Patent Publication Number: US-11390224-B2

Title: Fabric processing method and component

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application is a divisional of U.S. application Ser. No. 15/460,371 filed on Mar. 16, 2017, which is incorporated by reference in its entirety herein. U.S. application Ser. No. 15/460,371 claims the benefit of U.S. provisional patent application Ser. No. 62/313,083, filed Mar. 24, 2016, which is also incorporated by reference in its entirety herein. 
    
    
     BACKGROUND 
     Increasingly, vehicle manufacturers look to new materials and methods to increase structural integrity on vehicles, improve safety, reduce vehicle weight, etc. A preferred material for such purposes is carbon fiber reinforced plastic (CFRP). However, current CFRP processing methods are not efficient, particularly when working with very expensive raw materials. Specifically, yield rates are too low and this problem is particularly acute when working with very expensive raw materials. Accordingly, more efficient processing is needed to improve yield, reduce processing complexity and expense, improve quality, etc. 
     In one known method, carbon fiber fabric is used and cut into desired patterns (i.e., fabric charges). These are draped over a pre-form mold to form a preferred 3-dimensional shape and then the fabric is infused with a polymeric resin to create a vehicle component. Unfortunately, the current known process has excessive waste and thus a low yield. Also, the current known method requires significant handling steps as each fabric charge is individually applied to a desired location on the pre-form mold. Further, the current process involves long fabric loading time, long infusion time, long resin cure time, and other disadvantages. 
     SUMMARY 
     According to one aspect, a fabric processing method for forming a vehicle component includes providing a first fabric charge, providing a second fabric charge, and forming a multi-piece fabric assembly for single stage draping by stitching together the first and second fabric charges along a neutral stitching path. The method further includes forming the multi-piece fabric assembly into a three-dimensional shape and impregnating the multi-piece fabric assembly with a polymeric material while the multi-piece fabric assembly is formed into the three-dimensional shape. 
     According to another aspect, a vehicle fabric processing method is provided for forming a three-dimensional component. The method includes arranging first and second fabric charges relative to one another and stitching the first and second fabric charges together along a neutral stitching path. After stitching, the first and second fabric charges are formed into a three-dimensional shape. After forming into the three-dimensional shape, the first and second fabric charges are infused with a polymeric material. 
     According to a further aspect, a vehicle component includes an impregnated multi-piece fabric assembly comprising at least a first fabric charge and a second fabric charge stitched together along a neutral stitching path. The first and second fabric charges have distal portions spaced apart from the neutral stitching path that are three-dimensionally oriented relative to one another and relative to the neutral stitching path. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a block diagram schematically illustrating a fabric processing method accordingly to an exemplary embodiment. 
         FIG. 2  is a schematic illustration of a first fabric charge presented for placement on a staging platen. 
         FIG. 3  schematically shows the first fabric charge arranged on the staging platen. 
         FIG. 4  schematically shows a second fabric charge presented for placement on the staging platen. 
         FIG. 5  schematically shows the second fabric charge arranged in overlapping relation on the first fabric charge and on the staging platen. 
         FIG. 6  schematically shows a third fabric charge presented for placement on the staging platen. 
         FIG. 7  schematically shows the third fabric charge arranged relative to the first and second fabric charges and positioned on the staging platen. 
         FIG. 8  schematically shows stitching occurring along a neutral stitching path to stitch together the first, second, and third fabric charges into a multi-piece fabric assembly. 
         FIG. 9  schematically shows presentation of the multi-piece fabric assembly for draping onto a pre-form member. 
         FIGS. 10-12  schematically show the multi-piece fabric assembly being draped onto a lower pre-form member (and stitching applied in  FIG. 12 ). 
         FIGS. 13 and 14  schematically illustrate the multi-piece fabric assembly with additional reinforcement stitching patterns. 
         FIGS. 15-18  schematically illustrate sequences of stitching for the additional reinforcement stitching patterns of  FIGS. 13 and 14 . 
         FIG. 19  schematically illustrates an alternate arrangement wherein a multi-piece fabric assembly having zero overlap between fabric charges is draped onto a lower pre-form member according to an alternate exemplary embodiment. 
         FIG. 20  schematically illustrates another alternate arrangement wherein reinforcement charges are applied to a multi-piece fabric assembly, such as the one shown in  FIGS. 8-12 , according to an alternate exemplary embodiment. 
         FIG. 21  is a block diagram schematically illustrating further steps for the fabric processing method of  FIG. 1 . 
     
    
    
     DETAILED DESCRIPTION 
     Referring now to the drawings wherein the showings are only for purposes of illustrating one or more exemplary embodiments and not for purposes of limiting the same,  FIG. 1  shows a fabric processing method  10  for forming a vehicle component. In the method, as shown at  12 , fabric charges are provided. With additional reference to  FIGS. 2-4 , this can include providing a first fabric charge  14  and a second fabric charge  16 . Once provided, the fabric charges  14 ,  16  can be arranged relative to one another as indicated at  18  in  FIG. 1 . In particular, as shown in  FIGS. 2 and 3 , this can first include placing the first fabric charge  14  on a staging platen  20 . The staging platen  20  generally provides a flat or planar work surface arranged in a single plane. Arranging the fabric charges  14 ,  16  relative to one another in  18  can also include positioning the second fabric charge  16  on the staging platen  20 . In particular, the second fabric charge  16  can be arranged so that it overlaps, at least in part, the first fabric charge  14 , though alternatively such overlapping could be reversed so that the first fabric charge  14  overlaps the second fabric charge  16 . 
     Additionally, though not required, providing fabric charges in  12  can include providing any number of further fabric charges. For example, with further reference to  FIG. 6 , a third fabric charge  22  can be provided. When so provided, the third fabric charge  22  (and any additional fabric charges) can be arranged relative to the first and second fabric charges  14 ,  16  as shown in  FIG. 7 . Such arrangement can include placement of the additional fabric charges (e.g., fabric charge  22 ) onto the staging platen  20  and layering (overlapping or underlapping) with respect to the other fabric charges (e.g., the first and second fabric charges  14 ,  16 ). 
     Accordingly, at  18  in  FIG. 1 , the fabric charges  14 ,  16 , and  22  can be arranged relative to one another. As shown in  FIG. 7 , by way of example, the third fabric charge  22  can be arranged on the staging platen  20  such that it overlaps the first fabric charge  14 , and the second fabric charge  16  can be arranged on the staging platen  20  such that it overlaps both the third fabric charge  22  and the first fabric charge  14 . By this arrangement, the third fabric charge  22  is interposed, at least in part, between the first fabric charge  14  and the second fabric charge  16 . Of course, as will be understood and appreciated by those skilled in the art, the exact overlapping relationship between or among the fabric charges  14 ,  16 , and  22  can vary relative to the illustrated embodiment. 
     Once the fabric charges (e.g., fabric charges  14 ,  16 ,  18 ) are arranged relative to one another in a two-dimensional plane, such as on the staging platen  20  as shown in the illustrated embodiment, a multi-piece fabric assembly  30  can be formed for subsequent single stage draping as indicated at  32  in  FIG. 1 . In particular, the multi-piece fabric assembly  30  can be formed by stitching together the fabric charges (e.g., fabric charges  14 ,  16 ,  18 ) along a neutral stitching path, such as the neutral stitching path  34  illustrated in  FIG. 8 . In  FIG. 8 , some stitching  36  is illustrated along the neutral stitching path  34  (i.e.,  FIG. 8  shows the stitching in progress and shows a stitching device  36   a  in phantom applying the stitching  36  along the neutral stitching path  34 . Accordingly, as shown in the illustrated embodiment, the multi-piece fabric assembly  30  is formed by stitching together the first and second fabric charges  14 ,  16  along the neutral stitching path  34  and is further formed by stitching together the second and third fabric charges  16 ,  22  along the neutral stitching path  34 . Thus, forming the multi-piece fabric assembly  30  includes, in the illustrated embodiment of  FIG. 8 , stitching together the first, second, and third fabric charges  14 ,  16 ,  22  along the neutral stitching path  34  to form the multi-piece fabric assembly  30  and this occurs in a single plane on the staging platen  20 . 
     Though not shown in  FIG. 1 , optionally the step of forming the multi-piece fabric assembly  30  by stitching together the fabric charges along a neutral stitching path  34  can include or be considered to include the step  18  of arranging the fabric charges relative to one another. Thus, forming the multi-piece fabric assembly  30  in  FIG. 8  by stitching together the first, second, and third fabric charges  14 ,  16 ,  22  can include the step shown in  18  of arranging each of the first and second and third fabric charges  14 ,  16 ,  22  relative to one another in a two-dimensional plane (e.g., on the staging platen  20 ) with the first, second, and third fabric charges  14 ,  16 ,  22  overlapping one another (i.e., third fabric charge  22  overlapping first fabric charge  14  and second fabric charge  16  overlapping both the third fabric charge  22  and the first fabric charge  14  in the illustrated embodiment of  FIG. 8 ). 
     Specific to the illustrated embodiment, though not required, the first fabric charge  14  can be a V-shaped corner piece having, with specific reference back to  FIG. 2 , an inner apex or apex side  14   a , an outer wide side  14   b , and a pair of flanking or lateral sides  14   c ,  14   d  extending between the inner apex or apex side  14   a  and the outer wide side  14   b . Also particular to the illustrated embodiment, the second and third fabric charges  16 ,  22  can be arranged in  18 , respectively, relative to the first fabric charge  14  and in a single two-dimensional plane (i.e., provide by the staging platen  20 ) such that the second and third charges  16 ,  22  respectively overlap the first fabric charge  14  a greater amount adjacent the apex or apex side  14   a  than adjacent the outer wide side  14   b . Alternatively, though not shown in the illustrated embodiment, the first fabric charge  14  could overlap the second and third charges  16 ,  22  a greater amount adjacent the apex or apex side  14   a  then adjacent the outer wide side  14 B. Advantageously, such an arrangement wherein the second and third fabric charges  16 ,  22  overlap the first fabric charge  14  a greater amount near the apex side  14   a , which is particularly enabled by the method disclosed herein, can reduce the amount of trim waste and/or overlap waste related or relative to conventional methods wherein a significant portion of fabric charges are wasted due to trimming and/or due to excessive overlapping. Of course, it should be appreciated by those skilled in the art that the fabric charges can have any size and/or shape and the fabric charges can be optimized so as to best correspond to the final component to be formed to eliminate or reduce the amount of waste, such as by trimming or overlapping. 
     As shown, the neutral stitching path  34  can extend along the first fabric charge  14  between the flanking sides  14   c ,  14   d  and can be spaced apart from each of the inner apex or apex side  14   a  and the outer wide side  14   b . Similarly, the neutral stitching path  34  can be arranged along the second and third fabric charges such that the neutral stitching path  34  extends between respective pairs of flanking sides of the second and third fabric charges (i.e., flanking sides  16   c  and  16   d  of the second fabric charge  16  and flanking sides  22   c ,  22   d  of the third fabric charge  22 ). Also, the neutral stitching path can be spaced apart from inner sides  16   a ,  22   a  of, respectively, the second fabric charge  16  and the third fabric charge  22  and from outer sides  16 Bb,  22   b B of, respectively, the second fabric charge  16  and the third fabric charge  22 . Of course, the exact neutral stitching path used can vary depending on the fabric charges and/or the final component to be formed. 
     Returning reference to  FIG. 1 , after the multi-piece fabric assembly  30  is formed by stitching together the fabric charges along a neutral stitching path as indicated at  32 , the multi-piece fabric assembly  30  can be formed into a three-dimensional shape (i.e., a complex shape) as indicated at  38 . Accordingly, in the illustrated embodiment, the fabric charges  14 ,  16 , and  22  can be formed into a three-dimensional shape  40 , as shown sequentially in  FIGS. 9-12 , after the stitching  36  is applied along the neutral stitching path  34 . 
     In particular, the final three-dimensional shape  40  is shown in  FIG. 12 . For the illustrated embodiment, forming the multi-piece fabric assembly  30  into the three-dimensional shape  40  is shown sequentially in  FIGS. 9-12 . As shown, such forming includes draping the multi-piece fabric assembly  30 , which can also be referred to as an integrated fabric charge, over a lower pre-form member  42  in a single draping step. In contrast to known methods, the draping illustrated in  FIGS. 9-12  occurs in a single draping step. This is enabled because the individual fabric charges  12 ,  16 ,  18  in the illustrated embodiment are integrated into multi-piece fabric assembly  30  via the stitching  36  provided along the neutral stitching path  34 . In contrast, in prior known methods, each individual fabric charge was independently laid on a pre-form member resulting in a time-consuming and complex process. 
     As shown in the illustrated embodiment (and particularly shown in  FIG. 9 ), the pre-form member  42  can include an upper flat surface or area  42   a . As shown in  FIG. 10 , this area  42   a  receives directly thereon a portion of the multi-piece fabric assembly  30  that is disposed immediately adjacent the neutral stitching path  34  and thus the area  42   a  also receives the stitching  36  put in place along the neutral stitching path  34 . Then, as shown in  FIG. 11 , distal portions  14   e ,  14   f ,  16   e ,  16   f ,  22   e ,  22   f  of at least one of the first, second, and third fabric charges  14 ,  16 ,  22  can be moved relative to one another and relative to the neutral stitching path  34  while relative alignment between and among the fabric charges  14 ,  16 ,  22  is maintained along the neutral stitching path  34 . This is shown in sequence in  FIGS. 10, 11, and 12 . The distal portions particularly include inner distal portions  14   e ,  16   e , and  22   e  adjacent, respectively, the inner sides  14   a ,  16   a ,  22   a , and outer distal portions  14   f ,  16   f ,  22   f  disposed adjacent, respectively, the outer sides  14   b ,  16   b ,  22   b.    
     Accordingly, forming the fabric charges  14 ,  16 ,  22  into the three-dimensional shape  40  of  FIG. 12  includes draping the fabric charges  14 ,  16 ,  22  over the pre-form member  42  with central portions (i.e., portions  14   g ,  16   g ,  16   h , respectively, of the first, second, and third fabric charges  14 ,  16 ,  22 ) resting on the area  42   a  of the pre-form member  42  arranged in a single plane and the distal portions  14   e ,  14   f ,  16   e ,  16 Ff,  22   e ,  22   f  arranged in orientations angled and varying relative to the single plane defined by the area  42   a  as best shown in  FIG. 12 . Such moving of the distal portions  14   e ,  14   f ,  16   e ,  16   f ,  22   e ,  22   f  of the fabric charges  14 ,  16 ,  22  can be assisted by an upper pre-form member shown schematically in phantom as  44  in  FIG. 10 . As the upper pre-form member  44  is drawn or moved toward the pre-form member  42 , the multi-piece fabric assembly  30  is formed into the three-dimensional shape  40  shown in  FIG. 12 . 
     Returning reference to  FIG. 1 , as indicated at  48 , further stitching can be applied to the fabric charges, including the first, second, and third fabric charges  14 ,  16 , and  22 . In particular, the fabric charges  14 ,  16 , and  22  can be further stitched together after the multi-piece fabric assembly  30  is formed into the three-dimensional shape  40  along one or more three-dimensional stitching paths. For example, in the illustrated embodiment and with reference to  FIG. 12 , further stitching at  48  can occur along a first three-dimensional stitching path  50  and a second three-dimensional stitching path  52 . The three-dimensional stitching paths, including the first and second stitching paths  50 ,  52 , can be arranged such that the further stitching includes stitching together overlapping portions of the fabric charges, including the first, second, and third fabric charges  14 ,  16 ,  22  in the illustrated embodiment. 
     As shown, the one or more three-dimensional stitching paths, including stitching paths  50  and  52 , can each intersect the neutral stitching path  34  and thus the stitching  36  to form respective stitching intersections  54 ,  56  with each of the three-dimensional stitching paths being approximately perpendicular (i.e., perpendicular or nearly perpendicular, such as 90 degrees+/−five degrees) relative to the neutral stitching path  34  and thus stitching  36  at the respective stitching intersections  54 ,  56 . In the illustrated embodiment, the first stitching path  50  is formed or disposed along the side  16   d  of the second fabric charge and the side  14   c  of the first fabric charge  14 . As already discussed herein, the side  16   d  can slightly overlap (e.g., 15 mm overlap) the side  14   c  of the first fabric charge  14 . Similarly, the second stitching path  52  can be disposed on or adjacent the side  22   c  of the third fabric charge  22  and the side  14   d  of the first fabric charge  14  with a slight overlap (e.g., 15 mm overlap). Although not shown, it is to be appreciated that other variations of overlap could be used. For example, the overlap could be approximately 30 mm or some other dimension. 
     In addition to the three-dimensional stitching paths  50 ,  52 , additional stitching can be applied to functionally critical geometries of the fabric charges, including the first, second, and third fabric charges  14 ,  16 , and  22 . This additional stitching allows for more efficient connectivity between the fabric layers rather than depending on the shear stress transfer through a much lower stiffness resin matrix. By way of example, in  FIG. 13 , a stitching pattern  60  is created to locally enhance the connectivity on both sides of a functionally significant portion of a radius on the final three-dimensional shape  40 . The stitching pattern  60  can include a first group of stitching  62  provided on the central portion  16   g  and a second group of stitching  64  provided on the inner distal portion  16   e  of the second fabric charge  16 . The stitching pattern  60  can be approximately perpendicular relative to the stitching path  50 .  FIG. 14  illustrates another example of the final three-dimensional shape  40 . Stitching patterns  70 ,  72  and  74  are created to locally enhance the connectivity leading up to, through, and after a radius on the final three-dimensional shape  40 . Each of the stitching patterns  70 ,  72 , and  74  can be provided in addition to or separately from the other stitching patterns including stitching pattern  60  described above. As depicted, the individual stitching paths of each of stitching pattern  60 ,  70 ,  72  and  74  can be of differing lengths. Further, different stitching patterns could be implemented based on the preferred stress flow in the part geometry, as well as the sequence each of the stitching pattern  60 ,  70 ,  72  and  74  is implemented which can influence processing and fabric tolerance management. Examples of stitching sequences for each of the stitching patterns  60 ,  70 ,  72 , and  74  are depicted in  FIGS. 15, 16, 17 and 18 , respectively. 
     Alternatively, the fabric charges  14 ,  16 , and  22  could be sized and arranged such that when stitched together along the neutral stitching path  34  there is no measurable overlap between the fabric charges  14 ,  16 ,  22  when the multi-piece fabric assembly  30  is formed into the three-dimensional shape  40  without any trimming occurring after the fabric charges  14 ,  16 ,  22  are stitched together along the neutral stitching path  34 . Thus, there would be no overlap between the fabric charges. In this case, there would be no three-dimensional stitching and step  48  could be removed from the method  10  of  FIG. 1 . An example of such a three-dimensional shape  40 ′ according to this alternate embodiment is shown in  FIG. 19 . 
     With or without the further stitching, returning reference to  FIG. 1 , the fabric charges, including the first, second, and third fabric charges  14 ,  16 ,  22 , can next be infused with a polymeric material (i.e., after forming into the three-dimensional shape  40 ), as indicated at  64 . For example, the multi-piece fabric assembly  30  can be impregnated with a polymeric material while the multi-piece fabric assembly is formed into the three-dimensional shape. 
     With reference now to  FIG. 20 , optionally, one or more local reinforcement charges, such as illustrated local reinforcement charges  78 ,  80 , and  82 , can be stitched onto the multi-piece fabric assembly  30  after the multi-piece fabric assembly  30  is formed into the three-dimensional shape  40 . As shown, the reinforcement charges, including charges  78 ,  80 ,  82 , can be smaller in size than each of the first, second, and third fabric charges  14 ,  16 ,  22 . By way example, the locations for the reinforcement charges  78 ,  82  can be areas of high stress expected in the final, fully cured application, can help provide stiffness to a desired local area, and/or can increase fabric stability due to resin injection fluid loading. The local reinforcement charges  78 ,  80 ,  82  can be formed of the same material as the fabric charges  14 ,  16 ,  22 . 
     Now with reference to  FIG. 21 , the method  10  of  FIG. 1  can continue. In particular, after infusing at  64 , the multi-piece fabric assembly  30 , including the fabric charges  14 ,  16 ,  18 , can be cured prior to demolding from the pre-form members  42 ,  44 , as indicated at  86 . After some curing at  86 , the multi-piece fabric assembly  30 , including the fabric charges  14 ,  16 , and  22 , can be demolded (i.e., removed) from the pre-form members  42 ,  44 , as indicated at  88 . Next, optionally, further curing can occur for the multi-piece fabric assembly  30 , including the fabric charges  14 ,  16 , and  22  after demolding as indicated at  90 . 
     The resultant product is a three-dimensional component that can be applied on a vehicle, such as forming the vehicle&#39;s frame (or a portion of the frame) or some other vehicle component. Such a vehicle component formed according to the method or methods described hereinabove can comprise an impregnated multi-piece fabric assembly, such as multi-piece fabric assembly  30 , that itself comprises at least a first fabric charge and a second fabric charge (e.g., first, second, and third fabric charges  14 ,  16 , and  22 ) stitched together along the neutral stitching path  34 . As already described herein, the fabric charges can have distal portions spaced apart from the neutral stitching path  34  that are three-dimensionally oriented relative to one another and relative to the neutral stitching path  34 . Optionally, the distal portions  14   e ,  14   f ,  16   e ,  16   f ,  22   e ,  22   f  of the fabric charges  14 ,  16 ,  22  can be stitched together along one or more three-dimensionally stitching paths, such as the stitching paths  50  and  52 . 
     It is contemplated that different stitch patterns can be used, particularly along the neutral stitching path  34 . Such different stitching patterns can be used to balance differential forming loads between sides of the fabric charges, particularly during draping over the pre-form member. To minimize excessive local fabric distortion and stitching or even within a given fabric charge, different stitching patterns can be employed to help create compliance between different fabric charges and/or to help stabilize a fabric local area against highly localized distortion due to challenging forming geometry. 
     Still further, it is contemplated that multiple layers of fabric charges could be added and built up on top of one another to create the thickened fabric charge. Such material could then be stitched along a neutral stitching path as described herein in order to allow a single draping operation to apply shape to the material. Still further, optional frictional inserts (not shown) could be interposed between layers of fabric charges to help ease forming. In particular, this could avoid unwanted distortion in the material. The material for the friction reducing member could be in the form of a powder, as part of a thermal plastic material binder used in pre-forming fabrics, or could be a separate sheet material that is installed during a stacking process for the fabric charges and then removed after draping has been completed (and before resin injection) 
     It will be appreciated that the above-disclosed features and functions, or alternatives or varieties thereof, may be desirably combined into many other different systems or applications. Also that various presently unforeseen or unanticipated alternatives, modifications, variations or improvements therein may be subsequently made by those skilled in the art which are also intended to be encompassed by the present disclosure.