JP2001041370A - Bayonet pipe joint - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a bayonet pipe joint high in sealing performance, capable of easily inserting a connection pipe. SOLUTION: The packing 50 of this bayonet pipe joint is furnished with an inner circumferential surface 53 opposite to the outer surface of a connection pipe, an outer circumferential surface 51 opposite to the rear part side wall 8a of an annular cavity part 8, and with a rear end surface 54 opposite to the rear part side wall 8a. An inner side projection 55 abutting against the outer circumferential surface of the connection pipe, is formed up in the inner circumferential surface of the packing 50, and an outer side projection 56 abutting against the inner circumferential surface 8c of the annular cavity part 8, is formed in the outer circumferential surface 51.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plug-in type pipe joint having a retaining ring, and more particularly to a plug-in type pipe joint capable of easily inserting a connecting pipe and having high sealing performance.

[0002]

2. Description of the Related Art In connection with a water pipe, a conduit or the like, a plug-in type pipe joint having good workability has been developed which can be connected simply by inserting the tip of one connecting pipe into an opening of the pipe joint. Have been. In the plug-in type pipe joint, packing for holding the gap between the distal end portion of the connection pipe and the pipe joint in a liquid-tight or air-tight manner against leakage of internal fluid or inundation from the outside, and preventing the connection pipe from coming off from the pipe joint. An annular retaining ring is mounted in the opening.

FIG. 7 shows a sectional view of a conventional plug-in type pipe joint. The plug-in type pipe joint (1) has a joint body (2) having an opening (3) into which a connecting pipe (10) is inserted. The end (4) of the fitting body (2) has a tapered surface that gradually decreases in diameter toward the opening (3).
The inclined cavity (5) formed by (6) and the tapered surface (6)
And a bulging inner surface (7) formed on the inner side in the axial direction. An annular cavity (8) is formed inside the bulging inner surface (7), and a radial surface communicating with the central portion (2a) of the joint body (2).
(9) is formed. An inner flange (18) is formed at an appropriate position in a central portion (2a) of the joint body (2). Rubber packing (11) formed annularly with projections (12) is annular cavity
Retaining ring located in (8) and inclined cavity (5)
(13) is in contact with the projection (12) of the packing (11). Although not shown, a retaining ring provided with a notch at one location in the circumferential direction
(13) can be expanded and reduced in diameter.

The retaining ring (13) has an upper surface (14) that abuts against the tapered surface (6) of the joint body (2) and a projection (12) of the packing (11).
Is formed in a triangular cross section having a side surface (15) abutting on the inner surface and an inner surface (16) facing inward in the radial direction in an inclined state. The upper surface (14) is formed at an angle corresponding to the tapered surface (6). A sharp edge (17) is formed by the included angle between the side surface (15) and the inner surface (16).

[0005] A connecting pipe (10) connected to the joint body (2) is
When buried in soil, an outer resin-coated steel pipe is frequently used. To prevent corrosion, the connecting pipe (10) has a resin coating layer (20) on the outer surface.
Is formed. Connecting pipe (1) with plug-in fitting (1)
When connecting (0), after partially removing the resin coating layer (20) formed at the end of the connection pipe (10), the end of the connection pipe (10) is inserted into the opening (3). When inserted, the retaining ring (13) seals
It is pushed outward by the cylindrical projection (12) of (11), and the upper surface (14) of the retaining ring (13) is always in contact with the tapered surface (6). Therefore, the center axis of the retaining ring (13) and the center axis of the tapered surface (6) coincide with each other, so that the connecting pipe (10) can be easily inserted into the joint body (2). Also, connect the connecting pipe (1
When inserting (0), the end of the connecting pipe (10)
At the same time, the diameter of the retaining ring (13) comes into contact with the inner surface (16) of the connecting pipe (11), and at the same time, the packing (11) is compressed through the retaining ring (13) and further inserted into the back side to connect the connecting pipe (10). Abuts against the inner flange (18). Similarly, another connecting pipe (10) is inserted from the opposite end of the joint body (2). In this state, the packing (11) is arranged in a compressed state between the joint body (2) and the connection pipe (10), and the fluid in the connection pipe (10) leaks to the outside and a substance is connected from the outside. A seal is formed to prevent entry into the tube (10). Also, the retaining ring (1
Since the edge (17) of (3) comes into contact with the outer surface of the connecting pipe (10) and the upper surface (14) comes into contact with the tapered surface (6) of the joint body (2), the connecting pipe (10)
Is pulled outward in the axial direction, the retaining ring (13) that moves outward in the axial direction by the tapered surface (6) is reduced in diameter, and the
(17) bites into the outer surface of the connecting pipe (10) appropriately, and the connecting pipe (10)
Can be prevented from being pulled out.

In the plug-in type pipe joint (1), since the resin coating layer (20) formed at the end of the connection pipe (10) is partially removed, the connection pipe (10) which is a steel pipe is directly exposed. And the anticorrosion performance decreases. For this reason, in order to ensure anticorrosion performance, the connecting pipe (10)
Measures may be taken to apply a rust-preventive paint or the like to the part where the resin coating layer (20) has been removed, but since the work of applying the paint is required, the paint attached to the connection pipe (10) is peeled off, The deterioration of the workability and corrosion resistance of the pipe joint could not be avoided.

[0007] A plug-in type pipe joint having a structure in which the connection pipe (10) can be connected without removing the resin coating layer (20) at the end can also be designed. To secure a certain level or more, use the edge (1
7) must penetrate the resin coating layer (20) and reach the surface of the connection pipe (10). In this case, when the connection pipe (10) comes off, the edge (17) of the retaining ring (13) penetrates the resin coating layer (20) and reaches the surface of the connection pipe (10). )
Is destroyed and the surface of the connection pipe (10) is exposed, and as a result, the anticorrosion function is impaired.

[0008] Therefore, as shown in FIG.
A structure is conceivable in which is disposed outside the retaining ring (13) in the axial direction to maintain the anticorrosion function against the buried environment. In the structure shown in FIG. 8, packing (11) is arranged in an annular cavity (8) formed on the outside in the axial direction at the end (4) of the joint body (2),
An inclined cavity (5) having a tapered surface (6) is formed axially inside the annular cavity (8). The tapered surface (6) has a shape gradually reduced in diameter toward the opening (3), and an annular inner surface (6a) having a uniform inner diameter is formed inside the tapered surface (6) in the axial direction.
A retaining ring (13) is disposed axially outside the inclined cavity (5), and a rubber backup ring (25) having elasticity is disposed inside the retaining ring (13). In order to hold the retaining ring (13) so that the central axis of the retaining ring (13) coincides with the central axis of the inclined cavity (5), a plurality of cylindrical projections (25) formed on the backup ring (25). 26) is brought into contact with the retaining ring (13).

When the connecting pipe (10) is connected by the plug-in type pipe joint (1) shown in FIG. 8 and the connecting pipe (10) is inserted into the opening (3), the connecting pipe (10) firstly has a packing ( 11) Compress,
When further inserted, the tip of the connecting pipe (10) will be
The diameter of the retaining ring (13) is expanded by contacting the inner surface (16) of the rim, and the edge (17) comes into contact with the resin coating layer (20). As the retaining ring (13) moves further inward, the projection (26) of the backup ring (25) is compressed in the axial direction. When the connection pipe (10) is further inserted, the tip of the connection pipe (10) comes into contact with the inner flange (18), and the connection is completed.

When an axial pull-out force acts on the connecting pipe (10), a retaining ring (13) that moves outward in the axial direction by the tapered surface (6) with the outward movement of the connecting pipe (10). Reduced diameter,
The edge (17) penetrates the outer surface coating and bites into the outer surface of the connection pipe (10), so that the connection pipe (10) can be prevented from coming off.

[0011]

However, in the conventional plug-in type pipe joint (1) shown in FIGS. 7 and 8, the packing (11) is radially compressed with the insertion of the connecting pipe (10). However, there is a problem that a sufficient sealing performance cannot be achieved because a desired compression ratio cannot be secured. On the other hand, packing (1
If a structure that further increases the radial compression ratio of 1) is adopted, excessive force is required to insert the connecting pipe (10) during construction,
This leads to a reduction in workability. Therefore, an object of the present invention is to provide a plug-in type pipe joint which can maintain the anticorrosion function against a buried environment, can stably prevent the connection pipe from coming off, has high sealing performance, and is easy to construct. I do.

[0012]

A plug-in type pipe joint (30) according to the present invention comprises a joint body (2) having an opening (3) into which a connecting pipe (10) is inserted, and an inner surface of the joint body (2). An annular packing (50) disposed in an annular cavity (8) provided on the outer surface of the connecting pipe (10) and an annular cavity of the joint body (2);
The connecting pipe (10) is disposed in the inclined cavity (5) provided on the inner surface in the axial direction from (8) and abuts on the outer surface of the connecting pipe (10).
And a retaining ring (13) for preventing the liquid from coming off.
The packing (50) has an inner peripheral surface (5) facing the outer surface of the connecting pipe (10).
3) and the outer peripheral surface (5) facing the inner peripheral surface (8c) of the annular cavity (8).
1) and the rear end face facing the rear side wall (8a) of the annular cavity (8)
(54). An inner projection (55) is formed on the inner peripheral surface (53) of the packing (50) to contact the outer peripheral surface of the connection pipe (10),
An outer projection (56) is formed on the outer peripheral surface (51) to abut the inner peripheral surface (8c) of the annular cavity (8).

Since the inner projection 55 and the outer projection 56 are deformed by a relatively small force, the connecting pipe 10 can be easily and smoothly inserted into the assembled joint body 2.
When the connecting pipe (10) is inserted, the inner projection (55) falls down in the axial direction and is expanded by the connecting pipe (10), so that the inner projection (55) is attached to the outer peripheral surface of the connecting pipe (10). At the same time as being strongly pressed, the outer projection (56) is strongly pressed against the inner peripheral surface (8c) of the annular cavity (8), so that a high contact surface pressure can be obtained and sufficient sealing performance can be achieved.

In the embodiment of the present invention, a front projection (58) is formed on the front end face (52) of the packing (50) so as to face and abut the front side wall (8b) of the annular cavity (8). Thus, a high contact surface pressure can be obtained also in the axial direction by the front projection (58). Packing (50)
May have at least two inner protrusions (55) and at least two outer protrusions (56). The provision of the plurality of inner protrusions (55) and outer protrusions (56) improves the sealing performance. A rear projection (57) is formed on the rear end face (54) of the packing (50) so as to contact the rear side wall (8a) of the annular cavity (8). Since the rear projection (57) contacts the rear side wall (8a) of the joint body (2), the sealing performance is further improved. Also, the rear projection (57) forms an axial gap between the rear side wall (8a) of the annular cavity (8) and the packing (50), so that the inner projection (55) can be deformed inward in the axial direction. Become. The rear projection (57) has a radial thickness approximately equal to or less than the packing (50). For example, the inner protrusion (55) has a triangular cross section, and the outer protrusion (56) has a semicircular cross section.

The inclined cavity (5) is formed by a tapered surface (6) whose diameter gradually decreases toward the opening (3).
The radial surface (9) formed on the inside in the axial direction of (5) is the joint body
Contact the center (2a) of (2). In the inclined cavity (5) between the retaining ring (13) and the radial surface (9), the backup ring (3
1) is arranged, and the backup ring (31) is formed in an annular shape by a foamed resin. The backup ring (31) can easily move the retaining ring (13) by its own elastic deformation to smoothly insert the connecting pipe (10), and the retaining ring (13)
Is held in place. The backup ring (31)
Made of porous foamed polyethylene resin or foamed rubber,
When an external force is applied, the joint body (2)
Has an elastic deformation rate compressed to a thickness of 1/3 or less in the axial direction and an elasticity that returns to a thickness in an uncompressed state when an external force is removed. The retaining ring (13) is connected to the joint body (2).
The upper surface (14) abutting the tapered surface (6), the side surface (15) abutting the backup ring (31), and the inner surface (16) facing inward in the inclined direction and radially inward are formed in a triangular cross section. ,side
A sharp edge (17) is formed by the included angle between (15) and the inner surface (16), and a portion connecting the side surface (15) and the upper surface (14) and a portion connecting the upper surface (14) and the inner surface (16). Has an outer arc portion (19a) and a front arc portion (19b), respectively, and the taper angle of the upper surface (14) is larger than the angle of the taper surface (6) of the joint body (2), for example, 1 ° to 10 ° larger. It is formed, and a notch is provided at one place in the circumferential direction, so that the diameter can be increased and reduced. Outer arc (1
By forming 9a) and the front circular arc portion (19b), the upper surface (14) of the retaining ring (13) can move smoothly without catching on the tapered surface (6) of the joint body (2). Further, by setting the taper angle of the upper surface (14) larger than the angle of the tapered surface (6) of the joint body (2), the frictional resistance between the upper surface (14) and the tapered surface (6) is reduced. The diameter of the retaining ring (13) can be easily reduced. An annular step (60) continuous with the annular cavity (8) may be formed on the inner peripheral surface of the joint body (2) adjacent to the inside of the annular cavity (8) in the axial direction. The inner projection (55), which falls inward in the axial direction due to the insertion of the connection pipe (10), is housed in the annular step (60), so that the inner projection (55) is more than necessary.
Without obstructing the insertion, and smooth insertion becomes possible.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a plug-in type pipe joint according to the present invention will be described below with reference to FIGS. FIG.
6 to 6, the same parts as those shown in FIGS. 7 to 9 are denoted by the same reference numerals, and description thereof will be omitted.

As shown in FIG. 1, the plug-in type pipe joint (30) of the present embodiment includes a joint body (2) having an opening (3) into which a connecting pipe (10) is inserted, and a joint body (2). An annular packing (50) disposed in an annular cavity (8) provided on the inner surface of the joint body and abutting against the outer surface of the connection pipe (10), and an annular cavity (8) of the joint body (2). Inclined cavity provided on the inner surface in the axial direction
And (5) a retaining ring (13) that is disposed inside and abuts against the outer surface of the connecting pipe (10) to prevent the connecting pipe (10) from coming off.

The packing (50) has an inner peripheral surface (53) facing the outer surface of the connecting pipe (10), and an outer peripheral surface (51) facing the inner peripheral surface (8c) of the annular cavity (8). A rear end surface (54) facing the rear side wall (8a) of the annular cavity (8). On the inner peripheral surface (53) of the packing (50), an inner projection (55) having a triangular cross section continuous in the circumferential direction and contacting the outer peripheral surface of the connection pipe (10) is formed, and the outer peripheral surface (51) is formed. Has an outer protrusion (56) having a semicircular cross-section continuous in the circumferential direction and abutting on the inner peripheral surface (8c) of the annular cavity (8).

Since the inner projection 55 and the outer projection 56 are deformed with relatively small force, the connecting pipe 10 can be easily and smoothly inserted into the assembled joint body 2.
When the connecting pipe (10) is inserted, the inner projection (55) falls down in the axial direction and is expanded by the connecting pipe (10), so that the inner projection (55) is attached to the outer peripheral surface of the connecting pipe (10). At the same time as being strongly pressed, the outer projection (56) is strongly pressed against the inner peripheral surface (8c) of the annular cavity (8), so that a high contact surface pressure can be obtained and sufficient sealing performance can be achieved. The inner protrusion (55) and outer protrusion (56) are each 1
Although the object of the present invention can be achieved individually, the packing (50) has two inner projections (55) and two outer projections (56) in this embodiment. Although not shown, three or more inner projections (55) and outer projections (56) may be further provided. By providing the plurality of inner protrusions (55) and outer protrusions (56) in this manner, the sealing performance is further improved.

The front end face (52) of the packing (50) has a front projection (58) having a semicircular cross-section that is continuous in the circumferential direction and faces the front side wall (8b) of the annular cavity (8). ) Is formed. Two or more front projections (58) may be provided. Inner protrusion (5
In addition to achieving the radial contact surface pressure by 5) and the outer protrusions (56), the formation of the front protrusions (58) provides a high contact surface pressure in the axial direction, contributing to improved sealing performance. The cross sections of the outer protrusion (56) and the front protrusion (58) are not limited to a semicircular shape, but may be other shapes such as a rectangular shape or a triangular shape. Furthermore, packing (50)
An annular rear projection (57) is formed on the rear end surface (54) of the annular hollow portion (8) and is continuous with the rear side wall (8a) of the annular cavity (8). However, the form of the rear projection (57) is not limited to a continuous annular shape, and the rear projection (57) may be formed as a plurality of intermittent projections. The rear projection (57) is located on the rear side wall (8) of the joint body (2).
The contact with a) further improves the sealing performance. Also,
The rear projection (57) forms an axial gap between the rear side wall (8a) of the annular cavity (8) and the packing (50), so that when the connecting pipe (10) is inserted, the inner projection (57) will be described later. 55) can be easily deformed inward in the axial direction. In FIG. 1, the rear projection (57) is located at a position radially inward of the rear end face (54) of the packing (50) and has a radial thickness of 1/2 or less with respect to the main body of the packing (50). Although formed, the thickness of the rear projection (57) may be substantially the same as the packing (50), or may be another radial thickness smaller than the packing (50). The rear projection (57) is not necessarily formed, but the material of the packing (50), the plug-in fitting (30)
If the rear end surface (54) is not provided with a rear protrusion (57) due to the dimensions and shape of each part, the clearance relationship with the outer peripheral surface of the connecting pipe (10), etc., the inner protrusion of the inner peripheral surface (53) has a triangular cross section. When the (55) falls down in the axial direction, the tip of the inner protrusion (55) is connected to the connecting pipe (10).
Between the outer peripheral surface of the joint body and the inner peripheral surface of the joint body (2), making it difficult to insert the connection pipe (10).
It is more desirable to form (57).

The inclined hollow portion (5) of the joint body (2) has an opening.
A radial surface formed by a tapered surface (6) that gradually decreases in diameter toward (3) and formed axially inside the inclined cavity (5).
(9) communicates with the central part (2a) of the joint body (2). Further, a backup ring (31) is arranged in the inclined cavity (5) between the retaining ring (13) and the radial surface (9).

Backup ring used in the present embodiment
The point (31) is different from the backup ring (25) made of rubber having elasticity and formed with the projections (26) shown in FIG. That is, in the conventional structure shown in FIG. 8, when the projection (26) of the backup ring (25) falls radially inward when the backup ring (25) is compressed in the axial direction, the connection pipe (10) is Interference with the tip, connecting pipe
(10) may be difficult to insert. In addition, connection pipe (1
At the time of insertion of (0), since the elastic rubber backup ring (25) is compressed, the insertion force of the connecting pipe (10) is increased and the workability is reduced. Further, when the backup ring (25) is manufactured, the raw rubber is molded at a high temperature in a mold, so that the manufacturing cost is further increased. On the other hand, if the backup ring (25) is not used, as shown in FIG.
The connection pipe (10) could not be inserted smoothly, for example, because the connection pipe (13) was inclined in the inclined cavity (5) or displaced with respect to the radial plane. Therefore, in the present embodiment, the problem shown in FIGS. 8 and 9 has been solved by forming the backup ring (31) in an annular shape using a foamed resin.

That is, the backup ring (31) prevents the retaining ring (13) from being inclined or displaced with respect to the radial plane in the inclined cavity (5), so that the retaining ring (13) Center ring of the tapered surface (6)
While the function of holding the (13) in a predetermined position is exhibited, the retaining ring (1) is elastically deformed by the backup ring (31) itself.
3) can be easily moved, does not hinder insertion of the connecting pipe (10), and is advantageous in terms of manufacturing cost. The backup ring (31) is formed in an annular shape, and the cross-sectional shape is not limited to a rectangular cross-section, but comes into contact with the side surface (15) of the retaining ring (13),
Other shapes such as a circle, an ellipse, a step, and a projection may be used as long as they are compressed. Rectangular, arcuate and other shapes are possible. The backup ring (31) is made of a porous foam of polyethylene resin or rubber, and when subjected to an external force, has a thickness of not more than 1/3 in the axial direction of the joint body (2) from the length in a non-compressed state. It has an elastic deformation rate to be compressed and elasticity to return to a thickness in an uncompressed state when an external force is removed.

The backup ring (31) allows the inclined cavity to be formed.
The retaining ring (13) arranged inside (5) has an upper surface (14) that contacts the tapered surface (6) of the joint body (2), and a backup ring.
It is formed in a triangular cross section having a side surface (15) abutting on (31) and an inner surface (16) facing radially inward in an inclined state. Although not shown, the retaining ring (13) is provided with a notch at one location in the circumferential direction, so that the diameter can be increased and reduced. The upper surface (14) of the retaining ring (13) by the backup ring (31) is
The central axis of the retaining ring (13) coincides with the central axis of the tapered surface (6) because it comes into contact with the tapered surface (6) of (2). A slight gap is provided between the contact point between the backup ring (31) and the side surface (15) of the retaining ring (13) and the contact point between the upper surface (14) of the retaining ring (13) and the tapered surface (6). It is practically sufficient if the center axis of the retaining ring (13) is substantially coincident with the center axis of the tapered surface (6) even when is present.

A sharp edge (17) is formed by the included angle between the side surface (15) and the inner surface (16) of the retaining ring (13), and a portion connecting the side surface (15) and the upper surface (14) and the upper surface (14) are formed. ) And the inner surface (16) are formed with an outer circular arc portion (19a) and a front circular arc portion (19b), respectively. Thereby, the upper surface (14) of the retaining ring (13) can move smoothly on the tapered surface (6) of the joint body (2).

The taper angle of the upper surface (14) of the retaining ring (13) is larger than the angle of the taper surface (6) of the joint body (2), for example, 1 ° to 10 °. For this reason, connecting pipe
When the (10) is inserted, the entire upper surface (14) of the retaining ring (13) does not come into contact with the tapered surface (6),
Only a part of the upper surface (14) connected to (19a) contacts the tapered surface (6). That is, the front circular arc portion (19b) of the retaining ring (13) and the upper surface (14) in the vicinity thereof keep the state separated from the tapered surface (6). Therefore, the taper angle of the upper surface (14) is
By setting the angle larger than the angle of the tapered surface (6),
The frictional resistance between the upper surface (14) and the tapered surface (6) can be reduced, and the diameter of the retaining ring (13) can be easily reduced.

In the present embodiment, the taper angle of the upper surface (14) of the retaining ring (13) is made larger than the angle of the tapered surface (6) of the joint body (2), and the outer arc portion (19a) and the front side are formed. The arc portion (19b) is formed for the following reason. That is, since the material of the general joint body (2) is an iron material such as steel pipe or cast iron, it is necessary to apply a surface treatment such as hot-dip galvanizing to the joint body (2) so as to improve the anticorrosion performance with respect to the use environment. is there. For example, in the hot-dip galvanizing process, the joint body (2) that has been subjected to an appropriate pre-treatment is immersed in a hot-dip galvanizing tank, and a galvanized film is simultaneously formed on the inner and outer surfaces of the joint body (2). . In this case, irregularities are usually generated on the plating film or impurities in the plating tank adhere to the plating film.
It is difficult to form a galvanized film uniformly over the entire joint body (2). In the conventional plug-in type pipe joint (1) shown in FIGS. 7 and 8, the taper angle of the upper surface (14) of the retaining ring (13) substantially matches the angle of the taper surface (6) of the joint body (2). Since an edge is formed between the upper surface (14) and the inner surface (16) of the retaining ring (13), if irregularities or attached impurities are present on the surface of the tapered surface (6), the retaining ring (13 ) Of the front end interferes with foreign matter, the retaining ring (13) cannot move smoothly outward in the axial direction along the tapered surface (6), and the retaining ring (13)
Of the edge (17) into the connecting pipe (10) becomes insufficient. As a result, the connection pipe (10) cannot be sufficiently prevented from coming off, and the connection pipe (10) is
There is a risk of getting out of (2). On the other hand, according to the present embodiment, the front end of the retaining ring (13) is held with a gap between the retaining ring (13) and the tapered surface (6), and the front end of the retaining ring (13) is an edge. Instead, the retaining ring (13) is formed as a front circular arc (19b), so that even if foreign matter is present on the tapered surface (6), the retaining ring (13) can move axially outward without any trouble. Therefore, it is possible to always stably prevent the connection pipe (10) from coming off.

When the connecting pipe (10) is connected, the retaining ring (1
The edge (17) of (3) comes into contact with the resin coating layer (20) of the connection pipe (10). When an external force is applied to the connecting pipe (10) to start moving outward in the axial direction of the joint body (2), the retaining ring (13) also has a tapered surface (6).
Moves outward in the axial direction along the
(17) appropriately penetrates into the resin coating layer (20) and further to the outer surface of the connection pipe (10) to prevent the connection pipe (10) from coming off. Connection pipe
If (10) further moves outward in the axial direction, the movement of the retaining ring (13) and the diameter reduction further progress, and finally, the front arc portion (19b) of the retaining ring (13) is It abuts on a radial step (6b) formed at the axially outer end of the tapered surface (6). At this point, the diameter of the retaining ring (13) stops, so the connecting pipe
(10) is kept constant. If the radial step (6b) is not provided, with the connection pipe (10) coming out,
Since the retaining ring (13) continues to move and reduce the diameter without being caught, if the strength of the connecting pipe (10) is insufficient, the connecting pipe (10) itself reduces its diameter and the retaining ring (13 ) May fall off the tapered surface (6). Therefore, it is desirable to form a radial step (6b) at the axially outer end of the tapered surface (6).

As shown in FIG. 1, the end surface of the joint body (2) is provided with an end surface tapered surface (29) whose diameter gradually increases toward the outside of the joint body (2). When hot-dip galvanizing the fitting body (2), the fitting body (2)
When the end surface of the joint body (2) hits the jig, the galvanized surface of the contact surface with the jig will cause significant irregularities or sagging, resulting in a poorly finished appearance and poor commercial value. There was a problem of lowering. In addition, opening (3)
If the plating sagging occurs in the inner circumferential direction, the insertion of the connection pipe (10) may be hindered. On the other hand, in the present embodiment, the end surface of the joint body (2) is formed with the tapered end surface (29), so that the contact area with the jig is minimized, and at the same time, the excess plating solution is dripped. It can be guided in the direction of inclination of the end face tapered surface (29) to escape, and the degree of galvanized appearance can be improved. In addition, the end face taper surface (29)
Accordingly, there is an advantage that the connection pipe (10) can be smoothly inserted into the opening (3) of the joint body (2).

Hereinafter, the operation of each part when the connecting pipe (10) is inserted into the plug-in type pipe joint (30) of FIG. 1 for construction will be described.
When the connection pipe (10) having the resin coating layer (20) is inserted into the joint body (2) from the opening (3), the tip of the connection pipe (10) firstly has an inner peripheral surface (53) of the packing (50). ), The inner protrusion (55) having a triangular cross section is tilted inward in the axial direction and compressed in the radial direction.
When the inner protrusion (55) falls down in the axial direction, the rear protrusion (57) having a rectangular cross section provided on the rear end surface (54) substantially overlaps,
Since the rear projection (57) is deformed radially outward, the connection pipe (10) can be inserted smoothly. At this time, the packing (50) has an inner peripheral surface
Since a force to expand the diameter of (53) acts, the tip of the outer protrusion (56) having a semicircular cross section provided on the outer peripheral surface (51) is on the inner peripheral surface (8c) of the annular cavity (8). It is pressed strongly and a high contact pressure is obtained.

When further inserted, the distal end portion becomes a retaining ring (13).
The edge (17) comes into contact with the resin coating layer (20) to expand the diameter of the retaining ring (13). At the same time, the backup ring (31) having a large shrinkage is compressed in the axial direction by the side surface (15) of the retaining ring (13). When the connection pipe (10) is further inserted, the distal end abuts on the inner flange (18), and the connection is completed. The central axis of the retaining ring (13) always coincides with the central axis of the tapered surface (6) of the joint body (2), and the central axis of the connecting pipe (10) coincides with the central axis of the retaining ring (13). Since they match, the connecting pipe (10) can be easily inserted.

After completion of the construction, when an internal pressure such as a water pressure is applied to the connection pipe (10), the packing (50) moves axially outward in the annular cavity (8) by the action of the internal pressure. That is, packing
The inner protrusion (5) having a semicircular cross-section formed on the front end face (52) of (50)
5) is strongly pressed against the front side wall (8b) of the annular cavity (8), and high sealing performance is obtained. At the same time, the inner projection (55) having a triangular cross section that is inclined inward in the axial direction exerts a self-sealing effect, thereby further improving the sealing performance.

In this embodiment, the following operation and effect can be obtained. [1] Since the inner protrusion (55) and the outer protrusion (56) are deformed with relatively small force, the connecting pipe (10) can be easily and smoothly inserted into the assembled joint body (2). [2] When the connecting pipe (10) is inserted, the inner projection (55) falls down in the axial direction and is expanded in diameter by the connecting pipe (10). At the same time as being strongly pressed against the outer peripheral surface, the outer protrusion (56) is
c) is strongly pressed, and a high contact surface pressure is obtained, and sufficient sealing performance can be achieved. [3] With the backup ring (31) having a large elastic deformation rate, the center axis of the retaining ring (13) is always aligned with the center axis of the joint body (2), and the connecting pipe (10) is compressed with a relatively small force. Can be inserted smoothly. [4] Unlike the conventional backup ring made of rubber and having a projection, the backup ring (31) does not protrude to the inner peripheral side when compressed, so that it does not hinder the insertion of the connection pipe (10). [5] A backup ring (3
According to 1), the resistance when inserting the connecting pipe (10) is small enough not to hinder the construction, and the pipe inserting force can be reduced.
(10) can always be inserted stably. [6] The backup ring (31) having a rectangular cross section can be easily and inexpensively manufactured by punching a plate-like foamed resin with a simple mold. [7] The taper angle of the upper surface (14) of the retaining ring (13) is set to be larger than the angle of the tapered surface (6) of the annular cavity (8) by 1 to 10 °, and the front end of the retaining ring (13) is Since the front side arc portion (19b) is provided, even if the inner peripheral surface of the annular cavity (8) is slightly roughened due to plating or the like, the retaining ring (13) has a tapered surface (6). Since it can be moved and reduced in diameter, it is possible to stably prevent the connection pipe (10) from coming off. [8] Since the radial step (6b) is provided at the end of the tapered surface (6) of the inclined cavity (5), the connection pipe (10) can be more reliably prevented from coming off. [9] Since a plurality of triangular cross-section inner projections (55) having a self-sealing effect are provided on the inner peripheral surface of the packing (50), high sealing performance against internal pressure is obtained. [10] Since a plurality of outer protrusions (56) having a semicircular cross section are provided on the outer peripheral surface (51) of the packing (50), sealing performance against internal pressure and external pressure can be improved. [11] Since the front projection (58) having a semicircular cross section is provided on the front end surface (52) of the packing (50), the sealing performance against internal pressure can be improved. [12] Even if the surface of the inner peripheral surface of the annular cavity (8) has some roughness such as unevenness due to plating treatment or the like, the outer protrusion (56) having a semicircular cross-section and the front part Since the projection (58) can be deformed following these irregularities, stable sealing performance can be ensured. [13] Since the end face taper surface (29) is provided on the end face of the joint main body (2), contact with a plating jig during hot-dip galvanizing can be suppressed to a minimum, and the appearance quality of galvanizing can be improved. [14] A plug-in type pipe joint having high sealing performance, low cost and good workability can be obtained without impairing the corrosion resistance of the connecting pipe (10).

In an experiment using the present embodiment, a nominal diameter of 5
With the plug-in fitting of 0A, the sealing performance that can withstand the internal water pressure of 3 MPa (megapascal) and the external water pressure of 2 MPa was achieved.

The embodiment of the present invention can be modified. Although FIG. 1 shows only one end of the plug-in fitting (30), the other end of the plug-in fitting (30) may have the same configuration as that of the present invention. Other configurations, including conventional structures having rings and the like, may be provided. The annular inner surface (6a) having a uniform inner diameter formed on the inner side in the axial direction may be removed, and the tapered surface (6) may be directly connected to the radial surface (9).

FIGS. 2 and 3 show modified examples of the inclined hollow portion (8). In the embodiment shown in FIG. 1, the radial step (6b) is formed at the axially outer end of the tapered surface (6) as a stopper for the front arc portion (19b) of the retaining ring (13). Instead of the portion (6b), a tapered step portion (6c) having a larger angle than the tapered surface (6) shown in FIG. 2 or an arc-shaped step portion (6d) shown in FIG. 3 may be formed. Tapered step (6c) or arc-shaped step (6
d) exhibits the same function as the radial step (6b).

In another embodiment of the present invention shown in FIG.
An annular step (60) continuous with the annular cavity (8) is formed on the inner peripheral surface of the joint main body (2) adjacent to the inside of the annular cavity (8) in the axial direction. The inner projection (55), which falls inward in the axial direction due to the insertion of the connection pipe (10), is housed in the annular step (60), so the inner projection (55) prevents the connection pipe (10) from being inserted more than necessary. And smooth insertion becomes possible. Also, instead of the rear projection (57) of the rectangular cross section shown in FIG. 1, the rear projection (54) of the packing (50) of FIG.
7) is formed. In particular, in the embodiment shown in FIG. 4, the inner projection (55) that falls down in the axial direction by the insertion of the connecting pipe (10).
Can be accommodated in the annular step portion (60), so that the rear projection (57) of the packing (50) does not need to be protruded as large as in FIG.

Further, in FIG. 4, the joint body shown in FIG.
(2) An annular groove (71) is formed on the inner peripheral surface of the central portion (2a) of the joint body (2), instead of the inner flange (18) formed in a protruding shape on the inner peripheral surface, and the annular groove ( By inserting an annular member (70) having a circular cross section or a rectangular cross section into the inner flange (1).
Exhibit the same function as 8).

In a modification of the packing (50) shown in FIGS. 5 and 6, the inner projection (55) having a triangular cross section of the packing (50) shown in FIGS. 55) are provided two each. In the packing (50) of FIG.
(53) has a tapered shape in which the diameter is reduced toward the inside in the axial direction, and two lip-shaped inner projections (55) project from the inner peripheral surface (53) obliquely inward in the axial direction to form the lip shape. The inner projections (55) of the above exhibit a self-sealing effect against internal pressure. The packing (50) of FIG. 6 is formed with two inner projections (55) each having a circular portion (55b) at the tip of a trunk (55a) projecting radially inward from the inner peripheral surface (53). You. According to the packing (50) shown in FIGS. 5 and 6, the resistance when the connecting pipe (10) is inserted can be further reduced.

[0040]

As described above, according to the present invention, it is possible to maintain the anti-corrosion function of the plug-in type pipe joint, stably prevent the connecting pipe from coming off, and secure high sealing performance while at the same time ensuring good sealing performance. Workability can be achieved.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an embodiment of a plug-in type pipe joint according to the present invention.

FIG. 2 is a partial sectional view showing a modified example of the inclined cavity portion.

FIG. 3 is a partial sectional view showing another modified example of the inclined cavity portion.

FIG. 4 is a sectional view showing another embodiment of the plug-in type pipe joint.

FIG. 5 is a sectional view showing a modification of the packing.

FIG. 6 is a sectional view showing another modification of the packing.

FIG. 7 is a sectional view of a conventional plug-in type pipe joint.

FIG. 8 is a sectional view of another conventional plug-in type pipe joint.

FIG. 9 is a sectional view of the pipe joint shown in FIG. 8, showing a state in which the retaining ring is inclined.

[Explanation of symbols]

(2) ・ ・ Joint body, (2a) ・ ・ Central part, (3) ・ ・ Opening, (5) ・ ・ Slope cavity, (6) ・ ・ Tapered surface, (8)
・ ・ Circular cavity, (8a) ・ ・ Rear side wall, (8b) ・ ・ Front side wall, (8c) ・ ・ Inner peripheral surface, (9) ・ ・ Radial surface, (10)
・ ・ Connection pipe, (11) ・ ・ Packing, (13) ・ ・ Retaining ring, (14) ・ ・ Top surface, (15) ・ ・ Side, (16) ・ ・ Inner surface, (17) ・ ・ Edge, ( 18) ・ ・ Inner flange, (1
9a) ・ ・ Outside arc, (19b) ・ ・ Front arc, (29) ・
・ Tapered end face, (30) ・ ・ Plug-in fitting, (31)
..Backup rings, (50)
..Outer peripheral surface, (52) ・ ・ Front end surface, (53) ・ ・ Inner peripheral surface,
(54) ・ ・ Rear end face, (55) ・ ・ Inside projection, (56) ・ ・ Outside projection, (57) ・ ・ Rear projection, (58) ・ ・ Front projection, (6
0)

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Masaki Sudo 4-1-1, Suehiro, Kumagaya-shi, Saitama Prefecture Rikken Kumagaya Plant (72) Inventor Takashi Miyake 4-1-1, Suehiro, Kumagaya-shi, Saitama F-term in Riken Kumagaya Plant (reference) 3H015 CA01 CA05

Claims (10)

[Claims] A joint body having an opening through which a connecting pipe is inserted; an annular packing disposed in an annular cavity provided in an inner surface of the joint body and in contact with an outer surface of the connecting pipe;
A plug-in type pipe joint provided with a retaining ring disposed in an inclined cavity provided on an inner surface in the axial direction from the annular cavity of the joint body and abutting against an outer surface of the connection pipe to prevent the connection pipe from coming off. The packing includes an inner peripheral surface facing the outer surface of the connection pipe, an outer peripheral surface facing the inner peripheral surface of the annular cavity, and a rear end surface facing the rear side wall of the annular cavity. A plug-in type pipe joint characterized in that an inner projection is formed on the outer peripheral surface of the connecting pipe, and an outer projection is formed on the outer peripheral surface of the connecting pipe on the inner peripheral surface of the annular cavity. 2. The plug-in type pipe joint according to claim 1, wherein a front projection is formed on a front end surface of the packing so as to face and abut on a front side wall of the annular cavity. 3. The plug-in type pipe joint according to claim 1, wherein the packing has at least two inner projections and at least two outer projections. 4. The plug-in type pipe joint according to claim 1, wherein a rear projection is formed on a rear end surface of the packing so as to abut on a rear side wall of the annular cavity. 5. The plug-in fitting according to claim 4, wherein the rear projection has a radial thickness substantially equal to or less than the packing. 6. The plug-in type pipe joint according to claim 1, wherein the inner projection has a triangular cross section, and the outer projection has a semicircular cross section. 7. The inclined cavity portion is formed by a tapered surface that gradually decreases in diameter toward the opening, and a radial surface formed inside the inclined cavity portion in the axial direction communicates with a central portion of the joint body. The plug-in type pipe joint according to any one of claims 1 to 6, wherein a backup ring is disposed in the inclined cavity portion between the retaining ring and the radial surface, and the backup ring is formed in an annular shape with a foamed resin. 8. The backup ring is made of a porous foamed polyethylene resin or foamed rubber, and is compressed to a thickness of 1/3 or less in the axial direction of the joint main body from an uncompressed length when an external force is applied. The plug-in type pipe joint according to claim 7, wherein the pipe joint has elasticity that returns to a thickness in an uncompressed state when an elastic deformation rate and an external force are removed. 9. The retaining ring has an upper surface abutting on a tapered surface of the joint body, a side surface abutting on a backup ring,
It is formed in a triangular cross section having an inner surface facing radially inward in an inclined state, a sharp edge is formed by the included angle between the side surface and the inner surface, and a portion connecting the side surface and the upper surface and a portion connecting the upper surface and the inner surface are formed. An outer circular arc portion and a front circular arc portion are respectively formed, a taper angle of an upper surface is formed larger than an angle of a taper surface of a joint body, and a notch is provided at one position in a circumferential direction to enable diameter expansion and diameter reduction. Item 7. A plug-in type pipe joint according to item 7 or 8. 10. The insertion according to claim 1, wherein an annular step portion that is continuous with the annular cavity is formed on an inner peripheral surface of the joint body that is close to the inside of the annular cavity in the axial direction. Pipe fittings.