JPH0450906Y2 - - Google Patents

Description

[Detailed description of the invention] Industrial application field The present invention is an improvement of an electrostatic coating device widely used in the field of manufacturing machines and appliances, especially a portal type used for painting the upper surface of a car body in the automobile manufacturing industry. The present invention is based on an improvement of an electrostatic coating device in which a plurality of bell-shaped electrostatic coating devices are attached downward to a reciprocator and paint is performed while moving them back and forth.

Conventional technology Conventional electrostatic coating equipment, which is commonly used in the automobile manufacturing industry to paint the upper surface of car bodies, is usually installed in two or three gantry reciprocators installed across the car body transfer path on the car body painting line. The rotary bell-type electrostatic coating machines are installed in a row in the left-right direction, that is, in the direction across the transfer path, and electrostatic painting is performed while these machines are simultaneously moved back and forth in the left-right direction. Therefore, in the case of such electrostatic coating equipment, the spray pattern of atomized paint particles emitted from the paint atomizing rotary bell of each sprayer during painting work is determined by the left-right reciprocating movement of the sprayer. For paint sprayers that are fanned and equipped with a washing shroud (cleaning envelope) on the outer circumferential surface of the rotary bell of the adjacent paint sprayer, and on the outside of the rotary bell for paint atomization. The atomized paint particles then adhere to the outer peripheral surface of the rotating bell and the outer surface of the washing shroud. The paint particles that have adhered and accumulated on the outer peripheral surface of the rotary bell in this way are peeled off from the surface of the rotary bell due to the centrifugal force caused by the rotation of the rotary bell, form spits, and adhere to the surface of the object to be coated. Paint particles adhering to the outer surface of the washing shroud can also dry and fall to the surface of the object to be coated in the form of dust. It was necessary to stop the operation of the paint sprayer and clean the outer peripheral surface of the rotary bell and the outer surface of the washing shroud.

Purpose of the invention This invention is an electrostatic coating method in which multiple rotary bell-type electrostatic atomizers are installed in a row and facing downwards on a portal reciprocator, and each atomizer is simultaneously moved back and forth in the direction in which they are aligned. In the apparatus, the spray pattern of atomized paint particles emitted from the rotary bell of each atomizer is agitated based on the reciprocating motion of each atomizer, and the outer peripheral surface of the rotary bell of the adjacent atomizer or the rotation of the atomizer is agitated. To prevent atomized paint particles from adhering to the outer circumferential surface of the bell and the outer surface of the washing shroud, periodically stop the operation of each sprayer during painting work and remove the rotating bell or the rotating bell and washing shroud. It is an object of the present invention to provide an electrostatic coating device that eliminates the need for cleaning the paint.

Structure and operation of the invention The electrostatic coating device of the invention includes a plurality of rotating bell-type electrostatic coating machines arranged in a row at predetermined intervals and mounted downward on the reciprocating member of a portal reciprocator.
In an electrostatic coating device that performs painting by driving the reciprocating member to reciprocate the electrostatic coating machines simultaneously in the direction in which they are arranged, each position it,
An air injection device that injects an air stream in a flat pattern having a narrow and elongated cross section is oriented downward, and the long axis of the flat pattern is made approximately perpendicular to the direction of reciprocating motion of each of the electrostatic coating machines described above. It is configured so that it is attached to each reciprocating member and moves back and forth simultaneously with each electrostatic sprayer, so that the spray pattern of atomized paint particles emitted from the rotary bell of each electrostatic sprayer is always the same as each other. They are separated from each other by a thin air curtain formed by a flat pattern of airflow ejected from the air injection device, so that the spray pattern is adjusted based on the reciprocating motion of the electrostatic sprayer. Even when agitated, the atomized paint particles are reliably prevented from adhering to the surface of the rotating bell or washing shroud of an adjacent electrostatic coating device.

Embodiments Hereinafter, embodiments of the device of the present invention will be described with reference to the accompanying drawings.

FIG. 1 is a schematic front view showing the main parts of an embodiment of the electrostatic coating apparatus of the present invention, and is a schematic front view showing a main part of an embodiment of the electrostatic coating apparatus of the present invention, and is a suitable gate-shaped reciprocating machine installed across a car body transfer path in, for example, an automobile body painting line. The device is installed on a lifting member (not shown) to adjust the distance between the rotary bell of the electrostatic sprayer and the car body according to the size, shape, etc. of the car body to be painted. On the rod-shaped reciprocating member 1, there are two rotary bell-shaped stationary units, each of which has a washing shroud 3 (shown in cross section) movable up and down, surrounding the rotary bell 2 for atomizing paint. The electrocoating machines 4 and 5 are mounted and fixed, for example, with the axes of their rotating bells 3 set at a distance of about 62 cm, that is, with the openings of the rotating bells facing downward, and the rod-shaped reciprocating motion 1
An air injection device 9 that injects an air flow having a flat pattern with a narrow and elongated cross section is installed at a substantially central portion 8 between the mounting portions 6 and 7 of both the electrostatic atomizers 4 and 5. The flat pattern of the ejected air is directed downward and the longitudinal direction of the flat pattern is directed in the axial direction of the rod-shaped reciprocating member 1, that is, both electrostatic atomizers 4 and 5.
The two rotary bell-shaped static The electric coating machines 4 and 5 simultaneously discharge atomized paint particles, and the air injection device 9 sprays a flat pattern of airflow to paint the upper surface of an automobile body, which is the object to be coated.

FIG. 2 of the drawings shows atomization and radiation generated by the rotary bell-type electrostatic coating machines 4 and 5, respectively, when painting the upper surface of an automobile body using the electrostatic coating apparatus of the present invention shown in FIG. 1. spray patterns P ₄ and P ₅ formed by paint particles that are
The interaction with the pattern P _A of the flat air flow jetted from the air jet device 9 installed approximately at the center between both electrostatic atomizers 4 and 5 is shown by a cross section near the top surface of the object to be coated. This is a plan view schematically showing the spray pattern P ₄ of the electrostatic coating machine 4 and the spray pattern P 5 of the electrostatic coating machine ₅ , as is clear from this figure.
Even near the top surface of the object to be coated, it is completely separated and separated by an air curtain formed by a flat air flow jetted from the air jetting device 9.
Therefore, the atomized paint particles emitted from each electrostatic coating machine 4 and 5 are distributed between adjacent electrostatic coating machines based on the spray patterns _P5 and _P5 generated by the reciprocating motion of each electrostatic coating machine. 5 and 4 rotating cups 2
It is reliably prevented from adhering to the outer peripheral surface of the washing shroud and the inner surface of the washing shroud.

Note that an elongated pattern is created by the air injection device 9.
The flat air flow injected between both spray patterns P ₄ and P ₅ with P _A does not disturb the spray patterns P ₄ and P ₅ on both sides, and does not bounce back when reaching the surface of the workpiece. It is necessary to adjust the spray pressure so that the spray hits the surface of the coated object softly without causing spraying, and even if the length of the pattern P _A is small, it must be close to the outer diameter of each of the annular spray patterns P ₄ and P ₅ . It is desirable that it be approximately equal or somewhat larger.

In the above embodiment, the air injection device 9 for ejecting a flat air stream has a spray nozzle in the center for ejecting air for paint and atomization, and one spray pattern shaping device on each side of this spray nozzle. A conventional air atomization paint spray gun (air spray gun) is provided with a shaped air nozzle for spraying the atomized paint particles in a fan shape with a spray pattern having a thin flat cross section. By supplying only atomizing air without supplying paint, and supplying shaping air to each shaping air nozzle, and adjusting the atomizing air pressure and shaping air pressure respectively, the desired result can be achieved. Although it was possible to form a flat air stream, the air injection device is not limited to such a paint-free air atomizing spray gun, but any suitable device provided with an elongated slit-shaped air injection port may be used. I can do it.

In the above embodiment, two rotary bell-type electrostatic atomizers were simply attached to the rod-shaped reciprocating member, and one air injection device was installed in the center between both electrostatic atomizers. The number of machines is not limited to two; if desired, three, four, or more rotary bell-type electrostatic atomizers can be mounted in a row at equal intervals on a reciprocating member, and adjacent electrostatic It goes without saying that the electrostatic coating device of the present invention can be formed by installing one air injection device in each central portion between the coating machines.

Next, two and three rotary bell-type electrostatic atomizers were installed on the reciprocating member, respectively, with a distance of 62 cm between the bells, and the paint-free air atomization spray gun was placed in the center between the adjacent electrostatic atomizers. Regarding two examples equipped with an air injection device consisting of a bell rotation speed of 30,000 revolutions/min, a paint discharge amount of 300 c.c./min, a spraying distance (distance between the bell and the object to be coated) of 30 cm, and an electrostatic coating machine. When electrostatic painting is performed at a reciprocating speed of 20 m/min and a reciprocating stroke of 40 cm, no air is supplied to the air atomizing gun, which is an air injecting device, and no flat air stream is injected, and air atomizing injection 0.5Kg/cm ² for gun spray nozzle, 1.5Kg/cm ² for shaping air nozzle
To explain the results of an experiment in which air was supplied at a pressure of The outer peripheral surface of each rotary bell of both electrostatic atomizers and the inner surface of each washing shroud, and the electrostatic atomizer 3
In one embodiment, the outer peripheral surface of each rotary bell of all electrostatic atomizers and the outer surface of each washing shroud of both electrostatic atomizers and both sides of the washing shroud of a central electrostatic atomizer. Significant adhesion of paint particles to the surface was observed, but in all cases where the flat air stream was injected, the rotary bell and washing shutter of each electrostatic atomizer were Almost no paint particles were observed to adhere to the loud.

As can be easily understood from the above explanation, a plurality of downward rotating bell-shaped electrostatic coating machines arranged in a row are simultaneously moved back and forth in the arrangement direction to paint the upper surface of the object to be coated. When carrying out this process, the spray pattern of each electrostatic atomizer is agitated by the reciprocating motion of the electrostatic atomizer, causing paint to spill onto surfaces such as the rotating bell or washing shroud of the adjacent electrostatic atomizer. Since the adhesion of particles can be effectively prevented, there is no risk of deterioration of the quality of the paint film due to the spitting of adhering paint particles, and the electrostatic coating equipment must not be activated periodically during the painting process. Since there is no need to stop the process to clean adhering paint particles, it is possible to obtain the effect of improving work efficiency.

[Brief explanation of the drawing]

FIG. 1 of the accompanying drawings is a schematic front view showing the main parts of an embodiment of the electrostatic coating apparatus of the present invention, which is provided with two rotary bell-type electrostatic coating machines. Figure 2 shows the spray pattern of atomized paint particles ejected from the two rotary bell-type electrostatic atomizers of the electrostatic atomizer of the present invention shown in Fig. 1, and the flat particles injected from the air injector. FIG. 3 is a plan view showing the interaction with airflow patterns; In the figure, 1 is a reciprocating member, 2 is a rotating bell, 3 is a washing shroud, 4 and 5 are rotating bell type electrostatic atomizers, 9 is an air injection device, P ₄
and P ₅ is the spray pattern of electrostatic atomizers 4 and 5, and R _A is the flat air flow pattern of air injection device 9.

Claims (1)

[Scope of utility model registration request] A plurality of rotary bell-type electrostatic atomizers are arranged in a row at predetermined intervals and mounted downward on a reciprocating member provided in a portal reciprocator, and the reciprocating member is driven to move each of the electrostatic atomizers between them. In an electrostatic coating device that performs painting while simultaneously reciprocating in the arrangement direction, a flat pattern of air having a narrow and elongated cross section is positioned approximately in the center between two adjacent electrostatic coating devices. The electrostatic sprayer is characterized in that an air injection device for injecting a flow is attached to the reciprocating member, with the long axis of the flat pattern facing downward and perpendicular to the reciprocating direction of each of the electrostatic atomizers. Electric coating equipment.