JP5175770B2 - Manufacturing method of cylindrical tube - Google Patents

Description

  The present invention relates to a method for manufacturing a synthetic resin cylindrical tube.

  Conventionally, synthetic resin pipes are widely used because they are lighter and more durable and workable than metal pipes and concrete pipes. Further, among synthetic resin pipes, pipes made of fiber reinforced resin molded products are excellent in strength in addition to the advantages of conventional synthetic resin pipes, and are frequently used as underground pipes and water supply / drainage pipes.

  Such a fiber reinforced resin pipe (FRP composite pipe) is formed by a filament winding method (FW method), a centrifugal molding method, or the like, and among these, the filament winding method is often used. Since the fiber reinforced resin tube formed by this filament winding method is continuously molded with the inner surface in contact with a hollow cylindrical mold (mandrel), the inner peripheral surface of the molded product is defined as the mold surface. It can be formed so as to have the same smoothness, and there is an advantage that good flowing water can be obtained and the necessary diameter can be reduced.

  By the way, a fiber reinforced resin tube formed by a conventional filament winding method is formed by continuously winding a plurality of long reinforcing fiber materials around a mold rotating in the circumferential direction while moving in the axial direction. The reinforcing fiber material in the axial direction is regularly supplied so as to intersect between the long reinforcing fiber material in the circumferential direction wound on the upper side and the reinforcing fiber material is impregnated with the polymerizable resin composition. It is manufactured by thermosetting (see, for example, Patent Document 1).

JP 2003-112373 A

  By the way, in the above-described filament winding method, the mold is generally formed by spirally winding a steel belt having a predetermined width on the outer peripheral surface of a cylindrical frame. For this reason, in the obtained long fiber reinforced resin pipe, a trace of a steel belt wound spirally appears on the inner peripheral surface.

  Usually, since a steel belt is a very thin material, the inner peripheral surface of the fiber reinforced resin pipe which is a molded product is formed smoothly and does not affect the water flow in the pipe.

  Here, using a tubular body formed by cutting such a long fiber-reinforced resin tube into a certain length, it is considered to manufacture a receiving port provided with a water stop on the inner peripheral surface. In this case, a slight step due to the trace of the steel belt runs on the inner peripheral surface of the tube in a spiral manner over the entire length from the end of the tube. Then, when a rubber ring or the like is bonded to the inner peripheral surface as a water stop portion, the step is obliquely crossed between the rubber ring and the inner peripheral surface of the tubular body. For this reason, even a very small step may cause a slight gap between the inner peripheral surface of the tube and the adhesive surface of the rubber ring, so that water can penetrate beyond the water stop portion of the rubber ring. There is a concern to do.

  Further, even when a synthetic resin pipe molded by a method other than the filament winding method is used, the rubber ring has an adhesive strength to provide a water stop by bonding and fixing the rubber ring to the inner peripheral surface. It will greatly affect the waterstop. Therefore, a method of locking the rubber ring by providing a concave groove in advance at the place where the rubber ring is fixed is also conceivable, but the mold structure for providing the concave groove becomes complicated and the cost increases, There is a problem in that the press-fitting work of the rubber ring becomes complicated.

  Accordingly, the present invention has been made in view of the above-described problems. A cylindrical tube made of a synthetic resin having a water stop portion is manufactured at a low cost, and the water stop portion of the water stop portion is reliable. The present invention provides a method for manufacturing a cylindrical tube capable of improving the degree.

  In order to achieve the above-described object, the present invention provides a cylindrical tube provided with a water stop portion by a rubber ring on the inner peripheral surface of a synthetic resin tube formed using a mold in which a steel belt is spirally wound. In the manufacturing method, an attachment region of the rubber ring attached to the inner peripheral surface of the tubular body is set by retreating inward from an end portion of the tubular body, and a surface roughening treatment is performed on a surface of the attachment region; A step of applying an adhesive to the roughened attachment region, and a step of adhering and fixing a rubber ring to the attachment region to which the adhesive has been applied to dispose a water stop portion, and within the range of the attachment region The step formed spirally on the inner peripheral surface of the tubular body during the forming of the tubular body is scraped off in the roughening process to form a uniform surface without a step, and the attachment The water stop part is formed by watertightly bonding the surface of the region and the adhesive surface of the rubber ring to each other.

  By such a method of manufacturing a cylindrical tube, prior to the step of bonding and fixing the rubber ring to the attachment region to which the rubber ring is attached, a step due to the trace of the steel belt generated on the surface of the attachment region due to the molding of the tube is formed. This eliminates the possibility of completely blocking the water intrusion path extending in and out of the attachment region, so that an appropriate rough surface having no step can be formed in the attachment region. In addition, by forming such an attachment region, there is no risk of forming a water intrusion path (water) in the water stop portion, and the adhesion between the surface of the attachment region and the adhesive surface of the rubber ring is increased, thereby making the watertightness of each other. Therefore, it is possible to form a highly reliable water stop portion.

  In the above-described method for manufacturing a cylindrical tube, it is preferable that the mounting area is roughened by roughening. Further, the roughening treatment of the attachment region may be performed by covering and protecting the periphery of the attachment region and spraying a particulate abrasive.

  By such a manufacturing method, it is possible to easily perform the roughening treatment on the inner peripheral surface of the synthetic resin tube body, and a complicated mold or the like is unnecessary, and a cylindrical tube is manufactured without cost. It becomes possible.

  Moreover, in the manufacturing method of said cylindrical tube, it is preferable to form the attachment area | region to roughen as a recessed part which has a depth of 1 mm or less. A slight step may be formed by molding on the inner peripheral surface of the synthetic resin tube that constitutes the cylindrical tube, but by forming a recess in the mounting area, the step is eliminated and the rubber ring The adhesion between the rubber ring and the tube can be enhanced.

  According to the method for manufacturing a cylindrical tube of the present invention configured as described above, a cylindrical tube made of synthetic resin having a rubber ring can be manufactured at low cost with good workability, and the rubber ring of the cylindrical tube can be manufactured. The reliability with respect to the water stoppage of the water stop part by can be improved.

It is explanatory drawing of the shaping | molding apparatus for shape | molding a synthetic resin pipe body in the manufacturing method of the cylindrical tube which concerns on one Embodiment of this invention. It is sectional drawing of the pipe-axis direction which shows the fiber reinforced resin pipe obtained by the said shaping | molding apparatus. It is explanatory drawing which expands each process of the manufacturing method of the cylindrical tube which concerns on one Embodiment of this invention, and expands the cutting part end surface of the pipe body direction of a pipe body end part. It is sectional drawing which shows the pipe body in the process corresponding to FIG.3 (b) of the manufacturing method of the said cylindrical tube. It is a cutting part end view of a tube axis direction of a cylindrical tube obtained by a manufacturing method of a cylindrical tube concerning an embodiment. It is a perspective view of the cylindrical tube shown in FIG.

  Hereinafter, a method for manufacturing a cylindrical tube according to an embodiment of the present invention will be described with reference to the drawings.

  The cylindrical tube 1 obtained by the manufacturing method of the present embodiment is formed using a synthetic resin tube 2. As a material for the synthetic resin tube 2, synthetic resins such as FRP, polyvinyl chloride (PVC), polyethylene (PE), polypropylene (PP), and unsaturated polyester can be employed.

  Prior to the description relating to the manufacturing method of the cylindrical tube of the present embodiment, the molding of the synthetic resin tube 2 will be described first.

  The tube body 2 shown as an example is obtained by cutting a fiber reinforced resin tube continuously formed by the forming apparatus 10 as shown below into a required length.

  FIG. 1 is an example of a molding apparatus 10 for molding a fiber reinforced resin pipe (FRP composite pipe) according to a synthetic resin pipe body 2. The molding apparatus 10 includes a cylindrical mold 103 that rotates about a rotation shaft 102 that extends horizontally from the apparatus main body 101. An endless steel belt 104 is spirally wound around the mold 103, and a cylindrical mold surface formed by the outer surface of the steel belt 104 is advanced by the rotation of the mold 103. . The steel belt 104 that has reached the open end of the mold 103 returns to the original position through the interior of the mold 103 and is wound around the mold 103 again. The mold 103 is arranged so that the open end side faces the curing furnace 105.

  With such a forming apparatus, first, the mold cloth 103 is rotated to advance the mold surface around which the steel belt 104 is wound in the direction of the curing furnace 105, and the release cloth 106 is wound spirally. Next, the inner surface protective material 107 such as glass paper is spirally wound from above the release cloth 106. Next, after the inner layer side glass roving 108 is wound around the mold surface, a desired amount of uncured thermosetting resin composition 109 is supplied to the inner layer side glass roving 108 and is uniformly reinforced by the leveling roller 115. The inner FRP layer 110 is formed.

  Next, a desired amount of resin mortar 111 is supplied onto the inner FRP layer 110, and a resin mortar layer 112 having a uniform thickness is formed by using a spatula (not shown) as appropriate. Next, after winding the outer layer side glass roving 113 around the mold surface from above the resin mortar layer 112, a desired amount of uncured thermosetting resin composition 114 is supplied to the outer layer side glass roving 113, The outer FRP layer 120 is formed by uniformly impregnating the reinforcing fibers with the roller 116. Then, it heats in the curing furnace 105 and hardens the uncured thermosetting resin composition. After curing, the release cloth 106 is removed to obtain a fiber reinforced resin tube 20 as shown in FIG.

  In the fiber reinforced resin tube 20 continuously molded in this manner, the trace of the steel belt 104 spirally wound around the mold 103 at the time of molding appears on the inner peripheral surface, and a slight step 21 is formed. It occurs in a spiral. Moreover, the tube body 2 used in the method for manufacturing a cylindrical tube of the present embodiment is obtained by cutting the fiber reinforced resin tube 20 to a predetermined required length.

  3 to 6 show a method for manufacturing a cylindrical tube according to an embodiment of the present invention, and each figure in FIG. 3 sequentially shows each step of the method for manufacturing the cylindrical tube, and the end surface of the cut portion in the tube axis direction of the tube body end. 4 is an enlarged explanatory view, FIG. 4 is a sectional view in the tube axis direction of the synthetic resin tubular body 2 corresponding to FIG. 3B, and FIG. 5 shows an example of the manufactured cylindrical tube. FIG. 6 is a perspective view showing the cylindrical tube of FIG. 5.

  On the inner peripheral surface of the pipe body 2 obtained by cutting the fiber reinforced resin pipe 20 shown in FIG. 2, a water stop by a rubber ring 31 at one end and an O-ring 32 at the other end, as shown in FIG. The portion 4 is provided to form the cylindrical tube 1.

  Each process for manufacturing the cylindrical tube 1 will be described. FIG. 3A shows an enlarged one end portion of the tube body 2. As shown in FIG. 3A, a step 21 is formed on the inner peripheral surface of the tube body 2 due to the trace of the steel belt 104 over the entire length from the tube end. If the thickness of the steel belt 104 is taken into consideration, the generated step 21 is normally assumed to occur within a range of 0.5 mm or less. In addition, the inner peripheral surface of the tubular body 2 may be a tapered surface having a smaller diameter toward the inside.

  A rubber ring 31 is attached to the inner peripheral surface of the tubular body 2 to form the water stop portion 4. As shown in FIG. 3A, an attachment region T for attaching the rubber ring 31 is set on the inner peripheral surface of the tubular body 2.

  The attachment region T is not provided in contact with the end portion of the tube body 2 but is set to be retracted inward from the end portion of the tube body 2. The attachment region T is set in a range corresponding to the width of the rubber ring 31 to be bonded.

  In attaching the rubber ring 31 to the attachment region T, first, the surface of the attachment region T in the tubular body 2 is roughened. The roughening process is performed by grinding the surface to such an extent that the level difference 21 included in the attachment region T is scraped off and eliminated.

  Specifically, a roughing operation (sanding) is performed by moving an appropriate grinding tool such as a sanding machine along the attachment region T on the inner peripheral surface of the tubular body 2. Or you may roughen the attachment area | region T by the process by sandpaper application | coating or the sandblast process which sprays a particulate abrasive.

  In the roughening treatment, the periphery of the attachment region T on the inner peripheral surface of the tube body 2 is covered and protected. The covering protection is preferably performed by masking with a masking material or covering with a template. In addition, by marking the attachment region T in advance, the roughening process may be performed smoothly along the attachment region T.

  FIG. 3B is an end view showing an enlarged one end portion at the stage where the roughening process is performed on the attachment region T on the inner peripheral surface of the tubular body 2. As shown in the drawing, through the roughening process, the mounting region T has a step 21 cut away to form a surface having no step and a rough surface 22. Further, the roughened attachment region T is a recess 23 having a depth of 1 mm or less.

  For example, when a roughening process is performed on the mounting region T of the rubber ring 31 on the inner peripheral surface using the tubular body 2 having a nominal diameter of 800 (inner diameter of the tubular body 2: 820 mm) and a wall thickness of 10 mm, the mounting region T About 0.6 mm is sufficient for the depth of the recess 23 to be formed.

  Further, when a roughening process is performed on the mounting region T of the rubber ring 31 on the inner peripheral surface using the tubular body 2 having a nominal diameter 300 (inner diameter of the tubular body 2: 310 mm) and a thickness of 7 mm, the mounting region T A depth of the formed recess 23 of about 0.3 mm is sufficient.

  Thus, by roughening the mounting region T of the rubber ring 31 of the tubular body 2 and forming the recess 23, as shown in FIG. 4, inside and outside of the mounting region T (front and rear in the tube axis direction). The continuous step 21 that has reached can be completely eliminated in the attachment region T.

  After forming the rough surface 22 on the surface of the attachment region T to form the shallow groove-shaped recess 23, the adhesive 5 is applied to the attachment region T. Next, as shown in FIG. 3C, the rubber ring 31 is disposed so as to overlap the attachment region T to which the adhesive 5 is applied, and the rubber ring 31 is bonded and fixed. Thereby, the water stop part 4 is formed in the internal peripheral surface of the one end part of the pipe body 2. As shown in FIG. The O-ring 32 is attached to the water stop 4 at the other end through the same process.

  Since the attachment region T is formed with a recess 23 having a depth of 1 mm or less that completely eliminates the spiral step 21 on the inner peripheral surface, there is a water channel that allows water to enter beyond the water stop 4. It is completely blocked and disappears. For this reason, the step 21 is not interposed between the rubber ring 31 and the O-ring 32 and the surface of the attachment region T, and there is no possibility of generating a gap. Moreover, since the attachment area | region T is a rough surface, compared with the case where it adhere | attaches on a smooth surface, the adhesion strength of the adhesive agent 5 and the rubber ring 31 is remarkably high, and it becomes difficult to peel off. Thereby, the water stop part 4 provided in the cylindrical pipe | tube 1 becomes what closely_contact | adhered to the internal peripheral surface of the pipe body 2 without a gap, and it becomes possible to ensure high water stop.

  Moreover, as shown in FIG.3 (c), the surface of the rubber ring 31 has the uneven | corrugated | grooved part 31a, and it can improve adhesiveness with the joined pipe body and can improve water-stopping still more. It has become.

  As shown in FIG. 5 and FIG. 6, the cylindrical tube 1 obtained as described above has a water stop portion 4 on the inner peripheral surface and has a good water stoppage when combined with other tubular bodies. Can be secured. In addition, by using the manufacturing method as described above, it is not necessary to prepare a new mold for manufacturing the cylindrical tube 1, and using a synthetic resin tube obtained in the same manner as in the past, water-stop reliability is ensured. It is possible to manufacture a cylindrical tube 1 having a high height.

  The tube body 2 constituting the cylindrical tube 1 is not limited to the fiber reinforced resin tube continuously formed by the filament winding method as described above, but by any molding method such as an injection molding method or a centrifugal molding method. The obtained tube may be used. Moreover, the cross-sectional shape of the concavo-convex portion 31a of the rubber ring 31 is not limited to the illustrated one, and any form of the rubber ring 31 may be used.

  The cylindrical tube 1 obtained by such a manufacturing method is fitted into one end of a synthetic resin tube with a rubber ring 31 interposed therebetween, so that a receiving structure for a pipe joint having a high water-stopping property can be formed. The water-stop portion 4 of the cylindrical tube 1 is integrated with the rubber ring 31 and the inner peripheral surface of the tube body 2 with a high degree of adhesion, and there is no possibility of creating a gap that becomes a ridge, and high reliability. It will be equipped with.

  The present invention can be suitably used for manufacturing, for example, a receiving portion of a pipe joint between synthetic resin pipes.

DESCRIPTION OF SYMBOLS 1 Cylindrical pipe 2 Synthetic resin pipe body 20 Fiber reinforced resin pipe 21 Level difference 22 Rough surface 23 Recessed part 31 Rubber ring 31a Uneven part 32 O-ring 4 Water stop part 5 Adhesive T Attachment area 10 Molding apparatus 101 Apparatus main body 102 Rotating shaft 103 Mold 104 Steel belt 105 Curing furnace 106 Mold release cloth 107 Inner surface protection material 108 Inner layer side glass roving 109, 114 Thermosetting resin composition 110 Inner FRP layer 111 Resin mortar 112 Resin mortar layer 113 Outer layer side glass roving 115, 116 Roller 120 Outer FRP layer

Claims (4)

A method of manufacturing a cylindrical tube having a water stop portion by a rubber ring on the inner peripheral surface of a synthetic resin tube formed by using a mold in which a steel belt is spirally wound,
The mounting area of the rubber ring attached to the inner peripheral surface of the tubular body is set by retreating inward from the end of the tubular body,
A step of roughening the surface of the mounting region;
Applying an adhesive to the roughened mounting area;
Including a step of bonding and fixing a rubber ring to the attachment area where the adhesive is applied to form a water stop portion,
Within the range of the attachment region, a step formed in a spiral shape on the inner peripheral surface of the tubular body during the forming of the tubular body is scraped off in the step of performing the roughening treatment, so that there is no step. Formed on the surface,
A method for manufacturing a cylindrical tube, characterized in that the water stop portion is formed by watertightly bonding the surface of the attachment region and the adhesive surface of the rubber ring. In the manufacturing method of the cylindrical pipe according to claim 1,
A method for manufacturing a cylindrical tube, wherein the roughening treatment of the attachment region is performed by roughening. In the manufacturing method of the cylindrical pipe according to claim 1,
The method for producing a cylindrical tube, wherein the roughening treatment of the attachment region is performed by covering and protecting the periphery of the attachment region and spraying a particulate abrasive. In the manufacturing method of the cylindrical tube as described in any one of Claims 1-3,
The manufacturing method of a cylindrical tube, wherein the roughened attachment region is formed as a recess having a depth of 1 mm or less.

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