Complex positioning fastening system and positioning method

Abstract

Positioning and fastening system, including: a first component (204) with a complex surface (246), wherein the complex surface (246) has a smooth contour; a second component (206, 207, 208, 210, 212, 214, 216) shaped so that it can be connected to the first component (204); and a fastening (230) configured to position the first component (204) relative to the second component (206, 207, 208, 210, 212, 214, 216), wherein the fastening (226) comprises a first positioner comprising a complex surface area (260) shaped to fit the complex surface (246) of the first component (204) in order to position the fastening (230) relative to the first component (204), wherein the fastening (230) includes a second positioner configured to position the fastening (230) relative to the second component (206, 207, 208, 210, 212, 214, 216); wherein the fastening (230) comprises a body (252); wherein the second positioner comprises pins (254, 256); wherein the first component (204) is overdetermined relative to the second component (206, 207, 208, 210, 212, 214, 216) by means of the fastening (230) and removal of the pins allows removal of the body (252) of the fastening (230) once the first component (204) is attached to the second component (206, 207, 208, 210, 212, 214, 216).

Description

[0001] This description generally relates to manufacturing and service fixtures with complex positioning features and, more specifically, to additively manufactured fixtures for positioning and holding parts in joining processes using mathematical component data, additive manufacturing (3D printing), elastic averaging, and other features.

[0002] Positioning components for assembly and service work requires accurate and repeatable alignment before the components are joined to ensure quality function and / or appearance. A component has six degrees of freedom, including linear translations in the x, y, and z axes, as well as rotational movements about each of the x, y, and z axes. To fix two components for assembly, the components often need to be fixed relative to a datum point to eliminate twelve degrees of freedom for the two components. The various components to be joined can each be aligned relative to a fixed datum point to eliminate the various degrees of freedom between the components before the components are joined.To achieve this, special positioning features can be manufactured using additive or subtractive processes, or otherwise added to the various components solely for positioning purposes. To accommodate the component's tolerance deviations between the special positioning features, a certain amount of clearance must be incorporated into the positioning features, which reduces alignment precision.

[0003] Additive manufacturing, or 3D printing, technologies have become widely adopted due to their desirable properties such as efficiency and flexibility. Various types of 3D printing technologies have been developed to create objects from metal and polymer materials. These different 3D printing technologies typically each include a build surface, a material delivery system, an energy delivery system, and a control system. The build surface represents a reference surface onto which the material is applied layer by layer to successively build the part according to the design details. The material delivery system ensures the deposition of a starting material, for example, in the form of particles, fibers, or filaments, which is fused with the previously deposited layer.The energy supply system adds energy to the source material before, during, and / or after deposition to liquefy the material and fuse it with the part being created. The control system controls each of the other systems during the construction of the object being created, for example, according to a definition of mathematical data.

[0004] Although additive manufacturing is becoming increasingly common, the production of manufacturing and service tools typically still requires long lead times and high costs. In applications such as those requiring tools for short-run production, development phases, or field service / repair purposes, timelines and costs can be a barrier to tool creation. More efficient and faster creation of tools and fixtures would bring benefits.

[0005] DE 103 31 852 A1 describes a measurement fixture for components on a coordinate measuring station, comprising a flat measuring plate and support columns arranged thereon with support heads for the respective component. The support heads are designed for a directionally defined, positive engagement with alignment receptacles formed on the respective component, such that the engagement of a support head in the measuring arrangement of the component causes the respective support column to be aligned perpendicular to the measuring plate. The support columns can be arranged in any position on the measuring plate, so that the component is held stress-free.

[0006] DE 10 2017 111 588 A1 describes an element for holding a body component to be measured in a reference position, comprising a contact head that is applied to the body component and whose position relative to the element is adjustable in at least one spatial direction. The contact head comprises a magnet that attracts the adjacent body component.

[0007] DE 10 2014 103 796 A1 describes a system for elastically averaged alignment comprising a first alignment part with an alignment component and a first plurality of elastically deformable alignment elements.The alignment system also includes a second alignment portion having an elastically deformable alignment component configured and arranged to be received by and deformably and matingly engaged with the alignment component, and a second plurality of elastically deformable alignment elements configured and arranged to deformably and matingly engage the first plurality of deformable alignment elements, wherein the engagement of the alignment component and deformable component and the first plurality of elastically deformable alignment elements and the second plurality of elastically deformable alignment elements elastically averages a predetermined position of the second alignment portion relative to the first alignment portion.

[0008] US 10 392 131 B2 describes a tool assembly comprising a support frame with support beams and support brackets that support the support beams. The support frame is rigid and serves to transport the tool assembly. A support tool is carried by the support frame and includes a face plate and a support grid structure formed with the face plate as a monolithic structure defined by a series of AM layers. The face plate has a support surface on top of the support tool to support a working component. The support grid structure engages the support beams so that the loads between the support tool and the support frame are transferred via the support beams. The support frame maintains the dimensional stability of the support tool during transport and when resting within a permissible tolerance of the support tool.

[0009] EP 2 660 007 B1 describes a clamp assembly comprising a first clamp with a plurality of magnetic devices. Each magnetic device comprises a permanent magnet and a coil surrounding the permanent magnet. The clamp assembly further comprises a controller for pulsing the coils to selectively magnetize and demagnetize the permanent magnets.

[0010] Accordingly, it is desirable to manufacture fastening tools quickly and efficiently while maintaining high positioning accuracy. Furthermore, it is desirable to provide features that facilitate the positioning and fastening of components for joining, even for additively manufactured parts that desirably have complex features. Furthermore, other desirable features and characteristics of the present invention will become apparent from the following detailed description and the appended claims, taken in conjunction with the accompanying drawings and the foregoing technical field and background.

[0011] The invention is defined by means of the independent claims.

[0012] Systems and methods are provided for positioning a pair of components relative to each other using complex features. According to the invention, a positioning fixture system includes a first component having a complex surface having a smooth contour. A second component is shaped to be mated to the first component. A fixture is configured to position the first component relative to the second component. The fixture also includes a first positioner having a complex surface area shaped to mate with the complex surface of the first component to position the fixture relative to the first. The fixture includes a second positioner that positions the fixture relative to the second component. The fixture includes a body. The second positioner includes pins.The first component is over-determined relative to the second component by means of the fixture, and removal of the pins allows removal of the fixture body once the first component is attached to the second component.

[0013] In one embodiment, the fixture comprises an additively manufactured build material with compliance-tuned printed features that provide relatively lower compliance in at least one direction to achieve critical positioning dimensions and relatively higher compliance in at least one other direction.

[0014] In another embodiment, the attachment is configured for portability by comprising a polymeric material and by being configured solely for positioning the first component and the second component relative to each other.

[0015] In a further embodiment, the complex surface comprises at least one complex algebraic surface.

[0016] In another embodiment, a pin extends through the fixture and into the component at the complex surface.

[0017] In a further embodiment, at least one of the positioners comprises an elastically deformable structure and provides an elastic averaging effect in the positioning of the attachment relative to at least one of the components.

[0018] In a further embodiment, the attachment comprises a third positioner and an adjustment mechanism on the attachment that engages at least one positioner to adjust its position.

[0019] In one example, the attachment includes an integrated magnet that holds the attachment to at least one of the components.

[0020] In another embodiment, the mount includes an integrated sensor configured to monitor at least one parameter of the system.

[0021] In one example, the attachment comprises a magnet that holds the attachment to at least one component, and the parameter comprises an electromotive force generated by the magnet.

[0022] According to the invention, a positioning method comprises forming a first component with a complex surface, the complex surface having a smooth contour. A second component is formed that is shaped to mate with the first component. A fastener is formed with a first locator comprising a complex surface area shaped to mate with the complex surface of the first component. The fastener is formed to include a second locator configured to position the fastener relative to the second component. The first component is positioned relative to the second component by the fastener, and the first component is connected to the second component. Pins are removed for removing a body of the fastener once the first component is attached to the second component.The first component is overdetermined relative to the second component by means of the attachment. The attachment comprises the body. The second positioner comprises the pins.

[0023] In a further embodiment, the attachment is formed by additive manufacturing of a plurality of construction materials, wherein the different construction materials have different stiffnesses in order to control compliance in different directions.

[0024] In another embodiment, the device is formed from a polymeric material and is designed as a single fixture solely for positioning two specific components relative to each other. Furthermore, the fixture is designed to be portable for use in the field and during repairs.

[0025] In a further embodiment, the complex surface is formed as at least one complex algebraic surface.

[0026] In another embodiment, a pin extends through the fixture and into the first component at the complex surface to clamp the first component.

[0027] In a further embodiment, the first positioner is designed as an elastically deformable structure. The first positioner ensures an elastic averaging effect when positioning the fastening element relative to the first component.

[0028] In another embodiment, a screw extends through the fastener and engages at least one positioner. The screw adjusts a position of the engaging positioner.

[0029] In one example, a magnet is integrated into the mount. The magnet holds the mount to at least one component.

[0030] In another embodiment, a sensor is integrated into the mount. The sensor monitors at least one system parameter.

[0031] The exemplary embodiments are described below in conjunction with the following drawing figures, wherein like numerals indicate like elements, and wherein: Fig. Figure 1 is a schematic representation of an additive manufacturing system in the process of building a fixture; Fig. 2 is an exploded perspective view of an assembly including multiple components and associated assembly fasteners; Fig. 3 is a detailed view of part of the assembly of Fig. 2 is in preparation for joining two of the components; Fig. 4 is a perspective view of a fixture for positioning the two components of Fig. 3; Fig. 5 is a perspective view of the fastening of Fig. 4, which is used to position the two components from Fig. 3 is used; Fig. 6 is a perspective detail of the removable positioning pins of the attachment of Fig. 4; Fig. 7 is an exploded perspective view of two components of the assembly of Fig. 2 and a fixture for positioning the components; Fig. 8 is a cross-sectional view of the fastening of Fig. 7; Fig. Figure 9 is a schematic sectional view of a fastener connecting two components of the assembly of Fig. 2 positioned; Fig. 10 is a perspective view of a fixture for positioning components, such as the assembly of Fig. 2; and Fig. 11 is a detailed view of part of the fastening from Fig. 10.

[0032] There is no intention to be bound by any express or implied theory presented in the preceding technical field, background, brief description, or the following detailed description.

[0033] As disclosed herein, products and methods are disclosed for positioning multiple components to be joined together. In several embodiments, complex positioning features are incorporated into fixtures to position components relative to one another using features of the components themselves, without using a fixed reference point such as in an x, y, z coordinate system. The complex positioning features (positioners) may include elastically deformable features, contoured / complex surfaces, planar surfaces, magnets, pins, holes, adjustable features, and others. The complex positioning features may be combined to constrain each component in its six degrees of freedom and may be used so that the components are overconstrained.This approach creates a system and method for precisely positioning components relative to each other without reference to a common reference point, enabling the creation of a simple, portable fixture that can be manufactured efficiently and economically without large, heavy, and costly assembly cells. In addition to, or separate from, forming a positioning surface, magnets can hold surfaces together (clamp) to prevent them from moving during assembly. In several embodiments, sensors can be incorporated for monitoring and improving joint quality. In several embodiments, the fixtures can be manufactured efficiently and quickly using additive manufacturing techniques.Component fixtures can be manufactured in a fraction of the time and at the cost of traditional, dedicated tooling fixtures, making this approach advantageous for low-volume production, field service, and pre-production development activities. Furthermore, positioning using complex features enables accurate component positioning without the need to design dedicated reference points for component positioning. Over-determining components using elastic averaging features enables more precise positioning than otherwise possible, and additive manufacturing enables the embedding of magnets, sensors, and other features.

[0034] To avoid a common datum point, the components in an assembly are positioned using multiple independent, localized datum features for each individual component added to the assembly, as described here. This contrasts with an approach in which each component of the assembly is positioned with respect to a single common datum point for the entire assembly. The common datum point approach would require a single large, complex fixture that holds all components simultaneously with respect to a single common datum point. The approach described here reduces complexity by providing multiple smaller, independent component fixtures, each responsible for positioning an individual component of the assembly at a localized datum position.

[0035] With reference to Fig. 1 schematically illustrates an additive manufacturing cell 100. In general, the additive manufacturing cell 100, which may also be referred to as a 3D printing system, includes an energy delivery system in the form of a heat source 102, which may be of any heat-generating type, a material deposition system in the form of a material separator 104, a build chamber 106 defined by a build box 108, and a build platform 110 with a lifter 112. In several embodiments, a gas delivery system (not shown) may be included for supplying an inert gas to an outer chamber 114 to create a favorable environment for build. In the present embodiment, the additive manufacturing cell 100 is illustrated as a fused deposition modeling (FDM) type additive manufacturing / 3D printing system.In other embodiments, other additive manufacturing processes may be used, such as stereolithography, digital light processing, selective laser sintering, selective laser melting, fabrication of laminated objects, digital beam melting, or others. It will be appreciated that the fixture 116 being printed may comprise a polymer material, a metal material, and / or a combination of different material types, depending on the design and durability requirements of the fixture 116. Accordingly, the selected 3D printing process may be tailored to the materials selected for forming the fixture 116.

[0036] In the present embodiment, the additive manufacturing cell 100 is configured to apply a filament material 118 from a container 115 for constructing the fixture 116 by feeding it through the material separator 104 and melting / fusing the material 118 by the heat source 102 via a controlled exposure. The material 118 is applied to the build platform 110 in a series of successive layers by rollers 120 of the material separator 104. The fixture 116 is successively built up in layers on the build platform 110. In other embodiments, other mechanisms for distributing the material 118 may be used, for example, a roller, a brush, a blade, a sprayer, a sprayer, or others.

[0037] The energy to fuse the powder particles is provided by heat source 102. Material 118 is heated above its melting point to enable fusion with the previously applied layer. In other embodiments, a different form of energy source may be used.

[0038] The build platform 110 defines the floor of the build box 108 and is mounted with the elevator 112 for lowering during build and for raising after build or in preparation for build. In other embodiments, instead of the elevator 112, the build platform may remain at a static height, and the material separator 104 may change its height. The fixture 116 is built while the layers are being applied. Various materials may be applied to form various features of the fixture 116, and preformed features 122 (such as magnets, sensors, pins, and so on) may be mechanically added before or during printing. When the forming process for a particular layer is complete, the build platform 110 may be lowered by the amount of the layer thickness, and the next layer of material is applied. This process is repeated until the entire design geometry of the fixture 116 is created.

[0039] In Fig. 2, a mounting application in the form of a frame assembly and mounting kit 200 is shown. The frame assembly 202 includes a frame rail 204, a bumper tower 206, an angle 207, a stabilizer 208, a reinforcement 210, a bracket 212, a hanger 214, and a support 216. Each of the components of the bumper tower 206, the angle 207, the stabilizer 208, the reinforcement 210, the bracket 212, the hanger 214, and the support 216 must be positioned relative to the frame rail 204 and / or each other before being secured together in the frame assembly 202.The mounting kit 222 includes a mount 226 that positions the bumper tower 206 relative to the frame rail 204, a mount 227 that positions the bracket 207 relative to the frame rail 204, a mount 228 that positions the stabilizer 208 relative to the bumper tower 206 and the frame rail 204, a mount 230 that positions the reinforcement 210 relative to the frame rail 204, a mount 232 that positions the bracket 212 relative to the frame rail 204, a mount 234 that positions the suspension 214 relative to the frame rail 204, and a mount 236 that positions the support 216 relative to the frame rail 204 and the bracket 212.Instead of referencing a single fixed reference point, each of the mounts 226, 227, 228, 230, 232, 234, and 236 uses complex positioning features to position the respective components relative to each other for assembly, which in the current embodiment is accomplished by joining, for example, by welding and / or fastening. In the present embodiment, the mounts 226, 227, 228, 230, 232, 234, and 236 are manufactured using 3D printing and are made from various materials, generally a polymer. In other embodiments, any other material or combination of materials may be used to form the mount assembly 222.

[0040] In Fig. 3, the reinforcement 210 is shown on the frame rail 204 at or near its mounting position. The reinforcement 210 is located near an opening 240 in the frame rail 204, which has a rim 242 projecting outward from the surface 244 of the frame rail 204. The rim 242 forms a complex surface 238 (inner surface of the rim 242). The reinforcement 210 includes a complex surface 246, an elliptical-shaped hole 248, and a round hole 250. The elliptically shaped hole 248 and a round hole 250 may be formed by the reinforcement 210 at the complex surface 246. The opening 240, the complex surface 246, the elliptically shaped hole 248, and the round hole 250 are each features of the components that are not added for positioning purposes, but are each a candidate for use in clamping the reinforcement 210 relative to the frame rail 204 for positioning purposes prior to joining.The complex surfaces 238, 246 are complex in that they are defined according to the functional, shaping, packaging, and / or aesthetic requirements of the components and generally have curved and / or smoothly contoured surfaces. The complex surfaces 238, 246 may each be a complex algebraic surface or a set of complex algebraic surfaces, for example, if each surface in the set is a smooth projective variety of dimension 2 in a three-dimensional space.

[0041] Fig. 4 shows the fixture 230, which includes complex positioning features using the aforementioned candidates to position the reinforcement 210 relative to the frame rail 204. The fixture 230 includes a body 252 formed from a polymer, such as acrylonitrile butadiene styrene copolymer (ABS), by 3D printing, as in the additive manufacturing cell 100. The fixture 230 includes a pair of pins 254, 256, which in the present embodiment are machined from metal, such as steel. In other embodiments, the pins 254, 256 may be formed from a different material and additively manufactured along with the body 252 in the additive manufacturing cell 100.

[0042] The fastener 230 includes complex positioning features (complex positioners), including two complex surface areas 260, 262 and the two pins 254, 256. The complex surface areas 260, 262 are complex in that they are designed to mate with complex-shaped surfaces of the frame rail 204 and the reinforcement 210 (as defined above). The set of complex positioners overdetermine the strut 210 relative to the frame rail 204. The overdetermination with matching, compliant contact surfaces provides high precision in positioning the reinforcement 210 relative to the frame rail 204. The complex surface area 260 is shaped as a curved area that matches the profile of the stamped, complex surface 246 ( Fig. 3) corresponds to and is located on the reinforcement 210. The complex surface area 260 may be generated using the 3D mathematical data for the reinforcement 210 when printing the mount 230. The complex surface area 262 is shaped as the perimeter of a plug 266 that fits into the opening 240 and abuts the inside / complex surface 238 of the rim 242. The complex surface area 262 may be generated using the 3D mathematical data for the frame rail 204 when printing the mount 230. Each of the complex surface areas 260, 262 locates complex / contoured features and provides an elastic averaging effect, where the elasticity of the positioning features provides compliance that facilitates insertion of the mount 230 into an average position to accurately position the reinforcement 210 relative to the frame rail 204.The reinforcement 210 is positioned relative to the frame rail 204 without requiring positioning relative to a fixed reference point and without adding any special additional positioning features that are not otherwise required for the components to function. In the case of the plug 266, a cross-shaped projection 268 provides relatively more elasticity at the four corners 272 and relatively less elasticity at the four edges 270. This accommodates more variations in the corners 274 of the rim 242 and makes greater use of the edges 276 of the rim 242 for precise positioning.

[0043] The mount 230 includes pins 254, 256 to utilize the holes 248, 250 included in the design of the reinforcement 210 for purposes other than positioning. The pins 254, 256 constrain the mount 230 in the additional degrees of freedom required due to the shape of the stamped, complex surface 246, which would allow the mount 230 to move relative to the reinforcement 210 if left unconstrained. One pin ensures that all twelve degrees of freedom between the frame rail 204 and the reinforcement 210 are constrained. The second pin over-constrains and provides an elastic averaging effect, where the elasticity of the two pins 254, 256 in the two holes 248, 250 averages the position of the mount 230 relative to the reinforcement 210 for improved positioning accuracy.

[0044] As in Fig. 5, the plug 266 nests within the complex-shaped surface of the opening 240 and provides a resilient averaging effect between the complex surface region 262 and the complex surface 238 of the rim 242, thereby fixing the fastener 230 relative to the frame rail 204. The shaped, complex surface 246 of the reinforcement 210 nestles within the body 252 of the fastener 230 at the complex surface region 260, and the complex surface region 260 provides a resilient averaging effect between the complex surface region 260 and the complex surface 246. The pins 254, 256 can be inserted after the body 252 is positioned relative to the reinforcement 210 and relative to the frame rail 204.Once the reinforcement 210 is positioned relative to the frame rail by the fastener 230, the two may be joined together, for example by welding, fixing the components in their design orientation and position.

[0045] Fig. Figure 6 shows that the pins 254, 256 can be removed from the body 252 once the reinforcement 210 is connected / welded to the frame rail 204. The pin 254 includes a shank 277 sized to fit within the hole 248 and a larger segment 278 that provides a stop feature when inserted into the body 252 and can be manually or robotically grasped for insertion and removal. The pin 256 includes a shank 280 sized to fit within the hole 250 and a larger segment 282 that provides a stop feature when inserted into the body 252 and can be manually or robotically grasped for insertion and removal. Since the reinforcement 210 is over-determined by the attachment 230 relative to the frame rail 204, removal of the pins allows removal of the body 252 once the reinforcement 210 is attached to the frame rail 204.The fixture 230 provides a cost-effective and lightweight positioner for mounting the reinforcement 210 to the frame rail 204 that can be manufactured by 3D printing and is easily portable and can be used during product development, in an original manufacturing environment, and in the field for rework / repair.

[0046] Referring to Fig. 7, a bumper tower assembly system 300 includes the frame rail 204, the bumper tower 206, and the mount 226. The bumper tower 206 includes a platform 302 and a pair of extensions 304, 306 with respective ends 308, 310 configured for connection to the frame rail 204, for example, by welding. The platform 302 of the bumper tower 206 includes a central opening 312 and five openings 314, 316, 318, 329, and 322 distributed around the central opening 312. The bumper tower 206 includes a complex surface 303, also below the platform 302. The frame rail 204 includes a number of features, including an upper edge 330, a lower edge 332, a hole 334, and a complex surface 335. The mount 226 is generally L-shaped and includes a leg 336 that mates with the platform 302 and includes a complex surface area 355 that conforms to the shape of the complex surface 303.The mount 226 includes a leg 338 that mates with the frame rail 204 and has a complex surface portion 345 that conforms to the shape of the complex surface 335. The leg 338 includes various positioning features, including the complex surface portion 345 configured to lie on the complex surface 335, a rib 340 configured to lie on the upper edge 330, a rib 342 configured to lie on the lower edge 332, and a plug 344 configured to lie in the hole 334. The positioners are connected to the frame rail 204 and may include resilient averaging features that flex to find an average position in positioning the mount 226 relative to the frame rail 204.

[0047] The leg 336 of the mount 226 includes five positioners on its top surface 348 for positioning the mount 226 relative to the impact tower 206. The five positioners include a center positioner 352 that engages the opening 312 and centers the mount 226 relative to the platform 302 of the impact tower 206. The complex surface area 355 is configured to position itself on the complex surface 303. The rotational position of the mount 226 relative to the impact tower 206 is adjusted by the positioners 354, 356, 358, and 360, which engage the openings 314, 316, 318, and 320, respectively. The various positioners provide an elastic averaging effect in which their compliance effects find an average position among the various mating features.In the present embodiment, the centering of the mount 226 relative to the platform 302 of the impact tower 206 is more critical than the rotational position, which is why the center positioner 352 is printed from a material that has a lower compliance than the material from which the positioners 354, 356, 358, and 360 are printed. For example, the center positioner 352 may be printed from an ABS material whose hardness is greater than the hardness of the ABS material from which the positioners 354, 356, 358, and 360 are printed, and which therefore has a lower compliance. The use of the center positioner 352 together with the positioners 354, 356, 358, and 360 and the interface between the complex surface area 345 and the complex surface 335 results in an over-determination of the mount 226 relative to the impact tower 206.

[0048] As in Fig. 8, the center positioner 352 is adjustable in direction 361 due to the presence of an adjustment screw 362 that extends through the leg 336 and engages the center positioner 352. For example, the center positioner 352 may be adjusted to account for tolerance variations in the design of the shock tower 206 so that the component is accurately positioned prior to welding. In other embodiments, the center positioner 352 may be adjusted to perform positional tuning of a critical positioning feature to adjust the position of the shock tower 206 relative to the frame rail 204 to optimize assembly. In a number of embodiments, the screw 362 is printed into the fixture 226 during the additive manufacturing process. In other embodiments, the screw 362 is a separate part added to the fixture 226 after printing.In further embodiments, the screw 362 is replaced or supplemented by another adjustment mechanism, such as a linear slide, a rack and pinion, a gear, or others.

[0049] In relation to Fig. 9 shows a schematic representation of the fastening 227 from Fig. 2 illustrates the inclusion of integrated features, including magnets 370, 372 and a sensor array 374. The fixture 227 may be printed, for example, in the additive manufacturing cell 100, with the magnets 370, 372 and the sensor array 374 integrated. The fixture 227 positions the fixture 207 relative to the frame rail 204 using the complex surface areas / complex surface interfaces and pins 375, 377 extending through openings in the fixture 207 and the frame rail 204. The magnets 370, 372 hold the fixture 227 to the bracket 207, eliminating the need for a separate clamp to hold the two together. The magnetically coupled fixture 227 and bracket 207 are clamped to the frame rail 204 with a clamp 376 that applies pressure to hold the bracket 207 in position, while a welding tool 378 connects the bracket 207 to the frame rail 204.Embedding the magnets 370, 372 improves accessibility for the welding tool 378, simplifies positioning, and avoids interference with the clamp 376. The magnets 370, 372 can be embedded in printed cavities with inserted magnets, or the magnets 370, 372 can be printed directly into the fixture 227 using 3D printing of magnetic composite materials (for example, rare earth permanent magnet particles printed into a polymeric binding material). The magnets 370, 372 can be permanent magnets, switchable permanent magnets, or electromagnets. With switchable magnets and electromagnets, the magnets 370, 372 can be switched on and off to facilitate clamping and release. The placement and strength of the magnets 370, 372 are selected so that sufficient clamping forces are possible for the desired component pairing and the welding process is not impaired.

[0050] The sensor array 374 may be embedded in the printed fixture 227 and may be configured to monitor at least one parameter, for example, to determine position / location, electromotive force, temperature, or other parameters. The sensor array 374 is coupled to a controller 380, which receives signals from the sensor array 374 to make determinations related to the manufacture or modification of the frame assembly 202. In general, the controller 380 uses the available inputs, including those from the sensor array 374, to provide a control system that effectively regulates various functions of the assembly of the product. The controller 380 generally includes a processor and a memory device and may be coupled to a memory device. The processor performs the computation and control functions of the controller 380 and may include any one or more processor types.

[0051] In some embodiments, sensor assembly 374 includes a position sensor, such as a linear variable differential transform linear position sensor. Detecting the relative position of mount 227, bracket 207, and frame rail 204 provides a clear indication of whether the components are aligned and improves the quality of the joining process. The sensor function can be integrated into a robotic assembly process to make rapid adjustments.

[0052] In some additional embodiments, the sensor unit 374 includes an electromotive force sensor / magnetometer to measure the magnetic force attracting the mount 227 to the bracket 207, as generated by the magnets 370, 372. Measuring the magnetic force provides an indication of the alignment between the mount 227 and the bracket 207 and can be used to improve the positioning / quality of the assembly.

[0053] In a number of other embodiments, the sensor array 374 includes a temperature sensor, such as a thermocouple, that generates a temperature-dependent output. Providing a temperature input to the controller 380 enables process control, for example, interrupting operation of the welding tool 378 when a temperature threshold is reached. The threshold can be set so that the maximum temperature stress on the fixture 227 is not exceeded. Alternatively, the threshold can be set so that temperatures that would influence / distort the position determination of the fixture 207 relative to the frame rail 204 do not occur. When the threshold is reached, the welding process can be interrupted to allow cooling before resuming operation, thus improving assembly quality.In embodiments, the magnets 370, 372 and / or the sensor assembly 374 are incorporated into one or all of the mounts 226, 227, 228, 230, 232 and 234 of FIG. Fig. 2 integrated.

[0054] In Fig. 10, a fixture 382 is shown for connecting an angle 384 to the frame rail 204. The fixture 382 is positioned relative to the frame rail 204 via two positioners 386, 388 and relative to the fixture 384 via positioners 386, 388. In addition, complex surfaces / complex surface areas can also be used. In general, the fixture 382 provides an elastic averaging effect through the positioners 386, 388, includes an integrated handle 400 for easy manual handling, and includes printed features 402 for adjusting the compliance. In the present embodiment, the fixture 382 is printed from a common material. The elastic averaging effect can be provided by the positioners 386, 388. The positioner 386 is in Fig.11 is shown in cross-section, representative of the two positioners 386, 388. The positioner 386 is in the form of a compliant pin disposed in an opening in the frame rail 204 and includes a cylindrical body 394 with a hollow interior 396 and longitudinal slots 398. A pair of projections 404 extend outwardly from the cylindrical body 394. The hollow interior 396 and the longitudinal slots 398 increase the compliance for the elastic averaging effect.

[0055] In the mount 382, ​​the printed compliance adjustment features 402 provide greater compliance in direction 408 and less compliance in direction 410 to achieve the critical positioning dimensions of the assembly. For example, the positioning of the mount 384 on the frame rail 204 is more critical than the height of the mount 384 relative to the frame rail 204. The printed compliance adjustment features 402 include slots 412 that allow greater compliance in direction 408 and provide greater stiffness in direction 410. In addition, the printed compliance adjustment features 402 include ribs 414 that provide stiffness in direction 410. In a number of embodiments, additional compliance may be included in a selected direction to account for known production variations.The attachment 382 may also include regions of varying compliance achieved by printing with different materials, different shapes, and / or material properties (e.g., printing elastomeric material near contact points). In other embodiments, the contact surfaces may be harder to increase durability, while the underlying material may be more compliant to allow elastic averaging. In other embodiments, the contact surfaces may be electroplated with metal to increase durability. In embodiments, the additively manufactured build material may be composed of multiple materials, with the different materials having different stiffnesses that control compliance in different directions.

[0056] The embodiments disclosed herein utilize complex surfaces as positioning features for component assembly, enabling accurate part positioning with minimal technical features for positioning purposes. Component overdetermination and / or elastic averaging provide more precise component positioning, and additive manufacturing enables unique features such as the embedding of magnets and / or sensors. The simplicity of the fixtures extends the application to pre-production activities, on-site repairs, and maintenance work.

Claims

[1] Positioning fastening system, comprising: a first component (204) having a complex surface (246), the complex surface (246) having a smooth contour; a second component (206, 207, 208, 210, 212, 214, 216) shaped to be connected to the first component (204); and a fixture (230) configured to position the first component (204) relative to the second component (206, 207, 208, 210, 212, 214, 216), the fixture (226) comprising a first positioner comprising a complex surface area (260) shaped to mate with the complex surface (246) of the first component (204) to position the fixture (230) relative to the first component (204), wherein the attachment (230) comprises a second positioner configured to position the attachment (230) relative to the second component (206, 207, 208, 210, 212, 214, 216); wherein the attachment (230) comprises a body (252); wherein the second positioner comprises pins (254, 256); wherein the first component (204) is over-determined relative to the second component (206, 207, 208, 210, 212, 214, 216) by means of the attachment (230) and removal of the pins enables removal of the body (252) of the attachment (230) once the first component (204) is attached to the second component (206, 207, 208, 210, 212, 214, 216). [2] The positioning fixture system of claim 1, wherein the fixture (230) comprises an additively manufactured build material having compliance-tuned printed features that provide relatively lower compliance in at least one direction for achieving critical positioning dimensions and relatively higher compliance in at least one other direction. [3] The positioning fixture system of claim 1, wherein the fixture (230) is configured for portability by comprising a polymeric material and by being configured solely for positioning the first component (204) and the second component (206, 207, 208, 210, 212, 214, 216) relative to each other. [4] The positioning fixture system of claim 1, wherein the first positioner comprises an elastically deformable structure and is configured to provide an elastic averaging effect in positioning the fixture (230) relative to the first component (204). [5] The positioning fixture system of claim 1, wherein the fixture (230) includes an integrated sensor configured to monitor at least one parameter of the system. [6] Positioning method comprising: Forming a first component (204) having a complex surface (246), wherein the complex surface (246) has a smooth contour; Forming a second component (206, 207, 208, 210, 212, 214, 216) shaped to connect to the first component (204); Forming a fixture (230) with a first positioner comprising a complex surface area (260) shaped to mate with the complex surface (246) of the first component (204); Forming the attachment (230) to include a second positioner configured to position the attachment (230) relative to the second component (206, 207, 208, 210, 212, 214, 216); Positioning the first component (204) relative to the second component (206, 207, 208, 210, 212, 214, 216) by the attachment (230); and Connecting the first component (204) to the second component (206, 207, 208, 210, 212, 214, 216); Removing pins for removing a body (252) of the attachment (230) once the first component (204) is attached to the second component (206, 207, 208, 210, 212, 214, 216); wherein the first component (204) is overdetermined by means of the fastening (230) relative to the second component (206, 207, 208, 210, 212, 214, 216), wherein the attachment (230) comprises the body (252); wherein the second positioner comprises the pins (254, 256). [7] Positioning method according to claim 6, comprising: Forming the attachment (230) by additive manufacturing of a plurality of construction materials, wherein the different construction materials have different stiffnesses to control compliance in different directions. [8] Positioning method according to claim 6, comprising: forming the attachment (230) from a polymeric material; adapting the attachment (230) as a unique attachment (230) designed exclusively to position the first component (204) relative to the second component (206, 207, 208, 210, 212, 214, 216); and Adjust the mount (230) for portability in the field and during repairs.

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