JPH09112763A - Seal ring for pipe fittings - Google Patents

Abstract

(57) 【Abstract】 PROBLEM TO BE SOLVED: To provide a shaft between a socket and a socket in a seal ring which is used for a socket joint of a socket and socket system and which causes a self-sealing action on a lip portion by internal pressure of the pipe. (EN) Provided is a seal ring for a pipe joint, which is capable of sufficiently guaranteeing the sealing property even under a deviation, a decrease in a pipe internal pressure, or a decrease in a pipe internal / external pressure difference. SOLUTION: An outer surface of a base body 1 fixed to an insertion opening 71 is
The base portion 1 is hollow, and the liquid 3 is enclosed in the hollow portion 2 having the lip portion 4 that is pressed against the inner surface of the receiving port 72 by the internal pressure of the pipe.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention
A pipe joint seal used when joining by the socket method
It's about ruling.

[0002]

2. Description of the Related Art Various types of pipe joining structures are known, but the method of inserting a pipe insertion port into a pipe receiving port through a seal ring is easy to join. It has advantages such as flexibility and is widely used. In this insertion joining method, as shown in FIG. 4, a rubber seal ring A'having a lip portion 4'on the outer surface of an annular base portion 1'is attached to a pipe insertion port 71 'in the base portion 1'with an adhesive or the like. The seal ring-attached insertion port is inserted into the pipe receiving port 72 ', and the lip portion 4'is brought into pressure contact with the inner surface of the receiving port by the pipe inner pressure, that is, the self-sealing action is exerted on the lip portion by the pipe inner pressure. It is publicly known to operate.

[0003] In the underground burial pipe by the above-mentioned insertion / reception joining method, it is received by uneven settlement of the ground or flattening of the receptacle due to earth pressure (hereinafter, simply referred to as "uneven settlement of the ground"). It is inevitable that the spacing between the mouth and the spigot is non-uniform in the circumferential direction. In the above insertion joining method, the thickness corresponding to the distance between the maximum height of the seal ring and the inner surface of the receiving opening when there is no axial displacement between the receiving opening and the receiving opening is the standard crushing margin, If the lip part is not self-sealing and there is an axial misalignment that exceeds the crushing allowance between the receiving opening and the insertion opening, there is no local contact between the seal ring and the inner peripheral surface of the receiving opening. There are some spots and it becomes impossible to seal. However, if the lip is pressed against the inner surface of the receiving port by the internal pressure of the pipe,
Even if an axial displacement more than the crushing margin occurs between the receiving port and the insertion port, the lip is bent and deformed due to the axial displacement, and the pressure contact between the lip portion and the internal surface of the receiving port is maintained due to the internal pressure of the pipe. The sealing property can be sufficiently maintained by the self-sealing action.

[0004]

Therefore, the self-sealing action sufficiently maintains the sealing property in spite of the occurrence of the axial deviation more than the crushing margin between the receiving opening and the insertion opening. Even if it can be done, thereafter, if fluid transfer is interrupted and the pipe internal pressure temporarily becomes normal pressure, or if the action of external water pressure, for example, the pressure difference between the pipe internal and external due to the action of spring pressure becomes zero, the lip portion The self-sealing effect is lost, resulting in a non-sealing state. In this way, even if the pipe internal pressure or the pipe internal / external pressure difference is restored once the non-sealed state is caused under the axial deviation of the crushing margin or more between the receiving port and the insertion port. , The seal state cannot be restored.

An object of the present invention is to provide a seal ring which is used for an insertion / reception type pipe joint and has a self-sealing action on a lip portion due to an internal pressure of the pipe, and a shaft between the reception port and the insertion port. It is an object of the present invention to provide a seal ring for a pipe joint, which can sufficiently secure the sealability even if the pressure difference is reduced or the difference between the internal pressure and the external pressure of the pipe is reduced.

[0006]

A seal ring for a pipe joint according to the present invention has a lip portion, which is pressed against the inner surface of the receiving port by the internal pressure of the pipe, on the outer surface of the base portion fixed to the insertion opening. The base portion is hollow, and a liquid is enclosed in the hollow.

[0007]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is an explanatory view partially showing a cross section of a rubber seal ring A for pipe fittings according to the present invention. In FIG. 1, reference numeral 1 denotes an annular base portion, which has a hollow portion 2 in which a liquid 3 without fear of eroding rubber, for example, water is enclosed. Reference numeral 4 denotes a lip projectingly provided on the outer surface of the base portion, which has a self-sealing action by being brought into pressure contact with the inner surface of the receiving port by the inner pressure of the pipe as described later. The outer surface of the base immediately below the lip portion is formed as a valley surface 41 to secure a fluid gap for pressurizing the lip portion 4.
The outer surface of the rear end portion of the lip portion 4 is formed as a bulging surface 5 in order to exert a concentrated seal surface pressure against a spring water pressure and an intrusion pressure of earth and sand which will be described later. In addition, the rear end portion 110 of the base portion 1
Is thickened to form a barrier-111 against the intrusion of earth and sand.

The encapsulation of water is performed after molding the seal ring.
This can be performed by opening two holes communicating with the hollow portion, injecting air from one hole while injecting a liquid from the other hole, filling the liquid, and then sealing the hole. 2A shows the state immediately before the seal ring A according to the present invention is fixed to the pipe insertion port 71 with an adhesive or the like, and the insertion port with the seal ring is inserted into the pipe reception port 72. Similarly, in (b), there is no axial misalignment between the receiving opening 72 and the insertion opening 71.
Internal pressure is acting. ) Are shown respectively.

In FIG. 2A, a seal ring portion a (crushing margin) having a thickness corresponding to the distance between the maximum height of the seal ring A and the inner surface of the receiving opening is the receiving opening of the insertion opening 71. 72
When it is inserted into the inside, it is crushed on the inner surface of the receiving port, and the compression stress against the crushing causes the lip portion 4 to be pressed against the inner surface of the receiving port as shown in FIG.
(In some cases, the seal is sometimes referred to as the lip seal compression seal), and the liquid 3 in the base hollow portion 2 is also compressed and pressurized.

When the insertion opening 71 is inserted into the receiving opening 72, a gap is maintained between the lip portion 4 and the base portion valley surface 41, as shown in FIG. Is also brought into pressure contact with the inner surface of the receiving port by the fluid pressure in the pipe, and the higher the internal pressure of the pipe becomes, the higher the contact pressure becomes, and the so-called self-sealing action is performed. Therefore, the sealing property with respect to the internal pressure is well ensured by the compression pressure contact of the lip portion to the inner surface of the receiving port and the pressure contact by the self-sealing action.

In FIG. 2B, spring pressure and earth and sand intrusion pressure act on the seal ring A from the outside of the pipe, but due to the bulging portion (5 in FIG. 1) at the rear end of the seal ring, A high surface pressure is generated due to the crushing margin a (hereinafter, the seal due to this surface pressure may be referred to as a compression seal at the rear end of the lip), and moreover, the thick portion 110 at the rear end of the base body is formed. Since it acts as a barrier against the ingress of sediment, a good sealability against external pressure can be ensured.

In FIG. 2B, the receiving port 72 and the insertion port 7
1 even if there is an axis deviation between
It is possible to maintain the self-sealing effect of the above without being affected by the axis deviation. Further, regarding the compression seal of the lip portion and the compression seal of the lip rear end portion based on the crushing margin of the seal ring, the gap between the receiving opening and the insertion opening is determined based on the axial deviation between the receiving opening and the insertion opening. Even if the space between them is made non-uniform in the circumferential direction of the pipe, due to the pressure equalizing action of the liquid in the hollow portion of the base body, the compression seal surface pressure of the lip portion and the compression seal of the lip rear end portion due to the crushing margin are produced. Since the non-uniformity of the surface pressure in the circumferential direction is alleviated well, the compression sealability of the lip portion and the compression sealability of the lip rear end portion based on the crushing margin of the seal ring can be well ensured.

In the conventional seal ring, the base portion is a solid rubber elastic body, and the equalizing effect of the liquid cannot be expected, so that the axial deviation between the receiving port and the insertion port does not occur. When the crushing margin of the seal ring is reached, the compression seal surface pressure given by the crushing margin and the compression seal surface at the rear end of the lip at the position where the distance between the receiving opening and the insertion opening becomes the widest. If the pressure becomes substantially zero and the self-sealing action of the lip portion cannot be performed (when the internal pressure of the pipe is normal pressure or when the internal / external pressure difference becomes zero), the seal is released, and the seal is temporarily released. -If the seal is released, the seal cannot be recovered even under the condition that the internal pressure or the external pressure difference is recovered.

On the other hand, in the seal ring according to the present invention, since the base portion is hollow and easily deformed, the seal ring is inserted into the receiving port as compared with the conventional seal ring in which the base portion is solid. Under the same insertion force of the mouth, a large squeeze allowance of the seal ring can be obtained (thus, under the same axial deviation amount between the receiving opening and the insertion opening, the sealing property can be easily maintained. )
That is, even if the crushing margin of the seal ring is the same amount, due to the pressure equalizing action of the liquid in the hollow portion of the substrate with respect to the non-uniformity in the circumferential direction of the pipe due to the axial deviation between the receiving port and the insertion port. The non-uniformity in the circumferential direction of the compression seal surface pressure at the lip portion and the compression seal surface pressure at the rear end portion of the lip is well alleviated, and the sealability due to these seal surface pressures is the same as that of the conventional seal. Since it is held better than the seal ring, a more stable seal can be assured against axial misalignment between the receiving opening and the insertion opening than the conventional sealing ring.

The action and effect of this will be apparent from the comparison between the example and the comparative example described below.

[0016]

【Example】

[Example] As the pipe to be joined, a composite FRP pipe having a diameter of φ800 was used (one has a receiving port), and the difference ΔR between the receiving port inner diameter (radius) and the insertion port outer diameter (radius) was 12.05 mm. did. See
The hardness of the ruling is about 60, and in (a) of FIG.
b = 9 mm, c = 15 mm, d = 17 mm, e = 65 m
m, f = 9 mm, g = 4, h = 35 mm, and a hollow part with water enclosed was used. The crushing margin a of the seal ring was set to 6.75 mm, and the insertion / reception joining was performed.

[Comparative Example] The same as Example except that no hollow portion was provided. For each of the jointed product of the example and the jointed product of the comparative example, a shaft misalignment of 6.75 mm was forcibly applied between the receiving port and the insertion port, and the presence or absence of water leakage at the joint was inspected. Although water leakage was observed, no water leakage was observed in the example products.

In the seal ring for pipe fittings according to the present invention, the hollow base has an outer surface having a lip portion which is pressed against the inner surface of the receiving port by the internal pressure of the pipe, and the liquid is enclosed in the hollow. If so, it can be changed appropriately. For example, instead of the bulging portion (5 in FIG. 1) for the spring pressure seal described above, FIG.
As shown in, a spring water seal lip portion 50 is formed,
By inserting the insertion port 71 into the receiving port 72, the lip portion 50
Can be pressed against the inner surface of the receiving port against the reaction force of the rotational moment, and the lip portion 4 for internal pressure self-sealing can be rotated to be pressed against the inner surface of the tube. In FIG. 3, 1 is a base portion, 2 is a hollow portion, and 3 is a liquid filled in the hollow portion 2.

[0019]

EFFECTS OF THE INVENTION If the insertion / reception joint is sealed with the seal ring for pipe fittings according to the present invention, an axial deviation occurs between the reception and the insertion due to uneven settlement of the ground. Even if the pressure in the hollow portion of the substrate is equalized in the circumferential direction, the compression seal surface pressure of the seal ring is made sufficiently uniform in the circumferential direction, and the seal property due to the compression seal surface pressure is well maintained. Therefore, the seal can be sufficiently maintained even when the self-sealing action of the lip is lost due to normalization of the pipe internal pressure, and the self-sealing action can be automatically restored after the pipe internal pressure is restored, resulting in uneven ground. It is possible to guarantee a sufficiently stable seal even under sinking.

[Brief description of the drawings]

FIG. 1 is an explanatory view showing a part of a seal ring for a pipe joint according to the present invention in section.

FIG. 2 (a) is an explanatory view showing the insertion opening of the pipe joint using the seal ring according to the present invention before insertion of the receiving mouth, and FIG. 2 (b) is the insertion opening of the pipe joint. It is explanatory drawing which shows after inserting a receptacle.

FIG. 3 is an explanatory view showing an insertion opening of a pipe joint before another insertion of a sealing ring using another example of the seal ring according to the present invention.

FIG. 4 is an explanatory view showing a conventional seal ring for pipe fittings.

[Explanation of symbols]

 1 Base Part 2 Hollow Part 3 Liquid 4 Lip Part 71 Insertion Port 72 Receiving Port

Claims (1)

[Claims] 1. A lip portion, which is pressed against the inner surface of the receptacle by internal pressure of the pipe, is provided on the outer surface of the base portion fixed to the insertion opening, and the base portion is hollow, and a liquid is enclosed in the hollow. A seal ring for pipe fittings, which is characterized in that