JPH0410937Y2 - - Google Patents

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention relates to an apparatus for painting the inner surface of long pipes, which coats the inner surface of buried pipes for telephone lines, electric wires, water and sewerage pipes, etc.

<Conventional technology> Conventionally known methods for painting inside pipes include the AS method, NPC method, and KSS-DB method, but the structure of the painting equipment is complex and large, making it difficult to paint small diameter pipes. It is considered unsuitable. In addition, as a coating device for the inner surface of small diameter pipes, a special system is used in which the mixing part for two-component synthetic resin paint is connected to the rear part of the coating device with a flexible wire, and a spray cap with a small injection hole simply bored on the outer periphery is provided at the tip of the coating device. Publication No. 54-24420 has been proposed.

However, when actually applied, the film thickness distribution on the inner wall of the pipe is thicker on the bottom side in the circumferential direction, and unnecessary thicker on the tip end of the pipe where painting starts, as shown in Figure 5A and B. The film thickness is formed as shown in Fig. 6A and B.
It is difficult to obtain such a uniform film thickness distribution, and moreover, in order to maintain the minimum film thickness, unnecessary thick film parts are formed, resulting in a large amount of paint consumption, which is uneconomical.

<Problems to be Solved by the Invention> The present invention is capable of forming a uniform film thickness by ejecting a mixture of air and paint from the injection hole using the spraying pressure of the spray device of a conventional painting device. In view of the fact that it is not possible to obtain a large amount of paint, the paint is dispersed from the tip of the rotating cup to atomize it, and air is then ejected from the rear of the dispersed paint in the axial direction to promote atomization. The object of the present invention is to provide an apparatus for coating the inner surface of a long pipe, which can form a uniform coating film in the circumferential direction and length direction by appropriately dispersing paint particles diagonally forward. .

<Means for solving the problem> The present invention is a coating device that sprays the inner surface of the pipe by moving along the inner surface of the pipe and retreating while spraying paint from an atomizer installed at the tip. The heating device includes a rotary cup connected to an air motor in the main body of the painting device for dispersing paint, with a paint supply pipe directly facing the inner surface of the cup, and a shaving air hole arranged at the rear of the periphery of the rotary cup. The main body of the coating equipment has an exhaust gap formed on the outside in the center of the interior to accommodate the air motor.
The air inlet of the air motor communicates with an air inlet provided at the rear, and the exhaust port of the air motor faces the exhaust gap and communicates with the shaving air hole.

<Function> Due to the above-mentioned configuration, the paint pumped from the paint hose connected to the rear end of the painting device body passes through the paint passage inside the device body and is directly guided to the paint spout hole on the inner surface of the rotating cup. , and is radiated from the periphery of the tip of the cup due to the centrifugal force caused by the high-speed rotation of the rotating cup. On the other hand, the exhaust air that is introduced from the air hose connected to the rear end of the painting equipment body passes through the air motor that rotates, passes through the exhaust gap, and is injected from the shaving air hole toward the front of the periphery of the tip of the cup. It atomizes the paint emitted from the tip of the cup. in this case,
Since the air from the shaving air hole is injected forward, the width of the spray by the rotating cup can be increased in the axial direction, and the coating on the main body of the coating apparatus can also be avoided.

<Example> Hereinafter, the present invention will be described in detail based on the drawings of the example.

Reference numeral 1 denotes an atomizing device attached to the tip of a cylindrical coating device main body, and the atomizing device 1 has a rotating cup 5 whose base end is fixed to the rotating shaft 4 of an air motor 10;
It consists of a shaving air hole 7 disposed in an air guide 6 on the front periphery of the coating apparatus main body 2 at a rear position of the periphery of the rotary cup 5. Further, a large number of paint ejection holes 9 communicating with a paint supply pipe 8 are provided on the inner periphery of the rotary cup 5, and a large number of shaving air holes 7 are also provided on the front periphery of the coating apparatus main body 2. 10 is an oil-free vane type air motor housed in the center of the coating device body 2;
An air exhaust port 11 is provided on the outside of the air motor 10.
An exhaust gap 12 is formed, which communicates with the shaving air passage 13 and the shaving air hole 7 through the communication port 12a, and extends in the longitudinal direction on the outer periphery of the coating device main body 2. A plurality of sliding contact plates 14 (six in this embodiment) are provided protrudingly, and an air motor 10 is installed at the rear end of the coating device main body 2.
An air hose 16 communicating with the air introduction hole 15 of
A paint hose 17 is connected to the paint supply pipe 8 at the tip via a paint passage 8', and the inner surface coating device 3 is constituted as a whole. Although a two-component paint is used in the coating device of the present invention, the main agent and curing agent may be mixed using a static mixer (not shown) provided separately just before supplying the paint to the inner surface coating device 3. Alternatively, the base agent and the curing agent may be fed to the rotating cup 5 through separate systems and mixed within the rotating cup.

Next, to explain the operation, the inner surface coating device 3 is carried into one end of a predetermined pipe A to be coated, and the air hose 16 and paint hose 17 connected to the rear end of the coating device 3 are installed outside the pipe A. Drawer device 1
8, compressor 19 and paint supply device 20
Set to . Note that, if necessary, a dedicated pulling wire (not shown) may be attached to the inner surface coating device 3.

Here, if the pinch type pull-out device 18 is driven and the air hose 16 and paint hose 17 are pulled, the inner surface coating device 3 will retreat while sliding inside the pipe A, and compressed air will be supplied from the air hose 16 to the coating device. The air is supplied to the air motor 10 of the main body 2, and the rotating cup 5 attached to the rotating shaft 4 of the air motor 10 rotates at high speed (for example, 10,000 times/minute). Therefore,
The paint a pumped from the paint hose 17 comes out from the paint jetting hole 9 on the inner circumferential side of the rotary cup 5, is transmitted along the inner circumferential surface of the rotary cup 5 by centrifugal force due to high-speed rotation, and is radiated outward from the tip periphery 5'. Ru. At the same time, the air motor 10
Since the air exhausted from the air exhaust port 11 is ejected from the exhaust gap 12 through the air passage 13 and forward from the shaving air hole 7, the ejected air b is radiated from the peripheral edge 5' of the rotary cup 5. It acts to direct the painted paint a forward. That is, the atomized paint is sent obliquely forward by the shaving air, giving the spray width in the axial direction, thereby reducing coating unevenness. Furthermore, the paint atomized by the forward-injected shaving air does not pollute the coating device more than necessary, regardless of the coating device itself.

Note that if the overall area of the shaving air hole 7 is too small, the back pressure of the air motor will increase, which will hinder rotation.If the shaving air hole 7 is too large, the spray will have too much forward direction, and the It is necessary to set an appropriate size because this will reduce the rate of coating on the inner surface of the pipe. Further, in order to spread the spray in the axial direction, it is possible to take measures such as increasing the diameter of the shaving air holes 7 or arranging large and small shaving air holes 7 alternately.

<Effects of the invention> As described above, the apparatus for painting the inner surface of a long pipe of the present invention includes a rotary cup for spraying paint that is rotated by an air motor, and a rotary cup located behind the rotary cup that uses exhaust air from the air motor. By adopting a towed type inner surface coating device with communicating shaving air holes, the paint ejected from the paint injection holes of the rotating cup that rotates at high speed is reliably dispersed and atomized by centrifugal force. At the same time, shaving air is injected from the back into the diffusion area of the atomized paint, which atomizes the paint toward the front, that is, the axial direction, and appropriately distributes paint particles diagonally forward toward the inner surface of the pipe. Dispersion allows for uniform coating of the inner surface of the pipe, which in turn results in economical use of the paint.

In addition, the paint atomized by this shaving air can be prevented from flowing toward the painting equipment side, and can be prevented from contaminating the equipment by getting inside the pipe. Furthermore, the present invention has a simplified configuration. Therefore, there is no problem in handling such as carrying it into the pipe.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention; FIG. 1 is a partially cutaway side view, FIG. 2 is a cross-sectional view of the atomization device,
Figure 3 is a front view of the same, Figure 4 is an explanatory diagram of the state of use,
FIG. 5 is an explanatory diagram of the state of paint application according to the conventional method, and FIG. 6 is an explanatory diagram of the state of paint application according to the present invention. 1...Atomization device, 2...Painting device main body, 5...
Rotating cup, 7...Shaving air hole, 8...
...Paint supply pipe, 9...Paint injection hole, 10...
Air motor, 12...exhaust gap.

Claims (1)

[Scope of utility model registration request] In a painting device that moves along the inner surface of a pipe and sprays paint with an atomizer installed at the tip, it retreats to spray paint the inner surface of the pipe.The atomizer is a paint supply pipe on the inner surface of a cup connected to an air motor. The main body of the painting equipment consists of a rotating cup facing the air and a shaving air hole arranged behind the rotating cup. A long pipe inner surface coating device having an opening facing the exhaust gap and communicating with the shaving air hole.