JP2003094302A - Reinforced plastic pipe - Google Patents

Abstract

PROBLEM TO BE SOLVED: To uniformly and surely form irregularities for improving the roughness coefficient in the whole area of the inside of a reinforced plastic pipe P. SOLUTION: A grinding tool 30 of a rotation arm 27 is made to abut on the inside of the reinforced plastic pipe P and moved in the cylinder axis direction by a carriage 23 while grinding it with the reinforced plastic pipe P rotating in its circumferential direction and the grinding action forms the irregularities on the whole inside of the reinforced plastic pipe P. The grinding can easily form the fine irregularities so as to easily provide the prescribed roughness coefficient. The grinding can uniformly and surely form the irregularities on the whole surface of the pipe inside.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for increasing the roughness coefficient by forming irregularities on the inner surface of a reinforced plastic tube, and a reinforced plastic tube having an increased roughness coefficient.

[0002]

2. Description of the Related Art Reinforced plastic pipes used in many water supply and drainage pipes require a resin-impregnated circumferential and axial fiber layers on a protective layer formed by impregnating a base fabric such as a non-woven fabric with a resin. One provided with a step and further provided with a protective layer on it (outer surface) (FRP pipe), or one provided with a resin mortar layer on the FRP pipe, that is, as shown in FIGS. 4 to 6,
A fiber layer is formed on a protective layer, a resin mortar layer 2 and a resin layer are formed thereon, and a protective layer is further provided (FR
PM tube) etc. Hereinafter, as shown in the figure, the inner protective layer and the fiber layer are referred to as the inner surface reinforced plastic layer 3, the outer protective layer and the inner fiber layer are referred to as the outer surface reinforced plastic layer 1, and the space between them is referred to as the resin mortar layer 2.

The reinforced plastic pipe P is molded by a filament winding method (FW method), a centrifugal molding method or the like, and the FW method is often used. Since the reinforced plastic pipe P formed by the FW method is molded in a state where the inner surface on the running water side is in contact with the core die, the reinforced plastic tube P has an inner surface with high smoothness similar to the surface of the core die and has a roughness. The coefficient is relatively small. Therefore, the coefficient of roughness of the reinforced plastic pipe P is 0.010, but the coefficient of roughness of concrete pipe or cast iron pipe is 0.013, 0.014 for porcelain pipe, and 0.014 to 0.015 for concrete flume. , Culvert is 0.0
It is 15.

As described above, since the reinforced plastic pipe P has a small roughness coefficient on its inner surface, the flow velocity of the fluid flowing in the pipe is higher than that of pipes made of other materials. There must be many staircase joints and energy dams.

For this reason, unevenness is formed on the inner surface of the reinforced plastic pipe P to increase the roughness coefficient of the inner surface. As means for forming the unevenness, Japanese Patent Application Laid-Open No. 5-2
As shown in FIG. 4, Japanese Patent Publication No. 78125 discloses a means for exposing a part of the inorganic fine particles 4 on the inner surface of the tube to form irregularities. As shown in (b), after forming the tube, a cross tape 5 having irregularities 5a on its inner peripheral surface is wound around the core mold 7 via the cellophane tape 6 and formed, and then, as shown in FIG. The means for removing the cross tape 5 and the like to provide the unevenness 8 on the inner peripheral surface, and the means for forming the unevenness by attaching the sandy body 9 to the inner surface of the pipe via the adhesive 9a as shown in FIG. It is disclosed.

[0006]

However, in the technique described in the former publication, since the fine inorganic particles 4 having an uneven surface directly contact the core mold 7, there is a risk of damaging the core mold 7, and the resin to be impregnated. The amount of exposure determines the degree of exposure of the inorganic fine particles 4, and there is a case where no exposure is made, that is, unevenness is not formed.

Further, in the case of the technique described in the latter publication, since the cross tape 5 and the like are removed after the pipe is formed, the cross tape 5 must be discarded, and further, depending on the degree of winding of the resin during the pipe formation, In some cases, the unevenness 5a of the tape 5 may not be easily transferred to the inner peripheral surface. In the case where the sand-like body 9 is adhered, since it is after the pipe is molded, the sand-form body 9 is not adhered uniformly over the entire length of the pipe, and the adhesion degree is not uniform.

An object of the present invention is to uniformly and surely form irregularities.

[0009]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention is intended to form irregularities on the inner surface of a pipe by grinding. By grinding, fine irregularities can be easily formed, and a required roughness coefficient can be easily obtained. Further, the grinding can uniformly and surely form the unevenness on the entire inner surface of the pipe.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION As an embodiment of the invention relating to the method for forming the unevenness, a resin mortar layer is formed on an inner surface reinforced plastic layer, and further, an inner surface of a reinforced plastic pipe in which an outer surface reinforced plastic layer is laminated, In the method for forming irregularities for increasing the roughness coefficient, in the state in which the reinforced plastic pipe is rotated in the circumferential direction, the grinding tool is brought into contact with the inner surface of the reinforced plastic pipe P to grind the cylindrical shaft. It is possible to adopt a configuration in which the unevenness is formed on the entire inner surface of the reinforced plastic tube by moving the reinforced plastic tube by moving it in the direction.

The grinding depth is 0.05 mm to 0.5.
mm, preferably 0.1 mm to 0.2 mm. With this depth, a roughness coefficient similar to that of a concrete pipe can be obtained. The reinforced plastic tube and the grinding tool may be relatively brought into contact with each other, and which is to be moved in the cylinder axis direction is free.

Further, as an embodiment of the invention relating to the apparatus for forming the irregularities, a grinding table for placing the reinforced plastic tube in a horizontal state and rotating it in the circumferential direction thereof, and the grinding tool at the tip are provided. It is possible to adopt a configuration in which a horizontal rotating arm is supported in a cantilever shape and can move forward and backward toward the grinding table.

In the apparatus of this construction, as in the above-described forming method, the trolley is moved toward the grinding table while the reinforced plastic pipe is rotated in the circumferential direction on the grinding table, and the grinding tool is used. Is rotated and brought into contact with the inner surface of the reinforced plastic pipe. As the carriage advances and retracts, a rotating grinding tool grinds the inner surface of the reinforced plastic pipe from one end to the other end to form irregularities on the entire inner surface of the pipe. The reinforced plastic tube having the unevenness has a desired unevenness, that is, a desired roughness coefficient, by appropriately selecting the grinding degree.

Various grindstones can usually be used as the grinding tool, and the grain size of the grindstone is determined according to the required degree of unevenness. Instead of the grindstone, a wheel or paper wheel having diamond grains attached to the outer peripheral surface may be used.

[0015]

FIG. 1 shows an embodiment of a concavo-convex forming device according to the present invention, in which a grinding table 10 and a grinding device 20 are installed linearly on a ground W. The grinding table 10 has support tables 11a, 11b, and 11c at the center and front and back, and each support table 1a
1a, 11b, and 11c support the lower surface of the reinforced plastic pipe P by the right and left rollers 12, and rotate the roller 12 of the one support base 11a by a driving machine (not shown), so that the reinforced plastic pipe P is surrounded by the rollers. Rotate in the direction.

The grinding device 20 comprises a pair of left and right rails 2
1 is provided in the front-back direction, and the motor 2 is mounted on the rail 21 thereof.
A carriage 23, which is driven by 2, is provided so as to be movable. A pedestal 24 is provided on the dolly 23 so as to be swingable up and down with its rear end, and the front end of the pedestal 24 is supported by the dolly 23 by an air cylinder 25. A rotating arm 27 is provided on the pedestal 24 via a bearing 26 toward the front, and a grinding tool 30 is detachably provided at the tip of the rotating arm 27. The rotating arm 27 is rotated at a required speed by a motor 28 on the pedestal 24. The front portion of the rotary arm 27 is rotatably and swingably supported by a bearing 41 of a support device 40 provided on the ground W, and the bearing 41 is vertically movable by an air cylinder 42. The air cylinder 42 works in conjunction with the air cylinder 25.

As shown in FIG. 2, in the grinding tool 30, diamond particles are attached (attached) to the outer peripheral surface of the wheel 31 keyed to the rotating arm 27 by electrodeposition or the like to form the grinding layer 3
2 is formed. By appropriately selecting the grain size of the diamond grains, the irregularity of the inner surface of the reinforced plastic pipe P described later, that is, the grain size coefficient of the inner surface is determined. In the figure, 29 is a cable bear (registered trademark) for supplying electric power to the motors 22 and 28 on the carriage 23.

This concavo-convex forming device has the above-mentioned structure. To form concavo-convex on the inner surface of the reinforced plastic pipe P with this device, first, the reinforced plastic pipe P manufactured by the FW method or the like is used as in the conventional case. It is placed on the grinding table 10 and rotated. At this time, the inner surface protective layer 3 of the reinforced plastic pipe P is thickened, for example, by about 1 mm to secure a grinding allowance.

Next, the carriage 23 is advanced toward the grinding table 10 and the grinding tool 30 is rotated to abut the inner surface of the reinforced plastic pipe P. As the trolley 23 advances, the rotating grinding tool 30 grinds the inner surface of the reinforced plastic pipe P from one end to the other end to form the unevenness 50 on the entire inner surface of the pipe P as shown in FIG.

If the unevenness 50 is formed on the entire inner surface of the pipe P, the rotary arms 27 are raised by the air cylinders 25 and 42, the grinding tool 30 is separated from the inner surface of the pipe, the carriage 23 is retracted, and the pipe P is withdrawn. Let The formation of the unevenness 50 is
Insert the rotating arm 27 to the front end (left end in FIG. 1), not from the rear end (right end in FIG. 1) of the reinforced plastic pipe P,
The carriage 23 may be ground while being moved backward.
Further, the grinding device 20 can be fixed to the ground W, and the grinding table 10 can be moved back and forth with respect to the grinding device 20 via a rail or the like. At this time, the supporting device 40 is omitted. However,
Since the pipe P is placed on the grinding table 10 and rotates, it is advantageous to move the grinding device 20 by the carriage 23.

The reinforced plastic pipe P having the unevenness 50 formed on the inner surface in this manner forms a joint portion by fitting a joint pipe at one end thereof as needed.

In the above embodiment, the unevenness 50 is provided over the entire inner surface of the reinforced plastic pipe P. However, when there is a margin in the planned flow rate, only the desired range of the inner surface of the pipe P in the axial direction or the circumferential direction is provided. It is also possible to grind to provide the unevenness 50. The degree (depth) of the irregularities can be changed not only in the entire inner surface of the tube but also in a desired range. As a grinding method for those desired ranges and changes in the degree of unevenness,
The pressing position / amount and time of the rotary arm 27 can be determined by the grinding tool 3
It is conceivable to control the feeding speed / position of 0, the pressing depth, the rotation speed / time of the reinforced plastic pipe P, and the like.

[0023]

According to the present invention, since the unevenness is formed by grinding, the unevenness can be uniformly and easily formed on the inner surface of the reinforced plastic pipe, and the roughness coefficient can be increased by using the reinforced plastic pipe. The flow velocity of the fluid flowing in the pipe can be suppressed. Further, the roughness coefficient of the inner surface can be changed by changing the grinding allowance of the inner surface protective layer. Further, by grinding only a desired range of the inner surface of the pipe, the roughness coefficient of the inner surface based on the flow rate can be changed, and a rational effective cross section of the flow rate can be set.

[Brief description of drawings]

1A and 1B show an embodiment of an unevenness forming apparatus according to the present invention, in which FIG. 1A is a plan view and FIG. 1B is a front view.

FIG. 2 shows the grinding tool of the embodiment, (a) is a sectional view,
(B) Right side view

FIG. 3 is a sectional view of a main part of a reinforced plastic pipe according to the present invention.

FIG. 4 is a sectional view of a main part of a conventional reinforced plastic pipe.

FIG. 5 is a cross-sectional view of a main part for explaining the production of a conventional reinforced plastic pipe.

FIG. 6 is a sectional view of a main part of a conventional reinforced plastic pipe.

[Explanation of symbols]

1 External surface reinforced plastic layer 2 Resin mortar layer 3 Inner surface reinforced plastic layer 10 grinding table 11a, 11b, 11c support base 12 roller 20 Grinding equipment 21 rails 23 dolly 27 rotating arm 28 Rotating arm rotation motor 30 grinding tools 32 grinding layer 50 unevenness P reinforced plastic tube

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Hiroyuki Nokubo             1-12-19 Kitahori, Nishi-ku, Osaka City Stock Association             Kurimoto Ironworks (72) Inventor Tomonori Makino             1-12-19 Kitahori, Nishi-ku, Osaka City Stock Association             Kurimoto Ironworks (72) Inventor Toshio Yonehara             Kurimoto, 1-12-19 Kitahorie, Nishi-ku, Osaka-shi             Seisei Co., Ltd. (72) Inventor Teruhiro Mihara             Kurimoto, 1-12-19 Kitahorie, Nishi-ku, Osaka-shi             Seisei Co., Ltd. (72) Inventor Yoshitaka Yano             Kurimoto, 1-12-19 Kitahorie, Nishi-ku, Osaka-shi             Seisei Co., Ltd. F-term (reference) 3C043 AC03 CC02                 3H025 BA01

Claims (4)

[Claims] 1. A method for forming unevenness 50 on the inner surface of a reinforced plastic pipe P for increasing the roughness coefficient thereof, comprising a grinding tool in a state where the reinforced plastic pipe P is rotated in the circumferential direction. 30 is brought into contact with the inner surface of the reinforced plastic pipe P and is moved in the cylinder axis direction while being ground, and the grinding action forms the irregularities 50 on the inner peripheral surface of the reinforced plastic pipe P. Method for forming irregularities on the inner surface of a plastic pipe. 2. The method for forming irregularities on the inner surface of a reinforced plastic pipe according to claim 1, wherein the grinding depth is 0.05 mm to 0.5 mm. 3. A reinforced plastic pipe having unevenness 50 formed by the unevenness forming method according to claim 1. 4. An apparatus for performing the method for forming irregularities on the inner surface of a reinforced plastic pipe according to claim 1 or 2, wherein the reinforced plastic pipe P is placed horizontally and rotated in its circumferential direction. Grinding table 10 and the above grinding tool 3 at the tip
An apparatus for forming irregularities on the inner surface of a reinforced plastic pipe, which comprises a carriage 23 that supports a rotating arm 27 having a horizontal state of 0 in a cantilever shape and is capable of advancing and retracting toward the grinding table 10.