JPH0318500B2 - - Google Patents

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to an air atomization electrostatic coating device used, for example, for painting the body of an automobile, and particularly relates to improving the uniformity of the film thickness distribution. .

[Prior art]

In general, air atomizing electrostatic coating equipment discharges paint under high voltage application, atomizes it with atomizing air, and adjusts the coating pattern, that is, the coating area and film thickness distribution, with pattern adjustment air. This is a device that forms a desired coating film on a coated object. In such a coating device, the ratio of resin pigment and solvent varies depending on the paint, and therefore, in order to obtain the required film thickness, it is necessary to change the discharge amount depending on the type of paint. Therefore, air atomization electrostatic coating devices have conventionally changed the amount of paint discharged depending on the type of paint.

[Purpose of the invention]

By the way, in the air atomization type painting mentioned above,
In addition to the amount of paint discharged above, the amount of atomizing air and the amount of pattern adjustment air also have a large influence on the pattern shape value, which indicates the film thickness distribution, and the pattern width, which indicates the size of the coating area. The amount is also affected by the type of paint. Therefore, the purpose of the present invention is to
To provide an air atomization electrostatic coating device capable of obtaining the optimum atomizing air pressure and pattern adjustment air pressure depending on the coating color and obtaining a uniform film thickness distribution even when the coating color changes. It is an object.

[Structure of the invention]

The present invention provides an air atomization electrostatic coating device that includes an air pressure calculation means for calculating the optimum pressure of atomization air and pattern adjustment air according to the paint color, and adjusting both the air to the pressure from the calculation means. In addition, the air pressure calculation means can be used to adjust the amount of paint discharged according to each paint color and the optimum particle size.
The total air amount is calculated from the Qi value, and the optimum air ratio is calculated from the pattern shape value and each allowable value of the pattern width.The optimum atomizing air pressure according to the paint color is calculated from the above total air amount and optimum air ratio. It is configured to find the optimum pattern adjustment air pressure, so that even if the coating color changes, the optimum amount of air can be obtained according to the coating color, and the film thickness distribution can be made uniform. It is.

〔Example〕

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

1 and 2 show schematic configuration diagrams of an air atomization electrostatic coating apparatus according to an embodiment of the present invention. In the figures, 1 is a spray gun, and an electrode 1a is provided at the center of the gun 1. An annular paint nozzle 1b is formed around the periphery of the electrode 1a, and a paint supply passage 2 is connected to the paint nozzle 1b. Further, a large number of atomizing air nozzles 1c are formed outside the paint nozzle 1b of the spray gun 1, and pattern adjusting air nozzles 1b are further formed outside the atomizing air nozzles 1c.

An atomizing air supply passage 3 and a pattern adjustment air supply passage 4 are connected to each of the air nozzles 1c and 1d, respectively, and an atomization air regulator 3a and a pattern adjustment air regulator are connected to each of the passages 3 and 4, respectively. 4a is interposed. Further, the drive signal of the pressure controller 5a is inputted to each of the above-mentioned regulators 3a and 4a, and this pressure controller 5a and each of the above-mentioned regulators 3a and 4a are connected to each other.
4a constitutes an air pressure adjustment device 5 for adjusting the atomization air and pattern adjustment air to desired pressures.

In addition, 6 is an air pressure calculation device, which inputs the atomizing air pressure according to each paint color, the pattern adjustment air pressure, the input data to obtain the paint discharge amount described later, and the coating machine according to the performance of the painting machine. It is configured to perform calculation output based on data and coating compatibility conditions.

FIG. 3 shows the configuration of the air pressure calculation device 6,
In the figure, 7 is a first memory consisting of an input data area 7a, a coating machine data area 7b, and a coating suitability condition data area 7c.
The necessary paint discharge amount for each paint color is stored in , and the discharge amount is determined by the thickness of the coating film stored in the area 7a, the non-volatile value which is the solid content ratio of the paint,
It is determined by the speed of the conveyor that transports the car body, the reciprocating linear speed that is the moving speed of the spray gun, and the voltage applied to the paint.

The atomizer data area 7b also contains performance data of the atomizer, namely particle size-Qi value characteristics, coating efficiency-Qi value characteristics, and pattern shape value-air ratio characteristics shown in FIGS. 4 to 7. , and the pattern width-air ratio characteristics are memorized, the above particle size is the value obtained by atomizing the paint corresponding to each paint color in advance and measuring this atomized material, and the above Qi value is the value obtained by measuring the atomized material. This is the ratio of the total air amount, which is the sum of the atomizing air amount and the pattern adjustment air amount, to the paint discharge amount, and the air ratio is the ratio of the atomizing air amount to the pattern adjustment air amount. The above coating efficiency indicates the degree of adhesion of the paint to the workpiece,
This is mainly determined by the applied voltage and reciprocating linear velocity, and the higher the coating efficiency, the smaller the amount of paint discharged.

Further, the pattern width is the size of the coating area when the spray gun 1 is not moved, and the pattern shape value indicates the film thickness distribution, and as shown in FIG. 8, the pattern shape value is the film thickness h at the center. It is also expressed as the ratio of ₁ to the outer film thickness _h2 , and this ratio is 1
In the case of , the film thickness distribution becomes trapezoidal in the above pattern width, which is the most preferable (see figure b), the larger it is than 1, the more mountain-shaped (see figure a), and the smaller it is less than 1, it is hollow (see figure a). (See Figure c) Unfavorable.

In addition, in the coating compatibility condition data area 7c,
Optimal particle size, pattern width, and pattern shape value tolerance ranges are stored.

8a is a data input device, which is connected to the memory 7 mentioned above.
The data areas 7a to 7c are used to input input data, paint machine data, and coating compatibility conditions in advance, respectively, 8b is a paint color specification section for inputting the paint color to be painted, and 8c is a start button. Each of these signals is input via the input gate 8d.

Reference numeral 9 denotes a CPU which receives a command signal from the input gate 8d and calculates atomizing air pressure and pattern adjustment air pressure according to a designated paint color based on each data in the first memory 7; The CPU 9 realizes the functions of the air pressure calculation device 6 described above.

10 is a second memory for storing the calculated air pressure for each paint color; 11 is a paint color, paint discharge amount, total air amount, conformity condition and pattern width;
A display section displays the air ratio obtained from each of the pattern shape values, 12a is a first output gate that outputs the display contents to the display section 11, and 12b outputs both air pressures calculated above to the pressure controller 5a. This is the second output gate.

Next, the operation of the apparatus of this embodiment will be explained with reference to FIG. Here, FIG. 9 shows a flowchart of the apparatus of this embodiment. First, to explain the general operation of the apparatus of this embodiment, when a paint color is specified, the CPU 9
reads out the discharge amount according to the paint color and the Qi value according to the particle size, calculates the total air amount from this, reads out the allowable air ratio width according to the allowable pattern shape value and pattern width, and calculates both air Calculating an optimal air ratio from the ratio width, calculating an atomizing air amount and a pattern adjustment air amount from the optimal air ratio and the above-mentioned total air amount,
Calculate the optimal air pressure from each air amount.

To explain the operation of the apparatus of this embodiment in detail, in the apparatus of this embodiment, in step 21 as pre-processing, input data, paint machine data, and coating suitability condition data are input in advance through the data input device 8a. Each data is stored in each data area 7a to 7c of the first memory 7.

When the next normal operation is to be performed, in step 22, the paint color to be painted is designated via the paint color designation section 8b. Then, the CPU 9 performs the following operations. First, the paint discharge amount corresponding to the specified paint color is read from the input data area 7a (step 23), and the particle size-Qi value characteristic curve (fourth
The Qi value corresponding to the particle size is read out from the figure), and the total air amount (=Qi value x paint discharge amount) is calculated from the Qi value and the paint discharge amount (steps 24 and 25).

Next, from the pattern shape value-air ratio characteristic curve (Fig. 6) selected according to the paint discharge amount and total air amount obtained in steps 23 and 25 above, the allowable width (1.0 The allowable air ratio width (1.0 to 1.4) corresponding to (Figure), the allowable air ratio width (1.0
~1.2) (step 27), and from the obtained air ratio width, calculate, for example, the overlapping area between the two (1.0~1.2).
Obtain the average value (1.1) of 1.2) as the optimum air ratio (Step 28). Note that if there is no overlap between the two allowable air ratio widths, an NG value is displayed on the display section 11, and in this case, the process returns to step 21 and the first
After modifying the coating compatibility conditions stored in the memory 7, the operation of step 22 is started again.

Then, the atomization air amount and pattern adjustment air amount are calculated from the above-mentioned optimum air ratio and the total air amount, and the atomization air pressure and pattern adjustment air pressure are calculated according to the respective air amounts (step 30). pressure is second
It is stored in the memory 10 (step 31) and displayed on the display section 11.

After this optimum air pressure is obtained, when the start button 8c is pressed, the obtained atomizing air pressure and pattern adjustment air pressure are supplied to the pressure controller 5a. This causes the pressure controller 5a to switch to the atomizing air regulator 3.
a. The pattern adjustment air regulator 4a is controlled so as to obtain the above atomizing air pressure and pattern adjustment air pressure, respectively, thereby obtaining both air pressures and air amounts according to the above coating color, and as a result, the film thickness The distribution becomes uniform.

In this way, in this example device, the amount of paint discharged according to the paint color is determined from input data such as film thickness, the Qi value is determined from the particle size, the total air amount is calculated, and the allowable pattern shape value and pattern width are calculated. We calculated each air ratio width from the width, calculated each air amount from the calculated optimal air ratio, and then calculated the air pressure, so we can determine the optimal atomization air pressure and pattern adjustment air pressure depending on the paint color. can be obtained, and the film thickness distribution can be made uniform.

〔Effect of the invention〕

As described above, according to the air atomization electrostatic coating device according to the present invention, there is provided a calculation means for calculating the optimum pressure of atomization air and pattern adjustment air according to the coating color, and a calculation means for calculating the pressure of the atomization air and pattern adjustment air that is optimal according to the coating color, and a calculation means for calculating the pressure of the atomization air and pattern adjustment air that is optimal according to the coating color, and a calculation means for calculating the pressure of the atomization air and pattern adjustment air that is optimal according to the coating color, and a calculation means for calculating the pressure of the optimal atomization air and pattern adjustment air according to the coating color. and an air pressure adjustment means for adjusting the pressure to a pressure of
Paint discharge amount according to each paint color and optimum particle size
The total air amount is calculated from the Qi value, and the optimum air ratio is calculated from the pattern shape value and each allowable value of the pattern width.The optimum atomizing air pressure according to the paint color is calculated from the above total air amount and optimum air ratio. Since the structure is configured to determine the optimum pattern adjustment air pressure, a uniform film thickness distribution can be obtained even if the coating color changes.

[Brief explanation of the drawing]

Fig. 1 is a schematic configuration diagram of an air atomization electrostatic coating device according to an embodiment of the present invention, Fig. 2 is a front view of the spray gun portion thereof, and Fig. 3 is a configuration of the air pressure calculation device portion of the above embodiment. Figures 4 to 7 are characteristic diagrams showing the memory contents, Figures 8a to c are diagrams for explaining the pattern shape values, and Figure 9 is a flowchart for explaining the operation. It is. 3a, 4a...regulator for atomizing air and pattern adjustment air, 5...air pressure adjustment means, 5a...
...Pressure controller, 6...Air pressure calculation means.

Claims (1)

[Scope of Claims] 1. An air atomization electrostatic coating device that discharges paint under voltage application, atomizes the paint with atomizing air, and adjusts a coating pattern with pattern adjustment air. an air pressure calculation means that calculates and outputs atomization air pressure and pattern adjustment air pressure according to each paint color; and an air pressure adjustment that adjusts the atomization air and pattern adjustment air to the pressure from the air pressure calculation means. The air pressure calculation means includes an input data block storing the amount of paint discharged according to each paint color, a Qi value (total air amount/amount of paint discharged) according to the particle size, Painter data area that stores pattern shape value-air ratio (atomizing air amount/pattern adjustment air amount) characteristics, pattern width-air ratio characteristics, optimal particle system, pattern width compatibility conditions, and pattern shape values. It is equipped with a coating compatibility condition compatibility data area that stores compatibility conditions, calculates the discharge amount of each paint color from the input data, and calculates the amount of paint discharged according to the particle size.
The total air amount is calculated from the Qi value, and the pattern shape value conformity condition and pattern width conformity condition are determined from the pattern shape value-air ratio characteristic and pattern width-air ratio characteristic according to the discharge rate and total air amount obtained above. An air atomization electrostatic coating characterized in that the air atomization electrostatic coating is configured to find a matching air ratio, and to find an atomization air pressure and a pattern adjustment air pressure from the optimum air ratio of the overlapping portion of both air ratios and the total air amount. Device. 2. The air pressure adjustment means includes an atomization air regulator and a pattern adjustment air regulator that adjust the pressures of the atomization air and pattern adjustment air, and the atomization air pressure from the air pressure calculation means, 2. The air atomization electrostatic coating device according to claim 1, further comprising a pressure control that is driven to obtain a pattern adjusting air pressure.