Painting automobile bodies has progressed to require a significant amount of advanced technology housed in painting facilities costing of hundreds of millions of dollars. These paint facilities receive unfinished “body in white” vehicle bodies from a body shop for paint processing and transfer painted and sealed bodies to final assembly facilities where the vehicle is completely assembled. A typical paint facility requires up to a third or more of an assembly plant floor space, which is exceedingly costly adding to the cost of painting a vehicle body in terms of both facility construction and energy requirements for maintaining the paint facility.
Various attempts have been made to adjust the processing orientation of vehicle bodies through paint shops. However, the primary focus of these concepts are directed toward pretreatment and electro deposition primer tanks. One such concept is shown in U.S. Pat. No. 6,419,983, Method of Introducing and Removing Workpieces, Particularly Vehicle Bodies, An Apparatus and System for the Surface Treatment of Workpieces. This concept discloses a conveyor system where vehicle bodies are rotated, end over end, and submerged at steep angles into the various pretreatment and e-coat tanks for improving the conversion coating and electrodeposition primer application and enabling the tank length to be shortened from conventional tank lengths. Further concepts have been shown in U.S. Pat. No. 6,676,755, Installation for Treating, Especially Painting, Objects, Especially Vehicle Bodies, and U.S. Pat. No. 6,673,153, Treatment Plant, and Particularly for Painting Objects, In Particular Vehicle Bodies. These patents also are directed toward pretreatment and electro deposition primer tanks and require complex conveyor systems enabling vehicle bodies to be submerged in the various tanks at steep angles allowing the tank size to be reduced.
None of the prior art patents have addressed the need to reduce the overall paint application facility size by reducing the size of the various paint booths and ovens required to apply and secure subsequent paint coatings such as, for example, primer surfacer, base coat, and clear coat. Therefore, it would be desirable to introduce a new paint shop configuration that would enable the reduction in overall size of the paint shop providing both reduced capital cost to construct the paint application facility and reduced energy requirements to operate the facility.
Additionally, conventional paint application booths support vehicle bodies in longitudinal orientation on a conveyor centrally located inside the booth. The paint application booth generally provides a downwardly directed flow of air to remove particulate paint not adhered to the vehicle body, known as overspray, into flowing water disposed beneath the conveyor. However, much of this overspray is known to adhere to the conveyor, which results in frequent cleaning. This is known to result in contaminants in the paint application booth causing defects in the paint coating. Furthermore, the various paint technologies presently in use, including, urethanes, water borne based paints, and powder paint, require a precise airflow balance inside the booth in the absence of air turbulence to apply an even, high quality paint coating. Locating process equipment inside the booth is known to cause turbulent airflow. Attempts have been made to reduce the amount of application equipment located inside and access to the various paint application booths to improve the airflow characteristics through the booth thereby reducing the resultant dirt and contaminants inside the booth. However, no attempts have been made to reduce the impact of the conveyor upon the airflow through the booth.
Therefore, it would be desirable to provide a conveyor configuration that reduces the impact of the conveyor upon the balanced flow of air and amount of dirt inside the paint application booth. More preferably, it would be desirable to simultaneously achieve the benefits of a reduced paint application facility size and a reduction in the adverse effects of presently available conveyor systems upon the quality of the decorative paint finish being applied to the vehicle bodies.
A paint booth assembly is adapted to apply coatings to a plurality of vehicle bodies moving serially through the paint booth. The vehicle bodies define a longitudinal axis and move through the paint booth in a direction that is generally perpendicular to the longitudinal axis of the vehicle.
As stated above, prior art paint application facilities process automotive vehicle bodies moving upon a conveyor in a direction generally parallel to the longitudinal axis of the vehicle bodies. This is best represented in
Orienting the vehicle bodies serially in a side by side relationship and moving the vehicle bodies through the various paint application booths and tanks, as represented in the lower portion of
Two benefits are derived by moving the vehicles at a generally perpendicular direction in a longitudinal axis of the vehicles. First, the conveyor may be slowed down to half its conventional speed while processing the same vehicle rate, which will improve paint finish quality by enabling a reduction in the flow rate of particulate paint in the paint application equipment. Second, through processing vehicles upon a conveyor moving at its original rate enables twice as many vehicles to be processed. Furthermore, some combination of a partial reduction in line speed and a partial reduction in paint flow rate produces an improved paint finish while still increasing a vehicle processing rate through the paint application facility.
The novel paint application facility design associated with the present invention, uses a new conveyor orientation by moving the conveyors to the outer wall of the various paint application tanks and booths. Alternatively, the conveyors are located outside the booth eliminating all contact of the conveyors with the particulate paint being applied to the vehicle bodies. In either case, an improved airflow quality is derived inside the paint booth which results in improved paint quality and a reduction in paint defects.
Furthermore, paint shop construction economies of scale are derived by processing vehicle bodies through the paint booth and ovens in a direction that is generally perpendicular to the longitudinal axis of the vehicle. The wide range of vehicle bodies, such as, for example, compact vehicles, midsize vehicles, utility vehicles, and most vans have generally constant widths while the vehicle lengths vary significantly. Painting vehicle bodies moving in this orientation provides the benefit of commonizing paint shop design, even between a paint shop designed to paint a compact size vehicle and a paint shop designed to paint a utility vehicle because the length of the paint booth and ovens are is now determined by the width of the vehicles and not the length. Therefore, unlike prior art designs, many of the engineering and fabricating processes that are changed for each paint shop construction are now common and can be re-used or re-processed.
Other advantages of the present invention will be readily appreciated as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings wherein:
Referring to
The vehicle bodies 12 are processed serially, in a side by side relationship through pretreatment and e-coat stations 16 enabling a significant reduction in the length of the various pretreatment tanks and e-coat tank. In other words, each vehicle defines a longitudinal axis represented as 18 in
Subsequent to processing through the electrodeposition primer coating, the vehicle bodies 12 are subjected to a deionized water rinse, and occasionally a subsequent manual operation as indicated in a first manual station 20 of
Immediately following the first manual station 20 is an electrodeposition primer oven 22 where the electrodeposition primer is cured. Preferably, the vehicle bodies 12 are again oriented in a side by side relationship for processing through the oven 22. With appropriate oven thermal balancing, the gap disposed between each vehicle body 12 is narrowed, further shortening the overall length of the oven 22. As should be known to those of skill in the art, the electrodeposition primer oven 22 now requires only approximately half the length of a conventional oven. Appropriate oven thermal balancing is easily achieved through the use of thermal couples to determine the appropriate oven 22 zone temperatures for processing the vehicles 12 in a side by side relationship.
Subsequent to the electrodeposition primer oven 22, the vehicle bodies 12 are transferred through a miscellaneous station 24 where the preferred vehicle gap between adjacent vehicle bodies 12 is optionally returned depending on processing leading to a second manual work station 26. The miscellaneous station includes such processing as, for example, the application of stone guard.
A second manual work station 26 is configured to again return the vehicle bodies 12 to a longitudinal transfer generally aligned with the axis 18 of the vehicle bodies. Manual operations include, but are not limited to, tack off sealing operations, fixture installations, electrodeposition primer sanding, and inspection. It is believed that moving the vehicle bodies 12 in a direction generally parallel to the longitudinal vehicle access facilitates manual processing as will be explained further below.
Preferably, the vehicle bodies 12 are again oriented in a side by side relationship just prior to entering both the primer surfacer booth and the paint application booth 28. For the purposes of discussion, and as shown in
Benefits derived through processing the vehicle bodies 12 in the aforementioned orientation are most noticeably derived in the paint application booth 28. As set forth above, the application booth 28 is shortened by up to half the length of a conventional booth significantly reducing the application facility floor space required to apply primer surfacer and top coat to the vehicle bodies 12. Generally, the gap 13 disposed between each of the vehicles 12 inside the booth 28 is preferred to be about eight feet. This gap is required whether or not the vehicles are processed in a side by side manner or processed along the longitudinal axis 18 to prevent overspray from one vehicle body 12 to collect upon an adjacent vehicle body 12. While being transferred through the oven 30, the gap disposed between each of the vehicles 12 is significantly less than four feet, further shortening the overall length of the oven 30. The oven 30 requires a wider footprint over conventional designs, however, the booth 28 retains substantially the same width as that of a conventionally designed booth. Once the vehicles bodies 12 have been transferred from the oven to a third manual station 32, the vehicle bodies 18 are again returned to move along the longitudinal axis 18 to facilitate remaining manual operations such as, for example, removing process fixtures, final paint inspection, and wet sanding the clear coat when necessary.
A statistical average was take of over seventy vehicle bodies 12 having a variety of body types including, compact vehicles, midsize vehicles, full size vehicles, vans, sport utility vehicles, and pickup trucks. The calculated variance of the length of these sampled vehicles was sixty nine inches while the calculated variance of the width of these vehicles was only 22.3 inches. Given these variances, it is believed that a single paint process equipment configuration can be used to paint each of these vehicle bodies allowing a significant reduction in duplicated design and additional fabrication over present paint shops that process vehicle bodies 12 in an end to end relationship. Therefore, regardless the vehicle type, the processing equipment is oriented on a common pitch, even if the width of the application booths vary slightly between, for example, a compact vehicle body and a full size pickup truck. This provides the ability to harmonize mechanical designs, controls, facility layout, and facility foot print consistently as opposed to rarely as is presently the practice.
A flash off zone 29 is positioned subsequent to the paint booth 28, where solvent evaporates from the uncured paint adhered to each of the vehicle bodies 12. In the flash off zone 29 and the following bake oven 30, the vehicle bodies 12 are preferably spaced apart an oven distance b, which is less than the booth distance a. The oven distance b need merely be that distance required to allow for a uniform heat transfer to each vehicle body inside the oven 30 to provide adequate paint curing. It is believed that the oven distance b is as little as two feet or less.
A transfer line and/or strip out 33 is located subsequent to a cooler 31, which blows cool air onto the hot vehicle bodies 12 to rapidly bring down the temperature of the vehicle bodies 12 exiting the paint oven 30. Vehicle bodies 12 in each of these zones 31, 33 are spaced a strip out distance c, which is less than or greater than distances a and b respectively, or as required to facilitate transfer of the vehicle bodies 12 to subsequent operations. Furthermore, the vehicle bodies 12 alternatively are rearranged into an end to end relationship if necessary in these zones 31, 33.
Miscellaneous zones 35, where inspections, minor repairs, and fixture removal take place are located after the oven strip out zone 33. In these miscellaneous stations 35, the vehicle bodies 12 are spaced a miscellaneous zone distance d that enables workers to access the vehicles bodies 12 to perform the requisite functions. Additionally, it may be necessary to again rotate the vehicle bodies 12 to an end to end serial relationship to provide the required access set forth above.
As known to those of skill in the art of paint application facility construction, the final stage of the paint application process is the selectivity zone 37. The vehicle bodies 12 are again, preferably, positioned in a side by side relationship and conveyed in a direction generally perpendicular to the longitudinal axis of each vehicle body 12. The selectivity zone 37 is merely where the defectively painted vehicle bodies are cycled back to a repair zone (not shown). Therefore, the distance between each body, represented by selectivity zone distance e is very narrow, preferably less than two feet.
Referring to
Below the lower surface 48, at least one scrubber 50 receives the sheet water 46 and transfers the water 46 into a separation chamber 52. A series of baffles 54 receive the water and paint mixture in the separation chamber 52 providing additional intermixing of the chemicals disposed in the water 46. Subsequently, the water 46 and paint particles are transferred to a filtration station (not shown) and returned to the water pumps 44 for reuse in a like manner. Various preferred embodiments of the filtration systems are disclosed in U.S. Pat. No. 6,716,272, Scrubber for Paint Booths, U.S. Pat. No. 6,666,166, Spraybooth Scrubber Noise Reflector, U.S. Pat. No. 6,623,551, Baffle System for Separating Liquid From A Gas Stream, and U.S. Pat. No. 5,512,017, Paint Spray Booth and Supply Plenum Arrangement, the details of which are incorporated in this application by reference.
Each vehicle body 12 is supported upon a vehicle carrier 56 which is conveyed by at least one conveyor 58 through the paint application chamber 38. Preferably, the conveyor 58 is located adjacent a booth wall 60 to reduce the turbulent effect of blocking the flow of air 30 through the application chamber 38, which is received from the plenum 40. As represented in
Preferably, paint applicators 82 are disposed above in the vehicle bodies 12 and are represented in
Referring now to
The vehicle carrier 56 is modified to include the elongated members 68, which extend through a slot 70 disposed in an alternate booth wall 72. The slot 70 extends the entire length of the alternate booth 64, or alternatively, the full extent of which the alternate conveyor 66a, 66b is disposed outside the paint application chamber 38.
A truss 74 or other support is disposed outside the application chamber 38 to support the upper potion of the alternate paint booth 64 enabling the slot 70 to extend the full length of the alternate booth 64. The alternate conveyor 66a, 66b are preferably disposed within a conveyor chamber 76, which is sealed by access door 78 from the outside environment. Preferably, the paint application chamber 38 has a slightly higher air pressure than that of the conveyor chamber 76 to prevent contaminants disposed in the conveyor chamber 76 from entering the paint application chamber 38 through the slot 70.
Preferably, the elongated members 68 are aligned with a rotational axis 18 of the vehicle body 12, the purpose of which is shown in
Referring now to
To complete the rotation of movement of the vehicle body 12, the cam arms 88 engage the sixth cam 102, the seventh cam 104, the eighth cam 108 and the ninth cam 108, which returns the vehicle to an upright position associated with interaction of the first cam 92. Once the vehicle body is returned to the upright position, the paint application process is completed and the vehicle body 12 is transferred to the oven to cure the paint. While the preferred embodiment is the cams described above and shown in
The invention has been described in an illustrative manner, and it is to be understood that the terminology which has been used is intended to be in the nature of words of description rather than of limitation.
Obviously, many modifications and variations of the present invention are possible in light of the above teachings. It is, therefore, to be understood that within the scope of the appended claims, wherein reference numerals are merely for convenience and are not to be in any way limiting, the invention may be practiced otherwise than as specifically described.