JPH0753255B2 - Automatic multicolor coating device and method - Google Patents

Description

TECHNICAL FIELD The present invention relates to an automatic multicolor coating apparatus and method for coating automobile bodies and the like.

<Prior Art> As shown in FIG. 3, a conventional automatic multicolor coating apparatus includes a large number of color change valves 1 and the color change valves 1.
Is composed of a large number of paint color solenoid valves 2 for selectively supplying air to distribute the paint, and a regulator for adjusting the air to a constant pressure.

Further, the color change valve 1 is, as shown in FIG.
Paint inlet 3a and paint outlet 3b, a cylinder 4 having a piston 5, a needle 6 for opening and closing the paint outlet 3b by the piston 5, and a spring for pressing the needle 6 through the piston 5 in the closing direction of the paint outlet 3b. 8 and an air inlet 10 for actuating the piston 5 in the opening direction, the spring 8 is installed in a spring chamber 7 formed continuously with the cylinder 4, and the spring chamber 7 is connected to the breathing chamber 10 to communicate with atmospheric pressure. The structure is provided with an air inlet / outlet hole 9 for use.

<Problems to be Solved by the Invention> In the above conventional device, air is supplied from the air inlet 10 into the cylinder 4 by turning on the coating solenoid valve 2, and the piston 5 moves backward against the pressing force of the spring 8. The needle is the paint outlet
Open 3b to distribute paint and paint, and paint solenoid valve 2
Is turned off, the air supply to the cylinder 4 is stopped, the air in the cylinder 4 is discharged to the atmosphere, the piston 5 is advanced by the pressing force of the spring 8, and the needle 6 closes the paint outlet 3b to stop the flow of paint. It is to stop painting.

By the way, in the conventional apparatus, air in the spring chamber 7 flows in and out from the air inlet / outlet 9 based on the forward / backward movement of the piston 5, and the temperature difference between the outside air and the inside of the spring chamber 7 at the time of coating suspension due to repeated compression and expansion. Condensation occurs in 7 and in the cylinder 4, and water accumulates, which is jetted from the air inlet / outlet 9 by the operation of the piston 5 and adheres to the coated surface of the object to be coated, which is a cause of poor coating.

<Means for Solving the Problems> The present invention solves the above-mentioned conventional problems, and is characterized in that the apparatus has a configuration that a paint inlet and a paint outlet, a cylinder having a piston, and a paint outlet by the piston. A large number of color change valves equipped with a needle for opening and closing, a spring for pressing the needle in the closing direction of the paint outlet via the piston, and an air inlet for operating the piston in the opening direction. In an automatic multicolor coating apparatus comprising a large number of coating color solenoid valves for controlling the supply of air to an air heater, an air heater for heating the air, an air discharge path for discharging the air supplied to the color change valve, and the air discharge A solenoid valve for controlling the exhaust air installed in the passage is provided, and the method is a paint inlet and a paint outlet, and a piston. A large number of collars including a cylinder having a cylinder, a needle that opens and closes the paint outlet by the piston, a spring that presses the needle through the piston in the closing direction of the paint outlet, and an air inlet that operates the piston in the opening direction. In an automatic multi-color coating device consisting of a change valve and a large number of paint color solenoid valves that selectively control the supply of air to this color change valve, the air supplied to the color change valve is heated by a heater to The hot air supplied is discharged when the paint color solenoid valve is stopped, and the hot air is circulated in the color change valve, and the discharge is stopped when the paint color solenoid valve is activated.

<Operation> With the above configuration, hot air always flows in the cylinder of the color change valve to prevent dew condensation in the color change valve while coating is stopped.

<Examples> Examples of the present invention will be described below with reference to the drawings. FIG. 1 shows the overall structure of the present invention, and 1 is a color change valve. As shown in FIG. 2, the color change valve 1 includes a paint inlet 3a and a paint outlet 3b, a cylinder 4 having a piston 5, a needle 6 for opening and closing the paint outlet 3b by the piston 5, and the piston 5. Spring 8 that presses the needle 6 toward the closing direction of the paint outlet 3b
An air inlet 10 for operating the piston 5 in the opening direction, and an air outlet 28 for discharging the air supplied from the air inlet 10 into the cylinder 4. The spring 8 is formed continuously with the cylinder 4. The spring chamber 7 is internally provided with an air inlet / outlet 9 for breathing which communicates with the atmospheric pressure.

As shown in FIG. 1, the air inlet 10 of the color change valve 1 is connected to the regulator 3 and the air heater 2 from the air source.
Pipes are connected so that hot air is supplied through the hot air regulator 21 and the shuttle valve 22. Reference numeral 2 denotes a paint color solenoid valve, which is connected between the pipe immediately after the air heater 20 and the shuttle valve 22.
The hot air is introduced into the cylinder 4 of the color change valve 1 through the shuttle valve 22, and the piston 5 is retracted against the force of the spring 8 to raise the needle 6 to open the paint outlet 3b. .

On the other hand, the air outlet 28 is connected to an exhaust pipe 23 that communicates with the atmosphere. A solenoid valve 24 is provided in the path of the exhaust pipe 23.
A cooler 29 is also provided. Reference numeral 25 is a thermometer, 26 is a control circuit for the paint color solenoid valve 2 and the solenoid valve 24, and 27 is a power source.

Next, the operation of the present invention will be described. The air from the air source is regulated to a constant pressure by the regulator 3. This pressure adjustment is set to be larger than the force of the spring 8 of the color change valve 1. The air regulated by the regulator 3 is heated by the air heater 20 to be hot air. This hot air is decompressed by the hot air regulator 21. The depressurizing force of the hot air is set to be smaller than the force of the spring 8 so that the piston 5 does not operate. The low-pressure hot air decompressed by the hot air regulator 21 is guided to the air inlet 10 of the color change valve 1 through the shuttle valve 22 and is supplied into the cylinder 4 and the air outlet.
It is derived from 28.

Therefore, when not painting, the painting solenoid valve 2 is closed and the solenoid valve 24 is controlled to open. As a result, the hot air decompressed by the hot air regulator 21 flows through the color change valve 1 and is discharged to the atmosphere cooled by the cooler 29. Therefore, the color change valve 1 is heated by the hot air even when coating is stopped to prevent dew condensation.

At the time of coating, the paint color solenoid valve 2 is opened, the pressure is adjusted by the regulator 3, and hot air immediately after being heated by the air heater 20 is supplied into the cylinder 4 of the color change valve 1 through the shuttle valve 22. At this time, the solenoid valve 24 is switched to the closed state. The hot air immediately after exiting the air heater 20 has a higher pressure than the hot air exiting the hot air regulator 21. Moreover, since the solenoid valve 24 is closed, the piston 5 moves backward against the pressing force of the spring 8 and the needle valve 6 opens the paint outlet 3b.
The paint introduced from 3a is made to flow and supplied to a spray gun (not shown). The thermometer 25 measures the temperature of hot air and appropriately adjusts the temperature of air heating by the air heater 20.

<Effects of the Invention> As described above, according to the present invention, the air for opening and closing the color change valve is heated by the air heater, and this is reduced to a pressure smaller than the spring force of the color change valve by the hot air regulator. Since the solenoid valve is always supplied to the color change valve and the solenoid valve is opened to discharge the air from the air outlet when painting is stopped, dew condensation inside the color change valve is prevented by the flow of hot air. It has a special effect such as eliminating the accumulation of water droplets, eliminating the problem of coating failure due to water droplets scattering during coating, eliminating the rust inside the color change valve due to dew condensation, and preventing malfunction of the valve. There is.

[Brief description of drawings]

FIG. 1 is an overall configuration diagram of the present invention, FIG. 2 is a sectional view of a color change valve applied to the present invention, FIG. 3 is a conventional overall configuration diagram, and FIG. 4 is a conventionally applied color change valve. FIG. 1 ... Color change valve, 2 ... Paint solenoid valve, 3 ...
… Regulator, 20 …… Air heater, 21 …… Hot air regulator, 23 …… Exhaust pipe, 24 …… Solenoid valve.

Claims (2)

[Claims] 1. A paint inlet and a paint outlet, a cylinder having a piston, a needle for opening and closing the paint outlet by the piston, a spring for pressing the needle in the closing direction of the paint outlet through the piston, and an opening direction. In an automatic multicolor coating device comprising a large number of color change valves having an air inlet for operating a piston and a large number of coating color solenoid valves for selectively supplying and controlling air to the color change valves, the air is heated. An automatic multicolor coating apparatus comprising an air heater, an air discharge path for discharging the air supplied to the color change valve, and a discharge air control solenoid valve installed in the air discharge path. 2. A paint inlet and a paint outlet, a cylinder having a piston, a needle that opens and closes the paint outlet by the piston, a spring that presses the needle through the piston in the closing direction of the paint outlet, and an opening direction. Supply to the color change valve in an automatic multicolor coating device consisting of a large number of color change valves equipped with air inlets that operate pistons and a large number of paint color solenoid valves that selectively supply air to the color change valves The air to be heated is heated by an air heater, and hot air supplied to the color change valve is discharged when the paint color solenoid valve is stopped, and hot air is circulated in the color change valve. Automatic multicolor coating method that stops discharging.