JP2012135758A - Device and method for coating object with medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve a device and a method for coating an object with a medium.SOLUTION: The device has a flowing out opening part, a medium flows out from there, thereafter the medium is sprayed as a spray beam having a main beam direction and a beam profile. The beam profile of the spray beam can be formed by a pair of fixedly arranged beam forming unit, facing in a radial direction to the flowing out opening part, directing forming liquid to the spray beam via at least one forming liquid opening part. At least other one pair of beam forming unit facing in a radial direction are arranged in another angle position relating to the axis of the flowing out opening part to change angular orientation of the beam profile around a main moving direction of the spray beam while maintaining precision needed for automated coating, the beam forming unit can be driven independently from the first pair of beam forming units.

Description

The present invention
a) an outflow opening through which the medium flows out, said outflow opening after which the medium is sprayed as a spray beam with a main moving direction and a beam profile;
b) A pair of fixedly arranged beam shaping units diametrically with respect to the outflow opening, the beam shaping unit passing the shaping fluid to the spray beam via at least one shaping fluid opening. And a pair of beam shaping units, by which the beam profile of the spray beam can be shaped.

  The invention further relates to a method of coating an object, in which an apparatus of the kind described above is used.

  The beam profile is the profile that the spray beam forms in the cross section perpendicular to its main direction of movement, in which case the distance from the outflow opening approximately corresponds to the working interval of the device for the object to be coated. The beam profile is adjusted.

  This type of device is used in the form of a spray pistol to automatically coat the vehicle body or vehicle part, especially in the automotive industry. For this purpose, the spray pistol is attached to the arm of a painting automatic machine or a painting robot, which guides the spray pistol according to a predetermined movement pattern above the surface of the object to be painted.

  A spray pistol of the type mentioned at the beginning, known in the market, has two beam-shaping units that are diametrically opposed with respect to the outlet opening of the spray pistol, from the opening to the spray beam from both sides. Directed compressed air, so-called molding air, can flow out. Thereby, the spray beam can be shaped into a flat shaped flat beam having a substantially strip shaped beam profile. This type of flat beam allows the paint to be applied one after another on a relatively large area, such as the roof of a vehicle body, thereby obtaining an optimum paint distribution.

  In order to optimally paint objects of various geometries, in these known spray pistols and painting methods, according to the painting phase, respectively, by turning on and off the diametrically opposite beam-shaping units simultaneously, a rotationally symmetric It is possible to switch between a spray beam and a flat flat beam. However, unlike a rotationally symmetric spray beam, the beam profile of the flat beam has a priority direction. For example, when coating in a strip shape, the main beam movement direction is additionally centered. The angular direction of the spray pistol must be rotated and adapted with respect to the band direction. In particular, it is often necessary to redirect the flat beam when changing from one workpiece side to the other.

  This redirection of the beam profile can in principle be achieved by other link axes or rotation axes provided at the front end of the robot arm, but it is generally larger. Will lead to more complex painting robots. Thus, so far, the beam profile of the flat beam has been moved in the other angular direction by performing complex and extensive torsional movements using the existing joints and axes of rotation of the painting robot.

  The disadvantage of this method is that the complex twisting of the painting robot to reorient the beam profile requires time, which appears in a way that cannot be ignored in the entire painting time of the vehicle body. In addition, complicated robot motions twist the electrical connection with the supply hose, so to prevent the hose from twisting completely, follow each twist motion at some point and follow the reverse twist motion. I have to let it. Since the hose is also subjected to a stronger load due to twisting, it is necessary to increase wear and accordingly increase maintenance work.

  Patent Document 1 shows a manually operated color spray pistol, in which two beam forming units that are diametrically opposed are arranged in an air cap. By rotating the air cap with respect to the blocking plate located behind it, the beam shaping unit can be rotated 90 ° about the outflow opening, which properly orients the beam profile. Bring to rework. In the intermediate position of the air cap, the supply to the beam shaping unit is blocked, thereby forming a rotationally symmetric beam profile.

  However, this type of approach is not well suited for automatic painting using a painting robot. This is because the part that adjusts the beam shaping is moved, which can lead to inaccuracies in the beam shaping. However, it is important that the emitted spray beam always has a precisely defined beam profile in order to optimally paint during the programmed coating process. Therefore, for automated painting, a spray pistol with a beam forming unit formed with high precision is used, which is fixedly arranged with respect to the pistol body and the outflow opening.

German Patent Publication No. 692227907

  Therefore, the problem of the present invention is that the angle orientation of the beam profile can be changed around the main direction of movement of the spray beam while maintaining the accuracy required for automated painting. An apparatus and method is provided.

  This object is related to the device, according to the invention, in which at least another pair of diametrically opposed beamforming units are provided at other angular positions with respect to the axis of the outflow opening. This is solved by a device of the kind mentioned at the outset, which can be driven independently of the first pair of beam shaping units.

  According to the present invention, at least another pair of diametrically opposed beam shaping units are independently driven, despite the arrangement of the beam shaping unit being fixed with respect to the outflow opening or pistol body, The angular direction of the beam profile can be changed.

  When four beam-shaping units are used, two diametrically opposed pairs are preferably arranged in a cross, ie 90 ° displaced. Thereby, for example, an initially rotationally symmetric spray beam can be shaped into a flat beam in the first direction by supplying shaping fluid to two opposing beam shaping units. By turning off the two first beam-shaping units and turning on the other two beam-shaping units, the rotationally symmetric spray beam is then moved in a second direction perpendicular to the first direction. Can be formed into a flat beam.

  As coating medium, any substance that wets or covers the surface can be used, such as various paints of various functions, such as protective paints, color paints, wet paints or powder paints. However, the medium to be applied may be a liquid wax, plastic or adhesive that must be applied on the object as a protective or functional layer.

  Compressed air is often used as the forming fluid. However, for special use purposes, other fluids, such as inert gases such as nitrogen, are also considered as forming fluids.

  According to the development of claim 2, a large number of beam shaping units are provided, in particular at least four pairs.

  Multiple beam shaping units allow the beam profile orientation to be changed in fine steps. In that case, roughly an even number of beam-shaping units, such as 8, 12, 16 or 24, is selected, in which case the beam-shaping units are arranged in pairs and diametrically opposed. However, an odd number of beam shaping units can also be provided. Alternatively, some molding units can exist without pairing. Preferably, the beam shaping unit can be arranged on a circular track coaxial with the outflow opening about the outflow opening. Furthermore, when the shaping fluid openings of the individual beam shaping units are formed identically, the beam shaping unit acts symmetrically on the spray beam, which simplifies driving.

  According to the development of claim 3, the beam shaping units can be driven independently of one another at least in groups, in particular in pairs.

  By driving in groups, it is possible to switch between different beam profiles or beam profile angular directions. In particular, the diametrically opposed pairs with respect to the outflow opening can be driven independently of the other pairs, so that the flat beam can be rotated by switching between the various pairs. However, it is also possible to connect the beam shaping units together in a suitable group having three symmetry, for example to shape a triangular beam profile.

  According to the development of claim 4, all the beam shaping units can be driven individually.

  This gives as much freedom as possible when selecting the beam profile. For example, a semi-circular beam profile can be formed.

  According to the development of claim 5, the beam shaping unit is associated with a controllable shut-off valve for the shaping fluid.

  A shut-off valve that can interrupt the shaping fluid supply to the beam shaping unit in groups, in pairs or individually allows the beam shaping unit to be driven at least partially independently, respectively Depending on the state of the shut-off valve, the beam profile can be changed.

  According to the development of claim 6, a distribution member having a distribution passage for the forming fluid is provided.

  The distribution member allows multiple beam-shaping units to be connected to individual shut-off valves for driving in groups or in pairs, so that a slight shut-off is provided to supply the shaping fluid to the beam-shaping units. Only a valve is needed. For this purpose, the various distribution passages can be connected to different shut-off valves on the inflow side. Preferably, the distribution member is arranged in the vicinity of the shaping fluid opening, so that the branching to the individual beam shaping units takes place only at the end of the entire shaping fluid supply path.

  According to the development of claim 7, a controllable regulating valve with a valve slider is provided for the forming fluid.

  The controllable control valve has a valve slider with which various routes through the valve can be selected. That is, each other beam shaping unit or group of beam shaping units can be selectively connected with one or more supply passages of shaping fluid so that it switches between different configurations of the shaping fluid that flows out. There is no need to provide a shut-off valve for each shaping unit or group of beam shaping units. This maintains the existing shaping fluid supply system with little change and allows switching between the various beam shaping units using a regulating valve for the shaping fluid.

  According to a development as claimed in claim 8, the valve slider has a distribution passage to the beam shaping unit, which distribution passage is selectively connected to differently arranged inflow and / or outflow passages. Is possible.

  Various switching states of the control valve are realized by this kind of distribution passage provided in the valve slider. The valve slider can also have a plurality of distribution passages, which can be connected simultaneously or alternately with suitable inflow and / or outflow passages that are fixedly arranged.

  According to the development of claim 9, the valve slider has a ring shape and is rotatable.

  In the apparatus according to the present invention, a valve slider having a distribution passage is particularly effective, and the distribution passage can be selectively connected to various beam shaping units and shaping fluid supply passages by rotation of the valve slider. This enables the integration of the regulating valve into the device and the concomitant compact and reliable structure.

  According to a tenth aspect of the present invention, a drive device for driving the distribution valve is provided.

  This type of drive allows an automated switching of the beam shaping unit supplied with shaping fluid. The drive, which can be done for example via pneumatic, piezoelectric or electric motors, can be integrated into the program sequence of the painting robot, for example if a flat beam rotation is required, drive accordingly Can do. In the ring-shaped valve slider, an internal gear is provided, and the drive pinion of the electric motor meshes with it.

  According to the development of claim 11, a proportional valve is provided for at least one independently driveable beam shaping unit.

  Via the proportional valve, the amount of shaping fluid applied to the beam shaping unit can be controlled. That is, for example, when a pair of beam forming units is opposed to each other in the diametrical direction, it is possible to control how strongly the beam profile is deformed into a flat beam by appropriately squeezing. In particular, the beam profile can be fed with different strengths using proportional valves of various beam shaping units. Where a proportional valve is used, the proportional valve can be provided in addition to or instead of the shut-off valve.

  According to the development of claim 12, the beam shaping unit has a plurality of shaping fluid openings.

  A plurality of shaping fluid openings provided in the beam shaping unit, which can have different sizes or different contact angles with respect to the spray beam, are generated from the beam shaping unit and directed along the spray beam. It makes it possible to define the whole flow accurately. The shaping fluid openings belonging to one beam shaping unit are always supplied with shaping fluid in common and direct it towards the spray beam from substantially the same direction.

  As regards the method, the problem is solved according to the invention by using an apparatus according to any one of the above claims.

  According to the development of claim 14, the device is fixed to the painting robot and the beam profile is changed by switching between the various beam shaping units, in particular its angular direction around the main movement direction is changed. .

  This method has the advantage that only a small movement of the painting robot is required to rotate the beam profile. The reachability of certain areas of the body, such as joint areas, tank recesses or air inlets, can also be improved. In particular, a triangular beam profile can be effective in a given recess. The beam profile can therefore be adapted to the surface area to be coated, so that overspray is significantly reduced.

  Hereinafter, the present invention will be described in detail using embodiments with reference to the drawings.

It is a conceptual diagram which shows the termination | terminus part of the painting robot arm provided with the spray pistol based on this invention which has an air cap provided with four beam shaping units. It is a perspective view which shows the air cap based on a 1st Example. It is an axial sectional view showing an air cap based on FIG. It is a perspective view which shows the air cap based on a 2nd Example. It is an axial sectional view showing the air cap of FIG. FIG. 5 is an axial sectional view showing the air cap of FIG. 4 and a distribution member continuous therewith. It is sectional drawing which shows the distribution member of FIG. 6 along the VII-VII line there. It is a circuit diagram of the shaping fluid supply system which supplies shaping fluid to a beam shaping unit. It is an axial sectional view showing the head part of the spray pistol of the 2nd example, and a control valve which can be controlled is provided instead of a simple distribution member in that case. FIG. 10A shows the regulating valve of FIG. 9 in a first position according to line XX with a ring-shaped valve slider. FIG. 10B shows the regulating valve of FIG. 9 in a second position according to line XX with a ring-shaped valve slider.

  FIG. 1 shows a spray pistol 10 that is fixed to the tool housing 12 of a painting robot arm 14 shown partially.

  The spray pistol 10 has a pistol body 16 and a replaceable air cap 18 is disposed on the outlet side thereof.

  An air cap 18 of this kind according to the first embodiment is shown in FIGS.

  The disc-shaped air cap 18, whose end face 20 on the outlet side faces upward in FIG. 2 and whose rear side 22 faces downward in FIG. 2, is fringed at the center of the end face 20 by a truncated cone-shaped recess. From which the medium provided for the coating can flow out. For this purpose, the outflow opening 24 is connected to an axial medium supply passage 26 (see FIG. 3), which leads to the rear side 22 of the air cap 18 and is generally ( In this case, the vehicle body or a part thereof can be coated with the medium.

  As is clear from the cross section of FIG. 3, the outflow opening 24 is surrounded by an oblique surface 28 that rises obliquely outward in the radial direction, and is uniformly distributed over the peripheral surface within the oblique surface. Ten spray fluid openings 30 are arranged. The atomizing fluid opening 30 is similarly supplied with atomizing fluid (generally compressed air) via an atomizing fluid passage 32 leading to the rear side 22 of the air cap 18. Thereby, while driving the spray pistol 10, compressed air can flow out of the atomizing fluid opening 30, and the compressed air flows to the area in front of the outflow opening 24 based on the oblique bevel surface 28. Directed, resulting in, or at least assisting in, spraying of the flowing medium there.

  Four beam forming units 34 are provided on the end face 20 of the air cap 18 so as to be located further outward in the radial direction, and each of them has an angle protruding to the outflow side (upward in FIGS. 2 and 3). Such a protrusion 36 is formed. Since the beam shaping units 34 are uniformly distributed in the circumferential direction around the outflow opening 24, they are arranged in a cross at an angle of 90 ° with respect to each other and are therefore paired with respect to the outflow opening 24. It is opposed to the diameter direction.

  Each protrusion 36 has a slope 38 that faces radially inward, and the slope rises obliquely toward the outside.

  The slope 38 of each protrusion 36 has two shaping fluid openings 40 and 42, respectively, which are connected to the corresponding shaping fluid passages 44 and 46. The shaping fluid passages 44, 46 likewise end on the rear side 22 of the air cap 18. The shaping fluid openings 40, 42 to which the shaping medium (generally compressed air) is supplied during the drive of the spray pistol 10 due to the inclination of the bevel 38 faces the direction of the spray beam formed above the outlet opening 22 , Thereby forming a spray beam.

  4 and 5 show an air cap 118 according to a second embodiment, which is distinguished from the air cap 18 of the previous embodiment by the fact that the beam shaping unit 134 is not formed as a protrusion. .

  Instead, the shaping fluid openings 140, 142 of each beam shaping unit 134 are located directly on the flat end face 120 of the air cap 118. Nevertheless, the shaping fluid passages 144, 146 leading to the shaping fluid openings 140, 142 are directed to the end face 120 of the air cap 118 to direct the flowing shaping fluid to the spray beam in front of the outflow opening 124. At least immediately before flowing out, extends radially outward and rearward in the radial direction inward and forward with respect to the main movement direction of the spray beam.

  As shown in FIG. 6 by way of example of an air cap 118 without a protrusion 136, the spray pistol has a disc-shaped distribution member 150 for forming fluid, which includes a front side 152 and a rear side 154. have. The distribution member 150 is disposed behind the air cap 118 so that the front side 152 of the distribution member 150 directly contacts the rear side 122 of the air cap 118.

  The distribution member 150 itself has an axial through hole 156 in the center, and the through hole is aligned with the medium supply passage 126 of the air cap 118 and is used for supplying the medium.

  Further, the distribution member 150 has a circular annular passage 158 coaxially with the through hole 156 as a center on the front side 152 thereof, and the annular passage opens toward the air cap 118. The diameter of the annular passage 158 is selected to match the atomizing fluid passage 132 of the air cap 118 so that the atomizing fluid passage can be fed from the annular passage 158. A supply hole 160 communicates with the annular passage 158 from the rear side 154 of the distribution member 150.

  In order to distribute the shaping fluid to the individual beam shaping units 134, the distribution member 150 has four recesses 162 on its front side 152, which are arranged according to the four beam shaping units 134, and Each has a diameter that is sized to connect with two shaping fluid passages 144 and 146, respectively, leading to the shaping fluid openings 140, 142.

  Two recesses 162 associated with a pair of diametrically opposed beam shaping units 134 are connected via connection passages 164 and 166, respectively. For ease of formation, the connecting passages 164, 166 are guided from the front side 152 so as to be covered by a closed area on the rear side 122 of the air cap 118.

  Each of the pair of recesses 162 is connected to the rear side 154 of the distribution member 150 through the supply hole 168.

  As shown in FIG. 8 for the embodiment of FIGS. 4-7, the supply holes 168 of the distribution member 150 are connected to a forming fluid supply system, generally designated 170 in FIG.

  The forming fluid supply system 170 has first and second proportional valves 172 and 173, and the connection ends on the inlet side thereof are connected to a compressed air source (not shown).

  On the outlet side, the first proportional valve 172 is connected to the first cutoff valve 174, and the second proportional valve 173 is connected to the second cutoff valve 176. The outlet side of the first shut-off valve 174 is connected to the supply hole 168 of the first pair of beam shaping units 134. On the other hand, the second shut-off valve 176 is connected to the second pair of supply holes 168 displaced by 90 °.

  The spray pistol functions as follows:

  The medium supplied through the medium passage 126 is sprayed in the outflow opening 124 by the spray fluid flowing out in the spray fluid opening 130 to form a spray beam in front of the outflow opening 124.

  While the two shut-off valves 174 and 176 are closed, the spray beam is formed unrotarily symmetrically and can be used for coating.

  For example, a flat beam having a strip-shaped beam profile is desired in a special coating phase for painting a relatively large surface in a strip, and thus, for example, the first shut-off valve 174 is driven to open. Therefore, the forming fluid can flow out from the forming fluid openings 140 and 142 provided in the two beam forming units 134 opposed to each other in the diametrical direction of the first pair. A forming fluid that abuts the spray beam diagonally from the opposite side compresses the spray beam, resulting in a flat beam. In that case, the degree of flattening can be determined by the first proportional valve 172. The wider the proportional valve 172 is opened, the flatter the spray beam profile.

  In the course of the painting process, the first shut-off valve 174 is closed to face the second pair of diametrical directions when another angular orientation of the flat beam around the main travel direction is required. The second shut-off valve 176 connected to the beam shaping unit 134 is opened. Since both pairs are at a 90 ° angle to each other, the flat beam is “turned” by 90 °. That is, the orientation of the flat beam can be changed, for example, from vertical to horizontal, and the robot arm 14 does not have to perform a complicated twisting motion. The degree of flattening can also be adjusted in this orientation via the second proportional valve 173, whereby multiple beam profile shapes can be adjusted via control of the proportional valves 172, 173.

  A preferred variant of forming fluid supply is shown in FIGS. 9, 10A and 10B.

  Instead of using a non-switchable dispensing member 150 in combination with individual switching valves 174 and 176 that are opened and closed accordingly, a controllable regulating valve 278 can be used.

  The control valve 278 has a disc-shaped valve seat 280 that, like the distribution member 150, has a central through hole 256 for feeding to the outflow opening 224 or the spray fluid opening 230. And an annular passage 258.

  However, unlike the distribution member 150, the valve seat 280 has a sink 282 that wraps around in a ring shape from its front side 252, and a complementary ring-shaped valve slider 284 extends rotatably therein. .

  The valve slider 284 has a through hole 286 corresponding to the concave portion 168 of the distribution member 150, and the through holes are formed so as to be supplied to the forming fluid passages 244 and 246 of the forming unit 234, respectively. Yes. However, the valve slider 284 has only two through-holes 286 of this type, which are arranged diametrically opposed and extend in an arc along the valve slider 284. Connected only through.

  The valve slider 284 further has an internal gear 290 at its inner edge, and the driven pinion 292 of the electric motor 294 is fitted into the internal gear. Accordingly, by driving the electric motor, the valve slider 284 can be rotated along the sink 282 that makes a round.

  Displaced by 90 ° with respect to the central through hole 256, the valve seat 280 is provided with a first supply hole 296 and a second supply hole 298, which connect the sink 282 with the rear side 264 of the valve seat 280. . Therefore, the supply holes 296 and 298 are connected to a shutoff valve or a proportional valve of the forming fluid supply system.

  In the first position, the two through holes 286 of the valve slider 284 are connected to the first supply holes 296 so that the supplied shaping fluid is guided to the corresponding diametrically opposed beam shaping unit 234. can do.

  When the valve slider 284 is rotated 90 °, one of the two through holes 286 is connected to the second supply hole 298 to supply the shaping fluid to the other pair of beam shaping units.

  In the intermediate position, the valve slider 284 can completely block the shaping fluid supply so that the spray beam generated from the spray pistol has a rotationally symmetric beam profile. Thus, separate shut-off valves can be omitted if both pairs of beam shaping units 234 are to be used alternately.

  In a particularly preferred variant, not shown, a number of beam-shaping units can be provided, which go around the outflow opening and have appropriate shut-off valves, proportional valves and / or regulating valves. The molding fluids can be supplied independently of each other. That is, for example, the angular orientation of the beam profile can be changed in fine steps around the main moving direction. By using a proportional valve, different amounts of shaping fluid can be supplied to different beam shaping units, which allows for various forms of beam profiles.

  In another variant, instead of a plurality of atomizing fluid openings 30 centered on the outflow openings 24 for the medium, one atomizing fluid opening that circulates in an annular shape can be provided.

Claims (14)

a) an outlet opening (24; 124; 224) through which the medium flows out, said medium being subsequently sprayed as a spray beam having a main moving direction and a beam profile;
b) A pair of fixedly arranged beam shaping units (34; 134; 234) diametrically opposed with respect to the outflow opening (24; 124; 224), wherein said beam shaping unit is at least one Said beam shaping unit that directs the shaping fluid to the spray beam through two shaping fluid openings (40, 42; 140, 142; 240, 242), thereby shaping the beam profile of the spray beam;
In an apparatus (10) for coating an object with a medium having
c) At least another pair of diametrically opposed beam shaping units (23; 134; 234) are provided at different angular positions with respect to the axis of the outflow opening (24; 124; 224), the beam An apparatus for coating an object with a medium, characterized in that the shaping unit (34; 134; 234) is drivable independently of the first pair of beam shaping units (34; 134; 234).   Device according to claim 1, characterized in that a large number, in particular at least four pairs, of beam shaping units (34; 134; 234) are provided.   Device according to claim 1 or 2, characterized in that the beam shaping units (34; 134; 234) can be driven independently of one another at least in groups, in particular in pairs.   4. The device according to claim 1, wherein all the beam shaping units (34) can be driven individually.   5. The device according to claim 1, wherein a controllable shut-off valve (174, 176) is associated with the beam shaping unit (134).   6. A device according to any one of the preceding claims, characterized in that a distribution member (150) is provided having a distribution passage (164, 166) for the forming fluid.   7. A device according to any one of the preceding claims, characterized in that a controllable regulating valve (278) for the forming fluid is provided having a valve slider (284).   The valve slider (284) has a distribution passage (286, 288) to the beam shaping unit (234), said distribution passage being selectively arranged differently in and / or outflow passages ( 296, 298, 244, 246).   9. Device according to claim 7 or 8, characterized in that the valve slider (284) is ring-shaped and rotatable.   10. A device according to any one of the preceding claims, characterized in that a drive device (290, 292, 294) for driving the regulating valve (278) is provided.   11. Proportional valve (172, 173) for shaping fluid is provided for at least one independently driveable beam shaping unit (134). The device according to item.   12. The beam shaping unit (34; 134; 234) has a plurality of shaping fluid openings (40, 42; 140, 142; 240, 242). The apparatus according to item 1.   A method for coating an object, wherein an apparatus (10) according to any one of the preceding claims is used.   The device (10) is fixed to the painting robot (14) and the beam profile is changed by switching between the various beam shaping units (34), in particular its angular orientation about the main movement direction. 14. The method of claim 13, wherein the method is varied.

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