JP6183992B2 - Pipe joint, seal ring for pipe joint, and pipe connection method of pipe joint - Google Patents

Description

  The present invention relates to, for example, a pipe joint capable of connecting a pipe such as a cross-linked polyethylene pipe or a polybutene pipe to a pipe for water supply or hot water supply of a residential facility with a single touch, a seal ring for the pipe joint, and a pipe connection method of the pipe joint.

In recent years, water supply and hot water supply pipes for residential facilities and the like are mostly constructed using resin pipes such as cross-linked polyethylene pipes and polybutene pipes. When pipes such as resin pipes are connected, construction is easy. For this reason, one-touch type pipe joints are often used.
As this kind of one-touch type pipe joint, there are known an inner peripheral seal structure for sealing the inner peripheral surface of the pipe with a seal member, an outer peripheral seal structure for sealing the outer peripheral surface of the pipe, or a structure for sealing both surfaces. ing. In such a joint, in addition to ensuring the sealing performance after the pipe connection, it is necessary to consider the durability against catching on the seal member when the pipe is connected. Conventionally, chamfering to the inner and outer peripheral edges of the pipe cutting surface has been carried out as a countermeasure against catching of the cut surface of the pipe end surface to the seal member, but this chamfering work is omitted to improve workability. It has become desirable.

As a technique other than chamfering, for example, as shown in the prior art of Patent Document 1, a technique in which an in-core is inserted into a cut end surface of a pipe is known. In this case, the seal member is mounted inside the joint with an outer peripheral seal structure, and the pipe is inserted while the tapered surface formed on the end surface side of the in-core goes over the seal member to prevent damage to the seal member. .
In the plug-in type pipe joint of Patent Document 2, an elastic seal ring that is an O-ring is attached to the groove in the inner cylindrical body of the joint with an inner peripheral seal structure, and when inserting the resin pipe, the insertion guide is pushed at the end face of the resin pipe. It is intended to get over the O-ring through the insertion guide.
In the plug-in type pipe joint of Patent Document 3, the packing as a seal member is formed of an annular ring having a left-right asymmetric shape that is different from the O-ring shape, and the edge of the resin pipe cut surface passes through the seal member in this packing shape. I am trying to suppress the catch when I do.
In the pipe joint of Patent Document 4, a clearance is secured between the inner diameter of the resin pipe and the seal member to prevent damage to the seal member, and when the resin pipe is connected, the inside of the joint is tightened after the resin pipe passes through the seal member. The ring-attached body grips the outer periphery of the resin tube so that the inner diameter side of the tube is in close contact with the seal member.
In Patent Document 5, the seal member is mounted in the mounting groove of the joint body by the inner peripheral seal structure, the axial length of the seal member is set longer than the radial length, and the inclined surface is provided on the outer peripheral surface of the seal member. The maximum inclination angle of the inclined surface is set to be smaller than the maximum inclination angle of the virtual sealing member having a circular cross section, thereby preventing the resin pipe end surface from biting into the sealing member.
On the other hand, when the dimensions of the pipes to be inserted into the specified pipe joints are controlled and the applicable pipes are limited to minimize fluctuations in the pipe dimensions, and seal members such as O-rings are designed with the minimum necessary compression allowance There is also.

Japanese Patent No. 2685105 Japanese Patent No. 4268811 JP 2009-180272 A Japanese Patent No. 3411546 JP 2010-101406 A

In the case of connecting pipes using an in-core as in the prior art of Patent Document 1, when the outer peripheral seal structure is compared with the inner peripheral seal structure, the outer peripheral seal structure reduces the diameter of the seal member formed in advance with a larger outer diameter. Therefore, in a mounted state in which a compressive force is applied to the seal member, the seal is further compressed by the pipe, resulting in poor durability. In addition, since the outer diameter is reduced, the diameter reduction limit of the material is reduced, and when the seal member is attached, the material is fitted into the inner circumferential groove while resisting the force to increase the diameter. Since the seal member is mounted in a compressed state, the direction in which the seal member is engaged with the pipe is the same as the compression direction, and the force that the encapsulated seal member returns to the inner circumferential groove does not work. At the time of manufacturing the joint body, it is necessary to perform boring to form the inner circumferential groove, or it is necessary to form the inner circumferential groove with a separate member, which leads to high costs.
As described above, the seal member of the outer periphery seal structure is disadvantageous in various respects as compared with the inner periphery seal structure, and the outer periphery of the tube by rough handling of the pipe at the time of piping construction or by a cutter in the pipe If the side surface is scratched, sufficient sealing performance may not be exhibited and water leakage may occur.

The plug-in type pipe joint of Patent Document 2 has an inner peripheral seal structure using an O-ring. When a resin pipe is inserted straight into the O-ring, sealing performance is ensured, but one end of the resin pipe is If the resin pipe is inserted in an oblique direction or in a screwed state if it is constrained or remains bent, the insertion guide will cut the resin pipe if it is connected more than once. In some cases, the seal member is caught and bitten away from the surface.
In addition, since the resin tube comes into contact with the portion protruding from the mounting groove and compresses and seals, the protruding portion is relatively larger than the mounting portion, and the mounting volume to the mounting groove with respect to the volume of the protruding portion is reduced. Therefore, when the seal member is bitten, the seal portion is pulled out with the biting side facing portion remaining in the mounting groove, and this portion is between the inner peripheral surface of the resin tube and the inner cylinder. The attachment part may be pulled by the biting part, and the entire sealing member may be detached from the attachment groove, making it easier to remove when the protruding part is enlarged to improve the sealing performance. .
Since there are two O-rings, if the first O-ring close to the insertion side bites, both of them may be lost across the second O-ring. On the other hand, when only the second O-ring is caught, the first O-ring remains, but the resin tube is deformed by the second O-ring being caught in the gap, and the annular seal of the first O-ring is Non-uniform seal surface pressure. If it continues to be used in this state, it tends to lead to leakage over time.
Thus, when an O-ring is used as the seal member in the inner peripheral seal structure, it is difficult to achieve both sealing performance and tensile durability when the resin pipe is connected. In addition, since the O-ring is usually mounted in the mounting groove with almost no diameter expansion, it is easily pulled when it is bitten.

In the case of Patent Document 3, in order to prevent the sealing member from popping out from the packing fitting groove when the resin pipe is inserted, a tapered groove side wall is formed deeply and the sealing member is constricted in the groove side wall. It is necessary to mount in a state in which the contact area of the end surface of the taper is increased. However, when the mounting volume of the seal member is increased, the exposed surface of the seal portion becomes wider, and the seal member may be attracted to one side in the fitting groove by being caught by the resin tube inserted from an oblique direction. In this case, the resin tube cannot be inserted any more and the joining becomes incomplete.
Since the seal member has directionality at the time of mounting, there is a possibility that it is erroneously mounted in the reverse direction. In this case, the sealing performance is adversely affected and fluid leakage is likely to occur.

  The pipe joint of Patent Document 4 has the same problems as Patent Document 1 because the seal member is a normal O-ring, and further, a clearance between the resin pipe inner diameter and the seal member when the resin pipe is inserted is ensured. Therefore, this problem becomes larger when the volume of the seal member is reduced. In particular, with the inner circumference seal structure, it is difficult to increase the wire diameter that affects the volume of the O-ring because of the need to secure the water passage diameter of the joint, which is disadvantageous in terms of durability when the volume is reduced. Become. Furthermore, in this pipe joint, when an impact is applied to the pipe joint due to dropping or the like, the diameter-expanding piece that forcibly expands the diameter of the fastening ring is removed, and the diameter of the fastening ring is reduced to connect the resin pipe. It may not be possible.

  The pipe joint of Patent Document 5 prevents biting into the seal member to prevent scratching and biting of the seal member. However, the seal member can be removed by improving the pulling durability when inserting the resin pipe. It is not disclosed or suggested to prevent. For this reason, in this seal member, when the end surface of the resin tube bites into the seal member, the seal member may be pulled by the resin tube and detached. Moreover, in this pipe joint, the maximum inclination angle of the inclined surface is set smaller than the maximum inclination angle of the virtual seal member having a circular cross section, and the curvature radius of the arc surface of the outer peripheral surface is larger than the curvature radius of the outer peripheral surface of the virtual seal member. By being large, the sealing member seals the outer periphery of the resin tube by surface contact. As a result, the seal surface pressure is weaker and the sealing performance is worse than that of the virtual seal member (O-ring).

  On the other hand, when managing the dimensions of the pipe to suppress the dimensional variation, the manufacturer is limited depending on the pipe used, and the versatility of the joint is lost. In addition, even if a resin pipe having a predetermined dimension is selected according to the pipe joint, there is a risk of biting the seal member when the resin pipe is inserted in an oblique direction, inserted while being screwed, or repeatedly inserted twice or more. Still remains.

  The present invention has been developed in order to solve the conventional problems. The purpose of the present invention is to connect the pipes with a single touch while ensuring the sealing performance even when there is a flaw on the outer circumference of the pipe due to the inner peripheral seal structure. This is a pipe joint that improves the durability against pulling caused by biting when inserting the pipe, and prevents the seal ring from coming off even if the pipe is inserted diagonally or screwed or the pipe is repeatedly inserted. It is another object of the present invention to provide a pipe joint that can prevent fluid leakage by ensuring sealing performance equivalent to that of an O-ring seal.

In order to achieve the above object, the invention according to claim 1 connects a pipe for connection to be inserted into a gap between an inner cylinder and an outer cylinder provided in a joint body in a pull-out preventing state with a retaining member, and An outer peripheral groove having a substantially rectangular cross section is provided on the outer peripheral surface of the inner cylinder, and the pipe joint is hermetically connected by a seal ring attached to the outer peripheral groove. The seal ring has a substantially rectangular cross section attached to the outer peripheral groove. An annular pedestal, an outer peripheral O-ring portion integrally formed on the outer periphery of the annular pedestal from the outer peripheral surface, and a rounded protrusion integrally provided on the inner periphery of the annular pedestal to increase the seal surface pressure It is a pipe joint which consists of a part.

According to a second aspect of the present invention, the outer peripheral O-ring portion is formed in a state protruding from the outer peripheral surface at the outer peripheral central portion of the annular pedestal, and the wire diameter of the outer peripheral O-ring portion is the circumferential direction of the seal ring And a substantially rectangular cross-sectional area of the annular pedestal is 65 to 75% of the cross-sectional area of the outer circumferential groove .

According to a third aspect of the present invention, a pipe for connection to be inserted into a gap between an inner cylinder and an outer cylinder provided in a joint main body is connected in a pull-out preventing state by a retaining member, and is provided on an outer peripheral surface of the inner cylinder. A pipe joint provided with an outer peripheral groove having a substantially rectangular cross section and hermetically connected by a seal ring attached to the outer peripheral groove. The seal ring includes an annular pedestal having a substantially rectangular cross section attached to the outer peripheral groove, and An outer peripheral O-ring portion formed integrally and projecting from the outer peripheral surface on the outer periphery of the annular pedestal, and a round-shaped projecting portion integrally formed on the inner periphery of the annular pedestal to increase the seal surface pressure are formed. Next, when the one end of the tube is inserted into the gap, the outer peripheral O-ring portion seals the inner peripheral surface of the tube and the seal other than the outer peripheral O-ring portion remaining in the outer peripheral groove. The ring part is not pulled out from the outer peripheral groove. In a tube connecting method of the pipe joint for inserting the tube while positioning the sealing ring on the outer circumferential groove.

According to the first aspect of the present invention, a pipe for connection can be inserted between the inner cylinder and the outer cylinder, and can be connected with one touch while being prevented from being pulled out by the retaining member. Even if there is, the sealing performance is secured by the inner peripheral seal structure with the seal ring attached to the outer peripheral groove of the inner cylinder. An annular pedestal having a substantially rectangular cross section and an outer peripheral O-ring projecting from the outer peripheral surface of the inner cylinder are integrally formed on the outer periphery of the annular pedestal. The volume can be increased, and the volume of the outer peripheral O-ring can be reduced as compared with the annular pedestal. An annular pedestal that remains in the outer circumferential groove compared to the volume of the outer circumferential O-ring portion that is about to be pulled out of the outer circumferential groove even if it is caught, even if the outer circumferential O-ring portion can be made smaller, making it difficult for the tube to bite. Since the volume of is large, the whole is pulled back into the outer peripheral groove. This can improve the pulling durability against the biting of the end face of the pipe, and even if the pipe is inserted in an oblique direction or in a screwed state or the pipe is repeatedly inserted, the seal ring is prevented from being detached. An excellent sealing property can be secured by maintaining the sealing state. The outer peripheral O-ring contacts and seals the pipe and exhibits the same sealing performance as a general O-ring, and the surface contact sealing force can be increased by the line contact seal to reliably prevent fluid leakage. In particular, the round-shaped protrusion can increase the seal surface pressure on the inner peripheral surface of the seal ring, and this protrusion and the outer peripheral O-ring provide a seal surface pressure equivalent to that of a general O-ring shaft seal. Even if pressure is applied from one side in the axial direction and the seal ring moves in the outer circumferential groove, the seal surface pressure can be maintained.

According to the invention according to claim 2, by forming the outer peripheral O-ring portion to protrude from the outer peripheral center portion of the annular pedestal, the mounting property of the seal ring to the outer peripheral groove is improved, and the workability is also improved and easy to manufacture, When the seal ring is installed, even if the wire diameter shrinks due to the pulling force in the centripetal direction, it retains the mounting ability to the outer peripheral groove, ensures the pulling durability of the seal ring and prevents the separation. A constant sealing surface pressure by the O-ring part can be exhibited.
By setting the wire diameter of the outer peripheral O-ring part to 40 to 70% of the cross-sectional height in the circumferential direction of the seal ring, even if the seal ring diameter is different, the pipe can be securely bitten while maintaining the sealing performance. To prevent. Further, by setting the substantially rectangular cross-sectional area of the annular pedestal to 65 to 75% with respect to the cross-sectional area of the outer peripheral groove, a clearance space for accommodating the outer peripheral O-ring portion can be secured with a margin. For this reason, even if the pipe inner diameter of the joint body becomes small and it is difficult to form a large outer peripheral groove, a seal ring having an annular pedestal corresponding to the outer peripheral groove can be provided. Even if there is, the function of preventing biting into the seal ring can be exhibited to prevent the seal ring from being detached.

The relief space for the outer circumferential O-ring portion due to the insertion of the tube is deformed when mounting the sheet Ruringu the peripheral groove secured between the outer circumferential groove and the annular seat, while maintaining the sealing property during the seal ring deformation The biting of the tube can be prevented.

By providing the inclination of 3-6 degrees toward the outer O-ring in the ring-shaped pedestal, the outer periphery and inserted obliquely into the pipe joint tube, is inserted at the time of an edge portion of the end surface of the tube is beveled ends It progresses so as to slide naturally toward the tip of the O-ring part and becomes difficult to bite. By providing an angle in this way, it becomes easy to separate from the mold during the molding process of the seal ring, and furthermore, it is easy to remove from the mold by connecting the slope and the outer peripheral O-ring part with a smooth round shape. And the biting prevention property can be improved.

It is possible to improve the wearability of the annular seat to the outer peripheral groove, it is possible to prevent detachment of the seal ring from the outer peripheral groove fitted with an annular seat at a predetermined position of the circumferential groove

By the outer diameter of the outer peripheral groove to 110-125% of the seal ring inner diameter, it is attached to the outer circumferential groove in a state where the seal ring is pulled. This makes it difficult for the seal ring to come out of the outer peripheral groove, and the separation of the seal ring when the pipe end face is caught is reliably prevented. Furthermore, even when the inner diameter of the tube varies depending on the standard and the tube type, the seal ring can be made common. In addition, since the seal ring is mounted while acting to reduce the force in the centripetal direction, the mounting force on the outer peripheral groove of the annular pedestal increases, and the seal ring is more difficult to drop off.

By mounting with the inner peripheral seal structure, excellent sealing performance is exhibited even when there is a flaw on the outer periphery of the pipe. An annular pedestal having a substantially rectangular cross section and an outer peripheral O-ring projecting from the outer peripheral surface of the inner cylinder are integrally formed on the outer periphery of the annular pedestal, thereby increasing the volume of the annular pedestal when the outer peripheral groove is mounted. Compared to the annular pedestal, the volume of the outer peripheral O-ring portion can be reduced. An annular pedestal remaining in the outer circumferential groove compared to the volume of the outer circumferential O-ring part that is about to be pulled out of the outer circumferential groove even if it is bitten by any chance, since the pipe becomes difficult to bite because the outer circumferential O-ring part can be made smaller. Since the volume of is large, the whole is pulled back into the outer peripheral groove. This can improve the pulling durability against the biting of the end face of the tube, and even if the tube is inserted in an oblique direction or screwed state or the tube insertion operation is repeated, it is prevented from being detached and the sealed state is maintained. Excellent sealing performance. In addition, since the mounting force is applied while a force to shrink in the centripetal direction is exerted, the mounting force on the outer peripheral groove of the annular pedestal increases, and it becomes more difficult to drop off. The outer peripheral O-ring is in contact with the pipe and seals to achieve the same sealing performance as a general O-ring. The line contact seal increases the surface pressure sealing force and reliably prevents fluid leakage.

Line the outer circumferential O-ring portion is improved attachment of the outer peripheral groove by protruding on the outer peripheral center portion of the annular seat, easily fabricated improved its processability, tensile force at the time of mounting to the centripetal direction Even when the diameter is reduced, the mounting ability to the outer peripheral groove is maintained, the pulling durability is ensured to prevent separation, and a constant seal surface pressure by the outer peripheral O-ring portion can be exhibited. Since the cross-sectional shape of the outer peripheral O-ring protruding from the outer peripheral central part is symmetrical, there is no mounting directionality to the outer peripheral groove, and it can be mounted using the same outer peripheral groove as a general O-ring. The same handling as the ring is possible.
By setting the wire diameter of the outer peripheral O-ring part to 40 to 70% with respect to the cross-sectional height in the circumferential direction, even when the diameters are different, the biting of the pipe is reliably prevented while maintaining the sealing performance.

According to the third aspect of the present invention, the pipe for connection can be inserted between the inner cylinder and the outer cylinder, and this pipe can be connected with one touch while keeping the pull-out preventing state with the retaining member. Even when the outer periphery is scratched, the inner peripheral seal structure in which the seal ring is mounted in the outer peripheral groove of the inner cylinder exhibits excellent sealing performance. The seal ring is formed integrally with an annular pedestal having a substantially rectangular cross section and an outer peripheral O-ring projecting from the outer peripheral surface of the inner cylinder on the outer periphery of the annular pedestal. The volume of the pedestal can be increased, and the volume of the outer peripheral O-ring portion can be reduced compared to the annular pedestal. By making the outer periphery O-ring part smaller, it becomes difficult to bite the pipe, and even if it is caught, the annular pedestal remaining in the outer groove compared to the outer periphery O-ring part that is about to be pulled out from the outer groove Since the volume is large, the whole is pulled back into the outer circumferential groove. Therefore, it is possible to improve the pulling durability against the biting of the pipe end surface, and even if the pipe is inserted in an oblique direction or screwed state or the pipe is repeatedly inserted, the seal ring is not pulled out from the outer circumferential groove. It is possible to connect the pipes while ensuring a predetermined sealing property by the seal ring. After the pipe is connected, the outer ring O-ring seals against the pipe and exhibits sealing performance equivalent to that of a general O-ring, and fluid leakage can be reliably prevented while increasing the surface pressure sealing force with the line contact seal. . In particular, the round-shaped protrusion can increase the seal surface pressure on the inner peripheral surface of the seal ring, and this protrusion and the outer peripheral O-ring provide a seal surface pressure equivalent to that of a general O-ring shaft seal. Even if pressure is applied from one side in the axial direction and the seal ring moves in the outer circumferential groove, the seal surface pressure can be maintained.

It is a top view which shows 1st Embodiment of the pipe joint in this invention. It is a partially expanded sectional view of the seal ring for pipe joints. It is the schematic sectional drawing which showed the state before mounting | wearing of an insertion guide. FIG. 2 is a central cross-sectional view showing a state where a tube is inserted from the state of FIG. 1. FIG. 5 is a central cross-sectional view showing a state where a tube is further inserted from the state of FIG. 4. FIG. 6 is a central cross-sectional view showing a state where a tube is further inserted from the state of FIG. 5. FIG. 7 is a central cross-sectional view showing a state where a tube is further inserted from the state of FIG. 6. It is a top view which shows 2nd Embodiment of the pipe joint in this invention. It is a center sectional view showing the seal ring for pipe joints in FIG. It is a top view which shows 3rd Embodiment of the pipe joint in this invention. It is a center sectional view showing the seal ring for pipe joints in FIG.

  Below, the pipe joint in this invention and the seal ring for pipe joints are demonstrated. In FIG. 1, 1st Embodiment of the pipe joint in this invention is shown, In FIG. 2, the partial expanded sectional view of the seal ring with which a pipe joint is mounted | worn is shown. The nominal diameter of the pipe joint is assumed to be 10A to 20A, and FIG. 2 is a cross section showing the shape of the seal ring at the nominal diameter 10A.

  In FIG. 1, the pipe joint of the present invention has a joint body 1, an inner cylinder 2 is integrally provided on the joint body 1, and an outer cylinder 3 provided separately is attached. . A pipe 10 to be connected is inserted into the gap 5 between the inner cylinder 2 and the outer cylinder 3, and this pipe 10 is connected to a pull-out preventing state by a retaining member 11 made of a lock ring. A rubber seal ring 20 and an annular holding body 21 are attached to the pipe joint, and an insertion guide 22 is mounted in the pipe joint.

  The pipe for connection 10 is composed of, for example, a cross-linked polyethylene pipe, a polybutene pipe, etc. In addition to these, various resin pipes such as a metal reinforced polyethylene pipe, or a metal pipe such as a copper pipe may be used. This pipe is used for water supply and hot water supply. An insertion guide 22 is provided on the distal end side of the pipe 10, and the pipe 10 is connected to the pipe joint while being guided by the insertion guide 22.

  The joint body 1 is formed in a cylindrical shape from a highly rigid resin such as a metal such as a copper alloy or PPS (polyphenylene sulfide resin), and has a water passage port 23. The connection side of the joint body 1 with the pipe for connection 10 is provided with an appropriate outer diameter corresponding to the inner diameter of the pipe 10. On the tube 10 connection side, an uneven engaging portion 24 for attaching the outer cylinder 3 is provided, while on the other side, a male screw portion 25 is provided. Members or other external piping can be connected. In addition to the illustrated linear shape, the joint body 1 may be, for example, a cheese shape or an elbow shape.

  An outer peripheral groove 26 having a substantially rectangular cross section is formed on the outer peripheral surface of the inner cylinder 2 of the joint body 1, and the seal ring 20 is attached to the outer peripheral groove 26. In this case, the outer circumferential groove 26 is formed at two locations, that is, the opening side that is the outlet side of the pipe 10 of the joint body 1 and the insertion side of the pipe 10 from the opening side. 20 and 20 are mounted, respectively. The joint main body 1 is configured so that the pipe 10 can be hermetically connected by the two seal rings 20 and 20. At this time, the seal ring 20 on the opening side is disposed to face the portion in which the retaining member 11 is accommodated, and the seal ring 20 on the insertion side is disposed to face the inner periphery of the outer cylinder 3.

The seal ring 20 is made of NBR, EPDM, or other materials such as fluoro rubber, and in the case of fluoro rubber, durability is higher than that of EPDM (ethylene propylene rubber) generally used as this type of O-ring. Excellent in chlorine resistance. Further, when a fluororubber seal ring is used, it is possible to suppress the biting of the tube by utilizing the sliding property of fluorine.
The seal ring 20 includes an annular pedestal 30 having a substantially rectangular cross section that can be mounted in the outer circumferential groove 26, and an outer peripheral O-ring portion 32 that can protrude from the outer peripheral surface 31 of the inner cylinder 2 on the outer periphery of the annular pedestal 30. Is formed.

The outer peripheral O-ring part 32 is formed in the outer peripheral center part 30 a of the annular pedestal 30 so as to be able to protrude from the outer cylinder outer peripheral surface 31. In FIG. 2, the wire diameter of the outer peripheral O-ring portion 32, that is, the diameter D in the cross-sectional direction is the sum of the heights of the outer peripheral O-ring portion 32 and the annular pedestal 30. In contrast, it is formed at 40 to 70%. The dimension of the diameter D is appropriately set according to the nominal diameter of the pipe joint and the inner diameter dimension of the pipe 10. If it is less than 40%, the volume required for the sealing performance with respect to the tube 10 cannot be obtained, and if it exceeds 70%, deformation of the outer peripheral O-ring portion 32 described later becomes insufficient.
Here, the cross-sectional height H is set substantially equal to the wire diameter D1 of the O-ring 36 used in the conventional pipe joint. The outer peripheral O-ring portion 32 is formed at the outer peripheral center portion of the annular pedestal 30, and the cross-sectional shape of the seal ring 20 is bilaterally symmetrical by the outer peripheral O-ring portion 32, so that there is no mounting directionality in the outer peripheral groove 26. In addition, since the sealing performance is effectively exhibited even when the wire diameter is reduced by pulling, and it can be mounted using the outer peripheral groove 26 similar to the O-ring 36, the same handling as the O-ring 36 becomes possible. Yes.

  On the other hand, the annular pedestal 30 is provided with an inclined portion 33 of 3 to 6 degrees inclined at an angle α from the horizontal direction toward the outer peripheral O-ring portion 32 in FIG. . In this embodiment, in the enlarged cross-sectional view of FIG. 2, the annular pedestal 30 is provided symmetrically with respect to the outer peripheral O-ring portion 32, and in this case, the outer peripheral O-ring portion 32 has a wire diameter D due to the insertion of the tube 10. Stable durability can be demonstrated even when the size becomes smaller.

  Further, the annular pedestal 30 is provided with a substantially rectangular cross section, so that the filling rate of the outer circumferential groove 26 is increased, and the substantially rectangular cross sectional area S1 of the annular pedestal 30 (hatching in FIG. 2). And the cross-sectional area of the portion sandwiched between two-dot chain lines is 65 to 75% of the cross-sectional area S2 of the outer circumferential groove 26 of the joint body 1. This numerical range is such that the annular pedestal 30 remains in the outer circumferential groove 26 and bites the entire sealing ring 20 when a tensile force is applied to the outer circumferential O-ring portion 32 by inserting the tube 10 into the sealing ring 20 mounted in the outer circumferential groove 26. It is quantified from the volume of the annular pedestal 30 that is necessary for pulling it back.

In particular, if it is less than 65%, the seal ring 20 may not be pulled back sufficiently. In addition, the above numerical range is quantified with respect to the clearance space G necessary for accommodating a part of the outer peripheral O-ring portion 32 that is deformed with the insertion of the tube while maintaining the adhesion with the tube 10. Is. In particular, if it exceeds 75%, it is insufficient to accommodate a part of the outer peripheral O-ring portion 32, and the seal ring 20 may bite into the insertion guide 22 or the tube 10.
The above numerical range is appropriately set depending on the material of the seal ring 20 and the like, and is shown as an example of an FKM seal ring in the present embodiment.
In general, when the inner diameter of the tube 10 becomes smaller, it becomes difficult to form the outer peripheral groove 26 larger. Therefore, as the inner diameter of the tube 10 becomes smaller, it becomes more difficult to prevent biting. However, when the ratio of the cross-sectional area is set, biting can be prevented even with a small pipe inner diameter.

The volume in the present embodiment means the volume of the outer peripheral O-ring portion 32 or the annular pedestal 30 in the seal ring 20. However, since the seal ring 20 is an annular body having a constant cross-sectional shape in a plane parallel to the axis, the volume in the present embodiment will be described based on the cross-sectional shape and the cross-sectional area.
The numerical values such as the cross-sectional area and the cross-sectional shape will be described based on the shape of the seal ring 20 before being attached to the outer peripheral groove 26 of the pipe joint unless otherwise specified.

The width direction of the annular pedestal 30 is formed to be slightly smaller than the groove width direction of the outer circumferential groove 26, so that when the seal ring 20 is attached to the outer circumferential groove 26, the side surface portion of the annular pedestal 30 is defined as the outer circumferential groove 26. Since it can avoid making it contact an opposing surface, the mounting | wearing property of the seal ring 20 improves.
On the inner side of the annular pedestal 30 that is the inner peripheral surface of the seal ring 20, a round-shaped protruding portion 35 is provided at a position symmetrical to the outer peripheral O-ring portion 32, and the seal ring 20 (annular pedestal 30) is placed in the outer peripheral groove 26. When attached to, the projecting portion 35 comes into pressure contact with the bottom surface side of the outer circumferential groove 26, thereby increasing the seal surface pressure by the seal ring 20.

  The outer diameter L1 of the outer circumferential groove 26 is formed to be 110 to 125% of the inner diameter L2 of the seal ring 20. Thus, if the outer circumferential groove outer diameter L1 is larger than the seal ring inner diameter L2, the seal ring 20 is mounted in a state of being stretched on the outer circumferential groove 26. As a result, the seal ring 20 is strongly attached to the outer circumferential groove 26 and is not easily bitten, and the diameter expansion rate is set larger than the diameter expansion rate (about 105%) of a general O-ring. Even if the inner diameter of the pipe varies depending on the standard and the pipe type, the seal ring 20 can be used while being shared with a preferable tension. When the diameter expansion rate of the seal ring 20 is greater than 125%, it is difficult to attach the seal ring 20 to the outer circumferential groove 26.

  The seal ring 20 tries to expand its diameter by the outer circumferential groove 26 at the time of mounting. However, since the force to return to the original shape by the elastic force of the seal ring 20 main body also works, it is almost the same as the diameter before mounting. Therefore, a very small gap is formed between the side surface portion of the seal ring 20 and the opposing surface of the outer circumferential groove 26, but the sealing performance when the tube 10 is inserted by the outer circumferential O-ring portion 32 and the rounded protrusion 35. Therefore, no leakage occurs from this gap. Although not shown, a protrusion may be provided on the side surface of the annular pedestal 30, and the seal ring 20 may be mounted while the protrusion is in contact with the outer circumferential groove 26.

  As described above, the substantially rectangular cross-sectional area of the annular pedestal 30 is set to 65 to 75% with respect to the cross-sectional area of the outer peripheral groove 26, so that the outer peripheral O-ring portion 32 is deformed when the seal ring 20 is attached to the outer peripheral groove 26. A time clearance space G is secured between the outer circumferential groove 26 and the annular pedestal 30. For this reason, the sealing performance when the seal ring 20 is deformed is improved. Even when the pipe inner diameter of the joint body 1 is small and it is difficult to make the outer peripheral groove 26 large, the function of preventing the biting into the seal ring 20 can be reliably exhibited by providing the annular pedestal 30 corresponding to the outer peripheral groove 26. This prevents the seal ring 20 from being detached.

  The outer diameter dimension of the seal ring 20 is set to be equal to that of a conventional O-ring in a pipe joint. Thereby, the adhesiveness which followed the dimensional tolerance of the internal diameter prescribed | regulated to the JIS specification etc. of the to-be-connected pipe | tube 10 is obtained.

  Here, as described above, the outer peripheral O-ring portion 32 of the seal ring 20 is set to have a smaller diameter than the wire diameter of the conventional O-ring in the pipe joint. become.

  However, since the escape space G is secured between the outer circumferential groove 26 and the annular pedestal 30 at the side position of the outer circumferential O-ring portion 32, the outer circumferential O-ring portion 32 is inserted into the insertion guide when the pipe 10 is inserted. 22 or when the insertion guide 22 is not provided, the tube 10 is deformed with the contact of the tube 10, and a part of the outer peripheral O-ring portion 32 is accommodated in the escape space G while maintaining close contact with the tube 10.

Therefore, according to the seal ring according to the present invention, the insertion guide 22 is provided to the seal ring 20 regardless of whether or not the insertion guide 22 is provided while ensuring the adhesion that follows the dimensional tolerance of the inner diameter of the tube 10. Biting can be prevented and separation can be prevented.
Moreover, because of the annular pedestal 30 provided in the seal ring 20 and the relatively large diameter expansion rate, the seal that tends to be detached from the outer circumferential groove 26 when the insertion guide 22 or the insertion guide 22 is not provided is brought into contact with the tube 10. The ring 20 can be pulled back to the outer circumferential groove 26, and the sealing performance can be maintained.

  When the tube 10 is inserted into the joint obliquely or when the tube 10 whose end face is cut obliquely without using the insertion guide 22 is inserted, the insertion guide 22 and the tube 10 are at the root of the outer peripheral O-ring portion 32. There is a risk of being strongly pressed partially. However, according to the seal ring of the present invention, the small-diameter outer peripheral O-ring portion 32, the inclined portion 33, and the like can prevent biting and drawing.

  The outer cylinder 3 attached to the joint body 1 is provided with a transparent or semi-transparent material such as non-crystalline nylon or PPSU (polyphenylsulfone resin), and the state of the tube 10 and the insertion guide 22 from the outside. Can be seen through. At the attachment position of the outer cylinder 3 to the joint body 1, an engagement portion 40 that can be snap-fitted with the engagement portion 24 is provided, and an uneven engagement step is provided on the outer peripheral side of the other end side. A portion 41 is provided. The outer cylinder 3 is rotatably integrated with the joint main body 1 by snap fitting of the engaging portions 24 and 40, and the outer cylinder 3 and the joint main body 1 are in a state of being rotatable with respect to each other. A gap 5 is formed, and the tube 10 is connected while being guided by the gap 5. An R surface portion is formed on the contact side of the inner periphery of the outer cylinder 3 with the insertion guide 22, and a tapered surface portion is formed on the opening side of the R surface portion.

  The annular holder 21 is formed in a cap shape with a resin such as polyacetal having a higher tensile elastic modulus than that of the outer cylinder 3. On the inner peripheral side of the annular holding body 21, an engagement step portion 42 that is snap-fitted to the engagement step portion 41 of the outer cylinder 3 is formed. The annular holder 21 is rotatably attached to the opening side of the outer cylinder 3 by snap fitting of the engaging step portions 41 and 42. An annular protrusion 43 protruding in the inner circumferential direction is formed on the end portion side of the annular holding body 21, and the retaining member 11 is prevented from being pulled out by the annular protrusion 43. The annular holder 21 may be a material that does not have transparency, and may be provided as a bush, for example, in addition to being provided as a cap.

  The retaining member 11 is formed in a substantially annular shape from stainless steel or the like, and has a ring shape having an annular portion 50 and a claw portion 51 on the inner diameter side of the annular portion 50. The claw portion 51 is bent at a predetermined inclination angle from the annular portion 50, and the claw portion 51 is locked to the surface of the tube 10 while the tube 10 is smoothly inserted by the claw portion 51, so that the pulling load is reduced. When added, it quickly holds the tube 10 and exerts a pull-out preventing force. Although not shown, the inner diameter of the claw portion 51 on the tip side is formed to be substantially the same diameter as a step portion 60 of the insertion guide 22 described later.

  The retaining member 11 is mounted in the joint body 1 while the annular portion 50 is housed between the open end 3a of the outer cylinder 3 and the inner peripheral surface 21a of the annular holder 21, and at this time, the retaining member The seven claw portions 26 and the seal ring 20 are disposed to face each other. In this case, a space portion for accommodating the annular portion 50 of the retaining member 11 is formed between the opening end 3a and the inner peripheral surface 21a.

  The insertion guide 22 is provided with an elastic resin such as high-density polyethylene, for example, and is mounted so as to be externally fitted to the joint body 1 between the retaining member 11 and the seal ring 20. When the tube 10 is inserted, the tube 10 can be smoothly inserted while pressing the seal ring 20 with the insertion guide 22.

  As shown in FIG. 3, the insertion guide 22 has a rounded surface 61 on the distal end side, a contact surface 63 following the rounded surface 62, and a rear rounded surface 64, and further includes a slit 65 and a stepped portion 60. A locking claw portion 66 is formed. A plurality of slits 65 are formed in the axial direction alternately from the front end side and the rear end side of the insertion guide 22, and the insertion guide 22 can be deformed in the radial direction by the slit 65, and is deformed according to the end surface shape of the tube 10. The tube 10 can be guided. Even when the end surface of the tube 10 is cut obliquely by the slit 65, the insertion guide 22 is deformed following this shape.

  The step portion 60 is provided on the outer peripheral side of the insertion guide 22 so that the claw portion 51 of the retaining member 11 can be temporarily attached. The insertion guide 22 is formed so as to increase in diameter from the step portion 60 to the rear end side. The The locking claw portions 66 are formed on the outer periphery of the insertion guide 22 so as to protrude, for example, at four positions at equal intervals.

  When the insertion guide 22 is inserted into the joint body 1 from the opening side, the rounded surface 61 first comes into contact with the outer peripheral O-ring portion 32 and is guided through the rounded surface 61 as shown in the sectional view of FIG. Easy insertion is possible. When the insertion guide 22 is subsequently inserted, the rounded surface 61 gets over the outer peripheral O-ring portion 32 and the outer peripheral O-ring portion 32 comes into contact with the contact surface 63. At this time, the insertion guide 22 is expanded and contracted via the slit 65. Thus, a large load is not applied to the retaining member 11 and the seal ring 20. Further, the insertion is continued, the locking claw portion 66 of the insertion guide 22 is pressed with a tool or the like (not shown) to get over the claw portion, and the claw portion 51 of the retaining member 11 is locked to the stepped portion 60, so that FIG. As shown, the predetermined mounting of the insertion guide 22 is completed, and the insertion guide 22 is temporarily fixed at a predetermined position.

  At this time, since the claw portion and the seal ring are arranged to face each other, the insertion guide is sandwiched between them, and the seal ring is pressed against the inner peripheral surface of the insertion guide, whereby the retaining member is The insertion guide is prevented from falling off by strongly locking to the stepped portion.

Next, a pipe connection method for the above-described pipe joint will be described. In FIGS. 1 and 4 to 7, states when the pipe is inserted and connected are continuously shown.
As described above, when the seal ring 20 is attached to the joint body 1, the annular pedestal 30 of the seal ring 20 is attached to the outer peripheral groove 31 of the inner cylinder 2, and thereby the outer peripheral O-ring portion 32 protrudes from the outer peripheral surface 31. become. Furthermore, a pipe joint is constructed by attaching the outer cylinder 3, the retaining member 11, and the annular holding body 21 to the joint body 1 as described above, and the insertion guide 22 is attached to the pipe joint as described above. . The insertion guide 22 may not be attached to the joint body 1.
As shown in FIG. 1, when the insertion guide 22 is inserted until the claw portion 51 is locked to the stepped portion 60, the insertion guide 22 is sandwiched between the seal ring 20 and the retaining member 11. At this time, the seal ring 20 is brought into pressure contact with the inner periphery of the insertion guide 22, whereby the retaining member 11 is slightly strongly locked to the stepped portion 60, thereby preventing the seal ring 20 from falling off.

  Next, when one end of the tube 10 is inserted into the gap until the state shown in FIG. 4, the rear round surface 64 of the insertion guide 22 is pressed against the outer peripheral O-ring portion 32, so that the rear round surface 64 causes the outer peripheral O-ring portion 32 to move. When getting over, the insertion guide 22 is prevented from moving to the insertion side vigorously. Therefore, the tube 10 can be inserted while preventing the insertion guide 22 from separating from the end surface of the tube 10, and when the tube 10 gets over the outer periphery O-ring portion 32, the outer periphery O-ring portion 32 is damaged by the tube end side. To prevent. In the state of FIG. 4, the retaining member 11 is located on the rear end side of the insertion guide 22.

  When the tube is further inserted from the state of FIG. 4 to reach the state of FIG. 5, the distal end side of the tube 10 reaches the outer peripheral side of the outer peripheral O-ring portion 32, and in this case, the distal end side is covered with the insertion guide 22. There is no possibility that the inner diameter side of the distal end of the tube 10 contacts the outer peripheral O-ring portion 32. For this reason, the outer periphery O-ring part 32 is not caught and damaged by the tube 10 tip side. In this case, the retaining member 11 is brought into contact with the outer periphery of the tube 10 to prevent the tube 10 from being pulled out. Since the outer periphery O-ring part 32 is formed in a small diameter, it is easily deformed as the tube 10 is inserted, and biting is prevented. The outer peripheral O-ring portion 32 pushed in the insertion direction of the tube 10 can allow the deformation in the escape space G. As a result, the seal ring 20 is prevented from being pulled out of the outer peripheral groove 26 while maintaining a sealed state with the inner periphery of the pipe.

  Further, when the tube 10 is inserted to the state of FIG. 6, the outer peripheral O-ring portion 32 seals the inner periphery of the tube 10, and the annular pedestal 30 remaining in the outer peripheral groove 26 is pulled out from the outer peripheral groove 26. The tube 10 can be inserted without any problems. This is because the outer peripheral O-ring portion 32 is small and thus is difficult to be bitten by the pipe 10, and even if it is bitten, the outer peripheral O-ring portion 32 that is about to be pulled out from the outer circumferential groove 26. Since the volume of the annular pedestal 30 is larger than the volume of the outer peripheral O-ring portion 32, the outer peripheral O-ring portion 32 is pulled back by the annular pedestal 30. For this reason, the seal ring 20 can be reliably prevented from being bitten and the sealing performance by the seal ring 20 can be secured.

  Since the annular pedestal 30 is formed integrally with the outer peripheral O-ring portion 32 while being provided with an inclined portion 33 of 3 to 6 degrees toward the outer peripheral O-ring portion 32, the insertion guide 22 is smoothly moved by the inclined portion 33. Can guide you. Even when the tube 10 is inserted without the insertion guide 22 being provided, the edge portion on the inner peripheral side of the tube 10 is guided so as to naturally slide toward the tip of the outer peripheral O-ring portion 32 by this inclination angle, and bites. It becomes difficult to get in. When the tube 10 is inserted and a force in the insertion direction is applied to the outer peripheral O-ring portion 32, the outer peripheral O-ring portion 32 is elastically deformed toward the clearance space G provided by the inclined portion 33, so that an unreasonable force is applied. In addition, since the force is dispersed when the outer peripheral O-ring portion 32 is inclined to the inclined portion 33, it is prevented from being broken from the base.

  By providing the round-shaped protruding portion 35 on the inner peripheral surface of the seal ring 20, the surface pressure on the inner peripheral side of the seal ring 20 is increased, and the upper and lower lip structure formed by the protruding portion 35 and the outer peripheral O-ring portion 32. A seal surface pressure equivalent to a general O-ring shaft sealing force is exhibited. Even if pressure is applied from one side of the seal ring 20 and the seal ring 20 moves in the outer circumferential groove 26, the seal surface pressure is maintained.

  FIG. 6 shows a state where the insertion guide 22 attempts to get over the seal ring 20 on the insertion side while the tube 10 gets over the seal ring 20 on the distal end side. Also in this case, the tube 10 can be inserted in the same manner as when it passes over the seal ring 20 on the insertion side. Further, after the insertion, the durability against pulling due to the biting when the tube 10 is inserted is improved, and an excellent sealing property is obtained. Can demonstrate. In the figure, the tube 10 completely covers the outer peripheral groove 26 on the opening side. The outer peripheral O-ring portion 32 is further pushed in the insertion direction of the tube 10, but the deformation can be absorbed by the escape space G continuously.

In FIG. 7, the insertion completion state of the pipe | tube 10 is shown. In this case, each seal ring 20 is deformed in the insertion direction of the tube 10, the outer peripheral O-ring portion 32 is pulled back to the annular pedestal 30 and becomes bilaterally symmetric, and the outer peripheral O-ring portion 32 is moved to the tube 10 with a predetermined pressing force. It adheres closely to the inner periphery of and maintains a sealed state.
Even when the tube 10 is inserted without using the insertion guide 22, it is possible to connect the tube 10 while exhibiting the same sealing performance as that when the insertion guide 22 is used and durability against pulling by biting. It becomes possible.

8 and 9 show a second embodiment of the pipe joint according to the present invention. In the following embodiments, the same parts as those in the above embodiments are denoted by the same reference numerals, and the description thereof is omitted.
In this embodiment, the outer peripheral O-ring portion 32 of the seal ring 70 is formed to protrude at a position shifted from the outer peripheral central portion 30 a of the annular pedestal 30 toward the insertion side, and a round shape is formed at the symmetrical position of the outer peripheral O-ring portion 32. A protruding portion 35 is provided. Also in this case, like the seal ring 20, it is difficult to bite while securing the sealing property, and the continuous inner peripheral surface portion of the annular pedestal 30 becomes longer because the insertion side of the annular pedestal 30 becomes longer. As a result, the contact area with the outer circumferential groove 26 facing each other is increased, whereby the holding force of the annular pedestal 30 to the outer circumferential groove 26 is increased, and the drop off of the seal ring 70 due to biting is reliably prevented.

10 and 11 show a third embodiment of the pipe joint in the present invention.
In this embodiment, in the seal ring 80, the outer peripheral O-ring portion 32 protrudes in a state of being shifted to the most insertion side of the annular pedestal 30, and the round-shaped protruding portion 35 is provided at a symmetrical position of the outer peripheral O-ring portion 32. ing. In this case, the contact area between the inner peripheral surface portion of the annular pedestal 30 and the outer peripheral groove 26 can be maximized, and the annular ring pedestal 30 can be further dropped in the width direction without further omission of the seal ring 80 and the like. Make sure to prevent it.

DESCRIPTION OF SYMBOLS 1 Joint main body 2 Inner cylinder 3 Outer cylinder 5 Gap 10 Pipe 11 Detachment member 20 Seal ring 26 Outer periphery groove 30 Annular base 30a Outer periphery center part 31 Outer surface 32 Outer O-ring part 35 Projection part D Wire diameter H Section height L1 Outer part Groove outer diameter L2 Seal ring inner diameter S1 Cross-sectional area of annular pedestal S2 Cross-sectional area of outer peripheral groove

Claims (3)

A pipe for connection to be inserted into the gap between the inner cylinder and the outer cylinder provided in the joint body is connected to the pull-out preventing state by a retaining member, and an outer peripheral groove having a substantially rectangular cross section is formed on the outer peripheral surface of the inner cylinder. A pipe joint that is hermetically connected by a seal ring attached to the outer circumferential groove, the seal ring including an annular pedestal having a substantially rectangular cross section to be attached to the outer circumferential groove, and an outer periphery of the annular pedestal from the outer circumferential surface. A pipe joint comprising: an outer peripheral O-ring portion that is integrally formed and a round-shaped protrusion portion that is integrally provided on the inner periphery of the annular pedestal in order to increase the seal surface pressure . The outer peripheral O-ring portion is formed in a state protruding from the outer peripheral surface at the outer peripheral central portion of the annular pedestal, and the wire diameter of the outer peripheral O-ring portion is relative to the circumferential sectional height of the seal ring. 2. The pipe joint according to claim 1, which is 40 to 70%, and a substantially rectangular cross-sectional area of the annular pedestal is 65 to 75% with respect to a cross-sectional area of the outer circumferential groove . A pipe for connection to be inserted into the gap between the inner cylinder and the outer cylinder provided in the joint body is connected to the pull-out preventing state by a retaining member, and an outer peripheral groove having a substantially rectangular cross section is formed on the outer peripheral surface of the inner cylinder. A pipe joint hermetically connected by a seal ring attached to the outer peripheral groove, the seal ring including an annular pedestal having a substantially rectangular cross section to be attached to the outer peripheral groove, and the outer peripheral surface on an outer periphery of the annular pedestal; An outer peripheral O-ring portion formed integrally with the outer periphery and a round-shaped projecting portion provided integrally with the inner periphery of the annular pedestal for increasing the seal surface pressure are formed. When inserted into the gap, the outer peripheral O-ring portion seals the inner peripheral surface of the tube, and the seal ring portion other than the outer peripheral O-ring portion remaining in the outer peripheral groove is removed from the outer peripheral groove. The seal ring should not be pulled out. Tube connecting method of the pipe joint, which comprises inserting the tube while positioned Kigaishu groove.

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