JP2003232476A - Rubber packing for pipe joint - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent leakage even in the case of light fastening without causing de-centering of rubber packing even in a temporary assembled state. <P>SOLUTION: A contact part of the rubber packing 20 with a tapered socket face 3 of a joint body or a pipe is provided with a plurality of annular recesses and protrusions 14 along the tapered face of the socket face 3 and projectingly in the same direction as the axis of the pipe, and a plurality of annular protrusions 22 are provided on the inner peripheral surface side of the rubber packing 20, making the inner diameter of the protrusions 22 larger than the outer diameter of the pipe. Since the tip side of the annular protrusions 22 provided on the inner peripheral surface side of the rubber packing 20 is brought into pressure contact with the outer peripheral surface of the pipe, the diameter is considerably contracted with much smaller clamping force than the case of bringing the whole inner peripheral surface of the rubber packing 20 into pressure contact with the outer peripheral surface of the pipe, and moreover, since stress is concentrated on the tip side of the protrusions 22, powerful watertightness is exhibited. Sufficient leakage preventing effect is thereby acquired even by manual fastening. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention uses a tightening means such as a push ring by inserting a threadless joint pipe into a pipe or a joint body having a tapered receiving portion and inserting and inserting an annular rubber packing. The present invention relates to a rubber packing for a pipe joint that is tightened on a pipe or a joint body.

[0002]

2. Description of the Related Art As a pipe joint of this type, there is one shown in a partial vertical sectional view of FIG. This pipe joint is a joint pipe 1,
The joint main body 2 connects one to the other. That is, the inner diameter of the tapered receiving portion 3 is set to be larger than the outer diameter of the joining pipe 1, and the joint main body 2 in which the central portion in the axial direction swells like a drum and a wide cavity 4 is formed inside is prepared. The insertion opening 5 of the joint pipe 1 is inserted into the receiving opening 3. An annular rubber packing 6 for sealing is provided between the outer peripheral surface of the joint body 2 and the receiving portion 3 of the joint body 2.
Is inserted and pushed into the joint body 2 from behind by the push ring 7. This pushing is performed by the bolt hole 10 of the protrusion 8 formed on the outer periphery of the end surface of the joint body 2 and the bolt hole 10.
The tightening bolt 11 is inserted into the bolt hole 9 of the push wheel 7 corresponding to 10 and tightened with the nut 12.

As a result, the outer peripheral wedge surface and the inner peripheral wedge surface of the annular rubber packing 6 are pressed between the tapered receptacle 3 of the joint body 2 and the outer peripheral surface of the joint pipe 1, and the joint pipe 1 and the joint. The main body 2 and the main body 2 are held concentrically, and the leakage of fluid from the connecting portion is sealed. In this state, the pipe end of the joint pipe 1 can freely move in the cavity 4 of the joint body 2 without interfering with the inner wall of the joint body 2, and the axis of the joint body 2 can be moved. It is capable of refraction and has flexibility. Further, it is possible to expand and contract to some extent with respect to the tensile force acting in the axial direction of the joint pipe 1. That is, this pipe joint retains flexibility and elasticity.

By the way, the rubber packing 6 of the pipe joint
As described above, the outer peripheral wedge surface is pressed and closely contacted with the tapered receptacle 3 of the joint body 2, and the inner peripheral wedge surface is pressed and closely contacted with the outer peripheral surface of the joint pipe 1. Thus, the sealing property between the tapered receiving portion 3 and the outer peripheral surface of the joint pipe 1 is secured. In order to further secure this sealing property, the rubber packing 6 needs to strongly adhere to the tapered receiving portion 3 and the outer peripheral surface of the joint pipe 1. For that purpose, it is necessary to make the inner diameter of the rubber packing 6 smaller than the outer diameter dimension of the joint pipe 1 by 1 to 3%. The mounting procedure of such a pipe joint is as follows. First, mount the push ring 7 on the outer peripheral surface of the joint pipe,
Next, a rubber packing 6 having an inner diameter smaller than the outer diameter of the pipe by 1 to 3% is attached, and finally, the push ring 7 is fastened with a bolt 11 and a nut 12.

However, if the inner diameter of the rubber packing 6 is small, it is difficult to insert the joining pipe 1 into the through hole at the center of the rubber packing 6, and the rubber packing 6 and the push ring 7 conveyed to the joint body 2 in a temporarily tightened state. However, it was impossible to insert the joint pipe 1 from the outside in the state where it was temporarily tightened. Therefore, after the push ring 7 and the rubber packing 6 are disassembled and removed from the joint body 2 and externally fitted and mounted on the outer peripheral surface of the joint pipe 1, the insertion port portion 5 of the joint pipe 1 is inserted into the receiving portion of the joint body 2. The bolt 11 and the nut 12 of the push ring 7 must be fastened by inserting into 3 and the disassembling and reassembling are required, so that the connecting work of the pipe joint becomes extremely complicated.

The present applicant has already applied for the technique shown in FIG. 5 disclosed in Japanese Patent Laid-Open No. 07-113487 as a means for solving such complexity. This prior-art technique uses a rubber packing 13 whose diameter is reduced when tightened, so that the inner diameter of the rubber packing 13 is made larger than the outer diameter of the joint pipe 1 in advance, and the temporary assembly is performed. In this state, the joint pipe 1 can be inserted into the rubber packing 13 and the cavity 4 of the joint body 2. The rubber packing 13 has a plurality of annular ridges 1 at a portion that comes into contact with the tapered surface of the receiving portion 3 of the joint body 2.
4 and the annular recess 15 formed between the ridges 14
And are integrally molded. The ridges 14 are provided at regular intervals and in the same direction (horizontal direction) as the axis of the joint pipe 1. In FIG. 5, reference numeral 16 is a spacer made of plastic for holding the gap. The spacer 16 is for preventing the push ring 7 from pushing the rubber packing 13 in the temporarily assembled state, and it is possible to perform the tightening work by the push ring 7 with the spacer 16 attached during assembly. . The spacer 16 is brittlely broken and does not hinder the tightening work.

At the time of fastening, the rubber packing 13 is pushed forward by being pressed and urged by the tip end surface of the push wheel 7, and eventually the ridge 14 having the tapered surface first comes into contact with the inner peripheral surface of the receiving portion of the joint body 2. Become. When the push wheel 7 is tightened further, the ridge 14 is compressed and deformed as shown by the solid line in FIG. As a result, the main body of the rubber packing 13 moves diagonally downward along the taper surface of the tapered receiving portion 3 with the projection 14 as a fulcrum, and the diameter thereof is reduced. next,
The ridge 14 gradually deforms due to compression at that position, and spreads in the space between the tapered receptacle 3 and the rubber packing recess 15. Due to this deformation of the ridges 14, the rubber packing 13 rolls along the tapered surface irrespective of the frictional resistance, as indicated by the arrow in FIG. 7, with the portion in contact with the tapered surface as the fulcrum. Like The rubber packing 13 moves diagonally downward without resistance and further reduces its diameter, so that a large adhesive force with the joint pipe 1 is obtained.

As described above, according to the prior application of the present applicant, the inner diameter of the rubber packing 13 is made larger than the outer diameter of the joint pipe 1, and the members in the joint portion are not disassembled but remain in the temporarily assembled state. By inserting the joining pipe 1 and fastening the bolts 11 and the nuts 12 of the push ring 7, the assembly can be completed, and the connecting work of the entire pipe joint is significantly simplified.

[0009]

However, as shown in FIG. 8, the joint body 2 on the receiving side is composed of the tapered receiving surface 3 and the cylindrical inner diameter portion, and the joint body 2 and the push ring 7 are provided. In the case where there is no plastic ring or the like for fitting the two together, the rubber packing 13 and the push ring 7
There was nothing rigidly held, and the center line of the push ring 7 drooped downward from the center line of the joint body 2, causing a positional shift. Therefore, when the joining pipe 1 is inserted, the joining pipe 1 interferes with the rubber packing 13, which makes it difficult to smoothly insert the joining pipe 1.

Further, when the joining pipe 1 is inserted through the rubber packing 13, as shown in FIG. 9, the push ring 7 comes into contact with the top of the pipe, and a large gap is formed between the push ring 7 and the bottom of the pipe. To be done. Since the inner diameter of the rubber packing 13 is set to be larger than the outer diameter of the tube, the tube comes into contact with the lower inner peripheral surface of the rubber packing 13. The gap between the pipe and the inner peripheral surface of the rubber packing becomes large at the top and disappears at the bottom. As a result, the relationship between the push wheel 7 and the rubber packing 13 is eccentric, and it is difficult to evenly tighten them. If the bolts 11 and the nuts 12 are tightened under such a situation, the contact surfaces of the push ring 7 and the rubber packing 13 will not be uniformly tightened, and for a pipe having a nominal diameter of 75 mm, a light tightening of about 10 N · m will make the pipe and the rubber packing Water pressure from 13 to 2
Water leakage may occur at Mpa, and tightening torque should be 20
There was a drawback that a water pressure of 4 Mpa could not be achieved unless the pressure was Nm or more. Moreover, even when tightened with the same tightening torque of 20 N · m, it was loose enough to be able to be tightened again several days later, and water leakage could occur even at a water pressure of 3 MPa.
On the other hand, if it is tightened too much, the rubber packing may protrude into the larger gap, and the pipe may be inclined with respect to the joint body 2 even if the pipe is a straight pipe.

Further, even when the joint pipe 1 is inclined with respect to the joint body 2, when the pipe is deformed, or when the tapered portion 3 of the joint body portion 2 is deformed,
If the bolts 11 and the nuts 12 are tightened and the rubber packing 13 is compressed by the push ring 7, uneven portions are likely to be formed in the compression, and even a slight tightening may cause insufficient tightening and water leakage may occur. It was

Furthermore, in the case of a union nut, this method is adopted for a relatively small diameter of 40 mm.
As shown in FIG. 10, the joint body 2 and the union nut 17
In addition to these members, a rubber packing 13 having an inner diameter larger than the outer diameter of the pipe,
Teflon (Teflon is a registered trademark of DuPont) Film 3
It is composed of 1 and 1. Rubber packing 1 with a small tightening force
3 has a structure in which the diameter of 3 is reduced and then compressed. However, the nominal diameter is 20m
If it is about m, it will have a water tightness of 2 Mpa by hand tightening, but if it has a nominal diameter of 40 mm, it will leak water by about 0.5 Mpa by hand tightening. After several days, the rubber packing 13 was loosened and could be tightened further by hand, causing water leakage due to low water pressure. Normal water pipe water pressure is 0.
Although it is 75 Mpa, it is necessary to re-tighten it with a pipe wrench or the like for safety first, and thus the piping work becomes a heavy labor.

[0013]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems of the prior art and has been improved and removed. Even in a temporarily assembled state, the push ring, the rubber packing, and the joint body receiving opening are misaligned. Structure that does not cause pipe insertion and does not hinder pipe insertion, and even for pipes that are inclined or deformed with respect to the joint body, water leakage can be done with a light work by simply tightening lightly. An object of the present invention is to provide a rubber packing that can obtain a joint structure that does not occur.

In order to solve the above-mentioned problems, the means of claim 1 adopted by the present invention is to insert a threadless joint pipe into a pipe or a joint body having a tapered receiving portion, and press the ring. Or, in a rubber packing for pipe fittings, in which an annular rubber packing is inserted and inserted into the pipe or fitting body by tightening means such as a union nut to seal the pipe, the portion of the rubber packing that comes into contact with the pipe or the tapered receiving surface of the fitting body. A plurality of annular ridges and projections are provided along the tapered surface of the receiving surface and in the same direction as the axis of the pipe, and a plurality of annular ridges are provided on the entire inner peripheral surface side of the rubber packing. The rubber packing for a pipe joint is characterized in that the inner diameter of the ridge is made larger than the outer diameter of the pipe.

In the rubber packing of the present invention, the tapered surface of the pipe receiving portion can be rolled by the annular concave-convex ridges in the portion which comes into contact with the receiving surface so that the diameter can be greatly reduced. Can be larger than the outer diameter of
Easy tube insertion work. Further, an annular concave-convex ridge is provided on the entire inner peripheral surface side of the rubber packing, and the tip end of the convex ridge is pressed against the outer circumference of the pipe to be deformed when the diameter of the rubber packing is reduced. During the fastening process, the length of the rubber packing becomes shorter in the axial direction of the pipe socket and the push ring or the union nut.The compression deformation part of the ridge rolls at the part where the pipe contacts and the entire rubber packing is compressed without resistance. It Since the rubber packing does not have internal strain, the phenomenon of slackening over time also disappears. The same applies to a pipe that is inclined with respect to the joint body or a deformed pipe.

Comparing this with the prior art, in the case of the structure in which the entire inner peripheral surface of the rubber packing is pressed against the outer peripheral surface of the tube as in the prior art, the rubber packing and the outer peripheral surface of the tube are lightly tightened during the diameter reduction process. At the stage of contact, it suddenly becomes difficult to tighten. This is because the rubber packing has a function of making it difficult to shorten due to frictional resistance between the rubber packing and the outer peripheral surface of the pipe in the process of shortening the length of the pipe receiving port and the push ring or the union nut in the pipe axial direction. However, the frictional resistance decreases with the passage of time, and the inner peripheral surface of the rubber packing and the outer peripheral surface of the pipe gradually slide out, causing a phenomenon in which the entire rubber packing is loosened. Therefore,
There was a drawback that water leakage would occur at a later date unless tightened considerably. In the case of a pipe that is inclined or deformed with respect to the joint body, friction resistance suddenly occurs on a part of the rubber packing on the outer peripheral surface, causing unevenness on the outer peripheral surface. Sometimes there was a lack of compression. In the present invention, as described above, such a thing does not occur.

According to a second aspect of the present invention, in addition to the configuration of the first aspect of the invention, a positioning rib externally fitted and mounted on the outer peripheral surface side of the pressing wheel is provided on the outer peripheral side of the portion contacting the pressing wheel. ing. The positioning ribs allow the entire rubber packing to be externally fitted and held on the push ring, and the center position thereof does not deviate. Therefore, the joining pipe can be smoothly inserted into the rubber packing. Further, in the inserted state, the pipe comes into contact with the lower inner peripheral surface of the rubber packing. The gap between the pipe and the inner peripheral surface of the rubber packing becomes larger at the upper side and disappears at the lower side. However, the relationship between the push ring and the rubber packing is such that it can be tightened uniformly over the entire circumference, and the contact surfaces of the push ring and the rubber packing are tightened uniformly during the tightening process with the bolts and nuts, and the ridges on the entire inner surface of the rubber packing are The compressive deformation part of the part rolls at the part that contacts the pipe,
The entire rubber packing is compressed without resistance, pushing up the pipe and making the upper and lower gaps uniform with a light tightening force. Therefore, excellent water-tightness with good balance can be secured over the entire circumference.

Further, according to the invention of claim 3, an annular concave-convex strip is provided at a portion of the rubber packing which comes into contact with the tapered receiving surface of the pipe or the joint main body along the tapered surface of the receiving surface and the pipe. In addition to providing multiple protrusions in the same direction as the axis,
Positioning ribs that are externally fitted and mounted on the outer peripheral surface side of the pressing wheel are provided on the outer peripheral side of the portion that contacts the pressing wheel. Therefore, also in the case of the present invention, the effect of the positioning rib of the second aspect is exhibited, and the joining pipe can be smoothly inserted.

[0019]

BEST MODE FOR CARRYING OUT THE INVENTION The structure of the present invention will be described below with reference to the embodiments shown in the drawings. In addition,
The same reference numerals as those of the conventional one are the same members. FIG. 1 shows the first of the present invention.
3 is a semi-longitudinal sectional view of the pipe joint according to the embodiment of FIG. As shown in the figure, in this embodiment, the rubber packing 2
An annular rib 21 for positioning is formed so as to project in the same direction as the axis on the outer peripheral surface side of the portion of the contacting member 0 that contacts the push wheel 7. Further, a plurality of annular projections 22 and recesses 23 are alternately provided on the entire inner peripheral surface side of the rubber packing 20. The concave line 23 is a compression deformation space region of the convex line 22. Ridge 2
2 shows that the relation between the width W and the height H of the root of the convex portion is H> 1/2
It is W. The reason for limiting to this dimensional relationship is that when H is not sufficient to be 1/2 W, the height dimension and deformation area of the ridge 22 necessary for rolling the pipe outer peripheral surface when the ridge 22 is compressed and deformed. Cannot be secured, and the ridge 22 slides on the outer peripheral surface of the pipe with frictional resistance, and the rubber packing 20
This is because an internal strain is generated in the steel sheet, which is gradually released (creep phenomenon) with the lapse of time to generate slack, which causes water leakage. That is, the dimensional relationship of H> 1 / 2W is as shown in FIGS. 6 and 7 in which the ridge 22 does not cause internal strain in the rubber packing 20 between the inner peripheral surface of the rubber packing 20 and the outer peripheral surface of the pipe. It is for ensuring the height dimension for obtaining the rolling action. Further, a plurality of annular ridges 14 and annular recesses 15 formed between the ridges 14 are alternately provided at a portion of the rubber packing 20 that comes into contact with the tapered surface of the receiving portion 3 of the joint body 2. Moreover, it is provided by integral molding. The ridges 14 are provided at regular intervals and in the same direction (horizontal direction) as the axis of the joint pipe 1. Further, the inner diameter of the ridge 22 of the rubber packing 20 is set to be slightly larger than the outer diameter of the joint pipe 1.

In the pipe joint constructed as described above,
The tip end side of the rubber packing 20 is fitted into the tapered receiving portion 3 of the joint body 2 and fitted therein. In addition, in the pushing portion 7a of the push wheel 7,
The rubber packing 20 is joined to the rear end side thereof, and the annular rib 21 thereof is externally fitted and attached to the pressing portion 7a, so that the rubber packing 20 is held by the pressing wheel 7. And bolt 11
And the nut 12 is shipped from the factory as a set of pipe fittings in a temporarily tightened state. That is, the entire pipe joint is temporarily assembled and shipped from the factory.
In this temporary assembled state, the rubber packing 20 is externally fitted to and held by the pushing portion 7a of the pushing wheel 7 via the rib 21, so that the center position of the rubber packing 20 is at the center of the joint body 2.
Aligns with the axis line of and does not cause misalignment.

Next, as shown in FIG. 1, from this state, the rubber packing which is inserted through the insertion opening 5 of the joining pipe 1 into the push ring 7 and is retained in the receiving opening 3 of the joint body 2 by internal fitting. It penetrates through 20 and interposes in the cavity 4 of the receiving part 3.
In this case, as described above, the ridges 22 of the rubber packing 20 are
The inner diameter of is set larger than the outer diameter of the joint pipe 1,
Further, since the rib 21 of the rubber packing 20 is fitted onto the pushing portion 7a of the pushing wheel 7 and held by the rib 21 so as not to cause misalignment, the insertion work of the joining pipe 1 is performed in the state of the rubber packing 20. Can be easily performed even if it is not visible from the outside. Finally, push ring 7 to bolt 1
1 and the nut 12 are fastened together.

At the time of this fastening, in the rubber packing 20 which is pressed and urged by the push ring 7, the ridge 14 which comes into contact with the tapered surface of the receiving portion 3 of the joint body 2 is compressed and the rubber packing 20 of FIG. The main body of the rubber packing 20 is deformed as shown by the solid line, and the whole of the rubber packing 20 is uniformly slanted downwardly along the taper surface of the receiving portion 3 with the ridge 14 as a fulcrum to reduce the diameter. Like Due to this reduction in diameter, the ridge 22 of the rubber packing 20 comes into contact with the outer peripheral surface of the joint pipe 1.

When the pressing wheel 7 is further tightened, the rubber packing 20 has a frictional resistance as shown by an arrow in FIG. 7 with the portion in contact with the tapered surface of the receiving portion 3 as a fulcrum. Will roll along the taper surface regardless. As a result, the entire rubber packing 20 moves diagonally downward without resistance and further reduces its diameter. Due to the uniform diameter-reducing operation of the entire rubber packing 20, the adhesive force between the rubber packing 20 and the joint pipe 1 is remarkably increased, and excellent water tightness and pipe holding power are exhibited. In addition,
When the push wheel 7 is further tightened from this state, the bottom surface of the recess 15 of the rubber packing 20 is joined to the tapered receptacle 3 as shown in FIG. After that, the entire rubber packing 20 is deformed by the compression, and the adhesion force with the joint pipe 1 is further increased.

The rubber packing 20 is closely attached to the joint pipe 1 by a plurality of annular projections 22 provided on the entire inner peripheral surface side of the rubber packing 13. The tip of the ridge 22 is pressed against the outer peripheral surface of the pipe when the rubber packing 13 is reduced in diameter,
It is compressed and deformed in the space area of the groove 23. Then, in the process of tightening, the rubber packing 13 causes the distance between the pipe receiving port 3 and the push ring 7 to shrink, so that the compressive deformation portion of the ridge 22 is the joint pipe 1.
The compression deforming portion rolls at the portion in contact with, and the entire rubber packing 13 is compressed without resistance. Comparing this with the prior art, in the case of the structure in which the entire inner peripheral surface of the rubber packing 13 is pressed against the outer peripheral surface of the pipe as in the prior art, the rubber packing 13 and the outer peripheral surface of the pipe are slightly tightened during the diameter reduction process. At the stage of contact, it suddenly becomes difficult to tighten. This is because the rubber packing 13 has a function of making it difficult to shorten due to the friction resistance between the rubber packing 13 and the outer peripheral surface of the pipe in the process of shortening the distance between the pipe receiving port 3 and the push ring 7 in the pipe axial direction. However, the frictional resistance decreases with the passage of time, and the rubber packing 13
The inner peripheral surface and the outer peripheral surface of the pipe gradually slide out, and the rubber packing 13
The phenomenon that the whole loosens occurs. Therefore, there is a drawback that water leakage will occur at a later date unless it is tightened considerably. In this embodiment, as described above, this is not the case.

FIG. 2 relates to the second embodiment of the present invention. In this embodiment, a rubber packing 20 is tightened using a union nut 17, a male screw 18 is engraved on the outer peripheral surface of the joint body 2, and a female screw 19 is formed on the inner peripheral surface of the union nut 17. It is engraved. Teflon is placed between the union nut 17 and the rubber packing 20.
(Teflon is a registered trademark of DuPont) There is a lubricating member such as a film 31 so that the diameter of the rubber packing 20 can be smoothly reduced. The rubber packing 20 and other configurations, functions and effects are the same as in the case of the first embodiment. In the case of this union nut 17,
With a nominal diameter of 40 mm, the watertightness is 4 MPa or more when tightened by hand, the rubber packing 20 does not loosen over time and continues to maintain 4 MPa, and the actual water pressure is 0.75 MPa. From now on, it is no longer necessary to re-tighten with a large pipe wrench, and the work of joining pipe joints is now free from heavy labor.

FIG. 3 relates to the third embodiment of the present invention. In this embodiment, the rubber packing 2
An annular concave-convex strip 14 is provided on the front side portion facing the side of the taper-shaped receiving portion 3 of 0, and an annular rib 21 for positioning is formed on the rear outer peripheral surface side of the rubber packing 20 in contact with the push ring 7 as an axis line. The protrusions are formed in the same direction. Rubber packing 2
No. 0 has its ribs 21 fitted onto the pushing portion 7a of the pushing wheel 7 and held by the pushing portion 7a so as not to cause misalignment. Therefore, when the joining pipe 1 is inserted, the state of the rubber packing 20 is applied from the outside. It can be easily performed without visual inspection. Further, the rubber packing 2 of the push ring 7 can be tightened even further.
Since the distance between the end face that contacts 0 and the receiving end face of the joint body 2 is uniform in the entire circumferential direction, the rubber packing 20 does not protrude partially.
The pipe 1 is not inclined with respect to the joint body 2.

[0027]

As described above, according to the present invention,
A plurality of annular ridges and ridges are provided at a portion of the rubber packing which comes into contact with the tapered receiving surface of the joint body along the tapered surface of the receiving surface and in the same direction as the axis of the pipe. A plurality of annular ridges are provided on the inner peripheral surface side of the rubber packing, and the inner diameter of the ridge is made larger than the outer diameter of the pipe. The rubber packing can be greatly reduced in diameter by the annular ridge and groove on the part that comes into contact with the receiving surface, and the inner diameter of the rubber packing can be made larger than the outer diameter of the insertion tube. Is easy. Also, an annular convex strip is provided on the inner peripheral surface side of the rubber packing, and the tip side of the convex strip is pressed against the outer peripheral surface of the pipe, so compare with the case where the entire inner peripheral surface of the rubber packing is pressed against the outer peripheral surface of the pipe. Even with a much smaller tightening force, the multiple annular projections on the entire inner surface of the rubber packing compressively deform in the annular recess and roll on the outer surface of the tube, eliminating resistance to the tube and the entire rubber packing. Compresses effectively without causing internal distortion. Furthermore, since the tips of the multiple annular ridges on the inner peripheral surface of the rubber packing are compression-deformed into an annular shape, when the pipe is deformed or when the pipe is connected to the joint body at an angle. However, it has a great watertightness. For example, in the case of a pipe with a nominal diameter of 75 mm having a push ring structure, there is watertightness of 4 Mpa or more with a tightening force of about 5 N · m. Moreover, the rubber packing did not loosen, and the watertightness of 4 MPa or more was maintained even after several days. Further, in the case of a pipe having a nominal diameter of 40 mm with a union nut structure, the water pressure was 4 MPa or more when manually tightened, the rubber packing did not loosen, it was not necessary to re-tighten it later, and tools such as a pipe wrench were also unnecessary.

Further, according to the present invention, a portion of the rubber packing pipe or a portion of the joint body which is in contact with the tapered receiving surface is
A plurality of annular ridges and projections are provided along the tapered surface of the receiving surface and in the same direction as the axis of the pipe so as to protrude, and are fitted on the outer peripheral surface side of the pressing ring on the outer peripheral side of the portion in contact with the pressing ring. The positioning rib to be mounted is provided. Thus, in the present invention, the rib for positioning the rubber packing is externally fitted to and held by the tightening means such as the push ring even in the temporary assembled state, so that the center position of the rib does not deviate. Absent. Therefore, the joint pipe can be smoothly inserted. Also, since the push ring is tightened in the proper position with respect to the rubber packing, the gap between the pipe outer peripheral surface and the joint body will be uniform on the circumference even if it is tightened too much, so the rubber packing will not stick out to one side and On the other hand, there is no longer any need to incline and connect the pipe.

[Brief description of drawings]

FIG. 1 is a partial vertical sectional view of a pipe joint according to a first embodiment of the present invention.

FIG. 2 is a partial vertical sectional view of a pipe joint according to a second embodiment of the present invention.

FIG. 3 is a partial vertical sectional view of a pipe joint according to a third embodiment of the present invention.

FIG. 4 is a partial vertical sectional view showing a conventional pipe joint.

FIG. 5 is a partial vertical cross-sectional view showing a pipe joint according to the prior art.

FIG. 6 is a partially enlarged vertical cross-sectional view for explaining the deformation and diameter reducing action of the rubber packing of the prior application technology due to compression.

FIG. 7 is a partially enlarged vertical cross-sectional view for explaining the deformation and the diameter reducing action of the rubber packing of the prior application technology due to compression.

FIG. 8 is a partial vertical sectional view of a pipe joint according to another conventional technique.

9 is a partial vertical cross-sectional view of a conventional pipe joint showing a state in which a pipe is further inserted from the state of FIG.

FIG. 10 is a partial vertical sectional view of a conventional union nut joint.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Joining pipe, 2 ... Joint body, 3 ... Receptacle part, 4 ... Cavity, 7
... push ring, 14 ... rubber packing ridge, 15 ... rubber packing recess, 17 ... union nut, 20 ... rubber packing, 21 ... rib, 22 ... bellows

Claims (3)

[Claims] 1. A screwless joining pipe is inserted into a pipe or a joint body having a tapered receiving portion, and an annular rubber packing is inserted into the pipe or the joint body by tightening means such as a push ring or a union nut. In a rubber packing for a pipe joint that seals as little as possible, an annular concave-convex strip is provided along the tapered surface of the receiving surface and at the portion of the rubber packing that comes into contact with the tapered receiving surface of the pipe or the joint body. A pipe joint characterized in that a plurality of protrusions are provided in the same direction as the above, and a plurality of annular uneven ridges are provided on the entire inner peripheral surface side of the rubber packing, and the inner diameter of the ridge is made larger than the outer diameter of the pipe. Rubber packing. 2. A pipe joint in which a threadless joint pipe is inserted into a pipe or a joint body having a tapered receiving portion, and an annular rubber packing is inserted into the pipe or the joint body by a push ring to seal the pipe or joint body. In the rubber packing, at the part that comes into contact with the pipe of the rubber packing or the tapered receiving surface of the joint body,
A plurality of annular ridges and ridges are provided along the tapered surface of the receiving surface in the same direction as the axis of the pipe so as to project, and a plurality of annular ridges are provided on the entire inner peripheral surface of the rubber packing.
A pipe joint characterized in that an inner diameter of the ridge is made larger than an outer diameter of the pipe, and a positioning rib to be externally fitted and attached to an outer peripheral surface side of the push ring is provided on an outer peripheral side of a portion contacting the push ring. Rubber packing. 3. A pipe joint in which a threadless joint pipe is inserted into a pipe or a joint body having a tapered receiving portion, and an annular rubber packing is inserted into the pipe or the joint body by a push ring to seal the pipe or joint body. In the rubber packing, at the part that comes into contact with the pipe of the rubber packing or the tapered receiving surface of the joint body,
A plurality of annular ridges and projections are provided along the tapered surface of the receiving surface and in the same direction as the axis of the pipe so as to protrude, and are fitted on the outer peripheral surface side of the pressing ring on the outer peripheral side of the portion in contact with the pressing ring. A rubber packing for pipe fittings, which is provided with a positioning rib to be mounted.