Patent Application
20060054272
1. Field of the Invention
This invention relates to the field of sealing, adhesives, and applying structural enhancements. In one specific aspect, the invention relates to the field of applying tape onto a work piece using a robot and software.
2. Description of the Related Art
It is known in the art to employ mastics, foams and expandable materials for sealing cavities and joints between components, such as metal, glass, plastic, and composites. Examples of metal components comprise metal panels such as those used in metal buildings, roofing, pipelines, aircraft, medical instruments, marine, non-automotive equipment and vehicles such as tractors, tractor trailers, golf cars, construction equipment, recreational vehicles, etc, and automotive components, among other applications wherein robot assembly is desirable. In the case of automotive components, metal is typically stamped into a desired configuration and the joint between the stamped metal components, or over/under the metal seam, is sealed (e.g., to control wind, dust, noise, water intrusion, metal bonding, structural reinforcement, and function as an adhesion promoter).
In a typical manufacturing operation, a worker seals (including adding an adhesive, or a structural material or sound abatement material) a work piece (e.g., stamped automotive part) by applying tape onto the work piece. The worker is required to maneuver the tape (e.g., a sealant) along a linear or non-linear path, and to apply sufficient pressure on the tape in order to adhere the tape to the work piece. The work piece can have contours which can complicate the tape application. This requires a significant amount of manual dexterity on the part of the worker at various stages, laying down the tape and applying appropriate pressure to the tape in order to ensure that the tape will be fastened securely and function adequately. In addition, when applying two-sided adhesive tape, it is important to cut the tape cleanly and to avoid the paper or backing from sticking to the adhesive after the tape has been cut.
Accordingly, it would be desirable to reduce the time required to perform these taping operations while retaining, or improving the level of precision of a skilled worker. In addition, it would be advantagous to provide a method of applying tape that is uniform, predictable and reproducible, using an apparatus which is cost-effective. U.S. Patent Application Serial No. U.S. 2002/0124967A1 (published Sep. 12, 2002) discloses an applicator and method for applying two-sided adhesive tape between two work pieces; the disclosure of which is hereby incorporated by reference.
Embodiments of the present invention comprise systems and methods for applying material onto a work piece. One aspect of an embodiment of the present invention comprises storing path data for a predetermined path for applying a material to a work piece, storing length data for the length of the material to applied to the work piece, determining when to cut the material, applying the material to the work piece along the predetermined path using a material applicator apparatus, and cutting the material using a cutting component in the material applicator apparatus.
The exemplary embodiment is mentioned not to limit or define the invention, but to provide an example of an embodiment of the invention to aid understanding thereof. Exemplary embodiments are discussed in the Detailed Description, and further description of the invention is provided there. Advantages offered by the various embodiments of the present invention may be further understood by examining this specification.
The invention may take physical form in certain parts and arrangements of parts, certain aspects and methods which will be described in detail in this specification and illustrated in the accompanying drawings that form a part hereof. Any dimensions shown on the Figures are for illustration purposes only, and the components shown in these Figures can be employed in a wide range of dimensions and configurations.
The drawings are provided to illustrate certain aspects of the invention and shall not limit the scope of any claims appended hereto. Referring to
The adhesion or bond formed at the first contact location can increase the effectiveness of tape application (e.g., in the case of an oily work piece the initial bond permits the tape to unreel along the application path instead of sliding across the work piece surface without being dispensed). If desired, a downward pressure can be applied at the first contact location. This downward pressure can mimic a manual tape application. If desired, the robotic tape applicator 1 can employ a driven system to apply a sealer instead of using adhesion or friction. A driven system can allow less tension to be applied to the sealer thereby preventing unintended tape 3 dispensing (e.g., uncut tape 3 becomes adhered to the work piece surface thereby causing unintended tape 3 dispensing as the robotic tape applicator 1 is displaced). The robotic tape applicator 1 can be adapted to accommodate a wide range of tape widths.
The tape 3 can be an adhesive, a sealant, sound abatement material, single or double sided, as well as other known types of tapes. Tapes can be used in automotive, industrial, among other applications. Tapes suitable for robotic application can have a wide range of chemical compositions and physical properties. Examples of suitable tapes used in automotive sealing comprise tapes that can be welded through and seal the welded area, tapes with mastic and a thin film (e.g., EPDM, butyl, nitrile, SBR, polybutadiene, metallic filler); tapes having a weld through film only (e.g., EMA, ethylene acrylic, epoxy); tapes having a rigid or structural film (e.g., epoxy or ethylene acrylic); tapes that are heat cured subsequent to application and become rigid or function as structural reinforcements (e.g., nitrile, ethylene acrylic, epoxy, and SBR); tapes having various degrees of temperature resistance (e.g., high temperature resistant compounds such as fluoroelastomer, polysiloxane, ethylene arylic, EPDM, and acrylic and ambient to medium resistant compounds such as butyl, polybutadiene, SPR, nitrile, neoprene and low temperature compounds such as flouro, polysiloxane); heat expandable compositions; paintable sealants; tapes that melt when heated; as well as other tapes know to one of ordinary skill in the art used for automotive applications. Automotive tapes are available from Orbseal LLC, Richmond, Mo.
The tape 3 can also comprise a general purpose material such as PVC, mylar, polyethylene, or similar backings on pressure sensitive mastic, that can used for barrier wrap. An example of such a material comprises the laminar structure disclosed in U.S. Pat. No. 6,638,590B2; the disclosure of which is hereby incorporated by reference. The suitable tape 3 (including its backing material) will depend upon the end use of the tape 3. Examples of suitable backing material comprises at least one member selected from the group consisting of polypropylene film, metallic films, glass weave, Kevlar®, Mylar®, or specially formulated films of flouroelastomer. The tape 3 can also include special fillers in order to obtain certain desirable properties. Examples of suitable fillers comprise at least one member selected from the group of metallic (e.g., magnetic), paintable, ceramic, silicates (e.g., corrosion buffer), conductive graphite, expansion agents (e.g., an encapsulated blowing agent), UV cured or activated, among others.
Using the robotic tape applicator 1, tape 3 is applied to one or more work pieces for sealing, sound abatement, and/or joining the work pieces together. The work pieces can vary in configurations and sizes. For example, tape 3 can be applied to automotive work pieces, including, but not limited to, quarter panel seams/joints/panels; dash panel seams/joints/panels; cowl panel seams/joints/panels; A, B, C, D, or E post seams/joints; rocker or sill seams/joints; wheel arch seams/joints; fuel filler bowl seams/joints; rifle arm or shotgun rail seam/joints/panels; drain channel seam/joints; package tray seams/joints/panels; rood ditch seams/joints; body side to quarter panel seams/joints/panels; lower panel reinforcement seams/joints/panels; plenum chamber seams/joints; roof header and bow seams/joints/panels; hood and rear deck seams/joints/panels; floor pan seams/joints/panels; light can seams/joints; and door intrusion beams/joints/panels.
Referring to
The amount of downward vertical force on the tape applicator head 7 depends upon the tackiness of the tape 3, surface characteristics of the work piece, among other variables affecting adhesion between the tape 3 and work piece. If desired, a constant pressure can be maintained on the tape applicator head 7 by means of the pressure cylinder 2, typically regulated by hydraulic or pneumatic forces, which assists in downward vertical force and allows the tape applicator head 7 to be in constant compliance with the work piece. In addition, lips or projections 15, as shown in
In order to apply tape 3 in a controlled fashion, it is preferred to cut the tape 3 while the tape applicator head 7 remains in contact with the work piece so that the tape 3 that has been applied will not be pulled away from the work piece. In one aspect, as illustrated in
The knife blade 17 can operate under the control of a knife blade control piston 4. Referring to
It is beneficial to maintain a constant tension on the tape 3 during tape application. Inconsistent tension on the tape 3 can cause the tape 3 to break and/or can cause the tape 3 to be cut in improper lengths, e.g., shorter or longer of the desired length. In one aspect, one or more nip rollers 25 can provide a point of constant tape tension regardless of the amount of tape 3 on the roller 5. As the radius of the tape 3 on the roller 5 decreases, the tension on the tape 3 can vary unless such a tape tensioning means is employed. The nip rollers 25, 74 (one shown in
In order to keep the tape 3 moving completely in line with the tape applicator head 7, side guides can be provided. In one aspect, crown guides 28 on the idler rollers 29 keep the tape 3 moving in a straight line with the tape applicator head. These side guides can also include a non-stick coating in order to prevent the tape 3 from dragging, thus avoiding unwanted tensions. Side guide plates 31 can be located at one or more locations on the tape applicator head 7 in order to help guide the tape 3. In one embodiment, the side guide plates 31 are extended down to the application area of the nose 9 as shown in
The shape of the nose 9 can affect the efficiency of tape application. A smooth radius at the tip of the nose 9 prevents excess tension in the tape 3. If the center point 35 of the radius of the nose tip (as shown in
Referring to
The removable backing 6 can be removed by the robotic tape applicator 1 after applying the tape 3 to the work piece. The backing 6 can be removed by any suitable means that does not adversely affect the tape application or operation of the robot (e.g., using a vacuum system to pass the backing material over rollers and then into a collection system). For example, as shown in
Referring to
The robot controller 44 controls the robot 46 and can receive and transmit information between the robot 46 and the OPAAS controller 38. The OPAAS controller 38 controls the OPAAS tools 48 and the components on the OPAAS tools 48. The OPAAS controller 38 can receive information from the robot controller 44 or from the robot 46. The OPAAS controller 38 can interact with any suitable robot 46 which can be employed for transporting the robotic tape applicator 1. The robot 46 can be new robot or an existing robot can be retrofitted to receive the robotic tape applicator 1. An example of a suitable commercially available robot 46 comprises a Fanuc S-S Robot was chosen for the activator and tape application due to the shape and size of the part to be taped. On many of the parts, a large reach combined with the ability to manipulate a tool 48 at a complex tilt is required. The six-axis, articulated robot 46 can be programmed based on the nominal contours of the 3-dimensional mathematical part profile data of a work piece in which tape 3 is going to be applied. The 3-dimensional mathematical part profile can be used to generate the basic tool path for the work piece. Any difference in shape due to moisture content and shrinkage can be accommodated by the end of arm tooling. The robot 42 has the capacity to store a multitude of robot paths. Each of the proposed paths can be programmed into the robot controller 42 via known programming methodology. The proposed paths can be linear, nonlinear, three-dimensional, etc.
The robotic tape applicator 1 illustrated in
Referring to
Referring to
Referring to
Referring to
Referring to
Referring to
Referring to
At step S1, the three-dimensional profile of one or more work pieces, e.g., body parts, on which a tape 3 is to be applied, is recorded and stored in the computer 42, e.g., in memory or in an electronic database. After storing the one or more profiles, the method proceeds to step S2.
At step S2, based on the stored information about the work piece, an operator of the robotic tape applicator system can input or program into the robot controller 42, a three-dimensional path for the robotic tape applicator 1 to travel to apply tape 3 onto the work piece. Using the robot controller 44, the operator can program the plurality of different points through a number of ways as understood by one skilled in the art based on a reading of the present disclosure. For example, the operator can enter the actual coordinates for the desired points along the path, in accordance to the stored three-dimensional profile of the work piece. The number of points desired for a particular path depends on the desired accuracy of the tape application along the path and the complexity of the path. After storing the proposed path, the method proceeds to step S3.
At step S3, the robotic tape applicator is run at least once, through the path based on the designated points, to allow the OPAAS controller 38 (OPAAS software) to automatically monitor and capture data about the path necessary for the tape application along the path. If needed, the operator can correct the three-dimensional profile of a work piece if the profile of an actual work piece differs from the stored profile. In one embodiment, the OPAAS controller 38 monitors the tape applicator head 7 and its velocity as the robotic tape applicator system is run along the path the tape 3 is going to be applied to a work piece. For example, the robot 42 or robot controller 44 can provide velocity information regarding the tape applicator head 7 to the OPAAS controller 38. The OPAAS controller 38 uses this information to calculate the length of the path and the required amount of tape 3 that is being applied, e.g., fed by the robotic tape applicator 1. In an alternate embodiment, the robotic tape applicator 1 can include one or more counters (not shown) can provide information to the OPAAS controller 38 regarding how much tape 3 has been dispensed. The OPAAS controller 38 stores the calculated length of tape needed in memory, e.g., an electronic database. The OPAAS controller 38 robot controller 44 or robot 46 can also provide an indication where the tape application begins. Thus, the OPAAS controller 44 uses the starting point and the velocity of the tape applicator head 7 to determine how much tape 3 is applied and when to cut the tape 3. This step can be repeated for each piece of tape 3 that is being applied to a work piece. After the OPAAS software monitors and captures data about the path, the method proceeds to S4.
At step S4, based on the monitored and captured data about the path, the OPAAS software is run a second time to automatically calculate where to cut the tape 3 at about an end point, when to turn on and off components, e.g., pressure cylinder 2, knife blade 17, control piston 4, braking assembly 21, air ports 37, splicing component 50, adhesion promoter 52, cutting station 52, adhesion promoting component 54, 56, jet blaster cleaner 60, the motors in the tape applicator head 7 (which can affect the actual end point of the sealant on the surface of the work piece), and other factors critical to the tape application. The OPAAS software determines when to turn these components on and off based on the length of tape and the velocity of the tape applicator head 7. According to one embodiment, a standard cutting speed during all cuts is adopted to minimize error in the cut length in paths with different application speed, wherein an optimal cutting speed is determined, applied to all paths, and adopted as a “rule” for path programming. Optimal cutting speed is a function of the material type, thickness and width of the tape. Cutting speeds are determined with empirical testing results on that particular material type to be applied. Thus, the OPAAS software can calculate when the cutting means, e.g., the knife blade 17, needs to be actuated based on the length of tape 3 that is dispensed This calculation takes into account the mechanical and electrical time constants of the cutting means and adjusts accordingly. For example, slight variations in mechanical time constants of different cutting means or tools require each tool to be calibrated to determine the timing offset required to keep cut length consistent from tool to tool. A global offset for each tool can be predetermined and loaded into the OPAAS software during the time of startup of that particular cutting tool so as to achieve the optimal cutting speed for all cuts.
In another embodiment, the cutting means must be actuated faster or slower depending on the velocity of the robotic tape applicator 1 and/or the tape applicator head 7 in order for the end point of the tape 3 to be the same. The OPAAS controller 44 further allows the operator to input and finely change the end point (e.g., using an end-point slider) so as to trim the end point and affect the actual end point of the tape 3 on the surface of the work piece. This is important for a clean separation between the tape 3 applied on the surface of the work piece and the tape 3 remaining on the tape applicator head 7. In addition, based on the location of the tape applicator head 7, the operator can also determine where different functions can start and end. For example, when the adhesion promoter 52 is applied, when to heat the tape 3, when to shoot a blast of air, etc. This can also be done in a separate step. After the OPAAS software determines the control points for controlling the robotic tape applicator 1, the method proceeds to step S5.
At S5, based on the above calculations, the tape application is performed and the OPAAS controller 44 controls the various components of the robotic tape applicator 1 to effect proper tape application to the work piece along the desired path. Again, since the velocity of the tape applicator head 7 can differ based on the individual robot 46 being used, the OPAAS controller 44 is able to account for differences between individual robots 46 to consistently and efficiently apply tape 3 to work pieces.
During tape application, the OPAAS controller 44 can also communicate or interface with external programmable controllers for the robot cell that controls movement of the robotic tape applicator 1 and its tape applicator head 7 for health monitoring of the tape application. This ensures that the tape application is functioning properly and moving forward without any errors. Health monitoring can include monitoring various sensors to determine how much tape 3 is on the roller 5, whether the tape 3 is moving at substantially the same speed as its application through the tape applicator head 7, whether the pulling of the tape backing 6 is being done at substantially the same speed as the tape application through the tape applicator head 7, the position of the knife blade 17, the position of the compliance pressure cylinder 2 which controls how much pressure the nose 9 puts on work piece (the compliance pressure can be controlled by the OPAAS software, and it is adjustable as an input from the operator based on how much oil is on the work piece surface), etc. For example, the OPAAS controller 44 can monitor the level of tape 3 in the head via sensors in the tape applicator head 7, which indicate when there is two or three cycles of tape 3 left. This can be used to alert the operator and a countdown can be initiated to determine when to replace the tape cassette 72. The OPAAS controller 44 can also monitor if the tape cassette 72 has been dropped off and if the tape 3 has been replenished. The OPAAS controller 44 can also monitor if the covers of the tape applicator head 7 are on or before moving the tape applicator head 7 away from the tool post area. In one embodiment, the OPAAS controller 44 controls all aspects of actuation of all pneumatic devices and electric motors on the tape applicator head 7 in a specific order. Timing of each event can be changed through the OPAAS controller 44. These types of system parameters can be established at the factory or by the operator as desired based on the type of material being applied to the tape applicator head 7.
The OPAAS controller 44 can also interface with other controllers or control devices in the robot cell for seamless integration, whereby the OPAAS controller 44 can further monitor the status and health of the robot cell before allowing the tape application to proceed. For instance, the OPAAS controller 44 can interface with a supervisory controller in the robot cell that typically controls ancillary functions such as tasks like tool drop-off, doors opening and closing, part rotation, etc. To that end, the OPAAS controller 44 can include software modules to accommodate different communication protocols (e.g., Interbus-S, Profibus, Ethernet) used by those controllers with which the OPAAS controller 44 (and thus the OPAAS software) interfaces or communicates. Thus, the OPAAS software can include multiple software modules to afford communication with the various controllers.
The OPAAS software can include additional software modules to perform additional functions. For instance, a software module can be added to interface with an external vision system (not shown), or other sensors fitting to the OPAAS controller 44 for autoVScan capability. As referred herein, autoVScan is the ability to automatically detect what the tape 3 or tape cassette 72 is installed on the main bracket 18 for verification of appropriate tape types, batch information such as shelf life, date of manufacture etc. As mentioned earlier, this information could be encoded on the reel of tape 3 via the identification tag 62 thus ensuring that only approved tapes 3 can be allowed to run on the system or that the wrong type is not used.
While the above description emphasizes using the tape applicator head 7 for applying tapes 3, e.g., an adhesive, a sealant, structural or sound abatement material upon an automotive component, the tape applicator head 7 can be used for applying tape 3 to a wide range of automotive and non-automotive surfaces. Examples of such surfaces comprise steel, galvanized metal, aluminum, among other metals, glass, composites, carpets, pads, plastic, alloys and materials used in automotive construction. Examples of additional automotive and non-automotive components comprise previously painted articles, exterior and interior trim articles, among other areas of an automobile. In addition, the tape head can be employed for applying tape to non-metallic surfaces such as plastic, foam, wood, among other materials wherein it is desirable to apply a tape.
The invention has been described with reference to certain aspects. These aspects can be employed alone or in combination. Modifications and alterations will occur to others upon a reading and understanding of this specification. It is understood that mere reversal of components that achieve substantially the same function and result are contemplated. It is intended to include all such modifications and alterations insofar as they come within the scope of the appended claims or the equivalents thereof.
The current application claims priority to and incorporates by reference in its entirety U.S. Provisional Patent Application No. 60/601,139 filed Aug. 13, 2004, U.S. Provisional Patent Application No. 60/601,656 filed Aug. 16, 2004, and U.S. Provisional Patent Application No. 60/623,066 filed Oct. 29, 2004, each application entitled “Systems and Methods for Robotic Tape Applicator.”
| Number | Date | Country | |
|---|---|---|---|
| 60601139 | Aug 2004 | US | |
| 60601656 | Aug 2004 | US | |
| 60623066 | Oct 2004 | US |
