JP6874191B1 - Manufacturing method of painting equipment and pipes - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a coating device capable of forming a coating film on an inner surface of a receiving port of a pipe, and a method for manufacturing a pipe for painting the inner surface of the receiving port of the pipe using the coating device.
In a coating apparatus (100) according to an embodiment of the present invention, nozzle groups (10) attached to a support (20) that can be attached to the tip of a robot arm (16) paint in different directions. It has a first nozzle (11) and a second nozzle (12) for discharging.
[Selection diagram] Fig. 1

Description

The present invention relates to a coating apparatus and a method for manufacturing a pipe, and more particularly to a coating apparatus and a coating method for an inner surface of a pipe.

A type in which a paint is applied to the inner surface of a cast iron pipe having a straight pipe portion and a socket by using a spray is known. However, since the inner surface of the socket is provided with an uneven shape, there is a problem that a uniform coating film cannot be formed by relying only on spray coating. Therefore, for example, in the coating apparatus disclosed in Patent Document 1, after painting a part of the receiving surface by spray coating, a flat brush is applied to the back end surface of the receiving port, which is a region near the straight pipe portion in the receiving port. It is painted using.

Japanese Unexamined Patent Publication No. 60-183065 (published on September 18, 1985)

However, in the technique of using a flat brush after spray coating, the painting operation is complicated, a nozzle for spray painting and a flat brush must be prepared, and the apparatus is complicated and the mechanism is also complicated. In addition, the work efficiency is low for a person to manually paint a socket having a complicated uneven portion.

Therefore, one aspect of the present invention is a coating device capable of forming a coating film on the inner surface of the pipe socket with a simple painting operation, and the coating device is used to paint the inner surface of the pipe socket. The purpose is to realize a method for manufacturing pipes.

In order to solve the above-mentioned problems, the coating apparatus according to one aspect of the present invention is a coating apparatus for painting the inner surface of a pipe socket, and discharges a support that can be attached to the tip of a robot arm and paint. A group of nozzles having a plurality of nozzles to be used is provided, and the group of nozzles is attached to the support so as to discharge paint in different directions.

According to the above configuration, a coating film can be formed on the inner surface of the receiving port of the pipe by painting using a plurality of nozzles that discharge the paint in different directions with a simple painting operation. Since the nozzle groups discharge the paint in different directions, even if the inner surface of the receiving port of the pipe has an uneven shape, the coating film can be formed on the entire surface of the uneven shape. That is, according to the above configuration, it is not necessary to manually paint even a complicated uneven shape, and the work efficiency can be improved.

In the coating apparatus according to one aspect of the present invention, the nozzle group has at least a first nozzle and a second nozzle, and the first nozzle is provided on the inner surface of the receiving port. The paint is discharged toward the surface of the concave-convex-shaped surface for connection with the pipe toward the back of the pipe, and the second nozzle is directed to the pipe shaft of the concave-convex-shaped surface. The paint may be discharged toward the surface along the surface and the surface facing the pipe end.

According to the above configuration, even if the inner surface of the receiving port of the pipe has an uneven shape, the paint can be discharged over the entire inner surface by a simple painting operation.

In the coating apparatus according to one aspect of the present invention, the nozzle group is inserted into the inside of the pipe from the pipe end of the receiving port of the pipe to discharge the paint, and the first nozzle is along the direction of the insertion. The paint is discharged in a direction perpendicular to the vertical axis, or the paint is discharged in a direction inclined backward in the insertion direction from the vertical direction, and the second nozzle is in the insertion direction. The paint may be ejected in a direction inclined forward in the direction of insertion rather than a direction perpendicular to the axis along the axis.

According to the above configuration, with a simple painting operation, the paint discharged from the first nozzle in the vertical direction is parallel to the pipe axis, for example, having an uneven shape provided on the inner surface of the receiving port of the pipe. A coating film can be formed by discharging onto a surface. Further, by ejecting the paint from the second nozzle in the inclined direction, a coating film is formed on the surface of the uneven shape, which is perpendicular to the pipe axis and faces the pipe end of the pipe receiving port. can do.

In the coating apparatus according to one aspect of the present invention, the first nozzle and the second nozzle eject the first paint, and the nozzle group ejects the paint in different directions from each other. It further has a third nozzle and a fourth nozzle attached to the above, and the third nozzle and the fourth nozzle discharge a second paint different from the first paint. May be good.

According to the above configuration, even when the coating process of the second paint is performed after the coating process of the first paint, the coating process can be performed using the same coating device, so that the entire coating process can be applied. The time required can be shortened.

The coating device according to one aspect of the present invention may further include a masking installation mechanism for inserting a masking body that closes the inside of the pipe from the outside.

According to the above configuration, the masking body can prevent the paint discharged from the nozzle from being scattered in a region other than the coating range of the pipe.

In the coating apparatus according to one aspect of the present invention, a pipe holding portion for holding the pipe so that the pipe axis is horizontal is further provided, and the receiving port of the pipe in which the second nozzle is held by the pipe holding portion. When the paint is applied to the portion of the inner surface of the receiving port farthest from the pipe end, the second nozzle viewed from the pipe end side in the insertion direction applies the paint in an oblique direction. It may be applied.

According to the above configuration, the amount of paint that is inconveniently scattered toward the back of the pipe can be suppressed as compared with the case where the paint is discharged directly below. Therefore, when the masking body is installed in the back, the amount of paint adhering to the masking body can be reduced.

Further, in order to solve the above-mentioned problems, in the method for manufacturing a tube according to one aspect of the present invention, a paint is applied to the inner surface of a receiving port of the tube by using the above-mentioned coating device.

According to the above configuration, the same effect as that of the coating apparatus can be obtained.

According to one aspect of the present invention, a coating device capable of forming a coating film on the inner surface of a pipe socket with a simple painting operation, and the inner surface of the pipe socket can be efficiently coated by using the coating device. It is possible to realize a method for manufacturing a pipe to be painted.

It is a figure which shows the appearance of the coating apparatus 100 and the cast iron pipe 1 coated by the coating apparatus 100 which concerns on embodiment of this invention. It is a top view (the cast iron pipe 1 part is a cross-sectional view) of the coating apparatus 100 and the cast iron pipe 1 to be coated by the coating apparatus 100 which concerns on embodiment of this invention. It is a figure which showed the state which the inside of the cast iron pipe 1 is painted by the nozzle of the coating apparatus 100 which concerns on Embodiment 1 of this invention. It is a partially enlarged view of the B region of FIG. It is a perspective view and the partially enlarged view which showed the appearance that the cast iron pipe 1 to be painted by embodiment of this invention is painted by a 1st or 3rd nozzle. It is a perspective view and the partially enlarged view which showed the appearance that the cast iron pipe 1 to be painted by embodiment of this invention is painted by a 2nd or 4th nozzle. It is a perspective view and the partially enlarged view which showed the appearance that the cast iron pipe 1 to be painted by embodiment of this invention is painted by a 2nd or 4th nozzle. It is a process drawing explaining each process of the coating process of a pipe using the coating apparatus 100 which concerns on embodiment of this invention.

[Embodiment 1]
Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. FIG. 1 is a perspective view showing the appearance of the coating apparatus 100 according to the first embodiment. FIG. 2 shows a top view of the coating apparatus 100, and for convenience of explanation, the pipe 1 to be coated is also shown. Regarding the pipe 1, the pipe end on the receiving side and its vicinity are taken as a cross section. Shown.

<Pipe to be painted>
Here, first, the pipe 1 will be described. The pipe 1 has a substantially hollow cylindrical shape, and as shown in FIGS. 2 and 3, an uneven shape for connecting to another pipe provided on the inner surface from the end surface 2 (tube end) side of the socket is formed. There is a region A1 to have, a region A2 (D9 dimension portion) adjacent to the region A1, and a region A3 (straight portion) having a substantially flat inner surface. For example, the pipe 1 is a ductile cast iron pipe mainly used as a water pipe. The inner peripheral surface of the pipe 1 needs to be painted in order to prevent rust and affect the water quality, and the painting device 100 of the first embodiment can be used for the painting. The painting device 100 paints only the area A1, and the area A2 and the area A3 are not to be painted.

When painting the inner surface of the pipe 1, the pipe 1 is held by the pipe holding portion 40 described later so that the pipe axis is horizontal, and is rotated around the axis to be rotated around the axis, and the tip of the nozzle of the nozzle group 10 described later is used. The paint discharged from the portion is sprayed on the inner surface to form a coating film.

The coating device 100 paints the inner surface of the receiving port of the pipe 1 in two stages. First, as a primer coating step, a coating process of applying a zinc rich (zinc) paint is performed, and then as a main coating step, a coating process of applying a synthetic resin paint such as an epoxy resin is performed.

(1) Configuration of Painting Device The painting device 100 is a device for painting the inner surface of the receiving port of the pipe 1 described above. More specifically, it is a device for painting a region formed in an uneven shape on the inner surface of the receiving port of the pipe 1.

As shown in FIG. 1, the painting apparatus 100 includes a support 20 that can be attached to the tip of the robot arm 16 and a nozzle group 10 having nozzles 11 to 14 for discharging paint. Hereinafter, each part of the coating apparatus 100 will be described.

<Robot arm>
A support 20 can be attached to the tip of the robot arm 16, and a nozzle group 10 can be attached via the support 20.

The operation of the robot arm 16 is controlled by a control unit (not shown), and the tip portion of the robot arm 16 can move up, down, left, right, front and back. As shown in FIGS. 1 and 2, the "vertical direction" here means the vertical direction. Further, the "front-back direction" refers to a direction defined by the "forward direction" as the direction in which the nozzle group 10 approaches the pipe 1 because the nozzle group 10 is inserted into the pipe 1, and the opposite direction as the "rear direction". Further, the "left-right direction" means a direction orthogonal to the above-mentioned "vertical direction" and "front-back direction".

As shown in FIG. 1, a distance sensor 15 for measuring the distance L to the end surface 2 of the pipe end of the pipe 1 is provided in front of the robot arm 16. The distance sensor 15 can position the nozzle group 10 at an appropriate position with respect to the pipe 1. If the position of the pipe 1 can be accurately positioned by using the flow stop roller which is an example of the positioning device of the pipe 1, the distance sensor 15 may be omitted.

1 and 2 show the positions of the robot arm 16, the support 20, and the nozzle group in the state where the painting process is not performed. In FIG. 2, the positions of the robot arm 16, the support 20, and the nozzle group 10 in the state where the painting process is not performed (hereinafter referred to as the initial state) are shown by solid lines, and the state where the painting process is performed. The positions of the robot arm 16, the support 20, and the nozzle group 10 of the above are indicated by dotted lines. When the painting process is started from the initial state, the robot arm 16 attaches the support 20 at the position in the initial state (hereinafter referred to as the initial position) and the nozzle group 10 attached to the support 20 to the pipe 1. The nozzle used for the painting process (nozzle 11 in FIG. 2) is inserted into the pipe 1 by advancing toward the pipe 1. During the painting process, the robot arm 16 retracts toward the end surface 2 of the pipe 1. Along with this, the nozzle inserted in the pipe also moves rearward in the pipe, and the painting process proceeds from the front to the rear in the pipe. After the inserted nozzle reaches the position of the end surface 2 of the tube 1, the robot arm 16 returns the support 20 and the nozzle group 10 to the initial positions shown by the solid line in FIG.

<Support>
The support 20 supports a nozzle group composed of a plurality of nozzles and can be attached to the tip of the robot arm 16. In the present embodiment, four nozzles 11 to 14 are attached to the lower end of the support 20. Each nozzle will be described later.

The support 20 can be freely rotated clockwise and counterclockwise around the connection point with the robot arm 16 by the robot arm 16. Therefore, as shown by the dotted line in FIG. 2, when the coating device 100 executes the coating process on the inner surface of the pipe 1, the support 20 attached to the robot arm 16 is rotated to discharge the paint. In the case of FIG. 2, the nozzle 11) can be arranged in the front.

<Nozzle group>
The nozzle group 10 is composed of four nozzles 11 to 14. Each of the nozzles 11 to 14 has tip portions 11a, 12a, 13a, 14a for discharging paint at the tip of an extension extending from the support 20 to each tip portion. In the present embodiment, as shown in FIG. 2, in a top view, the four nozzles 11 to 14 are arranged in a direction in which they radiate around the support 20 at an angle of approximately 90 degrees to each other.

The position and orientation of the nozzle group 10 are changed by the robot arm 16, and in each coating process of the first coating process to the fourth coating process, which will be described later, only one of the four nozzles is subjected to the coating process. Used. The number of nozzles and the relative arrangement of the nozzles are not limited to those described above.

Of the above four nozzles, the first nozzle 11 and the second nozzle 12 discharge the first paint, and the third nozzle 13 and the fourth nozzle 14 are different from the first paint. Discharge the paint. For example, the first nozzle 11 and the second nozzle 12 are nozzles for primer coating, and discharge zinc-rich paint. Further, the third nozzle 13 and the fourth nozzle 14 are nozzles for main coating, and discharge synthetic resin paint such as epoxy resin paint. In the present embodiment, both the zinc rich paint and the synthetic resin paint are water-based paints, but a paint using an organic solvent (solvent paint) may be used. The paint discharge method may be either an air type or an airless type, but the airless type has less scattering of the discharged paint, simplifies incidental equipment such as a dust collector, and can reduce the size of the equipment. The formula is preferred.

The first nozzle 11 and the second nozzle 12 for discharging the first paint discharge the first paint in different directions from each other. Further, the third nozzle 13 and the fourth nozzle 14 that discharge the second paint also discharge the second paint in different directions from each other. This will be described in detail with reference to FIG.

FIG. 4 is a partially enlarged cross-sectional view showing how the inner surface of the socket of the pipe 1 is painted by each nozzle. In the present embodiment, the first nozzle 11 for discharging the first paint and the third nozzle 13 for discharging the second paint are nozzles having the same structure, and the first nozzle for discharging the first paint is discharged. The second nozzle 12 and the fourth nozzle 14 for discharging the second paint are nozzles having the same structure. Therefore, in the following, the difference between the first nozzle 11 and the second nozzle 12 having different structures will be described by taking as an example.

Whether the tip portion 11a for discharging the paint of the first nozzle 11 is inclined rearward (on the end surface 2 side of the pipe end) with respect to the downward direction in the vertical direction when the tip portion 11a is inserted into the pipe of the pipe 1. It faces downward in the vertical direction. The discharge direction of the paint from the tip portion 11a for discharging the paint of the first nozzle 11 is a direction inclined rearward (the end surface 2 side of the pipe end) with respect to the lower part in the vertical direction, or is downward in the vertical direction. As a result, the paint can be applied to the surface facing the back of the tube 1 (f1 in FIG. 4) of the uneven surface of the inner surface of the socket of the tube 1. Further, the paint can be applied to the surface along the pipe axis (a part of f2 in FIG. 4). Preferably, the discharge direction of the paint from the first nozzle 11 is more than 0 ° behind the pipe 1 with respect to the vertical direction, and is tilted within a range of 30 ° or less, or is 0 °. A notch is formed near the center of the first masking body 31, which will be described later, and the tip end portion 11a of the first nozzle 11 can cut into the notch of the first masking body 31. The above is the same for the third nozzle 13.

On the other hand, the tip portion 12a for discharging the paint of the second nozzle 12 faces the back of the pipe 1 in a state where the tip portion 12a is inserted into the pipe of the pipe 1. The direction of discharge of the paint from the tip portion 12a of the second nozzle 12 for discharging the paint is toward the back of the pipe 1 (front of the insertion direction). As a result, the paint can be applied to the surface along the pipe axis and the surface facing the pipe end (f2 and f'2 in FIG. 4) of the uneven surface. The above is the same for the fourth nozzle 14.

That is, as shown in FIG. 4, the first nozzle 11 and the third nozzle 13 (tip portions 11a, 13a) are perpendicular to the axis (coaxial with the tube axis) along the insertion direction of the nozzle group 10. The paint is discharged in a direction inclined to the rear of the insertion direction, and the second nozzle 12 and the fourth nozzle 14 (tip portions 12a, 14a) are directed with respect to the axis along the insertion direction. The paint is discharged in a direction inclined forward in the direction of insertion rather than in the vertical direction. Preferably, the discharge direction of the paint from the second nozzle 12 is more than 0 ° in front of the pipe 1 with respect to the vertical direction and is inclined in a range of 60 ° or less.

In this way, by performing the painting process using a plurality of nozzles having different discharge directions of the paint, it is possible to discharge the paint over the entire surface of the concave-convex shape of the inner surface of the socket of the pipe 1 for painting.

The position (height, horizontal direction) of the nozzle can be appropriately adjusted according to the diameter of the pipe 1 and the pipe type. Further, by adjusting the discharge direction of the paint so that the discharged paint is perpendicular to the rotation direction of the pipe 1, the yield of the paint can be improved.

The upper side of FIG. 5 is a perspective view showing how the pipe 1 is painted by the first nozzle 11, and the lower side of FIG. 5 is a discharge pattern of the paint discharged from the tip portion 11a of the first nozzle 11. It is an enlarged view which showed two kinds. The following contents are the same for the tip portion 13a of the third nozzle 13.

As shown on the upper side of FIG. 5, the paint can be discharged from the tip end portion 11a of the first nozzle 11 in a cone-shaped pattern as shown on the lower left side of FIG. As shown on the right, the paint can be discharged in a fan shape (sheet shape). It is more preferable to discharge the paint in a fan shape than to discharge the paint in a cone shape. By discharging the paint in a fan-shaped pattern, it is possible to paint perpendicular to the circumferential direction of the concave portion (sheet-shaped groove) 5 on the inner surface of the pipe 1, and the corner portion of the concave portion 5 and other places where the paint does not easily adhere. It becomes possible to paint more efficiently and more uniformly, and the painting time can be shortened.

On the other hand, the upper side of FIG. 6 is a perspective view showing how the pipe 1 is painted by the second nozzle 12, and the lower side of FIG. 6 is the paint discharged from the tip portion 12a of the second nozzle 12. It is an enlarged view which showed the discharge pattern. The following contents are the same for the tip portion 14a of the fourth nozzle 14.

From the tip portion 12a of the second nozzle 12, the paint is ejected in a fan shape (sheet shape) instead of a cone shape.

Further, the upper side of FIG. 7 is a perspective view showing how the second nozzle 12 paints the portion farthest from the pipe end, that is, the portion f'2 at the boundary between the first masking body 31 and the recess 5. The lower side of FIG. 7 is an enlarged view showing a discharge pattern of the paint discharged from the tip portion 12a of the second nozzle 12 at this time.

When painting the portion f'2, the second nozzle 12 viewed from the pipe end side in the direction of insertion of the nozzle group 10 is not directly downward but diagonally, specifically, diagonally downward. Apply paint. As a result, the fan-shaped discharge width from the tip portion 12a becomes a shape that crosses the recess 5 as shown in the lower side of FIG. 7, and while reducing the amount of paint adhering to the first masking body 31, the portion It is possible to efficiently and more uniformly coat f'2 and its concave portion 5.

Further, the heights of the tip portions 11a and 12a of the first nozzle 11 and the second nozzle 12 for discharging the first paint may be different from each other. Further, the heights of the tip portions 13a and 14a of the third nozzle 13 and the fourth nozzle 14 for discharging the second paint may be different from each other. The height here means the length in the axial direction along the vertical direction from a certain reference position, and corresponds to the distance from the reference position when a certain point on the inner surface of the pipe 1 is set as the reference position. .. For example, if the first nozzle 11 and the second nozzle 12 for discharging the first paint are used, the tip portion 12a of the second nozzle 12 is higher than the tip portion 11a of the first nozzle 11. It may be high. In short, the tip portion 12a of the second nozzle 12 is farther from the coating target region on the inner surface of the tube 1. In this case, the tip portion 12a of the second nozzle 12 can apply the paint in a wider area than the tip portion 11a of the first nozzle 11 in the application target area. Further, by applying the paint away from the inner surface of the pipe 1 (from a high position) to the flat portion of the socket where the paint is likely to adhere, the paint can be applied over a wide area and the painting time can be shortened. .. In addition, the amount of coating residue can be reduced, and the coating film thickness can be made more uniform. On the other hand, by applying the paint close to the inner surface of the pipe 1 (from a low position) to the portion of the groove of the socket where the paint is difficult to adhere, even in the portion where the paint is difficult to adhere, the coating omission can be eliminated and sufficient. It is possible to secure a sufficient film thickness.

<Masking installation mechanism>
The coating apparatus 100 further includes a masking installation mechanism 18 for inserting the first masking body 31 and the second masking body 32 that close the inside of the tube 1 from the outside of the tube 1. As described above, of the inner surface of the pipe 1, only the region A1 near the end surface 2 of the socket having the uneven shape is painted, and the region A2 of the D9 dimension portion located behind the region A1 and the region of the straight portion are directly formed. A3 is not painted. Therefore, it is necessary to prevent the paint from scattering and adhering to the regions A2 and A3 during the coating treatment on the region A1. Therefore, the masking installation mechanism 18 is used.

The masking installation mechanism 18 is composed of a first masking body 31, a second masking body 32, and a masking moving mechanism 17. The first masking body 31 and the second masking body 32 are disk-shaped iron plates having a diameter smaller than the inner diameter of the position where each of the pipes 1 is installed. As described above, when the recesses f1 and f2 farthest from the pipe end of the pipe 1 are painted by the first nozzle 11 or the third nozzle 13 near the center of the first masking body 31. , A notch is formed in which the first nozzle 11 or the third nozzle 13 can bite. The masking movement mechanism 17 moves the first masking body 31 and the second masking body 32 from the end surface 2 of the pipe 1 to the inner side of the pipe 1 in the pipe axial direction while holding the first masking body 31 and the second masking body 32 in parallel with each other. Before starting the painting process, first, the first masking body 31 and the second masking body 32 are installed at predetermined positions inside the pipe 1 by the masking moving mechanism 17. At the predetermined position, the first masking body 31 is installed at the boundary position between the area A1 and the area A2, and the second masking body 32 is installed at the boundary position between the area A2 and the area A3.

<Standby>
The standby table 26 is a table on which the tip portions 11a to 14a of the nozzle group 10 are placed when the coating process is not performed, that is, when the nozzle group 10 is in the initial state.

The standby table 26 of the present embodiment is provided with first to fourth immersion tanks 21 to 24 for immersing the tip portions (chips) 11a to 14a of the nozzles 11 to 14 in the initial state in water. Here, as the paint used in the painting apparatus 100 of the present embodiment, a water-based paint is used. Therefore, by immersing the tip portions (chips) 11a to 14a in the water of the first to fourth immersion tanks 21 to 24, the paint dries at the tip portions 11a to 14a while the nozzle group 10 is waiting in the initial state. This can prevent the nozzle from being blocked. When a solvent-based paint is used, an organic solvent may be put into the first to fourth immersion tanks.

<Dryer>
The coating device 100 further includes a dryer 25 that sends warm air toward the back of the pipe 1. The warm air sent from the dryer 25 can dry the paint applied from each nozzle, and also dry the paint adhering to the first masking body 31 and the second masking body 32 arranged inside the tube 1. By using warm air, the drying time of the paint can be shortened, and the waiting time until the next process (main coating) can be shortened. By drying and fixing the paint adhering to the surfaces of the first masking body 31 and the second masking body 32, the paint drips from the surfaces of the first masking body 31 and the second masking body 32, and the desired of the tube 1 is obtained. It is possible to prevent the paint from adhering to a place other than the place.

As shown in FIG. 1, the dryer 25 is arranged near the front center on the standby table 26. However, the arrangement position is not limited to this, and may be supported by a separate support means instead of the standby table 26.

<Pipe holder>
The pipe holding portion 40 rotates the pipe 1 around the axis while holding the pipe 1 so that the pipe axis is horizontal. Then, the pipe holding portion 40 can hold the pipe 1 so that the pipe shaft is positioned substantially coaxially with the insertion direction of the nozzle group 10. The pipe holding portion 40 may have a transport function of transporting the pipe 1 to a position where the pipe 1 is painted by the painting device 100. For example, the pipe 1 is conveyed (carried in) from another position so that the pipe shaft of the pipe 1 is located substantially coaxially with the insertion direction of the nozzle group 10, and then the pipe 1 painted by the painting device 100 is transferred. It may be configured to transport (carry out) from the substantially coaxial position to another position.

(2) Operation of the coating apparatus Next, the flow of the coating process in the coating apparatus 100 will be described with reference to FIG. FIG. 8 is a process diagram illustrating each step of the coating method using the coating apparatus 100 according to the first embodiment of the present invention. The operation of each configuration in each of the following steps is controlled by a control device (not shown).

The coating method using the coating apparatus 100 includes a coating preparation step until the coating of the coating is started, a coating step of applying the coating, and a coating ending step after the coating of the coating is completed. Further, the coating step includes a primer coating step of performing a primer coating performed prior to the main coating and a subsequent main coating step. Further, the primer coating process and the main coating process include a first coating process and a second coating process, respectively.

<Painting preparation process>
First, the pipe 1 is heated before being carried into the coating apparatus 100. When the temperature of the pipe 1 reaches an appropriate temperature, the pipe 1 is carried into the coating device 100, installed in the pipe holding portion 40 of the coating device 100, and the pipe 1 is held so that the pipe axis is horizontal.

In step S10, it is rotated around the axis. Next, in step S12, the masking bodies 31 and 32 are installed at predetermined positions in the pipe 1 by the masking installation mechanism 18. Subsequently, in step S14, air is started from the back of the masking bodies 31 and 32 inside the pipe 1 toward the end surface 2 of the pipe, and warm air is started from the dryer 25. Next, in step S16, the robot arm 16 pulls up the nozzles 11 to 14 from the first to fourth immersion tanks 21 to 24, respectively, and vibrates the nozzles 11 to 14, so that the water adhering to the tip portions 11a to 14a is formed. Drain the water. This completes the painting preparation process.

<Painting process>
<Primer painting process>
<First painting process>
When the draining of the tip portions 11a to 14a of the nozzles 11 to 14 is completed, the robot arm 16 advances the support 20 toward the pipe 1 in step S18. At this time, as shown by the solid line in FIG. 2, the support 20 is rotated from the state where the nozzle group 10 is pulled up from the first to fourth immersion tanks 21 to 24, and as shown by the dotted line in FIG. The nozzle 11 of 1 is moved so as to come forward. When the robot arm 16 advances, inserts the tip end 11a of the first nozzle 11 into the pipe 1, and advances to the vicinity of the first masking body 31 installed in the pipe 1, the advance is stopped and step S18. To finish. Here, the rotation of the support 20 described above may be performed at the initial position, or may be performed while advancing from the initial position to the vicinity of the end face 2 of the pipe. The relative position between the first nozzle 11 and the pipe 1 is obtained by measuring the distance L described above by the distance sensor 15 attached to the robot arm 16, and accurately positions the position of the first nozzle 11. be able to.

Subsequently, in step S20, the first paint (zinc rich paint) is discharged from the tip portion 11a of the first nozzle 11. As described above, the first paint discharged from the tip end portion 11a of the first nozzle 11 is applied to the surface facing the back of the pipe 1 (f1 in FIG. 4). More specifically, in step S20, the robot arm 16 ejects the first paint from the tip portion 11a of the first nozzle 11 while retracting the nozzle group 10 rearward at a constant speed. When the tip end portion 11a of the first nozzle 11 reaches the position of the end surface 2 of the pipe, the robot arm 16 further retracts the nozzle group 10 and pulls out the first nozzle 11 from the inside of the pipe. At this point, the first coating step of the primer coating for coating from the first nozzle 11 is completed.

<Second painting process>
When step S20 is completed, the process proceeds to step S22 and the second coating is started. In step S22, the support 20 attached to the robot arm 16 rotates to position the second nozzle 12 forward and to move the support 20 forward again toward the end surface 2 of the pipe 1. When the tip portion 12a of the second nozzle 12 is inserted into the pipe 1 and advanced to the vicinity of the first masking body 31 installed in the pipe 1, the advance is stopped and step S22 is completed. Note that step S22 is the same as step S18 except that the nozzle located in front is different from that of step S18, and thus the description thereof will be omitted.

Subsequently, in step S24, the first paint (zinc rich paint) is discharged from the tip portion 12a of the second nozzle 12. As described above, the first paint discharged from the tip portion 12a of the second nozzle 12 is applied to the surface along the pipe axis and the surface facing the pipe end (f2 and f'2 in FIG. 4). .. When painting the boundary portion f'2 between the first masking body 31 and the recess 5, the second nozzle 12 facing directly downward is tilted diagonally downward as described above to eject the first paint. To do.

In step S24, the robot arm 16 ejects the first paint from the tip portion 12a of the second nozzle 12 while retracting the nozzle group 10 rearward at a constant speed. When the tip portion 12a of the second nozzle 12 reaches the position of the end surface 2 of the pipe, the robot arm 16 further retracts the nozzle group 10 and pulls out the second nozzle 12 from the inside of the pipe 1. At this point, the second coating step of the primer coating for coating from the second nozzle 12 is completed.

The primer coating process is completed in the above first coating process and the second coating process.

The zinc paint used in the primer coating process is water-based and quick-drying, so it dries in seconds. Therefore, although the main coating process can be started relatively early after the primer coating process, a drying step for drying the primer coating may be provided before the main coating is performed. When the drying step is provided, the nozzle group 10 is returned to the initial position, and the tips 11a to 14a are immersed in the water of the first to fourth immersion tanks 21 to 24 to prevent drying.

<Main painting>
<First painting process>
When the main coating process is started, as step S26, the support 20 attached to the robot arm 16 rotates to arrange the third nozzle 13 in the front and to direct the support 20 toward the end surface 2 of the pipe 1. And move forward again. When the tip portion 13a of the third nozzle 13 is inserted into the pipe 1 and advanced to the vicinity of the first masking body 31 installed in the pipe 1, the advance is stopped and step S26 is completed. Note that step S26 is the same as step S18 except that the nozzle located in front is different from that of step S18, and thus the description thereof will be omitted.

Subsequently, in step S28, the second paint (synthetic resin paint) is discharged from the tip portion 13a of the third nozzle 13. As described above, the second paint discharged from the tip 13a of the third nozzle 13 faces the back of the tube 1 like the first paint discharged from the tip 11a of the first nozzle 11. It is applied to the surface (f1 in FIG. 4).

More specifically, in step S28, the robot arm 16 ejects the second paint from the tip portion 13a of the third nozzle 13 while retracting the nozzle group 10 rearward at a constant speed. When the tip portion 13a of the third nozzle 13 reaches the position of the end surface 2 of the pipe, the robot arm 16 further retracts the nozzle group 10 and pulls out the third nozzle 13 from the inside of the pipe. This completes the first coating step of the main coating, which applies the coating from the third nozzle 13.

<Second painting process>
When step S28 is completed, the process proceeds to step S30 and the second coating is started. In step S30, the support 20 attached to the robot arm 16 rotates to position the fourth nozzle 14 forward and to move the support 20 forward again toward the end surface 2 of the pipe 1. When the tip portion 14a of the fourth nozzle 14 is inserted into the pipe 1 and advanced to the vicinity of the first masking body 31 installed in the pipe 1, the advance is stopped and step S32 is completed. Note that step S30 is the same as step S18 except that the nozzle located in front is different from that of step S18, and thus the description thereof will be omitted.

Subsequently, in step S32, the second paint (synthetic resin paint) is discharged from the tip portion 14a of the fourth nozzle 14. As described above, the second paint discharged from the tip portion 14a of the fourth nozzle 14 is applied to the surface along the pipe axis and the surface facing the pipe end (f2 and f'2 in FIG. 4). .. When painting the boundary portion f'2 between the first masking body 31 and the recess 5, the fourth nozzle 14 facing directly downward is tilted diagonally downward to eject the second paint as described above. To do.

In step S32, the robot arm 16 ejects the second paint from the tip portion 14a of the fourth nozzle 14 while retracting the nozzle group 10 rearward at a constant speed. When the tip portion 14a of the fourth nozzle 14 reaches the position of the end surface 2 of the pipe, the robot arm 16 further retracts the nozzle group 10 and pulls out the fourth nozzle 14 from the inside of the pipe 1. At this point, the second coating step of the main coating, in which the coating is applied from the fourth nozzle 14, is completed.

Since the synthetic resin paint has a lower viscosity than the zinc paint, in the first painting step and the second painting step of the main painting, the tip of the nozzle is painted on the painted surface as compared with the first painting step and the second painting step of the prima painting. Painting can be performed from a position away from.

In the above embodiment, a method of painting the inner surface of the pipe by retracting the robot arm 16 has been described as an example. However, the method according to the present invention is not limited to this, and the robot arm 16 is not retracted, and the paint is discharged a plurality of times by changing the height of the nozzle or the discharge direction of the paint from the nozzle from a predetermined position. By doing so, the inner surface of the pipe may be painted.

<Painting end process>
When step S32 is completed, the process proceeds to step S34. In step S34, the blowing of hot air from the gap between the pipe 1 and the masking bodies 31 and 32 is stopped, and the blowing of warm air from the dryer 25 is stopped. Then, in step S36, the masking installation mechanism 18 is removed from the pipe 1. This is just an example, and the order of stopping the ventilation and taking out the masking does not matter.

In step S38, the rotation of the pipe 1 is completed. Finally, the pipe 1 is carried out from the coating apparatus 100.

As a result, the painting process by the painting device 100 is completed. According to the coating method of the present embodiment, by using a plurality of nozzles that discharge paints in different directions, it is possible to accurately form a coating film even on the inner surface of a pipe having an uneven shape. Further, in the present embodiment, since the water-based paint is used, the coating film dries in a short time. Therefore, it is possible to start the main coating process immediately after the completion of the primer coating process without providing the drying process. Since the primer coating and the main coating can be performed in such a short time, the main coating can be started at the same station after the primer coating and before the temperature of the pipe 1 drops, and the heating time of the pipe 1 is also shortened. can do. Therefore, if this coating method is adopted in the pipe manufacturing method, it contributes to the improvement of pipe productivity.

[Embodiment 2]
In the first embodiment, the case where two different types of nozzles are used once for each of the primer coating and the main coating has been described as an example. The embodiment of the present invention is not limited to this, and a further coating treatment step may be added to both the primer coating and the main coating. Hereinafter, this will be described as an additional coating process.

In the additional coating step, as a step performed after the step 24 of the primer coating, the second nozzle 12 is used again, and the height of the tip portion 12a of the nozzle from the coated surface is changed by the robot arm 16 to perform the step. The first paint is discharged from a position farther from the painted surface as compared with 24. As a result, the first paint can be sprayed over a wide area to more reliably form the coating film of the primer coating on the entire surface of the region A1.

The additional coating step may also be performed using the second coating material in step 32 of the main coating. By tilting the robot arm 16 as described above, the discharge direction may be tilted and the paint may be sprayed diagonally to the painted surface.

[Example of realization by software]
The control block (particularly the above-mentioned control device) of the painting device 100 may be realized by a logic circuit (hardware) formed in an integrated circuit (IC chip) or the like, or may be realized by software.

In the latter case, the painting apparatus 100 includes a computer that executes instructions of a program that is software that realizes each function. The computer includes, for example, one or more processors and a computer-readable recording medium that stores the program. Then, in the computer, the processor reads the program from the recording medium and executes it, thereby achieving the object of the present invention. As the processor, for example, a CPU (Central Processing Unit) can be used. As the recording medium, a "non-temporary tangible medium", for example, a ROM (Read Only Memory) or the like, a tape, a disk, a card, a semiconductor memory, a programmable logic circuit, or the like can be used. Further, a RAM (Random Access Memory) for expanding the above program may be further provided. Further, the program may be supplied to the computer via an arbitrary transmission medium (communication network, broadcast wave, etc.) capable of transmitting the program. It should be noted that one aspect of the present invention can also be realized in the form of a data signal embedded in a carrier wave, in which the above program is embodied by electronic transmission.

The present invention is not limited to the above-described embodiments, and various modifications can be made within the scope of the claims, and the embodiments obtained by appropriately combining the technical means disclosed in the different embodiments. Is also included in the technical scope of the present invention.

1 Pipe 5 (inner surface of the pipe) recess 10 Nozzle group 11 First nozzle 11a (first nozzle) tip 12 Second nozzle 12a (second nozzle) tip 13 Third nozzle 13a (third Tip (of 3 nozzles) 14 4th nozzle 14a (4th nozzle) Tip 15 Distance sensor 16 Robot arm 17 Masking movement mechanism 18 Masking installation mechanism 20 Support 21 1st immersion tank 22 2nd immersion tank 23 3rd immersion tank 24 4th immersion tank 31 1st masking body 32 2nd masking body 40 Tube holding part 100 Painting device

Claims (10)

It is a painting device that paints the inner surface of the pipe socket.
A support that can be attached to the tip of a robot arm and a group of nozzles having a plurality of nozzles that discharge paint toward the inner surface are provided.
The nozzle group is attached to the support so as to eject paint in different directions .
The support can rotate about a connection point with the robot arm and can rotate.
Each nozzle of the nozzle group is arranged at a different position around the support.
A painting device characterized by that. In the nozzle group, after one nozzle is inserted into the receiving port of the pipe to finish discharging the paint and exits from the receiving port of the pipe, the rotation of the support causes another nozzle to move. It is configured to be inserted into the socket, finish discharging the paint, and exit from the socket of the pipe.
The coating apparatus according to claim 1. The nozzle group has at least a first nozzle and a second nozzle.
The first nozzle ejects paint toward the back-facing surface of the concave-convex surface for connection with another pipe provided on the inner surface of the socket.
The second nozzle discharges paint toward the surface of the concave-convex shape along the pipe axis of the pipe and the surface of the receiving port of the pipe facing the pipe end.
The coating apparatus according to claim 1 or 2. The nozzle group is inserted into the inside of the pipe from the pipe end of the receiving port of the pipe, and the paint is discharged.
The first nozzle discharges the paint in a direction perpendicular to the axis along the insertion direction, or discharges the paint in a direction inclined rearward in the insertion direction with respect to the vertical direction. And
The second nozzle ejects paint in a direction inclined forward in the direction of insertion rather than a direction perpendicular to the axis along the direction of insertion.
The coating apparatus according to claim 3 , wherein the coating apparatus is characterized by the above. Further provided with a pipe holding portion for holding the pipe so that the pipe axis is horizontal,
When the paint is applied to the inner surface of the receiving port of the pipe held by the pipe holding portion at a position farthest from the pipe end of the receiving port, the insertion is performed from the side of the pipe end. The second nozzle, viewed in the direction, applies the paint diagonally.
The coating apparatus according to claim 4 , wherein the coating apparatus is characterized by the above. The first nozzle and the second nozzle discharge the first paint, and the first nozzle and the second nozzle discharge the first paint.
The nozzle group further includes a third nozzle and a fourth nozzle attached to the support so as to eject paint in different directions.
The third nozzle and the fourth nozzle discharge a second paint different from the first paint.
The coating apparatus according to any one of claims 3 to 5, wherein the coating apparatus is characterized by the above. The first nozzle and the second nozzle
The paint for primer painting used for primer painting before the main painting of the inner surface of the pipe socket is discharged, or
Discharge the paint for main coating applied on the primer coating film applied to the inner surface of the pipe socket.
The coating apparatus according to any one of claims 3 to 6, wherein the coating apparatus is characterized by the above. A masking installation mechanism for inserting a masking body that closes the inside of the pipe from the outside is further provided.
The coating apparatus according to any one of claims 1 to 7, wherein the coating apparatus is characterized by the above. A method for manufacturing a tube in which a paint is applied to the inner surface of the receiving port of the tube by using the coating device according to any one of claims 1 to 8. It is a painting device that paints the inner surface of the pipe socket.
A support that can be attached to the tip of a robot arm and a group of nozzles having a plurality of nozzles for discharging paint are provided.
The nozzle group is attached to the support so as to eject paint in different directions.
The nozzle group has at least a first nozzle and a second nozzle.
The first nozzle ejects paint toward the back-facing surface of the concave-convex surface for connection with another pipe provided on the inner surface of the socket.
The second nozzle ejects paint toward the surface of the concave-convex shape along the pipe axis of the pipe and the surface of the receiving port of the pipe facing the pipe end.
The first nozzle and the second nozzle discharge the first paint, and the first nozzle and the second nozzle discharge the first paint.
The nozzle group further includes a third nozzle and a fourth nozzle attached to the support so as to eject paint in different directions.
The third nozzle and the fourth nozzle discharge a second paint different from the first paint.
A painting device characterized by that.

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