JP3855170B2 - Water pipe fitting device - Google Patents

Description

  The present invention aims to reduce manufacturing costs, prevent electric corrosion, and is excellent in rotation in the circumferential direction during piping, rotation stop after piping construction, and ensuring water tightness. It is about.

  Conventionally, water pipes and sprinkler unwinding pipes are piped using various joint members such as nipples and cap nuts.

For example, as shown in FIG. 7 , the sprinkler unwinding pipe is made of a fire fighting pipe 1 piped on the back side of the ceiling A and a sprinkler head 2 mounted on the ceiling A with a stainless steel having a bellows part 3 b. It connects with the flexible steel pipe 3 etc. like a steel pipe . At the time of piping, an insulating member 4 is attached to a tubular body 3a on the sprinkler head 2 side such as a flexible steel pipe 3, the portion of the insulating member 4 is clamped by a mounting bracket 5, and the mounting bracket 5 is further attached to the back surface of the ceiling A. It is attached to a fixing member 6 disposed on the side.

  Thereby, insulation with respect to the tube body 3a is ensured, and stray current (leakage current, etc.) generated in the building and electric contact due to a potential difference generated between different metals from the tube body 3a are prevented.

In addition, a joint structure in which a nipple 8 is combined with the straight pipe portion 3c at the end of the pipe body 3a with respect to the branch joint portion 7 provided in the firefighting pipe 1 at a branch point from the fire fighting pipe 1 (see FIG. 5). ) Or a sprinkler unwind pipe 3 having a joint structure (see FIG. 6) in which the nipple 8 and the cap nut 9 are combined to prevent contact between different metals.

However, the connection to the branch joint 7 at the nipple 8 shown in FIG. 5 is because the nipple 8 and the tube body 3a are integrally fixed, and therefore it is necessary to rotate the entire tube body 3a when piping. There is a problem that there is, especially when the tube 3a becomes long, the rotation becomes difficult. In addition, in the case where both ends of the tube body 3a are fixed, there is a problem that re-piping is forced when additional tightening is required.

On the other hand, in the case of the combination of the nipple 8 and the cap nut 9 shown in FIG. 6, it is necessary to screw the nipple 8 into the branch joint portion 7 before mounting the pipe body 3a in advance. I was shooting.

In order to solve these problems, a joint device using a rotary nipple has been proposed. As shown in FIG. 4 , such a coupling device has an O-ring 11 and a green member 12 interposed between a rotary nipple 10 and a tube 3a, which are different metals, and a nipple. 10 circumferential rotation and prevention of electrolytic corrosion.

  Specifically, a metal sleeve 13 is externally fitted to the end portion side of the tube body 3a, and a resin sleeve 12 is interposed between the metal sleeve 13 and the nipple 10, so that the metal sleeve 13 is inserted. And the resin sleeve 12 are caulked with a metal caulking ring 14, and the metal stop ring 15 is used to prevent the nipple 10 from coming off. The resin spacer 16 is used to connect the branch joint 7 and the pipe body 3 a. This prevents the metals from contacting each other directly. The O-ring 11 is made of rubber (NBR), and one O-ring 11 is inserted between the metal sleeve 13 and the resin sleeve 12 and two are inserted between the nipple 10 and the resin sleep 12. .

  Since the joint device using such a rotary nipple 10 can freely rotate the nipple 10 and the tube body 3a in the circumferential direction via the rubber O-ring 11, as described above, Can be easily attached, and even if both ends of the tube 3a are fixed, there is an advantage that additional tightening can be performed, and there is an advantage that the connection is completed by screwing once.

  However, such a rotary joint device can be easily constructed by the rotation mechanism, but there is a problem that the rotation mechanism using the O-ring 11 works as a weak point against drainage after the construction. That is, from the viewpoint of workability, the compression rate of the O-ring 11 is set to be small so that rotation is easy. As a result, the risk of drainage increases due to the loose engagement of the O-ring 11. It will be.

  In addition, in the current situation that the resin green part 12 is sandwiched between metals for measures against dissimilar metals, the insulating member 12 receives an O-ring 11 for rotation and sealing. Since the accuracy of the insulating member 12 by injection molding is inferior to the metal processing accuracy, if the accuracy of the injection molded insulating member is increased, the price is inevitably increased. Moreover, since the inside of the sprinkler unwind pipe 3 is always used in a state where water is filled after piping, it is necessary to take measures against dissimilar metal corrosion that ensures a firm water tightness.

The present invention has been made in view of the circumstances as described above, and the object of the present invention is to make the pipe workability so that the end of the pipe body can be rotated by an O-ring made of water-expanded rubber before water expansion during construction. After construction, the tube end is automatically stopped by the O-ring with water-expanded rubber after water expansion, ensuring sufficient water tightness, and preventing electric corrosion and reducing costs. An object of the present invention is to provide a water pipe joint device that can be made simple.

In order to achieve the above object, according to the present invention, a metal sleeve that is externally fitted to the end side of the tube main body and is integrally fixed, and the metal sleeve, A resin ring that is fitted on the outer periphery to achieve insulation, and a nipple that is a fitting member loosely fitted to the outer periphery of the resin ring while preventing the metal sleeve and the resin ring from coming off. A water-expandable rubber O-ring that is inserted into a clearance between the resin rings and the metal sleeve, and a nipple that is the joint member,
At the time of piping construction, the nipple that is the joint member can be rotated in the circumferential direction by the O-ring before water expansion, and after the piping construction, the nipple that is the joint member is crimped by the O-ring after water expansion. Thus, the rotation is stopped, and water tightness and electric corrosion prevention property in the joint device are ensured.

According to a second aspect of the present invention , the annular groove for insertion, which is a clearance of the O-ring , is formed by externally fitting a resin ring on a step portion formed on the outer periphery of the metal sleeve, and adjacent resin rings. It is ensured by the interval of.

As an effect of the present invention , the nipple that is a joint member can be rotated in the circumferential direction by an O-ring before water expansion particularly during piping construction, and the joint can be rotated by an O-ring after water expansion after piping construction. Since the nipple, which is a member, can be crimped to stop rotation, the manufacturing cost can be reduced, and at the time of piping construction, the joint member formed at the end of the tube can be rotated to improve workability. It is possible to provide a joint device for a water distribution pipe in which the joint member automatically ensures sufficient water tightness after piping and piping construction, and is prevented from electrolytic corrosion.

  Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is an explanatory sectional view showing a joint device according to the present invention.

As shown in FIG. 1, the joint device according to the present invention is attached to an end portion of a stainless steel flexible steel pipe 3 having a bellows portion 3b. A metal sleeve 20 is fitted on the outer periphery of the end 3c of the tube 3a. Further, a step portion 21 is formed on the outer periphery of the metal sleeve 20, and a resin ring 22 is fitted into the step portion 21, and an O-ring 23 of water expansion rubber sandwiched between the resin ring 22 and the resin ring 22, The rotary nipple 24 is integrally fitted through the gap. A step portion 21 is formed on the outer peripheral surface of the metal sleeve 20 . Specifically, the first step portion 21 a formed on the bellows portion 3 b side of the metal sleeve 20, the second step portion 21 b formed on the central portion of the metal sleeve 20, and the metal sleeve 20. A third step portion 21c and a fourth step portion 21d that are formed on the opposite side of the bellows portion 3b are formed.

In addition, a resin ring 22 is fitted on the step portion 21 (step portions 21 a to 21 d) on the peripheral surface of the metal sleeve 20. Specifically, a first resin ring 22a is inserted into the first step portion 21a so as to fit into the full width of the step portion, and a second resin ring 22b is stepped into the second step portion 21b. The third resin ring 22c is inserted into the third step portion 21c so as to fit in shorter than the full width of the portion, and the convex portion 22c ′. Is inserted so as to be shorter than the full width of the second step portion. In addition, a fourth resin ring 22d is engaged with the fourth step portion 21d, and the convex portion 22d ′ is inserted and fitted so as to be shorter than the entire width of the third step portion 21c.

Thus, the second resin ring 22b and the convex portion 22c of the third resin ring 22c 'clearance (annular groove) _{S 2} is formed, the third resin ring 21c and the fourth resin ring 22d so that the clearance S ₁ is formed by the convex portion 22 d 'of. O-rings 23 and 23 made of water-expanded rubber are inserted into the clearances S ₁ and S ₂ . It is preferable that the O-ring 23 is formed to be large on the side (the right side in the drawing) from which water enters, and to be small on the downstream side.

A joint member (a nipple in this embodiment) 24 is rotatably fitted on the outer periphery of the resin ring 22, but an annular groove 24a is formed on the inner peripheral surface in the vicinity of the end portion on the bellows portion 3b side. A metal stop ring 25 is inserted into the annular groove 24a of the nipple 24, and the metal sleeve 20 that is externally fitted to the housing 3a is brought into contact with the first resin ring 22a. Is regulated.

  Since the joint device according to this embodiment is configured as described above, at the time of piping, the nipple 24 attached to the tubular body 3a is abutted against the mating joint portion and the nipple 24 is rotated and screwed together. At this time, since the O-ring 23 formed of the water expansion rubber does not contain water and is in an original state before being expanded, the nipple 24 is rotatable in the circumferential direction. That is, even if the pipe body 3a is in a fixed state, the nipple 24 can be freely rotated in the circumferential direction, and workability at the time of pipe construction can be improved.

Further, after the construction, the joint device is constantly pressurized with, for example, a water pressure of about 1.0 MPa, and water enters a slight gap between the nipple 24 and the resin ring 22, but the joint device is in contact with the water. The O-ring 23 expands and changes from the state shown in FIG. 2A to the state shown in FIG. 2B, and is strongly pressed against the inner peripheral surface of the nipple 24 by its own expansion force. In addition to stopping the rotation, flooding to the downstream side is prevented to ensure high water tightness (see FIG. 2A) . Note that the O-ring arranged on the downstream side fulfills the function of watertightness when water leaks from the upstream O-ring.

  Between the nipple 24 and the tube body 3a and the metal sleeve 20 fitted on the tube body 3a, a resin ring 22 formed in a divided manner is formed at a step portion 21 formed on the peripheral surface of the metal sleeve 20. Since it is externally fitted to insulate between the metal sleeve 20 and the nipple 24, and the clearance S for inserting the O-ring is formed, the labor for injection molding is reduced.

  In addition, since the O-ring is not a simple rubber material but a water-expanded rubber material as in the past, even if the molding accuracy of the O-ring is rough, the water tightness can be reliably improved. Even when the joining accuracy between the metal sleeve 24 and the metal sleeve 20 is rougher than before, the water tightness can be improved.

Further, the clearances S ₁ and S ₂ for insertion of the O-ring 23 are not formed in the outer periphery of the resin body as in the prior art, but are formed in the step portion 21 on the peripheral surface of the metal sleeve 20. Since the resin ring 22 can be formed by external fitting, the manufacturing cost can be further reduced.

  Therefore, the manufacturing cost is reduced, the end of the tube is rotatable during construction to improve the workability of the piping, and after construction, sufficient water tightness is automatically secured and electric corrosion is prevented. It can be set as the joint apparatus for water pipes with which it was planned.

FIG. 3 shows a second embodiment in which one resin ring 23 is arranged. In this case, as in FIG. 1, the first step portion 21 a drilled on the bellows portion 3 b side of the metal sleeve 20 and the center of the metal sleeve 20 are formed on the outer peripheral surface of the metal sleeve 20. A second step portion 21b drilled in the part and a third step portion 21c drilled on the side opposite to the bellows portion 3b side of the metal sleeve 20 are formed. In addition, the first resin ring 22a is inserted into the first step portion 21a so as to fit into the full width of the step portion, and the second resin ring 22b is inserted into the second step portion 21b from the full width of the step portion. The third resin ring 22c is inserted into the third step portion 21c so as to be shorter than the full width of the step portion, and the convex portion 22c ′ is formed in the second step portion 21c. It is inserted so that it may be shorter than the full width of the step.

Therefore, it is possible to form a clearance _{S 1} by the second resin ring 22b and the convex portion 22c of the third resin ring 22c '. An O-ring 23 formed of water-expanded rubber is inserted into the clearance S ₁ , and the O-ring 23 is formed on the downstream side (the right side in the figure) from which water enters. Is preferably formed small.

It is sectional drawing for description which shows the coupling apparatus which concerns on this invention. It is explanatory drawing which shows the fitting state of an O-ring. It is sectional drawing for description which shows one example of the connection of a tubular body. It is a connection structure figure which shows the conventional joint structure. It is an external view which shows the pipe body edge part of the joint structure which combined the conventional nipple. It is an external view which shows the pipe body edge part of the joint structure which combined the conventional nipple and the cap nut. It is explanatory drawing which shows the structure of the conventional sprinkler unwinding piping.

Brief description of symbols

3 Sprinkler unwinding pipe 3a Tubing body 3b Bellows part 3c Straight pipe part
20 Metal sleeve
21 Metal sleeve step 22 Resin ring 23 Water-swelling rubber O-ring 24 Rotating nipple 25 Metal stop ring

Claims (2)

A metal sleeve that is externally fitted to the end of the tube main body and is integrally fixed, a resin ring that is externally fitted to the outer periphery of the metal sleeve to achieve insulation, the metal sleeve, and the resin A nipple that is a fitting member loosely fitted to the outer periphery of the resin ring while preventing the ring from coming off, a gap between the resin rings, the metal sleeve, and a nipple that is the joint member A water-expandable rubber O-ring inserted into the clearance between
At the time of piping construction, the nipple that is the joint member can be rotated in the circumferential direction by the O-ring before water expansion, and after the piping construction, the nipple that is the joint member is crimped by the O-ring after water expansion. A joint device for a water distribution pipe characterized by ensuring a water tightness and an electric corrosion prevention property in the joint device by stopping the rotation. An annular groove for insertion, which is a clearance of the O-ring , is characterized in that a resin ring is externally fitted to a step portion formed on the outer periphery of the metal sleeve, and is secured by the interval between the adjacent resin rings, The joint device for water pipes according to claim 1.

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