CZ2002605A3 - Car production line, equipment for the production line and fluidization and/or heat hardening and/or drying anticorrosive coating within a car body cavity - Google Patents

Abstract

A arrangement comprising a device 1 for heating an anti-corrosive coating in a cavity (22) of a vehicle body (2), suitable for directing a medium, being of a temperature required for thermal curing of the coating or drying or fluidizing the coating (22, 23), in the cavity (21). Preferably, guidance elements (3) help to precisely direct the medium (A, B, C) into the cavity (21). <IMAGE>

Description

Technical field

The invention relates to a method and an apparatus for fluidizing and / or heat curing and / or drying a coating.

BACKGROUND OF THE INVENTION

In the manufacture of transport vehicles, such as cars, trucks or buses, cavities in vehicle bodies are normally protected against corrosion by coating the surfaces of the cavities.

The anticorrosive compounds or mixtures used for coating are in particular waxes or waxy substances. These waxes are selected from the group consisting of natural or semisynthetic compounds (e.g., vegetable resins), petroleum products (e.g., resin), or synthetic polymers (e.g., thermoplastics).

For coating purposes, waxes intended to form a solid coating on the inner surface of the cavity are required to be applied in a liquid state. The wax may be dissolved or dispersed in a liquid medium, particularly in a solvent (which may later evaporate), and may be fluidized by heat under heat treatment. or it can be applied as a polymerization liquid mixture.

All of the prior art methods require heating of the cavity either during or immediately after application of the coating. In the first case, the stiffening of the thermoplastic composition, which prevents the coating from having smooth access to all slits, is highly undesirable. In the latter case, solidification by means of physical drying or thermal curing requires the introduction of heat into the coating material after it is applied to the cavity.

In the prior art, only indirect methods of increasing the temperature on the inner surface of the cavity by heating the entire vehicle body are described.

WO 96/30128 discloses a method for protecting cavities in work articles. A working object, such as a vehicle body, is introduced into a working chamber at a predetermined operating temperature. The introduction of the vehicle body into the working chamber heats the entire vehicle body before applying the coating.

The disadvantage of this method is that conventional convection heating, for example in an oven, is too space-intensive. Heating the entire vehicle body by transferring heat from the ambient air is time consuming due to insufficient heat transfer rate. Conversely, the subsequent cooling of the vehicle body to protect workers from burns and to facilitate further processing on the production line is also time consuming.

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These circumstances make coating the cavities of the vehicle body a significant obstacle to overall production line productivity. Since the working chamber is part of a continuously operating production line, there is a significant loss of heat, so that energy costs are high. In addition, other parts of the partially processed vehicle body (such as paint, seals, etc.) are subject to undesirable thermal stresses.

EP-A1-003 223 describes a method of applying a coating of a corrosion prevention material to cavities of a vehicle body, wherein a part of the vehicle body is heated by infrared radiation from the outside.

U.S. Pat. No. 4,771,552 discloses an apparatus for drying car bodies with the aid of hot drying air. The apparatus comprises a drying chamber which is provided with conveying means and a device for supplying hot air. Stationary nozzles are arranged in the drying chamber. Hot air is supplied from these nozzles to the vehicle bodies that move in the drying chamber.

The disadvantage of this method is that the energy consumption is still too high, and the heat transfer from the outside of the vehicle body to the coating on the inner surface of the cavities is also indirectly transferred. Although this method of heating has a locally focused effect, heat dissipation occurs to all adjacent parts of the vehicle body. Cavities that have only a portion of their walls directly exposed to the outside of the vehicle body and hence from outside infrared radiation are insufficiently heated.

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SUMMARY OF THE INVENTION

SUMMARY OF THE INVENTION It is an object of the present invention to overcome the aforementioned disadvantages of the prior art and to provide a simple device and method for rapidly inexpensive and energy efficient fluidization or solidification of the anticorrosion coating in cavities of the vehicle body. Such a vehicle may be a car, a bus, a plane, a train, and the like.

The above object has been achieved in accordance with the present invention by developing a production line for vehicles, in particular for automobiles, comprising a device for fluidizing and / or heat curing and / or drying an anti-corrosion coating in a cavity of a vehicle body comprising a device comprising at least one guide element for directing the medium into the cavity, wherein the at least one guide element is designed to accommodate the opening of the cavity.

In accordance with another aspect of the present invention, a production line for vehicles, in particular automobiles, comprising a fluidizing and / or heat curing and / or drying device coating in a cavity of a vehicle body is also provided which includes a device for directing media into the cavity in such a manner. wherein the thermal stress of adjacent elements is minimized, wherein at least one guide element is designed to accommodate the cavity opening.

The apparatus comprises a heating unit for heating the medium.

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The at least one guide element is designed to be inserted into said cavity.

The apparatus comprises means for accelerating the medium, the means preferably comprising a fan or a pump.

In particular, the medium is a liquid or a gas, preferably air.

Equipment contains a set guide elements, especially for directing vehicles. media at the same time to more cavities in the body The device is with vehicles, in particular for advantage cars included manufacturing lines for Equipment according to this invention preferably contains

a fan for directing the air flow into the cavity of the vehicle body comprising an anti-corrosion coating.

In accordance with yet another aspect of the present invention, there is also provided a method of fluidizing and / or thermally curing and / or drying an anticorrosive coating in a cavity of a vehicle body, wherein the fluid flow is directed through the at least one guide to the cavity. the opening of the cavity into which the coating was applied.

The method of the invention preferably further comprises the following steps:

optionally heating the fluid stream, optionally heating the cavity by directing the hot fluid stream into said cavity, coating the cavity, and heating the coating by directing the hot fluid stream into the cavity.

The method of the invention preferably comprises the further step of cooling the coating by directing a fluid stream into the cavity.

The medium is directed into the cavity and / or is directed out of the cavity.

The method of the invention preferably further comprises the following steps:

providing at least one device for pressurizing the medium and / or removing or sucking the medium out of the cavity, attaching the device to one or more media-guiding members, and attaching the at least one guiding member to said cavity.

Preferably, the medium is forced into the cavity by pressure.

Said medium is drained or aspirated from the cavity.

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Pressure and / or vacuum is applied in the cavity.

The method of the invention preferably comprises the following additional steps:

providing a guide member that can be placed in the cavity, injecting a fluid stream through said guide member into the cavity, and / or sucking a fluid stream through said guide member out of the cavity.

In accordance with the present invention, the device for fluidizing and / or thermally curing and / or drying a coating in a cavity of a vehicle body by the method comprises a device for directing the medium into the cavity. In this context, directing the medium into the cavity means any means of forcing the medium to flow into and / or within the cavity.

Direct heating of the coating applied to the cavity in the vehicle body has the advantage of rapid and efficient heat transfer to the coating. The preset medium temperature is the actual reaction temperature of the coating, that is, the temperature required to fluidize the mixture or to initiate polymerization (curing) or to effectively evaporate the solvent, thereby drying the coating.

In the case of solvent evaporation from the solvent-based coating, it will be sufficient for the cavities to pass through the cavities. · · · · · · · · · · · · · · · · · · · · · · · · · · · · Unheated medium; ambient or room temperature will be sufficient, despite the fact that solvent vapors will be removed automatically.

The thermal stress of other adjacent parts of the vehicle body, such as seals or coatings, is completely minimized. Energy costs are also minimized due to the closure of the heated areas. Cooling is no longer necessary for further process and processing steps, except for working directly in cavities. Process cycle times are thus shortened, which can lead to an overall increase in the productivity of the entire production line. Workers have access to the vehicle body at the same time or in subsequent operating steps without the risk of coming into contact with hot parts.

It is possible to cool the vehicle body at the end of the process using the same device. It is also possible to use control units to automatically control predetermined changes in the temperature of the medium as a function of time, for example by switching from heating mode to cooling mode. This helps to avoid overheating of the cavities and adjacent parts of the vehicle body, making it possible to employ more complex heating procedures, for example using several intervals of different temperatures. The automated process can be adapted to the specific needs of the coating compounds and mixtures used.

In a further preferred embodiment, the device according to the invention comprises a medium heating unit. Such a unit may consist, for example, of radiator elements which are heated and which are located in the flow path »φ φ φ φ ·

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φφφφ média. The radiator element may be heated by electrical resistance, by combustion or by heat exchange with the heated medium.

The term "hot" in the context of the present invention refers to temperatures in the range of 50 ° C to 150 ° C, preferably 70 ° C to 120 ° C. From a functional point of view, this temperature makes it possible to achieve chemical or physical curing, solvent evaporation or fluidization of the thermoplastic composition.

In a further preferred embodiment, the device according to the invention comprises at least one guide element for directing and injecting the medium into the cavity. The medium emerges from the guide element into the cavity or is sucked in and removed from the cavity by the guide element.

The above-mentioned guide element may be formed by tubes or ducts, either of rigid or flexible resilient material, which may comprise flexible couplings. Thus, the guide element may be positioned in a fixed or conformable position in the cavity of the vehicle body. The end thereof may extend into the cavity or, by means of movement by the operator or an additional mechanism, be inserted into the cavity. The guide element according to the invention may be terminated by a wide opening or nozzle from which, for example, an air stream is released.

In another embodiment of the present invention, the at least one guide element is adapted to be adapted to the opening of the cavity. The term "adaptation in the context of the present invention" means any method of forming, directing, attaching or adjusting the size of the guide element relative to »0

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0 0 · «0 · · ·· • 0 to the cavity and with respect to the position, accessibility and size of the cavity. This feature contributes to optimizing the performance of the method.

In another preferred embodiment of the invention, the at least one guide element is adapted to be inserted into said cavity. The guiding element is, for example, a hollow tube or injection device introduced into the cavity. As a result, the medium is blown into or out of the cavity, while controlling the flow or flow pattern of the medium in the cavity. It is possible for the medium to be supplied under pressure from the guide element, or for the medium to be evacuated using a vacuum. The movement of the guide element in the cavity can be performed directly by the operator or by means of a mechanical auxiliary mechanism.

For example, the medium may be injected in close proximity to the corners or end of the blind cavity and may flow toward the opening in the cavity so as to come into contact with the entire surface area of the cavity.

In a further preferred embodiment, the device according to the invention comprises means for accelerating the medium, the means preferably being a fan or a pump. These means serve to move the medium from the device into the cavity of the vehicle body by generating a flow of medium. It is also possible that the flow of the medium, e.g. air, is produced by different means, for example by releasing compressed air from the pressure vessel or the like.

In another preferred embodiment, the medium according to the invention is a gas, preferably air. Advantage of this medium • 4 «· 4 • · • 4

it is easy to handle, has a good heat transfer capacity and does not have to be processed after use. Except for solvent vapors, it cannot be contaminated by the coating composition. In particular, air is readily and inexpensively available and non-toxic to humans.

In another embodiment, the medium of the invention is a liquid. For certain coatings, the liquid has the advantage that it has even greater heat transfer capacity compared to gas. However, the liquid must be adapted to chemical compounds or coating compositions to avoid the effects of dissolution.

In accordance with yet another embodiment, the device of the present invention comprises a plurality of guide elements, preferably for directing the medium simultaneously into several cavities in the vehicle body. This further reduces the cycle time.

In a preferred embodiment of the invention, the device according to the invention is part of a production line for vehicles, in particular automobiles. It is possible to arrange the device below the production line, thereby allowing access to the cavities in the vehicle body from below, preferably via said guide elements or a plurality of such guide elements. However, the vehicle body may still be accessible from the sides, for example for workers or for machine tools, in particular automatic workers. The device saves time, is easy to install and is suitable for automatic application.

In accordance with another object of the present invention, a method of fluidizing and / or heat curing has been developed and / or

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drying the coating in a cavity in the vehicle body, the gas or liquid stream being blown into the cavity into which the coating has been applied. This method has a number of preferred embodiments, within the scope of what has already been said.

For the purpose of one preferred embodiment, the term "attaching at least one guide member to said cavity" means any method of creating, targeting, attaching or adjusting the size of the guide member relative to the cavity, and with respect to the position, accessibility and size of the cavity and operational requirements.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will now be explained in more detail by way of examples of specific embodiments thereof, the description of which will be given with reference to the accompanying drawings, in which:

Fig. 1 is a schematic front view of a device according to the invention in connection with an assembly line for assembling cars;

Fig. 2 is a perspective schematic cross-sectional view of a cavity;

Fig. 3 is another schematic cross-sectional view of the cavity;

Fig. 4 illustrates one method of injecting heated medium into the cavity and removing the heated medium from the cavity;

Figure 5 Figure 5 Figure 5 Figure 5 Figure 5 Figure 5 Figure 5 Figure 5 Figure 5 Figure 5 illustrates another method of injecting heated medium into the cavity and removing the heated medium from the cavity; and Fig. 6 shows yet another method of injecting heated medium into the cavity and discharging the heated medium from the cavity.

DETAILED DESCRIPTION OF THE INVENTION

As shown in FIG. 1, the vehicle body 2 is positioned above a heating device 11 which is part of the production line 11. The vehicle body 2 is supported and conveyed by a conventional overhead conveyor 10.

The heating device 1 comprises fans 5 which produce air streams of mediums A and B, which are heated by two electric heating units 4. The hot air is blown towards the center 1a of the heating device 11 and is finally distributed over the guide elements 3. These guide elements 3 are directed into cavities 21 in the vehicle body 2. Hot air is blown into the cavities 21 to heat the coatings 22 and 23 (see FIGS. 2 and 3).

The cavities 21 are usually best accessible from below. By blowing hot air into the cavities 21, the entire body of the vehicle 2 is prevented from being heated.

The coating may be applied to the cavities 21 by means of conventional injection molding devices immediately before or during the heating process. In a first stage, hot air may be blown into the cavities 21 to heat the surface of the cavities 21 without coating,

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thereafter, a coating may be injected by means of known injection devices (not shown in the figures) _, after which hot air may again be blown into the cavities 21 to cure or dry the coatings 22 and 23 (see Figures 2 and 3).

FIG. 2 is a schematic perspective cross-sectional view of a portion of a vehicle body 2 having a cavity 21.

The surface area of the cavity 21 is coated with a coating 22. The coating 22 consists of a solvent-based anti-corrosion wax, but other coating materials, such as water-based or non-emission-based anti-corrosion waxes, may also be used (as described, for example). D. Symietz: "Protection Against Stone-Chip Damage and Corrosion, Verlag Modeme Industrie, Landsberg / Lech, 1998).

A heating device 11 comprising an electric heating unit 4 and a fan 5 is connected to the aperture 24 of the cavity 21. Hot air is blown into the cavity 21 and leaves the cavity 21 at the exit point of the medium C. The hot air temperature corresponds to the processing temperature of the coating 22. This treatment temperature in this context is about 180 ° C to 220 ° C, which is sufficient to heat the coating 22 of the water-based coating material in a sufficiently short time, causing the cure to begin.

The temperature of the medium C can be easily adapted to the coating composition and the specific temperature requirements which allow drying, curing or fluidization and complete coating

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The term &quot; fluidization &quot; means that, due to the action of hot air, the coating 22 becomes soft, becoming a liquid that penetrates into small gaps and covers the entire surface area of the cavity 21 in a substantially constant layer.

FIG. 3 shows a schematic cross-sectional view of a vehicle body 2 of an embodiment wherein the heater 1 comprises a liquid tank 1b which is connected via a pipe 25 and 26 to a cavity 21 of the vehicle body 2. The liquid tank 1b is provided with an electric heating unit 4. A pump 27 is provided in line 25 and is driven by a motor 28.

When the pump 27 is in operation, liquid medium D flows through line 25, through cavity 21 and back through line 26 to liquid tank 1b. The connector 29 serves to seal the conduit 26 before the liquid medium D flows out. If the coating 23 is, for example, synthetic wax, the liquid medium D may be water. Alternatively, an aqueous solution may be used as the heating liquid medium D.

In the embodiment of FIG. 2, after a period of time sufficient to cure or dry the coating 22, the electric heater 4 may be turned off, and the coating 22 and the cavity 21 may be cooled by blowing cold air into the cavity 21. If the cooling process is to be quicker, it is possible to use conventional cooling units to cool the air stream before blowing it into the cavity 21.

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Figures 4 and 6 show different embodiments of the invention in a schematic cross-section through the cavity 21. All embodiments have in common that cavities 21 are inserted with guide elements 3b, 3c and 3d which are either intended to be evacuated the medium E from the cavity 21 or for supplying the medium Fa G to the cavity 21, optionally under pressure.

4 shows a guide element 3a connected to the electric heater unit 4 and to the fan 5. The medium E is blown into the cavity 21, and is subsequently discharged by the guide element 3b, in which the vacuum generated by the pump or compressor 27c is applied.

FIG. 5 shows a guide 3c from which the pressure medium F passes through the cross-sectional opening 33 and through the additional side openings 32 into the cavity 21. Due to the applied pressure, the medium F flows towards the opening 24 of the cavity 21. The element 3c is characterized in that no temperature gradient is formed by releasing the heated medium F from a single point in the cavity 21.

FIG. 6 shows an embodiment where a guide member 3d is used to release the heated medium G from the cavity 21. To create a balanced bidirectional flow, the fans 5 evacuate the gaseous medium G from both sides from the cavity 21 via the guide elements. 3e.

Claims (18)

PATENT CLAIMS A production line for vehicles, in particular for automobiles, comprising a device for fluidizing and / or thermally curing and / or drying an anticorrosive coating (22, 23) in a cavity (21) of a vehicle body (2), comprising: 1) comprising at least one guide element (3, 3a, 3b, 3c, 3d, 3e) for directing the medium (A, B, C, D, E, F, G) into the cavity (21), wherein the at least one guide element (3) is designed to accommodate an opening (30) of the cavity (21). Production line for vehicles, in particular for automobiles, comprising a device for fluidizing and / or thermally curing and / or drying a coating (22, 23) in a cavity (21) of a vehicle body (2), characterized in that it comprises a device (1). ) for directing the medium (A, B, C, D, E, F, G) into the cavity (21) in such a way that the thermal stress of adjacent elements is minimized, wherein at least one guide element (3) is designed to match the hole ( 30) cavities (21). Production line device according to claim 1 or 2, characterized in that the device (1) comprises a heating unit (4) for heating the medium (A, B, C, D, E, F, G). The production line apparatus according to claim 1 or 2, characterized in that the at least one guide element (3b, 3c, 3d) is designed to be inserted into said cavity (21). • · · · · · · · · · · · Device according to one of the preceding claims, characterized in that the device (1) comprises means for accelerating the medium (A, B, C, D, E, F, G), the means preferably comprising a fan (5) or a pump (27). Device according to one of the preceding claims, characterized in that the medium (A, B, C, D, E, F, G) is a fluid. Device according to one of the preceding claims, characterized in that the medium (A, B, C, D, E, F, G) is a gas, preferably air. Device according to one of the preceding claims, characterized in that the device (1) comprises a plurality of guide elements (3), in particular for directing the medium (A, B, C, D, E, F, G) simultaneously to multiple cavities (3). 21) in the vehicle body (2). Device according to one of the preceding claims, characterized in that the device (1) is part of a production line (11) for vehicles, in particular for cars. Device according to one of the preceding claims, characterized in that it comprises a fan (5) for directing the air flow into the cavity (21) of the vehicle body (2), comprising an anti-corrosion coating (22, 23). Method for fluidizing and / or thermally curing and / or drying an anti-corrosion coating (22, 23) in a cavity (21) of a vehicle body (2), characterized in that the fluid flow is directed by at least one guide element (3, 3a, 3b) 3c, 3d, 3e) into the cavity (21), wherein at least one guide element (3) is adapted to the opening (30) of the cavity (21) into which the coating (22, 23) has been applied. The method of claim 11, comprising the steps of: optionally heating the fluid stream, optionally heating the cavity (21) by directing the hot fluid stream into said cavity (21), applying a coating (22, 23) in the cavity (21), and heating the coating (22) into the cavity (21). 23) directing the current hot A method according to the method of cooling a coating (22, 23) of a cavity (21). The method of claim 11 or 12, comprising the further step of directing the fluid stream into the fluid Method according to one or more of claims 11 to 13, characterized in that the medium (A, B, C, D) is directed into the cavity (21) and / or is directed out of the cavity (21). ο η ········· \ j ············· · · · · · · ··· · ··· Method according to one or more of claims 11 to 14, characterized in that it comprises the following steps: providing at least one device (1) for pressurizing the medium and / or for removing or sucking the medium out of the cavity (21), connecting the device (1a) to one or more guide means (3, 3a, 3b, 3c) for directing the medium B, C, D E, F, G), and attaching at least one guide element (3, 3a, 3b, 3c) to said cavity (21). Method according to claim 15, characterized in that the medium (A, B, C, D, E, F, G) is injected into the cavity (21) by pressure. Method according to claim 15 or 16, characterized in that said medium (A, B, C, D, E, F, G) is withdrawn or exhausted from the cavity (21). 18. Method according to claim 17, characterized with it that in the cavity (21) is pressure applied and / or vacuum. 19. The method of one or more of the claims 11 to 18, characterized with it that contains the next steps: guiding measures element (3a, 3b, 3c) which is possible positioned in the cavity (21), injecting a fluid flow through said guide element (3b, 3c) into the cavity (21), and / or aspirating a fluid flow through said guide element (3a) out of the cavity (21).