HK1214230B - Flexible conveyance system - Google Patents

Description

Flexible transportation system

Cross Reference to Related Applications

This application claims priority to united states provisional patent application No. 61/781,147 (pending) filed on 3/14/2013, united states patent application No. 14/211,793 (pending) filed on 3/14/2014, and united states patent application No. 14/211,572 (pending) filed on 3/14/2014, the disclosures of which are hereby incorporated by reference in their entireties.

Technical Field

The present invention relates generally to material handling systems and, more particularly, to a transport system for assembly-line manufacturing (assembly-line) manufacturing.

Background

Material processing systems for assembly-line manufacturing are generally designed to facilitate efficient and rapid manufacturing of assemblies from multiple parts or subassemblies (semi-finished products). One area particularly suited to such material handling systems is automotive manufacturing. For example, the material handling system may be used in the assembly of vehicle sheet metal bodies (vehicle bodies), power trains (power trains), chassis subassemblies, or trim (trim). The material handling system may also be used for painting operations, welding, gluing or other conventional assembly operations.

Generally, the carrier (i.e., the structure used to accumulate the various components and subassemblies ultimately joined to the vehicle body) travels through a plurality of stations. At each station, components may be added and/or joining operations (e.g., resistance welding, adhesive bonding, stud welding, etc.) may be performed by a plurality of robots or mechanics. The individual components or subassemblies may be set to different stations by a magazine (magazine) that presents the components to a robot or technician in a consistent orientation and with sufficient frequency to match the speed of the assembly line. Whether at a discrete station, or in conjunction with other tasks, a plurality of geometric orientation tools ("geometric tools") may be used to manipulate the parts into precise alignment with a plurality of reference points prior to permanent joining.

Typically, the carrier can be transported using a universal transfer frame. The transfer frame may utilize a variety of different transfer systems, such as an overhead rail system, for station-to-station movement, e.g., may be raised and lowered relative to the station.

Conventional transportation systems have several disadvantages. For example, the transfer frame and the carrier create a large combined assembly. At the end of the assembly line, each transfer frame and carrier assembly must be returned to the beginning of the assembly line. This often involves creating a loop (dedicate) usually located above the assembly line to return empty carriers and frames. Unfortunately, this loop often bisects the upper overpass (catwalk) and thus prevents maintenance personnel on one side from being able to safely pass to the other side of the overpass. This greatly hinders the detection and entry of faults in equipment cabinets and overhead (overhand) line facilities.

In addition, each frame and carrier may be collectively constrained to the overhead conveyor. Thus, the carrier and frame at one station cannot move independently of the carrier and frame at the other station. This results in a lack of flexibility and the carrier is not able to quickly pass through unnecessary stations. Furthermore, the carrier must move through the stations in a constant movement and delay pattern. Even when processing is complete, the carrier and corresponding part being processed at one station cannot be moved until all other stations have completed their respective tasks. The limit switch, the slow switch, and the stop switch control the overhead conveyor as a collective unit.

Accordingly, there is a need for an improved non-overhead transport system with increased flexibility.

Disclosure of Invention

The present invention overcomes the above-noted and other drawbacks and disadvantages of heretofore known conventional transport systems used in transferring assemblies along an assembly line. While the invention will be described in conjunction with certain embodiments, it will be understood that they are not intended to limit the invention to these embodiments. On the contrary, the invention includes all alternatives, modifications and equivalents as may be included within the spirit and scope of the invention.

According to one aspect of the invention, a flexible transport system includes a plurality of feed-forward track segments and at least one carrier supported for movement along the feed-forward track segments. Each feed-forward track segment has an upwardly facing channel and at least one carrier drive member disposed within the channel. Each carrier includes at least one drive engagement member that cooperates with the carrier drive members of the feed-forward track segments to move the carrier along the respective track segment. In one exemplary embodiment, the carrier drive member may be a belt extending within the channel and the drive engagement member may be a friction rail. In another exemplary embodiment, the carrier drive member may be a linear motor and the drive engagement member may be a magnet. A support structure associated with each carrier supports the mounting assembly above the feed forward track section.

Alternatively, the flexible transport system may further include a plurality of return track segments (return track segments) aligned end-to-end and spaced apart from the plurality of feed-forward track segments. Each return track segment has a channel extending longitudinally along the return track segment, and at least one carrier drive member disposed within the channel. In one exemplary embodiment, the carrier drive member may be a belt extending within the channel. In another exemplary embodiment, the carrier drive member may be a linear motor. The carrier drive members of the return track segments cooperate with the drive engagement members of the carriers received on the return track segments to move the carriers along the respective return track segments.

The above and other objects and advantages in accordance with the principles of the invention will be apparent from the accompanying drawings and from the description thereof.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and, together with the general description of the invention given above, and the detailed description given below, serve to explain the principles of the invention. Like reference numerals are used to refer to like features in the various figures of the drawing.

FIG. 1 is a plan schematic view of an assembly line including an exemplary transport system according to the principles of the present disclosure;

FIG. 2 is a schematic front view of the exemplary transport system of FIG. 1;

FIG. 3 is a more detailed top plan view of the transport system of FIG. 1;

FIG. 4 is a top plan view of the transport system of FIG. 3, further including an overpass and an elevated return track;

FIG. 5 is a perspective view of an exemplary carrier according to the principles of the present invention;

FIG. 6 is a perspective view of an exemplary track segment according to the principles of the present invention;

FIG. 7 is a partial cross-sectional view of the track segment of FIG. 6;

FIG. 8 is a partial cross-sectional view of the track segment of FIG. 7, further showing a carrier coupled to the track segment;

FIG. 9 is a detailed view of the encircled area of FIG. 5;

FIG. 10 is an end view of the carrier of FIG. 5, further showing the configuration of the rollers;

FIG. 11 is a perspective view of an exemplary component placement station according to the principles of the present invention;

FIG. 12 is a perspective view of an exemplary geometry tool station according to the principles of the present invention;

FIG. 13 is a top plan view of an exemplary geometry tool station according to the principles of the present invention;

FIG. 14 is a perspective view of an exemplary unloading station according to the principles of the present invention;

FIG. 15 is an end view of the unloading station of FIG. 14;

FIG. 16 is a side view of the transport system of FIG. 4 showing the overhead return track and overpass;

FIG. 17 is an enlarged side view of the overhead return track of FIG. 16;

FIG. 18 is a partial cross-sectional view taken along line 18-18 of FIG. 16;

FIG. 19 is an enlarged detailed view of the return track of FIG. 18;

FIG. 20 is a perspective view of an exemplary adjustable mounting assembly according to the principles of the present invention;

fig. 21 is a perspective view of an exemplary carrier including a two-dimensional code strip according to the principles of the present invention;

FIG. 22 is a schematic top plan view of an assembly line including another exemplary transport system according to the principles of the present invention;

FIG. 23 is a perspective view of an exemplary track segment of the transport system of FIG. 22;

FIG. 24 is a perspective view of the track segment of FIG. 23 showing another exemplary carrier coupled to the track segment;

FIG. 25 is a partial cross-sectional view of the track segment and carrier of FIG. 24;

fig. 26 is a detailed view of another embodiment of a carrier configured for use with the track segments of fig. 25 and 25 in accordance with the principles of the present invention.

Detailed Description

FIG. 1 is a schematic illustration of an exemplary flexible inverted (inverted) transport system 10 in accordance with the principles of the present invention. The plurality of stations 12 are configured to process and assemble a plurality of components and subassemblies, such as vehicle bodies.

The system 10 includes a track 14, the track 14 transporting components between the various stations 12. The carrier 16 (described in more detail below with reference to fig. 5 and 9) cooperates with the track 14 and acts as a seat (foundation) to receive various components and subassemblies. The carrier 16 is introduced at the beginning of the line 18 and transported by a plurality of belt segments 20 (described in more detail below with reference to fig. 6-8), which belt segments 20 are disposed below the track 14. It can be observed that several configurations of the band 20 can provide acceptable results. Two important design characteristics of the belt 20 include resistance to elongation and the application of sufficient frictional forces between the belt segments 20 and the carrier 16. For example, in the case of a load on the belt segments 20 while transporting the carrier 16, one embodiment of the present invention may use steel reinforced nylon belts to resist elongation. Additionally, certain embodiments may utilize a belt having grooves to enhance the friction between the belt segment 20 and the carrier 16, while other embodiments may utilize a molded polyurethane coating or other elastomeric compound. In exemplary system 10, band segment 20 may be completely surrounded by track segment 15. It should be noted that when the track 14 is shown as continuous in the figures, the track actually comprises a plurality of segments, wherein each segment is independent of adjacent segments. The carrier 16 is driven by the respective tape segment 20 towards the end of the line 22.

With continued reference to fig. 1, one possible configuration of each station 12 will be described, namely the passage of the carrier 16 over the track segments 15 and the belt segments 20. After engaging track segment 15, carrier 16 first enters assembly placement station 24, which may include a first placement station 24a and a second placement station 24 b. A plurality of infeed conveyors 40 hold, orient and advance the various vehicle body (body) components and subassemblies disposed adjacent track segment 15. A plurality of robots (described in more detail below) may grasp components from the infeed conveyor 40 and place the components on the carrier 16. The carrier 16 then proceeds to the next station 12 (geometry tool 28) where the multiple components on the carrier 16 are aligned with each other and initially joined together. The carrier 16 may then proceed to the next station 12, i.e., a re-spot tool 30. The repositioning tool 30 may apply additional welds that cannot be applied at the geometry tool station 28 due to obstructions in the geometry tool 28 or due to time constraints. The carrier 16 may then travel through a plurality of additional stations 12, the additional stations 12 may include adhesive bonding (adhesive bonding), additional geometric tools 28, additional component placement stations 24, or additional repositioning tools 30.

When the carrier 16 enters the geometry tool 28, the track segment 15 and the belt segment 20 are lowered to the ground. This effectively transfers the weight of the component or subassembly to the geometry tool 28 itself and away from the carrier 16. Once the component is no longer loaded on the carrier 16, the geometric tool 28 and its respective fixtures can manipulate the subassemblies and place each assembly into a particular geometric relationship with one another. When the carrier 16 is lowered out of the way, the robot can more easily access the various surfaces of the body without interfering with the projection (projection) of the carrier 16. As the track segment 15 is lowered, the belt segment 20 is placed into a free-spinning configuration, while the internal clutch disengages the drive from the belt segment 20. The carrier 16 can then be moved fore and aft, allowing the parts to be engaged by the geometric tool 28.

After each of the plurality of processing stations 12 is completed, the carrier 16 terminates at an unloading station 32 at the end of the line 22. At the unload station 32, the completed body subassembly is removed from the carrier 16. The carrier 16 is separated from the track 14 and the robot transfers the carrier 16 from the track 14 to an overhead return track 34 (described in more detail below with reference to fig. 14), which overhead return track 34 transports the carrier 16 back to the beginning of the line 18.

Fig. 2 is a side view of the exemplary transport system 10 of fig. 1, including an overhead return track 34 disposed between track 14 and an overpass 36. The overpass 36 may support equipment 60 (such as motor controllers, robotic control cabinets, utility distribution systems, etc.) and facilitate maintenance, repair, and fault detection thereof. It should be noted that this configuration of track 14, return track 34, and overpass 36 enables service personnel on overpass 36 to have an unobstructed path. By way of a counter example, if overhead return track 34 is located above overpass 36, service personnel will not be able to walk from one side of overpass 36 to the other side of overpass 36. The path may be obstructed by the overhead return track 34 and the carrier 16 at the beginning of the circulation loop 18. In this view, the geometry tool 28 and the repositioning tool 30 are depicted as having track segments 15, with the track segments 15 being configured to be raised and lowered independently of the other track segments 15 and independently of the other stations 12. It should also be noted that the stations 12 and their corresponding belt segments 20 can have independent linear speed control relative to adjacent belt segments 20. This causes the carrier 16 to advance down the track 14, thereby bypassing the unused station 12. In addition, this allows a carrier 16 to be released from a station 12 and placed into an empty station 12 even before an adjacent carrier 16 is released from an adjacent station 12.

Referring now to fig. 3, a plan view of the transport system 10 of fig. 1 is shown in greater detail, however, the overpass 36 and overhead return track 34 are omitted for clarity. Beginning at the beginning of line 18, the carrier 16 is seated at the component placement station 24a and has been loaded with a plurality of large subassemblies of an automobile body. The track segment 15 and the corresponding belt segment 20 of the station 24a are of static construction. For the purposes of this discussion, static track segments 15 are defined as not being able to be raised and lowered relative to the assembly line floor. At the component placement station 24b, the carrier 16 receives additional vehicle body components from a plurality of infeed conveyors 40. Some embodiments may utilize a horizontally configured infeed conveyor 40, while other embodiments may utilize a vertical conveyor to minimize the footprint of the assembly line floor space. Just like station 24a, station 24b is also configured to be static and only capable of linearly translating the carrier 16. A plurality of robots 42 transfer the vehicle body components from the infeed conveyors 40 to the carrier 16, the carrier 16 stopping in the component placement station 24 b. The components from the infeed conveyor 40 advance to the assembly line at a rate sufficient to feed the carriers 16 as they enter the assembly placement station 24 b.

The geometry tool 28 is the first station 12 of an assembly line constructed with a vertical transfer tower 44. Vertical transfer towers 44 are configured to move track segments 15, and corresponding belt segments 20, up and down relative to the assembly line floor. Because the vertical transfer tower 44 and the robot are the primary physical interface between the system 10 and the facility floor, most of the plant facilities need to be hidden therein. Accordingly, the robot 42 and the vertical transfer tower 44 may include passages or penetrations in their respective bases such that electrical power conductors, electrical signal conductors, hydraulic lines, pneumatic lines, and the like can travel from the assembly line floor to the system 10 in a protected and efficient manner.

With continued reference to FIG. 3, a plurality of geometric tool trays 46a-46c may be disposed below the track segment 15 and between a pair of vertical transfer towers 44. Each geometric tool tray 46a-46c is configured with a plurality of pointers, holding fixtures, clamping devices, and the like corresponding to a particular automobile make and model and combination of automobile body components. Thus, in this particular example, the transport system 10 is capable of accommodating at least three different deformations of the automotive body frame to be processed on the assembly line.

Once the carrier 16 is positioned on the appropriate geometric tool tray 46a-46c, the internal clutch mechanism is disengaged from the belt segments 20. This essentially places the carrier 16 in a configuration that allows the carrier 16 to move end-to-end relative to the geometric tool trays 46a-46 c. Thus, when the track segment 15 is lowered into contact with the geometric tool trays 46a-46c by the vertical transfer tower 44, the carrier 16 is free to reciprocate so that the components contact the appropriate portions of the geometric tool trays 46a-46 c. Once lowered, the carrier 16 no longer bears the weight of the automobile body component, which now contacts the various components of the geometric tool trays 46a-46 c. A plurality of robots 42 initially secure each body component in a desired relationship with other body components. Once the components are initially secured, the track segment 15 is raised using the vertical transfer tower 44 to return the vehicle assembly back into contact with the carrier 16. When the track segment 15 is fully raised, the entire weight of the car assembly is on the carrier 16 and the carrier 16 is ready to be moved into the next station 12.

The next station 12 is a repositioning tool 30. The repositioning tool 30 is configured to perform additional joining operations that are not feasible due to obstructions in the previous station 12 or due to time constraints at the previous station 12. In the same manner that the plurality of geometric tool trays 46a-46c are positioned in the geometric tool 28, a plurality of repositioning tool trays 48a-48c may be positioned below the track segment 15. Once the carrier 16 is positioned on the appropriate repositioning tool trays 48a-48c, a pair of vertical transfer towers 44 lower the track segment 15 into contact with the repositioning tool trays 48a-48 c. Robots 42 provide additional welding to the car components that are positioned and supported by the repositioning tool 30. After the additional welding step is completed, the pair of vertical transfer towers 44 raises the track segments 15 and mating carriers 16 vertically relative to the assembly line floor. The weight of the automobile body component is then transferred from the repositioning tool trays 48a-48c to the carrier 16. When the track segment 15 and the mating carrier 16 are fully raised, the carrier 16 is ready to advance to the next station 12. It should be noted that these exemplary views depict a truncated version of the entire assembly line. Any combination or number of individual stations 12 may be placed in sequence to provide flexibility in the manufacturing process. For example, additional operations may be performed at the various stations 12 to include bonding, stud or fastener placement, automated or mechanical adjustment of parts, automated or manual application of trim and other ancillary components, and the like.

The final exemplary station 12 shown in fig. 3 is an unloading station 32. Once the carrier 16 is in the unloading station 32, the plurality of lift forks 50 are reciprocated to a position between the carrier 16 and the vehicle body assembly. The vertical transfer tower 44 lowers the track segment 15 and carrier 16 a sufficient distance to transfer the weight of the automobile body assembly onto the lift forks 50. The lifting forks 50 are then retracted to their original position away from the rail 14 and the partially assembled car body is placed onto a truck or other transport device for movement throughout the facility. As will be described in more detail below with reference to fig. 14, robot 42 transfers carriers 16 from track segments 15 to overhead return track 34. Overhead return track 34 returns carrier 16 from the end of line 22 to the beginning of line 18. As will be explained in more detail in the discussion below, the configuration of the overhead return track is such that an unobstructed path is maintained over the overpass 36.

Fig. 4 is a plan view of transport system 10, which is similar to fig. 3, but now includes overpasses 36 and overhead return tracks 34. The overpass 36 and corresponding equipment 60 are located directly above the track 14. In this top view, overhead return track 34 is located below overpass 36. A plurality of stairs 62a and 62b join the assembly line ground level to the overpass 36. In the absence of a carrier return track disposed above the overpass 36, workers may travel up stairs 62a, across the overpass 36, and down stairs 62b to opposite sides of the overpass 36. This configuration provides greatly improved efficiency during fault detection and repair procedures. A technician on the overpass 36 may move freely from the left side 64 of the overpass 36 to the right side 66 of the overpass 36. The directions of the left side 64 and the right side 66 are defined when standing at the start of the station 18 and looking toward the end of the line 22. Thus, during the fault detection procedure, the performance of the equipment 60 on the left side 64 of the overpass 36 may be readily compared to the performance of the equipment 60 on the right side 66 of the overpass 36.

FIG. 4 also shows an optional repair station 68 located at the end of line 22. The damaged portion of the carrier 16 may be replaced, adjusted, or refurbished after being removed from the assembly line and placed onto the track segment 15 of the repair station 68. A partition (not shown) may be provided between the unloading station 32 and the repair station 68 so that the carrier 16 may be safely serviced while the main assembly line continues to operate.

Fig. 5 depicts an exemplary carrier 16 in accordance with the principles of the present invention. The friction rail 80 is mated to the mounting rail 82 by a plurality of standpipes 84. The carrier 16 includes friction rails 80 and mounting rails 82 that engage a riser 84 (e.g., using threaded fasteners, welding, rivets, or other suitable attachment methods). A plurality of transverse supports 86 are mounted in a vertical orientation relative to the mounting rail 82. The transverse support 86 terminates in a plurality of load bearing surfaces 88. The load bearing surface 88 is configured to support portions and subassemblies of the automobile body as the carrier 16 and mating body components travel down the rails 14. A plurality of parallel rollers 90 and angled rollers 92 cooperate with mating surfaces on track 14 and stabilize carrier 16 as carrier 16 travels down track 14. The engagement between the parallel rollers 90 and the oblique rollers 92 will be shown in detail in the following figures.

Fig. 6 depicts an exemplary track segment 15 and shows a strap segment 20 nested therein. The belt motor 94 may be operated by a motor controller (not shown) to drive the belt segments 20 of one track segment 15 independently of the other belt segments 20. As shown below with reference to fig. 7-10, the carrier 16 rides (ride) within a channel 96, the channel 96 being defined by a top surface 98, a first rail 100, a second rail 102, and the band segment 20. In some embodiments of the present invention, the bearing surfaces of the first and second rails 100, 102 may be fabricated from SAE4140 steel. When the mounting rail 82 and the transverse support 86 ride over the top surface 98 of the rail 14, the friction rail 80, the parallel rollers 90, and the oblique rollers 92 of the carrier 16 generally travel below the top surface 98 of the rail 14.

Reference is now made to fig. 7-10, which depict the coupling of the carrier 16 to the track segment 15. Fig. 7 shows a detailed cross-sectional view of a track segment 15. The first rail 100 and the second rail 102 are generally symmetrical, while the individual features of the first rail 100 apply equally to the second rail 102. The parallel face 110 of the track segment 15 and the cooperating parallel rollers 90 on the carrier 16 generally serve to guide the carrier 16 axially along the track segment 15. The inclined surface 112 of the track segment 15 and the cooperating inclined rollers 92 on the carrier 16 serve to trap the carrier 16 within the channel 94 of the track segment 15. The inclined roller 92 and the mating inclined surface 112 serve to hold the carrier 16 in constant frictional relationship with the belt segments 20. Under standard operating conditions, the parallel rollers 90 are suspended above the non-contact surface 114 by the lifting force exerted by the belt segments 20 on the friction rails 80. In some portions of the system 10, the first rail 100 and the second rail 102 are maintained in a movable relationship with each other. To couple and decouple the carrier 16 to the track segment 15, the first and second rails 100, 102 are enabled to be decoupled from one another. Fig. 8 shows an end view of the cooperation between the carrier 16 and its rollers 90 and 92 and the track segment 15 and its surfaces 110 and 112.

Referring to fig. 9 and 10, the oblique rollers 92 of the carrier 16 are fitted to the stand pipe 84 and are disposed such that the contact surfaces of the oblique rollers 92 form a substantially 45 degree angle with respect to the friction rail 80 and the mounting rail 82. The rotational center lines of the inclined rollers 92 form right angles with respect to each other. It will be appreciated that a variety of other angular orientations may produce acceptable results, provided the mating surfaces on the rails 14 are appropriately sized. Parallel rollers 90 are fitted to the mounting rails 82 to reduce lateral play between the carrier 16 and the track 14.

Fig. 11 shows an exemplary component placement station 24, in which the track segments 15 and the carrier 16 are located in the exemplary component placement station 24. This configuration is achieved by using the origin transfer robot 122 to transfer the empty carriers 16 from the overhead return track 34 onto the track segments 15 of the component placement station 24. A similar end transfer robot 124, depicted in fig. 4, is located at the end of the line 22 and is configured to take an empty carrier 16 from the unloading station 32 and place the carrier 16 onto the overhead return track 34. Once the carrier 16 is placed on the track segment 15, the belt segment 20 is disengaged from the belt motor 94 (not shown), thereby placing the belt segment 20 in a freely rotating configuration. A directional pin package (not shown) locks the carrier 16 in place along the track segment 15. This stabilizes the carrier 16 in preparation for receiving the automobile body parts. Once the empty carrier 16 has been spatially oriented in the component placement station 24, the robot 42 places the first body component 120 onto the carrier 16. The first body assembly 120 is fed to the assembly placement system using the infeed conveyor 40. As each empty carrier 16 enters the component placement station 24, the robot 42 repeatedly transfers a new first body component 120 from the infeed conveyor 40. Once the appropriate number of body components have been added to the carrier 16, the directional locator pin set (not shown) is retracted, the belt segment 20 is re-coupled to the belt motor 94 (not shown), and the carrier 16 is advanced to the next station 12.

Fig. 12 depicts an exemplary geometry tool 28 in accordance with the principles of the present invention. The geometric tool trays 46a-46c are disposed below the track segment 15. In this embodiment, the geometric tool tray 46b is selected to interact with the carrier 16. A pair of vertical transfer towers 44 suspend the track segment 15 above the geometric tool tray 46 b. Once the belt motor 94 positions the carrier 16 in a generally acceptable linear position above the geometric tool tray 46b, the belt motor 94 disengages the belt segment 20 allowing the carrier 16 to move freely end-to-end. As the vertical transfer tower 44 lowers the track segment 15 toward the geometry tool tray 46b, the carrier 16 is guided by the sloped surface of the yoke 130 into final alignment with the geometry tool tray 46 b. This final guidance is achieved with only a very small reaction, since the belt motor 94 has already disengaged from the belt segment 20, as described previously. Once the carrier 16 has been lowered into the yoke 130, the various fixtures and clamping assemblies of the geometric tool tray 46b grasp the automotive body parts. The preliminary welding is completed and the carrier 16 and track segment 15 are lifted by the vertical transfer tower 44 in preparation for moving the carrier 16 to the next station 12.

Fig. 13 is a plan view of the geometric tool shown in fig. 12, and it also shows the repositioning tool 30 and the plurality of robots 42. In this view, the geometry tool 28 and the repositioning tool 30 are essentially identical, but the two stations 12 are distinguished by their respective functions. As mentioned above, the geometric tool 28 first involves orienting the automotive body parts relative to each other and temporarily securing them with a weld. Similarly, repositioning the tool 30 involves providing additional structural welds to complete the assembly of the multiple components oriented by the geometric tool 28.

Fig. 14 depicts an exemplary unloading station 32 in accordance with the principles of the present invention. Here, the fork 50 has been positioned between the car body and the carrier 16. The vertical transfer tower 44 lowers the track section 15 so that the weight of the automobile body assembly is removed from the carrier 16 and placed on the transfer forks 50. The transfer fork 50 is then withdrawn from the rail section 15 and the carrier 16 will then be detached from the car body part. The end transfer robot 124 will remove the carrier 16 from the track segment 15. The end transfer robot 124 (not shown) will then invert the carrier 16 so that the friction rail 80 faces upward. The carrier 16 will then be coupled to the overhead return track 34 and the carrier 16 will travel from the end of line 22 back to the beginning of line 18 using friction rollers, belt drives, or other means known in the art.

Fig. 15 depicts an end view of the unload station 32. Track segment 15 is shown in two possible configurations. In the first configuration 140, shown in solid lines, the track segments 15 engage the carrier 16. In the second configuration 142, shown in phantom, the track segment 15 is unlocked from the carrier 16 or disengaged from the carrier 16. In this second instance 142, the first rail 100 and the second rail 102 have been pivoted away from the carrier 16 by means of a rail manipulator 144, shown in more detail in fig. 19. In the second case 142, the parallel rollers 90 and oblique rollers 92 do not contact their corresponding surfaces on the first track 100 and the second track 102. This allows the carrier 16 to be freely lifted from the track section 15 using the lifting forks 50. This same configuration may be used to couple and decouple carrier 16 from overhead return track 34 at the beginning of line 18 and the end of line 22. Likewise, this configuration may be used to couple the carrier 16 with the first track segment 15 at the beginning of the line 18.

Fig. 16 depicts a more detailed side view of the transport system 10. Beginning at the beginning of line 18 and proceeding to the end of line 22, a pair of component placement stations 24a and 24b are shown. The geometry tool 28, the repositioning tool 30, and the unloading station 32 complete the assembly line. The repair station 68 follows the unload station 32, but is not considered part of the assembly line itself. A plurality of carriers 16 are shown coupled to overhead return track 34. Overhead return track 34 is disposed between track 14 and overpass 36, and step 62b provides a user with access to overpass 36. Because the return track 34 does not encroach upon the ground space of the overpass 36, the user is free to service the various components of the equipment 60 in all areas of the overpass 36.

Fig. 17 is a detailed side view of overhead return track 34. The carrier 16 is coupled with the overhead return track 34 and spans a plurality of robots 42. The overpass 36 supports various equipment 60. In one embodiment, the friction roller 150 is in intermittent contact with the friction rail 80 of the carrier 16 and is used to advance the carrier 16 from the end of the line 22 to the beginning of the line 18.

Fig. 18 is an end view (looking down from the track 14) of the transport system 10 of fig. 16 taken along line 18-18. The overhead return track 34 and the mating carrier 16 do not obstruct the overpass 36 in any way. A worker walking up the left side 64 using the stairs 62a is able to move freely around the overpass 36 and descend on the right side 66 through the opposite stairs 62 b.

Fig. 19 is a detailed view of overhead return track 34 and carrier 16. In this view, overhead return track 34 is shown in a second configuration 142, in which first rail 100 and second rail 102 are disengaged from carrier 16. Track manipulator 144 has been actuated to disengage first rail 100 from second rail 102 to enable carrier 16 to be disengaged from overhead return track 34.

Fig. 20 shows a precision adjustment mounting assembly 160 for engaging vertical transfer tower 44 to track segment 15. The system 10 requires a high degree of alignment accuracy between the track segments 15 and, therefore, a high degree of accuracy and robust method of adjusting the alignment of the track segments 15. First plate 162 is attached to vertical transfer tower 44. Similarly, second plate 164 is mated to track segment 15 by load distribution assembly 166. In one embodiment, load distribution assembly 166 includes two or more protruding members 168 and mating receivers 170. The interface between the protruding member 168 and the receiving member 170 is configured to provide increased stiffness to the interface between the second plate 164 and the rail segment 15. This also helps to prevent twisting of the track segments 15 when under the asymmetric load created by the carrier 16.

A plurality of jack bolts 172 and retaining nuts 174 are disposed between the first plate 162 and the second plate 164. The jack bolts 162 are received in a plurality of threaded holes 176 of the first plate 162. The opposite side of the ejection bolt 172 is seated in a housing (pocket) (not shown) of the second plate 164. Rotating the jack-out bolt counterclockwise (when configured with right-hand threads) causes the second plate 164 to be driven from a position of the first plate 162 that is centered with respect to the actuated jack-out bolt 172. By adjusting the plurality of jack-out bolts 172, the pitch, yaw, and roll of the track segments 15 can be adjusted. The plurality of load pins 178 bear a majority of the weight applied to the precisely adjustable mounting assembly 160. Once the plurality of jack bolts 172 are adjusted in position, the retaining nuts 174 are tightened to fix the orientation of the jack bolts 172. Additionally, the plurality of load pin nuts 180 are tightened to hold the first plate 162 and the second plate 164 pulled in a fixed relationship to each other and to maintain the jack-out bolt 172 seated within the housing (not shown). To provide an improved degree of connection, the load pin 178 is disposed in a load pin bore 182 that is slightly larger in size than the load pin 178. This allows the second plate 164 to roll, tilt (pitch), and offset along with its mating track segment 15 during adjustment.

Fig. 21 depicts an optional additional feature of transport system 10 that provides additional motion control of carrier 16 as it advances through track segment 15. In this embodiment, a two-dimensional code 190 may be affixed to one side of the mounting rail 82. The two-dimensional code 190 contains unique two-dimensional indicia that uniquely identifies each carrier 16 and its relative position throughout the system 10. Because each belt segment 20 of the system 10 is individually driven by its respective belt motor 94, each carrier 16 can be moved, stopped, accelerated, decelerated, reversed, positioned, etc. independently throughout the system 10. The two-dimensional code 190, together with at least one cooperating camera reader (not shown), provides better quality control tracking, diagnostic features, and production speed to the system 10. The two-dimensional code 190 enables the system 110 to re-adjust a particular carrier 16 (even when the adjacent carrier 16 is stationary) as opposed to relying on limit switches, including stop switches and slow switches. In combination with the independently controlled belt motor 94, the carrier 16 can be rapidly advanced through the empty or idle station 12 by using the two-dimensional code 190. In addition to enhanced motion control, increased throughput, quality control, and fault detection are also achieved by uniquely identifying each carrier 16 as the carriers 16 pass through the system 10. The system 10 using the two-dimensional code 190 can uniquely identify and track defective carriers 16, or carriers 16 that cause failure in the manufacturing process or yield defective finished products.

Referring now to fig. 22-26, another exemplary embodiment of a flexible transport system 200 in accordance with the principles of the present invention will be described. The transport system 200 of this embodiment is similar in many respects to the transport system 10 described above with reference to fig. 1-21. Therefore, only the differences between the systems are further described below. Fig. 22 depicts a schematic illustration of a transport system 200, similar to the transport system 10 discussed above with reference to fig. 3. However, instead of an overhead return line, the transport system 200 includes an optional return line 202, the optional return line 202 being laterally spaced from the feed-forward line 204 and, in this embodiment, extending generally parallel to the feed-forward line 204 to return the carrier 206 toward the start point 208 of the feed-forward line 204. Various other aspects of the transport system 200 are similar to the transport system 10 described above, including a plurality of stations 210 for loading and unloading components to the carrier 206, a vertical transfer tower 212 for raising and lowering the carrier 206 relative to the assembly line, a component feeding conveyor 214, a geometric tool tray 216, and a robotic manipulator 218 for performing assembly operations.

As shown in fig. 22, a storage area 220 may be provided at an unloading station 222 adjacent the end of the feed-forward line 204 for storing carriers 206 that have been removed from the feed-forward line 204 with the robot. A repair station 224 may also be provided adjacent to the storage area 220 for repairing or conditioning the carrier 206 (as generally described above).

Fig. 23 depicts an exemplary track segment 230 used in both the feed line 202 and the return line 204. Track segment 230 includes an elongated track housing 232 having an open upper side defining an upwardly facing channel 234, channel 234 extending longitudinally along track segment 230. At least one linear motor 236 is disposed within channel 234 of each track segment 230 to control the movement of carrier 206 along track segment 230. In the illustrated embodiment, three linear motors 236 are disposed in the channels 234 of the track segments 230. However, it will be understood that each track segment 230 may alternatively include only a single linear motor 236, or a variety of other numbers of linear motors 236, disposed in channel 234 as desired. An exemplary linear motor 236 that may be used in track segment 230 is quicktick HT2, available from MagneMotion, inc, of Devens, Massachusetts.

A controller 238 in communication with each linear motor 236 controls the operation of each linear motor 236 to move the carriers 206 along the track segments 230 with high precision and independently of other carriers 206 supported on the plurality of track segments 230. While a single controller 238 is shown as communicating with the linear motors 236, it will be understood that each linear motor 236 may alternatively communicate with a dedicated controller that controls the operation of that particular linear motor 236, in coordination with other features of the transport system 200.

Fig. 24 and 25 depict an exemplary carrier 206 supported on a track segment 230 according to this embodiment. In this embodiment, carrier 206 includes an elongated mounting rail 240, to which elongated mounting rail 240a plurality of wheel assemblies 242 are coupled. In a manner generally similar to carrier 206 described above with reference to fig. 1-21, a plurality of risers 244 are secured to an upper surface of mounting rail 240. Riser 244 is in turn coupled to a cross support 246 having a load bearing surface 248, and a suitable fixture 250 for supporting the mounting assembly thereon. As shown in fig. 25, the track housing 232 includes first and second oppositely disposed side walls 252, 254 and a bottom wall 256 that define the channel 234 of the track housing 232. The wheel assembly 242 of the carrier 206 is configured such that the wheels 258 engage the upper surfaces 260, 262 of the first and second sidewalls 252, 254 to provide rolling movement of the carrier 206 along the rail segment 230. At least one permanent magnet 264 is secured to a lower surface of mounting rail 240 generally opposite riser 244. Permanent magnets 264 are supported on mounting rails 240 of carrier 206 at a fixed spacing from linear motor 236.

Fig. 26 depicts another exemplary embodiment of a carrier 206a, which carrier 206a may be used with track segments 230 described with reference to fig. 24-25. In this embodiment, the wheel 258a of the wheel assembly 240a includes a radially outwardly extending peripheral lip (circumferential lip)266 that cooperates with the side walls 252, 254 of the track housing 232 to facilitate alignment of the carrier 206a on the track segment 230.

In use, linear motor 236 is actuated to generate a magnetic field that cooperates with permanent magnets 264 on carrier 206 to provide a motive force for moving carrier 206 along the plurality of track segments 230 and to precisely position carrier 206 at a desired location along track segments 230. Advantageously, the transport system 200 described herein provides a fast and efficient method for transferring assembly components along an assembly line with real-time control of each carrier 206 independent of other carriers 206 moving along the assembly line. Furthermore, the linear motor 236 cooperates with the permanent magnets to provide a large hold down force that aids in the stability of the carrier 206 supported on the rail segments 230. As the carrier 206 moves along the track segments 230 of the feeder line 204, multiple components may be added, and assembly operations may be performed at the multiple stations 210 generally as described above with reference to the transport system 10 of fig. 1-21. While the vertical transfer tower 212 may be used to position the mounted components supported on the carrier 206 in the geometric tool tray 216 (as described above), the linear motor 236 provides such precise positioning of the carrier 206 on the track segments 230, which may eliminate the need to use the vertical transfer tower 212 to lower the components into the tool tray 216.

At the end of the front feed line 204, the completed assembly may be removed from the carrier 206 using one or more robots 218. The unloaded carrier 206 may then be removed from track segment 230 and placed in storage area 220, sent to repair station 224, or moved to return line 202 to move back toward the beginning 208 of feeder line 204. In this embodiment, the return track segment 230 is similar in structure to the feed-forward track segment 230 described above with reference to fig. 23-26. The storage area facilitates the addition and removal of carriers 206 from the front feed lines 204 and return lines 202 in a variety of orders as desired so that the carriers 206 can be set to the starting points 208 of the front feed lines 204 to accommodate variations in assembly requirements.

While the present invention has been illustrated by a description of one or more embodiments and while these embodiments have been described in considerable detail, it is not the intention of the appended claims to restrict or in any way limit the scope of the invention to such detail. The different features shown and described herein may be used separately or in any combination. Additional advantages and modifications will readily appear to those skilled in the art. The invention in its broader aspects is therefore not limited to the specific details, representative apparatus and method, and illustrative examples shown and described. Accordingly, departures may be made from such details without departing from the scope or spirit of applicant's general inventive concept.

Claims (11)

1. A flexible conveyance system, comprising:

a plurality of feed-forward track segments aligned end-to-end, each feed-forward track segment having an open upper side defining an upwardly facing channel extending longitudinally along the feed-forward track segment and at least one linear motor disposed within the channel; and

at least one carrier supported for movement along a plurality of said feed-forward track segments, each carrier comprising at least one magnet cooperating with a linear motor of said feed-forward track segment to move said carrier along a respective feed-forward track segment,

each carrier includes a support structure disposed opposite the at least one magnet and configured to support a mounting assembly on the feed-forward track segment.

2. The flexible conveyance system of claim 1, wherein the at least one carrier comprises:

mounting a rail;

a plurality of wheel assemblies coupled with the mounting rail,

wherein the support structure extends above the mounting rail for supporting a component to be assembled.

3. The flexible conveyance system of claim 2, wherein each feed-forward track segment includes first and second opposing sidewalls defining the channel; and is

The wheel assembly of the at least one carrier engages the first and second sidewalls of the feed-forward track segment to support the carrier for rolling movement along the feed-forward track segment.

4. The flexible conveyance system of claim 1, further comprising:

a plurality of return track segments aligned end-to-end and spaced apart from the plurality of feed-forward track segments;

each return track segment having an open upper side defining an upwardly facing channel extending longitudinally along the feed forward track segment and having the at least one linear motor disposed within the channel; and is

The at least one carrier is supported for movement along the plurality of return track segments, each carrier including at least one magnet that cooperates with the linear motor of the return track segment to move the carrier along the respective return track segment.

5. The flexible conveyance system of claim 1, further comprising:

at least one pair of vertical transfer towers supporting one of the plurality of feed-forward track segments;

the vertical transfer tower is adjustable between a first configuration in which the supported feed-forward track segment is longitudinally aligned with an adjacent feed-forward track segment, and a second configuration in which the supported feed-forward track segment is lowered relative to the adjacent feed-forward track segment.

6. The flexible transport system of claim 5, further comprising:

at least one tool tray associated with the vertical transfer tower;

the at least one tool tray is engageable with a carrier on the supported feed-forward track segment when the vertical transfer tower is adjusted to the second configuration and the supported feed-forward track segment is lowered.

7. The flexible transport system of claim 6, further comprising:

a yoke cooperating with the tool tray to align a component supported on a carrier with the tool tray when the feed-forward track segment is lowered by the vertical transfer tower.

8. The flexible conveyance system of claim 1, further comprising:

at least one robot proximate to at least one feed-forward track segment, the at least one robot adapted to perform at least one of:

placing a component on a carrier received in a channel of an adjacent said feed-forward track segment; or

Performing work on a part supported on a carrier received in a channel adjacent the feed-forward track segment.

9. A method of assembling a component using a transport system comprising a plurality of feed-forward track segments and at least one carrier adapted to be transported along the plurality of feed-forward track segments, each feed-forward track segment comprising at least one linear motor, the method comprising:

supporting the at least one carrier on one of the plurality of feed-forward track segments;

actuating at least one linear motor to move the carrier along the plurality of feed-forward track segments independently of other carriers supported on the feed-forward track segments;

stopping movement of the carrier with the at least one linear motor at a selected station; and

performing at least one assembly operation with the robotic manipulator.

10. The method of claim 9, wherein the at least one assembly operation comprises at least one of: placing a component on the carrier, removing a component from the carrier, or joining at least two components together.

11. The method of claim 9, further comprising:

removing the empty carrier from one of the plurality of feed-forward track segments;

placing the removed carrier onto a return line, the return line comprising a plurality of return track segments; and

actuating the at least one linear motor to move the carrier along the return track segment in a direction toward the starting point of the plurality of feed-forward track segments.