JP3273432B2 - Rotary atomizing head type coating equipment - 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 apparatus used as an electrostatic coating apparatus of, for example, a direct charging type or an indirect charging type.

[0002]

2. Description of the Related Art In general, a rotary atomizing head type electrostatic coating apparatus is
The high-speed rotation of the rotary atomizing head and the application of a high voltage to the object to be coated, the rotary atomization of the paint supplied to the paint smooth surface of the rotary atomizing head, the atomized charged paint The particles are directed toward the object to be coated in the axial direction, and are applied by flying along an electrostatic field between the object and the object.

A direct charging type electrostatic coating apparatus will be described as an example of a conventional rotary atomizing head type electrostatic coating apparatus of this type with reference to FIG.

In FIG. 1, reference numeral 1 denotes a coating machine main body constituting a main body of an electrostatic coating apparatus. The coating machine main body 1 includes an air bearing 2, an air motor 3 as a rotation source, a paint valve (not shown), and the like. The reciprocator (neither is shown) moves relative to the object to be coated.

Reference numeral 4 denotes a rotary shaft rotatably supported by the air bearing 2. The rotary shaft 4 has a distal end projecting outside the coating machine main body 1 and a rotary atomizing head 5 to be described later attached thereto. 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 distal end side of the rotary shaft 4. The rotary atomizing head 5 is formed in a cylindrical or cup shape as a whole, and its base end side is the rotary shaft 4 Is fixed to the distal end side of the device by means such as a screw. And
The rotary atomizing head 5 has a conical outer peripheral surface 5A, a smooth paint surface 5B on the inner peripheral surface, and a paint discharge edge 5 on its tip side.
C.

Reference numeral 6 denotes a center feed type paint supply pipe inserted into the rotary shaft 4, and the paint supply pipe 6 is provided in the coating machine main body 1 so as to extend in the axial direction. 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) through a paint pipe.

[0010] Reference numeral 7 denotes a cover of the coating machine main body 1. The cover 7 is formed in a cylindrical shape with an insulating resin material or the like, and covers the outer peripheral side of the coating machine main body 1 to protect the coating machine main body 1. It has become.

Reference numeral 8 denotes a shaping air ring which is located on the tip end side of the coating machine main body 1 and is fixed to the tip end of the cover 7. The shaping air ring 8 is located behind the paint discharge edge 5 C of the rotary atomizing head 5. The outer ring portion 8A and the inner ring portion 8B which are located on the side and form a double structure so as to surround the rotary atomizing head 5 from the outside in the radial direction. An air outlet 8C is formed between the outer ring portion 8A and the inner ring portion 8B at the tip side of the shaping air ring 8, and the air outlet 8C is provided at the paint discharge edge 5C of the rotary atomizing head 5. The shaping air is blown toward the periphery in the direction of arrow A (linear shape).

Reference numeral 9 denotes a high-voltage cable disposed on the base end side of the coating machine main body 1, and 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.

[0011] In the electrostatic coating apparatus configured as described above,
By applying a high voltage to the coating machine main body 1 through the high-voltage cable 9, the rotating shaft 4 and the rotary atomizing head 5 are charged to a high voltage, and between the rotary atomizing head 5 and the object to be coated. Form an electrostatic field. Then, the rotary shaft 4 and the rotary atomizing head 5 are rotated at a high speed by the air motor 3 in the coating machine main body 1 and the paint valve is opened in this state. Supply paint to

Here, the paint supplied to the rotary atomizing head 5 is directly contact-charged while spreading in a thin film on the paint smooth surface 5B by centrifugal force due to 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.

The paint which jumps out radially outward from the paint discharge edge 5C due to the centrifugal force of the rotary atomizing head 5 is divided (separated) from the film form into a liquid thread form, and is further converted from the liquid thread form into fine particles. (Mechanical atomization). Further, since the paint charged to a high voltage has a reduced surface tension and is charged with the same sign (positive or negative), each particle repels each other to promote atomization (electrostatic discharge). Atomization). The paint particles atomized (atomized) in this way fly toward the object to be coated along the electrostatic field and are applied to the object to be coated.

By the way, the paint discharge edge 5 of the rotary atomizing head 5
The paint particles released from C are scattered radially outward by centrifugal force from the rotating atomizing head 5 rotating at a high speed, and the spray pattern of the paint tends to largely spread.

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

[0016]

However, according to the above-mentioned prior art, the air ejection port 8C of the shaping air ring 8 is provided.
, The shaping air is only ejected in the direction of arrow A toward the periphery of the rotary atomizing head 5, so that the shaping air pressure is increased 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 or the like due to an insufficient number of times of application.

For this reason, in the prior art, it is necessary to take measures such as reducing the conveyor speed in the coating process such as metallic coating or making the movement of the reciprocator finer and faster. In practice, for example, in a finishing process such as a metallic coating, a countermeasure such as using a "gun type" coating machine including a nozzle tip is taken.

The present invention has been made in view of the above-mentioned problems of the prior art, and the present invention can effectively spread a spray pattern of a paint and can uniformly disperse paint particles. It is an object of the present invention to provide a rotary atomizing head type coating apparatus which can surely improve the finish such as.

[0019]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides a coating machine main body having a rotation source, and a rotatably provided tip end of the coating machine main body. The present invention is applied to a rotary atomizing head type coating apparatus including a rotary atomizing head formed in a tubular or cup-like shape, and a shaping air ring for discharging shaping air toward the periphery of the rotary atomizing head. Is done.

A feature of the structure adopted in the first aspect of the present invention is that a plurality of shaping air rings are formed in the shaping air ring so as to be spaced apart in a circumferential direction of the shaping air ring and eject the shaping air in an axial direction. The air ejection holes are separated from each other in the circumferential direction of the shaping air ring corresponding to the air ejection holes, and the shaft center of the shaping air ring is passed through the tip side of the shaping air ring.
That provided an air guide comprising a plurality of grooves formed obliquely with a certain twist angle with respect to the normal line, the respective air injection
The outlet is configured to open to the bottom side of each of the concave grooves .

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

According to a third aspect of the present invention, each of the air guides is formed on a tip side of the shaping air ring with a twist angle that is forward with respect to the rotation direction of the rotary atomizing head. Is also good.

Further, as in the invention according to claim 4,
The shaping air ring includes a plurality of auxiliary air ejection paths that are located between the respective air guides, open to the tip side of the shaping air ring, and eject auxiliary air toward an object to be coated. It may be.

On the other hand, in the invention according to claim 5 , a plurality of air ejection holes formed in the shaping air ring so as to be spaced apart in a circumferential direction of the shaping air ring to eject the shaping air in an axial direction, in each air ejection hole
Correspondingly, the tip of the shaping air ring is circumferentially separated from the tip of the shaping air ring.
Radially to the axis of the shaping air ring
An air guide consisting of a plurality of extending grooves formed is provided.
Only the respective air ejection holes adopts a configuration comprising a feature that it has an opening on the bottom side of the respective groove.

Also in this case, as in the invention according to claim 6 , the shaping air ring is located between the respective air guides and is opened at the tip end side of the shaping air ring. A plurality of auxiliary air ejection passages for ejecting auxiliary air toward the vehicle may be formed.

Further, according to a seventh aspect of the present invention, the air
The guide is small on the tip side of the shaping air ring.
Are arranged in the circumferential direction as concave grooves consisting of long grooves with various groove widths.
You may.

[0027]

[Action] In the invention described in claim 1, to form a <br/> air guide comprising a plurality of grooves spaced apart in the front end side of the shaping air ring in the circumferential direction at an angle with a constant helix angle, each d
(A) Since the injection hole is opened at the bottom side of each groove , the shaping air from each air injection hole is ejected in a twisted state toward the periphery of the rotary atomizing head by each groove .
The shaping air at this time can be a torsional flow close to a spiral flow along the wall surface of each groove, and the flow rate of the shaping air and the degree of mixing / dispersion with the paint particles can be determined by each groove.
Can be adjusted according to the twist angle of the paint, and the spray pattern of the paint can be widened.

In this case, each of the air guides has a torsion 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 the paint particles can be appropriately adjusted, and a spray pattern suitable for various paints can be obtained.

Further, a plurality of auxiliary air ejection passages located between the respective air guides and ejecting auxiliary air toward the object to be coated are formed in the shaping air ring. The energy toward the object to be coated can be reliably applied to the paint particles from the rotary atomizing head by the auxiliary air, and the auxiliary air and the shaping air are appropriately adjusted in pressure so that each of the paints can be applied in accordance with various types of paints. It is possible to arbitrarily adjust the forward straightness of the particles.

On the other hand, as in the invention of claim 5, shaping air phosphorus on the distal end side of the shaping air ring
Grooves extending radially with respect to the axis of the
Provided, also by opening the respective air ejection holes on the bottom side of the respective groove, the diffusion state with a spread along the high-pressure shaping air coming ejected from respective air ejection holes in the walls of each groove The flow rate of the shaping air and the degree of mixing / dispersion with the paint particles can be appropriately adjusted according to the groove width of each groove.

[0031] Then, even in this case, as in the invention according to claim 6, forming a plurality of auxiliary air ejection passage which opens on the distal end side of the shaping air ring located between the air guide, each of said auxiliary With the configuration in which the auxiliary air is 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 object by the jet flow of the auxiliary air, and the auxiliary air and the shaping are formed. By appropriately adjusting the pressure of the air, the forward straightness of each paint particle can be arbitrarily adjusted according to various paints.

Further, according to a seventh aspect of the present invention, the air
The guide is small on the tip side of the shaping air ring.
Are arranged in the circumferential direction as concave grooves consisting of long grooves with various groove widths
This allows shaping air to flow along the walls of each groove.
It can be a jet flow with a wide spread.

[0033]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 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. 13 described above are denoted by the same reference numerals, and description thereof will be omitted.

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

In the figure, reference numeral 11 denotes a rotary atomizing head which is provided by screwing on the tip end of the rotary shaft 4. 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 circumference side and a paint discharge edge 11C on the tip side, and rotates at a high speed in the direction of arrow C about the axis OO.

Numeral 12 denotes a disk-shaped hub member disposed on the bottom side of the rotary atomizing head 11. The hub member 12 is provided with a coating material and a thinner at a position closer to the outer periphery than the rotary atomizing head 11. , The first hub holes 12A, 12A, leading to the paint smooth surface 11B.
… And the second, which is located at the center and supplies thinner to the tip
Are formed in concentric circles, respectively.

Reference numeral 13 denotes a cover of the coating machine main body 1. The cover 13 is formed in a tubular shape with an insulating resin material or the like, and covers the outer peripheral side of the coating machine main body 1 to protect the coating machine main body 1. It has become. The cover 13 is provided with an air passage 13A for shaping air.
An annular air reservoir 13B, which is located between the coating machine main body 1 and communicates with the air passage 13A, and a nozzle ring 15, which will be described later, are fixed to the coating machine main body 1 on the inner periphery of the tip side of the coating machine 3. A screw portion 13C is formed.

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

Reference numeral 15 denotes a nozzle ring serving as a shaping air ring which is screwed to the screw portion 13C of the cover 13 and is positioned at the tip end of the coating machine main body 1. The nozzle ring 15 is as shown in FIGS. A stepped cylindrical nozzle body 15C having a small-diameter male screw 15A screwed to the screw portion 13C of the cover 13 and a large-diameter male screw portion 15B screwed to a retainer tube 20 described later formed on the outer peripheral side. When,
An annular portion 15D protruding radially inward from the nozzle body 15C and abutting against the front end surface of the coating machine main body 1 and a guide groove 19 described later protruding forward from the nozzle body 15C and formed on the tip side. And an annular 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. I have.

Here, a plurality of (for example, 12 to 36) nozzle holes 17, 17,... Are bored in the nozzle body 15C of the nozzle ring 15 at a constant interval in the circumferential direction in the axial direction. The nozzle hole 17 has a base end communicating with the air reservoir 13B and a tip end communicating with the air chamber 16. Each nozzle hole 17 allows the shaping air from the air reservoir 13B to be introduced into the air chamber 16. As shown in FIG. 2, the annular portion 15D of the nozzle ring 15 has a plurality of ventilation holes 15G, 15G,
Are formed, and each of the ventilation holes 15G is provided in the air bearing 2 (FIG. 13).
) Is ejected toward the outer peripheral surface 11A side of the rotary atomization head 11 as necessary.

Reference numerals 18, 18,... Denote small-diameter air ejection holes which are located on the bottom side of the respective guide grooves 19 and are formed in the cylindrical projecting portion 15E of the nozzle ring 15. As shown in FIGS. 2 and 3, the cylindrical protrusion 15 </ b> E extends in the axial direction, and has a base end opening to the air chamber 16 and a tip end opening to each guide groove 19. In addition, each of the air ejection holes 1
Numerals 8 are formed to have a slightly smaller diameter than the width of each guide groove 19, and a total of about 20 to 40 are arranged at regular intervals in the circumferential direction of the cylindrical projection 15E. As shown in FIG. 1, each air ejection hole 18 is disposed radially outside the paint discharge edge 11 </ b> C of the rotary atomizing head 11 and is spaced apart by a predetermined dimension L (for example, about 2 to 3 mm). Then, the shaping air from the air chamber 16 is jetted in the axial direction toward each guide groove 19.

Reference numerals 19, 19,... Denote guide grooves as air guides formed on the distal end side of the cylindrical projection 15E of the nozzle ring 15, and each of the guide grooves 19 has a cross section as shown in FIGS. Has a narrow U-shaped groove.
A total of about 20 to 40 rows are formed in the circumferential direction of the cylindrical protruding portion 15E corresponding to each air ejection hole 18 and are spaced from each other. Each guide groove 19 has a constant twist angle θ with respect to a normal line LO passing through the axis O of the nozzle ring 15.
1 (for example, 45 degrees), it extends obliquely between the inner and outer peripheral surfaces of the cylindrical projecting portion 15E, opens to the inner and outer peripheral surfaces of the cylindrical projecting portion 15E, and has a tip end side end surface of the cylindrical projecting portion 15E. It is open in the axial direction.

Here, as shown in FIG. 2, each guide groove 19 is formed with a twist angle θ 1 which is opposite to the rotation direction (direction of arrow C) of the rotary atomizing head 11, and each air ejection hole 18 is formed. The high-pressure shaping air ejected from the nozzle is guided along the wall surface of each guide groove 19, and this shaping air is turned into a torsional jet flow around the rotary atomizing head 11 as shown by the imaginary line in FIG. Spout toward. Then, the shaping air which has become the torsional jet flow is twisted in the opposite direction to the rotation direction (the direction of arrow C) of the rotary atomizing head 11, and the paint discharging end is caused by the centrifugal force of the rotary atomizing head 11. Shaping air can be made to strongly collide with the paint that protrudes radially outward from the edge 11C.

Numeral 20 denotes a retainer cylinder which is attached to the nozzle ring 15 so as to surround the outer peripheral side of the nozzle ring 15 and forms a shaping air ring together with the nozzle ring 15. The retainer cylinder 20 has a stepped cylindrical shape. The base end of the nozzle ring 15 is screwed to the external thread portion 15B of the nozzle ring 15. The inner periphery of the retainer cylinder 20 is fitted on the outer periphery of the cylindrical projecting portion 15E of the nozzle ring 15 to define an annular air chamber 16 between the retainer cylinder 20 and the annular recess 15F of the nozzle ring 15. I have.

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

However, according to the present embodiment, the coating machine main body 1
A rotary atomizing head 11 is provided on the tip side of a cover 13 provided integrally with the
A nozzle ring 15 and a retainer cylinder 20 are provided so as to surround the rotary atomizing head 11 on the rear side of the paint discharge edge 11C. The nozzle rings 15 are arranged at regular intervals.
A plurality of guide grooves 19, 19,... Inclined obliquely by the twist angle θ1 with respect to the LO are formed, and the respective guide grooves 19 are formed.
Since the air ejection holes 18 for ejecting the shaping air into the respective guide grooves 19 are provided on the bottom side of the above, the following operational effects can be obtained.

First, similarly to the prior art, a high voltage is applied to the coating machine main body 1 so that the rotating shaft 4 and the rotary atomizing head 1 are rotated.
The rotating shaft 4 and the rotary atomizing head 11 are rotated at a high speed by an air motor 3 in the coating machine main body 1 while charging the substrate 1 with a high voltage to form an electrostatic field between the substrate 1 and the object to be coated.

In this state, the paint is supplied to the rotary atomizing head 11, and the supplied paint is charged while the supplied paint is spread along the paint smooth surface 11 B by the rotation (centrifugal force) of the rotary atomizing head 11. Then, after the film is discharged as a film or a liquid thread-like charged paint from the paint release edge 11C, it is atomized by mechanical atomization and electrostatic atomization to form 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 radially outward from the paint discharge edge 11C. However, the shaping air ejected in the axial direction 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 imaginary line in FIG. 4, the jets are ejected toward the periphery of the rotary atomizing head 11 as torsional jets each having a substantially elliptical shape. By directly colliding the shaping air with the charged paint particles discharged to the surface, 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 torsional jet flow becomes a torsional flow that is close to a swirling flow, the direction of the shaping air is adjusted, and the paint spray pattern can be effectively spread. In addition, the shaping air is twisted in the opposite direction to the rotation direction (the direction of arrow C) of the rotary atomizing head 11, so that the centrifugal force of the rotary atomizing head 11 protrudes radially outward from the paint discharge edge 11 </ b> C. As a result, the charged paint particles come to strongly collide with each other, and the charged paint particles can be uniformly dispersed in the 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, so that the spray pattern of the paint is changed. In addition to being able to be effectively adjusted according to the twisting state of the shaping air, the charged paint particles can be uniformly dispersed in the shaping air, and the finish quality of the coated surface of the object to be coated can be reliably improved.

Also, by spraying the shaping air from each air ejection hole 18 in a twisted state by each guide groove 19 formed on the tip end side of the nozzle ring 15, the paint spray pattern can be made larger than in the prior art. For example, even during metallic coating, the thickness of the coating film can be made uniform and a wide pattern can be applied, and the coating time can be greatly reduced compared to the conventional coating equipment, and the painted surface can be cleaned Can be finished.

In particular, in the case of metallic coating, the particle speed of the coating particles when applying to the object to be coated becomes a problem, and when it is not an appropriate particle speed, it becomes difficult to realize glossy coating. . However, in the present embodiment, the collision speed with the object to be coated can be adjusted by ejecting the shaping air as a torsional ejection flow toward the periphery of the rotary atomizing head 11, and the glossy painted surface can be adjusted. Various effects are achieved, such as easy realization.

Next, FIG. 5 shows a second embodiment of the present invention. In this embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and description thereof will be omitted. I do. However, the feature of the present embodiment is that the guide grooves 31 as air guides arranged at regular intervals in the circumferential direction on the tip end side of the cylindrical projection 15E of the nozzle ring 15 are provided in the rotation direction of the rotary atomizing head 11 (arrows). Torsion angle θ2 which is the forward direction to
Is formed so as to extend diagonally.

Here, each guide groove 31 is formed as a concave groove formed of a narrow long groove having a U-shaped cross section, substantially in the same manner as each guide groove 19 described in the first embodiment. A total of about 20 to 40 cylindrical projections 15E are arranged in the circumferential direction of the cylindrical projections 15E corresponding to the air ejection holes 18.
Each of the guide grooves 31 is connected to the axis O of the nozzle ring 15.
A constant torsion angle θ2 (eg 45
) To extend 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 to open in the axial direction on the distal end side end surface of the cylindrical protruding portion 15E. are doing.

Thus, in the present embodiment having the above-described structure, substantially the same operation and effect as those of the first embodiment can be obtained.
By guiding the shaping air spouting in the axial direction from the air spouting holes 18 in the guide grooves 5 in the guide grooves 31,
An ejection flow of shaping air that is twisted in a forward direction with respect to the rotation direction of the rotary atomizing head 11 (the direction of arrow C) can be generated.

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

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 port of each auxiliary air ejection path is located between each concave groove (guide groove) as an air guide and is opened to the tip end side of the shaping air ring. In this embodiment, the same reference numerals are given to the same components as those in the first embodiment, 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 formed in a cylindrical shape with an insulating resin material or the like. Is covered. Further, 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 periphery of the distal end side of the cover 41.
And an annular air reservoir 41D communicating with the air passage 41B
And a screw portion 41E for fixing a nozzle ring 42 to be described later to the coating machine main body 1 side.

Reference numeral 42 denotes a nozzle ring serving as a shaping air ring which is screwed to the screw portion 41E of the cover 41 and is positioned at the tip end of the coating machine main body 1. The nozzle ring 42 is described in the first embodiment. Nozzle ring 15
7 and 8, a nozzle body 42C, an annular portion 42D, a cylindrical protrusion 42E, and an annular recess 42F each having an external thread 42A and an external thread 42B formed on the outer peripheral side as shown in FIGS. 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 bored in the nozzle body 42C of the nozzle ring 42 in the axial direction at a constant interval in the circumferential direction. The nozzle hole 43 has a base end communicating with the air reservoir 41C and a tip end communicating with the air chamber 16. Each nozzle hole 43 introduces shaping air from the air reservoir 41C into the air chamber 16. As shown in FIG. 7, the annular portion 42D of the nozzle ring 42 has a plurality of ventilation holes 42G, 42G,
Are formed, and each of the ventilation holes 42G is provided in the air bearing 2 (FIG. 13).
) Is ejected toward the outer peripheral surface 11A side of the rotary atomization head 11 as necessary.

Reference numerals 44, 44,... Designate auxiliary air ejection paths formed in the nozzle ring 42.
7 and 8 extend in the axial direction of the nozzle main body 42C and the cylindrical protrusion 42E, and the base end side has an air reservoir 41D.
It is open to. The tip end side of each auxiliary air ejection path 44 is a small-diameter ejection port 44A located between the guide grooves 19 and opening at the tip end face of the cylindrical projection 42E. The auxiliary air from 41D is jetted in the axial direction toward the object to be coated.

Here, as shown in FIG. 6, each of the jet ports 44A is disposed 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. A constant dimension L (for example, 2
Each air ejection hole 18 spaced apart by about 3 mm is arranged radially inward by a dimension L1 (L1≤L). Each of the ejection ports 44A has a cylindrical projection 42E.
For example, two (or one) openings are formed between the guide grooves 19 on the distal end surface of the cylindrical protrusion 42.
A total of about 20 to 80 pieces are arranged along the circumferential direction of E.

Thus, in this embodiment constructed as described above, substantially the same operation and effect as those of the first embodiment can be obtained. In this embodiment, however, the nozzle ring 42 extends in the axial direction. A plurality of auxiliary air ejection paths 44, 44, ...
And the outlets 4 of the auxiliary air outlets 44
4A is located between the guide grooves 19 and is opened at the distal end face of the cylindrical projection 42E, so that 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. Spout 44
Since A is configured to eject auxiliary air in the axial direction toward the object to be coated from A, the auxiliary air can effectively impart energy toward the object to be charged to the charged paint particles from the rotary atomizing head 11, The spray pattern of the paint can be effectively widened while giving these paint particles advancement toward the object to be coated.

Further, by separately adjusting the pressure of the auxiliary air and the shaping air, the jet of the shaping air and the jet of the auxiliary air can be appropriately adjusted in accordance with various kinds of 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 paint spray pattern can be reliably improved. it can.

Next, FIGS. 10 and 11 show a fourth embodiment of the present invention.
In this embodiment, the same reference numerals are given to the same components as those in the first embodiment, and the description thereof will be omitted. However, the feature of this embodiment is that the nozzle ring 1
A plurality of auxiliary air ejection paths 51, 51,... For ejecting the auxiliary air toward the object to be coated are formed on the cylindrical protrusion 15E of the fifth member.
The configuration is such that the distal end side of each of the auxiliary air ejection paths 51 is opened at the distal end side end face of the cylindrical projection 15E as an ejection port 51A located between the guide grooves 19.

Here, each auxiliary air ejection passage 51 extends in the axial direction of the cylindrical projecting portion 15E, the base end side is open to the air chamber 16, and the tip end side is an ejection port 51A. And
Each ejection port 51A of each auxiliary air ejection path 51 is substantially the same as the paint discharge edge 11C of the rotary atomizing head 11, similarly to the ejection port 44A of each auxiliary air ejection path 44 described in the third embodiment. Alternatively, for each of the air ejection holes 18 that are disposed slightly radially outward from the paint discharge edge 11C and are separated from the paint discharge edge 11C by a fixed dimension L, a dimension L2 (L
2 ≤ L) and are disposed radially inward.

Each of the ejection ports 51A has a cylindrical projection 15E.
Located between the guide grooves 19 on the front end surface of
It is formed so as to be opened one by one (or one by one), and a total of about 20 to 80 pieces are arranged in the circumferential direction of the cylindrical projection 15E.

Thus, in the present embodiment having the above-described structure, substantially the same operation and effect as those of the first embodiment can be obtained. Since the auxiliary air is ejected from the ejection port 51A of the auxiliary air ejection path 51 toward the object to be coated,
The auxiliary air can effectively impart energy toward the object to be charged to the charged paint particles from the rotary atomizing head 11, and give the paint particles advancement toward the object to be coated, while also effecting the spray pattern of the paint. Can be spread out.

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

Here, each of the guide grooves 61 is formed as a concave groove formed of a narrow long groove having a U-shaped cross section, similarly to the guide grooves 19 described in the first embodiment. A total of about 20 to 40 pieces are arranged in the circumferential direction of the cylindrical projecting portion 42E so as to correspond to the respective air ejection holes 18.
However, each guide groove 61 is formed such that the twist angle is zero with respect to a normal line LO passing through the axis O of the nozzle ring 42,
The cylindrical projection 42E has an opening on the inner and outer peripheral surfaces thereof, and has an opening in the axial direction on the distal end surface of the cylindrical projection 42E.

Each of the auxiliary air ejection passages 62 is located between the guide grooves 61 on the distal end surface of the cylindrical projection 42E.
Are opened, and the outlets 62A of the auxiliary air outlets 62 are configured to blow auxiliary air toward the object to be coated in the same manner as the auxiliary air outlets 44 described in the third embodiment. Has become.

Thus, also in the present embodiment having such a configuration, a plurality of guide grooves 61 as a plurality of concave grooves having a small groove width are arranged in the circumferential direction on the distal end side of the cylindrical projecting portion 42E of the nozzle ring 42. Since each air ejection hole 18 is formed at the bottom side of each guide groove 61 so as to open into each guide groove 61, high-pressure shaping ejected from each air ejection hole 18 is provided. The air can be made into a jet flow in a diffused state having a spread along the wall surface of each guide groove 61, and the flow rate of the shaping air and the degree of mixing / dispersion with the paint particles are determined according to the groove width of each guide groove 61. Thus, the same effects as those of the first embodiment can be obtained.

Further, in this embodiment, since the auxiliary air is ejected from the ejection ports 62A of the auxiliary air ejection passages 62 located between the guide grooves 61 toward the object to be coated,
The auxiliary air can effectively impart energy toward the object to be charged to the charged paint particles from the rotary atomizing head 11, and give the paint particles advancement toward the object to be coated, while also effecting the spray pattern of the paint. Can be spread out.

In the fifth embodiment, it is assumed that the auxiliary air ejection passages 62 located between the guide grooves 61 and open to the end face on the distal end side of the cylindrical projection 42E are formed in the nozzle ring 42. However, each of these auxiliary air ejection paths 62
Need not necessarily be provided. On the other hand, the nozzle ring 15 described in the second embodiment is provided with the same auxiliary air ejection path as the auxiliary air ejection path 44 (51) described in the third and fourth embodiments. You may.

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

[0078]

As described above in detail, according to the first aspect of the present invention, an air guide formed of a plurality of concave grooves formed circumferentially apart on the tip side of a shaping air ring is provided with a constant twist angle. And extend it obliquely with each air injection hole.
Since the opening is formed on the bottom side of the groove, the shaping air from each air ejection hole is guided by the wall surface of each groove.
As a result, it becomes almost elliptical toward the periphery of the rotary atomizing head
It can be ejected as a jet stream of the torsional state. This
For, it is possible to flow and torsional state close to shaping air to the swirling flow, it is possible to widen the spray pattern of the coating material effectively, it is possible to uniformly disperse the paint particles, for example metallic coating or the like Finish can be reliably improved. Also, the flow rate of shaping air and paint particles
Effectively mix and disperse with the child according to the twist angle of each groove
Can be adjusted.

In this case, as in the second or third aspect of the present invention, each of the air guides has a torsion angle that is opposite to or forward of the rotational direction of the rotary atomizing head. By forming it on the tip side, the flow rate of shaping air and the degree of mixing and dispersion with the paint particles can be stabilized, and a spray pattern suitable for various paints can be obtained.

Further, a plurality of auxiliary air ejection passages located between the respective air guides and ejecting the auxiliary air toward the object to be coated are formed in the shaping air ring. For example, the auxiliary air from each auxiliary air ejection path can effectively apply energy toward the object to be applied to the paint particles from the rotary atomizing head, and give these paint particles advancement toward the object to be applied. In addition, the spray pattern of the paint can be effectively widened. By separately adjusting the auxiliary air and the shaping air, the ejection flow of the shaping air and the ejection flow of the auxiliary air can be appropriately adjusted in accordance with various kinds of paint, so that the energy of the paint particles toward the object to be coated can be adjusted. Can be used as 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.

On the other hand, as in the fifth aspect of the present invention, a shaping air ring is provided on the tip side of the shaping air ring.
D comprising a plurality of grooves extending radially with respect to the axis of the grayed
By arranging the guides in the circumferential direction and forming the air ejection holes on the bottom side of each of the grooves so as to open into the respective grooves, the high pressure jetting from each of the air ejection holes can also be achieved. Of the shaping air can be made into a diffused jet flow that spreads along the wall of each groove, and the flow rate of the shaping air and the degree of mixing / dispersion with the paint particles can be adjusted according to the groove width of each groove. Can be adjusted appropriately.

[0082] Then, even in this case, as in the invention according to claim 6, forming a plurality of auxiliary air ejection passage which opens on the distal end side of the shaping air ring located between the air guide, each of said auxiliary By using a configuration in which auxiliary air is ejected from the air ejection hole toward the object to be coated, the energy directed toward the object to be coated can be reliably applied to the paint particles by the jet flow of the auxiliary air, which is suitable for various types of paint. It is possible to effectively impart the forward assisting performance to the paint particles, improve the spray pattern of the paint without fail, and obtain a spray pattern suitable for various paints.

Further, according to a seventh aspect of the present invention, an air guide
Small groove width on the tip side of the shaping air ring.
May be arranged in the circumferential direction as concave grooves formed by long grooves.

[Brief description of the drawings]

FIG. 1 is a longitudinal 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. 1;

FIG. 3 is an enlarged sectional view taken in the direction of arrows III-III in FIG. 2;

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

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

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

FIG. 7 is an enlarged front view showing a nozzle ring in FIG. 6;

8 is an enlarged sectional view taken in the direction of arrows VIII-VIII in FIG. 7;

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

FIG. 10 is an enlarged longitudinal sectional view showing a nozzle ring, an auxiliary air injection path, and the like of a rotary atomizing head type electrostatic coating apparatus according to a fourth embodiment.

FIG. 11 is an enlarged view of the nozzle ring in FIG. 10;
It is an enlarged 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 apparatus according to a fifth embodiment.

FIG. 13 is a longitudinal sectional view showing a rotary atomizing head, a shaping air ring, and the like of a conventional rotary atomizing head type electrostatic coating apparatus.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Coating machine main body 3 Air motor (rotation source) 11 Rotary atomization head 11A Outer peripheral 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 Exit 61 Guide groove (concave groove)

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) B05B 5/00-5/04

Claims (7)

(57) [Claims] 1. A coating machine main body having a rotation source, and a rotary atomizer rotatably provided at a tip side of the coating machine main body and formed in a tubular or cup shape such that the tip side is a paint discharge edge. and head, the rotary atomizing head type coating apparatus comprising a shaping air ring for ejecting shaping air toward the periphery of said rotary atomizing head, before Symbol shaping air ring, the circumferential direction of the shaping air ring A plurality of air ejection holes formed to be spaced apart from each other and ejecting the shaping air in the axial direction; and a plurality of air ejection holes corresponding to the respective air ejection holes are separated in a circumferential direction of the shaping air ring and at a tip side of the shaping air ring. With respect to the normal passing through the axis of the shaping air ring
Multiple grooves formed diagonally with a constant twist angle
Provided a Ranaru air guide, each air ejection hole, respective
A rotary atomizing head type coating apparatus characterized in that it is configured to open to the bottom side of the concave groove . 2. 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 opposite to a rotation direction of the rotary atomizing head. Mold 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 forward with respect to a rotation direction of the rotary atomizing head. Mold coating equipment. 4. The shaping air ring has a plurality of auxiliary air ejection paths which are located between the respective air guides and open to the tip side of the shaping air ring, and which eject auxiliary air toward an object to be coated. The rotary atomizing head type coating apparatus according to claim 1, 2 or 3, which is formed. 5. A coating machine main body having a rotation source, and a rotary atomizer which is rotatably provided at a tip end side of the coating machine main body and is formed in a cylindrical or cup shape such that the tip end side is a paint discharge edge. and head, the rotary atomizing head type coating apparatus comprising a shaping air ring for ejecting shaping air toward the periphery of said rotary atomizing head, before Symbol shaping air ring, the circumferential direction of the shaping air ring A plurality of air ejection holes formed at a distance from each other to eject the shaping air in the axial direction, and a tip side of the shaping air ring corresponding to each of the air ejection holes.
Said shaping air ring with spaced circumferentially
On the tip side of the shaping air ring
An air guide consisting of a plurality of radially extending grooves
And de provided, each air ejection holes on the bottom side of the respective grooves
A rotary atomizing head type coating apparatus characterized by having an opening . 6. The shaping air ring has a plurality of auxiliary air ejection passages located between the respective air guides and open to the tip side of the shaping air ring to eject auxiliary air toward the object to be coated. The rotary atomizing head type coating apparatus according to claim 5 , which is formed. 7. The shaping device according to claim 1 , wherein
A concave consisting of a long groove with a small groove width on the tip side of the ring
5. The method according to claim 1, wherein the grooves are arranged in a circumferential direction.
7. The rotary atomizing head type coating apparatus according to 5 or 6.