JPH0248063A - Painting device - Google Patents

Abstract

PURPOSE:To allow painting to a desired thickness by forming a suitable spacing to the outlet for the material to be painted of a paint tank for dip painting and further, providing a means for reducing the pressure in a painting chamber. CONSTITUTION:The paint is previously put into a paint storage part 20 in the painting chamber 2 and while the pressure in the painting chamber 2 is reduced by a blower 28, a pump 40 is operated to feed the paint into the paint tank 1 for dip painting. An inlet member 12 and an outlet member 14 are respectively kept closed by shutters 16, 18 at this time. The paint supplied into the paint tank 1 for dip painting overflows from the tank and is recovered into the paint storage part 20. The shutter 26 is opened to supply the material 4 to be coated from the aperture of the inlet member 12 into the paint tank 1 for dip painting at the point of the time when the top of the material to be coated is detected by a sensor 48. The material 4 to be coated is subjected to the dip painting in the tank 1.

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 devices have been proposed as devices for continuously painting objects to be coated while conveying them on a conveyor in a mass production factory.

For example, when painting a flat plate, conventionally the paint is
An air spray or airless spray system that atomizes fine particles with a diameter of 80 JLm for coating, or a roll coater or curtain flow coater is used.

However, the above-mentioned air spray painting equipment and airless spray painting equipment have poor coating efficiency because they atomize the paint, and the paint mist scatters a long time ago, causing contamination of equipment and causing health and safety hazards. It can also cause pollution. Further, when the surface of the object to be coated is uneven, the roll coater cannot coat all four parts well. Further, the flow coater has the disadvantage that it can only coat one side, and especially cannot coat the sides.

Furthermore, - the above spray coating device and flow coater:
Since the coating film thickness changes depending on the conveyance speed of the object to be coated, it is necessary to accurately control the conveyance speed. In addition, the above-mentioned conventional coating equipment supplies paint uniformly over the entire surface regardless of the surface condition of the object to be coated, so if the surface properties (for example, paint absorption) of the object to be coated are partially different, There is a problem that the coating film thickness becomes uneven. Therefore, even under the same coating conditions, the coating film thickness changes 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.

Therefore, the present invention does not have the above-mentioned problems of the conventional technology, and can easily coat the object to a desired thickness regardless of the surface properties of the object to be coated. Furthermore, it is possible to coat both upper and lower surfaces and both sides simultaneously. The purpose is to provide a coating device that can.

[Step F for Solving the Problems According to the present invention, the above object is achieved by: A means for transporting the object to be coated through the dip coating paint tank is disposed, and the above dip coating paint The tank is arranged in the painting room with the object to be coated and the outlet of the object to be painted facing the outside of the painting room, and the outlet of the coating material tank for dip coating is arranged so that the object to be coated and the outlet of the object to be painted face the outside of the painting room. This is achieved by a coating apparatus, characterized in that it has a shape structure in which an appropriate small gap is formed between the coating apparatus and the coating apparatus, and is further provided with means for reducing the pressure inside the coating chamber.

In the coating apparatus of the present invention, a means for recovering overflow paint from the dip coating paint tank may be provided in the coating chamber, and a means for feeding the paint from the recovery means to the dip coating paint tank may be provided. can.

Furthermore, in the coating apparatus of the present invention, a paint mist collecting means can be disposed at the connection between the painting chamber and the means for reducing the pressure inside the dip coating paint tank.

[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 these figures, reference numeral 2 denotes a painting room, and means for transporting the object 4 to be coated horizontally in the direction A through the painting room is arranged. The conveying means includes a belt conveyor 6 that supplies the workpiece 4 from outside the painting room 2 into the painting room, a roller 8 disposed inside the painting room 2, and a conveyor 6 that supplies the workpiece 4 from outside the painting room 2 to the outside of the painting room. The receiver includes a belt conveyor 10 for picking up the objects 4. 6a and 8a are presser rollers that are biased toward the belt conveyor 6 and roller 8, respectively.

In the painting room 2, there are objects to be coated 4 by means of conveying the objects to be coated.
An inlet member 12 having an opening shaped so that a slight gap is formed when the object to be coated passes through is attached to the inlet portion where the object is supplied. Further, the coating chamber 2 has an opening shaped so that a slight gap is formed when the object to be coated passes through the exit portion through which the object to be coated 4 is discharged by the object conveying means. An outlet member 14 is attached. Incidentally, a shutter 16 capable of closing the opening of the inlet member 12 and a shutter 18 capable of closing the opening of the outlet member 14 are attached to the painting room 2.

A paint tank 1 for dip coating is arranged in the coating room 2. The tank includes the inlet member 12 and the outlet member 1.
4 is formed using a part of the wall surface of the painting room 2, and is arranged so as to include the entire path through which the object 4 passes through the painting room 2. That is, the object to be painted 4 is in the painting room 2.
Inside, it passes only through the paint tank l for dip coating.

The coating chamber 2 is provided with a paint storage section 20 for collecting paint overflowing from the upper edge of the dip coating paint tank l. Further, a blower 28 is connected to the painting chamber 2 as a means for reducing the pressure inside the painting chamber 2 including the paint tank l for dip coating. The paint mist collection filter 30 is arranged so as to block the gas flow path during exhaust. In addition, the above-mentioned blower 28 is installed in the painting room 2.
Baffle plates 32 and 34 are provided to block paint mist generated during exhaustion.

A pump 40 is disposed outside the painting chamber 2, and can supply the paint from the paint storage section 20 to the dip coating paint tank 1.

Incidentally, a pressure reduction degree adjusting valve 46 is connected to the painting chamber 2 in order to suppress the degree of pressure reduction caused by exhaust gas from the blower 28 from becoming excessive.

Further, 48 is a sensor for detecting the object to be coated 4 conveyed on the belt conveyor 6F.

FIG. 2 is a partially sectional front view of the coating chamber 2 in the vicinity of the outlet of the object to be coated in this embodiment. When the object 4 to be coated is a plate-shaped object and both upper and lower surfaces and both left and right sides of the plate-shaped object are uniformly coated,
When the object 4 to be coated passes through the outlet member 14, it is located exactly at the center of the opening of the outlet member, and the gaps 50 between the opening and both upper and lower surfaces and both left and right end surfaces of the object 4 to be coated are, for example, 1 to 1. The opening of the exit member 14 is set so that the opening is 5 mm, and the exit member is arranged. However, the above-mentioned gap can be changed as appropriate depending on the degree of pressure reduction in the coating chamber 2 during coating, the length of the opening of the outlet member 14 along the conveyance direction of the object to be coated, and the like. In addition, 52 is the paint in the paint tank 1 for dip coating.

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

Paint is placed in a paint reservoir 20 in the painting chamber 2, and while the pressure inside the painting chamber 2 is reduced by the blower 28, the pump 40 is operated to feed the paint into the paint tank l for dip coating. At this time, the inlet member 12 and the outlet member 14 are each closed with shutters 16 and 18. The paint supplied into the dip coating paint tank l eventually overflows from the tank and is collected into the paint storage section 20.

The object to be coated 4 is transported in the direction A by the object conveying means, the shutter 16 is opened at the point where the leading edge of the object to be coated is detected by the sensor 48, and the object to be coated 4 is transported through the opening of the entrance member 12. Supplied into the paint tank l for dip coating. Inside the tank, the object 4 to be coated is subjected to dip coating.

Then, after a predetermined period of time after the sensor 48 detects the beginning of the object to be coated, the shutter 18 is opened and the object to be coated is moved to the exit member 14.
It is discharged to the outside of the dip coating paint tank 1 through the opening.

FIG. 3 is a sectional view showing the state when the object 4 to be coated leaves the coating chamber 2 (that is, when it leaves the paint tank 1 for dip coating).

When the object to be coated 4 passes through the opening of the outlet member 14, the pressure inside the coating chamber 2 is reduced, so that the coating chamber 2 is removed from outside the coating chamber 2.
A predetermined small gap 56 is formed between the opening and the paint 52 on the surface of the object 4 by the flow of outside air flowing into the inside (ie into the paint tank l for dip coating). Thus,
Due to the action of the outside airflow flowing through the gap 56, a coating film of a constant desired thickness is formed when the object 4 to be coated is discharged to the outside of the coating chamber 2. In this case, no matter what the surface properties of the object 4 to be coated are, the paint is appropriately absorbed into the object 4 depending on the surface properties from the inlet to the outlet. The thickness of the coating film upon leaving the section is a predetermined thickness. It should be noted that the outside air that has flowed into the paint tank l for dip coating becomes bubbles in the paint 52. Since the pressure inside the painting chamber 2 is reduced, the air bubbles quickly float to the surface and are degassed from the paint.

The shutters 16, 18 are each closed a predetermined time after the sensor 48 detects the last end of the object 4 to be coated.

The opening and closing times of these shutters 16 and 18 are appropriately set depending on the conveyance speed of the object 4 to be coated.

Note that the object to be coated 4 has not passed through the opening of the inlet member 12 and/or the opening of the outlet member 14, and the shutter 16.18
When the tank is open, outside air is introduced into the dip coating paint tank l through the openings of the inlet member and the outlet member, so the paint in the tank will not leak to the outside of the painting room.

Furthermore, when the shutter 16 and/or the shutter 18 are open, the coating material tank 1 for dip coating differs between when the object 4 is passing through these openings and when it is not passing through the openings.
Although the cross-sectional area of the communicating part with the outside is different, by setting the exhaust force of the blower 28 and the pressure reduction degree adjusting valve 46 appropriately, air can be appropriately introduced into the painting chamber 2 from the valve 46 when the object to be coated passes. As a result, the degree of reduced pressure in the coating chamber 2 can be maintained substantially constant.

Further, when the blower 28 exhausts the air, paint mist is collected by the filter 30.

In the above-described apparatus of this embodiment, the paint in the dip coating paint tank 1 is made to flow during coating.
Dust and debris adhering to the object are washed away by the fluid paint and collected in the paint storage section 20, so that less remains in the paint film formed on the object to be coated, and the quality of the coating is improved. Incidentally, the dust and debris in the paint collected in the paint storage section 20 can be removed by a filter (not shown).

Next, using the device of this example, a width of 450 mm and a thickness of 8 m was prepared.
An example in which a workpiece with a length of 2000 mm was coated is shown below.

The openings of the inlet member 12 and the outlet member 14 are both 3 m in the thickness direction and width direction with respect to the object to be coated 4 when the object 4 passes through.
The shape was such that a gap of m (sample No. 1) or 5 mm (sample No. 2) was formed. As the paint, a water-based acrylic emulsion paint [viscosity: 45 seconds (15° C.) at Ford Cup #4] was used.

The degree of vacuum in the painting chamber 2 was set to 650 mmAq (sample No. 1
) or 500mmAq (Sample No.

2), the conveyance speed of the object to be coated 4 is 40 m/min,
The thickness of the wet coating film formed was investigated.

The results are shown in Table 1 below.

[Effect of the invention 1 As explained in detail above, according to the coating device of the present invention,
It can be easily coated to the desired thickness regardless of the surface condition of the object to be coated.
Furthermore, both the upper and lower surfaces and both side surfaces can be coated satisfactorily at the same time.

FIG. 3 is a front view of the vicinity of the outlet of the object to be coated.

FIG. 3 is a sectional view showing the state in which the object to be coated leaves the coating room.

2: Painting room, 4: Object to be painted, 8.10: Belt conveyor, 12 two-person member, 14: Exit member, 16.18:
Shutter, 20: Paint reservoir, 28 Niblower, 30: Filter, 40: Pump.

48: Painted object detection sensor.

52: Paint.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram showing a coating apparatus according to the present invention.

Claims (3)

[Claims] (1) Means for conveying the object to be coated via the inside of the paint tank for dip coating is arranged, and the above paint tank for dip coating has an inlet of the object to be coated and an outlet of the object to be coated in the painting room outside the painting room. The outlet of the coating material tank of the dip coating paint tank has a shape structure such that an appropriate small gap is formed between the coating material and the coating material when the coating material passes through, A coating apparatus further comprising means for reducing the pressure inside the coating chamber. (2) The method according to claim 1, further comprising means for collecting overflow paint from the dip coating paint tank in the coating chamber, and means for feeding the paint from the recovery means to the dip coating paint tank. Painting equipment described. (3) The coating apparatus according to claim 1 or 2, wherein a paint mist collecting means is disposed at a connection between the painting chamber and a means for reducing the pressure inside the paint tank for dip coating.