EP2118603B1 - Apparatus for drying articles, in particular painted vehicle bodies - Google Patents

Abstract

The device has a conveying system that drives articles e.g. painted vehicle bodies (10), via an inlet-lock region (3), a drying tunnel (4) and an outlet-lock region (5). Locking chambers (19, 31) of the inlet-lock region and the outlet-lock region have units (20, 33) which are provided in a position to change the volume of respective locking chambers between a maximum value and a minimum value. The units are provided in the position to change the volume for displacing air contained in the respective locking chambers.

Description

1. a) einem Trockentunnel, dessen Innenraum mit einer Inertgasatmosphäre gefüllt ist;
2. b) einem Einlass-Schleusenbereich, der dem Trockentunnel vorgeschaltet ist, mindestens eine Schleusenkammer umfasst und die innerhalb des Trockentunnels herrschende Inertgasatmosphäre von der äußeren Normalatmosphäre trennt;
3. c) einem Auslass-Schleusenbereich, der dem Trockentunnel nachgeschaltet ist, mindestens eine Schleusenkammer umfasst und die innerhalb des Trockentunnels herrschende Inertgasatmosphäre von der äußeren Normalatmosphäre trennt;
4. d) einem Fördersystem, welches die Gegenstände durch den Einlass-Schleusenbereich, den Trockentunnel und den Auslass-Schleusenbereich hindurchführt.

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

1. a) a drying tunnel, the interior of which is filled with an inert gas atmosphere;
2. 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;
3. 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;
4. 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 that 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 be paid in inert gas atmospheres on the lowest possible consumption ,

A device of the type mentioned is in the WO 2005/116556 A and in the DE 10 2004 025 525 B3 described. 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 is in turn above the second lock chamber approximately at the level of the first lock chamber and adjacent to this 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 from the now dried objects in the reverse direction traversed outlet 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 ₂ , noble gases or combustion gases, there is always a need to further reduce the inert gas consumption.

Object of the present invention is thus to develop a device of the type mentioned so that the costs caused by inert gas consumption during operation are further reduced.

• e) mindestens eine Schleusenkammer des Einlass-Schleusenbereiches und/oder der Auslass-Schleusenbereiches eine Einrichtung aufweist, welche in der Lage ist, zur Verdrängung der in der jeweiligen Schleusenkammer enthaltenen Atmosphäre das Volumen der jeweiligen Schleusenkammer zwischen einem Maximalwert und einem Minimalwert, der im Wesentlichen gleich Null ist, zu verändern.

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 substantially is 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 blown 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 lock 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 the one embodiment of the invention, which comprises at least one variable in volume lock chamber, which is not crossed even by the coated objects, but is fluidly in communication with a traversed by the coated articles lock chamber. 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 a 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 adjustable in its volume lock chamber is so in communication that by opposing volume change in the two lock chambers, the atmospheres located in them between the two lock 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. In this way, the coated articles can be freed particularly effectively from entrained impurities before entering the furnace tunnel, which otherwise would pollute the inert gas atmosphere in the drying tunnel and necessitate 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.

Figur 1

einen Vertikalschnitt durch eine Ausschnitt eines ersten Ausführungsbeispieles einer Lackier- anlage für Fahrzeugkarosserien;

Figuren 2 bis 6

verschiedene Betriebsphasen eines Einlass- Schleusenbereichs, der Bestandteil der Anlage von Figur 1 ist;

Figuren 7 bis 12

verschiedene Betriebsphasen eines Auslass- Schleusenbereiches, der ebenfalls Bestandteil der in Figur 1 dargestellten Anlage ist;

Figuren 13 bis 18.

verschiedene Betriebsphasen eines alternativen Ausführungsbeispieles eines Einlass-Schleusen- bereiches;

Figur 19

eine Ansicht, ähnlich der Figur 1, eines alterna- tiven Ausführungsbeispieles einer Lackieranlage;

Figuren 20 bis 25

unterschiedliche Betriebsphasen des Auslass- Schleusenbereiches der Anlage von Figur 19;

Figur 26

eine Ansicht, ähnlich der Figur 1, eines weiteren Ausführungsbeispieles einer Lackieranlage;

Figur 27

die Draufsicht auf die Anlage der Figur 26.

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

FIG. 1

a vertical section through a section of a first embodiment of a painting system for vehicle bodies;

FIGS. 2 to 6

various phases of operation of an inlet lock area forming part of the installation of FIG. 1 is;

FIGS. 7 to 12

various operating phases of an outlet lock area, which is also part of the in FIG. 1 shown plant is;

FIGS. 13 to 18.

various operating phases of an alternative embodiment of an inlet lock area;

FIG. 19

a view similar to the one FIG. 1 , an alternative embodiment of a paint shop;

FIGS. 20 to 25

different operating phases of the outlet lock area of the system of FIG. 19 ;

FIG. 26

a view similar to the one FIG. 1 , Another embodiment of a paint shop;

FIG. 27

the top view of the plant of FIG. 26 ,

First, on the FIG. 1 Referenced. 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. Paint 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 in detail unspecified conveyor systems 7, 8, 9 are used, which are known in the art.

Upstream of the illustrated section are preparatory stations that 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 in FIG. 1 not shown. 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 ₂ .

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 such that the least possible loss of inert gases takes place.

How this happens for the inlet lock area 3, is now based on the FIGS. 2 to 6 explained. 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 connection chamber 11 so there is "normal atmosphere", which may also be loaded with solvent. The connecting chamber 11 can serve for a first "evaporation" of solvents and, if appropriate, a visual control of the applied coating.

The inlet lock area 3 further comprises, downstream of the connecting chamber 11, a lifting chamber 12, which is located at the same height level as the connecting chamber 11 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. The lifting platform 16 of the lifting device 13, however, is so large that it closes the opening 15 between the lifting chamber 12 and the transition chamber 14 completely gas-tight in the raised state.

The interior of the transition chamber 14 is connected via an outlet 26, in which a motor-controllable flap 27 is connected to the outside atmosphere or an air treatment device.

In the FIGS. 1 to 6 joins in the direction of movement of the vehicle bodies 10 to the transition chamber 14, a gas exchange chamber 16 at. 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 symbolically in the figures only insofar as their closed state is indicated by a line 17 and 18 led across the line. 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-Zylindereininheiten 21, 22.

Again FIG. 1 can be seen, joins the gas exchange chamber 16 in the direction of movement, the first chamber 23 of the drying tunnel 4 at. Between the transition 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 is in each case a vertically movable gate 24 and 25, the gates 24 and 25 separate in the closed state, the atmospheres of the adjacent chamber 14, 16 or 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, the in FIG. 2 is shown, the connecting chamber 11, the lifting chamber 12 and the transition chamber 14 to "normal atmosphere", while the gas exchange chamber 16 and the inert gas 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, the passage of which is viewed through the inlet lock area 3, has become in FIG. 2 just moved from the connecting chamber 11 in the lifting chamber 12. It will now, as in FIG. 3 indicated, 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 in FIG. 4 shown, the gate 24 between the transition chamber 14 and the gas exchange chamber 16 is opened. The piston 20 is moved by means of the piston-cylinder unit 21, 22 down. In this case, the transition chamber 14 adjacent connecting line 17 is 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 valve 27 located in the outlet line 26 is, as in FIG. 4 shown, of course, open. 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 in FIG. 5 shown, 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, in FIG. 6 illustrated 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 transferred to the first dryer chamber 23. At the same time the lifting device 13 is moved down again. In this case, the transition chamber 14 fills again largely with normal atmosphere. In the connecting 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 this, as already mentioned above, takes place in a conventional manner and the processes occurring are known. It can therefore immediately on the basis of FIGS. 7 to 12 the slinging of the vehicle body 10 out of the drying tunnel 4 will be described.

The outlet lock area 5, like both the FIG. 1 as well as the FIGS. 7 to 12 it can be seen, a transition chamber 28, which can be reached in the horizontal direction from the last chamber 29 of the drying tunnel 4 from is. Between the last dryer chamber 29 and the transition chamber 28 is a vertically movable gate 30, which in the closed state, the atmospheres of the two chambers 28, 29 separated from each other. 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 section 5 is formed similarly to the inert gas chamber 19 of the inlet lock section 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, the in FIG. 7 is shown, the vehicle body 10 is straight from the last dryer chamber 29 in the transition chamber 28 of the outlet lock area 5 retracted. 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 in FIG. 8 shown, the gate 32 closed. The standing on the lifting platform of the lifting device 38 vehicle body 10 is lowered down. In this case, 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. Once the lifting device 38 has reached its lower position, as in FIG. 9 shown, the vehicle body 10 moved out of the lifting chamber 37 in 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 in FIG. 10 illustrated state.

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. It will reach a state as in FIG. 12 is shown, in which both the transition chamber 28 and the gas exchange chamber 31 are filled with inert gas and the state in FIG. 7 equivalent. Now, another vehicle body 10 'can be discharged through the outlet lock area 5.

When passing a vehicle body 10 through the inlet lock area 3, as described above with reference to FIGS. 1 to 7 has been described, is obviously lost an inert gas amount corresponding to the volume of the inert gas chamber 19. 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 used even more sparingly, an embodiment of the inlet-lock area comes into question, as described in US Pat FIGS. 13 to 18 shown and described below.

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

Also in the inlet lock area 103 of FIGS. 13 to 18 Thus, there is a connection chamber 111, which is connected at its left side in the figures with the outlet of the painting 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 FIGS. 2 to 6 not to the outside atmosphere but into 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 this is a transition chamber 146, which is then followed again by the transport direction following the (not shown) first chamber of the drying tunnel. Between the gas exchange chamber 114 and the transition chamber 146 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 starting situation is in FIG. 13 shown. 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 in FIG. 14 illustrated, 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 FIG. 15 The situation shown is thus in the two chambers 111 and 112 normal atmosphere, while in the chambers 114, 146 Inertgasatmoshäre prevails.

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

In the next, in FIG. 17 Step shown now the flap in the connecting line between the storage chamber 141 and the gas exchange chamber 114 is 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 upwards in the direction of the corresponding arrow in FIG FIG. 17 pulls back upwards. 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 smear cycle finds its conclusion in that, as in FIG. 18 shown, the piston 120 is pushed by the piston-cylinder units 121, 122 back up and the connecting line 145 between the storage chamber 141 and the gas exchange chamber 114 is closed. The lifting device 113 is again moved downwards so that a vehicle body 110 'already provided in the connecting chamber 111 can be moved into the lifting chamber 112. 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.

As can be seen, this lock-up operation, in which substantially 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, with each Schleusungsvorgang a certain contamination of the inert gas by normal atmosphere and / or outgassing of the vehicle bodies 10 instead, 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 in FIG. 19 shown. The section of a paint shop shown here corresponds to that of FIG. 1 , Since the plant of FIG. 19 largely that of the FIG. 1 is similar, corresponding parts with the same reference numerals as in FIG. 1 plus 200 marked.

The main difference between the plant 1 of FIG. 1 and Annex 201 of the FIG. 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.

At the in FIG. 19 illustrated embodiment of a paint shop 201, the gas exchange chamber 231 is formed as an open-topped cylinder into which a piston 254 can be retracted.

Incidentally, the design of Annex 201 is completely identical to that of Annex FIG. 1 for simplicity, it can be referred to.

The passage of a vehicle body 210 through the system 201 of the FIG. 19 is referred to below with additional reference to FIGS. 20 to 25 described. These FIGS. 20 to 25 show different operating phases of the outlet lock area 205.

First, on the FIG. 20 Referenced. 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 is located in FIG. 20 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 FIG. 21 is shown. 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 operation is completed, the gate 256 is opened between the gas exchange chamber 231 of the outlet lock region 205 and the transition chamber 255, the lifting device 238 is extended and the opening 236 between the transition chamber 255 and the lifting chamber 237 is closed by the lifting platform. The vehicle body 210 travels, as in FIG. 22 shown in the transition chamber 255 a. Now, both in the gas exchange chamber 231 and in the transition chamber 255 mixing atmosphere.

In the next step, the in FIG. 23 is shown, the piston 233 is retracted by means of the piston-cylinder units 234, 235 in the gas exchange chamber 231. The mixing atmosphere, which is located in the gas exchange chamber 231; is 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 in FIG. 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 is closed. If now, as in FIG. 25 indicated, 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 is the FIG. 20 reached again and a new passage 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 plant sections on both sides, so that in each case lifting devices must be used to move the vehicle bodies in and 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 in the FIGS. 26 and 27 shown. Insofar as in this embodiment, elements of the embodiment of the FIG. 1 the same reference number plus 300 has been used.

In the FIGS. 26 and 27 again, a paint booth 302 is shown, other than in FIG FIG. 1 two guided by a robot application devices 360, 361 are located. 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 follows on the connecting cabin 311, 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 of that of the gas exchange chamber 216 in the embodiment of FIG. 19 equivalent. Unlike the embodiment of the FIG. 19 the gas exchange chamber 316 is still a piston lock chamber 365 downstream, which is associated with a vertically movable piston 364. The function of this piston lock chamber and the associated piston 364 is without further description of the above embodiments of the embodiments of FIGS. 1 and 19 understandable.

From the piston lock chamber 365, 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 in the FIGS. 26 and 27 not shown. The cooperation of the components 331, 354 and 316 corresponds completely to that of the components 231, 254 and 216 of the embodiment of the FIG. 19 ,

Unlike the embodiment of FIG. 19 However, the connecting chamber 339 connects directly at the same height to the gas exchange chamber 331 of the outlet lock area 305.

Claims (8)

1. A device for drying articles, in particular painted vehicle bodies, having

   a) a drying tunnel (4; 204; 304) whereof the interior is filled with an inert gas atmosphere;

   b) an inlet airlock region (3; 103; 203; 303) which is arranged upstream of the drying tunnel (4; 204; 304), includes at least one airlock chamber (19; 114, 141; 365) and separates the inert gas atmosphere prevailing inside the drying tunnel (4; 204; 304) from the normal atmosphere outside;

   c) an outlet airlock region (5; 205; 305) which is arranged downstream of the drying tunnel (4; 204; 304), includes at least one airlock chamber (31; 231; 331) and separates the inert gas atmosphere prevailing inside the drying tunnel from the normal atmosphere outside;

   d) a conveyor system (7, 8, 9; 108; 207, 208, 209) which guides the articles through the inlet airlock region (3; 103; 203; 303), the drying tunnel (4; 204; 304) and the outlet airlock region (5; 205; 305);
   characterised in that

   e) at least one airlock chamber (19, 31, 114, 141; 231; 331, 365) of the inlet airlock region (3; 103; 203; 303) and/or the outlet airlock region (5; 205; 305) includes equipment (20, 33; 120; 144; 254; 354, 364) which is able, for the purpose of displacing the atmosphere in the respective airlock chamber (19, 31, 114, 141; 231; 331, 365), to vary the volume of the respective airlock chamber (19, 31, 114, 141; 231; 331, 365) between a maximum value and a minimum value which is substantially equal to zero.
2. A device according to Claim 1, characterised in that the equipment for varying the volume (20, 120, 144; 254; 354, 364) includes a piston which may be retracted into the respective airlock chamber (19, 31, 114, 141; 231; 331, 365) and extended therefrom again.
3. A device according to Claim 1 or 2, characterised in that it includes at least one airlock chamber (19) whereof the volume is variable and which is not itself passed through by the coated articles (10) but which is in flow communication with an airlock chamber (16) through which the coated articles (10) pass.
4. A device according to one of Claims 1 to 3, , characterised in that it includes at least one airlock chamber (31; 114; 231; 331-, 365) whereof the volume is variable and which is itself passed through by the articles (10; 110; 210; 310) to be coated.
5. A device according to one of the preceding claims, characterised in that at least one airlock chamber (114) whereof the volume is variable is in communication, by way of a communication line (145) which may be closed off, with a second airlock chamber (141) whereof the volume is variable such that, by varying the volume in the two airlock chambers (114, 141) in opposite directions, the atmosphere therein may be pushed back and forth between these two airlock chambers (114, 141).
6. A device according to one of the preceding claims, characterised in that an airlock chamber (216; 316) of the inlet airlock region (203; 303) is connected by way of at least two lines (251, 252; 351, 352) to an airlock chamber (231; 331) of the outlet airlock region (205; 305) such that the atmosphere in the two airlock chambers (216, 231; 316, 331) may be guided through the two airlock chambers (216, 231; 316, 331) for the purposes of flushing.
7. A device according to one of the preceding claims, characterised in that there is provided in the inlet airlock region (3; 103; 203) and/or the outlet airlock region (5; 105; 205) a lifting device (13, 38; 113; 213, 238) by means of which the coated articles (10; 110; 210) may be raised to the vertical level of a drying tunnel (4; 204) which is higher up and/or lowered from this level.
8. A device according to one of Claims 1 to 6, characterised in that the drying tunnel (304) and all the airlock chambers (316, 365, 331) through which the coated articles (310) pass are located at the same vertical level.

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