JP5190646B2 - Attaching a water-absorbable expandable nonwoven fabric to a pipe joint - Google Patents

Description

  The present invention provides, for example, a water stop on the inner peripheral surface of a pipe joint for connecting a pipe port member embedded in a hand hole and a cable protection pipe, or a pipe joint for connecting cable protection pipes to each other. The present invention relates to an attachment method for integrally attaching a water-absorbent expandable nonwoven fabric.

  In general, a water-absorbing non-woven fabric for water stop is affixed to the inner peripheral surface as a pipe joint for connecting a pipe port member embedded in a hand hole and a cable protection pipe, or connecting cable protection pipes together It has been known. In the connection structure using such a pipe joint, a water absorbent expandable nonwoven fabric is interposed in the connection portion, and the water absorbable expandable nonwoven fabric absorbs moisture in the ground and expands, so that a gap generated in the connection portion is formed. It is designed to ensure good water-stopping properties.

  In this type of pipe joint, it is necessary to attach the nonwoven fabric precisely along the inner peripheral surface thereof with high precision. When poor pasting has occurred, a large force is required to connect the pipe joint to the pipe port member or cable protection tube by inserting or screwing, and the nonwoven fabric is wrinkled or twisted, resulting in a thin part, This makes it difficult to ensure good water stoppage.

  Therefore, conventionally, in order to obtain a pipe joint in which a nonwoven fabric is integrally attached with high precision, as disclosed in Patent Document 1 and Patent Document 2, for example, a mold is used to form a pipe joint. At times, a method of crimping a non-woven fabric on the inner peripheral surface is employed.

  In Patent Document 1, a non-woven fabric is temporarily attached to a core mold, and a parison for forming a pipe joint is supplied so as to cover the non-woven fabric from the outside. The joint and the nonwoven fabric are integrated. In Patent Document 2, a non-woven fabric is covered with a core mold, the first mold is clamped from the outside to mold the non-woven fabric, and then the second mold is set on the outside of the molded non-woven fabric. A synthetic resin for forming a joint is injected to integrate the pipe joint and the nonwoven fabric.

JP 2003-251686 A Japanese Patent No. 3647857

  However, in the methods disclosed in Patent Document 1 and Patent Document 2 described above, since the nonwoven fabric is pasted at the time of forming the pipe joint, the nonwoven fabric is pasted on the already formed pipe joint. could not.

  When a non-woven fabric is pasted on a pipe joint that has already been formed, a method is employed in which the non-woven fabric is pressed with a mold while the non-woven fabric is temporarily fixed to the inner peripheral surface of the pipe joint. The molds used at this time are generally halves or quadrants. However, when the nonwoven fabric is pressed with such a mold, the nonwoven fabric is lifted up by the edge of the adjacent divided mold material at the boundary part of the divided mold material of the mold, resulting in a protruding state, resulting in poor adhesion was there.

  Further, a method may be employed in which the nonwoven fabric is temporarily fixed to the inner peripheral surface of the pipe joint, and the nonwoven fabric is inserted into the pipe joint or pressed by a core fitted by screwing. However, in this case, when the core is tightly fitted, the non-woven fabric is wrinkled or twisted due to the frictional resistance between the core and the non-woven fabric. It was difficult to apply the nonwoven fabric with good precision while keeping the nonwoven fabric tightly aligned with the inner peripheral surface of the pipe joint.

  Therefore, the present invention eliminates the above-mentioned problems, and the water-swellable non-woven fabric to the pipe joint that can be attached with high precision while keeping the water-swellable non-woven fabric tightly aligned with the inner peripheral surface of the already formed pipe joint. The purpose is to provide a mounting method.

  In order to solve the above-described problem, the attachment method of the present invention supports a pipe joint 53 in which a water-swellable non-woven fabric 52 is wound around an inner peripheral surface by a support member 71 and can be inserted inside the pipe joint 53. In addition, an inner mold 81 composed of a plurality of divided mold members 82... Made movable in the direction of approaching and separating from the inner peripheral surface of the pipe joint 53 is inserted inside the pipe joint 53, By pressing the split mold material 82 of the inner mold 81 in several times over the entire circumference of the water-absorbable expandable nonwoven fabric 52 of the pipe joint 53, the water-absorbable expandable nonwoven fabric 52 is pressed against the inner peripheral surface of the pipe joint 53. So as to be partly overlapped while shifting the pressing portion of each time in the circumferential direction along the inner peripheral surface of the pipe joint 53. West It is characterized in.

  Specifically, the inner mold 81 is divided into three in the circumferential direction, and the three-piece divided mold member 82 is pressed against the water-swellable nonwoven fabric 52 several times at the same time. .. Alternatively, the pipe joint 53 is rotated by a predetermined angle around the pipe axis, and the end portions of the pressed portions are mutually moved while shifting the pressed portions in the circumferential direction along the inner peripheral surface of the pipe joint 53. I try to overlap.

  Further, the pressing angle 83 of each of the divided mold members 82... Has a central angle of 60 degrees around the tube axis of the pipe joint 53 when the divided mold members 82. It is formed in an arc shape as described above.

  Further, on the pressing surfaces 83... Of the divided mold members 82..., Spiral convex portions 84 that fit into the spiral concave portions 56 formed on the inner peripheral surface of the pipe joint 53 are formed.

  Further, when the divided mold members 82 of the inner mold 81 are inserted into the pipe joint 53 in a cantilevered state and pressed against the water-absorbent expandable nonwoven fabric 52, the inner mold 81 A pressing member 72 that presses the free end side of the split mold members 82... Against the water-swellable nonwoven fabric 52 is inserted between the free ends of the split mold members 82. Further, the support member 71 is a frame member with an insertion hole 70 for inserting and fixing the pipe joint 53 therein.

  According to the attachment method of the present invention, when the divided mold material of the inner mold is pressed in several times over the entire circumference of the water-absorbent and expandable nonwoven fabric of the pipe joint, it is partially overrun while shifting the pressing part of each time in the circumferential direction. Since it is wrapped, it is possible to eliminate the conventional sticking failure such that the water-swellable non-woven fabric swells in a protruding shape at the boundary part of each divided mold material, and the inner circumference of the pipe joint that has already been formed The water-swellable non-woven fabric can be attached with a uniform thickness with good accuracy.

  In addition, the inner mold is composed of a three-piece split mold material, and the three-piece split mold material is divided into several times and pressed against the water-absorbent expandable nonwoven fabric at the same time, thereby holding the water-absorbent expandable nonwoven fabric from the inside in a balanced manner It is possible to attach the water-absorbent expandable nonwoven fabric more accurately and accurately.

  Furthermore, even if the inner peripheral surface of the pipe joint has a spiral shape by forming a spiral convex part that fits into the concave portion formed on the inner peripheral surface of the pipe joint on the pressing surface of the split mold material, the spiral shape It is possible to attach a water-swellable non-woven fabric while keeping it tightly aligned.

  Furthermore, by inserting a pressing member between the free ends of the cantilevered inner mold split mold material and pressing the free end side of the split mold material against the water-absorbent expandable nonwoven fabric, the split mold material tends to be weakened. It is possible to increase the pressing force on the free end side, and to make the attachment state of the water absorbent expandable nonwoven fabric uniform at both ends of the pipe joint.

  In addition, by fixing the pipe joint in the insertion hole of the frame material, it is possible to support the pipe joint in a stable state while suppressing inclination and deformation of the pipe joint when pressed from the inside of the inner mold. It is possible to attach the water-swellable non-woven fabric more accurately and accurately.

It is a longitudinal cross-sectional view of the pipe joint which affixed the water absorptive expandable nonwoven fabric to the inner peripheral surface by the attachment method which concerns on one Embodiment of this invention. It is the side view similarly. It is a longitudinal cross-sectional view which shows the usage example of a pipe joint. It is a schematic plan view of an attachment apparatus. It is a schematic plan view which shows the operation | movement middle of an attachment apparatus. It is a schematic plan view which shows the operation | movement middle of an attachment apparatus. It is a schematic plan view which shows the operation | movement middle of an attachment apparatus. It is a cross-sectional view which shows the state which inserted the inner metal mold | die inside the pipe joint fixed to the frame material. It is a side view which shows the state which inserted the inner metal mold | die inside the pipe joint fixed to the frame material. It is a side view which shows the state of a 1st hot press process. It is a cross-sectional view which shows the state of a 1st hot press process. It is a side view which shows the state of a 2nd hot press process. It is a figure which shows the pressing range of a division | segmentation die material. It is a side view which shows the state of a hot press auxiliary | assistant process. It is a side view which shows the state of a hot press auxiliary | assistant process. It is a cross-sectional view which shows the state of a hot press auxiliary | assistant process.

  FIG.1 and FIG.2 has shown the pipe joint 53 to which the water-absorbing expandable nonwoven fabric 52 for water stop was affixed integrally by the attachment method which concerns on one Embodiment of this invention.

  As shown in FIG. 3, the pipe joint 53 is for connecting the underground buried type cable protection pipes 54, 54 through which electric wires and optical fiber cables are inserted. The pipe joint 53 is formed by blow molding, and is formed of a spiral corrugated pipe in which a spiral convex portion 55 is formed on the outer peripheral surface and a spiral concave portion 56 is formed on the inner peripheral surface. The cable protection tubes 54 and 54 are also formed of a spiral corrugated tube in which spiral irregularities are formed on the inner and outer peripheral surfaces.

  Moreover, as shown in FIG.1 and FIG.2, the sheet-like water-swellable nonwoven fabric 52 is affixed integrally on the internal peripheral surface of this pipe joint 53 over the perimeter. The water-absorbent expandable nonwoven fabric 52 is, for example, a synthetic resin nonwoven fabric containing a highly water-absorbing polymer excellent in water absorption and water retention, and has the ability to absorb water and expand.

  Then, the end portions of the cable protection tubes 54 and 54 are screwed into the both ends of the tube joint 53 and are fitted inside, so that the cable protection tubes 54 and 54 are connected to each other via the tube joint 53 as shown in FIG. It has come to be. In this connected state, a water-swellable non-woven fabric 52 is interposed between the pipe joint 53 and the cable protection tubes 54 and 54, and the water-swellable non-woven fabric 52 absorbs moisture in the ground and expands. A good water-stopping property is ensured by closing a gap generated at the connection portion between the pipe joint 53 and the cable protection pipes 54 and 54.

  4 to 7 show an attachment device 51 for integrally attaching the water-absorbent expandable nonwoven fabric 52 to the inner peripheral surface of the pipe joint 53. In this attachment device 51, two sets of rail members 61 and 62 are attached on a base 60. One rail member 61 includes a pair of shafts 61a and 61a parallel to each other, and is disposed along the front-rear direction. The other rail member 62 includes a pair of shafts 62a and 62a that are parallel to each other, and is disposed along the left-right direction. That is, the rail members 61 and 62 are arranged in directions orthogonal to each other.

  A first movable base 63 that is slidable along the rail member 61 is attached to one rail member 61, and a first movable base 63 that is slidable along the rail member 62 is attached to the other rail member 62. Two movable stands 64 are attached. In addition, the 1st movable stand 63 and the 2nd movable stand 64 are moved by drive means, such as a pneumatic or hydraulic cylinder which is not shown in figure, and a drive motor.

  And on the 1st movable stand 63, as shown in FIG. 8, the frame material (supporting material) with the insertion hole 70 which inserts and fixes the pipe joint 53 which wound the water-absorbent-expandable nonwoven fabric 52 around the inner peripheral surface, and was temporarily fixed. Member) 71 and a pressing member 72 that can be inserted into and removed from the insertion hole 70 of the frame member 71 are provided. The pressing member 72 includes a shaft portion 75 supported by a pair of bearings 74, 74 on the first movable base 63, and an insertion portion 76 having a tapered surface attached to the distal end portion of the shaft portion 75. These are moved in the left-right direction by driving means such as pneumatic or hydraulic cylinders or drive motors (not shown).

  On the second movable stand 64, a case 80 having a pneumatic or hydraulic cylinder, a drive motor and other driving means (not shown) is installed, and is cantilevered by the case 80, and is inserted into the insertion hole 70 of the frame member 71. An inner mold 81 that can be inserted inside the fixed pipe joint 53 is provided.

  As shown in FIG. 9, the inner mold 81 is divided into three in the circumferential direction along the inner peripheral surface of the pipe joint 53 that is inserted and fixed in the insertion hole 70 of the frame member 71. That is, the inner mold 81 is composed of three-piece divided mold members 82 of the same shape. These three-piece split mold members 82... Can be heated by a heater (not shown), and the driving means in the case 80 are connected to each other so as to move simultaneously in the direction of approaching and separating from the inner peripheral surface of the pipe joint 53. The pipe shaft of the pipe joint 53 in a state where the entire inner mold 81 can be enlarged / reduced and is separated from the inner peripheral surface of the pipe joint 53 (the whole inner mold 81 is reduced in diameter). , And can be simultaneously moved in the pipe axis direction of the pipe joint 53 in a state of being separated from the inner peripheral surface of the pipe joint 53 (in a state where the entire inner mold 81 is reduced in diameter). . Although the detailed operation will be described later, the divided mold members 82... Are appropriately moved and rotated while appropriately moving and rotating the first movable table 63 and the second movable table 64, the pressing member 72, and the inner mold 81. Are pressed against a water-absorbent expandable nonwoven fabric 52 wound around the inner peripheral surface of the pipe joint 53, and the water-absorbable expandable nonwoven fabric 52 is heated and compressed. The driving of each driving means of the first movable base 63 and the second movable base 64, the pressing member 72, and the inner mold 81 is controlled by a microcomputer (not shown).

  The pressing surfaces 83 of the split mold members 82... Have a central angle of 60 degrees or more when the split mold members 82. Is formed in an arc shape in a side view of about 70 degrees. Then, as shown in FIG. 8, spiral pressing portions 84 corresponding to the concave portions 56 on the inner peripheral surface of the pipe joint 53 are formed on the pressing surfaces 83. Is pressed against the water-absorbable expandable nonwoven fabric 52, and the convex portion 84 of the pressing surface 83 is fitted into the concave portion 56 of the pipe joint 53.

  Next, an operation when the water-swellable non-woven fabric 52 is integrally attached to the inner peripheral surface of the pipe joint 53 using the mounting device 51 having the above configuration will be described. First, a blow-molded pipe joint 53 is used to superpose two sheet-like water-swellable non-woven fabrics 52 on the inner peripheral surface on one end side of the pipe joint 53. Wound and temporarily fixed to the inner peripheral surface on the other end side in the same manner, and wound and temporarily fixed the sheet-like water-swellable nonwoven fabric 52 divided into two pieces so that the ends overlap each other To do. In this case, an adhesive is applied to one side of each of the water-absorbing expandable nonwoven fabrics 52, and the one side with the adhesive is wound while adhering to the inner peripheral surface of the pipe joint 53. When temporarily fixing the water-swellable non-woven fabric 52, one end of the water-swellable non-woven fabric 52 is used at both ends of the inner peripheral surface of the pipe joint 53 so that the ends overlap each other. However, by using the water absorbent expandable nonwoven fabric 52 divided as described above, it is possible to wind the water absorbent expandable nonwoven fabric 52 along the spiral shape of the inner peripheral surface of the pipe joint 53. it can.

  Subsequently, the pipe joint 53 that is temporarily fixed by winding the water-swellable non-woven fabric 52 is inserted into the insertion hole 70 of the frame member 71 of the attachment device 51 and fixed. The attachment device 51 at this time is in the state shown in FIG. 4 and can fix the pipe joint 53 without interfering with the inner mold 81. After the pipe joint 53 is set on the frame member 71, the first movable base 63 and the second movable base 64 are moved, and the inner mold 81, the pipe joint 53, and the pressing member 72 are arranged in a straight line, and the inner mold 81 is inserted inside the pipe joint 53 (see FIGS. 5, 8, and 9). In this state, the split mold members 82 of the inner mold 81 heated to 150 ° C. or more by the heater are appropriately moved and rotated, and the pressing surfaces 83 are simultaneously numbered over the entire circumference of the water-swellable non-woven fabric 52. The water-swellable non-woven fabric 52 that has been temporarily fixed is integrally attached to the inner peripheral surface of the pipe joint 53 while being pressed and divided and used as a paste by melting the adhesive of the water-swellable non-woven fabric 52.

  That is, first, the inner mold 81 is expanded in diameter, and the pressing surfaces 83 of the divided mold members 82 are simultaneously pressed against the water-absorbent expandable nonwoven fabric 52 (see FIGS. 6, 10, and 11). Heat compression is performed over a total range of about 210 degrees around the pipe axis of the pipe joint 53, and after a predetermined time has passed, the inner mold 81 is reduced in diameter to separate the split mold member 82 from the water-absorbent expandable nonwoven fabric 52. (First heat pressing step). Subsequently, the split mold members 82 are rotated about 60 degrees around the pipe axis of the pipe joint 53, and the split mold members 82 are moved in the pipe axis direction of the pipe joint 53 to press the split mold members 82. Alignment of the convex portions 84 of the surfaces 83 and the concave portions 56 of the pipe joint 53 is performed. From this state, the diameter of the inner mold 81 is expanded again, and the pressing surfaces 83 of the split mold members 82 are simultaneously pressed against the water-absorbent expandable nonwoven fabric 52 (see FIG. 12). Heat compression is performed over a total range of about 210 degrees around the tube axis, and after a predetermined time has passed, the inner mold 81 is reduced in diameter to separate the split mold material 82. Hot press process).

  When such a first heat pressing step and a second heat pressing step are completed, pressing is performed over the entire circumference of the water-absorbent expandable nonwoven fabric 52, and the expandable nonwoven fabric 52 is pressed against the pressing surfaces 83 of the split mold members 82. A total of six areas (range of about 10 degrees centering on the pipe axis of the pipe joint 53) are generated (overlapping) twice by the end portion (see FIG. 13). Conventionally, these regions are the boundary portions of the divided mold material that are easily lifted up by the edges of the divided mold material, and are likely to rise up into a protruding shape. Such a region is expanded by being heated and compressed twice. Sticking failure of the conductive nonwoven fabric 52 can be eliminated.

  In addition, after the completion of the first hot pressing step and the second hot pressing step, the first hot pressing step and the second hot pressing step are further repeated several times so that the water-absorbing expandable nonwoven fabric 52 is further adhered. You can be sure. What is necessary is just to set suitably about the frequency | count of a setting according to the thickness, the diameter, etc. of the water absorptive non-woven fabric 52 and the pipe joint 53.

  Further, in the middle of the first hot press process and the second hot press process, the pressing member 72 is used to assist the pressing of the split mold material 82.. Process).

  That is, in the first hot pressing process and the second hot pressing process, the split mold material 82... In a cantilevered state is pressed against the water-absorbent expandable nonwoven fabric 52, so that the free end side pressing of the split mold material 82. The pressure may be weaker than the pressing force on the base end side. For this reason, in the hot press auxiliary process, when the split mold member 82 is pressed against the water-absorbent non-woven fabric 52 in the first hot press process or the second hot press process, The insertion part 76 of the pressing member 72 is inserted between the free ends of the divided mold members 82... Inserted into the water, so that the free end side of the divided mold members 82. (See FIGS. 7, 14, 15, and 16). Thereby, the sticking condition of the water-swellable nonwoven fabric 52 at both ends of the pipe joint 53 is made uniform. In addition, what is necessary is just to set the timing and frequency | count of a hot press auxiliary | assistant process suitably according to the thickness, the diameter, etc. of the water absorptive nonwoven fabric 52 and the pipe joint 53. FIG.

  In this way, in the mounting device 51 described above, while the three-piece split mold member 82 is simultaneously pressed into the water-absorbent non-woven fabric 52 in several times, the split mold member 82. The ends of the pressed portions are overlapped with each other while being rotated at a predetermined angle as the center and shifting the pressed portions in the circumferential direction along the inner peripheral surface of the pipe joint 53. Accordingly, it is possible to eliminate the conventional sticking failure such that the water-swellable non-woven fabric 52 swells in a protruding shape at the boundary portion between the divided mold members 82... And the entire inner peripheral surface of the pipe joint 53 that has already been formed. In addition, the water-swellable non-woven fabric 52 can be attached with a uniform thickness with good accuracy while being closely aligned.

  In the above-described embodiment, an example in which the inner mold 81 including the three-piece divided mold material 82 is used has been described. However, the present invention is not limited to this. For example, using an inner mold composed of a split mold material of 2 pieces or 4 pieces or more, these split mold materials are pressed several times over the entire circumference of the water-swellable non-woven fabric, and each pressing portion is shifted in the circumferential direction. You may make it overlap partially.

  In addition, when the divided mold material of the inner mold is pressed each time, the pipe joint is rotated by a predetermined angle around the tube axis so that the pressing portion of each time is partially overlapped while being shifted in the circumferential direction. good.

  The present invention is not limited to the above embodiment, and it is needless to say that many modifications and changes can be made to the above embodiment within the scope of the present invention.

  52 .. Water-absorbing expandable nonwoven fabric, 53 .. Pipe joint, 56 .. Recess of pipe joint, 70 .. Insertion hole, 71 .. Frame material (support member), 72 .. Press member, 81. , 82 .. Divided mold material, 83 .. Pressing surface, 84 .. Convex part of divided mold material

Claims (6)

The pipe joint (53) wound around the inner peripheral surface of the water-absorbent expandable nonwoven fabric (52) is supported by the support member (71) and can be inserted into the pipe joint (53). 53) Inserting an inner mold (81) made of a plurality of divided mold members (82,...) That is movable in a direction approaching and separating from the inner peripheral surface of 53) into the inside of the pipe joint (53). The water-swellable non-woven fabric (52) of the pipe joint (53) is pressed several times over the entire circumference of the inner mold (81) so that the water-swellable non-woven fabric is pressed. (52) is an attachment method in which the pipe joint (53) is integrally attached to the inner peripheral surface of the pipe joint (53). (53) Partially shifting in the circumferential direction along the inner circumferential surface Mounting of water-swellable nonwoven to the pipe joint being characterized in that so as to overlap. The inner mold (81) is divided into three in the circumferential direction, and the three-piece divided mold material (82) is pressed against the water-swellable nonwoven fabric (52) several times at the same time. (82...) Or the pipe joint (53) is rotated by a predetermined angle around the pipe axis, and the pressing parts are pushed while being shifted in the circumferential direction along the inner peripheral surface of the pipe joint (53). The method for attaching a water-swellable nonwoven fabric to a pipe joint according to claim 1, wherein the end portions of the parts are overlapped with each other. The pressing surface (83...) Of each divided mold member (82...) Is the tube axis of the pipe joint (53) when the divided mold material (82...) Is pressed against the water-absorbent expandable nonwoven fabric (52). The method for attaching a water-absorbent expandable nonwoven fabric to a pipe joint according to claim 2, wherein the center angle of the center is formed in an arc shape having a central angle of 60 degrees or more. Helical convex portions (84) that fit into helical concave portions (56) formed on the inner peripheral surface of the pipe joint (53) are formed on the pressing surfaces (83,...) Of the divided mold members (82,...). The method for attaching a water-swellable non-woven fabric to the pipe joint according to any one of claims 1 to 3. When the split mold material (82) of the inner mold (81) is inserted into the pipe joint (53) in a cantilevered state and pressed against the water-absorbent expandable nonwoven fabric (52), Between the free ends of the split mold members (82) of the inner mold (81), a pressing member (72) that presses the free end sides of the split mold members (82,...) Against the water-swellable nonwoven fabric (52). A method for attaching a water-swellable non-woven fabric to a pipe joint according to any one of claims 1 to 4, wherein the water-swellable nonwoven fabric is inserted. The absorbent member according to any one of claims 1 to 5, wherein the support member (71) is a frame member with an insertion hole (70) for inserting and fixing the pipe joint (53). Mounting method.