Automated method and system for making painted vehicle body panel skins and vehicle body panels, such as instrument panels, utilizing same

Abstract

An automated method and system for making painted vehicle body panel skins and vehicle body panels, such as instrument panels, are provided wherein throughput and equipment utilization are greatly improved at a relatively low cost. The method includes transferring a mold having a mold surface from an entrance station to a paint station within a dispensing area. The method further includes applying paint on the mold surface to form a layer of paint on the mold surface at the paint station. The method still further includes spraying curable polyurethane elastomer on the painted surface at a spray station within the dispensing area. The paint and spray stations may be coincident. The method still further includes, after the step of spraying and while the polyurethane elastomer is uncured, transferring the mold with the paint and the uncured polyurethane elastomer from the spray station to at least one accumulator station in a curing area to allow the polyurethane elastomer to completely cure in the mold and form the skin.

Claims

1. A method of producing painted vehicle panel skins, comprising the steps of: placing a mold in an entrance station, the mold having an inner surface; transporting the mold along a first segment of a closed-loop guide path to a combined paint and spray station; painting the inner surface of the mold within the paint and spray station; spraying a layer of curable polyurethane elastomer onto the painted inner surface of the mold within the paint and spray station; transporting the mold along a second segment of the closed-loop guide path to one of a plurality of separate accumulator stations adjacent to and separate from the paint and spray station; exposing an entire surface of the layer of curable polyurethane elastomer to ambient air for a complete cure of the polyurethane elastomer in the mold at the accumulator station receiving the mold; transporting the mold along a third segment of the guide path for unloading of the painted vehicle panel skin from the mold; unloading the painted vehicle panel skin from the mold; and readying the mold for a successive cycle of production of a painted vehicle panel skin.

2. The method of claim 1 wherein the mold is carried on a pallet adapted for transport on the guide path.

3. The method of claim 1 wherein the painted vehicle panel skin is unloaded at the entrance station.

4. The method of claim 1 wherein the combined paint and spray station has separate enclosed chambers.

5. The method of claim 4 wherein the method includes the further step of pressurizing each of the chambers with ambient air at sub-atmospheric pressure to facilitate exhaustion of fumes.

6. The method of claim 1 wherein each of the accumulator stations has an enclosed chamber.

7. The method of claim 6 wherein the method includes the further step of pressurizing each of the chambers with ambient air at sub-atmospheric pressure to facilitate exhaustion of fumes.

8. The method of claim 1 wherein each of the entrance, paint and spray, and accumulator stations has an enclosed chamber.

9. The method of claim 8 wherein the method includes the further step of pressurizing each of the enclosed chambers with ambient air at sub-atmospheric pressure to facilitate exhaustion of fumes from the entrance, paint and spray, and accumulator stations.

10. The method of claim 1 comprising the further steps of placing an unloaded skin in a plastic injection mold, injecting molten plastic to at least partially cover a surface of the skin opposite the paint, and permitting the molten plastic to solidify and bond with the skin in the mold to form a vehicle body panel.

11. The method of claim 1 comprising the further steps of placing an unloaded skin and a preformed injection molded part in a foam mold with a space between the skin and the part, injecting a foamable material into the space between the skin and the part, and permitting the foamable material to cure and bond to the skin and the part in the mold to form a vehicle body panel.

12. The method of claim 1 wherein the readying step includes cleaning the inner surface of the mold.

13. The method of claim 1 wherein the readying step includes applying a release agent on the inner surface of the mold.

14. The method of claim 1 wherein one or more of the transporting steps is facilitated by pneumatic force.

15. The method of claim 1 wherein the entrance, paint and spray, and accumulator stations are commonly enclosed within a framework.

16. The method of claim 15 wherein the step of placing a mold in an entrance station is carried out by opening a door in the framework.

17. A method of producing a painted vehicle panel comprising the steps of: placing a mold in an entrance station, the mold having an inner surface; transporting the mold along a first segment of a closed-loop guide path to a combined paint and spray station; painting the inner surface of the mold within the paint and spray station; spraying a layer of curable polyurethane elastomer onto the painted inner surface of the mold within the paint and spray station; transporting the mold along a second segment of the closed-loop guide path for receipt at one of a plurality of separate accumulator stations adjacent to and separate from the paint and spray station; exposing an entire surface of the layer of curable polyurethane elastomer to ambient air for a complete cure of the polyurethane elastomer in the mold at the accumulator station receiving the mold; transporting the mold along a third segment of the guide path for unloading of a painted vehicle panel skin thus formed from the mold; unloading the painted vehicle panel skin from the mold; placing the unloaded skin in a plastic injection mold; injecting molten plastic to at least partially cover a surface of the skin opposite the paint; and permitting the molten plastic to solidify and bond with the skin in the mold to form the vehicle panel.

18. A method of producing a painted vehicle panel comprising the steps of: placing a mold in an entrance station, the mold having an inner surface; transporting the mold along a first segment of a closed-loop guide path to a combined paint and spray station; painting the inner surface of the mold within the paint and spray station; spraying a layer of curable polyurethane elastomer onto the painted inner surface of the mold within the paint and spray station; transporting the mold along a second segment of the closed-loop guide path for receipt at one of a plurality of separate accumulator stations adjacent to and separate from the paint and spray station; exposing an entire surface of the layer of curable polyurethane elastomer to ambient air for a complete cure of the polyurethane elastomer in the mold at the accumulator station receiving the mold; transporting the mold along a third segment of the guide path for unloading of a painted vehicle panel skin thus formed from the mold; unloading the painted vehicle panel skin from the mold; placing the unloaded skin and a preformed injection molded part in a foam mold with a space between the skin and the part; providing a foamable material into the space between the skin and the part; and permitting the foamable material to cure and bond to the skin and the part in the mold to form the vehicle panel.

19. The method of claim 18 wherein the providing step is at least partially performed by injection of the foamable material.

20. The method of claim 18 wherein the providing step is at least partially performed by pouring the foamable material.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 is a perspective view of a prior art molded vinyl skin for covering a rigid substrate panel and a layer of padding;

(2) FIG. 2 is a sectional view taken along lines 2-2 of FIG. 1 which shows an air bag assembly installed behind an instrument panel cover, which includes a rigid substrate panel, a layer of padding, and the vinyl skin of FIG. 1;

(3) FIG. 3 is a schematic view of a system (with its top removed) constructed in accordance with one embodiment of the present invention with the flow or transport of molds between stations indicated by arrows;

(4) FIG. 4 is a side elevational view, partially broken away, illustrating one of various possible drive mechanisms for transferring molds horizontally between the stations of the system of FIG. 3;

(5) FIG. 5 is a schematic diagram of a robotic paint/polyurethane elastomer dispensing subsystem;

(6) FIG. 6 is a schematic block diagram of an overall control system for the system of FIG. 3;

(7) FIGS. 7a-7d are views, partially broken away and in cross section, of a plastic injection mold and illustrating method steps for forming a vehicle body panel as shown, partially broken away in cross section, in FIG. 7d; and

(8) FIGS. 8a-8d are views, partially broken away and in cross section, of a foam mold and illustrating method steps for forming a vehicle body panel as shown, partially broken away and in cross section, in FIG. 8d.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT(S)

(9) Referring now to the drawing figures, there is illustrated in FIG. 3 a system, generally indicated at 110, for making a series of painted vehicle body panel skins along a loop-shaped guide path in a manufacturing area and constructed in accordance with one embodiment of the present invention. The system 110 also performs one embodiment of the method of the present invention.

(10) In the embodiment of the invention described herein, the system 110 is utilized to make painted vehicle body panel skins (two of which are shown in FIGS. 7d and 8d at 200 and 202, respectively) for use with vehicle body panels (two of which are generally indicated in FIGS. 7d and 8d at 204 and 206, respectively), such as an instrument panel. The skins 200 and 202, as well as the resulting panels 204 and 206, respectively, have a soft and luxurious look and feel. The skin 200 or 202 may be similar in overall appearance to the skin 22 of FIGS. 1 and 2.

(11) In general, initially a first material such as polyurethane paint, and then a second material such as a liquid polyurethane elastomer are sprayed onto a surface 147 of an open mold 145 (FIG. 4) which has been transferred by a transport mechanism into paint/spray stations 114 (FIG. 3). The open mold 145 is originally transferred from an unload station to an entrance station which are preferably coincident (hence “entrance/unload stations” in block 112). However, it is to be understood that the entrance/unload stations 112 may be spaced apart from one another. When the mold 145 is transferred from the entrance/unload stations 112 into paint/spray stations 114 within a dispensing area 118, the inner surface 147 of the mold 145 is initially painted at a paint station which is preferably coincident with the spray station (hence “paint/spray stations” in block 114). Then, the painted inner surface 147 is sprayed with polyurethane elastomer at the spray station. However, it is to be understood that the paint/spray stations 114 may be spaced apart from one another.

(12) Then, the mold 145 is transferred into one or more accumulating stations 119 within a curing area 120. After the polyurethane elastomer has cured at the one or more accumulating stations 119 within the curing area 120, the cured skin is typically removed from the mold 145 at the unload station, which, as previously mentioned, is preferably coincident with the entrance station. The skin is typically placed into either a plastic injection mold 210 for bonding molten plastic to form a substrate 208 for a panel 204 or placed into a foam mold 212 containing an injection molded part 214 (i.e., FIGS. 7a-7d and FIGS. 8a-8d, respectively). Foam is injected into and fills the mold 212 to secure the injection molded part 214 to the skin 202 thereby forming the panel 206.

(13) The system 110 is especially designed so as to take up a minimum amount of floor space (i.e. has a small footprint) while making such skins in a production environment at a high throughput while efficiently using the production equipment of the system 110.

(14) The system 110 may include framework or framing which includes a plurality of beams (one of the horizontal beams is shown at 116 in FIG. 4), all interconnected together such as by welds and gaskets. The framework is completely enclosed within a structure, generally indicated at 115 in FIG. 3 (but with its top removed), which may be made up of a plurality of interconnected plexiglass panels which are supported above and about the framework by spacers and brackets (not shown).

(15) A blower or exhaust 126 is preferably located at or near the top of the plexiglass structure 115 and provides a partial vacuum within the plexiglass structure 115 at each of the stations 112, 114, and 119 therein in order to evacuate fumes from the paint and polyurethane elastomer which form the skins. A conduit 128 extending from the blower 126 may dispense the fumes outside of the building in which the system 110 is located or may dispense the fumes into a filter system. Air is drawn into the plexiglass structure 115 at the lower end of the plexiglass structure 120.

(16) Referring now to FIG. 3 in combination with FIG. 4, the entrance station of the stations 112 is provided adjacent the dispensing area 118 and may receive and retain a mold support fixture or pallet 132 in a predetermined position. In turn, each pallet 132 is adapted to receive and retain one of the molds 145 thereon for conveying the molds along the loop-shaped guide path. Preferably, the pallet 132 is made of a lightweight material, such as aluminum. The pallet 132 has downwardly extending projections or followers 131 which ride in guide tracks 134 (only one of which is shown in FIG. 4). The lower surface of the pallet 132 rides upon supported roller balls 133 between stations. The pallet 132 also includes a downwardly extending member 135 which is engaged by brackets, such as a bracket 158, mounted on various air cylinders to move the pallet 132 in a linear fashion.

(17) Alternatively, the mold 145 itself may serve as its own pallet if properly modified to include the structures of the pallet 132 at its bottom surface to enable the mold 145 to be moved between the stations 112, 114 and 119 and then held with the stations 112, 114 and 119 as previously described.

(18) Yet, still alternatively, a different transport mechanism may be utilized to transport the molds 145 between the stations 112, 114 and 119. The transport mechanism may take the form of a rotary table that can index the molds supported thereon between the stations 112, 114 and 119 and hold the molds in the stations 112, 114 and 119.

(19) A movable door, indicated by solid lines at 113 in FIG. 3, also made of plexiglass, may be raised to allow a human or robotic operator to perform the following tasks: 1) remove a cured skin from the mold 145 at the entrance/unload stations 112; 2) clean the emptied mold 145, if necessary; and 3) apply a release agent to the inner surfaces 147 of the mold 145, if necessary.

(20) After the door 113 is subsequently lowered, another door, indicated by phantom lines 111 separating the stations 112 from the dispensing area 118, is raised and the pallet 132 (and supported mold 145) is then moved along the guide track 134 into the paint/spray stations 114 in the dispensing area 118. The door 111 is lowered and initially paint, such as polyurethane paint, is dispensed or applied on the inner surfaces 147 of the mold 145 such as by a robot or manipulator 140 of a dispensing system, generally indicated at 138 in FIG. 5. The details of such a robot dispensing system 138 are illustrated in FIG. 5. The system 138 is illustrated for spraying both paint and polyurethane elastomer (hence “paint/polyurethane containers” of block 146; “pumps” of block 148; “filtered pressure regulators” of block 150 and “paint/polyurethane dispensers” of block 144).

(21) Alternatively, the paint can be applied to the inner surface 147 of the mold 145 by a human operator. In that event, typically the stations 114 would be separated and a door similar to the door 113 would be provided to allow the operator to access the inner surfaces 147 of the mold 145 in the dispensing area 118.

(22) The robot or manipulator 140 operates under control of a robot control unit 142. The robot manipulator 140 has a work envelope and, alternately, either an automatic paint or polyurethane elastomer spray gun or dispenser 144 may be supported on the manipulator 140 for movement relative to at least two control axes for initially dispensing the paint and then the polyurethane elastomer, respectively, on the inner mold surfaces 147 at the paint/spray station 114, respectively.

(23) Typically, initially the robot 140 automatically has the paint dispenser supported thereon. Then, after paint application, the robot 140 removes the paint dispenser and secures the polyurethane elastomer dispenser thereon. After the polyurethane elastomer is sprayed on the painted surface 147, then the robot 140 removes the polyurethane elastomer dispenser and replaces it with the paint dispenser in anticipation of painting a new unpainted surface 147 of a new mold 145 at the paint station.

(24) A plurality of video cameras 143 can be spaced apart and are located at the paint/spray stations 114 to collect image data for use by the robot control unit 142 to determine not only the position and attitude of the mold 145 but also whether the paint and/or the polyurethane elastomer is being properly applied on the inner surfaces 147 of the mold 145. In this way, the movement of the robot manipulator 140 is accurately controlled.

(25) The dispensers 144 for the paint and polyurethane are typically alternatively attached to a wrist of the robot manipulator 140 together with inlet hoses for paint, polyurethane elastomer and cleaning solvent. The dispensers 144 may be stored in a rack accessible to the robot 140 in the dispenser area 118 when not in use. The robot 140 can typically attach or unattach the dispensers 144 in an automatic fashion without human intervention.

(26) When a mixing unit is used, such as for two-component polyurethane elastomers, the combined weight of the particular dispenser 144, the mixer unit and multiple hoses may necessitate the mounting of these on the arm of the robot manipulator 140.

(27) The system 138 also includes paint/polyurethane containers 146, pumps 148 for pumping the paint and polyurethane from their respective containers 146, to their respective filtered pressure regulators 150 and to their respective dispensers 144.

(28) Pump selection depends on the properties of the paint/polyurethane, size of the containers 146 and the dispensing rate required. The system 138 should keep track of the level of the paint/polyurethane in the containers 146 by means of a programmable controller 152 and stop the automatic operation of the paint/polyurethane dispensers 144 when the paint/polyurethane is depleted.

(29) Because certain paints/polyurethanes dry out, harden or solidify if not mixed or if left unused for a period of time, the system 138 typically has the capability of automatically purging spoiled material and cleaning the containers 146 and the lines which run between the components of the system 138.

(30) The programmable controller 152 is generally used to supervise the overall dispensing of the paint and the polyurethane elastomer and enables communication between the robot manipulator 140, the containers 146 and the dispensers 144. Typically, the programmable controller 152 is in communication with the robot control unit 142 to control the actuation of the dispensers 144 in coordination with the robot motion and for control of the level of the paint and the polyurethane in the containers 146.

(31) Alternatively, an additional robot may be provided so that one robot applies the paint and the other robot applies the polyurethane elastomer. If two robots are used, then typically two robot control units are needed.

(32) Yet, still alternatively, instead of one or more robots, one or more hard automations subsystems may be used to apply the paint and the polyurethane elastomer. In this case, robot control units are not used.

(33) Each pallet 132 is pushed (or pulled) into the paint/spray stations 114 in the area 118 by an air cylinder (FIG. 6) which drives a driver or bracket 158 upon extension of its push rod 159, as generally indicated in FIGS. 3 and 4. The bracket 158 engages the member 135 on the lower surface of the pallet 132. The bracket 158 is guided in its movement by a guide rod 160.

(34) Once the pallet 132 is in the paint/spray stations 114 (as sensed by the limit switches of FIG. 6), shot pins actuated by air cylinders (FIG. 6) together with a bracket actuated by another air cylinder lock the pallet 132 in a known predetermined position prior to the dispensing of the paint and then the polyurethane by the system 138. After both the paint and then the polyurethane are dispensed, the shot pins and the bracket are retracted by their respective air cylinders.

(35) The mold 145 (the inner surface 147 of which is coated with the paint and then the polyurethane elastomer) is then moved into the one or more accumulator stations 119 in the curing area 118 from the paint/spray station 114 by means of one of the air cylinders which causes a bracket attached thereto to pull (or push) the pallet 132 into the adjacent accumulator station 119. The bracket is guided along a guide rod during movement of the bracket.

(36) While two accumulator stations 119 are shown in FIG. 3, one or more than two accumulator stations 119 may be provided in the curing area to increase throughput of the system 110 while maximizing utilization of the robot 140. The pallet 132 stays in one or both of the accumulator stations 119 within the curing area 120 until the polyurethane elastomer in the mold 145 has completely cured.

(37) Between the accumulator stations 119, the pallets 132 are transferred or indexed horizontally. Once in the accumulator stations 119, the pallet 132 engages stop and limit switches (FIG. 6). The limit switches also signal the other air cylinders to push or pull the pallets 132 currently in the entrance/unload and paint/spray stations 112 and 114, respectively, into their next successive stations. A pallet 132 in the accumulator station 119 adjacent the entrance/unload stations 112 is pulled (or pushed) by an air cylinder through a bracket attached thereto into the entrance/unload stations 112. The bracket is guided in its movements along a guide rod.

(38) When the pallet 132 supporting the mold 145 containing the completely cured skin has moved from the accumulator station 119 adjacent to the entrance/unload stations 112, the polyurethane is completely cured. The operator raises the door 113 and then removes the skin from the mold 145. Consequently, the entrance station also serves as an unload station. While the door 113 is still open, the operator may clean the mold 145, if necessary, and/or place more release agent on the mold surface 147, if necessary.

(39) Referring now to FIG. 6, there is illustrated the overall control system for controlling the operation of the method and system of one embodiment of the present invention. 230 controls the programmable controller 152, the pneumatic controller 232 and the blower 126. The pneumatic controller 232 communicates with the master controller 230 to control actuation of the air cylinders as previously described. The limit switches, as also previously described, provide feedback signals to the pneumatic controller 232 which, in turn, provides actuating signals to the air cylinders as well as signals to the master controller 230 to control the blower 126 and the programmable controller 152, as previously described with reference to FIG. 5.

(40) Referring again to FIGS. 7a-7d, there is illustrated the sequence of steps to make the body panel 204 of FIG. 7d from the skin 200. With the mold 210 open in FIG. 7a, the skin 200 is placed on the inner surface of the lower mold half. Then the mold 210 is closed in FIG. 7b. In FIG. 7c, molten plastic is injected into the mold 210 between the skin 200 and the lower surface of the upper mold half After cooling, the mold 210 is opened and the resulting body panel 204 including the newly formed thermoplastic substrate 208 is removed from the mold 210. A view, partially broken away and in cross section, of the resulting panel 204 is shown in FIG. 7d.

(41) Referring again to FIGS. 8a-8d, there is illustrated the sequence of steps to make the body panel 206 from a thermoplastic substrate 214 and the skin 202 (which is substantially identical to the skin 200). With the mold 212 open in FIG. 8a, the skin 202 is placed on the inner surface of the lower mold half. The injection molded substrate 214 is received and retained on the inner surface of the upper mold half. Then the mold 212 is closed in FIG. 8b. In FIG. 8c, molten foam is poured or injected in the space between the skin 202 and the plastic substrate 214. After the foam has cured, thereby bonding the skin 202 to the substrate 214, the resulting body panel 206 is removed from the opened mold 212. FIG. 8d is a view, partially broken away and in cross section, of the resulting panel 206.

(42) While the best mode for carrying out the invention has been described in detail, those familiar with the art to which this invention relates will recognize various alternative designs and embodiments for practicing the invention as defined by the following claims.