System and method with lattice structure for joining materials during molding

Abstract

Systems and methods for manufacturing a product include at least one fabrication system to create a substrate having a lattice structure. The model receives a substrate. The model defines a cavity around the substrate. The shaping system is to deliver a material into the cavity of the model such that the material flows into the lattice structure, interleaving the material with the substrate, thereby creating a feature on the substrate from the material, the material being locked to the substrate by the lattice structure.

Description

Technical Field

[0001] The present disclosure relates to a manufacturing system and method for securing one portion of a product (a base portion) to another portion of the product (a formed portion), the other portion of the product being created by a mechanism that causes material to flow onto the base portion, and more specifically to using a grid structure to securely connect the formed material to a substrate. Background Art

[0002] The strength of the connection between two parts of a product is important when the product is subjected to various forces and stresses. For example, molding, casting, or otherwise forming one part of a product onto another part of the product may rely on friction or a limited interference fit to hold the two component parts together.

[0003] There are various types of manufacturing processes to create or modify products. Printing technology has been widely used due to its desirable qualities, such as efficiency and flexibility. Various types of 3D printing technologies have been developed for creating objects from metals, ceramics, and polymer materials. Various 3D printing technologies generally include a build surface, a material delivery system, an energy delivery system, and a control system. The build surface provides a reference surface on which material is deposited layer by layer to continuously build the part according to the design details. The material delivery system performs the deposition of feedstock material, such as feedstock material in the form of particles, fibers, or filaments, for fusing with previously deposited layers. The energy delivery system adds energy to the feedstock material before, during, and / or after deposition for liquefying / fusing the material into the part being created. The control system operates each of the other systems, such as when building the object being created according to mathematical data definitions.

[0004] Both conventional manufacturing and printing processes can be used in a variety of applications to achieve desired results. However, improving the strength of the interface between two parts of a component, where one part is formed on, around, or within another part by a mechanism that allows material of one part to flow relative to the other part, remains a goal.

[0005] Therefore, it is desirable to provide improved methods and systems for securing one portion of a component to another portion of a component. Furthermore, other desirable features and characteristics of the present disclosure will become apparent from the subsequent detailed description and the appended claims, taken in conjunction with the accompanying drawings and the foregoing technical field and background. Summary of the invention

[0006] The system and method for manufacturing a product includes at least one fabrication system to create a substrate having a grid structure. A mold receives the substrate. The mold defines a cavity around the substrate. A forming system is configured to deliver a material into the cavity of the mold so that the material flows into the grid structure, interweaving the material with the substrate, thereby creating features on the substrate by the material, the material being locked to the substrate by the grid structure.

[0007] In additional embodiments, the grid structure includes a series of cells. Each cell is formed by a plurality of structural members connected at nodes and defining open spaces between the structural members.

[0008] In additional embodiments, the feature is a shaped portion on the substrate.

[0009] In additional embodiments, the grid structure includes a plurality of interconnected structural members, and the material is embodied as a plurality of elements extending through the plurality of interconnected structural members.

[0010] In additional embodiments, the grid structure includes a plurality of structural members connected at nodes and defining open spaces between the structural members. The material completely fills the open spaces.

[0011] In additional embodiments, the molding system is an injection molding machine.

[0012] In additional embodiments, the grid structure is an integral part of the substrate.

[0013] In additional embodiments, the lattice structure includes a plurality of structural members, the plurality of structural members being load-bearing portions of the lattice structure.

[0014] In additional embodiments, the material is embodied as an element that fills spaces in the grid structure.

[0015] In additional embodiments, the grid structure defines an open space, and the grid structure is designed to maximize penetration of material into the open space.

[0016] In many other embodiments, a method for manufacturing a product includes forming a substrate having a grid structure by at least one forming system. The substrate is received in a mold. The mold defines a cavity around the substrate. The forming system delivers a material into the cavity of the mold, including flowing the material into the grid structure. During the flow of the material, it interweaves with the substrate to create features on the substrate by the material, and the material is locked to the substrate by the grid structure.

[0017] In an additional embodiment, the grid structure is fabricated as a series of units. Each unit includes a plurality of structural members connected at nodes and defining open spaces between the structural members.

[0018] In additional embodiments, the features are created as shaped portions on the substrate.

[0019] In additional embodiments, the grid structure is fabricated as a plurality of interconnected structural members.The material is formed into a plurality of elements extending through the plurality of interconnected structural members.

[0020] In an additional embodiment, the grid structure is fabricated as a plurality of structural members connected at nodes and defining open spaces between the structural members. Material is delivered to completely fill the open spaces.

[0021] In additional embodiments, the molding system includes an injection molding machine.

[0022] In additional embodiments, a grid structure is fabricated as part of a substrate having open spaces. The grid structure is designed to maximize the penetration of material into the open spaces.

[0023] In an additional embodiment, the lattice structure is made as a plurality of structural members, the plurality of structural members being load-bearing parts of the lattice structure.

[0024] In additional embodiments, the grid structure is filled with elements of material.

[0025] In many additional embodiments, a product includes a substrate having a grid structure. Features are formed in cavities of a forming system by a material disposed on the substrate. The material is interwoven with the grid structure such that the features are locked to the substrate by the grid structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The present disclosure will hereinafter be described in conjunction with the following drawings, wherein like numerals represent like elements, and wherein:

[0027] Figure 1 is a schematic diagram of a manufacturing system in the process of building a product according to various embodiments;

[0028] Figure 2 According to various embodiments, Figure 1 A schematic diagram of a grid structure unit produced by a portion of a manufacturing system;

[0029] Figure 3 According to various embodiments, Figure 1 A schematic diagram of a grid structure having a plurality of cells produced by a portion of a manufacturing system;

[0030] Figure 4 According to various embodiments Figure 3 A schematic diagram of a portion of a grid structure;

[0031] Figure 5 According to various embodiments Figure 3 a schematic force diagram on a portion of a grid structure of; and

[0032] Figure 6 is the use according to the exemplary embodiment Figure 1 systems and Figure 2 A flowchart of the process of manufacturing a product using a grid structure. DETAILED DESCRIPTION

[0033] The following detailed description is merely exemplary in nature and is not intended to limit the application and uses. Furthermore, no one is intended to be bound by any expressed or implied theory presented in the preceding introduction, summary, or this detailed description.

[0034] refer to Figure 1 , schematically illustrating a manufacturing system 100. In general, the manufacturing system 100 includes a manufacturing system 102, a substrate 104, a model 106, a forming system 108, and a product 110, the product 110 including the substrate 104 and a feature 114 connected to the substrate 104. The manufacturing system 102 can be any of a variety of object creation systems that can operate to create or modify a workpiece, which in the current embodiment is the substrate 104 or at least a portion thereof. The manufacturing system 102 can use any of a variety of operations, such as machining, casting, molding, forming, deforming, bending, perforating, drilling, stamping, cutting, additive manufacturing, 3D printing, etc. In the current embodiment, the manufacturing system 102 includes a printing system 112, such as a machine based on laser powder bed fusion. In other embodiments, another printing technology can be used, such as binder jetting, powder bed fusion using an electron beam, material extrusion / FDM, high speed sintering, selective laser sintering, multi-jet fusion, or another printing technology.

[0035] In an embodiment, the printing system 112 includes an energy delivery system in the form of an energy source 120 (which may be heat-generating), a material deposition system in the form of a material depositor 122, a build chamber 124 defined by a build box 126, and a build platform 128 having an elevator 130. In various embodiments, a gas delivery system (not shown) may be included for delivering an inert gas to the build chamber 124 to provide a favorable environment for the build. The material depositor 122 may be any mechanism for dispensing a material 132, such as a roller, a brush, a doctor blade, a spreader, a sprayer, a feeder, or other, and the substrate 104 is formed of the material 132.

[0036] In the current embodiment, the printing system 112 is shown as using a powder bed fusion type additive manufacturing / 3D printing technology. In other embodiments, the additive manufacturing unit 100 can be configured for another type of additive manufacturing. It should be understood that the printed substrate 104 can be constructed of a material that is or includes one or more of a metal, a ceramic, a polymer, or other materials.

[0037] Thus, the selected 3D printing method can be tailored for the material selected to form the substrate 104. In other embodiments, additive manufacturing may not be used, or may only be used in part, and conventional machining / forming techniques may be used. For example, the substrate 104 and / or grid structure 140 may be created by any material forming operation.

[0038] In the current embodiment, the printing system 112 is configured to apply a material 132 in powder form by a material depositor 122. Melting / fusion of the material 132 is selectively performed by the energy source 120 via controlled exposure. The material 132 is applied to the build platform 228 in a series of consecutive layers by a spreader 134 of the material depositor 122. The substrate 104 is continuously built into layers on the build platform 128, which is moved via the elevator 130 during the build. When the formation process of a given layer is completed, the build platform 128 can be lowered by the amount of layer thickness, and the next material layer can be applied. Repeat the process until the entire design geometry of the substrate 104 or a specified portion thereof is produced.

[0039] In various embodiments, the substrate 104 built by the production system 102 (printing system 112 in the current embodiment) can be part of another product 110 that includes other physical parts, such as features 114. A portion of the product 110 (substrate 104) can be referred to as a "substrate" because it is formed and then another portion of the product 110 (feature 114) is formed on, over, around and / or inside the substrate 104. The substrate 104 is formed with a segment 136 and another segment 138. In the current embodiment, the segments 136 and 138 have differences. For example, the segment 136 has a grid structure 140, while the segment 138 does not. In other embodiments, the segment 138 can also include a grid structure, such as the grid structure 140. In some embodiments, the grid structure 140 can extend completely through the segment 136 and / or the segment 138. In some embodiments, the grid structure 140 can only exist on the surface 142 of the segment 136 and / or the segment 138. In additional embodiments, the entire surface 142 of both segments 136, 138 may include a grid structure 140. In some embodiments, the grid structure 140 may be formed in an opening into the substrate 104, such as in an opening in the substrate 104 to connect the feature 114 to the substrate 104. In general, the grid structure 140 may be included on any area of ​​the substrate 104 where bonding with another portion, such as the feature 114, is desired.

[0040] refer to Figure 2 and Figure 3 Together with Figure 1, the grid structure 140 will be described in more detail. In general, the grid structure 140 includes a framework having components referred to as structural members 150 that are interconnected to define spaces 152 that are open between the structural members 150 in two or three dimensions, or in some that may be referred to as 2.5 dimensions. The structural members 150 are typically the physical load-bearing portions of the grid structure 140. The grid structure 140 may fill a volume such as segment 136, or may conform to a surface such as surface 142. The grid structure 140 may be a configuration based on repeating unit cells that are composed of specific shapes or random patterns in a mesh of any complexity or simplicity. The repeating unit cells may have any physical size tailored for the application. The grid structure 140 may be periodic, aperiodic, or random. In general, the grid structure 140 includes structural members 150 of any shape to define open spaces 152 for receiving intermediate materials.

[0041] The grid structure 140 may be honeycomb-shaped, having Figure 2 A unit 154 and Figure 3 Six interconnected cells 154 are shown. In this example, the cells 154 are cubic. Each cell 154 has 12 structural members 150, designated as members 157-168. Each of the members 157-168 is formed as a beam, and the members 157-168 of a cell 154 are connected at nodes 171-178. In other embodiments, the members 157-168 can be beams, surfaces, plates, trusses, cells, webs, nodes, struts, which are assembled together in an orderly, repeated or random pattern. The members 157-168 can be interlocking, interwoven, interconnected or otherwise interconnected material patterns to form a grid structure 140. In other embodiments, the cells 154 may not be cubic, but rather triangular, star, octagonal, hexagonal, rhombus, tetrahedron, solid of revolution, pyramidal, body-centered cubic, spiral, or any configuration that includes a member (such as structural member 150) and defines an open space (such as space 152).

[0042] Reference again Figure 1, the model 106 can be any of a variety of structures configured to receive the substrate 104 and capable of directing a material flow at the substrate 104 to form the feature 114. The model 106 can be a mold, a die, or any tool for forming the feature 114 in a manner connected to the substrate 104. The model 106 can be configured for injection molding. In the current embodiment, the model 106 includes a section 180 that joins with the section 182 at the parting line 184 to define a seat 186 and a cavity 188. The seat 186 is a space that receives and / or holds the substrate 104, and is arranged so that the grid 140 extends into the cavity 188. The cavity 188 defines an open volume into which material can be directed to create the feature 114. The model 106 includes a channel 190 through which the material of the feature 114 can be directed into the cavity 188 under the action of a force.

[0043] The pattern 106 is used in a forming system 108. The forming system 108 may be any of a variety of systems capable of forming a desired shape of a feature 114 on and / or in the substrate 104. The feature 114 is formable because the forming system 108 receives a material that flows or induces melting of a material 192, which enables the material to be introduced into the cavity 188 to form the feature 114. The composition of the material 192 is formulated to be directed into the cavity 188, or to respond to an applied energy by melting and flowing into the cavity 188 to form a continuous structure of the feature 114. Due to the properties of the material 192, flowing in a consistent and predictable manner is accomplished by a defined preparation of the material 192 for the forming system 108, such as a molding machine referred to as the forming system 108.

[0044] In the current embodiment, the forming system 108 is an injection molding system having a hopper 200 for introducing material 192, an injection unit 202 for melting and moving the material 192, a mold 106, and a fixture 204 for opening and closing the mold 106. The injection unit 202 moves the material 192 through the channel 190 and into the cavity 188 to form the feature 114. After forming in the forming system 108, the product 110 includes the substrate 104 having the feature 114 integral with the substrate 104.

[0045] refer to Figure 4 During forming, material 192 flows into spaces 152 around structural member 150, and material 192 forms elements 194 that fill spaces 152. The flow of material 192 completely impregnates spaces 152 of lattice structure 140, wherein elements 194 are interwoven with structural member 150. After forming, material 192 solidifies in spaces 152 as elements 194 lock features 114 to substrate 104. As a result, full integration and interaction of material 192 with lattice structure 140 is achieved in addition to surface level interaction.

[0046] In an overmolding process where one part is molded onto another part through surface level interaction, only surface level friction / adhesion can hold the two parts together. f ) is the applicable friction coefficient (μ) and normal force (F N ) function, we can use the relation F f =μF N Indicates. The friction between a typical overmolded part and the part overmolded onto it tends to be low. For example, when the force applied between the overmolded parts reaches the slip threshold, they will move relative to each other. If this movement is undesirable, it can be described as a failure of the associated product.

[0047] In an embodiment, depending on the material used, an adhesion force (F a ). Adhesion is proportional to the contact surface area (A) and can be expressed by the relationship F∝A. Adhesion occurs between two surfaces through bonding, which is produced by chemical action, such as when chains of two polymers are linked to each other, or when the materials undergo another form of chemical reaction. For typical overmolded parts, such as polymers molded on metal, adhesion is low. As a result, the sum of friction and adhesion provides only modest force carrying capacity.

[0048] In the current embodiment, where the entire interaction of material 192 with grid structure 140 occurs between structural member 150 and element 194, the material of feature 114 is interwoven with the material of substrate 104. Thus, rather than relying on surface-level friction / adhesion to hold product 110 together, a large number of structural members 150 and elements 194 secure product 110. Shear / tensile strength plays a role in holding feature 114 in place relative to substrate 104. Any force applied between substrate 104 and feature 114 is distributed across a large number of locations (structural member 150 and element 194), and the average stress per unit area on the material is low. This is because stress (σ) is a function of force (F) and area (A), where Because in the present embodiment, the total area is large due to the sum of all structural members 150 and / or elements 194, the average stress is relatively low and product failure is avoided over a large stress bandwidth.

[0049] refer to Figure 5, when stress is created between the components of the product 100 (substrate 104 and feature 114), the sum of the forces 210 on the feature 114 is offset by the sum of the forces 212 on the substrate 104. Because the forces 210, 212 are carried by the sum of all areas of the structural member 150 and the element 194, they are distributed over a large area. The large area results in a large total area over which the force is applied, thereby generating low stress at each site in the two-dimensional-three-dimensional space. In an embodiment where the molded material 192 has a lower strength than the material of the substrate 104, the area 152 can be designed to be substantially larger than the cross-sectional area of ​​the structural member 150. Therefore, the stress on the material 192 in any given space 152 is low, and the feature 114 is optimally fixed to the substrate 104. In addition, because the friction and adhesion strength are functions of the surface area, the amount of force that the interface between the substrate 104 and the feature 114 can carry from a friction and adhesion perspective is also increased.

[0050] For example, the friction / adhesion strength between the substrate 104 and the feature 114 can be optimized. Through the physical structural interference caused by the grid structure 140 and the interweaving material 192 between the substrate 104 and the feature 114, significantly higher normal forces can be sustained at the interface. In addition, the interweaving properties of the substrate 104 and the feature 114 through the grid structure 140 result in a higher contact surface area and higher load-bearing capacity due to friction and adhesion. In summary, the load-bearing capacity of the product 110 between the substrate 104 and the feature 114 is increased in three ways, including higher shear / tensile strength, higher friction strength, and higher adhesion strength.

[0051] Reference again Figure 1 , the product 110 exiting the forming system 108 includes a substrate 104 with features 114 that are fully integrated together. In addition to the surface level interaction, there is a complete interaction and integration of the substrate 104 and the features 114 as the material 192 flows through the grid structure 140, impregnating, contacting and bonding the entire grid structure 114. The geometry of the grid structure 140 with the spaces 152 enables the material 192 to flow through and interact with the structural members 150. The grid structure 140 is configured to maximize the penetration of the material 192 in the open spaces 152. The strength of the connection is not limited to the friction and shear forces of the connection, but also includes the area of ​​the material 192 in the spaces 152, which distributes the force / stress over multiple segments with very large equivalent cross-sectional areas relative to the surface interface between the substrate 104 and the features 114.

[0052] refer to Figure 6 , a method 300 is shown for connecting a component (such as substrate 104 and feature 114) to a grid structure, such as in a molding operation. It will be understood from the present disclosure that the order of operations within method 300 is not limited to the following. Figure 6 110 is not performed in the order shown, but can be performed in one or more different orders when applicable and in accordance with the present disclosure. The method 300 begins when an item such as a product 110 is designed 302. The product 110 may include a substrate 104 or multiple substrates 104 designed 302 for functional and / or aesthetic purposes. The substrate 104 may be designed for functional and / or aesthetic purposes. The substrate 104 may be a structural item, a tool, a body, a fastener, a housing, a locator or a decorative object, or any part that is desired to be connected to another molded part. Typically, the substrate 104 is designed to mate / connect with one or more other parts (such as a feature 114). In some embodiments, there may be multiple features 114. The feature 114 may be a functional feature, such as a handle, a wall, a cam, a lever, a torque transfer element, a beam, etc., and / or may be an aesthetic feature, such as a panel, a graphic, a decorative object, or may be any object that is desired to be connected to the substrate 104. The substrate 104 and the feature 114 may be made of any material, whether a common material or a different material from each other. In the following description, substrate 104 and feature 114 are described as being singular, but in all examples, one or both may be plural.

[0053] In summary, substrate 104 and features 114 are designed to be connected together to form a product, such as product 110, or to form a portion of a larger product. After design step 302, substrate 104 can be fabricated 304, such as by fabrication system 102. Fabricate 304 substrate 104, at least a portion of which includes a grid, such as grid structure 140. Substrate 104 can be fabricated 304 by any means that produces substrate 104 with grid structure 140. For example, segment 136 with grid structure 140 can be fabricated 304 integrally with segment 138, or segment 136 can be fabricated 304 separately from segment 138, and the two segments 136, 138 can be joined together. The joining can be achieved by means of fasteners, chemical bonding, welding, mechanical deformation, or any other joining method. In any case, substrate 104 includes grid structure 140.

[0054] During fabrication 304, the substrate 104 includes one or more regions of a grid structure 140, either as an integral part or as a joined portion. The grid structure 140 is configured to be formed by the fabrication system 102. As part of the design step 302, the details of the grid structure 140 can be generated in a computer-aided design (CAD) system and can be tuned. The properties (mechanical, thermal, etc.) of the grid structure 140 are determined by the grid type and other design parameters, such as unit cell size and component thickness. The grid structure 140 is optimized to maximize strength (shear / stretch and adhesion / friction), address deformation mechanisms, maximize surface area, optimize cell size and density, optimize component thickness, cell orientation, and other parameters.

[0055] The method 300 proceeds by positioning 306 the substrate 104 in the model 106. The model 106, such as within a forming system 108 (molding machine), is closed 308, and material 192 is applied around the substrate 104 within the cavity 188, such as by injection. The material 192 flows around the structural member 150 and into the space 152. The grid structure 140 may be configured to optimize the flow of the material 192 within the cavity 188, such as by designing part of step 302. The behavior of the material 192 in the model 106 may be considered the behavior of a liquid. The CAD system used may use available fluid dynamics modeling software to take into account rheological properties, including the direction of flow of the material 192 within the model 106, temperature gradients within the model 106, changes in viscosity of the material 192 within the model 106, flow rate gradients within the model 106, pressure changes within the model 106, surface interactions between the materials involved, and any other governing parameters to ensure that the material 192 is fully integrated into the grid structure 140. In a specific example, the size of the area 152 can increase to reduce the amount of heat loss through the mold 106 and increase the flow area as the material moves through the grid structure 140. In other words, as the material 192 moves through the grid structure 149, the size of the area 152 for open flow increases to maintain flow (e.g., the downstream area 152 is larger than the upstream area 152). This design ensures that the material 192 completely fills the open area 152.

[0056] As material 192 is fully integrated with grid structure 140, it solidifies within mold 106 and locks features 114 to substrate 104. Material 192 in solid form then exists within grid structure 140. Method 300 continues with opening 312 mold 106, removing 314 product 110 for any required post-processing, and method 300 ends 316.

[0057] Although at least one exemplary embodiment has been proposed in the foregoing detailed description, it should be understood that there are a large number of variations. It should also be understood that one or more exemplary embodiments are merely examples and are not intended to limit the scope, applicability or configuration of the present disclosure in any way. On the contrary, the foregoing detailed description will provide a convenient roadmap for implementing one or more exemplary embodiments for those skilled in the art. It should be understood that various changes may be made to the functions and arrangements of the elements without departing from the scope of the present disclosure as set forth in the attached claims and their legal equivalents.

Claims

1. A system for manufacturing a product, comprising: at least one fabrication system configured to create a substrate having a grid structure; a mold configured to receive the substrate, the mold defining a cavity around the substrate; as well as A forming system is configured to deliver material into the cavity of the mold so that the material flows into the grid structure, interweaving the material with the substrate, thereby creating features on the substrate from the material, and the material is locked to the substrate by the grid structure.

2. The system according to claim 1, wherein: The grid structure includes a series of cells, wherein each cell is formed from a plurality of structural members connected at nodes and defining open spaces between the structural members.

3. The system according to claim 1, wherein: The feature includes a molded portion on the substrate.

4. The system according to claim 1, wherein: The grid structure includes a plurality of interconnected structural members, and the material includes a plurality of elements extending through the plurality of interconnected structural members.

5. The system according to claim 1, wherein: The grid structure includes a plurality of structural members connected at nodes and defining open spaces between the structural members, and wherein the material completely fills the open spaces.

6. The system according to claim 1, wherein: The grid structure comprises an integral part of the substrate.

7. The system according to claim 1, wherein: The lattice structure comprises a plurality of structural members which are load-bearing parts of the lattice structure.

8. The system according to claim 1, wherein: The material includes elements that fill spaces in the grid structure.

9. A method for manufacturing a product, comprising: Manufacturing a substrate having a grid structure by at least one manufacturing system; receiving the substrate in a mold, the mold defining a cavity around the substrate; as well as Material is delivered into the cavity of the mold by a forming system, including flowing the material into the grid structure, interweaving the material with the substrate to create features on the substrate with the material, and locking the material to the substrate by the grid structure.

10. The method of claim 9, comprising fabricating the grid structure as a series of cells, wherein each cell comprises a plurality of structural members connected at nodes and defining open spaces between the structural members.

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