JPH0461943A - Electrostatic coating device for conductive coating material - Google Patents

Abstract

PURPOSE:To obviate the need for an insulating measure to be applied to the subject device by connecting a coating supply pipe and a liq. cleaner supply pipe detachably to a connecting opening on the input port side and a connecting opening on the liq. cleaner supply port side of a reciprocating pump, respectively. CONSTITUTION:A predetermined high voltage is applied to an electrostatic coating machine 1, an air signal A is supplied from an air valve 32a to switch a valve 24a so as to supply operating oil from an operating oil tank 28 through a pipe 29 to a hydraulic cylinder 11a and, at the same time, an air signal H is supplied from an air valve 32h to turn on a color changing valve CCV1 so as to supply the conductive coating material introduced in a cylinder 7a to the electrostatic coating machine 1 in a predetermined amt. by force feed through an output port 9 under the power of a hydraulic cylinder 11a. This method eliminates the possibility of the high voltage applied to the electrostatic coating machine 1 leaking to a coating supply system such as coating supply pipe 20a and obviates the need for troublesome insulating measure.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to an electrostatic coating device for conductive paint that coats water-based paint, slurry paint, metallic paint, etc. using an electrostatic coating machine to which a high voltage is applied. .

[Conventional technology]

When applying conductive paint such as water-based paint using an electrostatic paint applicator to which high voltage is applied, insulate the paint supply system of the paint applicator to prevent leakage of the high voltage applied to the electrostatic paint applicator. Because it is necessary to take countermeasures (Japanese Patent Application Laid-open No. 114-1983
(No. 366, Publication No. 56-141869), in multi-color electrostatic coating equipment for automobile painting that changes paint colors from dozens of colors, the paint supply piping and paint tank are separated for each color paint. There is the trouble of having to insulate the other parts.

For this reason, in automobile painting, electrostatic painting using insulating resin paints, which consumes large amounts of harmful organic solvents, is currently the mainstream, and the use of non-polluting water-based paints has been postponed.

However, recently, as the global environmental conservation movement has increased, there have been calls for restrictions on the use of organic solvents that generate pollutants such as hydrocarbons in the coating industry.

[Problem to be solved by the invention]

Therefore, the present invention eliminates the need for troublesome insulation measures for the paint supply piping, paint tank, or cleaning liquid supply piping and cleaning liquid tank, even when performing electrostatic painting using conductive paint such as water-based paint. This is considered a technical issue.

[Means to solve the problem]

In order to solve this problem, the present invention provides an electrostatic coating device for electroconductive paint that uses an electrostatic coating machine to which a high voltage is applied. A reciprocating pump that forces out the adhesive paint at a predetermined flow rate from an output port and supplies it to the electrostatic coating machine in a fixed amount, and a cleaning liquid supply port that sends the cleaning liquid supplied through the cleaning liquid supply piping to the electrostatic coating machine are provided. The supply piping and the cleaning liquid supply piping are configured to be detachably connected to the input port side connection port and the cleaning liquid supply port side connection port of the reciprocating pump, respectively.

[Effect]

According to the present invention, first, the paint supply pipe is connected to the input port side connection port of the reciprocating pump, and the conductive paint is introduced into the reciprocating pump from the input port.

When the reciprocating pump is filled with a required amount of conductive paint, the paint supply pipe is removed from the input port side connection port of the pump.

On the other hand, the cleaning liquid supply pipe is left disconnected from the connection port on the cleaning liquid supply port side.

In this state, a predetermined high voltage is applied to the electrostatic coating machine, and the conductive paint is forced out at a predetermined flow rate from the output port of the reciprocating pump to supply a fixed amount to the electrostatic coating machine.

At this time, the paint supply pipe and the cleaning liquid supply pipe are separated from the input port side connection port and the cleaning liquid supply port side connection port of the reciprocating pump, respectively, so they are electrically isolated from the electrostatic sprayer to which high voltage is applied. has been done.

Therefore, there is no need to take insulation measures to prevent high voltage leakage in the paint supply system and the cleaning liquid supply system that are connected to the paint supply pipe and the cleaning liquid supply pipe.

In addition, when painting is completed and the application of high voltage to the electrostatic sprayer is stopped, the cleaning fluid supply pipe is connected to the cleaning fluid supply port side connection port, and the paint remaining in the electrostatic sprayer is quickly removed. Washed and removed.

〔Example〕

Embodiments of the present invention will be specifically described below based on the drawings.

FIG. 1 is a flow sheet diagram showing an example of the structure of an electrostatic coating apparatus according to the present invention, and FIGS. 2 and 3 are a front view and a plan view, respectively, showing the specific structure of the main parts thereof.

In this example, an electrostatic coating machine 1 that applies a DC high voltage of about 80 to 120 KV is installed on an insulating support 2 in an electrically insulated state, and a plurality of paint hoses 3 of the electrostatic coating machine 1 are connected to each other. A manifold 5 of a color change valve device 4 having color change pulp CCV, ˜CCV, is connected.

6a to 6C are hollow pipe-shaped insulating supports provided in parallel with the insulating support 2 of the electrostatic coating machine 1, and conductive paint introduced from the input port 8 is applied to the tip of each insulating support from the output port 9. Electrostatic coating machine 1 by squeezing out at a predetermined flow rate
Cylinders 78 to 7c, which serve as reciprocating pumps for supplying a fixed amount to
An insulating shaft 10 serving as a piston rond of a to 7C is inserted through the insulating shaft 10, and further, the insulating shaft 1 is inserted at the rear end.
Hydraulic cylinders Ila to 11c for reciprocating the 0 are attached. Note that 12.13 is a proximity switch that outputs a start/stop signal for each of the hydraulic cylinders lla to llc.

In addition, air valves 14a to 14c, which are turned on and off by an air signal, are attached to the tip sides of the insulating supports 6a to 6c, and input port side connection ports each made of a female coupler are provided on the inlet side of each pulp. 15, the outlet sides of which are connected to the input ports 8 of the respective cylinders 7a to 7c, respectively.

The output port 9 of each cylinder 7a-7c is located adjacent to each air valve 14a-14c on insulation support 6a-14c.
The color changing valves ccv and -ccv of the color changing valve device 4 disposed on the distal end side of the color changing valve 6C are respectively connected to the color changing valves ccv and -ccv.

Further, an air valve 14d that is turned on and off by an air signal is attached to the tip side of the insulating support 6c adjacent to the air valve 14c, and on the inlet side of the pulp 14d,
A cleaning liquid supply port side connection port 15' consisting of a female coupler is provided, and its outflow side is connected to a cleaning liquid supply port 16 for supplying cleaning liquid to the electrostatic coating machine 1.

This cleaning liquid supply port 16 is connected to the color change valve CCV of the color change valve device 4.

Next, on the rear end side of each of the insulating sabots 6a to 6C, air valves 19a to 19. Double-acting air cylinders 17a to 17d are provided with air valves 17a to 17d equipped with air valves 17a-17d.
Paint supply pipes 20a to 20c for supplying conductive paint of each color are connected to the inlet sides of the cylinders 9a to 19c, respectively. A female coupler 21 to be released is connected.

Further, a cleaning liquid supply pipe 22 for supplying cleaning liquid is connected to the inlet side of the air valve 19d, and a female coupler 21' that is connected to and disconnected from the cleaning liquid supply port side connection port 15' is connected to the outlet side thereof. has been done.

Note that 23 is a cleaning air supply pipe directly connected to the color change valve CCV.

Further, 24a to 24c are hydraulic cylinders lla to llc.
This is a switching valve that supplies hydraulic oil to the hydraulic oil tank 28, which is circulated and supplied by the gear pump 25 and regulators 26 and 27 at a constant flow rate depending on the amount of paint discharged from the electrostatic atomizer 1. , each pair of piping 29.30
The hydraulic oil is sent to each of the hydraulic cylinders lla to llc through the hydraulic cylinders lla to llc, and the hydraulic oil discharged from each of the hydraulic cylinders lla to llc is returned into the hydraulic oil tank 28.

31a to 31d are air valves that supply driving air to the air cylinders L7a to 17d; 32a to 32m are air signals A-C for switching the switching valves 24a to 24c;
Air signal D that turns on and off air valves 14a to 14d and 19a to 19d and color change valves CCv1 to CC5.
- This is an air valve that outputs M.

Therefore, first, from the air valve 31a to the air cylinder 1,
By supplying driving air to extend the piston rod 18 of the cylinder 7a and engaging the female coupler 21 with the input port side connection port 15 made of a female coupler, the paint supply pipe 20a is connected to the cylinder 7a. Connect to the input port side connection port 15 of.

For example, when applying conductive paint of paint color I supplied from the paint supply pipe 20a, the air valve 32
d outputs an air signal to turn on the valves on the air valves 14a and 19a, and connects the input port 8 of the cylinder 7a to the input port side connection port 1 consisting of a female coupler.
5 and the paint supply pipe 20a of paint color I.
and the female coupler 21 are communicated with each other.

Next, the air valve 32a outputs an air signal A to the switching valve 24a to switch the valve 24 so that the hydraulic oil in the hydraulic oil tank 28 is sent to the hydraulic cylinder lla through the pipe 30.

As a result, the cylinder 7a connected to the hydraulic cylinder lla via the insulating shaft 10 is actuated, and the conductive paint of color I is sucked and introduced from the input port 8 of the cylinder 7a.

Incidentally, at this time, conductive paints of paint colors ① and ② are also introduced in advance into the other cylinders 7b and 7c, respectively.

When the required amount of conductive paint is introduced into the cylinder 7a, the proximity switch 13 is activated, and the signal output from the switch outputs an air signal A that switches the pulp 24a from the air valve 32a to the air valve 24a. At the same time, the air valve 32d outputs an air signal to turn off the air valves 14a and 19a, and the air valve 31a is turned off.
Driving air for contracting the piston rod 18 is supplied to the air cylinder 17a from the air cylinder 17a.

As a result, the paint supply pipe 20a is again separated from the input port side connection port 15 of the cylinder 7a, and is electrically insulated from the cylinder 7a.

Further, the cylinder 7a and the hydraulic cylinder lla are also electrically insulated by the insulating support 6a and the insulating shaft 10 inserted therein.

Therefore, in this state, a predetermined high voltage is applied to the electrostatic sprayer 1, and the air valve 32a is directed to the switching valve 24a so that the hydraulic oil in the hydraulic oil tank 28 is sent to the hydraulic cylinder lla through the piping 29. At the same time as outputting the air signal A that switches the valve 24, the air valve 3
From 2h, the air signal H that turns on the color change valve CCV is output, and the conductive paint introduced into the cylinder 7a is forced out from the output port 9 using the power of the hydraulic cylinder lla, and a fixed amount is supplied to the electrostatic coating machine 1. Then, there is no risk that the high voltage applied to the electrostatic atomizer 1 will leak into the paint supply system such as the paint supply pipe 20a, and troublesome insulation measures are not required.

When painting with the conductive paint of paint color I is completed in this way, the color change valve CCV is turned off by the air signal H from the air valve 32h, and the air signal M from the air valve 32m is turned off.
Turn on the color change valve CCV5 with
The compressed air supplied through 3 discharges the paint of color ■ remaining in the manifold 5 of the color change valve device 4, the paint hose 3, and the electrostatic atomizer from the atomizer 1, and performs electrostatic painting. Stop applying high voltage to machine 1.

Next, the air valves 14d and 1 are connected from the air valve 32g.
9d, outputs an air signal G that turns on both valves, connects the cleaning liquid supply port 16 with its connection port 15' made of a female coupler, and connects the cleaning liquid supply pipe 22.
and the female coupler 21', and further supply driving air from the air valve 31d to the air cylinder 17d to extend the piston rod 18 of the cylinder, and clean the female coupler 21' with the cleaning liquid made of the female coupler. The cleaning liquid supply pipe 22 is connected to the cleaning liquid supply port 16 by engaging with the supply port side connection port 15''.

And air valve 32i! The color change valve CCV is turned on by the air signal from , and the inside of the manifold 5 of the color change valve device 4, the inside of the paint hose 3, and the inside of the electrostatic sprayer 1 are cleaned with the cleaning liquid that is force-fed through the cleaning liquid supply piping 22. Then, compressed air is supplied again from the cleaning air supply piping 23,
The cleaning liquid remaining in the electrostatic coating machine 1 is discharged from the manifold 5 from the electrostatic coating machine 1.

After repeating this operation several times and cleaning the conductive paint of paint color I is completed, air valves 32g to 14d
and an air signal G that turns off 19d is output, and
Driving air for contracting the piston rod 18 is supplied from the air valve 31d to the air cylinder 17d, and the cleaning liquid supply pipe 22 is again separated from the cleaning liquid supply port side connection port 15', and the cleaning liquid supply pipe 22 is disconnected from the cleaning liquid supply port connected to the coating machine 1. 16 and the cleaning liquid supply pipe 22 are electrically insulated.

Therefore, when a high voltage is applied to the electrostatic coating machine 1 again to start painting after cleaning is completed, there is no risk that the high voltage will leak into the cleaning liquid supply system such as the cleaning liquid supply pipe 22.

In the above embodiment, the hydraulic cylinders lla to l are used as reciprocating pumps that supply a fixed amount of conductive paint to the electrostatic coating machine 1.
Although cylinders 7a to 7c driven by lc are used,
The cylinders 7a to 7c may be configured such that an insulated shaft 1° corresponding to the piston rod is driven by a screw feeding mechanism that converts rotation of an air motor or the like into linear reciprocating motion.

Further, the reciprocating pump is not limited to the cylinders 7a to 7c, but may be a diaphragm pump.

〔Effect of the invention〕

As described above, according to the present invention, even when coating conductive paint such as water-based paint with an electrostatic coating machine to which a high voltage is applied, the paint supply system and cleaning liquid supply system of the electrostatic coating machine This has the very valuable effect of eliminating the need for troublesome insulation measures in all cases.

Therefore, it is possible to promote the transition from electrostatic coating using insulating resin paint to electrostatic coating using non-polluting water-based paint, and this invention is extremely useful.

[Brief explanation of drawings]

FIG. 1 is a flow sheet diagram showing an example of the structure of an electrostatic coating apparatus according to the present invention, and FIGS. 2 and 3 are a front view and a plan view, respectively, showing the specific structure of the main parts thereof. 22. Cleaning liquid supply piping.

Claims (1)

[Claims] In an electrostatic coating device for conductive paint that coats conductive paint with an electrostatic coating machine (1) to which a high voltage is applied, the input port (8) The conductive paint introduced from the output port (9
) reciprocating pumps (7a), (7b), (7c) that pump out at a predetermined flow rate and supply a fixed amount to the electrostatic coating machine (1);
A cleaning liquid supply port (16) is provided to send the cleaning liquid supplied through the cleaning liquid supply pipe (22) to the electrostatic coating machine (1), and the paint supply pipes (20a), (20b), (2)
0c) and the cleaning liquid supply pipe (22) are connected to the input port side connection port (15) and the cleaning liquid supply port side connection port (15') of the reciprocating pumps (7a), (7b), and (7c), respectively. An electrostatic coating device for conductive paint, characterized in that the device is configured to be removably connected.