JPH07148447A - Coating apparatus and method - Google Patents

Abstract

PURPOSE:To minimize the generation of an edge sump of coating material at the time of the spraying of coating material on the vicinal region of the edge of a surface to be coated in a coating apparatus applying coating to the surface to be coated having the edge by spraying coating material on the surface to be coated. CONSTITUTION:In consideration of that it can be elucidated that an edge sump of coating material is generated because the air stream branching point P of coating material streams F is shifted to an edge inner side with respect to the central position just under a coating gun 12, a negative suction duct 14 is arranged toward the inside of the edge of a surface 4 to be coated in the vicinity of the outside of the edge and the coating gun is moved to the part above the vicinal region of the edge of the surface 4 to be coated to operate the negative pressure suction duct 14. By this constitution, coating material streams (two-dot broken line) ready to flow downwardly in the vicinity of the outside of the edge are corrected to coating material streams (solid line) going toward the outside of the edge to correct the positional shift of an air stream branch point P.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a coating apparatus and a coating method configured to apply a coating to a surface to be coated having an edge by spraying the coating on the surface to be coated. .

[0002]

2. Description of the Related Art In the vehicle body painting process of a vehicle manufacturing line, a painting apparatus is widely used for painting a vehicle body surface by spraying paint from a painting gun onto the vehicle body surface. When the coated surface has edges, when paint is sprayed to the edge vicinity area of the surface to be coated, a so-called paint edge pool, that is, a portion near the edge on the surface to be coated (hereinafter referred to as “edge portion”) That is, a phenomenon in which a large amount of paint adheres occurs. When such a paint edge pool occurs, the appearance of the vehicle body surface deteriorates to some extent, but this has not been a serious problem.

[0003]

However, in recent years,
In order to give the coating film a deep feeling, the clear layer, which is the uppermost layer of the coating film, is often formed by coating with a Nigori clear type coating material in which a pigment is mixed in a low concentration. In the case of using, the above-mentioned paint edge accumulation has become a big problem. That is, when a simple clear paint is used as in the conventional case, the clear layer remains substantially colorless and transparent regardless of whether the coating film is thick or thin, but the clear layer formed by coating with the Nigoriguri-based paint ( Nigori clear layer), the thicker the coating, the darker the color, and the thinner the coating, the lighter the color.
The color of the edge part becomes darker than the other parts, and the appearance is completely different depending on the part of the vehicle body surface. Therefore, the appearance quality (look) of the vehicle body is significantly deteriorated, and the commercialability of the vehicle is deteriorated.

By the way, the paint edge pool is generated not only by the effect of surface tension acting on the coating film after coating but also by the way of coating. Then, as shown in FIG. 24, if the paint edge pool does not occur immediately after coating, a new paint edge pool does not occur thereafter ((a) in the same figure). When the pool is formed, the size of the paint edge pool tends to be further increased due to surface tension or the like due to a change with time after coating (FIG. 2B). Therefore, in order to effectively suppress the generation of the paint edge pool, it is important to minimize the generation of the paint edge pool during coating.

Incidentally, such a problem is not a problem that occurs only when painting a vehicle body, but a problem that can similarly occur in general when a surface to be painted having an edge is painted.

The present invention has been made in view of the above circumstances, and a coating device capable of minimizing the occurrence of paint edge pools when the paint is sprayed onto a region near the edge of the surface to be coated. And a coating method.

Incidentally, Japanese Patent Application Laid-Open No. 3-26379 discloses that
When there is a gap between the surface to be coated and the surface to be coated, the above-mentioned gap is closed from the back side and spraying of paint is performed, so that the portion of each surface to be coated that is wraparound to the gap side is coated. A coating method intended to make the film have the same thickness as the other parts is disclosed.However, this is because when the paint is sprayed in the area near the gap, the coating film in the wraparound part becomes thin. Therefore, it is carried out in order to suppress this, and the coating edge pool cannot be solved even by using such a coating method.

[0008]

As will be described later, in the present invention, the positional relationship between the coating flow gun and the air flow branching point of the paint flow on the surface to be coated in the vicinity of the edge is such that the spraying of the coating material with respect to the general surface of the surface to be coated. In view of the fact that it has been clarified in the experiment that the deviation of the edge inward relative to that at the time of application is the cause of the paint edge pool, by adopting a configuration that corrects this deviation, the above object is achieved. It is intended to.

That is, the coating apparatus according to the present invention is constructed such that, as described in claim 1, the coating is sprayed from the coating gun toward the surface having the edge to be coated. In the coating apparatus described above, when spraying the paint on the area near the edge of the surface to be painted, the paint flow toward the outer side of the edge and the inner side of the edge generated on the surface to be painted by the spraying of the paint. An air flow branch point position correcting means for correcting a predetermined amount of displacement of the air flow branch point with the paint flow toward the outside of the edge is provided.

The above "airflow branch point position correcting means" is not limited to a specific structure as long as it can correct the displacement of the airflow branch point to the outside of the edge by a predetermined amount. The paint flow suction means as described in claim 2 or the paint flow pressurization means as described in claim 7 can be adopted. Further, as a specific configuration of the paint flow suction means, for example, a configuration as described in claims 3 to 6 is described, and as a specific configuration of the paint flow pressurizing means, for example, claims 8 to 11 are described. Such a configuration can be adopted.

Further, the coating method according to the present invention is a coating method for applying a coating to a surface to be coated by spraying the coating from a coating gun toward the surface to be coated having an edge. When the paint is sprayed onto the area near the edge of the surface to be coated, a paint flow directed to the outer side of the edge and a paint flow directed to the inner side of the edge are generated on the surface to be coated by the paint spraying. It is characterized in that the air flow branch point is corrected by a predetermined amount toward the outside of the edge. Then, as a concrete method thereof, for example, the configurations described in claims 13 to 17 can be adopted.

[0012]

Operation and Effect of the Invention Generally, when observing a state in which paint is sprayed from the coating gun toward the surface to be coated, in a longitudinal section along the coating flow from the coating gun to the surface to be coated,
The paint flow that hits the surface to be painted by spraying the paint becomes a paint flow that branches left and right on the surface to be painted at a certain point as a boundary. This "certain point" is called an air flow branch point, and when the paint is sprayed vertically toward the surface to be coated, it is as shown in FIG.
As shown in, the airflow branch point P is located in the center right below the coating gun 12. Since the paint flow velocity becomes small in the vicinity of the airflow branch point P on the surface to be coated 4, the paint easily adheres to the surface to be coated. However, on the general surface of the coated surface 4, the positional relationship between the coating gun 12 and the coated surface 4 is always substantially constant even if the coating gun 12 is moved left and right.
The positional relationship between the coating gun 12 and the airflow branch point P is also the coating gun 1
It is maintained substantially constant with respect to the horizontal movement of 2. In other words, the air flow branch point P and the paint flow low velocity area A on the surface 4 to be coated which is caused by the air flow branch point P move together with the movement of the coating gun 12. For this reason, on the general surface of the surface 4 to be coated, no paint accumulation occurs and a uniform coating film can be obtained.

On the other hand, in the area near the edge of the surface to be coated, as shown in FIGS.
Part of the paint flow F flowing from 2 to the coated surface 4 is the coated surface 4
Although it does not hit, it flows downward as it is, but this downwardly flowing paint flow is in a low pressure state as compared with other portions because the velocity is not reduced. Therefore, the paint flow adjacent to the downward high-speed paint flow is attracted by the high-speed paint flow, wraps around the outside of the edge, and flows downward. For this reason, the air flow branch point P of the paint flow that splits left and right on the surface to be coated 4 is displaced inward toward the edge with respect to the center position directly below the coating gun 12. Moreover, in the area near the edge, when the coating gun 12 is moved left and right, the coating gun 12 and the surface 4 to be coated are moved.
Because the positional relationship with the edge 4E of the
The relative positional relationship between 2 and the airflow branch point P also changes. The change is that the airflow branch point P is set to the coating gun 1 as the coating gun 12 approaches the edge 4E from the general surface of the coating surface 4.
The position is shifted inward from the center position directly below 2. Therefore, the airflow branch point P always stays at a portion (edge portion) near the edge on the surface 4 to be coated.

This can be clarified by an experiment that examines the relationship between the position of the coating gun 12 and the position of the paint flow branch point P when the coating gun 12 is moved to the left and right.

FIG. 26 is a graph showing the results of the experiment, in which the above relationship is expressed as positive on the inner side of the edge.

As is clear from this graph, for example, when the coating gun is moved from the position above the general surface of the surface to be coated to the position outside the edge, the coating gun and the air flow branch point have the same moving speed on the general surface. , In the area near the edge, the moving speed of the air flow branching point is delayed with respect to the moving speed of the coating gun (Note that the straight line shown by the broken line in the figure has no edges and the general surface of the coated surface continues as it is. It is a graph which shows the airflow branching point position at the time of assumption). The delay in the movement of the air flow branch point with respect to the coating gun means that the air flow branch point stays at a portion near the edge of the surface to be coated, that is, the edge portion. Then, due to the staying at the edge portion of the airflow branch point, a large amount of paint adheres to the edge portion,
A paint edge pool will be generated.

In the above description, in order to make it easier to understand the principle of the occurrence of paint edge pool, a case has been described in which the paint is sprayed vertically from the coating gun to the surface to be coated. However, the paint is sprayed obliquely toward the surface to be coated. Even in the case of spraying, due to the same principle as the above description, the phenomenon that the paint is not accumulated on the general surface of the coated surface and the paint is accumulated on the edge portion occurs.

In the present invention, in light of the fact that the principle of such paint edge pooling has been clarified, when the paint is sprayed onto the area near the edge of the surface to be coated, the spraying of the paint causes the surface of the surface to be coated to be sprayed. The air flow branch point between the generated paint flow toward the outside and the paint flow toward the inside of the edge,
Since it is designed to correct the displacement to the outside of the edge by a predetermined amount, the positional relationship between the air flow branching point and the coating gun when spraying paint to the area near the edge is the same as that when spraying paint to the general surface of the painted surface. In comparison, it is possible to minimize the inward shift of the edge.

Therefore, according to the present invention, it is possible to minimize the occurrence of the paint edge pool at the time of spraying the paint onto the area near the edge portion of the surface to be painted.

[0020]

Embodiments of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 is a perspective view showing a first embodiment of a coating apparatus according to the present invention.

The coating apparatus 10 is configured to spray a paint onto a surface 4 to be coated of a plate-shaped object 2 to apply a clear top coat to the surface 4 to which the intermediate coating has been applied. It is provided with a coating gun 12, a pair of negative pressure suction ducts 14, a conveying means (not shown) and a coating gun driving means.

The coating gun 12 is a bell-type rotary atomization type electrostatic coating gun, which is applied above the surface 4 to be coated of the object 2 to be coated with a predetermined distance from the surface 4 to be coated. The bell 16 of the gun 12 is arranged so as to face the surface 4 to be painted,
The surface to be painted 4 is adapted to be sprayed with a Nigori clear type paint.

The conveying means conveys the article to be coated 2 in the direction A shown in the drawing, and the coating gun drive means causes the coating gun 12 to move the coating gun 12 in the direction B perpendicular to the direction A, that is, the article to be coated. It is designed to horizontally reciprocate in the width direction of 2. As a result, the coating gun 12 sprays the coating material 4 on the surface to be coated 4 while relatively moving in zigzag between the regions near the edges on both sides in the width direction (regions including the edge portion 4a that is a region near the edges). Is supposed to do.

The negative pressure suction ducts 14 are provided so as to face each other on both sides in the width direction of the article to be coated 2. The opening 14a of each of the negative pressure suction ducts 14 has an elongated rectangular shape in the A direction, and opens toward the inside of each edge. In addition, each negative pressure suction duct 14
Is connected to a negative pressure source (not shown) so as to perform negative pressure suction at a predetermined timing.

As shown in FIG. 2, the bell 1 of the painting gun 12 is
6, a shaping air outlet 20 is provided all around the rotating bell body 18,
From the shaping air outlet 20, the bell body 1
Shaping air for controlling the spraying direction of the paint scattered from 8 is blown out. By this shaping air, as shown in FIG. 1, a paint flow F flowing vertically toward the surface to be coated 4 is generated.

As described above with reference to FIG. 25, as shown in FIG. 3A, the coating gun 12 is moved to the left and right when spraying paint onto a general surface such as the central region of the surface 4 to be painted. Even if it is moved, the position of the air flow branch point P is always maintained at the center position immediately below the coating gun 12, so that a paint film does not occur and a uniform coating film can be obtained, but as shown in FIG. When the paint is sprayed to the area near the edge of the surface 4 to be coated, the airflow branch point P is displaced inward from the center position directly below the coating gun 12, and the coating gun 12 is moved left and right. Then, the displacement amount changes so that the airflow branch point P is always retained at the edge portion 4a on the surface 4 to be coated, so that a paint accumulation occurs at the edge portion 4a.

Therefore, in the present embodiment, as shown in FIG. 4, when the coating gun 12 moves to a position above the edge vicinity region of the surface 4 to be coated, the negative pressure suction duct 14 on the edge side is subjected to negative pressure. A suction operation is performed, and a paint flow (shown by a two-dot chain line) that tends to flow downward in the vicinity of the outside of the edge is corrected to a paint flow (shown by a solid line) toward the outside of the edge. As a result, the air flow branch point P is corrected by displacing the air flow branch point outward by a predetermined amount, and the air flow branch point P is always brought close to the center position directly below the coating gun 12.

Alternatively, each of the negative pressure suction ducts 14 is always kept in a negative pressure suction operation, and the coating gun 12 causes the coating surface 4 to move.
The negative pressure suction force of the negative pressure suction duct 14 on the edge side may be increased when moving to a position above the edge vicinity region.

As described above in detail, in the present embodiment, when the paint is sprayed on the area near the edge, the airflow branch point P is always moved to the outside of the edge by the displacement correction of the airflow branch point P to the outside of the edge. Since it is arranged to be close to the central position just below, it is possible to minimize the occurrence of paint edge pool when the paint is sprayed onto the edge vicinity region of the surface 4 to be painted.

Next, a second embodiment of the present invention will be described.

FIG. 5 is a side view showing the coating apparatus according to this embodiment (FIG. 5 (a)) together with a conventional example (FIG. 5 (b)).

As shown in FIG. 5 (a), the coating gun 12 according to the present embodiment has a second shaping air outlet 22 provided around the bell 16 over the entire circumference thereof. From the mouth 22, when the coating gun 12 moves to a position above the edge vicinity region of the surface to be coated 4, a high speed assist air is directed from the edge outer side portion of the shaping air outlet 22 to slightly below the edge outer side. It is designed to blow out.

In the conventional example, as shown in FIG. 5 (b), when the paint is sprayed on the area near the edge, most of the paint flow F flows downward near the outside of the edge. The branch point P was displaced inward from the center position directly below the coating gun 12, but in this embodiment, as shown in FIG.
As shown in (a), the paint flow F hitting the edge portion 4a
Is pulled by the high-speed assist air (Coanda effect)
Once the flow toward the outer side of the edge is formed, the flow starts downward.

This makes it possible to correct the displacement of the air flow branch point P toward the outside of the edge by a predetermined amount when the paint is sprayed to the area near the edge, so that the air flow branch point P can always be brought close to the central position directly below the coating gun 12. .

Next, a third embodiment of the present invention will be described.

FIG. 6 is a diagram showing a coating apparatus according to this embodiment.

As shown in FIG. 6A, in this embodiment, an air passage 26 is formed in the carriage 24 that conveys the article 2 to be coated. The air passage 26 is connected to an air supply source (not shown), and as shown in FIG. 6B, assist air is blown out in the horizontal directions along the back surface of the article 2 to be coated. .

By thus forming the gas flow flowing from the back side of the surface to be coated 4 toward the outside of the edge, the paint flow F can be sucked toward the outside of the edge. It is possible to increase the speed of the paint flow F that is directed to the outside of the edge in the area near the edge 4a. In this case, the strength of the assist air blowing from the air passage 26 may be set so that the paint flow F toward the outside of the edge and the paint flow F toward the inside of the edge have substantially the same paint flow velocity. . This makes it possible to correct the air flow branch point when the paint is sprayed to the area near the edge by displacing the air flow branch point toward the outer side of the edge by a predetermined amount so that the air flow branch point can always come close to the central position directly below the coating gun 12.

Next, a fourth embodiment of the present invention will be described.

FIG. 7 is a diagram showing a coating apparatus according to this embodiment.

As shown, the coating gun 1 according to this embodiment.
2 is provided on both sides of the bell 16 from the bell 16 to be coated 2
A pair of assist air blowing nozzles 30 are attached to each other through a pair of arms 28 extending in the width direction of the coating gun 12 so as to incline inward by a predetermined angle, and the coating gun 12 is near the edge of the surface 4 to be coated. When moving to the upper part of the area,
Assist air blowing nozzle 30 located on the inner side of the edge
Assist air is blown from the pressurizing the paint flow F toward the outside of the edge.

As a result, since the paint flow F is diverted to the outside of the edge to some extent, the speed of the paint flow F toward the outside of the edge can be increased in the area near the edge, and the paint flow F toward the outside of the edge can be increased. It is possible to make the paint flow velocity approximately the same as the paint flow F toward the inside of the edge. Therefore, the air flow branch point at the time of paint spraying to the area near the edge is corrected to the outside of the edge by a predetermined amount,
The airflow branch point can always be brought close to the central position directly below the coating gun 12.

Next, a fifth embodiment of the present invention will be described.

FIG. 8 is a diagram showing a coating apparatus according to this embodiment.

As shown, the coating gun 1 according to the present embodiment.
2 is provided with a pair of control plates 32 on both sides of the bell 16 in the width direction of the object to be coated 2. Each of these control plates 32 is rotatably supported by the bell 16 at the upper end thereof, and is positioned on the inner side of the edge when the coating gun 12 moves to a position above the edge vicinity region of the surface 4 to be coated. The control plate 32 rotates in the direction C in the drawing to pressurize the paint flow F toward the outside of the edge, and to direct the paint flow F to the outside of the edge to some extent as indicated by the two-dot chain line in the drawing. There is.

Next, a sixth embodiment of the present invention will be described.

FIG. 9 is a diagram showing a coating apparatus according to this embodiment.

As shown in FIG. 6A, in the coating gun 12 according to this embodiment, the shaping air outlet inner wall portion 36 of the shaping air outlet nozzle 34 of the bell 16 is made of silicone rubber. This inner wall 36
As shown in FIG. 2B, which is an enlarged view of a portion b in FIG. 2A, double grooves 38, 40 to which control air is supplied are formed inside, and each of these grooves 38 is formed. By controlling the control air supply amounts A and B to the inner and outer wall portions 40, 40, the inner wall portion 34 is bent to the left and right from the position shown in FIG. There is. That is, when the control air supply amount A is raised and B is lowered, the inner wall portion 36 is bent and deformed in the right direction in the drawing, and when the control air supply amount A is lowered and B is raised, the inner wall portion 36 is bent and deformed in the left direction in the drawing. To do. FIG. 13C is a view from the direction c in FIG.
As shown in, the inner wall portion 36 is formed by being divided into eight segments in the circumferential direction, and the above-described bending deformation is possible in each segment inward and outward in the radial direction.

The inner wall portion 36 is formed by the coating gun 12
Is moved to a position above the edge portion 4a of the surface to be coated 4, the opening area of the edge outer side portion of the inner wall portion 36 is made smaller and the opening area of the inner side portion is made larger. F is directed to the outside of the edge to some extent.

Next, a seventh embodiment of the present invention will be described.

FIG. 10 is a diagram showing a coating apparatus according to this embodiment.

As shown in FIG. 7A, in the coating gun 12 according to this embodiment, the shaping air outlet inner wall portion 36 of the nozzle 34 of the bell 16 has a left side portion 36A and a right side portion which are made of a shape memory alloy. It is formed by being divided into portions 36B, and each of the above portions 36 of the nozzle 34 is formed.
Control currents A and B can be supplied to the base ends of A and 36B, respectively. The coating gun 12 is the surface 4 to be coated.
When moving up to the area near the left edge of,
Supply the control current B to the right side part (edge inner side part) 3
By heating 6B, the right side portion 36B is shown in FIG.
As shown by the dashed line, the shape memory alloy is deformed into a substantially rectangular shape that is stored in advance to increase the opening area of the inside portion of the edge of the shaping air outlet 20, thereby increasing the opening area.
The paint flow F is directed to the outer side of the edge to some extent. Similarly, when the coating gun 12 has moved to a position above the right edge region of the surface to be coated 4, by supplying the control current A, the same operation as described above can be obtained.

Next, an eighth embodiment of the present invention will be described.

FIG. 11 is a diagram showing a coating apparatus according to this embodiment.

As shown in the figure, in the coating gun 12 according to this embodiment, the tip portion 34a of the nozzle 34 of the bell 16 is divided into a plurality of portions in the circumferential direction of the nozzle 34, and each tip portion 34a is , And is separated from the main body of the nozzle 34 via the piezo actuator 42. By controlling the operation of the piezo actuator 42, each tip 3
4a is displaced between the solid line position and the two-dot chain line position as shown in the figure, whereby the shaping air outlet 20
Is partially increased or decreased to obtain the action of directing the paint flow F to the outer side of the edge.

Next, a ninth embodiment of the present invention will be described.

FIG. 12 is a diagram showing a coating apparatus according to this embodiment.

As shown in the figure, in the coating gun 12 according to the present embodiment, a plurality of bypass passages 44 for bypassing shaping air are formed in the nozzle 34 of the bell 16 and the tip end portion of each bypass passage 44. A valve 46 is provided in the. Each valve 46 is made of a transformable substance such as a bimetal or a shape memory alloy.
Is deformed between the solid line position and the two-dot chain line position as shown in the drawing, whereby the amount of shaping air blown out from the shaping air blowout port 20 is partially increased or decreased, and the paint flow F
The effect of directing the edge to the outer side is obtained.

Next, a tenth embodiment of the present invention will be described.

FIG. 13 is a diagram showing a coating apparatus according to this embodiment.

As shown in the figure, in the coating gun 12 according to this embodiment, the nozzle 34 of the bell 16 is movable. That is, the nozzle 34 is formed by being divided into a plurality in the circumferential direction, and each nozzle 34 is supported by the bell 16 by the leaf spring 48 and the bimetal 50, and the restoring force of the leaf spring 48 and the bimetal 50. The orientation of each nozzle 34 is determined by the balance with the tension. Then, by controlling the energization of the bimetal 50, each nozzle 34 is oscillated and displaced between the illustrated solid line position and the two-dot chain line position, thereby changing the shaping air blowing direction from the shaping air blowing port 20, Flow F
The effect of directing the edge to the outer side is obtained.

Next, an eleventh embodiment of the present invention will be described.

14 and 15 are a vertical sectional view and a bottom view showing a bell of the coating apparatus according to this embodiment.

The coating gun 12 according to this embodiment has a plurality of outlet elements 52A, 52B, 52C and 52C in which the outlet of the shaping air outlet nozzle 34 of the bell 16 is circumferentially divided into four parts. It consists of The outlet elements 52A and 52B are located in the moving direction of the coating gun 12, and the outlet elements 52C and 52C are located in a direction orthogonal to the moving direction. The air outlet elements 52A, 52B, 52C, and 52C are aired in different directions (indicated by "inside", "middle", and "outside" in the figure) from the outlet element in the radial direction of the outlet. Is formed so as to communicate with a plurality of air outlet passages 56, 58, 60, and these air outlet passages 56, 58, 60 are formed.
By controlling the air supply pressure to the air outlet elements 52A, 52B, 52C, 52C, the shaping air jet direction from the outlet element 52A, 52B, 52C, 52C is controlled.

Each of the outlet elements 52A, 52 when the coating gun 12 sprays the paint on the area near the edge.
B, 52C, 52C air blowing direction and air pressure,
If set as shown in Table 1, as shown by the broken line in FIG.
The paint flow F can be directed to the outer side of the edge.

[0067]

[Table 1]

An experiment was conducted with the setting values shown in Table 1 using this coating gun. The paint used in this experiment was "OTO563 clear" manufactured by Nippon Paint Co., Ltd., the bell speed of the coating gun at that time was 30,000 rpm, and the moving speed of the coating gun was 40 cm / sec.

As a result of the above experiment, the film thickness ratio between the coating film b on the edge portion 4a and the coating film a on the central portion was b / a = 1.4.

For comparison with the eleventh embodiment,
As shown in FIG. 18, an experiment was conducted using a conventional coating gun in which the outlets of the shaping air blowing nozzles were not divided in the circumferential direction. The air pressure at that time is 3.5 kg
An experiment was conducted under the same coating conditions as in the above eleventh example except that the setting was f / cm ² . As a result, the film thickness ratio between the coating film b of the edge portion 4a and the coating film a of the central portion was b / a = 1.8.

As is clear from the above experimental results, by adopting the configuration of this embodiment, the film thickness ratio can be brought close to 1, and the occurrence of paint edge pool can be effectively suppressed.

In Table 1, the outlet element 52C is shown.
Is set to the same value as the air pressure of the air outlet element 52B, the reason why the air pressure is set to such a high value is to suppress the spread of the air outlet pattern, and from the viewpoint of reducing the above film thickness ratio. It is not always necessary to raise the height in this way.

FIG. 17 is a diagram showing a modification of this embodiment.

The outlet of the shaping air outlet nozzle 34 of the present modification is 45 with respect to the outlet of the present embodiment.
4 outlet elements 52 arranged in a rotated state
D, 52D, 52E, 52E.

Each of the outlet elements 52D, 52 when the coating gun 12 sprays the paint on the area near the edge.
D, 52E, 52E air blowing direction and air pressure,
If set as shown in Table 2, as shown by the broken line in FIG.
The paint flow F can be directed to the outer side of the edge. In order to confirm this, an experiment was conducted under the same conditions as in this example with the set values shown in Table 2.

[0076]

[Table 2]

As a result of the above experiment, the film thickness ratio between the coating film b of the edge portion 4a and the coating film a of the central portion was b / a = 1.4, which was the same value as that of this embodiment.

Next, a twelfth embodiment of the present invention will be described.

In each of the above-described embodiments, as shown in FIG. 19A, when the coating gun 12 sprays the paint onto the general surface of the surface 4 to be painted, the spraying direction of the paint flow F is changed. On the other hand, when the paint is sprayed to the area near the edge, the paint flow F is directed to the outer side of the edge to reduce the occurrence of paint edge pool. When the switching is performed, the spraying target area on the surface 4 to be coated changes abruptly, which causes a problem that the coating film thickness at that portion tends to be thin.

Therefore, in this embodiment, FIG.
As shown in (b), when the coating gun 12 moves from above the general surface of the coated surface 4 to above the edge vicinity region, the blowing direction of the paint flow F is gradually changed from right below to outside the edge. As shown in FIG. 19 (c), when the coating gun 12 moves from the area near the edge to above the general surface of the upper coating surface 4, the blowing direction of the paint flow F is changed from the outside of the edge to directly below. The configuration is such that it gradually changes, whereby not only the occurrence of paint edge pooling is reduced, but also the coating film thickness is made uniform over the entire surface 4 to be coated.

FIG. 20 is a system configuration diagram showing a coating apparatus according to this embodiment, and FIGS. 21 and 22 are a vertical sectional view and a bottom view showing the coating gun 12.

As shown in FIGS. 21 and 22, the coating gun 12 according to this embodiment has a plurality of blowouts in which the outlets of the shaping air blowout nozzles 34 of the bell 16 are divided into four in the circumferential direction. Mouth elements 62A, 62B, 62
It consists of C and 62C. Outlet element 62A, 62
B is located in the moving direction of the coating gun 12, and the outlet elements 62C and 62C are located in the direction orthogonal to the moving direction. Then, each of these outlet elements 62A, 62
B, 62C, and 62C have different directions (“inside” and “middle” in the drawing) from the outlet element in the radial direction of the outlet.
Indicate. ) Multiple air outlet passages 6
4 and 66 are communicated with each other, and by controlling the air supply pressure to each of the air outlet passages 64 and 66,
It is configured to control the direction in which shaping air is ejected from the outlet elements 62A, 62B, 62C, 62C.

In the figure, the ring 68 existing around the bell 16 is an electrostatic repulsion ring and is given the same negative charge as the paint, whereby the paint wraps around to the rear side of the bell 16. The bell body 18 and the hose are prevented from becoming dirty.

As shown in FIG. 20, the air supply pressure control to the air blowing passages 64 and 66 is performed by the air control device 7.
0, it is performed by adjusting the air pressure variable valve 74 connected to the air source 72.
In addition, the air controller 70 includes the existing coating machine controller 7
The point data indicating the movement position of the coating gun 12 is input from 6.

The air control device 70 controls the outlet elements 62A, 62B, 6 according to the moving position of the coating gun 12.
The air supply pressure to the air outlet passages 64 and 66 of 2C and 62C is controlled, and a concrete air pressure control pattern is shown in FIG.

By controlling the air supply pressure as described above, the blowing direction of the paint flow F between the general surface of the surface to be coated 4 and the area near the edge is shown in FIGS. 19 (b) and 19 (c). It is possible to reduce the occurrence of paint edge pool and to make the coating thickness uniform over the entire surface 4 to be coated.

Instead of controlling the air supply pressure as in the 12th embodiment, the shaping air blowing nozzle 3 is used.
It is also possible to mechanically variably control the direction of the blowout port of No. 4 to gradually change the ejection direction of the paint flow F between the general surface of the surface to be coated 4 and the area near the edge. At this time, as a specific configuration of the shaping air blowing nozzle 34, for example, those shown in FIGS. 8 to 13 can be adopted.

[Brief description of drawings]

FIG. 1 is a perspective view showing a first embodiment of a coating apparatus according to the present invention.

FIG. 2 is a vertical sectional view showing a bell of a coating gun according to the first embodiment.

FIG. 3 is a vertical view showing a state of a conventional paint flow F as a premise for explaining the operation of the first embodiment.

FIG. 4 is a vertical view showing the operation of the first embodiment.

FIG. 5 is a vertical view showing a coating apparatus according to the second embodiment of the present invention (FIG. 5A) together with a conventional example (FIG. 5B).

FIG. 6 is a diagram showing a coating apparatus according to a third embodiment of the present invention.

FIG. 7 is a diagram showing a coating apparatus according to a fourth embodiment of the present invention.

FIG. 8 is a diagram showing a coating apparatus according to a fifth embodiment of the present invention.

FIG. 9 is a diagram showing a coating apparatus according to a sixth embodiment of the present invention.

FIG. 10 is a diagram showing a coating apparatus according to a seventh embodiment of the present invention.

FIG. 11 is a diagram showing a coating apparatus according to an eighth embodiment of the present invention.

FIG. 12 is a view showing a coating apparatus according to a ninth embodiment of the present invention.

FIG. 13 is a view showing a coating device according to a tenth embodiment of the present invention.

FIG. 14 is a vertical sectional view showing a bell of a coating apparatus according to an eleventh embodiment of the present invention.

FIG. 15 is a bottom view showing the bell of the eleventh embodiment.

FIG. 16 is a perspective view of the bell as seen from below, showing the operation of the eleventh embodiment.

FIG. 17 is a view similar to FIG. 15 showing a modification of the eleventh embodiment.

FIG. 18 is a diagram showing a comparative example of the eleventh embodiment.

FIG. 19 is a view showing the operation of the coating apparatus according to the twelfth embodiment of the present invention.

FIG. 20 is a system configuration diagram of the coating apparatus according to the twelfth embodiment.

FIG. 21 is a vertical sectional view showing a bell of a coating apparatus according to a twelfth embodiment.

FIG. 22 is a bottom view showing the bell of the twelfth embodiment.

FIG. 23 is a graph showing the operation of the twelfth embodiment.

FIG. 24 is a diagram showing a state of a defect in the conventional example.

FIG. 25 is a diagram showing an operation of a conventional example.

FIG. 26 is a graph showing the operation of the conventional example.

[Explanation of symbols]

 2 coating object 4 coating surface 4a edge part 4E edge 10 coating device 12 coating gun 14 negative pressure suction duct 14a opening 16 bell 18 bell body 20 shaping air outlet F paint flow P air flow branching points 52A, 52B, 52C, 52C outlet element 56, 58, 60 air outlet passage 62A, 62B, 62C, 62C outlet element 64, 66 air outlet passage

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kazunori Sawamura No. 3 Shinchi Fuchu-cho, Aki-gun, Hiroshima Mazda Co., Ltd. (72) Inventor Takakazu Yamane No. 3 Shinchi, Fuchu-cho, Hiroshima-ken Mazda Stock In-house (72) Inventor Makoto Aizawa 3-1, Shinchi Fuchu-cho, Aki-gun, Hiroshima Prefecture Mazda Co., Ltd. (72) Inventor Yukifumi Taniguchi 3-1, Shinchi, Fuchu-cho, Aki-gun, Hiroshima Prefecture Mazda Co., Ltd.

Claims (17)

[Claims] 1. A coating apparatus configured to coat a surface to be coated by spraying the coating from a coating gun onto the surface to be coated having an edge, wherein the coating is applied to a region near the edge of the surface to be coated. At the time of spraying, the air flow branch point between the paint flow toward the outer side of the edge and the paint flow toward the inner side of the edge, which is generated on the surface to be coated by the paint spraying, is changed to the outer side of the edge. A coating apparatus, comprising: an air flow branch point position correcting means for correcting a displacement by a predetermined amount. 2. The paint flow suctioning means for sucking the paint flow on the surface to be painted toward the outside of the edge, the air flow branch point position correcting means comprising a paint flow suction means. Coating equipment. 3. The coating apparatus according to claim 2, wherein the paint flow suction means is composed of a negative pressure suction duct provided outside the edge and opening toward the edge. 4. The paint flow suction means performs the suction by supplying a gas flow flowing along the paint flow to the outer side of the edge of the paint flow from the coating gun toward the surface to be coated. The coating device according to claim 2, wherein 5. The coating gun comprises a rotary atomization type coating gun having a shaping air outlet for regulating a paint spraying direction. The shaping air of the rotary atomization type coating gun is used for the gas flow. The coating apparatus according to claim 4, wherein the coating apparatus is configured to form 6. The paint flow suction means is configured to perform the suction by supplying a gas flow flowing from the back side of the surface to be coated toward the outside of the edge,
The coating apparatus according to claim 2, wherein the coating apparatus is a coating apparatus. 7. The air flow branch point position correcting means comprises a paint flow pressurizing means for pressurizing the paint flow from the coating gun toward the surface to be coated toward the outside of the edge. The coating apparatus according to claim 1. 8. The paint flow pressurizing means is provided in the coating gun, and presses a gas flow against the paint flow from an inner side of the edge of the paint flow from the paint gun to the surface to be coated. The coating apparatus according to claim 7, comprising the means. 9. The coating gun is a rotary atomizing type coating gun having a shaping air outlet for regulating a paint spraying direction, and the gas flow is formed by utilizing the shaping air of the rotary atomizing type coating gun. The coating apparatus according to claim 8, wherein the coating apparatus is configured to form 10. The outlet comprises a plurality of outlet elements formed in a circumferentially divided manner, and each of the outlet elements blows air from the outlet element in different directions with respect to the radial direction of the outlet. It is formed so as to communicate with a plurality of air outlet passages, and is configured to control the shaping air outlet direction from the outlet element by controlling the air supply pressure to each of these air outlet passages. The coating apparatus according to claim 9, wherein the coating apparatus is a coating apparatus. 11. The coating gun is configured to move between a paint spraying position with respect to a general surface of the painted surface and a paint spraying position with respect to the edge vicinity region, The means is configured to gradually change the pressure applied to the paint flow from the coating gun toward the surface to be coated in accordance with the movement of the coating gun between the spraying positions. The coating device according to claim 7. 12. A coating method for applying a coating to a surface to be coated having an edge by applying a coating from the coating gun to the surface to be coated, the method comprising: spraying the coating onto a region near the edge of the surface to be coated. Correcting the air flow branch point between the paint flow directed to the outer side of the edge and the paint flow directed to the inner side of the edge, which is generated on the surface to be coated by the spraying of the paint, toward the outer side of the edge by a predetermined amount. A coating method characterized by that. 13. The coating method according to claim 12, wherein the displacement correction is performed by sucking the paint flow on the surface to be coated toward the outside of the edge. 14. The coating method according to claim 12, wherein the displacement correction is performed by pressurizing a coating material flow from the coating gun toward the surface to be coated toward the outside of the edge. 15. The pressurization is performed by pressing a gas flow against the paint flow from an inner side of the edge of the paint flow from the coating gun toward the surface to be coated. How to paint. 16. A rotary atomizing type coating gun having a shaping air outlet for regulating a paint spraying direction is used as the coating gun, and the gas flow is produced by using the shaping air of the rotary atomizing type coating gun. The coating method according to claim 15, wherein the coating is formed. 17. The paint moving from the coating gun to the surface to be coated by moving the coating gun between a paint spraying position on the general surface of the surface to be coated and a paint spraying position on the edge vicinity region. 17. The pressure applied to the flow is gradually changed according to the movement of the coating gun between the spraying positions.
Any one of the coating methods.