Patent Grant
10913100
Currently, low volume production of sheet metal components is a relatively high cost, inflexible process, requiring costly sets of dies, typically made of cast steel. These dies, while well suited to mass production, are poorly matched to relatively low volume production and prototyping needs. Die sets can cost over $1 million per set, can be difficult to move, and/or costly to modify if the final required geometry of parts is not met.
Some implementations of incremental forming utilize single point incremental forming, which allows for the formation of basic sheet metal components without a die. Single point incremental forming is a process by which a hemispherical tool is moved along a preprogrammed path into a peripherally clamped metal sheet, to impart a desired shape. This process allows for the creation of a shape in one direction, without the need for a shape-specific die.
However, complications still exist in the form of unwanted sheet bending and deformation. This has been partially addressed with partial and full dies implemented on the opposing side of the forming tool to create a support structure; however, use of such partial or full dies re-introduces the high costs and low flexibility of a die.
Double-sided incremental forming (see
Some embodiments include the capability to introduce a current, for example a relatively high current, through two forming tools disposed on opposite sides of a workpiece (e.g., a sheet of metal), which reduces the required forming force of a metal, while simultaneously or concurrently allowing a metal to be stretched further than under normal conditions. In some embodiments, current may be introduced via sheet material surrounding or proximate to one or more tool contact points by attaching a current-introducing apparatus to the material proximate to a forming tool. Some embodiments also may include the capability to monitor temperature of the metal through, for example, a thermal infrared camera (e.g., camera 308 depicted schematically in
Double-sided incremental forming utilizes two opposing tools to deform and support a workpiece such as a sheet of metal, generally resulting in sheet deformation only where desired (see
Currently, few other prototype machines capable of double-sided incremental forming (DSIF) are known to Applicants to exist. The design of such machines generally heavily relied on components retrofitted to meet the demands of a DSIF machine. At least one embodiment of the system disclosed herein is particularly suited to the demands of double-sided incremental forming, while surpassing the capabilities of these existing machines, and remaining relatively low cost.
In one embodiment, a system includes a frame configured to hold a workpiece and first and second tool positioning assemblies coupled with the frame. The first and second tool positioning assemblies are configured to be opposed to each other on opposite sides of the workpiece. Each of the first and second tool positioning assemblies includes a toolholder, a first axis assembly, a second axis assembly, and a third axis assembly. The toolholder is configured to secure a tool to the tool positioning assembly. The first axis assembly is configured to articulate the toolholder along a first axis. The first axis assembly includes first and second guides extending generally parallel to the first axis and disposed on opposing sides of the toolholder with respect to the first axis. The first axis assembly includes first and second carriages articulable along the first and second guides of the first axis assembly, respectively, in the direction of the first axis. The second axis assembly is configured to articulate the toolholder along a second axis that is substantially perpendicular to the first axis. The second axis assembly includes first and second guides extending generally parallel to the second axis and disposed on opposing sides of the toolholder with respect to the second axis. The second axis assembly includes first and second carriages articulable along the first and second guides of the second axis assembly, respectively, in the direction of the second axis. The third axis assembly is configured to articulate the toolholder along a third axis that is substantially perpendicular to the first axis and substantially perpendicular to the second axis. The third axis assembly includes first and second guides extending generally parallel to the third axis and disposed on opposing sides of the toolholder with respect to the third axis. The third axis assembly includes first and second carriages articulable along the first and second guides of the third axis assembly, respectively, in the direction of the third axis.
In another embodiment, a system is provided including a frame configured to hold a workpiece, first and second tool positioning assemblies coupled with the frame, and a current source configured to deliver a current. The first and second tool positioning assemblies are configured to be opposed to each other on opposite sides of the workpiece. The first tool positioning assembly includes a first toolholder configured to secure a first tool, and the second tool positioning assembly includes a second toolholder configured to secure a second tool. The first and second toolholders are configured to receive the current from the current source and to pass the current between the first and second toolholders and through the workpiece when the first tool and the second tool engage the workpiece.
In yet another embodiment, a method for forming a workpiece is provided. The method includes securing the workpiece in a frame. The method also includes drawing opposing first and second tools toward each other, with the first tool engaging a first side of the workpiece, and the second tool engaging a second, opposite side of the workpiece. The method further includes passing a current between the first and second tools, wherein the current passes through the workpiece. Also, the method includes articulating at least one of the first and second tools while the first and second tools engage the workpiece and the current passes through the workpiece.
One or more technical effects of at least one embodiment include reduced costs for forming operations (e.g., low production forming), improved forming at reduced forming forces, improved control of forming operations, reduced reliance upon application specific tooling, increased utility of non-specific tooling across a variety of forming applications, improved mobility of forming equipment, and/or improved user friendliness of forming equipment or processes.
The figures of the application illustrate one or more embodiments of the inventive subject matter. The dimensions, scales, and/or relative sizes of the components shown in the attached figures are meant to be examples of dimensions, scales, and/or relative sizes, but are not intended to be limiting on all embodiments of the subject matter described herein.
In the embodiment depicted in
Each of the tool positioning assemblies 302, 304 may be understood as axis assemblies that in turn include one or more individual axis assemblies or sub-assemblies. In the depicted embodiment, for example, each of the tool positioning assemblies 302, 304 includes an x-axis assembly, a y-axis assembly, and a z-axis assembly. (See
The frame 306 is configured to secure components of the system 300 in place for stable performance during a forming operation. A perspective view of the frame 306 is shown in
The frame 306 includes a top axis section 802, a top blankholder section 804, a bottom blankholder section 806, and a bottom axis section 808. The top axis section 802 is configured to secure and house the top tool positioning assembly 302, and the bottom axis section 808 is configured to secure and house the bottom tool positioning assembly 304. The top blankholder section 804 and the bottom blankholder section 806 are disposed between the top and bottom axis sections 802, 808, and are configured to secure the blankholder frame 2100 in place between the top blankholder section 804 and the bottom blankholder section 808. The frame 306, for example, may have a width of about 39 inches, a depth of about 28.5 inches, and a height of about 78 inches. Other sizes and configurations may be utilized in various embodiments. For example, the embodiment depicted in
In the illustrated embodiment, the frame 306 is fabricated from generally low cost steel beam extrusions. In some embodiments, only basic welding may be required to assemble the various sections of the frame 306. For example, as best seen in
In one embodiment, the system 300 includes a gantry-style axis assembly 400 for several or all degrees of movement, neutralizing torque about each linear drive and guide, and allowing for smaller components to be used while maintaining stiffness and rigidity. Such an axis assembly 400 may be used for both the top tool positioning assembly 302 and the bottom tool positioning assembly 304. A first axis assembly 400 may be oriented with a secured tool 402 positioned downward in the sense of
The x-axis assembly 420 includes first and second guides 422, 423, corresponding first and second drive assemblies 424, 425, and corresponding first and second carriages 426, 427. The first and second guides 422, 423 extend generally parallel to the x-axis and are configured to be disposed on opposite sides of the toolholder 2000 when the axis assembly 400 is in an assembled configuration. The guides 422, 423, for example, may be supported by the frame 306. The first carriage 426 is articulable along the first guide 422, and the second carriage 427 is articulable along the second guide 423. The first drive assembly 424 is configured to articulate the first carriage 426 along the first guide 422, and the second drive assembly 425 is configured to articulate the second carriage 427 along the second guide 423. For example, the drive assemblies 424, 425 may include linear drive assemblies that are operably connected to motors. In some embodiments, a linear drive assembly may threadedly engage a motor such that a rotation of the motor is translated to linear motion of a corresponding carriage. The depicted motors are one example of a drive assembly that may be used to articulate a toolholder. Other mechanisms, such as a rack-and-pinion, pneumatic cylinder, or the like, may be used in various embodiments. Each drive assembly may also include carriage mounts (not shown for the x-axis assembly 420) that accept corresponding portions of a carriage that is supported by the guide.
Generally similarly, the y-axis assembly 440 includes first and second guides 442, 443, corresponding first and second drive assemblies 444, 445, and corresponding first and second carriages 446, 447. The first and second guides 442, 443 extend generally parallel to the y-axis and are configured to be disposed on opposite sides of the toolholder 2000 when the axis assembly 400 is in an assembled configuration. The first carriage 446 is articulable along the first guide 442, and the second carriage 447 is articulable along the second guide 443. The first drive assembly 444 is configured to articulate the first carriage 446 along the first guide 442, and the second drive assembly 445 is configured to articulate the second carriage 447 along the second guide 443. Each drive assembly may also include carriage mounts 450 that accept corresponding portions of a carriage that is supported by the guide.
Also, generally similarly, the z-axis assembly 460 includes first and second guides 462, 463, a first drive assembly 464, and corresponding first and second carriages 470, 472. Only one drive assembly 464 is depicted in
Thus, the first drive assembly 464 of the z-axis assembly 460 may articulate the tool 402 along the z-axis (e.g., into and out of engagement with a workpiece secured in the blankholder frame 2100). Further, because the z-axis assembly 460 is articulable in the x- and y-directions by the x-axis assembly 420 and the y-axis assembly 440, the tool 402 may thus be articulated in the x- and y-directions as well. For example, during a double-sided incremental forming operation, the tool 402 may be articulated along the z-axis into engagement with a workpiece (with a corresponding tool brought into engagement with an opposite side of the workpiece). Then, with the tool 402 urged into the workpiece a desired distance and/or at a desired level of force provided by the first drive assembly 464, the tool 402 may be articulated in the x- and/or y-directions by the drive assemblies of the x- and y-axis assemblies 420, 440.
As seen in
As seen in
In the illustrated embodiment, the toolholder device 2000 is mounted to an insulator device 1900. The insulator device 1900 is configured to electrically insulate various components of the system 300 from a current introduced into the toolholder device 2000. The insulator device 1900, for example, may be made of a ceramic material.
The illustrated embodiment also includes a load cell 1800 to which the insulator device 1900 is mounted. The load cell 1800 may be configured to convert an imparted force to an electrical signal. The electrical signal may be communicated to the control module 310, with the control module 310 configured to analyze the signal to determine, for example, if the signal corresponds to an imparted force that may be a source of concern (e.g., a sudden unexpected reduction in force that may indicate a failure), and/or determine if a force used to urge a tool against the workpiece may be modified for improved forming.
As discussed above, each of the x-, y-, and z-axis assemblies position the toolholder between corresponding carriages and guides along the respective axis. This arrangement, for example, may allow for improved neutralization of torques induced during a forming operation while still allowing the use of relatively lightweight structural members and reducing overall size and/or weight of a forming device. In this context, neutralization of a torque may be understood as the effective and efficient addressing of a torque induced during a forming operation. By centering or positioning the tool (the point of application of an applied force during a forming operation) between carriage assemblies along the respective axis, cantilevering may be avoided, and each resulting torque may be addressed by at least one compressive reactive engagement between a carriage and a guide along a given axis (e.g., an urging of a carriage bearing surface against a guide bearing surface). In contrast, if the applied force were not disposed between carriage assemblies along a given axis, it would be possible for a tensile engagement (e.g., an urging of a carriage away from a guide) to bear the entire reactive force, and/or for an applied force to result in a cantilevering about a guide and carriage, which may result in increased bending and/or torsion.
Similarly, a force 520 in the y-direction may result in a torque 522. The torque 522, for example, may be effectively and efficiently addressed by the engagement of the carriages of the y-axis assembly 440 along at least a portion of the length of the guides of the y-axis assembly 440. Further, the torque 522 may be effectively and efficiently addressed by the engagement of the carriages of the z-axis assembly 460 along at least a portion of the length of the guides of the z-axis assembly 460 (the imposed force may be generally centered between the guides of the z-axis assembly). The torque 522 may also be effectively and efficiently addressed by the engagement of the carriages in the dual guides of the x-axis assembly 420. (The positioning of the tool and resulting imparted force between the carriages of the x-axis assembly 420 helps insure that one of the engagements between a carriage and a guide of the x-axis assembly 420 will be a compressive engagement instead of a tensile engagement.)
Similarly, a force 530 in the z-direction may result in a torque 532. As the tool (and thus the force applied) is not aligned with the guides of the z-axis assembly 460, the torque 532 may act in a similar direction as the torque 522 discussed above, as shown in
Thus, the upper and bottom tool positioning assemblies may be employed to articulate tools into engagement with a workpiece, as well as to articulate the tools laterally with respect to the workpiece while engaged as part of a double-sided incremental forming operation. In some embodiments, the forming operation may be assisted by the use of a current applied to the workpiece, which may reduce the required force to perform the forming operation. For example, an isolated high current pathway configured to pass through a workpiece may be introduced within the system 300, which can result in improved formability of the workpiece.
The first tool assembly 610 includes a toolholder 614 configured to secure a tool 612 in place. The toolholder 614 is electrically coupled to a current source (e.g., current source 320, see discussion below). An insulating member 616 is interposed between the toolholder 614 and a load cell 618, to protect the load cell 618 and/or other components (e.g., one or more frames) to which the load cell 618 may be coupled directly or indirectly from the current from the current source. Similarly, the second tool assembly 620 includes a toolholder 624 configured to secure a tool 622 in place. The toolholder 624 is electrically coupled to a ground in the illustrated embodiment. An insulating member 626 is interposed between the toolholder 624 and a load cell 628, to protect the load cell 628 and/or other components (e.g., one or more frames) to which the load cell 628 may be coupled directly or indirectly from the current from the current source.
To perform a forming operation, the first tool assembly 610 may be articulated downward in the sense of
The passage of current and/or the bending or other forming of the workpiece may result in increased temperatures in the workpiece, tools, and/or toolholders. The temperature of these items may be monitored to improve current control, improve motion control of one or more tools engaging the workpiece, and/or help prevent overheating or other unsafe conditions. The temperature of the workpiece, tools, and/or toolholders may be monitored, for example, by a thermal imaging camera 308 that provides information corresponding to a temperature distribution.
In the illustrated embodiment, the tool 704 and the workpiece 702 include several regions having various temperature ranges that form a temperature distribution. The temperatures may range, for example, from about 35 degrees Celsius to about 204 degrees Celsius. The tool 704 includes a first region 710, a second region 712, a third region 714, and a fourth region 716. The first region 710 includes the highest temperature range present in the tool 704, the second region 712 includes the second highest temperature range present in the tool 704, the third region 714 includes the second lowest temperature range present in the tool 704, and the fourth region 716 includes the lowest temperature range present in the tool 704.
The workpiece 702 includes a first region 720, a second region 722, a third region 724, a fourth region 726, and a fifth region 728. In the illustrated embodiment, the first region 720 includes the highest temperature range present in the workpiece 702, the second region 722 includes the second highest temperature range present in the workpiece 702, the third and fourth regions 724, 726 include the second lowest temperature range present in the workpiece 702, and the fifth region 728 includes the lowest temperature range present in the workpiece 702. Generally speaking, the closer a portion of the workpiece 702 is to the tool 704 during a forming operation, the higher the temperature.
If any of the temperature ranges exceed a threshold, then the current may be reduced or turned off, a forming force may be reduced, or a speed of articulation of one or more tools engaging the workpiece as part of an incremental forming process may be reduced. In some embodiments, a current, force, or speed may be adjusted, based on the distribution information obtained by the thermal imaging camera 308, to conform to or more closely match a previously determined preferred distribution associated with a given forming activity.
Returning to
In the illustrated embodiment, the control module 310 includes a detection module 312, a motion module 314, and a memory 316 associated therewith. The detection module 312 is configured to receive or otherwise obtain information from one or more sensors or detectors. The motion module 314 is configured to control the positioning and movement of tools used for forming a workpiece. Further, the control module 310 may be operably connected to a current source 320 and configured to control an amount of current provided from the current source 320 to a workpiece via toolholders and tools of the system 300. In some embodiments, the amount of current may be controlled based on thermal information (such as, for example, a thermal distribution obtained via the thermal imaging camera 308). The current source 320 in some embodiments may be a battery or other power supply contained within the system 300, while in other embodiments the current source 320 may include a plug, wire, socket, or the like configured to receive a current from an external current supply.
The detection module 312 may receive information from, for example, the load cell 1800 and the thermal imaging camera 308. The information from the load cell 1800 may be used to determine a forming force. If the forming force is lower than a desired amount, then a corresponding tool or tools may be urged further into a workpiece (e.g., increasing an engagement distance) and/or urged with a larger amount of force. If the forming force is higher than a desired amount, the forming force or engagement distance may be reduced. Further, information from the load cell 1800 may indicate a fracture or other failure in the workpiece. The detection module 312, in some embodiments, is configured to receive thermal distribution information (e.g., from the thermal imaging camera), and determine if a temperature of a workpiece or tool exceeds a threshold, and/or determine if a temperature at a given location of the workpiece and/or a temperature distribution conforms to a desired temperature or distribution for a given forming activity.
The motion module 314 may receive input, for example, from an operator, or, as another example, from a stored pattern, and articulate the upper tool positioning assembly 302 and the lower tool positioning assembly 304 responsive to the input to form a desired shape or feature on a workpiece. Further, the motion module 314 may receive input from the detection module and adjust the articulation of the tool positioning assemblies 302, 304 accordingly. For example, if the detection module 312 determines that a fracture failure of the material has occurred (using, for example, information from the load cell 1800), the motion module 314 may cease forming operations and withdraw the tools from engagement with the workpiece. As another example, if the detection module determines that forces used in the forming process are too high (or too low), using, for example, information from the load cell 1800 and/or the thermal imaging camera 308, then the motion module 314 may decrease one or more engagement force used to urge a tool against a workpiece. For instance, if a threshold corresponding to a high risk of fracture is detected, the motion module 314 may control the tool positioning assemblies to reduce one or more forces being applied to the workpiece. As another example, the motion module 314 may adjust an engagement force, an amount of tool displacement, and/or a speed of tool displacement during a forming operation based on information received from the thermal imaging camera 308. Thus, the motion module 314 may adjust control of a forming operation using information (e.g., thermal information and/or force information) obtained during the forming operation.
Some embodiments may also include the capability to real-time heat treat a workpiece. The heat treatment may be controlled or varied temporally (e.g., varied over a given time period) or controlled or varied spatially (e.g., varied over a given area or volume). In the illustrated embodiment, the system 300 includes a heat treatment module 309 operably connected to the control module 310. In some embodiments, the heat treatment module 309 may include a laser. Alternatively or additionally, in some embodiments, the heat treatment module 309 may include a cooling pipe. For example, a laser may be used to locally heat all or a portion of a workpiece, and a cooling pipe (e.g., hose) may be used to cool the workpiece. In some embodiments, an air nozzle may be used to cool down the workpiece at a desired rate. In some embodiments, an optical fiber or other component of a laser and/or a cooling element (e.g., air nozzle) may be attached to one or more tools such that the movement of a heat treatment module and a tool are synchronized.
A bridge section 1200 may be included in the axis assembly 400 (as shown in
A top brace 1600 and a bottom brace 1500 may be included in the axis assembly 400 (as shown in
As discussed above, a load cell 1800 that may be included in the axis assembly 400 (as shown in
An insulator member 1900 may be included in the axis assembly 400 (as shown in
The axis assembly 400 may include a toolholder device 2000 (see
The blankholder frame 2100 (see
In some embodiments, the frame 306 and other components of the system 300 (e.g., toolholder frame 2500, carriage supports, bridge structures, and the like) may be fabricated or otherwise made using low cost materials. Various structural members may be assembled to construct a highly rigid frame (e.g., frame 306), which is easily assembled, and able to be modified at minimal cost.
In some embodiments, the system 300 includes modular, lightweight components of the frame 306. These components include, for example, the toolholder frame 2500, which may be made from low cost plate and tube steel, and modular X-Y and Z axis aluminum frame components.
In accordance with various embodiments, systems for and methods of tool movement and motion control utilize gantry-style axis assemblies (e.g., axis assembly 400) for each tool, allowing for consistent positional accuracy and force application throughout the 3-axis system range of motion (e.g., x, y, and z axes). Motors or other actuators may be included or coupled to the axis assemblies 400 to cause forming tools 402 (see
Components may also be designed to minimize or reduce costs. As discussed above, a frame 306 including low cost steel beam extrusions may be used to house the individual axis assemblies (e.g., the top and bottom tool positioning assemblies 302, 304), as well as the blankholder frame (e.g., blankholder frame 2100). In some embodiments, only basic welding may be required to assemble the various sections of the frame 306. Other relatively lower cost methods, such as casting, may be used for components of a double-sided incremental forming system formed in accordance with various embodiments. Thus, use of CNC machining and precision assembly techniques may be reduced, further lowering costs and material used in fabrication.
In one embodiment, the system 300 uses relatively high electrical current assisted forming.
Double-sided incremental forming (DSIF) systems and methods may find a wide variety of uses or applications. DSIF may be understood, for example, as a complete product consisting of a DSIF machine and/or toolpath design software, or, as a service involving fabrication of parts using such a machine and/or software.
Various related issues, such as commercial issues, that may be addressed by or considered in connection with embodiments formed in accordance with the present disclosure may include reliability and repeatability targets, desired machine life vs. machine cost, machine size and weight, and software packaging. Additional attention may be given to supplemental manufacturing technologies required, supply chain requirements, lead time estimation, throughput capabilities and process planning. The analysis of these factors may be further divided into requirements specific to particular industrial or domestic sectors.
For example, in the aerospace industry, manufacturing is often characterized by low batch volumes. When conventional product specific tooling is used, a significant amount of investment goes into fabricating massive tooling and storing these tools for future repair or part replacement. If annual production volume is less than 5000 pieces and about 200 stamping dies are required every year, about 60% of these dies may be eliminated by using DSIF (e.g., DSIF performed using systems or methods disclosed herein) instead of conventional forming.
As another example, in the automotive industry, inexpensive rapid prototyping without repetitive fabrication of new tooling may be used to allow greater number of design iterations cheaply. It is estimated that the United States automotive industry uses about 300 low volume production dies and 2200 prototyping dies annually. It is estimated that about 80% of the prototyping dies and 60% of the low volume production dies may be replaced by DSIF. As each stamping die may cost about $1,000,000 on average, replacing conventional stamping in the aerospace and automotive industries alone may save up to about $2,060,000,000 annually.
As yet further examples, the defense sector has use for forming technologies that enable low recurring costs in low volume batch production and which have the portability and expendability to enable rapid, inexpensive on-site replacement and repairs of just a single component. In the biomedical industry, in-situ fabrication of sheet metal implants may reduce implant surgery time. The small machine size and high level of product customization achievable by DSIF allow these needs to be fulfilled.
In the domestic sector, use of DSIF systems and methods disclosed herein will enable improved, less expensive test marketing of new sheet metal products. Moreover, flexible forming technologies like DSIF may find further uses in emerging decentralized manufacturing paradigms, such as crowd sourcing and remote manufacturing.
Systems and methods formed in accordance with various embodiments may address one or more of the applications discussed above.
At 2302, a workpiece upon which one or more forming operations are to be performed is secured in place in a frame. In some embodiments, the workpiece is a sheet of metal. The workpiece may be secured to a blankholder frame (e.g., blankholder frame 2100) via clamps, with the blankholder frame mounted to a frame (e.g., frame 306) and interposed between axis assemblies (e.g., top and bottom tool positioning assemblies 302, 304), with each axis assembly having at least one tool secured thereto.
At 2304, a first tool is positioned. For example, the first tool may be urged toward a first surface (e.g., an upper surface) of the workpiece. The first tool may be positioned by articulation of an axis assembly (e.g., top tool positioning assembly 302) urging the tool along an axis into engagement with the workpiece at a desired location. The first tool may be engaged with the workpiece by being urged into the workpiece at a desired force level and/or a desired engagement distance (e.g., a distance extending past the point of first contact between the tool and the workpiece).
At 2306, a second tool is positioned. For example, a second tool may be urged toward a second surface (e.g., a lower surface) of the workpiece. The second tool may be positioned by articulation of an axis assembly (e.g., bottom tool positioning assembly 304) urging the tool along an axis into engagement with the workpiece at a selected location. The selected location may be proximate to the point of contact between the first tool positioned at 2304, for example displaced a relatively small amount in one or more lateral directions along the workpiece. The second tool may be engaged with the workpiece by being urged into the workpiece at a desired force level and/or a desired engagement distance (e.g., a distance extending past the point of first contact between the tool and the workpiece).
At 2308, a current is applied to the workpiece. For example, a current may be provided from a source to a first toolholder, from the first tool through the workpiece to the second tool, and then to a ground via a second toolholder. The current may be controlled by a control module. In some embodiments, the control module may control the current based on a measured characteristic of the workpiece. For example, a thermal imaging camera may provide thermal information of the workpiece used to determine appropriate adjustments to an amount of current, and the control module may adjust the current accordingly. The current is configured or controlled to allow forming of the workpiece with reduced force levels. For example, the introduction of the current may reduce the elastic recovery of a shape or feature formed in the workpiece. Various insulated components (e.g., insulating members disposed between the toolholders and corresponding load cells, insulating workpiece clamps) may be provided to eliminate or reduce the threat of danger or damage from uncontrolled current.
At 2310, with the first and second tools engaging opposite sides of the workpiece and a current passing therebetween, one or more of the first and second tools may be articulated in one or more lateral directions to form a shape or feature in the workpiece as part of a double-sided incremental forming process. The path of articulation may be provided by a pre-determined plan or pattern input into a control module. Further, the pre-determined plan or pattern may be adjusted based on one or more measured characteristics (e.g., a temperature detected by a thermal imaging camera 308, a force detected by a load cell 1800) determined during the forming operation.
For example, at 2312, the temperature of the workpiece and/or one or more of the tools is monitored. The temperature may be monitored by obtaining thermal distribution information during the forming operation via a thermal imaging camera 308. The temperature may be analyzed to help ensure a threshold temperature that may damage a tool or the workpiece is not exceeded, and/or to optimize the forming process, with the current, control of a tool path, or control of a force exerted on the workpiece adjusted responsive to the temperature information.
At 2314, it is determined if there is an issue raised by a detected temperature or temperature distribution based on the monitoring performed at 2312. If there is an issue, the issue is addressed at 2316. For example, if a temperature or temperature distribution deviates from a desired temperature or temperature distribution for a given forming operation, the current and/or articulation and/or force applied to the tools may be adjusted based on the determined temperature or temperature distribution. As another example, if a temperature exceeds a threshold, the forming operation may be terminated, or may be controlled to reduce the temperature (e.g., by reducing a current and/or force applied to the workpiece). If the issue raised by the detected temperature information is satisfactorily addressed, the method 2300 may proceed.
At 2318, a load or loads experienced during the forming process are monitored. During the forming process, forces exerted on the workpiece via the tools results in a loading of the particular axis assembly securing a given tool. This loading may be measured and/or monitored by a load cell, such as load cell 1800. Loading information may be provided by the load cell to a control module for analysis to help ensure that a threshold loading that may damage a tool, the workpiece, and/or a support structure such as an axis assembly or a frame, is not exceeded. Additionally or alternatively, the load may be monitored to optimize the forming process, with the control of a tool path or force adjusted responsive to the loading information.
At 2320, it is determined if there is an issue raised by a detected load based on the monitoring performed at 2318. If there is an issue, the issue is addressed at 2322. For example, if a sudden change in load is detected that indicates a fracture or impending fracture of the workpiece and/or damage to a support structure, the forming process may be halted, and the tools withdrawn from the workpiece. In some embodiments, an alarm (e.g., an audible alarm, a visible lighting alarm, a prompt provided on a screen, or the like) may be provided to alert an operator of the issue. As another example, if the load varies sufficiently from a desired loading for a particular forming operation, a control module may vary a force exerted on the workpiece. If the issue raised by the detected load information is satisfactorily addressed, the method 2300 may proceed until the desired shape or feature is completed.
At 2324, the current is removed from the workpiece, and the tools are drawn away from the workpiece. If, at 2326, it is determined that an additional feature or shape is to be formed, the method may return to 2304 with the tools positioned and articulated to form the additional shape or feature. If, at 2326, it is determined that no additional features or shapes are to be formed (e.g., the forming operation is complete), the workpiece may be removed from the frame at 2328.
Thus, embodiments disclose systems and methods that provide for a forming technique that is cheaper, smaller, more mobile and/or more user friendly than conventional forming technologies. Various embodiments provide for reduced costs for forming operations (e.g., low production forming), improved forming at reduced forming forces, improved control of forming operations, reduced reliance upon application specific tooling, increase utility of non-specific tooling across a variety of forming applications, improved mobility of forming equipment, and/or improved user friendliness of forming equipment or processes.
In one embodiment, a system includes a frame configured to hold a workpiece and first and second tool positioning assemblies coupled with the frame. The first and second tool positioning assemblies are configured to be opposed to each other on opposite sides of the frame. Each of the first and second tool positioning assemblies includes a toolholder, a first axis assembly, a second axis assembly, and a third axis assembly. The toolholder is configured to secure a tool to the tool positioning assembly. The first axis assembly is configured to articulate the toolholder along a first axis. The first axis assembly includes first and second guides extending generally parallel to the first axis and disposed on opposing sides of the toolholder with respect to the first axis. The first axis assembly includes first and second carriages articulable along the first and second guides of the first axis assembly, respectively, in the direction of the first axis. The second axis assembly is configured to articulate the toolholder along a second axis that is substantially perpendicular to the first axis. The second axis assembly includes first and second guides extending generally parallel to the second axis and disposed on opposing sides of the toolholder with respect to the second axis. The second axis assembly includes first and second carriages articulable along the first and second guides of the second axis assembly, respectively, in the direction of the second axis. The third axis assembly is configured to articulate the toolholder along a third axis that is substantially perpendicular to the first axis and substantially perpendicular to the second axis. The third axis assembly includes first and second guides extending generally parallel to the third axis and disposed on opposing sides of the toolholder with respect to the third axis. The third axis assembly includes first and second carriages articulable along the first and second guides of the third axis assembly, respectively, in the direction of the third axis.
In another aspect, the tool may include at least one of a substantially hemispheric surface, a conical surface, or a freeform surface configured to engage the workpiece.
In another aspect, the system may include a current source configured to deliver a current passing between the toolholder of the first tool positioning assembly and the toolholder of the second tool positioning assembly, wherein the current passes through the workpiece when a first tool secured to the first toolholder and a second tool secured to the second toolholder engage the workpiece.
In another aspect, each of the first and second tool positioning assemblies may include a toolholder frame movably coupled to the first and second guides of one of the first axis assembly, second axis assembly, or third axis assembly. The toolholder frame is configured to translate substantially along the first and second guides. The first and second tool positioning assemblies may also include an insulating member interposed between the toolholder frame and the toolholder. The insulating member is configured to insulate the toolholder frame from the current passing between the toolholder of the first tool positioning assembly and the toolholder of the second tool positioning assembly. In some embodiments, the insulating member may comprise a ceramic material.
In another aspect, the system may include a temperature detection unit configured to detect a temperature distribution corresponding to at least one of the tool and the workpiece as the current passes between the toolholder of the first tool positioning assembly and the toolholder of the second tool positioning assembly. The temperature detection unit may include a thermal imaging camera. Further, the system may include a control module configured to receive temperature information from the temperature detection unit and to control the articulation of one or more of the first tool or the second tool responsive to the temperature information.
In another aspect, the first and second carriages of the first axis assembly may be configured to be coupled to and to support the second axis assembly, the first and second carriages of the second axis assembly may be configured to be coupled to and to support the third axis assembly, and the toolholder may be operably connected to the third axis assembly whereby the toolholder articulates with the third axis assembly.
In another aspect, the system may include first, second, and third drive assemblies. The first drive assembly is operably coupled to at least one of the first and second guides of the first axis assembly, and configured to articulate the first and second carriages of the first axis assembly along the first and second guides of the first axis assembly. The second drive assembly is operably coupled to at least one of the first and second guides of the second axis assembly, and configured to articulate the first and second carriages of the second axis assembly along the first and second guides of the second axis assembly. The third drive assembly is operably coupled to at least one of the first and second guides of the third axis assembly, and configured to articulate the first and second carriages of the third axis assembly along the first and second guides of the third axis assembly.
In another aspect, the system may include a heat treatment module configured to heat treat the workpiece during a forming operation.
In another embodiment, a system is provided including a frame configured to hold a workpiece, first and second tool positioning assemblies coupled with the frame, and a current source configured to deliver a current. The first and second tool positioning assemblies are configured to be opposed to each other on opposite sides of the workpiece. The first tool positioning assembly includes a first toolholder configured to secure a first tool, and the second tool positioning assembly includes a second toolholder configured to secure a second tool. The first and second toolholders are configured to receive the current from the current source and to pass the current between the first and second toolholders and through the workpiece when the first tool and the second tool engage the workpiece.
In another aspect, each of the first and second tool positioning assemblies may include a toolholder frame movably coupled to a support structure of the tool positioning assembly, and an insulating member interposed between the toolholder frame and the one of the first and second toolholders associated with the tool positioning assembly. The insulating member is configured to insulate the toolholder frame from the current passing between the first toolholder and the second toolholder. Further, the insulating member may be made of a ceramic material.
In another aspect, the system may include at least a temperature detection unit or a displacement detection unit. The temperature detection unit may be configured to detect a temperature distribution corresponding to at least one of the tool and the workpiece as the current passes between the first toolholder and the second toolholder. Additionally, the temperature detection unit may include a thermal imaging camera. The system, in another aspect, may further include a control module configured to receive temperature information from the temperature detection unit and to control the articulation of one or more of the first tool or the second tool responsive to the temperature information.
In yet another embodiment, a method for forming a workpiece is provided. The method includes securing the workpiece in a frame. The method also includes drawing opposing first and second tools toward each other, with the first tool engaging a first side of the workpiece, and the second tool engaging a second, opposite side of the workpiece. The method further includes passing a current between the first and second tools, wherein the current passes through the workpiece. Also, the method includes articulating at least one of the first and second tools while the first and second tools engage the workpiece and the current passes through the workpiece.
In another aspect, the method may further include determining a temperature distribution of one or more of the workpiece or one or more of the first and second tools. In another aspect, determining a temperature distribution may include observing the one or more of the workpiece or one or more of the first and second tools with a thermal imaging camera.
In another aspect, the method may include controlling the articulating of the at least one of the first and second tools responsive to the temperature distribution.
In another aspect, the articulating the at least one of the first and second tools may include articulating a toolholder securing the at least one of the first and second tools. The toolholder in some embodiments is secured to an assembly including a first gantry-style axis assembly configured to articulate the toolholder along a first axis, a second gantry-style axis assembly configured to articulate the toolholder along a second axis that is substantially perpendicular to the first axis, and a third gantry-style axis assembly configured to articulate the toolholder along a third axis that is substantially perpendicular to the first axis and substantially perpendicular to the second axis.
It is to be understood that the above description is intended to be illustrative, and not restrictive. For example, the above-described embodiments (and/or aspects thereof) may be used in combination with each other. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the inventive subject matter without departing from its scope. While the dimensions and types of materials described herein are intended to define the parameters of the inventive subject matter, they are by no means limiting and are example embodiments. Many other embodiments will be apparent to one of ordinary skill in the art upon reviewing the above description. The scope of the inventive subject matter should, therefore, be determined with reference to the appended clauses, along with the full scope of equivalents to which such clauses are entitled. In the appended clauses, the terms “including” and “in which” are used as the plain-English equivalents of the respective terms “comprising” and “wherein.” Moreover, in the following clauses, the terms “first,” “second,” and “third,” etc., are used merely as labels, and are not intended to impose numerical requirements on their objects. Further, the limitations of the following clauses are not written in means-plus-function format and are not intended to be interpreted based on 35 U.S.C. § 112, sixth paragraph, unless and until such clause limitations expressly use the phrase “means for” followed by a statement of function void of further structure.
This written description uses examples to disclose several embodiments of the inventive subject matter, including the best mode, and also to enable one of ordinary skill in the art to practice the embodiments of inventive subject matter, including making and using any devices or systems and performing any incorporated methods. The patentable scope of the inventive subject matter is defined by the clauses, and may include other examples that occur to one of ordinary skill in the art. Such other examples are intended to be within the scope of the clauses if they have structural elements that do not differ from the literal language of the clauses, or if they include equivalent structural elements with insubstantial differences from the literal languages of the clauses.
The foregoing description of certain embodiments of the present inventive subject matter will be better understood when read in conjunction with the appended drawings. To the extent that the figures illustrate diagrams of the functional blocks of various embodiments, the functional blocks are not necessarily indicative of the division between hardware circuitry. Thus, for example, one or more of the functional blocks (for example, processors or memories) may be implemented in a single piece of hardware (for example, a general purpose signal processor, microcontroller, random access memory, hard disk, and the like). Similarly, the programs may be stand alone programs, may be incorporated as subroutines in an operating system, may be functions in an installed software package, and the like. The various embodiments are not limited to the arrangements and instrumentality shown in the drawings.
As used herein, an element or step recited in the singular and proceeded with the word “a” or “an” should be understood as not excluding plural of said elements or steps, unless such exclusion is explicitly stated. Furthermore, references to “one embodiment” of the presently described subject matter are not intended to be interpreted as excluding the existence of additional embodiments that also incorporate the recited features. Moreover, unless explicitly stated to the contrary, embodiments “comprising,” “comprises,” “including,” “includes,” “having,” or “has” an element or a plurality of elements having a particular property may include additional such elements not having that property.
This application claims priority to U.S. Provisional Application No. 61/555,951, which was filed on 4 Nov. 2011, and is entitled “System And Method For Incremental Forming” (the “'951 application”); U.S. Provisional Application No. 61/612,034, which was filed on 16 Mar. 2012, and is entitled “System And Method For Accumulative Double-sided Incremental Forming” (the “'034 application”); and U.S. Provisional Application No. 61/642,598, which was filed on 4 May 2012, and is entitled “System And Method For Accumulative Double-sided Incremental Forming” (the “'598 application”). This application also is related to U.S. Nonprovisional application Ser. No. 13/654,071, which was filed on 17 Oct. 2012, and is entitled “System And Method For Accumulative Double-sided Incremental Forming” (referred to herein as the “'071 application”) and U.S. Provisional Application Ser. No. 61/550,666, which was filed on 24 Oct. 2011, and is entitled “System And Method For Incremental Forming” (referred to herein as the “'666 application”). The entire disclosures of the '951 application, the '034 application, the '598 application, the '071 application, and the '666 application are incorporated by reference herein.
This invention was made with government support under DE-EE00033460 awarded by the Department of Energy and CMMI0727843 awarded by the National Science Foundation. The government has certain rights in the invention.
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| Number | Date | Country | |
|---|---|---|---|
| 20160082498 A1 | Mar 2016 | US |
| Number | Date | Country | |
|---|---|---|---|
| 61642598 | May 2012 | US | |
| 61612034 | Mar 2012 | US | |
| 61555951 | Nov 2011 | US |
| Number | Date | Country | |
|---|---|---|---|
| Parent | 13667846 | Nov 2012 | US |
| Child | 14954098 | US |
