WO2008098662A1

WO2008098662A1 - Apparatus for drying articles, in particular painted vehicle bodies

Info

Publication number: WO2008098662A1
Application number: PCT/EP2008/000474
Authority: WO
Inventors: Werner Swoboda; Josef Krizek
Original assignee: Eisenmann Anlagenbau Gmbh & Co. Kg
Priority date: 2007-02-15
Filing date: 2008-01-23
Publication date: 2008-08-21
Also published as: DE102007007478B3; ATE478311T1; EP2118603A1; EP2118603B1; DE502008001156D1

Abstract

A description is given of an apparatus for drying articles, in particular painted vehicle bodies, which, in a manner which is known per se, has a drying tunnel (4) of which the interior is filled with an inert gas atmosphere. The freshly coated articles (10) pass into the drying tunnel (4) via an entry air-lock region (3), by means of which the inert gas atmosphere which prevails within the drying tunnel (4) is separated from the normal exterior atmosphere. Correspondingly, an exit air-lock region (5), which separates the inert gas atmosphere from the normal exterior atmosphere, is located at the exit of the drying tunnel (4). At least one air-lock chamber (19, 31, 33) of the entry air-lock region (3) and/or or the exit air-lock region (5) has a device (20, 33) which, for the purpose of displacing the atmosphere contained in the respective air-lock chamber (19, 31, 33), is capable of changing the volume of the respective air-lock chamber (19, 31, 33) between a maximum value and a minimum value, which is essentially equal to zero. In this way, the consumption of inert gas which takes place each time an article (10) is passed through can be kept to a low level.

Description

Device for drying objects, in particular painted vehicle bodies

The invention relates to a device for drying objects, in particular of painted vehicle bodies, with

a) a drying tunnel, the interior of which is filled with an inert gas atmosphere;

b) an inlet-lock area, which is connected upstream of the drying tunnel, comprises at least one lock chamber and separates the prevailing inside the drying tunnel inert gas atmosphere from the outer normal atmosphere;

c) an outlet lock region downstream of the drying tunnel, comprising at least one lock chamber and separating the inert gas atmosphere prevailing inside the drying tunnel from the outer normal atmosphere;

d) a conveyor system which passes the articles through the inlet lock area, the drying tunnel and the outlet lock area.

In recent years, increasing importance is given to paints which have to be cured in an inert gas atmosphere, for example under UV light, in order to prevent unwanted reactions with constituents of the normal atmosphere, in particular with oxygen. These novel coatings are characterized by a very high surface hardness and by short polymerization times. The latter advantage is in paint shops, which are operated in a continuous cycle, directly into smaller plant lengths, which of course leads to significantly lower investment costs.

While in conventional dryers or dry processes, which operate with normal air as the atmosphere, the amount of air that is introduced into the dryer and also out of this is of lesser importance for cost reasons, must in inert gas atmospheres on the lowest possible consumption be respected.

A device of the type mentioned is in the

DE 10 2004 025 525 B3. Here, the inlet-lock area substantially comprises three chambers: a first, which is filled with normal atmosphere and the freshly coated objects are supplied from the coating station. A second chamber is partially below the first chamber, is connected thereto via a large-area opening through which the coated articles can be lowered, and contains an inert gas atmosphere whose density is greater than that of the outer normal atmosphere. A third lock chamber in turn lies above the second lock chamber approximately at the level of the first lock chamber and next to it and is also connected to the second lock chamber via a large-area opening. It also contains an inert gas atmosphere and communicates with the inert gas atmosphere within the drying tunnel. The coated objects are guided through these lock chambers in the order listed. A similar but in the opposite direction from the now dried articles Lock area is at the end of the drying tunnel.

In this construction, although the inert gas losses can be kept relatively low. However, in view of the cost of the inert gas, which may be nitrogen, CO, noble gases or also combustion gases, there is always a need to further reduce the consumption of inert gas.

Object of the present invention is therefore, a

Device of the type mentioned in such a way that the costs caused by inert gas consumption during operation are further reduced.

This object is achieved in that

e) at least one lock chamber of the inlet lock area and / or the outlet lock area has a device which is capable of displacing the atmosphere contained in the respective lock chamber, the volume of the respective lock chamber between a maximum value and a minimum value essentially equal to zero, change.

In the construction according to the invention, it is possible to better separate the outer normal atmosphere from the inner inert gas atmosphere and to limit the inert gas loss, which must be tolerated when a coated article is passed through, to at most the volume of the lock chamber which can be changed in volume.

In an expedient embodiment of the invention, the means for changing the volume comprises a piston which is retractable into the respective lock chamber and out of this retractable. This lock chamber is open in one direction, similar to a cylinder. A boundary side of the spin chamber is formed by the end face of the piston. When the piston is fully retracted into the lock chamber, its effective volume is practically zero. When the piston is extended, the lock chamber receives its maximum volume.

Particularly reliable is that embodiment of the invention, which comprises at least one variable in volume lock chamber, which is not traversed by the coated objects, but in terms of flow with one of the coated

Objects crossed lock chamber communicating. An object that traverses the inlet or outlet lock area can therefore not be damaged by an undesired change in volume of a lock chamber traversed by it even in the case of faulty control.

Structurally simpler is that embodiment of the invention which comprises at least one variable in volume lock chamber, which is itself traversed by the coated objects. In this case, special care must be taken to ensure that the lock chamber can not change its volume even if an error occurs during operation of the device, as long as there is an object in it.

Particularly large savings in inert gas result in a preferred embodiment of the invention, in which a variable in its volume lock chamber via a closable connection line with a second variable in its volume lock chamber is so connected that by opposing volume change in the two lock chambers, the atmospheres located in them between the two spin chambers can be pushed back and forth. In this way, inert gas, which in the simpler embodiments of the invention is lost each time an article passes through, can be stored and used for another sluice.

In addition or as an alternative to a lock, which makes use of a variable in its volume lock chamber, can take place to reduce the inert gas consumption, a rinse. For this purpose, a lock chamber of the inlet lock area can be connected via at least two lines to a lock chamber of the outlet lock area such that the atmosphere located in the two lock chambers can be guided through the two lock chambers in a circle for flushing purposes. The coated objects can be on this

Prior to entering the furnace tunnel particularly effectively freed of entrained impurities that would otherwise pollute the inert gas atmosphere in the drying tunnel and would require an early replacement of this inert gas atmosphere.

An embodiment of the invention in which a lifting device is provided in the inlet lock area and / or the outlet lock area with which the coated objects can be raised to the height level of a higher-lying drying tunnel and / or lowered from this level is energetically favorable.

Structurally simpler, albeit less energetically, is the embodiment in which the drying tunnel and all lock chambers traversed by the coated articles are at the same height level.

Embodiments of the invention will be explained in more detail with reference to the drawing; show it

1 shows a vertical section through a detail of a first embodiment of a Lackier- anläge for vehicle bodies;

FIGS. 2 to 6 show different phases of operation of an inlet lock area which is part of the installation of FIG. 1;

Figures 7 to 12 different operating phases of an outlet lock area, which is also part of the system shown in Figure 1;

FIGS. 13 to 18 different operating phases of an alternative exemplary embodiment of an inlet-lock region;

Figure 19 is a view, similar to Figure 1, of an alternative embodiment of a paint shop;

Figures 20 to 25 different operating phases of the outlet lock area of the system of Figure 19;

Figure 26 is a view, similar to Figure 1, of another embodiment of a paint shop; FIG. 27 shows the plan view of the system of FIG. 26.

First, reference is made to FIG. In this, a section of a paint shop for vehicle bodies 10 is shown in vertical section, which carries the reference number 1 in total. This section comprises a painting booth 2, an inlet lock area 3 for a drying tunnel 4, the drying tunnel 4 itself, which is only partially shown, and an outlet lock area 5. Painting booth 2, inlet lock area 3, drying tunnel 4 and outlet Lock area 5 are cyclically traversed by the vehicle bodies 10 in the direction of the arrow 6 at least in the lock areas 3, 5, wherein conveyor systems 7, 8, 9, which are not explained in more detail, are used which are known to the person skilled in the art.

Preceding the section shown are preparatory stations, which correspond to the state of the art; Downstream is a conventional cooler.

In the paint booth 2 are in a known manner application devices with which automatically or by hand on the vehicle bodies 10 paint can be applied. These application devices are not shown in FIG. The drying tunnel 4 is also built according to the state of the art and contains suitable heating and irradiation facilities, with which the applied paint can be brought to dry or curing.

While in the drying tunnel 4 upstream painting booth 2 and in the drying tunnel 4 downstream cooling area oxygen-containing "normal atmosphere" is located in the interior of the drying tunnel 4, an inert gas atmosphere containing, for example, nitrogen and / or CO.

In the present context, essentially only the inlet lock area 3 and the outlet lock area 5 are of interest, with which the two named atmospheres are kept separated during the passage of the vehicle bodies 10 in such a way that the least possible loss of inert gases takes place.

How this happens for the inlet lock area 3, will now be explained with reference to Figures 2 to 6. The inlet lock area 3 comprises a connection chamber 11, which is immediately downstream of the paint booth 2 and is permanently connected to it at atmospheric pressure. In this Verbindungsämämmer 11 so there is "normal atmosphere", which may also be loaded with solvent. The Verbindungsungskämmer 11 may serve a first "evaporation" of solvents and optionally a visual control of the applied paint.

The inlet lock region 3 further comprises, downstream of the connecting chamber 11, a lifting chamber 12 which is at the same height level as the connecting chambers

11 is located and in which a lifting device 13 is arranged. Above the lifting chamber 12, in turn, there is a transition chamber 14, which is connected to the lifting chamber 12 via an opening 15. The opening 15 is so large area that the vehicle bodies 10 can be moved upwards out of the lifting chamber 12 into the transition chamber 14. By contrast, the lifting platform 16 of the lifting device 13 is so large that, in the raised state, it closes off the opening 15 between the lifting chamber 12 and the transitional chamber 14 completely gastight. The interior of the transition chamber 14 is connected via an outlet line 26, in which a motor-controllable flap 27 is located, with the outside atmosphere or an air treatment device.

In FIGS. 1 to 6, a gas exchange chamber 16 adjoins the transition chambers 14 in the direction of movement of the vehicle bodies 10. The gas exchange chamber 16 communicates via two lines 17, 18 with an inert gas chamber 19 in connection. In the lines 17, 18 each have a flap attached, which can be opened and closed by a motor. These flaps are shown only symbolically in the figures to the extent that their closing state is indicated by a line drawn transversely through the line 17 or 18. An open flap, however, is not specifically shown.

The inert gas chamber 19 is formed in the manner of an upwardly open cylinder. In this cylinder can dip from above a provided with a corresponding cross section piston 20 which is vertically movable by means of two piston-cylinder units 21, 22.

As can be seen from FIG. 1, the first chamber 23 of the drying tunnel 4 adjoins the gas exchange chamber 16 in the direction of movement. Between the transitional chamber 14 and the gas exchange chamber 16 on the one hand and between the gas exchange chamber 16 and the first dryer chamber 23 on the other hand there is a respective vertically movable gate 24 and 25, respectively. The gates 24 and 25 separate the atmospheres of the adjacent chamber 14, 16 and 16, 23 from each other.

The passage of the vehicle bodies 10 through the inlet Lock area 3 happens in the following way:

In the initial situation, which is shown in FIG. 2, the connecting chamber 11, the lifting chamber 12 and the transition chambers 14 are at "normal atmosphere", while the gas exchange chamber 16 and the inert gas chamber 19 are filled with inert gas. The filling of the inert gas chamber 19 with inert gas takes place continuously from the interior of the dryer 4. The gates 24 and 25 are located as well as the flap 27 of the outlet 26 in the closed position.

The vehicle body 10, whose passage is viewed through the inlet lock area 3, has just moved from the connecting chamber 11 into the lifting chamber 12 in FIG. It is now, as indicated in Figure 3, lifted by means of the lifting device 13 in the transition chamber 14. The lifting platform of the lifting device 13 closes in its end position, the opening 15 between the lifting chamber 12 and transition chamber fourteenth

Now, as shown in Figure 4, the gate 24 between the transition chamber 14 and the gas exchange chamber

16 open. The piston 20 is moved downwards by means of the piston-cylinder unit 21, 22. In this case, the transition chamber 14 adjacent connecting line

17 closed by the corresponding flap. The inert gas contained in the inert gas chamber 19 is forced into the gas exchange chamber 16 through the piston 20 via the other open communication line 18. The inert gas now exits into the transition chamber 14 and displaces the "normal atmosphere" located there via the outlet line 26 to the outside. The flap 27 located in the outlet line 26 is naturally open, as shown in FIG. When the piston 20 is all the way down has moved, sets itself in this way, a state in which in the transition chamber 14 and the gas exchange chamber 16 is substantially pure inert gas atmosphere.

Now, as shown in Figure 5, the vehicle body 10 are moved from the transition chamber 14 horizontally into the gas exchange chamber 16. In this case, the flap 27 is closed again in the outlet line 26.

In the final, shown in Figure 6 Schleusungsschritt the gate 24 between the transition chamber 14 and the gas exchange chamber 16 is closed again; the gate 25 between the gas exchange chamber 16 and the first

Dryer chamber 23 is opened. The vehicle body

10 is spent in the first dryer chamber 23. At the same time the lifting device 13 is moved down again. In this case, the transition chamber 14 again largely fills with NormaIatmoSphäre. In the connection chamber

11 is already another vehicle body 10 'ready for passage into the drying tunnel 4 ready.

The passage of the vehicle body 10 through the drying tunnel 4 itself need not be described in more detail, since, as already mentioned above, this takes place in a conventional manner and the processes taking place are known. It can therefore be described immediately with reference to the figures 7 to 12, the slipping of the vehicle body 10 from the drying tunnel 4.

As can be seen from both FIG. 1 and FIGS. 7 to 12, the outlet lock region 5 comprises a transition chamber 28, which can be reached in the horizontal direction from the last chamber 29 of the drying tunnel 4 is. Between the last dryer chambers 29 and the transition chamber 28 there is a vertically movable gate 30, which in the closed state separates the atmospheres of the two chambers 28, 29 from one another. A gas exchange chamber 31 adjoins the transition chamber 28 in the transport direction at the same height. Between the chambers 28 and 31 is another, vertically movable gate 32, which in the closed state, the atmospheres of the chambers 28 and 31 separated from each other.

The gas exchange chamber 31 of the outlet lock area 5 is formed similarly to the inert gas chamber 19 of the inlet lock area 3 as an upwardly open cylinder. In this cylinder can dip from above a piston 33 which can be moved vertically by means of two piston-cylinder units 34, 35.

Below the gas exchange chamber 31 and connected to this via a large-area opening 36, there is a lifting chamber 37. This contains a lifting device 38, the upper lifting platform is so large that it closes the opening 36 in the raised state and in this way the two chambers 31st and 37 of the outlet lock area 5 are separated from each other. Connects to the lifting chamber 37, connected to this permanently atmospheric, in the transport direction to a connection chamber 39, which connects to downstream equipment parts, such as a cooling device, a connection.

The passage of the vehicle body 10 is done in the following steps.

In the initial situation, which is illustrated in FIG. 7, the vehicle body 10 is just emerging from the last dryer chamber 29 into the transition chamber 28 of the exhaust chamber. Retracted lock area 5. The gate 30 has already been closed after passing through the vehicle body 10 and the gate 32 is opened. The lifting device 38 is raised. The chambers 28 and 31 are now filled with an inert gas atmosphere and the vehicle body 10 can change from the transition chamber 28 into the gas exchange chamber 31.

Now, as shown in Figure 8, the gate 32 is closed. The on the lifting platform of the lifting device

38 standing vehicle body 10 is lowered down the opening 36 between the gas exchange chamber 31 and the lifting chamber 37 is opened, so that now the gas exchange chamber 31 can be filled with normal atmosphere. As soon as the lifting device 38 has reached its lower position, as shown in FIG. 9, the vehicle body 10 is moved out of the lifting chamber 37 into the connecting chamber 39. At the same time, the piston 35 lowers and displaces the normal atmosphere from the gas exchange chamber 31. This is the state shown in Figure 10.

Now the lifting device 38 moves back up and seals with its lifting platform, the opening 36 between the gas exchange chamber 31 and the lifting chamber 37 from. Now the gate 32 between the transition chamber 28 and the gas exchange chamber 31 can be opened and the piston 35 can be driven up again. A state is achieved, as shown in FIG. 12, in which both the transition chamber 28 and the gas exchange chamber 31 are filled with inert gas and corresponds to the state in FIG. Now, another vehicle body 10 'can be discharged through the outlet lock area 5. When passing through a vehicle body 10 through the inlet lock area 3, as described above with reference to FIGS. 1 to 7, an amount of inert gas corresponding to the volume of the inert gas chamber 19 is obviously lost. In most cases, this is quite tolerable, since a certain gas throughput is required in any case for the removal of the resulting gases in the drying tunnel 4 during the curing process. However, if the inert gas is to be handled even more sparingly, an embodiment of the inlet-lock region comes into question, as illustrated in FIGS. 13 to 18 and described below.

This alternative inlet lock area largely corresponds to the inlet lock area 3 of FIGS. 1 to 6; corresponding parts are therefore identified by the same reference sign plus 100.

Also in the inlet lock region 103 of FIGS. 13 to 18 there is thus a connection chamber 111, which is connected at its left side in the figures to the outlet of the paint booth (not shown). On the opposite side of the connecting chamber 111 is followed, again at the same height, a lifting chamber 112 at. A lifting device 113 is designed such that it can convey a vehicle body 110 standing on its lifting platform through an upper opening 115 into a gas exchange chamber 114. In the illustrated case, the gas exchange chamber 114 is designed as an open-topped cylinder into which a vertically movable piston 120 can be retracted from above. The piston-cylinder units used for this purpose are provided with the reference numeral 121, 122.

The outlet line 126 of the gas exchange chamber 114 leads now unlike the embodiment of Figures 2 to 6 not to the outside atmosphere but in a storage chamber 141, which is also open at the top and thus designed as a cylinder. In the storage chamber 141, a piston 144 can be retracted from above by means of the piston-cylinder units 142, 143.

In the connecting line 145 between the gas exchange chamber 114 and the storage chamber 141 is in turn a motor-operated flap, which is symbolized only in its closed position by a transverse line through the connecting line 145.

Downstream in the transport direction of the gas exchange chamber 114 and at the same level as the latter is a transition chamber 146, to which the first chamber (not shown) of the drying tunnel follows again following the direction of transport. Between the gas exchange chamber 114 and the transition chamber 146 there is a first vertically movable gate 147 and on the opposite side of the transition chamber 146, a second vertically movable gate 148th

The passage of the vehicle body 110 through this inlet lock area 103 takes place in the following manner:

The initial situation is shown in FIG. In this is located in the chambers 111, 112 and 114 normal atmosphere. The storage chamber 141 is filled with inert gas; the flap in the connecting line 145 is closed. Also, inert gas is in the transition chamber 146; the two side gates 147 and 148 are closed. As can be seen from the drawing, the vehicle body 110 to be passed through has already become retracted into the Hubkammer 112.

Now, as shown in Figure 14, the vehicle body 110 is retracted by means of the lifting device 113 in the gas exchange chamber 114, wherein the lifting platform of the lifting device 113, the opening 115 closes.

Now the flap lying in the connecting line 145 is opened and the piston 144 is retracted into the storage chamber 141. In this case, the inert gas in the storage chamber 141 is pressed via the connecting line 145 into the gas exchange chamber 114; This inert gas displaces the normal atmosphere previously located in the gas exchange chamber 114 via a closable outlet opening which is not shown in the drawing. In the in

Thus, the situation shown in FIG. 15 is in the two chambers 111 and 112 normal atmosphere, while in the chambers 114, 146 Inertgasatmoshäre prevails.

Next, as shown in FIG. 16, the gate 147 located between the gas exchange chamber 114 and the transition chamber 146 is opened and the vehicle body 110 is transferred to the transition chamber 146.

In the next step, shown in FIG. 17, the flap in the connecting line between the storage chamber 141 and the gas exchange chamber 114 is now opened again; by retracting the piston 120 into the gas exchange chamber 114 by means of the piston-cylinder units 121, 122, the inert gas is forced out of the gas exchange chamber 114 in the storage chamber 141, of course, the piston 144 upwardly retracts upward in the direction of the corresponding arrow in Figure 17. It is also understood that prior to this process, the gate 147 between the gas exchange chamber 114 and the Transition chamber 146 has been closed.

The Schleusungszyklus concludes that, as shown in Figure 18, the piston 120 is pushed back by means of the piston-cylinder units 121, 122 and the connecting line 145 between the storage chamber 141 and gas exchange chamber 114 is closed. The lifting device 113 is moved downwards again, so that ^■ 110 can be retracted into the sliding chamber 112 a is already in the compound comber 111 readiness standing vehicle body. At the same time, the gate 148 between the transition chamber 146 and the subsequent drying tunnel is opened and the vehicle body 110 is introduced into the drying tunnel.

Obviously, this lock-up process, in which essentially the inert gas is pushed back and forth between the storage chamber 141 and the gas exchange chamber 114, can be repeated several times without the inert gas having to be discarded. Of course, however, a certain contamination of the inert gas by normal atmosphere and / or outgassing of the vehicle bodies 10 takes place with each Schleusungsvorgang, so that after a certain number of Schleusungsvorgängen the inert gas in the storage chamber 141 must be replaced.

Nevertheless, in comparison to the embodiment of an inlet lock area 3 described first, there is a considerable saving in inert gas.

In many cases, it is also possible to use inert gas more generously. This is especially true if the equipment costs of the paint shop can be kept to a minimum. An example of how to proceed in this case is shown in FIG. The section of a paint shop shown here Anläge corresponds to that of Figure 1. Since the system of Figure 19 is largely similar to that of Figure 1, corresponding parts with the same reference numerals as in Figure 1 plus 200 are indicated.

The main difference between the plant 1 of Figure 1 and the plant 201 of Figure 19 is that the gas exchange chamber 216 is not connected via connecting lines with an inert gas, from which inert gas can be pressed into the gas exchange chamber 216. Instead, two connecting lines 250, 251 extend between the gas exchange chamber 216 of the inlet lock area 203 and the gas exchange chamber 231 of the outlet lock area 205. In the connecting line 250 there is a first blower 252, which effects gas flow from the gas exchange chamber 231 into the gas exchange chamber 216, while in the connecting line 251, a second blower 253 is mounted, which causes a gas flow in the opposite direction.

In the exemplary embodiment of a painting installation 201 shown in FIG. 19, the gas exchange chamber 231 is designed as an upwardly open cylinder, into which a piston 254 can be retracted.

Incidentally, the construction of the installation 201 is completely identical to that of the installation 1 of FIG. 1, so that reference can be made to this for the sake of simplicity.

The passage of a vehicle body 210 through the system 201 of FIG. 19 will be described below with reference to FIGS. 20 to 25. These FIGS. 20 to 25 show different operating phases of the outlet lock area 205. First, reference is made to FIG. In this is a vehicle body 210 in the adjacent to the drying tunnel 204 transition chamber 228 of the outlet lock area 205. The gate 230, which is adjacent to the last dryer chamber is already closed and the gate 232 already open, so that the vehicle body 210 in the Gas exchange chamber 231 can retract. The associated piston 233 is of course moved upwards. The gate 256 between the gas exchange chamber 231 and the transition chamber 255 is closed.

Another body 210 'is already in the gas exchange chamber 216 of the inlet lock area 203. The gates 224 and 225 of the gas exchange chamber 216 are closed.

In the chambers 228 and 231 in Figure 20 is Inertgasatmosphäre, while the transition chamber 255, the Hubkammer 237 and the connecting chamber 239 contain normal atmosphere. In the gas exchange chamber 216 of the inlet lock area 203 is at this time a mixture of normal and inert gas atmosphere.

As soon as the vehicle body 210 is completely within the gas exchange chamber 231 of the outlet lock area 205, the gate 232 is also closed, as shown in FIG. Now, with the help of the pumps 252, 253 via the connecting lines 250, 251, the inert gas atmosphere in the gas exchange chamber 231 of the outlet lock section 205 flushed into the gas exchange chamber 216 of the inlet lock section 203 and vice versa, the mixing atmosphere in the gas exchange chamber 216 of the inlet lock section 203 in the gas exchange chamber 231 of the outlet lock area 205 introduced. It turns in the two gas exchange chambers 216 and 231 a mixed atmosphere.

When this process is completed, the gate becomes

256 between the gas exchange chamber 231 of the outlet lock region 205 and the transition chamber 255, the lifting device 238 being extended and the opening 236 between the transition chamber 255 and the lifting chamber 237 being closed by the lifting platform. The vehicle body 210 enters the transition chamber 255 as shown in FIG. Now, both in the gas exchange chamber 231 and in the transition chamber 255 are mixed atmosphere.

In the next step, which is shown in FIG. 23, the piston 233 is retracted into the gas exchange chamber 231 with the aid of the piston-cylinder units 234, 235. The mixing atmosphere, which is located in the gas exchange chamber 231, is thereby displaced into the transition chamber 255. At the same time, the lifting device 238 lowers the vehicle body 210 into the lifting chamber 237.

As shown in Figure 24, now the gate 232 between the transition chamber 228 and the gas exchange chamber 231 is opened again and the opposite port 256 between the gas exchange chamber 231 and the transition chamber 255 closed. If now, as indicated in Figure 25, the piston 233 is raised, the gas exchange chamber 231 fills with inert gas again. The lifting device 238 moves upwards. Now, the initial state of Figure 20 is reached again and a new pass-through of a vehicle body 210 'can begin.

In the previously described embodiments of painting The drying tunnel is located at a higher level than the adjacent sections of equipment on both sides, so that in each case lifting devices must be used to bring the vehicle bodies in or out of the drying tunnel. The reason for this arrangement, which is known in the art as "A lock", is an energetic: it escapes in this way less atmosphere from the drying tunnel, whose temperature is higher than that of the atmosphere in the adjacent plant areas.

However, it is also possible to dispense with such "A-locks" and to arrange all chambers of the paint shop at the same height. An example of this is shown in FIGS. 26 and 27. As far as in this embodiment elements corresponding to those of the embodiment of Figure 1, the same reference number plus 300 was used.

FIGS. 26 and 27 again show a painting booth 302, wherein, unlike in FIG. 1, two application devices 360, 361 guided by a robot are shown. The painting booth 302 is adjoined in the direction of movement initially by a connecting chamber 311, in which an evaporation process can take place. An air supply system 362 supplies both the paint booth 302 and the connecting booth 311 with conditioned fresh air.

In the direction of movement, the connecting booth 311 is followed by a pre-dryer booth 363, in which a large part of the solvent is expelled from the paint, and then a gas exchange chamber 316, whose function corresponds to that of the gas exchange chamber 216 in the embodiment of FIG. Unlike the embodiment 19 of the gas exchange chamber 316 is still a piston lock chamber 363 downstream, which is associated with a movable piston 604 in the vertical direction. The function of this piston lock chamber and the associated piston 364 can be understood without further description from the above explanations of the embodiments of Figures 1 and 19.

From the piston lock chamber 363, the vehicle bodies 310 then enter the actual drying tunnel 304, where the coating is cured in an inert gas atmosphere and optionally under UV irradiation. The vehicle bodies 310 leave the drying tunnel 304 and enter the outlet lock area 305, which in this case comprises a gas exchange chamber 331 and an associated piston 354. The gas exchange chamber 331 is connected via connecting lines 350, 351 to the gas exchange chamber 316 of the inlet lock area 303. The promotional pumps are not shown in Figures 26 and 27. The cooperation of the components 331, 354 and 316 completely corresponds to that of the components 231, 254 and 216 of the embodiment of FIG. 19.

Unlike the embodiment of FIG. 19, however, the connection chambers 339 directly adjoin the gas exchange chamber 331 of the outlet lock region 305 at the same height.

Claims

claims

1. Device for drying objects, in particular of painted vehicle bodies, with

b) an inlet-lock area, which is connected upstream of the drying tunnel, comprises at least one lock chamber and separates the inert gas atmosphere prevailing inside the drying tunnel from the outer normal atmosphere;

d) a conveyor system which passes the articles through the inlet lock area, the drying tunnel and the outlet lock area;

characterized in that

e) at least one lock chamber (19, 31, 33, 114, 141, 231, 331, 363) of the inlet lock area (3, 103, 203, 303) and / or the outlet lock area (5, 205, 305) ) has means (20, 33; 120; 144; 254; 354, 364) capable of displacing each other in the respective one Locking chamber (19, 31, 33, 114, 141, 231, 331, 336) contained the volume of the respective lock chamber (19, 31, 33, 114, 141, 231, 331, 363) between a maximum value and a minimum value , which is essentially zero, to change.

Device according to claim 1, characterized in that the means (20, 33, 120, 144, 254, 354, 364) for varying the volume comprise a piston which can be inserted into the respective lock chamber (19, 31, 33, 114, 141, 231, 331, 363) and retractable from this.

3. Apparatus according to claim 1 or 2, characterized in that it comprises at least one variable in its volume lock chamber (19) which is not itself crossed by the coated articles (10), but fluidly with one of the coated objects ( 10) traversed lock chamber (16) is in communication.

4. Device according to one of claims 1 to 3, characterized in that it comprises at least one variable in its volume lock chamber (31; 114; 231;

331, 363), which itself is traversed by the objects to be coated (10, 110, 210, 310).

5. Device according to one of the preceding claims, characterized in that at least one variable in its volume lock chamber (114) via a lockable connection line (145) with a second variable in volume lock chamber (141) is such that by opposing volume change the two lock chambers (114, 141) the atmosphere in them between these two lock chambers (114, 141) can be pushed back and forth.

6. Device according to one of the preceding claims, characterized in that a lock chamber (216; 316) of the inlet lock area (203; 303) via at least two lines (251, 252; 351, 352) with a lock chamber (231; 331 The atmosphere in the two lock chambers (216, 231, 316, 331) can be conducted through the two lock chambers (216, 231, 316, 331) for flushing purposes ,

7. Device according to one of the preceding claims, characterized in that in the inlet-lock area (3; 103; 203) and / or the outlet lock area (5; 105; 205) a lifting device (13, 38, 113; 213, 238) is provided, with which the coated articles (10, 110, 210) can be raised to the height level of a higher lying drying tunnel (4, 104, 204) and / or lowered from this level.

8. Device according to one of claims 1 to 6, characterized in that the drying tunnel (304) and all of the coated articles (310) traversed lock chambers (316, 363, 331) are at the same height level.