The present invention relates to positioning devices, and more particularly relates to a positioning device for a moveable portion of a workpiece.
Robotic apparatuses are commonly employed in modern high-volume fabrication operations to perform repetitive tasks which would otherwise be tedious, fatiguing and/or difficult to perform manually in a cycle time of relatively short duration. One such task concerns the painting of a workpiece, such as an automotive vehicle, where high flow paint atomizers are frequently employed to coat the vehicle body with a film of liquid paint. The robust nature of a robotic apparatus permits the paint to be applied at relatively high flow rates, with or without high speed rotary atomization and with or without electrostatic charging of the paint material. In addition to applying paint to the vehicle, robotic apparatuses are often utilized to position movable portions of the vehicle. For example, vehicle doors are often pivoted relative to the vehicle body by robotic apparatuses to permit the doorjamb of the vehicle body to be painted or to permit components such as seats to be installed in the vehicle.
Although robotic apparatuses have worked for their intended purposes, some disadvantages remain. For instance, programmed movements of the robot may not adequately position the workpiece, especially if the workpiece is unexpectedly and/or improperly spaced in relation to the robot. In the case of a vehicle door, for instance, the robot might not be able to properly manipulate the door if the vehicle is closer to the robot than expected, thereby leading to extended production times, damage to the vehicle, and/or damage to the robot. Furthermore, many robotic end effectors of the prior art can exert excessive load on the workpiece and can damage the workpiece. In addition, many end effectors can deposit dirt, lubricant, or other undesirable substances on the workpiece.
Accordingly, there remains a need in the art for a device which allows a robot to properly position a workpiece despite unexpected spacing between the workpiece and the robot. There also remains a need for a positioning device that is unlikely to damage the workpiece during operation. In addition, there remains a need for a positioning device that is unlikely to deposit unwanted materials onto the workpiece during operation.
Accordingly, the present invention is a positioning device for a workpiece that has a body and a portion that is movably mounted to the body, and wherein the portion has an exterior surface and also defines an exterior and interior space. The positioning device includes an abutment assembly having a first abutment member and a second abutment member. The positioning device also includes an actuator assembly adapted for moving the abutment assembly between a locating position, in which the first abutment member is disposed adjacent the exterior surface while the second abutment member is disposed in the exterior space defined by the portion of the workpiece, and an inserted position, in which the second abutment member is disposed in the interior space defined by the portion of the workpiece while the first abutment member is disposed in the exterior space defined by the portion of the workpiece. The actuator assembly is further adapted to move the portion relative to the body due to abutment between the portion of the workpiece and at least one of the first abutment member and the second abutment member.
In another aspect the present invention is a method of positioning a movably mounted portion of a workpiece relative to a body of the workpiece. The portion of the workpiece has an exterior surface, and the portion of the workpiece defines an exterior and an interior space. The method includes the step of locating an abutment assembly having a first abutment member and a second abutment member relative to the portion of the workpiece by moving the first abutment member adjacent to the exterior surface of the portion of the workpiece while the second abutment member is disposed in the exterior space defined by the portion of the workpiece. The method also includes the step of inserting the second abutment member into the interior space defined by the portion of the workpiece while the first abutment member is disposed in the exterior space defined by the portion of the workpiece. In addition the method includes the step of moving at least one of the first abutment member and the second abutment member into abutting contact with the portion of the workpiece to thereby move the portion relative to the body of the workpiece.
Further areas of applicability of the present invention will become apparent from the detailed description provided hereinafter. It should be understood that the detailed description and specific examples, while indicating the preferred embodiment of the invention, are intended for purposes of illustration only and are not intended to limit the scope of the invention.
The present invention will become more fully understood from the detailed description and the accompanying drawings, wherein:
With reference to
In the embodiment shown, the automated fabrication system 14 includes a transfer line 28 which is operable for conveying the automotive vehicle 18 through one or more work stations to facilitate its fabrication. The robotic apparatus 12 is illustrated to include a base structure 23, an arm assembly 24 and an end effector 26. The base structure 23 is selectively pivotable about a generally vertical axis. The arm assembly 24 is coupled to base structure 23, and in the embodiment shown, the arm assembly 24 includes a wrist assembly 30 and a plurality of arm members 32 which pivotably couple wrist assembly 30 to base structure 23. The wrist assembly 30 is coupled to the distal end of the arm member 32a and permits the end effector 26 to be selectively rotated about the longitudinal axis of the arm member 32a. The end effector 26 is illustrated to include a plurality of spray nozzles 34 for applying a liquid material, such as paint, to the workpiece 16. It should be appreciated that the robotic apparatus 12 could be of any suitable type and could be operable to perform any suitable task other than painting operations without departing from the scope of the invention. In addition, although the embodiment of the positioning device 10 shown in
The positioning device 10 includes an abutment assembly 36, shown in
In addition, the first abutment member 38 is axially longer than the second abutment member 40. More specifically, the first abutment member 38 includes a first terminal end 44, the second abutment member 40 includes a second terminal end 46, and the first and second abutment members 38, 40 are mounted such that the first terminal end 44 is disposed further away from the mount member 42 than the second terminal end 46. As will be discussed in greater detail below, the lengths of the first and second abutment members 38, 40 allow for proper positioning of the movable portion 21 of the workpiece 16.
The positioning device 10 also includes an actuator assembly 48. The actuator assembly 48 is adapted for moving the abutment assembly 36 relative to the body 19 of the workpiece 16. The actuator assembly 48 can be of any suitable type and can employ any number of suitable mechanisms for moving the abutment assembly 36. For instance, the actuator assembly 48 can include any number of pneumatic, hydraulic, electric, or any combination of actuator types for moving the abutment assembly 36. In one embodiment, the actuator assembly 48 moves the plurality of arm members 32 of the robotic apparatus 12 as described above, and in so doing, the actuator assembly 48 moves the abutment assembly 36. In another embodiment, the positioning device 10 includes a dedicated actuator assembly 48 that moves the abutment assembly 36 independent of the robotic apparatus 12. As will be discussed in greater detail below, the actuator assembly 48 moves the abutment assembly 36 such that at least one of the first and second abutment members 38, 40 abuts against the movable portion 21 of the workpiece 16 to thereby move the portion 21 relative to the body 19 of the workpiece 16 as will be discussed in greater detail.
The positioning device 10 also includes a controller, schematically illustrated at 49. The controller 49 is operable to transmit various control signals to the actuator assembly 48 to cause movement of the abutment assembly 36. The controller 49 can be of any suitable type. In one embodiment, the controller 49 also transmits control signals to the other components of the robotic apparatus 12 as well as the positioning device 10. In another embodiment, the positioning device 10 includes a dedicated controller that transmits control signals to the actuator assembly 48 independent of the robotic apparatus 12.
As stated above, the positioning device 10 can be used to move a vehicle door 22 relative to a vehicle body, 20 during painting or other fabrication operations. In the embodiment illustrated in
Furthermore, the vehicle door 22 is movably attached to the vehicle body 20 via a plurality of hinges 70 (
The actuator assembly 48 of the positioning device 10 is operable to move the abutment assembly 36 between a locating position (
Thus, assuming that the vehicle door 22 is closed, and the vehicle door 22 is to be opened, the abutment assembly 36 is moved into the locating position shown in
It should be appreciated that the lengths of the first and second abutment members 38, 40 can be designed for efficient movement of the abutment assembly 36 while locating the vehicle door 22. More specifically, in the embodiment shown, the first abutment member 38 is longer than the second abutment member 40 such that the abutment assembly 36 can be moved in a horizontal plane toward the exterior surface 54 of the door 22 without creating contact between the second abutment member 40 and the vehicle door 22. Thus, in one embodiment, the abutment assembly 36 is moved into the vehicle body 20 through the window opening 66, then the abutment assembly 36 is moved downward, and then the abutment assembly 36 is moved in a horizontal plane until the first abutment member 38 abuts against the exterior surface 54 and the first sensor 72 detects the abutment. At this point, the vehicle door 22 has been located.
It should be appreciated that on an assembly line, the position of the vehicle 18 with respect to the positioning device 10 may vary between vehicles 18 arriving at the robotic apparatus 12. The process of locating the vehicle door 22 described above accommodates for any variations in the position of the vehicle door 22 with respect to the positioning device 10. As such, the vehicle 18 can be fabricated and completed more quickly and efficiently.
Once the vehicle door 22 has been located, the abutment assembly 36 is moved into the inserted position shown in
In the embodiment shown, the positioning device 10 includes at least one second sensor 74 mounted to the second abutment member 40 to thereby detect distance between the second abutment member 40 and at least one of the inner and outer panels 50, 52 of the vehicle door 22. The second sensor 74 can of any suitable type, such as a contact sensor or a proximity sensor to detect proper insertion of the second abutment member 40 into the vehicle door 22. It should be appreciated, however, that the second abutment member 40 could be inserted into the vehicle door 22 according to the known dimensions of the vehicle door 22 without detecting distance between the second abutment member 40 and the vehicle door 22.
Once in the inserted position, the abutment assembly 36 is moved away from the vehicle body 20 to thereby pivot the vehicle door 22 about the hinges 70 away from the vehicle body 20. More specifically, as the abutment assembly 36 moves away from the vehicle body 20, abutment occurs between the vehicle door 22 and at least one of the first abutment member 38 and the second abutment member 40. Further movement of the abutment assembly 36 away from the vehicle body 20 causes the vehicle door 22 to open away from the vehicle body. To open the door 22, the abutment assembly 36 could be moved in any suitable direction away from the vehicle body 20. For instance, the abutment assembly 36 can be moved linearly, rotationally, or in a combination of both types of movements.
In one embodiment, the abutment assembly 36 remains in the inserted position (
In another embodiment, structures other than the abutment assembly 36 (e.g., the hinges 70, a prop bar, or other separate structures) hold the door 22 open while additional processing of the vehicle 18 occurs. Before this additional processing occurs, the abutment assembly 36 is moved away from the vehicle 18. To move the abutment assembly 36 away from the inserted position (
In the embodiment shown, the positioning device 10 also includes at least one load sensor 76 (shown schematically) that is operable to detect a load on the abutment assembly 36. The load sensor 76 can be of any suitable type, such as a strain gauge, and can be used to monitor the loading of the abutment assembly 36. In one embodiment, the controller 49 utilizes the load sensor 76 to detect if the loads on the abutment assembly 36 exceed a predetermined level. If the loads exceed this level, the controller 49 automatically stops movement of the abutment assembly 36 to thereby limit any potential damage. In another embodiment, the controller 49 automatically triggers an alarm to notify operators of the excessive loading.
In one embodiment, the load sensor 76 is operatively connected to the second abutment member 40 such that the load sensor 76 can detect force and/or torque on the second abutment member 40. As such, the user can more accurately monitor the loading occurring while the vehicle door 22 is opened and closed, and overloading the vehicle door 22 is unlikely.
Also, in one embodiment, the vehicle door 22 may include a clip or other device (not shown) that positively retains the door 22 in the closed position. When closing the door 22, the door 22 will eventually press against the clip, and the clip will resist further movement of the door 22 toward the closed position. However, the resistance force from the clip can be overcome, and the door 22 will fully close and be retained by the clip or latch. Thus, as the abutment assembly 36 moves the door 22 from the open position toward the closed position, loading will increase on the abutment assembly 36 due to the resistance of the clip. In one embodiment, the abutment assembly 36 overcomes the resistance of the clip and moves the door 22 a predetermined distance based on the type of clip to fully close the door 22. In another embodiment, the abutment assembly 36 overcomes the resistance of the clip and moves the door 22 until the load sensor 76 detects another load increase caused by the door 22 pressing against the vehicle body 20. As such, the load sensor 76 provides more precise indication of the position of the vehicle door 22 relative to the vehicle body 20.
It should be appreciated that the positioning device 10 has a high degree of control of the opening and closing of the vehicle door 22 because the inner panel 50 lies between the first and second abutment members 38, 40 during opening and closing. In other words, the first abutment member 38 will inhibit the vehicle door 22 from moving more than the desired distance toward the vehicle body 20, and the second abutment member 40 will inhibit the vehicle door 22 from moving more than the desired distance away from the vehicle body 20. As such, the vehicle 18, the positioning device 10, the robotic apparatus 12, and/or other external structures are unlikely to be damaged due to inadvertent movement of the vehicle door 22.
Turning now to
Furthermore, in the embodiment shown, the actuator assembly 148 is adapted for moving at least one of the first abutment member 138 and the second abutment member 140 relative to the other of the first abutment member 138 and the second abutment member 140. For instance, in the embodiment shown, the actuator assembly 148 is operable to move the second abutment member 140 toward and away from the first abutment member 138 for gripping and releasing the vehicle door. Such movement of the second abutment member 140 can provide greater control of the movement of the vehicle door. As shown in
As such, the second abutment member 140 can be flipped up and away from the vehicle door as the first abutment member 138 locates the vehicle door. Once the door is located, the second abutment member 140 can be flipped down such that the axes of the first and second abutment members 138, 140 are parallel, and in so doing, the second abutment member 140 can inserted into the vehicle door.
Turning now to
In operation, the actuator assembly 248 moves the first abutment member 238 adjacent the exterior surface 254 of the vehicle door 222 to thereby “locate” the vehicle door 222. Once the door 222 has been located, the actuator assembly 248 rotates the abutment assembly 236 to move the second abutment member 240 through the window slot 268 into the interior space 264 of the vehicle door 222. Those having ordinary skill in the art will appreciate that the rotational movement of the abutment assembly 236 may be more efficient than linear movement of the abutment assembly in some instances.
In summary, the positioning device 10, 110, 210 of the present invention can be used to position a moveable portion 21 of a workpiece 16 with improved control. Also, the positioning device 10, 110, 210 accommodates for any variation in the position of the workpiece 16 relative to the positioning device 10, 110, 210 because the moveable portion 21 is located by the positioning device 10, 110, 210 before movement. Furthermore, the positioning device 10, 110, 210 exerts relatively low loads on the moveable portion 21 of the workpiece 16 such that damage to the workpiece 16, the positioning device 10, 110, 210 and/or the robotic apparatus 12 is unlikely to occur. In addition, the positioning device 10, 110 is unlikely to deposit foreign materials on the workpiece 16. The description of the invention is merely exemplary in nature and, thus, variations that do not depart from the gist of the invention are intended to be within the scope of the invention. Such variations are not to be regarded as a departure from the spirit and scope of the invention.
This application is a divisional of U.S. patent application Ser. No. 11/262,381 filed on Oct. 28, 2005.
Number | Date | Country | |
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Parent | 11262381 | Oct 2005 | US |
Child | 12257696 | US |