JPH07286686A - Seal ring for mechanical joint - Google Patents

Abstract

PURPOSE:To solve such a conventional problem as an air tight condition in a joint cannot be easily obtained without causing any crack in a principal part, of a seal ring. CONSTITUTION:A vertical cross section of a ring main body part is formed into an oblong, and a swelling part, 3a swelling to a taper face 2a side while fitted around a conduit P serves as a part of the ring main body part and is arranged over the whole circumference. At the same time, a wedge part 3b, whose vertical cross sectional shape is formed into a wedge shape different from that of the main body part, is connected to the ring main body part.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a seal ring as a component of a mechanical joint used in a connecting portion of a conduit such as a gas pipe, and more specifically, it is fitted onto the end portion of the conduit to be connected. A push ring and a joint body that is externally fitted to the conduit end in a state where a female thread of the push ring is externally fitted to a male thread formed on the outer peripheral surface of the push ring are provided, and the female thread in the joint body is In a mechanical joint in which a taper surface with a reduced diameter on the inner side is formed on the inner peripheral surface on the inner side of the forming position, the mechanical joint outside the conduit is sandwiched between the tapered surface and the outer peripheral surface of the end portion of the conduit. A seal ring for a mechanical joint that is fitted and that is elastically deformed by a fastening operation of the push ring to the joint body using the screwing of the female and male screws to seal between the joint body and the conduit. Regarding

[0002]

2. Description of the Related Art As a seal ring for a mechanical joint, one having a vertical cross section of a substantially polygonal shape (for example, a substantially heptagonal shape as shown in FIG. 1B) has been conventionally used. Was there.

[0003]

In a mechanical joint adopting such a conventional seal ring for a mechanical joint, a fastening operation by the push ring is performed to bring the seal ring into close contact with the tapered surface. Even if you try to tighten as much as you can, until the final tightening stage when the tightening amount becomes the maximum amount or a close amount to it, a sufficient airtight state (more specifically, a sufficient airtight state based on the close contact of the seal ring with the tapered surface). Was not obtained (see the broken line in FIG. 3). The present invention has been made in view of such circumstances, and an object thereof is to provide a means capable of solving the conventional problem that the airtight state of the joint cannot be easily obtained.

[0004]

A characteristic feature of a seal ring for a mechanical joint according to the present invention (hereinafter referred to as the present invention ring) is that a push ring externally fitted to an end portion of a conduit to be connected and a push ring for the push ring. Provided with a male body formed on the outer peripheral surface of the ring is a joint body which is externally fitted to the end of the conduit in a state where the female thread of the female body can be screwed, and the inner side of the joint body from the formation position of the female thread. In a mechanical joint in which a tapered surface having a reduced diameter on the inner side is formed on the inner peripheral surface, the mechanical joint is externally fitted to the conduit so as to be sandwiched between the tapered surface and the outer peripheral surface of the end portion of the conduit, and An elastic seal ring for a mechanical joint, which is elastically deformed by a fastening operation of the pushing ring to the joint body using the screwing of the male and female screws, and seals between the joint body and the conduit. Vertical section shape of the main body In the oblong, the bulging portion that bulges to the tapered surface in fitted position of the said conduit, provided with over the entire circumference as part of the ring body portion,
At the outermost end of the joint body in the external fitting posture, a wedge-shaped portion having a wedge-shaped vertical cross-section that is different from the ring body portion is connected to the ring body portion. .

[0005]

If the ring of the present invention having the above-mentioned characteristic structure is adopted, since the bulging portion is provided over the entire circumference of the ring, when performing the fastening operation by the push wheel,
From a relatively early stage, the portion of the bulging portion is largely elastically deformed, and based on the large elastic deformation, the seal ring is sufficiently attached to the tapered surface from the stage before reaching the final tightening stage. (See the solid line in FIG. 3), it becomes easier to obtain a sufficient airtight state in the joint than in the conventional case.

[0006]

Therefore, when the ring of the present invention is adopted, as described above, the ring is sufficiently brought into close contact with the tapered surface from the stage before reaching the final tightening stage to obtain the airtight state in the joint. As a result, the sealability of the joint is improved and the conventional problems can be solved.

When a seal ring is used, in which two annular projections are formed on the inner peripheral surface of the ring main body along the entire length of the conduit so as to project in the longitudinal direction of the conduit, the two annular projections are used. By the presence of the above, the sealing property between the seal ring and the conduit is further improved, and the above-described effect of improving the sealing property is more surely realized.

[0008]

Embodiments of the present invention will be described below with reference to the drawings. In the drawings, the portions denoted by the same reference numerals as the conventional example indicate the same or corresponding portions.

FIG. 1 (a) shows a vertical sectional shape of a seal ring according to the present invention, and FIG. 2 shows the seal ring (denoted by reference numeral 3 in FIG. 2) as one component. The overall structure of the mechanical joint is shown.

As shown in FIG. 2, the mechanical joint has a cylindrical push ring 1 fitted onto the end of the conduit P, and a male screw 1 m formed on the outer peripheral surface of the push ring 1 and a female thread of its own. The main body includes a joint body 2 that is externally fitted to the end of the conduit P in a state where the screw 2f can be screwed, and a seal ring 3 described in detail later.

The main body of the conduit P is composed of a steel pipe having a passage for allowing city gas to flow therein, the outer peripheral portion of which is covered with a corrosion prevention layer P ₁ and the outer peripheral portion of which is provided with a protective layer P _1.
2 is coated to form the entire conduit P that has been subjected to anticorrosion treatment.

The body of the push wheel 1 is composed of a steel ring 1g having a male screw 1m formed on the outer peripheral portion of a portion to be fitted inside the joint body 2. A portion of the outer peripheral portion of the main body other than the portion where the male screw 1m is formed is coated with an anticorrosion layer 1h to form the entire push wheel 1 that has been subjected to anticorrosion treatment. The anticorrosion layer 1h
Are formed so as to project to the opposite side of the male screw 1m forming portion in the longitudinal direction.

In the main body of the joint main body 2, female threads 2f are formed at the inner peripheral portions of the portions into which the push ring 1 is fitted at both ends in the longitudinal direction, and are deeper than the positions where the female threads 2f are formed. It is composed of a cylindrical steel ring 2g having a tapered inner surface 2a formed on the inner peripheral surface on the inner side, and its central portion is slightly reduced in diameter. The outer periphery of the main body is covered with the anticorrosion layer 2h over the entire length to form the entire joint main body 2 that has been subjected to anticorrosion treatment.

Specifically, the seal ring 3 is composed of a rubber ring which is elastically deformable by application of an external force. The ring body portion is formed to have an elliptical longitudinal cross-section, and by the formation of the oval shape, the ring body portion is fitted to the conduit P toward the tapered surface 2a side. A bulge and a bulge 3a over the entire circumference are present as part of the ring body. Further, a wedge-shaped portion 3b having a vertical cross-sectional shape, which is a wedge shape different from that of the ring main body portion, is continuously provided at the end portion of the ring main body portion which is the innermost side of the joint main body 2 in the external fitting posture. ing. Further, on the inner peripheral surface of the ring main body portion, two annular projections 3d and 3e are formed so as to extend along the entire circumference side by side in the longitudinal direction of the conduit P.

In the mechanical joint having the push ring 1, the joint body 2 and the seal ring 3 as the main constituents, which are constructed as described above, the tapered surface 2a of the joint body 2 is used.
And the outer peripheral surface of the end portion of the conduit P, the seal ring 3 is fitted onto the conduit P so as to be sandwiched therebetween, and the joint of the push wheel 1 utilizing the screw engagement of the male and female screws 2f and 1m. The seal ring 3 is elastically deformed by a fastening operation to the main body 2, and the elastic deformation causes a seal between the joint main body 2 and the conduit P.

In FIG. 2, reference numeral 4 denotes a retainer that effectively transmits the pressing force received from the push ring 1 to the seal ring 3 when the seal ring 3 is pressed against the tapered surface 2a. Further, 5 is a ball band in which steel balls are fitted at equal intervals in order to prevent the pulling force due to the displacement of the ground, and 6 is the push wheel 1
And an anti-corrosion O-ring interposed between the joint body 2 and the joint body 2.

Since the bulging portion 3a is provided over the entire circumference of the ring (that is, the seal ring 3) of the present invention having such a structure, it is relatively early in the fastening operation by the push wheel 1. From the stage, the bulging portion 3a is largely elastically deformed, and based on the large elastic deformation, the seal ring 3 is sufficiently adhered to the tapered surface 2a from the stage before reaching the final tightening stage (Fig. 3), a sufficient airtight state in the joint can be obtained more easily than before. Moreover, the above 2
Due to the presence of the annular protrusions 3d and 3e of the book, the sealing property between the seal ring 3 and the conduit P is further improved.

Next, another embodiment will be described. In the above-described embodiment, the present invention is applied when the conduit P is a gas pipe. However, even when the conduit P is a pipe for carrying fluid other than the gas pipe (for example, a water pipe), The present invention can be applied.

It should be noted that reference numerals are given in the claims for convenience of comparison with the drawings, but the present invention is not limited to the configurations of the accompanying drawings by the entry.

[Brief description of drawings]

FIG. 1 is a longitudinal sectional view showing a ring of the present invention in comparison with a conventional product.

FIG. 2 is a longitudinal sectional view showing the structure of a mechanical joint using the ring.

FIG. 3 is a graph showing the sealing property of the ring in comparison with that of a conventional product.

FIG. 4 is an explanatory view showing how the force of the ring is applied (a) in comparison with that of a conventional product (b).

[Explanation of reference symbols] 1 push ring 1m male screw 2 joint body 2a tapered surface 2f female screw 3 seal rings 3d, 3e annular protrusion P conduit

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Masaya Kinugawa 4-1-2, Hirano-cho, Chuo-ku, Osaka City, Osaka Prefecture Osaka Gas Co., Ltd. 1 Nihon Steel Pipe Fitting Co., Ltd. (72) Inventor Hideo Nozaki Hitachi, Ltd. In-house, 2 Daifuku, Kuwana City, Mie Prefecture

Claims (2)

[Claims] 1. A push ring (1) externally fitted to an end of a conduit (P) to be connected, a male screw (1 m) formed on an outer peripheral surface of the push ring (1), and a female screw ( 2f) is a fitting body (2) which is externally fitted to the end of the conduit (P) in a freely screwable state.
And the female screw (2) in the joint body (2).
In a mechanical joint in which a tapered surface (2a) having a reduced diameter on the inner side is formed on the inner peripheral surface on the inner side from the formation position of f), the tapered surface (2a) and the outer peripheral surface of the end portion of the conduit (P) are Is fitted onto the conduit (P) so as to be sandwiched between
In addition, elastically deforming by the fastening operation of the pushing wheel (1) to the joint body (2) using the screwing of the male and female screws (2f) and (1m), the joint body (2) and the conduit are connected. A seal ring for a mechanical joint that seals between (P) and (P), wherein the ring body has an oval longitudinal cross-section, and the tapered surface (2a ) Side is provided over the entire circumference as a part of the ring body portion, and a longitudinal cut is made at the end that is the innermost side of the joint body (2) in the external fitting posture. A wedge-shaped portion (3b) whose surface shape is a wedge shape separate from the ring body portion.
Is a seal ring for a mechanical joint that is connected to the ring body. 2. The two annular projections (3d), (3e) extending over the entire circumference are formed on the inner peripheral surface of the ring main body so as to be juxtaposed in the longitudinal direction of the conduit (P). Seal ring for mechanical joints.