JPH0791551A - Seal ring for pipe fitting and manufacture thereof - Google Patents

Abstract

PURPOSE:To provide a seal ring for pipe fitting, which can improve the sealing property, pressure resistance and durability, and manufacture thereof by eliminating offset of a seal ring. CONSTITUTION:A reinforcing member 3 is embedded in a thick part 7 of a ring main body 7, and a projection part 4 for positioning a ring main body 2 at a center position is provided in the periphery of the ring main body 2. A rip 5 for improving the sealing property is provided in both side surfaces. A pin part to be inserted to a recessed hole 12 at the time of forming so as to hold the reinforcing member 3 at a predetermined position for vulcanization is formed into an up-type or a down-type, and the reinforcing member 3 is pinched by the pin part for vulcanization.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a seal ring for a pipe joint which is attached to a connecting portion of a pipe joint such as a water pipe for sealing, and a method for manufacturing the same, and in particular, the mounting position is stable and the sealing property is secured. The present invention relates to a manufacturing method capable of stabilizing the insertion position of the reinforcing member and improving durability and reliability.

[0002]

2. Description of the Related Art As shown schematically in FIG. 9, water pipes are connected by pipe joints 8a, 9a as shown. That is, a female threaded portion 14a having a diameter larger than that of the through hole 10a is threaded into the female side pipe joint 8a, and a contact surface 15a with which the side surface of the seal ring 1b abuts is formed on the axial line of the through hole 10a and the female threaded portion 14a. Is formed orthogonally to. On the other hand, between the contact surface 15a and the female screw portion 14a, a screw relief portion 13 required when the female screw portion is threaded is formed. Seal ring 1
Normally, b is mounted in the screw relief portion 13. On the other hand, the male side pipe joint 9a is formed with a male threaded portion 16a screwed into the female threaded portion 14a and a conduction hole 11a having the same diameter as the conduction hole 10a, and abutment surface 17a that abuts the side surface of the seal ring 1b. Is formed. The seal ring 1b is mounted in the screw relief portion 13 as described above, is sandwiched between the contact surfaces 15a and 17a of the pipe joints 8a and 9a, and seals between the pipe joints 8a and 9a.

As shown in FIGS. 10 and 11, the seal ring 1b is made of a ring-shaped member having a thickness t, and is generally made of hard rubber or the like. The thickness t is substantially equal to the width of the screw relief portion 13 in FIG. 9, and the outer diameter thereof is slightly larger than the inner diameter of the female screw portion 14a of the pipe joint 8a. The inner hole 6a has a diameter substantially the same as that of the conductive holes 10a and 11a. The outer diameter of the seal ring 1b is set to be close to the inner diameter of the female screw portion 14a to reduce the insertion resistance when the seal ring 1b passes through the female screw portion 14a and is inserted into the screw escape portion 13 to enable insertion. This is because

[0004]

As shown in FIG. 9, the inner diameter of the screw relief portion 13 of the pipe joint 8a is formed to be larger than the root diameter of the female screw portion 14a. Therefore, the internal thread 1
When the seal ring 1b having an outer diameter substantially equal to the inner diameter of 4a is mounted in the screw relief portion 13, the seal ring 1b falls down and is set as shown in the figure. In this state, as shown in the drawing, the pipe joints 8a and 9a are screwed together, and the seal ring 1b is sandwiched between the abutment surfaces 15a and 17a, so that the seal ring 1b and the abutment surfaces 15a and 17a come into uniform contact with each other by the amount of the depression. do not do. That is, a one-sided contact portion is formed on the seal ring 1b.
Therefore, the protruding portion 32 and the non-contact portion 33 are formed in the seal ring 1b, which causes a problem that the sealing function cannot be sufficiently exerted. Further, the inner hole 6a and the conductive holes 10a, 11
There is a deviation from a, which becomes a resistance of the water flow flowing in the conduction holes 10a and 11a. Although not shown, even if the reinforcing member is inserted into the thick portion of the seal ring 1b, the reinforcing member is displaced from the position facing the contact surfaces 15a and 17a, so that the reinforcing member does not function sufficiently. Occurs.
Further, in the case of this structure, it is necessary to increase the tightening force of the pipe joints 8a and 9a in order to secure the sealing property. for that reason,
There is also a problem that the seal ring 1b is pressed more than necessary and its life is shortened.

The present invention solves the above problems and provides a seal ring for pipe fittings, which has a stable mounting position, ensures a sufficient sealing property, has improved durability, and is easy to mount. In addition, it is an object of the present invention to provide a manufacturing method capable of stably manufacturing the seal ring having the above characteristics.

[0006]

In order to achieve the above object, the present invention is a seal ring which is interposed between the pipe joints of a pair of pipes which are screwed together, and which is made of a hard rubber body. It consists of a ring-shaped main body and a ring-shaped reinforcing member that is embedded in approximately the middle portion of its thick portion, and the pipe joint or the pipe joint is tightened on the outer periphery of the ring main body at the portion where the seal ring is mounted. The seal ring for a pipe joint is formed by forming an abutting portion that substantially comes into contact with the inner diameter of the tool. Further, more specifically, the portion of the pipe joint to which the seal ring is attached is a screw clearance groove of the connecting screw portion of both pipe joints, and the abutting portion projects radially from the outer periphery of the ring body. , The ring body is composed of three or more protrusions arranged substantially evenly along the circumferential direction,
A seal ring for a pipe joint is characterized in that both sides thereof form lips that contact the side faces of the pair of pipe joints. Further, the reinforcing member is previously inserted into the space portions of the upper die and the lower die that form a space portion matching the cross-sectional shape of the ring body at the time of uniting, and a rubber material is injected into the space portion to vulcanize the seal ring. A manufacturing method of molding, wherein a positioning recess or display portion is formed on both side surfaces in the thickness direction of the reinforcing member, and the recess or display portion can be engaged with a predetermined position of the upper die and the lower die. A plurality of pin portions are formed so as to project substantially equally along the circumferential direction, and when the upper die and the lower die are united, the reinforcing members are positioned and fixed by the pin portions of both dies, and then predetermined vulcanization molding is performed. The method for producing a seal ring for a pipe joint as described above is characterized.

[0007]

The reinforcing member positioned by the pin portions of the upper die and the lower die is integrally inserted into the thick portion of the ring body of the seal ring. Since the contact part (projection part) that can contact the inner diameter of the screw relief part is formed on the outer periphery of the ring body,
The ring body mounted on the screw relief portion is centered and positioned at the center thereof. Therefore, hole shift does not occur.
Although the seal ring is pressed by tightening the pipe joint, the pressing force can be sufficiently countered by interposing the reinforcing member. Further, since the seal ring is positioned at the central portion, both side surfaces thereof evenly contact the abutting surface of the pipe joint, and a sufficient sealing property can be maintained with a relatively small tightening force. Further, since the seal ring has a lip, the sealability can be further improved.

[0008]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a seal ring for a pipe joint attached to a pipe joint having a screw relief portion, FIG. 2 is a sectional view taken along the line AA of FIG. 1, and FIG. 3 is a pair of pipe joints equipped with a seal ring for a pipe joint. FIG. 4 is a partially enlarged axial cross section for clearly showing the mounting state of the seal ring for pipe fittings, and FIG. 5 is a sectional view showing the mounted state of the seal ring for pipe fittings in a pipe joint having no screw relief portion. FIG. 6, FIG. 6 is a plan view of the seal ring for pipe fittings of FIG. 5, FIG. 7 is an axial sectional view showing a manufacturing method of the seal ring for pipe fittings of the present embodiment, and FIG. 8 is a pipe fitting by a pin portion of the manufacturing method. FIG. 6 is an explanatory axial cross-sectional view for explaining whether or not the recessed hole formed on the seal ring side has an effect on the sealing action.

As shown in FIGS. 1 and 2, a seal ring 1 for a pipe joint (hereinafter referred to as a seal ring 1) is made of a ring-shaped member formed by vulcanizing hard rubber and has a ring body 2 having an inner hole 6. A reinforcing member 3 integrally embedded in the thick portion 7, four protrusions 4 formed on the outer circumference of the ring body 2 so as to project in the radial direction, and both sides of the ring body 2. The lip 5 and the like formed on the surface. As shown in FIGS. 3 and 4, the inner hole 6 has a diameter substantially equal to that of the through holes 10 and 11 of the pipe joints 8 and 9. Further, the ring body 2 is provided with four concave holes 12 (FIGS. 1 and 2) formed during vulcanization molding. The thickness of the ring body 2 excluding the protrusion 4 and the lip 5 is almost the same as that of the screw relief portion 1.
It is slightly thinner than the width dimension of 3 and is formed so that it can be inserted into the screw relief portion 13. The projection 4 is for positioning the center of the seal ring 1 and is formed of a thin width.

As shown in FIG. 3, the female side pipe joint 8 is formed with the female screw portion 14, the through hole 10, the screw relief portion 13 and the like as described above, and the contact surface 15 with which the seal ring 1 abuts. Are formed orthogonal to the axis. On the other hand, the male side pipe joint 9 is formed with a male screw portion 16 that is screwed into the female screw portion 14 and a through hole 11 having the same diameter as the through hole 10, and a contact surface 17 that comes into contact with the side surface of the seal ring 1 abuts. It is arranged so as to face the surface 15.

Next, the seal ring 1 shown in FIGS.
The mounting method of will be described. First, the seal ring 1 is inserted into the female screw portion 14 from the opening side of the female pipe joint 8. The diameter of the outer circumference of the seal ring 1 is substantially equal to that of the female screw portion 14, but the protrusion 4 is substantially equal to the inner diameter of the screw relief portion 13. Therefore, the protrusion 4 comes into contact with the female screw portion 14, but since the protrusion has a thin wall, even if it comes into contact with the female screw portion 14, a large resistance does not occur. Therefore, the seal ring 1 is smoothly inserted from the opening side. The protrusion 4 of the seal ring 1 inserted into the screw relief portion 13 contacts the inner diameter of the screw relief portion 13 and positions the seal ring 1 at the center. Therefore, the inner hole 6 of the seal ring 1 is arranged so as to coincide with the through holes 10 and 11, and the reinforcing member 3 and the rubber portion surrounding the reinforcing member 3 are also located at positions facing the contact surfaces 15 and 17 of the pipe joints 8 and 9. Positioned. In this state, when the male screw portion 16 of the male side pipe joint 9 is screwed to the female screw portion 14 and the seal ring 1 is tightened, the seal ring 1 is pressed between the contact surfaces 15 and 17. As described above, since the reinforcing member 3 is embedded in the ring body 2, the pressing force can be sufficiently endured. As described above, the seal ring 1 and the contact surfaces 15 and 17 of the pipe joints 8 and 9 uniformly contact each other, and the reinforcing member 3 is pressed in the pressing direction.
As a result, the sealing performance can be sufficiently maintained with a relatively small tightening force. Further, since the lips 5 and 5 are formed on both side surfaces of the ring main body, a sufficient sealability can be secured by the pressure contact between the lips 5 and 5 and the contact surfaces 15 and 17.

5 and 6 show another embodiment of the present invention. The pipe joints 18 and 19 in this case are formed by forming the outer diameter portion 20 and the screw portion 21 on the outer circumference, and are arranged to face each other and have the contact surfaces 22 and 23.
2 and 23, a seal ring 1a is interposed, and a female screw 24a of a nut-shaped member 24 that is arranged to be engaged with the outer diameter portion 20 is screwed to a screw portion 21 of the pipe joint 19 to form a contact surface 22, 23 is brought close to each other, and the seal ring 1a between them is tightened to exert a sealing function. The seal ring 1a in this case is composed of a ring body 2a having a reinforcing member 3a embedded therein, as shown in FIGS. 5 and 6, and does not have a protrusion as in the above embodiment. However, since the outer diameter of the seal ring 1a is formed to be substantially the same as the inner thread of the nut-shaped member 24, the seal ring 1a is arranged at the concentric position with the pipe joints 18 and 19. Therefore, hole shift does not occur. Although not shown in the drawing, the lips are formed on both side surfaces in this embodiment as well. As described above, it is possible to exert the same functions as the sealing property and the durability as in the above-mentioned embodiment.

Next, a method for manufacturing the above seal rings 1, 1a will be described. Although FIG. 7 shows a method of manufacturing the seal ring 1, the same applies to the case of the seal ring 1a. Although the detailed structure is omitted, the upper mold 25 and the lower mold 26 have a structure in which the upper mold 25 and the lower mold 26 are united at a parting line 34, and a space portion 31 having the same sectional shape as the seal ring 1 is formed therebetween. Although the reinforcing member 3 is interposed in the space 31, it is necessary that the reinforcing member 3 is properly set at an intermediate position that does not approach the inner side or the outer side. That is, if it is too close to any direction, the thickness of the rubber becomes thin, which causes damage to the seal ring 1. Further, the reinforcing member 3 improves the pressure resistance of the seal ring 1, and if the set position is incorrect, there is a problem that the function cannot be sufficiently exhibited. Various methods can be considered as means for positioning the reinforcing member 3 at a predetermined position, but in this embodiment, the pin portions 27 and 28 are used.
That is, the upper die 25 and the lower die 26 have a thin pin portion 2
7,28 are planted in advance. The pin portions 27 and 28 are arranged to face each other. On the other hand, the reinforcing member 3 has a pin portion 2
Positioning marks 29, 30 are provided for abutting engagement of 7, 28. The marks 29 and 30 may be in the shape of notches or may be simple display marks. The reinforcing member 3 is positioned at a predetermined position by aligning the marks 29 and 30 with the pin portions 27 and 28.

In order to manufacture the seal ring 1, first, the reinforcing member 3 is put in the lower mold 26 without covering the upper mold 25, and the reinforcing member 3 is fitted with the pin portion 28 and the mark 30 as described above. Position and support. Next, the upper mold 25 is covered, and the pin portion 27 of the upper mold 25 is brought into contact with and engaged with the mark 29 of the reinforcing member 3. As described above, the reinforcing member 3 is housed in the space 31 at a predetermined position. In this state, by introducing rubber into the space portion 31, the space portion 31 is filled and the seal ring 1 having a predetermined shape is manufactured. When the completed seal ring 1 is released from the mold, a concave hole 12 is formed as shown in FIGS. However, the recessed hole 12 has a small diameter, the conduction is blocked by the reinforcing member 3, and as shown in FIG.
When 9 and 9 are tightly connected, they are blocked by the contact surfaces 15 and 17, so that the sealing performance is not affected. In addition, because of the small holes, the appearance is not affected and the pressure resistance does not change.

In the above description, the seal rings 1, 1a
However, the detailed structure is not limited to that shown in the drawings. Further, the number of protrusions 4 may be determined by centering the seal ring 1, and is not limited to the shape and number shown in the figure. Further, the shape content of the reinforcing member is not limited to that illustrated.

[0016]

According to the present invention, the following remarkable effects are obtained. 1) The seal ring is positioned at the center position by forming an abutting portion on the seal ring side that abuts the inner diameter of the seal ring mounting portion of the pipe joint or the inner diameter of the connector of the pipe joint. As a result, the seal ring is prevented from being offset and the sealing property is improved. 2) Providing a reinforcing member inside improves pressure resistance and durability. 3) In the case where the seal ring is attached to the screw escape portion, a protrusion is applied as the abutting portion, and the protrusion allows the center positioning when the seal ring is attached, and the resistance during insertion is small and smooth. Can be inserted and installed. 4) The material forming the lip can further improve the sealing property. 5) The reinforcing member is correctly positioned and inserted in a predetermined position by the manufacturing method of the present invention. As a result, the pressure resistance of the seal ring can be made uniform. Also, the recessed holes produced by the manufacturing do not affect the function of the seal ring.

[Brief description of drawings]

FIG. 1 is a plan view of an embodiment of the present invention.

FIG. 2 is a sectional view taken along line AA of FIG.

FIG. 3 is an axial sectional view showing a mounted state of the embodiment of FIGS.

FIG. 4 is a partially enlarged axial sectional view showing a mounted state of the seal ring of the present embodiment.

FIG. 5 is an axial sectional view showing a mounted state of another embodiment of the present invention.

6 is a plan view of the seal ring of FIG.

FIG. 7 is a cross-sectional view showing an embodiment of the method for manufacturing the seal ring of the present invention.

FIG. 8 is a partial axial cross-sectional view for explaining the influence of the recess of the seal ring on the sealability by the manufacturing method of FIG.

FIG. 9 is an axial cross-sectional view showing a mounted state of a conventional seal ring.

FIG. 10 is a plan view of a conventional seal ring.

11 is a sectional view taken along line BB of FIG.

[Explanation of symbols]

 1 Sealing Rings for Pipe Joints (Seal Rings) 1a Sealing Rings for Pipe Joints (Seal Rings) 2 Ring Body 2a Ring Body 3 Reinforcing Member 4 Protrusion 5 Lip 6 Inner Hole 7 Wall Thickness 8 Pipe Joint 9 Pipe Joint 10 Conducting Hole DESCRIPTION OF SYMBOLS 11 Conduction hole 12 Recessed hole 13 Screw escape part 14 Female screw part 15 Contact surface 16 Male screw part 17 Contact surface 18 Pipe joint 19 Pipe joint 20 Outer diameter part 21 Screw part 22 Contact surface 23 Contact surface 24 Nut-shaped member 24a Female screw 25 Upper mold 26 Lower mold 27 Pin part 28 Pin part 29 Mark 30 Mark 31 Space part 34 Parting line

Claims (4)

[Claims] 1. A seal ring, which is interposed between pipe joints of a pair of pipes that are screw-coupled to each other, and is embedded in a ring-shaped main body made of a hard rubber body and substantially in the middle of a thick portion thereof. A ring-shaped reinforcing member, and an abutting portion is formed on the outer periphery of the ring body so as to substantially come into contact with the inner diameter of the pipe joint or the tightening tool of the pipe joint at a portion to which the seal ring is attached. A seal ring for pipe fittings. 2. A portion of a pipe joint to which the seal ring is attached is a screw clearance groove of a connecting screw portion of both pipe joints, and the abutting portion projects in a radial direction from an outer periphery of a ring body,
The seal ring for a pipe joint according to claim 1, comprising three or more protrusions arranged substantially equally along a circumferential direction. 3. The seal ring for a pipe joint according to claim 1, wherein the ring body has lips formed on both side surfaces thereof so as to abut against side faces of the pair of pipe joints. 4. A seal ring by previously inserting the reinforcing member into the space of the upper mold and the lower mold that form a space corresponding to the cross-sectional shape of the ring main body at the time of uniting and injecting a rubber material into the space. A manufacturing method for vulcanizing and molding,
Positioning recesses or indicators are formed on both side surfaces of the reinforcing member in the thickness direction, and pin portions engageable with the recesses or indicators are provided at predetermined positions of the upper die and the lower die along the circumferential direction. A plurality of protrusions are formed substantially evenly, and when the upper die and the lower die are united, the reinforcing member is positioned and fixed by the pin portions of both dies, and then predetermined vulcanization molding is performed. Seal ring manufacturing method.