Sewing device and sewing method for rotary fabric with narrow cavity

Abstract

The invention relates to a sewing device for rotary fabric with a narrow cavity. The sewing device comprises a clamping and fixing device, a supporting device and a sewing mold. A supporting device is mounted on an optical axis of the clamping and fixing device and comprises a large supporting plate and a small supporting plate; a sewing mold is mounted between the large supporting plate and the small supporting plate and comprises an inner pressing plate and an outer pressing plate; in the sewing process, the inner pressing plate and the outer pressing plate clamp the to-be-sewn rotary-like fabric in the middle, and the small supporting plate and the large supporting plate are installed at the upper end and the lower end of the rotary-like fabric respectively. The outer pressing plate is provided with an equidistant straight opening groove for a fiber suture line to penetrate through the revolving-like fabric. The invention further provides a suturing method using the suturing device. According to the method, a novel improved lock type sewing mode is adopted to integrally sew the revolving-like fabric, and a method of firstly punching a prefabricated hole and externally penetrating a bottom thread is adopted, so that the problems that the internal space of the fabric is narrow and small and the fabric is difficult to sew are solved, and the interlayer strength of the fabric is improved.

Description

Technical Field

[0001] The invention belongs to the technical field of composite material preform processing, and particularly relates to a sewing device and a sewing method for rotary fabrics of narrow cavity type. Background Art

[0002] Composite material preform stitching technology is a composite material preform preparation technology that uses fiber stitching lines to combine multiple layers of fabric or multiple separate pieces of fabric into an integral structure. It is widely used in high-tech fields such as aerospace, national defense, and rail transportation.

[0003] In the existing process technology, the composite material preform stitching methods include single-sided stitching and double-sided stitching. Single-sided stitching includes tufting stitching, double-needle blind stitching and I-fiber stitching. Double-sided stitching includes N-type path stitching and improved lock stitching.

[0004] The yarns of tufted stitching are easy to break and have no locking effect, so it is difficult to sew preform fabrics with high volume density; the thickness of double-needle blind stitching is relatively thin, which is not suitable for sewing high-thickness preforms; I-fiber stitching uses compressed air and a hollow needle tube to implant the yarn into the thickness direction of the preform fabric. Due to the large needle hole, there is a problem that the yarn is easy to fall off; the N-path stitching process requires a large operating space and is difficult to be used for sewing fabrics with narrow internal space; like tufted stitching, the yarns of improved lock stitching are also prone to wear and breakage during the stitching process. In summary, the existing preform stitching methods are difficult to meet the high-quality stitching and molding of preform fabrics with high density, high thickness and narrow internal space. Therefore, it is necessary to explore a stitching device and stitching method for rotating fabrics with narrow cavities. Summary of the invention

[0005] In order to solve the technical problems existing in the known technology, the present invention provides a sewing device and a sewing method for a quasi-revolving fabric with a narrow cavity, which meets the sewing preparation needs of a quasi-revolving fabric with a narrow internal space, irregular shape and large axial size.

[0006] The present invention includes the following technical solutions:

[0007] A sewing device for a revolving fabric with a narrow cavity, comprising a clamping device, a supporting device and a sewing mold; the supporting device is installed on the optical axis of the clamping device, and the supporting device comprises a large supporting plate and a small supporting plate; the sewing mold is installed between the large supporting plate and the small supporting plate, and the sewing mold comprises an inner pressure plate and an outer pressure plate; during the sewing process, the inner pressure plate and the outer pressure plate clamp the revolving fabric to be sewn in the middle, and the small support plate and the large support plate are respectively installed at the upper and lower ends of the revolving fabric; the outer pressure plate is provided with equidistant straight grooves for fiber sewing lines to pass through the revolving fabric.

[0008] Furthermore, the clamping and fixing device also includes a T-slot workbench, a connecting base plate, a three-jaw chuck, an optical axis and a group of optical axis fixing seats; the connecting base plate is fixedly mounted on the T-slot workbench, the three-jaw chuck is connected to the connecting base plate, and the optical axis is fixed on the T-slot workbench through the three-jaw chuck, and the overall translation and rotation can be achieved as required; the shaft end of the optical axis fixing seat is provided with two double-cut edge openings and two threaded holes, and the optical axis fixing seat is connected to the large support plate or the small support plate and fixedly clamped on the optical axis; the position of the supporting device and the stitching mold can be adjusted up and down by adjusting the position of the optical axis fixing seat on the optical axis as required.

[0009] Furthermore, the large support plate and the small support plate both include a clamping connection part, a fabric support part and a wire screw sleeve; the clamping connection part is provided with an optical axis hole which is equal to the diameter of the optical axis, and is mounted on the optical axis through the optical axis hole; four optical holes are provided around the optical axis hole, which are the same in size and position as the four optical holes provided on the base of the optical axis fixing seat, and are connected and fixed to the optical axis fixing seat through matching hexagonal bolts and hexagonal nuts; the fabric support part is inlaid with a wire screw sleeve, and the inner pressure plate and the outer pressure plate of the sewing mold are detachably installed through the connection between the hexagonal bolts and the wire screw sleeve.

[0010] Furthermore, the inner pressure plate is divided into 23 pieces, which is convenient for segmented removal during suturing, thereby facilitating fabric suturing; after assembly, the inner pressure plate fits in with the inner cavity of the quasi-rotating fabric; the outer pressure plate is divided into 6 pieces, which are three large curved surface positions and three corner positions connected to the curved surfaces, which is convenient for installation and compression to adjust the thickness of the fabric, and at the same time, it is convenient to open a straight groove on the outer pressure plate to provide a suturing position, thereby facilitating ensuring the suturing line spacing; after assembly, the outer pressure plate fits in with the outer surface of the quasi-rotating fabric.

[0011] Furthermore, the thickness of the inner and outer pressure plates are both 10mm; the inner and outer pressure plates are provided with through holes that are staggered and connected to the fabric support part; the through holes of the inner and outer pressure plates are no longer inlaid with wire screw sleeves, which is economical and convenient and improves the durability of the sewing device to a certain extent, so the through holes of the inner and outer pressure plates are staggered to connect the wire screw sleeves inlaid with different fabric support parts. In addition, due to the small internal space, it is inconvenient to install the inner and outer pressure plates through the through holes located at the corners, so the through holes at the corners are all set to have an inclined angle in the horizontal direction. The thickness of the fabric is compressed and controlled by adjusting the regulating bolts connecting the outer pressure plate and the fabric support part; the straight groove on the outer pressure plate is 3mm wide, and the distance between adjacent grooves is 5mm.

[0012] Furthermore, the large support plate, the small support plate, the inner pressure plate and the outer pressure plate are all made of a resin base through 3D printing technology according to the shape of a quasi-revolving fabric.

[0013] A method for sewing a rotating fabric with a narrow cavity, using the above-mentioned sewing device, comprises the following steps:

[0014] S1. Design fabric layup: Design the fabric layup according to the shape, thickness, size and specifications of the carbon fiber spread fabric and other technical requirements of the quasi-rotation fabric; cut the carbon fiber spread fabric according to the layup design to form a spread fabric of appropriate size;

[0015] S2. Laying the carbon fiber spreader cloth: Assemble the inner pressure plate of the stitching mold, and lay each unit layer of the carbon fiber spreader cloth on the inner pressure plate of the stitching mold in sequence according to the layer design. After the spreader cloth is laid, assemble the outer pressure plate of the stitching mold;

[0016] S3. Planning the suture trajectory: setting the suture point spacing according to the technical requirements, printing the suture ruler with the set interval, cutting the suture ruler into strips, and sticking it on the partition between two adjacent straight-mouth grooves of the outer pressing plate of the suture mold; the setting of the suture ruler enables the suture to be performed along the length direction of the groove according to the ruler, so as to control the distance between the suture points;

[0017] S4, stitching the quasi-revolving fabric: according to the stitching trajectory planned in S3, the quasi-revolving fabric is stitched as a whole by using an improved lock stitching method in which pre-made holes are first punched and the bottom line is passed outside.

[0018] Furthermore, the S1 fabric ply design includes S1-1 ply design and S1-2 carbon fiber spread cloth cutting; S1-1 uses relevant design software to draw the shape of the upper and lower end views of the quasi-revolving fabric, divides the quasi-revolving fabric into N unit layers equidistantly according to thickness to obtain a ply plane design drawing, and then imports the above-drawn quasi-revolving fabric ply plane design drawing into another design software to loft it layer by layer into a three-dimensional graphic, and divides and flattens each unit layer; S1-2 exports each unit layer divided and flattened in S1-1 into a two-dimensional graphic, marks each graphic with a unit layer division position, writes a cutting program for a cutting table according to the flattened ply model, and uses the cutting table to cut the carbon fiber spread cloth.

[0019] Furthermore, in the S1-1, each unit layer is split and flattened, that is, each unit layer is split and flattened in seven equally divided positions. Since the curvature of the corner position of the quasi-revolving fabric is large, the carbon fiber widening cloth is relatively flat and it is difficult to fit the large curvature shape of the corner position. At the same time, the corner position of the quasi-revolving fabric is subjected to large force during application, so the corner position is avoided, and the laying cuts of each layer of the widening cloth skip the large curvature corner position; in the S1-1, the laying position of each layer is set according to the surface intersection, and the cuts of each layer are staggered, and the laying angles are divided and flattened in turn according to 30 degrees, 100 degrees, 330 degrees, 130 degrees, 270 degrees, 70 degrees, and 210 degrees. This design of the split position avoids the influence of the cut on the overall thickness of the quasi-revolving fabric, and at the same time avoids the relatively weak performance of the overlap position caused by the overlap of each layer of cuts when the carbon fiber widening cloth is laid.

[0020] Furthermore, the structure of the carbon fiber widened fabric in S1-2 is a plain weave, and the specifications of the widened fabric are a grid width of 8 to 9 mm and a surface density of 200 to 205 g / m 2 Or grid width 16 ~ 17mm, surface density 100 ~ 105g / m 2 Or the grid width is 20-21mm, the surface density is 80-85g / m 2 .

[0021] Furthermore, in the S2, the carbon fiber spreader cloth is laid, and first, the inner pressure plate of the stitching mold is assembled, and 23 inner pressure plates of the stitching mold are arranged according to the shape of the inner cavity of the stitched fabric, and are connected with wire screw sleeves in sequence by bolts, and are installed on the inner side of the fabric support part of the large support plate and the small support plate; then, the carbon fiber spreader cloth cut in S1-2 is laid on the inner pressure plate of the stitching mold according to the layer design, and each unit layer is laid to ensure that the spreader cloth is tightly fitted with the inner pressure plate of the stitching mold or the upper layer of spreader cloth; after the spreader cloth is laid, the outer pressure plate of the stitching mold is assembled, and 6 outer pressure plates of the stitching mold are arranged according to the shape of the outer surface of the stitched fabric, and are connected with wire screw sleeves in sequence by regulating bolts, and are installed on the outer side of the fabric support part of the large support plate and the small support plate, and the thickness of the fabric is controlled by compression of the adjustable bolts.

[0022] Furthermore, when laying in S2, it is necessary to ensure that the carbon fiber spread cloth is tightly fitted with the pressure plate inside the sewing mold or the previous layer of spread cloth. However, since the shape of the fabric and the pressure plate inside the sewing mold is an irregular quasi-rotational structure, there are negative curvature areas, and the carbon fiber spread cloth is relatively flat and has a certain toughness, the spread cloth cannot be tightly fitted when laid. Therefore, when laying the first layer of spread cloth, a slender suture needle with a fiber suture line is passed through the gap assembled between the inner pressure plates and through the hollow inner cavity to sew and tighten the two sides of the spread cloth laid on the inner pressure plate to fix it on the inner pressure plate. After that, when laying each layer of spread cloth, a curved needle pre-sewing method is used to sew and connect it with the laid spread cloth. After all the spread cloths are laid, all the pre-sewn fiber suture lines are pulled out, so as to achieve the purpose of making the spread cloth tightly fit the pressure plate inside the sewing mold or the previous layer of spread cloth.

[0023] Furthermore, the S4 suture-type rotating fabric: when suturing, the inner pressure plate corresponding to the suture position is removed, and the fabric is sewed in sequence at the open groove position according to the marks on the suture ruler; first, a punching needle is used to punch a preset hole at the suture point, and then a suture needle with a fiber suture thread is introduced into the fabric along the prefabricated hole to form a thread loop, and a hook needle is used to hook the thread loop out of the opening at the large end of the fabric, and after being tied to the bottom line reserved outside the suture mold, the fiber suture thread is brought out by the suture needle for the next cycle, thereby suturing the fabric.

[0024] The present invention has the advantages and positive effects:

[0025] 1. The present invention adopts a new improved lock-type stitching method to stitch the quasi-revolving fabric as a whole. Prefabricated holes are first punched, and the method of threading the bottom line outside is adopted. This overcomes the problem of narrow space inside the fabric and difficulty in stitching, reduces the wear and breakage of the stitching line, improves the interlayer strength of the fabric, reduces the in-plane fiber damage, and has a relatively high damage tolerance.

[0026] 2. The present invention uses resin-based 3D printing technology to manufacture the support device and the suturing mold, which has the advantage of low manufacturing cost, and by embedding wire screw sleeves in the threaded connection parts, the stability of the connection and the durability of the suturing device are enhanced.

[0027] 3. The present invention cross-divides each unit layer at seven positions and cross-distributes the interface positions during layer laying, thereby avoiding the influence of the incision on the overall thickness and local performance of the quasi-revolving fabric and ensuring the overall structural strength of the preform fabric.

[0028] 4. The present invention adopts a curved needle pre-stitching method to fix the layers, which ensures the compactness of the layers in the negative curvature area of ​​the quasi-revolutionary curved surface preform, and improves the layer density and overall volume density of the preform.

[0029] 5. The suture track planning of the present invention sets the suture track by setting the interval suture scale, which improves the accuracy of the suture point spacing and improves the suture quality.

[0030] 6. The present invention uses a large support plate, a small support plate, an inner pressure plate, and an outer pressure plate to clamp, sew and support, and compress and shape the stitched fabric, thereby increasing the volume content of the fabric fiber and thus improving the strength of the stitched fabric.

[0031] 7. The present invention adopts a method of removing the inner pressure plates corresponding to the sewing positions in sequence during sewing, so that the fabric will not be deformed due to the sewing force during sewing. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 is a schematic diagram of the structure of the suturing device;

[0033] Figure 2 It is a schematic diagram of the structure of the large support plate;

[0034] Figure 3 for Figure 2 Schematic diagram of the enlarged structure of the AA part;

[0035] Figure 4 It is a schematic diagram of the structure of the small support plate;

[0036] Figure 5 It is a schematic diagram of the top view of the stitching mold structure;

[0037] Figure 6 It is a schematic diagram of the three-dimensional structure of the inner pressure plate;

[0038] Figure 7 Schematic diagram of the three-dimensional structure of the outer pressure plate;

[0039] Figure 8 It is a schematic diagram of the design of the quasi-rotational fabric ply;

[0040] Fig. 9 for Figure 8 A magnified schematic diagram of the BB part structure;

[0041] Fig.10 Schematic diagram of unit layer segmentation;

[0042] Fig.11 Schematic diagram for suture trajectory planning;

[0043] Fig.12 for Fig.11 A magnified schematic diagram of the CC site structure;

[0044] Fig.13 It is a schematic diagram of the suturing operation of the suturing device;

[0045] Fig.14A flow chart for sewing quasi-rotational fabrics;

[0046] In the figure, 1 is a T-slot workbench; 2 is a connecting base plate; 3 is a three-jaw chuck; 4 is an optical axis; 5 is an optical axis fixing seat;

[0047] 6 is a large support plate; 6-1 is a clamping connection portion of the large support plate; 6-2 is a fabric support portion of the large support plate; 6-3 is a wire screw sleeve;

[0048] 7 is a sewing mold; 7-1 is an inner pressure plate; 7-2 is an outer pressure plate;

[0049] 8 is a small support plate; 8-1 is a clamping connection part of the small support plate; 8-2 is a fabric connection part of the small support plate;

[0050] 9 is a quasi-rotation fabric; 9-1 is a 30° split point; 9-2 is a 100° split point; 9-3 is a 330° split point; 9-4 is a 130° split point; 9-5 is a 270° split point; 9-6 is a 70° split point; 9-7 is a 210° split point;

[0051] 10 is a unit layer; 11 is a suture track; 12 is a suture ruler; 13 is a fiber suture line; 14 is a suture needle; 15 is a bottom line; 16 is a hook needle; and 17 is a punching needle. DETAILED DESCRIPTION

[0052] In order to further disclose the content, features and effects of the present invention, the following examples are given and described in detail with reference to the accompanying drawings.

[0053] Example:

[0054] See attached Figure 1-7 A sewing device for a quasi-revolving fabric with a narrow cavity, comprising a clamping and fixing device, a supporting device and a sewing mold 7; the supporting device is installed on the optical axis 4 of the clamping and fixing device, and the supporting device comprises a large supporting plate 6 and a small supporting plate 8; the sewing mold 7 is installed between the large supporting plate 6 and the small supporting plate 8, and the sewing mold 7 comprises an inner pressure plate 7-1 and an outer pressure plate 8-1; during the sewing process, the inner pressure plate 7-1 and the outer pressure plate 8-1 clamp the quasi-revolving fabric 9 to be sewn in the middle, and the large supporting plate 6 and the small supporting plate 8 are respectively installed at the upper and lower ends of the quasi-revolving fabric 9; the outer pressure plate 7-2 is provided with equidistant straight grooves for the fiber sewing line 13 to pass through the quasi-revolving fabric 9. The large supporting plate 6, the small supporting plate 8, the inner pressure plate 7-1 and the outer pressure plate 7-2 are all made of resin based by 3D printing technology according to the shape of the quasi-revolving fabric 9.

[0055] like Figure 1As shown, the clamping and fixing device also includes a T-slot workbench 1, a connecting base plate 2, a three-jaw chuck 3, an optical axis 4 and a group of optical axis fixing seats 5. The connecting base plate 2 is fixed on the T-slot workbench 1 through T-nuts and bolts, the three-jaw chuck 3 is connected to the connecting base plate 2 through bolts, and the optical axis 4 is fixed on the T-slot workbench 1 through the three-jaw chuck 3, and the overall translation and rotation can be achieved according to needs; the shaft end of the optical axis fixing seat 5 is provided with two double-cut edge openings and two threaded holes, and the optical axis fixing seat 5 is fixedly clamped on the optical axis 4 by hexagonal bolts, and the position of the optical axis fixing seat 5 on the optical axis 4 can be adjusted according to needs, so as to adjust the position of the supporting device and the stitching mold 7 up and down; the base of the optical axis fixing seat 5 is provided with four light holes, and the optical axis fixing seat 5 is connected to the large support plate 6 or the small support plate 8.

[0056] like Figure 1-Figure 4 As shown, the large support plate 6 includes a large support plate clamping connection part 6-1 and a large support plate fabric support part 6-2; the small support plate 8 includes a small support plate clamping connection part 8-1 and a small support plate fabric support part 8-2; the large support plate clamping connection part 6-1 and the small support plate clamping connection part 8-1 are both provided with an optical axis hole having the same diameter as the optical axis 4, which is used to be mounted on the optical axis 4; four light holes are provided around the optical axis hole, which are the same in size and position as the four light holes provided on the base of the optical axis fixing seat 5, and are connected and fixed to the optical axis fixing seat 5 by matching hexagonal bolts and hexagonal nuts; the large support plate fabric support part 6-2 and the small support plate fabric support part 8-2 are both inlaid with wire screw sleeves 6-3, and the inner pressure plate 7-1 and the outer pressure plate 7-2 of the sewing mold 7 are detachably installed by connecting the hexagonal bolts and the wire screw sleeves.

[0057] like Figure 5-Figure 7 As shown, the inner pressure plate 7-1 is divided into 23 pieces, which is convenient for segmented removal during sewing, thereby facilitating fabric sewing; the inner pressure plate 7-1 fits the inner cavity of the quasi-revolving fabric 9 after assembly; the outer pressure plate 7-2 is divided into 6 pieces, which are respectively three large curved surface positions and three corner positions connected by the curved surfaces, which are convenient for installation and compression to adjust the fabric thickness, and at the same time, it is convenient to open a straight-mouth groove on the outer pressure plate 7-2 to provide a sewing position, thereby facilitating ensuring the sewing line spacing; the outer pressure plate 7-2 fits the outer surface of the quasi-revolving fabric 9 after assembly; The thickness of the inner pressure plate 7-1 and the outer pressure plate 7-2 are both 10mm; the inner pressure plate 7-1 and the outer pressure plate 7-2 are provided with through holes that are staggered and connected to the large support plate fabric support part 6-2 and the small support plate fabric support part 8-2; the fabric thickness is compressed and controlled by adjusting the regulating bolts connecting the outer pressure plate 7-2 with the large support plate fabric support part 6-2 and the small support plate fabric support part 8-2; the straight groove on the outer pressure plate 7-2 is 3mm wide, and the distance between adjacent grooves is 5mm.

[0058] See attached Figure 1-14 The present invention also provides a method for sewing a type of rotating fabric with a narrow cavity, using the above-mentioned sewing device, comprising the following steps: S1 designing fabric layup, S2 laying carbon fiber widening cloth, S3 planning sewing trajectory and S4 sewing the type of rotating fabric.

[0059] The S1 design fabric ply includes S1-1 ply design and S1-2 carbon fiber spread fabric cutting. First, S1-1 uses relevant design software to draw the shape of the upper and lower ends of the quasi-revolving fabric 9, divides the quasi-revolving fabric 9 into six unit layers 10 at equal intervals according to thickness, and then imports the above-drawn quasi-revolving fabric ply plan design drawing into another design software to loft it layer by layer into a three-dimensional graphic, and each unit layer 10 is divided and flattened in turn at seven equally divided positions of 30° division point 9-1 to 210° division point 9-7. Since the curvature of the quasi-revolving fabric 9 at the corner position is large, the carbon fiber widening cloth is relatively flat and it is difficult to fit the large curvature shape at the corner position. At the same time, the corner position of the quasi-revolving fabric 9 is subjected to large force during application, so the corner position is avoided, and the ply cuts of each layer of widening cloth skip the large curvature corner position; the ply division position of each layer is set according to the surface intersection, and the cuts of each layer are staggered, and are divided and flattened in turn according to the laying angles of 30 degrees, 100 degrees, 330 degrees, 130 degrees, 270 degrees, 70 degrees, and 210 degrees. This design of the splitting position avoids the incision affecting the overall thickness of the quasi-rotational fabric 9, and at the same time avoids the relatively weak performance of the overlap position caused by the overlap of the incisions of each layer when the carbon fiber widened cloth is laid. Then S1-2 exports each unit layer 10 split and flattened in S1-1 as a two-dimensional graph, marks each unit layer splitting position, writes a cutting program based on the flattened layer model, and uses the cutting table to cut the structure into a plain weave with a grid width of 16 mm and a surface density of 100 g / m 2 , and cut the carbon fiber stretched cloth with a thickness of 0.12mm.

[0060] Among them, the S2 laying of carbon fiber widening cloth includes the assembly of the sewing mold inner pressure plate 7-1, the laying of carbon fiber widening cloth and the assembly of the sewing mold outer pressure plate 7-2. First, assemble the sewing mold inner pressure plate 7-1, arrange the 23 sewing mold inner pressure plates a1-a23 according to the inner cavity shape of the quasi-rotational fabric 9 to be sewn, and connect them with the wire screw sleeve 6-3 in turn through bolts, and install them on the inner side of the large support plate fabric support part 6-2 and the small support plate fabric support part 8-2; then lay each unit layer 10 of the cut carbon fiber widening cloth in S1-2 on the sewing mold inner pressure plate 7-1 according to the layer design, and ensure that the widening cloth is tightly fitted with the sewing mold inner pressure plate 7-1 or the previous layer of widening cloth during laying.

[0061] Since the quasi-rotational fabric 9 and the inner pressure plate 7-1 of the sewing mold are irregular quasi-rotational structures with negative curvature areas, and the carbon fiber spread cloth is relatively flat and has a certain toughness, the spread cloth cannot fit tightly when laid. Therefore, when laying the first layer of spread cloth, a slender sewing needle 14 with a fiber sewing thread 13 is passed through the gap between the inner pressure plate 7-1 and the hollow inner cavity to sew and tighten the two sides of the spread cloth laid on the inner pressure plate 7-1 to fix it on the inner pressure plate 7-1 of the sewing mold 7. After that, when laying each layer of spread cloth, a curved needle pre-sewing method is used to sew and connect it with the laid spread cloth. After all the spread cloths are laid, all the pre-sewn fiber sewing threads 13 are pulled out, so as to achieve the purpose of making the spread cloth fit tightly to the inner pressure plate 7-1 of the sewing mold 7 or the previous layer of spread cloth. After the widened cloth is laid, the outer pressure plate 7-2 of the sewing mold 7 is assembled, and the six outer pressure plates b1-b6 of the sewing mold 7 are arranged according to the outer surface shape of the quasi-revolving fabric 9 to be sewn, and are connected to the wire screw sleeve 6-3 in turn through adjusting bolts, and installed on the outside of the large support plate fabric support part 6-2 and the small support plate fabric support part 8-2, and the thickness of the quasi-revolving fabric 9 is controlled by compression with adjustable bolts.

[0062] Among them, the S3 plans the suture trajectory: the suture point spacing is set according to the technical requirements, the suture ruler 12 with the set interval is printed, and after cutting into strips, it is pasted on the partition between two adjacent straight-mouth grooves on the outer pressure plate 7-2 of the suture mold 7, so that suture can be performed along the length direction of the groove according to the suture ruler 12, thereby controlling the distance between the suture points.

[0063] Wherein, the S4 stitched rotary fabric: Fig.14 As shown, according to the planned sewing trajectory, the quasi-revolving fabric 9 is sewn as a whole using a new improved lock-type sewing method. When sewing, the inner pressure plates a1-a23 corresponding to the sewing positions are removed, and the fabric 9 is sewn in sequence at the opening slot positions according to the marks on the sewing scale 12. First, a pre-set hole is punched at the sewing point using a punching needle 17, and then a sewing needle 14 with a fiber sewing thread 13 is introduced into the quasi-revolving fabric 9 along the pre-made hole to form a thread loop, and a thread hooking needle 16 is used to hook the thread loop out of the large end opening of the quasi-revolving fabric 9, and after being tied with the bottom thread 15 reserved outside the sewing mold 7, the fiber sewing thread 13 is brought out by the sewing needle 14 for the next cycle, thereby sewing the quasi-revolving fabric 9.

[0064] Although the preferred embodiments of the present invention are described above, the present invention is not limited to the above specific embodiments, which are merely illustrative and not restrictive. Under the guidance of the present invention, a person skilled in the art can make many forms without departing from the scope of the present invention and the claims. All of these belong to the protection scope of the present invention.

Claims

1. A sewing device for rotating fabrics with narrow cavities, characterized in that: It includes a clamping and fixing device, a supporting device and a sewing mold; a supporting device is installed on the optical axis of the clamping and fixing device, and the supporting device includes a large supporting plate and a small supporting plate; a sewing mold is installed between the large supporting plate and the small supporting plate, and the sewing mold includes an inner pressure plate and an outer pressure plate; during the sewing process, the inner pressure plate and the outer pressure plate clamp the quasi-revolving fabric to be sewn in the middle, and the small supporting plate and the large supporting plate are respectively installed at the upper and lower ends of the quasi-revolving fabric; the outer pressure plate is provided with equidistant straight grooves for the fiber sewing line to pass through the quasi-revolving fabric.

2. A sewing device for rotating fabrics with narrow cavities according to claim 1, characterized in that: The clamping and fixing device also includes a T-slot workbench, a connecting base plate, a three-jaw chuck, an optical axis and a group of optical axis fixing seats; the connecting base plate is fixedly mounted on the T-slot workbench, the three-jaw chuck is connected to the connecting base plate, and the optical axis is fixed on the T-slot workbench through the three-jaw chuck; the shaft end of the optical axis fixing seat is provided with two double-cut edge openings and two threaded holes, and the optical axis fixing seat is connected to the large support plate or the small support plate and fixedly clamped on the optical axis.

3. The sewing device for rotating fabrics with narrow cavities according to claim 1, characterized in that: The large support plate and the small support plate both include a clamping connection part, a fabric support part and a wire screw sleeve; the clamping connection part is provided with an optical axis hole which is equal to the diameter of the optical axis, and is sleeved on the optical axis through the optical axis hole; four optical holes are provided around the optical axis hole, which are the same in size and position as the four optical holes provided on the base of the optical axis fixing seat, and are connected and fixed to the optical axis fixing seat through matching hexagonal bolts and hexagonal nuts; the fabric support part is inlaid with a wire screw sleeve, and the inner pressure plate and the outer pressure plate of the sewing mold are detachably installed through the connection between the hexagonal bolts and the wire screw sleeve.

4. The sewing device for rotating fabrics with narrow cavities according to claim 1, characterized in that: The inner pressure plate is divided into 23 pieces, which fit with the inner cavity of the quasi-revolving fabric after assembly; the outer pressure plate is divided into 6 pieces, which are three large curved surface positions and three corner positions connected to the curved surfaces. After assembly, the outer pressure plate fits with the outer surface of the quasi-revolving fabric.

5. A method for sewing a rotating fabric with a narrow cavity, using the sewing device according to any one of claims 1 to 4, characterized in that: The following steps are involved: S1. Design fabric layup: Design fabric layup according to the shape, thickness, size of the quasi-rotational fabric and the specifications of the carbon fiber spread fabric; cut the carbon fiber spread fabric according to the layup design to form a spread fabric of appropriate size; S2. Laying the carbon fiber spreader cloth: Assemble the inner pressure plate of the stitching mold, and lay each unit layer of the carbon fiber spreader cloth on the inner pressure plate of the stitching mold in sequence according to the layer design. After the spreader cloth is laid, assemble the outer pressure plate of the stitching mold; S3, planning the suture track: setting the interval between suture points, printing a suture ruler with set intervals, cutting the suture ruler into strips, and sticking them on the partition between two adjacent straight grooves of the outer pressing plate of the suture mold; S4, stitching the quasi-revolving fabric: according to the stitching trajectory planned in S3, the quasi-revolving fabric is stitched as a whole by using an improved lock stitching method in which pre-made holes are first punched and the bottom line is passed outside.

6. A method for sewing a rotating fabric with a narrow cavity according to claim 5, characterized in that: The S1 specifically includes S1-1 ply design and S1-2 carbon fiber spread cloth cutting; S1-1 uses relevant design software to draw the upper and lower end view shapes of the quasi-revolving fabric, divides the quasi-revolving fabric into N unit layers at equal intervals according to thickness to obtain a ply plane design drawing, and then imports it into another design software to loft it layer by layer into a three-dimensional graphic, and divides and flattens each unit layer; S1-2 exports each unit layer divided and flattened in S1-1 into a two-dimensional graphic, marks each graphic with a unit layer division position, writes a cutting program for a cutting table according to the flattened ply model, and uses the cutting table to cut the carbon fiber spread cloth.

7. A method for sewing a rotating fabric with a narrow cavity according to claim 6, characterized in that: In S1-1, each unit layer is split and flattened, and the split position of each layer is set according to the cross-plane, and the cuts of each layer are staggered. The layers are split and flattened in sequence according to the laying angles of 30 degrees, 100 degrees, 330 degrees, 130 degrees, 270 degrees, 70 degrees, and 210 degrees. The structure of the carbon fiber widening cloth in S1-2 is a plain weave, and the specifications of the widening cloth are a grid width of 8 to 9 mm and a surface density of 200 to 205 g / m 2 Or grid width 16 ~ 17mm, surface density 100 ~ 105g / m 2 Or the grid width is 20-21mm, the surface density is 80-85g / m 2 .

8. The method for sewing a rotating fabric with a narrow cavity according to claim 6, characterized in that: The carbon fiber widening cloth in S2 is laid, first assemble the inner pressure plate of the stitching mold, arrange 23 inner pressure plates according to the shape of the inner cavity of the stitched fabric, connect them with wire screw sleeves in sequence through bolts, and install them on the inner side of the fabric supporting part of the large support plate and the small support plate; then lay each unit layer of the carbon fiber widening cloth cut in S1-2 on the inner pressure plate in sequence according to the layer design, and ensure that the widening cloth is tightly fitted with the inner pressure plate or the upper layer of widening cloth during laying; after the widening cloth is laid, assemble the outer pressure plate, arrange 6 outer pressure plates according to the shape of the outer surface of the stitched fabric, connect them with wire screw sleeves in sequence through regulating bolts, install them on the outer side of the fabric supporting part of the large support plate and the small support plate, and control the thickness of the fabric by compressing with adjustable bolts.

9. A method for sewing a rotating fabric with a narrow cavity according to claim 8, characterized in that: When laying in S2, the carbon fiber spread cloth is closely fitted with the inner pressure plate of the sewing mold or the previous layer of spread cloth. When laying the first layer of spread cloth, a slender sewing needle with a fiber suture line is passed through the gap between the inner pressure plates and the hollow inner cavity to sew and tighten the two sides of the spread cloth laid on the inner pressure plate to fix it on the inner pressure plate of the sewing mold. After that, when laying each layer of spread cloth, a curved needle pre-sewing method is used to sew and connect it with the laid spread cloth. After all the spread cloths are laid, all the pre-sewn fiber suture lines are pulled out to make the spread cloth closely fit the inner pressure plate of the sewing mold or the previous layer of spread cloth.

10. The method for sewing a rotating fabric with a narrow cavity according to claim 5, characterized in that: The S4 specifically includes removing the inner pressure plate corresponding to the stitching position during stitching, and stitching the fabric in sequence at the opening groove position according to the marks on the stitching ruler; first, using a punching needle to punch a prefabricated hole at the stitching point, and then introducing a stitching needle with a fiber stitching thread into the fabric along the prefabricated hole to form a thread loop, and using a hooking needle to hook the thread loop out of the opening at the large end of the fabric, and after tying it with the bottom thread reserved outside the stitching mold, the stitching needle then brings the fiber stitching thread out for the next cycle, thereby stitching the fabric.

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