JP2003214573A - Pipe joint structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent a large load from being applied to a lock ring by smoothly bending a joint part even when large force acts on the joint part of a pipe in the direction for bending this joint part. <P>SOLUTION: In this pipe joint structure, a lock ring housing groove 4 is formed on the inner periphery of a socket 2 in one pipe 1, a lock ring 5 having a dividing part in the peripheral direction in an annular shape is housed in this lock ring housing groove 4, a spigot projecting part 10 is formed on the outer periphery of a spigot 9 in the other pipe 8, and the spigot 9 is inserted into the socket 2 until the spigot projecting part 10 is positioned between the lock ring 5 and the inmost end surface 3 in the socket 2 to join the socket 2 and the spigot 9. A socket recessed surface 19 is formed on the opening side of the socket 2 in the lock ring housing groove 4, and a lock ring projecting surface 20 having curvature larger than the socket recessed surface 19 is formed on the opening side of the socket 2 in the lock ring 5, so that the socket recessed surface 19 and the lock ring projecting surface 20 contact with each other. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a pipe joint structure.

[0002]

2. Description of the Related Art Conventionally, there is a joint structure as shown in FIG. 5 as one of the joint structures for a pipe having an earthquake resistance function.

As shown in FIG. 5, a receiving port 2 is formed at the end of one of the pipes 1, and a rear end face 3 is formed at the back side of the receiving port 2. A lock ring accommodating groove 4 having a rectangular cross section is formed on the opening side of the receiving port 2 with respect to the inner end surface 3, and the lock ring accommodating groove 4 has an annular cross section in a circumferential direction. A rectangular lock ring 5 is housed.

A taper surface 6 that widens toward the opening side is formed further on the opening side than the lock ring receiving groove 4. A radially outward flange 22 is formed on the outer periphery of the end of the receiving port 2. A plurality of round holes 24 are formed in a penetrating state in the pipe axis direction at positions at a constant interval in the circumferential direction of the flange 22.

On the other hand, an insertion port 9 is formed at the end of the other tube 8, and an insertion port projection 10 is formed on the outer periphery of the end of this insertion port 9.
Are formed. A taper surface 11 is formed on the tip end side of the insertion protrusion 10. In addition, the insertion port 9 is the insertion port protrusion 10
Is inserted into the receptacle 2 until it is located between the lock ring 5 and the rear end face 3. Further, the outer diameter of the insertion protrusion 10 is formed larger than the inner diameter of the lock ring 5, and the inner diameter of the lock ring 5 and the outer diameter of the insertion port 9 are formed in the same manner.

A backup ring 12 and an annular rubber seal member 13 are disposed on the outer periphery of the insertion opening 9 on the opening side of the receiving opening 2 with respect to the position of the lock ring 5, and are divided in the circumferential direction. Further, an annular push ring 15 having an outer diameter similar to that of the receiving port 2 is provided on the outer circumference of a portion of the other pipe 8 that does not enter the receiving port 2.

The push wheel 15 has a flange 22 of the receptacle 2.
A plurality of round holes 16 corresponding to the plurality of round holes 24 formed in
Are formed. A T-shaped bolt 25 is inserted into each of the round hole 16 and the round hole 24 as shown in the drawing, and a nut 18 is screwed onto the T-shaped bolt 25.

Due to the tightening force of the T-shaped bolt 25 and the nut 18, the push ring 15 is arranged in the pipe axial direction on the outer periphery of the insertion opening 9 and the backup ring 1.
2 is pressed, and the sealing material 13 is pressed against the tapered surface 6 formed in the receiving port 2. As a result, the sealing function of this pipe joint is exerted.

When a compressive force acts on the pipe joint in the axial direction of the pipe due to an earthquake or the like, the insertion projection 10 is locked by the lock ring 5.
And the rear end face 3 of the receiving port 2 can be moved. Further, when a tensile force is applied, the insertion opening projection 10 is inserted into the receiving opening 2
From the inner side of the lock ring 5 to the end surface 5a on the tip side of the insertion opening 9 of the lock ring 5, and the end surface 5b of the lock ring 5 on the opening side of the receiving opening 2 is the side surface 4a of the lock ring receiving groove 4 on the opening side of the receiving opening 2. It is possible to reliably prevent the insertion opening 9 from coming out of the receiving opening 2 by contacting with. In this way, a seismic function is added to the joint portion of the pipe.

[0010]

In a conventional pipe joint structure provided with a seismic resistant function, when a large force is applied to the joint portion in the direction of bending the joint portion, as shown in FIG. The lock ring housing groove 4 and the lock ring 5 at the outer side of the portion, that is, at the position above the center line when viewed as shown in the drawing, are such that the end surface 5b of the lock ring 5 on the opening side of the socket 2 accommodates the lock ring. The groove 4 comes into contact with the side surface 4a on the opening side of the receiving port 2 in an inclined state.

When the lock ring 5 comes into contact with the lock ring receiving groove 4 in such a tilted state, even if the insertion opening 9 tries to bend further with respect to the receiving opening 2, the end surface of the lock ring 5 Since 5b engages with the side surface 4a of the lock ring housing groove 4, it has a large resistance to bending, and it is difficult for the joint portion to smoothly bend. Further, a large load is also applied to the lock ring 5 at this time.

Therefore, the present invention solves such a problem and smoothly bends the joint portion even when a large force acts on the joint portion of the pipe in the direction of bending the joint portion, and The purpose is to prevent heavy load on the lock ring.

[0013]

In order to solve the above-mentioned problems, the invention according to claim 1 is characterized in that a lock ring receiving groove is formed in the inner periphery of the receiving opening of one of the pipes, and the lock ring receiving groove is formed. An annular lock ring having a divided portion in the circumferential direction is housed therein, and an insertion opening projection is formed on the outer periphery of the insertion opening in the other pipe, and the lock ring and the rear end surface of the receiving opening are formed. A joint structure of a pipe in which the insertion opening is inserted into the receiving opening and the receiving opening and the insertion opening are joined until the insertion opening protrusion is located between A concave curved surface is formed on the opening side of the receiving opening, and a convex curved surface having a larger curvature than the concave curved surface is formed on the opening side of the receiving opening of the lock ring.

According to a second aspect of the present invention, a lock ring accommodating groove is formed on the inner circumference of the receiving opening of one of the pipes,
An annular lock ring having a divided portion in the circumferential direction is accommodated in the lock ring accommodating groove, and an insertion opening projection is formed on the outer periphery of the insertion opening in the other pipe, and the lock ring and the receiving member are formed. A joint structure of a pipe in which the insertion opening is inserted into the receiving opening and the receiving opening and the insertion opening are joined until the insertion opening protrusion is located between the rear end surface of the opening,
On the opening side of the receiving opening in the lock ring receiving groove,
A taper surface that narrows toward the opening side of the receiving opening is formed, and a convex curved surface is formed on the opening side of the receiving opening of the lock ring.

According to such a structure, the joint portion of the pipe is
When a large force acts in the direction of bending the joint portion, the lock ring receiving groove and the lock ring come into contact with each other on the concave curved surface and the convex curved surface having a larger curvature than the concave curved surface, or the tapered surface and the convex surface. By making contact with the curved surface, the convex curved surface of the lock ring can smoothly move while being in contact with the concave curved surface or the tapered surface of the lock ring receiving groove. Therefore, since the contact state between the lock ring receiving groove and the lock ring does not cause resistance when the joint portion is bent, the insertion opening and the receiving opening are likely to incline relative to each other. As a result, the joint portion can be smoothly bent, and a large load can be prevented from being applied to the lock ring when the joint portion is bent.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of a pipe joint structure of the present invention will be described with reference to FIGS. FIG. 1 is a cross-sectional view in the pipe axial direction showing a pipe joint structure according to an embodiment of the present invention, and FIG. 2 is a joint portion of a pipe joint structure according to an embodiment of the present invention. FIG. 6 is a cross-sectional view in the tube axis direction showing a state in which a large force in a bending direction is applied. Also, FIG.
FIG. 3 is an enlarged view of a main part of FIG. In the embodiments, the same parts as those already described in the conventional pipe joint structure are designated by the same reference numerals as those used in FIGS. 5 and 6, and the detailed description thereof will be omitted. .

As shown in FIGS. 1 to 3, the opening side of the receiving port 2 in the lock ring receiving groove 4 formed in the receiving port 2 of one of the pipes 1 constituting the pipe joint structure of the present invention. A receiving concave surface 19 as a concave curved surface is formed on the side surface of the.

A lock ring convex surface 20 as a convex curved surface having a curvature larger than that of the socket concave surface 19 is formed on the opening side of the socket 2 in the lock ring 5 housed in the lock ring housing groove 4. . The cross-sectional shape of the lock ring 5 according to the embodiment of the present invention is formed in a mountain shape, that is, in the figure, the lock ring 5 is erroneously oriented in the opposite direction to that shown in the figure.
The end surface 21 on the insertion end side of the lock ring 5 is also formed with a convex curved surface so that the convex surface is arranged on the opening side of the receiving port 2 even when the lock ring 5 is accommodated in the. However, the shape of this portion may be an appropriate shape as long as it can engage with the insertion protrusion 10.

When a large force is applied to the joint portion of the pipe having such a structure in the direction of bending the joint portion, as shown in FIGS. 2 and 3, the lock ring receiving groove 4 and the lock ring 5 are separated from each other. As a result of the contact between the socket concave surface 19 and the lock ring convex surface 20 having a larger curvature than the socket concave surface 19, the contact state between the lock ring housing groove 4 and the lock ring 5 does not become resistance when the joint portion is bent. Therefore, the insertion opening 9 and the receiving opening 2 are likely to incline relative to each other. As a result, the joint portion can be smoothly bent, and a large load can be prevented from being applied to the lock ring 5 when the joint portion is bent. Further, since the cross section of the lock ring 5 is formed in a mountain shape, the lock ring 5 can come into contact with the lock ring receiving groove 4 at the skirt of the mountain shape, that is, at a position closer to the central axis of the pipe. Therefore, the resistance when the joint portion tries to bend can be reduced. That is, since the load applied to the lock ring 5 when the joint portion is bent can be reduced, the joint portion can be bent more smoothly.

Further, as shown in FIG. 4, the socket concave surface 19 of the lock ring housing groove 4 in the pipe joint structure shown in FIGS. 1 to 3 is tapered toward the opening side of the socket 2 as shown in FIG. In the case of No. 26, when a large force in the direction of bending the joint portion acts on the joint portion of the pipe,
Similarly to the case shown in FIG. 3, the lock ring receiving groove 4 and the lock ring 5 are brought into contact with each other at the tapered surface 26 and the lock ring convex surface 20, so that the lock ring 5 is locked to the tapered surface 26 in the lock ring receiving groove 4. The lock ring convex surface 20 can contact and move smoothly. Therefore, the insertion opening 9 and the receiving opening 2 are easily inclined relative to each other, the joint portion can be smoothly bent, and a large load applied to the lock ring 5 when the joint portion is bent can be reduced. .

[0021]

As described above, according to the present invention, when a large force acts on the joint portion of the pipe in the direction of bending the joint portion, the lock ring receiving groove and the lock ring are
The concave curved surface and the convex curved surface having a larger curvature than this concave curved surface, or the tapered curved surface and the convex curved surface are brought into contact with each other, so that the concave curved surface or the tapered curved surface in the lock ring receiving groove has a convex shape in the lock ring. The curved surface can move smoothly while contacting. Therefore, since the contact state between the lock ring receiving groove and the lock ring does not cause resistance when the joint portion is bent, the insertion opening and the receiving opening are likely to incline relative to each other. As a result, the joint portion can be smoothly bent, and a large load can be prevented from being applied to the lock ring when the joint portion is bent.

[Brief description of drawings]

FIG. 1 is a sectional view in a pipe axis direction showing a pipe joint structure according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view in the pipe axis direction showing a state in which a large force in a direction of bending the joint portion is applied to the joint portion of the pipe joint structure according to the embodiment of the present invention.

FIG. 3 is an enlarged view of a main part of FIG.

FIG. 4 is a sectional view in the axial direction of the pipe, showing a joint structure for a pipe of the present invention, which is different from those shown in FIGS. 1 and 2.

FIG. 5 is a cross-sectional view of a conventional pipe joint structure in the pipe axis direction.

FIG. 6 is a cross-sectional view in the axial direction of the pipe showing a case where a large force in the direction of bending the joint portion acts on the joint portion of the conventional pipe joint structure.

[Explanation of symbols]

One tube 2 mouth 3 Inner edge 4 Lock ring receiving groove 5 lock ring 8 the other tube 9 insertion 10 Insert protrusion 19 Recessed surface 20 Lock ring convex

Claims (2)

[Claims] 1. A lock ring accommodating groove is formed on an inner periphery of a receiving opening of one of the pipes, and the lock ring accommodating groove accommodates an annular lock ring having a divided portion in a circumferential direction, An insertion opening projection is formed on the outer periphery of the insertion opening in the other pipe, and the insertion opening is located inside the reception opening until the insertion opening projection is located between the lock ring and the rear end surface of the reception opening. Is a joint structure of a pipe that is inserted into the socket to join the receiving port and the insertion port, wherein a concave curved surface is formed on the opening side of the receiving port in the lock ring receiving groove, and the receiving port in the lock ring is formed. A joint structure for a pipe, wherein a convex curved surface having a curvature larger than that of the concave curved surface is formed on the opening side of, and the concave curved surface and the convex curved surface are contactable with each other. 2. A lock ring accommodating groove is formed on the inner periphery of the receiving opening of one of the pipes, and the lock ring accommodating groove accommodates an annular lock ring having a divided portion in the circumferential direction, An insertion opening projection is formed on the outer periphery of the insertion opening in the other pipe, and the insertion opening is located inside the reception opening until the insertion opening projection is located between the lock ring and the rear end surface of the reception opening. A joint structure of a pipe that is inserted into the receiving port and the receiving port and is joined to the receiving port, wherein a taper is formed on the opening side of the receiving port in the lock ring receiving groove, the taper becoming narrower toward the opening side of the receiving port. The pipe joint structure is characterized in that a surface is formed, a convex curved surface is formed on the opening side of the receiving opening in the lock ring, and the tapered surface and the convex curved surface can contact each other.