JPH0268168A - Painting apparatus - Google Patents

Abstract

PURPOSE:To easily perform painting in a desired thickness regardless of the surface properties of an object to be painted by coating the object to be painted with excessive paint in a coating part and subsequently removing the excessive part of the coated paint in a film thickness control part. CONSTITUTION:A coating part 6 for coating an object M to be painted with paint and a film thickness control part consisting of a casing 14 and a seal plate 42 removing excessive paint from the coated object to be painted to form a desired film thickness are provided. Further, means 2, 4 for feeding the object M to be painted from the coating part 6 through the film thickness control part are arranged. A means 24 for spraying air to the paint coated surface of the object M to be painted fed through the casing 14 and a means 32 for reducing the pressure in the casing 14 are provided to the film thickness control part. The outlet 18 of the object to be painted of the casing 14 is brought to a structure having a shape for forming an appropriate slight gap between the outlet 18 and the paint coated surface of the object M to be painted when the object M to be painted is passed through the outlet 18. As a result, the object to be painted can be painted in a desired thickness.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a coating device, and particularly to a coating device that can continuously and satisfactorily coat an object to a desired thickness regardless of the surface properties of the object to be coated.

[Prior art and problems to be solved by the invention] Conventionally,
Various types of equipment have been proposed for continuous painting while conveying the object to be coated on a conveyor in a mass production factory.When painting a flat plate, for example, curtain flow coater, shower coater, and mist spray A coater etc. are used.

However, in these coating apparatuses, the coating film thickness changes depending on the conveyance speed of the object to be coated, so it is necessary to accurately control the conveyance speed in order to obtain a coating film of a constant thickness. In addition, since the paint is supplied uniformly over the entire surface regardless of the surface condition of the object to be coated, if the surface properties (for example, paint absorption) of the object to be coated are partially different, the thickness of the coating may be uneven. Even under the same coating conditions, the coating film thickness may change depending on the difference in the surface properties of the object to be coated, and there is a possibility that the desired film thickness accuracy cannot be maintained. This applies to slate,
This is particularly true when porous materials such as concrete, wood, and ceramics are used.

SUMMARY OF THE INVENTION An object of the present invention is to provide a coating apparatus that does not have the above-mentioned problems of the prior art and can easily coat the object to a desired thickness regardless of the surface properties of the object to be coated.

[Means for Solving the Problems] According to the present invention, the above object is to remove excess paint from a coating part that applies paint to an object to be coated and from the applied object to obtain a desired coating. A means for conveying the object to be coated from the application section via the film thickness adjustment section is arranged, and the film thickness adjustment section has a casing and a film thickness adjustment section configured to control the coating thickness. The casing is equipped with a means for blowing gas onto the paint-coated surface of the object to be coated and a means for reducing the pressure inside the casing. A coating device characterized by having a shape structure that forms an appropriate small gap between the coating device and the coating surface of the object to be coated.

This is achieved by

In the present invention, the inlet of the object to be coated in the casing has a shape structure such that an appropriate small gap is formed between the inlet of the object and the paint-applied surface of the object when the object passes through. be able to.

In the present invention, the opening of the inlet of the object to be coated and the opening of the outlet of the object to be coated of the casing may be formed to include shutters of these openings.

In the present invention, the paint mist collecting means may be disposed at the connection between the casing and the means for reducing the pressure inside the casing.

In the present invention, the gas spraying means may be moved back and forth in a direction transverse to the conveying direction of the object to be coated.

In the present invention, a means for removing paint adhering to the object conveying means in the coating section may be provided.

In the present invention, the means for reducing the pressure inside the casing may be connected to the means for blowing gas.

In the present invention, the casing is provided with a means for covering the non-coated portion of the object when it passes along the conveying direction of the object from the inlet of the object to the outlet of the object. be able to.

[Example] Hereinafter, specific examples of the present invention will be described with reference to the drawings.

FIG. 1 is a schematic diagram showing an embodiment of a coating apparatus according to the present invention. In this embodiment, the object to be coated is a plate-shaped object, and the upper surface of the plate-shaped object is coated uniformly.

In the figure, reference numeral 2.4 is a conveyor constituting a means for conveying the object to be coated, which can convey the object to be coated M in the direction of arrow A. As these conveyors, for example, a chain conveyor or a belt conveyor can be used.

Reference numeral 6 denotes a paint application means disposed above the conveyor 2. As the coating means, for example, a two-slit type curtain flow coater, a one-slit type curtain flow coater, an overflow type curtain flow coater, a shower coater, a humist spray coater, etc. can be used. The conveyor 2 is configured to run through a cleaning solvent tank 8 disposed below, and a solvent 10 for dissolving and removing paint adhering to the conveyor chain is contained in the tank. . A roll brush 12 is placed in the solvent tank 8 and is driven to rotate in contact with the conveyor chain to physically remove paint adhering to the chain.

A coating section includes the conveyor 2 and the coating means 6.

Reference numeral 14 denotes a casing, which is disposed between the conveyor 2 and the conveyor 4, and is connected to an inlet 16 through which the object to be coated M is supplied by the conveyor 2 and to the conveyor 4.
An outlet 18 is provided through which the object to be coated M is discharged. Furthermore, a vertically movable shutter 20 is attached to the casing 14 above the inlet, which can limit the opening shape of the inlet 16 by its lower edge and can block the inlet. A vertically movable shutter 22 that can limit the opening shape of the outlet 18 and close the outlet is mounted above the outlet.

A nozzle 24 is provided in the casing 14 for spraying compressed air onto the upper surface of the object to be coated M being transported. The nozzle is capable of reciprocating in the horizontal direction (direction B) perpendicular to the input direction by a reciprocator 26.

28 is a blower for sending compressed air to the nozzle;
Inside the casing, a pipe 30 having a partially flexible portion is connected to the nozzle 24 .

A blower 32 is connected to the casing 14 as a means for reducing the pressure inside the casing 14, and a paint mist collection filter is installed in the casing 14 at the connection point so as to block the gas flow path during exhaust by the blower 32. 34 are arranged. 36 is a tank for recovering paint collected by the filter. Further, 38.40 is a baffle plate.

A seal plate 42 is arranged inside the casing 14 along the lower part of the conveyance path of the object M to be coated.

A film thickness adjustment section includes the casing 14 to the seal plate 42.

Further, 44 is a sensor for detecting the object to be coated M being conveyed on the conveyor z.

FIG. 2 is a partially sectional front view of the casing 14 in the vicinity of the outlet of the object to be coated in this embodiment.

In the figure, 46 is an opening setting member that can be used to set the position in the lateral direction to limit the right side of the opening of the outlet 1B of the casing 14. Although not shown, a similar opening setting member is also arranged on the left side. has been done. When the object M to be coated is a plate-shaped body and the upper surface of the plate-shaped body is to be uniformly coated, when the object M to be coated passes through the outlet 18, the object M is positioned exactly in the center of the opening of the outlet, and the opening and the coating The lateral position of the aperture setting member 46 and the vertical position of the shutter 22 are set so that the gaps 50 between the upper and lower surfaces and both the left and right end surfaces of the coating M are, for example, 1 to 5 mm. However, the above gap is for casing 1.
It can be changed as appropriate depending on the degree of pressure reduction in 4, etc.

A shallow recess is formed in the seal plate 42 at a portion facing the lower surface of the object M along the direction of conveyance of the object to be coated (direction A). The depth of the recess is, for example, about 3 to 7 mm. However, the width of the recessed portion is slightly narrower than the width of the object to be coated M,
Therefore, in the width direction, it is completely covered by the object M to be coated.

The vicinity of the exit 18 has been described above, but the vicinity of the entrance 16 is also similar to the vicinity of the exit.

Next, the operation of the coating apparatus of this embodiment will be explained.

In the coating section, the object M to be coated is conveyed in the direction A on the conveyor 2, and an excessive amount of paint is applied to the upper surface by the coating means 6.

On the other hand, in the film thickness adjustment section, first, the inlet 16 and the outlet 18 are blocked by moving the shutters 20 and 22 sufficiently downward, and while the inside of the recasing 14 is reduced in pressure by the blower 32, the blower 28 is Activate nozzle 2
Compressed air is discharged from 4. The velocity of the discharged air is, for example, 100 to 150 m/sec. Further, the amount of air discharged from the nozzle is, for example, two to four times the amount of air exhausted to the outside of the casing 14 by the blower 32. Further, a portion of the air exhausted by the blower 32 may be supplied to the nozzle 24, and the blower 28 may be omitted.

Then, in the application section, the object M to be coated with the paint is
When the beginning of the image is detected by the sensor 44, the shutter 2
0 upward to form a predetermined inlet opening shape;
The object to be coated M is supplied into the casing 14 through the opening.

FIG. 3(a) shows the distribution of the paint 52 applied to the object M in the coating area, and FIG. 3(b) shows the distribution of the paint 52 applied to the object M in the application area, and FIG. It shows the coating film thickness distribution when it reaches the casing 14 in the case where the coating film has a coating thickness. Here, a case is shown in which the central part of the object M has high paint absorbency and both ends have low paint absorbency. That is, the paint 52 is absorbed in accordance with the paint absorption characteristics of the object M for a certain period of time after application, and the thickness of the paint film is thinner at the center and thicker at both ends.

FIG. 4(a) is a cross-sectional view showing the object to be coated M approached to the entrance of the casing 14 in such a state, and FIG. 4(b) is a sectional view showing the object to be coated M approached from the artificial opening. FIG. 3 is a cross-sectional view showing a state where the supply into the casing 14 has started.

Since the inside of the casing 14 is under reduced pressure, an outside air flow flows in from outside the casing through the inlet opening, and therefore, a portion of the excess paint 52 applied to the upper surface of the object M is stripped away by the air flow and the paint is removed. It becomes a mist and spreads into the casing 14. At this time, the lower surface of the object to be coated M is always covered by the seal plate 42 within the casing 14, and the airflow flowing in from outside the casing 14 always flows along the lower surface of the object to be coated, so that the sucked paint mist is does not reach the bottom surface of the object to be coated, so no paint adheres to the bottom surface of the object to be coated.

FIG. 5 is a sectional view showing the action of the nozzle 24 within the casing 14.

Three slits facing different directions and long in the inlet direction are formed at the tip of the nozzle 24, and compressed air is discharged from the slits. Since the nozzle 24 is reciprocated in the direction B, even if the object M has an uneven surface, compressed air can be effectively sprayed from different angles to the four parts to remove part of the excess paint. The coating thickness can be kept constant.

Then, after a predetermined period of time after the sensor 44 detects the top of the object, the shutter 22 is moved upward to form a predetermined opening shape, and the object M is moved through the opening into the casing 1.
4 Discharge outside.

FIG. 6 is a sectional view showing the state in which the object M to be coated leaves the casing 14.

When the object to be coated M passes through the opening of the outlet 18, the pressure inside the casing 14 is reduced, so the paint 52 applied to the opening and the upper surface of the object to be coated M is caused by the external airflow flowing from outside the casing. Excess paint (excess paint includes paint mist sucked into the casing 14 and paint mist deposited inside the casing by spraying compressed air from the nozzle 24) ) is removed and sucked into the casing 14. In this way, a coating film of a desired constant thickness is formed on the object M discharged from the casing 14.

The paint mist inside the casing 14 is collected by the filter 34 as it is exhausted by the blower 32, and is removed from the tank 3 as needed.
6 and reused as necessary.

Incidentally, by positioning the shutters 20, 22 so that the inlet opening of the casing 14 is slightly larger than the outlet opening, it is possible to prevent the burden of paint suction at the inlet from becoming excessive.

Each of the shutters 20 and 22 is moved downward after a predetermined time after the sensor 44 detects the last end of the object M, and the inlet and outlet openings are closed. The timing of movement of these shutters 20.degree. 22 is appropriately set according to the conveyance speed of the object M to be coated.

[Effects of the Invention] As explained in detail above, according to the coating device of the present invention,
By applying excess paint to the object to be coated in the application section and then removing the excess amount of the applied paint in the film thickness adjustment section, the desired thickness can be easily achieved regardless of the surface properties of the object to be coated. Can be painted. Furthermore, paint mist does not leak to the outside from the film thickness adjustment section, making it sanitary.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram showing a coating apparatus according to the present invention. FIG. 2 is a partially sectional front view of the casing near the outlet of the object to be coated in the coating apparatus according to the present invention. Figure 3(a) shows the distribution of the paint applied to the object to be coated at the coating area, and Figure 3(b) shows the distribution of the paint applied to the object to be coated in the coating area, and Figure 3(b) shows the distribution of the paint applied to the object to be coated in the application area. This shows the coating thickness distribution when it reaches the casing. FIGS. 4(L), (b), 5, and 6 are cross-sectional views for explaining the operation of the coating apparatus according to the present invention. 6: Application means, 2.4: Conveyor, 8: Cleaning solvent tank, 14: Casing, 16: Inlet, 18: Outlet, 20, 227 Shutter, 24: Nozzle, 26: Reciprocator, 28, 32 Niblower, 42: Seal plate, 44: Painted object detection sensor, 52: Paint. 34: Filter, Figure (b) Figure (b)

Claims (5)

[Claims] (1) It has an application part that applies paint to the object to be coated, and a film thickness adjustment part that removes excess paint from the applied object to obtain a desired coating thickness, and Means for transporting the object to be coated via a film thickness adjustment section is arranged, and the film thickness adjustment section includes means for spraying gas onto the paint-applied surface of the casing and the object to be coated that is transported within the casing. and a means for reducing the pressure inside the casing, and an appropriate small gap is formed between the outlet of the casing and the paint-applied surface of the object when the object passes through. A coating device characterized by having a shape structure in which (2) The coating apparatus according to claim 1, wherein the opening for the inlet of the object to be coated and the opening for the outlet of the object to be coated of the casing are formed to include shutters for these openings. (3) a paint mist collection means is disposed at the connection between the casing and the means for reducing the pressure inside the casing;
The coating device according to any one of claims 1 to 2. (4) The coating apparatus according to any one of claims 1 to 3, wherein the gas blowing means is made to reciprocate in a direction transverse to the conveyance direction of the object to be coated. (5) The coating device according to any one of claims 1 to 4, wherein the means for reducing the pressure inside the casing is connected to the gas blowing means.