JP3843432B2 - Method for coating inner surface of tubular body - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for coating an inner surface of a tubular body having a branch pipe, and more particularly to a method for coating an inner surface of a tubular body while moving the inside of the tubular body with an elastic body.
[0002]
[Prior art]
Tubular bodies such as water and sewage pipes, industrial water pipes, seawater pipes, pipes around water turbines in hydroelectric power stations, especially metal tubular bodies, the inner surface gradually corrodes when used for a long period of time, and the corrosion progresses. This causes problems such as weakening of the pipe wall and generation of holes.
[0003]
Therefore, conventionally, the inner surface of the tubular body is coated with a coating material such as a resin to prevent corrosion or to recover (renovate) the function of the tubular body in which corrosion has progressed. However, these tubular bodies are often embeded in concrete foundation slabs and walls of buildings and can be efficiently coated from the outside to coat the inner surface of the tubular body of such buried parts. It is necessary to adopt a special construction method.
[0004]
As one of the above construction methods, by pulling the rope attached with the front elastic body and the rear elastic body into the tubular body, and pulling the rope with the coating material filled between the front elastic body and the rear elastic body, A method of coating the inner surface of a tubular body is known (for example, see Patent Document 1).
[0005]
[Patent Document 1]
JP 2002-233818 A (Claims, FIG. 1)
[0006]
7 and 8 are schematic views for explaining the procedure for coating the inner surface of the tubular body. In order to coat the inner surface of the tubular body 1, first, as shown in FIG. 7, a coating tool 3 in which one front elastic body 5 and a plurality of rear elastic bodies 6 are attached to a rope 4 is prepared. The front elastic body 5 and the respective rear elastic bodies 6 attached to the rope 4 are made of elastic balls such as urethane foam having a large number of communicating bubbles, and the rope 4 is slidably inserted into a through hole provided at the center thereof.
[0007]
For reference, an enlarged structure of a conventional elastic body made of an elastic ball such as urethane foam is shown in FIG. Urethane foam has a structure in which a large number of fine spherical cells A are three-dimensionally connected, and the foam is formed by fine pores formed in each cell membrane, or fine gaps formed at the cell-cell connection part. Air permeability (or water permeability) as a whole is ensured.
[0008]
In FIG. 7, stoppers 4 a fixed to the rope 4 are provided on the front side of the front elastic body 5 and on the front side and rear side of each rear elastic body 6, respectively. Movement of the body 6 in the front-rear direction is restricted. The position of the stopper 4a is adjusted so that the distance between the front elastic body 5 and the front rear elastic body 6 matches the capacity of the coating material to be filled first.
[0009]
Next, an insertion body 7 having an inlet / outlet 8 and a coating material injection portion 9 is connected to one end of the tubular body 1, and the rope 4 is inserted into the tubular body 2 from the portion of the inlet / outlet 8. Pull out from the other end. The rope 4 can be inserted by using a pilot wire or vacuum suction, for example. The coating material 10 is, for example, a vinyl ester resin or an epoxy resin, or a material in which glass flakes are dispersed therein.
[0010]
Next, the coating material 10 is filled between the front elastic body 5 and the front rear elastic body 6 from the injection portion 9, and then the tip of the rope 4 is pulled from the other end of the tubular body 1 with a winch or the like to pull the coating tool 3. Then, the inner surface of the tubular body 1 is continuously coated.
[0011]
That is, as shown in FIG. 8, when the coating tool 3 is pulled inside the tubular body 1 in the direction of the arrow, the coating material filled between the front elastic body 5 and the front rear elastic body 6 becomes the front rear elastic body. The inner surface of the tubular body 1 is coated while flowing downstream from between 6 and the inner surface of the tube. The formed coating layer is repeatedly pressed by a plurality of subsequent elastic bodies 6 to be further smoothed and uniformed.
[0012]
At this time, since the backward movement of the front elastic body 5 is not limited by the stopper 4a, the front elastic body 5 moves toward the front rear elastic body 6 according to the amount of decrease in the filled coating material 10. Therefore, the space between the front elastic body 5 and the front rear elastic body 6 is always filled with the coating material 10, so that the inner surface of the pipe can be coated uniformly.
[0013]
FIG. 10 is a schematic perspective view showing an example of a tubular body having a branch pipe. This example is a piping system around a water turbine in a hydroelectric power plant, and a tubular body 1 is constituted by a mother pipe 2 formed in a loop shape and a plurality of branch pipes 2a, 2b, 2c and 2d connected to the mother pipe 2. The flow from the water turbine flows into the mother pipe 2 from the branch pipes 2a, 2b, and 2c, and the flow from the mother pipe 2 flows out downstream via the branch pipe 2d (and there is a flow in the opposite direction). All of the mother pipe 2, the branch pipes 2a, 2b, and 2c and the middle of the branch pipe 2d are embedded in the concrete foundation slab, and the end of the branch pipe 2d is exposed to the outside.
[0014]
When coating the inner surface of the tubular body 1 having a branch pipe as shown in FIG. 10, for example, the inner surface of the mother pipe 2, it is impossible to pull the rope from the branch pipe 2d and pull out the rope 4 from the same place. . Therefore, as a method that can be implemented, it is conceivable to coat the mother pipe 2 separately in two left and right parts.
[0015]
That is, the left half of the mother pipe 2 is first coated by pulling the rope of the coating tool 3 on the towing path that first passes through the mother pipe 2 clockwise from the branch pipe 2d and reaches the branch pipe 2b, and then the same branch pipe. This is a method of coating the right half of the mother pipe 2 by pulling the rope of the coating tool 3 on the towing path that passes the mother pipe 2 from 2d counterclockwise and reaches the branch pipe 2b.
[0016]
[Problems to be solved by the invention]
However, since the mother pipe 2 itself is branched into two on the left and right at the branch portion to the branch pipe 2d, for example, when coating is performed by setting the traction path of the rope 4 in the clockwise direction, A large amount of coating material leaks to the right side of 2. Therefore, the coating material cannot be sufficiently supplied to the mother pipe 2 in the set traction path, and it becomes difficult to form a good coating layer. Further, since another branch pipe 2c is branched in the middle of the clockwise traction path, the coating material also leaks from there.
[0017]
Accordingly, it is an object of the present invention to solve these problems, and a first object of the present invention is to provide a new method for coating the inner surface of a tubular body that prevents leakage of the coating material to the branch pipe. The second object of the present invention is to provide a coating method capable of forming a good coating layer on the inner surface of the branch pipe.
[0018]
[Means for Solving the Problems]
  Claim 1The inventionIt has a three-dimensional network-like fiber skeleton B that does not have a cell membrane, and has a breathability and elasticity by itself.A rope (4) with a front elastic body (5) and a rear elastic body (6) attached is a tubular body.(1)Pull inside
  By pulling the rope (4) with the coating material (10) filled between the front elastic body (5) and the rear elastic body (6)MultipleBranch pipe (2a , 2b ,2c, 2d)Loop-shaped mother pipe (2) Said consisting ofCoating the inner surface of the tubular body (1)When
  Communicate in the middle of the rope towing route (24)MultipleBranch pipe (2a , 2b ,2c, 2d) Seal the branch (20) with the seal body (21)SaidBranch pipe (2a , 2b ,2c, 2dTo prevent leakage of coating material (10)In the method for coating the inner surface of the tubular body,
  Tow path of the rope (twenty four) Towing route of the rope bent at a right angle at the part where is bent at a substantially right angle (twenty four) On the other side of the branch pipe ( 2a , 2b , 2c , 2d Or main (2) If there is  The branch pipe on the opposite side ( 2a , 2b , 2c , 2d Or main (2) Rope pulling path inside (twenty four) On the side, its surface is a front elastic body (Five) And rear elastic body (6) Sealed body with a concave curved surface that matches the surface shape (twenty one) And its branching section (20) And seal the front elastic body (Five) And rear elastic body (6) It is a coating method of the inner surface of a tubular body characterized by guiding the above.
[0024]
DETAILED DESCRIPTION OF THE INVENTION
  Next, embodiments of the present invention will be described with reference to the drawings. In the following embodiment, the rod-shaped body 1 of FIG. 10 is taken as an example, but the present invention can be similarly applied to a rod-shaped body having other branch pipes.
  1 shows the left half of the mother pipe 2 shown in FIG.And by the technology that is the premise of the present invention,It is a fragmentary sectional view which shows the state to coat. In the drawing, only the mother pipe 2, the branch pipe 2c, and the branch pipe 2d are shown,MinThere is a manifold 2b.
[0025]
The branch pipe 2 c is connected to the mother pipe 2 by a branch part 20 having a small curved surface part 20 a, and a seal body 21 is attached to the branch part 20. A similar seal body 21 is also attached to the branch portion 20 of the mother pipe 2 that branches rightward from the branch pipe 2d. These sealing bodies 21 are made of a foam having elasticity such as a cell-communication type urethane having a cell membrane as shown in FIG. 9, or a semi-rigid foam having a mixture of communication cells and closed cells in a cylindrical shape. Can be made by processing.
[0026]
In order to attach the seal body 21 to the branch portion 20 of the branch pipe 2c, the seal body 21 attached to the tip of the rope 22 is compressed and inserted into the inside through the opening 23 of the branch pipe 2c, and the tip surface is the mother pipe. What is necessary is just to make it the state which reached to the 2 side wall surface. In this state, the sealing body 21 is stably attached to the branch portion 20 due to its elasticity, and the mother pipe 2 is sealed from the branch pipe 2c side by the sealing action, and the coating material leaks from the mother pipe 2 to the branch pipe 2c during coating. Can be prevented.
[0027]
On the other hand, in order to attach the seal body 21 to the branch portion 20 of the main pipe 2 branching to the right side from the branch pipe 2d, the seal body 21 attached to the tip of the rope 22 is compressed to the right side from the opening of the branch pipe 2a. What is necessary is just to make it the state which inserted in the inside of the mother pipe 2, and the front end surface reached the said branch part 20. FIG. At that time, the seal body 21 can be easily moved to the branch portion 20 by pushing the seal body 21 with compressed air or the like from the rear side in a state where the seal body 21 is inserted into the opening of the branch pipe 2a. Then, the left mother pipe 2 is sealed from the right mother pipe 2 side by the sealing action of the seal body 21, and the coating material can be prevented from leaking from the left mother pipe 2 to the right mother pipe 2 during coating.
[0028]
The coating tool 3 is pulled inside the mother pipe 2 of FIG. 1 as indicated by an arrow, and the coating tool 3 is configured in the same manner as shown in FIG. Then, the coating material 10 is filled between the front elastic body 5 and the front rear elastic body 6 of the coating tool 3 by the same method as in FIG. 7, and the tip of the rope 4 is routed from the branch pipe 2d through the left half of the mother pipe 2. Then, the coating material 10 is coated on the inner surface of the mother pipe 2 in the left half by pulling out (pulling) from the opening of the branch pipe 2b (not shown).
[0029]
  At that time, as described above, the branch part of the mother pipe 2 that branches rightward from the branch part 2d.20And a branch portion of the branch pipe 2c in the middle of the left mother pipe 220Are respectively sealed with the sealing body 21, so that the coating material 10 filled between the front elastic body 5 and the front rear elastic body 6 is divided into the branch portions.20Good coating can be performed without leaking from.
  In this example, the portion from the branch pipe 2d portion of the mother pipe 2 through the left half to the branch pipe 2b portion is the pulling route 24 of the rope 4.
[0030]
Next, the remaining right mother pipe 2 is coated by the same procedure as described above. However, in that case, the branch part 20 of the left mother pipe 2 branched from the branch pipe 2d part and the branch part 20 of the branch pipe 2a are respectively sealed with the seal body 21, and the rope 4 is inserted from the branch pipe 2d. The coating tool 3 is pulled out from the branch pipe 2b. In this case, the traction path 24 of the rope 4 is from the branch pipe 2d portion of the mother pipe 2 through the right half to the branch pipe 2b portion.
[0031]
FIG. 2 shows another embodiment of the branch portion 20 portion. The seal body 21 attached to the branch portion 20 is made of the same elastic material as described above, but the shape thereof is different from that of the seal body 21 of FIG. In general, when the portion where the pulling route of the rope 4 is bent is branched, the front elastic body 5 and the rear elastic body 6 to be pulled by the rope 4 change direction in a state of being close to a right angle at the bent portion, so that the hook 4 is caught. easy.
Therefore, in this embodiment, the branch portion 20 is sealed by the seal body 21 whose surface on the pulling path side of the rope is a concave curved surface that conforms to the surface shapes of the front elastic body 5 and the rear elastic body 6, and the front elastic body 5 The rear elastic body 6 is guided by the concave curved surface so that it can be pulled smoothly.
[0032]
FIG. 3 is a cross-sectional view showing an example of the front elastic body 5 or the rear elastic body 6 used in the coating tool 3. The front elastic body 5 or the back elastic body 6 is formed by cutting a foam having elasticity such as a cell-communication type urethane having a cell membrane as shown in FIG. It can be made by attaching a sleeve 12 to a through hole 11 formed in the center of the elastic body.
[0033]
The front elastic body 5 or the rear elastic body 6 manufactured from a foam having elasticity such as a cell-communication type urethane having a cell membrane as shown in FIG. 9 is suitable for coating the inner surface of the linear tubular body 1. Yes. However, for example, when the diameter of the tubular body 1 changes midway or when it includes a bent portion such as an elbow, a good coating layer may not always be formed.
[0034]
According to the experiment, when the inner surface of the tubular body 1 is coated by the above method, a good coating layer can be efficiently formed in the straight portion of the tubular body 1, but there is a bent portion such as an elbow or the like where the diameter changes midway. When present, it was confirmed that it was difficult to form a satisfactory coating layer.
[0035]
When the tubular body 1 is continuous in the order of, for example, a large-diameter portion, a medium-diameter portion, and a small-diameter portion, a relatively large diameter front elastic body 5 and a plurality of rear elastic bodies 6 adapted to the internal diameter of the large-diameter portion. When the coating tool 3 attached to the rope 4 is prepared and the coating tool 3 is pulled and the coating operation is performed, the coating of the first large-diameter portion can be performed smoothly, but the medium-diameter portion and the small-diameter portion are changed. As the elastic body is deformed due to compression or wrinkles are generated on the surface thereof, it becomes impossible to accurately adhere to the inner surface of the tube, resulting in uneven coating and a large amount of adhesion. Further, in some cases, the front elastic body 5 and the rear elastic body 6 may be damaged or destroyed when shifting to the middle diameter portion or the small diameter portion.
[0036]
Further, when the tubular body 1 has a bent portion such as an elbow, the elastic body is subjected to irregular deformation stress when passing through the bent portion, thereby deforming the surface or causing wrinkles on the surface. It may cause the same problem as described above.
[0037]
FIG. 4 is an enlarged structural view of an elastic body that can be used as a material for producing the front elastic body 5 or the rear elastic body 6. This elastic body includes a three-dimensional mesh-like fiber skeleton B having no cell membrane. Yes. This material has great elasticity and repulsive force due to the peculiarity of the skeletal structure, and the elastic body produced therefrom is not deformed or wrinkled on the surface even if the diameter changes as described above, and the inside of the tubular body 1 When the tow is pulled, the inner surface can be closely adhered and followed, so that the above problems can be solved.
[0038]
The elastic body shown in FIG. 4 can be manufactured, for example, by removing the cell film from the elastic cell structure shown in FIG. The elastic body from which the cell membrane has been removed is generally referred to as “filmless foam” and has been conventionally used for applications such as filter materials such as engine filters and air conditioner filters, cleaners, and puff materials.
[0039]
In order to remove the cell film of the cell structure of FIG. 9 to obtain an elastic body as shown in FIG. 4, known alkali treatment methods and heat treatment methods can be employed. The former alkali treatment method is a method in which a foam having a cell membrane is immersed in an alkaline aqueous solution under a certain condition to remove the membrane, and is mainly applied to polyester foam. The latter heat treatment method is a method in which a foam having a cell membrane is placed in a pressure vessel, and a cell membrane is instantaneously removed by introducing a volatile gas and igniting, such as polyester foam or polyether foam. Applies to
[0040]
The elasticity of an elastic body manufactured using the elastic body of FIG. 4 as a raw material is significantly greater than that of a conventional elastic body such as urethane foam. Further, the repulsive force can be changed in a considerably wide range without impairing its high elasticity and soft characteristics. Specifically, the repulsive force of the elastic body can be set within a desired range depending on the type of foam used as a raw material, the molecular weight range, the amount of plasticizer, and the like. According to experiments, the repulsive force of the elastic body suitable for the coating method of the present invention is 50% compression force of 8 g / cm.^ThreeAbove, 70% compression force is 15g / cm^ThreeAbove, preferably 50% compressive force is 6-12 g / cm^Three70% compression force is 14-20 g / cm^ThreeRange. The repulsive force is measured as follows.
It is a value measured by cutting an elastic body into a regular cubic size of 10 cm × 10 cm × 10 cm, placing rigid plates on the upper and lower surfaces, and placing a weight on the upper rigid plate.
[0041]
For example, polyester foam or polyether foam having the structure shown in FIG. 9 can be used as a raw material for the production of the elastic body of FIG. 4, but it has high elasticity and repulsive force that can follow the inner surface of the tubular body 1 well. If the coating material to be used is stable, the type is not particularly limited.
[0042]
Since the air permeability (water permeability) of the elastic body used in the present invention has a correlation with the pressure loss, the air permeability can be known by measuring the pressure loss. According to the experiment, the pressure loss of the elastic body of the present invention is 10 to 0.8 mmH under the conditions of a thickness of 10 mm and a wind speed of 2 m / sec.₂It was found that when it is in the range of O, it has a favorable effect on the adhesion to the inner surface of the tubular body 2 and the like.
[0043]
The ball body or spherical front elastic body 5 or rear elastic body 6 as shown in FIG. 3 can be made using the elastic body of FIG. In addition, the shape of such an elastic body can also be made into a column shape. In order to manufacture such an elastic body, the raw material stage before the cell film removal or the elastic body stage after the cell film removal may be used.
[0044]
When coating is performed using an elastic body having a three-dimensional network fiber skeleton, a coating material suitable for the characteristics of the elastic body is required. Such a coating material only needs to have fluidity and a viscosity sufficient to fill and hold the pair of elastic bodies. Examples of the material include vinyl ester resins and epoxy resins. .
[0045]
Unlike the elastic body manufactured from the elastic material of FIG. 9, the elastic body manufactured from the elastic material of FIG. 4 does not have a cell membrane substantially, and the space | gap is very large.
[0046]
Therefore, when coating is performed using an elastic body having a large gap as described above, a good coating can be achieved if the viscosity of the resin constituting the coating material is within the range of 60 to 200 P at room temperature (around 20 ° C.). all right.
[0047]
When the coating method of the present invention is carried out, the durability of the coating layer can be further improved by using a coating material in which a flaky filler, particularly a filler made of glass flakes is dispersed in a resin. For example, the water vapor permeability of a coating material made of an epoxy resin that does not contain glass flakes, and 30 to 40% by weight (inside) of glass flakes having a thickness of 2 to 3 μm, a length of 40 to 150 μm, and a width of 10 to 40 μm are dispersed. When the water vapor permeability of the coating material made of epoxy resin is compared, the former is 0.257, while the latter is drastically reduced to 0.03.
[0048]
When a coating layer is formed by a coating material in which glass flakes are dispersed in a resin, the glass flakes dispersed in the resin tend to be aligned in parallel with the surface direction of the coating layer due to the stretching action by the elastic body. When a corrosive solution or gas tries to permeate through the coating layer having a low water vapor transmission rate from the surface side, it cannot be moved straight by being disturbed by the glass flakes that overlap each other in a scale shape. As a result, it is estimated that the water vapor transmission rate is significantly suppressed.
[0049]
When a coating layer is formed by using a coating material having a low water vapor transmission rate as described above, even when a highly corrosive fluid such as a waste solution containing chlorine flows through the inside of the tubular body 1, they are formed in the coating layer. Since it does not easily penetrate inside, its life can be significantly extended.
Further, according to experiments, by adjusting the dispersion ratio of the glass flakes with respect to the resin, the linear expansion coefficient can be brought close to the linear expansion coefficient of iron. If it does so, it can suppress that a thermal stress is repeatedly generated in a coating material by the thermal expansion of the tubular body 2, and the durability of a coating layer can be improved also from the surface.
[0050]
Furthermore, it is possible to reduce the linear expansion coefficient of the coating layer by adjusting the dispersion amount of the glass flakes with respect to the resin. By doing so, shrinkage and thermal expansion during curing of the coating layer are reduced, and the tubular body 1 Since the adhesiveness with the inner surface can be improved, the durability of the coating layer can be improved from that surface.
Ceramic powder can be used instead of the glass flakes. This is particularly favorable in an environment in which a substance such as hydrofluoric acid (hydrogen fluoride) in which glass flakes are easily corroded flows.
[0051]
FIG. 5 is a sectional view showing a state in which the inner surface of a branch pipe, for example, the branch pipe 2c shown in FIG. 1, is coated by the coating method of the present invention. The coating operation on the inner surface of the branch pipe 2c may be performed either after or before the inner surface of the mother pipe 2 is coated as shown in FIG. The branch part 20 of the branch pipe 2c to be coated usually has a curved surface part 20a, but the branch pipe elastic body 30 is attached to the branch part 20 prior to the coating operation.
[0052]
The branching elastic body 30 is a foam having elasticity such as a cell-communication type urethane having a cell membrane as shown in FIG. 9, and an elastic body having a three-dimensional network fiber skeleton having no cell membrane as shown in FIG. Etc. can be manufactured by cutting or the like. This branch pipe elastic body 30 has a closing body 31 formed of a cylindrical elastic body, and a cylindrical derivative 32 extending coaxially therefrom.
[0053]
  Closure 31 is a bifurcation20And the coating material 10 is held. In addition, the derivative 32 has a function of guiding the coating material 10 from the periphery to the curved surface portion 20a and saving the amount of the coating material 10 held by the closing body 31, and further stabilizing the elastic body 30 for the branch pipe. Deformation when the branch pipe elastic body 30 is pulled inside the branch pipe 2 c is suppressed to prevent wrinkles from being generated on the surface of the closing body 31.
[0054]
FIG. 6 shows the branch pipe elastic body 30 in an enlarged manner. The diameter L of the closing body 31 constituting the branch pipe elastic body 30 is in contact with the peripheral edge of the curved surface portion 20a from the mother pipe 2 side, and is deformed or pulled on the surface of the branch pipe 2c when pulled inside. Although it is set in a range in which wrinkles and the like do not occur, it is preferably set to a value slightly larger than the outer diameter of the curved surface portion 20a. The height H1 of the closing body 31 is set in a range that can be easily pulled, but is preferably set to an inner diameter of the branch pipe 2c or a value slightly larger than that.
[0055]
On the other hand, the diameter d of the derivative 32 is set in a range in which the coating material 10 held in a state where the branch portion 20 is closed by the closing body 31 can be guided to the curved surface portion 20a, but is preferably smaller than the inner diameter of the branch pipe 2c. Value. The height H2 of the derivative 32 is set to the same value as the height H1 of the closing body 30.
Although it is desirable to make the closing body 31 and the derivative 32 integrally with the same material, it is not limited to this. The derivative 32 may be omitted depending on circumstances.
[0056]
  BranchtubeTo attach the elastic body 30 to the branch portion 20 of the branch pipe 2c, first, the branch attached to the tip of the rope 33tubeThe closed body 31 of the elastic body 30 for use is compressed and inserted into the inside through the opening 23 of the branch pipe 2c, and the closed body 31 is further inserted into the branch pipe20Projecting into the mother tube 2 Then, the closing body 31 naturally recovers to its original large state. When the rope 33 is pulled back to the opening 23 in this state, the rope 33 side surface of the opening / closing body 31 comes into contact with the peripheral portion of the branch portion 20, specifically, the peripheral portion of the curved surface portion 20 a to close the branch portion 20. To do.
[0057]
Next, when a predetermined amount of the coating material 10 is injected from the opening 23 and the coating material 10 is held on the rope 33 side of the branch pipe elastic body 30, as shown in the drawing, the curved surface portion 20a and the lower portion of the branch pipe 2c are coated. Is done. Next, when the rope 33 is pulled out to the opening 23 side and the branch pipe elastic body 30 is pulled, the closing body 31 is compressed on the inner peripheral surface of the branch pipe 2c and returned to the inside of the branch pipe 2c. When pulling, the closing body 31 pushes up the coating material 10 to continuously coat the inner surface of the branch pipe 2c.
[0058]
By coating the inner surface of the branch pipe 2c with the branch pipe elastic body 30 having the closing body 31 as described above, leakage of the coating material 10 from the branch pipe elastic body 30 to the mother pipe 2 side can be reliably prevented. At the same time, the inner surface of the branch pipe 2c can be reliably coated by pulling it out with the rope 33.
[0059]
In particular, when the elastic body 30 for the branch pipe is manufactured by using an elastic body having a three-dimensional mesh-like fiber skeleton as shown in FIG. 4, when the inside of the branch pipe 2c is pulled while the closed body 31 is compressed, Compression deformation can be performed more smoothly without causing deformation or wrinkles on the surface thereof. Therefore, a better coating layer can be formed in the branch pipe 2c.
[0060]
In the above-described embodiments of the branch pipe coating, the branch pipe 2c has been described as an example, but it is needless to say that the other branch pipes 2a, 2b, and 2d can be coated by the same method.
[0061]
【The invention's effect】
  As described above, in the method for coating the inner surface of the tubular body according to the present invention, the inner surface of the tubular body having a branch pipe is coated by pulling the rope in a state where the coating material is filled between the front elastic body and the rear elastic body. At this time, the branch part to the branch pipe communicating with the rope towing path is sealed with a sealing body to prevent the coating material from leaking to the branch pipe.The
[0062]
Therefore, it is possible to prevent leakage of the coating material to the branch pipe, thereby sufficiently supplying the coating material to the inner surface of the target tubular body, so that a good coating layer is formed on the portion. be able to.
[0063]
  further,The front elastic body and the rear elastic body have a three-dimensional network-like fiber skeleton B having no cell membrane, and have a breathability and elasticity alone.TheThe inner surface of the tubular body is coated using the front elastic body and the rear elastic body configured as described above.BecauseEven when the tubular body has a plurality of calibers or a bent portion such as an elbow, the front elastic body and the rear elastic body can always follow the inner surface of the tubular body, and the inner surface of the entire tubular body is good. A simple coating layer can be formed.
[0064]
  MoreoverThe branch pipe is branched from the bent part of the rope pulling pathPart, Seal the branch with a sealing body that is formed in a concave curved surface so that the surface of the rope towing path side matches the surface shape of the front elastic body and the back elastic bodyDo. By attaching the sealing body having such a shape to the branch portion, the front elastic body 5 and the rear elastic body 6 to be pulled can be guided by the concave curved surface and smoothly turned.
[Brief description of the drawings]
FIG. 1 shows the present invention.The technology that is the premise ofThe typical sectional view showing the state which coats the inner surface of the bowl-shaped object which has a branch pipe.
2 is a schematic cross-sectional view showing another embodiment of a branching portion 20 in FIG.
FIG. 3 is an enlarged cross-sectional view of a front elastic body 5 or a rear elastic body 6 used in a coating method according to the present invention.
FIG. 4 is an enlarged structural view of an elastic body without a cell membrane that can be used as a material for manufacturing the front elastic body 5 or the rear elastic body 6 according to the present invention.
FIG. 5 is a cross-sectional view showing a state in which the inner surface of a branch pipe is coated by the coating method of the present invention.
6 is an enlarged cross-sectional view of the branch pipe elastic body 30 in FIG. 5;
FIG. 7 is a schematic diagram illustrating a procedure for coating the inner surface of a tubular body.
FIG. 8 is a schematic diagram illustrating a procedure for coating the inner surface of a tubular body.
FIG. 9 is an enlarged structural view of an elastic body made of an elastic ball having a cell membrane such as a conventional urethane foam and in which bubbles communicate or mixed with closed cells.
FIG. 10 is a perspective view showing an example of a tubular body having a branch pipe.
[Explanation of symbols]
1 Tubular body
2 Mother pipe
2a-2d branch pipe
3 Coating tool
4 rope
4a Stopper
5 Front elastic body
6 Back elastic body
7 Insert
8 doorway
9 Injection part
10 Coating material
11 Through hole
12 sleeve
20 branch
20a Curved surface
21 Seal body
22 rope
23 opening
24 Rope pulling route
30 Elastic body for branch pipe
31 Closure
32 Derivatives
33 rope
A cell
B Fiber skeleton

Claims (1)

A front elastic body (5) and a rear elastic body (6) each having a three-dimensional network-like fiber skeleton B having no cell membrane and having air permeability and elasticity alone are attached. Pull the rope (4) into the tubular body (1),
By pulling the rope (4) with the coating material (10) filled between the front elastic body (5) and the rear elastic body (6), a plurality of branch pipes ( 2a , 2b , 2c , 2d ) are provided. When coating the inner surface of the tubular body (1) comprising the loop-shaped mother pipe (2) ,
A plurality of branch pipes communicating with the middle of the tow path of rope (24) (2a, 2b, 2c, 2d) branching unit to (20) sealed by a sealing member (21), said branch pipe (2a, 2b, 2c , in the coating method of the tubular body surface to be coated to prevent leakage of the coating material to 2d) (10),
A branch pipe ( 2a , 2b , 2c , 2d ) or main pipe (2) is installed on the opposite side of the rope pulling path (24) bent at a right angle at a portion where the rope pulling path (24) is bent at a substantially right angle. If there is
The surface of the branch pipe ( 2a , 2b , 2c , 2d ) on the opposite side or the pulling path (24) side of the rope inside the main pipe (2) has a front elastic body (5) and a rear elastic body (6 ) Is provided with a concave curved surface that conforms to the surface shape, and seals the branch portion (20 ) and guides the front elastic body (5) and the rear elastic body (6). A method for coating the inner surface of a tubular body.

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