JPS6115746B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a spray coating apparatus, and more particularly to an electrostatic spray coating apparatus that charges the sprayed paint and adsorbs it to an object to be coated.

In general, this type of automated electrostatic spray painting equipment uses a paint spraying chamber in which objects to be coated arranged at equal intervals in the traveling direction are continuously conveyed, and a paint sprayer that sprays paint sequentially onto the objects to be coated. In preparation, the sprayer is set to one electrode (usually the negative pole) and the object to be coated is set to the other electrode (positive pole), and a high voltage is applied between the two electrodes to create an electrostatic field. The object to be coated is coated by charging the paint particles and adsorbing them to the object to be coated, which is the opposite polarity.

By the way, in such electrostatic spray painting equipment, most of the paint particles sprayed from the paint sprayer are adsorbed to the object being painted, but a portion remains unadsorbed and floats around inside the paint spraying chamber. This may cause the paint to adhere to objects other than the one being painted, especially the front and rear objects, staining the painted surfaces of the front and back objects, or when painting different colors on each object. There was a problem with the color tone becoming muddy.

Therefore, in order to deal with this problem, conventional methods have been to reduce the conveyance speed of the objects to be coated or to extend the coating pitch of each object to be coated. In the latter case, the overall length of the paint spraying chamber becomes longer. It is also possible to increase the wind speed of the ventilation air that normally flows slowly in the paint spraying chamber in order to collect excess paint floating in the paint spraying chamber, but in that case, the energy consumption of the air will be reduced. As the amount increases, paint particles that would normally be adsorbed to the object being coated are scattered by the ventilation air, resulting in a problem that the coating efficiency is reduced.

Therefore, the present invention has been developed in view of these points, and is designed to provide air flow between the object to be painted that is being conveyed in the paint spraying chamber and the objects to be painted before and after it, compared to the wind speed of normal ventilation air. By forming an air curtain using relatively high-speed wind and moving the air curtain to follow the movement of the object by sequentially changing the blowout position of the high-speed wind, the above-mentioned air curtain is moved. The curtain completely blocks out defective paint particles from flying from the paint sprayer to objects other than those being painted, so it does not reduce painting efficiency or increase the space in the paint spraying room, and is simple and easy to use. It is an object of the present invention to provide a spray coating device that can provide a coated surface of excellent quality.

Hereinafter, the present invention will be explained in detail based on an embodiment shown in the drawings.

Figures 1 and 2 show a case in which the present invention is applied to an intermediate coating or top coating line for automobile bodies, where 1 is a paint spraying chamber, and a setting chamber 2 is located in front of it (on the right side in the figure). , and a preparation room 3 is connected to the rear (left side in the figure), and each of the above rooms 1,
A series of rails 5 for moving trolleys 4, 4, etc. are laid on the floor surfaces of 2 and 3, and the rails 5, which are automobile bodies, are arranged at equal intervals in the direction of travel (from the left to the right in the figure). Objects w, w... are placed on trolleys 4, 4,... respectively.
After being placed on top and carried into the paint spraying room 1 from the preparation room 3, it is carried out to the setting room 2.

In the paint spraying chamber 1, a coating zone 1a is formed approximately at the center in the direction of movement, and the coating zone 1a
The objects to be coated are lined up on the left and right in the direction of travel on the ceiling.
The upper surface coating machines 6, 6 that paint the upper surfaces of w,...
In addition, on the left and right walls slightly behind the position of the upper surface coating machines 6, 6, objects to be coated w,
Side coating machine 7, 7 for painting the left and right sides of w,...
... are arranged respectively, and each of the coating machines 6 and 7 is used as a negative electrode, and the object to be coated w on the trolley 4 located at a position corresponding to each of the coating machines 6 and 7 (within coating zone 1) is a positive electrode. The paint spraying chamber 1 is sprayed using a so-called electrostatic atomization method in which paint is sprayed from each paint sprayer 6, 7 while applying a high voltage between both electrodes.
It is configured to spray paint onto the objects to be coated w, w, . Incidentally, reference numeral 8 denotes an air conditioning room which is connected to the upper part of the paint spraying chamber 1 and supplies ventilation air at a gentle wind speed into the paint spraying chamber 1.

Furthermore, 9 is a high-speed wind blowing device that blows out high-speed wind at a relatively high speed compared to the wind speed of the ventilation air from the air conditioning room 8 from the upper part of the paint spraying room 1 downward, and includes a blower 10; The blower 10 is made up of air outlets 12a to 12n connected in parallel via a plurality of air pipes 11a to 11n, and each air pipe 11a to 11n of the high-speed wind blowing device 9 has one air pipe 1.
Normally closed solenoid valves 13a-1 that open and close 1a-11n
3n are respectively arranged, and the above-mentioned air outlets 12a to 1
2n is disposed on the ceiling of the coating zone 1a in the paint spraying room 1 in the direction of movement of the objects to be coated w, w, . . . and in front and rear positions of the coating machines 6 and 7. Then, high-speed wind is blown from each of the blow-off ports 12a to 12n of the high-speed wind blowing device 9 between the object w being painted in the coating zone 1a and the objects w, w before and after it. An air curtain is formed between the objects to be coated w, and by switching the opening and closing of each of the electromagnetic valves 13a to 13n, the air curtain directs the high speed air blowing position of the air outlet 12a to 12n to the object to be coated w. , w, . . . are repeatedly changed within a preset section (painting zone 1a).

Next, the operation of the above embodiment will be explained.
Each object to be coated w, w, ... moves within the paint spraying chamber 1, and when the object to be coated w approaches the arrangement position of each coating machine 6, 7, that is, the coating zone 1a, this object to be coated A solenoid valve 13 of a blowing pipe 11e corresponding to an outlet 12e of a high-speed wind blowing device 9 located in front of an object w.
e opens, high-speed air is blown out from the air outlet 12e, and an air curtain is formed between the object to be coated w and the object to be coated located in front of it. When the object to be coated w further moves, the solenoid valves 13e to 13i of the blower pipes 11a to 11i are sequentially opened and closed, and the blowout position of the high-speed air changes sequentially from the blower outlet 12e to the blower outlet 12i in the traveling direction. As a result, the air curtain moves following the movement of the object to be coated w. When the object w to be coated enters the coating zone 1a, the solenoid valve 13i closes and the blowing of high-speed air from the outlet 12i is stopped, and at the same time, the outlet 12j corresponding to the front and back positions of the object w is closed. Solenoid valves 13j and 13a corresponding to 12a are opened, and high-speed air is blown out from both the air outlets 12j and 12a, and the workpiece w and the workpieces before and after it w,
An air curtain is formed between each of the solenoid valves 13j to 13n as described above.
The opening/closing switching operation between 13a and 13d is performed to follow the movement of the object w to be coated. At the same time, paint starts to be sprayed in order from the paint machines 6 and 7 located at the rear of the traveling direction, and the object to be coated w
Electrostatic spray painting is performed.

Therefore, during this painting, the object being painted w
Since an air curtain is always formed between the front and rear objects w, w, the coating particles blown out from each sprayer 6, 7 onto the object w due to the air blocking effect of the air curtain. The particles do not float and adhere to the painted object w on the front side or the unpainted object w on the rear side. In addition, the formation position of the air curtain is limited to only between the object w being painted and the objects w, w before and after it, and the high-speed wind forming the air curtain is relatively gentle. Paint particles are not scattered by the air curtain, and the coating efficiency of the paint on the object w is not reduced.

Furthermore, when the object to be coated w moves and exits the coating zone 1a, the solenoid valves 13n and 13d are closed and the high-speed air blowing from the air outlets 12n and 12d is stopped, and the air curtains in front and behind the object to be coated are closed. At the same time, the first solenoid valve 1
3e opens and high-speed wind blows out from the outlet 12e.
An air curtain that moves following the object to be coated w is again formed behind the object to be coated w. As described above, the coating of one object to be coated w is completed, and the same coating cycle as described above is repeated thereafter.

In the above embodiment, a large number of outlets 12a to 12n of the high-speed air blowing device 9 are arranged on the ceiling of the coating zone 1a in the paint spraying room 1, and the outlets 12a to 1
Solenoid valve 1 of blow pipe 11a-11n corresponding to 2n
By sequentially opening and closing 3a to 13n, the high-speed air blowing position was changed and the air curtain was moved to follow the object w to be coated. Although a pair of air outlets may be disposed so as to be movable back and forth, and the air curtain may be moved to follow the object by moving the air outlet itself, the above embodiment is advantageous in that the operating mechanism is simple. is preferable.

Furthermore, although the above embodiments are cases in which the present invention is applied to an intermediate coating or top coating line for automobile bodies, the present invention can also be applied to automatic spray painting processes for various other articles. Needless to say.

As explained above, according to the present invention, there is provided a paint spraying chamber in which the objects to be coated arranged at equal intervals in the traveling direction are continuously conveyed, and objects arranged in the paint spraying chamber and continuously conveyed. A paint sprayer that sequentially sprays paint onto the object to be coated; a blower outlet disposed in the upper part of the paint spraying chamber in the direction of movement of the paint object and at a position in front and rear of the sprayer; and a blower outlet connected to the blower outlet via a blower pipe. It is equipped with a high-speed air blowing device that blows relatively high-speed air from the top of the paint spraying room to the bottom. During this time, high-speed wind is blown out from the outlet of the high-speed wind blowing device to form an air curtain between the objects to be coated, and the air curtain follows the movement of the object to be coated in the high-speed air blowing position of the outlet. By changing the movement sequentially within a preset interval, the air curtain keeps the painting zone in the paint spraying chamber in a sealed state, and the paint that flies from the paint sprayer to the object being painted is kept in a sealed state. It is an object of the present invention to provide a spray coating device that can completely block out particles, so that it can coat an object to be coated with high quality even with a simple structure without reducing coating efficiency or increasing the coating space. It is possible.

[Brief explanation of the drawing]

The drawings illustrate embodiments of the present invention, with FIG. 1 being a schematic side view and FIG. 2 being a schematic plan view. 1...Paint spraying room, 6...Top surface coating machine, 7...
...Side coating machine, 9...High speed air blowing device, 10...
...Blower, 11a~11n...Blower pipe, 12a~
12n...Air outlet, 13a-13n...Solenoid valve,
w...The object to be painted.

Claims (1)

[Claims] 1. A paint spraying chamber in which objects to be coated arranged at equal intervals in the direction of travel are continuously conveyed; and a coating machine that is disposed within the paint spraying chamber and sequentially sprays paint onto the objects to be coated that are continuously conveyed. , equipped with an air outlet disposed in the upper part of the paint spraying chamber in the direction of movement of the object to be coated and at the front and back of the atomizer, and a blower connected to the air outlet via a blower pipe, from above the paint spraying chamber. It consists of a high-speed wind blowing device that blows relatively high-speed air downwards, and the outlet of the high-speed wind blowing device is installed between the object being painted in the paint spraying chamber and the objects before and after it. A high-speed wind is blown out from the outlet to form an air curtain between the objects to be coated, and the high-speed wind blowing position of the outlet is sequentially set within a preset section so that the air curtain moves in accordance with the movement of the object to be coated. A spray painting device characterized in that it is configured to change.