GB2099731A - Repairing an article coated on a finish-coating line - Google Patents

Abstract

The repair of the finish on an automobile during an assembly-line (16, 24, 40, 50) finishing operation is performed by determining in which zones of the automobile body (14) finish repairs are necessary, returning the automobile body to the finish- application line, and actuating those finish dispensing devices to dispense finish material upon those zones in which repairs are necessary. The line includes finish application sections (16, 40) and baking/drying sections (24, 50). At the outlet ends (28, 32) of each section (24, 50) inspection zones (56, 70) are provided, those bodies requiring repair being recycled through sections (16, 40) via masking stations (62, 74). Repair information is fed to the sections (16, 40) via data terminals (64, 78) and programmable controllers (22, 44). <IMAGE>

Description

SPECIFICATION Method of repairing an article coated on a finish-coating line This invention relates to the repair of applied finishes on articles to which finish is applied from atomization and dispensing devices in, for example, assembly-line-type operations. More specifically, the invention relates to a repair method useful on larger articles which may be thought of as divisible into various zones for finishapplication purposes. Examples of such articles are large appliances (e.g., refigerators, dish washers, and clothes washers and dryers) and automobiles and truck bodies.

As automobile and truck bodies, for example, are painted, defects sometimes occur in the various stages of the paint application. Repair of these defects is handled in many different ways, depending upon how the automobile bodies are processed through a finishing system, and in what stage of the finish-application procedure the defect occurs. For example, repair of a defect may be treated differently if the defect occurs in the prime coating stage, rather than in the finishcoating application stage. Similarly, repairs for single-color vehicle bodies typically will be performed differently from repairs on "two-tone" bodies.Lacquer repairs are handled somewhat differently from enamel repairs, since lacquers are typically thermoplastic and can be "spot repaired" as opposed to enamels, which typically are thermosetting and require masking and painting of entire vehicle body panels, such as doors, fenders, hoods, etc., upon which repairs are necessary.

In the majority of cases, vehicle body repair, even during the manufacture of a vehicle, is performed using manual finish material atomizing and dispensing equipment. There are a number of finishing systems presently in use which employ stationary, or semi-stationary, eiectrostatically aided, finish-material atomizing and dispensing systems. Typically, these systems include a group of atomizing devices arranged in a manner such that each atomizing device is primarily responsible for covering a specific area or zone of the particular article being finish-coated. In many cases, some of these atomizing devices are manipulated or moved to follow the contours of the particular configurations of the articles being finish-coated.

In automobile finish-coating systems of this type, automobile bodies being finish-coated are typically thought of as divisible into various zones.

Each atomizing device, or group of atomizing devices, is primarily responsible for dispensing coating material which eventually finds its way mainly or solely to a particular one or more of these zones. For example, overhead groups of atomizing devices are typically charged primarily with the responsibility of coating the hood, top, and trunk lid of an automobile body. Those atomizing devices or groups of atomizing devices situated generally on the left-hand side of the finish-coating line, as the automobile body passes along this line, are charged primarily with the dispensing of finish-coating material onto the lefthand side of the automobile door (i.e., left front fender, left front door, left rear door - in fourdoor and station wagon models - and left rear fender).Those atomizing devices or groups of atomizing devices situated generally on the righthand side of the finish-coating line or conveyor are responsible primarily for dispensing finishcoating material onto the right-hand side of the automobile body (i.e., the right front fender, right front door, right rear door, and right rear fender).

In such prior art systems for the application of "two-tone" finishes, the vehicle body is next passed through a second similar finish-application area. However, just prior to passage of the vehicle body through the second finish-application area, specific zones or portions of zones of the automobile body are masked, e.g., with pre-cut, pressure-sensitive, adhesive backed paper or tape which prevents the second color of finish-coating material from appearing on the masked zones or sub-zones.

If repair is required on a lacquer-coated automobile body, lacquer can typically be applied to the spot requiring repair; and the "spot repaired" body can then be "rubbed-out" with rubbing compound so that the repair cannot be detected. As discussed, the repair is conducted using manual equipment. On an enamel-finished vehicle body, the body is masked to leave exposed the zone or zones requiring repair, enamel is applied from manual spray equipment to those zones, and any necessary further treatment is performed. As can be readily appreciated, such repair methods are highly labor-intensive, increasing the production costs of vehicle bodies upon which repairs must be made, and thereby reducing profit margin on these vehicle bodies.

Major efforts have been directed toward reduction of all labor-intensive operations performed upon automobiles. The thrust of many improvements in automobile productions has been automation with the primary objective of reducing cost. The added benefit of automation in automotive body finish repair, as well as various other areas, is improved quality and uniformity of the repair.

According to the invention, a method is presented for repairing the finish of an article coated by a finish on a finish-coating line. The article includes a plurality of zones into which it may be thought of as divided for coating. The finish-coating line includes a plurality of devices for atomizing and dispensing finish-coating material for coating the article, with each device being primarily used to finish-coat a particular one or more of the zones. The repair method includes the steps of determining in which zones of an article repairs are necessary, returning the article to the finish-coating line, and actuating those devices primarily used to finish-coat those zones in which repairs are necessary.

Additionally, according to an illustrative embodiment of the invention, the method includes the steps of masking zones of the article adjacent the zones in which repairs are necessary.

According to an illustrative embodiment, the devices for atomizing and dispensing finishcoating material are controlled by a programmable controller to coat the various zones in accorda, Ice with predetermined parameters ano criteria of the coating materials and zone articles leing coated, and these parameters and criteria are stored in the controller.

Additionally according to the invention, the articles are coated with selected different colors of coating materials, and the controller also controls the sequence in which the different colors are dispensered by the devices onto the various articles which pass along the finish-coating line.

Further according to the invention, selected ones of the articles to be coated are coated with selected multiple colors, the controller controlling the combinations of devices dispensing the colors and the flows of the selected colors being supplied in selected ones of the devices.

The invention may best be understood by referring to the following description and accompanying drawings which illustrate the invention. In the drawings: Fig. 1 is a top plan view of a finish-coating line employing the method of the present invention; and Fig. 2 is a diagrammatic view of an automobile body which has been illustrated as having been cut along certain lines and "unfolded" into a single plane for purposes of illustration of the invention.

With particular reference to Fig. 1, a line 10 for the finish-coating of automobile bodies 14 includes a first section 1 6 for the application of a first coat of finish material. The bodies 14 pass through finish application section 1 6 in the direction of the arrows from the right-hand, or entry, end 1 8 to the left-hand, or exit, end 20. As the auto bodies 14 pass through section 16, they are coated sequentially by batteries of coating equipment of the type illustrated in U.S. Patent Application Serial No. 13,125, filed February21, 1979, and assigned to the same assignee as the present invention, now U.S. Patent No.

4,275,838. The bodies 14 are coated with finishes of selected different characteristics, e.g., different colors, with the control of the devices for the application of the various colors being provided by a programmable controller 22, of the type illustrated in U.S. Patent Application Serial No. 35,105, filed May 1, 1979, and assigned to a subsidiary of the assignee of the present invention.

From the exit end 20 of the finish-application section 16, the vehicle bodies 14 with finish applied enter a baking, curing, or drying section 24 in which the finish material applied in section 1 6 is baked, cureo, and/or dried to the necessary degree.

The bodies 14 enter section 24 at its left-hEnd, or entry, ene 26, are conveyed past the equipment which bakes, cures, and/or dries the finish, and exit from section 24 at its right-hand, or exit, end 28.

For many vehicle bodies 14, this ends the finish-application procedure. Those bodies 14 move in the direction indicated by arrow 30 away from the finish-application area for further processing or the like. For certain other vehicle bodies, however, additional processing may be required. For example, certain vehicle bodies 32 are sche -juled for the applicazicn of additional finish material ic give them "two-tjne' finishes. These venice bodies 32 pass througn a masking area 34 in which certain zones of the vehicie bodies 32 are masked using, e.g., pre-cut, pressure-sensitive, adhesive-backed paper or tape to cover those zones or portions of zones to which the second color of finish material is not to be applied.Once this masking operation is completed, those vehicle bodies 32 proceed in the direction of arrow 36 to the entry end 38 of a second finish-application section 40. Again, the devices employed to atomize and dispense the finish-coating material in section 40 are typically of the same type as those used to atomize and dispense finish-coating material in section 16. Also, control of the atomization and dispensing of the various colors of coating material to be dispensed in section 40 onto the automobiles moving in sequence through section 40 is controlled by a programmable controller 44 of the same type as programmable controller 22.

Once the additional finish-coating material is applied to the two-tone vehicle bodies 32, they exit from the right-hand, or exit, end 46 of finishapplication section 40 and proceed to the lefthand, or entry, end 48 of a baking, curing, and/or drying section 50 in which the additional coating material applied in section 40 is baked, cured, and/or dried to a desired consistency. From righthand, or exit, end 52 of section 50, the completed "two-tone" vehicle bodies 32 proceed to further processing or the like in the direction illustrated by arrow 54.

Returning now to the exit end 28 of baking, curing, and/or drying section 24, an inspection, illustrated diagrammatically in broken line 56, is performed on the vehicle bodies 14 to determine if repairs are required on the finish applied in section 1 6. Those vehicle bodies with acceptable finishes not needing repair, and not programmed to receive two-tone finishes, move along in the direction of arrow 30. Other vehicle bodies with acceptable finishes which are scheduled to receive two-tone finishes move along in the direction of arrow 58 to the masking area 34 as previously dicussed. Those vehicle bodies which require repair are returned in the direction indicated by arrow 60 to a masking area 62 where those areas, or "zones," of the vehicle body requiring repair are left unmasked for any necessary refinishing, and adjacent zones which do not require repair are covered with pre-cut, pressure-sensitive, adhesivebacked paper or tape.At the masking station 62, information relative to those zones of the vehicle body which are to be refinished, the body type, the body style, and the color of finish required is entered in a repair data terminal 64 which is linked to prgrammable controller 22 which controls the finish-application section 1 6. The data entered at terminal 64 also includes data relative to where the body 66 requiring repair will be inserted into the line of vehicle bodies 14 moving toward the entry end 18 of finish application section 1 6. This complete set of data ensures that ,,r sgrammable controller 22 will control the atomization and dispensing devices and color-change systems in finish application section 1 6 in the proper sequence to ensure repair of vehicle body 66.

Returning now to the exit end 52 of the baking, curing, and/or drying section 50, the repair procedure is also performed. An inspection to determine if the second color of "two-tone" finishes requires repair is performed at an inspection station 70 downstream from the exit end 52 of section 50. Those "two-tone" finishes requiring repair are returned in the direction indicated by arrow 72 to a masking station 74 where the zones or portions of zones requiring repair are left unmasked, and pre-cut, pressuresensitive, adhesive-backed paper or tape patches are applied to those adjacent zones of the twotone vehicle body not requiring repair.Information relative to the color of finish to be applied to the body 76 requiring repair, the style of the body 76 requiring repair, and the position in the line of vehicle bodies 32 at which the vehicle body 76 is being inserted is entered through a repair data terminal 78 into the programmable controller 44 which controls the atomization and dispensing devices and color-change equipment in "twotone" finish-application section 40.

Turning now to Fig. 2, the masking operations performed in the masking areas 34, 62, and 74, and the manner in which programmable controllers 22, 44 and repair data terminals 64, 78 operate upon the atomizing and dispensing devices in color-change equipment in finishapplication sections 1 6, 40, will be explained in somewhat greater detail. In Fig. 2, a typical vehicle body may be thought of as divisible into eleven zones: Zone 1 including the left front fender; Zone 2, the left front door; Zone 3, the left rear door; Zone 4, the left rear fender; Zone 5, the right front fender; Zone 6, the right front door; Zone 7, the right rear door; Zone 8, the right rear fender; Zone 9, the hood; Zone 10, the top; and, Zone 1 the trunk lid.Each of these Zones 1-11 1 can further be divided into sub-zones, e.g., for the application of two-tone finishes. In a typical finish-coating section 1 6, 40, three devices of the type described in the above-identified application Serial No.

1 3,125 are provided for application of finishcoating material to Zones 9, 10, and 11. These devices are mounted on hydraulic ram motors for vertical movement so that they may be projected into closely spaced relation to Zones 9 and 11, and retracted somewhat to clear Zone 1 0.

Similarly, typically two or three of these devices are provided for dispensing finish-coating material onto Zones 1--4 on the left side, and an additional two or three are provided for dispensing finishcoating material into Zones 5-8 on the right side.

Typically, two of such devices dispense material below the window level, and one is dedicated to dispensing of material above the window level.

The programmable controllers 22, 44 control the devices such that, for example, the flow of finishcoating material starts as Zones 1, 5, and 9 approach the positions of the devices, the flow of material decreases slightiy as the front wheel well 81 in each of Zones 1, 5 passes the devices, and the devices then dispense until the ends of Zones 1, 5, and 9 are reached. At this point, the devices responsible for covering Zones 9, 10, and 11 are retracted slightly so that they will clear the Zone 10 region. The devices dispensing coating material onto Zones 1 and 5 remain on.In addition, at this point, the devices responsible for coating from the window level up in Zones 2, 3, and 6, 7 are actuated to dispense finished coating material at a relatively lower rate to cover the windshield side pillars 82, the door tops 84, the center piller 86, and rear roof supports 88. Then these devices are turned off. At about this time, the devices dedicated to coating Zones 4, 8 are provided with reduced flows to account for the rear wheel wells 90, and the devices dedicated to coating of Zones 9, 10, 11 are reciprocated downward into close proximity to Zone 11 and dispensed material to coat it.Toward the end of the rear wheel well 90 regions of Zones 4, 8, the lower two devices on each of the right and left sides of the vehicle begin dispensing at somewhat higher rates to account for the increased area which coating material dispensed from them must cover. Finally, as the ends of Zones 4, 8, and 11 pass by the dispensing devices, flow in these devices is terminated by programmable controllers 22, 44. Typically, at this time, programmable controllers 22, 44 initiate a solvent flushing sequence prior to delivery of a different color of coating material to the dispensing devices to coat with a different color the next vehicle body in finish-application sections 1 6, 40.

Now let it be assumed that, in inspection station 56 (Fig. 1), finish flaws are detected in Zones 2 and 8 of body 66. The vehicle body 66 in which flaws are detected is returned to masking station 62, and Zones 1, 3, 7, 9, 10, and 11 are masked using pre-cut, pressure-sensitive, adhesive-backed paper or tape. Information is entered at repair data terminal 64 relative to the particular vehicle body type and style, the zones requiring repair, the color of material necessary to perform the repair, and the point at which the vehicle body 66 (Fig. 1) is to be reinserted in the line of vehicle bodies 14 entering entry end 1 8 of finish-application section 1 6. The program being executed in programmable controller 22 is updated to conduct the repair refinishing, and the vehicle body 66 requiring repair is refinished in Zones 2, 8.

Substantially the same kinds of activities are performed at masking station (Fig. 1) for a vehicle body 76 having a two-tone finish, the second color of which requires repair. However, typically, in masking station 74, only portions of zones requiring repair may be left unmasked, since twotone finishes frequently divide the eleven illustrated vehicle body zones into sub-zones.

Claims (8)

1. A method of repairing the finish of an article finish-coated on a finish-coating line, the article including a plurality of zones into which it is divided for coating, the finish-coating line including a plurality of devices for dispensing finish-coating material for coating the article, each device being primarily used to finish-coat a particular zone or zones, the method including the steps of determining in which zone or zones of an article repairs are necessary, returning the article to the finish-coating line, and actuating that device or those devices primarily used to finishcoat the zone or zones in which repairs are necessary.

2. A method according to claim 1, comprising the steps of masking zones of the article adjacent the zone or zones in which repairs are necessary.

3. A method according to claim 1 or claim 2 wherein the devices are controlled by a programmable controller to coat the various zones in accordance with predetermined parameters and criteria of the coating material and the articles being coated and these parameters and criteria are stored in the controller.

4. A method according to claim 3 wherein the articles are coated with selected different colours of coating materials, the controller also controlling the sequence in which the different colours are dispensed by the devices.

5. A method according to claim 3 wherein the devices are controlled by a programmable controller and the articles are coated with selected different colours of coating materials, the controller controlling the sequence in which the different colours are dispensed by the devices, the controller also having stored parameters and criteria of the various colours of coating material to be dispensed, selected parameters and criteria also controlling the dispensing of respective selected colours.

6. A method according to any of claims 3 to 5 wherein selected articles to be coated are coated with selected multiple colours, the controller controlling the combinations of devices dispensing the colours and the flows of the selected colours being supplied to selected devices.

7. A method of repairing the finish of an article, the method being substantially as herein described with reference to the drawing.

8. A finish-coating line constructed and arranged substantially as herein described and shown in Figure 1 of the drawing.