JP2002054781A - Pipe joint structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a small-size pipe joint structure surely preventing a male pipe and a female pipe from being pulled out. SOLUTION: This pipe joint connecting the male pipe 1 to the female pipe 2 by fitting is formed with radially opposed annular recessed grooves 14 and 26 in the mutually fitted internal and outer circumferential faces 11 and 24 of the male pipe 1 and the female pipe 2 and an insertion hole 27 penetrating from the recessed groove 26 of the female pipe 2 to the outer circumferential face. A wire rod 3 is inserted into the recessed grooves 14 and 26 from the outer circumferential part of the female pipe 2 via the insertion hole 27 with the male pipe 1 and the female pipe 2 fitted to each other, the radial movement of the wire rod 3 is limited in the bottoms of the both recessed grooves 14 and 26 so that the wire rod 3 is engaged thereto over the recessed groove 14 of the male pipe and the recessed groove 26 of the female pipe. A lock portion 31 is bently formed in the tip of the wire rod 3, the lock portion 31 is engaged with a lock hole 15 formed in the bottom of the recessed groove 14 of the male pipe 1, and the male pipe 1 and the female pipe 2 are relatively rotated so that the wire rod 3 is automatically inserted into the recessed grooves 14 and 26.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a joint structure between a male pipe and a female pipe.

[0002]

2. Description of the Related Art Conventionally, a structure as shown in FIGS. 5 and 6 has been known as a pipe joint structure for a water supply pipe or the like. FIG.
Is formed on the outer periphery of the distal end portion of the male tube 40 with a fitting portion 41 having an O-ring 42 mounted thereon, and an engaging groove formed on an inner peripheral surface of a fitting surface 44 of the female tube 43 fitted with the fitting portion 41. 45,
A retaining ring 46 for retaining the fitting surface 41 of the male pipe 40 is attached to the engaging groove 45. The retaining ring 46 is formed in a C shape as shown in FIG. 5B, and a tool hole 46b for bending the retaining ring 46 inward in the radial direction is formed at both ends 46a.
Are formed. The other end of the female tube 43 has a screw 4
7 is formed, and a pipe 48 is screwed to the screw 47.

FIG. 6 shows a retaining ring 5 on the outer periphery of the distal end of a male pipe 50.
1 is formed, and the female tube 53 is formed.
Forming a fitting portion 54 on which an O-ring 55 is mounted,
The fitting ring 54 is prevented from coming off by the retaining ring 51. The retaining ring 51 is also formed in a C shape as shown in FIG. 6B, and tool holes 51b for bending the retaining ring 51 outward in the radial direction are formed at both ends 51a. In addition, female pipe 5
A screw 56 is formed on the inner surface of the other end of the screw 3.
A pipe 57 is screwed into the pipe.

[0004]

However, in the case of the connection structure shown in FIG. 5, after the male pipe 40 and the female pipe 43 are fitted, the retaining ring 46 is inserted into the engaging groove 45 of the female pipe 43. Since it is necessary to mount, a gap d1 corresponding to at least the radial width of the retaining ring 46 must be provided between the fitting surface 44 of the female tube 43 and the outer peripheral surface of the male tube 40. Therefore, there is a disadvantage that the diameter of the female pipe 43 is increased by the gap d1. Further, since a radial gap d1 exists between the female pipe 43 and the male pipe 40, and the retaining ring 46 is engaged with the engaging groove 45 by a spring force, the male pipe 40 and the female pipe 4
When a large tensile force acts between the male pipe 40 and the female pipe 3, there is a problem that the retaining ring 46 comes off the engagement groove 45 and the male pipe 40 and the female pipe 43 come off.

Also in the case of FIG. 6, a gap d2 for arranging the retaining ring 51 must be provided between the outer peripheral surface of the male pipe 50 and the inner peripheral surface of the female pipe 53. However, there is a disadvantage that the diameter becomes large. In particular, both ends 51a of the retaining ring 51
Protrudes outward in the radial direction, the gap d
2 must be secured. Further, since there is a radial gap d2 between the female pipe 53 and the male pipe 50 and the retaining ring 51 is engaged with the engaging groove 52 by a spring force, the male pipe 50 and the female pipe 53 If a large tensile force acts between them, there is a problem that the retaining ring 51 tends to come off from the engagement groove 52.

Accordingly, an object of the present invention is to provide a pipe joint structure capable of reducing the size in the radial direction and reliably preventing the male pipe and the female pipe from coming off.

[0007]

In order to achieve the above object, an invention according to claim 1 is a pipe joint structure for fitting and connecting a male pipe and a female pipe, wherein the male pipe and the female pipe are connected. An annular concave groove facing in the radial direction is formed on the inner and outer peripheral surfaces of the male tube and the female tube, and an insertion hole communicating from the concave groove of the female tube to the outer peripheral surface of the female tube is formed. With the pipe fitted, a wire is inserted into the groove from the outer periphery of the female pipe via the insertion hole, and the wire is engaged across the concave groove of the male pipe and the groove of the female pipe. The pipe joint structure is characterized in that the movement of the wire in the radial direction is restricted at the bottom surfaces of the two concave grooves.

According to the present invention, an annular concave groove facing in the radial direction is formed on the inner and outer peripheral surfaces which are the fitting surfaces of the male pipe and the female pipe, and the wire is inserted into the cavity formed by the two concave grooves. This keeps both pipes from coming off. In particular, instead of fitting a ring-shaped wire into the groove in advance, after connecting the male pipe and the female pipe, the wire is inserted from the insertion hole provided on the outer peripheral surface of the female pipe toward the groove. By inserting, it inserts in the said cavity. Therefore, the workability is excellent and the connection work can be easily performed. Once the wire is inserted,
The wire rod straddles and engages between the concave groove of the male pipe and the concave groove of the female pipe, and the radial movement of the wire is restricted at the bottom of the concave groove, so a large tensile force acts. Even if the wire is not removed from the groove, the male pipe and the female pipe do not come off. Furthermore, since an annular concave groove that can insert a wire can be formed between the male pipe and the female pipe, the space in the radial direction can be small, and the diameter of the female pipe does not need to be large. Therefore, a small-sized pipe joint can be realized.

In the present invention, the engaging portion is bent at the distal end of the wire, and the engaging hole for engaging with the engaging portion is formed in the bottom surface of the concave groove of the male pipe. Preferably, the wire rod is inserted into the groove by rotating the male pipe and the female pipe relatively while being engaged with the locking hole. That is, various methods for inserting the wire into the concave groove are conceivable. For example, when the wire has a predetermined rigidity, it is possible to insert the wire into the cavity formed by the double grooves by pushing the wire through the insertion hole, but due to frictional resistance between the wire and the groove. In addition, it is difficult to completely push the end of the wire. On the other hand, if the wire is inserted by the method as described in claim 2, it is not necessary to push the wire, and the wire is automatically inserted by relatively rotating the male pipe and the female pipe. Therefore, the insertion operation is very simple, and the terminal can be reliably inserted to the end.

It is preferable that the end of the wire is bent in an inclined direction so as to face the bottom of the concave groove of the male pipe. That is, when the end of the wire is straight, the wire may come out of the insertion hole when the wire is inserted into the concave groove and then the male pipe and the female pipe are relatively reversely rotated. . Then, by bending the end of the wire so as to face the concave groove bottom side of the male pipe, the end of the wire can be prevented from falling out of the insertion hole.

It is preferable that the insertion hole is provided substantially in a tangential direction of the concave groove of the female pipe. When a straight wire is inserted into the insertion hole, the wire can be smoothly inserted into the groove if the insertion hole is substantially tangential to the groove. It is preferable that the opening of the insertion hole is inclined so that the opening gradually decreases toward the outer peripheral side. In this case, the insertion of the wire is easy, and even if the male pipe and the female pipe are relatively reversely rotated, the end of the wire hits the opening of the insertion hole and stops, and the wire comes out of the insertion hole. Can be prevented. As in claim 6, a seal member for preventing liquid leakage is arranged between the inner and outer peripheral surfaces of the male pipe and the female pipe which are fitted to each other, and the concave groove is provided outside a portion sealed by the seal member. It is good to provide. In other words, since the groove communicates with the outside through the insertion hole, if it is provided inside the seal portion, the liquid that has passed through the male pipe and the female pipe will pass from the groove to the outside through the insertion hole. This is because there is a possibility of leakage.

[0012]

1 to 3 show an example of a pipe joint structure according to the present invention. The pipe joint structure of this embodiment includes a metal male pipe 1, a metal female pipe 2, and a wire 3.
Two fitting grooves 13 into which a seal material 12 such as an O-ring is fitted are formed on the outer peripheral surface of the distal end portion of the male pipe 1, that is, the fitting surface (outer peripheral surface) 11 with the female pipe 2. An annular groove 14 is formed slightly outside the fitting groove 13 (on the side opposite to the distal end side). A bottomed locking hole 15 is formed in the bottom of the concave groove 14. Note that a positioning mark 16 may be provided at a position corresponding to the locking hole 15 on the outer peripheral surface of the male pipe 1 that is separated from the fitting surface 11. The mark 16 is for confirming the positional relationship between the locking hole 15 and an insertion hole 27 described later. The male pipe 1 may be formed integrally with the tip of a long pipe, or may be fixed to the tip of another pipe.

A nut 21 is integrally formed at one end of the female pipe 2 facing the male pipe 1, and a screw 23 for screwing a pipe 22 is formed at the other end. Nut part 2
A fitting surface (inner circumferential surface) 24 that fits with the fitting surface 11 of the male pipe 1 is formed on the inner peripheral side of the male pipe 1. A stopper 25 is formed in contact with the inner surface of the fitting surface 24, and the male pipe 1 is fitted to the stopper 25 until it comes into contact with the groove 14. Are formed. The female pipe 2 has an insertion hole 27 that extends from the concave groove 26 to the outer peripheral surface of the nut portion 21. As shown in FIG. 2, the insertion hole 27 is formed so that the inner diameter side is wide in the circumferential direction and the outer diameter side is narrow in the circumferential direction, and the insertion hole 27 is inclined so that the opening gradually decreases toward the outer circumference. are doing. And the insertion hole 27
Is provided substantially in the tangential direction of the concave groove 26 of the female pipe 2.

The wire 3 is made of a metal wire such as a stainless steel wire, and has a straight shape when not inserted as shown in FIG. At the tip of the wire 3 is a female tube 2
A locking portion 31 inserted through the insertion hole 27 of the male tube 1 and engaged with the locking hole 15 formed on the bottom surface of the concave groove 14 of the male pipe 1 is bent substantially at a right angle. An inclined portion 32 inclined in the same direction as the bending direction of the locking portion 31 is bent. The wire 3 is provided with the concave grooves 14, 16 of the male pipe 1 and the female pipe 2.
The wire 3 is restricted from moving in the radial direction by the bottom surfaces of both the grooves 14 and 16 so that the wire 3 is engaged across the grooves 14 and 16 (see FIG. 1). .

The wire 3 may be a metal wire having a predetermined or higher shear stress, and is not limited to a spring wire. The diameter D of the wire 3 is not more than the width L in the axial direction of the grooves 14, 26, not less than the depths H1, H2 of the grooves 14, 26, and not more than the sum H1 + H2 of the depths. Good. H1, H2 ≦ D ≦ LD ≦ H1 + H2 Here, the width dimension L of the concave grooves 14 and 26 is L = 1.5 mm, the depth H1 = 0.6 mm, H2 = 0.6 mm, and the wire diameter D = 1.
0 mm. The width dimension of the insertion hole 27 in the axial direction was the same as the width dimension L of the concave grooves 14 and 26. The length of the wire 3 is desirably such that it engages with at least a half or more of the concave grooves 14 and 26. However, if the length of the wire 3 is such that it engages with at least 2/3 or more of the entire circumference as in the present embodiment, it is extremely difficult. Demonstrate a powerful retaining effect.

Next, a method of assembling the pipe joint structure having the above configuration will be described with reference to FIG. First, the fitting surface 11 of the male pipe 1 is fitted to the fitting surface 24 of the female pipe 2. When the male pipe 1 is fitted until the distal end surface thereof comes into contact with the stopper portion 25 of the female pipe 2, the concave groove 14 of the male pipe 1 and the concave groove 26 of the female pipe 2 oppose each other in the radial direction. Then, the sealing material 4 fitted in the fitting groove 5 of the male pipe 1 is pressed against the fitting surface 24 of the female pipe 2 to seal between the male pipe 1 and the female pipe 2. Next, the male pipe 1 and the female pipe 2 are relatively rotated such that the locking hole 15 of the male pipe 1 corresponds to the position of the insertion hole 27 of the female pipe 2 as shown in FIG. Then, the wire 3 is inserted into the insertion hole 27 from the locking portion 31 side, and the locking portion 31 is engaged with the locking hole 15 of the male pipe 1. Next, when the male pipe 1 is rotated relative to the female pipe 2 in the direction of the arrow as shown in FIG. 4B in a state where the locking portion 31 is engaged with the locking hole 15, the wire 3 becomes Grooves 14, 26 with rotation
It is drawn into. Then, as shown in FIG.
When the inclined portion 32 at the end of the wire 3 is inserted into the insertion hole 27, the assembly is completed. Since the inclined portion 32 of the wire 3 is bent in a tilting direction so as to face the bottom side of the concave groove 14 of the male pipe 1, the male pipe 1 and the female pipe 2 are connected with the arrow direction of FIG. Even if it is relatively rotated in the opposite direction, the inclined portion 32 contacts the bottom surface of the concave groove 14 of the male pipe 1 and does not fall out of the insertion hole 27. Further, even if the terminal portion 32 of the wire 3 is the male pipe 1
4D, when the male pipe 1 and the female pipe 2 are relatively rotated in the opposite directions as shown in FIG. 4D, the end portion 32 contacts the inclined inner surface of the insertion hole 27. Restricting contact and getting out.

The male tube 1 and the female tube 2 are fitted as described above,
With the wire 3 inserted into the grooves 14, 26, the two pipes 1,
Even if an external force in the pulling direction acts between the two, or a force in the pulling-out direction acts due to the water pressure flowing in the pipes 1 and 2, the wire 3 is engaged with almost the entire circumference of the concave grooves 14 and 26. In addition, since the movement of the wire 3 in the radial direction is limited by the bottom surfaces of the grooves 14 and 26, the wire 3 does not come off from the grooves 14 and 26. Therefore, the force in the pull-out direction applied to both pipes 1 and 2 acts as a shearing force on almost the entire length of the wire 3, and the pull-out can be strongly prevented.

In the case of the structure having the screw portion 23 for screwing the pipe 22 to the other end of the female pipe 2 as in the above embodiment, there are the following advantages. That is, male pipe 1 and pipe 2
If 2 is a long pipe or a bent pipe,
The pipe 22 or the male pipe 1 cannot be turned,
Cannot be fastened to the screw portion 23 in some cases. Even in this case, according to the structure of the present invention, since the female pipe 2 is rotatably fitted to the male pipe 1, the pipe 22 is screwed by rotating the female pipe 2 with respect to the male pipe 1. It can be easily fastened to the part 23, and the work efficiency can be improved.

In the above embodiment, the fitting groove 13 is formed on the outer peripheral surface of the male pipe 1 for fitting the sealing material 12. On the contrary, the sealing material is fitted on the inner peripheral surface of the female pipe 2. It goes without saying that fitting grooves that fit together may be formed. In the above embodiment, a wire having a circular cross section is used as the wire 3, but a wire having a square or rectangular cross section may be used.
Further, the wire is not limited to a wire having spring elasticity such as stainless steel, and even a general metal wire has a sufficient retaining function. After the wire is inserted into the groove through the insertion hole, as a structure for preventing the wire from coming out of the insertion hole, the end of the wire is bent as in the embodiment, or the inner surface of the insertion hole is directed toward the outer peripheral side. It is not limited to a tapered structure. For example, after inserting the wire, the insertion hole may be closed by filling the insertion hole. The nut portion 21 is provided on the outer peripheral portion of the female pipe 2 and the insertion hole 27 is opened in the nut portion 21. However, the nut portion 21 may be omitted to be a cylindrical portion.

[0020]

As is apparent from the above description, according to the present invention, the male pipe and the female pipe are formed with radially opposed annular concave grooves on the inner and outer peripheral surfaces of the male pipe and the female pipe which are fitted to each other. In a state where the female pipe and the female pipe are fitted, by inserting a wire into the concave groove from the outer peripheral part of the female pipe through the insertion hole, the two pipes were prevented from coming off,
Once the wire is inserted, the wire is straddled between the male groove and female groove, and the wire does not come off the groove. However, the male and female tubes do not fall off. In addition, since an annular concave groove enough to insert a wire can be formed between the male pipe and the female pipe, a space in the radial direction can be small, and the diameter of the female pipe does not increase. Therefore, a small-sized and low-cost pipe joint structure can be obtained.

[Brief description of the drawings]

FIG. 1 is a sectional view of an example of a pipe joint structure according to the present invention.

FIG. 2 is a sectional view taken along line II-II of FIG.

FIG. 3 is an exploded perspective view of the pipe joint structure according to the present invention.

FIG. 4 is a process chart showing a method of assembling a wire rod.

FIG. 5 is a sectional view of an example of a conventional connection structure between a male pipe and a female pipe and a front view of a retaining ring.

FIG. 6 is a sectional view of another example of a conventional connection structure between a male pipe and a female pipe, and a front view of a retaining ring.

[Description of Signs] 1 Male pipe 2 Female pipe 3 Wire rod 11 Fitting surface (outer peripheral surface) 14 Concave groove 15 Locking hole 24 Fitting surface (inner peripheral surface) 26 Groove 27 Insertion hole 31 Locking part

Claims (6)

[Claims] 1. A pipe joint structure in which a male pipe and a female pipe are fitted and connected to each other. A groove is formed, an insertion hole communicating from the concave groove of the female pipe to the outer peripheral surface of the female pipe is formed, and in a state where the male pipe and the female pipe are fitted, the outer peripheral portion of the female pipe is inserted through the insertion hole. A wire is inserted into the groove, and the radial movement of the wire is restricted at the bottom surfaces of both grooves so that the wire engages over the groove of the male pipe and the groove of the female pipe. A pipe joint structure characterized in that: 2. A locking portion is bent at a distal end portion of the wire rod, and a locking hole for engaging with the locking portion is formed on a bottom surface of the concave groove of the male pipe to lock the locking portion. 2. The pipe according to claim 1, wherein the wire is inserted into the groove by relatively rotating the male pipe and the female pipe while being engaged with the hole. Joint structure. 3. The pipe joint structure according to claim 1, wherein an end of said wire is bent in a tilting direction so as to face a concave groove bottom side of the male pipe. 4. The pipe joint structure according to claim 1, wherein said insertion hole is provided substantially in a tangential direction of the concave groove of the female pipe. 5. The pipe joint structure according to claim 1, wherein the opening of the insertion hole is inclined so that the opening gradually decreases toward the outer peripheral side. 6. A seal member for preventing leakage of liquid is disposed between inner and outer peripheral surfaces of the male pipe and the female pipe which are fitted to each other, and the concave groove is a portion sealed by the seal member. 2. The device as claimed in claim 1, wherein the device is provided further outside.
6. The pipe joint structure according to any one of claims 5 to 5.