EP2581136A1 - Transport device for liquids and varnishing assembly - Google Patents

Abstract

The unit (1) has a transportation carriage (8) comprising a receiving chamber (10) that is fillable with liquid to be transported. The transportation carriage is displaceably arranged in a housing cover (6) in a longitudinal direction. Front sides of the transportation carriage are limited with cover caps (26, 28) and provided with non-return valves (22, 24). Hydraulic chambers (12, 14) exhibit total length of 30 mm in a longitudinal direction of the housing cover. The transportation carriage comprises a release valve for releasing rinsing agents. An independent claim is also included for a paint finishing system.

Description

The invention relates to a transport device for liquids, in particular for use in a paint shop. It further relates to a paint shop with a number of provided for applying paint on an object to be coated atomizers.

Such paint systems are used for example in the coating or painting of motor vehicle bodies. For the supply of various atomizers, which can be arranged in succession, for example in the manner of a Lackierstraße and provided for applying paint in different stages, a main supply line for supplying the paint is usually provided, for example, in the manner of a so-called loop at a corresponding Lackierkabine along or around this can be. From this main supply line or loop then branches off with the interposition of suitable components such as valves or the like from spurs that open into the respective atomizer and can convey the paint to this. Optionally, in particular for systems provided for coating with paints of different colors, it is also possible to provide a plurality of ring lines, with suitable color changers usually being able to be connected to the system at the branch of the respective branch lines.

The main supply line, so in particular the loop, is usually connected on the input side to a paint supply unit via which the paint material from a paint container, such as a replaceable paint bucket or the like, can be fed into the main supply line by means of a feed pump or a conveying member. In the embodiment of the main supply line as a so-called loop this can in turn also in the manner of a circular or annular guide to the paint reservoir be connected so that the circulated in the loop loop, circulated paint on the output side can flow back into the paint reservoir. Alternatively, the main supply line but also run in the manner of a spur line and connected only on the input side to the paint reservoir.

In the majority of such systems are used in the manner of a large-scale production, with comparatively large numbers of components such as vehicle bodies are painted and coated with consistent standard shades. With such an operating mode, it is thus possible to maintain a virtually constant paint throughput in the overall system without discarding residual stocks or recovering amounts of paint present in the system due to media changes or the like.

On the other hand, however, such systems can also be used for the processing of very small series or an individual production of individual components, for example, when attaching a special finish for an individually designed motor vehicle. When applying to such a low-sized workpiece numbers or the like adapted amounts of paint decentralized provision of individual paint reservoir in the immediate application area, so close to the individual atomizers may be provided.

Painting plants of the above embodiments can be designed as so-called electrostatic painting, in which water-dilutable paints are processed. In such an electrostatic painting installation, paint material is supplied to a high-voltage potential atomizer during electrostatic painting via a line. If this paint material is electrically conductive, it must be ensured that it does not come to an electrical short circuit via the paint supply line, since the other end of the paint supply line is below ground potential. For this reason are at electrostatic Paint shops usually in a secured against commissioning high voltage area the paint supply line and the associated paint container also placed at high voltage potential. This in turn has the consequence that this container during operation can not be refilled from a lying at ground supply line.

In order to still be able to ensure a continuous supply of the paint material from a lying at high voltage potential container to the atomizer in such a paint shop, lying at high voltage potential container in a suitable form discontinuously and with consistent maintenance of the potential separation between the high voltage potential on the container on the one hand and ground potential on the supply side on the other hand filled with paint material. To make matters worse in such systems, especially in the processing of small amounts of paint, for example, for individual production of very small series, frequent color changes in the paint can be required, so that an intermediate flushing of the affected components must be made. Especially with the use of components under high voltage, this can cause a considerable effort and a frequent interruption of the operational processes.

The invention is therefore an object of the invention to provide a transport device for liquids, especially for paint, with the particularly simple held, particularly suitable for use in such a paint system construction reliable transfer of liquid or paint amounts of one - especially at ground potential held - input side to a - in particular at high voltage potential - output side under consistent compliance with a potential separation between the input side and output side is possible.

This object is achieved according to the invention in that the transport device has a transport carriage for the liquid or the paint which can be filled with the liquid to be transported or the paint to be transported Has receiving chamber, and in a housing shell in the longitudinal direction displaceable, more preferably hydraulically displaceable, is arranged.

The invention is based on the consideration that the transport device should be designed just in view of the desired use in a painting on the one hand in a mechanically stable and simple design. On the other hand, but especially the handling of the overall system with frequent color change and thus the rinses required in the meantime particularly to facilitate the transport should be designed so that they - and with it the potential separation between ground potential and high voltage potential - as far as possible in the paint strand, ie close to or immediately before the respective atomizer, can be arranged. By such an arrangement of the transport device and thus the separation point is namely guaranteed that as many components of the overall system, such as guide lines, color changer and the like, held at ground potential and thus can be handled comparatively easy. On the other hand, only the actual atomizer and the line elements immediately upstream of it must be kept at high voltage potential.

Especially in the - common in modern systems - arrangement of atomizers on robot arms and the like for this design concept, ie a consistent displacement of the transport device and thus given potential separation point to the atomizer out, a particularly compact design of the intended as potential separation point transport device for the paint desirable. Such a particularly compact, yet mechanically stable and simple design with consistent adherence to the proposed potential separation can be achieved by the transport of the respective amounts of paint on a suitably designed transport carriage is made, which in turn is performed in a suitable, preferably consistently insulating, housing shell , To move the transport carriage - and thus the optionally entrained paint quantity - to the inlet end and the outlet end of the transport device (or vice versa) is provided for a suitable displacement of the transport carriage within the housing shell.

The displacement can take place with suitably chosen means which preferably do not impede the intended potential separation, for example pneumatically. Particularly preferred, however, a hydraulic drive is provided for the transport carriage. For this purpose, the housing shell preferably has on both sides of the transport slide in each case a fillable with a hydraulic oil hydraulic chamber, wherein both hydraulic chambers are each connected in an associated hydraulic circuit. In the respective hydraulic circuit, in each case an electrically non-conductive, thus insulating hydraulic oil is advantageously guided as the hydraulic medium. In the manner of a double function of this electrically non-conductive hydraulic oil thus serves as a drive medium for the required displacement of the transport carriage within the housing shell, and on the other hand contributes to the electrical insulation and thus the potential separation between the transport carriage and the respective end of the housing shell. In a particularly advantageous embodiment, a hydraulic oil is provided, the water absorption capacity is less than 1%, and / or its kinematic viscosity at a temperature of 20 ° C less than 10 mm ² / s.

In order to further favor the desired use of hydraulic chambers filled with hydraulic oil for isolation purposes, the hydraulic chambers are advantageously dimensioned appropriately in this respect. In particular, advantageously, the total length of both hydraulic chambers together, which is given essentially by the total length of the housing shell minus the Au βenlänge of the transport carriage, chosen such that taking into account the essential electrical properties of the hydraulic oil, in particular its breakdown field strength, with respect to the provided operating voltages sufficiently dimensioned insulating distance and / or in particular gives a distance between the high voltage and ground potential of less than 50 mm.

A particularly simple and compact design is further favored by the transport carriage advantageously in turn hydraulically emptied. Thus, the transport carriage is advantageously provided with a receiving chamber for the liquid or the paint at least on one side delimiting, hydraulically actuated discharge piston. The receiving chamber sensed with liquid or varnish can thus be emptied by the hydraulic control of the discharge piston.

Preferably, the transport carriage is each frontally bounded by a provided with a check valve end cover, which can be done via the check valve, the filling or emptying of the receiving chamber with liquid or paint. Preferably, the transport carriage is designed such that the respective check valve cooperates with a corresponding nozzle of the respective associated wall of the housing shell. In a filling position, in which the transport carriage is located within the housing shell adjacent to the filling side, thus engages the corresponding check valve in the respective nozzle on the filling side of the housing shell, whereas in the opposite unloading position, in which the transport carriage in the longitudinal direction of the housing shell seen other end edge is engaged, the other check valve engages in the wall located in this wall. The receiving chamber is advantageously connected by suitable channel guide within the transport carriage with the check valves of both end cover, so that a filling and emptying of the receiving chamber is made possible with appropriate operation of the check valves.

In an alternative or additional advantageous development, the transport carriage has a release valve for a rinsing agent, so that paint changes are particularly easy to carry out. Advantageously, the check valves are designed as so-called "clean-break" valves, which practically without leaks within the respective inlet and outlet ports can open and close, as in the EP 1 045 732 B1 are executed. The revelation of EP 1 045 732 B1 with regard to the design of the potential-separating valve is explicitly included ("Incorporation by reference").

In a particularly advantageous embodiment, the transport device is used in a paint shop with a number of provided for applying paint on an object to be coated atomizers. In order to ensure a particularly simple and reliable operation of the paint shop, the transport device is advantageously arranged spatially and structurally as close to each associated atomizer, so that the total holding at high voltage potential range both in terms of space and in terms of the number of high voltage held components can be kept very low. In a particularly advantageous embodiment, the paint shop comprises a number of atomizers arranged on pivotable robot arms, wherein a transport device for the paint associated with such an atomizer is likewise arranged on the robot arm carrying the respective atomizer.

The advantages achieved by the invention are in particular that a reliable potential separation between ground potential in a connection region of the transport device on the one hand and high voltage potential on the other connection region of the transport device on the other hand reliably and in a particularly compact design can be achieved by the guided in the housing shell, longitudinally hydraulically slidably arranged transport carriage , Due to the compact design, but also by the mechanical simplicity and high stability by dispensing with other active drive components or the like, the integration of the transport device in the paint strand is comparatively close to the respective atomizer and in particular as together with the atomizer on a robot arm movable component allows , So that the separation point between ground potential and high voltage potential can be moved particularly far to the atomizer out. This allows the spatial area and also the number of components of the high voltage potential to keep particularly low. The transport carriage acts as a pendulum container or "shuttle" for paint transport.

Figur 1:

eine Transporteinrichtung für Flüssigkeiten, und

Figur 2:

ein Zerstäubersystem einer Lackieranlage.

An embodiment of the invention will be explained in more detail with reference to a drawing. Show:

FIG. 1:

a transport device for liquids, and

FIG. 2:

an atomizer system of a paint shop.

Identical parts are provided in both figures with the same reference numerals.

The transport device 1 according to FIG. 1 is provided for transporting a liquid amount, in particular a paint amount, from an inflow region with an input port 2 to an outflow region with an output port 4. The transport device 1 is provided in particular for use in an electrostatic paint shop, not shown in detail, are processed in the highly electrically conductive paints, such as water-dilutable paints. Since in such paint spraying the atomizer provided for the application of the paint is usually at high voltage potential, care must be taken when using electrically conductive paint material that electrical short circuits can not occur since the actual paint supply area of the paint shop is usually below ground potential. In order to meet these requirements, the transport device 1 for the paint in the manner of a potential-isolation valve is designed such that under consistent compliance with the potential separation between the held at ground inlet region on the one hand and held at high voltage potential outlet region of the transport of an electrically conductive Amount of paint can be made from the inlet opening 2 to the outlet opening 4. The inlet opening 2 is connected on the paint side in a manner not shown with a paint supply system of the paint shop, whereas the Exit opening 4 is connected on the paint side with an associated, held at high voltage potential atomizer.

In order to ensure the intended consistent potential separation between the inlet and outlet areas in a particularly compact design, the transport device 1 comprises a housing shell 6 made of an electrically insulating material, such as a suitably chosen plastic, in the exemplary embodiment. In this cylindrically designed housing jacket 6, a transport carriage 8 which is displaceable in the longitudinal direction of the housing shell 6 is arranged for the actual transport of a quantity of paint from the inlet to the outlet region, which in turn has a receiving chamber 10 which can be filled with the amount of paint to be transported.

For a comparatively simple and mechanically stable design of the transport carriage 8 is displaceable within the housing shell 6. The displacement can be achieved in a suitable manner, for example pneumatically. In the exemplary embodiment, the transport carriage 8 in the housing shell 6 each of the preferred embodiment is hydraulically displaceable. For this purpose, located within the housing shell 6 on both sides of the transport carriage 8 hydraulic chambers 12, 14, which are, if necessary, filled with hydraulic oil. For a transport of the transport carriage 8, for example, from the inlet to the outlet region, for example, the outlet-side hydraulic chamber 14 emptied of hydraulic oil and parallel to the inlet-side hydraulic chamber 12 are filled with hydraulic oil. As a result, the hydraulic pressure in the hydraulic chamber 12 increases, and the transport carriage 8 moves toward the exit end of the housing shell 6. Conversely, a displacement of the transport carriage 8 can be carried out within the housing shell 6 from its exit to its inlet end by the hydraulic chamber 12 is emptied and parallel to the hydraulic chamber 14 is filled with hydraulic fluid. To ensure the desired potential separation, the use of a suitable, electrically non-conductive hydraulic fluid is provided. The hydraulic oil should be chosen such that it is also at fluctuations in the operating temperature is as stable as possible viscosity, and / or that it causes no surface defects in the paint.

The insulating effect of the entire system thus results on the one hand by the insulating housing shell 6 and on the other hand by the combination of each free lengths in the hydraulic chambers 12, 14 of the insulating hydraulic fluid therein. An interpretation of the overall system adapted to given requirements in terms of insulation effect can thus be made in a particularly simple manner by a suitable dimensioning in particular the length of the housing shell 6 in relation to the length of the transport carriage 8, since the remaining free length within the housing shell 6, not for Transport carriage 8 is filled and thus is felt with hydraulic fluid, which produces the desired insulation effect.

The transport carriage 8 is in turn provided with a receiving chamber 10 on one side delimiting, also hydraulically actuated discharge piston 16. The discharge piston 16 is in turn connected via a hydraulic line 18 to a connecting piece 20 connected to a hydraulic system, so that the position of the discharge piston 16 within the receiving chamber 10 can be adjusted via the corresponding hydraulic pressure in relation to the pressure in the receiving chamber 10. At the other, open end of the receiving chamber 10 via suitable in the walls of the transport carriage 8 extending channels both the input side and the output side connected to the media channel of a check valve 22 and 24, respectively. The check valves 22, 24 are in the exemplary embodiment in each case on a transport carriage 8 frontally limiting end cap 26 and 28, but could for example also be disposed within the nozzle 30, 32.

For filling or emptying of the receiving chamber 10, the check valves 22, 24 are dependent on the position of the transport carriage 8 within the housing shell 6, each with associated nozzles, ie in particular on the inlet side with an inlet nozzle 30 and the output side with an outlet nozzle 32, engageable. The configuration of the respective combination of shut-off valve 22, 24 on the one hand and associated nozzle 30, 32 on the other hand is in turn also made such that a consistent potential separation is maintained even when filling or emptying the paint. For this purpose, the check valves 22, 24 and the associated nozzles 30, 32 in turn as potential separation means according to the information in the EP 1 045 732 B1 whose disclosure content with regard to the design of these components is expressly included in full.

The transport device 1 is thus designed, on the one hand, for consistent adherence to potential separation between the inlet and outlet regions for the paint. On the other hand, the design of the transport device 1 allows a particularly compact and thus space and weight-saving design. This can be used in a particularly advantageous embodiment, in order to shift the given by the transport device 1 separation point within the paint shop between ground potential on the one hand and voltage potential on the other hand particularly far towards the high-voltage potential to be held consumers, ie the actual atomizer. As a result, therefore, many parts and components of the paint shop can be kept at ground potential by this compact design, so that a particularly advantageous use of the transport device 1 is possible both for safety considerations and with regard to the required operational resources. This use of the transport device 1 close to the actual atomizer is exemplary of the system element according to FIG. 2 shown.

Like in FIG. 2 can be seen, two transport devices are arranged 1,1 'of the type mentioned on a robot arm 40 used as part of a paint shop. The robot arm 40 in turn carries the atomizer 42 provided for discharging the paint, which is kept at high voltage for operational reasons. On the input side, the transport devices 1,1 'are connected to the paint supply system and in particular to a color changer of the paint shop. Due to the compact design of the transport devices 1, 1 ' Thus, it is possible to arrange them in the manner of a mobile use on the robot arm 40 and thus particularly close to the atomizer 42 and position. The potential separation between ground potential on the one hand and high voltage potential on the other hand is thus now only on the actual robot arm, so that its other control units, mechanical, hydraulic joints and the like kept at ground potential and thus can be operated very easily.

LIST OF REFERENCE NUMBERS

1, 1 '

transport means

2

input port

4

output port

6

housing jacket

8th

transport carriage

10

receiving chamber

12, 14

hydraulic chambers

16

delivery plunger

18

hydraulic line

20

spigot

22, 24

spear valve

26, 28

End cover

30

inlet connection

32

outlet connection

40

robot arm

42

atomizer

Claims (8)

Transport device (1) for liquids with a transport carriage (8) which has a receiving chamber (10) which can be filled with the liquid to be transported, and which is displaceably arranged in a housing jacket (6) in its longitudinal direction. Transport device (1) according to claim 1, whose transport slide (8) is provided with a receiving chamber (10) at least on one side delimiting, hydraulically actuated discharge piston (16). Transport device (1) according to claim 1 or 2, whose transport carriage (8) is delimited on the front by a respective end cap (26, 28) provided with a check valve (22, 24). Transport device (1) according to claim 3, the receiving chamber (10) on the media side with the check valves (22, 24) of the end cover (26, 28) is connected. Transport device (1) according to one of claims 1 to 4, in the housing shell (6) on both sides of the transport carriage (8) each having a fillable with an electrically non-conductive hydraulic fluid hydraulic chamber (12, 14) is provided. Transport device (1) according to claim 5, the hydraulic chambers (12, 14) together seen in the longitudinal direction of the housing shell (6) have a total length of at least 30 mm. Transport device (1) according to one of claims 1 to 6, whose transport carriage (8) has a release valve for detergent. Painting installation having a number of atomizers (42) provided for applying paint to an article to be coated, to which at least one transport device (1) according to any one of claims 1 to 7 is connected in front of the paint supply.

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