JP5534154B2 - Sealing structure for water pipe fittings - Google Patents

Description

  The present invention relates to a sealing structure for preventing water leakage between a water distribution pipe and a joint main body connecting the water distribution pipe in a water distribution pipe joint.

  For fittings that connect tap water distribution pipes, by inserting the water distribution pipe into the fitting body, the packing attached to the inner circumference of the fitting body fits closely to the outer circumference of the water distribution pipe, thereby preventing water leakage. In addition, there is known a one-touch type joint (see, for example, Patent Document 1) that is prevented from coming off at the same time.

JP 2005-133748 A

  FIG. 7 is a cross-sectional view showing a conventional sealing structure in this type of water pipe joint. Reference numeral 100 is a water pipe joint, and reference numerals 200 and 200 are a pair of water pipes connected to each other by the water pipe joint 100. is there. The water distribution pipe joint 100 is a cylindrical joint main body 101 into which the water distribution pipe 200 is inserted on the inner periphery, and the water distribution pipe 200 is prevented from coming off from the joint main body 101 by biting into the outer peripheral surface of the water distribution pipe 200. The water distribution pipe holder and a packing 102 which is mounted in an annular groove 101a formed on the inner peripheral surface of the joint body 101 and is closely fitted to the inner surface of the groove and the outer peripheral surface of the water distribution pipe 200 to prevent water leakage. With. Reference numeral 101 b is a protrusion formed on the inner peripheral surface of the joint body 101 in order to limit the insertion length of the water distribution pipe 200 with respect to the joint body 101.

  Here, since the tap water W to be sealed flowing in the distribution pipe 200 contains chlorine for sterilization, the packing 102 is made of water-resistant EPDM (ethylene propylene rubber) or chlorine-resistant. In addition, FKM (fluororubber) having hot water resistance is used. In particular, FKM is preferably used because it exhibits high resistance in an evaluation test immersed in chlorine water in a compressed state.

  However, in actual use in which tap water flows through the water distribution pipe 200, the material may deteriorate at an early stage as compared with the evaluation result in the static immersion test in tap water, which has been a problem. . This is because a part of the tap water W flowing in the water distribution pipe 200 flows into the space between the joint body 101 and the water distribution pipe 200 from the end of the water distribution pipe 200 and is indicated by an arrow F in the figure. The rubber composition dynamically contacts the packing 102 while forming a vortex, and the aggressiveness of chlorine contained in the tap water W leaches out the composition in the rubber material from the wetted surface of the packing 102 into the water. It was found that deterioration was promoted.

  The present invention has been made in view of the above points, and its technical problem is to suppress the deterioration of the packing made of a rubber-like elastic material provided in the water pipe joint as much as possible. It is to improve life.

As a means for effectively solving the technical problem described above, a sealing structure for a water distribution pipe joint according to the invention of claim 1 is a seal interposed between the water distribution pipe and a joint body connecting the water distribution pipe. In the annular groove formed on the inner peripheral surface of the joint main body, a packing made of a rubber-like elastic material and an inner diameter portion located on the end side of the water distribution pipe from the packing are disposed. A protective ring that is close to and opposed to the outer peripheral surface of the water pipe is disposed , and an inner diameter portion of the protective ring forms a tapered surface or a curved surface that decreases in diameter toward the side opposite to the packing .

  If constituted in this way, even if a part of the water flowing in the distribution pipe flows into the space between the joint body and the distribution pipe from the end opening of the distribution pipe and forms a vortex, such a flow is not Since the water that is blocked by the protective ring and flows between the protective ring and the packing makes static contact with the packing, for example, the composition in the rubber material of the packing into the water by a substance such as chlorine contained in the water. Even if leaching, the leaching material saturates between the guard ring and the packing, thereby suppressing the leaching of the composition and thus not promoting the deterioration of the packing.

Also, when inserting the water distribution pipe into the inner circumference of the joint body, even if the tip of the water distribution pipe interferes with the inner diameter part of the protective ring, this inner diameter part faces the side opposite to the packing, in other words, the insertion of the water distribution pipe By forming a tapered surface or a curved surface having a smaller diameter in the direction, the water distribution pipe is guided in the insertion direction, and thus is not caught by the protective ring.

  According to the sealing structure of the water distribution pipe joint according to the invention of claim 1, since the water to be sealed is in static contact with the packing made of a rubber-like elastic material provided in the water distribution pipe joint, chlorine in water It is possible to improve the service life by minimizing the deterioration of the packing caused by such substances.

Further, the work at the time of the inner periphery of the joint body plugging the water pipes can be smoothly performed, moreover Therefore, with sufficiently small clearance between the inner diameter of the protective ring and the outer circumferential surface of the water pipe, the The effect can be realized even better.

It is principal part sectional drawing which shows the 1st form of the sealing structure of the water distribution pipe joint which concerns on this invention. It is principal part sectional drawing which shows the 2nd form of the sealing structure of the water distribution pipe joint which concerns on this invention. In a 2nd form, it is principal part sectional drawing which shows the state which the edge part of the water distribution pipe interfered with the internal diameter part of the protection ring in the insertion process to a coupling main body. It is principal part sectional drawing which shows the 3rd form of the sealing structure of the water pipe coupling which concerns on this invention. It is principal part sectional drawing which shows the 4th form of the sealing structure of the water pipe coupling which concerns on this invention. It is principal part sectional drawing which shows the 5th form of the sealing structure of the water pipe coupling which concerns on this invention. It is a fragmentary sectional view which shows the conventional sealing structure in a water pipe coupling.

  Hereinafter, a preferred embodiment of a sealing structure for a water distribution pipe joint according to the present invention will be described in detail with reference to the drawings. First, FIG. 1 is a cross-sectional view of a principal part showing a first form of a sealing structure for a water pipe joint according to the present invention. In FIG. 1, reference numeral 10 is a water pipe joint, and reference numerals 20 and 20 are this water pipe. A pair of water pipes connected to each other by a joint 10.

  The water distribution pipe joint 10 has a tubular joint main body 11 into which the water distribution pipe 20 is inserted on the inner periphery, and prevents the water distribution pipe 20 from coming off from the joint main body 11 by biting into the outer peripheral surface of the water distribution pipe 20 to be inserted. A water distribution pipe holder (not shown) and an annular groove 11a formed on the inner peripheral surface of the joint body 11 are fitted into the groove inner surface and the outer peripheral surface of the water distribution pipe 20 to prevent water leakage. And a protective ring 13 disposed in the annular groove 11a located on the end 20a side of the water distribution pipe 20 (the side into which the water to be sealed flows in) from the packing 12. Reference numeral 11 b is a protrusion formed on the inner peripheral surface of the joint body 11 in order to limit the insertion length of the water pipe 20 into the joint body 11.

  The packing 12 is made of a water-resistant rubber-like elastic material (rubber material or synthetic resin material having rubber-like elasticity), in particular, a chlorine-resistant and hot-water-resistant FKM (fluoro rubber). In the example, a so-called O-ring having a circular cross section is used, and is interposed between the bottom surface of the annular groove 11a of the joint body 11 and the outer peripheral surface of the water distribution pipe 20 in an appropriately compressed state.

  The protection ring 13 has a flat washer shape, and is made of a material excellent in chlorine resistance and hot water resistance, for example, a fluororesin material such as PTFE (tetrafluoroethylene resin). The outer circumferential surface of the water distribution pipe 20 inserted in the space is close to and opposed to the bottom surface of the annular groove 11a through a slight gap.

  In FIG. 1, the right side of the protruding portion 11 b is not shown, but the sealing structure for the water distribution pipe 20 inserted into the right side of the protruding portion 11 b is similarly configured (the packing 12 and the protective ring 13 are symmetrical with the illustration). Can be arranged).

  In the above configuration, if it is assumed that the tap water W flows in the water distribution pipe 20 from the left side to the right side in the figure, a part of the tap water W is a water distribution pipe opposed to the inner peripheral projection 11b of the joint body 11. 20 flows into the space S1 between the joint main body 11 and the water distribution pipe 20 through the gap between the end 20a and forms a vortex as shown by an arrow F in the figure.

  However, since such a flow F is interrupted by the protection ring 13, there is almost no flow in the tap water W flowing into the spaces S <b> 2 and S <b> 3 between the protection ring 13 and the packing 12. Static contact. Therefore, even if the rubber composition of the packing 12 leaches into the tap water W in the spaces S2 and S3 over time due to the aggressiveness of chlorine in the tap water W, the leached substance is saturated in the spaces S2 and S3. Prevents new leaching of the composition. For this reason, it is possible to effectively prevent the deterioration of the packing 12 from being promoted by the dynamic contact with the tap water W.

  By the way, in order to reliably block the flow F from the packing 12 by the protection ring 13, the inner diameter of the protection ring 13 is made as close as possible to the outer diameter of the water distribution pipe 20, and the clearance between the protection ring 13 and the water distribution pipe 20 is reached. However, in this case, when connecting the water pipes 20 and 20 by inserting the water pipes 20 and 20 into the inner periphery of the joint body 11, the end 20 a of the water pipe 20 is connected to the inner diameter portion of the protective ring 13. There is a concern that the connection work becomes difficult due to the interference. 2nd form pays such a concern, FIG. 2 is principal part sectional drawing which shows the 2nd form of the sealing structure of the water pipe coupling which concerns on this invention, FIG. In a 2nd form, it is principal part sectional drawing which shows the state which the edge part of the water distribution pipe interfered with the internal diameter part of the protection ring in the insertion process to a coupling main body.

  That is, the second embodiment shown in FIG. 2 is different from the first embodiment described above in that the inner diameter portion 13a of the protective ring 13 forms a tapered surface having a smaller diameter toward the side opposite to the packing 12. . In other words, the inner diameter portion 13a forms a tapered surface having a smaller diameter in the insertion direction (right side in the figure) of the water pipe 20 inserted from the left side in the figure. The configuration of the other parts is the same as in FIG.

  Therefore, also in the second embodiment, the flow F of the tap water W that has flowed into the space S1 between the joint body 11 and the water distribution pipe 20 is blocked by the protective ring 13 as in the first embodiment. On the other hand, the tap water W is statically contacted, and the promotion of deterioration of the packing 12 due to chlorine in the water is effectively prevented.

  In addition, according to the second embodiment, as shown in FIG. 3, in the process of inserting the water distribution pipe 20 into the inner periphery of the joint body 11, the end 20 a of the water distribution pipe 20 is the inner diameter portion of the protection ring 13. Even if it interferes with 13a, as described above, this inner diameter portion 13a has a tapered surface that decreases in diameter toward the insertion direction of the water distribution pipe 20, so that the end 20a of the water distribution pipe 20 slides in the insertion direction while guiding it. Is done. For this reason, the end 20a of the water distribution pipe 20 is not caught by the protective ring 13 and insertion is not hindered.

  For this reason, the inner diameter of the protection ring 13 can be made as close as possible to the outer diameter of the water distribution pipe 20 to make the gap between the protection ring 13 and the water distribution pipe 20 as small as possible. The edge may be in close contact with the outer peripheral surface of the water distribution pipe 20, and therefore the flow F in the space S <b> 1 shown in FIG. 2 can be reliably blocked by the protective ring 13.

  Even if the inner diameter portion 13a of the protective ring 13 is bent toward the side opposite to the packing 12 so as to form a curved surface having a smaller diameter toward the insertion direction of the water distribution pipe 20, the same effect as described above is obtained. Can be realized.

  Next, FIG. 4 is a principal part sectional view showing a third embodiment of the sealing structure of a water pipe joint according to the present invention, and FIG. 5 is a principal part sectional view showing a fourth embodiment. In these forms, the difference from the first and second forms described above is that the shape of the protective ring arranged in the annular groove 11a of the joint body is located closer to the end 20a of the water pipe 20 than the packing 12. It is in. The configuration of the other parts is basically the same as that shown in FIGS.

  That is, the protection ring 14 used in the third embodiment shown in FIG. 4 is made of a material excellent in chlorine resistance and hot water resistance, for example, a fluororesin material such as PTFE (tetrafluoroethylene resin). The inner diameter portion is close to and opposed to the outer peripheral surface of the water pipe 20 inserted into the joint body 11 via the gap G1, and the outer diameter portion is close to and opposed to the bottom surface of the annular groove 11a via the slight gap G2. . And while the end surface which faced the packing 12 side has comprised the planar shape substantially orthogonal to the center axis line of the water distribution pipe 20, the surface which faced the other side (end part 20a side of the water distribution pipe 20) of packing 12 The concave curved surface 14a is formed.

  Therefore, according to the third embodiment, a part of the tap water W flowing from the left side to the right side in the drawing in the water pipe 20 is the inner peripheral projection 11b of the joint body 11 and the end 20a of the water pipe 20 facing this. Even if it flows into the space S1 between the joint main body 11 and the water distribution pipe 20 from the gap between them, when the flow F1 reaches the concave curved surface 14a of the protective ring 14, the concave curved surface 14a causes the annular groove 11a to Since the flow F2 is formed so as to return while wrapping around the inner surface, the flow F2 counteracts the flow F1 from the end 20a side of the water distribution pipe 20 and significantly reduces the flow velocity thereof. For this reason, there is almost no flow of tap water W from the gaps G1 and G2 on the inner and outer circumferences of the protective ring 14 to the spaces S2 and S3 between the protective ring 14 and the packing 12, and static contact with the packing 12 is achieved. In addition, it is possible to effectively prevent the deterioration of the packing 12 due to chlorine in the water.

  Further, the protective ring 15 used in the fourth embodiment shown in FIG. 5 is also made of a material excellent in chlorine resistance and hot water resistance, for example, a fluororesin material such as PTFE (tetrafluoroethylene resin). Both end surfaces in the axial direction have a planar shape that is substantially perpendicular to the central axis of the water distribution pipe 20, and the inner diameter portion has a large number of concavities and convexities 15a that are continuous in the circumferential direction. A labyrinth gap G <b> 3 is formed between the unevenness 15 a and the outer peripheral surface of the water distribution pipe 20.

  Therefore, according to the fourth embodiment, part of the tap water W flowing from the left side to the right side in the drawing in the water distribution pipe 20 is the inner peripheral projection 11b of the joint body 11 and the end 20a of the water distribution pipe 20 facing this. Even if it flows into the space S <b> 1 between the joint body 11 and the water distribution pipe 20 from the gap between the protective ring 15 and the water distribution pipe 20, the flow F <b> 1 is between the irregularities 15 a of the protection ring 15. Is effectively damped in the labyrinth gap G3 having alternately a narrowing gap and an expansion gap in the radial direction. For this reason, the flow of the tap water W to the spaces S2 and S3 between the protective ring 15 and the packing 12 is almost eliminated, static contact is made with the packing 12, and the deterioration of the packing 12 due to chlorine in the water is promoted. It can be effectively prevented.

  Next, FIG. 6 is principal part sectional drawing which shows the 5th form of the sealing structure of the water pipe coupling which concerns on this invention. The feature of this form is that the protective ring 14 in the third form and the protective ring 15 in the fourth form are placed in the annular groove 11a from the packing 12 to the end 20a side of the water distribution pipe 20 (water to be sealed). This is because it is placed on the side where the air flows in).

  Specifically, of the two protective rings 14 and 15, the surface facing the side opposite to the packing 12 (the end 20 a side of the water distribution pipe 20) is relatively concave on the end 20 a side of the water distribution pipe 20. And a protective ring 15 having a large number of concavities and convexities 15a continuously formed in the circumferential direction on the inner diameter portion is disposed on the subsequent stage, that is, on the packing 12 side.

  Therefore, according to the fifth embodiment, a part of the tap water W flowing from the left side to the right side in the drawing in the water pipe 20 is the inner peripheral projection 11b of the joint body 11 and the end 20a of the water pipe 20 facing this. Even if it flows into the space S1 between the joint main body 11 and the water pipe 20 from the gap between them, the flow F1 is formed so as to return while turning around the concave curved surface 14a of the protective ring 14 first. By resisting the flow F2, the flow velocity decreases. Further, even if a part of the flow F1 whose flow velocity is reduced passes through the gap G1 between the inner diameter portion of the protective ring 14 and the outer peripheral surface of the water distribution pipe 20, the outer peripheral surface of the latter-stage protective ring 15 and the water distribution pipe 20 Since the labyrinth gap G3 is formed by the irregularities 15a formed on the inner diameter portion of the protective ring 15, the flow passing therethrough is significantly attenuated.

  For this reason, the flow of the tap water W flowing into the space S1 is more reliable as compared with the case where the protective ring 14 is provided alone as shown in FIG. 4 and the case where the protective ring 15 is provided alone as shown in FIG. Can be blocked.

  Further, in the case of the third to fifth embodiments described above, the blocking of the water flow toward the packing 12 is not dependent only on the narrowness of the gap between the protective ring 14 or 15 and the water distribution pipe 20, so that protection is provided. The inner diameter of the ring 14 or 15 can be appropriately larger than the outer diameter of the water distribution pipe 20. Therefore, when connecting the water pipes 20 and 20 by inserting the water pipes 20 and 20 into the inner periphery of the joint body 11, the end 20 a of the water pipe 20 interferes with the inner diameter part of the protective ring and is inserted, thereby preventing the insertion. Can be prevented, and workability does not deteriorate.

  Of course, in order to reliably block the water flow toward the packing 12 by the protection rings 14 and 15, the protection is performed to such an extent that the workability at the time of inserting and connecting the water distribution pipes 20 and 20 to the inner periphery of the joint body 11 is not deteriorated. It is desirable that the inner diameters of the rings 14 and 15 are made closer to the outer diameter of the water distribution pipe 20 so that the gaps G1 and G3 between the protection rings 14 and 15 and the outer peripheral surface of the water distribution pipe 20 are as narrow as possible.

DESCRIPTION OF SYMBOLS 10 Water pipe coupling 11 Joint main body 11a Annular groove 12 Packing 13-15 Protection ring 13a Inner diameter part 14a Concave curved surface 15a Concavity and convexity 20 Water distribution pipe 20a End part G1 Gap G3 Labyrinth gap

Claims (1)

A sealing device interposed between the water distribution pipe and the joint body connecting the water distribution pipe, in an annular groove formed on the inner peripheral surface of the joint body, a packing made of a rubber-like elastic material, A protective ring is located closer to the outer peripheral surface of the water distribution pipe and positioned closer to the end of the water distribution pipe than the packing, and the inner diameter of the protective ring has a smaller diameter toward the opposite side of the packing. A watertight pipe joint sealing structure characterized by forming a tapered surface or a curved surface .

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