JPS6110769Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a powder coating apparatus for attaching paint powder to an object to be coated using an electrostatic field to form a powder layer on the surface of the object to be coated.

Conventionally, in this type of powder coating equipment, a plurality of linear electrodes are buried in parallel to each other near the surface of a dielectric substrate such as an insulator or a semiconductor, and a plurality of linear electrodes are buried at a predetermined distance from the linear electrodes. It has an electric field panel with planar electrodes embedded in a substrate, and a high voltage generator connected to both of the electrodes, and the electric field panel faces the object to be coated which is grounded and kept at a positive potential. Some devices are installed in such a way that an electrostatic field is formed between the electric field panel and the object to be painted, so that coating powder is electrically attracted and adhered to the surface of the object to be painted.

By the way, as shown in FIG. 6, the electric field panel in a conventional powder coating apparatus includes a linear electrode 3 and a planar electrode (not shown) embedded in the substrate 2 of the electric field panel 1, and an AC high voltage generating circuit. A high-voltage cable 6 is used to connect the high-voltage generator 5 comprising a DC high-voltage generating circuit. In the figure, 7 is a control device for controlling the high voltage generator. Therefore, there was a risk of damage to the high-voltage cable 6, sparks caused by disconnection, explosion of paint powder, or electric shock. Further, there was a problem that electric charges were accumulated in the high voltage cable 6 and energy was dissipated.

Therefore, the purpose of this invention is to solve the above-mentioned problems and provide a powder coating device with a simple structure, in which the AC high voltage generation circuit and the DC high voltage generation circuit are housed in an insulating synthetic resin member. The above objective is achieved by joining an enclosed high voltage generator with an electric field panel with embedded electrodes to form an integrated structure, and then assembling this structure into a tunnel-shaped bulkhead through which the object to be coated passes. It is something to do.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In FIG. 1, 21 is a tunnel-shaped partition wall, and a paint supply hole 22 communicating with a paint powder tank (not shown) is opened in the upper part. and the supply hole 22
The paint powder is supplied to the inside of the partition wall 21. 3
0 is an object to be painted, which is suspended on a hanger 24 that is moved by a conveyor device 23, and is conveyed within the partition wall 21.

A plurality of electric field panels 1 are bonded to the inner surface of the partition wall 21 on both sides and the entire bottom surface thereof.
A high voltage generator 10 having a high voltage generating circuit sealed in an insulating synthetic resin member is integrally attached to the back surface of each of these electric field panels 1, and each of these high voltage generators 10 is connected to a partition wall. A sealed high voltage generating circuit protruding from the opening formed in the partition wall 21 is connected by a low voltage cable 8 to a control device 7 for controlling the high voltage generating circuit.

Each of the above electric field panels 1 and high voltage generator 10
The structure of the electric field panel 1 is as shown in FIGS. 2 to 4. As shown in FIGS. Linear electrodes 3 are buried parallel to each other, and planar electrodes 4 are buried along these electrodes 3 at predetermined intervals. A high voltage generating device 10 comprising an AC high voltage generating circuit and a DC high voltage generating circuit sealed in an insulating synthetic resin member 11 is integrally connected to the back side of the substrate 2. The circuit and control device 7 are connected by a low voltage cable 8. The high voltage generator 10 has a thickness similar to or slightly thicker than the substrate 2,
It has a smaller area than the substrate 2 and is bonded to the center of the back surface of the substrate 2. Then, the back surface of the substrate 2 is fixed to the inner surface of the partition wall so as to close the opening of the partition wall 21,
A high voltage generator 10 projects outward from the opening.

FIG. 4 shows an example 12 of a high voltage generating circuit sealed in the synthetic resin member 11, in which 14 is a high voltage diode forming a rectifier, 15 is a high voltage capacitor, and a plurality of diodes and capacitors are used to generate a high DC voltage. A generating circuit 13 is formed. 17 is a transformer connected in multiple stages, and by increasing the turns ratio, an AC high voltage generating circuit 16 is formed. One output end of the AC high voltage generating circuit 16 is connected to a linear electrode 3 buried in the substrate 2 of the electric field panel 1, and the other end is connected to a planar electrode 4 buried in the substrate 2.

On the other hand, the - potential side of the DC high voltage generation circuit 13 is
It is connected to the planar electrode 4 via the linear electrode side of the AC high voltage generating circuit 16 and the secondary coil of the transformer 17. The connecting portion is embedded within the integrated substrate 2 and synthetic resin member 11. The + potential side of the DC high voltage generating circuit 13 is connected to the object to be coated via a hanger 24. Note that 18 is a current limiting resistor.

When performing powder coating using the above equipment,
The paint powder is supplied from the paint supply hole 22, and the hanger 24 attached to the conveyor device 23
The object to be coated 30 is transported by. Then, by applying an AC high voltage between the linear electrode 3 and the planar electrode 4 of the electric field panel 1, lines of electric force are generated on the surface of the electric field panel 1, thereby charging the paint powder. The charged powder receives a repulsive force from the surface of the electric field panel 1 due to the action of electric lines of force and floats up. At the same time, a DC high voltage is applied to the linear electrode 3 and the planar electrode 4 to create a potential difference between the object to be coated 30 and the electric field panel 1, thereby forming a DC electrostatic field between the two, and the charged coating is applied. The powder is electrically attracted to the object 30 to be coated and adheres to its surface.

Therefore, the paint powder supplied from the top of the partition wall 21 is floated from the surface of the electric field panel 1, especially the bottom electric field panel, thereby preventing the paint powder from settling to the bottom and becoming ineffective. , the coating efficiency is extremely good.

In the present invention, the substrate 2 of the electric field panel and the synthetic resin member 11 for the high voltage generator are integrally combined, and the electrodes 3, 4, the high voltage generating circuit 12, and their connection parts are embedded therein. , the particle loading device is simplified and compact. In addition, because conventional high-voltage cables are not used, there is no risk of sparks, fires, or electric shocks due to damage or disconnection, and the power input terminal of the high-voltage generator and one side of the electric field panel are isolated by a partition wall. There is no risk of the powder paint exploding. It also eliminates the problem of energy release from high voltage cables and improves the reliability of the device. In addition, the device of the present invention has an opening in the tunnel-shaped partition wall through which the object to be coated is transferred, an electric field panel is fixed inside the opening, and a resin-coated high voltage generator integrated with this panel is protruded from the opening to the outside of the partition wall. It is possible to realize a powder coating device with a simple assembly structure.

As shown in FIG. 5, if a lattice-shaped protective cover 40 made of insulating synthetic resin is provided on the surface of each electric field panel 1, the object 30 to be coated can be prevented from swinging or falling. Even if the electric field panel 1 does come into contact with the surface of the electric field panel 1, it will not be damaged, and short-circuit discharge is prevented, so safety can be further improved.

[Brief explanation of the drawing]

Figures 1 to 5 show an embodiment of the device of the present invention. Figure 1 is a vertical cross-sectional view of the device, Figure 2 is a schematic external view of the electric field panel used in the device and its attached equipment, and Figure 3 2 is a sectional view of a main part of FIG. 2, FIG. 4 is a circuit diagram, and FIG. 5 is a diagram showing a protective structure of an electric field panel. FIG. 6 is a schematic external view of an electric field panel and its attached devices in a conventional device. DESCRIPTION OF SYMBOLS 1... Electric field panel, 2... Substrate, 3... Linear electrode, 4... Planar electrode, 5... Conventional high voltage generator, 6... High voltage cable, 7... Control device, 8...
...Low voltage cable, 10...High voltage generator of the present invention, 13...DC high voltage generation circuit, 16...AC high voltage generation circuit, 21...Partition wall, 30...Object to be painted, 40...Electric field panel protective cover.

Claims (1)

[Scope of utility model registration request] A plurality of linear electrodes are buried in parallel with each other near the surface of a substrate made of a dielectric material such as an insulator or a semiconductor, and a planar electrode is buried in the substrate at a predetermined distance from the linear electrodes. An electric field panel is constructed, and an AC high voltage generation circuit for applying an AC voltage between the two electrodes and a DC high voltage generation circuit for applying a DC high voltage to both electrodes are enclosed in an insulating synthetic resin member. The above-mentioned high-voltage generation device, which has a smaller opposing area than the above-mentioned substrate, is coupled to the center part of the back surface of the substrate, and the above-mentioned electrodes, the high-voltage generation circuit, and their connection parts are connected to each other. An opening is provided in the partition wall of the tunnel through which the coating powder is supplied and the object to be coated passes through, and the electric field panel is placed inside the tunnel, and the back side of the substrate is inserted into the opening. A powder coating device characterized in that the high voltage generator is fixed to the inner surface of a partition wall so as to close the partition wall, and the high voltage generator is made to protrude outside through an opening.