Rotary atomization-type coating machine

Abstract

To provide a rotary atomization-type coating machine capable of maintaining high coating performance and ensuring coating quality without increasing the rotation speed of the air flow rate of rotary atomization.SOLUTION: In a cover body 31 of a rotary atomization-type coating machine 1, many inclined air guides 44 for guiding shaving air in a direction D2 opposite to the rotation direction D1 of a rotary atomization 22 are formed in the terminal position of an air supply path 51. At a position between the cover body 31 and a columnar member 21 before the inclined air guides 44, a rectifier space 52 communicated with the air supply path 51 through the inclined air guides 44 is formed. Between the tip opening 31a of the cover body 31 and the outer peripheral surface 21a of the columnar member 21, an annular air jetting slit 53 communicated with the rectifier space 52 is formed. Through the air jetting slit 53, curtain-like shaving air SA1 is discharged outside the cover body 31.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a rotary atomizer type atomizer. [Background technology]

[0002] Because strict coating quality is required for painting automobile bodies and automobile parts, rotary atomizer atomizers are used to produce uniform, high-quality coatings. This type of atomizer is equipped with a rotary atomizer head, and is configured to atomize and spray the paint using centrifugal force generated by rotating the rotary atomizer head.

[0003] One prior art rotary atomizer sprayer proposed is one in which numerous grooves are formed on the inner surface of the outer edge of the rotary atomizing head, from which the paint is released in thread-like form, thereby atomizing the paint particles (see, for example, Patent Document 1). The particle size of the paint particles is directly linked to the quality of the paint film, and it is known that using small-diameter paint particles results in a smooth paint film. While the prior art of Patent Document 1 has high coating performance, the rotation speed and air flow rate of the rotary atomizing head are limited, which can result in insufficient atomization performance, and there remains a challenge in improving the quality of the paint film.

[0004] Another prior art technique related to rotary atomizer sprayers is one that aims to promote atomization of paint particles by increasing the impact force by hitting the paint with high-pressure air (shaping air) from the direction opposite to the rotation of the rotary atomizing head (see, for example, Patent Document 2).The sprayer in Patent Document 2 is configured so that a number of inclined grooves are formed in the cover member that surrounds the rotary atomizing head, and shaping air is sprayed through these inclined grooves to act on the paint. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent No. 7028593 [Patent Document 2] Patent No. 5973078 Summary of the Invention [Problem to be solved by the invention]

[0006] However, in the prior art of Patent Document 2, the paint passes through many grooves provided on the inner surface of the outer edge of the rotary atomizing head and is sprayed in the form of threads, and the shaping air also passes through many inclined grooves and is sprayed from many points. When the shaping air is sprayed from many points in this way, paint particles tend to escape through the gaps between adjacent points (i.e., the gaps between adjacent linear shaping air particles). As a result, the paint particles that escape tend to become large in diameter, which leads to a problem of deterioration in the quality of the paint film.

[0007] To prevent paint particles from leaking through the gaps between the shaping air jets, it may be possible to eject a tight curtain of shaping air from a slit-like opening. However, this would likely result in insufficient air pressure, adversely affecting pattern controllability and atomization performance. Furthermore, increasing the air flow rate would reduce economic viability due to factors such as poor coating efficiency.

[0008] The present invention has been made in view of the above-mentioned problems, and its object is to provide a rotary atomizer coater that can maintain high coating performance and ensure coating quality without increasing the rotation speed or air flow rate of the rotary atomizing head. [Means for solving the problem]

[0009] In order to solve the above problems, the invention described in Means 1 is a rotary atomization type sprayer comprising: a sprayer body; a cylindrical member having a rotary atomizing head at its tip for spraying paint and rotated by a drive unit provided in the sprayer body; and a cover body surrounding the cylindrical member from the outer periphery, the cover body having a tip opening into which the cylindrical member can be inserted and which is disposed in close proximity to the outer periphery of the cylindrical member, wherein an air supply passage is formed in the cover body for supplying shaping air from the base end side of the cover body to the vicinity of the tip opening, and the air supply passage extends over the entire circumferential direction of the cylindrical member at the terminal position of the air supply passage. The gist of the rotary atomization coater is that a number of inclined air guiding sections that guide the shaping air in the direction opposite to the rotation direction of the rotary atomizing head are formed on the cover body, a straightening space that communicates with the air supply path via the inclined air guiding sections is formed forward of the inclined air guiding sections and between the cover body and the cylindrical member, and an annular air ejection slit that communicates with the straightening space and that ejects a curtain of shaping air to the outside of the cover body is formed between the tip opening of the cover body and the outer circumferential surface of the cylindrical member.

[0010] Therefore, according to the invention described in Measure 1, the shaping air is guided in the opposite direction to the rotation of the rotary atomizing head by the numerous inclined air guide portions formed on the cover body, allowing it to flow into the rectifying space in a directional manner. Furthermore, as the shaping air passes through the rectifying space, it is rectified into a curtain-like flow, and is then ejected to the outside from the air ejection slit located immediately behind it while maintaining its directional flow. This uniform, gap-free curtain-like shaping air collides with the paint particles emitted from the rotary atomizing head from opposite directions, without any gaps or omissions. This ensures that the paint particles are evenly broken down into fine particles, ensuring efficient and reliable atomization of the paint particles without increasing the rotation speed or air flow rate of the rotary atomizing head.

[0011] The invention described in means 2 is characterized in that in means 1, the cover body is composed of an outer cover and an inner cover, and the air supply path and the inclined air guide portion are formed at the interface between the outer cover and the inner cover.

[0012] The invention described in means 3 is characterized in that, in means 2, the inner cover comprises a cylindrical main body and a tapered portion formed at the tip of the main body, and the inclined air guide portion is an inclined groove formed around the entire outer periphery of the tapered portion.

[0013] The invention described in means 4 is characterized in that, in means 3, the inner cover has a flange portion at the base end of the main body, and the flange portion is joined in a supported state to a support step portion provided on the inner side of the outer cover.

[0014] The invention described in means 5 is based on means 4, and is characterized in that grooves constituting part of the air supply passage are formed radially at a plurality of locations on the flange. [Effects of the Invention]

[0015] As described above in detail, the inventions of claims 1 to 5 provide a rotary atomizer coater that can maintain high coating performance and ensure coating quality without increasing the rotation speed or air flow rate of the rotary atomizing head. [Brief explanation of the drawings]

[0016] [Figure 1] 1 is a schematic diagram showing a rotary atomizer type atomizer according to an embodiment of the present invention; [Figure 2] FIG. 2 is a partially enlarged cross-sectional view showing the tip portion of the rotary atomizer sprayer according to the embodiment. [Figure 3] FIG. 3 is a partially enlarged cross-sectional view showing the shaping air discharge portion of the rotary atomizer sprayer. [Figure 4] FIG. 2 is a perspective view showing an inner cover that constitutes a cover body in the rotary atomizer atomizer. [Figure 5] FIG. 2 is a side view showing an inner cover constituting a cover body of the rotary atomizer sprayer. DETAILED DESCRIPTION OF THE INVENTION

[0017] Hereinafter, one embodiment of the present invention embodied in a rotary atomizer sprayer 1 will be described in detail with reference to FIGS.

[0018] As shown in Figure 1, the rotary atomizer coater 1 of this embodiment is an electrostatic coater for coating objects such as automobile bodies, and is used while supported, for example, on the tip of a robot arm. This rotary atomizer coater 1 is configured to discharge paint filaments from a rotary atomizing head 22 and electrostatically atomize them, forming paint particles (atomized paint) and forming a coating film on the object.

[0019] The rotary atomizer sprayer 1 of this embodiment comprises a sprayer body 11, an air motor 12, a paint cartridge 13, a voltage generator 14, a cylindrical member 21 having a rotary atomizing head 22, a cover body 31, and the like.

[0020] 1, the coater body 11 of this embodiment is composed of a cylindrical first tubular portion 11a and a second tubular portion 11b that branches off from the outer circumferential surface of the first tubular portion 11a and extends obliquely upward. The second tubular portion 11b is connected and supported to the tip of a robot arm.

[0021] A paint cartridge 13 is detachably attached to the base end of the first cylindrical portion 11a of the sprayer main body 11. The paint cartridge 13 is filled with paint. A voltage generator 14 is housed in the second cylindrical portion 11b. The voltage generator 14 generates a negative high voltage for electrostatic painting and applies the negative high voltage to the rotary atomizing head 22. The voltage generator 14 forms an electric field between the grounded workpiece and the rotary atomizing head 22. As a result, the paint filaments are electrostatically atomized, and the charged paint particles are applied to the workpiece. A voltage control unit 18 is electrically connected to the voltage generator 14, and the voltage control unit 18 controls the output voltage of the voltage generator 14. Note that a current control unit, for example, may be provided instead of the voltage control unit 18 to control the output current of the voltage generator 14.

[0022] The air motor 12, which is driven to rotate by supplying pressurized air, is housed in the center of the interior near the tip of the first cylindrical portion 11a. The air motor 12 is a drive unit for driving the cylindrical member 21 to rotate, and has a hollow rotary shaft 16 at one end. A metal feed tube 17, which serves as a paint supply pipe, is disposed inside the rotary shaft 16 and extends along the central axis (see FIG. 2). The feed tube 17 is a member for supplying paint filled in the paint cartridge 13 to the rotary atomizing head 22, and has a nozzle (not shown) at its tip.

[0023] The cylindrical member 21 is connected to the rotary shaft 16 of the air motor 12 so as to be rotatable integrally with it, and is disposed at the tip of the first cylindrical portion 11a. The cylindrical member 21 has a rotary atomizing head 22 (bell cup) at its tip that sprays paint. Here, the term "cylindrical member" in this embodiment is defined broadly to refer to "a rotating body that rotates about the rotary shaft 16, in which the portion corresponding to the outer circumferential surface 21a is circular when cut perpendicular to the rotary shaft 16, and in which at least a portion of the portion corresponding to the outer circumferential surface 21a is parallel to the rotary shaft 16 when cut along the rotary shaft 16." Therefore, the term "cylindrical member" naturally includes, for example, a member having a step on the outer circumferential surface 21a or a member that is relatively short in the direction of the rotary shaft.

[0024] The rotary atomizing head 22 is formed in a cup shape whose diameter expands toward the tip. It is located at the tip-most portion of the first cylindrical portion 11a and on the central axis C1. A circular recess 25 is formed in the center of the rotary atomizing head 22 when viewed from the direction of the central axis C1, and a hub 26 is provided to close the recess 25. The recess 25 and the hub 26 define a paint space S1, and the tip of the feed tube 17 is positioned so as to face the paint space S1. Outlet holes 26a and 26b are formed in the center and outer edge of the hub 26, respectively, for allowing paint to flow out of the paint space S1. The inner surface of the recess 25 of the rotary atomizing head 22 functions as a diffusion surface that diffuses the paint by centrifugal force. This centrifugal force is generated by the rotation of the rotary atomizing head 22 as the air motor 12 rotates. The diffusion surface is formed so that its diameter expands toward the tip. A number of grooves (not shown) are formed in the outer edge 27 of the diffusion surface.

[0025] The numerous grooves on the outer edge 27 of the diffusion surface are provided to release the paint in the form of threads. The grooves are formed to extend in the radial direction, and many of them are formed around the entire circumference of the outer edge 27 of the diffusion surface. There is no particular limit to the number of grooves, but for example, about 600 to 1200 grooves are formed. In addition, there is no particular limit to the cross-sectional shape of the grooves, but for example, they are formed in a V-shape.

[0026] 2 and other figures, the cover body 31, which is a protective member, is a member for surrounding and covering the cylindrical member 21 from the outer peripheral surface 21a side, and is formed in a tapered shape that reduces in diameter toward the tip side. The cover body 31 has a circular tip opening 31a, into which the cylindrical member 21 can be inserted. At this time, the tip opening 31a is positioned close to the outer peripheral surface 21a of the cylindrical member 21.

[0027] 2, the cover body 31 of this embodiment is basically composed of an outer cover 32 and an inner cover 33. The outer cover 32 is a member that is exposed to the outside, and the inner cover 33 is a member that is disposed inside the outer cover 32 and is therefore not exposed to the outside.

[0028] The outer cover 32 has a base end 32a and a tip end 32b. The tip end 32b is thin and tapered. A first support step 34 and a second support step 35 are formed on the inner surface of the base end 32a. A connecting block 36 is supported on the first support step 34. The connecting block 36 connects and fixes the outer cover 32 (cover body 31) to the first cylindrical portion 11a of the sprayer body 11. Body-side air supply passages 37 for supplying shaping air to the cover body 31 are formed through the connecting block 36 at multiple locations. These body-side air supply passages 37 are connected to an air supply source (not shown) located outside the rotary atomizer sprayer 1. The body-side air supply passages 37 are also connected to an internal space 38 defined by the outer cover 32, the inner cover 33, and the connecting block 36. The internal space 38 is a continuous annular space that is formed to surround the entire periphery of the base end side of the inner cover 33 .

[0029] 2 and 3, the inner cover 33 includes a cylindrical main body 41, a tapered portion 42 formed at the tip end of the main body 41, and a flange portion 43 formed at the base end of the main body 41. The inner cover 33 is disposed on the inner circumferential side of the outer cover 32, and is attached with the flange portion 43 supported by the second support step 35 of the outer cover 32. Bolt insertion holes 45 are formed at multiple locations in the flange portion 43. The inner cover 33 is joined and fixed to the outer cover 32 by inserting bolts 47 into the bolt insertion holes 45 and screwing the bolts 47 into the bolt holes 39 on the second step 35 side.

[0030] 2 and 3, a cover body side air supply passage 51 is formed inside the cover body 31. The cover body side air supply passage 51 is a flow path for supplying high-pressure shaping air from the base end side of the cover body 31 to the vicinity of the tip opening 31a. Specifically, in this embodiment, the cover body side air supply passage 51 is formed at the interface between the outer cover 32 and the inner cover 33.

[0031] Grooves 46 that form part of the cover body side air supply passage 51 are formed radially at multiple locations on the flange portion 43 of the inner cover 33. These grooves 46 are formed by cutting out a generally L-shape and are arranged around the entire periphery on the front side of the flange portion 43. The number of grooves 46 is not particularly limited, but it is preferable that the number of grooves 46 is greater than the number of bolt insertion holes 45. In this embodiment, for example, the bolt insertion holes 45 are formed in five locations, while the grooves 46 are formed in 20 or more locations.

[0032] The cover body 31 is formed with a number of inclined grooves 44 as a number of inclined air guide portions 44. Specifically, in this embodiment, the inclined grooves 44 are formed on the outer peripheral surface of the tapered portion 42 of the inner cover 33, along the entire circumference of the tapered portion 42. That is, the inclined grooves 44 are formed at the interface between the outer cover 32 and the inner cover 33. The inclined grooves 44 are located at the terminal positions of the cover body-side air supply passages 51 and are arranged along the entire circumferential direction of the outer peripheral surface 21a of the cylindrical member 21. As shown in FIG. 5, the inclined grooves 44 are inclined with respect to the direction in which the central axis C1 extends. The inclination angle of the inclined grooves 44 is not particularly limited, but is set to, for example, approximately 30° to 60° in this embodiment. Furthermore, the inclined grooves 44 are inclined in the direction D2 opposite to the rotational direction D1 of the rotary atomizing head 22, and thus guide the shaping air in the opposite direction D2. That is, the numerous inclined grooves 44 impart flow directionality to the shaping air passing therethrough.

[0033] A rectifying space 52 is formed between the cover body 31 and the cylindrical member 21 and forward of the inclined groove 44. The rectifying space 52 is connected to the cover body side air supply path 51 via the inclined groove 44. The shaping air supplied from the cover body side air supply path 51 flows into the rectifying space 52 in a directional manner. The rectifying space 52 rectifies the shaping air passing therethrough, forming a curtain-like flow. Note that the rectifying space 52 in this embodiment is annular so as to continuously surround the entire outer circumferential surface 21a of the cylindrical member 21. The maximum width of the rectifying space 52 is slightly larger than the width of the cover body side air supply path 51 at the end position, specifically set to approximately 1.1 to 3.0 times (see FIG. 3 ). When the maximum width of the rectifying space 52 is within the above range, the desired, favorable rectifying effect is easily achieved. The width of the cover-body-side air supply passage 51 at its termination point refers to the width of the gap between the inner circumferential surface of the outer cover 32 and the outer circumferential surface of the tapered portion 42 of the inner cover 33 in FIG. 3 . The width of the rectifying space 52 refers to the width of the gap between the inner circumferential surface of the outer cover 32 and the outer circumferential surface 21a of the cylindrical member 21 in FIG. 3 . The width of the rectifying space 52 is largest at the base end adjacent to the numerous inclined grooves 44, gradually decreases from the base end toward the tip end, and is smallest at the tip end adjacent to the air ejection slit 53. Furthermore, the portion of the inner circumferential surface of the outer cover 32 facing the rectifying space 52 is a smooth surface with almost no irregularities. This configuration ensures that the airflow is rectified while reliably maintaining directionality, and the shaping air curtain formed therefrom is easily introduced into the air ejection slit 53. Furthermore, the length of the rectifying space 52 is not particularly limited, but is formed, for example, to be slightly longer (about 1.5 to 5 times) than the length of the air ejection slit 53. Moreover, the length of the rectifying space 52 is formed, for example, to be somewhat shorter (about 0.2 to 0.7 times) than the length of the tapered portion 42.

[0034] An annular air ejection slit 53 is formed between the tip opening 31a of the outer cover 32 constituting the cover body 31 and the outer peripheral surface 21a of the cylindrical member 21. The air ejection slit 53 communicates with the rectifying space 52 and ejects directional curtain-like shaping air to the outside of the cover body 31.

[0035] Next, the operation of the rotary atomizer type atomizer 1 of this embodiment will be described. During painting, first, a negative high voltage is applied to the rotary atomizing head 22 by the voltage generator 14, while the object to be coated is grounded. This creates an electric field between the rotary atomizing head 22 and the object to be coated. Then, the air motor 12 is driven to rotate the rotary atomizing head 22 at high speed.

[0036] Next, the paint filled in the paint cartridge 13 is supplied to the rotary atomizing head 22 through the feed tube 17. At this time, the liquid paint is discharged from the nozzle of the feed tube 17, thereby supplying the paint into the paint space S1. The paint supplied into the paint space S1 flows out through the outlet holes 26a, 26b toward the diffusion surface due to the action of centrifugal force.

[0037] The paint that reaches the diffusion surface flows radially outward along the diffusion surface due to the action of centrifugal force. As it does so, the paint forms a film and is supplied to the numerous grooves formed in the outer edge 27. At the outer edge 27, the paint does not overflow from the grooves, and the paint in each groove is separated from the paint in the adjacent grooves. In other words, the film-like paint is divided by the grooves. The centrifugal force makes the thickness of the film-like paint uniform, and the paint is supplied to each groove almost evenly. The paint then forms threads as it passes through the grooves, and is discharged from the outer edge 27 of the rotary atomizing head 22 in a twisted state in the rotation direction D1 of the rotary atomizing head 22 (see FIG. 4). In FIG. 3, the arrow TR1 indicates the flow of the paint that flows along the rotary atomizing head 22 and is then discharged.

[0038] When supplying paint as described above, shaping air is also supplied to the cover body 31 side. In Figure 3, the flow of shaping air is indicated by arrow SA1. The shaping air that flows from the main body side air supply passage 37 into the internal space 38 flows through multiple grooves 46 into the cover body side air supply passage 51 formed at the interface between the outer cover 32 and the inner cover 33. The multiple grooves 46 are provided around the entire circumference of the flange portion 43. Therefore, even if the flange portion 43 is bolted to the second support step 35 in surface contact with the flange portion 43, the shaping air can flow centripetally and evenly into the cover body side air supply passage 51 from the entire circumference of the flange portion 43.

[0039] Furthermore, the shaping air that has flowed into the cover body side air supply passage 51 flows from the base end side to the tip end side while being guided along the outer circumferential surface of the main body 41. In other words, from a relatively early stage (in other words, when it reaches the base end of the inner cover 33), the shaping air flows in the direction along the central axis C1 (i.e., linearly) in close proximity to the outer circumferential surface 21a of the cylindrical member 21, separating it from the main body 41.

[0040] The shaping air that has reached the terminal position of the cover-side air supply passage 51 passes through the numerous inclined grooves 44 and is guided in the direction D2 opposite to the rotation direction D1 of the rotary atomizing head 22, before flowing into the rectifying space 52. The tapered portion 42 has an extremely small taper angle, set to approximately 10° to 20°, allowing the shaping air to flow smoothly into the rectifying space 52 with almost no change in its direction of travel (in other words, without any disturbance to the flow). The shaping air that has flowed into the rectifying space 52 in a directional state is rectified as it passes through the rectifying space 52, forming a curtain-like flow before reaching the air ejection slit 53. The shaping air that has passed through the air ejection slit 53 is then discharged to the outside of the cover body 31 as a directional curtain-like shaping air. The air ejection slit 53 is disposed in close contact with the outer peripheral surface 21a of the cylindrical member 21, and is also disposed extremely close (for example, 1 to 5 mm away) to the tip of the outer edge 27 of the rotary atomizing head 22. Therefore, the high-pressure curtain-like shaping air discharged to the outside collides with the thread-like paint flow TR1 discharged from the rotary atomizing head 22 before it attenuates. As a result, the paint particles further atomized by the action of the curtain-like shaping air form a coating film on the surface of the object to be coated.

[0041] Therefore, according to this embodiment, the following effects can be obtained.

[0042] (1) In the rotary atomizer sprayer 1 of this embodiment, the components for supplying and discharging shaping air are formed in this order: an air supply passage 51, multiple inclined grooves 44, a flow straightening space 52, and an annular air ejection slit 53. That is, the cover body side air supply passage 51, which is an air supply passage, is formed in the cover body 31 to supply shaping air from the base end side of the cover body 31 to the vicinity of the tip end opening 31a. The multiple inclined grooves 44 are formed in the cover body 31 at the terminal position of the cover body side air supply passage 51 so as to extend over the entire circumferential direction of the cylindrical member 21. The multiple inclined grooves 44 guide shaping air in a direction D2 opposite to the rotation direction D1 of the rotary atomizing head 22. The flow straightening space 52 is formed forward of the inclined grooves 44 and between the cover body 31 and the cylindrical member 21, and is in communication with the cover body side air supply passage 51 via the inclined grooves 44. The air ejection slit 53 is located between the tip opening 31a of the cover body 31 and the outer circumferential surface 21a of the cylindrical member 21, and communicates with the rectifying space 52. The air ejection slit 53 ejects a curtain of shaping air to the outside of the cover body 31.

[0043] With this configuration, a curtain of shaping air, directed in the direction D2 opposite the rotation direction D1 of the rotary atomizing head 22, is ejected from the air ejection slit 53 to the outside while maintaining this directionality. This uniform, gap-free curtain of shaping air collides with paint particles ejected from the rotary atomizing head 22 from opposing directions, without any gaps or omissions. This uniform, gap-free curtain of shaping air uniformly breaks up paint particles into fine particles. Therefore, paint particles are efficiently and reliably atomized without increasing the rotation speed or air flow rate of the rotary atomizing head 22. This allows for high coating performance and ensures high coating quality. Furthermore, since there is no need to increase the air flow rate to obtain a curtain of shaping air, economic efficiency is not compromised due to factors such as poor coating efficiency. Furthermore, there is no need to worry about insufficient air pressure, which does not adversely affect pattern controllability or atomization performance.

[0044] (2) The cover body 31 of this embodiment is configured to include an outer cover 32 and an inner cover 33, and the cover body side air supply passage 51 and the numerous inclined grooves 44 are formed at the interface between the outer cover 32 and the inner cover 33. With this configuration, for example, the cover body side air supply passage 51 can be formed without drilling, and the numerous inclined grooves 44 can be formed finely and accurately. This makes it possible to reduce the processing cost of the cover body 31, making it easier to achieve cost reductions for the entire device.

[0045] (3) The inner cover 33 constituting the cover body 31 of this embodiment includes a cylindrical main body 41 and a tapered portion 42 formed at the tip of the main body 41. The inclined grooves 44 are formed around the entire outer circumferential surface of the tapered portion 42. Therefore, the directional shaping air can be smoothly and evenly introduced into the rectifying space 52 around the entire circumference. The inner cover 33 also includes a flange portion 43 at the base end of the main body 41. The flange portion 43 is supported and joined to the second support step 35 provided on the inner circumferential side of the outer cover 32. Additionally, multiple grooves 46 are provided around the entire circumference of the flange portion 43. Therefore, the inner cover 33 can be joined and fixed to the outer cover 32 relatively easily and reliably, and the shaping air can be introduced into the cover body-side air supply passage 51 in an optimal state via the joint interface between the inner cover 33 and the outer cover 32 around the entire circumference of the flange portion 43. Therefore, the above configuration has the advantage of making it easier to obtain a desired curtain-like shaping air.

[0046] Each embodiment of the present invention may be modified as follows.

[0047] In the above embodiment, the multiple inclined grooves 44 (multiple inclined air guide portions) are formed on the outer peripheral surface of the inner cover 33. However, this is not limiting. In another embodiment, the multiple inclined grooves 44 (multiple inclined air guide portions) may be formed on the inner peripheral surface of the outer cover 32.

[0048] In the above embodiment, the cover body 31 is composed of two members, the outer cover 32 and the inner cover 33, and the cover body side air supply passage 51 and the numerous inclined grooves 44 (numerous inclined air guide portions) are formed in one of the two members, but this is not limited to this. In another embodiment, the cover body 31 may be composed of a single member, and the cover body side air supply passage 51 and the numerous inclined grooves 44 (numerous inclined air guide portions) may be formed in that member by drilling holes or grooves, etc. It is also possible to compose the cover body 31 of three or more members.

[0049] In the above embodiment, the rotary atomizer sprayer 1 of the present invention is embodied as an electrostatic sprayer, but is not limited to this. In another embodiment, it may be embodied as a sprayer that does not perform electrostatic painting. Furthermore, the paint used in the rotary atomizer sprayer 1 of the present invention is not particularly limited, and may be, for example, a water-based paint or a solvent-based paint.

[0050] In the above embodiment, the multiple inclined grooves 44 (multiple inclined air guide portions) are formed continuously around the entire outer periphery of the tapered portion 42. However, this is not limited to this. In another embodiment, the multiple inclined grooves 44 (multiple inclined air guide portions) may be formed discontinuously at multiple locations on the outer periphery of the tapered portion 42.

[0051] In the above embodiment, the inner cover 33 is provided with a flange portion 43, and the flange portion 43 is supported on the second support step portion 35 of the outer cover 32 and joined and fixed with the bolts 47, but this is not limiting. In another embodiment, the inner cover 33 may be joined and fixed by means other than the bolts 47. Alternatively, a portion other than the flange portion 43 may be joined and fixed to the outer cover 32.

[0052] In the above embodiment, the grooves 46 constituting part of the cover body side air supply passage 51 are formed radially at a plurality of locations on the flange 43. However, this is not limiting. In another embodiment, communication holes may be formed in the flange 43 instead of the grooves 46.

[0053] 1: Rotating atomizing paint machine 11: Sprayer body 12: Air motor as a drive unit 21: Cylindrical member 21a: (cylindrical member) outer surface 22: Rotating atomization head 31: Cover body 31a: Tip opening 32: Outer cover 33: Inner cover 35: Second support step as support step 41: Main body 42: Tapered section 43: Flange 44: Inclined groove as an inclined air guide 46: Groove 51: Air supply path on the cover body side 52: Rectification space 53: Air ejection slit D1: Rotation direction of the rotary atomizing head D2: opposite direction SA1: Curtain-like shaping air flow TR1: Paint flow

Claims

1. The paint sprayer body and a cylindrical member having a rotary atomizing head at its tip for spraying paint, the cylindrical member being rotationally driven by a drive unit provided within the coating machine body; a cover body that has a tip opening into which the cylindrical member can be inserted and that is disposed close to the outer circumferential surface of the cylindrical member, and that surrounds the cylindrical member from the outer circumferential side; A rotary atomizer type coating machine comprising: an air supply passage for supplying shaping air from the base end side of the cover body to the vicinity of the tip opening is formed in the cover body; a plurality of inclined air guide portions are formed on the cover body at the terminal position of the air supply passage so as to extend over the entire circumferential direction of the cylindrical member, the inclined air guide portions guiding the shaping air in a direction opposite to the rotation direction of the rotary atomizing head; a rectifying space communicating with the air supply path via the inclined air guide portion is formed at a position forward of the inclined air guide portion and between the cover body and the cylindrical member, An annular air ejection slit is formed between the tip opening of the cover body and the outer circumferential surface of the cylindrical member, the air ejection slit communicates with the rectifying space, and ejects a curtain of shaping air to the outside of the cover body. A rotary atomizer coating machine characterized by:

2. 2. The rotary atomizer according to claim 1, wherein the cover body includes an outer cover and an inner cover, and the air supply passage and the inclined air guide portion are formed at an interface between the outer cover and the inner cover.

3. 3. The rotary atomizer according to claim 2, wherein the inner cover comprises a cylindrical main body and a tapered portion formed at the tip of the main body, and the inclined air guide is an inclined groove formed around the entire outer periphery of the tapered portion.

4. 4. The rotary atomizer according to claim 3, wherein the inner cover has a flange portion at a base end of the main body, and the flange portion is joined to and supported by a support step portion provided on the inner periphery of the outer cover.

5. 5. The rotary atomizer according to claim 4, wherein grooves constituting part of the air supply passage are formed radially at a plurality of locations on the flange.

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