ES2232374T3 - PAINT INSTALLATION. - Google Patents

Abstract

The system has two reservoir containers and a device for electrostatic isolation of at least one container and a spray device from the delivery system so the container and spray device can be brought to a high voltage relative to the object. The isolating device has an insulating line section between the containers and a pad movable reciprocally in the line that removes electrically conducting coating material from its inner surface. The system has two reservoir containers (8,10) in series or in parallel and an isolation device (14,16) for electrostatic isolation of at least one container and a following spray device (12) from the delivery system so that the container and spray device can be brought to a high voltage relative to the object to be sprayed. The isolating device consists of an electrically insulating line section (18) between the containers that also forms the paint feed into the second container and a pad (22) movable reciprocally in the line that removes electrically conducting coating material from the inner surface of the line section as it passes through it.

Description

Paint installation

The invention relates to an installation of paint with a spray device to apply material coating on an object, especially a body of car, with two accommodation containers connected one behind of the other serving as an intermediate deposit and with a device separation for electrostatic isolation of at least one of the housing and spray device containers connected next to a power side, of so that at least one of the accommodation containers and the Spray device can be placed under high voltage regarding the object to be painted during the process of covering.

The electrostatic painting installations of This type is known, for example, from US 5340289. To be able to apply almost the entire amount of paint on the object that must be painted, the spray device and a container of paint housing of the paint mechanism arranged in front of it placed at high voltage at a magnitude greater than 50 kV with respect to object to be painted maintained at ground potential. Due to the electric field that is generated in this way, almost all the amount of paint on the object to be painted and minimized the excess correspondingly. To do this, through a electrostatic container separation device intermediates that acts mechanically and the device spray or atomization are separated from each other mechanically after fill the intermediate container and then place high tension with respect to the object to be painted. Construction, configuration and operation of a separation device This type of mechanics is expensive and expensive, since the pipes that conduct the liquid for filling the container of Paint housing must be tightly attached to the liquid and separated from each other. The coating material that remains in the junction sections of the pipes entails equally problems.

Mainly, in the operation of a paint installation of this type there is the problem that the accommodation containers that serve as intermediate deposits not can be filled with coating material continuously, since in that case a high isolation would not be possible tension.

In a paint installation of the type mentioned previously, there is the possibility of decoupling each other Containers mechanically, to achieve insulation High voltage electrical containers between each other. Of this mode, one of the high voltage containers can be placed, to perform a painting process, while filling the other one that is Find ground potential. To be able to pass from a container to the other or fill in the second container, in case of an arrangement In series, the painting process should be interrupted.

There is also the possibility of arranging the first container above the second container, which in that case It is configured as an open container, so that the material coating can reach from the top container to the second container arranged below as a result of the gravity, and through an exit that flows freely out of the first container. Such an arrangement allows a continuous coating operation, in which the first top container during coating operation is fill from the second container, then isolate electrostatically and decouple the power side and place at the high voltage of the second lower container. In this state, it is possible to fill the lower container by opening the exit of the top container that empties freely and, thus, a continued transport operation. The high tension in the Top container can be disconnected again and the container, After filling, you can join with the feed side.

An aggravating disadvantage should be that the second lower container has to be configured as a container open. Vapors of solvents escape and there is a danger of that impurities can reach the second container. That's it difficult to clean the second container, for example, with solvents

When between the accommodation containers provides a decoupling device that acts mechanically to electrostatically isolate both containers from each other, represents a technically expensive solution, with risk of breakdowns and difficult handling

Document DE 19937426 A1, which has not been previously published, unveils a painting installation electrostatic with a single housing container that serves as intermediate tank, which can be placed under high voltage by means of a feed line that can be cleaned with a pipe cleaner and which electrostatically isolates.

Document DE 19817377 A1 discloses a installation of non-generic paint, in which by means of a pipe cleaners in a feed line can reduce the paint consumption in case of color change.

Document DE 19710216 A1 discloses a installation of electrostatic paint with a conduction of very long spiral feeding or return of material insulating. In this way, high voltage insulation is achieved between a spray device of the paint installation and The paint feed side. A container is not disclosed of housing that serves as an intermediate deposit in the device Spray

Document DE 3717929 A1 discloses a installation of electrostatic paint with two containers of accommodation connected in parallel that serve as reservoirs intermediate, which can be placed at high voltage alternately. Also here, a feed line forms a path of electrostatic insulation The use of a pipe cleaners

The present invention is based on the objective of improve a paint installation of the type mentioned at the beginning, by the fact that a simple structure constructively, without the need to mechanically decouple the components, be possible a continuous transport operation without losses and The disadvantages described above do not appear.

This objective is achieved according to the invention in a painting installation of the type mentioned at the beginning, of so that the electrostatic separation device comprises a electrically provided insulating conduction section between the first and second housing container, which also serves for feeding paint to the second container of accommodation, and a pipe cleaner that can move both ways in the inside of the driving section, which when moving through the conduction section releases its inner surface of material electrically conductive coating.

As pipe cleaners is understood a body that can move through a means of driving in the broadest sense, which is currently mounted on paint mechanisms to push coating materials outside the pipes, as well as clean the pipes during or after the cleaning process with the solvent. For this, the pipe cleaner bodies are known in themselves; are configured at least limitedly flexible, so that they can be introduced into a medium of driving with the least excess and, they are supported, basically flexible elastic against the inner side of the driving means and, however, at the same time they can move. When they ride elastically flexible conduction means, for example, tubes that They are made of plastic materials, they can also be used, basically rigid pipe cleaner bodies. However, the use of pipe cleaner bodies in paint mechanisms served, exclusively for cleaning purposes. With the invention proved that by using a pipe cleaner in conjunction with a conduction section formed from an insulating material electrically a separation device can be formed electrostatic, in which only by a movement of the pipe cleaners through the conduction section can be achieved an electrostatic insulation in a high paint mechanism voltage, without a separation of the components of the paint mechanism Through the movement of the pipe cleaner to through the conduction section, its inner surface is released of any electrically conductive liquid (material of coating, washing agent) almost like using a lip or scraper and, thus, high insulation is achieved tension.

According to the invention, an insulation of electrically non-conductive voltage or basically non-conductive by the length of the cleaned driving section. Respect to this it should be understood that when applying a voltage of 100 kV in a driving section length of approx. 300 mm fits a current flow less than 50 µA, preferably, less than 30 µA.

With the invention it has been proven that by use of a pipe cleaner can achieve high insulation voltage in an electrically insulating conduction section between both containers because the tube cleaner releases the inner side of the conduction section of electrically coated material driver. In an especially advantageous way, a closed leak-proof container under pressure as container accommodation. This has the advantage that they do not escape solvent vapors and a closed system that can be request with pressure. Likewise, it has been proven as advantageous that a piston means is provided in the housing container which on the one hand it limits the filling volume and, on the other hand, it can requested with a drive pressure. The plunger can rest, therefore, to some extent on the material of covering. By applying the drive pressure a discretionary pressure within the container can be predetermined accommodation. Through the movement of the plunger means it is scratched, at the same time, the inner side of the respective container, of so that the volume of the side of the medium drive means Piston does not need to be cleaned. The plunger means may limit a minimum volume that can be filled with coating material, what which is very advantageous with respect to solvent cleaning, since it is not necessary to fill the entire volume of the container solvent housing.

In a particularly advantageous variant of the invention is envisaged, both between both housing containers as, also, on the feed side of the first container of housing a separation device according to the invention with a electrically insulating conduction section and a pipe cleaner that It can move inside. In that case, it is not necessary in absolute no separation device that is disengaged by acting mechanically, and high insulation can also be achieved tension. The driving system is completely closed and is not it is necessary to remove coating material in sections of driving that end freely from a device decoupling The operation of the installation can Perform absolutely without losses.

In this context it turns out to be especially advantageous that the tube cleaner can be ordered on the one hand with the actuating means, preferably pressurized air, and in its other side is in permanent contact with material covering. In that case, the pipe cleaner limits on this side a column of coating material within the system conduction and can be used to press out or move the coating material Although it would be conceivable the pipe cleaner movement through pushing or pulling means Discretionary, also empty, has been proven as especially advantageous when the pipe cleaner can be requested, at least, by a side by pressurized air and so that, in case of solicitation by pressurized air on one side moves in the direction of the configuration of an electrical insulation. The return movement can be carried out advantageously by the effect of the material of coating, for example predetermining within the second housing container an actuation pressure, which in case corresponding ventilation of the driving section mentioned press the pipe cleaner back in the opposite direction and, at the same time, fill in the second driving section again of coating material

Other features, details and advantages of the invention follows from the subordinate claims and the graphic representation and the following description of a form of preferred embodiment of the invention. In the drawing, the figure shows a schematic representation of a paint installation according to the invention.

The figure shows a painting installation according to the invention, that to cover an object by means of a 2 color changer is linked with an annular conduction system not shown, which can lead for example different colors of paint, solvents and also pressurized air. To the changer of color 2 joins a pressure regulating device 4, as well as a quantity dosing device 6. The installation of paint also includes a first and a second container of accommodation 8 or 10 that serve as intermediate deposits, which are configured as closed pressure containers. Then of the second housing container 10 is connected a spraying device 12, by which the atomizer is atomized coating material and can be applied or sprayed on a object to be covered.

Between accommodation containers 8 and 10 as well as on the feeding side of the first housing container 8 an electrostatic separation device 16 or 14 is provided for be able to place the second housing container 10 and the high voltage spraying device 12 relative to an object It must be coated. By means of the separation device 16 of feed side can be insulated the first container of accommodation 8 with respect to the feeding side and placed high tension.

Both separation devices 14 or 16 they comprise a conduction section 18 or 20 of insulating material and a pipe cleaner 22 or 24 that can move inside. He pipe cleaners 22 or 24 can be requested, on the one hand, by air pressure within the respective conduction section 16 or 18 by means of a valve 26 or 28 and, at the same time, You can move to the right in the figure. Also, the pipe cleaner 22, 24 limits the column of color found in the driving section 18, 20 and moves it in the figure towards the right, that is, into the housing container 8, 10 respective. Also, the tube cleaner 22, 24 scratches the color of the inner surface of the conduction sections 18, 20. These are clean of electrically conductive coating material and, of In this way, high voltage insulation can be achieved. The length of the conduction sections 18, 20 amounts to at least 300 mm and, thus, high insulation could be achieved voltage, so that when applying a high voltage of 100 kV on a conduction section 18, 20 could measure a current less than 50 µA, preferably less than 30 µA, which It has been proven as sufficiently insulating. To go back the pipe cleaner 22, 24 serves the coating material within the driving system. To do this, devices are opened of closing 30, 32 between the driving section 18, 20 and the second accommodation container 10 or the first housing container 8. If the pressure inside the housing containers 8, 10 is higher than the pressure on the other side of the pipe cleaner 22, 24, the pipe cleaner 22, 24 goes back in the figure to the left, and the respective components are linked together in turn of electrically conductive form by means of the material existing coating in conduction sections 18, 20.

A cycle of painting.

In the initial state, both containers of accommodation 8, 10 are almost empty (contrary to the representation of the figure); both piston means 34, 36 are They are in the lower position. The respective position of the piston means 34, 36 can be verified by means of sensors filling status 38, 40 and used for drive or regulation.

In the initial state, both tube cleaners 22, 24 are they find in their final left position in the figure. When opening all valves in the color conduction to the device spraying 12, the coating material can arrive from the annular conduction system to the second container of housing 10. Likewise, a shut-off valve 42 that joins the conduction towards spray device 12 is closed. The entire paint installation is at the potential of land.

Through pressurized air connections 44, 46 and closing or actuating mechanisms 48 or 50, on the side of actuation of the piston means 34, 36 within the containers 8, 10 an actuation pressure of so that the pressure in the first container 8 is greater than the pressure in the second container 10, which results in that the second container 10 is filled and, at the same time, the medium of piston 34 moves up into the second container 10. During this phase of pressure or filling, above the medium of piston 34 in the second container 10 predetermines a pressure of approx. 2 bar, and above the middle of drive 36 in the first container 8, a pressure of approx. 6 bar The inlet pressure on the side of feeding of the first container 8 is among these pressure values, taking into account that the piston means 36 in the first container 8 it is in an end position lower, which causes a circulation of coating material to through the first housing container 8.

Therefore, through the driving section 16, the first container 8 and the other conduction section 18 are fill the second housing container 10. Once the filling process of the second housing container 10, after close a shut-off valve 52, pressurized air is delivered through from actuation valve 26 to conduction section 18, the tube cleaner 22 moving to the final position represented by Right in the figure. At the same time, the pipe cleaner 22 scratches or clean the inner side of the second driving section, so It achieves high voltage insulation. In addition, the pipe cleaner 22 presses the column of coating material into the conduction section 18 towards the second housing container 10. Then valve 30 closes. The first and second accommodation container 8 and 10 are isolated from each other electrostatically The second housing container 10 and the spray device 12 assigned below can placed at high voltage (approx. 100 kV) and the coating process after opening valve 42 and starting another transport device 54, as well as a pressure regulator 56. Meanwhile the first housing container 8 is filled, what is conveniently done so that the pressure by above the piston means 36 it drops to atmospheric pressure. After reaching a desired filling state, which can be verified through the filling status sensors 40, air is delivered to pressure via actuator valve 28 on the left side in the drawing of the tube cleaner 24, and the tube cleaner 24 moves towards the right in the figure, until it reaches its final position in front of valve 32. In this way, too, the inner side of the conduction section 20 of conductive coating material, and high voltage insulation is achieved. The first container 8 and the components that bind to it are placed equally to the same high voltage as the second housing container 10 and the spraying device 12. To be able to refill the second container 10, valve 30 is opened and due to the upper pressure which dominates within the second housing container 10 with respect at atmospheric pressure in the first housing container 8, and in the conduction section 18, the tube cleaner 2 moves through of the coating material from the second container 10 of new to its left end position, which is represented by the number reference 58 and is expected slightly to the left of the mouth of the outlet line 60 of the first container 8. After applying a drive pressure above the means of piston 36 via the pressurized air connection 46 of approx. 6 bar, in any case higher than the pressure within the second housing container 10 and open the valve 52, the contents of the first container 8 can be filled in the second container 10. Meanwhile, a paint operation can be maintained continued and lossless. After filling the coating material and closing valve 52 is delivered again using the valve 26 air pressure drive to the rear of the pipe cleaner 22 and this, in turn, moves to its final position represented in the figure, cleaning the conduction section 18 and reaching a High voltage insulation between containers 8 and 10. The first container 8 can be placed in turn to ground potential and, opening the valve 32 the tube cleaner 34, which is in its right end position, you can move to your left end position represented in the figure and by the effect of the material of remaining coating found in container 8. The container 8 can be filled again.

At the end of the painting process, through the downward movement of the piston means 34, 36 the material remaining in the annular conduction system can go back to the maximum possible. If then the driving sections 16, 18 as well as the remaining components of the paint installation are clean by introducing pressurized air and / or solvent, it turns out advantageous that for this the solvent volume is minimized necessary, since the piston means 34, 36 have moved to their final position In case the piston means is renounced 34, 36, the entire volume of the containers 8, 10 should be filled with solvent or cleaning liquid.

Claims (11)

1. Paint installation with a spray device (12) to apply coating material to an object, especially a car body, with two housing containers (8, 10) connected one behind the other that serve as an intermediate tank and with a separation device (14, 16) for electrostatic isolation of at least one of the housing containers (10) and the spraying device (12) connected next to a supply side, so that, at least one of the housing containers (10) and the spraying device (12) can be placed under high tension with respect to the object to be painted, characterized in that the electrostatic separation device (14) comprises a conduction section (18) electrically provided insulator between the first and second housing container (8, 10), which also serves to feed paint to the second housing container nto (10), and a pipe cleaner (22) that can move both ways inside the conduction section (18), which when moving through the conduction section (18) releases its inner surface of coating material electrically conductive 2. Paint installation according to claim 1, characterized in that the conduction section (18) has a length of at least 300 mm. 3. Paint installation according to claim 1 or 2, characterized in that the conduction section (18) is made of a flexible high-strength plastic flexible tube material or is formed by a highly resistant and tear-resistant glass tube. 4. Paint installation according to claim 1, 2 or 3, characterized in that the electrical potential is above 50 kV, preferably above 70 kV, especially between 70 and 100 kV. 5. Paint installation according to one of the preceding claims, characterized in that the pipe cleaner (22, 24) has at least one groove or lip that serves as a means of sealing or extraction and can be placed under tension against the inner surface of the driving section. 6. Painting installation according to one of the preceding claims, characterized in that on one and / or the other side of the conduction section (18, 20) a power connection is provided for a displacement means for moving the pipe cleaner (22, 224) through the driving section (18, 20). 7. Paint installation according to claim 6, characterized in that the displacement means is gaseous. 8. Painting installation according to one of the preceding claims, characterized in that, also, on the feeding side of the first housing container (8) an electrically insulating conduction section (20) is provided with a pipe cleaner (24) that can move through, which form an electrically insulating separation device (16). 9. Paint installation according to one of the preceding claims, characterized in that at least the second housing container (10) is configured as a closed leak-proof container under pressure. 10. Paint installation according to one of the preceding claims, characterized in that at least the second housing container (10) comprises a piston means (34) that limits, on the one hand, the filling volume, which on the other side can be requested with a drive pressure. 11. Paint installation according to one of the preceding claims, characterized in that the pipe cleaner (22, 24) can be ordered on one side with a drive means, especially pressurized air and, on the other hand, is in permanent contact with material of coating.