JPH1076190A - Rotary atomizing head type coater - Google Patents

Abstract

PROBLEM TO BE SOLVED: To surely atomize paint to finish the coated surface well. SOLUTION: Each jetting hole 26 is inclined so that an opening 26A on the jetting side thereof may be opened toward the direction of the arrow B reverse to the rotating direction of a rotary atomizing head 19, and also the opening 26A on the jetting side is inclined to the center of rotation side of the rotary atomizing head 26A. Therefore, shaping air jetted from each jetting hole has a head-on collision with liquid thread of paint flying the tangential direction the same amount as the jetting hole opening 26A is inclined to the center of rotation side of the rotary atomizing head 19. In this way, most of energy of the shaping air is acted on the liquid thread to atomize the paint and better coating finish. And a shaping air ring 21 is made to have a large diameter, and the shaping ring 21 can be attached and detached with the rotary atomizing head 19 being fitted to the rotating shaft.

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 machine suitable for coating an object such as an automobile body.

[0002]

2. Description of the Related Art In general, a rotary atomizing head type coating machine is widely used as a coating machine for coating an object such as a car body. This rotary atomizing head type coating machine has a coating machine cover having an air motor built therein, and a rotary atomization that discharges paint from a paint discharge edge by being rotated by the air motor at a tip side of the coating machine cover. A head, a shaping air ring provided on the coating machine cover at an outer peripheral side of the rotary atomizing head, and a shaping air ring formed on the shaping air ring, toward a vicinity of a paint discharge edge of the rotary atomizing head. It is roughly constituted by a plurality of air ejection holes for ejecting shaping air.

Further, in the rotary atomizing head type coating machine configured as described above, each of the air ejection holes is disposed so as to be inclined in the same direction or the opposite direction to the rotation direction of the rotary atomizing head. There is. Of these, those with each air ejection hole inclined so that the ejection side opening faces in the direction opposite to the rotation direction of the rotary atomizing head,
For example, it is known from JP-A-3-101858.

FIGS. 7 to 9 show a rotary atomizing head according to the prior art, in which each of the rotary atomizing heads has a respective air jetting hole inclined so that the ejection side opening faces in the direction opposite to the rotation direction of the rotary atomizing head. This shows a head type coating machine.

In the drawing, reference numeral 1 denotes a coating machine cover formed in a stepped cylindrical shape, and the coating machine cover 1 has a built-in air motor (not shown). Further, a rotary atomizing head 2 and the like described later are provided on the distal end side of the coating machine cover 1, and the base end side is attached to a reciprocator, a coating robot (neither is shown), or the like.

Reference numeral 2 denotes a rotary atomizing head which is located on the tip side of the coating machine cover 1 and is attached to a rotary shaft (not shown) of an air motor. The rotary atomizing head 2 is a bell which expands forward. It has a shape, and its outer peripheral edge is a paint release edge 2A for releasing paint as a liquid thread. Then, as shown in FIG. 8, the rotary atomization head 2 is rotated at a high speed in the direction of arrow A by the air motor, thereby discharging the supplied paint as a liquid thread from the paint discharge edge 2A by centrifugal force. Things.

Reference numeral 3 denotes a cylindrical shaping air ring which is provided on the tip side of the coating machine cover 1 at a position on the outer peripheral side of the rotary atomizing head 2.
An annular chamber chamber (not shown) is provided therein,
A plurality of air ejection holes 4, 4,... Are formed on the distal end side so as to communicate with the chamber chamber. Then, the shaping air ring 3 blows out the air supplied from a compressed air source (not shown) as shaping air toward the vicinity of the paint discharge edge 2A of the rotary atomizing head 2 from each of the air blowing holes 4. Thus, the shaping air ring 3 shears and atomizes the liquid thread of the paint discharged from the rotary atomizing head 2,
The spray pattern of the atomized paint is shaped.

Here, each of the air ejection holes 4 is formed such that its ejection side opening is inclined in the direction indicated by arrow B which is opposite to the direction indicated by arrow A which is the direction of rotation of the rotary atomizing head 2. This allows
As shown in FIG. 9, each air ejection hole 4 collides shaping air so as to face the paint discharged as a liquid thread from the paint discharge edge 2 </ b> A of the rotary atomizing head 2.

In the rotary atomizing head type coating machine thus configured, the rotary atomizing head 2 is rotated at a high speed by an air motor, and paint is supplied to the rotary atomizing head 2 in this state.
Thereby, the paint supplied to the rotary atomizing head 2 is discharged as a liquid thread from the paint discharging edge 2A by the centrifugal force when the rotary atomizing head 2 rotates. At this time, the liquid thread of the paint flies toward the object in a state where it is sheared and atomized by the shaping air ejected from each air ejection hole 4 while being shaped into a desired spray pattern, and Painted on.

[0010]

By the way, in the above-mentioned rotary atomizing head type coating machine according to the prior art, each air ejection hole 4 is provided.
In the direction of rotation of the rotary atomizing head 2 (arrow A).
Direction) and in the direction indicated by the arrow B in the opposite direction.
As a result, as compared with the case where the shaping air is jetted straight forward, the shaping air collides with the liquid thread of the paint discharged from the rotary atomizing head 2 so as to face the shaping air.

However, simply tilting each air ejection hole 4 in the direction opposite to the rotation direction of the rotary atomizing head 2 (the direction indicated by the arrow A) limits the setting range of the shaping air ejection direction. The jet direction cannot be effectively opposed to the paint discharged from the rotary atomizing head 2 and flying.
Therefore, as shown in FIG. 9, of the energy E of the shaping air, only the energy E1 acts on the discharged paint. As a result, there is a problem that the paint discharged from the rotary atomizing head 2 cannot be effectively atomized by shaping air, and the finished state of the painted surface cannot be improved. Thus, for example,
When applying metallic paint, the brightness (I
There is a problem that it is not possible to improve the N.sub.tensity Value (IV value).

Therefore, in order to effectively atomize the paint discharged from the rotary atomizing head 2, a large amount of shaping air may be sprayed. But in this case,
Since a large air chamber is required to supply a large amount of air to each air ejection hole 4, there is a problem that providing the large air chamber increases the size of the coating machine.

Further, the use of a large amount of shaping air increases the size of an air compressor (not shown) for supplying the air, thereby increasing the running cost associated with the air supply.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems of the prior art, and provides a rotary atomizing head type coating machine capable of surely atomizing a coating material and satisfactorily finishing a coated surface. With the goal.

[0015]

In order to solve the above-mentioned problems, a rotary atomizing head type coating machine according to the first aspect of the present invention comprises:
A coating machine cover having an air motor built therein, a rotary atomizing head that discharges paint from a paint discharging edge by being rotated by the air motor at a tip side of the coating machine cover, and an outer peripheral side of the rotary atomizing head. A shaping air ring provided on the coating machine cover and a plurality of air ejection holes formed on the shaping air ring and ejecting shaping air toward a vicinity of a paint discharge edge of the rotary atomizing head. Become.

A feature of the structure adopted by the first aspect of the present invention is that each of the air ejection holes has its ejection side opening inclined in a direction opposite to the rotation direction of the rotary atomizing head, and the ejection side opening is provided with the air ejection side opening. It has been tilted toward the center of rotation of the rotary atomizing head.

With this configuration, the shaping air ejected from the ejection side openings of the respective air ejection holes is supplied so as to face the paint discharged from the rotary atomizing head. Many can be used for shearing and atomizing the liquid thread, and the coating can be reliably atomized. Further, since much of the energy of the shaping air can act, it is possible to atomize the paint and shape the spray pattern with a small amount of shaping air.

According to a second aspect of the present invention, the shaping air ring has a minimum inner diameter set to be larger than a maximum outer diameter of the rotary atomizing head.

Thus, the shaping air ring can be attached to and detached from the coating machine cover while the rotary atomizing head is mounted on the rotating shaft of the air motor. When the shaping air ring is removed, the rotary atomizing head can be removed. Can be easily removed from the rotating shaft of the air motor.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a rotary atomizing head type coating machine according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

In the figure, reference numeral 11 denotes a bottomed cylindrical coating machine cover which is an outer shape of a rotary atomizing head type coating machine, and an inner peripheral side of the coating machine cover 11 is a motor accommodating portion 12. Also,
The base end of the coating machine cover 11 is attached to a reciprocator, a coating robot (both not shown), and the like. Further, an outer cylinder 14 and an inner cylinder 15 are formed on the outer peripheral side of the distal end of the coating machine cover 11 with an annular ring mounting groove 13 into which a fitting cylinder 21A of a shaping air ring 21 described later is fitted. Screw portions 14A and 15A are formed on the inner peripheral side of the outer cylinder 14 and the inner cylinder 15.

Reference numeral 16 denotes the motor housing 1 of the coating machine cover 11.
The air motor 17 accommodated in the air motor 2
The rotating shaft 17 is rotatably supported at a high speed via an air bearing (not shown). The rotation shaft 17 has a proximal end fixed to an air turbine (not shown) and a distal end protruding from the air motor 16.

Reference numeral 18 denotes a motor fixing ring provided on the opening side of the motor accommodating portion 12, and a screw portion 18A is engraved on an outer peripheral surface of the motor fixing ring 18. Then, the motor fixing ring 18 is provided with the screw portion 18A for the coating machine cover 11.
The air motor 16 is fixed in the motor accommodating portion 12 by being screwed into a screw portion 15A engraved on the inner cylinder 15.

Reference numeral 19 denotes a bell-shaped rotary atomizing head attached to the distal end of the rotary shaft 17, and the rotary atomizing head 19 is formed so as to expand toward the distal end. Further, the base end side of the rotary atomizing head 19 is attached to the mounting portion 1 which is screwed to the distal end of the rotary shaft 17.
9A, and the front side, which is the tip side, is a paint smoothing surface 19B.
It has become. Further, the outer periphery of the paint smoothing surface 19B has a paint release edge 19 that releases the smoothed paint as a liquid thread.
C.

A feed tube 20 is inserted into the rotary shaft 17 and discharges paint or thinner toward the rotary atomizing head 19. The feed tube 20 has a base end protruding from the rotary shaft 17 and is fixed to the air motor 16. Have been. The distal end of the feed tube 20 protrudes from the rotary shaft 17 and extends into the rotary atomizing head 19.

Reference numeral 21 denotes a cylindrical shaping air ring which is detachably attached to the tip end of the coating machine cover 11, and the base end of the shaping air ring 21 is inside the ring mounting groove 13 of the coating machine cover 11. Is formed with a thin fitting cylindrical portion 21A. Further, the shaping air ring 21 is provided with a screw portion 21B which is located on the outer peripheral surface of the fitting tube portion 21A and is screwed to the screw portion 14A of the outer tube 14. Further, the shaping air ring 21 is provided with air ejection holes 26 to be described later, which are opened at the front end surface 21C.

The fitting cylindrical portion 21A is fitted in the ring mounting groove 13 to define an annular passage 22. The annular passage 22 is connected to an air supply source such as an air tank through an air supply passage 23 or the like. (Not shown). Here, the shaping air ring 21 has a minimum inner diameter dimension d that is larger than the maximum outer diameter dimension D of the rotary atomizing head 19 by a radial dimension δ for the reason described later. Even in the state of being attached to the rotating shaft 17,
It is configured to be removable from the coating machine cover 11.

Are a plurality of air passages formed in the shaping air ring 21; 25 is an annular air chamber formed in communication with each of the air passages 24; Supply passage 23, annular passage 2
2. By temporarily storing the air supplied through each air passage 24, the air is uniformly supplied to each air ejection hole 26.

Are a plurality of air ejection holes provided at the tip end of the shaping air ring 21. Each of the air ejection holes 26 has an annular shape air ring 21 as shown in FIG. They are arranged at equal intervals on a concentric pitch circle C. The upstream side of each of the air ejection holes 26 communicates with the air chamber 25, and the downstream side of the air ejection hole 26 opens to the tip end surface 21 </ b> C of the shaping air ring 21 to form an ejection side opening 26 </ b> A.

Here, as shown in FIG. 3, each of the air ejection holes 26 has an ejection side opening 26A in a direction indicated by an arrow B where the direction of rotation of the rotary atomizing head 19 is opposite to the direction indicated by an arrow A. It is open towards. That is, it is inclined at an angle α with respect to an axis OO provided in parallel with the axis of the rotating shaft 17.
Further, as shown in FIG. 2, each air ejection hole 26 has its ejection side opening 26A side inclined toward the rotation center of the rotary atomizing head 19 (the axis center of the rotation shaft 17). That is, each air ejection hole 26 is inclined radially outward with an angle β with respect to a tangent line FF that is in contact with the pitch circle C at a portion where each air ejection hole 26 is opened. In addition, the inclination angle α of each air ejection hole 26
Is set, for example, between 10 degrees and 70 degrees, and preferably 45 degrees. The inclination angle β is, for example, 1 degree to 45 degrees.
It is set to between degrees, preferably 5 degrees 12 minutes.

Each of the air ejection holes 26 having such inclination forms the shaping air ejected from the ejection opening 26A in a spiral shape as shown in FIGS. The shaping air is supplied to each air ejection hole 26.
Are ejected from the formed pitch circle C so as to gradually reduce the diameter. Thus, the shaping air flows so as to gradually increase in diameter after being reduced in diameter in the vicinity of the paint discharge edge 19C of the rotary atomizing head 19.

Accordingly, as shown in FIG. 6, the shaping air jetted from each air jet hole 26 is jetted inward from the jetting direction of the shaping air according to the prior art shown by the two-dot chain line. This allows the shaping air to
Since the collision occurs so as to face the paint discharged from the rotary atomizing head 19, a large amount of energy E2 of the energy E of the shaping air may act to atomize the liquid thread of the discharged paint. it can.

Further, when the position where the shaping air collides with the discharged paint is set on the same circular arc in the embodiment and the prior art, the air ejection according to the embodiment corresponds to the amount of the shaping air ejected inward. The hole 26 will be disposed radially outward. For this reason, the diameter of the shaping air ring 21 can be increased, and the rotary atomizing head 19 can be used.
The minimum inner diameter d of the shaping air ring 21 can be made larger than the maximum outer diameter D by the radial dimension δ.

The rotary atomizing head type coating machine according to the present embodiment has the above-described configuration, and its operation will be described below.

First, for example, when coating an object to be coated such as a vehicle body, the rotary atomizing head 19 is rotated at a high speed together with the rotating shaft 17 by the air motor 16 and in this state, the rotary atomizing head 19 is moved from the feed tube 20 to the rotary atomizing head 19. Supply paint for
As a result, the paint discharged to the rotary atomizing head 19 moves onto the paint smoothing surface 19B by centrifugal force and is discharged as a liquid thread from the paint discharge edge 19C. The paint discharged from the rotary atomizing head 19 is sheared and atomized by shaping air ejected from each air ejection hole 26 through the air supply passage 23, the annular passage 22, each air passage 24, and the air chamber 25. Meanwhile, it is shaped into a desired spray pattern. At this time, the atomized coating material is charged to a high voltage by, for example, an external electrode (not shown), and flies along an electrostatic field formed toward the coating object at the ground potential. Paint on.

At the time of this coating, the ejection side opening 26A of each air ejection hole 26 is inclined and opened in the direction of arrow B opposite to the rotation direction of the rotary atomizing head 19, and the rotary atomizing head 19 is opened. Is opened so as to be inclined toward the rotation center side of. For this reason, since the shaping air can collide with the paint flying in the tangential direction from the paint discharge edge 19C of the rotary atomizing head 19 so as to face the paint, a large amount of energy E2 of the energy E of the shaping air can be obtained. It can act on the paint, and can further promote the atomization of the paint.

On the other hand, the ejection side opening 26 of each air ejection hole 26
By opening A toward the rotation center side of the rotary atomizing head 19, each of the air ejection holes 26 can be arranged at a position radially outward from the rotary atomizing head 19, and the shaping air ring 21 can be enlarged. The diameter can be increased. Therefore, the minimum inner diameter d of the shaping air ring 21 can be made larger than the maximum outer diameter D of the rotary atomizing head 19 by the radial dimension δ. Thus, the shaping air ring 21 can be easily attached to and detached from the coating machine cover 11 with the rotary atomizing head 19 attached to the rotary shaft 17.

When the rotary atomizing head 19 is attached to and detached from the rotary shaft 17, the shaping air ring 21 is removed.
With the rotation of the rotating shaft 17 regulated by a tool such as a spanner,
By rotating the rotary atomizing head 19, it can be easily attached and detached.

Thus, according to the present embodiment, the shaping air ejected from each air ejection hole 26 is supplied to the rotary atomizing head 19.
Can be made to collide with the paint discharged from the front side. Thereby, the atomization of the paint by the shaping air can be promoted, and for example, when a metallic paint is applied, the brightness (IV value) can be improved. As a result, the finish of the coated surface can be improved, and the coating performance of the rotary atomizing head type coating machine can be improved.

Further, since the atomization of the paint by the shaping air can be promoted, the atomization and pattern shaping of the paint can be performed with a small amount of shaping air. Therefore,
The air chamber 25 can be reduced in size, and the rotary atomizing head type coating machine can be reduced in size. Further, since the amount of air used is reduced, the size of the air compressor and the like can be reduced, and the running cost can be reduced.

Further, the ejection side opening 2 of each air ejection hole 26 is provided.
The minimum inner diameter d of the shaping air ring 21 is made larger than the maximum outer diameter D of the rotary atomizing head 19 by the radial dimension δ by opening 6A toward the rotation center side of the rotary atomizing head 19. Can be. Accordingly, the shaping air ring 21 can be easily attached to and detached from the coating machine cover 11 while the rotary atomizing head 19 is attached to the rotating shaft 17, and the shaping air ring 21 can be easily cleaned and replaced at the time of cleaning work and replacement work. Workability can be improved.

In addition, when the rotary atomizing head 19 is to be attached or detached for cleaning or repairing the entire coating machine, the rotation of the rotary shaft 17 should be restricted by a tool such as a wrench with the shaping air ring 21 removed. Thereby, the rotary atomizing head 19 can be easily attached and detached. Thus, for example, there is no need to provide an opening or the like through which a tool such as a wrench is inserted toward the rotating shaft 17 in the shaping air ring 21, and the shape of the shaping air ring 21 can be simplified.

Further, in this embodiment, the coating machine cover 11
Each air ejection hole 26 is provided in a shaping air ring 21 which can be attached to and detached from each other. Therefore, for example, a plurality of types of shaping air rings 21 are prepared, and the air ejection holes 26 having different hole diameters, numbers, inclination angles, etc. are formed as appropriate for each shaping air ring 21. Thus, when the paint to be coated is changed and the characteristics of the paint are changed, the shaping air according to the paint can be easily selected by exchanging the shaping air ring 21, and the setting change work can be easily performed. Can do it.

In the above-described embodiment, the case where the paint discharged from the rotary atomizing head 19 is charged to a high voltage by the external electrode is exemplified. Alternatively, for example, a high voltage may be generated in the coating machine cover. The paint may be directly charged to a high voltage via a rotating shaft, a feed tube or the like by incorporating a device.

[0045]

As described above in detail, according to the first aspect of the present invention, each air ejection hole has its ejection side opening inclined in the direction opposite to the rotation direction of the rotary atomizing head, and the ejection side opening rotates. Since it is configured to be inclined to the rotation center side of the atomizing head, it is possible to supply the shaping air ejected from the ejection side opening of each air ejection hole in opposition to the paint discharged from the rotating atomization head. . Therefore, a large amount of the energy of the shaping air can be used to shear the liquid thread of the paint to atomize the paint, and the paint can be reliably atomized. Thereby, the atomization of the paint by the shaping air can be promoted. For example, when a metallic paint is applied, the lightness and darkness (IV value) can be improved, and the finish of the painted surface can be improved, and the rotation can be improved. The coating performance of the atomizing head type coating machine can be improved.

Further, since the energy of the shaping air can be made to act efficiently, it is possible to atomize the paint and shape the spray pattern with a small amount of shaping air. As a result, the size of the air chamber and the like for supplying air to each air ejection hole can be reduced, and the rotary atomizing head type coating machine can be reduced in size. Further, since the amount of air used can be reduced, the size of the air compressor and the like can be reduced, and the running cost for supplying air can be reduced.

According to the second aspect of the present invention, the minimum inner diameter of the shaping air ring is made larger than the maximum outer diameter of the rotary atomizing head, so that the rotary atomizing head is mounted on the rotary shaft of the air motor. In this state, the shaping air ring can be easily attached to and detached from the coating machine cover.
The workability of the cleaning work and the replacement work of the shaping air ring can be improved. In addition, when the rotary atomizing head is to be attached or detached for cleaning or repairing the entire coating machine, the rotation of the rotary shaft is restricted by a tool such as a wrench with the shaping air ring removed. As a result, the rotary atomizing head can be easily attached and detached, so that, for example, it is not necessary to provide an opening or the like for inserting the tool toward the rotating shaft in the shaping air ring, thereby simplifying the shape of the shaping air ring. Can be.

[Brief description of the drawings]

FIG. 1 is a partially broken side view showing a main part of a rotary atomizing head type coating machine according to an embodiment of the present invention.

FIG. 2 is an enlarged front view of a main part viewed from a direction indicated by arrows II-II in FIG. 1;

FIG. 3 is a cross-sectional view taken from the direction of arrows III-III in FIG.

FIG. 4 is a side view showing a trajectory of shaping air ejected from each air ejection hole.

FIG. 5 is a front view showing the trajectory of shaping air ejected from each air ejection hole from the front of the rotary atomizing head.

FIG. 6 is an enlarged front view of a main part showing a jetting direction of shaping air for a liquid thread of paint discharged from a rotary atomizing head.

FIG. 7 shows a conventional rotary atomizing head type coating machine.
It is a side view which shows the locus | trajectory of the shaping air ejected from each air ejection hole.

FIG. 8 is a front view showing the trajectory of shaping air ejected from each air ejection hole from the front of the rotary atomizing head.

FIG. 9 is an enlarged front view of a main part showing a jetting direction of shaping air for a liquid thread of the paint discharged from the rotary atomizing head.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Coating machine cover 16 Air motor 17 Rotating shaft 19 Rotary atomizing head 19C Paint discharge edge 21 Shaping air ring 26 Air ejection hole 26A Ejection side opening α, β Tilt angle D Maximum outer diameter dimension of rotary atomizing head d Shaping air ring Minimum inner diameter of

Claims (2)

[Claims] A coating machine cover having a built-in air motor;
A rotary atomizing head that is rotated by the air motor on the tip side of the coating machine cover to release paint from a coating release edge, and is provided on the coating machine cover at an outer peripheral side of the rotary atomizing head. The shaping air ring,
In the rotary atomizing head type coating machine formed on the shaping air ring and comprising a plurality of air jetting holes for jetting shaping air toward the vicinity of the paint discharge edge of the rotary atomizing head, each of the air jetting holes is A rotary atomization head type coating characterized in that the ejection side opening is inclined in the direction opposite to the rotation direction of the rotary atomization head, and the ejection side opening is inclined toward the rotation center of the rotary atomization head. Machine. 2. The rotary atomizing head type coating machine according to claim 1, wherein the shaping air ring has a minimum inner diameter set larger than a maximum outer diameter of the rotary atomizing head.