Ultrasonic and vibration welding of thermoplastics using vibrating tools
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- BRANSON ULTRASONICS CORP
- Filing Date
- 2024-05-08
- Publication Date
- 2026-06-01
Smart Images
Figure 00000000_0000_ABST
Abstract
Description
[Technical field]
[0001] The present disclosure relates to ultrasonic and vibration welding, crimping, swaging, forming, and degating of thermoplastics using vibrable tools. [Background technology]
[0002] This section provides background information related to the present disclosure, but not necessarily prior art.
[0003] Ultrasonic welding is a process for joining two or more parts using high frequency ultrasonic vibrations. For example, as shown in Figure 1, two thermoplastic parts 10, 12 may be clamped between a fixture 14 (sometimes called an anvil or nest) and an ultrasonic horn 16 (sometimes called a sonotrode). The horn 16 emits ultrasonic energy that causes melting at the interface of the two plastic parts 10, 12, creating a weld 20.
[0004] In addition to the horn 16 shown in FIG. 1, the ultrasonic welding machine may include a converter, a transducer, and / or a booster (sometimes collectively referred to as an ultrasonic stack), as well as a press for holding the parts 10, 12 together under pressure, an ultrasonic generator, and / or a controller.
[0005] As shown in FIG. 1 , the top surface 22 of the part 10 may be flat (i.e., planar). Similarly, the face 24 of the ultrasonic horn 16 that contacts and delivers ultrasonic energy to the top surface 22 of the part 10 may also be flat. Alternatively, the top surface 22 of the part 10 may have a three-dimensional contour (i.e., with one or more peaks and valleys). In that case, the face 24 of the ultrasonic horn 16 may be provided (e.g., machined or cast) to have a three-dimensional custom contour that is complementary to the three-dimensional contour of the top surface 22 of the part 10, as shown in FIG.
[0006] Typically, the ultrasonic horn is coupled to a press that moves the horn vertically (indicated by arrow 26) so that the horn moves between an extended position in contact with the workpiece (e.g., as shown in FIG. 1 ) and a retracted position in which the horn is spaced from the workpiece (e.g., as shown in FIG. 2 ).
[0007] Welding films can be used between the ultrasonic horn 16 and the top surface 22 of the part 10 to act as a buffer and prevent the horn 16 from placing undesirable visible marks on the part 10. These films are typically provided on a roll or spool and are used in a film feeder mechanism that pulls a new segment of welding film between the horn and each new part to be welded. Because each segment of welding film is used only once, an undesirable amount of waste can be generated during the ultrasonic welding process. Additionally, due to its thin and flexible nature, the welding film can have a tendency to fold over on itself, resulting in undesirable visible marks on the part 10. Summary of the Invention
[0008] This section provides a general overview of the disclosure, but is not an exhaustive disclosure of its entire scope or all of its features.
[0009] According to the teachings of the present disclosure, a vibratable tool may be disposed between the vibratable horn and the thermoplastic workpiece to transfer energy from the horn through the vibratable tool to the workpiece. The vibratable tool may reduce or prevent marking of the thermoplastic workpiece, but may be used for extended periods or indefinitely to process multiple thermoplastic workpieces, sequentially and / or simultaneously. The upper surface of the vibratable tool may be flat to interface with the flat-surfaced horn. Alternatively, the upper surface of the vibratable tool may have a three-dimensional contour that is complementary to the three-dimensional contour of the horn. Similarly, the lower surface of the vibratable tool may be flat or have a three-dimensional contour to interface with a flat surface or three-dimensional contour on the thermoplastic workpiece. In this manner, the vibratable tool may be used with a flat-surfaced or contoured horn to process a thermoplastic workpiece having a surface that is complementary or non-complementary to the horn surface.
[0010] According to one aspect of the disclosure, a system includes a vibratable horn having a surface, a thermoplastic workpiece, and a vibratable tool disposed between the vibratable horn and the thermoplastic workpiece, the system configured to energize the vibratable horn to transfer energy from the vibratable horn through the vibratable tool to the thermoplastic workpiece to induce welding, staking, swaging, forming, or degating of the thermoplastic workpiece.
[0011] According to another aspect of the present disclosure, a system includes a vibratable horn having a surface, a thermoplastic workpiece, and means for transferring energy from the vibratable horn to the thermoplastic workpiece without contact between the vibratable horn and the thermoplastic workpiece to induce welding, staking, swaging, forming, or degating of the thermoplastic workpiece.
[0012] According to another aspect of the present disclosure, a method includes disposing a vibratable tool having an upper surface and a lower surface between a vibratable horn and a thermoplastic workpiece, and moving at least one of the vibratable horn and the thermoplastic workpiece relative to the other such that the lower surface of the vibratable tool contacts an upper surface of the thermoplastic workpiece while the upper surface of the vibratable tool contacts a surface of the vibratable horn. The method further includes energizing the vibratable horn to transfer energy from the vibratable horn, through the vibratable tool, to the thermoplastic workpiece to induce welding, staking, swaging, forming, or degating of the thermoplastic workpiece.
[0013] Additionally or alternatively, the method may include using the tool multiple times to process multiple thermoplastic workpieces and / or using the tool to process multiple thermoplastic workpieces simultaneously.
[0014] Additionally or alternatively, the thermoplastic workpiece may include a first portion and a second portion, and the method may include using the vibrable tool to induce welding, staking, swaging, forming, or degating of the first portion and / or the second portion.
[0015] Additionally or alternatively, the thermoplastic workpiece may include a runner, and the method may include moving at least one of the vibratable horn and the thermoplastic workpiece relative to the other so that a lower surface of the vibratable tool contacts the runner while an upper surface of the vibratable tool contacts a surface of the vibratable horn.
[0016] Additionally or alternatively, the method may include energizing the vibratable horn at ultrasonic frequencies.
[0017] Additionally or alternatively, the method may include energizing the vibratable horn to create a weld in the thermoplastic workpiece that extends parallel or perpendicular to a direction of vibration of the vibratable horn.
[0018] Additionally or alternatively, the lower surface of the vibrable tool may be complementary to the upper surface of the thermoplastic workpiece, thereby allowing substantially uniform contact between the lower surface of the vibrable tool and the upper surface of the thermoplastic workpiece during electrical current application.
[0019] Additionally or alternatively, the upper surface of the thermoplastic workpiece may have a three-dimensional contour and the lower surface of the vibrable tool may have a three-dimensional contour that is complementary to the three-dimensional contour of the upper surface of the thermoplastic workpiece.
[0020] Additionally or alternatively, the face of the vibratable horn may have a three-dimensional contour and the top surface of the vibratable tool may have a three-dimensional contour that is complementary to the three-dimensional contour of the horn face.
[0021] Additionally or alternatively, the face of the vibratable horn may be substantially planar.
[0022] Additionally or alternatively, the vibratable tool may include one or more of a metal, a thermoplastic, and / or a thermoset plastic.
[0023] Additionally or alternatively, the method may include producing the vibrationable tool using an additive or subtractive manufacturing process.
[0024] Additionally or alternatively, the method may include supporting the vibratable tool and / or the thermoplastic workpiece in a fixture during energization. Further, the fixture may include one or more adjustable alignment members.
[0025] Additionally or alternatively, the vibratable tool may be coupled to a horn.
[0026] According to another aspect of the disclosure, an ultrasonic welding system for a thermoplastic workpiece includes an ultrasonic horn having a face and a thermoplastic workpiece including at least a first portion and a second portion. Each of the first portion and the second portion has an upper surface and a lower surface. The upper surface of the first portion has a three-dimensional contour and the lower surface of the first portion contacts the upper surface of the second portion at one or more locations. The system further includes a vibratable tool disposed between the face of the ultrasonic horn and the upper surface of the first portion of the thermoplastic workpiece. The vibratable tool includes an upper surface and a lower surface. The lower surface of the vibratable tool has a three-dimensional contour that is complementary to the three-dimensional contour of the upper surface of the first portion of the thermoplastic workpiece. The system is configured to energize the ultrasonic horn and transfer energy from the ultrasonic horn through the vibratable tool to the one or more locations to ultrasonically weld the first portion of the thermoplastic workpiece to the second portion of the thermoplastic workpiece.
[0027] According to another aspect of the disclosure, an ultrasonic welding system for a thermoplastic workpiece includes an ultrasonic horn having a face and a thermoplastic workpiece including at least a first portion and a second portion. The face of the ultrasonic horn has a three-dimensional contour. The first portion and the second portion of the thermoplastic workpiece each have an upper surface and a lower surface. The lower surface of the first portion contacts the upper surface of the second portion at one or more locations. The system further includes a vibratable tool disposed between the ultrasonic horn and the upper surface of the first portion of the thermoplastic workpiece. The vibratable tool includes an upper surface and a lower surface. The upper surface of the vibratable tool has a three-dimensional contour that is complementary to the three-dimensional contour of the face of the ultrasonic horn. The system is configured to energize the ultrasonic horn and transfer energy from the ultrasonic horn through the vibratable tool to the one or more locations to ultrasonically weld the first portion of the thermoplastic workpiece to the second portion of the thermoplastic workpiece.
[0028] According to yet another aspect of the present disclosure, a method of ultrasonic welding includes positioning a vibratable tool between an ultrasonic horn having a surface and a thermoplastic workpiece having at least a first portion and a second portion. The first portion of the thermoplastic workpiece has an upper surface having a three-dimensional contour. The vibratable tool has an upper surface and a lower surface having a three-dimensional contour that is complementary to the three-dimensional contour of the upper surface of the first portion of the thermoplastic workpiece. The method further includes moving at least one of the ultrasonic horn and the thermoplastic workpiece relative to the other such that the lower surface of the vibratable tool contacts the upper surface of the first portion of the thermoplastic workpiece while the upper surface of the vibratable tool contacts a surface of the ultrasonic horn, and energizing the ultrasonic horn to transfer energy from the ultrasonic horn through the vibratable tool to the thermoplastic workpiece to form a weld between the first and second portions of the thermoplastic workpiece.
[0029] According to yet another aspect of the present disclosure, a method of ultrasonic welding includes positioning a vibratable tool between an ultrasonic horn having a face and a thermoplastic workpiece having at least a first portion and a second portion. The face of the ultrasonic horn has a three-dimensional contour. The vibratable tool has a lower surface and an upper surface having a three-dimensional contour that is complementary to the three-dimensional contour of the face of the ultrasonic horn. The method further includes moving at least one of the ultrasonic horn and the thermoplastic workpiece relative to the other such that the lower surface of the vibratable tool contacts an upper surface of the first portion of the thermoplastic workpiece while the upper surface of the vibratable tool contacts the face of the ultrasonic horn, and energizing the ultrasonic horn to transfer energy from the ultrasonic horn through the vibratable tool to the thermoplastic workpiece to form a weld between the first and second portions of the thermoplastic workpiece.
[0030] Further aspects and further areas of applicability will become apparent from the description provided herein. It is to be understood that various aspects of the present disclosure can be implemented individually or in combination with one or more other aspects. It is also to be understood that the description and specific examples herein are for illustrative purposes only and are not intended to limit the scope of the present disclosure. Further areas of applicability will become apparent from the description provided herein. The description and specific examples in this summary are for illustrative purposes only and are not intended to limit the scope of the present disclosure. [Brief description of the drawings]
[0031] The drawings described herein are only for purposes of illustrating selected embodiments rather than all possible implementations and are not intended to limit the scope of the present disclosure. [Figure 1] 1 is a cross-sectional view of an ultrasonic welding system according to the prior art. [Diagram 2] 1 is a cross-sectional view of an ultrasonic welding system having a contoured horn according to the prior art. [Diagram 3] FIG. 1 is a cross-sectional view of a system for ultrasonic or vibration welding, staking, swaging, forming, or degating a thermoplastic workpiece according to one embodiment of the present disclosure. [Figure 4] 1 is a cross-sectional view of a system for simultaneously processing multiple thermoplastic workpieces. [Diagram 5] FIG. 13 is a cross-sectional view of a system for stud welding according to another embodiment of the present disclosure. [Figure 6] FIG. 13 is a cross-sectional view of a system for ultrasonic staking according to another embodiment of the present disclosure. [Figure 7] FIG. 13 is a cross-sectional view of a system for ultrasound degating, according to another embodiment of the present disclosure. [Figure 8] 13 is a cross-sectional view of a system including a horn and a vibratable tool having complementary contoured surfaces according to another embodiment. [Figure 9]13 is a cross-sectional view of a system including a vibratable tool and a workpiece having complementary contoured surfaces according to another embodiment. [Figure 10] 1 is a cross-sectional view of a system including a vibratable tool having multiple contoured surfaces; [Figure 11] 1 is a cross-sectional view of a system including a vibratable tool having multiple surfaces with contoured contours and a uniform thickness. [Figure 12] 1 is a cross-sectional view of a system including a vibratable tool adapted for ultrasonic staking, according to yet another illustrative embodiment. [Figure 13] FIG. 13 is a cross-sectional view of a system including a vibratable tool adapted for ultrasonic swaging and shaping, according to another example embodiment. [Figure 14] 1 is a cross-sectional view of a system including a fixture having a contoured surface supporting a contoured workpiece; [Figure 15] 1 is a cross-sectional view of a system including a vibratable tool having a relief for receiving a workpiece having a port. [Figure 16] 1 is a cross-sectional view of a system including a vibratable tool having a lower surface that is narrower than an upper surface. [Figure 17] FIG. 13 is a cross-sectional view of a system including a torsion horn according to yet another exemplary embodiment. [Figure 18] 1 is a cross-sectional view of a system including a vibratable tool having protrusions for engaging a thermoplastic sheet or film. [Figure 19] FIG. 1 is an isometric view of a system including a fixture having alignment guides for positioning an oscillatory tool. [Figure 20] FIG. 1 is a cross-sectional view of a system including a vibratable tool coupled to a vibratable horn. [Figure 21] 13 is an isometric view of a system having a contoured vibratable tool according to yet another exemplary embodiment of the present disclosure; FIG. [Figure 22]FIG. 22 is a top view of the contoured vibratable workpiece and contoured tool shown in FIG. 21 . [Diagram 23] FIG. 13 is a front view of an ultrasonic welding machine including a vibratable tool according to yet another exemplary embodiment of the present disclosure.
[0032] Corresponding reference numerals indicate corresponding parts throughout the several views of the drawings. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0033] Exemplary embodiments are more fully described with reference to the accompanying drawings.
[0034] The exemplary embodiments are provided so that the disclosure will be thorough and will fully convey the scope of the present disclosure to those skilled in the art. Numerous specific details are described, such as examples of specific components, devices, and methods, to provide a thorough understanding of the embodiments of the present disclosure. It will be apparent to those skilled in the art that specific details need not be used, that the exemplary embodiments can be embodied in many different forms, and that none of these should be construed to limit the scope of the present disclosure. In some exemplary embodiments, well-known processes, well-known device structures, and well-known technologies are not described in detail.
[0035] The terms used herein are for the purpose of describing specific exemplary embodiments only and are not intended to be limiting. As used herein, the singular forms "a," "an," and "the" may be intended to include the plural unless the context clearly indicates otherwise. The terms "comprises," "comprising," "including," and "having" are inclusive and thus specify the presence of stated features, integers, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof. The method steps, processes, and operations described herein should not be construed as necessarily requiring their execution in the particular order described or illustrated, unless specifically identified as an order of execution. It should also be understood that additional or alternative steps may be used.
[0036] Terms such as first, second, third, etc. may be used herein to describe various elements, components, regions, layers, and / or sections, but these elements, components, regions, layers, and / or sections should not be limited by these terms. These terms may only be used to distinguish one element, component, region, layer, or section from another region, layer, or section. Terms such as "first," "second," and other numerical terms, when used herein, do not imply a sequence or order unless clearly indicated by the context. Thus, a first element, component, region, layer, or section described below can be referred to as a second element, component, region, layer, or section without departing from the teachings of the exemplary embodiments.
[0037] Spatially relative terms such as "inner," "outer," "beneath," "below," "lower," "above," "upper," and the like may be used herein to facilitate the description of the relationship of one element or feature as depicted in the figures to another element or feature. Spatially relative terms may be intended to encompass different orientations of a device in use or operation in addition to the orientation depicted in the figures. For example, if a device in the figures were turned over, elements described as "below" or "beneath" other elements or features would be oriented "above" the other elements or features. Thus, the exemplary term "below" can encompass both an orientation of above and below. A device may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptive terms used herein would be interpreted accordingly.
[0038] A system according to one exemplary embodiment of the present disclosure is shown in FIG. 3 and generally designated by reference numeral 300. As shown in FIG. 3, the system 300 includes a vibratable horn 302 having a surface 304, a thermoplastic workpiece 306, and a vibratable tool 308 disposed between the vibratable horn 302 and the thermoplastic workpiece 306. The system 300 is configured to energize the vibratable horn 302 to transfer energy from the vibratable horn 302 through the vibratable tool 308 to the thermoplastic workpiece 306 to induce welding of the thermoplastic workpiece. In this manner, the vibratable tool 308 is used as an intermediate device to transfer energy from the vibratable horn 302 to the thermoplastic workpiece 306 as needed to induce welding.
[0039] The vibratable tool 308 prevents the ultrasonic horn 302 from contacting the thermoplastic workpiece 306, thus preventing the horn from creating undesirable visible marks on the thermoplastic workpiece. Additionally, as described further below, the vibratable tool 308 may be designed to avoid or inhibit marking of the thermoplastic workpiece where the vibratable tool contacts the thermoplastic workpiece.
[0040] 3, the system 300 is adapted to weld a first portion 306A of a thermoplastic workpiece to a second portion 306B of a thermoplastic workpiece. As will be apparent to one skilled in the art, prior to welding, the first portion 306A and the second portion 306B may be separate components or may be different portions of the same component.
[0041] Once the vibratable tool 308 is used to guide the welding of the workpiece 306 shown in FIG. 3, the tool may be used repeatedly to create welds on a series of workpieces (e.g., in an automated production line process). Similarly, the vibratable tool 308 may be used to create welds on multiple workpieces 310, 312, 314 simultaneously, as shown in FIG. 4. Additionally, because the vibratable tool 308 is reusable for extended periods or indefinitely, it may be used in place of disposable welding film to reduce waste in the welding process. Alternatively, a welding film may be placed between the vibratable tool 308 and the workpiece 306 to inhibit marking of the workpiece.
[0042] As shown in FIG. 3, the system 300 may also include a fixture 330 to assist and / or prevent movement of the thermoplastic workpiece 306 during the welding process.
[0043] The system 300 is preferably configured to move at least one of the vibratable horn 302 and the thermoplastic workpiece 306 relative to the other when the vibratable horn is energized such that a lower surface 316 of the vibratable tool 308 contacts an upper surface 318 of the thermoplastic workpiece 306 and an upper surface 320 of the vibratable tool 308 contacts a surface 304 of the vibratable horn 302 (as shown in FIG. 3). For example, the system 300 may include a press configured to move the vibratable horn 302 between an extended position (as shown in FIG. 3) and a retracted position in which the horn 302 is spaced apart from the vibratable tool 308 (or, if the vibratable tool is coupled to the horn, the vibratable tool 308 is spaced apart from the workpiece 306, as discussed below). Alternatively, the system 300 may be configured to move, for example, the thermoplastic workpiece 306, or a fixture 330 supporting the workpiece, between the extended and retracted positions.
[0044] The system 300 may operate the vibratable horn 302 at an ultrasonic frequency (e.g., 20-40 kHz) to induce ultrasonic welding of the workpiece 306. Alternatively, the system may operate the vibratable horn at a lower frequency to induce vibration welding of the workpiece. As will be appreciated by those skilled in the art, the direction of vibration of the horn is typically perpendicular to the weld 322 (as shown by arrow 324) for ultrasonic welding and parallel to the weld 322 (as shown by arrow 326) for vibration welding. In other embodiments, the direction of vibration of the horn may be circumferential or other, depending on the particular application.
[0045] The system 300 of Figure 3 may be used to create continuous or intermittent welds between multiple portions of a thermoplastic workpiece 306, depending on the configuration of the workpiece and / or the vibrable tool 308 in any given implementation of these teachings. For example, a first portion 306A and a second portion 306B of a thermoplastic workpiece may be configured to form one or more stud weld joints, as shown in Figure 5. High frequency ultrasonic vibrations from the horn 302 are applied to the first portion 306A of the thermoplastic workpiece via the vibrable tool 308, driving a formed stud 309 into a hole 311 with an interference fit.
[0046] The teachings of the present disclosure are not limited to ultrasonic and vibration welding, as the vibratable tool 308 may be readily adapted for other applications, including ultrasonic staking, ultrasonic swaging and forming, ultrasonic degating, and the like. For example, the thermoplastic workpiece 306 may include a plastic stud 332 (sometimes referred to as a boss) for ultrasonic staking, as shown in FIG. 6. The stud 332 may protrude through a hole 333 in a component 334 that is locked in place relative to the thermoplastic workpiece 306. High frequency ultrasonic vibrations from the horn 302 are applied to the top of the stud 332 via the vibratable tool 308, melting the stud and locking the part 334 in place. While the workpiece 306 is thermoplastic, the part 334 may be a dissimilar material, such as a metal, a dissimilar plastic, and the like. As will be apparent to one skilled in the art, ultrasonic staking and / or swaging may also be used to capture one or more additional portions or parts between the workpiece 306 and the part 334.
[0047] The teachings of the present disclosure may also be used to separate a first portion 306A and a second portion 306B of a thermoplastic workpiece, as shown in FIG. 7. In this example, the first portion 306A is configured as a runner and the second portion 306B is the component to be separated from the runner. High frequency ultrasonic vibrations from the horn 302 are applied to the runner 306A via the vibrable tool 308, introducing ultrasonic energy into the gate section 336 to bond the runner 306A to the part 306B. This introduces a cyclic bending moment into the component 306B until the component 306B separates from the runner 306A.
[0048] The upper and lower surfaces of the vibratable tool 308 preferably have shapes that are complementary to the mating surfaces of the horn 302 and the workpiece 306, respectively. For example, in the embodiment shown in Figures 3 and 4, the upper and lower surfaces of the vibratable tool 308 are flat (i.e., planar) for engaging a flat horn surface and a flat workpiece. In other embodiments, the vibratable tool 308 may have one or more surfaces with a contoured contour to interface with a contoured horn and / or a contoured workpiece.
[0049] For example, if the face 304 of the vibratable horn 302 has a three-dimensional contour, then the top surface 320 of the vibratable tool 308 may have a three-dimensional contour that is complementary to the three-dimensional contour of the horn face 304, as shown in Figure 8. As a result, the vibratable tool 308 can be used to interface a contoured horn 302 designed to engage a workpiece with a matching contour with essentially any workpiece 306 having a flat top surface, as shown in Figure 8.
[0050] Alternatively, the vibratable tool 308 may have a flat upper surface 320 for engaging the flat-surfaced horn 302 and a contoured lower surface 316 that is complementary to the contoured workpiece 306, as shown in FIG. 9. In this manner, the vibratable tool 308 may be used to interface the flat-surfaced horn with a contoured workpiece, significantly expanding the potential applications of the flat-surfaced horn. At the same time, the vibratable tool may eliminate the need to design and fabricate a contoured horn for interfacing with a contoured workpiece. Instead of fabricating a contoured horn (which requires complex FEA analysis) to fabricate a custom part, the vibratable tool 308 may be easily adapted or fabricated at a fraction of the cost to interface the flat-surfaced horn with a contoured workpiece. Similarly, a variety of vibratable tools may be fabricated (e.g., via 3D printing) to interface the flat-surfaced horn with a number of different workpieces having different three-dimensional contours.
[0051] In other embodiments, the lower surface 316 and the upper surface 320 of the vibratable tool 308 may have contoured contours to engage a contoured horn and a contoured workpiece, respectively. Additionally, the contour of the horn face 304 may be different and non-complementary to the contour of the workpiece, as shown in FIG. 10. As a result, the vibratable tool 308 may be used to allow an existing horn 302 designed to contact a workpiece with a matching contoured contour to interface with essentially any workpiece having a non-matching contoured upper surface.
[0052] Alternatively, the contour of the horn face 304 may be complementary to the workpiece, as shown in Figure 11. In that case, the vibratable tool 308 may have an upper surface 320 that is complementary to the contoured horn 302 and a lower surface 316 that is complementary to the contoured workpiece 306. The vibratable tool 308 may also have a uniform thickness (i.e., in the vertical direction in the example shown in Figure 11). Thus, the vibratable tool 308 may be used in place of, for example, a welding film to reduce or inhibit marking of a thermoplastic workpiece.
[0053] The vibratable tool 308 may also have contours that are undulating as desired to implement various ultrasonic staking configurations. For example, as shown in FIG. 12, the vibratable tool 308 may include one or more cavities 340, 342 on its lower surface 316. High frequency ultrasonic vibrations from the horn 302 may be applied to the top of the stud 332 through the vibratable tool 308 to melt and fill the cavities 340, 342 to create a head that locks the part 334 in place. The top surface of the vibratable tool 308 may be flat to engage with a flat-sided horn, as shown in FIG. 12. Alternatively, the top surface of the vibratable tool and the horn surface may have contours that are complementary as described above. As described above, the component 334 may be a dissimilar material compared to the thermoplastic workpiece 306, such as a metal, a dissimilar plastic, or the like.
[0054] Similarly, the vibratable tool 308 may have an undulating contour as desired to perform ultrasonic swaging and forming. For example, as shown in FIG. 13, the vibratable tool 308 may have a cavity 344 on its underside. High frequency ultrasonic vibrations from the horn 302 are applied through the vibratable tool to the wall 346 of the thermoplastic workpiece 306 to melt and reform the plastic ridges over another component 334, mechanically capturing the component 334. The top surface of the vibratable tool 308 may be flat to engage with a flat-sided horn, as shown in FIG. 13. Alternatively, the top surface of the vibratable tool 308 and the horn face may have complementary contours as described above. As will be apparent to one skilled in the art, ultrasonic staking and / or swaging may also be used to capture one or more additional parts or components between the workpiece 306 and the component 334.
[0055] In any implementation in which the vibrable tool 308 has a contoured surface to match a contoured horn and / or a contoured workpiece, the contoured surface may include multiple raised and / or recessed portions (e.g., ridges and valleys), curves, stepped portions, and / or sloped portions as necessary to fit the complex and unique surface shape (i.e., the contour) of a particular workpiece.
[0056] Additionally, the vibratable tool 308 may include one or more openings or relief areas 354 to avoid contact with ports 356 or other surface features in the thermoplastic workpiece 306, as shown in Figure 15. Additionally, the portion of the vibratable tool 308 that contacts the workpiece 306 may be narrower than the portion of the vibratable tool 308 that contacts the horn 302, as shown in Figure 16. Alternatively, the portion of the vibratable tool 308 that contacts the workpiece 306 may have a width that is the same as or greater than the portion of the vibratable tool that contacts the horn 302.
[0057] Additionally, the vibratable tool 308 may be adapted for use with a torsionally vibratable horn that vibrates in a circumferential direction to impart torsional vibrations. For example, as shown in FIG 17, the vibratable tool 308 may include one or more keyed surface features (e.g., projections or slots 360) for engaging with corresponding keyed surface features (e.g., slots or projections 362) on the horn 302 to transfer vibrational energy from the horn to the vibratable tool 308.
[0058] Additionally, the underside of the vibrable tool 308 may be provided with one or more protrusions 364, 366 adapted to contact the thermoplastic workpiece 306, as shown, for example, in Figure 18. This may be desirable for various applications, including when the tool 308 is used for ultrasonic or vibration welding of two or more sheets or films 306A, 306B comprising thermoplastic material (e.g., woven or nonwoven fabrics or composites that include a sufficient amount of thermoplastic material for welding).
[0059] In any given implementation, the fixture 330 may include a flat surface for supporting the thermoplastic workpiece 306, as shown, for example, in Figures 3-13. Alternatively, the fixture 330 may have a contoured surface for supporting the contoured workpiece 306, as shown, for example, in Figure 14, or may include side walls 370, 372 to hold the workpiece 306 therebetween, as shown, for example, in Figures 15-17. Additionally, the thermoplastic workpiece 306 may include one or more energy directors 350, 352 in any given implementation, as shown, for example, in Figures 14-17.
[0060] The vibratable tool 308 may be placed on or positioned by the workpiece 306, for example, as shown in Figures 3 and 9. Additionally or alternatively, the fixture 330 may be adapted to maintain the position of the vibratable tool 308 relative to the workpiece 306. For example, in the embodiment of Figure 19, the fixture 330 includes one or more alignment guides 374 for maintaining the position of the vibratable tool 308 therebetween. The alignment guides 374 are preferably movable between an extended position in which the guides do not contact the vibratable tool (to allow the tool and / or workpiece to be removed from and / or placed into the fixture) and a retracted position (shown in Figure 19) in which the guides 374 contact the vibratable tool 308 and hold the vibratable tool in the proper position. Additionally, the alignment guides 374 may be actuated to facilitate, for example, an automated production line. Additionally or alternatively, fixture 330 may include a partial recess 376 that is complementary to workpiece 306, as shown in FIG. 19, to receive and hold the workpiece in place.
[0061] In other embodiments, the vibratable tool 308 may be coupled to the horn 302 as shown in FIG. 20 and therefore move with the horn (if the horn is movable relative to the workpiece as illustrated in FIG. 20 by arrow 378). The vibratable tool 308 may be loosely coupled to the horn 302 and therefore the tool may not resonate with the horn. For example, the vibratable tool may be coupled to the horn (e.g., with fasteners) but spaced from the horn such that the tool 308 can vibrate independently of the horn 302. Alternatively, the vibratable tool 308 may be rigidly coupled to the horn 302 via any suitable means such as fasteners (e.g., screws), adhesives, welding, etc. such that the vibratable tool resonates with the horn. In that case, a Mylar sheet (such as BoPET) may be inserted between the horn and the vibratable tool.
[0062] The vibratable tool 308 can transfer the greatest amount of energy to the workpiece if the tool resonates with the horn. On the other hand, if the vibratable tool resonates with the horn, the vibratable tool is more likely to mark the workpiece where the vibratable tool contacts the workpiece. Furthermore, the vibratable tool 308 does not need to resonate with the horn to transfer a sufficient amount of vibrational energy to the workpiece to accomplish welding, staking, swaging, forming, degating, etc. If the vibratable tool 308 does not resonate with the horn 302, the horn may be less susceptible to cracking and may tolerate higher amplitudes that may be required in some implementations to compensate for the damping provided by the vibratable tool.
[0063] The vibratable tool 308 may be made from any suitable material(s), including metal (e.g., aluminum or steel), thermoplastic (including glass-filled thermoplastic), thermoset plastic, carbon fiber, and the like. In general, the material(s) should be selected such that the tool 308 is rigid enough to transfer the required amount of energy to the workpiece, but flexible enough to inhibit marking on the workpiece. In one exemplary implementation in which the vibratable tool 308 is used to process a workpiece including a hard plastic, such as ABS plastic, the vibratable tool is formed from an aluminum-filled nylon SLS material. In another exemplary implementation in which the vibratable tool 308 is used to process a softer workpiece, such as a workpiece formed from polystyrene, the vibratable tool is formed from a softer material, such as an SLA thermoset plastic that is softer (i.e., more compliant) than the aluminum-filled nylon SLS material.
[0064] Furthermore, the vibratable tool 308 may be fabricated by any suitable process, including additive manufacturing (e.g., via 3D printing with an SLS or SLA printer), subtractive manufacturing (e.g., using a CNC machine), casting, molding, etc. For best results, the material composition and / or manufacturing technique for the vibratable tool 308 may be selected based on the material composition and / or geometry of the workpiece being machined.
[0065] If the vibratable tool 308 has one or more surfaces with an undulating contour that does not perfectly match the undulating contour of the horn or workpiece, the vibratable tool 308 may be used repeatedly with such horn and / or workpiece until wear of the vibratable tool causes the vibratable tool's undulating contour to more closely match or follow the undulating contour of the horn and / or workpiece. A three-dimensional scan of the vibratable tool 308 may then be taken and used to generate (e.g., manually or with a 3D printer, CNC machine, etc.) one or more replicas of the worn tool, which thus more closely match the contour of the horn and / or workpiece as compared to the original vibratable tool before wear.
[0066] 21 illustrates another embodiment of a system including a vibratable horn 302 having a surface 304, a thermoplastic workpiece 306, a vibratable tool 308 disposed between the horn 302 and the workpiece 306, and a fixture 330 for supporting the thermoplastic workpiece 306 and the vibratable tool 308. Additionally, a lower surface 316 of the vibratable tool 308 has a complex three-dimensional contour that is complementary to the complex three-dimensional contour of an upper surface 318 of the workpiece 306, as shown in FIG.
[0067] As will be apparent, the vibratable horn 302 described herein may be part of an ultrasonic stack in an ultrasonic welder. For example, FIG. 23 shows an ultrasonic welder 400 including an ultrasonic stack 402 including an ultrasonic transducer 404, a booster 406, and a vibratable horn 302. The welder 400 may also include a controller 408, and a power supply that is preferably integrated with the controller 408. Alternatively, the vibratable horn 302 may be part of a vibration welder, or the like. Any suitable welding or vibration machine having a vibratable horn 302 may be used to perform the welding, staking, swaging, forming, and degating processes described herein.
[0068] The vibratable tool 308 described herein and shown in the figures can be thought of as a means for transferring energy from the vibratable horn to the thermoplastic workpiece without contact between the vibratable horn and the thermoplastic workpiece.
[0069] The foregoing description of the embodiments is provided for purposes of illustration and description. It is not intended to be exhaustive or to limit the present disclosure. Individual elements or features of a particular embodiment are generally not limited to that particular embodiment, but where applicable, even if not specifically shown or described, can be interchangeable and used in selected embodiments. The same may be modified in many ways. Such variations should not be considered as departures from the present disclosure, and all such modifications are intended to be included within the scope of the present disclosure.
Claims
1. It is a system, A vibrating horn having a surface, A thermoplastic workpiece including the top and bottom surfaces, A vibrable tool, including an upper and lower surface, is positioned between the vibrable horn and the thermoplastic workpiece. The system is configured to energize the vibrable horn and transmit energy from the vibrable horn to the thermoplastic workpiece via the vibrable tool to induce welding, riveting, swaging, forming, or degating of the thermoplastic workpiece. The upper surface of the thermoplastic workpiece has a three-dimensional contour, The lower surface of the vibrable tool has a three-dimensional contour that is complementary to the three-dimensional contour of the upper surface of the thermoplastic workpiece.
2. The system according to claim 1, wherein when the vibrable horn is energized, at least one of the vibrable horn and the thermoplastic workpiece is moved relative to the other, so that the lower surface of the vibrable tool contacts the upper surface of the thermoplastic workpiece and the upper surface of the vibrable tool contacts the surface of the vibrable horn.
3. The system according to claim 2, wherein the thermoplastic workpiece comprises a first portion and a second portion, and the system is configured to energize the vibrable horn to induce welding, crimping, swaging, molding, or decating of the first portion and / or the second portion.
4. The system according to claim 3, wherein the first and second parts are separate components of the thermoplastic workpiece prior to welding, riveting, swaging, molding, or decating of the thermoplastic workpiece.
5. The system according to any one of claims 1 to 4, wherein the system is configured to energize the vibrable horn at an ultrasonic frequency.
6. The system according to claim 1, further comprising a fixture adapted to support the thermoplastic workpiece and the vibrable tool.
7. A system for welding, riveting, swaging, forming, or degating thermoplastic workpieces, A vibrable horn having a surface, A thermoplastic workpiece having a top surface with a three-dimensional contour, Means for transmitting energy from the vibrable horn to the thermoplastic workpiece without contact between the vibrable horn and the thermoplastic workpiece, to induce welding, crimping, swaging, forming, or decating of the thermoplastic workpiece, Equipped with, The means for transmitting energy includes a lower surface having a three-dimensional contour complementary to the three-dimensional contour of the upper surface of the thermoplastic workpiece.
8. A method for welding, riveting, swaging, forming, or degating a thermoplastic workpiece, The vibrable tool is positioned between a vibrable horn and a thermoplastic workpiece, wherein the vibrable horn has a surface, and the vibrable tool has an upper surface and a lower surface. Move at least one of the vibrable horn and the thermoplastic workpiece relative to the other such that the lower surface of the vibrable tool contacts the upper surface of the thermoplastic workpiece, and the upper surface of the vibrable tool contacts the surface of the vibrable horn. The vibratory horn is energized to transmit energy from the vibratory horn to the thermoplastic workpiece via the vibratory tool, thereby inducing welding, crimping, swaging, forming, or degating of the thermoplastic workpiece. Includes, The upper surface of the thermoplastic workpiece has a three-dimensional contour, A method wherein the lower surface of the vibrable tool has a three-dimensional contour that is complementary to the three-dimensional contour of the upper surface of the thermoplastic workpiece, thereby allowing uniform contact between the lower surface of the vibrable tool and the upper surface of the thermoplastic workpiece when energized.
9. The method according to claim 8, wherein the thermoplastic workpiece is a first thermoplastic workpiece, and the method further comprises arranging a second thermoplastic workpiece in place of the first thermoplastic workpiece; moving at least one of the vibratory horn and the second thermoplastic workpiece relative to the other such that the lower surface of the vibratory tool contacts the upper surface of the second thermoplastic workpiece, while the upper surface of the vibratory tool contacts the surface of the vibratory horn; and energizing the vibratory horn to transfer energy from the vibratory horn through the vibratory tool to the second thermoplastic workpiece to induce welding, riveting, swaging, molding or decating of the second thermoplastic workpiece.
10. Arrangement includes positioning the vibrable tool between the vibrable horn and a plurality of thermoplastic workpieces, wherein the plurality of thermoplastic workpieces include the thermoplastic workpieces, and movement includes moving the vibrable horn and at least one of the plurality of thermoplastic workpieces relative to the other such that the lower surface of the vibrable tool contacts the upper surface of the plurality of thermoplastic workpieces, while the upper surface of the vibrable tool contacts the surface of the vibrable horn, and energization. The method according to claim 8, comprising energizing the vibrable horn to transfer energy from the vibrable horn to the plurality of thermoplastic workpieces via the vibrable tool to induce welding, riveting, swaging, forming, or decating of each of the plurality of thermoplastic workpieces.
11. The method according to claim 8, wherein the thermoplastic workpiece comprises a first portion and a second portion, and the energization induces welding, crimping, swaging, forming, or decating of the first portion and / or the second portion.
12. The method according to claim 11, wherein the first part and the second part are separate components of the thermoplastic workpiece before energization.
13. The method according to claim 8, wherein the energizing includes energizing the vibrable horn at an ultrasonic frequency.
14. The method according to claim 13, wherein the thermoplastic workpiece includes a runner, and the movement includes moving at least one of the vibratory horn and the thermoplastic workpiece relative to the other such that the lower surface of the vibratory tool contacts the runner, while the upper surface of the vibratory tool contacts the surface of the vibratory horn.
15. The method according to claim 8, wherein energizing includes energizing the vibrable horn to generate a weld in the thermoplastic workpiece that extends parallel to the vibration direction of the vibrable horn, the weld extending parallel to the vibration direction of the vibrable horn.
16. The method according to claim 8, wherein the three-dimensional contour of the upper surface of the thermoplastic workpiece includes one or more inclined portions.
17. The method according to claim 8, wherein the surface of the vibrable horn has a three-dimensional contour, and the upper surface of the vibrable tool has a three-dimensional contour complementary to the three-dimensional contour of the surface of the vibrable horn, and uniform contact is permitted between the upper surface of the vibrable tool and the surface of the vibrable horn.
18. The method according to claim 17, wherein the three-dimensional contour of the vibrable horn includes one or more inclined portions.
19. The method according to any one of claims 9 to 18, wherein the surface of the vibrable horn is planar.
20. The system according to claim 7, wherein the surface of the vibrable horn has a three-dimensional contour, and the means for transmitting energy includes an upper surface having a three-dimensional contour complementary to the three-dimensional contour of the surface of the vibrable horn, thereby allowing uniform contact between the upper surface of the vibrable tool and the surface of the vibrable horn.
21. The system according to claim 20, wherein the three-dimensional contour of the vibrable horn includes one or more inclined portions.
22. The system according to claim 7, wherein the surface of the vibrable horn is planar.
23. The surface of the vibrable horn has a three-dimensional contour, and the upper surface of the vibrable tool is The system according to claim 1, wherein the vibrable horn has a three-dimensional contour that is complementary to the three-dimensional contour of the surface.
24. The system according to claim 23, wherein the three-dimensional contour of the vibrable horn includes one or more inclined portions.
25. The system according to claim 1, wherein the surface of the vibrable horn is planar.