JP2012112440A - Seal member, and method of manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the cost of a branch joint for branching a live pipe from an aerial pipe, and to execute a branch jointing easily and without producing explosive sound.SOLUTION: This annular seal member 1 includes an inner layer 2, and an outer layer 3 arranged on the outer periphery of the inner layer 2. The inner layer 2 contains a rubber material and a fireproof foaming material, and the outer layer 3 contains a rubber material.

Description

  The present invention relates to an annular seal member that can be applied to a branch joint for gas piping and includes an inner layer and an outer layer disposed on the outer periphery of the inner layer, and a method for manufacturing the same.

  As a branch joint used in order to install a branch pipe in the aerial pipe for gas piping, what is shown, for example in patent documents 1 is known. The branch joint described here is constructed using the explosive force of the explosive, and the existing pipe is cut with the cutting blade at the tip of the piston by exploding the explosive and forcibly moving the piston in the joint body. A part of the pipe is perforated so that the existing aerial pipe and the branch pipe connected to the joint body communicate with each other. Further, in the case of a branch joint used for such an aerial pipe, it is necessary to separately provide a fire-resistant member in addition to the seal member so that gas leakage does not occur from the branch joint in the event of a fire.

JP-A-9-159089

In the case of the branch joint described in Patent Document 1, it is expensive and difficult to construct because it has a special structure with a large size compared to a general branch joint. In particular, since the seal member and the refractory member need to be mounted separately, the work is troublesome. In addition, a popping sound was generated during construction, which caused problems for residents around the construction site.
Therefore, the object of the present invention is to reduce the cost of the branch joint for branching the live pipe from the overhead pipe, and to carry out it easily and without generating a plosive sound when constructing the branch joint. There is to do.

  A first characteristic configuration of a seal member according to the present invention is an annular seal member including an inner layer and an outer layer disposed on an outer periphery of the inner layer, and the inner layer includes a rubber material and a fireproof foam material. And the outer layer includes a rubber material.

[Action and effect]
According to this configuration, since the outer layer includes the rubber material, it is easily elastically deformed, and any portion of the outer peripheral surface of the outer layer can be securely adhered to the member to be sealed. Moreover, since the shape is annular and sealing is performed so as to surround it, no gap is generated. Therefore, in a normal time, high sealing performance is exhibited by the outer layer.

  On the other hand, in the event of a fire, the outer layer burns, but the refractory foam material in the inner layer expands in an annular shape and seals without gaps, so high sealing performance is exhibited. Therefore, by using the seal member of the present invention as a packing for a branch joint for buried piping, fire resistance can be imparted to the branch joint for buried piping, and the branch joint for buried piping can be used for aerial piping. It can be used as a branch joint.

  Since the branch joint for buried piping is smaller in size than the conventional branch joint for overhead piping and does not have a special structure, it is inexpensive and easy to install. Moreover, since it is not necessary to use explosives at the time of construction, there is no plosive sound. Furthermore, if the sealing member of the present invention is attached, it is not necessary to separately provide a fireproof member, and the attaching operation is simple.

  The second characteristic configuration has a circular cross section, and a ratio (d2 / d1) of the outer diameter (d2) of the outer layer to the outer diameter (d1) of the inner layer is 1.67 to 3 In that point.

[Action and effect]
According to this configuration, high sealing performance is ensured by the outer layer in normal times, and in the event of a fire, the fireproof foam material of the inner layer is promptly at least as large as the inner diameter of the outer layer so as to fill the packing groove. As a result, high sealing performance is exhibited.

  The third characteristic configuration is that the rubber material of the inner layer and the rubber material of the outer layer are the same rubber material.

[Action and effect]
As in this configuration, when the inner layer and the outer layer contain the same rubber material, the inner layer and the outer layer can be bonded to each other, and the inner layer has the same or similar elastic behavior as the outer layer, thereby improving the followability. Thereby, even if the seal member of the present invention is used after being deformed, the possibility that the inner layer is broken is reduced, so that excellent flexibility as the whole seal member is exhibited.

  A fourth characteristic configuration is that the rubber material is nitrile rubber.

[Action and effect]
With this configuration, since the nitrile rubber is a material excellent in oil resistance, water resistance, gas permeability resistance, and the like, it can exhibit more excellent sealing performance.

  A fifth characteristic configuration is that the refractory foam is thermally expanded graphite.

[Action and effect]
If it is this structure, higher sealing performance can be exhibited with the outstanding thermal expansion performance of thermal expansion graphite.

  A sixth characteristic configuration is that the content of thermally expanded graphite in the inner layer is 20% by weight to 40% by weight.

[Action and effect]
According to this configuration, high sealing performance can be exhibited in the event of a fire without impairing the flexibility of the inner layer of the rubber material.

  The characteristic structure of the branch joint which concerns on this invention exists in the point provided with the sealing member of any one of the said 1st-6th characteristic structure.

[Action and effect]
As in this configuration, if the seal member according to any one of the above first to sixth characteristic configurations is provided, high fire resistance is exhibited in the event of a fire. It can be used as a branch joint.

  The characteristic structure of the manufacturing method of the sealing member according to the present invention includes a step of vulcanizing an annular member including a rubber material and a refractory foam material, and a circular groove having a circular cross section including the rubber material. Two unvulcanized annular recess members are prepared, the vulcanized annular member is arranged in the annular groove of one of the annular recess members, and the other annular recess member is replaced with the one annular recess member. And vulcanizing by placing the vulcanized annular member in an annular space formed by the two annular recess members after being overlapped so that the annular grooves face each other. There is in point to do.

[Action and effect]
According to the manufacturing method of this configuration, it is possible to produce a homogeneous seal member with no seam over the entire circumference.

  The characteristic structure of the method for producing a seal member according to the present invention includes a step of simultaneously extruding and molding an inner layer including a rubber material and a fireproof foam material and an outer layer including a rubber material, And a step of curving the extruded molded product, vulcanizing them together and cyclizing them.

[Action and effect]
According to the manufacturing method of this structure, since a sealing member can be manufactured continuously and efficiently, manufacturing cost can be kept low.

It is a disassembled perspective view of the seal member and branch joint which concern on this invention. It is a longitudinal cross-sectional view of the sealing member which concerns on this invention. It is a longitudinal cross-sectional view of the branch joint to which the sealing member which concerns on this invention is applied. It is a longitudinal cross-sectional view of the branch joint of another form to which the sealing member which concerns on this invention is applied.

Embodiment
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
(Seal member)
As shown in FIG. 1, the seal member 1 of the present invention is annular, and includes an inner layer 2 and an outer layer 3 disposed on the outer periphery of the inner layer 2 as shown in FIG. 2.

  The inner layer 2 includes a rubber material and a fireproof foam material. As the rubber material, nitrile rubber (NBR) excellent in oil resistance, water resistance, gas permeation resistance and the like is preferable, but is not limited thereto. As the refractory foam material, thermal expansion graphite having high thermal expansion performance is suitable, but is not limited thereto.

  The content of the refractory foam in the inner layer 2 is preferably 20% by weight to 40% by weight, particularly preferably 25% by weight to 35% by weight. With this content, a high sealing performance can be exhibited in the event of a fire without impairing the flexibility of the inner layer of the rubber material.

  The outer layer 3 includes a rubber material. As the rubber material, nitrile rubber (NBR) excellent in oil resistance, water resistance, gas permeation resistance and the like is preferable, but is not limited thereto.

  The rubber material used for the inner layer 2 is desirably the same material as the rubber material used for the outer layer 3. By using the same material, it is possible to bond the inner layer 2 and the outer layer 3, and the inner layer 2 has the same or similar elastic behavior as the outer layer 3, and the followability is improved. Thereby, even if the sealing member 1 of the present invention is used after being deformed, the possibility that the inner layer 2 is broken is reduced, so that excellent flexibility as a whole sealing member is exhibited.

  The sealing member 1 of the present invention preferably has a circular cross section in order to ensure sufficient sealing performance. The ratio (d2 / d1) of the outer diameter (d2) of the outer layer 3 to the outer diameter (d1) of the inner layer 2 is preferably 1.67 to 3, particularly preferably 2.20. 2.64. This ensures high sealing performance by the outer layer 3 in normal times, and in the event of a fire, the refractory foam material of the inner layer 2 can quickly expand so as to fill at least the packing groove. High sealing performance is demonstrated.

(Application to branch joint)
As shown in FIGS. 1 and 3, the seal member 1 of the present invention can be used as a packing for the branch joint 4. The branch joint 4 may have the same configuration as a general branch joint for buried piping. That is, the branch joint 4 is configured to include an upper saddle body 5 and a lower saddle body 10. The upper saddle body 5 and the lower saddle body 10 surround the outer peripheral surface of the existing pipe T, and a bolt B and nut N can be firmly fastened and fixed.

  As shown in FIG. 1, the upper saddle body 5 includes a saddle body 6 and a flange 7. The saddle body 6 has a substantially semicircular inner circumferential surface 6a, and the flange 7 has a through hole 7a for inserting a bolt.

  The saddle body 6 of the upper saddle body 5 is provided with a branching portion 8 for connecting a branch pipe (not shown). The branch portion 8 includes a communication hole 8a that communicates with the inner peripheral surface 6a, and a female screw portion (not shown) into which a male screw portion of a branch pipe (not shown) can be screwed is formed on the inner peripheral surface of the communication hole 8a. Has been.

  An annular groove 9 is formed on the inner peripheral surface 6 a of the saddle body 6 at the periphery of the communication hole 8 a, and the seal member 1 is fitted into the groove 9.

  On the other hand, the lower saddle body 10 includes a saddle body portion 11 and a flange portion 12. The saddle body 11 has a substantially semicircular inner peripheral surface 11a, and the flange 12 has a through hole 12a for inserting a bolt. An internal thread portion (not shown) is formed on the inner peripheral surface of the through hole 12a.

  As shown in FIG. 3, when the branch joint 4 is attached to the existing pipe T, first, the upper saddle body 5 is first disposed at the planned position for installing the branch pipe of the existing pipe T, and the seal member 1 of the saddle body 6 is attached to the existing pipe T. The inner peripheral surface 6a of the saddle body 6 is brought into contact with the outer peripheral surface of the existing pipe T so as to surround the scheduled drilling portion.

  Next, the lower saddle body 10 is opposed to the upper saddle body 5 so that the existing pipe T is sandwiched between the upper saddle body 5 and the lower saddle body 10, and the upper saddle body 5 side of the existing pipe T Are arranged on the opposite side, and the inner peripheral surface 11a of the saddle main body 11 of the lower saddle main body 10 is brought into contact with the outer peripheral surface of the existing pipe T.

  After the through-hole 7a of the flange portion 7 of the upper saddle body 5 and the through-hole 12a of the flange portion 12 of the lower saddle body 10 are matched, the bolt B is inserted into the through-hole 7a of the upper saddle body 5. The male screw part formed at the tip of the bolt B is screwed into the through hole 12a of the lower saddle body 10.

  Next, the nut N is screwed into a male thread portion formed at the rear end of the bolt B and fastened to complete the attachment of the upper saddle body 5 and the lower saddle body 10. Then, a drilling operation is performed in the same manner as when a branch joint for an embedded pipe is constructed, and a hole is provided in the existing pipe T. A tubular ring member 13 having a flange portion is inserted from the communication hole 8a of the upper saddle body 5 and is fitted into the hole of the existing pipe T previously provided to prevent the branch joint 4 from rotating. Is connected to the branching portion 8 of the upper saddle body 5.

  Since the outer layer 3 contains a rubber material, the seal member 1 of the present invention is easily elastically deformed, and can reliably adhere to the entire periphery of the planned drilling portion of the existing pipe T and the entire periphery of the groove 9 of the upper saddle body 5. Moreover, since the sealing member 1 of the present invention has an annular shape and seals so as to surround a portion to be drilled in the existing pipe T, no gap is generated. Therefore, in a normal time, high sealing performance is exhibited by the outer layer 3.

  On the other hand, in the event of a fire, the outer layer 3 burns, but the refractory foam material of the inner layer 2 expands in an annular shape and seals without gaps, so that high sealing performance is exhibited. Therefore, by using the seal member 1 of the present invention as a packing for a branch joint for buried piping, fire resistance can be imparted to the branch joint for buried piping, and the branch joint for buried piping can be used for aerial piping. It can be used as a branch joint.

  Since the branch joint for buried piping is smaller in size than the conventional branch joint for overhead piping and does not have a special structure, it is inexpensive and easy to install. Moreover, since it is not necessary to use explosives at the time of construction, there is no plosive sound. Furthermore, if the seal member 1 of the present invention is attached, it is not necessary to separately provide a refractory member, and the attachment operation is simple.

(Seal member manufacturing method)
The following two methods are mentioned as a manufacturing method of the sealing member of the present invention.
[First production method]
First, a material containing a rubber material and a refractory foaming material is supplied to a circular mold having a circular cross section, subjected to heat treatment to form an annular member, and then vulcanized.
Next, a material including a rubber material is supplied to a predetermined mold, and an unvulcanized annular recess material having a semicircular cross section and an annular groove is molded to facilitate the two annular recess materials.
And after arrange | positioning the cyclic | annular member after vulcanization in the cyclic | annular groove | channel of one cyclic | annular recessed part material, the other cyclic | annular recessed part material is piled up so that a mutual cyclic | annular groove may oppose with respect to one cyclic | annular recessed part material. In addition, the vulcanized annular member is placed in an annular space formed by two annular recess members and vulcanized at 150 ° C. for 15 minutes.

[Second production method]
A first material including a rubber material and a refractory foam material and a second material including a rubber material are supplied to a predetermined mold. Then, the inner layer composed of the rubber material and the refractory foaming material and the outer layer composed of the rubber material are simultaneously extruded and molded by being strongly pressed and extruded from the die hole.
Next, the extruded string is bent, and both ends thereof are combined and vulcanized at 150 ° C. for 15 minutes to form a ring.

[Other Embodiments]
As shown in FIG. 4, the seal member 1 of the present invention can also be used as a packing for a branch joint 21 for aerial piping. The branch joint 21 includes an upper saddle body 22 and a lower saddle body 23 as in the case of the branch joint 4 in the above-described embodiment. The branch joint 21 is provided by the upper saddle body 22 and the lower saddle body 23. It surrounds the outer peripheral surface of the pipe T and can be firmly fastened and fixed with bolts B and nuts N.

  The upper saddle body 22 includes a branch part 24 to which the branch pipe t is connected, a drilling operation space 25 in which a drilling machine (not shown) can move, and an existing pipe contact port 26 with which the outer peripheral surface of the existing pipe T abuts. . The branch portion 24, the drilling operation space 25, and the existing pipe contact port 26 communicate with each other. A branch pipe t is connected to the branch portion 24 via a retaining ring 27 for retaining. The opening of the drilling operation space 25 is closed by a screw plug 28 after a drilling operation is performed by a drilling machine (not shown).

  An annular groove 29 is formed on the inner peripheral surface of the existing pipe contact port 26, and the seal member 1 is fitted into the groove 29. With such a configuration, the sealing member 1 is in close contact with the entire peripheral edge of the perforated portion in the existing pipe T and the entire periphery of the groove 29 of the upper saddle body 22, so that high sealing performance is exhibited.

  The seal member according to the present invention can be applied not only to a branch joint but also to various members that require fire resistance.

DESCRIPTION OF SYMBOLS 1 Seal member 2 Inner layer 3 Outer layer 4 Branch joint 5 Upper saddle main body 6 Saddle main body part 6a Inner peripheral surface 7 Flange part 7a Through-hole 8 Branch part 8a Communication hole 9 Groove part 10 Lower saddle main body 11 Saddle main body part 11a Inner peripheral surface 12 Flange part 12a Through hole 13 Ring member 21 Branch joint 22 for overhead piping Upper saddle body 23 Lower saddle body 24 Branch part 25 Drilling operation space 26 Existing pipe contact port 27 Push ring 28 Screw plug 29 Groove part T Existing pipe t Branch pipe B Bolt N nut

Claims (9)

An annular sealing member comprising an inner layer and an outer layer disposed on the outer periphery of the inner layer,
A sealing member in which the inner layer includes a rubber material and a refractory foam material, and the outer layer includes a rubber material.   The ratio (d2 / d1) of the outer diameter size (d2) of the outer layer to the outer diameter size (d1) of the inner layer (d2 / d1) is 1.67 to 3. The sealing member as described.   The sealing member according to claim 1 or 2, wherein the rubber material of the inner layer and the rubber material of the outer layer are the same rubber material.   The seal member according to claim 3, wherein the rubber material is nitrile rubber.   The seal member according to any one of claims 1 to 4, wherein the refractory foam material is thermally expanded graphite.   The seal member according to claim 5, wherein the content of thermally expanded graphite in the inner layer is 20 wt% to 40 wt%.   A branch joint provided with the seal member according to claim 1. Vulcanizing an annular member including a rubber material and a refractory foam and having a circular cross section;
Prepare two unvulcanized annular recess materials containing a rubber material and having a semicircular cross section and an annular groove, and placing the vulcanized annular member in the annular groove of one of the annular recess materials, After the other annular recess material is overlaid on the one annular recess material so that the annular grooves face each other, the vulcanized annular member is formed by the two annular recess materials. A method for producing a seal member, comprising the step of vulcanizing by placing in an annular space. A step of simultaneously extruding and molding an inner layer comprising a rubber material and a refractory foam material and an outer layer comprising a rubber material;
A method for producing a sealing member, comprising the step of curving the extruded product and vulcanizing both ends together to form a ring.

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