Composite vehicle body
10717512 ยท 2020-07-21
Assignee
Inventors
Cpc classification
B33Y10/00
PERFORMING OPERATIONS; TRANSPORTING
B32B2307/50
PERFORMING OPERATIONS; TRANSPORTING
B32B21/13
PERFORMING OPERATIONS; TRANSPORTING
B64C3/20
PERFORMING OPERATIONS; TRANSPORTING
B29C70/56
PERFORMING OPERATIONS; TRANSPORTING
B33Y80/00
PERFORMING OPERATIONS; TRANSPORTING
B32B2260/04
PERFORMING OPERATIONS; TRANSPORTING
B32B2262/14
PERFORMING OPERATIONS; TRANSPORTING
B64C3/34
PERFORMING OPERATIONS; TRANSPORTING
B33Y30/00
PERFORMING OPERATIONS; TRANSPORTING
B29C64/106
PERFORMING OPERATIONS; TRANSPORTING
B32B5/02
PERFORMING OPERATIONS; TRANSPORTING
B32B2262/106
PERFORMING OPERATIONS; TRANSPORTING
B32B19/06
PERFORMING OPERATIONS; TRANSPORTING
B32B5/12
PERFORMING OPERATIONS; TRANSPORTING
B32B3/12
PERFORMING OPERATIONS; TRANSPORTING
B64C2001/0054
PERFORMING OPERATIONS; TRANSPORTING
B29C70/302
PERFORMING OPERATIONS; TRANSPORTING
B29L2031/30
PERFORMING OPERATIONS; TRANSPORTING
B64C1/08
PERFORMING OPERATIONS; TRANSPORTING
B32B5/26
PERFORMING OPERATIONS; TRANSPORTING
B32B2255/02
PERFORMING OPERATIONS; TRANSPORTING
B64F5/10
PERFORMING OPERATIONS; TRANSPORTING
B64C1/12
PERFORMING OPERATIONS; TRANSPORTING
B29D99/001
PERFORMING OPERATIONS; TRANSPORTING
B64C3/26
PERFORMING OPERATIONS; TRANSPORTING
B64C1/26
PERFORMING OPERATIONS; TRANSPORTING
B29C64/118
PERFORMING OPERATIONS; TRANSPORTING
B32B2260/021
PERFORMING OPERATIONS; TRANSPORTING
B64C1/06
PERFORMING OPERATIONS; TRANSPORTING
B29C64/165
PERFORMING OPERATIONS; TRANSPORTING
International classification
B64C1/12
PERFORMING OPERATIONS; TRANSPORTING
B29C70/38
PERFORMING OPERATIONS; TRANSPORTING
B29C64/106
PERFORMING OPERATIONS; TRANSPORTING
B64C3/34
PERFORMING OPERATIONS; TRANSPORTING
B64C1/06
PERFORMING OPERATIONS; TRANSPORTING
B29D99/00
PERFORMING OPERATIONS; TRANSPORTING
B29C70/56
PERFORMING OPERATIONS; TRANSPORTING
B64C1/08
PERFORMING OPERATIONS; TRANSPORTING
B32B5/02
PERFORMING OPERATIONS; TRANSPORTING
B64C3/26
PERFORMING OPERATIONS; TRANSPORTING
B33Y80/00
PERFORMING OPERATIONS; TRANSPORTING
B64C1/26
PERFORMING OPERATIONS; TRANSPORTING
B64F5/10
PERFORMING OPERATIONS; TRANSPORTING
B29C70/30
PERFORMING OPERATIONS; TRANSPORTING
B64C3/20
PERFORMING OPERATIONS; TRANSPORTING
B33Y10/00
PERFORMING OPERATIONS; TRANSPORTING
B33Y30/00
PERFORMING OPERATIONS; TRANSPORTING
B29C64/118
PERFORMING OPERATIONS; TRANSPORTING
Abstract
A vehicle body may have an internal skeleton, and a skin fabricated in-situ over the internal skeleton. The internal skeleton may be fabricated via a first additive manufacturing system. The skin may be fabricated via a second additive manufacturing system that is different from the first additive manufacturing system.
Claims
1. A vehicle body, comprising: an internal skeleton fabricated via a first additive manufacturing system; and a skin fabricated in-situ over the internal skeleton via a second additive manufacturing system that is different from the first additive manufacturing system; wherein the internal skeleton includes a plurality of adjacent hollow tubes; wherein the internal skeleton and the skin together form a wing shape; wherein the plurality of adjacent hollow tubes extend in a length direction of the wing shape; wherein the plurality of adjacent hollow tubes are fabricated from a matrix material and a plurality of continuous fibers encased within the matrix material; wherein the skin is fabricated from a matrix material and a plurality of continuous fibers encased within the matrix material; and wherein at least some of the plurality of continuous fibers of the internal skeleton extend into and form a portion of the skin.
2. The vehicle body of claim 1, wherein the plurality of continuous fibers of at least one of the internal skeleton and the skin are in tension.
3. The vehicle body of claim 1, wherein the plurality of continuous fibers of at least one of the internal skeleton and the skin are oriented in a plurality of different directions.
4. The vehicle body of claim 1, wherein the plurality of continuous fibers of at least one of the internal skeleton and the skin have trajectories that curve in at least two dimensions.
5. The vehicle body of claim 4, wherein the plurality of continuous fibers are organically arranged within the skin.
6. The vehicle body of claim 5, wherein the plurality of continuous fibers in the skin extend from a base end near a fore/aft center of the wing shape toward a tip end at leading and trailing edges of the wing shape.
7. The vehicle body of claim 6, wherein a density of the plurality of continuous fibers in the skin varies along a length of the wing shape.
8. The vehicle body of claim 7, wherein a density of the plurality of continuous fibers in the skin is greater at the base end than at the tip end.
9. The vehicle body of claim 1, wherein the matrix material of both the internal skeleton and the skin includes a UV-cured resin.
10. The vehicle body of claim 1, wherein the plurality of continuous fibers of at least one of the internal skeleton and the skin includes at least one of an electrically conductive wire, a shape memory fiber or a fiber optic coated with at least one of an insulation layer and a strength-enhancing layer.
11. The vehicle body of claim 1, wherein: the internal skeleton and the skin together also form a fuselage shape; and the plurality of continuous fibers in the skin extend from the wing shape into the fuselage shape.
12. The vehicle body of claim 1, wherein at least one of the plurality of adjacent hollow tubes is coated to function as at least one of a fuel tank and a fuel passage.
13. A vehicle body having a wing and a fuselage, comprising: an internal skeleton fabricated via a first additive manufacturing system and having a plurality of adjacent hollow tubes extending in a length direction of the wing and being formed from a plurality of continuous fibers coated with a matrix; and a skin fabricated in-situ over the internal skeleton via a second additive manufacturing system that is different from the first additive manufacturing system, the skin having a plurality of continuous fibers coated with a matrix and laid over the internal skeleton; wherein the plurality of continuous fibers of both the internal skeleton and the skin are in tension; wherein at least one of the plurality of adjacent hollow tubes is coated to function as at least one of a fuel tank and a fuel passage; wherein the internal skeleton and the skin together form a wing shape; and wherein at least some of the plurality of continuous fibers of the internal skeleton extend into and form a portion of the skin.
14. A method of fabricating a vehicle body, comprising: providing the vehicle body of claim 1 by implementing a first additive manufacturing technique to fabricate an internal skeleton from continuous fibers coated with a matrix; and implementing a second additive manufacturing technique to fabricate a skin over the internal skeleton from continuous fibers coated with a matrix.
15. The method of claim 14, wherein implementing the first additive manufacturing technique to fabricate the internal skeleton includes implementing the first additive manufacturing technique to fabricate a plurality of adjacent hollow tubes.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
(1)
(2)
(3)
(4)
DETAILED DESCRIPTION
(5)
(6) As shown in
(7) The first additive manufacturing process may be a pultrusion and/or extrusion process that creates hollow tubular structures 20 from a composite material (e.g., a material having a matrix M and at least one continuous fiber F). In particular, one or more heads 22 may be coupled to a support 24 (e.g., to a robotic arm) that is capable of moving head(s) 22 in multiple directions during discharge of structures 20, such that resulting longitudinal axes 26 of structures 20 are three-dimensional. Such a head is disclosed, for example, in U.S. patent application Ser. Nos. 13/975,300 and 15/130,207 and in PCT Application Number 2016042909, all of which are incorporated herein in their entireties by reference.
(8) Head(s) 22 may be configured to receive or otherwise contain the matrix material M. The matrix material M may include any type of liquid resin (e.g., a zero volatile organic compound resin) that is curable. Exemplary resins include epoxy resins, polyester resins, cationic epoxies, acrylated epoxies, urethanes, esters, thermoplastics, photopolymers, polyepoxides, thermoset acrylates, thermosets, bismaleimides, silicon, and more. In one embodiment, the pressure of the matrix material M inside of head(s) 22 may be generated by an external device (e.g., an extruder or another type of pump) that is fluidly connected to head(s) 22 via corresponding conduits (not shown). In another embodiment, however, the pressure may be generated completely inside of head(s) 22 by a similar type of device and/or simply be the result of gravity acting on the matrix material M. In some instances, the matrix material M inside head(s) 22 may need to be kept cool and/or dark in order to inhibit premature curing; while in other instances, the matrix material M may need to be kept warm for the same reason. In either situation, head(s) 22 may be specially configured (e.g., insulated, chilled, and/or warmed) to provide for these needs.
(9) The matrix material M stored inside head(s) 22 may be used to coat any number of continuous fibers F and, together with the fibers F, make up walls of composite structures 20. The fibers F may include single strands, a tow or roving of several strands, or a weave of many strands. The strands may include, for example, carbon fibers, vegetable fibers, wood fibers, mineral fibers, glass fibers, metallic wires, SiC Ceramic fibers, basalt fibers, etc. The fibers F may be coated with the matrix material M while the fibers F are inside head(s) 22, while the fibers F are being passed to head(s) 22, and/or while the fibers F are discharging from head(s) 22, as desired. In some embodiments, a filler material (e.g., chopped fibers) may be mixed with the matrix material M before and/or after the matrix material M coats the fibers F. The matrix material, the dry fibers, fibers already coated with the matrix material M, and/or the filler may be transported into head(s) 22 in any manner apparent to one skilled in the art. The matrix-coated fibers F may then pass over a centralized diverter (not shown) located at a mouth of head(s) 22, where the resin is caused to cure (e.g., from the inside-out, from the outside-in, or both) by way of one or more cure enhancers (e.g., UV lights and/or ultrasonic emitters) 27.
(10) In the example of
(11) In some embodiments, a fill material (e.g., an insulator, a conductor, an optic, a surface finish, etc.) could be deposited inside and/or outside of structures 20 while structures 20 are being formed. For example, a hollow shaft (not shown) could extend through a center of and/or over any of the associated head(s) 22. A supply of material (e.g., a liquid supply, a foam supply, a solid supply, a gas supply, etc.) could then be connected with an end of the hollow shaft, and the material forced through the hollow shaft and onto particular surfaces (i.e., interior and/or exterior surfaces) of structure 20. It is contemplated that the same cure enhancer(s) 27 used to cure structure 20 could also be used to cure the fill material, if desired, or that additional dedicated cure enhancer(s) (not shown) could be used for this purpose. The fill materials could allow one or more of structures 20 to function as fuel tanks, fuel passages, electrical conduits, ventilation ducts, etc.
(12) The second additive manufacturing process used to fabricate the exemplary wing 14 of
(13) Head 28 may be similar to head 22 and configured to receive or otherwise contain a matrix material M (e.g., the same matrix material M contained within head 22). The matrix material M stored inside head(s) 28 may be used to coat any number of separate fibers F, allowing the fibers F to make up centralized reinforcements of the discharging tracks, ribbons, and/or sheets. The fibers F may include single strands, a tow or roving of several strands, or a weave of multiple strands. The strands may include, for example, carbon fibers, vegetable fibers, wood fibers, mineral fibers, glass fibers, metallic wires, etc. The fibers F may be coated with the matrix material M while the fibers F are inside head(s) 28, while the fibers F are being passed to head(s) 28, and/or while the fibers F are discharging from head(s) 28, as desired. The matrix material, the dry fibers, and/or fibers already coated with the matrix material may be transported into head(s) 28 in any manner apparent to one skilled in the art. The matrix-coated fibers F may then pass through one or more circular orifices, rectangular orifices, triangular orifices, or orifices of another curved or polygonal shape, where the fibers F are pressed together and the resin is caused to cure by way of one or more cure enhancers 27.
(14) In another exemplary embodiment shown in
(15) As described above, the first and second additive manufacturing processes can be extrusion or pultrusion processes. For example, extrusion may occur when the liquid resin matrix M and the associated continuous fibers F are pushed from head(s) 22 and/or head(s) 28 during the movement of supports 24 and/or 30. Pultrusion may occur after a length of resin-coated fibers is connected to an anchor (not shown) and cured, followed by movement of head(s) 22 and/or heads (28) away from the anchor. The movement of head(s) 22 and/or head(s) 28 away from the anchor causes the fibers F to be pulled from the respective head(s) along with the coating of the matrix material M.
(16) In some embodiments, pultrusion may be selectively implemented to generate tension in the fibers F that make up skeleton 16 and/or skin 18 and that remains after curing. In particular, as the fibers F are being pulled from the respective head(s), the fibers F may be caused to stretch. This stretching can create tension within the fibers F. As long as the matrix M surrounding the fibers F cures and hardens while the fibers F are stretched, at least some of this tension remains in the fibers F and functions to increase a strength of the resulting composite structure.
(17) Structures fabricated via conventional pultrusion methods may have increased strength in only a single direction (e.g., in the one direction in which fibers were pulled through the corresponding die prior to manual resin impregnation and curing). However, in the disclosed embodiment, the increased strength in the skeleton 16 and/or skin 18 of body 10 (e.g., within wing 14) caused by residual tension within the corresponding fibers F may be realized in the axial direction of each the fibers F. And because each fiber F could be pulled in a different direction when being discharged by head(s) 22 and/or 28, the tension-related strength increase may be realized in multiple (e.g., innumerable) different directions.
(18) Structures fabricated via conventional pultrusion methods may have strength increased to only a single level (e.g., to a level proportionate to an amount in which the fibrous cloth was stretched by the pulling machine prior to manual resin impregnation and curing). However, in the disclosed embodiment, because the matrix M surrounding each fiber F may be cured and harden immediately upon discharge, the force pulling on the fiber F may be continuously varied along the length of the fiber F, such that different segments of the same fiber F are stretched by different amounts. Accordingly, the tensile stress induced within each of the different segments of each fiber F may also be different, resulting in a variable strength within the different segments of skeleton 16 and/or skin 18 of body 10. This may be beneficial in variably loaded areas of body 10 (e.g., at the intersection of wing 14 and fuselage 12, within a center of wing 14, at the leading edge of wing 14, etc.).
(19)
(20) In one exemplary embodiment shown in
(21) Structures fabricated via conventional pultrusion and/or extrusion methods may be limited in the orientation of the associated fibers. That is, the fibers may be generally overlapping and lie in parallel layers. However, in the embodiment illustrated in
(22) As described above and shown in
(23) In the exemplary embodiment shown in
(24)
(25) Part 32 may be created following a unique tool path that allows for use of continuous fibers and provides for high-strength in a low-weight configuration. In particular, part 32 may be fabricated using a middle-out strategy.
(26) For example, in a first layer, head 28 may be controlled to start discharging and curing one or more continuous resin-coated fibers at a lower-left corner (e.g., adjacent an internal intersection of a lower support surface 34 and a left brace 36), and continue discharging and curing the same resin-coated fiber(s) during travel upward to an adjacent upper-left corner. Head 28 may then move diagonally inward toward a general center of part 32, and then double back prior to reaching the center to move toward the upper-left corner following a generally parallel trajectory. During this doubling-back maneuver, head 28 may be spaced apart a distance from its original trajectory (e.g., spaced more toward the right of part 32), such that an empty space will exist along a diagonal of part 32 and a box shape is formed at internal ends of the diagonal parallel tracks. Head 28 may then move rightward to an upper-right corner of part 32, followed by about a 90 turn downward upon reaching an internal edge of part 32. The same general pattern may be repeated at the lower-right corner of part 32 that was made at the upper-left corner, such that a mirror image across a virtual diagonal dividing line is created. Head 28 may then move leftward and stop short of its starting point, after which head 28 may turn through about 45 clockwise and travel diagonally completely across part 32 to the upper-right corner. Head 28 may then double back toward the lower-left corner along a spaced-apart parallel track, such that head 28 is near its starting point (e.g., radially outward and slightly lower than the starting point). During this doubling-back maneuver, head 28 may be spaced apart a distance from its original trajectory (e.g., spaced more toward the left of part 32), such that an empty space will exist along a diagonal of part 32. As head 28 moves towards the upper-right corner, it may deviate from its trajectory at a turn-around point and head into the corner, such that an arrow-head shape is formed at internal ends of the parallel tracks. The arrow-head shape may bond to the hardened fibers laid down previously at this corner location. The diagonally laid fiber(s) may bond to the box shape previously laid down at the center of part 32. The entire process may be repeated any number of times to add a corresponding number of material tracks to the first layer and thereby increase a cross-sectional area of the first layer. During repetition, part 32 may grow outward and the empty spaces described above as being located between the parallel tracks may be filled in. It should be noted that, during formation of any one layer, the fibers discharging from head 28 may not overlap other fibers such that all fibers are laid down within the same plane. When head 28 reaches an endpoint of a particular layer, the fiber(s) may be cut from head 28, such that head 28 may be repositioned for start of a new layer.
(27) A second layer may be formed directly on top of the first layer, for example by rotating the pattern of the first layer through a desired angle (e.g., through about 90). By rotating the pattern through about 90, the fibers extending diagonally completely across part 32 in the second layer may overlap the fibers that doubled back at the center of part 32 in the first layer. This overlapping of different portions of the repeating pattern may help to increase a strength of part 32. It is contemplated that any number of fibers may be deposited at any location and oriented generally normal to the overlapping layers (e.g., fibers F.sub.n like those shown in
(28) Any number of additional layers may be formed on top of the first two layers in alternating orientations and/or in orientations of incremental rotating angles (e.g., when the angle is not a multiple of 90). This may continue until a desired thickness of part 32 is achieved. In one example, an entire fuselage 12 and/or wing 14 could be fabricated in this manner. For example, skin 18 could be simultaneously fabricated over part 32 when using the middle-out approach. In particular, an empty space may be created inside of fuselage 12 and/or wing 14 and between adjacent parts 32, by only creating outer portions of supports 34 and/or braces 36.
INDUSTRIAL APPLICABILITY
(29) The disclosed arrangements and designs of skeleton 16 and skin 18 may be used in connection with any type of vehicle body 10. For example, skeleton 16 and skin 18 may be used in connection with an airplane body, a drone body, a car body, a boat body, or any other type of vehicle body where light-weight, low-cost, and high-performance are important. Vehicle body 10 may be light-weight and low-cost due to the reduction in the number of fasteners required to secure skin 18 to skeleton 16 and/or to secure components of vehicle body 10 to each other. In addition, vehicle body 10 may be light-weight do to the use of composite materials used to make both of skeleton 16 and skin 18. The high-performance may be provided in the unique ways that particular fibers and resins are used and laid out within skeleton 16 and skin 18.
(30) It will be apparent to those skilled in the art that various modifications and variations can be made to the disclosed vehicle body. Other embodiments will be apparent to those skilled in the art from consideration of the specification and practice of the disclosed vehicle body. It is intended that the specification and examples be considered as exemplary only, with a true scope being indicated by the following claims and their equivalents.