If the outer diameter of the tip of the plug 10 is smaller than the outer diameter of the plug 10, the top surface 11 of the plug 10 is shifted toward the pipe 2. Therefore, the external device 4
The outer peripheral surface opening 15 must be located at a position closer to the pipe 2 than the lower end of the second sealing surface 8 when the connection between the flared nut 3 and the flare nut 3 is completed.

FIG. 3 is a perspective view showing the configuration of another embodiment of the present invention. The plug 10 shown in this figure has a groove 17 formed in a direction perpendicular to the axis instead of the inverted T-shaped hollow portion 13 shown in FIG. The bottom of the groove 17 must be located at the same position as the outer peripheral surface opening 15 shown in FIG. In this embodiment as well, the same effect in use as the hollow structure shown in FIG. 2 can be obtained, but manufacturing is easy.

Next, the operation of the embodiment of the present invention will be described. Before the external device 4 is connected to the flare nut 3, the plug 10 is inserted into the flare nut 3 as shown in FIG. 1, and the outer peripheral surface 12 of the plug 10 and the second sealing surface 8 of the flare nut 3 are in close contact with each other. The internal pressure of the container 1 is sealed by friction,
Further, since the outer peripheral opening 15 of the plug 10 is not in communication with the pipe 2, the internal pressure of the container 1 is sealed.

FIG. 4 is a vertical sectional view showing the operation of the embodiment of the present invention. As shown in the figure, the screw portion of the external device 4 is connected to the screw portion 6 of the flare nut 3 in order to connect the external device 4.
When the plug 10 is engaged with the plug 10, the external device 4 pushes the plug 10 in the direction of the pipe 2. In this state, since the outer peripheral surface opening 15 is in close contact with the second sealing surface 8 of the flare nut 3, the plug 10 is still pressed. The outer peripheral surface opening 15 does not communicate with the pipe 2 side, and the internal pressure of the container 1 is sealed even if the tapered sealing surface at the tip of the external device 4 does not adhere to the first sealing surface 7.

FIG. 5 is a longitudinal sectional view showing the operation of the embodiment of the present invention. As shown in this figure, the connection of the external device 4 is completed, and the outer peripheral surface opening 15 of the hollow portion 13 is
, When the inner diameter is increased, the close contact state is released, and the pipe 2 and the external device 4 communicate with each other through the hollow portion 13 of the plug 10. In this state, the internal pressure of the container 1 is increased by the outer peripheral surface 12 of the plug 10, the second sealing surface 8 of the flare nut 3, the tapered sealing surface of the tip of the external device 4, and the first sealing surface 7 of the flare nut 3. Double sealed.

Further, the configuration of another embodiment of the present invention will be described. FIG. 6 is a perspective view showing the configuration of another embodiment of the present invention. As shown in this figure, in the present embodiment, the top structure of the plug 10 shown in FIG. 3 is changed and an annular spacer 21 is fitted. The spacer 21 is made of an elastic material, such as hard rubber, and has a hole 22 formed at the center, and fits with the top of the plug 10. The outer diameter of the spacer 21 is the same as the outer diameter of the tip of the external device 4 and the bottom surface 23 is chamfered. The top of the plug 10 of the present embodiment has an outer diameter that fits into the hole 22 of the spacer 21, and the outer diameter on the side of the pipe 2 from the fitting portion is smaller than the outer diameter of the spacer 21. Other shapes are shown in FIG.
Same as 0.

FIG. 7 is a longitudinal sectional view showing the structure of another embodiment of the present invention. The shape of the flare nut 3 shown in this figure is almost the same as that shown in FIG. 1, but the inner diameter of the second seal surface 8 is reduced to receive the compressive force applied to the spacer 21 when the external device 4 is connected. The part 20 is formed. The outer diameter of the plug 10 on the side of the pipe 2 from the fitting portion is set so as to be slidable with the step portion 20. The stepped portion 20 of the flare nut 3 according to the present embodiment has a small contact area with the plug 10 because the spacer 21 is disposed, and the plug 10 may be displaced by the internal pressure of the container 1 before the external device 4 is engaged. Therefore, it is desirable to provide a step having an outer diameter larger than the inner diameter of the step portion 20 on the pipe 2 side of the plug 10 because there is a possibility that the step portion 20 will fall off.

Here, the operation of the embodiment of the present invention will be described. Before connecting the external device 4 to the flare nut 3, the plug 10 is inserted into the flare nut 3 and formed on the outer peripheral surface 12 of the plug 10 and the second sealing surface 8 of the flare nut 3 as shown in FIG. The stepped portion 20 adheres closely, and the opening 15 on the outer peripheral surface of the plug 10 is located closer to the external device 4 than the stepped portion 20 and does not communicate with the pipe 2 side, so that the internal pressure of the container 1 is sealed.

FIG. 8 is a longitudinal sectional view showing the operation of another embodiment of the present invention. When the external device 4 is engaged with the screw portion 6 of the flare nut 3 to connect the external device 4 as shown in the figure, the plug 10 is pushed out toward the pipe 2 by the external device 4, but in this state, the plug 10 is pushed out. The outer peripheral surface 12 of the plug 10 and the step 20 formed on the second sealing surface 8 of the flare nut 3 are in close contact with each other, and the outer peripheral opening 15 of the plug 10 is located in the step 20 and does not communicate with the pipe 2 side. Therefore, the internal pressure of the container 1 is sealed, and the internal pressure of the container 1 is sealed even if the tapered sealing surface at the tip of the external device 4 does not adhere to the first sealing surface 7.

FIG. 9 is a longitudinal sectional view showing the operation of another embodiment of the present invention. As shown in the figure, when the connection of the external device 4, that is, screwing is completed, and the outer peripheral surface opening 15 of the hollow portion 13 passes through the position of the step portion 20 and reaches the inner diameter enlarged portion 9, the close contact state with the step portion 20 is released. Then, the pipe 2 and the external device 4 communicate with each other through the hollow portion 13 of the plug 10. In this state, the internal pressure of the container 1 is reduced by the outer peripheral surface 12 of the plug 10 and the sealing surface of the step portion 20 of the flare nut 3, the spacer 21 and the second sealing surface 8, and the external device 4
And the first sealing surface 7 of the flare nut 3 is triple-sealed. In this embodiment, since the internal pressure of the container 1 is triple-sealed, after the external device 4 and the flare nut 3 are connected, the internal pressure of the container 1 can withstand high internal pressure. Further, since the top of the plug 10 comes into contact with the external device 4 via the spacer 21, no crush occurs.

[0016]

According to the present invention, a slidable plug is inserted into the flare nut to seal the internal pressure of the container before the external device is connected, and the hollow portion of the plug connects the container to the external device after the external device is connected. By doing so, it is possible to obtain an effect of enabling connection with an external device while maintaining the internal pressure of the container. The seal is triple-sealed by the sealing surface and the first sealing surface 7 of the flare nut 3. In addition, by fitting a spacer made of an annular elastic material to the top of the plug on the side of the external device, the inner surface of the spacer and the flare nut are in close contact with each other to improve the sealing property, and the crush of the top of the plug in contact with the external device is prevented. The effect of preventing is obtained.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing an overall configuration of an embodiment of the present invention.

FIG. 2 is a perspective view showing a configuration of the stopper according to the embodiment of the present invention.

FIG. 3 is a perspective view showing a configuration of another embodiment of the present invention.

FIG. 4 is a longitudinal sectional view showing the operation of the embodiment of the present invention.

FIG. 5 is a longitudinal sectional view showing the operation of the embodiment of the present invention.

FIG. 6 is a perspective view showing a configuration of another embodiment of the present invention.

FIG. 7 is a longitudinal sectional view showing the configuration of another embodiment of the present invention.

FIG. 8 is a longitudinal sectional view showing the operation of another embodiment of the present invention.

FIG. 9 is a longitudinal sectional view showing the operation of another embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Container 2 Piping 3 Flare nut 4 External device 6 Screw part 7 1st sealing surface 8 2nd sealing surface 9 Inner diameter expansion part 10 Plug 11 Top surface 12 Outer peripheral surface 13 Hollow part 14 Top opening 15 Outer peripheral opening 16 Bottom 17 Groove 20 Step 21 Spacer 22 Hole 23 Bottom

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-51-66526 (JP, A) JP-A-48-15612 (JP, U) JP-A-51-19326 (JP, U) JP-A-51-19326 124917 (JP, U) Actually open 63-188373 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) F16K 1/00-1/10 F16K 3/22-3/26 F16B 37/00

Claims (2)

(57) [Claims] 1. A threaded portion attached to a tip of a pipe having an internal pressure and formed inside a tip end opening to which an external device is connected, and a tip of the external device from an end of the threaded portion toward the pipe side. The tapered first surface that is in close contact with the tapered sealing surface
A flare nut having a sealing surface having an outer diameter larger than the inner diameter of the tapered sealing surface tip of the external device, forming a hollow portion communicating with the external device side end surface opening and the outer peripheral surface opening in the axial direction. The plug is inserted into the flare nut, and has an inner diameter substantially equal to the outer diameter of the plug so that the plug can be inserted. When the connection of the external device is completed, the outer peripheral surface opening is exposed. A second seal surface extending from the minimum diameter portion of the first seal surface to the pipe side so as to have an inner diameter larger than the outer diameter of the stopper and smaller than the outer diameter of the pipe. A flare nut, wherein an inner diameter enlarged portion extending from a pipe end to a connection portion with the pipe is formed inside the flare nut. 2. An annular spacer made of an elastic material is fitted to the top of the plug on the external device side, and a step portion having an inner diameter smaller than the outer diameter of the spacer from the fitting portion toward the pipe is formed. The flare nut according to claim 1, wherein the flare nut is formed on a second sealing surface of the flare nut.