JPH0446823Y2 - - Google Patents

Description

[Detailed explanation of the idea]

[Industrial Application Field] The present invention is designed to control the thickness of the resin film to be applied by adjusting the thickness of the resin film to be coated on metal wires, particularly rectangular wires, by using the electrostatic flow dipping method. The present invention relates to an electrostatic powder coating apparatus that is provided with a coating film thickness adjustment mechanism that makes the thickness substantially uniform on each surface of the outer periphery and adjusts the coating thickness to a desired thickness. [Prior Art] An electrostatic flow dipping method is known as a method for continuously coating a metal wire with a resin film using a powder coating method. In this method, a grounded metal wire, which is the object to be coated, is run through a coating tank in which a cloud of particles of resin powder charged with static electricity is formed, and the resin powder is deposited on the wire. A coating film is formed by heating the resin powder and melting the resin powder. Therefore, when this method is applied to the coating of rectangular filaments such as rectangular insulated wires, the thickness of the coating film is the same as that of rectangular enameled electric wires painted using the conventional enamel coating method. There was a problem in that the coating was not uniform on each surface and, particularly when the coating device was horizontal, there was a further problem in that the thickness of the coating film on the lower surface was significantly different. Therefore, as a measure to improve this,
In the proposal for 8221, by installing a barrier board at a distance from the running position of the object streak in the coating tank, the amount of powder resin adhering to the streak at that location is adjusted. There is. Furthermore, in the proposal of JP-A-58-150218, the amount of powdered resin adhering to the streaks at that location is adjusted by bringing the board into direct contact with the streaks of the object being coated. ing. [Problem to be solved by the invention] However, if a barrier board is provided at a distance from the traveling position of the object to be painted, as in the proposal of the above-mentioned Japanese Patent Publication No. 55-8221, the thickness of the coating film It is difficult to adjust accurately, and if it is operated continuously for a long time, resin powder may accumulate on the top surface of the cutting board, form a lump, and fall off, resulting in a poor appearance of the coating film. There is a point. In addition, as in the proposal of JP-A No. 58-150218, when the board is brought into direct contact with the moving object filament, if the abutting point is on the lower surface of the filament, If the machine is operated for a long period of time, trace amounts of metal powder and foreign matter adhering to the surface of the striations will accumulate between the striations and the surface of the striations, causing damage to the surface of the striations or sticking to the striations. There is a problem in that it affects its operation. [Means for solving the problems] The present invention was devised to solve the above-mentioned problems in conventional electrostatic powder coating equipment. Electrostatic powder coating equipped with a coating thickness adjustment mechanism that can always maintain a uniform coating thickness with high precision and adjust the coating thickness to the desired thickness, even in certain cases. It is related to the device. That is, the gist of the present invention is that a grounded metal wire is run through a coating tank in which a cloud of particles of resin powder charged with static electricity is formed, and the resin powder is deposited on the metal wire. In an electrostatic powder coating device for adhering resin powder to a metal wire body, the above-mentioned method is used as a means for uniformizing the thickness of the coating film of resin powder on the metal wire body and adjusting the coating film thickness to a desired thickness. An air wiper is arranged around the metal wire running path in the coating tank so as to be in contact with the running metal wire, and an air wiper is provided outside the coating tank, and the air wiper is arranged at a position in the longitudinal direction of the coating tank. This is an electrostatic powder coating apparatus characterized by comprising a position moving arm that moves the electrostatic powder coating apparatus. [Operation] According to the electrostatic powder coating apparatus equipped with the coating film thickness adjustment mechanism of the present invention configured as described above, the air wiper adjusts the thickness of the metal wire on the object to be coated to the maximum coating thickness. Even in the case of rectangular filaments where the coating thickness is uneven, the powder resin adhering to the bottom surface and both side surfaces, where the coating film is thick, is appropriately blown off, so that the coating film on the outer peripheral surface can be made uniform. Also, since it is an air wiper, it does not damage the metal wire while it is running. Furthermore, by installing a position moving arm outside the coating tank that moves the position of the air wiper in the longitudinal direction of the coating tank, adjustment becomes easier and the coating thickness can be adjusted. It has the effect of becoming. [Embodiment of the invention] Next, an electrostatic powder coating apparatus of the invention will be described based on an embodiment shown in the drawings. Fig. 1 is a sectional view showing an example of a horizontal coating device equipped with the coating film thickness adjustment mechanism of the present invention used in the electrostatic flow dipping method, and Figs. FIG. 2 is a perspective view of essential parts of an example of an air wiper used for this purpose.
Reference numeral 1 in the figure indicates a coating tank, and a porous plate 4 is provided inside this coating tank 1.
Powdered resin 9 is placed on top of it. Reference numeral 6 denotes an electrode, to which a high DC voltage is applied by the high voltage generator 5. Therefore, dry air is sent from the dry air inlet 13 provided at the bottom of the coating tank 1, and the powder resin 9 on the porous plate 4 is fluidized by this air, and at the same time, the powder particles are A high voltage imparts a charge and a cloud of particles forms on the fluidized bed. 14 is an air outlet. Reference numeral 3 denotes a rectangular filament of the object to be coated, which is grounded and runs through the particle cloud in the coating tank 1. Reference numeral 2 denotes an air wiper for adjusting the coating film thickness, which is guided by a guide rail 7 as shown in FIG. They are placed close together. The air wiper 2 is equipped with a pressure equalizing chamber 10 and a discharge port 11, as shown in FIGS. 2 and 3, for example, and is supplied with high pressure air from a high pressure air (preferably dry air) source (not shown). It is sent via piping 12. Further, the air wiper 2 is configured so that its position can be changed from the outside of the coating tank 1 by means of a position moving arm 8. Next, the operation of the electrostatic powder coating apparatus of the present invention having the above structure will be explained. In order to form an electrically insulating coating film by coating the powder resin 9 on the rectangular filament 3 of the object to be coated using the electrostatic flow dipping method, the grounded rectangular filament 3 is run in the coating tank 1. A high DC voltage is sent from the high voltage generator 5 to the electrode 6, and at the same time, dry air is sent from the dry air inlet 13. Then, this dry air causes the powdered resin 9 on the porous plate 4 to flow, giving charge to the powder particles and forming a particle cloud on the fluidized bed. Powder resin 9 adheres to the entire surface of the rectangular filament 3. next,
In a heating device for the next step (not shown), the powder resin 9 is heated to a temperature higher than its melting temperature to form a coating film. Next, this coating film is cooled and fixed onto the rectangular filament 3. In this case, the thickness of the coating film to be applied is determined by the amount of dry air sent into the fluidized bed and the voltage applied to the electrodes, but as it is, the powder resin 9 is thick on the bottom surface of the rectangular filament 3 and thin on the top surface. It is painted and the thickness of the flat and edge surfaces are also different. Therefore, in the device of the present invention, in order to make the thickness of the coating film uniform on the entire circumferential surface, flat surface, and edge surface, the powder resin 9 is adhered by the air wiper 2 placed in advance at the location where the coating film will be thick. The amount can be adjusted. This air wiper 2 moves on a guide rail 7 by operating a position moving arm 8 outside the coating tank 1, and adjusts the amount of powder resin 9 adhering to the rectangular filament 3 running there at a desired location. The thickness of the coating film can be adjusted by blowing it off. The following Table 1 shows the results obtained using the electrostatic powder coating equipment shown in Figure 1, wire sizer: 2 x 8 mm copper rectangular wire, wire speed 9.
m/min, powder resin: epoxy (Sumitomo Duress
EPC208), an example in which painting was performed with an air wiper discharge pressure of 0.3 Km/cm ² and a comparative example in which the air wiper 2 was not used are shown.

[Effect of idea]

According to the electrostatic powder coating apparatus of the present invention, even when the metal filaments of the object to be coated are rectangular filaments, the thickness of the coating film is approximately uniform on each surface, and unlike conventional apparatuses, the coating film thickness is approximately uniform on each surface. To prevent the occurrence of a large difference in the coating film thickness on both sides, and to adjust the coating film thickness by adjusting the position of the metal wire of the air wiper in the running direction, and to adjust the coating film thickness with high precision. I can do it. Furthermore, since the air wiper does not come into contact with the object to be painted, there is no risk of damaging it.

[Brief explanation of the drawing]

1 to 3 show an embodiment of the present invention, and FIG. 1 is a sectional view of a horizontal electrostatic powder coating apparatus equipped with the coating film thickness adjustment mechanism of the present invention. FIG. 3 is a perspective view showing an example of an air wiper used for adjusting the coating film thickness. In the figure, numeral 1 is a coating tank, 2 is an air wiper,
3 is a rectangular wire, 4 is a porous plate, 5 is a high voltage generator, 6 is an electrode, 7 is a guide rail, 8 is a position moving arm, 9 is a powder resin, 10 is a pressure equalization chamber, 11 is a discharge port , 12 is a high-pressure air pipe, 13 is a dry air inlet, and 14 is an air outlet.

Claims (1)

[Scope of Claim for Utility Model Registration] A grounded metal wire is run through a coating tank in which a particle cloud of resin powder charged with static electricity is formed, and the metal wire is coated on the metal wire. In electrostatic powder coating equipment that attaches resin powder, it is used as a means to equalize the thickness of the coating film of resin powder on the metal linear body and to adjust the coating thickness to the desired thickness. , an air wiper disposed around the metal wire running path in the coating tank so as to be close to the running metal wire; and an air wiper provided outside the coating tank to move the air wiper in the longitudinal direction of the coating tank. An electrostatic powder coating device characterized by comprising a position moving arm that moves the electrostatic powder coating device to a position.