JPH09150096A - Method and apparatus for painting inner surface of pipe - Google Patents

Abstract

PROBLEM TO BE SOLVED: To paint a peripheral welded part using solventless paint by running through a pipeline having an arranging shape containing a straight pipe and a different diameter pipe. SOLUTION: A paint bag 284 filled with paint is housed in a box-shaped internal space and a rodless cylinder piston 266 is connected to a paint extruding element 267 pressing the bag housed in the box-shaped internal space from above to squeeze out paint. The paint extruding element 267 presses the paint bag 284 from above to squeeze out paint. The extruded paint is spread over the inner surface of a pipe under pressure by a coating plate (spatula) 310.

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 performing in-pipe coating of a weld portion of a pipe line welded by field welding. TECHNICAL FIELD The present invention relates to a pipe painting method and apparatus for running a pipe inner surface welded portion or the like by running in a water pipe where mixed bent pipes including straight pipes and different diameter pipes are mixed.

[0002]

2. Description of the Related Art Conventionally, various types of in-pipe coating machines have been developed and used for coating the pipes such as steel pipes when they are welded and joined on site. The paints used in these coating machines are mainly tar epoxy and liquid epoxy resin having a relatively low viscosity, and as a coating method, a method called airless coating is adopted. The airless coating is a method of applying a pressure of 10 to 20 MPa to the paint and discharging the paint from a special nozzle tip to apply the paint, and is used in a very wide range.

The paint used for the airless coating is called a solvent type, contains an organic solvent as a component, and has a low viscosity, so that it is suitable for spray coating. However, in recent years, the odor of organic solvents has become a problem, and solventless paints that do not contain organic solvents have been developed and used for the inner coating of steel pipes for water supply.

[0004]

There are two types of solvent-free paints, a type that is mainly used for spray painting in a factory and a high-viscosity type that is manually painted by an operator after on-site welding. The spray-type solventless coating is a coating in which the base material and the curing agent are heated to reduce the viscosity, sent separately to a mixer, mixed immediately before discharge, and sprayed from a nozzle. The device used for this coating is composed of a heating device, a mixer, an injection device and the like. It is not impossible to transfer the device used for factory coating to local coating, but it is necessary to insert the mixer, a hard hose, etc. into the pipe,
It is very difficult to apply it to existing pipelines such as curved pipes. Further, in the case of a highly viscous type paint that is hand-painted, if the pipe diameter becomes small, it becomes impossible for an operator to enter the pipe and paint.

The present invention has been made in order to solve such a problem, and travels in pipes of any arrangement shape including straight pipes and pipes of different diameters, and uses solvent-free paint to weld peripheral welds and the like. An object of the present invention is to provide a self-propelled pipe inner surface coating method and apparatus for coating.

[0006]

In order to achieve this object, the pipe inner surface coating method of the present invention employs a method in which the paint is present in the bag from mixing the paint to discharging the paint. Also,
The paint was applied to the inner wall of the pipe by squeezing the bag to push out the paint from one end side and at the same time applying it to the inner wall of the pipe with a spatula.

That is, the present invention is characterized in that a solventless paint is mixed in a bag, the bag is squeezed to squeeze the paint to the inner surface of the pipe, and the squeezed paint is spread on the wall of the pipe. It is a painting method. In this case, it is preferable that the bag is loaded and mixed with a paint and then loaded into a box having a paint discharge port, the discharge port of the bag is opened, and then the paint is squeezed out by pressing in the box. Is. Further, it is preferable that the spreading pressure is spread by pressing so as to fill a step in a portion to be newly coated on the basis of the painted portions on both sides of the pipe circumference welded portion.

An apparatus of the present invention capable of suitably carrying out the above method is a bag for mixing and holding a solventless coating material,
A bag storage chamber in which this bag is loaded and a paint discharge port is provided close to the pipe wall, a paint extrusion device that presses the bag to squeeze the paint, and a spatula that spreads the squeezed paint on the pipe inner wall The pipe inner surface coating apparatus is characterized by comprising:

According to the present invention, solventless paint is mixed in a bag, the bag is loaded into a storage chamber and inserted into a pipe, the paint is squeezed out by a paint extrusion device, and the paint is separated from the inner wall of the pipe in a predetermined gap. It is applied by painting with a spatula on the pipe wall, and after the completion of coating, the bag is collected and discarded. Further, the gap between the spatula and the tube wall is important for obtaining a predetermined thickness. For this gap, we decided to use the thickness of the painted part that was implemented in the factory for the part that is not related to on-site welding. Such a coated portion exists at a position separated from both sides of the welded portion by a certain distance.

Since the method of the present invention is constructed as described above,
The inside of the pipe can be cleaned very easily after painting, and even if the painting time is prolonged and the paint is hardened, most of the paint remains inside the bag, and the paint that exists outside has a narrow area at the paint outlet. Limited to Therefore, it is easy to deal with the residual paint. Further, since the coating thickness in the factory is based on the coating thickness in the factory, it is similar to that in the factory, which is convenient.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention is an apparatus for running inside a pipe in which an operator cannot enter the inside and painting the inside surface of the pipe at the on-site circumference welded portion using a solventless paint. The structure is such that the coating cart is placed at the top and the traveling unit is placed behind it. The traveling is performed by the power of the traveling unit, and the arrival at a predetermined welding portion is confirmed by a camera mounted on the coating head, and the coating head is clamped and fixed.

Next, the paint push-out portion is pressed against the inner wall of the pipe with an air cylinder, the paint bag is squeezed by the air cylinder, and the paint push-out portion is pressed while pushing out the paint.
Rotate in the circumferential direction, apply with a spatula, apply pressure, and apply.
Check the painting status with a camera and repeat painting if there are unpainted areas. After the painting is completed, the clamp is released, the main traveling machine is moved backward, and is taken out of the pipe, and the paint bag is removed from the paint pushing part and discarded, and the paint outlet is cleaned to finish the work.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A pipe inner surface coating apparatus according to the present invention will be described in detail below with reference to the drawings. The basic structure of the pipe inner surface coating apparatus according to the present invention is composed of a traveling unit 100 and a coating carriage 200 for coating the pipe 1 as shown in FIG. The traveling unit 100 includes a traveling machine 110 that travels inside the pipe 1, and an external control device and a control carriage 130 that has an interface function.

In the traveling unit 100, the traveling machine 110 and the control carriage 130 are connected by a link 124, and a connecting portion 150 for connecting a cable (not shown) continuing to the outside of the pipe is provided at the rearmost portion, and this cable has a coating carriage. A signal line for controlling the 200 and the traveling unit 100, a signal line for transmitting information inside the pipe to the outside of the pipe, and the like are built in. The traveling machine 110 includes an upper structure 114, a lower structure 116, and a central structure 122. The upper structure 114 is composed of two upper drive wheels 112 and a steering motor 115, and the support 1
17 is swingably supported, and the support 117 is extensiblely connected to the upper base 126 via an air cylinder 118.

Further, the upper base 126 is vertically movable and fixedly attached to the fixture 125 of the central structure 122. Therefore, the upper structure 114 and the lower structure 128 of the traveling machine 110 can be positioned at a predetermined distance with respect to the fixture 125, and at the same time, they can be expanded and contracted to accommodate various pipe diameters. The lower structure 128 has two lower drive wheels 120.
The individual pieces are fixed at positions separated by a predetermined distance. The upper drive wheel 112 is a normal rubber wheel, and the lower drive wheel 12
Reference numeral 0 denotes a skid wheel which has a structure in which a roller is fitted to a shaft arranged tangentially on the wheel circumference, and which is movable in the pipe circumferential direction while rotating. With this configuration, the range of pipe diameters that can be handled is 250 mm to 400 m.
It can take a wide range like m.

The control carriage 130 is equipped with a control device and a rear camera (not shown), has an interface function with the ground control device, and has a function of providing a driving image when the pipeline inner surface working device is moving backward. Have. In addition, the wheels 132 of the control carriage 130 are provided with arms 136 that change the height of the wheels 132 at a predetermined pitch to position the wheels on the carriage.

A side view of the coating carriage 200 is shown in FIG. The coating carriage 200 is a clamp carriage 2 having a clamp function.
10 and the paint squeezing device 220 are basic components.
The clamp carriage 210 has a clamp wheel that expands and contracts by an air cylinder to fix the carriage inside the pipe, and a fixed wheel. The paint squeezing device 220 is the paint squeezing device 22.
Through two sliding bearings 222 fixed to 0, the sliding pair connection is made with the two shafts 223 fixed to the angle 224, and at the same time, it is connected to the drive shaft of the cylinder 226 fixed to the angle 224. There is.

Further, the angle 224 has a rotation fulcrum 22.
At the same time, the angle 224 and the beam 230 are connected to each other via two springs 232 and 234. With such a configuration, the paint squeezing device 220 is configured so that the cylinder 2 is not attached to the angle 224.
By contracting 26, the pipe is lowered in the state shown in the drawing and the pipe 1
Pressed against the inner wall of the.

Further, the beam 230 and the paint squeezing device 220
Are connected by a rotation fulcrum 228, the paint squeezing device 220 can make uniform contact with the pipe wall even if the clamp carriage 210 is slightly inclined with respect to the pipe axis direction. As shown in FIG. 2, both ends of the paint squeezing device 220 are positioned so as to be positioned in the in-pipe coating portion 3 which is coated at the factory, and the coating portion 3 is used as a reference for coating. Therefore, a proper gap can be obtained for applying the paint to the inner surface of the pipe to be painted.

The beam 230 is connected to the base 236 by a rotation fulcrum 238 and at the same time by a spring 240. Therefore, the beam 230 is kept pressed against the base 236 by the normal spring 240. The base 236 is rotated by the motor in the clamp carriage 210. The beam 230 rotates about the rotation fulcrum 238 only when passing through a curved pipe or the like. That is, when passing through the curved pipe, the wheels 242 pass in a posture that is on the great circle side of the curved pipe, the wheels 242 contact the great circle side pipe wall of the curved pipe, and the reaction force causes the beam 230 to move to the base. It rotates about a rotation fulcrum 238 with respect to 236.
In this way, it is possible to pass through a curved pipe.

Reference numeral 250 is a camera, and camera 25
No. 0 can be rotated by a certain amount by the rotary actuator 252, observation in the pipe axial direction and pipe radial direction is possible, and of course the coating state can be confirmed. 3 and 4 are a side view, a front view, and a cross-sectional view of the paint squeezing device 220.
Each is shown in FIG. The paint squeezing device 220 is composed of a main body base 260 and a lid 262 (front view), and forms a box-shaped space. A paint bag 284 filled with paint is loaded into the box-shaped internal space. Two rodless cylinders 264 are attached to the main body base 260, and a movable portion (piston) 266 of the rodless cylinder penetrates through a slit 265 provided in the main body base 260 and the rear side of the main body base 260 (rodless cylinder 264 And the other side)
It is connected to the arm 268 projecting to the outside. Arm 268
Is connected to a paint extruding body 267 that squeezes the paint by pressing a bag loaded in the box-shaped internal space from above. The paint extruding body 267 presses the paint bag 284 so as to squeeze the paint from above and squeezes the paint in the bag.
The movement of the piston 266 of the rodless cylinder 264 causes the arm 268 to move up and down.

Further, metal fittings 270 for fixing the positioning pins are attached to the main body base 260 at three places, and a lid 262 is provided.
Is a metal fitting 27 having a hole for fitting with the positioning pin.
2 are installed. With these, the main body base 26
0 and the lid 262 are positioned and further fixed by two thumbscrew nets 274 to form a box-shaped space. Lid 2
62 includes a bag end stopper 280 and a coating plate (spatula) 310.
And the clearance adjuster 300 is attached. Paint bag 284
Is loaded in this box-shaped space as shown in the cross-sectional view (FIG. 5), and one end (open end) thereof is fixed by a bag end stopper 280. The other end (blocking end) of the bag is fixed at both ends on the blocking side of the bag by a stopper 290 provided on the lower portion of the main body base 260 and a stopper 292 provided on the lower portion of the lid 262.
After fixing, cut the bag closed end with a knife to make a paint outlet.

With the above structure, by pushing down the piston 266 of the rodless cylinder 264,
The paint extruding body 267 can squeeze the paint bag 284 to push out the paint from the lower end of the paint squeezing device. The extruded paint is spread on the inner surface of the pipe by a coating plate (spa) 310. After the painting is completed, remove the painting equipment from the pipe and put the lid 26
If 2 is removed, the paint bag 284 can also be removed at the same time.

According to the above embodiment, the paint squeezing device 220 is pressed against the inner wall of the pipe, and while the paint is being pushed out, the paint squeezing device 220 is rotated to utilize the gap between the coating plate (spa) 310 and the pipe wall. It becomes possible to apply a solventless paint.

[0025]

As described above, the pipe inner surface coating machine for a solventless paint of the present invention can efficiently coat a solventless paint having a high viscosity. In addition, the gap between the paint coating plate and the inner wall of the pipe can be automatically set by using the step between the factory painting part and the newly painted part, and uniform painting is possible.

[Brief description of the drawings]

FIG. 1 is a basic configuration diagram of a solventless coating machine.

FIG. 2 is a side view of a coating carriage of a solventless coating machine.

FIG. 3 is a side view of a paint squeezing device of a solventless coating machine.

FIG. 4 is a front view of a paint squeezing device of a solventless coating machine.

FIG. 5 is a sectional view of a paint squeezing device of a solventless coating machine.

[Explanation of symbols]

1 Pipe 2 Weld 3 Paint (existing work) 100 Traveling unit 110 Traveling machine 130 Control dolly 200 Paint dolly 210 Clamping dolly 220 Paint squeezing device 230 Beam 260 Body base 262 Lid 264 Rodless cylinder 265 Slit 266 Piston 267 Paint extruding body 268 Arm 284 Paint bag 300 Gap adjuster 290 Fastener 310 Coating plate (spatula)

Front page continued (72) Inventor Mitsuho Akita 2-3-3 Uchisaiwaicho, Chiyoda-ku, Tokyo Kawasaki Steel Works (72) Inventor Sataro Takashina 2-3-2 Uchiyuki-cho, Chiyoda-ku, Tokyo Kawasaki Steel Incorporated (72) Inventor Shigeru Fujiwara 2-4-10 Sanjo, Kure City, Hiroshima Prefecture

Claims (4)

[Claims] 1. A method for coating an inner surface of a pipe, which comprises mixing solvent-free paint in a bag, squeezing the paint from the bag to the inner surface of the pipe, and spreading the squeezed paint onto the wall of the pipe. 2. The bag is loaded and mixed with a paint and then loaded into a box having a paint discharge port, a part of the bag on the discharge port side is opened, and the bag is pressed from the opposite opening side. The pipe inner surface coating method according to claim 1, which is a bag for squeezing out paint. 3. The spreading is performed by pressing and spreading so as to fill a step in a newly painted portion with reference to the painted portions on both sides of the pipe circumference welded portion. Item 1. The method for coating a pipe inner surface according to item 1. 4. A bag for holding a mixture of solventless paint,
A bag storage box in which the bag is loaded and a paint discharge port is provided in the vicinity of the pipe wall, a paint extruding device that presses the bag to squeeze the paint, and the squeezed paint is applied to the pipe inner wall to extend the pressure. A pipe inner surface coating device having a spatula.