JPH08108103A - Rotational spray head type coating apparatus - Google Patents

Abstract

PURPOSE: To improve finishing by adjusting a spray pattern of a coating to a required size (dimension) and dispersing uniformly coating particles. CONSTITUTION: An air passage 13A for shaping air and an air passage 13B for control air are formed on a cover 13 of a spraying machine main body 1 and they are connected with an air source 22 through air pipelines 25 and 26 and pressure-control valves 23 and 24. Further, the first and second air nozzles 15, 16 are provided on the apex side of the cover 13 in such a way that a rotational spray head 11 is surrounded thereby at the rear side of the coating releasing terminal edge 11C of the rotational spray head 11. Then, shaping air under a swirling flow condition is sprayed from a ring-shaped swirl chamber 19 formed between the first air nozzle 15 and the second air nozzle 16 through a ring-shaped air spray hole 20 to obtain a coating spray pattern (size) corresponding to the swirling flow condition.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotary atomizing head type coating device used as an electrostatic coating device by, for example, a direct charging system or an indirect charging system.

[0002]

2. Description of the Related Art Generally, a rotary atomizing head type electrostatic coating device is
The rotating atomizing head is rotated at a high speed, a high voltage is applied between the rotating atomizing head and the object to be coated, and the paint supplied to the smooth surface of the coating of the rotating atomizing head is rotationally atomized. The particles are directed toward the object to be coated axially forward and fly-coated along the electrostatic field between the particles and the object to be coated.

A direct charging type electrostatic coating device will be described as an example of a rotary atomizing head type electrostatic coating device according to this type of prior art with reference to FIG.

In the figure, reference numeral 1 denotes a main body of a coating machine which constitutes a main body of an electrostatic coating apparatus. The main body 1 of the coating machine has an air bearing 2, an air motor 3 as a rotation source, a paint valve (not shown) and the like. However, it is configured to be moved relative to the object to be coated by a reciprocator (neither is shown) or the like.

Reference numeral 4 denotes a rotary shaft which is rotatably supported by the air bearing 2. The rotary shaft 4 has a tip end side protruding outside the main body 1 of the coating machine, and a rotary atomizing head 5 to be described later is attached to the base end thereof. The side is attached to the air motor 3. And the rotating shaft 4
Is rotationally driven by the air motor 3 to rotate the rotary atomizing head 5 at high speed.

Reference numeral 5 denotes a bell-shaped rotary atomizing head provided on the tip side of the rotary shaft 4. The rotary atomizing head 5 is formed in a tubular shape or a cup shape as a whole, and the base end side thereof is the rotary shaft 4. It is fixed to the tip end side by using a means such as a screw. And
An outer peripheral surface 5A of the rotary atomizing head 5 has a conical shape, an inner peripheral surface thereof is a paint smoothing surface 5B, and a tip end side thereof is a paint discharge edge 5
It is C.

Reference numeral 6 denotes a center-feed type paint supply pipe inserted through the rotary shaft 4. The paint supply pipe 6 is provided in the main body 1 of the coater so as to extend in the axial direction, and its tip is rotary atomized. It extends into the head 5. The paint valve is provided on the base end side of the paint supply pipe 6, and the paint valve is connected to a paint tank (neither is shown) via the paint pipe.

Reference numeral 7 denotes a cover of the main body 1 of the coating machine. The cover 7 is formed of an insulating resin material in a cylindrical shape and covers the outer peripheral side of the main body 1 of the coating machine to protect the main body 1 of the coating machine. Has become.

Reference numeral 8 denotes a shaping air ring located on the tip side of the main body 1 of the coating machine and fixed to the tip of the cover 7. The shaping air ring 8 is located behind the paint discharge edge 5C of the rotary atomizing head 5. The outer ring portion 8A and the inner ring portion 8B, which are located on the side and surround the rotary atomizing head 5 from the outside in the radial direction, have a double structure. An air ejection port 8C is formed between the outer ring portion 8A and the inner ring portion 8B on the tip side of the shaping air ring 8, and the air ejection port 8C is the paint ejection edge 5C of the rotary atomizing head 5. Shaping air is ejected in the direction of arrow A (straight line) toward the surroundings.

Reference numeral 9 denotes a high-voltage cable arranged on the base end side of the coating machine main body 1. The high-voltage cable 9 is connected to a high-voltage generator (not shown) installed outside the coating machine main body 1. The high voltage from the high voltage generator is applied to the coating machine main body 1.

In the electrostatic coating device thus constructed,
By applying a high voltage to the coating machine main body 1 via the high-voltage cable 9, the rotary shaft 4 and the rotary atomizing head 5 are charged to a high voltage, and the rotary atomizing head 5 and the object to be coated are charged. Form an electrostatic field. Then, the rotary shaft 4 and the rotary atomizing head 5 are rotated at high speed by the air motor 3 in the main body 1 of the coating machine, and the paint valve is opened in this state, so that the rotary atomizing head 5 is passed through the paint supply pipe 6. Supply paint to.

Here, the coating material supplied to the rotary atomizing head 5 is directly contact-charged while being spread as a thin film on the coating smooth surface 5B by the centrifugal force generated by the rotation of the rotary atomizing head 5. An electrostatic field is formed between the paint discharge edge 5C of the rotary atomizing head 5 and the object to be coated.

Then, the coating material that is ejected radially outward from the coating material discharge edge 5C by the centrifugal force of the rotary atomizing head 5 is divided (separated) from the film shape to the liquid thread shape, and is further finely divided from the liquid thread shape into particles. Be converted (mechanical atomization). In addition, since the coating material charged to a high voltage has a reduced surface tension and is charged with the same sign (positive or negative), the particles repel each other to promote atomization (electrostatic discharge). Atomization). Then, the paint particles atomized (atomized) in this way fly toward the object to be coated along the electrostatic field and adhere to the object to be coated.

By the way, the paint discharge edge 5 of the rotary atomizing head 5
The paint particles discharged from C are blown outward in the radial direction by the centrifugal force from the rotary atomizing head 5 rotating at a high speed, and the spray pattern of the paint tends to spread greatly.

Therefore, by spraying shaping air from the air outlet 8C of the shaping air ring 8 in the direction of arrow A, the paint particles discharged from the paint discharge edge 5C of the rotary atomizing head 5 are rotary atomized. The pattern is formed so as to be narrowed down toward the front of the head 5, so that a paint spray pattern having a small diameter in the direction of the arrow B is obtained as shown by the solid line in FIG.

[0016]

However, in the above-mentioned conventional technique, the air ejection port 8C of the shaping air ring 8 is used.
Since the shaping air is merely ejected in the direction of the arrow A toward the periphery of the rotary atomizing head 5, the shaping air pressure is increased so as to improve the finish (gloss) of, for example, metallic coating. Then, the spray pattern of the paint becomes small, which causes a problem such as uneven color due to insufficient number of times of coating.

For this reason, in the prior art, it is necessary to reduce the conveyor speed in the painting process such as metallic painting or to make the movement of the reciprocator finer to speed up, which not only increases the painting time and cost but also makes it practical. However, in the finishing process such as metallic coating, it is the actual situation that special measures such as using a "gun type" coating machine consisting of nozzle tips are taken.

The present invention has been made in view of the above-mentioned problems of the prior art, and the present invention can easily adjust the spray pattern of the paint to a desired size (size) and uniformly disperse the paint particles to obtain a finish. It is an object of the present invention to provide a rotary atomizing head type coating device which can be improved.

[0019]

In order to solve the above-mentioned problems, the invention according to claim 1 is such that a coating machine main body having a rotation source and a tip end side of the coating machine body are rotatably provided. A rotary atomizing head formed in a tubular shape or a cup shape so that the side thereof serves as a paint discharge edge, a first air jetting means for jetting shaping air in the axial direction of the rotary atomizing head, and the first air jetting means. The second air jetting means for jetting the control air for the swirling flow is adopted so that the shaping air by the first air jetting means is jetted in the swirling flow state around the rotary atomizing head.

In this case, as in the invention described in claim 2,
The first air ejecting means includes a first air pressure control means for adjusting the air pressure of the shaping air between the first air ejecting means and the air source, and the second air ejecting means for controlling the control air between the second air ejecting means and the air source. It is preferable that the second air pressure control means for adjusting the air pressure is used.

Further, according to a third aspect of the present invention, the second air jetting means gives a swirling flow to the shaping air in a direction opposite to the rotation direction of the rotary atomizing head. It is preferable that the control air is ejected.

Further, as in the invention described in claim 4,
The second air jetting means may jet the control air so as to give a swirling flow to the shaping air that is a forward direction with respect to the rotation direction of the rotary atomizing head.

Further, as in the invention described in claim 5, on the tip side of the main body of the coating machine, the rotary atomizing head is positioned rearward of the paint discharge edge of the rotary atomizing head. A ring-shaped first air nozzle that surrounds the outer peripheral side, and a ring that configures an annular swirl chamber between the first air nozzle and the first air ejection unit that ejects the shaping air. -Shaped second air nozzle is provided, and a plurality of air ejection holes for ejecting the control air in a substantially tangential direction toward the inside of the swirl chamber are formed in the second air nozzle. You may make it comprise the 2 air ejection means.

[0024]

With the above construction, in the invention described in claim 1,
With the control air ejected from the second air ejecting means, the swirling flow state of the shaping air by the first air ejecting means can be easily adjusted, and the paint spray pattern can be changed to a desired size (size). Become.

In this case, as in the second aspect of the invention, the air pressure of the shaping air is adjusted by the first air pressure control means, and the air pressure of the control air is adjusted by the second air pressure control means. By adjusting the pressure adjustment, the air pressure of the shaping air and the air pressure of the control air can be adjusted independently and independently.
For example, by increasing the air pressure of control air,
The spray pattern of the paint can be widened, and the spray pattern suitable for various paints can be obtained.

Further, as in the invention described in claim 3 or 4, the control air from the second air jetting means causes a swirling flow which is in a reverse direction or a forward direction with respect to a rotating direction of the rotary atomizing head. Can be given to the shaping air, and the spray pattern of the paint can be finely adjusted according to the ejection direction of the control air.

Further, as in the invention described in claim 5,
Ring-shaped first and second air nozzles are provided on the front end side of the coating machine body, the ring-shaped first and second air nozzles being located rearward of the paint discharge edge of the rotary atomizing head and surrounding the outer peripheral side of the rotary atomizing head. An annular swirl chamber is defined between the first and second air nozzles, and a plurality of air ejection holes for ejecting the control air in a substantially tangential direction toward the inside of the swirl chamber are formed in the second air nozzle. As a result, the swirling flow can be surely given to the shaping air in the swirl chamber, and the shaping air can be jetted in the swirling flow state from the inside of the swirl chamber toward the periphery of the rotary atomizing head.

[0028]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the present invention will be described below with reference to FIGS. In the embodiment, the same components as those of the conventional technique shown in FIG. 7 described above are designated by the same reference numerals, and the description thereof will be omitted.

In the figure, reference numeral 11 denotes a rotary atomizing head provided by being screwed to the tip side of the rotary shaft 4, and the rotary atomizing head 11 is substantially the same as the rotary atomizing head 5 described in the prior art. Outer peripheral surface 11A,
It has a paint smooth surface 11B on the inner peripheral side and a paint discharge edge 11C on the front end side, and rotates at a high speed in the direction of arrow C about the axis O-O shown in FIG. 4, for example.

Reference numeral 12 denotes a disk-shaped hub member disposed on the bottom side of the rotary atomizing head 11, and the hub member 12 is provided with paint and thinner on the outer peripheral side thereof and the rotary atomizing head 11 is provided therewith. Of the first hub holes 12A, 12A leading to the paint smooth surface 11B of
… And the second, which is located on the center side and supplies thinner to the tip side
And a plurality of hub holes 12B, 12B, ... Are formed in concentric circles.

Reference numeral 13 denotes a cover of the coating machine main body 1. The cover 13 is formed of an insulating resin material in a cylindrical shape and covers the outer peripheral side of the coating machine main body 1 to protect the coating machine main body 1. Has become. Further, an air passage 13A for shaping air and an air passage 13B for control air are formed in the cover 13, and an air passage 13A located on the inner circumference of the tip side of the cover 13 between the air passage 13A and the main body 1 of the coating machine. 13C of annular air reservoirs communicating with the air nozzle 1 described later.
13D for fixing 5 etc. to the body 1 side of the coating machine
And are formed.

Reference numeral 14 denotes a retainer ring screwed to the threaded portion 13D of the cover 13, and the retainer ring 14 positions the cover 13 on the main body 1 of the coating machine and defines an air reservoir 13C in the cover 13. . Further, the retainer ring 14 has a plurality of ventilation holes 14 at regular intervals in the circumferential direction.
A is provided in the axial direction, and each of the ventilation holes 14A has an air reservoir 1
The shaping air in 3C is circulated toward the air nozzle 15 side.

Reference numeral 15 denotes a first air nozzle which is screwed to the screw portion 13D of the cover 13 and is positioned at the tip side of the main body 1 of the coating machine. The air nozzle 15 is, as shown in FIGS. Male thread 15A screwed to the threaded portion 13D of the nozzle is formed on the outer peripheral side, and a flange section 15D is formed on the outer peripheral side with a threaded portion 15C protruding radially outward from the nozzle cylindrical section 15B. And a cylindrical projection 15F that projects forward from the nozzle cylinder 15B and has a spray end edge 15E that expands in diameter in a tapered shape on the tip side, and a coating machine body 1 that projects radially inward from the nozzle cylinder 15B.
And an annular portion 15G that abuts on the front end face of the.

Here, a plurality of vent holes 15H are formed in the annular portion 15G of the air nozzle 15 at regular intervals in the circumferential direction, and each vent hole 15H requires exhaust from the air bearing 2 (see FIG. 7). According to the outer peripheral surface 11A of the rotary atomizing head 11
It is configured to eject to the side. Also, the air nozzle 1
5, an annular recess 15J is formed between the flange 15D and the cylindrical protrusion 15F in the nozzle cylinder 15B, and the annular recess 15J is detachably engaged with an end 16A of the second air nozzle 16 described later. The second air nozzle 16 is then positioned.

Further, the nozzle tube portion 15 of the air nozzle 15
In B, a plurality (for example, 12
... 36) nozzle holes 15K, 15K, ... Are bored in the axial direction, and the tip side of each nozzle hole 15K is a small-diameter air ejection hole 15L communicating with a swirl chamber 19 described later. The base end of each nozzle hole 15K communicates with the air reservoir 13C via each ventilation hole 14A of the retainer ring 14, and shaping air from the air reservoir 13C is axially fed from each air ejection hole 15L into the swirl chamber 19. Eject in the direction.

Reference numeral 16 denotes a second air nozzle which constitutes the first air jetting means together with the first air nozzle 15, and the second air nozzle 16 is formed in a symmetrical stepped tubular shape as shown in FIGS. Left and right ends 16A, 16
In A, the ejection end edges 16B, 1 which taper to the inner peripheral side are formed
6B is integrally formed. In addition, the second air nozzle 16
A pair of left and right annular flange portions 16C, 16C protruding outward in the radial direction are formed on the outer peripheral side of each of the annular flange portions 16C, and an annular air chamber 17 is defined between the annular flange portion 16C and a retainer cylinder 21 to be described later. Is made. Then, the air chamber 17 includes the second air nozzle 1
6 through the annular flange portion 16C and the air passage 18 formed in the flange portion 15D of the first air nozzle 15 and the like, and communicates with the air passage 13B of the cover 13, and these air passages 13B and 18 are provided in the air chamber 17. Control air is supplied via.

Here, the second air nozzle 16 is located between the annular flanges 16C, and is provided with, for example, three rows in the axial direction and is obliquely drilled at regular intervals in the circumferential direction (for example, at intervals of about 60 degrees). A plurality of (for example, a total of 18) air ejection holes 16D, 16D, ... Are provided, and each air ejection hole 1 is formed.
6D constitutes the second air ejection means together with the air chamber 17 and the like. Each of the air ejection holes 16D ejects the control air from the air chamber 17 toward the swirl chamber 19 in a substantially tangential direction (the direction of the arrow D shown in FIG. 3), and the control air is generated in the swirl chamber 19. , Swirl is generated in the shaping air introduced from each air ejection hole 15L.

Reference numeral 19 denotes a cylindrical protruding portion 1 of the first air nozzle 15.
5F shows a swirl chamber defined between the 5F and the second air nozzle 16, the swirl chamber 19 being located rearward of the paint discharge edge 11C of the rotary atomizing head 11 and having an outer periphery of the rotary atomizing head 11. It is formed as an annular air chamber surrounding the side so as to extend relatively long in the axial direction. The tip end side of the swirl chamber 19 has a jetting edge 15E of the first air nozzle 15 and a jetting edge 16B of the second air nozzle 16.
An annular air ejection port 20 is formed between the air ejection ports 20, and the shaping air swirled by the control air is ejected as a swirling flow in the direction of arrow E as shown in FIG.

Here, as shown in FIG. 2, the annular air ejection port 20 is separated from the paint discharge end edge 11C of the rotary atomizing head 11 by a fixed dimension L (for example, about 2 to 3 mm) radially outward. The shaping air in a swirling flow state is ejected toward the periphery of the rotary atomizing head 11. When the shaping air is ejected as a swirling flow in the E direction indicated by the arrow, the swirling direction of the shaping air (E direction indicated by the arrow)
And the direction of rotation of the rotary atomizing head 11 (the direction of arrow C) are opposite to each other, and the centrifugal force of the rotary atomizing head 11 causes the paint discharge edge 1 to move.
The shaping air can be made to strongly collide in the opposite direction with respect to the coating material that is projected radially outward from 1C.

The second air nozzle 16 has a bilaterally symmetrical shape, and has tapered ejection edges 16B and 16B formed at the end portions 16A at both ends, respectively.
When one end 16A of A is engaged with the annular recess 15J of the first air nozzle 15 to integrate the air nozzles 15 and 16, the air ejection holes 16D are directed into the swirl chamber 19 in the direction of the arrow D ( The control air can be ejected in a substantially tangential direction to give the shaping air a swirling flow in the direction of arrow E (see FIG. 4).

Further, each end portion 16A of the second air nozzle 16 is
When the other end 16A is engaged with the annular recess 15J of the first air nozzle 15 to integrate the air nozzles 15 and 16, the air ejection holes 16 shown by phantom lines in FIG.
Control air is ejected from D toward the inside of the swirl chamber 19 in a direction (substantially tangential direction) opposite to the D direction indicated by the arrow,
The shaping air can be provided with a swirling flow in the direction opposite to the arrow E direction (forward direction with respect to the rotation direction of the rotary atomizing head 11).

Next, reference numeral 21 denotes a retainer tube for fixing the second air nozzle 16 to the first air nozzle 15. The retainer tube 21 is formed in a stepped tube shape, and the tip end side thereof projects inward in the radial direction. An annular engaging portion 21A that engages with the annular flange portion 16C of the two-air nozzle 16 is integrally formed. The retainer cylinder 21 has a proximal end side screwed into the male screw portion 15C of the first air nozzle 15, and the second air nozzle 16 having the end portion 16A fitted in the annular recess 15J of the first air nozzle 15.
Is detachably positioned with respect to the first air nozzle 15 by an annular engaging portion 21A and the like.

Reference numeral 22 denotes an air source including an air pump and the like, 2
3 and 24 refer to the air source 22 for the air passages 13A and 13B.
The first and second pressure regulating valves provided in the middle of the air pipelines 25 and 26 connected to the
Reference numeral 24 is an electromagnetic proportional pressure reducing valve or the like, and constitutes first and second air pressure control means. Then, the first pressure regulating valve 2
3 regulates the air pressure of shaping air supplied into the air passage 13 A of the cover 13 via the air duct 25 to an arbitrary pressure, and the second pressure regulating valve 24 controls the air passage 13 of the cover 13.
The air pressure of the control air supplied into B through the air conduit 26 is adjusted to an arbitrary pressure.

That is, these pressure control valves 23 and 24 are variably controlled in their set pressures in accordance with control signals output from an external controller (not shown), and the air pressure of the shaping air and the control air are controlled. The air pressure and the first air nozzle 15 are independently adjusted to an arbitrary pressure value.
The amount of shaping air ejected from each of the air ejection holes 15L into the swirl chamber 19 and the amount of control air ejected from each of the air ejection holes 16D of the second air nozzle 16 into the swirl chamber 19 are individually adjusted. It is like this.

The rotary atomizing head type electrostatic coating apparatus according to the present embodiment has the above-mentioned structure, and its basic operation is not different from that of the prior art.

However, according to this embodiment, the coating machine main body 1
An air passage 13A for shaping air and an air passage 13B for control air are formed in the cover 13 of the above, and these are connected to the air source 22 via the air pipes 25, 26 and pressure regulating valves 23, 24, etc. At the tip side of the cover 13, the first air nozzle 15 and the second air nozzle 15 are provided so as to surround the rotary atomizing head 11 on the rear side of the paint discharge edge 11C of the rotary atomizing head 11.
An air nozzle 16 is provided, and shaping air in a swirling flow state is ejected from an annular swirl chamber 19 formed between the cylindrical protrusion 15F of the first air nozzle 15 and the second air nozzle 16 via an annular air ejection port 20. Since the configuration is adopted, the following operational effects can be obtained.

First, as in the prior art, by applying a high voltage to the main body 1 of the coating machine, the rotary shaft 4 and the rotary atomizing head 1 are rotated.
1 is charged to a high voltage to form an electrostatic field with the object to be coated, and the rotary shaft 4 and the rotary atomizing head 11 are rotated at high speed by the air motor 3 in the main body 1 of the coater.

In this state, the paint is supplied to the rotary atomizing head 11, and the supplied paint is charged while being spread along the paint smooth surface 11B by the rotation (centrifugal force) of the rotary atomizing head 11. Then, after being discharged as a film or a liquid thread type charged paint from the paint discharge edge 11C, it is atomized by mechanical atomization or electrostatic atomization to obtain charged paint particles.

At this time, since the rotary atomizing head 11 is rotating at a high speed, the centrifugal force causes the charged paint particles to fly outward from the paint discharge edge 11C in the radial direction. However, as illustrated in FIG. 4, the shaping air becomes a swirling flow in the direction of arrow E from the air ejection port 20 between the air nozzles 15 and 16 and is ejected toward the periphery of the rotary atomizing head 11, By directly colliding the shaping air with the charged paint particles discharged radially outward from the paint discharge edge 11C, the charged paint particles can be uniformly dispersed, and the spray pattern of the paint is swirled by the shaping air. It can be adjusted according to the condition.

That is, while shaping air is ejected from the air ejection holes 15L of the first air nozzle 15 into the swirl chamber 19, the shaping air is ejected from the air ejection holes 16D of the second air nozzle 16 into the swirl chamber 19 in a substantially tangential direction. Since the control air is ejected in the direction of arrow D in FIG. 3, a swirling flow corresponding to the amount of control air is generated in the shaping air, and the pattern width of the spray pattern according to the swirling flow state at this time. (Size) can be obtained.

In this case, if the air pressure of the control air is increased by the pressure regulating valve 24 to increase the air amount, a stronger swirling flow can be given to the shaping air in the swirl chamber 19, so that the straightness of the shaping air is weakened. In this way, the spray pattern of the paint can be expanded, and the spray pattern suitable for various paints can be obtained according to the air pressure of the control air.

The second air nozzle 16 has a bilaterally symmetrical shape, and has tapered ejection edges 16B and 16B formed at the end portions 16A on both end sides, respectively.
When one end 16A of A is engaged with the annular recess 15J of the first air nozzle 15 to integrate the air nozzles 15 and 16, the air ejection holes 16D are directed into the swirl chamber 19 in the direction of the arrow D ( The control air can be ejected in a substantially tangential direction to give the shaping air a swirling flow in the direction of arrow E (see FIG. 4).

In this case, the turning direction of the shaping air (E direction indicated by the arrow) and the rotation direction of the rotary atomizing head 11 (direction indicated by the arrow C) are opposite to each other, and the centrifugal force of the rotary atomizing head 11 is increased. As a result, the shaping air can be made to collide strongly with the paint that is projected radially outward from the paint discharge edge 11C in the opposite direction.

On the other hand, each end 16A of the second air nozzle 16
When the other end 16A is engaged with the annular recess 15J of the first air nozzle 15 to integrate the air nozzles 15 and 16, the air ejection holes 16 shown by phantom lines in FIG.
Control air can be ejected from D into the swirl chamber 19 in the direction opposite to the arrow D direction (substantially tangential direction), and the shaping air can be directed in the direction opposite to the arrow E direction (of the rotary atomizing head 11). It is possible to generate a swirling flow in the forward direction with respect to the rotation direction, and it is possible to more finely adjust the spray pattern of the paint according to the jet direction of the control air.

Therefore, according to the present embodiment, the air amount (air pressure) of shaping air is adjusted by the pressure regulating valve 23 according to various paints such as metallic paint and the coating condition, and the air of control air is controlled by the pressure regulating valve 24. By arbitrarily adjusting the amount (air pressure), the spray pattern of the paint can be effectively and finely adjusted, and the finish quality of the coated surface of the coated object can be significantly improved.

Further, by applying swirl (swirl flow) to the shaping air with the control air ejected from each air ejection hole 16D of the second air nozzle 16, the spray pattern of the paint can be made larger than in the prior art. For example, even in the case of metallic coating, the coating thickness can be made uniform and a wide pattern can be coated, and the coating work time can be significantly shortened compared to conventional coating equipment, and the coated surface can be finished neatly. You can

In particular, in the case of metallic coating using a metallic coating as the coating, the particle velocity of the coating particles when applied to the object to be coated becomes a problem, and when it is not an appropriate particle velocity, glossy coating is realized. However, in the present embodiment, a swirling flow is generated in the shaping air by the control air, and the shaping air is jetted in the swirling flow state from the air ejection port 20 toward the periphery of the rotary atomizing head 11. With this, it is possible to adjust the collision speed with respect to the object to be coated, and it is possible to easily realize a glossy coated surface, and to obtain various effects.

In the above embodiment, the cover 13 is provided with the air passage 13A for shaping air and the air passage 13B for control air, but the present invention is not limited to this. A radial air passage may be bored in the air passage, and control air may be supplied into the air chamber 17 through the air passage.

[0059]

As described in detail above, according to the present invention of claim 1, the first air jetting means for jetting shaping air in the axial direction of the rotary atomizing head, and the first air jetting means The second air jetting means comprises the second air jetting means for jetting the control air for the swirling flow so that the shaping air by the means is jetted around the rotary atomizing head in the swirling flow state. The spray pattern of the paint can be easily adjusted to the desired size (size) by adjusting the swirling flow state of the shaping air by the first air ejecting means with the control air ejected from To improve the finish.

In this case, as in the invention described in claim 2, the first air ejection means is provided with the first air pressure control means for adjusting the air pressure of the shaping air between the first air ejection means and the air source.
The second air ejecting means is provided with a second air pressure control means for adjusting the air pressure of the control air between the second air ejection means and the air source, so that the second air pressure control means controls the air pressure of the control air. When raised, the spray pattern of the paint can be expanded, and a spray pattern suitable for various paints can be obtained.

Further, as in the invention described in claim 3 or 4, the control air from the second air jetting means,
A swirling flow that is opposite or forward to the rotation direction of the rotary atomizing head can be applied to the shaping air, and the spray pattern of the paint can be adjusted more finely according to the jet direction of the control air.

Further, as in the invention described in claim 5,
Ring-shaped first and second air nozzles are provided on the front end side of the coating machine body, the ring-shaped first and second air nozzles being located rearward of the paint discharge edge of the rotary atomizing head and surrounding the outer peripheral side of the rotary atomizing head. An annular swirl chamber is defined between the first and second air nozzles, and a plurality of air ejection holes for ejecting the control air in a substantially tangential direction toward the inside of the swirl chamber are formed in the second air nozzle. This allows the swirling flow to be effectively generated in the shaping air in the swirl chamber, and the shaping air is ejected in the swirling flow state from the inside of the swirl chamber toward the periphery of the rotary atomizing head, resulting in an effective paint spray pattern. Can be expanded.

[Brief description of drawings]

FIG. 1 is a longitudinal sectional view showing a rotary atomizing head, first and second air nozzles, etc. of a rotary atomizing head type electrostatic coating apparatus according to an embodiment of the present invention.

FIG. 2 is a half sectional view showing an enlarged main part in FIG.

FIG. 3 is an enlarged sectional view taken along the line III-III in FIG.

FIG. 4 is a perspective view of a rotary atomizing head, a cover and the like showing a swirling flow state of shaping air.

5 is a half cross-sectional view of the first air nozzle shown in FIG.

FIG. 6 is a partial cross-sectional view of the second air nozzle shown in FIG.

FIG. 7 is a vertical cross-sectional view showing a rotary atomizing head, a shaping air ring and the like of a rotary atomizing head type electrostatic coating device according to a conventional technique.

[Explanation of symbols]

 1 Coating Machine Main Body 3 Air Motor (Rotation Source) 11 Rotary Atomizing Head 11A Outer Surface 11B Paint Smooth Surface 11C Paint Discharge Edge 13 Cover 13A, 13B Air Passage 15 First Air Nozzle (First Air Spouting Means) 16 Second Air Nozzle 16D Air ejection hole (second air ejection means) 17 Air chamber 19 Swirl chamber 20 Air ejection port 21 Retainer cylinder 22 Air source 23 Pressure regulating valve (first air pressure control means) 24 Pressure regulating valve (second air pressure control) Means) 25,26 Air pipeline

Claims (5)

[Claims] 1. A main body of a coating machine having a rotation source, and a rotary atomizer which is rotatably provided on the tip side of the body of the coating machine and is formed in a cylindrical shape or a cup shape so that the tip side serves as a paint discharge edge. A head, a first air ejecting means for ejecting shaping air in the axial direction of the rotary atomizing head, and shaping air by the first air ejecting means in a swirling flow state around the rotary atomizing head. A rotary atomizing head type coating device comprising a second air jetting means for jetting control air for swirling flow so as to jet. 2. The first air ejecting means includes a first air pressure control means for adjusting the air pressure of the shaping air between the first air ejecting means and the air source, and the second air ejecting means forms an air source. The rotary atomizing head type coating device according to claim 1, further comprising second air pressure control means for adjusting the air pressure of the control air. 3. The second air ejection means is configured to eject the control air so as to give a swirling flow to the shaping air that is in a direction opposite to the rotation direction of the rotary atomizing head. The rotary atomizing head type coating apparatus according to 1 or 2. 4. The second air ejecting means is configured to eject the control air so as to give a swirling flow to the shaping air that is a forward direction with respect to the rotation direction of the rotary atomizing head. The rotary atomizing head type coating apparatus according to 1 or 2. 5. A ring-shaped first air nozzle, which is located on the front end side of the coating machine body, behind the paint discharge edge of the rotary atomizing head and surrounds the outer peripheral side of the rotary atomizing head. , The first
A ring-shaped second air nozzle that forms a first air ejection unit that ejects the shaping air together with an air nozzle and defines an annular swirl chamber between the first air nozzle and the second air nozzle is provided. 2. A plurality of air ejection holes for ejecting the control air in a substantially tangential direction toward the inside of the swirl chamber are formed, and the respective air ejection holes constitute the second air ejection means. The rotary atomizing head type coating device according to 3 or 4.