Thermal spraying apparatus and thermal spraying method for long-sized materials

Abstract

Provided is an improved structure of a spraying device for a long material, and also provided are a spraying device and a spraying method capable of stabilizing the quality of a sprayed film on the long material. 【Solution means】In the spraying housing 12, a plurality of spraying guns 18a, 18b, 18c are respectively arranged around an Al alloy pipe 20 which is a long material and at different positions in the axial direction, and a predetermined spraying material is sprayed from each spraying gun toward the Al alloy pipe 20 so that a sprayed film is formed on the outer surface of the Al alloy pipe 20. At the positions located outside the inlet 24 and the outlet 26 of the Al alloy pipe 20 in the spraying housing 12, roller devices 30, 32 which are restricting means for allowing the Al alloy pipe 20 to move in the axial direction but restricting the movement in the direction perpendicular to the axis are arranged, and the spraying operation on the Al alloy pipe 20 is allowed to proceed while its movement is restricted.

Description

Technical Field

[0001] The present invention relates to a spraying apparatus and a spraying method for a long material, and more particularly to a spraying apparatus and a spraying method used for forming a predetermined spraying film in the axial direction of the long material.

Background Art

[0002] Conventionally, as one of the surface modification techniques for long materials such as pipes and bars, a spraying technique has been adopted in which a sprayed material (particles) melted on the outer surface of such a long material is sprayed to form a predetermined spraying film in the axial direction. For example, in Japanese Patent No. 6105561, after spraying Zn or an Al-Zn alloy on an extruded or drawn heat transfer tube made of an aluminum alloy, a diffusion heat treatment is performed to form a sacrificial corrosion prevention layer composed of a Zn diffusion layer. Also, in Japanese Patent Application Laid-Open No. 57-67158, a method for manufacturing a metal sprayed clad steel pipe with improved appearance and corrosion resistance is disclosed, in which a plurality of spraying guns arranged in the radial direction are used to spray a metal different from the base material on the surface of a traveling base material pipe to form a spraying film.

[0003] By the way, in those spraying techniques, as a spraying apparatus for forming a spraying film in the axial direction on the outer peripheral surface (outer surface) of a long material such as a heat transfer tube or a steel pipe to be sprayed, a plurality of spraying guns are arranged concentrically around the long material so as to be located around it, and from these plurality of spraying guns, a predetermined spraying material (spray droplet particles) is sprayed all at once onto the outer peripheral surface at the same position in the axial direction of the long material. For this reason, in such a spraying apparatus, among the spraying materials sprayed from the spraying gun onto the long material, those that do not adhere to the long material adhere to the spraying gun located on the opposite side with the long material in between, resulting in the problem that the spraying gun becomes unusable. There is also an inherent problem that the spraying particles collide with each other and coarsen, and this adheres to the surface of the long material, leading to poor quality of the formed spraying film.

[0004] In addition, in Japanese Utility Model Publication No. 60-136355, as one of the embodiments of a metal spraying apparatus for a long object, a structure is adopted in which a plurality of spraying guns are arranged while being shifted in the circumferential direction of the long object as the object to be sprayed, and also shifted in the axial direction of the long object, so that the plurality of spraying guns are not arranged facing each other. Thus, a spraying apparatus is disclosed, which eliminates the need to consider problems such as the adhesion of spraying particles to the above-described spraying guns and the coarsening due to the collision of spraying particles with each other.

[0005] However, in a spraying apparatus having a structure in which a plurality of spraying guns are arranged while being shifted in the axial direction and the circumferential direction of a long object, such as in Japanese Utility Model Publication No. 60-136355, since the injection forces of the spraying materials from the plurality of spraying guns in a plurality of directions cannot cancel each other out, the axial center position of the long object in the spraying zone changes due to the momentum of the injection of the spraying material from the spraying guns, resulting in a problem that it becomes difficult to keep the spraying distance from each spraying gun constant. Moreover, such a change in the spraying distance between the spraying gun and the long object changes the temperature and velocity of the spraying particles at the time of collision with the long object, which inherently poses a risk of causing variations in the quality of the sprayed coating formed on the long object, such as the characteristics and surface properties of the sprayed coating.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Patent Document 2

Patent Document 3

Summary of the Invention

Problems to be Solved by the Invention

[0007] Here, the present invention has been made against such a background, and the problem to be solved is to provide an improved structure or method for a spraying device and a spraying method for a long material. Another problem is to provide a spraying device and a spraying method capable of stabilizing the quality of the sprayed coating on the long material.

Means for Solving the Problems

[0008] And the present invention can be preferably implemented in various aspects listed below in order to solve the above-mentioned problems. Moreover, each of the aspects described below can be adopted in any combination. It should be understood that the aspects or technical features of the present invention are not limited to those described below and can be recognized based on the inventive concept disclosed in the entire description of the specification and the drawings.

[0009] First, the first aspect of the present invention for solving the above-mentioned problems is a spraying device that forms a predetermined sprayed coating on the outer surface of a long material that is moved axially in a spraying zone using a plurality of spraying guns arranged in the spraying zone. The plurality of spraying guns are arranged in the spraying zone around the long material and at different axial positions, respectively, and a predetermined spraying material is sprayed from each spraying gun toward the long material so that the sprayed coating is formed. At the same time, a regulating means that allows movement of the long material in the axial direction but restricts movement in the direction perpendicular to the axis is arranged at a site located outside the entrance portion of the long material in the spraying zone and at a site located outside the exit portion of the long material in the spraying zone. In a state where the movement of the long material is restricted by the regulating means on both sides of the spraying zone, the spraying operation on the long material is allowed to proceed. The spraying device for a long material is characterized by this.

[0010] Also, the second aspect of the present invention is characterized in that the long material travels horizontally in the axial direction in the spraying zone.

[0011] Furthermore, in a third aspect of the present invention, among the plurality of spraying guns, the spraying gun that sprays the spraying material from below toward the long material is arranged closer to the inside of the spraying zone than the spraying gun arranged closest to the exit portion of the long material in the spraying zone.

[0012] In addition, in a fourth aspect of the present invention, among the plurality of spraying guns, the spraying gun that sprays the spraying material from below toward the long material is arranged closer to the inside of the spraying zone than the spraying gun arranged closest to the entry portion of the long material in the spraying zone.

[0013] In a fifth aspect of the present invention, the plurality of spraying guns are arranged at equal angles in the circumferential direction of the long material.

[0014] Also, in a sixth aspect of the present invention, the regulating means is characterized in that it is constituted by at least one roller arranged to support the long material.

[0015] Furthermore, in a seventh aspect according to the present invention, the regulating means is configured to include at least a first guide roller that supports the long material and two second guide rollers arranged on both sides of the long material.

[0016] And, in an eighth aspect according to the present invention, the spraying zone is constituted by a spraying housing partitioned from the outside, and an entry portion and an exit portion of the long material are respectively provided for the spraying housing.

[0017] Also, in a ninth aspect according to the present invention, the inside of the spraying housing is partitioned into a plurality of spraying chambers corresponding to the plurality of spraying guns, and the long material is configured to be moved in its axial direction, and the spraying material is respectively sprayed from the corresponding spraying guns in the plurality of spraying chambers.

[0018] In addition, in a tenth aspect according to the present invention, while a gun insertion port for inserting and disposing the thermal spraying gun with respect to the thermal spraying housing is provided, an exhaust port for sucking the atmosphere inside the thermal spraying housing is provided in the thermal spraying housing so as to face the thermal spraying gun inserted into the gun insertion port with the long material therebetween, and overspray particles of the thermal spraying material sprayed from the thermal spraying gun that are not welded to the long material are sucked into the exhaust port.

[0019] Furthermore, in an eleventh aspect according to the present invention, while a gun insertion port for inserting and disposing the thermal spraying gun is provided in each wall portion of the thermal spraying housing corresponding to each of the plurality of thermal spraying chambers, an exhaust port for sucking the atmosphere inside those thermal spraying chambers is provided in each wall portion of the thermal spraying housing so as to face the thermal spraying gun inserted into the gun insertion port with the long material therebetween, and overspray particles of the thermal spraying material sprayed from the thermal spraying gun that are not welded to the long material are sucked into the exhaust port.

[0020] And, a twelfth aspect according to the present invention is a method for thermal spraying a long material using the thermal spraying apparatus according to any one of the first to eleventh aspects. While moving the long material in its axial direction, a thermal spraying film covering the entire circumferential surface of the long material is continuously formed in the axial direction of the long material by thermal spraying a predetermined thermal spraying material from the plurality of thermal spraying guns onto the outer surface of the long material.

[0021] Moreover, the thirteenth aspect of the present invention is that in the spraying zone, when forming a target sprayed coating on the outer surface of a long material to be sprayed by spraying a predetermined spraying material from a plurality of spraying guns arranged at different positions in the axial direction and different positions in the circumferential direction of the long material, while restricting the movement of the long material in the direction perpendicular to its axis, the long material is moved in its axial direction to enter the spraying zone. On the other hand, the long material with the sprayed coating formed in the spraying zone is moved in the axial direction while restricting the movement in the direction perpendicular to its axis on the exit side from the spraying zone, and is taken out from the spraying zone. The gist of the present invention also lies in a method for spraying a long material characterized by the above.

Advantages of the Invention

[0022] Thus, in the spraying apparatus and method for a long material according to the present invention, a predetermined spraying material is vigorously sprayed from a plurality of spraying guns arranged offset in the axial direction (longitudinal direction) of the long material to be sprayed. Even when such a long material receives the pressing action due to the spraying pressure, the long material is supported by regulating means and the like respectively arranged on both sides of the spraying zone, and the movement of the long material in directions other than the axial direction can be effectively restricted. As a result, the spraying distances between the plurality of spraying guns and the long material can all be kept constant, and thus it becomes possible to advantageously stabilize the quality of the sprayed coating formed on the outer surface of the long material.

Brief Description of the Drawings

[0023]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Embodiments for Carrying out the Invention

[0024] Hereinafter, in order to more specifically clarify the configuration of the present invention, representative embodiments of the present invention will be described in detail with reference to the drawings.

[0025] First, FIG. 1 schematically shows an example of a spraying device for long materials according to the present invention in a form where the spraying housing constituting the spraying zone is taken as a vertical cross-section. Therein, the spraying device 10 has a spraying housing 12 whose inside is a spraying zone. And the inside of such a spraying housing 12 is divided into three by two partition walls 14a and 14b, and three spraying chambers 16a, 16b, and 16c are formed. That is, here, the spraying zone is constituted by these three spraying chambers 16a, 16b, and 16c.

[0026] In addition, in the three spraying chambers 16a, 16b, and 16c formed in the spraying housing 12, spraying guns 18a, 18b, and 18c are respectively arranged in such a form that the spraying ports of the respective spraying materials (molten particles) are opened into the respective spraying chambers 16a, 16b, and 16c. And those three spraying guns 18a, 18b, and 18c are respectively arranged at different positions in the axial direction of the Al alloy pipe 20, which is a long material, within the spraying housing 12.

[0027] Moreover, as shown in FIG. 2, those three spraying guns 18a, 18b, and 18c are arranged with a phase difference of 120° from each other in the circumferential direction of the Al alloy pipe 20 having a circular cross-section. More specifically, in the central spraying chamber 16b in the spraying housing 12, a spraying gun 18b for spraying the spraying material from below, here from directly below upward, toward the Al alloy pipe 20 is arranged such that its spraying port opens upward. Also, in the spraying chambers 16a and 16c located on both sides of the central spraying chamber 16b, spraying guns 18a and 18c are respectively arranged with a phase difference of 120° so as to be in opposite directions to each other in the circumferential direction of the Al alloy pipe 20 with respect to the spraying gun 18b. From those three spraying guns 18a, 18b, and 18c, as shown in the figure, the spraying material is sprayed so as to reach the entire circumferential surface of the Al alloy pipe 20.

[0028] Incidentally, the Al alloy tube 20 as the long material is extruded from a known extrusion device 22 as before, and while being in its hot state, it is introduced into the spraying housing 12. While being axially moved in the spraying housing 12, a predetermined spraying material (for example, Zn) is sprayed from the three spraying guns 18a, 18b, and 18c described above, and a predetermined spraying film (for example, Zn spraying film) is formed over the entire outer surface of the Al alloy tube 20. For the axial movement of the Al alloy tube 20, an inlet 24 (corresponding to the "entry part" according to the present invention) is provided in the wall of the spraying chamber 16a of the spraying housing 12, while an outlet 26 (corresponding to the "exit part" according to the present invention) is provided in the wall of the spraying chamber 16c on the side where the Al alloy tube 20 is taken out from the spraying housing 12. Further, communication ports 28, 28 through which the Al alloy tube 20 can pass are provided in the partition walls 14a, 14b that partition the inside of the spraying housing 12 into three parts. In short, through the inlet 24, the communication ports 28, 28, and the outlet 26, the Al alloy tube 20 can be moved or run in its axial direction and pass through the inside of the spraying housing 12.

[0029] And outside the inlet 24 of the spraying housing 12, in other words, on the rear side of the inlet 24 in the moving direction of the Al alloy tube 20, an inlet-side roller device 30 as a regulating means for supporting or holding the Al alloy tube 20 supplied from the extrusion device 22 is arranged. On the other hand, outside the outlet 26 of the spraying housing 12, in other words, on the front side of the outlet 26 in the moving direction of the Al alloy tube 20, an outlet-side roller device 32 as a regulating means for supporting or holding the Al alloy tube 20 with the spraying film formed, taken out from the outlet 26, is arranged. That is, by these two roller devices 30, 32, the Al alloy tube 20 is allowed to move in its axial direction in the spraying housing 12, in other words, in the spraying zone, while the movement in the direction perpendicular to the axis is regulated. In the spraying housing 12, a predetermined spraying material is sprayed from the three spraying guns 18a, 18b, and 18c, and a predetermined spraying film is formed on the outer surface of the Al alloy tube 20.

[0030] Specifically, as shown in FIGS. 3(a) and (b), both of those roller devices 30 and 32 include a freely rotatable support roller 34a that receives and supports the gravity of the Al alloy tube 20 and has a horizontal rotation axis positioned perpendicular to the axis of the Al alloy tube 20, and guide rollers 34b and 34b that are freely rotatable with vertical rotation axes and are positioned on both sides of the Al alloy tube 20 at positions displaced in the axial direction of the Al alloy tube 20 with respect to the support roller 34a. Therefore, even when the spraying force of the spraying material from the spraying guns 18a, 18b, and 18c acts, the downward movement of the Al alloy tube 20 is blocked by the support roller 34a, and the displacement in the left-right direction (sideways) can be blocked by the two guide rollers 34b and 34b.

[0031] Note that the self-weight of the Al alloy tube 20 acts thereon, and thus the upward movement is suppressed. Therefore, here, no roller for restricting or blocking the upward movement is provided, but if necessary, a roller for restricting the upward movement can be provided above the Al alloy tube 20.

[0032] In addition, here, in addition to the spraying material being sprayed onto the Al alloy tube 20 from the spraying gun 18c provided in the spraying chamber 16c on the outlet side of the spraying housing 12 from an obliquely upward direction so that the target sprayed coating is formed, in consideration of the occurrence of defects due to contact with the formed sprayed coating, etc., a slight gap is formed between each of the two guide rollers 34b and 34b disposed on both sides of the Al alloy tube 20 and the Al alloy tube 20.

[0033] In addition, in order to avoid the adverse effects caused by contact with the sprayed coating formed on the outer surface of the Al alloy tube 20, the distance from the exit 26 of the outlet-side roller device 32 is set to be longer in the axial direction of the Al alloy tube 20 than the distance from the inlet 24 of the inlet-side roller device 30. Among the three rollers 34a, 34b, 34b that make up the outlet-side roller device 32, the guide rollers 34b, 34b arranged on both sides of the Al alloy tube 20 are configured such that the distance from the exit 26 is larger than that of the support roller 34a. In other words, in the traveling direction of the Al alloy tube 20, they are located on the front side of the support roller 34a.

[0034] And in the spraying device 10 with such a configuration, even when the spraying material is vigorously sprayed from the plurality of spraying guns 18a, 18b, 18c at different positions in the axial direction of the long Al alloy tube 20 and a large spraying force acts, the Al alloy tube 20 is supported by the inlet-side roller device 30 and the outlet-side roller device 32 outside the inlet 24 and the outlet 26 of the spraying housing 12, respectively. Since the movement in the vertical and horizontal directions, in other words, the movement in the direction perpendicular to the axis is restricted, the spraying distance between the spraying guns 18a, 18b, 18c and the Al alloy tube 20 can be substantially kept constant. As a result, it becomes easy to stabilize the quality of the sprayed coating formed on the outer surface of the Al alloy tube 20.

[0035] Moreover, since the inlet-side roller device 30 and the outlet-side roller device 32 are respectively arranged outside the spraying housing 12, the spraying material (particles) sprayed from the spraying guns 18a, 18b, 18c will not adhere, and the occurrence of malfunctions in the roller devices 30, 32 due to the adhesion of such spraying particles can also be advantageously avoided.

[0036] Also, in such an exemplary embodiment, a spraying gun 18b for performing spraying on the Al alloy pipe 20 from below (directly below) is disposed not in the first spraying chamber 16a or the last spraying chamber 16c but in the middle spraying chamber 16b. On the other hand, in the spraying chambers 16a and 16c before and after it, spraying from obliquely above is performed by the spraying guns 18a and 18c. As a result, the upward floating of the Al alloy pipe 20 due to the injection from below is suppressed by the two injection actions from obliquely above. Therefore, the forces acting on the Al alloy pipe 20 by spraying can be effectively canceled or alleviated, and the out-side roller device 32 can be made to contact the sprayed coating immediately after spraying formed on the outer surface of the Al alloy pipe 20 as much as possible. Problems such as damage or peeling of the sprayed coating due to rubbing can be advantageously avoided.

[0037] Furthermore, the inside of the spraying housing 12 is partitioned by partition walls 14a and 14b to form a plurality of spraying chambers 16a to 16c, and spraying guns 18a to 18c are disposed in the respective spraying chambers. As a result, the spraying guns can be arranged close to each other in the axial direction of the Al alloy pipe 20, the device can be made more compact, and the distance between the in-side roller device 30 and the out-side roller device 32 disposed on both sides of the spraying housing 12 can also be narrowed. Therefore, the support of the Al alloy pipe 20 in the spraying housing 12, in other words, in the spraying zone, can be made more stable.

[0038] Incidentally, each spraying chamber 16a to 16c defined within the spraying housing 12 as described above is preferably configured such that, as illustrated in FIG. 4, it has a gun insertion port 40 and an exhaust port 42 that are positioned opposite to the wall portion of the spraying housing 12 corresponding to each spraying chamber 16a to 16c. Specifically, at each gun insertion port 40, an annular gap is formed between the opening edge and the outer peripheral portion of the spraying guns 18a to 18c inserted and arranged therein, and air is introduced into the spraying chambers 16a to 16c from the outside through this gap. Further, the exhaust port 42 is provided in the wall portion of the spraying housing 12 so as to face the spraying guns 18a to 18c inserted and positioned at the gun insertion port 40 with the Al alloy pipe 20 therebetween, and an exhaust hood 44 connected to a suction device (not shown) is attached to the outer surface of the spraying housing 12 so as to cover the exhaust port 42.

[0039] Then, by the operation of a suction device (not shown), the atmosphere in each spraying chamber 16a to 16c is sucked into the exhaust port 42, while external air is taken into each spraying chamber 16a to 16c from the annular gap between the gun insertion port 40 and the spraying guns 18a to 18c. As a result, an intake air flow is generated in each spraying chamber 16a to 16c from the annular gap formed around the spraying guns 18a to 18c toward the exhaust port 42. Riding on this intake air flow, the overspray particles of the spraying material sprayed from each spraying gun 18a to 18c that are not welded to the Al alloy pipe can be advantageously excluded from each spraying chamber 16a to 16c through the exhaust port 42. This makes it possible to prevent the spraying material from adhering and depositing on the inner surface of the wall portion of the spraying housing 12. It should be noted that the entire spraying device 10, and in particular, at least the entire spraying housing 12, is accommodated in a booth that can prevent the entry of foreign objects from the outside. Thus, it is of course considered that no foreign objects are included in the air taken into each spraying chamber 16a to 16c from the annular gap around each spraying gun 18a to 18c.

[0040] As described above in detail for representative embodiments of the present invention, they are merely illustrative, and it should be understood that the present invention is not to be construed in any limiting way by such specific descriptions of the embodiments.

[0041] For example, the long material to be sprayed is not limited to a pipe material such as the exemplified Al alloy pipe 20, and it can be a bar or a wire without any problem. As its cross-sectional outer shape, in addition to a circular shape, various known outer shapes such as an elliptical shape can be targeted. Also, regarding the material of the long material (20) and the material of the spraying material sprayed from the spraying guns 18a to 18c, in addition to metals, those of various known materials such as ceramics, plastics, and cermets can be used. Furthermore, as the spraying method of the spraying guns (18a to 18c), various known spraying methods such as arc spraying, flame spraying, plasma spraying, and laser spraying can be adopted, and the present invention is applicable to spraying apparatuses according to those known spraying methods.

[0042] Also, regarding the number of spraying guns installed, in addition to the case of installing three (18a to 18c) as exemplified, it can be two, or four or more without any problem. Depending on the number of installations, it is desirable that the inside of the spraying housing (12) is partitioned by partition walls (14a, 14b ···) to form spraying chambers (16a, 16b, 16c ···) corresponding to the respective spraying guns (18a, 18b, 18c ···). However, it is not necessary to partition the inside of one spraying housing 12 by partition walls (14a, 14b ···) to form the respective spraying chambers (16a, 16b, 16c ···), and it is also possible to form the respective spraying chambers in individually independent spraying chambers. Furthermore, when it is possible to arrange the spraying guns sufficiently apart in the axial direction of the long material (20), it is also possible to eliminate the need for arranging the spraying chambers corresponding to the respective spraying guns.

[0043] Furthermore, regarding the restricting means disposed on the inlet side and the outlet side of the spraying zone (spraying housing 12), any structure can be adopted as long as the movement of the long material (Al alloy pipe 20) that can be moved in the axial direction is restricted in the direction perpendicular to its axis. For example, it may be a low-friction sliding member provided with a concave groove or a through hole that can slidably receive the long material. Generally, as illustrated, a roller device (30, 32) that supports and holds the long material using rollers is advantageously adopted.

[0044] Note that the restricting means (30) on the inlet side of the spraying zone (12) and the restricting means (32) on the outlet side of the spraying zone (12) may have the same structure or different structures without any problem.

[0045] Also, when the long material (20) is introduced into the spraying zone (12) in a high-temperature state, it goes without saying that the restricting means on the inlet side of the spraying zone should be made of a material that can withstand such high temperatures (heat-resistant). Furthermore, the restricting means (32) on the outlet side of the spraying zone is desirably made of a material with a low friction coefficient, such as a graphite-based material, so that the sprayed coating formed on the outer surface of the long material (20) is not damaged.

[0046] Furthermore, in the illustrated embodiment, the hot long material (Al alloy pipe 20) is introduced into the spraying device 10 in the state of being extruded from the extrusion device 22. Otherwise, prior to spraying, (a) heat treatment by an induction annealer, (b) blasting treatment (laser blasting, sand blasting, etc.), (c) other known treatments that can contribute to improving the fixing property, etc. can be performed on the long material (20) to improve the fixing property of the sprayed coating.

[0047] In addition, even in a device using rollers as the restricting means, in addition to the roller devices 30 and 32 formed by combining three rollers 34a, 34b, and 34b as illustrated, devices using rollers with various known structures can be adopted. For example, various rollers (devices) as shown in FIGS. 5(a) to 5(c) can be used.

[0048] In FIG. 5, (a) shows a structure in which two guide rollers 52, 52 are arranged in a V shape to support a pipe material 50 that can be moved in the axial direction. Further, (b) shows a structure in which a grooved roller 54 having a concave groove 54a with a V-shaped cross-sectional shape or the like on its outer peripheral surface supports the pipe material 50. Furthermore, (c) shows a pinch roller having a structure in which a pair of arc-shaped grooved rollers 56, 56 are used to sandwich and hold the pipe material 50. By adopting such a pinch roller structure, as shown in the figure, by making the interval between the rollers 56, 56 variable according to the outer shape (outer dimension) of the pipe material 50, it becomes possible to handle pipe materials 50 of various outer shapes.

[0049] Although not listed one by one, the present invention can be implemented in various modified, corrected, and improved forms based on the knowledge of those skilled in the art, and it should be understood that any such embodiments belong to the scope of the present invention as long as they do not depart from the spirit of the present invention.

Explanation of Reference Numerals

[0050] 10 Spraying device 12 Spraying housing 14a, 14b Partition walls 16a, 16b, 16c Spraying chambers 18a, 18b, 18c Spraying guns 20 Al alloy pipe 22 Extrusion device 24 Inlet 26 Outlet 28 Communication port 30, 32 Roller devices 34a Support roller 34b Guide roller 40 Gun insertion port 42 Exhaust port 50 Pipe material 52 Guide roller 54 Grooved roller 54a Concave groove 56 Roller

Claims

1. A spraying apparatus for forming a predetermined sprayed coating on the outer surface of a long material that is axially moved in a spraying zone using a plurality of spraying guns arranged in the spraying zone, wherein the plurality of spraying guns are respectively arranged in the spraying zone around the long material and at different axial positions, and a predetermined spraying material is sprayed from each spraying gun toward the long material so that the sprayed coating is formed, and restricting means for supporting the long material are respectively arranged at a portion located outside the entry portion of the long material in the spraying zone and at a portion located outside the exit portion of the long material in the spraying zone, allowing movement of the long material in the axial direction but restricting movement in a direction perpendicular to the axis, and the spraying operation on the long material is carried out in a state where the movement of the long material is restricted by the restricting means on both sides of the spraying zone. A spraying apparatus for a long material, characterized in that.

2. The spraying apparatus for a long material according to claim 1, wherein the long material is run horizontally in the axial direction in the spraying zone.

3. Among the plurality of spraying guns, the spraying gun that sprays the spraying material downward toward the long material is arranged more inward in the spraying zone than the spraying gun arranged closest to the exit portion of the long material in the spraying zone. The spraying apparatus for a long material according to claim 2, characterized in that.

4. Among the plurality of spraying guns, the spraying gun that sprays the spraying material downward toward the long material is arranged more inward in the spraying zone than the spraying gun arranged closest to the entry portion of the long material in the spraying zone. The spraying apparatus for a long material according to claim 2, characterized in that.

5. The spraying apparatus for a long material according to claim 1, wherein the plurality of spraying guns are arranged at equal angles in the circumferential direction of the long material.

6. The spraying apparatus for a long material according to claim 1, wherein the restricting means is constituted by at least one roller arranged to support the long material.

7. The spraying apparatus for a long material according to claim 6, wherein the restricting means comprises at least a first guide roller for supporting the long material and two second guide rollers arranged on both sides of the long material.

8. The thermal spraying zone is constituted by a thermal spraying housing partitioned from the outside, and an inlet portion and an outlet portion of the long material are respectively provided for the thermal spraying housing. The thermal spraying apparatus for a long material according to claim 1, characterized in that.

9. The inside of the thermal spraying housing is partitioned into a plurality of thermal spraying chambers corresponding to the plurality of thermal spraying guns, and the long material is configured to be moved in its axial direction, and in the plurality of thermal spraying chambers, the thermal spraying material is blown from the corresponding thermal spraying guns respectively. The thermal spraying apparatus for a long material according to claim 8, characterized in that.

10. While a gun insertion port for inserting and arranging the thermal spraying gun is provided for the thermal spraying housing, an exhaust port for sucking the atmosphere in the thermal spraying housing is provided for the thermal spraying housing so as to face the thermal spraying gun inserted into the gun insertion port with the long material in between, and the overspray particles not welded to the long material among the thermal spraying materials blown from the thermal spraying gun are sucked into the exhaust port. The thermal spraying apparatus for a long material according to claim 8, characterized in that.

11. While a gun insertion port for inserting and arranging the thermal spraying gun is provided for each wall portion of the thermal spraying housing corresponding to the plurality of thermal spraying chambers respectively, an exhaust port for sucking the atmosphere in the thermal spraying chambers is provided for each wall portion of the thermal spraying housing so as to face the thermal spraying gun inserted into the gun insertion port with the long material in between, and the overspray particles not welded to the long material among the thermal spraying materials blown from the thermal spraying gun are sucked into the exhaust port. The thermal spraying apparatus for a long material according to claim 9, characterized in that.

12. The distance between the restricting means disposed outside the outlet portion of the long material in the thermal spraying zone and the outlet portion is configured to be longer in the axial direction of the long material than the distance between the restricting means disposed outside the inlet portion of the long material in the thermal spraying zone and the inlet portion. The thermal spraying apparatus for a long material according to claim 1, characterized in that.

13. A method of thermal spraying a long material using the thermal spraying apparatus according to any one of claims 1 to 12. While moving such a long material in its axial direction, a spraying film that covers the entire circumferential surface of the long material is continuously formed in the axial direction of the long material by spraying a predetermined spraying material from the plurality of spraying guns onto the outer surface thereof. A spraying method for a long material, characterized in that.

14. In the spraying zone, when forming a target spraying film on the outer surface of the long material to be sprayed by spraying a predetermined spraying material from a plurality of spraying guns arranged at different positions in the axial direction and different positions in the circumferential direction of the long material, while supporting the long material and restricting its movement in the direction perpendicular to the axis, moving it in the axial direction to enter the spraying zone, while supporting the long material on which the spraying film has been formed in the spraying zone on the exit side from the spraying zone and restricting its movement in the direction perpendicular to the axis, moving it in the axial direction to take it out of the spraying zone. A spraying method for a long material, characterized in that.

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