DE10338064A1 - Flushing paint valves in painting system involves alternately passing compressed air and solvent through the paint feed line and the paint valve in the opposite direction to paint delivery direction - Google Patents

Abstract

The method involves alternately subjecting the paint feed line (26,28) and the paint valve (33a) with compressed air and solvent that are passed through the paint valve and feed line in the opposite direction to the paint delivery direction. The feed line to the valve to be cleaned is set to no pressure and the line for paint application is blocked.

Description

The The present invention relates to a method for rinsing Color valves in a paint shop and the simultaneous rinsing of Supply lines of color-leading Pipes of the paint shop to the paint valves.

One Use case for the invention is the series coating of motor vehicles in Paint shops.

at Color changes or regular cleaning is to ensure that as possible no residues in the color-leading Plant parts remain and thus the defect rate when restarting the plant as possible can be kept low.

From the DE 199 51 956 A1 a method for rinsing a color change valve arrangement with a plurality of color lines for coating with different colors is known, wherein in a color change of the common color channel is applied alternately and in opposite directions with detergent and compressed air.

Of Further it is in conventional Paint shops usual, for cleaning purposes, the in itself color leading line, the supply line to the paint valves, the paint valves themselves and the pipe of the Color valves up to the atomizer the paint shop with detergent and / or pressurize compressed air. Take the cleaning media doing the same way as the applied paint medium in Lackierbetrieb. The color valves and possibly upstream controllers are in this Process expanded and cleaned separately to avoid the shortcomings when restarting to minimize the paint shop by possibly remaining paint residues.

Of the The present invention is based on the object, a method for rinsing the paint valves in a paint shop and the supply lines too develop, with a consistently high cleaning performance the amount of mechanical cleaning work is minimized.

to solution This object is a method with the features of the claim 1 proposed.

The alternating counterflushing the paint valves and the supply lines with compressed air and solvent leads to a significantly improved cleaning result, what on the one hand the opposite flow direction the cleaning media opposite the flow direction the auszubringenden color medium is due, in particular in the area of the valves and in the area of the valve seats to clear Improvements leads and on the other hand, that the cleaning media in spatial Close to the primary to be cleaned parts of the paint shop introduced into the system become.

Under Paint valve are in the same way paint valves in color change arrangements as well as color valves at hand injection points to understand.

In Advantageous development of the method is the supply depressurized to the color valve to be cleaned and the line for the color discharge locked during operation. This ensures that the pulse air and the solvent without bypass and without impairment the paint valves can flow through opposite to the direction of ink discharge and these are cleaned up.

there It makes sense, the compressed air and the solvent on the ink-carrying Discharge pipe to the paint shop. This means, that the cleaning media over existing, for the paint application necessary lines can be dissipated.

Around To further improve the cleaning, the compressed air and the solvent pulsating introduced into the paint system. This is another Improvement, with the excess color after a color change or dried paint residues from the paint valve and the supply line to the paint valve can be removed, making the complex Removal and separate cleaning of individual components can be avoided can.

In better Training the process, the compressed air with a pressure between 7 and 10 bar, which corresponds to the value of the air supply in a conventional Painting system already available stands.

Further Advantageously, the solvent introduced at a pressure of about 8 bar.

Further Advantages and features of the invention can be found in the following description to the embodiment and the individual claims be removed.

In the drawing shows the single figure is a schematic representation a paint shop.

The painting system shown schematically 10 shows a loop 12 with the paint from a storage container 14 to a spraying machine 16 or to a hand-held sprayer 18 to be led.

The paint is made by a pump 20 transported in the loop, which is next to the collection point 22 for the hand injection unit 18 and the delivery point 24 for the automatic spray gun 16 a return line 26 having the color not delivered to the injection units into the reservoir 14 can be returned. At the delivery points 22 . 24 are three-way valves in the loop 12 arranged, with which the color can be passed to the injection units.

The ring line 12 is with the manual injection unit 18 over a stub line 28 and with the automatic spray gun 16 over a stub line 30 connected.

In the automatic spray gun 16 becomes the ring line 12 and the stub line 30 a color change block 32 with a plurality of paint valves 33 , fed. From the exit 34 of the color change block 32 the color is guided via a controller, not shown, to an atomizer, also not shown, and applied by this on the motor vehicle to be painted. The color change block 32 can have a first access 36 Pulse air and another access 38 Thinners are supplied with which, for example, the cleaning of a central pipe 40 of the color change block to the atomizer, not shown, which is connected to all color valves and the two accesses for thinner and pulse air can take place.

If in the area between the color change block 32 and the ring line 12 Color sludge deposits or similar impurities occur, which show, for example, in a declining quality in the applied color, this area is purified by the method according to the invention. Particularly susceptible to such deposits are the seats of the paint valves, color pressure regulators, fittings and transitions on pipelines.

The cleaning of the paint valves 33 , the stub line 30 and arranged in the stub line controllers can be done without the entire loop 12 must be cleared of color. This is the stub 30 depressurized and the output 34 of the color change block 32 blocked. The paint valve intended for cleaning 33a will be opened. The color change block 32 will about the access 36 with pulse air and over the access 38 Thinner applied through the opened paint valve 33a in the stub line 30 enter and about the return line 26 the ring line 12 be dissipated.

In order to maximize the cleaning result, the compressed air and the thinner become alternating and each pulsating the color change block 32 fed. Thus, the paint sludge and other deposits is pushed back against the normal flow direction of the color in the loop and disposed of over this. The cleaning result, in particular the color valves and the controller concerning, is so good with the inventive method that disassembly and separate cleaning of these components can be omitted. The service life of the system for this cleaning process is thus shortened considerably.

One Another advantage of the method is that it is based on a conventional Lackieranlage without large structural measures can be realized by the wiring for the compressed air and the dilution only over the Color valve and the stub is done.

This also referred to as backward flushing Procedure allows the cleaning of the paint valves and the stub line with a filled loop, which leads to significant potential savings in color material, since at earlier Cleaning process in the direction of the paint discharge quite the loop rinsed had to be before the stub also in the existing plant and the paint valve could be cleaned.

The Backwashing at a manual injection unit takes place analogously to the backwashing at the automatic injection machine, however, in the field of color coupling, a mobile device for introducing of the thinner and the compressed air is attached.

The Procedure led at a pressure of the thinner from about 8 bar and the compressed air from 7 to 10 bar to such good results, that extra cleaning steps are no longer necessary and only a small amount of paint in the Restarting the system must be deducted until the quality requirements were met again to the applied color. This leads to the Further, a cost reduction, since deducted at a smaller amount Color also reduce its disposal costs accordingly.

Claims (6)

Method for rinsing at least one color valve ( 33a ) in a paint shop ( 10 ) and the supply lines ( 28 . 30 ) from a paint-carrying line ( 12 ) to the paint valve ( 33a ), wherein the paint valve and the supply line are alternately acted upon by compressed air and a solvent and the compressed air and the solvent against the discharge of the paint through the paint valve ( 33a ) and the supply line ( 26 . 28 ). Method according to claim 1, characterized in that the supply line ( 26 . 28 ) to the color valve to be cleaned ( 33a ) depressurized and the line ( 40 ) is blocked for the color discharge during operation. A method according to claim 1 or 2, characterized in that the compressed air and the solvent via the ink-carrying line ( 12 ) of the paint shop ( 10 ) is discharged. A method according to claim 1 or 2, characterized in that the compressed air and the solvent pulsating in the paint shop ( 10 ) are introduced. Method according to claim 1 or 2, characterized that the compressed air is introduced at a pressure between 7 and 10 bar becomes. Method according to claim 1 or 2, characterized that the solvent is introduced at a pressure of about 8 bar.