JP2020148286A - Rubber ring and piping member using the same - Google Patents

Abstract

To provide a rubber ring capable of easily inserting a pipe into the rubber ring without applying a lubricant to the rubber ring.SOLUTION: A rubber ring 1 comprises: a rubber ring body 2 having a first surface 6 and a second surface 7 along a radial direction of the rubber ring; a flap part 3 formed on an inner side in the radial direction of the rubber ring and extending in a circumferential direction of the rubber ring in the rubber ring body 2, wherein the flap part 3 extends so as to incline from the first surface 6 side toward the second surface 7 side; and a coating film 5 formed on a first inclined surface 4 facing inward in the radial direction of the rubber ring in the flap part 3, wherein the coating film 5 contains a solid wetting agent and a binder resin.SELECTED DRAWING: Figure 2

Description

The present invention relates to a rubber ring and a member for piping using the rubber ring, and in particular, a rubber ring capable of easily inserting a pipe into the rubber ring without applying a lubricant to the rubber ring. It is about.

Plumbing equipment is installed in buildings such as apartment houses and office buildings to supply water and drain water. Such piping equipment is installed by combining a large number of pipes such as vertical pipes extending vertically and horizontal pipes extending in the horizontal direction, and joints are used for connecting portions of the pipes. Further, when the pipe constituting the piping equipment is a resin pipe, the pipe may expand and contract due to a temperature change, so an expansion joint is used for the purpose of mitigating the influence of the thermal expansion and contraction of the pipe. ..

For example, in Japanese Patent Application Laid-Open No. 2013-68263 (Patent Document 1), a rubber seal ring is attached to the inner peripheral surface of a receiving portion capable of accommodating a pipe member, and the seal ring is a ring-shaped seal body. Disclosed is a telescopic joint structure provided with an elastic joint portion provided on the inner peripheral surface of the seal body so as to be elastically contactable with respect to the outer peripheral surface of the pipe member. The rubber seal ring referred to here is also called a rubber ring.

Further, when the pipe is inserted into the expansion joint, a large insertion load is applied, so that the lubricant is applied to at least one of the end portion of the pipe and the rubber ring. The expansion joint structure described in Patent Document 1 further provides a lubricant storage portion capable of accommodating and holding the lubricant in the elastic contact portion of the seal ring, so that the effect of the lubricant applied at the time of insertion can be maintained for a long time. It is possible to reduce the resistance at the time of thermal expansion and contraction.

Japanese Unexamined Patent Publication No. 2013-68263

However, since the lubricant is applied to the rubber ring when the pipe is inserted, there is a risk of forgetting to apply the lubricant. Indoor piping structures such as buildings are often complicated, but in this case, many members are used, and members with complicated structures such as joints with multiple sockets are also used. The fear of forgetting increases. In addition, as a method of attaching the rubber ring to the joint, a method of wetting the rubber ring with water and then attaching the rubber ring to improve the sliding of the rubber ring is also known, and the lubricating material is applied when inserting the pipe. Some installers wet the rubber ring with water without doing so. Furthermore, since there is also a method of using an adhesive for joining the pipes, some installers mistakenly apply the adhesive to the rubber ring.

Therefore, an object of the present invention is to provide a rubber ring capable of solving the above-mentioned problems of the prior art and easily inserting a tube into the rubber ring without applying a lubricant to the rubber ring. It is in. Another object of the present invention is to provide a piping member provided with such a rubber ring.

As a result of diligent studies to achieve the above object, the present inventor has found that if it is a piping member (joint, pipe, etc.) using a rubber ring having a coating film containing a solid lubricant on its surface, it slides on the rubber ring. We have found that the insertion of a pipe can be easily achieved without applying a material, and have completed the present invention. Further, since the piping member using such a rubber ring can exert the effect of reducing the frictional resistance for a long period of time even after being inserted, the slidability of the inserted pipe is maintained high, and the pipe is thermally expanded or contracted. It is possible to sufficiently cope with the adjustment of the insertion amount of the pipe that may be performed after the insertion.

That is, the rubber ring of the present invention includes a rubber ring body having a first surface and a second surface along the rubber ring radial direction.
A flap portion formed inside the rubber ring body in the radial direction of the rubber ring and extending in the circumferential direction of the rubber ring, and a flap portion extending from the first surface side toward the second surface side while being inclined.
It is a coating film formed on a first inclined surface facing inward in the radial direction of the rubber ring in the flap portion, and is characterized by including a coating film containing a solid wetting agent and a binder resin.

In a preferred example of the rubber ring of the present invention, the coating film is further formed on the second inclined surface of the flap portion facing outward in the radial direction of the rubber ring.

In another preferred example of the rubber ring of the present invention, the coating film is further formed on the tip surface connecting the first inclined surface and the second inclined surface at the flap portion.

In another preferred example of the rubber ring of the present invention, the solid lubricant is at least one selected from the group consisting of molybdenum disulfide, polytetrafluoroethylene, graphite and boron nitride.

In another preferred example of the rubber ring of the present invention, the solid lubricant has an average particle size of 0.1 μm or more and 40 μm or less.

In another preferred example of the rubber ring of the present invention, the binder resin is at least one selected from the group consisting of polyurethane resin, hydroxyl group-containing fluororesin, epoxy resin, urethane-modified epoxy resin, silicone resin, and polyamide-imide resin. Is.

In another preferred example of the rubber ring of the present invention, the film thickness is 1 μm or more and 100 μm or less.

In another preferred example of the rubber ring of the present invention, the rubber constituting the rubber ring includes at least one of chloroprene rubber and ethylene propylene diene rubber.

In another preferred example of the rubber ring of the present invention, the flap portion is further fixed to the ridge portion formed inside the rubber ring body in the radial direction of the rubber ring and extending in the circumferential direction of the rubber ring. A ridge portion located on the second surface side of the position of the rubber ring main body is provided.

In another preferred example of the rubber ring of the present invention, the rubber ring body further includes a recess formed on the outer side in the radial direction of the rubber ring and extending in the circumferential direction of the rubber ring.

In another preferred example of the rubber ring of the present invention, both the first surface and the second surface are flat.

Further, the piping member of the present invention is characterized by including the above-mentioned rubber ring. Here, as the piping member of the present invention, a joint or a pipe is suitable.

According to the rubber ring of the present invention, it is possible to provide a rubber ring capable of easily inserting a tube into the rubber ring without applying a lubricant to the rubber ring. Further, according to the piping member of the present invention, it is possible to provide a piping member provided with such a rubber ring.

It is sectional drawing of an example of the rubber ring of this invention. It is an enlarged view of the area A circled in FIG. It is sectional drawing of an example of the joint of this invention.

<Rubber ring>
One aspect of the present invention is a rubber ring body having a first surface and a second surface along the rubber ring radial direction, and extending in the rubber ring circumferential direction formed inside the rubber ring body in the rubber ring radial direction. A flap portion, which is a coating formed on a flap portion extending from the first surface side toward the second surface side while inclining, and a first inclined surface facing inward in the radial direction of the rubber ring in the flap portion. It is a rubber ring provided with a film containing a solid wetting agent and a binder resin.
Hereinafter, the rubber ring of the present invention will be described in detail with reference to the drawings, but the present invention is not limited thereto.
FIG. 1 is a cross-sectional view of an example of a rubber ring of the present invention, and FIG. 2 is an enlarged view of a region A circled in FIG. The rubber ring 1 in the illustrated example has an annular rubber ring body 2, a flap portion 3 formed inside the rubber ring body 2 in the radial direction of the rubber ring and extending in the circumferential direction of the rubber ring, and a rubber ring diameter in the flap portion 3. It includes a coating film 5 formed on a first inclined surface 4 facing inward in the direction. In FIGS. 1 and 2, the cross-sectional shape of the rubber ring 1 in the cross section parallel to the rubber ring axis direction is shown, but the rubber ring 1 in the illustrated example has the same cross section over the entire circumference.
In the present specification, the radial direction of the rubber ring means the radial direction of the circle centered on the central axis of the rubber ring, and the circumferential direction of the rubber ring means the circumferential direction of the circle centered on the central axis. The rubber ring axis direction means the direction in which the central axis extends. FIG. 1 shows the central axis C of the rubber ring. The inner side in the radial direction of the rubber ring means the side close to the central axis of the rubber ring in the radial direction of the rubber ring, and the outer side in the radial direction of the rubber ring means the side far from the central axis of the rubber ring in the radial direction of the rubber ring. To do.

In the rubber ring 1 of the illustrated example, the rubber ring main body 2 has a first surface 6 and a second surface 7 along the rubber ring radial direction. The rubber ring of the present invention is preferably a rubber ring for piping used for piping members such as joints and pipes. When the rubber ring of the present invention is used for a piping member, the first surface of the rubber ring main body along the radial direction of the rubber ring is formed of another piping member in order to join with another piping member such as a pipe or a joint. The surface on which the insertion port is inserted faces the receiving side of the piping member, and the second surface of the rubber ring body along the rubber ring radial direction is the surface facing the receiving side of the piping member. Is.
In the rubber ring main body 2 of the illustrated example, the first surface 6 connects the first inclined surface 4 of the flap portion 3 and the surface (outer peripheral surface) 8 of the rubber ring main body 2 facing outward in the radial direction of the rubber ring. The second surface 7 is a surface that connects the surface of the ridge portion 9 described later and the outer peripheral surface 8. Here, when the rubber ring 1 does not have the ridge portion 9, the second surface 7 has a surface (inner peripheral surface) 10 facing inward in the radial direction of the rubber ring and an outer peripheral surface 8 of the rubber ring main body 2. It will be the connecting surface.

Further, in the rubber ring main body 2 of the illustrated example, both the first surface 6 and the second surface 7 are flat and form a surface parallel to the rubber ring radial direction. In the rubber ring of the present invention, the first surface and the second surface of the rubber ring body are flat from the viewpoint of firmly fitting the rubber ring body to the rubber ring receiving portion when the rubber ring of the present invention is used for a piping member. Is preferable. In the present invention, the rubber ring main body is not limited to this, and a recess extending in the circumferential direction of the rubber ring may be formed on at least one of the first surface and the second surface.

In the rubber ring 1 of the illustrated example, the flap portion 3 extends in the rubber ring circumferential direction inside the rubber ring main body 2 in the radial direction of the rubber ring. Here, the flap portion 3 is the second rubber ring main body 2. It extends from the 1st surface 6 side toward the 2nd surface 7 side while inclining. That is, the flap portion 3 has a fixed end fixed to the rubber ring main body 2 and a free end (tip) extending inclined from the rubber ring main body 2.
When the rubber ring of the present invention is used for a piping member, the flap portion has a reduced diameter from the receiving side to the back side of the piping member. When the pipe is inserted into such a pipe member, the rubber ring is compressed by the contact with the pipe, and sealing can be achieved at the joint between the pipe and the rubber ring. The presence of a flap portion whose diameter is reduced so as to extend while inclining from the side to the back enables reliable and effective compression of the rubber ring.

The flap portion 3 of the illustrated example connects the first inclined surface 4 facing inward in the radial direction of the rubber ring, the second inclined surface 11 facing outward in the radial direction of the rubber ring, and the first inclined surface 4 and the second inclined surface 11. It has a tip surface 12. When the rubber ring of the present invention is used for a piping member, the second inclined surface of the flap portion facing outward in the radial direction of the rubber ring is inserted into the piping member from the viewpoint of effectively compressing the rubber ring. When the above is completed, it is preferable that the entire surface is in close contact with the opposite surface of the rubber ring (in FIG. 2, the inner peripheral surface 10 of the rubber ring main body 2 and the surface of the ridge portion 9).
The flap portion 3 of the illustrated example forms a tapered surface that is tapered toward the tip surface 12 in a cross section parallel to the rubber wheel axis direction, but the shape of the flap portion is limited to this in the rubber ring of the present invention. It's not something.

Further, the rubber ring 1 of the illustrated example includes a recess 13 formed in the rubber ring main body 2 on the outer side in the radial direction of the rubber ring and extending in the circumferential direction of the rubber ring. The rubber ring of the present invention preferably has a recess on the outer peripheral surface of the rubber ring body as shown in the illustrated example. In this case, when the rubber ring of the present invention is used for a piping member, a space can be formed between the outer peripheral surface of the rubber ring main body and the surface of the rubber ring receiving portion facing the outer peripheral surface, as described above. When the rubber ring is compressed, the compressive stress can be relaxed. The recess 13 in the illustrated example draws a curved shape in a cross section parallel to the rubber ring axis direction, but the shape of the recess in the rubber ring of the present invention is not limited to this.

Further, the rubber ring 1 in the illustrated example is a ridge portion 9 formed in the rubber ring main body 2 inward in the radial direction of the rubber ring and extending in the circumferential direction of the rubber ring, and the flap portion 3 is fixed to the rubber ring. A ridge portion 9 located on the second surface 7 side of the rubber ring main body 2 with respect to the position of the main body 2 (or the fixed end of the flap portion 3) is provided. As shown in the illustrated example, the rubber ring of the present invention preferably includes a ridge portion inside the rubber ring body in the radial direction of the rubber ring. For example, even when the flap portion 3 forms a tapered surface that is tapered toward the tip surface 12 in a cross section parallel to the rubber ring axis direction as shown in the illustrated example, the flap portion 9 is present. The entire second inclined surface facing outward in the radial direction of the rubber ring can be brought into close contact with the opposite surface of the rubber ring, and the rubber ring can be effectively compressed. In the rubber ring 1 of the illustrated example, the ridge portion 9 draws a semicircular shape in a cross section parallel to the rubber ring axis direction, but the shape of the ridge portion in the rubber ring of the present invention is not limited to this.

The rubber ring of the present invention is mainly composed of rubber, and the rubber components used for the rubber include polyisoprene rubber (IR), styrene-butadiene rubber (SBR), butadiene rubber (BR), and chloroprene rubber (CR). Examples thereof include ethylene propylene diene rubber (EPDM) and acrylonitrile butadiene rubber (NBR). These rubber components may be used alone or in combination of two or more. The rubber constituting the rubber ring is usually vulcanized rubber, although it depends on the type of rubber component used.
In the rubber ring of the present invention, it is preferable that the portion excluding the coating film is made of rubber, and specifically, the rubber ring body, the flap portion and the ridge portion formed as needed are made of rubber. It is preferable to have.
Further, in the rubber ring of the present invention, since a film is formed at least on the first inclined surface of the flap portion, a rubber component such as styrene-butadiene rubber that tends to exude a compounding agent such as an antiaging agent onto the rubber surface. It is preferable to use chloroprene rubber or ethylene propylene diene rubber as the rubber component.

As the rubber constituting the rubber ring, a filler such as carbon black, an antiaging agent, a compounding agent usually used in the rubber industry such as a silane coupling agent, etc. are appropriately used as long as the object of the present invention is not impaired. It can be selected and blended. In the case of vulcanized rubber, in addition to the above-mentioned compounding agents such as rubber components and fillers, vulcanization accelerators, vulcanization accelerator aids, vulcanization agents, etc. are used to manufacture rubber ring bodies and the like. Can be blended in rubber compositions.

In the rubber ring of the present invention, the rubber ring body, the flap portion and the ridge portion formed as needed are prepared, for example, by kneading a rubber component and a compounding agent appropriately selected as necessary. It can be produced by molding using the rubber composition and then vulcanizing. Here, it is preferable that the rubber ring body, the flap portion, and the ridge portion formed as needed are integrally formed.

Next, in the rubber ring 1 of the illustrated example, the coating film 5 is formed on at least the first inclined surface 4 of the flap portion 3 facing inward in the radial direction of the rubber ring, where the coating film 5 is a solid lubricant and a binder. It is a film containing a resin. When a rubber ring 1 having a coating film 5 on at least the first inclined surface 4 is used as a piping member, the pipe is inserted by the coating film 5 containing a solid lubricant and a binder resin without applying a lubricant to the rubber ring 1. Can be easily achieved, and the joint and the pipe can be easily joined even at the construction site. In addition, it is possible to eliminate the worry of forgetting to apply the lubricant or applying water or an adhesive. Further, in the piping member using such a rubber ring 1, the coating 5 containing the solid lubricant and the binder resin can exert the effect of reducing the frictional resistance for a long period of time even after the insertion, so that the sliding of the inserted pipe can be exhibited. The motility is maintained high, and it is possible to sufficiently cope with the thermal expansion and contraction of the pipe and the adjustment of the insertion amount of the pipe that can be performed after the insertion.

Further, although not shown, in the rubber ring of the present invention, it is preferable that the coating film is further formed on the second inclined surface of the flap portion facing outward in the radial direction of the rubber ring. When the rubber ring of the present invention is used for a piping member, when the insertion of the pipe is completed, the second inclined surface of the flap portion is in close contact with the facing surface of the rubber ring, which may cause sticking. .. Therefore, in order to prevent the second inclined surface of the flap portion from sticking to the rubber ring surface, it is preferable to form the coating film on the second inclined surface of the flap portion facing outward in the rubber ring radial direction.

Further, in the rubber ring of the present invention, the flap portion connects the first inclined surface 4 facing inward in the radial direction of the rubber ring and the second inclined surface 11 facing outward in the radial direction of the rubber ring as shown in the illustrated example. In the case of, it is preferable that the coating film is further formed on the tip surface connecting the first inclined surface and the second inclined surface in the flap portion. When the above-mentioned thermal expansion and contraction of the pipe occurs or the insertion amount of the pipe is adjusted, the tip surface of the flap portion can also come into contact with the inserted pipe, thus improving the slidability of the pipe. From the viewpoint of making the flap portion, it is preferable to form the coating film on the tip surface connecting the first inclined surface and the second inclined surface of the flap portion.

In the rubber ring 1 of the illustrated example, the coating film 5 is also formed on the first surface 6 of the rubber ring main body 2. As described above, in the rubber ring of the present invention, the coating film may be formed on the surface of the rubber ring other than the surface of the flap portion, for example, the entire surface of the rubber ring, specifically, the rubber ring body and the flap portion. And the above-mentioned coating film may be formed on the entire surface of the ridge portion formed as needed.

In the rubber ring of the present invention, the coating film contains a solid lubricant and a binder resin. When the coating film contains a solid lubricant, the effect of reducing frictional resistance can be exhibited for a long period of time, and the slidability of the pipe inserted into the rubber ring can be highly maintained. A solid lubricant is a substance that is solid but has lubricity at the time of use, and is distinguished from a semi-solid lubricant having a viscosity such as a liquid lubricant or grease. In the rubber ring of the present invention, molybdenum disulfide, polytetrafluoroethylene (PTFE), graphite, boron nitride and the like are preferably used as the solid lubricant used for the coating film. These solid lubricants may be used alone or in combination of two or more. Further, the content of the solid lubricant in the coating film is preferably 5% by mass or more and 70% by mass or less.

The solid lubricant preferably has an average particle size of 0.1 μm or more and 40 μm or less. When the average particle size of the solid lubricant is 0.1 μm or more, the effect of reducing frictional resistance can be more reliably exhibited. On the other hand, from the viewpoint of forming a smooth film, the average particle size of the solid lubricant is preferably 40 μm or less. The lower limit of the average particle size of the solid lubricant is more preferably 0.5 μm or more, further preferably 1 μm or more, while the upper limit of the average particle size of the solid lubricant is more preferably 20 μm or less, further preferably 10 μm or less. It is preferably 8 μm or less, more preferably 5 μm or less. In detail, since the range of the preferable average particle size of the solid lubricant differs depending on the type of the solid lubricant, the range of the preferable average particle size according to the type of the solid lubricant will be described. For example, in the case of molybdenum disulfide, the average particle size is preferably 0.1 μm or more and 10 μm or less, and more preferably 0.5 μm or more and 5 μm or less. The average particle size of PTFE is preferably 0.1 μm or more and 20 μm or less, more preferably 0.5 μm or more and 5 μm or less, and the average particle size of graphite is preferably 0.1 μm or more and 40 μm or less, further preferably 0. It is .5 μm or more and 5 μm or less, and the average particle size of boron nitride is preferably 0.5 μm or more and 15 μm or less, and more preferably 1 μm or more and 8 μm or less.
In the present specification, the average particle size of the solid lubricant, refers to the 50% particle diameter on a volume basis particle size distribution (D _50), be determined from the particle size distribution measured using a laser diffraction / scattering particle size distribution measuring apparatus Can be done. The particle size in the present specification is represented by a sphere equivalent diameter by a laser diffraction / scattering method.

In the rubber ring of the present invention, the binder resin used for the coating is a polyurethane resin, a hydroxyl group-containing fluororesin, an epoxy resin (more preferably a diglycidyl ester type epoxy resin), a urethane-modified epoxy resin, a silicone resin, and a polyamide-imide resin. Etc. are preferably mentioned. These binder resins may be used alone or in combination of two or more. Further, the binder resin in the coating film may exist as a cured product by a curing agent such as polyamine or polyisocyanate. The content of the binder resin in the coating film is preferably 30% by mass or more and 95% by mass or less.

In the rubber ring of the present invention, in addition to the solid lubricant and the binder resin, a compounding agent such as a silane coupling agent and a surfactant is appropriately selected for the coating film within a range that does not impair the object of the present invention. Can be blended. A volatile component such as an organic solvent can be added to the coating agent prepared for forming the film.

In the rubber ring of the present invention, the coating film is formed by using, for example, a coating agent prepared by mixing a solid lubricant and a binder resin with a compounding agent appropriately selected if necessary, and at least the first flap portion. It can be formed by coating an inclined surface.

In the above method for forming a film, it is preferable to perform a pretreatment on the surface on which the film is to be formed before coating, and it is particularly preferable to perform a degreasing treatment. By performing the pretreatment of the surface on which the film is formed, the adhesion of the film to the surface can be improved, and the effect exerted by the film as described above can be more reliably exhibited.

In the above-mentioned film forming method, examples of the coating method include a coating method such as brush coating, spray coating, roller coating, and dipping coating, and a printing method such as inkjet printing.

In the above-mentioned film forming method, a means for drying or curing the film formed by the coating is appropriately selected. For example, it may be dried by heating, cured by heating or the like, a coating agent in which the curing reaction proceeds spontaneously (for example, a two-component coating agent), or a coating agent capable of natural drying (for example, a volatile solvent). If it is a system coating agent), it is not necessary to adopt a special drying or curing means.

In the rubber ring of the present invention, the film thickness is preferably 1 μm or more and 100 μm or less, more preferably 5 μm or more and 50 μm or less, further preferably 5 μm or more and 30 μm or less, and 10 μm or more and 20 μm or less. Is the most preferable.

<Piping members>
Next, the piping member of the present invention will be described in detail. The piping member of the present invention is characterized by including the rubber ring of the present invention described above. The piping member of the present invention usually includes an end (receptacle) into which an insertion port of another piping member is inserted in order to join with another piping member such as a pipe or a joint. A rubber ring receiving portion is provided on the receiving side of the piping member of the present invention, and the rubber ring is arranged so that the first surface of the rubber ring main body faces the receiving port of the piping member. The flap portion formed on the ring body is arranged so as to extend from the receiving side of the piping member to the back while inclining. The flap portion at this time has a reduced diameter from the receiving side to the back side of the piping member.

According to the pipe member of the present invention, when the pipe member and the pipe are joined, the pipe can be easily inserted without applying the lubricant to the rubber ring. Further, since the piping member of the present invention can exert the effect of reducing frictional resistance for a long period of time even after insertion, the slidability of the inserted pipe is maintained high, and the pipe can be thermally expanded or contracted or performed after insertion. It can also be used to adjust the amount of pipe insertion.
Since the piping member of the present invention is provided with the rubber ring of the present invention described above, the insertion / pull-out load in the insertion test is 500 N or less, preferably 350 N or less. Further, in the insertion / pull-out test after the long-term fatigue test assuming the influence of the expansion and contraction of the pipe on the rubber ring surface when used for a long period of time, the insertion / pull-out load is 500 N or less, which is 350 N or less. Is preferable.

The piping member of the present invention is preferably used for a pipe-to-pipe joint, a pipe-to-pipe joint, and other pipe joints in a pipe structure. Specific examples of the pipe member of the present invention include joints. Alternatively, a pipe is preferably used. Further, the piping member of the present invention can maintain high slidability of the inserted pipe and can sufficiently cope with thermal expansion and contraction of the pipe. Therefore, the pipe or joint made of resin such as polyvinyl chloride or polyolefin can be used. It is preferably a piping member used for joining.

The piping member of the present invention can be used in either indoor piping or outdoor piping. Further, the piping member of the present invention can be used not only for piping for forming a fluid flow path such as a drain pipe, but also for piping for protecting wiring such as electric wires. However, in consideration of the complexity of the piping structure, the slidability of the pipe, and the like, the piping member of the present invention is preferably used as a drainage joint (more preferably, a so-called expansion joint) installed indoors.

Hereinafter, an example of the piping member of the present invention will be described in detail with reference to FIG. The piping member of the present invention is not particularly limited except that the rubber ring of the present invention is provided as described above, and can be applied to various structures of the piping member.

FIG. 3 is a partial cross-sectional view of an example of the joint of the present invention. The joint 21 shown in FIG. 3 is a cylindrical joint that communicates both ends (insertion port and receiving port), and is an insertion port for inserting into a receiving port of another piping member (for example, a branch merging joint) (not shown). A portion 22, a receiving portion 23 into which an insertion port of another piping member (specifically, a pipe or the like) (specifically, a pipe or the like) is inserted, and a central portion 24 connecting the insertion opening portion 22 and the receiving portion 23 are provided.
In the present specification, the joint radial direction means the radial direction of the circle centered on the central axis of the joint, and the joint circumferential direction means the circumferential direction of the circle centered on the central axis. , The joint axial direction means the direction in which the central axis extends. Here, the central axis of the joint is an axis that passes through the center of the circular cross section of the joint. Further, the inner side in the radial direction of the joint means the side close to the central axis of the joint in the radial direction of the joint, and the outer side in the radial direction of the joint means the side far from the central axis of the joint in the radial direction of the joint.

Further, in the joint 21 of the illustrated example, as shown in the cross section parallel to the joint axial direction, the joint main body 25 and the receiving portion forming the insertion port 22, a part of the receiving portion 23, and the central portion 24. A cap portion 26 that constitutes a part of 23 and covers the end portion of the joint body 25 on the receiving side is provided, and the joint main body 25 and the cap portion 26 form a groove-shaped rubber ring receiving portion in the receiving portion 23. Is formed. Here, the joint 21 includes a rubber ring 27 fitted to a rubber ring receiving portion formed in the receiving portion 23. In FIG. 3, the central axis of the joint 21 and the central axis of the rubber ring 27 coincide with each other.

In the joint 21 of the illustrated example, the rubber ring 27 of the present invention described above is applied to the rubber ring 27, the first surface of the rubber ring body of the present invention faces the receiving side of the joint 21, and the rubber ring body of the present invention. The second surface is arranged so as to face the insertion port side of the joint 21. Here, when the insertion of the pipe from the receiving portion 23 is completed, the joint 21 is in bullet contact with the pipe inserted via the rubber ring 27.

In the joint 21 of the illustrated example, the joint body 25 has a locking portion that prevents the cap portion 26 from coming off on the surface (outer peripheral surface) facing outward in the joint radial direction, and the cap portion 26 has the inner side in the joint radial direction. The facing surface (inner peripheral surface) has a locking portion that prevents the joint body 25 from coming off, and the joint body 25 and the cap portion 26 are fixed by engaging with each other via the locking portions. ing. FIG. 3 shows a locking structure 28 of the joint body 25 and the cap portion 26. The locking structure 28 shown in FIG. 3 extends along the circumferential direction of the joint, but the shape of the locking structure is not limited to this.

The joint body 25 shown in FIG. 3 is provided with three reinforcing flanges 29a, 29b, and 29c extending in the circumferential direction of the joint on the outer peripheral surface located at the central portion 24, and the most of these reinforcing flanges is on the insertion port side. The reinforced flange 29c located has an outer diameter larger than that of the other reinforced flanges 29a and 29b. The number and shape of the reinforcing flanges are not limited to this.

Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited to the following examples.

(Examples 1 to 5 and Comparative Example 1)
A rubber ring (outer diameter 90 mm) made of the material shown in Table 1 and having the structure shown in FIGS. 1 and 2 (excluding the coating film) was produced according to a conventional method.
A coating agent for forming a film having the composition shown in Table 1 was prepared according to a conventional method. When preparing the coating agent, methyl ethyl ketone was used as the solvent.
Next, the rubber ring was coated by spray coating at the coating portion shown in Table 1 so as to have the film thickness shown in Table 1, and then dried at 80 ° C. for 8 hours to prepare a rubber ring having a film.
Further, a rubber ring was attached to a plug socket (nominal diameter 75) manufactured by Sekisui Chemical Co., Ltd. to prepare a test joint having the structure shown in FIG. 3, and the following test was performed. Here, in Comparative Example 1, water was applied to the first inclined surface of the flap portion of the rubber ring mounted on the joint. An Eslon pipe (nominal diameter 75) manufactured by Sekisui Chemical Co., Ltd. was used as a pipe to be inserted into the joint. The results are shown in Table 1.

(1) Initial insertion / pull-out test Using a series of fatigue tester EHF-ED10-70L manufactured by Shimadzu Corporation, a pipe is inserted from the end of the receiving part of the joint at an insertion speed of 100 mm / min, and the pipe is inserted. The load (tube end face) from the state where the end face is in contact with the rubber ring until the end face of the pipe passes through the tip surface 12 of the rubber ring and the side surface of the pipe is in contact with the rubber ring, and the side surface of the pipe is the rubber ring. The load (side surface of the pipe) from the contact with the rubber ring until the end surface of the pipe passed through the second surface of the rubber ring was measured.
Next, the pipe is pulled out at a pulling speed of 100 mm / min, and the load from the state where the end surface of the pipe is below the second surface of the rubber ring to the end surface of the pipe passing through the tip surface 12 of the rubber ring (tube side surface). ), And the load (tube end face) from the state where the side surface of the pipe is in contact with the rubber ring until the end face of the pipe does not come into contact with the rubber ring was measured.

(2) Insertion / pull-out test after long-term fatigue test After joining the joint and the pipe, a 14 mm x 0.5 min insertion / pull-out cycle using a series-type fatigue tester EHF-ED10-70L manufactured by Shimadzu Corporation. A long-term fatigue test was performed 10,000 times.
Then, the insertion / extraction test was performed in the same manner as in "(1) Insertion / extraction test", and the load was measured.

* 1 MoS2: Molybdenum disulfide (average particle size 2 μm)
* 2 PTFE: Polytetrafluoroethylene (average particle size 4 μm)
* 3 Graphite: Graphite (average particle size 2.5 μm)
* 4 Binder resin: Polyurethane resin, Epoxy resin * 5 EPDM: Ethylene propylene diene rubber * 6 CR: Chloroprene rubber * 7 SBR: Styrene butadiene rubber * 8 Coating location: An example with "○" on the first inclined surface is A coating is formed on the first inclined surface 4 and the first surface 6 of the rubber ring shown in FIG. In the example in which the first inclined surface and the second inclined surface are marked with "○", a film is formed on the entire surface of the rubber ring.

In Examples 1 to 3, the insertion / extraction load was 350 N or less in both the initial insertion / extraction test and the insertion / extraction test after the long-term fatigue test, which were good results.
In Example 4, since the second inclined surface was not coated, the load in the insertion / extraction test after the long-term fatigue test was larger than that in Examples 1 to 3.
In Example 5, the initial insertion / extraction test was a good result, but the load in the insertion / extraction test after the long-term fatigue test was larger than 500 N due to the influence of the antiaging agent from the SBR of the rubber ring.
In Comparative Example 1, the load in both the initial insertion / extraction test and the insertion / extraction test after the long-term fatigue test was larger than 500N.

1 Rubber ring 2 Rubber ring body 3 Flap part 4 1st inclined surface 5 Coating 6 1st surface 7 2nd surface 8 Outer peripheral surface 9 Protruding part 10 Inner peripheral surface 11 2nd inclined surface 12 Tip surface 13 Recession 21 Joint 22 Insertion Mouth 23 Receiving part 24 Central part 25 Joint body 26 Cap part 27 Rubber ring 28 Locking structure 29a, 29b, 29c Reinforcing flange

Claims (14)

A rubber ring body having a first surface and a second surface along the rubber ring radial direction,
A flap portion formed inside the rubber ring body in the radial direction of the rubber ring and extending in the circumferential direction of the rubber ring, and a flap portion extending from the first surface side toward the second surface side while being inclined.
A rubber ring formed on a first inclined surface facing inward in the radial direction of the rubber ring in the flap portion, the rubber ring comprising a film containing a solid wetting agent and a binder resin. The rubber ring according to claim 1, wherein the coating film is further formed on a second inclined surface facing outward in the radial direction of the rubber ring at the flap portion. The rubber ring according to claim 1 or 2, wherein the coating film is further formed on a tip surface connecting the first inclined surface and the second inclined surface at the flap portion. The rubber ring according to any one of claims 1 to 3, wherein the solid lubricant is at least one selected from the group consisting of molybdenum disulfide, polytetrafluoroethylene, graphite and boron nitride. .. The rubber ring according to any one of claims 1 to 4, wherein the solid lubricant has an average particle diameter of 0.1 μm or more and 40 μm or less. The binder resin according to claim 1 to 5, wherein the binder resin is at least one selected from the group consisting of polyurethane resin, hydroxyl group-containing fluororesin, epoxy resin, urethane-modified epoxy resin, silicone resin, and polyamideimide resin. The rubber ring according to any one item. The rubber ring according to any one of claims 1 to 6, wherein the film has a film thickness of 1 μm or more and 100 μm or less. The rubber ring according to any one of claims 1 to 7, wherein the rubber constituting the rubber ring contains at least one of chloroprene rubber and ethylene propylene diene rubber. Further, the second ridge portion formed in the rubber ring main body in the radial direction of the rubber ring and extending in the circumferential direction of the rubber ring, and the position of the rubber ring main body to which the flap portion is fixed is higher than the position of the rubber ring main body. The rubber ring according to any one of claims 1 to 8, further comprising a ridge portion located on the surface side. The rubber ring according to any one of claims 1 to 9, further comprising a recess formed in the rubber ring body on the outer side in the radial direction of the rubber ring and extending in the circumferential direction of the rubber ring. The rubber ring according to any one of claims 1 to 10, wherein both the first surface and the second surface are flat. A piping member comprising the rubber ring according to any one of claims 1 to 11. A joint comprising the rubber ring according to any one of claims 1 to 11. A tube comprising the rubber ring according to any one of claims 1 to 11.

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