JP2008289360A - Pipe joint - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a pipe joint capable of hardly dropping off a water-swollen fiber or a liquid-absorbent resin from the base material of an unwoven cloth, and repeatedly utilizing even it is absorbed and swollen in water due to previous utilization. <P>SOLUTION: The pipe joint has a joint body 3 to joint the end of a tubular body. The joint is fabricated into the unwoven cloth using a resinous base-material fiber 9 as a base material and a water-swollen fiber 12 with a low-melting water-swollen resin material fabricated thereinto. In the pipe joint, a waterproof layer 4 is formed with the water-swollen fiber 12 softened by a heat on processing and connected to the base-material fiber 9. Otherwise, the pipe joint is fabricated into the unwoven cloth using the resinous base-material fiber 9 as the base material, the waterproof layer 4 is formed in the pipe joint with the liquid-absorbent resin 13 impregnated into the unwoven cloth, and the waterproof layer 4 is integrated on the side opposite to the tubular body of the joint body 3. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a pipe joint that connects pipe bodies that are buried in the ground and protect electric wires and cables.

  In general, the pipes for protecting the electric wires or cables and the pipe joints connecting the pipes in the above example are buried in the ground. In particular, between the pipe and the pipe joint, a reliable and sufficient waterproof structure, Water structure is required.

Conventionally, various pipe joints have already been invented in response to such demands.
In other words, a central tube is provided at the center of the pipe joint, and a short tube portion is rotatably connected to one side and the other side of the central tube, respectively, and a spiral having a trapezoidal cross section is formed on the short tube portion on one side. The concave and convex strips are integrally formed, and the short pipe portion on the other side is integrally formed with a spiral concave and convex strip having a semicircular cross section, and a fiber sheet for watertight sealing is fused and integrated on the inner peripheral surface of both the short pipe portions. There is a pipe joint with a watertight sealing sheet (see Patent Document 1).
As disclosed in this prior art publication, as shown in FIG. 8 (a), the above-described watertight sealing fiber sheet 80 includes a water-swellable resin material 81 in powder form and is included in the fiber 82. Since it is adhered and held on the outer peripheral surface of the fiber 82, the bonding force between the water-swellable powdery resin material 81 and the fiber 82 is low, and the water-swellable powder as shown in FIG. When the resin material 81 (so-called water-swellable resin powder particles) expands by absorbing water, the resin powder particles 81 are peeled off from the fibers 82 and dropped off. There is a problem that it cannot be used and is a so-called disposable type. In the figure, reference numeral 83 denotes a joint body.

  On the other hand, when the water-stopping layer is molded with a mold, the non-woven fabric is mixed with or retained with a highly water-absorbing resin (see Patent Document 2), or the water-absorbing fiber non-woven fabric is used as the water-stopping material ( However, since the high water-absorbing resin is merely fibrous, the binding force of the fibrous high water-absorbing resin to the nonwoven fabric substrate is insufficient, and after use once It was difficult to reuse.

No. 7-52467 (utility model registration No. 2133706) JP 2002-33086 A JP 2003-74770 A.

  An object of the present invention is to provide a pipe joint in which water-expandable fibers or liquid water-absorbent resin hardly fall off from a nonwoven fabric base material and can be reused even if it is a pipe joint that has been used once and absorbs water. To do.

  A pipe joint according to the present invention is a pipe joint provided with a joint main body that continues the end of a pipe body, and is made of a resin-made base fiber serving as a base material and water in which a low-melting-point water-expandable resin material is fiberized. The water expansion fiber processed into a non-woven fabric using the expansion fiber and softened by heat during processing forms a water stop layer bonded to the base fiber, and the water stop layer is formed on the surface of the joint body facing the tube body. The layers are integrated.

  The water-expandable fiber obtained by fiberizing the low-melting-point water-expandable material having the above-described structure is softened by heat during processing, and for example, a run seal (registered trademark, product of Toyobo Co., Ltd.) may be used. As the material fiber, PET fiber or PE fiber may be used.

According to the above configuration, since the water expansion fiber softened by the heat during processing is bonded to the base fiber, the water expansion fiber hardly falls off the nonwoven fabric base material, and the water expansion fiber is not Even when the water expands by absorbing water, the water-expanding fibers are very little dropped.
Moreover, since the above-mentioned water expansion fiber shrinks to the original volume when dried, it can be reused even after the pipe joint is used once.

  The pipe joint according to the present invention is a pipe joint provided with a joint main body for connecting the ends of the pipe body, processed into a nonwoven fabric using a resin base fiber as a base material, The water-stopping layer impregnated with the conductive resin is formed, and the water-stopping layer is integrated on the surface of the joint body facing the pipe body.

  PET fiber or PE fiber may be used as the base fiber having the above structure, and Equos (trademark, product of Sun Add Co., Ltd.) may be used as the liquid water-absorbing resin.

According to the above configuration, the water-stopping layer is impregnated with the liquid water-absorbing resin in the nonwoven fabric made of the base fiber, and both are firmly bonded, so that the water-swelling fiber hardly falls off the base material of the nonwoven fabric, Further, even when the water absorbent resin absorbs water and expands, the water absorbent resin falls off very little.
Moreover, since the above-mentioned water-absorbent resin shrinks to the original volume when dried, it can be reused even after the pipe joint has been used once.

In one embodiment of the present invention, a clearance for water circulation is formed between the water blocking layer and the pipe body before drying and after drying after water expansion.
The clearance of the above configuration may be set to an arbitrary value of 0.2 mm to 5.0 mm corresponding to the tube outer diameter.

According to the above configuration, since the clearance is formed between the water blocking layer and the pipe body at both the time before the water expansion and the time after the water expansion, the operation of attaching and removing the pipe joint is performed. It can be done very smoothly and easily. In other words, the contact resistance between the water-stopping layer and the pipe body is small both when the pipe joint is attached and removed, thereby further reducing the falling off of the water-swelling fibers and the liquid water-absorbent resin due to mechanical external force. The reusability of the pipe joint is further improved.
Moreover, since water permeates well into the water-stopping layer by the clearance, a good water-stopping effect can be exhibited by rapid expansion of the water-stopping layer.

  A pipe joint manufacturing method according to the present invention is a pipe joint manufacturing method provided with a joint main body for connecting ends of pipe bodies, including a resin base fiber serving as a base material and a low-melting-point water-expandable resin material Processed into a non-woven fabric using the fiberized water-expanded fibers, and formed a water-stopping layer in which the water-expanded fibers softened by heat during processing are bonded to the base fiber, and the tube body of the joint body The water blocking layer is integrated with the opposing surface.

  A pipe joint manufacturing method according to the present invention is a pipe joint manufacturing method provided with a joint body for connecting ends of pipes, and is processed into a non-woven fabric using a resin base fiber as a base material. The water stop layer in which the liquid nonwoven resin is impregnated with the nonwoven fabric is formed, and the water stop layer is integrated with the surface of the joint body facing the tube.

  According to the present invention, the water-expandable fiber or the liquid water-absorbent resin hardly drops off from the nonwoven fabric base material, and there is an effect that even a pipe joint that has been used once and absorbs water can be reused.

An embodiment of the present invention will be described below in detail with reference to the drawings.
The drawings show a pipe joint. In FIGS. 1 and 2, the pipe joint 1 has a water stop layer 4 integrally formed on the entire inner peripheral surface of a joint body 3 made of synthetic resin or synthetic rubber having a continuous spiral concave and convex strip 2. In other words, one pipe body 6 (so-called pipe) having the spiral ridges 5 and the other pipe body 8 (so-called pipes) having the spiral ridges 7 are connected.

  That is, the pipe joint 1 is inserted and connected to the pipe body 6 until the other end 1A of the pipe joint 1 coincides with the end 6A of the one pipe body 6, and then the end 6A of the pipe body 6 and the other end 6A are connected. After the end portion 8A of the pipe body 8 is matched or substantially matched, the pipe joint 1 once screwed is screwed back about half of the screwed amount, whereby the other end of the pipe joint 1 is inserted into the pipe body 8 and connected. As shown in FIG. 3, both pipe bodies 6 and 8 are connected by the pipe joint 1.

  As shown in FIG. 3, between the water stop layer 4 integrated on the inner peripheral surface of the joint body 3 of the pipe joint 1 and the outer peripheral surface of each tubular body 6, 8, the water stop layer 4 supplies water. A clearance C (so-called water passage) for water circulation (for water ingress) is formed before water absorption and expansion before water expansion (at the time of water release).

  The pipe bodies 6 and 8 and the pipe joint 1 are buried in the ground with electric wires or cables inserted through the pipe bodies 6 and 8, and the water stop layer 4 absorbs water. As shown in FIG. 4 from the state shown in FIG. 3, the water stop layer 4, particularly the portions on both end sides of the pipe joint 1 swell, and the water absorption layer 4 causes the joint body 3 and each pipe to be expanded by the water absorption expansion. By sealing the space between the outer peripheral surfaces of the bodies 6 and 8 in a liquid-tight manner, a reliable water stop effect is exhibited.

  FIG. 5 is an enlarged view showing the detailed structure of the water-stopping layer 4. First, about 10 to 25 wt% of base fiber 9 made of resin such as PET which is a base material of the nonwoven fabric, and a high melting point water-expandable resin material Fiberized water-expandable fiber 10 (fiber that expands when absorbing water and releases moisture when the surrounding humidity is low), about 70 to 90 wt%, and binder 11 such as low-melting point PET (specifically, a binder resin) about 2 Using 15 wt%, these are mixed almost uniformly to form a nonwoven fabric (nonwoven fabric forming step).

  Here, as the above-mentioned water-expandable fiber 10, Beloasis (registered trademark, Kanebo Synthetic Co., Ltd. product) whose softening point is about 170 ° C., and directly spinning a polymer mainly composed of sodium polyacrylate, (High water absorption and high moisture absorption fiber). As the binder 11, a binder having a softening point of about 120 ° C. and a low melting point is used.

  Next, a flat non-woven fabric is formed into a cylindrical shape and attached to an inner mold (specifically, an inner mold having a multi-divided structure and a shape surface that forms spiral irregularities), and the outer peripheral side of the non-woven fabric. A melted state in which a joint structure 3 is formed between the inner surface of the outer mold and the outer peripheral surface of the non-woven fabric by arranging an outer mold having a halved structure (specifically, an outer mold having a shape surface forming a spiral ridge) When the outer mold is filled and the outer mold is clamped and heated and pressed at a molding temperature of about 150 to 180 ° C., the binder 11 is melted by the heat during the processing, and the ) To form a water-stopping layer 4 in which the base fiber 9 and the water-swelling fiber 10 are firmly bonded (bonding process using the binder) with the molten binder 11, and the water-stopping layer 4 is integrated with the joint body 3. Since the (integration process) is performed, the pipe joint 1 shown in FIG.

  The water-swelling fiber 10 in the water-stopping layer 4 expands in the radial direction at the time of water absorption and becomes the state of (b) in FIG. 5, and exhibits a water-stopping effect. Since the base fiber 9 is firmly bonded to the base fiber 9, the water-expanding fiber 10 is hardly dropped.

  Thus, the pipe joint of the embodiment shown in FIGS. 1 to 5 is a pipe joint 1 provided with a joint body 3 for connecting the ends of the pipe bodies 6 and 8, and is made of a resin base serving as a base material. The base fiber 9 and the water expandable with the binder 11 which is processed into a non-woven fabric using the material fiber 9, the water expandable fiber 10 in which the high melting point water expandable resin material is made into a fiber, and the binder 11. A water-stopping layer 4 bonded to the fiber 10 is formed, and the water-stopping layer 4 is integrated with the opposing surfaces (inner peripheral surfaces in this embodiment) of the joint body 3 to the pipe bodies 6 and 8. It is.

  According to this configuration, in addition to the entanglement between the fibers 9 and 10, the waterstop layer 4 is bonded to the base fiber 9 and the water-expandable fiber 10 by the binder 11 melted by the heat during processing. In the past, the water-swelling fiber 10 hardly fell off the nonwoven fabric base material, and when the water-swelling fiber 10 swells by absorbing water, the water-swelling fiber 10 falls off very little.

  Moreover, since the above-mentioned water expansion fiber 10 shrink | contracts to the original volume at the time of drying, even after using the pipe joint 1 once, it can utilize again. In addition, since the water expansion fibers 10 are present almost uniformly in the water blocking layer 4, an appropriate water blocking effect can be ensured.

Further, a clearance C for water circulation is formed between the water blocking layer 4 and the pipe bodies 6 and 8 before drying and after drying after water expansion.
According to this configuration, since the clearance C is formed between the water blocking layer 4 and the pipe bodies 6 and 8 at both time points before the water expansion and during the drying after the water expansion, Installation and removal operations can be performed very smoothly and easily. That is, the contact resistance between the water-stopping layer 4 and the pipe bodies 6 and 8 is small both when the pipe joint 1 is attached and removed, thereby further reducing the dropout of the water expansion fiber 10 due to mechanical external force. Further, the reusability (repetitive use performance) of the pipe joint 1 is further improved.

Moreover, since water permeates well into the water-stopping layer 4 due to the clearance C, a good water-stopping effect can be exhibited by rapid expansion of the water-stopping layer 4.
Of course, the pipe joint 1 can be removed against the fitting force of the water blocking layer 4 even during water absorption expansion.

FIG. 6 is an enlarged view showing another embodiment of the water blocking layer 4. First, a base fiber 9 made of resin such as PET and a low-melting-point water-expandable resin material that is a base material of the nonwoven fabric is fiberized. The water-expandable fibers 12 (fibers that expand when absorbing water and release moisture when the ambient humidity is low) are mixed almost uniformly to form a nonwoven fabric (nonwoven fabric forming step).
Here, as the above-mentioned water-expandable fiber 12, a run seal (registered trademark, product of Toyobo Co., Ltd.) having a softening point of about 120 ° C. is used.

  Next, a flat non-woven fabric is formed into a cylindrical shape and attached to an inner mold (specifically, an inner mold having a multi-divided structure and a shape surface that forms spiral irregularities), and the outer peripheral side of the non-woven fabric. A melted state in which a joint structure 3 is formed between the inner surface of the outer mold and the outer peripheral surface of the non-woven fabric by arranging an outer mold having a halved structure (specifically, an outer mold having a shape surface forming a spiral ridge) When the outer mold is filled and the outer mold is clamped and heated and pressed at a molding temperature of about 150 to 180 ° C., the water-expanding fiber 12 is heated by this processing heat to form the water-expandable fiber 12 in FIG. 6 is softened as shown in FIG. 6 (b), so that the softened water-expandable fiber 12 becomes the water-stopping layer 4 firmly bonded (bonding step) to the base fiber 9 in a wide area. Since the water blocking layer 4 is integrated into the joint body 3 (integration process), the pipe joint 1 shown in FIG.

  The water expansion fiber 12 in the water blocking layer 4 described above expands in the radial direction at the time of water supply, and the state shown in FIG. That is, the swollen fiber 12 follows the water-stopped surface and stops water. At this time, the water-expandable fibers 12 are softened by the heat during the processing described above and are firmly bonded to the base fiber 9 in a wide area, so that the water-expandable fibers 12 are very little dropped off.

  As described above, the pipe joint of the embodiment shown in FIG. 6 is the pipe joint 1 including the joint main body 3 that connects the ends of the pipe bodies 6 and 8, and the resin base fiber 9 serving as the base material. And a water-expandable fiber 12 in which a low-melting-point water-expandable resin material is made into a fiber (see FIG. 6A), and the water-expandable fiber 12 softened by heat at the time of processing is a base fiber. 9 (see (b) in FIG. 6) is formed, and the water blocking layer 4 is integrated on the surface of the joint body 3 facing the pipes 6 and 8. .

According to this configuration, in addition to the entanglement between the fibers 9 and 12, the water-stopping layer 4 is bonded to the base fiber 9 as shown in FIG. Therefore, the water expandable fiber 12 hardly falls off the nonwoven fabric base before water absorption, and when the water expandable fiber 12 expands by absorbing water as shown in FIG. The falling off of the water expansion fiber 12 is extremely small.
Moreover, since the above-mentioned water expansion fiber 12 shrink | contracts to the original volume at the time of drying, even after using the pipe joint 1 once, it can be utilized again. In addition, since the water expansion fibers 12 are present almost uniformly in the water blocking layer 4, an appropriate water blocking effect can be ensured.

Further, a clearance C for water circulation is formed between the water blocking layer 4 and the pipe bodies 6 and 8 before drying and after drying after water expansion.
According to this configuration, since the clearance C is formed between the water blocking layer 4 and the pipe bodies 6 and 8 at both time points before the water expansion and during the drying after the water expansion, Installation and removal operations can be performed very smoothly and easily. In other words, the contact resistance between the water blocking layer 4 and the pipe bodies 6 and 8 is small both when the pipe joint 1 is attached and removed, thereby further reducing the dropout of the water expansion fiber 12 due to mechanical external force. The reusability of the pipe joint 1 is further improved.
Moreover, since water permeates well into the water-stopping layer 4 due to the clearance C, a good water-stopping effect can be exhibited by rapid expansion of the water-stopping layer 4.

FIG. 7 is an enlarged view showing another embodiment of the water blocking layer 4. First, a nonwoven fabric is formed by using a base fiber 9 made of resin such as PET as a base material of the nonwoven fabric (nonwoven fabric forming step).
Next, the nonwoven fabric is impregnated with a liquid water absorbent resin 13 (impregnation step). Here, as the liquid water-absorbing resin 13, Equos (trademark, product of Sun Add Co., Ltd.) is used.

  Next, a flat non-woven fabric is formed into a cylindrical shape and attached to an inner mold (specifically, an inner mold having a multi-divided structure and a shape surface that forms spiral ridges) on the outer peripheral side of the non-woven fabric. An outer mold having a half structure (specifically, an outer mold having a shape surface that forms a spiral projection and recess) is disposed, and a joint body 3 is formed between the inner surface of the outer mold and the outer peripheral surface of the nonwoven fabric. Filling with a synthetic resin or synthetic rubber, the outer mold is clamped, and heated and pressurized at a molding temperature of about 150 to 180 ° C. to form the water stop layer 4. Since the water blocking layer 4 is integrated (integrated step) with the joint body 3, the pipe joint 1 shown in FIG.

  The liquid water-absorbing resin 13 in the water-stopping layer 4 expands upon water absorption and changes from the state shown in FIG. 7 (a) to the state shown in FIG. 7 (b) to exhibit a water-stopping effect. Since the water-absorbing resin 13 is firmly bonded to the base fiber 9 by impregnation over a wide area, the liquid water-absorbing resin 13 falls off very little.

  As described above, the pipe joint of the embodiment shown in FIG. 7 is the pipe joint 1 including the joint main body 3 that connects the ends of the pipe bodies 6 and 8, and the resin base fiber 9 serving as the base material. Is formed into a non-woven fabric, and the non-woven fabric is impregnated with the liquid water-absorbing resin 13 to form the water-stopping layer 4. The water-stopping layer 4 is integrated on the surface of the joint body 3 facing the pipes 6 and 8. It has been

According to this structure, since the water-stopping layer 4 is impregnated with the liquid water-absorbing resin 13 in the non-woven fabric composed of the base fiber 9 and the both 9 and 13 are firmly bonded, the water-swelling fiber 10 is formed before water absorption. Even when the water-absorbing resin 13 swells by absorbing water, the water-absorbing resin 13 hardly falls off from the nonwoven fabric base material.
Moreover, since the above-mentioned water-absorbent resin 13 shrinks to the original volume when dried, it can be reused even after the pipe joint 1 is used once.

Further, a clearance C for water circulation is formed between the water blocking layer 4 and the pipe bodies 6 and 8 before drying and after drying after water expansion.
According to this configuration, since the clearance C is formed between the water blocking layer 4 and the pipe bodies 6 and 8 at both time points before the water expansion and during the drying after the water expansion, Installation and removal operations can be performed very smoothly and easily. In other words, the contact resistance between the water blocking layer 4 and the pipe bodies 6 and 8 is small both when the pipe joint 1 is attached and removed, thereby further reducing the liquid water-absorbing resin 13 from dropping due to mechanical external force. Thus, the reusability of the pipe joint 1 is further improved.
Moreover, since water permeates well into the water-stopping layer 4 due to the clearance C, a good water-stopping effect can be exhibited by rapid expansion of the water-stopping layer 4.

  In the above-described embodiment, the liquid water-absorbing resin 13 is impregnated before the water-stopping layer 4 is formed. However, the liquid water-absorbing resin 13 may be applied before the water-stopping layer 4 is formed. The liquid water absorbent resin 13 may be applied after the formation of the layer 4. In any case, it is desirable that the liquid water-absorbing resin 13 is impregnated or applied almost uniformly over the entire water blocking layer 4. Moreover, what processed the above-mentioned water expansion fiber 10 and 12 into foaming urethane may be integrally formed in the joint main body 3 of the pipe joint 1, and may be integrated.

The perspective view of the pipe joint of this invention. The perspective view of a pipe joint and a pipe body. Sectional drawing which shows the connection state of the pipe body by a pipe joint. Sectional drawing at the time of water stop. (A) is explanatory drawing which shows the combined state by a binder, (b) is explanatory drawing at the time of fiber expansion | swelling. (A) is explanatory drawing of base fiber and water expansion fiber, (b) is explanatory drawing which shows the combined state by softening, (c) is explanatory drawing at the time of fiber expansion. (A) is explanatory drawing which shows the coupling | bonding state of base fiber and liquid water absorbent resin, (b) is explanatory drawing at the time of water absorbent resin expansion | swelling. (A) is explanatory drawing which shows the conventional water stop layer structure, (b) is explanatory drawing which shows omission of the resin powder particle.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Pipe joint 3 ... Joint main body 4 ... Water stop layer 6, 8 ... Pipe body 9 ... Base material fiber 10, 12 ... Water expansion fiber 13 ... Liquid water absorbing resin C ... Clearance

Claims (5)

A pipe joint comprising a joint body for connecting the ends of the pipe body,
It is processed into a non-woven fabric using a base fiber made of resin as a base material and a water expansion fiber in which a low melting point water expansion resin material is made into a fiber,
The water expansion fiber softened by the heat during processing forms a waterstop layer bonded to the base fiber,
A pipe joint in which the water blocking layer is integrated with a surface of the joint body facing the pipe body. A pipe joint comprising a joint body for connecting the ends of the pipe body,
It is processed into a non-woven fabric using a resin base fiber as a base material.
Forming a water-stopping layer impregnated with a liquid water-absorbent resin on the nonwoven fabric,
A pipe joint in which the water blocking layer is integrated with a surface of the joint body facing the pipe body. The pipe joint according to claim 1 or 2, wherein a clearance for water circulation is formed between the water blocking layer and the pipe body before drying and after drying after water expansion. A method for manufacturing a pipe joint including a joint body for connecting ends of pipe bodies,
Processing into a non-woven fabric using a base fiber made of resin as a base material and a water expansion fiber in which a low melting point water expansion resin material is made into a fiber,
The water expansion fiber softened by the heat during processing forms a waterstop layer bonded to the base fiber,
A method for manufacturing a pipe joint in which the water blocking layer is integrated with a surface of the joint body facing the pipe body. A method for manufacturing a pipe joint including a joint body for connecting ends of pipe bodies,
Processed into a non-woven fabric using resin-made base fiber as the base material,
Forming a water-stopping layer impregnated with a liquid water-absorbent resin on the nonwoven fabric,
A method for manufacturing a pipe joint in which the water blocking layer is integrated with a surface of the joint body facing the pipe body.

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