JP3731908B2 - Pipe end anti-corrosion fitting - Google Patents

Description

[0001]
[Industrial application fields]
The present invention relates to a pipe end anticorrosion joint used in a piping system for water supply.
[0002]
[Prior art]
In the piping system currently in widespread use, the inner surface of a steel pipe is used as a tubular body as a synthetic resin lining layer in order to prevent deterioration of water quality due to rusting on the inner surface of the tubular body used in piping and at the connecting portion. In addition to the use of the inner surface coated steel pipe coated with, a pipe end anticorrosion joint is used for the connecting portion.
[0003]
And what was disclosed by Unexamined-Japanese-Patent No. 1-111492 is known as a conventional pipe end anti-corrosion joint, and this pipe end anti-corrosion joint is shown in FIG. 7 and FIG. As shown in FIG. 8, this pipe end anticorrosion joint is provided with a sleeve portion 3 made of a synthetic resin inside a joint body 1 having a tapered inner screw 2. The sleeve portion 3 is fixed to the joint body 1 by screwing a flange portion integrally provided at a base end portion thereof with a predetermined portion of the taper inner screw 2. Further, an annular lip portion (integrated with the same kind of synthetic resin as the sleeve portion 3) 5 is integrally provided on the outer peripheral surface of the sleeve portion 3 in the vicinity of the tip portion. A ring-shaped sealing material 8 having elasticity is held in a fitting manner in an annular recess 7 provided adjacent to the outside of the root portion of the portion 5.
[0004]
In such a pipe end anti-corrosion joint, an O-ring made of synthetic rubber is used as the sealing material 8. When the inner surface coated steel pipe 100 is screwed into the joint body 1 and the sleeve portion 3 is gradually fitted into the inner surface coated steel pipe 100 as indicated by an arrow a in FIG. The seal material 8 comes into pressure contact, and the seal material 8 is gradually deformed while being elastically backed up by the lip portion 5 having elasticity. And in the state which screwed the inner surface covering steel pipe 100 completely like the figure, the sealing material 8 will be in the state crushed, backed up by the lip | rip part 5 which bent inward. Therefore, the sealing material 8 is strongly pressed against the inner surface 102 of the inner surface-coated steel pipe 100 by the restoring force due to its own elasticity and the backup force due to the elasticity of the lip portion 5, and in some cases, the lip portion 5 also has its The outer peripheral portion is in pressure contact with the inner surface 102, and the watertightness of the portion is reliably maintained.
[0005]
[Problems to be solved by the invention]
In the conventional pipe end anticorrosion joint described above, the lip portion 5 prevents the sealing material 8 that presses against the inner surface 102 of the inner surface coated steel tube 100 screwed into the joint body 1 from following the inner surface coated steel tube 100 and moving backward. The function of backing up the sealing material 8 with the restoring force associated with its own elasticity and making the sealing material 8 press strongly against the inner surface 102 of the inner surface-coated steel pipe 100 to reliably exert the watertightness maintaining function by the sealing material 8 have. Therefore, the lip portion 5 itself is not necessarily required to have a function of maintaining watertightness.
[0006]
By the way, in the conventional pipe end anticorrosive joint, when the inner surface coated steel pipe 100 is screwed into the joint body 1, the outer peripheral surface of the sealing material 8 is in close contact with the inner surface 102 of the inner surface coated steel pipe 100 and rubs in the circumferential direction. On the other hand, the seal material 8 is backed up by the lip portion 5 so as not to be retracted while being forced to push in the direction. For this reason, the extending portion of the sealing material 8 that is pressed in the axial direction while being in close contact with the inner surface 102 of the inner surface coated steel pipe 100 and rubbing in the circumferential direction is extended so as to deform its cross-sectional shape. It cannot be said that there is no risk of overcoming the outer periphery of the lip portion 5 or, in some cases, causing a part of the sealing material 8 over the outer periphery of the lip portion 5 to be torn off. In such a situation, when there is variation within the tolerance range in the thickness of the coating layer of the inner surface coated steel pipe 100, the taper outer screw 103 formed on the inner surface coated steel pipe 100 or the taper inner screw 2 of the joint body 1 is within the tolerance range. This is likely to occur when there is eccentricity. And if such a situation may occur, even if the sealing material 8 is backed up by the lip part 5, it is inevitable that the reliability of the watertightness maintaining function by the sealing material 8 is lowered. .
[0007]
The present invention has been made under the above circumstances. When a tubular body such as an inner surface coated steel pipe is screwed into a joint body, a sealing material such as an O-ring is brought into close contact with the inner surface of the tubular body in the circumferential direction. In addition to taking measures to prevent accidental pushing in the axial direction while rubbing with each other, even if such measures are taken, the inner surface of the tube and the synthetic resin fitted inside the tube are made To provide a pipe end anti-corrosion joint that can reliably keep the gap between the sleeve part watertight, prevent water from entering the pipe end, and reliably prevent rusting of the pipe end due to water adhesion. Objective.
[0008]
[Means for Solving the Problems]
The pipe end anti-corrosion joint according to the present invention is a pipe end anti-corrosion joint in which a joint body into which a pipe body is screwed and a synthetic resin sleeve part fitted into the pipe body is provided. A flexible annular sealing lip portion made of synthetic resin is integrally provided on the surface, and a resilient backup material is positioned on the sleeve portion adjacent to the inside of the root portion of the lip portion. And the lip portion projects radially outward from the outer peripheral surface of the backup material, and the protruding length from the outer peripheral surface of the backup material at the lip portion is By contacting the inner surface of the pipe body that has been screwed into the joint body and following the lip portion, the backup material can be crushed and covered inward while collapsing the backup material. And since has, of, between the inner surface and the sleeve portion of the tubular body by lip fell dramatically to a state of covering the backup material is in close contact with the inner surface of the tube body in a state of being backed up by the backup material The water-tightness of the gap is maintained , and the backup material is configured to be in a non-contact state with the inner surface of the tubular body.
[0009]
[Action]
According to the pipe end anticorrosion joint according to the present invention, when the pipe body is screwed into the joint main body, the outer peripheral surface of the synthetic resin-made flexible sealing lip that is in contact with the inner face of the pipe body is the inner surface of the pipe body. By being pushed in the axial direction while rubbing against each other in the circumferential direction, the tube body falls down and deforms. Here, since the sealing lip portion is made of a synthetic resin provided integrally with a synthetic resin sleeve portion, the inner surface of the tubular body can be used even if the sealing lip portion is in close contact with the inner surface of the tubular body. The sliding resistance when rubbing against each other is small, and the situation in which the sealing lip is stretched in the axial direction while being in close contact with the inner surface of the tube does not occur. Then, when the sealing lip portion falls down and deforms following the tube body, the sealing lip portion crushes the elastic backup material disposed adjacent to the inside of the root portion, and the backup material. Cover and fall inward. For this reason, the sealing lip portion is in close contact with the inner surface of the tube body while being backed up by the backup material, and the watertightness of the gap between the inner surface of the tube body and the sleeve portion is maintained.
[0010]
【Example】
FIG. 1 is a partial sectional view of a pipe end anticorrosion joint according to an embodiment of the present invention. In this pipe end anticorrosion joint, a tapered internal thread 2 is provided at the end of the joint body 1 and a synthetic resin sleeve 3 is provided concentrically with the tapered internal thread 2 inside the joint body 1. This is the same as the conventional pipe end anticorrosion joint described in FIG.
[0011]
In the pipe end anticorrosion joint of FIG. 1, the sleeve portion 3 is integrally formed of a synthetic resin such as polyvinyl chloride, and a flexible annular sealing lip portion 9 is formed on the outer peripheral surface of the sleeve portion 3 in the vicinity of the tip portion. Are provided integrally. The sealing lip portion 9 is made of the same type of synthetic resin as the sleeve portion 3 and is integrally formed with the sleeve portion 3. When a synthetic resin such as polyvinyl chloride resin is used as the molding material, the sealing lip portion 9 Since it is thin, it has a certain flexibility. The sealing lip portion 9 in the illustrated example has a thin bowl-shaped cross-sectional shape, but the cross-sectional shape of the lip portion 9 is not limited to this. In other words, the sealing lip portion 9 may be bent inward and may have a cross-sectional shape that does not break or break even if bent.
[0012]
In the sleeve portion 3, an annular groove portion 11 is provided adjacent to the inside of the root portion of the sealing lip portion 9, and a backup material 12 having elasticity such as a rubber O-ring is provided in the annular groove portion 11. The back-up material 12 is positioned on the sleeve portion 3 by the annular groove portion 11 while being held in a fitted state. The axial width of the backup material 12 may be shorter than or equal to the groove width of the annular groove 11, but when the backup groove 12 is crushed by the fall of a sealing lip 9 described later, the annular groove 11 It is preferable that it can be closed. In the illustrated example, since the annular protrusion 13 is provided inside the annular groove portion 11, when the backup material 12 is crushed by the fall of the sealing lip portion 9, the annular groove portion of the backup material 12 is caused by the annular protrusion 13. The protrusion from 11 is prevented.
[0013]
As shown in detail in FIG. 2, the sealing lip portion 9 protrudes radially outward from the outer peripheral surface of the sleeve portion 3 by the dimension H1, whereas the backup material fitted and held in the annular groove portion 11 is used. 12 projects from the outer peripheral surface of the sleeve portion 3 outward in the radial direction by a dimension H2 (H2 <H1). The difference (H1−H2) between the protruding dimension H1 of the sealing lip portion 9 and the protruding dimension H2 of the backup material 12, that is, the protruding length H from the outer peripheral surface 12a of the backup material 12 in the sealing lip portion 9 However, when the lip portion 9 follows the inner surface 102 of the tube body 100 that has been screwed into the joint body 1, the backup material 12 is crushed and covers the backup material 12 and falls inward. (See FIGS. 3 and 4).
[0014]
Next, the sleeve portion 3 is reinforced at its full length in the axial direction by an axially extending rib portion 14 provided integrally with the sleeve portion 3. The rib portions 14 are provided in a bulging shape at a plurality of locations in the circumferential direction of the inner peripheral surface of the sleeve portion 3. If the rib portions 14 are provided over the entire length in the axial direction of the sleeve portion 3 in this way, the sleeve portion 3 is fitted inside a tubular body (for example, an inner surface-coated steel pipe 100 described later), and the lip portion 9 is formed. This prevents the thin annular groove 11 in the sleeve 3 from being pushed inward and deformed inwardly when the back-up material 12 backs up the lip 9 while being pressed against the inner surface of the tube. Is done. In addition, the inner peripheral surface of the sleeve portion 3 is a tapered surface 15 that is widened in the vicinity of the tip portion.
[0015]
When the inner surface coated steel pipe 100 is screwed into the joint body 1 of the pipe end anticorrosion joint of FIG. 1 and the sleeve portion 3 is gradually fitted into the inner surface coated steel pipe 100, it can be inferred from FIG. As described above, the outer peripheral surface of the sealing lip portion 9 in contact with the inner surface 102 of the inner surface coated steel pipe 100 is pushed in the axial direction while rubbing against the inner surface 102 of the inner surface coated steel tube 100 in the circumferential direction. As a result, the sealing lip portion 9 follows the inner surface coated steel pipe 100 and falls inward and deforms, and the backup material 12 is gradually crushed against its own elasticity along with the falling deformation. In this case, since the sealing lip portion 9 is made of synthetic resin, the sliding resistance when the inner surface 102 of the inner surface coated steel pipe 100 and the sealing lip portion 9 rub against each other is small. There is no situation in which it is stretched in the axial direction while being in close contact with the inner surface 102 of 100.
[0016]
As shown in FIGS. 3 and 4, in the state where the inner surface coated steel pipe 100 is completely screwed into the joint body 1, the sealing lip portion 9 that has fallen and deformed following the inner surface coated steel pipe 100 crushes the backup material 12 to form an annular shape. The groove 11 is filled with the backup material 12, and the backup material 12 is covered from the outside by the sealing lip portion 9. Therefore, the sealing lip portion 9 is in close contact with the inner surface 102 of the inner surface coated steel pipe 100 in a state where it is backed up by the backup material 12, and the watertight state of the gap between the inner surface 102 of the inner surface coated steel tube 100 and the sleeve portion 3 is ensured. Therefore, there is no possibility that water will enter the remaining screw portion 2a of the taper inner screw 2 on the pipe end 101 or the joint body 1 side through the gap and rust them.
[0017]
By the way, the backup material 12 merely has a function of elastically supporting the sealing lip portion 9 from the back side and strongly pressing the sealing lip portion 9 against the inner surface 102 of the inner surface coated steel pipe 100. In general, even if an O-ring used as a sealing material is used, the backup material 12 does not need to be in contact with the inner surface 102 of the inner surface coated steel pipe 100. Therefore, there is no room for the O-ring used for the backup material 12 to be extended or torn off.
[0018]
The embodiment shown in FIG. 5 and FIG. 6 is different from that of FIG. 1 only in the cross-sectional shape of the backup material 12, and the other configurations and operations are the same as those in FIG. That is, the cross-sectional shape of the backup material 12 used in the embodiment of FIG. 1 is circular, whereas the cross-sectional shape of the backup material 12 used in the embodiment of FIG. The cross-sectional shape of the backup material 12 used in the embodiment of FIG. 7 is a cannonball shape. The cross-sectional shape of the backup material 12 may be a shape other than the illustrated example. 5 and 6, the same parts as those in FIG. 1 are denoted by the same reference numerals, and detailed description thereof is omitted.
[0019]
【The invention's effect】
According to the pipe end anticorrosion joint of the present invention, the seal lip portion backed up by the elasticity of the backup material contacts the inner surface of the tube screwed into the joint body, and the gap between the inner surface of the tube body and the sleeve portion is in a watertight state. Therefore, water does not enter through the gap to the end of the pipe and a reliable pipe end anti-corrosion effect is exhibited.
[0020]
Further, according to the pipe end anticorrosion joint according to the present invention, when the pipe body is screwed into the joint main body, the flexible sealing lip portion made of synthetic resin provided on the sleeve portion of the joint main body is provided with the pipe body. It contacts the inner surface, and the outer peripheral surface of the sealing lip portion is pushed in the axial direction while rubbing against the inner surface of the tube body in the circumferential direction, and falls down and deforms following the tube body. In this case, since the sealing lip portion is made of a synthetic resin integrally provided on the synthetic resin sleeve portion, the inner surface of the tubular body can be used even if the sealing lip portion is in close contact with the inner surface of the tubular body. The sliding resistance when rubbing against each other is small, and the situation where the sealing lip sticks to the inner surface of the tube body and extends in the axial direction does not occur. Even if a rubber ring such as an O-ring is used as the backup material, the backup material is covered with the sealing lip portion that has fallen and deformed as described above, so that the backup material rubs against the inner surface of the tube body. There is no room for a situation such as being stretched or torn. Therefore, pipe end anticorrosion reliability is increased.
[Brief description of the drawings]
FIG. 1 is a partial sectional view of a pipe end anticorrosion joint according to an embodiment of the present invention.
FIG. 2 is an enlarged cross-sectional view of a portion II in FIG.
3 is a partial cross-sectional view showing a use state of the pipe end anti-corrosion joint of FIG. 1. FIG.
4 is an enlarged cross-sectional view of a portion IV in FIG.
FIG. 5 is a partial cross-sectional view of a pipe end anticorrosion joint employing a backup material according to a modification.
FIG. 6 is a partial cross-sectional view of a pipe end anticorrosion joint employing a backup material according to another modification.
FIG. 7 is a partial cross-sectional view showing a conventional pipe end anticorrosion joint.
8 is a partial cross-sectional view showing a use state of the pipe end anti-corrosion joint of FIG. 8. FIG.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Joint body 3 Sleeve part 9 Sealing lip part 12 Backup material 12a Outer peripheral surface of backup material 14 Rib part 15 Tapered taper surface 100 Inner surface coated steel pipe (tube)
102 Inner surface of inner surface coated steel pipe H Projection length from outer peripheral surface of backup material at lip part for seal

Claims (1)

In the pipe end anti-corrosion joint, in which the synthetic resin sleeve portion fitted into the pipe body is provided in the joint body into which the pipe body is screwed.
A flexible annular sealing lip portion made of synthetic resin is integrally provided on the outer peripheral surface of the sleeve portion, and a backup material having elasticity adjacent to the inside of the root portion of the lip portion is the sleeve portion. The lip portion projects outward in the radial direction from the outer peripheral surface of the backup material, and the lip portion projects from the outer peripheral surface of the backup material. The projecting length is a length that can contact the inner surface of the tube that has been screwed into the joint body and fall down inward while covering the backup material while crushing the backup material by following the lip portion. And the lip part that has fallen into a state of covering the backup material is backed up by the backup material on the inner surface of the tube body. With watertight the gap between the inner surface and the sleeve portion of the tube is maintained by Chakusuru, the backup material is characterized by being configured so as to be non-contact state with the inner surface of the tube Pipe end anticorrosion joint.

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