JPH11319641A - Electrostatic coating machine using handgun - Google Patents

Abstract

PROBLEM TO BE SOLVED: To adjust applied voltage without stopping a coating work and to enhance the working efficiency. SOLUTION: Output voltage of a high voltage generator 19 is automatically controlled in accordance with increase or decrease of a flow rate of pressurized air, and when the flow rate of the pressurized air is controlled with an operation of throttle valves 7, 8 of the handgun, the applied voltage is automatically controlled, then the applied voltage can be adjusted without stopping the coating work and the working efficiency can be enhanced.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to electrostatic coating using a hand gun which uses pressurized air to atomize a liquid paint or to control a spray pattern of the atomized paint.

[0002]

2. Description of the Related Art In an electrostatic coating, there is an effect that the coating efficiency of a coating material can be remarkably increased. Since it is difficult to apply to deep and narrow parts, uneven coating and dripping are likely to occur.

[0003] For this reason, when painting a deep part, spraying is performed by canceling the application of high voltage so that the Faraday cage phenomenon does not occur.

[0004] In particular, in the case of a hand gun for electrostatic coating using a nozzle called a flat spray nozzle for spraying atomized paint in a fan-shaped pattern, when painting a large flat surface,
In order to further increase the width of the fan-shaped pattern, a large amount of pressurized air called pattern air is jetted from both sides of the nozzle, and the applied voltage is increased to increase the coating efficiency, whereas the narrower recessed part is painted In order to increase the straightness of the paint and improve the penetration, the width of the fan-shaped pattern air is reduced by reducing the pattern air, and the applied voltage is reduced or cut off so that the Faraday cage phenomenon does not occur. I have.

[0005] In the case of repair coating, a small amount of paint is ejected and applied little by little. Therefore, the amount of atomizing air blown to atomize the paint ejected from the nozzles and the applied voltage are reduced. Painting is being done.

As described above, it is common to increase the applied voltage when the air flow rate is high and to decrease the applied voltage when the air flow rate is low.

[0007] This also applies to the relationship between the flow rate of the shaping air that regulates the discharge range of the atomized paint and the applied voltage in the rotary atomization type electrostatic spray gun in addition to the air atomization type air spray gun. It is.

[0008]

However, in a conventional electrostatic coating machine using a hand gun, the flow rate of pressurized air is adjusted by a throttle valve provided in the hand gun. The adjustment of the applied voltage is performed by the control panel located away from the handgun, so the painting operation had to be interrupted every time the applied voltage was adjusted, which hindered the improvement of work efficiency. .

[0009]

According to the present invention, an output voltage of a high voltage generator is automatically controlled in accordance with an increase or decrease in a flow rate of pressurized air. When the flow rate of the pressurized air is adjusted by operating the throttle valve of the hand gun, the applied voltage is automatically controlled, so that the applied voltage can be adjusted without interrupting the painting operation. This has the effect of improving work efficiency.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the accompanying drawings. In the figure, reference numeral 1 denotes a hand gun main body,
And the high-voltage application electric wire 4 are guided into the handgun body 1, and the pressurized air pressure feed pipe 3 is connected to the atomizing air passage 5 and the pattern air passage 6.
And throttle valves 7 and 8 are interposed respectively.

The valve body 9 is retracted by pulling the trigger 10 into the hand gun body 1 so that the paint that is pressure-fed from the paint pipe 11 is discharged from the nozzle 12 in a vertically elongated fan-shaped pattern. An electrode 13 for applying a high voltage to the paint protrudes from the nozzle 12.

The atomized air is sprayed from a large number of ejection holes 14 formed around the nozzle 12 onto the paint discharged from the nozzle 12 to form a mist, and the pattern air is formed at corners provided on both sides of the nozzle 12. The sprayed paint flow is sprayed from an ejection hole 15 formed in the spray paint flow 16 so that the paint flow is further elongated vertically in a fan-like pattern.

Although the above is a conventionally known air atomizing type electrostatic painting hand gun, in the present embodiment, an air flow sensor is provided between the pressurized air supply pipe 3 and the pressurized air supply source 17. The detection signal is input to the high voltage generator 19, and the output voltage is controlled.

That is, in the air atomization type electrostatic painting hand gun, when painting a large flat surface, a large amount of pattern air is ejected from both sides of the nozzle 12 in order to further increase the width of the fan-shaped pattern. In contrast to increasing the applied voltage to increase the coating efficiency, when painting a narrow and deep part, the pattern air is weakened by increasing the straightness of the paint and improving the penetration, by weakening the pattern air. And the applied voltage is reduced or cut off so that the Faraday cage phenomenon does not occur.

In the case of repair painting, since a small amount of paint is discharged and applied little by little, the amount of atomizing air blown to atomize the paint discharged from the nozzle and the applied voltage are also reduced. Painting is being done.

As described above, it is common to increase the applied voltage when the air flow rate is high and to decrease the applied voltage when the air flow rate is low.

Therefore, the output voltage of the high voltage generator 19 is controlled so that the output voltage is increased when the air flow rate is high and the output voltage is reduced when the air flow rate is low. Is preset in a control device incorporated in the high voltage generator 19.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of one embodiment of the present invention.

FIG. 2 is a partially cutaway sectional view of the hand gun.

[Explanation of symbols]

 1: Hand gun body 3: Pressurized air pressure feed pipe 4: High voltage application wire 5: Atomizing air passage 6: Pattern air passage 7, 8: Throttle valve 12: Nozzle 13: Electrode 14, 15: Jet hole 18: Air flow rate Sensor 19: High voltage generator

Claims (1)

[Claims] 1. An electrostatic coating machine using a hand gun that uses pressurized air to atomize a liquid paint or to control the shape of the spray of the atomized paint. An electrostatic coating machine that uses a hand gun that automatically controls the output voltage of a high-voltage generator.