JPH0679690B2 - Liquid and powder paint electrostatic coating control device - Google Patents

Description

Detailed Description of the Invention

[0002]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid / powder coating electrostatic coating control device which can be used for both liquid coating electrostatic coating and powder coating electrostatic coating.

[0003]

2. Description of the Related Art In recent years, in order to reduce the amount of waste and blowback, and to improve the adhesion efficiency of the paint by the covering effect to save the paint, and to improve the production efficiency and the working environment, the electrostatic charge of the paint particles has been improved. An electrostatic coating method in which an attractive force is used to adsorb to an object to be coated is often used. On the other hand, powder coatings made of epoxy resin, acrylic resin, polyester resin, etc. eliminate various problems of liquid coatings, such as organic solvents, and also make the coating film robust, easy to apply thick, pinholes, etc. It is widely used because it has few coating film defects and good edge coverage.

However, although the coating using this powder coating has the above-mentioned various advantages, it is difficult to adjust the colors, mix the colors, change the colors, have a high baking temperature, and make the beautiful finish a little difficult. For some reason, liquid paints using organic solvents, solvents such as water, etc. have been used before. Also in this powder paint, as in the case of the liquid paint, electrostatic coating is adopted as one coating method, and the air spraying method of applying the paint using an electrostatic spraying gun that sprays the paint with air is It is often adopted as a flexible and simple coating method.

[0005]

However, although the liquid paint electrostatic coating and the powder paint electrostatic coating are common in that high pressure air and electrostatic are used, the structure of the spray gun itself is different, and In liquid paint electrostatic coating, the paint is pumped using a diaphragm or plunger type pump, whereas in powder paint electrostatic coating, the powder is made into a fluid state by a powder flow tank by an air injector pump. Since many basic configurations such as sending by using are different, for liquid paint electrostatic coating and powder paint electrostatic coating,
Separate and independent ones were used as control devices, and commonality was not a consideration. In addition, liquid coating electrostatic coating and powder coating electrostatic coating are used differently depending on the above-mentioned use each time, and therefore the painter has to prepare two control devices, respectively, which is expensive and occupies a place. However, there was a problem to be solved such as maintenance of two devices, which was inferior in usability.

The present invention has been completed as a result of finding out common points of each apparatus between liquid coating electrostatic coating and powder coating electrostatic coating and making various studies on sharing of apparatuses. An object of the present invention is to provide a liquid paint electrostatic coating, a liquid that can be commonly used for powder paint electrostatic coating, and a powder paint electrostatic coating control device.

Further, in the present invention, in the liquid paint electrostatic painting, the paint is turned on and off by using the trigger switch in the gun body and the air flow switch for detecting the air blown by the trigger operation. 2 with those that turn on and off
There are various types of electrostatic coating guns, but the liquid and powder coating electrostatic coating control device of the present invention can use these two types of electrostatic coating guns for electrostatic coating of liquid coatings.

[0008]

SUMMARY OF THE INVENTION The present invention is directed to an airflow switch FS which operates by the flow of air blown onto an electrostatic coating gun, and a trigger switch TS provided on the electrostatic coating gun.
A spray actuation line L1 in which terminals SO, SO that can be connected to each other are connected in parallel, and a relay R is connected in series, and first contacts S1, S1 that are turned on during liquid electrostatic coating, and the first contacts S1, S1 connected in parallel and said first contact S
A solenoid for turning on and off an air flow is connected in series to a changeover switch CS having, as an alternative, 1 and S1 and a second contact point which is turned on at the time of electrostatic powder coating.
A switching line L2 having a contact which is turned on by the relay R is provided at the contacts S2 and S2 of the liquid, and a liquid or powder coating static liquid to which a high-frequency generator having a contact which is turned on at the time of spraying by the relay R is connected. It is an electric painting control device.

[0009]

The electrostatic coating gun for liquid electrostatic coating is a trouble mainly caused by the water-based coating which operates the solenoid of the control unit by the trigger switch TS provided on the gun itself and the spark caused by turning the switch on and off. To prevent this, an air opening / closing valve is provided in the gun body, and the air flow switch FS in the control unit detects the air flow caused by opening the opening / closing valve by a trigger operation. Some are used for liquid paints.

Since the terminals capable of connecting the airflow switch FS and the trigger switch TS are connected in parallel to the spray operation line of the liquid / powder paint electrostatic coating control device of the present invention, the electrostatic coating gun Either type can be used as it is.

Also, the switching line is provided with liquid paint electrostatic coating,
In addition to providing a changeover switch for changing electrostatic coating of powder paint, the solenoid SOL is operated at the same time when the changeover switch is changed during electrostatic coating of liquid paint, and high-pressure air is sent to a pump for feeding liquid paint and an electrostatic coating gun. Can be supplied and used.

In electrostatic coating of powder paint, the solenoid SOL is activated by switching the changeover switch and operating the trigger switch TS by triggering the electrostatic coating gun to convey air to the powder flow tank. , It supplies powder metering air and enables spraying. In each case, the high frequency generation circuit is turned on with the operation of the solenoid SOL.

As described above, the liquid and powder paint electrostatic coating control device can be commonly used as a control device for liquid paint electrostatic coating and powder paint electrostatic coating.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 schematically shows an embodiment of a liquid / powder coating electrostatic coating control device 1 together with a connection state when it is used as liquid coating electrostatic coating or powder coating electrostatic coating, and FIG. 2 shows its electric circuit diagram. 3 shows an example of an air system path connected to the solenoid SOL.

The liquid / powder paint electrostatic coating control device 1 has a spraying operation line L1 and a switching line L2, and includes a main switch MS, a power lamp WL, and a step-down transformer T. The high frequency generation circuit HF is connected in parallel on the downstream side of the transformer T.

Further, as shown in FIG. 1, a high pressure air source C such as a compressor is connected to the liquid / powder paint electrostatic coating control device 1 together with a ground wire and an outlet.

Further, in the case shown in FIG. 1, an opening / closing valve 11 is provided in the box body 10 of the liquid / powder paint electrostatic coating control device 1.
Switching valves 12 and 13 having two outlet ports and a switching box 14 are juxtaposed, and levers provided for the switching valves are integrally operatively connected by a connecting shaft 16. Further, the switching box 14 has a connector 17, 19 is provided.

In FIG. 1, the right side illustrates the connection state of each device for electrostatic coating of liquid paint and the left side illustrates the connection state of each device for electrostatic coating of powder coating, and electrostatic coating guns 3A and 3B are used respectively. In addition, in the case of liquid paint electrostatic painting, the paint tank 4 and
Pump P and are used.

In the case of electrostatic coating of powder coating, the tank 6
A powder flow tank 8 having an air injector pump 7 provided above is used.

Further, the electrostatic coating gun 3A for electrostatic coating of liquid paint is, in this example, a gun for an organic solvent which is turned on and off by a trigger operation and has no trigger switch TS.
The electrostatic coating gun 3B for powder electrostatic coating is provided with a trigger switch TS, and the trigger switch TS is connected to the connector 17 via a cord a.

Further, the on-off valve 11 is connected to the intake port of the powder coating material flowing air of the powder flow tank 8 through a flow path b such as a hose, and the outlet of each one of the switching valves 12 and 13. The ports are respectively connected to the carrier air intake port 7A and the powder metering air intake port 7B of the air injector pump 7 and flow paths c1 and d.
1 is connected.

Further, the carrier air supply port 7C of the air injector pump 7 is connected to the paint air intake port of the electrostatic coating gun 3B via the flow path e. The air injector pump 7
A well-known one that uses a combination of a nozzle and a Venturi insert can be used, and a well-known one that uses an automatic valve for opening and closing the paint at the paint inlet can also be used by controlling using a relay of an electric circuit. .

Further, the connector 17 of the switching box 14 is connected with a cord f1 leading to a high voltage electrostatic circuit (not shown) provided in the electrostatic coating gun 3B. Like the connector 19, the connector 17 is a multi-core type connector in which the cords a and f1 are simultaneously divided and connected.
When the electrostatic coating gun 3A has a trigger switch, it is similarly connected to the connector 19.

For liquid paint electrostatic coating, the other outlet ports of the switching valves 12 and 13 are connected to the pump P and the blowing air inlet of the electrostatic coating gun 3A through the flow paths c2 and d2. It The pump P is a diaphragm pump,
A plunge pump, a gear pump or the like can be used, and the pump P sucks the paint from the paint tank 4 and feeds it to the paint inlet of the electrostatic painting gun 3A via the flow path g. A high voltage electrostatic circuit (not shown) of the electrostatic coating gun 3A is connected to the connector 19 via a cord f2.

The on-off valve 11 and the switching valves 12 and 13 are
As shown in FIG. 3, connected to the high-pressure air source C, and between the on-off valve 11, the switching valves 12, 13 and the high-pressure air source C, display units 21, 22, 23 are provided. The metering valves 31, 32, 33, which can be adjusted by the knobs 24, 25, 26 in FIG. 1, are connected. Further, in this embodiment, the two first solenoids SOL are used as the solenoid SOL.
The first and second solenoids SOL2 are used, the switching valve 12 is provided with the first solenoid SOL1, and the switching valve 13 is provided with a detection portion of the air flow switch FS and a second solenoid.
Of the solenoid SOL2.

The first and second solenoids SOL1 and S
OL2 is arranged on the switching line L2 of the electric circuit of FIG. The switching line L2 has first contacts S1 and S2 that are turned on during the liquid electrostatic coating and second contacts S2 and S2 that are turned on during the powder electrostatic coating, and are connected in parallel. The first and second solenoids SOL1 and SOL2 are connected in series.

The first and second contacts S1, S1, S
The switches S and S2 are selectively turned on to form a changeover switch CS for switching between liquid electrostatic coating and powder electrostatic coating, which is housed in the switching box 14 and can be switched by the lever. Is configured as follows.

The second contact S2 for electrostatic powder coating is also provided.
A contact r1a0 of a relay R1 provided in the spray operation line L1 is interposed in S2, and in this embodiment, the relay R1 and another relay R2 are used as the relay R.

The spraying operation line L1 connects in parallel the contacts of the airflow switch FS and the terminals SO, SO to which the trigger switch TS can be connected using the cord a, and the spraying lines L1 are connected in parallel, respectively. Indicator lamp OL that lights up when attached, and the relays R1 and R2
And are connected in series.

Further, as described above, on the downstream side of the transformer T,
A high frequency generating circuit HF which is turned on / off by the contacts r1a1 and r2a1 of the relays R1 and R2 is connected, and this output is supplied from the connectors 17 and 19 to a high voltage electrostatic circuit of the electrostatic coating guns 3A and 3B (Fig. (Not shown) via cords f1 and f2. The high frequency generation circuit HF can be adjusted by the knob 40, and its value is displayed on the display unit 41.
Is displayed.

Next, the operation of the device 1 will be described. Connecting shaft 16
To the liquid electrostatic coating side, the first contacts S1, S
1 is closed, and the first and second solenoids SOL1 and SOL2
Immediately turns on, operates the pump P, and conducts blowing air to the electrostatic coating gun 3A.

The pump P automatically stops when the paint is pressurized to a predetermined saturation pressure. When the trigger is operated in this state, the blowing air first flows through. This is detected by the airflow switch FS, the relays R1 and R2 are turned on, and the high-frequency current of the high-frequency generation circuit HF is sent to the electrostatic coating gun 3A via the code f2, and is discharged by the subsequent pulling of the trigger. Spray the paint into electrostatic particles.
By releasing the trigger, the paint is first cut off, and then the blowing air is stopped, and when the airflow switch FS detects this, the relays R1 and R2 are opened and the high frequency current is cut off.

Further, the electrostatic coating gun 3A has a trigger switch T.
The same applies when S is included.

Next, when the connecting shaft 16 is switched to the electrostatic coating side of the powder paint, the second contacts S2 and S2 are closed. Air for powder flow flows into the powder flow tank 8 by the open / close valve 12 to fluidize the paint. Next, when the trigger is pulled, the trigger switch TS is turned on and the relays R1 and R2 are operated, so that the contact r1a0 causes the first and second solenoids S to operate.
OL1 and SOL2 are closed, and carrier air and powder metering air are supplied to the air injector pump 7. Thereby, the flow path e
The powder from is closed by closing the contacts r1a1 and r2a1.
Powder electrostatic coating is possible by discharging the electrostatic coating gun 3A while converting it into electrostatic particles.

In the apparatus of the present invention, the electrostatic coating guns 3A and 3B, the pump P, the powder flow tank 8, the air injector pump 7 and the like can be known ones, and an air cleaner, a paint pressure regulator and the like can be used. Equipment and parts are also used as needed. Furthermore, it is possible to switch using a switch instead of the connecting shaft, reduce the number of ports connected to each hose, and change the connection of the hose and cord to liquid paint electrostatic coating or powder paint electrostatic coating. Along with the switching, various modifications can be made such as automatically setting the air pressure and air amount suitable for liquid paint electrostatic coating and powder paint electrostatic coating.

[0036]

As described above, the liquid / powder coating electrostatic coating control device of the present invention can be commonly used for liquid coating electrostatic coating and powder coating electrostatic coating, which can reduce the cost of the device and enhance the usability. .

[Brief description of drawings]

FIG. 1 is a perspective view showing an embodiment of the present invention together with a connected state.

FIG. 2 is a diagram showing an example of an electric circuit.

FIG. 3 is a diagram showing an example of a connected state of solenoids.

[Explanation of symbols]

 3A, 3B Electrostatic coating gun 7 Air injector pump 8 Powder flow tank CS changeover switch FS Airflow switch TS Trigger switch P Pump

Claims (1)

[Claims] 1. Terminals SO, SO capable of connecting an air flow switch FS that operates by the flow of blowing air to an electrostatic coating gun and a trigger switch TS provided on the electrostatic coating gun.
Is connected in parallel and the relay R is connected in series, and the first contact points S1 and S1 which are turned on during electrostatic coating of liquid paint, and the first contact points S1 and S1 are connected in parallel and A solenoid for turning on / off an air flow is connected in series to a changeover switch CS having a first contact point S1, S1 and a second contact point which is turned on when electrostatically coating the powder paint. Electrostatic liquid or powder coating which is provided with a switching line L2 having contacts S2 and S2 which are turned on by the relay R, and a high-frequency generator connected to the contacts which are turned on at the time of spraying by the relay R. Painting control device. [0001]