Coating system with a painting robot

Abstract

Coating system with a) a program-controlled painting robot (1) for painting motor vehicle bodies with exterior surfaces to be painted on the outside of the motor vehicle bodies and interior surfaces to be painted inside the motor vehicle bodies by means of an application device (7) guided by the painting robot (1), b) wherein the painting robot (1) b1) has a swiveling upper arm (4) and a distal robot arm (5) swiveling at its end, which guides the application device (7) via a robot hand axis (6), and b2) is suitable for painting both the exterior and interior surfaces of motor vehicle bodies, and b3) is able to insert the application device (7) into the engine and trunk compartments of the body with the doors and hoods installed, i.e., in the way, and through door openings into the interior of the body to a sufficient extent for painting the interior, and b4) has a robot base (2) which is permanently mounted on a machine foundation, characterized by c) that the pivot axis of the distal robot arm (5) of the painting robot (1) is located below the pivot axis of the upper arm (4) of the painting robot (1) adjacent to the distal robot arm (5) when painting at least one interior space, and d) that the distal robot arm (5) inserted into the at least one interior space is in a horizontal position during the painting of the interior space.

Description

[0001] The invention relates to a coating system with a painting robot for painting motor vehicle bodies according to the preamble of the main claim. "Painting robot" here refers to any program-controlled multi-axis coating machine or other automated motion system.

[0002] Modern paint shops for painting vehicle bodies use multi-axis painting robots which, as application devices, for example, carry a rotary atomizer and enable highly efficient painting operations.

[0003] Occasional or frequent color changes are necessary when vehicle bodies are to be painted with different colored paints. Known painting robots therefore feature a color changer, as described, for example, in DE 103 35 358 A1, which is connected to several paint supply lines through which different colored paints are fed. Within the color changer, the individual paint supply lines each terminate via a paint valve in a common central paint channel, which supplies the rotary atomizer with the paint to be applied via a paint pressure regulator and a metering pump.

[0004] With this design of the color changer, the central color channel between the color changer and the main needle valve of the atomizer must be flushed after a color change before another paint with a new color can be applied.

[0005] Flushing the central paint channel during a color change is important because otherwise, any paint residue remaining in the central paint channel would contaminate the new paint.

[0006] The problem here, however, is that when changing colors, the paint volume between the color changer and the main needle valve of the atomizer has to be discarded, so that, for example, with a color changer offering 24 possible colors, a paint loss of between 45 and 55 ml occurs.

[0007] Therefore, to minimize color loss during a color change, it is known to mount the color changer as close as possible to the atomizer, i.e., in the distal robot arm, which is also referred to as "Arm 2".

[0008] However, the installation of the color changer in the distal robot arm currently requires such a large installation space in the distal robot arm that the known painting robots with a color changer mounted in the distal robot arm are only suitable for exterior painting, i.e., for painting the exterior surfaces of vehicle bodies, since the size of the distal robot arm plays only a minor role in this application.

[0009] For interior painting of vehicle bodies, however, it is not yet possible to use painting robots in which the color changer is mounted on the distal robot arm. This is because interior painting requires narrow, slim robot arms that can be guided through body openings (e.g., door openings) into the interior of the vehicle body to paint the interior surfaces. Therefore, in known painting systems for vehicle bodies, painting robots with a different design are used for interior painting. In these systems, the color changer is not mounted on the distal robot arm, and higher paint losses are accepted in order to allow for a slimmer design of the distal robot arm. Alternatively, more complex techniques are used, such as paint containers in atomizers or pigging systems with piston dispensers.

[0010] A disadvantage of existing paint systems is that different types of robots are required for interior and exterior painting, which generally necessitates different application technologies, especially if the system is not optimally designed. The different designs of the painting robots and their associated application technologies, however, lead to increased engineering and logistical complexity.

[0011] For the technical background of the invention, reference should also be made to DE 10 2008 015 258 A1, DE 10 2005 013 014 A1, WO 2005 / 046 880 A2, DE 10 2006 005 341 A1, US 2008 / 0 020 135 A1, EP 1 245 295 A2 and DE 601 23 924 T2.

[0012] The invention is therefore based on the objective of creating a correspondingly improved coating system.

[0013] This problem is solved by a coating system according to claim 1.

[0014] The invention comprises the general technical teaching of creating a painting robot which, by design, i.e., by means of a suitable arrangement of components with a small space requirement, is suitable for both painting the outer surfaces of motor vehicle bodies and for painting the inner surfaces of motor vehicle bodies.

[0015] This means that the robot should be able to insert the atomizer into the engine compartment and trunk of the vehicle body, even with the doors and hoods installed and obstructing access, and into the interior of the vehicle body through door openings (and in special cases, through window openings) to a sufficient extent for painting the interior. In typical cases, the vertical height of "Arm 2" (or, in the case of other painting machines, the distal machine arm) at its atomizer-side end must not exceed 350 mm, preferably 300 mm, and its width measured transversely to this in this area must not exceed 300 mm, preferably 250 mm. This limit should not be exceeded to ensure sufficient length in the direction of the pivot axis of this arm, for example, to at least 300 mm from the mounting surface of the hand axis, or in other cases to at least 500 mm. The arm can then widen in its rear section, e.g.,for lateral hose exit, and also higher for design reasons.

[0016] Such slim robot arms are known for the interior painting of car bodies, but due to space constraints, they could not previously contain the components required for the application, such as color changers, dosing pumps, paint pressure regulators, etc., thus suffering from the aforementioned disadvantages such as paint, rinsing, and time losses, etc.

[0017] The painting robot according to the invention therefore has several kinetically serially arranged robot arms to spatially position an application device (e.g., a rotary atomizer, air atomizer, airless atomizer, or ultrasonic atomizer), which is known in the prior art. In the painting robot according to the invention, however, the distal robot arm (i.e., the so-called "arm 2") is so narrow and slim that the distal robot arm with the application device mounted on it can be inserted through body openings (e.g., window openings) into the interior of the vehicle body to paint the interior surfaces there.

[0018] Furthermore, the painting robot according to the invention preferably has a color changer which, in order to minimize the color losses occurring during a color change, is preferably mounted on the distal robot arm (“Arm 2”) of the painting robot, which is made possible by a special design of the color changer without impairing the suitability for interior painting.

[0019] In a preferred embodiment of the invention, the color changer has several docking points (e.g., on a color bar) that are supplied with different colored paints from individual color feed lines. Furthermore, in this embodiment, the color changer has a movable paint pickup (e.g., a docking slide) that can selectively dock at one of the docking points and, when docked, extracts the paint from the corresponding color feed line and supplies the common paint line with the extracted paint. To select the paint of the desired color, the paint pickup is positioned so that it docks at the corresponding docking point, whereupon the paint can be extracted from the corresponding color feed line via the docking point.In this embodiment, the color changer, unlike the known color changer described at the beginning, does not have a central color channel, so that, due to its design, the color changer prevents paint contamination even in the event of a malfunction of the color valves or an incorrect control of the color valves, since only a single paint supply line is connected to the paint extraction point at any given time.

[0020] In the color changer according to the invention described above, a color valve is preferably arranged in each of the individual color supply lines, which selectively blocks or enables the flow of paint through the respective color supply line. The individual color valves are controlled by one and the same control signal, which can be, for example, a pneumatic, electrical, or mechanical control signal. Preferably, the control signal for actuating the individual color valves is routed from the paint outlet via the respective docking point to the respective color valve, so that the control signal can only reach one of the color valves when the paint outlet is docked to the corresponding docking point. This type of control of the color valves inherently ensures that the individual color valves can only be opened when the paint outlet is docked to the corresponding docking point.The individual color valves are therefore preferably designed so that they block the corresponding color supply line in the absence of a control signal. Instead of or instead of conventional color valves, elements known as quick-release or quick-connect couplings, externally controlled check valves, or valves that open by actuation with a plunger can also be used.

[0021] The movable ink extraction system can, for example, consist of a docking carriage that can be moved linearly relative to the docking points of the individual ink supply lines. Alternatively, the ink extraction system can also be rotatable to dock at the desired docking point.

[0022] Similar color changers are known, for example, from patent application EP 1 245 295 A2, so that the content of this patent application can be fully attributed to this description with regard to the structure and function of the color changer.

[0023] Furthermore, the painting robot according to the invention preferably has two separate rinsing circuits, namely a first rinsing circuit for rinsing the docking points of the color changer and a second rinsing circuit for rinsing the common ink line for the different colored paints between the color changer and the atomizer, wherein the two rinsing circuits are separate or at least separable, so that the docking points can be rinsed independently and separately from the common ink line. With this design, it is therefore possible for the common ink line for the different colored paints to be rinsed all the way to the atomizer, while simultaneously or at least overlapping in time the docking points of the color changer are rinsed. This simultaneous or overlapping rinsing reduces the color change time during a color change.Furthermore, when changing colors, the paint extraction system can already move to and dock at a new docking point, while the common paint line for the different colored paints is flushed up to the atomizer, which also contributes to a reduction in the required color change time.

[0024] In this design, the separation of the two rinsing circuits is preferably achieved by at least one separating valve located in the paint extraction area.

[0025] In this process, the first rinsing circuit preferably leads from a rinsing agent supply line, via a rinsing agent valve, downstream through the common paint line behind the separating valve to the atomizer, and finally optionally via a check valve into a return line or via the main needle valve of the atomizer. Thus, various options exist for rinsing the common paint line within the scope of the invention.

[0026] One possibility is that the thinning fluid, which is usually used as a rinsing agent, is sprayed off the atomizer in the same way as the paint being applied after the common paint line has been flushed. In this case, the rinsing fluid introduced into the common paint line acts as a displacement medium, pushing the remaining paint out of the atomizer. Another operating mode, known as "push-out operation," is also possible. In this mode, the remaining paint in the line, sprayed off by the atomizer, is almost entirely used for painting until the rinsing fluid, acting as the displacement medium, is finally dispensed. Therefore, in this "push-out operation," precise knowledge of the switchover point is required, specifically when the paint valve closes and the rinsing fluid valve opens.The painting process must be completed with a sufficient safety margin before the rinsing agent, which acts as the displacement medium, is dispensed from the atomizer. In a known manner, "push-out" can be carried out using a pig that pushes the paint, with the pig being propelled by the rinsing agent. However, if the residual paint is directly pushed by a rinsing agent (the same applies to reflow operation), lines with a sufficiently small diameter are required to avoid the well-known "lance effect." The inner diameter of all lines and channels in components through which paint is directly pushed by the rinsing agent or other displacement medium should therefore be less than 6 mm, for example, between approximately 2 and approximately 4 mm. Furthermore, these lines and channels should also avoid corners and sharp bends to prevent the lance effect and turbulence, etc.

[0027] Secondly, when flushing the common paint line, there is the possibility that a first non-return valve is arranged in the atomizer, through which the rinsing agent can be diverted into a non-return line.

[0028] The two aforementioned rinsing methods can also be combined by first using the paint forced out of the common paint line by the rinsing agent for painting. Shortly before the rinsing agent reaches the main needle valve of the atomizer, the main needle valve is closed and the check valve in the atomizer is opened to prevent the rinsing agent from being sprayed out.

[0029] Furthermore, the color change system according to the invention enables the reuse of the lacquer located in the common ink line between the color changer and the atomizer by pushing the lacquer, which is present in the common ink line between the color changer and the atomizer during a color change, back into the corresponding ink supply line via the docking point. This is why this operating mode is also referred to as "reflow operation". The backflow of the lacquer from the section of the common ink line between the color changer and the atomizer into the ink supply line is preferably achieved by introducing a displacement medium, such as rinsing fluid, into the common ink line upstream of the atomizer's main needle valve.The rinsing agent introduced into the common ink line then forces the lacquer located in the common ink line back into the corresponding ink supply line. In the corresponding embodiment of the invention, a rinsing agent supply line therefore opens into the common ink line upstream of the main needle valve of the atomizer via a rinsing agent valve arranged in the atomizer, in order to force the lacquer remaining in the common ink line back through the color changer into the corresponding ink line for later reuse, with the introduced rinsing agent serving as the displacement medium.

[0030] Reflow operation can also be carried out in the usual way using a pig.

[0031] The introduction of the displacement or sliding medium, for example a solvent or rinsing agent, into the atomizer preferably does not take place directly via the rinsing agent supply line and the rinsing agent valve, but via a rinsing agent dispenser which is arranged upstream of the rinsing agent valve in the rinsing agent supply line and which can push the rinsing agent contained in the rinsing agent dispenser into the common paint line when the rinsing agent valve is open.

[0032] The term "doser" here refers to a device that is intended to deliver a predetermined volume of liquid (dose), but does not need to generate a defined volume flow rate per unit of time.

[0033] Such a metering device, e.g., a piston metering device, which is preferably only pressurized and operates without defined time or speed control, has significant advantages over, for example, a volumetrically operating gear metering pump. Besides the reduced control complexity, the main advantage is significantly lower losses, which in metering pumps are caused by slippage and increase continuously and unpredictably due to wear during operation.

[0034] Upstream of the detergent dispenser, a further detergent valve is preferably located for the controllable filling of the detergent dispenser via the detergent supply line. On the inlet side, the detergent dispenser can therefore preferably be filled with detergent from the detergent supply line via the detergent valve. On the outlet side, the detergent dispenser is connected to the common paint line via the detergent valve in order to dose the detergent, which serves as the displacement medium, into the common paint line.

[0035] In the preferred embodiment of the invention, the cleaning agent dispenser has a dosing volume that is essentially equal to the filling volume of the ink line between the respective docked ink valve on the one hand and the main needle valve of the atomizer on the other. Thus, the dosing volume of the cleaning agent dispenser is sufficient to fill the entire section of the common ink line between the ink changer and the atomizer with the cleaning agent, which serves as the displacement medium, and thereby force the paint located in this section of the line back into the corresponding ink line.

[0036] For example, the detergent dispenser for "reflow operation" can be designed as a dosing cylinder or formed by a pigging tube.

[0037] There are various options for driving the detergent dispenser, with the detergent dispenser preferably being driven electrically or pneumatically.

[0038] As explained above, the color changer according to the invention has a movable color extractor that can dock at one of several docking points to extract the paint of the desired color from the associated paint supply line via the docking point. Preferably, a clamping device is provided which mechanically clamps the color extractor (e.g., the docking slide) and the respective docking point (e.g., in the paint strip) together in the docked state. This advantageously allows the color extractor to dock to the respective docking point without external force, so that no large-dimensioned brackets or supports are required.

[0039] In a preferred embodiment, the clamping device has a groove with an undercut against which a movable clamping element engages. For example, the individual paint supply lines and the associated paint valves and docking points can be arranged in a row in a paint strip, the paint strip having the groove for clamping to the paint outlet. The paint outlet preferably consists of a docking slide that is displaceable in the longitudinal direction of the groove relative to the paint strip, wherein the docking slide can, by means of a docking cylinder, attract a gripping disc guided in the groove in order to clamp the docking slide to the paint strip.

[0040] Despite the tension between the docking carriage on the one hand and the paint strip on the other, a leak can occur in the docking area in the event of a fault, e.g., a failure of one of the seals provided there, with paint escaping into the groove in the paint strip. It is therefore advantageous if the groove has no undercut on its underside, so that any paint that has leaked out due to the fault can flow out of the groove at the bottom. In the preferred embodiment of the invention, the groove therefore has an undercut only on its upper groove flank, whereas the groove is free of undercuts on its lower groove flank.

[0041] As mentioned earlier, the color changer is preferably mounted on the distal robot arm ("Arm 2") so that the common ink line between the color changer and the atomizer is as short as possible, resulting in correspondingly low color change losses. Furthermore, a color pressure regulator and / or a metering pump are preferably also mounted on the distal robot arm, so that essential parts of the application technology are located on the distal robot arm. It is also advantageous if a servo-pneumatic actuator is also arranged in the distal robot arm to move the ink pickup (e.g., the docking carriage) relative to the docking points (e.g., on the ink strip) in order to select the paint with the desired color.

[0042] Furthermore, it is advantageous if the ink pressure regulator, the actuator for ink dispensing, and / or the metering pump are arranged in a common connection block, thus eliminating connecting hoses between the ink pressure regulator and the metering pump and therefore hose-related disturbances. In addition, integrating the ink pressure regulator and the metering pump into a single connection block allows for short connection lengths and a simple and compact design.

[0043] Furthermore, the invention provides for a special connection of the individual color leads to the color changer. For this purpose, receiving bores are arranged in the color changer for each individual color lead, into which the color leads are inserted for connection to the color changer. At their free end, the color leads have an inclined clamping surface, which can, for example, consist of a conical outer surface extending coaxially to the receiving bore. The color changer also contains a clamping bore that runs essentially perpendicular to the receiving bore and opens into it, the clamping bore having an internal thread. A clamping screw (e.g., a hex socket, Torx, slotted, or Phillips head screw, or the like) can then be inserted into the clamping bore.) are screwed in, which presses with its free end against the inclined clamping surface at the free end of the paint supply line, thus axially securing the paint supply line and clamping it in the receiving bore.

[0044] The connection design described above is also suitable for connecting other cables.

[0045] In the case of a color change, the operating procedure preferably provides that the movable color pickup (e.g. a docking carriage) of the color changer docks to one of several docking points (e.g. on a color bar) which are fed from several color supply lines with different colored paints.

[0046] After docking, the lacquer to be applied is taken from the associated paint supply line via the docked docking point, and the atomizer is fed with the lacquer selected by the color changer via a common paint line for the different colored lacquers.

[0047] Furthermore, the operating method preferably provides that the docking points in the color changer are rinsed with a rinsing agent via a first rinsing circuit, whereas the common color line between the color changer and the atomizer is rinsed with a rinsing agent via a second rinsing circuit, wherein the first rinsing circuit is or is separated from the second rinsing circuit.

[0048] Advantageously, the docking points and the common color supply line between the color changer and the atomizer are rinsed simultaneously or at least overlapping in time in order to shorten the required rinsing time and thus also the color change time.

[0049] The two flushing circuits are preferably separated from each other by at least one separating valve to allow simultaneous or overlapping flushing.

[0050] Within the framework of the aforementioned “push-out operation”, the operating procedure provides that, in the event of a color change, the paint remaining in the common paint line is pushed out via the second rinsing circuit, either through a non-return valve located in the atomizer into a non-return line or through the main needle valve of the atomizer out of the common paint line.

[0051] In contrast, the operating procedure for the aforementioned “reflow operation” involves pushing the lacquer remaining in the common color line back into the corresponding color supply line via the docking point of the color changer and reusing it later.

[0052] The invention described here is particularly suitable for the application of 2K lacquers, whereby the necessary additional components such as two metering pumps can also be accommodated in the slim arm of the painting machine.

[0053] Other advantageous embodiments of the invention are characterized in the dependent claims or are explained in more detail below together with the description of the preferred embodiments of the invention with reference to the figures. The figures show: Fig. 1 a perspective view of a painting robot according to the invention, Fig. 2 a perspective view of the distal robot arm (“Arm 2”) of the painting robot according to the invention, Fig. 3 Another perspective view of the distal robot arm, Fig. 4. A perspective view of a color bar that is part of a color changer. Fig. 5 a schematic view of the docking system in the painting robot according to the invention, Fig. 6A, Fig. 6B Schematic cross-sectional representations of different construction methods of the color strip, Fig. 7 and Fig. 8. Connecting the individual color wires to the color changer, Fig. 9A-9D different operating states of the painting robot according to the invention within the framework of the so-called “push-out operation”, Fig. 10. the “push-out operation” in the form of a flowchart, Fig. 11A-11E various operating states of the painting robot according to the invention within the framework of the so-called “reflow operation” as well as Fig. 12 the “reflow operation” in the form of a flowchart.

[0054] The Fig. Figures 1 to 8 show different views or parts of a painting robot 1 according to the invention, which is used in a painting system for painting motor vehicle bodies, wherein the painting robot 1 is suitable for painting both the outer surfaces of the motor vehicle bodies and the inner surfaces of the motor vehicle bodies, as will be described in detail below.

[0055] The painting robot 1 is largely of conventional design and has a robot base 2 which in this embodiment is permanently mounted on a machine foundation.

[0056] A robot arm 3 is rotatably mounted on the robot base 2, the robot arm being rotatable about a vertical axis of rotation relative to the robot base 2.

[0057] Another robot arm 4 is swivellingly mounted on the robot arm 3.

[0058] Finally, a distal robot arm 5 is pivotably mounted at the distal end of the robot arm 4, with the robot arm 5 guiding a rotary atomizer 7 via a conventional, e.g. three- or four-axis robot hand axis 6.

[0059] The distal robot arm 5 is shown here without a housing cover, so that it can be seen that essential parts of the application technology are mounted on the distal robot arm 5, namely a color changer 8, a color pressure regulator 9, a metering pump 10 for metering a base lacquer and a metering pump 11 for metering a hardener.

[0060] The color changer 8 has a so-called color bar 12, which is supplied with different colored lacquers via numerous color supply lines 13. Each of the individual color supply lines 13 in the color bar 12 leads via a color valve 14 to a docking point 15, from which the desired lacquer can be drawn. Space-saving color valves 14 can be advantageously provided as needle valves, preferably electrically or pneumatically actuated, with conical valve needles at their ends, as are known from conventional color changers per se (e.g., DE 198 46 073 A1, EP 1 250 964 B1, DE 10 2007 037 663 A1).

[0061] The color valves 14 can be located, for example, on one longitudinal side of the color strip 12 in one or preferably at least two in its longitudinal direction (arrow direction in Fig. 2 and Fig. 3) arranged in parallel rows, preferably obliquely with needle axes inclined in parallel planes against the longitudinal direction. The associated docking points 15 ( Fig. 4) in one or more rows parallel to the longitudinal direction, e.g. in one of the side faces of the color bar 12.

[0062] Furthermore, the color changer 8 has a docking carriage 16 which extends in the direction of the arrow (cf. Fig. 2-4) is displaceable relative to the color strip 12 in its longitudinal direction, wherein the docking carriage 16 is positioned in the direction of the arrow by, for example, a servo-pneumatic linear drive 17 in order to dock at the desired docking point 15 of the color strip 12. Alternatively, a drive with an electric motor or another linear drive of a known type can also be used.

[0063] For the precise positioning of the docking points, the linear drive is equipped with a measuring device 32 in a manner known per se ( Fig. 2) provided. Since the atomizer 7 and, in some cases, parts of the robot arm 5 may be under high voltage during operation, the measuring device 32 is insulated against the high voltage in these cases. In the case of an electrical measuring device, it may also be encapsulated to meet known explosion protection requirements. The same applies to any other electrical components that may be present in the robot arm.

[0064] The atomizer-side connection cable assembly of the docking carriage 16 can be located in a U-shaped, movable cable drag or guide chain parallel to the direction of movement, similar to an energy chain known per se in painting machines, which is fixed at one end to the docking carriage and at the other end. The atomizer-side cable assembly is connected to openings in the docking carriage 16, each of which is aligned with one of the rows of docking points 15 of the ink bar 12. Additional docking openings may be provided in the docking carriage 16 for rinsing purposes.

[0065] At the in Fig. For example, the color strip 12 shown in figures 2 to 4, representing 24 colors, assumes that the color hoses are connected as dead ends. If there is space for, for example, twice the number of color valves, one row of which can also be installed laterally, the color strip could also be designed for color recirculation.

[0066] From the Fig. 4 and Fig. 5 it can be seen that the color bar 12 between the two rows of docking points 15 runs in the direction of the arrow ( Fig. 2 and Fig. 3) has a groove 18 extending along its upper surface, with an undercut. In the assembled state, a gripping disc 19 slides in the groove 18 and is guided by the docking slide 16 via a pneumatic cylinder 20. The docking slide and the color bar are transversely displaceable relative to each other by means of the pneumatic cylinder 20, which serves as both a docking and clamping cylinder. An electric motor or other drive could also be provided instead of the pneumatic cylinder 20.

[0067] In the docked state, the pneumatic cylinder 20 pulls the gripping disc 19, so that the gripping disc 19 pulls the undercut of the groove 18 towards the docking slide 16, resulting in a mechanical tension between the docking slide 16 on the one hand and the color bar 12 on the other.

[0068] Firstly, this mechanical tension between the docking carriage 16 and the color bar 12 enables largely leak-free docking at the docking points 15 of the color bar 12.

[0069] Secondly, this type of mechanical tensioning between the docking carriage 16 and the color strip 12 enables docking without external force, so that no elaborate brackets or supports are required to press the docking carriage 16 against the color strip 12.

[0070] In the undocked state, the pneumatic cylinder 20 is relaxed, so that the gripping disc 19 can slide freely in the groove 18 with a clearance, so that the servopneumatic linear drive 17 can freely position the docking slide 16 in the direction of the arrow in order to dock at the desired docking point 15.

[0071] From the Fig. 4 and Fig. Figure 6A further shows that the groove 18 has an undercut only on its upper side, while the groove 18 is free of undercuts on its lower side and even has a groove flank that slopes downwards. This design of the groove 18 is advantageous because any paint that leaks out of the groove 18 can easily drain away and be removed.

[0072] Fig. Figure 6B shows an alternative design of the groove 18, in which the groove 18 is arranged on the outside of the color strip 12.

[0073] In the example shown, the docking carriage 16 can be moved relative to the color strip 12 which is fixedly mounted in the arm 5, but a reverse arrangement with a movable color strip is also conceivable.

[0074] A key advantage of the design of the color changer 8 is its extremely slim construction, which allows the distal robot arm 5 to also be very slim despite the application technology mounted on it. This is important because the distal robot arm 5 can thus be easily inserted through body openings (e.g., window openings) into the vehicle body to be painted in order to paint interior surfaces. Due to its slim design, the painting robot 1 according to the invention is therefore suitable for painting both interior and exterior surfaces. This makes it possible to use only a single type of robot for painting vehicle bodies in a single painting line, which represents a significant simplification.

[0075] Fig. 2 and Fig. Figure 3 shows a connection block 21 in which the metering pump 10 for the base paint, the paint pressure regulator 9, and associated pressure sensors 33 are integrated. This integration of the metering pump 10 and the paint pressure regulator 9 in the connection block 21 offers the advantage that hose lines and thus hose-related disturbances between the paint pressure regulator 9 and the metering pump 10 are eliminated. Furthermore, the integration of the paint pressure regulator 9 and the metering pump 10 in the connection block 21 offers the advantage of short connection lengths and a simple and compact design. Figure 21 is shown in Fig. 2 is the second connection block for the aforementioned 2K system.

[0076] The Fig. 7 and Fig. Figure 8 shows a connection design for connecting the paint supply line 13 to the paint strip 12. Each individual paint supply line has a push-in nipple 22 with a union nut 23 at its free end. The push-in nipple 22 is inserted into a corresponding receiving bore in the paint strip 12 for connection. To secure the push-in nipple 22, and thus also the associated paint supply line, in the receiving bore of the paint strip 12, the paint strip 12 also has a clamping bore that runs transversely, i.e., at right angles or obliquely, to the receiving bore and opens into it. A clamping screw 24 is screwed into this clamping bore to secure the push-in nipple 22 until the conical tip of the clamping screw 24 abuts a correspondingly conical clamping surface of the push-in nipple 22.As the clamping screw 24 is screwed in further, the clamping screw 24 then clamps the plug nipple 22 in the receiving bore, thereby fixing the plug nipple 22 and the associated paint supply line in the receiving bore.

[0077] The clamping screw 24 can, for example, be designed as a socket head cap screw or the like, so that only an Allen key or similar tool is required to connect the individual paint supply lines 13. This tool is easier to handle between the individual paint supply lines 13 than an open-end or ring wrench. The individual connections of the paint supply lines 13 on the paint strip 12 can therefore be arranged closer together, further reducing the required installation space.

[0078] The Fig. Figures 9A to 9D show various operating states of the painting robot 1 according to the invention within the framework of a so-called "push-out operation", wherein the various operating states are shown in Fig. 10 are presented in the form of a flowchart.

[0079] The following will first refer to Fig. 9A describes the normal painting operation.

[0080] In normal painting operations according to Fig. 9A the docking carriage 16 is docked to the paint bar 12 and a paint of the desired color is taken from the paint bar 12 via a paint supply line 13.1 and a paint valve F.

[0081] The paint taken from the paint strip 12 is then directed via a separating valve FGV / F into a common paint line 25, the common paint line 25 leading via the metering pump 10 to the rotary atomizer 7, which applies the supplied paint with the main needle valve HN open.

[0082] The following section will discuss the in Fig. Figure 9B explains the operating state of the painting robot.

[0083] Firstly, in this operating state, the paint located in the common paint line 25 is pushed out of the common paint line 25, which is why this operating state is also referred to as "push-out operation". In this operating state, the paint valve F1 is closed, so that the paint bar 12 does not deliver any paint to the docking carriage 16.

[0084] Instead, a rinsing agent is introduced into the common paint line 25 via a rinsing agent supply line 26 and a rinsing agent valve V / PO, whereby the rinsing agent acts as a displacement medium and forces the paint remaining in the common paint line 25 out of the common paint line 25 via the rotary atomizer 7. The paint atomized via the rotary atomizer 7 can initially still be used for painting; however, the painting operation must be stopped in time before the rinsing agent introduced via the rinsing agent supply line 26 exits the rotary atomizer 7.

[0085] In this operating state, the separating valve FGV / F is closed, thus separating the common paint line 25 from the docking point on the paint strip 12, which allows the docking point to be flushed.

[0086] For this purpose, rinsing liquid is introduced into the docking carriage 16 via a rinsing liquid supply line 27 and a rinsing liquid valve V, whereby the rinsing liquid reaches the docking points on the paint strip 12 and thus rinses it. Finally, the introduced rinsing liquid is then returned via a non-return valve RF2 and a non-return line 28.

[0087] In this embodiment, two separate rinsing circuits are provided, which enable simultaneous rinsing of the common color line 25 and the docking points.

[0088] The first rinsing circuit leads from the rinsing agent supply line 27 via the rinsing agent valve V and the valve V / PL to the docking points of the color strip 12 and finally via the non-return valve RF2 into the non-return line 28.

[0089] The second rinsing circuit, on the other hand, leads from the rinsing agent supply line 26 via the rinsing agent valve V / PO into the common paint line 25, from where the first rinsing circuit runs via the dosing pump 10 into the rotary atomizer 7 to the main needle valve HN.

[0090] In addition, pulsed air is introduced in this operating state via a check valve RV and a pulsed air valve PL to improve the flushing effect.

[0091] As shown in the flowchart in Fig. 10 (to the right of “ Fig. As shown in 9B “), the docking interface is not rinsed before or after the line leading through the atomizer, but in parallel to it, i.e. at the same time, in order to avoid operational delays.

[0092] The following section will discuss the in Fig. The operating state shown in section 9C is explained.

[0093] Firstly, in this operating state, the docking carriage 16 docks to a different docking point on the color bar 12 to extract a different colored paint. For this purpose, the docking carriage 16 is moved relative to the color bar 12 in the direction of the arrow by the servo-pneumatic linear drive 17, whereby the docking carriage 16 docks to the docking point of a paint valve F2 in the drawing, which is supplied with paint of a specific color via a paint supply line 13.2.

[0094] Secondly, in this operating state, the rotary atomizer 7 and the metering pump 10 are rinsed. For this purpose, rinsing fluid is introduced via the rinsing fluid supply line 27 and the rinsing fluid valve V, which enters the common paint line 25 via an open valve V1 / PL. From there, the introduced rinsing fluid reaches the rotary atomizer 7 and is then returned via the main needle valve HN and a non-return valve RF1 located in the rotary atomizer 7 and a non-return line 29.

[0095] In addition, pulsed air is introduced in this operating state via the check valve RV and the pulsed air valve PL to improve the flushing effect.

[0096] The following section will discuss the in Fig. Figure 9D illustrates the operating state of the painting robot 1, in which the new paint is applied. Here, the desired paint from the paint supply line 13.2 reaches the rotary atomizer 7 via the open paint valve F2 and the open isolating valve FGV / F, while the main needle valve HN is initially still closed. At the end of this operating state, the rotary atomizer 7 is then able to apply the new paint.

[0097] The Fig. 11A to 11E indicate different operating states in a modified embodiment of the painting robot, which enables a so-called "reflow operation", in which the paint remaining in the common paint line 25 during a color change is pushed back into the associated paint supply line 13.1 or 13.2 to enable reuse.

[0098] The following section will first describe the operating status according to Fig. Figure 11A explains the process, which involves normal painting operations. In this operating state, paint flows via the paint supply line 13.1, the paint valve F1, the isolating valve FGV / F and the common paint line 25 to the rotary atomizer 7, which applies the supplied paint when the main needle valve HN is open.

[0099] The following section will discuss the in Fig. The operating state shown in Figure 11B is explained, in which, during a color change, the paint located in the common color line 25 between the color changer 8 and the rotary atomizer 7 is pushed back into the associated color supply line 13.1.

[0100] For this purpose, a detergent dispenser 30 is used, which can be filled with detergent via a detergent supply line 31 and a detergent valve AV2 / V on the inlet side. The meaning of "dispenser" here was explained above.

[0101] On the output side, the detergent dispenser 30 is connected via a detergent valve AV1 / V in the rotary atomizer 7 upstream of the main needle valve HN to the common paint line 25.

[0102] In the so-called "reflow operation", the detergent dispenser 30 pushes the detergent contained therein via the detergent valve AV1 / V into the common paint line 25, whereby the introduced detergent serves as a displacement medium and pushes the paint located in the common paint line 25 back into the associated paint supply line 13.1 via the separating valve FGV / F and the paint valve F1, which enables subsequent reuse of the pushed-back paint.

[0103] The following section will discuss the in Fig. Figure 11C explains the operating condition in which the metering pump 10 and the rotary atomizer 7 are rinsed.

[0104] For this purpose, rinsing agent is introduced from the rinsing agent supply line 27 via the rinsing agent valve V and the valve V1 / PL into the common paint line 25, whereby the rinsing agent passes through the main needle valve HN of the rotary atomizer 7 and the non-return valve RF1 into the return line 29. In addition, pulsed air is introduced in this operating state via the check valve RV and the pulse air valve PL to improve the rinsing effect.

[0105] The following section will discuss the in Fig. Figure 11D explains the operating condition in which the docking carriage 16 is flushed up to the docking points on the paint strip 12.

[0106] For this purpose, detergent is introduced from the detergent supply line 27 via the detergent valve V and the valve V / PL, reaching the docking points of the paint strip 12 and thus rinsing it. The introduced detergent is then directed via the non-return valve RF2 into the return line 28.

[0107] In addition, pulsed air is also introduced during the rinsing of the docking slide 16 via the check valve RF and the pulse air valve PL to improve the rinsing effect.

[0108] The following section will discuss the in Fig. The operating state shown in section 11E is explained.

[0109] Firstly, in this operating state, the docking carriage 16 docks at a different docking point on the paint bar 12 in order to take off a paint of a different color.

[0110] Secondly, in this operating state, the new paint is primed. The paint flows from the paint supply line 13.2 via the paint valve F2 and the isolating valve FGV / F to the rotary atomizer 7, where the new paint is then present at the initially closed main needle valve HN. After this primer application, the rotary atomizer 7 can then apply the new paint.

[0111] One particular aspect is the use of a painting robot for the interior painting of car bodies. This robot is mounted in a known elevated position, as mentioned above, and is designed and mounted in such a way that the pivot axis of its distal arm ("axis 3") can be located vertically below the pivot axis of the upper arm ("axis 2"), designated as "arm 1," during painting (known as "elbow down"). In this position, the distal arm can be inserted into the interior of the car body more easily than with the previously common position of "axis 3" vertically above "axis 2," at least approximately horizontally. This avoids the risk of collisions, even when installing or mounting bulky application equipment, including color changers and, if necessary, metering pumps, paint pressure regulators, etc., on or in the distal arm.For painting other, especially outer, surfaces of the car body, the robot arms can also be swivelled into the reverse position, where "axis 3" is located above "axis 2".

Claims

[1] Coating plant with a) a program-controlled painting robot (1) for painting motor vehicle bodies with exterior surfaces to be painted on the outside of the motor vehicle bodies and interior surfaces to be painted inside the motor vehicle bodies by means of an application device (7) guided by the painting robot (1), b) wherein the painting robot (1) b1) has a swiveling upper arm (4) and a distal robot arm (5) swiveling at its end, which guides the application device (7) via a robot hand axis (6), and b2) is suitable for painting both the exterior and interior surfaces of motor vehicle bodies, and b3) is able to insert the application device (7) into the engine and trunk compartments of the body with the doors and hoods installed, i.e., in the way, and through door openings into the interior of the body to a sufficient extent for painting the interior, and b4) has a robot base (2) which is permanently mounted on a machine foundation, characterized by , c) that the pivot axis of the distal robot arm (5) of the painting robot (1) is located below the pivot axis of the upper arm (4) of the painting robot (1) adjacent to the distal robot arm (5) when painting at least one interior space, and d) that the distal robot arm (5) inserted into the at least one interior space is in a horizontal position during the painting of the interior space. [2] Coating system according to claim 1, characterized bya color changer (8) for selecting a paint from several different colored paints, wherein the color changer (8) is mounted on the distal robot arm (5) and has the following features: a) on the input side several color supply lines (13, 13.1, 13.2) for supplying different colored lacquers, b) on the output side a common color line (25) for conveying the paint selected by the color changer (8) to the application device (7), c) several docking points (15) which are supplied by the individual color supply lines (13, 13.1, 13.2), and d) a paint extraction unit (16) which can optionally dock to one of the docking points (15) and, when docked, extracts the paint from the associated paint supply line (13, 13.1, 13.2) and feeds the common paint line (25) with the extracted paint, e) wherein the color extraction point (16) and the docking points (15) are movable relative to each other. [3] Coating system according to claim 2, characterized by , a) that in each of the individual color supply lines (13, 13.1, 13.2) of the color changer (8) a color valve or other color control device (F1, F2,..., Fn) is arranged which selectively blocks or enables the color supply line (13, 13.1, 13.2), b) that the color control devices (F1, F2,..., Fn) are each controlled by a control signal, and c) that the control signal is routed from the color pickup (16) via the respective docked docking point to the respective color control unit (F1, F2,..., Fn), so that the control signal can only reach one of the color control units (F1, F2,..., Fn) if the color pickup (16) is docked to the corresponding docking point. [4] Coating system according to claim 2 or 3, characterized by a) a first rinsing circuit for rinsing the docking points (15) of the color changer (8) with a rinsing agent, and b) a second rinsing circuit for rinsing the common color line (25) between the color changer (8) and the application device (7) with a rinsing agent, wherein the first rinsing circuit is separate or separable from the second rinsing circuit so that the docking points (15) can be rinsed independently and separately from the common color line (25). [5] Coating system according to one of claims 2 to 4, characterized by the painting robot (1) with a) a color pressure regulator (9) mounted in or on the distal robot arm (5), and / or b) a metering pump (10) mounted in or on the distal robot arm (5) for metering the paint to be applied, wherein the metering pump (10) is connected on the inlet side to the paint changer (8) and on the outlet side to the application device (7), and / or c) an actuator (17) for moving the ink removal (16) relative to the docking points (15), wherein the actuator (17) is arranged in the distal robot arm (5). [6] Coating system according to claim 5, characterized by a common connection block (21) of the painting robot (1) in which the paint pressure regulator (9) and / or the actuator (17) and / or the metering pump (10) are arranged. [7] Coating system according to one of the preceding claims, characterized by , that the upper arm (4) of the painting robot (1) is pivotably mounted on another robot arm (3), which in turn is rotatably mounted on the robot base (2), wherein the robot arm (3) is rotatable about a vertical axis of rotation relative to the robot base (2).

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