JPH08131902A - Rotary atomization head type coating apparatus - Google Patents

Abstract

PURPOSE: To provide a rotary atomization head type coating apparatus by which finishing of e.g. metallic coating is enhanced by broadening a spray pattern of paint and also uniformly dispersing paint particles. CONSTITUTION: A nozzle ring 15 and a retainer cylinder 20 are provided so as to surround a rotary atomization head 11 in the rear of the paint discharge edge 11C of the rotary atomization head 11 at the tip side of a cover 13 which is integrally provided in the body 1 of a coater. A plurality of guide grooves 19 are formed in the cylindrical projection part 15E of the nozzle ring 15 and also respective air spout holes 18 for spouting shaping air are bored in the bottom sides of the respective guide grooves 19. A plurality of guide grooves 19 are sequentially provided at the specified intervals in the circumferential direction at the tip side of the cylindrical projection part 15E and obliquely tilted by a specified angle of torsion. Shaping air is spouted in the axial direction toward the insides of the respective guide grooves 19 from the respective air spout holes 18 of the nozzle ring 15 and guided by the wall surfaces of the respective guide grooves 19. Thereby, shaping air is spouted toward the circumference of the rotary atomization head 11 as a spout stream of a twisting state.

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. A pattern is formed so as to be narrowed down toward the front of the head 5, so that a small-diameter paint spray pattern in the direction of 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, there is a problem that the spray pattern of the paint becomes small, which causes color unevenness 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 and 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. The present invention can effectively spread the spray pattern of the paint and can evenly disperse the paint particles, for example, metallic coating. It is an object of the present invention to provide a rotary atomizing head type coating device capable of surely improving the finish of the above.

[0019]

In order to solve the above-mentioned problems, the present invention provides a coating machine main body having a rotation source, a rotatably provided on the front end side of the coating machine main body, and the front end side being a paint discharge edge. Applicable to a rotary atomizing head type coating device comprising a rotary atomizing head formed in a cylindrical shape or a cup shape and a shaping air ring for ejecting shaping air toward the periphery of the rotary atomizing head. To be done.

The feature of the configuration adopted by the present invention is that a plurality of shaping air rings are formed in the shaping air ring so as to be spaced apart from each other in the circumferential direction of the shaping air ring to eject the shaping air in the axial direction. An air ejection hole and a plurality of air guides that are spaced apart from each other in the circumferential direction of the shaping air ring in correspondence with the air ejection holes and that are formed obliquely at the tip side of the shaping air ring with a constant twist angle. It is provided.

In this case, as in the invention described in claim 2, each of the air guides is formed on the tip side of the shaping air ring with a twist angle opposite to the rotation direction of the rotary atomizing head. Is preferred.

Further, as in the invention described in claim 3, each of the air guides is formed at the tip end side of the shaping air ring with a twist angle that is a forward direction with respect to the rotation direction of the rotary atomizing head. Good.

Further, as in the invention described in claim 4,
The shaping air ring has a plurality of auxiliary air ejection paths which are located between the air guides and open toward the tip side of the shaping air ring to eject auxiliary air toward the object to be coated. May be

Further, as in the invention described in claim 5, each of the air guides is formed by a plurality of concave grooves arranged in the circumferential direction on the tip side of the shaping air ring with a small groove width, It is preferable that each air ejection hole is formed on the bottom side of each groove so as to open in each groove.

On the other hand, in the invention according to claim 6, a plurality of air ejection holes are provided in the shaping air ring so as to eject the shaping air in the circumferential direction of the shaping air ring so as to eject the shaping air in the axial direction. In order to guide the shaping air from the ejection holes, a plurality of concave grooves that are arranged in a row in the circumferential direction with a small groove width are formed on the tip side of the shaping air ring, and each of the air ejection holes is formed in the concave groove. The configuration is characterized in that it is provided on the bottom side of each of the concave grooves so as to open at the bottom.

Also in this case, as in the invention according to claim 7, the shaping air ring is located between the concave grooves and is opened at the tip end side of the shaping air ring to be coated. A plurality of auxiliary air ejection paths may be formed to eject the auxiliary air toward the.

[0027]

According to the invention described in claim 1, a plurality of air guides which are spaced apart in the circumferential direction at the tip end side of the shaping air ring are formed obliquely with a constant twist angle, and shaping air from each air ejection hole is formed in each of the air ejection holes. Since the air guide is configured to eject in a twisted state toward the periphery of the rotary atomizing head, the shaping air at this time can be made to have a twisted state close to a swirling flow, and the flow velocity of the shaping air can be changed to a twisted state. The spray pattern of the paint can be expanded.

In this case, as in the invention described in claim 2 or 3, each of the air guides of the shaping air ring has a twist angle which is opposite or forward to the rotation direction of the rotary atomizing head. By forming it on the tip side, the flow velocity of shaping air and the degree of mixing / dispersion with paint particles can be adjusted appropriately, and a spray pattern suitable for various paints can be obtained.

Further, as in the invention described in claim 4, by forming a plurality of auxiliary air ejection passages located between the air guides and ejecting auxiliary air toward the object to be coated, in the shaping air ring, The energy toward the object to be coated can be reliably applied to the coating particles from the rotary atomizing head by the auxiliary air, and the auxiliary air and the shaping air can be pressure-controlled appropriately, so that each of the coating materials can be applied in accordance with various coating materials. It is possible to arbitrarily adjust the forward straightness of the particles.

Further, as in the invention described in claim 5,
By forming each air guide by a plurality of concave grooves arranged in the circumferential direction with a small groove width on the tip side of the shaping air ring, and by arranging each air injection hole on the bottom side of each concave groove. , High-pressure shaping air ejected from each air ejection hole can be made into a twisted ejection flow along the wall surface of each groove (air guide), and the mixing speed of shaping air and mixing / dispersion with paint particles The condition can be adjusted according to the twist angle of each groove (air guide).

On the other hand, as in the sixth aspect of the present invention, a plurality of recessed grooves having a small groove width are provided in a row in the circumferential direction on the tip side of the shaping air ring, and are opened in each recessed groove. By forming each air ejection hole on the bottom side of each groove, the high-pressure shaping air ejected from each air ejection hole spreads along the wall surface of each groove. The flow rate of shaping air and the degree of mixing / dispersion with coating particles can be appropriately adjusted according to the groove width of each concave groove and the like.

Also in this case, as in the invention described in claim 7, a plurality of auxiliary air ejection passages which are located between the concave grooves and open to the tip side of the shaping air ring are formed, and the auxiliary air ejection passages are formed. By arranging the auxiliary air to be ejected from the air ejection hole toward the object to be coated, the energy toward the object to be coated can be reliably applied to the paint particles by the jet flow of the auxiliary air, and the auxiliary air and shaping can be performed. By appropriately adjusting the pressure with the air, the forward straightness of each paint particle can be arbitrarily adjusted according to various paints.

[0033]

Embodiments 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. 13 described above are designated by the same reference numerals, and the description thereof will be omitted.

1 to 4 show a first embodiment of the present invention.

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 tip side, and rotates at high speed in the direction of arrow C around the axis O-O.

Reference numeral 12 denotes a disk-shaped hub member arranged on the bottom side of the rotary atomizing head 11, and the hub member 12 is provided with the paint and thinner on the outer peripheral side thereof. 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 main body 1 of the coating machine. The cover 13 is formed in a cylindrical shape by an insulating resin material or the like, 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. Further, an air passage 13A for shaping air is formed in the cover 13, and the cover 1
On the inner circumference of the tip side of 3, the annular air reservoir 13B, which is located between the main body 1 of the coating machine and communicates with the air passage 13A, and a nozzle ring 15 described later are fixed to the main body 1 side of the coating machine. The screw portion 13C is formed.

Reference numeral 14 denotes a retainer ring screwed to the threaded portion 13C of the cover 13. The retainer ring 14 positions the cover 13 on the main body 1 of the coater and defines an air reservoir 13B 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 3B is circulated toward the nozzle ring 15 side.

Reference numeral 15 denotes a nozzle ring as a shaping air ring which is screwed to the screw portion 13C of the cover 13 and is positioned at the tip end side of the coating machine main body 1. The nozzle ring 15 is as shown in FIGS. In addition, a stepped tubular nozzle body 15C in which a small diameter male screw 15A screwed into the screw portion 13C of the cover 13 and a large diameter male screw portion 15B screwed into a retainer cylinder 20 described later are formed on the outer peripheral side. When,
An annular portion 15D that projects radially inward from the nozzle body 15C and abuts the front end surface of the coating machine body 1, and a guide groove 19 that will be described below and that projects forward from the nozzle body 15C and is formed on the tip side. And a cylindrical recess 15F formed between the cylindrical projection 15E and the nozzle body 15C and defining an annular air chamber 16 between the cylindrical projection 15E and the nozzle body 15C. There is.

Here, a plurality of (for example, 12 to 36) nozzle holes 17, 17, ... Are axially bored in the nozzle body 15C of the nozzle ring 15 at regular intervals in the circumferential direction. The nozzle hole 17 communicates with the air reservoir 13B at the base end side and communicates with the air chamber 16 at the tip end side. Then, each nozzle hole 17 introduces shaping air from the air reservoir 13B into the air chamber 16. Further, as shown in FIG. 2, the annular portion 15D of the nozzle ring 15 has a plurality of ventilation holes 15G, 15G, and
Are formed in the air bearing 2 (see FIG. 13).
It is configured such that exhaust air or the like from the reference atom) is ejected toward the outer peripheral surface 11A side of the rotary atomizing head 11 as necessary.

Reference numerals 18, 18, ... Denote small-diameter air ejection holes formed in the cylindrical protrusion 15E of the nozzle ring 15 located on the bottom side of each guide groove 19, and each air ejection hole 18 is shown in FIG. As shown in FIG. 2 and FIG. 3, it extends in the axial direction of the cylindrical protruding portion 15E, and the base end side is opened to the air chamber 16 and the tip end side is opened to each guide groove 19. In addition, each of the air ejection holes 1
8 is formed to have a diameter slightly smaller than the groove width of each guide groove 19, and a total of about 20 to 40 pieces are arranged at regular intervals in the circumferential direction of the cylindrical protrusion 15E. Then, as shown in FIG. 1, the air ejection holes 18 are arranged radially outward of the paint discharge end edge 11C of the rotary atomizing head 11 by a predetermined dimension L (for example, about 2 to 3 mm). Shaping air from the air chamber 16 is ejected in the axial direction toward each guide groove 19.

Reference numerals 19, 19, ... Show guide grooves as air guides formed on the tip side of the cylindrical projection 15E of the nozzle ring 15, and each guide groove 19 has a cross section as shown in FIGS. Is formed as a narrow groove having a "U" shape, and the cylindrical protruding portion 15 corresponds to each air ejection hole 18.
A total of about 20 to 40 pieces are arranged in a row in the circumferential direction of E. Each guide groove 19 has a constant twist angle θ 1 (for example, 4 °) with respect to a normal line LO passing through the axis O of the nozzle ring 15.
5 °) and extends obliquely between the inner and outer peripheral surfaces of the cylindrical protruding portion 15E to open in the inner and outer peripheral surfaces of the cylindrical protruding portion 15E, and axially to the end surface on the tip side of the cylindrical protruding portion 15E. It is open.

Here, as shown in FIG. 2, each guide groove 19 is formed with a twist angle θ 1 which is the opposite direction to the rotation direction of the rotary atomizing head 11 (direction C shown by the arrow), and each air ejection hole 18 is formed. By guiding the high-pressure shaping air ejected from each of the guide grooves 19 along the wall surface of each guide groove 19, the shaping air is twisted as shown in phantom lines in FIG. Squirt toward. Then, the shaping air, which has become a jet flow in a twisted state, is twisted in a direction opposite to the rotation direction of the rotary atomizing head 11 (direction of arrow C), so that the centrifugal force of the rotary atomizing head 11 causes the paint discharge end. The shaping air can be strongly collided with the coating material that is projected radially outward from the edge 11C.

Reference numeral 20 denotes a retainer tube which is attached to the nozzle ring 15 so as to surround the outer peripheral side of the nozzle ring 15 and constitutes a shaping air ring together with the nozzle ring 15. The retainer tube 20 has a stepped tubular shape. The base end side is screwed to the male screw portion 15B of the nozzle ring 15. The inner circumference of the retainer cylinder 20 is fitted to the outer circumference of the cylindrical protrusion 15E of the nozzle ring 15, and an annular air chamber 16 is defined between the retainer cylinder 20 and the annular recess 15F of the nozzle ring 15. There is.

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
The rotary atomizing head 11 is attached to the tip side of the cover 13 that is integrally provided on the
The nozzle ring 15 and the retainer cylinder 20 are provided so as to surround the rotary atomizing head 11 on the rear side of the paint discharge end edge 11C, and the cylindrical protrusion 15E of the nozzle ring 15 has a constant circumferential direction on the tip side thereof. Normal line of the nozzle ring 15 that is lined up at intervals
A plurality of guide grooves 19, 19 ... Inclined with respect to LO by an angle of twist angle θ1 are formed, and each guide groove 19 is formed.
Since the air ejection holes 18 for ejecting shaping air toward the respective guide grooves 19 are provided on the bottom side, 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, the shaping air axially ejected from each air ejection hole 18 of the nozzle ring 15 into each guide groove 19 is guided by the wall surface of each guide groove 19,
As shown by the phantom line in FIG. 4, as a jet flow in a twisted state, it is jetted toward the periphery of the rotary atomizing head 11, so that the shaping air is applied to the charged paint particles discharged radially outward from the paint discharge edge 11C. By directly colliding, the charged paint particles can be uniformly dispersed, and the spray pattern of the paint can be adjusted according to the twisting state of the shaping air.

That is, the shaping air that has become a jet flow in a twisted state becomes a flow in a twisted state close to a swirling flow, the direction of the shaping air is adjusted, and the spray pattern of the paint can be effectively expanded. Further, the shaping air is twisted in a direction opposite to the rotation direction of the rotary atomizing head 11 (direction indicated by an arrow C), and the centrifugal force of the rotary atomizing head 11 causes the shaping air to fly outward from the paint discharge edge 11C in the radial direction. It strongly collides with the incoming charged paint particles, and the charged paint particles can be uniformly dispersed in this shaping air.

Therefore, according to the present embodiment, the high-pressure shaping air ejected from each air ejection hole 18 of the nozzle ring 15 is formed into a twisted ejection flow in each guide groove 19 to form a spray pattern of the paint. It is possible to effectively adjust the shape of the shaping air according to the twisting state of the shaping air, and to uniformly disperse the charged paint particles in the shaping air, so that the finish quality of the coated surface of the object to be coated can be surely improved.

Further, by making each of the guide grooves 19 formed on the tip side of the nozzle ring 15 eject the shaping air from each of the air ejection holes 18 in a twisted state, the spray pattern of the paint can be made larger than in the prior art. For example, even when metallic coating is performed, 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 the conventional coating equipment, and the coated surface can be made clean. Can be finished.

In particular, in the case of metallic coating, the particle velocity of the coating particles when applied to the object to be coated becomes a problem, and it is difficult to realize glossy coating if the particle velocity is not appropriate. . However, in the present embodiment, the shaping air is jetted toward the periphery of the rotary atomizing head 11 as a jet flow in a twisted state, whereby the collision speed with respect to the object to be coated can be adjusted, and a glossy coated surface can be obtained. It has various effects such as being easily realized.

Next, FIG. 5 shows a second embodiment of the present invention. In this embodiment, the same components as those of the first embodiment are designated by the same reference numerals and the description thereof will be omitted. To do. However, the feature of the present embodiment is that the guide grooves 31 as air guides arranged in a row in the circumferential direction at the tip side of the cylindrical protrusion 15E of the nozzle ring 15 are provided in the rotation direction (arrow) of the rotary atomizing head 11. Twist angle θ2 that is the forward direction with respect to C direction)
It is formed so as to extend diagonally.

Here, each of the guide grooves 31 is formed as a narrow groove having a U-shaped cross section in a manner similar to each of the guide grooves 19 described in the first embodiment. Corresponding to the air ejection holes 18, a total of about 20 to 40 pieces are arranged in a row in the circumferential direction of the cylindrical protrusion 15E. Each of the guide grooves 31 has a normal line LO passing through the axis O of the nozzle ring 15.
With a constant twist angle θ2 (for example, 45 degrees), the pipes 15E extend obliquely between the inner and outer peripheral surfaces of the cylindrical protrusion 15E and are opened in the inner and outer peripheral surfaces of the cylindrical protrusion 15E. The end surface of the portion 15E is opened in the axial direction.

Thus, although the present embodiment having such a structure can obtain substantially the same operational effect as that of the first embodiment, the nozzle ring 1 is particularly used in this embodiment.
By guiding the shaping air ejected in the axial direction from each air ejection hole 18 of No. 5 with each guide groove 31,
It is possible to generate a jetting flow of shaping air that is twisted in the forward direction with respect to the rotation direction of the rotary atomizing head 11 (direction of arrow C).

The shaping air in this case is
By twisting in the forward direction with respect to the rotation direction of the rotary atomizing head 11 (direction indicated by the arrow C), the centrifugal force of the rotary atomizing head 11 causes the charged paint particles to fly out radially outward from the paint discharge edge 11C. In addition to being able to uniformly disperse in the shaping air, the flow rate of the shaping air and the degree of mixing / dispersion with the coating particles can be appropriately adjusted, and a spray pattern suitable for various coating materials can be obtained.

Next, FIGS. 6 to 9 show a third embodiment of the present invention. The feature of this embodiment is that a plurality of auxiliary air ejection passages are formed in the shaping air ring at intervals in the circumferential direction. The configuration is such that the ejection ports of the respective auxiliary air ejection paths are located between the concave grooves (guide grooves) as air guides and opened to the tip side of the shaping air ring. In this embodiment, the same components as those of the first embodiment are designated by the same reference numerals and the description thereof will be omitted.

In the figure, reference numeral 41 denotes a cover of the main body 1 of the coating machine. The cover 41 is made of an insulating resin material in a cylindrical shape and is provided on the outer peripheral side of the main body 1 of the coating machine to protect the main body 1 of the coating machine. It is configured to cover. An air passage 41A for shaping air and an air passage 41B for auxiliary air are formed in the cover 41, and an annular air reservoir 41C communicating with the air passage 41A is formed on the inner circumference of the tip end side of the cover 41.
And an annular air reservoir 41D communicating with the air passage 41B.
And a threaded portion 41E for fixing the nozzle ring 42, which will be described later, to the coating machine body 1 side.

Reference numeral 42 denotes a nozzle ring as a shaping air ring, which is screwed to the screw portion 41E of the cover 41 and is positioned at the tip end side of the coating machine main body 1. The nozzle ring 42 is the same as that described in the first embodiment. Nozzle ring 15
The nozzle main body portion 42C, the annular portion 42D, the cylindrical protruding portion 42E, and the annular concave portion 42F each having the same structure as that of FIG. 7 and FIG. ing. However, in the nozzle ring 42, the nozzle body 42C extends relatively long toward the male screw 42A and faces the air reservoirs 41C and 41D of the cover 41.

Here, a plurality of (for example, 12 to 36) nozzle holes 43, 43, ... Are axially bored in the nozzle body portion 42C of the nozzle ring 42 at regular intervals in the circumferential direction. The nozzle hole 43 has a proximal end communicating with the air reservoir 41C and a distal end communicating with the air chamber 16. Then, each nozzle hole 43 introduces shaping air from the air reservoir 41C into the air chamber 16. Further, as shown in FIG. 7, the annular portion 42D of the nozzle ring 42 has a plurality of ventilation holes 42G, 42G, at regular intervals in the circumferential direction.
Are formed in the air bearings 42G (see FIG. 13).
It is configured such that exhaust air or the like from the reference atom) is ejected toward the outer peripheral surface 11A side of the rotary atomizing head 11 as necessary.

Reference numerals 44, 44, ... Depict auxiliary air jet passages formed in the nozzle ring 42.
7A and 8B, the nozzle body portion 42C and the cylindrical protrusion portion 42E extend in the axial direction, and the base end side is an air reservoir 41D.
It is open to. The tip side of each of the auxiliary air ejection passages 44 is located between the guide grooves 19 and serves as a small-diameter ejection port 44A that opens to the tip end side end surface of the cylindrical protrusion 42E, and each of the ejection ports 44A has the air reservoir 44A. Auxiliary air from 41D is ejected in the axial direction toward the object to be coated.

Here, as shown in FIG. 6, each of the ejection ports 44A is arranged at the same position as the paint discharge edge 11C of the rotary atomizing head 11 or slightly outside the paint discharge edge 11C in the radial direction. The dimension L (for example, 2
Each of the air ejection holes 18 separated by about 3 mm) is arranged radially inward by a dimension L1 (L1.ltoreq.L). Then, each of the ejection ports 44A has a cylindrical protrusion 42E.
The cylindrical protrusion 42 is formed on the end surface of the distal end side of each of the guide grooves 19 so as to open, for example, two pieces (or one piece).
A total of 20 to 80 pieces are arranged in the circumferential direction of E.

Thus, in this embodiment having such a structure, it is possible to obtain substantially the same effect as that of the first embodiment, but particularly in this embodiment, the nozzle ring 42 extends in the axial direction. A plurality of auxiliary air ejection paths 44, 44, ...
And the jet port 4 of each of the auxiliary air jet passages 44
Since 4A is positioned between the guide grooves 19 and opened to the end face on the tip side of the cylindrical protrusion 42E, the following operational effects can be obtained.

That is, the shaping air from each air ejection hole 18 is ejected in a twisted state by each guide groove 19 formed on the tip end side of the nozzle ring 42, and each auxiliary air ejection passage 44 located between each guide groove 19 is formed. Spout 44
Since A is configured to eject auxiliary air in the axial direction toward the object to be coated, the auxiliary air can effectively impart the energy toward the object to be charged to the charged paint particles from the rotary atomizing head 11. It is possible to effectively widen the spray pattern of the paint while giving these paint particles advanceability toward the object to be coated.

Further, by separately adjusting the pressures of the auxiliary air and the shaping air, it is possible to appropriately adjust the jetting flow of the shaping air and the jetting flow of the auxiliary air according to various paints, which is suitable for various paints. Forward assisting performance (energy toward the object to be coated) can be reliably applied to the paint particles, the forward straightness of the paint particles can be effectively adjusted, and the spray pattern of the paint can be reliably improved. it can.

Next, FIGS. 10 and 11 show a fourth embodiment of the present invention.
In the present embodiment, the same components as those in the first embodiment are designated by the same reference numerals and the description thereof will be omitted. However, the feature of this embodiment is that the nozzle ring 1
5, a plurality of auxiliary air ejection paths 51, 51 for ejecting auxiliary air toward the object to be coated are formed on the cylindrical protruding portion 15E of 5,
The configuration is such that the tip end side of each auxiliary air ejection passage 51 is opened to the tip end side end surface of the cylindrical protrusion 15E as the ejection port 51A located between the guide grooves 19.

Here, each auxiliary air ejection passage 51 extends in the axial direction of the cylindrical projection 15E, the base end side is opened to the air chamber 16, and the tip end side is the ejection port 51A. And
The respective outlets 51A of the respective auxiliary air outlets 51 are substantially the same as the outlets 44A of the respective auxiliary air outlets 44 described in the third embodiment, and are equivalent to the paint discharge edge 11C of the rotary atomizing head 11. Alternatively, for each air ejection hole 18 which is disposed slightly outside in the radial direction of the paint discharge edge 11C and is separated from the paint discharge edge 11C by a fixed distance L, the size L2 (L
2 ≤ L) are arranged radially inward.

Further, each ejection port 51A has a cylindrical projection 15E.
Located between the guide grooves 19 on the tip end side of the
It is formed so as to open one by one (or one by one), and a total of about 20 to 80 are arranged in the circumferential direction of the cylindrical protrusion 15E.

Thus, in this embodiment having such a structure, it is possible to obtain substantially the same effect as that of the first embodiment, but particularly in this embodiment, each of the guides located between the guide grooves 19 is provided. Since the auxiliary air is ejected from the ejection port 51A of the auxiliary air ejection passage 51 toward the object to be coated,
By the auxiliary air, the energy toward the object to be coated can be effectively applied to the charged paint particles from the rotary atomizing head 11, and the spray pattern of the paint can be effectively applied to these paint particles while advancing toward the object to be coated. Can be expanded.

Next, FIG. 12 shows a fifth embodiment of the present invention. In this embodiment, the same components as those in the third embodiment are designated by the same reference numerals and the description thereof will be omitted. To do
The feature of this embodiment is that the cylindrical protrusion 42 of the nozzle ring 42 is used.
The guide grooves 61, 61, ... As concave grooves (air guides) formed on the tip end side of E are configured to extend radially with respect to the axis O of the nozzle ring 42.

Here, each guide groove 61 is formed as a narrow groove having a "U" -shaped cross section in a manner similar to each guide groove 19 described in the first embodiment, and each air guide groove 61 is formed. Corresponding to the ejection holes 18, a total of about 20 to 40 pieces are arranged in a row in the circumferential direction of the cylindrical protruding portion 42E. However, each of the guide grooves 61 is formed so that the twist angle is zero with respect to the normal line LO passing through the axis O of the nozzle ring 42, and the guide groove 61 is opened on the inner and outer peripheral surfaces of the cylindrical protrusion 42E, and Protrusion 42
The end face of E is open in the axial direction.

Further, on the tip end side surface of the cylindrical protruding portion 42E, each auxiliary air ejection passage 62 is located between the guide grooves 61.
62A of the auxiliary air jet passages 62 are opened, and the auxiliary air jet passages 62A of the respective auxiliary air jet passages 62 jet the auxiliary air toward the object to be coated similarly to the auxiliary air jet passages 44 described in the third embodiment. Has become.

Thus, also in this embodiment having such a configuration, the guide grooves 61 as a plurality of concave grooves having a small groove width are arranged in a row in the circumferential direction on the tip end side of the cylindrical protrusion 42E of the nozzle ring 42. Since the air ejection holes 18 are formed on the bottom side of the guide grooves 61 so as to open in the guide grooves 61, the high-pressure shaping ejected from the air ejection holes 18 is formed. Air can be made to be a jet flow in a diffused state that spreads along the wall surface of each guide groove 61, and the flow rate of shaping air and the mixing / dispersion degree with paint particles can be adjusted according to the groove width of each guide groove 61. Therefore, it is possible to obtain the same effects as those of the first embodiment.

Further, in this embodiment, the auxiliary air is jetted from the jet outlets 62A of the auxiliary air jet passages 62 located between the guide grooves 61 toward the object to be coated.
By the auxiliary air, the energy toward the object to be coated can be effectively applied to the charged paint particles from the rotary atomizing head 11, and the spray pattern of the paint can be effectively applied to these paint particles while advancing toward the object to be coated. Can be expanded.

In the fifth embodiment, the auxiliary air ejection passages 62 that are located between the guide grooves 61 and open to the end surface of the cylindrical protrusion 42E on the front end side are formed in the nozzle ring 42. However, each of these auxiliary air ejection paths 62
Etc. are not necessarily provided. On the other hand, the nozzle ring 15 described in the second embodiment is also provided with an auxiliary air ejection passage similar to the auxiliary air ejection passage 44 (51) described in the third and fourth embodiments. May be.

In each of the first to fourth embodiments, each guide groove 1 formed on the tip side of the nozzle ring 15 (42).
9 (31), for example, twist angle θ1 (θ2) of about 45 degrees
However, the present invention is not limited to this, and in order to obtain an optimum spray pattern for various paints, the twist angle θ1 (θ2) may be arbitrarily set within an angle range of, for example, 0 to 70 degrees. It may be changed to.

[0078]

As described above in detail, according to the present invention of claim 1, a plurality of air guides formed at the tip end side of the shaping air ring so as to be spaced apart in the circumferential direction are obliquely extended with a constant twist angle. Since the shaping air is ejected in a twisted state toward the periphery of the rotary atomizing head by the air guides from each air ejection hole, the shaping air can have a twisted state close to a swirling flow. As a result, the spray pattern of the paint can be effectively spread, and the paint particles can be uniformly dispersed, so that the finish of, for example, metallic coating can be surely improved.

In this case, as in the invention described in claim 2 or 3, each of the air guides of the shaping air ring has a twist angle that is opposite or forward to the rotation direction of the rotary atomizing head. By forming it on the tip side, the flow rate of shaping air and the degree of mixing / dispersion with paint particles can be stabilized, and a spray pattern suitable for various paints can be obtained.

Further, as in the invention described in claim 4, it is preferable that a plurality of auxiliary air ejection passages located between the air guides and ejecting auxiliary air toward the object to be coated are formed in the shaping air ring. For example, the auxiliary air from each auxiliary air jet can effectively impart the energy toward the coating object to the coating particles from the rotary atomizing head, and give these coating particles the advancing property toward the coating object. At the same time, the spray pattern of the paint can be effectively spread. Then, by separately adjusting the pressure of the auxiliary air and the shaping air, the jet flow of the shaping air and the jet flow of the auxiliary air can be appropriately adjusted according to various paints, so that the energy of the paint particles toward the object to be coated can be adjusted. Can have a front assisting performance suitable for various kinds of paints, the forward straightness of the paint particles can be effectively adjusted, and the spray pattern of the paint can be surely improved.

Further, as in the invention described in claim 5,
By forming each air guide by a plurality of concave grooves arranged in the circumferential direction with a small groove width on the tip side of the shaping air ring, and by arranging each air injection hole on the bottom side of each concave groove. While the high-pressure shaping air ejected from each air ejection hole is guided by the wall surface of each groove (air guide), it can be made to be a twisted ejection flow close to a swirl flow, and the flow velocity of the shaping air and the paint The degree of mixing and dispersion with particles can be effectively adjusted according to the twist angle of each groove (air guide).

On the other hand, as in the sixth aspect of the present invention, a plurality of concave grooves having a small groove width are provided in a row in the circumferential direction on the tip side of the shaping air ring, and the grooves are opened in the respective concave grooves. By forming each air ejection hole on the bottom side of each groove, the high-pressure shaping air ejected from each air ejection hole spreads along the wall surface of each groove. The flow rate of shaping air and the degree of mixing / dispersion with coating particles can be appropriately adjusted according to the groove width of each concave groove and the like.

Also in this case, as in the invention described in claim 7, a plurality of auxiliary air jet passages are formed between the concave grooves and open to the tip side of the shaping air ring, and the auxiliary air jet passages are formed. By constructing a structure in which auxiliary air is ejected from the air ejection holes toward the object to be coated, the energy toward the object can be reliably applied to the paint particles by the jet flow of the auxiliary air, and it is suitable for various paints. Further, it is possible to effectively impart the front assisting performance to the paint particles, and it is possible to surely improve the spray pattern of the paint, and it is possible to obtain the spray pattern suitable for various paints.

[Brief description of drawings]

FIG. 1 is a vertical sectional view showing a rotary atomizing head, a nozzle ring and the like of a rotary atomizing head type electrostatic coating apparatus according to a first embodiment of the present invention.

FIG. 2 is an enlarged front view showing a nozzle ring in FIG.

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

FIG. 4 is a partial perspective view of each guide groove of the nozzle ring and a cover showing a twisted state of shaping air.

5 is a front view similar to FIG. 2 showing a nozzle ring of a rotary atomizing head type electrostatic coating device according to a second embodiment.

FIG. 6 is an enlarged vertical sectional view showing a nozzle ring, an auxiliary air injection path and the like of a rotary atomizing head type electrostatic coating device according to a third embodiment.

7 is an enlarged front view showing the nozzle ring in FIG.

8 is an enlarged cross-sectional view taken along arrow VIII-VIII in FIG.

FIG. 9 is a partial perspective view of each guide groove of the nozzle ring and the cover showing a twisted state of shaping air.

FIG. 10 is an enlarged vertical cross-sectional view showing a nozzle ring, an auxiliary air injection path and the like of a rotary atomizing head type electrostatic coating device according to a fourth example.

11 is an enlarged view of the nozzle ring in FIG.
It is an expanded sectional view similar to.

FIG. 12 is a front view similar to FIG. 2, showing a nozzle ring of a rotary atomizing head type electrostatic coating device according to a fifth embodiment.

FIG. 13 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 Rotating Atomizing Head 11A Outer Surface 11B Paint Smooth Surface 11C Paint Discharge Edge 13,41 Cover 13A, 41A, 41B Air Passage 15,42 Nozzle Ring (Shaping Air Ring) 15C, 42C Nozzle body 15E, 42E Cylindrical protrusion 16 Air chamber 17,43 Nozzle hole 18 Air ejection hole 19,31 Guide groove (air guide) 20 Retainer cylinder 44, 51, 62 Auxiliary air ejection passage 44A, 51A, 62A Jet Outlet 61 Guide groove (concave groove)

Claims (7)

[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. In a rotary atomizing head type coating device comprising a head and a shaping air ring for ejecting shaping air toward the periphery of the rotary atomizing head, the shaping air ring includes a shaping air ring in a circumferential direction of the shaping air ring. A plurality of air ejection holes that are formed separately and eject the shaping air in the axial direction, and a plurality of air ejection holes that are spaced apart in the circumferential direction of the shaping air ring corresponding to the respective air ejection holes and that are on the tip side of the shaping air ring. A rotary atomizing head type coating device, comprising: a plurality of air guides formed obliquely with a constant twist angle. 2. The rotary atomizing head according to claim 1, wherein each of the air guides is formed on the tip side of the shaping air ring with a twist angle opposite to the rotating direction of the rotary atomizing head. Type coating equipment. 3. The rotary atomizing head according to claim 1, wherein each of the air guides is formed on a tip side of the shaping air ring with a twist angle that is a forward direction with respect to a rotation direction of the rotary atomizing head. Type coating equipment. 4. The shaping air ring is provided with a plurality of auxiliary air ejection paths located between the air guides and opening toward the tip end side of the shaping air ring for ejecting auxiliary air toward an object to be coated. The rotary atomizing head type coating device according to claim 1, 2, or 3 formed. 5. Each of the air guides is formed by a plurality of recessed grooves that are arranged in a row in the circumferential direction with a small groove width on the tip side of the shaping air ring, and each of the air ejection holes is formed in each of the recessed grooves. 5. The rotary atomizing head type coating device according to claim 1, 2, 3 or 4, wherein the concave groove is formed so as to be open at the bottom side. 6. A main body of a coating machine having a rotation source, and a rotary atomizer which is rotatably provided at a tip end side of the painter body and is formed in a tubular shape or a cup shape so that the tip end side serves as a paint discharge edge. In a rotary atomizing head type coating device comprising a head and a shaping air ring for ejecting shaping air toward the periphery of the rotary atomizing head, the shaping air ring includes a shaping air ring in a circumferential direction of the shaping air ring. A plurality of air ejection holes that are separated from each other and eject the shaping air in the axial direction, and a plurality of air ejection holes are arranged in a row in the circumferential direction at the tip end side of the shaping air ring to guide the shaping air from the respective air ejection holes. A plurality of recessed grooves are formed, and each air ejection hole is formed on the bottom side of each recessed groove so as to open in each recessed groove. Type Coating equipment. 7. The shaping air ring is provided with a plurality of auxiliary air ejection passages located between the concave grooves and opening toward the tip end side of the shaping air ring for ejecting auxiliary air toward an object to be coated. The rotary atomizing head type coating device according to claim 6, which is formed.