JPS5933486Y2 - Electrostatic powder coating equipment - Google Patents

Description

[Detailed description of the invention] This invention is an electrostatic powder coating device for forming a coating film on the surface of an object to be painted by charging paint powder using an electrostatic field and making it adhere to the object. Regarding.

The purpose of this invention is to improve the efficiency of applying paint powder to the object to be painted, and its features are as follows: A planar electrode is provided on the side not facing the object to be coated, and on the side facing the object to be coated, the electrodes are formed in a lattice or net shape parallel to each other at approximately equal intervals in the direction from the surface of the substrate toward the object to be coated. A plurality of opposing electrodes, or a plurality of opposing electrodes formed by meandering one linear electrode, are arranged, and every second opposing electrode is connected in the same phase, and each phase of the opposing electrode is connected to the same phase. A three-phase AC power source for applying a three-phase AC voltage is connected to the substrate, and a DC high voltage power source is connected for applying a DC high voltage between the planar electrode and the counter electrode and the object to be coated. It is in.

This invention will be described in detail below based on embodiments shown in the drawings.

FIG. 1 is an overall perspective view schematically showing the electrostatic powder coating apparatus according to this invention, in which 1 is an object to be coated, 2 is a flat substrate made of a dielectric material such as an insulator or a semiconductor, and the substrate 2 is arranged substantially horizontally facing the object 1 to be coated.

A planar electrode 3 made of a flat metal plate having approximately the same size as the substrate 2 is provided in contact with the surface of the substrate 2 that does not face the object 1 to be painted, while the object 1 to be painted On the side facing the substrate 20, parallel to each other at approximately equal intervals in the direction from the surface of the substrate 20 toward the object 1 to be coated, and approximately parallel to the surface of the substrate 20, the size is approximately equal to that of the substrate 2. A counter electrode 4 (4a) formed in a grid shape.

4b, 4c) are arranged.

In the embodiment shown in the drawings, three opposing electrodes 4a,
4b.

Although only 4c is shown, more counter electrodes can be provided, in which case every second counter electrode is connected in phase.

Note that the planar electrode 3 is not limited to the plate shape as described above, but may be a net shape or a conductive film such as metal foil or metal plating formed on the surface of the substrate 20.

Further, the counter electrode 4 is not limited to the grid-like one described above, but may be a counter electrode 14 in which a single linear electrode has a meandering shape as shown in FIG. In short, any material having gaps through which paint powder can freely pass may be used, such as the counter electrode 24 having a net shape.

Further, the counter electrodes 4, 14, 24 are arranged as shown in FIGS.
Bare electrodes as shown in the figure may be used, but in order to prevent spark discharge due to high voltage being applied,
It is desirable to cover it with an insulator, etc.

Further, in the embodiment shown in FIG. 5, a plurality of linear electrodes 6a, 6b, and 6c are buried in parallel to each other at approximately equal intervals near the surface of a panel 5 made of a dielectric material such as an insulator or a semiconductor. By erecting the panel 5 almost perpendicularly to the substrate 2, the linear electrodes 6a, 6b, 6c are formed in a direction from the surface of the substrate 2 toward the object 1 to be coated. The above-mentioned counter electrode 4゜1
4.24 has exactly the same effect.

According to this embodiment, there is no risk of spark discharge occurring and no risk of damaging the linear electrodes 6 a t 6 b and 6 C.

Moreover, by making the counter electrode 34 removable from the substrate 2, the main body of the coating apparatus can be cleaned extremely easily, and the counter electrode 34 can also be easily replaced. can.

In the coating apparatus main body constructed as described above, the fourth
As shown in the figure and FIG.
4 b, 4 c, or each linear electrode 6a, 6b, 6
c) are connected to the U-phase, ■-phase, and W-phase of the three-phase AC power supply 7, respectively, and a three-phase AC voltage is applied to each phase.

Further, by connecting one pole of a DC high voltage power supply 8 to the planar electrode 3 and the counter electrodes 4 and 34, and grounding the other pole of the DC high voltage power supply 8, the object to be coated 1 is grounded. , a DC high voltage is applied between the planar electrode 3 and the counter electrodes 4 and 34 and the object to be coated 1 to generate a potential difference.

Next, to explain the operation of the electrostatic powder coating apparatus according to this invention, first, in the embodiment shown in FIGS. 1 and 4, the three-phase AC voltage applied to the counter electrode 4 is As shown in detail in , the counter electrode 4 (
Between the adjacent electrodes (4a, 4b, 4c), electric lines of force are generated that curve outward with respect to the straight line connecting them, as shown by the broken line, and at the same time, as shown by the solid arrow, A traveling wave type alternating current electric field is formed that advances towards the painted object.

Further, due to the DC high voltage applied between the planar electrode 3 and the counter electrode 4 and the object to be coated 1, the surface of the substrate 2 is coated as shown by the broken line arrow in FIGS. 4 and 6. A direct current electrostatic field directed toward the coating object 1 is formed.

In this state, when paint powder is supplied onto the substrate 2, the paint powder is strongly charged by the action of the electric lines of force, and the charged paint powder is applied to the substrate 2 by the action of the traveling wave AC electric field. While being conveyed toward the object, the paint powder is attracted toward the object 1 by the action of the DC electrostatic field formed between the planar electrode 3 and counter electrode 4 and the object 1 to be painted. and adheres to the surface of the object 1 to be coated to form a powder layer.

Thereafter, by heating the object 1 to be coated, the powder layer becomes a strong coating film, and the coating is completed.

Further, in the embodiment shown in FIG. 5, the three-phase AC voltage applied to the counter electrode 34 causes the mutually adjacent linear electrodes 6a, 6b of the counter electrode 34 to , 6c, outward curved lines of electric force are generated on the surface of the panel 50, as shown by the broken line, and progress toward the object to be coated along the surface of the panel 5, as shown by the solid arrow. A wave-shaped alternating current electric field is formed.

Further, due to the DC high voltage applied between the planar electrode 3 and the counter electrode 34 and the object to be coated 1, as shown by the broken line arrow in FIG. 5 and FIG.
A DC electrostatic field is formed from the 0 surface toward the object 1 to be coated.

By supplying paint powder onto the substrate 2 in this state, a powder layer can be formed on the surface of the object 1 to be coated, just as in the previous embodiment.

As described above, the electrostatic powder coating apparatus according to this invention has a substrate made of a dielectric material on the side facing the object to be coated, which is spaced from each other at approximately equal intervals in the direction from the surface of the substrate toward the object to be coated. A plurality of counter electrodes formed in parallel in a lattice shape or a net shape, or a plurality of counter electrodes formed in a meandering shape from a single linear electrode are arranged, and a three-phase alternating current voltage is applied to each of the counter electrodes. By forming a traveling wave alternating current electric field that travels from the substrate surface toward the object to be painted, the paint powder supplied onto the substrate is strongly charged, and the charged paint powder is transferred to the object to be painted. This conveyance action and the direct current static current directed from the substrate surface toward the object to be coated are generated by the high DC voltage applied between the planar electrode, the counter electrode, and the object to be coated. Combined with the action of the electric field, the charged paint powder is accelerated uniformly and stably toward the surface of the object to be painted in an extremely short time, and the paint powder is accelerated toward the surface of the object to be painted. The adhesion efficiency can be increased, and the application efficiency in powder coating can be significantly improved.

In addition, in the case of the other embodiment of the counter electrode shown in FIG.
If the meandering electrodes are formed to diverge toward the object to be coated at a desired angle of inclination, a traveling wave type alternating current that travels from the substrate surface toward the object to be coated can be created by applying a three-phase AC voltage. By creating an electric field, it has the advantage of being able to transport charged paint powder over a wide range of objects to be painted.

Furthermore, when it is necessary to apply the paint powder to the object to be coated more precisely than in the case of the embodiment of the lattice-shaped counter electrode of the present invention shown in FIG. 1, the method shown in FIG. The counter electrode may be formed into a net shape as in the embodiment shown in FIG.

Furthermore, the device structure of the present invention has the advantage of being extremely simple to manufacture.

[Brief explanation of the drawing]

The drawings show an embodiment of this invention, and FIG. 1 is an overall perspective view schematically showing an electrostatic powder coating apparatus according to this invention;
Figures 2 and 3 are perspective views showing other embodiments of the counter electrode in this invention, Figure 4 is a sectional view showing the wiring connection of the electrostatic powder coating device according to this invention, and Figure 5 is a perspective view showing another embodiment of the counter electrode in this invention. FIGS. 6 and 7 are enlarged sectional views of essential parts showing the operating state of the embodiment shown in FIGS. 4 and 5, respectively. 1...Object to be painted, 2...Substrate, 3...
... Planar electrode, 4 (4a, 4b, 4c), 14, 2
4, 34------Counter electrode, 7---3-phase AC power supply, 8---DC high-voltage power supply.

Claims (1)

[Scope of utility model registration request] In an electrostatic powder coating device that forms a coating film on the surface of an object by adhering paint powder to the object using an electrostatic field, it is used to coat substrates made of insulators or dielectric materials such as semiconductors. A planar electrode is provided on the side that does not face the object, and between the substrate and the object to be coated, the electrodes are formed in a lattice or net shape parallel to each other at approximately equal intervals in a direction from the surface of the substrate toward the object to be painted. A plurality of opposing electrodes, or a plurality of opposing electrodes formed by meandering one linear electrode, are arranged, and every two opposing electrodes are connected in the same phase, and each layer of the opposing electrode is A three-phase AC power source for applying a three-phase AC voltage is connected to the substrate, and a DC high voltage power source is connected for applying a DC high voltage between the planar electrode and the counter electrode and the object to be coated. Electrostatic powder coating equipment featuring: