JPS60102965A - Electrostatic coating method using powdery coating material and ejecting nozzle for said material - Google Patents

Abstract

PURPOSE:To enable to coat easily and uniformly even an object to be coated which has a recessed part, by a method wherein a plurality of nozzles are provided slantly against the moving direction of an object to be coated so that the ejecting directions of the nozzles are provided opposite to each other. CONSTITUTION:Two ejecting parts 4, 5 for a powdery coating material are provided slantly (not perpendicularly) against the moving direction of the object so that the ejecting direction of the nozzles are provided opposite to each other. Accordingly, even when the object has a part recessed in the moving direction thereof or in the vertical direction, the recessed part can be coated easily and uniformly.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electrostatic coating method using a powder coating material and a powder coating injection nozzle suitable for carrying out the method.

In the electrostatic coating method using powder paint, the powder paint supplied by air is guided to the nozzle of a powder paint injection gun, and the powder paint is transferred from the nozzle using air pressure or centrifugal force provided by a rotating diffuser. For example, the spray is dispersed in the form of mist toward a workpiece suspended by a chain conveyor and moving along a certain path, and at the same time high pressure is applied between an electrode disposed in the nozzle and the workpiece. In this method, the powder coating material is charged with a DC voltage, and the powder coating material is adsorbed to the object to be coated using electric force.

This electrostatic coating method using powder coating has the advantage of high coating efficiency and large labor savings because it uses a conveyor for assembly line work, but on the other hand, It is also known that the four recessed parts have a drawback in that it is not possible to coat them uniformly, and the objects to be coated are limited due to their shape.

The purpose of the present invention is to solve the problems of the electrostatic coating method using powder paint as described above, and to solve the above-mentioned problems in the electrostatic coating method using powder coating. To provide a coating method that can easily and uniformly coat the concave portions of objects to be coated, and a powder paint injection nozzle that can be conveniently used when carrying out the coating method. It is something.

Hereinafter, one embodiment of the present invention will be described based on the attached illustrative drawings. Figs. 1 to 3 show a nozzle 1 constructed according to the present invention, and the nozzle 1 is a powder paint injection gun. A base 2 attached to the tip, a branch 3 branching into a figure 7 shape from the base 2, and a powder paint discharge part 4.5 provided at the top of the branch 3, and both powder paint discharge parts Four electrodes 8.9 for charging the powder coating material are disposed in each circumferential hook in the branch flow path 6.7 between 4.5 and 4.5.

The nozzle base 2 has small-diameter cylindrical power receiving jacks 12a and 12b buried in two radial locations on the outer end surface of a cylinder 11 having a flange 10 on the intermediate outer periphery, and small-diameter power receiving jacks 12a and 12b embedded in two radial locations on the inner end. Rod-shaped power supply plugs 13a, 13b are provided protrudingly, and these jacks 12a, 12b and plug 13a are provided.
, 13b are connected to each other separately by electric wires 14 embedded in the cylindrical body 11, and a nut 15 for coupling with a powder paint injection gun is loosely fitted on the inner end side of the flange 10. It is.

The nozzle branch part 3 consists of a Y-shaped cylinder 16,
A base portion 16a of the cylindrical body 16 is fitted onto the inner small diameter portion 11a of the base cylindrical body 11 and is removably fixed with a fixing screw 17. 18a and 18b are Y-shaped cylinders 1
A small-diameter cylindrical power receiving jack buried in 6,
The terminals of the plurality of electric wires 19 connected to the jacks 18a, 18b and embedded in the Y-shaped cylinder 16 are exposed from the inner periphery of the west end opening of the Y-shaped cylinder 16, and the electrodes 8, 9 are connected to the jacks 18a, 18b. It is said that These double weight receiving jacks 18a, 18
b fits into the power supply plugs 13a and 13b when the Y-shaped cylinder 16 and the base cylinder 11 are connected. In addition, to explain an example of the connection between the electrodes 8, 9 and the power receiving jacks 18a, 18b, one set of the four electrodes 8 facing each other, and one set of the four electrodes 9 facing each other. The electrodes are connected to one jack 18a, and each remaining set of electrodes is connected to the other jack 18b.

The powder coating discharge part 4.5 has an attachment 20 detachably screwed to the west end of the Y-shaped cylinder 16.
．． 21, these two attachments 20.2
The powder coating discharge ports 20a and 21a are formed in the shape of slits that are parallel to each other.

In addition, when using the connecting nut 15, the base cylinder 11 and the branch Y-shaped cylinder 16 are separated in order to incorporate the nut 15, and after the nut 15 is installed, both parts 11.16 are connected. However, after the nut 15 is assembled, both parts 11 and 16 may be integrated inseparably. In this case, plugs 13a, 13b and jack 1
8a.

It is also possible to connect the power receiving jacks 12a, 12b and the electrode 8.9 without using the wire 11. Also, the connecting nut 15
When not in use, the base cylindrical body 11 and the branch Y-shaped cylindrical body 16 can be constructed integrally.

FIG. 4 shows an example of the object 22 to be coated. The object to be painted 22 is a lattice frame structure used for prefabricated buildings, etc., and channel steels 22a and 22b are used as diagonal members, and are suspended by a chain conveyor or the like in the direction of an arrow 23. transported to.

FIG. 5 shows an embodiment of the method of the present invention, in which 24 is a gun for powder coating injection with the nozzle 1 attached to the tip using the coupling nut 15, and in this nozzle coupled state, the gun The two power supply plugs protruding from the 24 side fit into the power receiving jacks 12a and 12b of the nozzle base 2, and the anode side cable 26 of the high voltage DC power supply 25 and the electrode 8°9 of the nozzle example are connected. In addition to being electrically connected, the hose 28 that supplies powder paint from the powder paint containers 27 using air pressure is connected to the Y-shaped flow path 29 (see Fig. 1) in the nozzle 1, unlike the conventional method. It is similar to Also, the object to be painted 22 is 11! ! It is electrically connected to the cathode side of the high-voltage DC power supply 25 through the conveying chain conveyor.

During the painting operation, the gun 24 is supported such that the pair of powder coating discharge parts 4 and 5 in the nozzle 1 are aligned one behind the other in the moving direction 23 of the object 22 to be coated. The gun 24 can be supported manually or by a machine such as a manipulator. With the gun 24 supported in this manner, if powder coating is supplied to the Y-shaped channel 29 in the nozzle 1 by air pressure when the object 22 to be coated passes in front of it, the powder coating will be It is divided into front and rear parts at the branching part 3, and is diffused into a vertical belt shape by air pressure from the vertically elongated slit-shaped powder paint discharge ports 20a and 21a of the pair of front and rear powder paint discharge parts 4 and 5 toward the object 22 to be coated. Injected. On the other hand, electrode 8.9
Since a high DC voltage is applied between the discharge ports 20a and 21a, the powder coating material sprayed from the discharge ports 20a and 21a is charged and attracted to the object 22 by electric force.

In this way, the object to be painted 22 is electrostatically coated with powder paint, which is diffused and sprayed in a vertically long strip form from one of the powder paint discharge parts 4 which is oriented diagonally forward in the direction of movement of the object to be painted 22. When the groove type steel 22a of the object to be coated 22 reaches the position facing the discharge part 4, the powder coating is applied to the groove type 1.
It flows forcefully into the groove-shaped recess opening diagonally rearward and upward at 122a, and is attracted to the entire inner surface of the groove-shaped recess. Further, the powder paint diffused and sprayed in a vertically long strip from the other powder paint discharging section 5 oriented diagonally rearward in the moving direction of the object 22 to be coated is applied to the object 2 at a position opposite to the discharging section 5.
When the second channel steel 22b reaches, it flows forcefully into the groove-shaped recess that opens obliquely forward and upward of the channel steel 22b, and
It will be attracted to the entire inner surface of the groove-like recess. As a result, the entire surface of the object 22, including the inner surfaces of the grooves 1122a and 22b, is uniformly electrostatically coated.

In addition, if the object to be coated has a recess that is vertically recessed with respect to the moving direction, the gun 24 is arranged so that the pair of powder coating discharge parts 4.5 in the nozzle 1 are vertically disposed. It is best to support them in the same direction.

Further, when painting an object to be coated which has a recessed part recessed in the vertical direction and a recessed part recessed in the front and back direction, the guns 24 are arranged in parallel at appropriate intervals in the moving direction of the object to be painted, and one gun 24 is The gun 24 may be supported in the direction shown in FIG. 5, and the other gun 24 may be supported in the direction in which the pair of powder coating discharge portions 4.5 in the nozzle 1 are aligned vertically, as described above.

The method of the present invention can be carried out as described above, and the powder coating is sprayed at an angle to the moving direction of the object, rather than at right angles to the direction of movement of the object. At least two powder paint discharge units are arranged so that the spray directions are opposite to each other, and powder paint is sprayed from each of these powder paint discharge units to keep the object to be coated still. It is characterized by the fact that it is electrically coated. According to the method of the present invention, as shown in the examples, even if the object to be coated has a recess that is recessed in the front-rear direction or the vertical direction of the moving direction, the recess is recessed in the direction of the recess. By arranging the two powder coating discharging sections in parallel, the entire surface of the object to be coated, including the inner surface of the recess, which passes relatively in front of the powder coating discharging section, can be covered by the two powder coating discharging sections. It is possible to perform electrostatic coating uniformly using a powder coating material sprayed from the coating material, which eliminates the drawbacks of conventional coating methods of this type. Moreover, since the two powder paint discharging parts need only be held in a fixed direction, even when the powder paint spraying gun equipped with the powder paint discharging parts is manually supported during work, it is possible to maintain a flat The work can be done easily and efficiently, just like when painting a wooden board.

In the above embodiment, two powder coating discharge parts 4.5 were provided in one nozzle 1, and this nozzle 1 was attached to one powder paint injection gun 24. The method of the present invention is carried out by separately supporting at least two powder paint spraying guns each having a conventional nozzle attached thereto so that the direction of the powder paint discharging portion of each gun is slanted as described above. is also possible.

However, as shown in the examples, there is a base attached to the tip of the gun for powder paint injection, a branch part branching from this base in a figure 7 shape, and a powder paint discharge part provided at the tip of this branch part. The powder paint injection nozzle is equipped with an electrode for charging the powder paint in the branch flow path up to the two powder paint discharge parts or in the vicinity of the frontage of the discharge part, and the powder paint injection nozzle has an electrode for charging the powder paint. It has the advantage that the method of the present invention described above can be carried out satisfactorily by simply attaching it to a paint spraying gun and using it in the conventional manner.

In addition, the nozzle in which the openings of both powder coating discharge parts are arranged in parallel to each other in the form of slits is suitable for coating objects having groove-shaped recesses according to the method of the present invention as shown in the examples. This is particularly effective as a nozzle.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional plan view of a nozzle according to the present invention, FIG. 2 is a side view of the same, FIG. 3 is a vertical cross-sectional view of the same essential parts, FIG. 4 is a perspective view showing an example of an object to be coated, and FIG. The figure is a diagram illustrating an embodiment of the method of the present invention. ■... Nozzle, 2... Base, 3... Branch, 4,
5... Powder paint discharge part, 8.9... Electrode, 1]...
・Base cylinder, 12a, +2b, 18a, 18b-・Power receiving jack, 13a, 13b...Power feeding plug, 14
．． 19...Electric wire, 15...Nand for coupling, 16...
・Y-shaped cylinder, 20.21-attachment, 20a,
21a...Powder coating discharge port, 22...Object to be coated, 2
2a. 22b... Channel steel, 24... Powder paint injection gun,
25...High voltage DC power supply, 26...Anode side cable,
27... Powder paint container, 28... Powder paint supply bowl. Patent Applicant Jin Keihisa:: 312f 4 A Procedural Amendment Written Form) March 1980 191 1. Indication of the Case 1984 Patent Application No. 210413 3. Relationship with each case to be amended Applicant Location (Residence) Name Keikyu Jin 4, Agent 660 February 8, 1980 (Delivery date February 28, 1982) 6, Subject of amendment

Claims (1)

[Claims] ■As a nozzle that sprays powder paint toward an object to be painted that moves along a certain path, a powder that sprays the powder paint not at right angles to the moving direction of the object to be painted but at an angle. At least two paint discharge parts are arranged in parallel so that the spraying directions are opposite to each other, and the powder paint is sprayed from these powder paint discharge parts to perform electrostatic coating of the object to be coated. Electrostatic painting method using powder paint. ■Equipped with a base that is attached to the tip of a gun for powder paint injection, a branch part that branches from this base in a figure 7 shape, and powder paint discharge parts provided at both ends of this branch part, A powder paint injection nozzle that has an electrode for charging the powder paint in the branch flow path between the discharge part or near the frontage of the discharge part. (2) The nozzle according to item 0, wherein the openings of both the powder coating discharge parts are arranged in the shape of slits arranged in parallel with each other.