JP2002188768A - Pipe joint - Google Patents

Abstract

PROBLEM TO BE SOLVED: To connect pipe such as buried pipes receiving external and internal hydraulic pressures to each other in a state of holding sufficient sealability. SOLUTION: This pipe joint comprises a joint body 10 having a socket 11 for inserting, a spigot 31 at the end part of a pipe and an annular sealing member 20 installed on the inner surface of the socket 11. A self-seal part 22 having a lip part 22a tilted in the direction for inserting the spigot 31 is provided in the sealing member 10 and a seal part 23 of a chevron shape in its cross section positioned on the end part side of the joint body 10 is provided on the self-seal part 22 to assure sufficient sealability against internal and external hydraulic pressures.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pipe joint used for connecting a pipe such as a buried pipe on which external water pressure and internal water pressure act.

[0002]

2. Description of the Related Art As a pipe joint for connecting pipe ends of a buried pipe buried underground, for example, there is a pipe joint having, at both ends, receptacles into which insertion ports of the buried pipe ends are inserted. In such a pipe joint, an annular water stopping member (water stopping rubber) is attached to the inner surface of the receiving port, and the water stopping member is compressed by the outer peripheral surface of the insertion port of the buried pipe inserted into the receiving port. Thereby, the space between the inner peripheral surface of the receiving port and the outer peripheral surface of the insertion port of the buried pipe is sealed in a watertight state over the entire circumference.

As a water-stopping member provided at a receiving port of a pipe joint, there is, for example, one having a shape described in Japanese Utility Model Laid-Open Publication No. 59-152289.

The water stopping member described in this publication has a shape in which a single or a plurality of serrated convex portions (lip portions) are integrally formed on an inner surface of an annular elastic body (seal rubber) attached to a socket of a pipe joint. Has become. Also, in this water-stopping member, the lip portion is processed so as to fall down toward the depth of the pipe joint so as to withstand the internal water pressure, and has a self-sealing structure against the internal water pressure. .

[0005]

In the case where the buried pipe is buried deep and a high external water pressure acts, it is not possible to sufficiently stop water with the water stopping member having the above-mentioned shape.
That is, since the external water pressure acts in the direction of expanding the gap between the insertion port and the lip portion of the water stopping member, a simple self-sealing structure has no effect on the external water pressure.

The present invention has been made in view of such circumstances, and is a pipe capable of connecting pipes such as buried pipes to which external water pressure and internal water pressure act while maintaining sufficient water stoppage. The purpose is to provide joints.

[0007]

SUMMARY OF THE INVENTION A pipe joint according to the present invention comprises a joint body having a receptacle into which an insertion port at a pipe end is inserted, and an annular water blocking member attached to an inner surface of the receptacle. The water member is formed with a self-sealing portion having a lip portion inclined in a direction in which the insertion port is inserted, and a sealing portion having a mountain-shaped cross section located on the end side of the joint body with respect to the self-sealing portion. It is characterized by having.

According to the pipe joint of the present invention, in addition to the self-sealing portion having the lip portion, the sealing portion having a mountain-shaped cross section and having a large compression allowance is provided outside the self-sealing portion in addition to the self-sealing portion having the lip portion. Therefore, due to the sealing effect of the sealing portion having the mountain-shaped cross section, it is possible to secure sufficient water stopping performance against external water pressure.

[0009] In the pipe joint of the present invention, it is preferable that a straight portion having a substantially constant thickness is provided in a portion in contact with the insertion opening of the lip portion.

As described above, if the straight portion is provided on the lip portion of the self-sealing portion, the straight portion is uniformly compressed over the entire length by the insertion port when the insertion port of the tube is inserted into the receiving port. In addition, the waterproofness against water pressure can be further increased. In addition, even if a problem such as sand getting into the seal portion having a mountain-shaped cross section occurs, the press-contacted portion of the straight portion serves as a secondary water stop function, so that the reliability of the water stop is improved.

In the pipe joint of the present invention, the thickness t1 of the straight portion of the lip portion and the thickness t2 of the base portion located between the straight portion and the insertion port when the insertion port is inserted into the receiving port (FIG. 2) and (t1 + t2)
Is the gap size s between the inner surface of the receptacle and the outer surface of the insertion opening.
It is preferable to set the dimensions of each part so as to be at least 05 times (the following compression ratio is at least 1.05).

Here, the ratio of the thickness (t1 + t2) of the self-sealing portion to the clearance dimension s (s = [inner diameter of receiving port−outer diameter of receiving port] / 2) between the inner surface of the receiving port and the outer surface of the receiving port. [T1 + t2] / s) is called the compression ratio of the self-sealing portion. This compression ratio is appropriately determined according to the material of the water stopping member, the required external water pressure resistance, and the like. However, the compression ratio needs to be 1.05 or more as described above.

If the compression ratio is less than 1.05, the self-sealing effect can hardly be expected. That is, when the insertion port of the pipe is inserted into the reception port of the pipe joint, it is normal that a misalignment of several percent occurs, and the gap s between the reception port and the insertion port is not uniform. When the compression ratio is less than 1.05, a part of the self-sealing portion does not adhere to the receiving port (or the insertion port), so that it is not possible to secure water stoppage.

[0014] The pipe joint of the present invention comprises a joint body having a receptacle into which the insertion port at the pipe end is inserted, and an annular water-stopping member attached to the inner surface of the reception port. A self-sealing portion having a lip portion inclined in a direction in which the mouth is inserted, and a sealing portion having a mountain-shaped cross section located on the end side of the joint body with respect to the self-sealing portion are formed. Is provided with a bent portion that is bent toward the inside of the water blocking member at a portion that is in contact with the insertion opening.

According to the pipe joint of the present invention, in addition to the self-sealing portion having the lip portion, the sealing portion having a mountain-shaped cross section and having a large compression allowance is provided outside the self-sealing portion in addition to the self-sealing portion having the lip portion. Therefore, due to the sealing effect of the sealing portion having the mountain-shaped cross section, it is possible to secure sufficient water stopping performance against external water pressure.

Further, since the lip portion of the self-sealing portion is provided with a bent portion bent inside the water blocking member, the inclination angle is increased from the bent point of the bent portion to the tip of the lip (see FIG. 5). ) When inserting the insertion end of the pipe end into the socket of the fitting, even if the lip is excessively pushed down by the insertion opening, the lip easily adheres to the outer peripheral surface of the insertion opening. The effect can be obtained.

Next, details of the pipe joint of the present invention will be described for each item.

<Material of Joint Body> The material of the joint body used in the pipe joint of the present invention may be a thermoplastic resin such as hard vinyl chloride or polyethylene, a thermosetting resin or a thermoplastic resin and a reinforcing fiber such as glass fiber. Fiber reinforced resin or metal.

It is also possible to use a fiber-reinforced resin composite pipe made of fiber-reinforced resin and resin concrete, or a composite pipe of metal and resin for the joint body.

<Material of Water-Stopping Member> The water-stopping member used in the pipe joint of the present invention may be SBR, CR, NR, NBR, EPDM, or synthetic / natural rubber used in general pipe joints. And the like. Further, it is also possible to use a rubber made of a mixture obtained by appropriately mixing them. Further, an elastic body having a synthetic resin such as polyethylene or polypropylene as a component can also be used.

<Sealing Portion with Mountain Cross Section> It is preferable that the sealing portion with the mountain cross section has a shape and size with a large compression allowance so as to withstand external water pressure. In the present invention, the term “cross-sectional mountain shape” means that when an arbitrary parallel line parallel to the inner surface of the receptacle is drawn in the drawing of the cross-sectional shape, it is parallel to the contour line of the corresponding portion (seal portion) except for its vertex. It refers to the shape where a line intersects at two points.

<Number of Seals / Self-Seal Part> The number of seal parts having a mountain-shaped cross section formed on the water-stopping member may be one or plural for one water-stopping member. Is also good. Similarly, the number of self-sealing portions is also 1
One or two or more water stopping members may be provided. However, it is an essential requirement that at least one seal portion and a self-sealing portion each having a mountain-shaped cross section are provided for one water stopping member.

The order of (a) the seal portion having a mountain-shaped cross section and (b) the self-sealing portion is such that (a) → (b) from the inlet side of the joint body. However, when there are a plurality of (a) and (b), the joint body is arranged so that (a) is at the most inlet side and (b) is at the farthest side, and (b) , (B) does not matter in particular.

[0024]

Embodiments of the present invention will be described below with reference to the drawings.

<Embodiment 1> FIG. 1 is a half sectional view showing the structure of a pipe joint according to an embodiment of the present invention. FIG. 2 is a partial cross-sectional view showing only the water stopping member used in the embodiment.

A pipe joint 1 shown in FIG.
The joint body 10 includes an annular water blocking member 20, 20 disposed on the inner surface of each of the receiving ports 11. Each water blocking member 20 is fixed to the inner surface of the receiving port 11 with an adhesive.

The water-stopping member 20 is a molded product of rubber such as SBR. The self-sealing portion 22 having the lip portion 22a and the sealing portion 23 having a mountain-shaped cross section are integrally formed on the inner surface of an annular base portion 21. It has a structure.

The lip portion 22a of the self-sealing portion 22
The direction opposite to the seal portion 23 having the mountain-shaped cross section (the buried pipe 3
0 insertion direction). The lip portion 22a is formed with a straight portion 22b having a substantially constant thickness at a portion in contact with the insertion opening 31 (FIG. 3) of the buried pipe 30.

As shown in FIG. 1, in the water stopping member 20 having the above-described structure, the sealing portion 23 having a mountain-shaped cross section is located outside the self-sealing portion 22 at the receiving port 11 of the joint body 10 (the end portion of the joint body 10). Side).

Here, in this embodiment, the thickness t1 of the straight portion 22b of the lip portion 22a of the water stopping member 20
And the total thickness (t1 + t2) of the portion of the base portion 21 opposed to the lip portion 22a is (t1 + t2), which is a gap dimension s between the inner surface of the receiving port 11 and the outer surface of the insertion port 31 shown in FIG.
The dimensions of each part are set so as to be 1.05 times or more (s = [inner diameter of receiving port 11−outer diameter of insertion port 31] / 2) (compression rate is 1.05 or more).

According to the pipe joint 1 of this embodiment, as shown in FIG.
The self-sealing portion 22 and the sealing portion 23 having a mountain-shaped cross section of the water-stopping member 20 are pressed against the outer peripheral surface of the insertion port 31 by inserting the insertion port 31 of The waterproofness against the internal water pressure of 30 is ensured. In addition, the outer seal portion 23 having a mountain-shaped cross section ensures the water stoppage against external water pressure acting on the buried pipe 30. Moreover, the lip portion 22 of the self-sealing portion 22
Since the straight portion 22b formed at a is uniformly compressed over the entire length by the outer peripheral surface of the insertion port 31, the reliability of the water stoppage is improved.

Embodiment 2 FIG. 4 is a half sectional view showing the structure of another embodiment of the pipe joint of the present invention. FIG. 5 is a partial cross-sectional view showing only the water stopping member used in the embodiment.

The pipe joint 101 shown in FIG.
11 and 111, and annular water blocking members 120, 12 arranged on the inner surface of each receiving port 111 thereof.
0. Each water blocking member 120 is fixed to the inner surface of the receiving port 111 with an adhesive.

The water stopping member 120 is a molded product of rubber such as SBR, and has a lip 122 a
And a self-sealing portion 122 having a cross section and a sealing portion 123 having a mountain-shaped cross section are integrally formed.

Lip section 122a of self-sealing section 122
Is inclined in a direction opposite to the seal portion 123 having a mountain-shaped cross section (a direction in which the insertion port 31 of the buried pipe 30 is inserted). The lip 122a is provided with a bent portion 122b that is bent inward (toward the center of the water blocking member 120), and the inclination angle increases from the bending point of the bent portion 122b to the tip of the lip.

As shown in FIG. 6, in the water stopping member 120 having the above-described structure, the sealing portion 123 having a mountain-shaped cross section is located outside the self-sealing portion 122 at the receiving port 111 of the joint body 110 (the end portion of the joint body 110). Side).

According to the pipe joint 101 of this embodiment, as shown in FIG. 6, by inserting the insertion port 31 of the buried pipe 30 into the receiving port 111 of the joint body 110, the self-sealing portion of the water stopping member 120 is formed. The seal section 123 and the mountain-shaped seal section 123 are pressed against the outer peripheral surface of the insertion port 31, and the self-sealing section 122 on the inner side of the seal section 123 secures the waterproofness against the internal water pressure of the buried pipe 30. In addition, the seal portion 123 having a mountain-shaped cross section on the outer side secures water stoppage against external water pressure acting on the buried pipe 30.

Further, a bent portion 122b is provided on the lip portion 122a of the self-sealing portion 122, and the bent portion 122b
Since the inclination angle is increased from the bending point to the tip of the lip, when the insertion port 31 of the buried pipe 30 is inserted into the receiving port 111 of the joint body 110, the insertion port 31 excessively pushes down the lip portion 122a. Even if it is, almost the entire lip portion 122a closely adheres to the outer peripheral surface of the insertion port 31 without any gap. As a result, the reliability of the water stoppage against the internal water pressure of the buried pipe 30 is further improved.

Here, in addition to the structure shown in FIGS. 1 and 4, the present invention provides a structure in which a joint body is integrally provided at the end of a pipe such as a buried pipe by adhesive fixing or the like to constitute a pipe joint. Alternatively, the present invention can also be applied to a structure in which a pipe joint is formed by expanding the end of a pipe such as a buried pipe to form a receiving port (joint main body).

[0040]

Embodiments of the present invention will be described below.

<Embodiment 1> The connection target is 1500 mm in diameter.
A pipe joint 1 having the shape shown in FIG. The material of the water stopping member 20 was SBR having a hardness of 60 degrees HA.
In addition, the size of each part of the water stopping member 20 shown in FIG.
0 mm, H1 = 11 mm, H2 = 12 mm, t1 = 5 m
m, t2 = 3 mm, and A = 5 mm. Further, a clearance dimension s between the inner surface of the receiving port 11 of the pipe joint 1 and the outer surface of the insertion port 31 of the buried pipe 30 is 6.5 mm (the self-sealing portion 2).
2 = 1.23).

When pipes having a diameter of 1500 mm were connected to each other using the above-mentioned pipe joints and subjected to an internal water pressure test, it was found that 1.0 M
Pa tolerated water pressure. In addition, when an external water pressure test was performed, it was able to withstand water pressure up to 0.7 MPa.

From the results of this experiment, it was confirmed that by adopting the structure shown in FIG. 1, a pipe joint which can withstand high internal water pressure and can withstand relatively high external water pressure can be realized.

<Embodiment 2> The connection target is 1500 mm in diameter.
The pipe joint 101 having the structure shown in FIG. The material of the water stopping member 120 is SBR having a hardness of HA 60 degrees.
And The dimensions of each part of the water blocking member 120 were the values shown in FIG.

When pipes having a diameter of 1500 mm were connected to each other using the above-mentioned pipe joints and subjected to an internal water pressure test, it was found that 1.0 M
Pa tolerated water pressure. In addition, when an external water pressure test was performed, it was able to withstand water pressure up to 0.7 MPa.

From the experimental results, it has been confirmed that by employing the structure shown in FIG. 4, a pipe joint which can withstand a high internal water pressure and can withstand a relatively high external water pressure can be realized.

[0047]

As described above, according to the pipe joint of the present invention, the joint body having the receptacle into which the insertion port at the pipe end is inserted, and the annular water blocking member attached to the inner surface of the receptacle are provided. A self-sealing portion having a lip portion inclined in the direction in which the insertion port is inserted, and a sealing portion having a mountain-shaped cross section located on the end side of the joint body with respect to the self-sealing portion. Since the pipes are provided, when connecting the pipes such as the buried pipes on which the internal water pressure and the external water pressure act, the pipes can be connected in a state where sufficient waterproofness is secured against the internal water pressure and the external water pressure.

[Brief description of the drawings]

FIG. 1 is a half sectional view of an embodiment of the pipe joint of the present invention.

FIG. 2 is a partial cross-sectional view illustrating only a water stop member used in the embodiment of FIG. 1;

FIG. 3 is a diagram illustrating a use state of the embodiment of FIG. 1;

FIG. 4 is a half sectional view of another embodiment of the pipe joint of the present invention.

FIG. 5 is a partial cross-sectional view showing only a water stop member used in the embodiment of FIG. 4;

FIG. 6 is a diagram illustrating a use state of the embodiment of FIG. 4;

DESCRIPTION OF SYMBOLS 1 Pipe joint 10 Joint body 11 Receptacle 20 Water blocking member 21 Base part 22 Self-sealing part 22a Lip part 22b Straight part 23 Seal part with a mountain cross section 30 Buried pipe 31 Insertion port 101 Pipe joint 110 Joint body 111 Receiving port 120 Water blocking member 121 Base part 122 Self-sealing part 122a Lip part 122b Bent part 123 Seal part having a mountain-shaped cross section

Claims (4)

[Claims] 1. A joint body having a receptacle into which an insertion port at a pipe end is inserted, and an annular water-stopping member attached to an inner surface of the reception port, wherein the insertion port is inserted into the water-stopping member. A pipe joint comprising: a self-sealing portion having a lip portion inclined in a direction; and a seal portion having a mountain-shaped cross section located on the end side of the joint body with respect to the self-sealing portion. 2. In a portion of the lip portion which is in contact with the insertion opening,
The pipe joint according to claim 1, wherein a straight portion having a substantially constant thickness is formed. 3. The sum of the thickness of the straight portion and the thickness of the base portion located between the straight portion and the inner surface of the insertion port when the insertion port is inserted into the reception port, is defined as an inner surface of the reception port. 3. The pipe joint according to claim 2, wherein the size of each part is set so as to be at least 1.05 times the gap size between the outer surface of the insertion opening. 4. A joint body having a receptacle into which an insertion port at a pipe end is inserted, and an annular water blocking member attached to an inner surface of the reception port, wherein the insertion port is inserted into the water blocking member. A self-sealing portion having a lip portion inclined in the direction, and a sealing portion having a mountain-shaped cross section located on the end side of the joint body with respect to the self-sealing portion are formed, and are in contact with the insertion opening of the lip portion. A pipe joint, wherein a bent portion bent toward the inside of the water blocking member is provided at a portion.