JP2018008260A - Pipe coating apparatus and coating method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pipe coating apparatus which can satisfactorily coat a pipe even if the pipe has a small bore diameter.SOLUTION: The coating apparatus is provided that coats an inner surface of a rotating pipe 2 with a powdered paint 22 in which inorganic powders 21 are mixed. The coating apparatus has: a powdered paint supply member 27, 28 which supplies the powdered paint 22 into the pipe 2; a powdered paint discharge port 31, 32 which discharges the powdered paint 22 in the powdered paint supply member 27, 28 onto the inner surface of the pipe 2; an inorganic powder supply member 34 which supplies the inorganic powders 21 into the pipe 2; and an inorganic powder discharge port 35 which discharges the inorganic powders 21 in the inorganic powder supply member 34 onto the inner surface of the pipe 2. A position of the inorganic powder discharge port 35 is deviated in a pipe axial direction A with respect to the position of the powdered paint discharge port 31, 32.SELECTED DRAWING: Figure 6

Description

  The present invention relates to a coating apparatus and a coating method for coating the inner surface of a pipe.

  Conventionally, it is known to coat the inner surface of a pipe using a powder paint mixed with silica sand (for example, powder epoxy paint (powder epoxy resin paint) or powder polyethylene paint (powder polyethylene resin paint)). Yes. At this time, since the specific gravity of silica sand and powder paint is different, if the powder paint is transported in a state where silica sand is mixed or projected onto the inner surface of the pipe, the powder paint and silica sand will be separated and uniform. There was a problem that a good coating film could not be obtained.

  On the other hand, as shown in FIG. 14, in Patent Document 1 below, a powder paint 101 mixed with silica sand (hereinafter referred to as “silica sand mixed powder paint 101”) is transferred from the carriage to the inside of the tube 102. A coating apparatus having a transfer device 103 and a projection device 104 provided at the tip of the transfer device 103 is described. The projection device 104 includes a primary hopper 105, a secondary hopper 106, and a guide cover 107.

  According to this, while supplying air from the air supply pipe 108 to the projection device 104, the silica sand mixed powder coating material 101 is transferred to the projection device 104 by the transfer device 103 and sent into the primary hopper 105, And is supplied from the primary hopper 105 into the secondary hopper 106 and ejected from the ejection port 109 of the secondary hopper 106 to the inner surface of the tube 102. At this time, since excessive diffusion of air is suppressed by the guide cover 107, it is possible to prevent the silica sand from being separated from the silica sand mixed powder coating material 101 after the ejection, and the inner surface of the tube 102 is excellent. A coating film of the silica sand mixed powder coating 101 is formed.

Shokai 58-91470

  However, in the above-described conventional type coating apparatus, since the projection device 104 having a complicated structure and a large size is attached to the tip of the transfer device 103, the projection device 104 is inserted into the tube 102 when the diameter of the tube 102 is small. There is a problem that it is difficult to perform coating on the small-diameter pipe 102.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a pipe coating apparatus and a coating method capable of satisfactory coating even for a small diameter pipe.

In order to achieve the above object, the first aspect of the present invention is a coating apparatus that coats the inner surface of a rotating tube with a powder coating mixed with an inorganic powder,
A powder coating material supply member for supplying powder coating material into the pipe;
A powder coating outlet for discharging the powder coating in the powder coating supply member to the inner surface of the pipe;
An inorganic powder supply member for supplying inorganic powder into the tube;
An inorganic powder discharge port for discharging the inorganic powder in the inorganic powder supply member to the inner surface of the tube
The position of the inorganic powder discharge port is shifted in the tube axis direction with respect to the position of the powder coating material discharge port.

  According to this, while rotating the heated pipe, the powder paint supply member and the inorganic powder supply member are inserted into the pipe, and the powder paint in the powder paint supply member is discharged from the powder paint discharge port. While discharging to the inner surface of a pipe | tube, the inorganic type powder in an inorganic type powder supply member is discharged to the inner surface of a pipe | tube from an inorganic type powder discharge port.

  At this time, the powder coating material supply member and the inorganic powder supply member are connected to the tube so that the powder coating material discharge port is forward and the inorganic powder discharge port is behind the powder coating material discharge port in the tube axis direction. In contrast, the powder paint discharged from the powder paint discharge port adheres to the inner surface of the tube and melts, and the inorganic powder discharged from the inorganic powder discharge port is added to the molten powder paint. Adhere later. The adhering inorganic powder has a specific gravity greater than that of the powder paint, and therefore enters the melted powder paint by the action of the centrifugal force of the tube. As a result, the inorganic powder is appropriately dispersed in the powder coating material, and a good coating film of the powder coating material (hereinafter referred to as inorganic powder mixed powder coating material) mixed with the inorganic powder is formed on the inner surface of the tube. It is formed.

  Further, since the powder coating material is supplied to the powder coating material discharge port by the powder coating material supply member and the inorganic powder is supplied to the inorganic powder discharge port by the inorganic powder supply member, the powder coating material and the inorganic powder material Are fed to and discharged from the powder coating material discharge port and the inorganic powder discharge port in an individual state in which the powder is not mixed. Therefore, it is not necessary to provide a large projection device with a complicated structure as in the prior art, and the structure can be reduced in size with a simple structure, and satisfactory coating can be performed even on a small-diameter pipe.

  In the coating apparatus according to the second aspect of the invention, the discharge direction of the powder paint discharged from the powder paint discharge port to the inner surface of the tube is inclined in the tube axis direction with respect to the inner surface of the tube.

  According to this, when the powder paint is discharged from the powder paint discharge port to the inner surface of the tube, the discharge direction is inclined with respect to the inner surface of the tube, so that the powder paint is applied over a wide range of the inner surface of the tube.

In the coating apparatus according to the third invention, the powder paint discharge port has a first powder paint discharge port and a second powder paint discharge port,
The first discharge direction of the powder paint discharged from the first powder paint discharge port to the inner surface of the pipe is opposite to the second discharge direction of the powder paint discharged from the second powder paint discharge port to the inner surface of the pipe. The direction.

  According to this, while rotating the heated tube, the powder coating material supply member and the inorganic powder supply member are inserted into the tube, and the powder coating material in the powder coating material supply member is removed from the first and second powders. While discharging to the inner surface of a pipe | tube from a body coating material discharge port, the inorganic type powder in an inorganic type powder supply member is discharged to the inner surface of a pipe | tube from an inorganic type powder discharge port.

  At this time, by moving the powder coating material supply member and the inorganic powder supply member in the tube axis direction with respect to the tube, the insertion end formed at one end of the tube becomes the first and second powder coating materials. It is surely applied by the powder paint discharged from one of the powder paint discharge ports, and the step portion at the back of the receiving port formed at the other end of the tube is the first and second powder paint discharges. It is reliably applied by the powder paint discharged from the other powder paint outlet of the outlet.

In the coating apparatus of the fourth invention, the first discharge direction is directed to the inorganic powder discharge port side in the tube axis direction,
The second discharge direction is directed to the opposite side of the inorganic powder discharge port in the tube axis direction,
The second powder paint discharge port is located between the first powder paint discharge port and the inorganic powder discharge port in the tube axis direction.

  According to this, the powder paint is supplied so that the first and second powder paint discharge ports are in front and the inorganic powder discharge port is behind the first and second powder paint discharge ports in the tube axis direction. When the member and the inorganic powder supply member are moved with respect to the pipe, the first discharge direction from the first powder coating material discharge port even if the inorganic powder discharged from the inorganic powder discharge port tries to flow forward. The powder coating material discharged to the front prevents the inorganic powder from flowing forward.

  Thereby, for example, the state where the inorganic powder discharge port is located on the tube insertion side with respect to the first and second powder coating discharge ports, with the tube receiving side as the front and the insertion side as the rear. In the case of coating from the inlet side of the tube toward the receiving side, the first powder coating material is discharged even if the inorganic powder discharged from the inorganic powder discharging port tries to flow forward (that is, the receiving side). Since the powder coating material discharged from the outlet in the first discharge direction prevents the forward flow of the inorganic powder, the inorganic powder discharged from the inorganic powder discharge port is prevented from flowing forward and entering the receiving port. be able to.

In the coating apparatus according to the fifth aspect of the invention, the second discharge direction is directed to the inorganic powder discharge port side in the tube axis direction.
The first discharge direction is directed to the opposite side of the inorganic powder discharge port in the tube axis direction,
The second powder paint discharge port is located between the first powder paint discharge port and the inorganic powder discharge port in the tube axis direction.

  According to this, it is possible to prevent the powder paint discharged from the first powder paint discharge port in the first discharge direction from rebounding on the inner surface of the pipe and adhering to the powder paint supply member or the inorganic powder supply member. . Thereby, the adhesion amount of the powder coating material to a powder coating material supply member or an inorganic type powder supply member can be reduced.

The sixth invention is a coating method in which the inner surface of a tube is coated with a powder paint mixed with an inorganic powder while rotating the heated tube,
By discharging powder paint and inorganic powder individually to the inner surface of the pipe, the powder paint adheres to the inner face of the pipe and melts, and the inorganic powder adheres to the molten powder paint with a delay. And
The adhered inorganic powder enters the molten powder coating material by the action of centrifugal force.

  According to the seventh aspect of the present invention, the powder coating material in the powder coating material supply member is inserted from the powder coating material discharge port to the inner surface of the tube while the powder coating material supply member and the inorganic powder supply member are inserted into the tube. The inorganic powder in the inorganic powder supply member is discharged from the inorganic powder discharge port onto the inner surface of the tube.

  In the coating method according to the eighth aspect of the invention, coating is performed from the insertion side of the tube toward the receiving side with the inorganic powder discharge port positioned on the insertion side of the tube with respect to the powder coating material discharge port. Is.

  According to this, powder paint is discharged from the powder paint discharge port to the inner surface of the tube, and inorganic powder is discharged from the inorganic powder discharge port to the inner surface of the tube while moving from the insertion side of the tube toward the receiving side. When the powder coating discharge port reaches the receiving port from the insertion port, the inorganic powder discharge port does not reach the receiving port and is positioned in front of (just before) the receiving port. For this reason, the inorganic powder discharged from the inorganic powder discharge port is not supplied to the inner surface of the receiving port, and the inorganic powder is not mixed with the powder coating material discharged to the inner surface of the receiving port.

  As a result, the inner diameter of the lock ring formed on the inner surface of the tube receiving port or the housing groove of the seal member can be kept within a predetermined tolerance range, and the seal member can be mounted appropriately. Therefore, after painting the inner surface of the tube, when the tube is inserted into the tube receiving port and the tubes are connected to each other, a seal sandwiched between the inner periphery of the receiving port and the outer periphery of the inserting port The sealing function (water stop function) by the member is sufficiently secured.

  The coating method according to the ninth aspect of the present invention is such that, after coating while moving in one direction along the axis of the tube, when coating is performed by folding back in the opposite direction, the inorganic powder is discharged from the inorganic powder discharge port at the folding point. The discharge of the system powder is temporarily stopped.

  According to this, it is possible to prevent the amount of inorganic powder discharged at the turning point from becoming larger than the amount of inorganic powder discharged at other points, and between the turning point and other points. The amount of inorganic powder can be kept substantially uniform. As a result, a substantially uniform coating film of the inorganic powder mixed powder coating can be formed on the inner surface of the tube.

  The coating method according to the tenth aspect of the present invention is to discharge heated inorganic powder onto the inner surface of the tube.

  According to this, the inorganic powder is sequentially supplied from the inorganic powder supply member to the inorganic powder discharge port, and is discharged from the inorganic powder discharge port to the inner surface of the tube. At this time, since the heated inorganic powder having a high temperature is discharged to the inner surface of the tube, the coating efficiency is improved.

  The coating method according to the eleventh aspect of the present invention is a coating apparatus that individually discharges powder coating material and inorganic powder to the inner surface of a tube, while moving at least one of the tube relative to the other in the tube axis direction. It is for painting.

The twelfth aspect of the present invention is a pipe coating method using the coating apparatus according to the fifth aspect of the present invention,
While rotating the heated tube, the powder coating material is discharged from the first powder coating material discharge port in the first discharge direction while moving at least one of the coating device and the tube in the tube axis direction with respect to the other. In addition, the inorganic powder is discharged from the inorganic powder discharge port to the inner surface of the tube, and the inner surface of the tube is coated from the insertion side toward the receiving side,
When the second powder coating material discharge port passes through the step portion formed in the receiving port, the powder coating material is discharged from the second powder coating material discharge port in the second discharge direction.

  According to this, since the second discharge direction is directed to the inorganic powder discharge port side in the tube axis direction, when the second powder paint discharge port passes through the stepped portion in the receiving port, the powder paint is applied to the second powder. By discharging from the body paint discharge port in the second discharge direction, the stepped portion in the receiving port is reliably applied by the powder paint.

  As described above, according to the present invention, the powder coating material supply member and the inorganic powder are arranged so that the powder coating material discharge port is forward and the inorganic powder discharge port is behind the powder coating material discharge port in the tube axis direction. By moving the supply member with respect to the pipe, the powder paint discharged from the powder paint discharge port adheres to the inner surface of the pipe and melts. The discharged inorganic powder adheres later, and the adhered inorganic powder enters the molten powder coating material by the centrifugal force of the tube. As a result, the inorganic powder is appropriately dispersed in the powder coating material, and a good coating film of the inorganic powder mixed powder coating material is formed on the inner surface of the tube.

  Further, since the powder coating material is supplied to the powder coating material discharge port by the powder coating material supply member and the inorganic powder is supplied to the inorganic powder discharge port by the inorganic powder supply member, the powder coating material and the inorganic powder material Are fed to and discharged from the powder coating material discharge port and the inorganic powder discharge port in an individual state in which the powder is not mixed. Therefore, it is not necessary to provide a large projection device with a complicated structure as in the prior art, and the structure can be reduced in size with a simple structure, and satisfactory coating can be performed even on a small-diameter pipe.

It is a schematic side view of the pipe | tube and coating device in the 1st Embodiment of this invention. It is a XX arrow line view in FIG. It is sectional drawing of the coating material supply apparatus of a coating device. It is a XX arrow line view in FIG. It is a side view of the coating material supply apparatus of a coating device, and shows a state in which coating is performed on the inner surface of a tube insertion opening. It is a side view of the coating material supply apparatus of a coating device, and shows a state in which coating is performed on the inner surface near the boundary between the straight tube portion and the receiving port of the tube. It is a schematic side view of the pipe | tube and coating device in the 2nd Embodiment of this invention. It is a side view of the coating material supply apparatus of a coating device, and shows a state in which coating is performed on an end portion of a tube insertion port. It is a side view of the coating material supply apparatus of a coating device, and shows a state in which coating is performed on the inner surface of a straight pipe portion of a pipe. FIG. 6 is a side view of the coating material supply device of the coating apparatus, showing a state when the second powder coating material discharge port reaches a predetermined switching position while moving forward. It is a side view of the coating material supply apparatus of a coating device, and shows a state where painting is performed on a stepped portion. FIG. 6 is a side view of the coating material supply device of the coating apparatus, showing a state where the second powder coating material discharge port is folded back and reaches a predetermined switching position while moving backward. It is a XX arrow line view in FIG. It is a partial enlarged view of the conventional coating apparatus.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(First embodiment)
In the first embodiment, as shown in FIGS. 1 and 2, reference numeral 1 denotes a coating apparatus that coats the inner surface of the pipe 2. The pipe 2 is made of, for example, cast iron, and includes a straight pipe portion 3, a receiving port 4 provided at one end of the straight pipe portion 3, and an insertion opening 5 provided at the other end of the straight pipe portion 3. Yes.

  As shown in FIG. 6, a stepped portion 7 having a different inner diameter is formed in the back of the receiving port 4. Further, a seal member accommodation groove 13 and a lock ring accommodation groove 14 are formed on the inner periphery of the opening 4 closer to the opening end than the step 7. An annular rubber seal member 15 is fitted into the seal member housing groove 13 of the completed pipe 2 after painting, and a lock ring (not shown) is fitted into the lock ring housing groove 14. A protrusion 8 (see FIG. 1) is formed on the outer periphery of the insertion slot 5.

  The tube 2 is supported by a support device 11 having a plurality of rotating rollers 10 while rotating around an axis.

  The coating apparatus 1 coats the inner surface of the pipe 2 with an inorganic powder mixed powder paint obtained by mixing silica sand 21 (an example of an inorganic powder) with a powder paint 22, and the pipe 2 supported by the support apparatus 11. On the other hand, a carriage 24 that can reciprocate in the tube axis direction A and a paint supply device 25 provided on the carriage 24 are provided.

  For example, a powder epoxy paint (powder epoxy resin paint) or a powder polyethylene paint (powder polyethylene resin paint) is used as the powder paint 22, but it is not limited thereto. Further, the carriage 24 is supported and guided by the rail 26 on the outer side of the tube 2 on the insertion port 5 side, and can move in the tube axis direction A.

  As shown in FIGS. 3 and 4, the paint supply device 25 includes first and second powder paint supply members 27 and 28 that supply the powder paint 22 to the inside of the pipe 2, and a first powder paint supply member. A first powder paint discharge port 31 for discharging the powder paint 22 in 27 to the inner surface of the pipe 2 and a second powder for discharging the powder paint 22 in the second powder paint supply member 28 to the inner surface of the pipe 2. A body paint discharge port 32, an inorganic powder supply member 34 that supplies the silica sand 21 into the tube 2, and an inorganic powder discharge port 35 that discharges the silica sand 21 in the inorganic powder supply member 34 to the inner surface of the tube 2. have.

  The first powder coating material supply member 27 is for transferring the powder coating material 22 to the first powder coating material discharge port 31 by air, and is provided at the first supply tube 37 and the tip of the first supply tube 37. And a first nozzle 38. The first powder coating material discharge port 31 is formed in the first nozzle 38.

  The second powder coating material supply member 28 is used to transfer the powder coating material 22 to the second powder coating material discharge port 32 by air, and is provided at the second supply tube 40 and the tip of the second supply tube 40. A second nozzle 41. The second powder coating material discharge port 32 is formed in the second nozzle 41.

  The inorganic powder supply member 34 is, for example, a spring feeder, and includes a supply pipe 43, a coil spring 44 that is rotatably provided in the supply pipe 43, and a rotation driving device 45 that rotationally drives the coil spring 44 (see FIG. 1). ). The inorganic powder discharge port 35 is a slit-like opening that is elongated in the length direction of the supply pipe 43, and is formed in the lower part of the tip of the supply pipe 43.

  As shown in FIG. 1, the supply pipe 43 and the rotation drive device 45 are provided on the carriage 24. Further, the cart 24 is provided with a hopper 47 for introducing the silica sand 21 into the supply pipe 43. As shown in FIGS. 3 and 4, the first supply tube 37 and the second supply tube 40 are attached to the outer periphery of the supply pipe 43. Further, as shown in FIG. 1, on the upstream side of the first and second supply tubes 37, 40, a powder coating material charging device 50 for charging the powder coating material 22 into both the supply tubes 37, 40 and compressed air are both supplied. An air supply device 51 for supplying the supply tubes 37 and 40 is provided.

  As shown in FIGS. 3 and 6, the position of the inorganic powder discharge port 35, the position of the first powder paint discharge port 31, and the position of the second powder paint discharge port 32 are shifted in the tube axis direction A, respectively. Yes. That is, the first powder paint discharge port 31 is located at the tip of the supply pipe 43, and the inorganic powder discharge port 35 is located closer to the carriage 24 than the first powder paint discharge port 31. The second powder paint discharge port 32 is located between the first powder paint discharge port 31 and the inorganic powder discharge port 35 in the tube axis direction A.

  Further, the first discharge direction B1 of the powder coating material 22 discharged from the first powder coating material discharge port 31 and the second discharge direction B2 of the powder coating material 22 discharged from the second powder coating material discharge port 32, respectively. The tube 2 is inclined in the tube axis direction A with respect to the inner surface of the tube 2 and is opposite to each other.

  The inclination of the first and second discharge directions B1 and B2 is preferably 20 ° or more and 70 ° or less when the direction perpendicular to the inner surface of the tube 2 is 0 ° and the tube axis direction A is 90 °. More preferably, it is 40 ° or more and 60 ° or less. By setting such an inclination, when the powder coating material 22 is discharged from the first and second powder coating material discharge ports 31 and 32 to the inner surface of the tube 2, the powder coating material 22 spreads over a wide area on the inner surface of the tube 2. Evenly applied.

  The first nozzle 38 is formed with a guide surface 39 for guiding the powder coating material 22 so that the first discharge direction B1 is inclined in the tube axis direction A with respect to the inner surface of the tube 2. Further, the first discharge direction B1 is directed to the inorganic powder discharge port 35 side in the tube axis direction A, and the second discharge direction B2 is directed to the opposite side of the inorganic powder discharge port 35 in the tube axis direction A.

  Further, the discharge amount per unit time of the powder paint 22 discharged from the second powder paint discharge port 32 is the discharge amount per unit time of the powder paint 22 discharged from the first powder paint discharge port 31. Is set to be less.

  Hereinafter, a method for coating the inner surface of the pipe 2 using the coating apparatus 1 will be described.

  First, as shown in FIGS. 1 and 2, the heated tube 2 is supported on the rotating roller 10 of the support device 11. At this time, assuming that the direction from the insertion opening 5 to the receiving opening 4 of the tube 2 is the front and the direction from the receiving opening 4 to the insertion opening 5 is the rear, the coating apparatus 1 is on standby at a standby position C behind the insertion opening 5. Let

  Thereafter, while rotating the rotating roller 10 to rotate the tube 2 in one direction around the axis, the carriage 24 of the coating apparatus 1 is moved forward, and the paint supply device 25 is moved from the opening end of the insertion port 5 to the tube 2. As shown in FIG. 3, the powder coating material 22 is caused to flow along with the air to the first supply tube 37 and the second supply tube 40, and the inner surface of the tube 2 from the first powder coating material discharge port 31. To the inner surface of the pipe 2 from the second powder coating material discharge port 32 (while spraying), and further rotating the coil spring 44 of the inorganic powder supply member 34, The silica sand 21 in the supply pipe 43 is transferred to the inorganic powder discharge port 35 and discharged from the inorganic powder discharge port 35 to the inner surface of the pipe 2.

  When the carriage 24 is moved forward in this way, the first and second powder coating material discharge ports 31 and 32 are in front and the inorganic powder discharge port 35 is the first and second powders in the tube axis direction A. Since it is behind the body paint discharge ports 31, 32, the powder paint 22 discharged from the first and second powder paint discharge ports 31, 32 adheres to the inner surface of the tube 2 and is heated and melted. The silica sand 21 discharged from the inorganic powder discharge port 35 adheres to the powder coating 22 that is slightly delayed later, and the attached silica sand 21 is melted by the action of centrifugal force inside the powder coating 22. Get in. Thereby, the silica sand 21 is appropriately dispersed in the powder coating material 22, and a good coating film 49 of the powder coating material 22 (hereinafter referred to as inorganic powder mixed powder coating material) mixed with the silica sand 21 is formed in the tube 2. Formed on the inner surface.

  In addition, although it is desirable for the powder coating material 22 adhering to the inner surface of the pipe | tube 2 to melt | dissolve completely at the time of the silica sand 21 adhering, the location which is not melt | dissolving partially may exist.

  While moving the carriage 24 forward as described above, the powder coating material 22 is discharged from the first and second powder coating material discharge ports 31, 32 to the inner surface of the pipe 2, and the silica sand 21 is discharged from the inorganic powder discharge port. It is made to discharge to the inner surface of the pipe | tube 2 from 35, and it coats from the insertion port 5 of the pipe | tube 2 toward the receiving port 4.

  At this time, as shown in FIG. 5, since the second discharge direction B2 of the second powder coating material discharge port 32 faces obliquely forward, the end portion of the insertion port 5 of the pipe 2 is the second powder coating material discharge port. It is reliably applied by the powder coating material 22 discharged from 32.

  Thereafter, as shown in FIG. 6, when the first powder coating material discharge port 31 reaches the receiving port 4 of the pipe 2, the inorganic powder discharge port 35 does not reach the receiving port 4, and is in front of the receiving port 4. It is located in the straight pipe part 3. For this reason, the silica sand 21 discharged from the inorganic powder discharge port 35 is not supplied to the inner surface of the receiving port 4, and the silica sand 21 is not mixed with the powder coating material 22 discharged to the inner surface of the receiving port 4.

  Furthermore, since the first discharge direction B1 of the first powder coating material discharge port 31 is directed obliquely rearward, even if the silica sand 21 discharged from the inorganic powder discharge port 35 is about to flow forward, the first powder coating material discharge port The powder coating material 22 discharged from the outlet 31 in the first discharge direction B <b> 1 prevents the silica sand 21 from flowing forward. Thereby, it is possible to prevent the silica sand 21 discharged from the inorganic powder discharge port 35 from flowing forward and entering the receiving port 4.

  Further, since the first discharge direction B1 of the first powder paint discharge port 31 is directed obliquely backward, the stepped portion 7 in the receiving port 4 is caused by the powder paint 22 discharged from the first powder paint discharge port 31. It is surely applied.

  Immediately after the powder coating material 22 is sprayed from the first powder coating material discharge port 31 to the stepped portion 7 in the receiving port 4 as described above, as shown by the phantom line in FIG. When the turn-around point D set in the receiving port 4 is reached, the carriage 24 is moved backward in the opposite direction, and the paint supply device 25 is moved from the opening end of the insertion port 5 to the pipe 2 as shown by the phantom line in FIG. Pull out to the outside. As a result, while the coating material supply device 25 moves backward, the powder coating material 22 is discharged from the first and second powder coating material discharge ports 31 and 32 onto the inner surface of the pipe 2 in the same manner as in the forward movement. The silica sand 21 is discharged from the inorganic powder discharge port 35 to the inner surface of the tube 2.

  6, at the turning point D, the rotation of the coil spring 44 of the inorganic powder supply member 34 is temporarily stopped, and the discharge of the silica sand 21 from the inorganic powder discharge port 35 is temporarily stopped. Let Thereby, it can prevent that the quantity of the silica sand 21 discharged by the folding | turning point D becomes larger than the quantity of the silica sand 21 discharged | emitted by the other point, and the quartz sand of the folding | turning point D and other points The amount of 21 can be kept substantially uniform. As a result, a substantially uniform coating film 49 of the inorganic powder mixed powder coating can be formed on the inner surface of the pipe 2 other than the inner surface of the receiving port 4.

  As described above, the coating material supply device 25 is inserted into the tube 2 from the opening end of the insertion port 5 (see FIG. 1), and the inner surface of the tube 2 is coated from the insertion port 5 side toward the receiving port 4 side. After that, the coating film 49 of a good inorganic powder mixed powder coating material can be formed on the inner surface of the tube 2 by coating from the receiving port 4 side toward the insertion port 5 side.

  Thereafter, the discharge of the powder paint 22 from the first and second powder paint discharge ports 31 and 32 and the discharge of the silica sand 21 from the inorganic powder discharge port 35 are stopped, the rotation of the pipe 2 is stopped, The tube 2 is lowered from the support device 11.

  In the coating apparatus 1, the first discharge direction B <b> 1 of the first powder paint discharge port 31 and the second discharge direction B <b> 2 of the second powder paint discharge port 32 are respectively in the tube axis direction A with respect to the inner surface of the tube 2. Since it is inclined, the powder coating material 22 discharged from the first and second powder coating material discharge ports 31 and 32 is applied to a wide range of the inner surface of the tube 2.

  In the coating method, as shown in FIG. 3, the silica sand 21 is sequentially supplied from the supply pipe 43 of the inorganic powder supply member 34 to the inorganic powder discharge port 35 by the coil spring 44, and the inorganic powder discharge port 35. To the inner surface of the tube 2. At this time, since the supply pipe 43 is inserted into the pipe 2, the silica sand 21 in the supply pipe 43 is heated using the heat of the pipe 2, and the high-temperature silica sand 21 is placed on the inner surface of the pipe 2. Since it is discharged, the coating efficiency is improved.

  In the above example, the silica sand 21 is heated using the heat of the pipe 2, but the present invention is not limited to this, and when the silica sand 21 is supplied to the coil spring 44 of the inorganic powder supply member 34. It may be heated.

  In the coating apparatus 1, the powder coating material 22 is supplied to the first and second powder coating material discharge ports 31 and 32 by the first and second powder coating material supply members 27 and 28, and the silica sand 21 is used as the inorganic powder supply member. 34 is supplied to the inorganic powder discharge port 35, so that the powder coating material 22 and the silica sand 21 are not mixed with each other and are sent to the powder coating material discharge ports 31 and 32 and the inorganic powder discharge port 35, respectively. Discharged. Therefore, it is not necessary to provide a large projection device 104 (see FIG. 14) with a complicated structure as in the prior art, and the paint supply device 25 of the coating device 1 can be reduced in size with a simple structure, and has a small diameter. The tube 2 can be well painted.

  Moreover, since the coating film 49 in which the silica sand 21 is mixed with the powder coating material 22 is formed, the cost can be reduced and the thermal expansion and contraction of the coating film 49 can be improved.

  In the above coating method, since the silica sand 21 is not supplied to the inner surface of the receiving port 4, the silica paint 21 is not mixed with the powder coating material 22 discharged to the inner surface of the receiving port 4, thereby After the inner surface is painted, the inner diameter dimensions of the receiving grooves 13 and 14 of the receiving port 4 can be kept within a predetermined tolerance range, and the seal member 15 can be mounted appropriately. Therefore, when the insertion port 5 of another tube 2 is inserted into the receiving port 4 of the tube 2 and the tubes 2 are connected to each other, the seal member compressed between the inner periphery of the receiving port 4 and the outer periphery of the insertion port 5 The sealing function (water stop function) by 15 is sufficiently secured.

  In the above coating method, it is desirable that the weight ratio between the powder coating material 22 and the silica sand 21 is 1 to 1.5 or less. This is because if the ratio of the silica sand 21 is greater than 1.5, the silica sand 21 may be exposed on the inner surface of the coating film 49 formed on the pipe 2.

  Further, it is desirable that the particle size of the silica sand 21 is less than half the film thickness of the coating film 49 formed on the tube 2. For example, when the film thickness of the coating film 49 is 500 μm, it is desirable that the silica sand 21 has a particle size of 200 μm or less (more preferably, the average particle size is 100 μm or less). Thereby, it is possible to suppress the silica sand 21 from being exposed to the inner surface of the coating film 49.

  In the above coating method, the pipe 2 is rotated to apply a centrifugal force to the silica sand 21. The magnitude of the centrifugal force at this time is preferably 8 G or more (G is gravitational acceleration). Thereby, it is possible to suppress the silica sand 21 from being exposed to the inner surface of the coating film 49.

  In the first embodiment, since the coating is performed from the insertion port 5 side toward the receiving port 4 side, then the coating is folded and the coating is performed from the receiving port 4 side toward the insertion port 5 side. The painting was performed by reciprocating the inside of 2 in the front-rear direction. However, it is not limited to one reciprocation, and a plurality of reciprocations may be performed.

  Further, when the carriage 24 is moved backward, the powder coating material 22 is discharged from the first and second powder coating material discharge ports 31 and 32 and the discharge of the silica sand 21 from the inorganic powder discharge port 35 is stopped. May be. Alternatively, when the carriage 24 is moved backward, the discharge of the powder coating 22 from the first and second powder coating discharge ports 31 and 32 and the discharge of the silica sand 21 from the inorganic powder discharge port 35 are performed. , You may stop together.

In the first embodiment, the discharge amount per unit time of the powder coating material 22 discharged from the second powder coating material discharge port 32 is set to the powder coating material 22 discharged from the first powder coating material discharge port 31. Is set to be smaller than the discharge amount per unit time, but may be set to the same amount.
(Second Embodiment)
As shown in FIGS. 7 to 13, in the second embodiment, the first discharge direction B <b> 1 and the second discharge direction B <b> 2 are set in opposite directions to those in the first embodiment, respectively. That is, as shown in FIGS. 10 and 11, the second discharge direction B2 is directed to the inorganic powder discharge port 35 side (that is, obliquely rearward) in the tube axis direction A, and as shown in FIGS. The first discharge direction B1 is directed to the opposite side of the inorganic powder discharge port 35 in the tube axis direction A (that is, obliquely forward).

  The first nozzle 38 is provided at the tip of the supply pipe 43, and the tip of the first supply tube 37 is connected to the first nozzle 38.

  Further, the second discharge direction B2 is directed obliquely rearward in the tube axis direction A as described above, and as shown in FIG. 13, the drop path 55 of the quartz sand 21 that is discharged from the inorganic powder discharge port 35 and falls. From the pipe 2 to the circumferential direction E of the tube 2.

  Hereinafter, a method for coating the inner surface of the pipe 2 using the coating apparatus 1 will be described.

  First, as shown in FIG. 7, the heated tube 2 is supported on the rotating roller 10 of the support device 11, and the coating device 1 is put on standby at a standby position C behind the insertion slot 5.

  Thereafter, while rotating the rotating roller 10 to rotate the tube 2 in one direction around the axis, the carriage 24 of the coating apparatus 1 is moved forward, and the paint supply device 25 is moved from the opening end of the insertion port 5 to the tube 2. As shown in FIGS. 8 and 9, the powder coating material 22 flows along with the air to the first supply tube 37 and is discharged from the first powder coating material discharge port 31 onto the inner surface of the tube 2 as shown in FIGS. In addition, the coil spring 44 of the inorganic powder supply member 34 is rotationally driven to transfer the silica sand 21 in the supply pipe 43 to the inorganic powder discharge port 35, and from the inorganic powder discharge port 35 to the tube 2. Discharge to the inner surface. At this time, the discharge (spraying) of the powder paint 22 from the second powder paint discharge port 32 to the inner surface of the tube 2 is stopped.

  When the carriage 24 is moved forward in this way, as shown in FIG. 9, the first and second powder coating material discharge ports 31, 32 are in front and the inorganic powder discharge port 35 in the tube axis direction A. Is behind the first and second powder paint discharge ports 31, 32, so that the powder paint 22 discharged from the first powder paint discharge port 31 adheres to the inner surface of the tube 2 and is heated and melted. Silica sand 21 discharged from the inorganic powder discharge port 35 adheres to the molten powder coating 22 with a slight delay later, and the adhered silica sand 21 is melted by the action of centrifugal force. 22 Thereby, the silica sand 21 is appropriately dispersed in the powder coating material 22, and a good coating film 49 of the powder coating material 22 (hereinafter referred to as inorganic powder mixed powder coating material) mixed with the silica sand 21 is formed in the tube 2. Formed on the inner surface.

  In particular, as shown in FIG. 8, since the first discharge direction B1 of the first powder coating material discharge port 31 faces obliquely forward (that is, the opposite side of the inorganic powder discharge port 35 in the tube axis direction A), The end of the mouth 5 is reliably applied by the powder coating material 22 discharged from the first powder coating material discharge port 31. Also, the powder coating material 22 discharged from the first powder coating material discharge port 31 in the first discharge direction B1 rebounds on the inner surface of the pipe 2 and the first and second powder coating material supply members 27 and 28 or the inorganic powder supply member. 34 can be prevented from adhering. Thereby, the adhesion amount of the powder coating material 22 to the 1st and 2nd powder coating material supply members 27 and 28 or the inorganic type powder supply member 34 can be reduced.

  While continuously moving the carriage 24 forward as described above, the powder paint 22 is discharged from the first powder paint discharge port 31 to the inner surface of the pipe 2 and the silica sand 21 is discharged from the inorganic powder discharge port 35 to the pipe 2. It is made to discharge toward the inner surface of the tube 2 and paints from the insertion port 5 of the tube 2 toward the receiving port 4. Also at this time, as shown in FIG. 9, the discharge of the powder coating material 22 from the second powder coating material discharge port 32 to the inner surface of the tube 2 is stopped.

  Thereafter, as shown in FIG. 10, when the second powder coating material discharge port 32 reaches a predetermined switching position F set immediately before the stepped portion 7 of the receiving port 4, The discharge of the powder coating material 22 in the first discharge direction B1 is stopped, the powder coating material 22 is caused to flow along with the air to the second supply tube 40, and discharged from the second powder coating material discharge port 32 in the second discharge direction B2.

  Accordingly, as shown by the solid line in FIG. 11, when the second powder coating material discharge port 32 passes through the stepped portion 7 from the rear to the front, the powder coating material 22 moves from the second powder coating material discharge port 32 to the stepped portion 7. The step portion 7 is reliably applied by the powder coating material 22.

  At this time, as shown in FIG. 13, the second discharge direction B <b> 2 of the powder coating material 22 from the second powder coating material discharge port 32 is a direction that escapes (moves away) from the falling path 55 of the silica sand 21 to the circumferential direction E of the tube 2. Therefore, the powder coating material 22 discharged from the second powder coating material discharge port 32 is not directly sprayed onto the falling quartz sand 21 discharged from the inorganic powder discharge port 35, and the inorganic powder discharge port. It is possible to prevent the silica sand 21 discharged from 35 from being sprayed backward by the momentum of the powder coating material 22 discharged from the second powder coating material discharge port 32.

  Immediately after that, as shown by the phantom line in FIG. 11, when the tip of the paint supply device 25 reaches the turn-back point D, the carriage 24 is moved backward in the opposite direction, and the paint supply device 25 is opened to the opening 5. Pull out from the end to the outside of the tube 2. Accordingly, the powder coating material 22 is discharged from the second powder coating material discharge port 32 in the second discharge direction B2 while the coating material supply device 25 moves rearward.

  Then, as shown in FIG. 12, when the second powder coating material discharge port 32 passes through the stepped portion 7 from the front to the back and returns to the predetermined switching position F, the silica sand 21 is discharged from the inorganic powder discharge port 35. However, the discharge of the powder coating material 22 from the second powder coating material discharge port 32 in the second discharge direction B2 is stopped, and the powder coating material 22 is caused to flow along with the air to the first supply tube 37 to discharge the first powder coating material. Discharge from the outlet 31 in the first discharge direction B1, and in this state, the carriage 24 continues to move backward. As shown by the phantom line in FIG. Pull it out.

  As described above, between the predetermined switching position F (see FIG. 10) and the turning point D (see FIG. 11), the powder paint 22 from the first powder paint discharge port 31 in the first discharge direction B1. Therefore, it is possible to prevent the powder coating material 22 from being applied to the receiving grooves 13 and 14 of the receiving port 4.

  In addition, as shown by the phantom line in FIG. 11, when the tip of the coating material supply device 25 reaches the turning point D, the inorganic powder discharge port 35 does not reach the receiving port 4 and is in front of the receiving port 4. Located in the straight pipe section 3. For this reason, the silica sand 21 discharged from the inorganic powder discharge port 35 is not supplied to the receiving grooves 13 and 14 of the receiving port 4.

  Thus, since the powder coating 22 and the silica sand 21 are not supplied to the receiving grooves 13 and 14 of the receiving port 4, the inner diameter dimensions of the receiving grooves 13 and 14 can be kept within a predetermined tolerance range. The seal member 15 can be properly attached. Therefore, when the insertion port 5 of another tube 2 is inserted into the receiving port 4 of the tube 2 and the tubes 2 are connected to each other, the seal member compressed between the inner periphery of the receiving port 4 and the outer periphery of the insertion port 5 The sealing function (water stop function) by 15 is sufficiently secured.

  As shown by the phantom line in FIG. 11, at the turning point D, the rotation of the coil spring 44 of the inorganic powder supply member 34 is temporarily stopped, and the discharge of the silica sand 21 from the inorganic powder discharge port 35 is temporarily stopped. Let Thereby, it can prevent that the quantity of the silica sand 21 discharged by the folding | turning point D becomes larger than the quantity of the silica sand 21 discharged | emitted by the other point, and the quartz sand of the folding | turning point D and other points The amount of 21 can be kept substantially uniform. As a result, a substantially uniform coating film 49 of the inorganic powder mixed powder coating can be formed on the inner surface of the pipe 2 other than the inner surface of the receiving port 4.

  As described above, the paint supply device 25 is inserted into the tube 2 from the opening end of the insertion port 5 (see FIG. 7), and the inner surface of the tube 2 is coated from the insertion port 5 side toward the receiving port 4 side. After that, the coating film 49 of a good inorganic powder mixed powder coating material can be formed on the inner surface of the tube 2 by coating from the receiving port 4 side toward the insertion port 5 side.

  Thereafter, the discharge of the powder coating material 22 from the first powder coating material discharge port 31 and the discharge of the silica sand 21 from the inorganic powder discharge port 35 are stopped, the rotation of the tube 2 is stopped, and the tube 2 is supported. Remove from 11.

  In the coating apparatus 1, a first discharge direction B1 (see FIG. 9) of the first powder paint discharge port 31 and a second discharge direction B2 (see FIGS. 10 and 11) of the second powder paint discharge port 32 are present. Since each is inclined in the tube axis direction A with respect to the inner surface of the tube 2, the powder coating material 22 discharged from the first and second powder coating material discharge ports 31, 32 is applied to a wide range of the inner surface of the tube 2. .

  In the second embodiment, the length of the tube 2 from the end on the insertion port 5 side to the receiving port 4 is determined according to the standard, and the standby position C (see FIG. 7), the position of the carriage 24 is detected, and based on this, the turn-back point D (see FIG. 11) and the predetermined switching position F (see FIGS. 10 and 12) are detected.

  In the second embodiment, since the coating is performed from the insertion port 5 side toward the receiving port 4 side, the coating is turned back and the coating is performed from the receiving port 4 side toward the insertion port 5 side. The painting was performed by reciprocating the inside of 2 in the front-rear direction. However, it is not limited to one reciprocation, and a plurality of reciprocations may be performed.

  In addition, as shown in FIG. 9, while discharging the powder coating material 22 from the second powder coating material discharge port 32, the powder coating material 22 is discharged from the first powder coating material discharge port 31. While discharging 21 from the inorganic powder discharge port 35, the space between the end portion of the insertion slot 5 (see FIG. 8) and a predetermined switching position F (see FIG. 10) is applied. While discharging from both the first powder paint discharge port 31 and the second powder paint discharge port 32 and discharging the silica sand 21 from the inorganic powder discharge port 35, the end of the insertion port 5 and a predetermined switching position You may paint between F. In this case, the discharge amount per unit time of the powder paint 22 discharged from the second powder paint discharge port 32 is set to the discharge amount per unit time of the powder paint 22 discharged from the first powder paint discharge port 31. It may be set smaller than the amount, or may be set to the same amount.

  In each of the above-described embodiments, the silica sand 21 is used as an example of the inorganic powder, but is not limited to the silica sand 21, and for example, silica powder, talc, or the like may be used.

  In each of the above-described embodiments, the spring feeder that rotates the coil spring 44 and transfers the silica sand 21 is used as an example of the inorganic powder supply member 34. However, the present invention is not limited to the spring feeder. You may use the screw conveyor etc. which rotate the screw of this and convey the silica sand 21.

  In each of the above embodiments, as shown in FIGS. 1 and 7, the pipe 2 is fixed in the pipe axis direction A, and the coating apparatus 1 is moved in the pipe axis direction A with respect to the pipe 2, thereby providing a paint supply device. 25 is inserted into the inside of the pipe 2, but at least one of the coating apparatus 1 and the pipe 2 may be moved relative to the other in the pipe axis direction A. For example, the coating apparatus 1 is fixed in the pipe axis direction A, and the pipe 2 is moved in the pipe axis direction A with respect to the coating apparatus 1, so that the paint supply device 25 is inserted into the pipe 2 to perform coating. Also good. Alternatively, the coating apparatus 1 and the pipe 2 may be moved in opposite directions (approaching and separating directions) in the pipe axis direction A to insert the coating material supply apparatus 25 into the pipe 2 for coating. When the tube 2 is moved in the tube axis direction A, for example, the support member 11 may be configured to be movable in the tube axis direction A.

DESCRIPTION OF SYMBOLS 1 Coating apparatus 2 Pipe 4 Receptacle 5 Insert 21 Silica sand (inorganic powder)
22 Powder paint 27 First powder paint supply member 28 Second powder paint supply member 31 First powder paint discharge port 32 Second powder paint discharge port A Pipe axis direction B1 First discharge direction B2 Second discharge direction D Folding point

In order to achieve the above object, the first invention includes a receiving port provided at one end, an insertion port provided at the other end, and a stepped portion having a different inner diameter formed at the back of the receiving port. A coating apparatus that coats the inner surface of a tube with a powder coating mixed with an inorganic powder while rotating the tube having :
A powder coating material supply member for supplying powder coating material into the pipe;
First and second powder paint discharge ports for discharging the powder paint in the powder paint supply member to the inner surface of the pipe;
An inorganic powder supply member for supplying inorganic powder into the tube;
An inorganic powder discharge port for discharging the inorganic powder in the inorganic powder supply member to the inner surface of the tube
The position of the inorganic powder discharge port is shifted in the tube axis direction with respect to the position of the first and second powder coating material discharge ports ;
The first discharge direction of the powder paint discharged from the first powder paint discharge port to the inner surface of the tube and the second discharge direction of the powder paint discharged from the second powder paint discharge port to the inner surface of the tube are: Tilted in the direction of the tube axis with respect to the inner surface of the tube and reverse
The second powder paint discharge port is located between the first powder paint discharge port and the inorganic powder discharge port in the tube axis direction .

According to this, while rotating the heated tube, the powder coating material supply member and the inorganic powder supply member are inserted into the tube, and the powder coating material in the powder coating material supply member is removed from the first and second powders. While discharging to the inner surface of a pipe | tube from a body coating material discharge port, the inorganic type powder in an inorganic type powder supply member is discharged to the inner surface of a pipe | tube from an inorganic type powder discharge port.

In this case, as in the first and second powder coating material delivery port is to the rear than and inorganic powder discharge opening at the front first and second powder coating discharge opening in the tube axis direction, the powder paint supply member The powder coating material discharged from the first and second powder coating material discharge ports adheres to the inner surface of the tube and is melted by moving the inorganic powder supply member and the inorganic powder supply member relative to the tube. The inorganic powder discharged from the inorganic powder discharge port adheres to the paint later. The adhering inorganic powder has a specific gravity greater than that of the powder paint, and therefore enters the melted powder paint by the action of the centrifugal force of the tube. As a result, the inorganic powder is appropriately dispersed in the powder coating material, and a good coating film of the powder coating material (hereinafter referred to as inorganic powder mixed powder coating material) mixed with the inorganic powder is formed on the inner surface of the tube. It is formed.

Further, the powder coating material is supplied to the first and second powder coating material discharge ports by the powder coating material supply member, and the inorganic powder is supplied to the inorganic powder discharge port by the inorganic powder supply member. In an individual state where the inorganic powder and the inorganic powder are not mixed, they are respectively sent to the first and second powder coating material discharge ports and the inorganic powder discharge port and discharged. Therefore, it is not necessary to provide a large projection device with a complicated structure as in the prior art, and the structure can be reduced in size with a simple structure, and satisfactory coating can be performed even on a small-diameter pipe.

In addition, when the powder coating material is discharged from the first and second powder coating material discharge ports to the inner surface of the tube, the first and second discharge directions are inclined in the tube axis direction with respect to the inner surface of the tube. Paint is applied over a wide area on the inner surface of the tube.

Also, powder coating by moving the tube axis direction with respect to the supply member and the tube and the inorganic powder supply member, the inserting end portion formed in the other end first and second powder coating of the tube be reliably applied by powder coating discharged from either of the powder coating material discharge opening of the discharge port, the back of the stepped portion of the socket formed in one end of the tube first and second powder coating ejection It is reliably applied by the powder paint discharged from the other powder paint outlet of the outlet.

In the coating apparatus of the second invention, the first discharge direction is directed to the inorganic powder discharge port side in the tube axis direction,
Second discharge direction are those in the tube axis direction, it faces the opposite side of the inorganic powder discharge port.

In the coating apparatus according to the third invention, the second discharge direction is directed to the inorganic powder discharge port side in the tube axis direction,
First ejecting direction are those in the tube axis direction, it faces the opposite side of the inorganic powder discharge port.

The fourth invention is a pipe coating method using the coating apparatus according to the first invention,
While rotating the heated tube, the powder paint supply member and the inorganic powder supply member are inserted into the tube from the insertion side at the other end of the tube toward the receiving side at one end. The powder paint in the supply member is discharged from the first and second powder paint discharge ports to the inner surface of the tube, and the inorganic powder in the inorganic powder supply member is discharged from the inorganic powder discharge port to the inner surface of the tube. As a result, the powder coating melts on the inner surface of the tube, and the inorganic powder adheres to the molten powder coating with a delay,
The adhered inorganic powder enters the molten powder coating material by the action of centrifugal force.

According to this, the powder paint is discharged from the first and second powder paint discharge ports to the inner surface of the tube, and the inorganic powder is discharged from the inorganic powder discharge port to the inner surface of the tube. When coating is performed toward the receiving side, and the first and second powder coating material discharge ports reach the receiving port from the insertion port, the inorganic powder discharge port does not reach the receiving port, but before the receiving port ( Located just before). For this reason, the inorganic powder discharged from the inorganic powder discharge port is not supplied to the inner surface of the receiving port, and the inorganic powder is not mixed with the powder coating material discharged to the inner surface of the receiving port.

The fifth invention is a pipe coating method using the coating apparatus according to the third invention,
While rotating the heated tube and moving at least one of the coating apparatus and the tube in the tube axis direction with respect to the other, from the insertion side of the other end of the tube toward the receiving side of the one end, While discharging the powder paint from the first powder paint discharge port in the first discharge direction, and performing the coating to discharge the inorganic powder from the inorganic powder discharge port to the inner surface of the tube ,
When the second powder coating material discharge port passes through the step portion formed in the receiving port, the powder coating material is discharged from the second powder coating material discharge port in the second discharge direction.

As described above, according to the present invention, the powder coating material supply is performed so that the first and second powder coating material discharge ports are in front and the inorganic powder discharge port is behind the powder coating material discharge port in the tube axis direction. By moving the member and the inorganic powder supply member with respect to the pipe, the powder paint discharged from the first and second powder paint discharge ports adheres to the inner surface of the pipe and melts, and the molten powder The inorganic powder discharged from the inorganic powder discharge port adheres to the body paint later, and the adhered inorganic powder enters the molten powder paint by the centrifugal force of the tube. As a result, the inorganic powder is appropriately dispersed in the powder coating material, and a good coating film of the inorganic powder mixed powder coating material is formed on the inner surface of the tube.

Further, the powder coating material is supplied to the first and second powder coating material discharge ports by the powder coating material supply member, and the inorganic powder is supplied to the inorganic powder discharge port by the inorganic powder supply member. In an individual state where the inorganic powder and the inorganic powder are not mixed, they are respectively sent to the first and second powder coating material discharge ports and the inorganic powder discharge port and discharged. Therefore, it is not necessary to provide a large projection device with a complicated structure as in the prior art, and the structure can be reduced in size with a simple structure, and satisfactory coating can be performed even on a small-diameter pipe.

Claims (12)

A coating device that coats the inner surface of a rotating tube with a powder coating mixed with inorganic powder,
A powder coating material supply member for supplying powder coating material into the pipe;
A powder coating outlet for discharging the powder coating in the powder coating supply member to the inner surface of the pipe;
An inorganic powder supply member for supplying inorganic powder into the tube;
An inorganic powder discharge port for discharging the inorganic powder in the inorganic powder supply member to the inner surface of the tube
A coating apparatus, wherein the position of the inorganic powder discharge port is shifted in the tube axis direction with respect to the position of the powder coating material discharge port. 2. The coating apparatus according to claim 1, wherein the discharge direction of the powder paint discharged from the powder paint discharge port to the inner surface of the tube is inclined in the tube axis direction with respect to the inner surface of the tube. The powder coating outlet has a first powder coating outlet and a second powder coating outlet,
The first discharge direction of the powder paint discharged from the first powder paint discharge port to the inner surface of the pipe is opposite to the second discharge direction of the powder paint discharged from the second powder paint discharge port to the inner surface of the pipe. The coating apparatus according to claim 2, wherein the coating apparatus is oriented. The first discharge direction is directed to the inorganic powder discharge port side in the tube axis direction,
The second discharge direction is directed to the opposite side of the inorganic powder discharge port in the tube axis direction,
The coating apparatus according to claim 3, wherein the second powder coating material discharge port is located between the first powder coating material discharge port and the inorganic powder discharge port in the tube axis direction. The second discharge direction is directed to the inorganic powder discharge port side in the tube axis direction,
The first discharge direction is directed to the opposite side of the inorganic powder discharge port in the tube axis direction,
The coating apparatus according to claim 3, wherein the second powder coating material discharge port is located between the first powder coating material discharge port and the inorganic powder discharge port in the tube axis direction. A coating method in which the inner surface of the tube is coated with a powder coating mixed with inorganic powder while rotating the heated tube,
By individually discharging the powder paint and inorganic powder to the inner surface of the tube, the powder paint melts on the inner surface of the tube, and the inorganic powder adheres to the molten powder paint with a delay,
A coating method, wherein the adhered inorganic powder is allowed to enter a molten powder paint by the action of centrifugal force. While inserting the powder coating material supply member and the inorganic powder supply member into the inside of the tube, the powder coating material in the powder coating material supply member is discharged from the powder coating material discharge port to the inner surface of the tube, and the inorganic powder supply The coating method according to claim 6, wherein the inorganic powder in the member is discharged from the inorganic powder discharge port to the inner surface of the tube. 8. The coating is performed from the insertion side of the tube toward the receiving side with the inorganic powder discharge port positioned on the insertion side of the tube with respect to the powder coating material discharge port. Painting method. When coating is performed while moving in one direction along the axis of the tube and then folded in the opposite direction, the discharge of the inorganic powder from the inorganic powder discharge port is temporarily stopped at the turn-back point. The coating method according to claim 7 or 8, characterized in that: The coating method according to any one of claims 7 to 9, wherein the heated inorganic powder is discharged to the inner surface of the tube. A coating apparatus that individually discharges powder coating material and inorganic powder to the inner surface of a pipe, and at least one of the pipes is coated while moving in the pipe axis direction with respect to the other. The coating method according to any one of claims 6 to 10. A pipe coating method using the coating apparatus according to claim 5,
While rotating the heated tube, the powder coating material is discharged from the first powder coating material discharge port in the first discharge direction while moving at least one of the coating device and the tube in the tube axis direction with respect to the other. In addition, the inorganic powder is discharged from the inorganic powder discharge port to the inner surface of the tube, and the inner surface of the tube is coated from the insertion side toward the receiving side,
A coating method, comprising: discharging a powder paint from a second powder paint discharge port in a second discharge direction when the second powder paint discharge port passes through a stepped portion formed in the receiving port.

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