JP2002276866A - Joint - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a joint preventing stress corrosion cracking of a flare nut. SOLUTION: The joint comprises a half union 4 provided with a male screw 1 in an outer circumference part and a tapered inclined part 3 in a tip, the cross sectionally U-shaped flare nut 7 provided with an insertion hole 5 in a center position of a bottom face 7a and a female screw 6 screwed to the male screw 1, a connecting pipe 8 with a tip flared after passing through the insertion hole 5, and a washer 9 provided between the bottom face of the flare nut 7 and the inclined part of the half union 4 so as to press the tip of the connecting pipe 8 against the inclined part and having front and rear faces respectively parallel to the bottom face 7a of the flare nut 7 and the inclined part of the half union 4. When connecting the connecting pipe 8 to the half union 4, the male screw 1 is screwed in the female screw 6, and the tip of the connecting pipe 8 is pressed against the inclined part 3 of the half union 4 via the washer 9.

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 pipe joint used in an air conditioner for connecting a connection pipe forming a refrigerant flow path.

[0002]

2. Description of the Related Art As shown in FIG. 2 (A), a conventional pipe joint used in an air conditioner has a male screw 1 at an outer peripheral portion and a center hole 2 at an inner portion thereof, and a tapered slope at a tip end. A half union 4 having a portion 3, a flare nut 7 having an insertion hole 5 at a center position of a bottom surface parallel to the inclined portion 3, and a female screw 6 screwed into the male screw 1, After the insertion, the distal end portion is formed of a connection pipe 8 having a flared finish. When connecting the connection pipe 8 to the half union 4, the female screw 6 of the flare nut 7 is screwed into the male screw 1 of the half union 4. Then, the distal end of the connection pipe 8 was pressed against the inclined portion 3 of the half union 4.

However, when the flare nut 7 is screwed into the half union 4 and tightened, the flare nut 7 is not affected by the stress in the oblique direction F shown in FIG. In addition, there is a problem that the stress progresses and the proof stress is reduced, thereby causing stress corrosion cracking as shown in part a of FIG. 2B.

[0004]

SUMMARY OF THE INVENTION In view of the above problems, an object of the present invention is to provide a pipe joint in which a flare nut does not cause stress corrosion cracking.

[0005]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention comprises a half union having an external thread at the outer periphery and a tapered inclined portion at the tip, and an insertion hole at the center of the bottom surface. A flare nut having a concave cross section provided with a female screw to be screwed into the male screw, a connection pipe having a tip portion flared after the insertion hole is inserted, and a bottom surface of the flare nut and an inclined portion of the half union. And a washer provided so as to press the tip of the connection pipe against the inclined portion, and a washer having front and back surfaces parallel to the bottom surface of the flare nut and the inclined portion of the half union, respectively. When connecting the connection pipe to the union, the female screw of the flare nut is screwed into the male screw of the half union, and the tip of the connection pipe is pressed to the inclined part of the half union via the washer. And it has a configuration that.

[0006] Further, the insertion hole is formed so as to pass through the connection pipe without any gap.

[0007] The washer has a center hole whose diameter is slightly larger than that of the insertion hole.

Further, when the distal end portion of the connection pipe is pressed against the inclined portion of the half union, a gap is formed between the outer diameter of the washer and the flare nut.

Further, the washer is made of a member having corrosion resistance and rigidity.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings as examples. FIG. 1 is an explanatory view of a pipe joint according to the present invention, and FIG.
(B) is a perspective view of the washer.

As shown in FIG. 1A, the pipe joint according to the present invention is formed by screwing and tightening a flare nut 7 having a concave cross section to the half union 4 with a washer 9 interposed therebetween. After inserting the insertion hole 5 of the flare nut 7 into the tapered inclined portion 3 formed at the tip of 4, the distal end of the flared connection pipe 8 corresponding to the inclined portion 3 is pressed. Has become.

The half union 4 is made of brass,
A male screw 1 is provided on the outer periphery, a center hole 2 is provided inside, and the tapered inclined portion 3 is provided at a tip.

The flare nut 7 is made of brass and has a bottom surface.
The insertion hole 5 for inserting the connection pipe 8 without any gap is provided at the center position of 7a, and the female screw 6 is screwed into the male screw 1 of the half union 4 to be formed in a concave cross section. And the inner peripheral surface continuous with the female screw 6 are joined to each other at right angles.

The connection pipe 8 is a pipe forming a refrigerant flow path of the air conditioner and made of copper. After the insertion pipe 5 is inserted through the insertion hole 5 of the flare nut 7, the tip corresponds to the inclined section 3. It is designed to be flared.

The washer 9 has a rigidity such as, for example, high-tensile steel, and is made of a member subjected to a surface treatment so as not to corrode. As shown in FIGS. 1A and 1B, A central hole having a diameter slightly smaller than the insertion hole 5 at the center thereof, and the connecting pipe 8 provided between the bottom surface 7a of the flare nut 7 and the inclined portion 3 of the half union 4; Of the flare nut 7 and the inclined surface of the half union 4 are parallel to the front and back surfaces, respectively.

With the above configuration, as shown in FIG. 1A, when connecting the connection pipe 8 to the half union 4, the distal end of the connection pipe 8 is connected to the insertion hole 5 of the flare nut 7. After the insertion, it is expanded corresponding to the inclined part 3,
The flat surface side of the washer 9 is the flare nut 7
The female screw 6 of the flare nut 7 is screwed into the male screw 1 of the half union 4 and the flare nut 7 is tightened, so that the connection is made by the inclined surface side of the washer 9. The distal end of the tube 8 is pressed against the inclined portion 3 of the half union 4.

At this time, a gap A shown in FIG. 1A is provided between the outer peripheral portion of the washer 9 and the flare nut 7, whereby the flare nut 7 is formed. The stress F received by the tightening is not a horizontal stress that causes a horizontal crack as in the prior art, but a vertical stress. Most of the stress F is received by the washer 9 having rigidity. Will be given.

The center hole of the washer 9 has a diameter slightly smaller than that of the insertion hole 5, so that the center hole of the washer 9 slides smoothly along the outer shape of the connecting pipe 8, and the tip of the connecting pipe 8 is connected to the inclined portion. 3 can be pressed accurately.

The washer 9 has corrosion resistance and rigidity. In addition, since the insertion hole 5 penetrates the connection pipe 8 without a gap, the washer 9 is in a sealed state, so that it is harder to corrode. It can withstand F sufficiently well.

[0020]

As described above, according to the present invention, there is provided a pipe joint in which the flare nut does not cause stress corrosion cracking.

[Brief description of the drawings]

FIG. 1 is an explanatory view of a pipe joint according to the present invention, in which (A) is a sectional view and (B) is a perspective view of a washer.

2A and 2B are explanatory views of a conventional pipe joint, in which FIG. 2A is a cross-sectional view and FIG. 2B is a front view of a flare nut.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Male screw 2 Center hole 3 Inclined part 4 Half union 5 Insertion hole 6 Female screw 7 Flare nut 7a Bottom surface 8 Connection pipe 9 Washer A Gap F Stress

Claims (5)

[Claims] 1. A half-union having an external thread at an outer peripheral portion and a tapered inclined portion at an end thereof, an insertion hole at a center position of a bottom surface, and a concave flare having a female screw screwed to the external thread. A nut, a connection pipe having a flared tip after being inserted through the insertion hole, and a bottom end of the flare nut and a sloped portion of the half union, and a tip end of the connection pipe pressed against the sloped portion. And a washer having a front surface and a back surface that are parallel to the bottom surface of the flare nut and the inclined portion of the half union. When the connection pipe is connected to the half union, the male screw of the half union is used. A female screw of the flare nut, and a tip end of the connection pipe is pressed into contact with an inclined portion of the half union via the washer. 2. The apparatus according to claim 1, wherein the insertion hole is formed so as to pass through the connection pipe without any gap.
The pipe joint according to 1. 3. The pipe joint according to claim 1, wherein a center hole of the washer has a diameter slightly larger than that of the insertion hole. 4. A gap is formed between the outer diameter of the washer and the flare nut when the distal end of the connection pipe is pressed against the inclined portion of the half union. The pipe joint according to claim 1 or 3. 5. The washing machine according to claim 1, wherein the washer is made of a member having corrosion resistance and rigidity.
Or the pipe joint according to claim 4.