DE19500872A1 - Powder spray coating installation with spray cabin - Google Patents

Abstract

The cabin is bounded at the top by a roof (12,2) with underside face, laterally by the inner wall surface (40), and below by an excess powder collector (34). The cabin roof, or at least its outer peripheral edge, is in the form of a lifted body, lowerable along the vertical cabin inner wall approximately down to the excess powder collector, and hoistable into its starting position. There is at least one hoist (134) for the lifted roof body which comprises cleaning members (156.1-156.6) for cleaning the opposite cabin inner wall faces during its vertical movement.

Description

The invention relates to a Spray coating apparatus according to claim 1.

The spray coating device according to the invention for spray coating objects with Coating powder is particularly suitable for  automatic spray coating operation, however also for coating with hand spray guns be used.

Known spray coating device booths have essentially one in the horizontal cross section rectangular form. With elongated cabins are at the narrow end faces openings or doors or doors with openings for the transport of the objects through the Cabin by means of a transport device, usually a overhead conveyor. In the Longitudinal walls are openings or vertical slots for Introduction of hand spray guns or Automatic spray guns provided in the cabin, with which in the longitudinal direction of the cabin in the middle of the cabin transported by means of the transport device Objects are coated. From EP-B1-0 200 681 a completely plastic cabin known whose length is greater than their width and the bottom of which has the shape of a wedge-shaped channel. In a groove is formed at the tip of the gutter, which is wedge-shaped from one channel end to the other channel end expanded and under which there is a channel, the narrow slot end to a suction device for Suction of air and powder particles connected is. All longitudinal and vertical inner ones Cabin corners are rounded. There is a similar cabin known from the older CM-B-560 558, whose walls and Double-walled roof and on the inside with  Openings are provided so that the spaces between the walls Compressed air supplied into the cabin and powder flow can blow off from the inner cabin surface. Cabins Made entirely of plastic and suitable Plastic materials are from AT-B-340 021 known. All cabins are used in particular for electrostatic powder spray coating, in which that sprayed from a hand or automatic gun Powder is electrostatically charged to prevent it from electrostatically attracted to the object to be coated becomes. The powder layer on the objects is not in the cabin, but then in one Melting furnace melted onto the object and thus permanently connected to the object.

From CH-B-577 346 is a so-called omega cabin known with a circular shape in horizontal cross-section, in the radial center of which a vertically movable, rotating atomizer disc powder towards Spraying cabin wall. The objects to be coated seen in top view, are in the form of the Greek Letter Omega between the cabin wall and Atomizer disk transported through the cabin. A Omega cabin with angular shape and spray guns is out known from DE-A-41 31 287.

That sprayed in the known cabins, not on Powder adhering to the object mostly falls on the Cabin floor, while a small proportion of the Cabin walls are liable. This does not adhere to the object Excess powder can be extracted from the cabin floor  by means of powder separation, in particular cyclone and / or Filter elements, separated from the suction air flow, then sieved and then mixed with fresh powder be fed to the sprayer before and is sprayed again. When changing colors (change from one type of powder to another type of powder) not only all of the interior of the cabin, but also the cyclones and filter devices as well as the Powder lines are cleaned extremely precisely so no powder particles of the powder used first be mixed with the powder used afterwards. Already individual powder particles can cause coating defects lead on the object which is the coating to make something useless. Just think of the change from a black or red powder on white powder or the other way around. The objects to be coated can Household appliances or car bodies, the Buyers do not tolerate color errors. The recovery of the Excess powder reduces manufacturing costs, However, the problem that remains with a change of color a lot of time and / or additional Plant parts (for example interchangeable Powder separators, sieves, fluid lines) are required to prevent long plant downtimes to avoid. From this it can be seen that at Multicolor coatings and then when objects with different colors are to be coated, the called spray coating company with recovery of the excess powder becomes unprofitable and on loss must be driven. "Driving for Loss" means that the excess powder is not processed and  reused, but thrown away as waste. Cleaning is all the more difficult and time consuming, ever more the powder itself in the cabin and the other Parts can deposit. For this reason, instead of metal cabins plastic cabins used since on them the powder particles less strong and in stick less than in metal cabins. The Powder particles mostly consist of plastic, can but also made of ceramic or another material consist.

The object of the invention is to solve the problem required for a color change or powder change Time expenditure and / or expenditure on additional Plant parts to be reduced further, without a good one To have to do without coating quality. Through the Invention is to be achieved that a Spray coater from both Manufacturing costs as well for the Coating operation is profitable even when it is alternately for long operating periods with constant powder type and then again often changing powder types is used.

This object is achieved according to the invention by the Features of claim 1 solved.

Advantageous improvements in solving this task are contained in the subclaims.  

The invention provides a cabin, which at least in the area of your coating room, in Seen horizontal section, a circular cylindrical Has shape, with holding means for the to be coated Objects are arranged so that they are too coating object in the radial central region of the keep circular cylindrical coating space, and wherein the spray device or the Spraying devices from outside to inside in the radial Center area are directed against the object. As "Radial center area" of the coating room here the area in the cabin viewed with Regarding that in the radial center of the cabin interior vertical cabin center axis one Radius that is 75% or less than the radius, preferably equal to or less than half the Radius of the coating bounded by the cabin space is. This results in comparison to the stand the technology several major differences: with reference the circular has on the well-known square cabins cylindrical cabin has the advantage that its inner circumference area is smaller and there are no "dead corners" are. This is a much smaller cabin interior surface to clean, and cleaning is easier and lighter. The spray device or spray devices spray the powder into the radial cabin center and so far from the inner cabin surface, so that not just less excess powder on the inside Cabin area arrives, but the Impact speed of the powder particles on them Inner wall area is lower. A third advantage of  Invention is that the excess powder through Gravity automatically in the radial center area of the Cabin falls on the cabin floor, i.e. without additional funds from the inner wall surfaces of the Cabin is diverted. Only a very small percentage of the excess powder gets onto the inner wall surface the cabin and sticks there or falls next to the Inner wall surface on the cabin floor. The surplus powder can be by gravity and / or a Suction air flow fall on the cabin floor or sideways can be suctioned off and it can pass from the cabin floor Gravity and / or by a suction air flow from the Cabin are discharged. Furthermore, it is through the Invention also easily possible, the cabin in between for coating with another powder in the Use lossy operation. For lossy operation For example, the relatively small floor area of the Cabin covered and then when renewed Color change the cover element with the one in its center collected powder can be removed from the cabin.

The spray coating device according to the invention can be used in conjunction with hand spray guns and auto matik spray guns can be used. She's hiring Fast color change system. Preferred version form consists of the cabin, a cyclone separator with downstream screening machine and powder conveyor, as well as from a powder center which the spray device or spray devices be supplied with coating powder, either from special powder containers or directly from containers  (Containers in which the coating powder from Powder manufacturer is supplied to powder users).

Have particular embodiments of the invention preferably the following features: a horizontal Cross section seen from circular cylindrical cabin insulating material, preferably made of plastic; the Wall of the cabin is a double wall construction, in which is air; there are several Spray devices are provided, which in one or several vertical rows one above the other or are arranged opposite to each other in such a way that their sprays are directed towards each other; of the The cabin floor has a funnel-shaped suction device made of plastic for the promotion of excess powder from the powder recovery booth and Reuse; to minimize Powder deposits can be funnel-shaped Suction device and possibly also the cabin be vibrated by a vibrating device; at the There is a cabin floor along the cabin wall ring-shaped suction line for the loss operation, by which during the coating operation or only during the cabin wall cleaning powder by a Suction air flow is extracted; for cleaning the Cabin interior is a rotating device or Lifting device provided; the types of cleaning can scraping, blowing, sucking individually or in combination, Sponge cleaning or another type of cleaning; during the cleaning process the powder will not recovered, but the device is on loss  hazards. When using the same powder type objects are coated and in between only during short periods of operation Powder must be used, it is advantageous to use this other powders "drive for loss" and as waste to remove from the cabin without the need for long Operating periods provided powder Recovery device fed excess powder becomes. This eliminates for these color changes or Powder change a cleaning the powder Recovery device. It just has to be the cabin getting cleaned. While cleaning the cabin, whether with or without cleaning the powder Recovery device, it is advantageous that of powder continuously removed from the interior of the cabin suck off by means of a suction air flow, which is separated from a suction air flow the powder Recovery device is generated in the cabin.

The invention is described below in relation to the Drawings based on several embodiments as Examples described. Show in the drawings

Fig. 1 shows schematically and with reference to a cabin in the axial vertical section of a spray coating device for manual operation and automatic operation for spray coating of objects with coating powder,

Fig. 2 is a plan view of essential parts of the apparatus of Fig. 1,

Fig. 3 is an enlarged with respect to Fig. 1 cross section of a wall of the booth of FIG. 1,

Fig. 4 schematically shows a further embodiment of a spray coating device according to the invention having a composition shown in axial vertical section cabin,

Fig. 5 is a plan view of the spray coating apparatus of FIG. 4,

Fig. 6 shows schematically, in axial vertical section another embodiment of a cabin of the spray coating apparatus of FIG. 1,

Fig. 7 is a plan view of the cabin of Fig. 6,

Fig. 8 is a side view of the booth of FIG. 7 from the left along an arrow IX seen,

Fig. 9 schematically shows a vertical section through different embodiments of cleaning means for cleaning the interior surfaces Kabinenwand-,

Fig. 10 is a side view of another embodiment of a round cross-section cab of a spray coating device according to the invention,

Fig. 11 is a plan view of the cabin of Fig. 10.

The spray coating device for manual and automatic operation for spray coating objects 2 shown in FIGS . 1 to 3 contains a cabin 4 which forms a coating space 6 in which the objects 2 are coated by means of one or more spray devices 8 . The cabin wall 10 and the cabin ceiling 12 , seen in horizontal section, have a circular shape or at least an all round shape approximating a circle, in the radial center of which the theoretical vertical central axis 16 of the cabin 4 lies. According to a modified embodiment, not shown, the cabin 4 has seen in horizontal section, instead of a circular shape, an oval shape approximating a circle. In the cabin wall 10 there are diametrically opposite sides one through opening 18 and 19 each in the form of a vertical slot, which divides the cabin wall 10 and the cabin ceiling 12 into two segments of equal size. This division of the cabin 4 into identical segments, each of which extends over the entire height of the coating space 6 , simplifies the manufacture and transportation of the cabin 4 . Doors can be on the through openings 18 and 19 and, in a modified embodiment, the through openings 18 and 19 can be formed in such doors. The objects 2 to be coated hang on hooks 23 of a transport device 22 , which the objects to be coated through one through opening 18 into the radial center region 24 of the coating space 6 , in which the objects 2 are coated, and then through the other through opening 19 again Cab 4 transported out. The central region 24 , seen in horizontal section, is the region of the coating space 6 that lies radially within half the radius of the coating space 6 .

Offset about the central axis 16 , preferably offset by 90 °, to the through openings 18 and 19 are two diametrically opposite spray openings 26 and 28 in the form of vertical, all-round slits in the cabin wall 10 , through which the spray devices 8 extend. The spray directions 30 of the spray devices 8 of the one spray opening 26 are preferably aligned and opposite to the spray directions 32 of the spray devices 8 of the other spray opening 28 , so that the air jets of the spray jets flowing past the object 2 collide with one another and excess powder is concentrated in the center area 24 by gravity on the cabin floor 34 drops. The spray devices 8 are carried at each spray opening 26 and 28 by a lifting stand 36 and 38 , which stands outside the cabin 4 on a building floor 39 and which automatically move the spray devices 8 up and down. Each lifting stand 36 and 38 can carry one or more spray devices 8 , which can be arranged one above the other or next to one another. According to another embodiment, the spray devices 8 can be directed past one another with respect to their spray directions 30 and 32 . If the spray directions 30 and 32 are arranged offset to one another in the same direction of rotation with respect to the radial central axis 16 , their powder-air streams can generate a vortex flow in the round cabin 4 . Instead of the automatically controlled spray devices 8 , manually operated spray devices or spray guns can be used. All spray devices 8 are preferably moved synchronously with one another in order to coat the objects 2 in their entire height.

The cabin floor 34 is designed such that excess powder falling from the inner wall surfaces 40 of the cabin wall 10 can be removed from the cabin 4 separately from the excess powder falling onto the cabin floor 34 without first touching these inner wall surfaces 40 . For this purpose the cabin floor 34 is divided into outer collecting means 34.1 and inner collecting means 34.2 . The outer collecting means 34.1 extend around the entire inner circumference of the inner wall surfaces 40 in the form of a relatively narrow strip. The inner collecting means 34.2 are surrounded by the outer collecting means 34.1 and directly adjoin them and cover the entire area of the cabin floor 34 located within the outer collecting means. The two collection means 34.1 and 34.2 are designed such that the powder falling on them cannot reach the other collection means in question and can mix with the powder there. The excess powder falling on the inner collecting means 34.2 must not be mixed or "contaminated" with excess powder from the outer collecting means 34.1 . In contrast, it is without disadvantage (except that it is treated as loss powder) when a small proportion of the excess powder of the inner collecting means 34.2 reaches the outer collecting means 34.1 . In the embodiment shown in FIGS. 1 and 2, the inner collecting means 34.2 have a collecting funnel 42 , to whose downward-pointing tip a powder suction line 44 of a cyclone 46 is connected. An exhaust air suction line 48 of the cyclone 46 is connected to the input side of a filter device 50 , which filters residual powder from the exhaust air of the cyclone 46 and a suction fan 52 is connected to the output side thereof. The powder separated from the powder-air flow of the powder suction line 44 by the cyclone 46 passes from the lower end of the cyclone to a screening machine 54 and then falls into a powder container 56 . The powder container 56 can be a container with which fresh powder is supplied by the powder manufacturer to the powder user. The fresh powder and the excess powder recovered by the cyclone 46 and the screening machine 54 are fed from the powder container 56 to the spray devices 8 via powder lines 58 . The collecting funnel 42 can be vibrated by means of a vibrating device 60 so that powder falling into it slides more easily to the funnel tip. The upper funnel edge 62 , which is the largest in diameter, extends laterally beyond the central region 24 lying above it and directly adjoins the outer collecting means 34.1 .

The outer collecting means 34.1 have a suction air collecting line 66 , which is arranged at the lower end of the cabin wall 10 and extends over the entire circumferential length of the cabin wall 10 . The suction air manifold 66 has at least one (slot) or a plurality of suction openings 68 distributed over its entire length over its entire length, which are located between the inner wall surface 40 and a transition wall 70 and directly adjoin these two. The top of the suction air collecting line 66 and thus also its suction openings 68 are at a lower height than the upper funnel edge 62 of the inner collecting means 34.2 . The transition wall 70 has a conical outer diameter that increases downwards and bridges the small height difference and the small radial width difference of the cabin floor 34 between the suction openings 68 and the funnel edge 62 . Powder particles falling from the inner wall surface 40 therefore either get directly into the suction openings 68 or first onto the transition wall 70 and then slide from it into the suction openings 68 . If the transition wall 70 consists of flexible material, for example rubber, then the vibrations of the vibration generator 60 are prevented from being transmitted from the funnel 42 to the cabin wall 10 . If such a vibration transmission is desired or if no vibration generator 60 is used, the transition wall 70 can be made of a rigid material, preferably plastic. According to other embodiments, the transition wall 70 may have a different shape, e.g. B. cylindrical shape, have or be completely omitted and the funnel edge 62 of the funnel 42 directly adjoin the suction air manifold 66 .

The suction air collecting line 66 is connected by means of a second powder suction line 74 to the input side or upstream side of the filter device 50 in order to be able to remove excess powder by means of a second suction air flow. The excess powder filtered by the filter device 50 from the second suction air flow of the suction air line 66 and the excess powder separated from the exhaust air suction line 48 of the cyclone 46 in the filter device 50 are thrown away and are therefore lost. The suction fan 52 can thus generate a first suction air flow in the collecting funnel 42 and a second suction air flow in the suction openings 68 of the suction air collecting line 66 . A shut-off element 74.2 and / or 74.3 can be located in the two, or at least one of the two, powder suction lines 44 and / or 74 for their optional closing. According to another embodiment, separate suction fans 52 can be used to generate each suction air stream. Compressed air flows could be used instead of suction air flows, but this has several disadvantages.

The basic idea of this embodiment is that sprayed powder, which does not adhere to object 2, hereinafter referred to as excess powder, a) is divided into first excess powder, which did not reach the inner surfaces 40 of the cabin wall 10 , and second excess powder, which applied to these inner surfaces 40 reached, in particular was sprayed by the spray devices 8 , and then falls off by itself or falls off by a cleaning process, and b) the first excess powder and the second excess powder are removed from the cabin 4 separately from one another. For this purpose, the cabin wall 10 , seen in horizontal cross-section, can have the circular shape shown in the drawings, an oval or any angular shape. The second excess powder must not get into the first excess powder. In contrast, it is not harmful if a small proportion of the first excess powder gets into the second excess powder. This basic idea enables different processes:
Step 1 During a spray coating phase, when coating powder is sprayed onto the objects 2 , the first excess powder (without wall contact) of the inner collecting means 34.2 is conveyed out of the cabin 4 continuously or discontinuously, preferably pneumatically, and recovered for reuse.
Step 1.1.1 During the spray coating phase after step 1, the second excess powder (with wall contact) is left in the cabin 4 on the outer collecting means 34.1 , or according to
Step 1.1.2 conveyed out of the cabin 4 continuously or discontinuously, preferably pneumatically suctioned off.
Step 2 During the cleaning phase (e.g. in a spray coating break when changing powder or changing color), the second excess powder (with wall contact) is removed from the cabin 4 by means of the external collecting means 34.1 , whereby
Step 2.1.1 first excess powder (without wall contact) can be removed from the cabin 4 by the internal collecting means 34.2 or according to
Step 2.1.2 no first excess powder (without wall contact) is removed from the cabin 4 by the inner collecting means 34.2 , and for example the inner collecting means 34.2 are covered with a cover 80 .
Step 3 instead of step 1, step 1.1.1 and step 1.1.2:
During a spray coating phase, when coating powder is sprayed onto the objects 2 , either according to
Step 3.1.1, no excess powder (neither the first nor the second) is conveyed out of the cabin, and the inner 34.2 and outer 34.1 collection means are covered with a cover 80 or the like so that they are not “contaminated” with excess powder, or it is according to
Step 3.1.2 only the second excess powder of the outer collecting means 34.1 is conveyed out of the booth 4 , but no first excess powder of the inner collecting means 34.2 , in that only the inner collecting means 34.2 are covered by a cover 80 .
Step 4 follows steps 3 and 3.1.1 or 3.1.2 in the same way as steps 2 and 2.1.1 or 2.1.2.

The collection means 34.1 and / or 34.2 are only connected to a suction air flow through the suction lines 44 and / or 74 if excess powder is to be extracted through them, but not if no powder is to be extracted through the collection means 34.1 and / or 2 in question.

The procedure according to step 1, 1.1.1, 1.1.2 is preferably used when the same coating powder is used. The Procedure according to step 3, 3.1.1 and 3.1.2 preferably used when there are frequent color changes or powder changes are required or longer Spray coating phases are interrupted to another coating powder for a short time use. It can be used with a single system various application purposes can be fulfilled.

If a powder change is to be carried out between spray coating phases during which the first excess powder of the inner collecting means 34.2 is recovered, then only the powder recovery device (collecting funnel 42 , its powder suction line 44 , the cyclone 46 and the sieving machine 54 ) and the inner surface 40.1 of the cabin 4 need to be thoroughly cleaned cleaned, and the container 56 to be replaced. In contrast, the inner wall surfaces 40 of the booth 4 need only be roughly cleaned, since residual powder particles, if they fall off when another powder is used, cannot get into the collecting funnel 42 , and thus also not into the powder container 56 . This saves a lot of time and cleaning effort. If the other type of powder is only to be used for a short time when changing to another type of powder, then the funnel 42 and its powder suction line 44 or the cyclone 46 and the screening machine 54 do not even need to be cleaned for the powder change, but it is sufficient to co-operate with the coating to cover the other powder with the funnel 42 by a cover 80 (shown schematically in broken lines) as long as objects 2 are coated with the other powder. The interior surfaces 40 of the booth 4 need only be cleaned roughly so that no previous powder falls off them while the other powder is being coated.

The circular cabin 4 seen in the horizontal cross section is constructed symmetrically. Their inner wall surfaces 40 are circular in the same way and have their radial center in the central axis 16 . The lower tip 42.1 of the collecting funnel 42 lies in this central axis 16 , and the suction air collecting line 66 is arranged concentrically to the central axis 16 . The collecting funnel 42 has a straight, conical shape which narrows downward. The cabin wall 10 , the cabin ceiling 12 , the funnel 42 , the suction air manifold 66 and the transition wall 70 are preferably all made of electrically non-conductive material, preferably plastic, since this material allows the powder particles to adhere less than metal, for example. Likewise, the lines 44 , 48 , 74 through which powder flows can be made of electrically non-conductive material, for example plastic.

The cabin 4 is divided by the slot-like through openings 18 and 19 into two identical shell-like cabin halves. It can also be in one piece or divided into several segments of the same size. According to a preferred embodiment, the cabin wall 10 , preferably also the cabin ceiling 12, consists of a double wall construction according to FIG. 3, which has an inner wall 82 and an outer wall 84 , which are connected to one another by webs 85 and delimit a cavity 86 which is filled with air , preferably with atmospheric pressure. The intermediate space 86 can be open to the outside air and closed to the coating space 6 . The inner wall 82 and the outer wall 84 are each made of plastic.

In the embodiment according to FIGS . 4 and 5, the spray devices 8 are not introduced through spray openings in the cabin wall, but through spray openings 26.2 and 28.2 of the cabin ceiling 12 into the refitting space 6 of the cabin 4 and they are carried by lifting devices 36.2 and 38.2 . These can be fastened to a building ceiling 41 or stand on the building floor 39 .

The spray coating device according to FIGS . 6, 7 and 8 is identical to the spray coating device according to FIGS . 1, 2 and 3 with the exception of the cabin roof which is only shown schematically there and which is shown here in greater detail and is designated 12.2 . The cabin roof 12.2 can be lowered along the vertical interior wall walls 40 into the cabin up to the cabin floor 34 . The outer periphery 120 of the cabin roof 12.2 is located directly next to the cabin inner wall surfaces 40 and has cleaning agents for cleaning these cabin wall inner surfaces 40 during the downward movement of the cabin roof 12.2 from its uppermost starting position (shown in solid lines in FIG. 6) to its lowest position (in FIG. 6 shown in dash-dotted lines). The cabin roof 12.2 is thus a type of lift "which can be moved downwards and upwards. When traveling downwards, its entire circumference and the entire height of the cabin inner wall surfaces 40 are cleaned by its cleaning agents on its outer circumference 120. A further special feature of the cabin roof 12.2 is that its underside is adapted to the shape of the cabin floor 34 , but at least to the shape of the inner collecting means 34.2 , in that the roof surface 122 pointing downward into the coating space 6 is frustoconical in the same way as the collecting funnel 42 and thereby fits in shape and size into this collecting funnel 42 During the cleaning process for a powder change, the canopy 12.2 is preferably only lowered to such an extent that a narrow gap 126 remains between the lower canopy surface 122 and the inner funnel surface 124 pointing upwards. This gap 126 , hereinafter referred to as the powder suction gap called, is so narrow that it acts as a flow restrictor and thereby results in an acceleration of the air which is sucked out of the cabin 4 by the suction air blower 52 below the lowered cabin roof 12.2 through the collecting funnel 42 . The accelerated air travels in Pulverabsaugspalt 126 on the lower surface 122 of the lowered cabin car roof 12.2 and at the upwardly facing inner surface 124 funnel powder adhering with and cleans thoroughly characterized, these surfaces 122 and 124th

The canopy 12.2 can be carried by one or more lifting devices and moved down and up. According to the embodiment according to FIGS. 6 to 8, the cabin roof 12.2 is provided with a carrying device 130 which extends through the through openings 18 and 19 out of the cabin 4 and can be moved vertically together with the cabin roof 12.2 within these through openings 18 and 19 . The carrying device 130 is carried by at least one lifting device 134 arranged outside the cabin next to the movement path 132 of the transport device 22 and is moved vertically in the manner mentioned. The carrying device 130 can be guided vertically in vertical guides 136 , so that the lifting device 134 only has to generate the lifting forces, but is not loaded with transverse forces of the cabin roof 12.2 and its carrying device 130 transversely to the central axis 16 of the cabin 4 . Since the lifting device 134 must be located next to the transport path 132 of the transport device 22 and the objects 2 , it is inevitably arranged next to the through openings 18 or 19 . In the preferred embodiment shown, such a lifting device 134 is arranged next to each of these two through openings 18 and 19 , the second lifting device being designated by 134.2 in FIG. 8. As shown schematically, four lifting devices 134 , 134.2 , 134.3 and 134.4 could be arranged outside the cabin 4 to compensate for transverse forces.

In the embodiment according to FIGS. 6, 7 and 8, the cabin roof 12.2 is divided into two mirror-identical halves, which are arranged symmetrically to the through openings 18 and 19 next to the movement path 132 of the transport device 22 with the objects 2 and connected to one another by the carrying device 130 are. The carrying device 130 has a longitudinal beam 140 which carries one cabin roof half 12.2.1 and extends in the direction of the movement path 132 of the objects 2 , and a second longitudinal beam 142 which carries the other cabin roof half 12.2.2 and is arranged parallel to it. The two side members 140 and 142 are connected to each other outside the cabin 4 at each end by a cross member 144 and 146 . These two cross beams 144 and 146 are arranged outside the booth 4 to avoid coating with powder and they are so deep that the hooks 23 with the objects 2 can run over them. According to an embodiment not shown, the two cross members 144 and 146 are omitted and each longitudinal member 140 and 142 is carried by its own lifting device 134 ( 134.2, 134.3, 134.4 ). As a result, the longitudinal beams 140 and 142 together with their cabin roof halves 12.2.1 and 12.2.2 can be lowered and raised separately or synchronously together.

According to a further embodiment, not shown, the lower canopy surface 122 can be adapted to the shape of the outer collecting means 34.1 opposite it, that is to say in particular to the shape of the suction air collecting line 66 and the transition wall 70, so that a narrow powder suction gap is also formed between them its air acceleration, powder adhering to its surfaces is torn off and removed by the suction air flow.

According to FIG. 9, the cleaning agents provided around the entire outer circumference 120 of the cabin roof 12.2 for cleaning the cabin wall inner surfaces 40 can be, for example, one or more of the following agents, which are each arranged around the entire inner cabin wall circumference and which, when using a plurality of such cleaning agents, can be arranged one above the other: compressed air nozzles 150 for blowing compressed air, possibly ionized air, onto the cabin interior surfaces 40 , suction air nozzles 152 for suctioning powder particles from the cabin interior surfaces 40 , scraping elements 154 or wiping elements 156 , e.g. B. brush elements or a sponge, as shown schematically in Fig. 10. Instead of bristles, the wiping elements 156 can have a fabric cover made of velvet or another material for wiping powder off the interior wall surface 40 of the cabin.

In Fig. 7, as an example of such detergent Abwischelemente 156 in the form of segments 156.1, 156.2, 156.3, 156.4, 156.5 and 156.6 shown schematically, which are annularly arranged in a horizontal plane of the cabin wall inner surfaces 40 adjacent to each other and elastically by springs 158 against the cabin wall inner surfaces 40 are pressed. They are carried by the side members 140 and 142 . The segments can blow off, vacuum off and / or wipe or brush off the interior walls of the cabin dry or wet. Instead of springs 158 , other elastic pressing elements can be used, e.g. B. Air cylinder.

According to an embodiment not shown, only provided with the cleaning agents canopy outer circumference 120 can be lowered, but not the radially gelegende within this scope 120 cabin roof part. In this case, the cabin wall inner surfaces 40 can be cleaned as described above. Only then is no powder suction gap 126 formed on the cabin floor, but the suction air flow must, without such a gap formation, be sufficient to suction all powder particles from the elements of the cabin floor 34 .

FIG. 10 shows a side view and FIG. 11 a top view of an embodiment of a spray coating device according to the invention with a cabin 4.2 , which is essentially circular when viewed in horizontal cross section and a cabin floor 42.2 in which narrows uniformly downwards towards the radial, vertical cabin center axis 16 Has the shape of a funnel on which excess powder, which drops due to gravity, slides towards the radial center of the cabin and falls through a lower funnel opening 42.3, for example, into a container 4.3 standing under the cabin 4.2 . The funnel serving as the cabin floor 42.2 extends over the entire interior cross-section of the cabin.

According to a further embodiment of the invention, which is not shown, the cabin 4 can be open at the bottom (no built-in cabin floor) and under it there can be a fixed or exchangeable container which is open at the top and which forms the "cabin floor" by gravity in the cabin and / or catches oversupply powder that drops in suction air flow. The container can extend over the entire cross section of the cabin.

In all embodiments, the coating space 6 is delimited by the cabin wall 10 , the cabin ceiling 12 , and powder collecting means below the objects 2 to be coated.

Claims (14)

1. Spray coating device for spray coating objects with coating powder, comprising a booth ( 4 ), which forms a coating space ( 6 ), which is at the top through a booth roof with a lower booth roof surface ( 122 ), laterally through booth wall inner surfaces ( 40 ) and below by powder collecting means ( 34 ) which collects the sprayed coating powder which does not adhere to the objects ( 2 ), hereinafter referred to as excess powder, characterized in that the cabin roof ( 12.2 ) or at least its outer peripheral edge ( 120 ) is designed as an elevator body which runs along the vertical cabin wall inner surfaces ( 40 ) can be lowered to at least close to the powder collecting means ( 34 ) and raised again to its starting position, in which the objects ( 2 ) are coated, that at least one lifting device ( 134 ) is provided, which carries the lifting body ( 12.2 ) and in the above-mentioned way moved vertically, and that the Liftkö rper has cleaning agents ( 150 , 152 , 154 , 156 , 156.1 to 156.6 ) for cleaning the opposite interior wall surfaces ( 40 ) of the cabin during vertical movement. 2. Spray coating device according to claim 1, characterized in that the at least one lifting device ( 134 ) is arranged outside next to the cabin ( 4 ) and with the inside of the cabin wall surfaces ( 40 ) arranged, designed as a lift body car roof ( 12.2 ) or car roof part ( 12.2. 1 , 12.2.2 ) is functionally connected. 3. Spray coating device according to claim 2, characterized in that the at least one lifting device ( 134 ) through at least one through opening ( 18 , 19 ) of the cabin wall ( 4 ) with the car roof designed as a lift body ( 12.2 ) or car roof parts ( 12.2.1 , 12.2. 2 ) is connected. 4. Spray coating device according to claim 3, characterized in that the through openings ( 18 , 19 ) in the cabin wall ( 4 ) are the through openings through which the objects to be coated ( 2 ) through the cabin ( 4 ) by means of a transport device ( 22 ) are transported, and that the at least one lifting device ( 134 ) is arranged outside next to the cabin ( 4 ) next to the path of movement of the objects ( 2 ) to be coated. 5. Spray coating device according to one of the preceding claims, characterized in that the cabin roof ( 12.2 ) is divided into at least two roof segments of the same size ( 12.2.1 , 12.2.2 ), which are uniform on both sides of the movement path of the objects to be coated ( 2 ) distributed through the cabin ( 4 ). 6. Spray coating device according to one of the preceding claims, characterized in that the downward-facing surface ( 122 ) of the lowerable cabin roof ( 12.2 ) is adapted to the surface structure of the powder collecting means ( 34.1 , 34.2 ) in such a way that they fit onto one another or into one another and that they form a narrow powder suction gap ( 126 ) between them when the canopy ( 12.2 ) or its lowerable canopy part ( 12.2.1 , 12.2.2 ) is lowered close to these powder collecting means ( 34.1 , 34.2 ) such that the powder collecting means ( 34.1 , 34.2 ) are provided with air suction means ( 66 , 42 , 44 ) which suck off excess powder from the cabin ( 4 ), whereby when the cabin roof ( 12.2 ) is lowered or the cabin roof parts ( 12.2.1 , 12.2.2 ) are lowered in the powder suction gap ( 126 ) then formed Suction air is accelerated significantly, and is therefore better able to adhere to surfaces of the powder suction gap ( 126 ) sweep along and vacuum. 7. Spray coating device according to one of the preceding claims, characterized in that the powder collecting means ( 34 ) are divided into inner collecting means ( 34.2 ) and outer collecting means ( 34.1 ), which collect excess powder which has been sprayed separately but without mutual powder transfer, but not at the objects to be coated ( 2 ) is liable that the outer collecting means ( 34.1 ) adjoin the entire inner circumference of the cabin ( 4 ) on their inner wall surface ( 40 ) and extend over such a width that they drop everything from the inner wall surface ( 40 ) Collect coating powder, but no or only a small proportion of the excess powder that does not touch the inner wall surfaces ( 40 ) gets onto the outer collecting means ( 34.1 ), and that the inner collecting means ( 34.2 ) over the radially inside of the outer collecting means ( 34.1 ) the bottom area of the Extend cabin ( 4 ) and thereby the Collect a larger proportion of the excess powder, but no powder falling off from the inner wall surface ( 40 ), since they lie outside of its fall area. 8. Spray coating device according to claim 7, characterized in that the inner collecting means ( 34.2 ) to a first powder suction device ( 44 , 46 , 48 , 50 , 52 ) for suction of the excess powder collected by them from the cabin ( 4 ) are connected in terms of flow. 9. Spray coating device according to claim 7 or 8, characterized in that the outer collecting means ( 34.1 ) to a second powder suction device ( 66 , 68 , 74 , 50 , 52 ) for suction of the excess powder collected by them from the booth ( 4 ) connected in terms of flow are. 10. Spray coating device according to claim 8 or 9, characterized in that the first powder suction device ( 44 , 46 , 48 , 50 52, 54, 56 ) of the inner collecting means ( 34.2 ) is a powder recovery device for recovering and reusing the excess powder. 11. Spray coating device according to claim 7, characterized in that the inner collecting means ( 34.2 ) are connected in terms of flow ( 42, 44 ) to the suction inlet of a first powder separator ( 46 ), preferably at least one cyclone, which separates recovered excess powder from a suction air stream for reuse this excess powder that a suction outlet of the first powder separator ( 46 ) is connected in terms of flow ( 48 ) to the suction inlet of a second powder separator ( 50 ), preferably at least one filter, for sieving out residual excess powder from a suction air stream, and that to a suction outlet of the second powder separator ( 50 ) a suction fan ( 52 ) is connected so that the outer collecting means ( 34.1 ) are connected in terms of flow ( 66, 68, 74 ) to the suction inlet of the second powder separator ( 50 ) for suctioning off the excess powder collected by them. 12. Spray coating device according to one of claims 7 to 11, characterized in that the inner collecting means have a downwardly narrowing collecting funnel ( 42 ), the upper funnel opening comprises substantially the entire bottom region of the inner collecting means ( 34 ) and the lower funnel center with one Powder outlet opening ( 44 ) is provided. 13. Spray coating device according to one of claims 1 to 6, characterized in that the cabin floor ( 42.2 ) seen in vertical section has the shape of a funnel ( 42.2 ) becoming narrower on all sides uniformly narrowing towards the radial central axis ( 16 ) of the cabin ( 4 ) the upper funnel opening has the same cross-sectional size as the inner cross-section of the cabin ( 4 ), and that there is a powder outlet opening ( 44.3 ) at the narrowest, deepest funnel location. 14. Spray coating device according to one of the preceding claims, characterized in that at least the coating space ( 6 ) of the cabin ( 4 ), seen in horizontal section, has a circular shape or an all-round shape approximated to a circle, that holding means ( 22 , 23 ) for holding the objects ( 2 ) are arranged such that they hold the object ( 2 ) to be coated with its object surface to be coated in the radial center region ( 24 ) of the round coating space ( 6 ), and that at least one spray device ( 8 ) with its spray direction ( 30 , 32 ) is directed from the outside inwards into the center area ( 24 ), the radial center area ( 24 ), seen in the horizontal section of the cabin ( 4 ), being the area of the coating space ( 6 ) that is radially within 75% , preferably 50% or less, of the radius of this coating space ( 6 ).