Special stitching equipment for high-performance fiber conical sleeve variable cross-section preform

Abstract

The application discloses a special stitching device for high-performance fiber conical sleeve variable cross-section preform, which comprises a stitching head, a conical preform clamp and a four-degree-of-freedom feeding workbench. The stitching head comprises a rack and a lead mechanism, a threading mechanism, a tension control mechanism, a pressing mechanism, a main shaft and a driving mechanism arranged on the rack. The four-degree-of-freedom feeding workbench is located below the front end of the stitching head, and the conical preform clamp is arranged on the four-degree-of-freedom feeding workbench. The relative movement of the preform and the stitching head can be realized through the cooperation of the conical preform clamp and the four-degree-of-freedom feeding workbench, and the required threading path can be obtained by setting the program to control the movement track of the four-degree-of-freedom feeding workbench, so that the stitching effect is ensured. The application improves the automation degree of the high-performance fiber conical sleeve variable cross-section preform stitching technology, expands the application range of the composite preform, effectively improves the working efficiency of the preform processing, reduces the cost and improves the economic benefits.

Description

Technical Field

[0001] This invention belongs to the field of three-dimensional stitching technology for high-performance fiber composite materials, and specifically relates to a special stitching device for a high-performance fiber conical sleeve variable cross-section preform. Background Technology

[0002] Currently, the stitching of heavy, irregularly shaped high-performance composite material preforms has always been a technical challenge in the field of three-dimensional stitching of high-performance fiber composite materials. Whether it is the sewing equipment already on the market or the publicly available information and literature, there is almost no technical solution that can perfectly overcome this technical challenge.

[0003] Looking at existing sewing equipment, for example, the sewing machine developed by Zhejiang Huibao Sewing Machine Co., Ltd., a domestic enterprise, has a maximum stitch thickness of only 20mm; another example is the Tufting sewing head, which was jointly developed by the German DLR Institute for Structural Mechanics and KSL GmbH. Although it is in an internationally leading position in the industrial production and scientific research of composite materials, it is difficult to effectively sew thick carbon / carbon composite materials because it uses a single-sided sewing method.

[0004] Based on publicly available patent documents, for example, the Chinese utility model patent CN207347761U, "A Comprehensive Feeding Thick Material Sewing Machine," while achieving automatic feeding, cannot sew prefabricated bodies with variable cross-sections. Another example is the Chinese utility model patent CN215713860U, "An Automatic Thick Material Sewing Mechanism," which, while enabling independent synchronous rotation of the machine head spindle and the rotary hook spindle to improve sewing quality and precision, is only suitable for flat fabrics and cannot sew irregularly shaped curved prefabricated bodies. Yet another example is the Chinese invention patent CN116479588A, "A Long-Arm Thick Material Sewing Device," which, while capable of sewing conical carbon / carbon composite materials with a thickness of 50mm or more, does not mention how to clamp and move the conical sewing material.

[0005] Therefore, the current stitching methods for heavy, irregularly shaped high-performance composite material preforms are mostly still in the manual or semi-manual stage, which cannot meet the needs of the widespread industrial application of high-performance composite materials and seriously limits the application of high-performance composite materials. Summary of the Invention

[0006] Based on this, the present invention provides a special sewing device for high-performance fiber conical sleeve variable cross-section preforms to meet the sewing requirements of composite material preforms with hollow cylinder and hollow cone shapes.

[0007] To solve the above-mentioned technical problems and achieve the above-mentioned technical effects, the present invention is implemented through the following technical solution: A special sewing device for high-performance fiber conical sleeve variable cross-section prefabricated bodies includes a sewing head, a conical prefabricated body clamp, and a four-degree-of-freedom feeding table. The four-degree-of-freedom feeding table is located below the front end of the sewing head, and the conical prefabricated body clamp is mounted on the four-degree-of-freedom feeding table. The conical prefabricated body clamp is used to hold the sewing material, and the four-degree-of-freedom feeding table is used to move the sewing material through the conical prefabricated body clamp to obtain the required stitching path. The sewing head is used to sew the sewing material located on the conical prefabricated body clamp.

[0008] Furthermore, the sewing machine head includes a thread guiding mechanism, a thread threading mechanism, a tension control mechanism, a pressing mechanism, an upper spindle, a drive mechanism, and a frame; the thread guiding mechanism, the thread threading mechanism, the tension control mechanism, the pressing mechanism, the upper spindle, and the drive mechanism are all mounted on the frame. The thread guiding mechanism is used to pierce the sewing fabric and introduce the top thread into the lower surface of the sewing fabric to form a thread loop; the thread threading mechanism is used to hook and enlarge the thread loop and feed in the bobbin thread; the tension control mechanism is used to control the tension of the sewing thread to form a stable stitch; the pressing mechanism is used to press down on the sewing joint of the sewing fabric; the drive mechanism is used to directly or indirectly drive the thread guiding mechanism, the thread threading mechanism, the tension control mechanism, and the pressing mechanism to move via the upper spindle.

[0009] Furthermore, the tension control mechanism includes a tension control cam, a tension rod, and a roller. The tension control cam is located at the front end of the upper spindle. A tension adjustment groove is formed on the circumferential surface of the tension control cam, and the trajectory of the tension adjustment groove undulates along the axial direction of the tension control cam. The roller is rotatably disposed within the tension adjustment groove. The tension rod is L-shaped, with its long side serving as a thread take-up portion, extending forward and having a thread eye at its front end. The short side of the tension rod is an adjustment portion, with a tension rod pin at its end. One end of the tension rod pin is rotatably connected to the roller, and the other end is rotatably connected to the frame. The tension rod is hinged to the frame via the tension rod pin. The roller undulates back and forth with the rotation of the tension control cam via the tension adjustment groove. When the tension rod is hinged to the frame, it undulates up and down through the back-and-forth movement of the roller, thereby controlling the stitch tension to form a stable stitch.

[0010] Furthermore, the thread-leading mechanism includes a needle bar connecting rod seat, a needle bar connecting rod, a needle bar slider, a needle bar, and a needle. The needle bar connecting rod seat is disposed on the front end face of the tension control cam. One end of the needle bar connecting rod is hinged to one side of the front surface of the needle bar connecting rod seat via an upper pin, and the other end of the needle bar connecting rod is hinged to the outer surface of the needle bar slider via a lower pin. The needle bar is vertically fixed in the needle bar slider, and the needle is disposed at the bottom end of the needle bar. The needle bar is hinged to the needle bar connecting rod seat via the upper pin, the needle bar connecting rod, and the lower pin. The needle bar connecting rod drives the needle to move up and down as the tension control cam rotates, thereby piercing the fabric and introducing the top thread into the lower surface of the fabric to form a thread loop.

[0011] Furthermore, the threading mechanism includes a swing shaft eccentric wheel, a swing shaft connecting rod, a swing shaft, a clamping plate, a lower main shaft connector, a lower main shaft slider, a lower main shaft, and a swing hook. The swing shaft eccentric wheel is located at the rear of the upper main shaft. The upper end of the swing shaft connecting rod is hinged to the swing shaft eccentric wheel, and the lower end of the swing shaft connecting rod is hinged to the center hole of the swing shaft. The swing shaft is parallel to the upper main shaft, and the rear end of the swing shaft is hinged to the frame. The clamping plate is located at the front end of the swing shaft, and is provided by two clamping plates. The lower spindle slider is described above. The rear end of the lower spindle is hinged to the lower spindle slider via the lower spindle connector. The lower spindle is parallel to the upper spindle. The swing hook is located at the front end of the lower spindle. With the cooperation of the eccentric wheel of the swing shaft, the swing shaft connecting rod, the swing shaft, the clamping plate, the lower spindle connector, the lower spindle slider, and the lower spindle, the full rotation of the upper spindle is converted into the reciprocating swing of the swing hook, thereby hooking and enlarging the loop and feeding the bottom line.

[0012] Furthermore, a threading mechanism base is provided on the outside of the threading mechanism, and a threaded hole is provided on the frame. The threading mechanism base is fixedly connected to the frame by bolts. The cross-section of the threading mechanism base is hollow and circular. The threading mechanism base includes a shuttle cover, a swing hook guide ring seat and a needle plate. The shuttle cover is fixed to the front end of the threading mechanism base. The swing hook guide ring seat is installed inside the circular cavity of the threading mechanism base. The needle plate is installed on the top of the threading mechanism base.

[0013] Furthermore, the pressing mechanism includes a pressing lifting eccentric wheel, a pressing lifting connecting rod, a pressing lifting adjusting crank, a pressing lifting shaft, a pressing lifting crank, a pressing lifting front connecting rod, a swinging rocker, a swinging small connecting rod, an inner pressing clamping rod, a small pressure foot, a clamping rod sliding block, a clamping rod, and a large pressure foot. The pressing lifting eccentric wheel is located at the front of the upper main shaft and after the tension control cam. One end of the pressing lifting connecting rod is hinged to the pressing lifting eccentric wheel, and the other end of the pressing lifting connecting rod is hinged to the pressing lifting adjusting crank by a screw. The pressing lifting adjusting crank is fixedly connected to the rear end of the pressing lifting shaft, the front end of the pressing lifting shaft is fixedly connected to the upper end of the pressing lifting crank, the lower end of the pressing lifting crank is hinged to the upper end of the pressing lifting front connecting rod, and the lower end of the pressing lifting front connecting rod is hinged to the lower left end hole of the swinging rocker. The upper right end hole of the swing rocker is hinged to the upper end of the swing small connecting rod, the lower end of the swing small connecting rod is hinged to the upper end of the inner pressing material clamping rod, the small presser foot is located at the bottom end of the inner pressing material clamping rod, the upper left end hole of the swing rocker is hinged to the pressing rod sliding block, the pressing rod is fixedly connected to the pressing rod sliding block, the large presser foot is located at the bottom end of the pressing rod, and the small presser foot is located in the large presser foot (I413); with the cooperation of the pressing material lifting eccentric wheel, the pressing material lifting connecting rod, the pressing material lifting adjusting crank, the pressing material lifting shaft, the pressing material lifting crank, the pressing material lifting front connecting rod, the swing rocker, the swing small connecting rod, the inner pressing material clamping rod, the pressing rod sliding block, and the pressing rod, the full rotation of the upper main shaft is converted into the up-and-down reciprocating motion of the small presser foot and the large presser foot, thereby pressing down the seam of the sewing material.

[0014] Furthermore, the drive mechanism includes an upper spindle drive motor, a transmission belt, a driving pulley, and a driven pulley. The upper spindle drive motor is mounted on the frame, the driving pulley is mounted on the output shaft of the upper spindle drive motor, the driven pulley is mounted at the rear end of the upper spindle, and the transmission belt is wound between the driving pulley and the driven pulley.

[0015] Furthermore, a housing is provided on the outside of the upper spindle, the rear end of the housing is fixedly connected to the frame, and the front end of the housing is rotatably connected to the front part of the upper spindle.

[0016] Furthermore, the four-degree-of-freedom feeding table includes a table base, on which a sliding plate movable along the X-axis under the drive of a first servo motor is provided. A lifting plate movable along the Z-axis under the drive of a second servo motor is provided on the sliding plate. A tilting plate rotatable around the Y-axis under the drive of a third servo motor is provided on the lifting plate. A fourth servo motor for driving the conical preform fixture to rotate around the X-axis is provided on the tilting plate. The upper surface of the tilting plate has a first arc-shaped recess and a second arc-shaped recess to facilitate the rotation of the conical preform fixture. The conical prefabricated fixture is used to clamp the variable cross-section irregular prefabricated body to be sewn and drive it to rotate around the X-axis; the flipping plate is used to drive the variable cross-section irregular prefabricated body to be sewn to rotate around the Y-axis; the lifting plate is used to drive the variable cross-section irregular prefabricated body to be sewn to move along the Z-axis; the sliding plate is used to drive the variable cross-section irregular prefabricated body to be sewn to move along the X-axis; the first servo motor, the second servo motor, the third servo motor, and the fourth servo motor are all under the comprehensive control of the controller, thereby realizing the linkage of the sliding plate, the lifting plate, the flipping plate, and the conical prefabricated fixture.

[0017] Furthermore, the conical preform fixture includes a turntable rotatably supported on the first arc-shaped concave platform and a conical support body disposed between the first and second arc-shaped concave platforms. The left end of the turntable is connected to the fourth servo motor for transmission. A conical pressure sleeve is disposed at the center of the right side of the turntable. The conical tip of the conical support body is aligned with the conical pressure sleeve. The open end of the conical support body is rotatably supported on the second arc-shaped concave platform. The circumference of the open end of the conical support body and the circumference of the turntable are fixedly connected by four parallel connecting columns. Two gripper structures are disposed on the circumference of the open end of the conical support body. Arc-shaped moving plates are disposed on both sides of the conical support body. The two arc-shaped moving plates are synchronously moved outward or inward on both sides of the conical support body through a spacing adjustment mechanism.

[0018] The beneficial effects of this invention are as follows: The special sewing equipment of the present invention can realize the relative movement of the preform with the sewing machine head by clamping the conical preform clamp and moving the four-degree-of-freedom feeding table. Furthermore, the required stitching path can be obtained by controlling the movement trajectory of the four-degree-of-freedom feeding table through a set program, thereby ensuring the sewing effect.

[0019] The special sewing equipment of this invention uses a double-sided sewing method to sew high-performance fiber conical sleeve variable cross-section preforms. Using an improved lockstitch process, the knot between the top and bottom threads is placed on the surface of the sewing material. The stress generated by the improved lockstitch is on the surface of the sewing material, without affecting the interlayer performance of the preform.

[0020] The special sewing equipment of this invention can sew together thick, high-performance composite material preforms with irregular cross-sections ranging from 5 to 40 mm in thickness, thereby enhancing the mechanical properties of the composite material preforms. This special sewing equipment is not limited to a thickness of 40 mm; it can also be used to sew together 100 mm thick conical sleeve preforms with irregular cross-sections, as well as cylindrical, frustum-shaped, and irregularly shaped annular bodies.

[0021] The special sewing equipment of this invention improves the automation level of high-performance fiber conical sleeve variable cross-section preform sewing technology, expands the application range of composite material preforms, and can effectively improve the working efficiency of preform processing, reduce costs, and improve economic benefits.

[0022] The above description is merely an overview of the technical solution of the present invention. In order to better understand the technical means of the invention and to implement it according to the contents of the specification, the preferred embodiments of the present invention are described in detail below with reference to the accompanying drawings. Specific embodiments of the present invention are given in detail below with reference to the accompanying drawings. Attached Figure Description

[0023] The accompanying drawings, which are included to provide a further understanding of the invention and form part of this application, illustrate exemplary embodiments of the invention and, together with their description, serve to explain the invention and do not constitute an undue limitation thereof. In the drawings: Figure 1 This is a schematic diagram of the overall structure of the present invention.

[0024] Figure 2 This is a three-dimensional structural diagram of the suture head of the present invention.

[0025] Figure 3 This is a schematic diagram of the lead wire mechanism of the present invention.

[0026] Figure 4 This is a schematic diagram of the threading mechanism of the present invention.

[0027] Figure 5 This is a schematic diagram of the tension control mechanism of the present invention.

[0028] Figure 6 This is a schematic diagram of the pressing mechanism of the present invention.

[0029] Figure 7 This is a three-dimensional structural diagram of the four-degree-of-freedom worktable and conical prefabricated fixture assembly of the present invention.

[0030] Figure 8 This is a front view of the four-degree-of-freedom worktable and conical prefabricated fixture assembly of the present invention.

[0031] Figure 9This is a right view of the four-degree-of-freedom worktable and conical prefabricated fixture assembly of the present invention.

[0032] Figure 10 This is a cross-sectional view of the connection relationship between the base and the sliding plate in the four-degree-of-freedom worktable of the present invention.

[0033] Figure 11 This is a three-dimensional structural diagram of the conical preform fixture of the present invention.

[0034] Figure 12 This is a perspective view of the gripper structure of the conical preform fixture of the present invention.

[0035] Figure 13 This is a schematic diagram of the structure of the conical preform stitched together according to the present invention.

[0036] Figure 14 This is a cross-sectional schematic diagram of the conical preform stitched together according to the present invention.

[0037] Figure 15 These are the contour curve and model diagram of the tension control cam of the present invention, wherein... Figure 15 a is the contour curve diagram. Figure 15 b is the model diagram.

[0038] Figure 16 This is a simplified diagram of the lead wire mechanism of the present invention.

[0039] Figure 17 This is a simplified diagram of the threading mechanism of the present invention.

[0040] Figure 18 It is a graph showing the displacement curve of the needle eye and the hook tip of the shuttle along the y-axis.

[0041] Figure 19 This is a schematic diagram showing how the shuttle hook tip can hook the line loop at different deflection angles. Figure 19 a is a schematic diagram of hooking the swivel when the hook tip is deflected by 20°. Figure 19 b is a schematic diagram of hooking the swivel when the hook tip is deflected by 15°. Figure 19 c is a schematic diagram of hooking the swivel when the hook tip is deflected by 10°. Figure 19 d is a schematic diagram of hooking the swivel when the hook tip is deflected by 5°.

[0042] Figure 20 It is the relative positional relationship between the hook tip of the shuttle and the eye of the needle in the y-axis direction under different initial deflection angles of the shuttle. Detailed Implementation

[0043] The preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings to provide a clearer understanding of the invention's purpose, features, and advantages. It should be understood that the embodiments shown in the drawings are not intended to limit the scope of the invention, but are merely illustrative of the essential spirit of the invention's technical solution.

[0044] In the following description, certain specific details are set forth for the purpose of illustrating various disclosed embodiments in order to provide a thorough understanding of the various disclosed embodiments. However, those skilled in the art will recognize that embodiments may be practiced without one or more of these specific details. In other instances, well-known apparatuses, structures, and techniques associated with this application may not have been shown or described in detail to avoid unnecessarily obscuring the description of the embodiments.

[0045] Unless the context requires otherwise, throughout the specification and claims, the word “comprising” and its variations, such as “including” and “having”, shall be understood to have an open, inclusive meaning, that is, to be interpreted as “including, but not limited to”.

[0046] Throughout this specification, references to "an embodiment" or "an embodiment" indicate that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment. Therefore, the appearance of "in an embodiment" or "an embodiment" in various places throughout the specification does not necessarily refer to the same embodiment. Furthermore, a particular feature, structure, or characteristic may be combined in any manner in one or more embodiments.

[0047] The singular forms “a” and “the” used in this specification and the appended claims include plural references unless otherwise expressly stated herein. It should be noted that the term “or” is generally used to mean “and / or” unless otherwise expressly stated herein.

[0048] Furthermore, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0049] See Figure 1 As shown, a special sewing device for high-performance fiber conical sleeve variable cross-section prefabricated bodies includes a sewing head I, a conical prefabricated body clamp II, and a four-degree-of-freedom feeding table III. The four-degree-of-freedom feeding table III is located below the front end of the sewing head I, and the conical prefabricated body clamp II is mounted on the four-degree-of-freedom feeding table III. The conical prefabricated body clamp II is used to hold the sewing material, and the four-degree-of-freedom feeding table III is used to move the sewing material through the conical prefabricated body clamp II to obtain the required stitching path. The sewing head I is used to sew the sewing material located on the conical prefabricated body clamp II.

[0050] See Figure 2As shown, the sewing machine head I includes a thread guiding mechanism I1, a thread threading mechanism I2, a tension control mechanism I3, a pressing mechanism I4, an upper spindle I5, a drive mechanism I6, and a frame I7. The thread guiding mechanism I1, the thread threading mechanism I2, the tension control mechanism I3, the pressing mechanism I4, the upper spindle I5, and the drive mechanism I6 are all mounted on the frame I7. The thread guiding mechanism I1 is used to pierce the sewing material and introduce the top thread into the lower surface of the sewing material to form a thread loop; the thread threading mechanism I2 is used to hook and enlarge the thread loop and feed in the bobbin thread; the tension control mechanism I3 is used to control the tension of the sewing thread to form a stable stitch; the pressing mechanism I4 is used to press down on the sewing joint of the sewing material; the drive mechanism I6 is used to directly or indirectly drive the thread guiding mechanism I1, the thread threading mechanism I2, the tension control mechanism I3, and the pressing mechanism I4 through the upper spindle I5.

[0051] See Figure 5 As shown, the tension control mechanism I3 includes a tension control cam I301, a tension rod I302, and a roller I303. The tension control cam I301 is disposed at the front end of the upper main shaft I5, and a bushing is provided between the tension control cam I301 and the upper main shaft I5. A tension adjusting groove I304 is formed on the circumferential surface of the tension control cam I301, and the trajectory of the tension adjusting groove I304 undulates along the axial direction of the tension control cam I301. The roller I303 is rotatably disposed within the tension adjusting groove I304. The tension rod I302 is L-shaped, and the long side of the tension rod I302 is the thread take-up portion, which extends forward and... The tension bar I302 is provided with a thread eye at one end. The short side of the tension bar I302 is an adjustment part. The end of the adjustment part is provided with a tension bar pin I305. One end of the tension bar pin I305 is rotatably connected to the roller I303, and the other end of the tension bar pin I305 is rotatably connected to the frame I7. The tension bar I302 is hinged to the frame I7 through the tension bar pin I305. The roller I303 moves back and forth with the rotation of the tension control cam I301 through the tension adjustment wheel groove I304. When the tension bar I302 is hinged to the frame I7, it moves up and down through the back and forth movement of the roller I303, thereby controlling the thread tension to form a stable stitch.

[0052] See Figure 3As shown, the lead wire mechanism I1 includes a needle bar connecting rod seat I101, a needle bar connecting rod I102, a needle bar slider I103, a needle bar I104, and a needle I105. The needle bar connecting rod seat I101 is disposed on the front end face of the tension control cam I301. One end of the needle bar connecting rod I102 is hinged to one side of the front surface of the needle bar connecting rod seat I101 via an upper pin I106. The other end of the needle bar connecting rod I102 is hinged to the outer surface of the needle bar slider I103 via a lower pin I107. The needle bar I104... 104 is vertically fixed in the needle bar slider I103, and the needle I105 is disposed at the bottom end of the needle bar I104; the needle bar I104 is hinged to the needle bar connecting rod seat I101 through the upper pin I106 of the needle bar connecting rod, the needle bar connecting rod I102 and the lower pin I107 of the needle bar connecting rod; the needle bar connecting rod I102 drives the needle I105 to move up and down under the rotation of the needle bar connecting rod seat I101 with the tension control cam I301, thereby piercing the sewing fabric and introducing the top thread into the lower surface of the sewing fabric to form a thread loop.

[0053] See Figure 4 As shown, the threading mechanism I2 includes a swing shaft eccentric wheel I201, a swing shaft connecting rod I202, a swing shaft I203, a clamping plate I204, a lower main shaft connector I205, a lower main shaft slider I206, a lower main shaft I207, and a swing hook I208. The swing shaft eccentric wheel I201 is located at the rear of the upper main shaft I5. The upper end of the swing shaft connecting rod I202 is hinged to the swing shaft eccentric wheel I201, and the lower end of the swing shaft connecting rod I202 is hinged to the center hole of the swing shaft I203. The swing shaft I203 is parallel to the upper main shaft I5, and the rear end of the swing shaft I203 is hinged to the frame I7. The clamping plate I204 is located at the front end of the swing shaft I203, and the lower main shaft slider I206 is mounted on two clamping plates I204. 206. The rear end of the lower spindle I207 is hinged to the lower spindle slider I206 via the lower spindle connector I205. The lower spindle I207 is parallel to the upper spindle I5. The swing hook I208 is located at the front end of the lower spindle I207. A spool is provided inside the swing hook I208, and the spool is wound with a bottom thread. With the cooperation of the swing shaft eccentric wheel I201, the swing shaft connecting rod I202, the swing shaft I203, the clamping plate I204, the lower spindle connector I205, the lower spindle slider I206, and the lower spindle I207, the full rotation of the upper spindle I5 is converted into the reciprocating swing of the swing hook I208, thereby hooking and expanding the loop and feeding in the bottom thread.

[0054] See Figure 2As shown, a threading mechanism base I9 is ​​provided on the outside of the threading mechanism I2. The frame I7 is provided with threaded holes. The threading mechanism base I9 is ​​fixedly connected to the frame I7 by bolts. The cross-section of the threading mechanism base I9 is ​​hollow and circular. The threading mechanism base I9 includes a shuttle cover, a swing hook guide ring seat and a needle plate. The shuttle cover is fixed to the front end of the threading mechanism base I9. The swing hook guide ring seat is installed inside the circular cavity of the threading mechanism base I9. The needle plate is installed on the top of the threading mechanism base I9.

[0055] See Figure 6 As shown, the pressing mechanism I4 includes a pressing lifting eccentric wheel I401, a pressing lifting connecting rod I402, a pressing lifting adjusting crank I403, a pressing lifting shaft I404, a pressing lifting crank I405, a pressing lifting front connecting rod I406, a swinging rocker I407, a swinging small connecting rod I408, an inner pressing clamping rod I409, a small pressing foot I410, a clamping rod sliding block I411, a clamping rod I412, and a large pressing foot I413.

[0056] The pressure lifting eccentric wheel I401 is located at the front of the upper main shaft I5 and behind the tension control cam I301. One end of the pressure lifting connecting rod I402 is hinged to the pressure lifting eccentric wheel I401, and the other end of the pressure lifting connecting rod I402 is hinged to the pressure lifting adjusting crank I403 by screws. The pressure lifting adjusting crank I403 is fixedly connected to the rear end of the pressure lifting shaft I404. The front end of the pressure lifting shaft I404 is fixedly connected to the upper end of the pressure lifting crank I405. The lower end of the pressure lifting crank I405 is hinged to the upper end of the pressure lifting front connecting rod I406. The lower end of I406 is hinged to the lower left end hole of the swinging rocker I407, the upper right end hole of the swinging rocker I407 is hinged to the upper end of the swinging small connecting rod I408, the lower end of the swinging small connecting rod I408 is hinged to the upper end of the inner pressure material clamping rod I409, the small pressure foot I410 is located at the bottom end of the inner pressure material clamping rod I409, the upper left end hole of the swinging rocker I407 is hinged to the pressure rod sliding block I411, the pressure rod I412 is fixedly connected to the pressure rod sliding block I411, the large pressure foot I413 is located at the bottom end of the pressure rod I412, and the small pressure foot I410 is located in the large pressure foot I413. A spring is provided at the upper end of the pressure rod sliding block I411, an adjusting screw is provided at the upper end of the spring, and an adjusting nut is installed on the adjusting screw.

[0057] With the combined action of the pressing and lifting eccentric wheel I401, the pressing and lifting connecting rod I402, the pressing and lifting adjusting crank I403, the pressing and lifting shaft I404, the pressing and lifting crank I405, the pressing and lifting front connecting rod I406, the swinging rocker I407, the swinging small connecting rod I408, the inner pressing and pressing rod I409, the pressing rod sliding block I411, and the pressing rod I412, the full rotation of the upper main shaft I5 is converted into the up-and-down reciprocating motion of the small pressing foot I410 and the large pressing foot I413, thereby pressing down the seam of the sewing material.

[0058] See Figure 2 As shown, the drive mechanism I6 includes an upper spindle drive motor, a transmission belt, a drive pulley, and a driven pulley. The upper spindle drive motor is mounted on the frame I7, the drive pulley is mounted on the output shaft of the upper spindle drive motor, the driven pulley is mounted at the rear end of the upper spindle I5, and the transmission belt is wound between the drive pulley and the driven pulley.

[0059] See Figure 2 As shown, a large pressure foot I8 is provided on the outside of the upper spindle I5. The rear end of the large pressure foot I8 is fixedly connected to the frame I7, and the front end of the large pressure foot I8 is rotatably connected to the front of the upper spindle I5.

[0060] See Figure 7-10 As shown, the four-degree-of-freedom feeding worktable III includes a worktable base III1. A sliding plate III2, movable along the X-axis under the drive of a first servo motor III10, is mounted on the worktable base III1. A lifting plate III3, movable along the Z-axis under the drive of a second servo motor III15, is mounted on the lifting plate III3. A rotating plate III4, rotatable around the Y-axis under the drive of a third servo motor III17, is mounted on the rotating plate III4. A fourth servo motor III25, used to drive the conical preform fixture II to rotate around the X-axis, is mounted on the rotating plate III4. The conical preform fixture II is used to clamp the object to be sewn. The variable cross-section irregular prefabricated body is rotated around the X-axis; the flipping plate III4 is used to rotate the variable cross-section irregular prefabricated body to be sewn around the Y-axis; the lifting plate III3 is used to move the variable cross-section irregular prefabricated body to be sewn along the Z-axis; the sliding plate III2 is used to move the variable cross-section irregular prefabricated body to be sewn along the X-axis; the first servo motor III10, the second servo motor III15, the third servo motor III17, and the fourth servo motor III25 are all under the comprehensive control of the controller, thereby realizing the linkage of the sliding plate III2, the lifting plate III3, the flipping plate III4 and the conical prefabricated body clamp II.

[0061] The sliding plate III2 is slidably connected to the workbench base III1 via two parallel linear slide rails III6 on its lower surface. Two lead screw fixing seats III7 are arranged in series on the lower surface of the sliding plate III2 along the X-axis. A first lead screw III8 is installed in each of the two lead screw fixing seats III7. A first lead screw III9 is ​​passed through the two first lead screw III8. One end of the first lead screw III9 is ​​connected to the output shaft of the first servo motor III10. The first servo motor III10 drives the sliding plate III2 to move along the X-axis through the first lead screw III9 and the first lead screw III8.

[0062] The upper surface of the sliding plate III2 is provided with two first moving tracks III11a parallel to each other in the X-axis direction, and the lower surface of the lifting plate III3 is provided with two second moving tracks III11b parallel to each other in the X-axis direction. The two second moving tracks III11b correspond vertically to the two first moving tracks III11a. An X-shaped lifting bracket III12 is provided between the lifting plate III3 and the sliding plate III2. A second servo motor III15 is provided on one side of the X-shaped lifting bracket III12. The ends of the two first moving tracks III11a and the two second moving tracks III11b near the second servo motor III15 are provided with sliding grooves. Sliding first sliding rods III13a are provided in the sliding grooves of the two first moving tracks III11a, and sliding second sliding rods III13b are provided in the sliding grooves of the two second moving tracks III11b. The lower end of the X-shaped lifting bracket III12 near the second servo motor III15 is connected to the sliding plate III2. The first sliding rod III13a is hinged, and the upper end of the X-shaped lifting bracket III12 on the side near the second servo motor III15 is hinged to the second sliding rod III13b. The lower end of the X-shaped lifting bracket III12 on the side away from the second servo motor III15 is simultaneously hinged to the ends of the two first moving tracks III11a away from the second servo motor III15. The upper end of the X-shaped lifting bracket III12 on the side away from the second servo motor III15 is simultaneously hinged to the ends of the two second moving tracks III11b away from the second servo motor III15. A second lead screw III14 is provided in the middle of the first sliding rod III13a. One end of the second lead screw III14 is connected to the output shaft of the second servo motor III15. The second servo motor III15 drives the X-shaped lifting bracket III12 to extend and retract up and down through the second lead screw III14 and the second lead screw nut, thereby driving the lifting plate III3 to move along the Z-axis.

[0063] A vertical plate is provided at one end of the upper surface of the lifting plate III3. A rotary shaft III22, which can rotate around the Y-axis, is provided on the upper surface of the vertical plate via a rotary shaft bracket III23. The third servo motor III17 is vertically mounted on both sides of the other end of the lifting plate III3. The lower surface of the tilting plate III4 is provided with two parallel swing tracks III21 in the X-axis direction. One end of each swing track III21 is hinged to the rotary shaft III22, and the other end of each swing track III21 is provided with a groove. A swing rod III20 is provided in the groove of each of the two swing tracks III21. A swing block III19 is provided at each end of the swing rod III20. A third lead screw nut is provided in each of the two swing blocks III19. A third lead screw III18 is passed through each of the two third lead screws III18. The lower ends of the two third lead screws III18 are respectively connected to the output shaft of the corresponding third servo motor III17. The third servo motor III17 drives the rotating plate III4 to rotate around the Y-axis through the third lead screws III18 and the third lead screw nut.

[0064] The upper surface of the flip plate III4 is provided with a first arc-shaped recess III26a and a second arc-shaped recess III26b arranged in series along the X-axis. The conical preform fixture II is rotatably placed on the first arc-shaped recess III26a and the second arc-shaped recess III26b around the X-axis. The fourth servo motor III25 is provided on one side of the conical preform fixture II. The fourth servo motor III25 is fixedly connected to the upper surface of the flip plate III4 through the fourth servo motor bracket III24. The central axis of the conical preform fixture II is connected to the output shaft of the fourth servo motor III25 through the coupling III16. The fourth servo motor III25 drives the conical preform fixture II to rotate around the X-axis through the coupling III16.

[0065] The controller uses position control to precisely move the first servo motor III10, the second servo motor III15, the third servo motor III17, and the fourth servo motor III25. When the controller outputs a single pulse, the moving distance of the first servo motor III10, the second servo motor III15, the third servo motor III17, and the fourth servo motor III25, i.e., the pulse equivalent, is 0.001 mm.

[0066] See Figure 11-12As shown, the conical preform fixture II includes a turntable II7 rotatably supported on the first arc-shaped recess III26a and a conical support II5 disposed between the first arc-shaped recess III26a and the second arc-shaped recess III26b. The left end of the turntable II7 is connected to the fourth servo motor III25. A conical pressure sleeve II9 is ​​disposed at the center of the right side of the turntable II7. The conical tip of the conical support II5 is aligned with the conical pressure sleeve II9. The open end of 5 is rotatably supported on the second arc-shaped concave platform III26b. The circumference of the open end of the conical support body II5 and the circumference of the turntable II7 are fixedly connected by four parallel connecting columns II8. Two gripper structures II6 are provided on the circumference of the open end of the conical support body II5. Arc-shaped moving plates II12 are respectively provided on both sides of the conical support body II5. The two arc-shaped moving plates II12 are adjusted by a spacing mechanism to achieve synchronous outward or inward movement on both sides of the conical support body II5.

[0067] The circumferential contour of the turntable II7 is adapted to the arc contour of the first arc-shaped concave platform III26a; the circumferential contour of the open end of the conical support II5 is adapted to the arc contour of the second arc-shaped concave platform III26b; the inner surface of the conical pressure sleeve II9 is ​​adapted to the outer surface of the cone tip of the variable cross-section hollow conical sleeve preform.

[0068] The gripper structure II6 includes a connecting base II601. Two support columns II602 are fixedly connected to both the front and rear sides of the connecting base II601. The lower ends of the four support columns II602 are jointly fixedly connected to a cylinder base II603. A small cylinder II605 is fixedly connected to the upper surface of the cylinder base II603 via a cylinder flange II604. The cylinder rod of the small cylinder II605 passes downwards through the cylinder base II603 and is fixedly connected to a moving rod II606. The left and right ends of the moving rod II606 are respectively hinged to the upper ends of a corresponding transmission connecting rod II607. The left and right ends of the cylinder base II603 are respectively hinged to the upper ends of a corresponding finger connecting rod II608. The lower ends of the two transmission links II607 are respectively hinged to the middle bending point of the corresponding finger link II608. The bottom ends of the two finger links II608 are respectively fixedly provided with a concave clamping block II609 and a convex clamping block II610. When the claw structure II6 is installed on the conical support II5, the connecting base II601 is circumferentially fixedly connected to the open end of the conical support II5. The concave clamping block II609 is installed on the bottom end of the finger link II608 located on the outer side wall of the open end of the conical support II5, and the convex clamping block II610 is installed on the bottom end of the finger link II608 located on the inner side wall of the open end of the conical support II5.

[0069] The concave surface of the concave clamping block II609 is adapted to the outer surface of the open portion of the variable cross-section hollow conical sleeve preform, and the convex surface of the convex clamping block II610 is adapted to the inner surface of the open portion of the variable cross-section hollow conical sleeve preform.

[0070] The main body of the conical support II5 is a conical cylinder. The upper surface of the conical cylinder has a fan-shaped gap for the sewing machine head to pass through during sewing. The open end of the conical cylinder has a semi-circular ring plate for installing the gripper structure II6 and for connecting the connecting column II8. The two sides of the conical cylinder have sliding groove holes for the arc-shaped moving plate II12 to move outward or inward. The lower surface of the conical cylinder has clearance holes for the spacing adjustment mechanism to be installed on the flip plate III4.

[0071] Two arc-shaped movable plates II12 are movably embedded in the left and right sliding slots, respectively. The spacing adjustment mechanism includes a T-shaped bracket II18, a lead screw II13, a lead nut, a worm gear II14, and a worm II15, all located within the conical support II5. The bottom of the T-shaped bracket II18 is fixedly connected to the chassis II17 through the clearance hole. The worm II15 is rotatably mounted on the top of the T-shaped bracket II18. The two ends of the lead screw II13 are threadedly connected to the inner surfaces of the left and right arc-shaped movable plates II12 through corresponding leads. The worm gear II14 is fixedly sleeved on the lead screw II13 and meshes with the worm II15. A rocker adjustment shaft II16 is provided on the worm II15 to facilitate its rotation.

[0072] The present invention also provides a design method for the above-mentioned special suture equipment, which mainly includes the design of the tension control cam profile curve and the optimization design of the suture guiding mechanism.

[0073] 1. Design of tension control cam profile curve: The present invention adopts an improved lockstitching process, in which the top thread is first introduced into the lower surface of the fabric by the needle of the thread guide mechanism, and then the excess top thread is retracted and the stitch is locked by the tension rod of the tension control mechanism, thereby completing the locking action.

[0074] In a tension control mechanism, a tension control cam drives a tension rod to perform circular motion. To ensure accurate and stable movement of the tension control mechanism, it is necessary to meet the requirements of vibration and impact, etc. Therefore, the motion law of the tension rod must be rationally selected and designed when designing the tension control cam.

[0075] Taking the upward movement of the tension bar as the starting point, the lifting and returning phases of the tension bar both adopt the five-term motion law, and the swing law of the tension bar is shown in Table 1.

[0076] Table 1. Motion Laws of the Tension Bar in the Fifth Order Polynomial

[0077] The formula for calculating the center distance 'a' is:

[0078] In formula (1), l is the length from the center point of the tension bar swing to the center of the roller; ψm is the angular displacement of the tension bar, which is taken as 60°.

[0079] Considering the coordination between the tension control mechanism and other mechanisms, we take l=19.5mm and substitute it into formula (1) to get a≈18.7mm.

[0080] In cylindrical coordinates, the coordinate equation of the theoretical profile of the cam is: (2) In formula (2), ψ = f (φ); R is the radius of the base circle; and φ is the rotation angle of the main axis.

[0081] Substituting R=32, l=19.5, and a=18.7 into formula (2), we obtain the spatial curve of the theoretical cam profile in cylindrical coordinates: (3) The three-dimensional curve of the cam is obtained in MATLAB as follows: Figure 15 As shown in (a). Import the 3D curve coordinates into SolidWorks to complete the 3D modeling of the tension control cam, as shown in (a). Figure 15 As shown in (b).

[0082] 2. Design of the lead wire mechanism: Given the lead pin stroke H, the lead mechanism is optimized using a, b, and e as design variables. These design variables can be expressed as follows: (4) See Figure 16 As shown, the maximum pressure angle αmax of the lead-wire mechanism occurs when the crank OA is perpendicular to the movement path of the lead-wire needle. In practical engineering, the magnitude of αmax is usually used to measure the force transmission performance of the mechanism; the smaller the αmax, the more beneficial it is for transmission. The minimum value of the maximum pressure angle αmax is used as the objective function, and its calculation formula is: (5) After further simplification, the objective function can be expressed as: (6) In practical applications, the range of values ​​for design variables is subject to certain restrictions, which are used as constraints in the mathematical model during optimization design. In the biased crank-slider mechanism, the condition for the existence of the crank, a+e≤b, can be expressed as an inequality constraint:

[0083] See Figure 16 As shown, where B1 and B2 are the left and right extreme positions of the slider, respectively, the following geometric relationship exists in triangles OCB2 and OCB1: (7) (8) The lead pin travel H can be expressed as: (9) The mechanism constraint equations are obtained as follows: (10) Combining the above equations, the constraint conditions for the offset crank-slider mechanism can be obtained as follows: (11) Considering the limitations of the internal space of the sewing device and the coordination between the needle and the shuttle, the boundary conditions of crank a, connecting rod b and offset e are shown in Table 2.

[0084] Table 2 Boundary Conditions

[0085] The above inequalities were solved using MATLAB, and the results after rounding are shown in Table 3.

[0086] Table 3 Lead wire mechanism parameters

[0087] The present invention also provides an analytical method for analyzing the motion coordination between the lead-in mechanism and the threading mechanism.

[0088] 3. The relationship between the lead-in mechanism and the threading mechanism: (1) Working principle of the threading mechanism The swing hook driven six-bar linkage is a planar six-bar linkage consisting of a crank, rocker arm, and swing guide rod connected in series. It comprises a crank OA, connecting rod AB, rocker arm O2C, swing rod O1C, slider, and frame. O is the upper main shaft, serving as the power input for the drive mechanism; O2 is the rotation center of rocker arm O2C; and O1 is the lower main shaft. A simplified diagram of the mechanism is shown below. Figure 17 As shown. Crank OA is the driving element. The rotation of crank OA drives rocker O2C to swing. The slider slides on rocker O2C and drives rocker O1C to swing back and forth, thus completing the threading process.

[0089] (2) The coordination relationship between the lead-in mechanism and the threading mechanism The working relationship between the lead-in mechanism and the hook mechanism determines the success rate of hooking the wire loop. Therefore, this section analyzes the optimal initial deflection angle of the shuttle by conducting a joint simulation analysis of the lead-in mechanism and the hook mechanism.

[0090] In the motion analysis environment of SolidWorks software, the upper spindle speed was set to 72 deg / s, the motion time to 5s, and the lead-in mechanism was in its upper limit position. A joint motion simulation of the lead-in mechanism and the hook mechanism was performed. After the simulation, with the lower spindle center as the origin, the displacement of the needle eye and the displacement of the shuttle hook tip in the y-axis direction were measured. The corresponding data were exported, and then the two sets of data were displayed in the same coordinate system using Origin plotting software, resulting in the displacement curves of the lead-in needle eye and the shuttle hook tip in the y-axis direction, as shown in the figure. Figure 18 As shown.

[0091] The initial position of the shuttle greatly affects the success of hooking the loop. If the shuttle's extreme deflection angle is too large, the hook tip may not reach the eye of the needle in time, thus failing to hook the optimal loop. Conversely, if the angle is too small, the optimal loop may not be formed by the time the hook tip reaches the eye of the needle, also resulting in missed hooking. Both situations lead to sewing failure. The diagram illustrates the relative positions of the needle and hook tip under four different initial deflection angles. Figure 19 As shown.

[0092] from Figure 19 As can be seen, the hook point deflects by 5° (e.g.) Figure 19 In the case shown in d), when the eye of the needle meets the hook tip of the shuttle, the loop has not yet been formed, leading to sewing failure; the hook tip deflects 15° (as shown in d). Figure 19 (as shown in c) and 20° (as shown in c) Figure 19 In the situation shown in (a), the tension control mechanism begins to take in the line before the shuttle has hooked it, causing the loop to become smaller. When the eye of the lead needle meets the hook tip of the shuttle, the shuttle misses the optimal state of the loop, resulting in a low success rate of hooking the line; the hook tip deflects by 10° (as shown in a). Figure 19 In the case shown in b), when the eye of the needle and the tip of the shuttle hook meet, the optimal loop is formed, resulting in the highest success rate of hooking the line.

[0093] To verify the above analysis and provide theoretical guidance for the assembly of subsequent physical prototypes, four sets of simulation analyses were performed again using the Motion analysis plugin in SolidWorks software. The initial deflection angles of the shuttle were adjusted to 5°, 10°, 15°, and 20°, respectively, to simulate the combined motion of the lead-wire mechanism and the hook-wire mechanism. After the simulations were completed, the corresponding data were exported, and the angular displacement data of the shuttle under the four different deflection angles were plotted as curves in the same coordinate system using Origin plotting software, as shown below. Figure 20 As shown.

[0094] Depend on Figure 20 It can be seen that when the movement pattern of the guide needle remains unchanged, the needle eye displacement curve and the y-direction displacement curve of the shuttle hook tip intersect at two points. The first intersection on the left represents: the guide needle pierces the fabric downwards, and at the same time, the shuttle rotates counterclockwise, and the two intersect in the y-direction; the second intersection on the left represents: the guide needle moves upwards and forms a loop, at which point the shuttle rotates clockwise, and the two intersect again in the y-direction. The position of the second intersection point is of great reference significance for whether the loop can be successfully hooked, combined with... Figure 19 It can be seen that the success rate of suturing is highest when the deflection angle of the shuttle at its limit position is about 10°.

[0095] The working principle of this invention is to plan a control program by analyzing the motion coordination process between the sewing machine head and the four-degree-of-freedom worktable. The working steps of this invention are described below with reference to the position of the thread-leading mechanism: S1, Input suture parameters Because the PLC outputs pulse counts, which are not consistent with the commonly used distance units such as millimeters during actual operation, it is necessary to calculate and convert them into a commonly used unit form. The distance in millimeters is input on the touch screen, converted into the corresponding pulse count by the F312 instruction, converted from a floating-point number to an integer by the F330 instruction, and then written into the data table by the F3855 instruction.

[0096] Write the required position control commands, such as the movement of the sliding plate on the base along the X-axis, the movement of the lifting plate on the sliding plate along the Z-axis, the rotation of the flipping plate on the lifting plate around the Y-axis, and the rotation of the precast fixture on the flipping plate around the X-axis. Write the displacement actions required for each stage in advance, and finally call them directly by the loop program.

[0097] The origin return function is set and called when the system starts or stops. Since the required functions are the same for both, only the origin return function needs to be edited. Other functions can be called directly using the SET function when needed.

[0098] S2, Precast Clamping The variable cross-section precast body to be sewn is mounted on the conical precast body fixture, with the sewing area facing upwards. The controller retracts the small cylinder extension rod of the gripper structure, causing the concave and convex clamping blocks of the gripper structure to clamp the variable cross-section precast body to be sewn onto the conical precast body fixture. The controller checks whether the gripper structure is properly clamped. If not, it re-controls the gripper structure to clamp; if it is properly clamped, it proceeds to the next step.

[0099] S3, the lead wire mechanism is in its initial position. The controller moves the suture guide mechanism in the suture head to its initial position (upper limit position). The controller detects whether the suture guide mechanism has moved into place. If it has not, the controller readjusts the position of the suture guide mechanism until it is in the initial position. If it is in place, the controller proceeds to the next step.

[0100] S4, the four-degree-of-freedom worktable moves to its initial position. The controller controls the coordinated movement of three degrees of freedom of the four-degree-of-freedom worktable: simultaneously controlling the movement of the sliding plate along the X-axis on the base, the movement of the lifting plate along the Z-axis on the sliding plate, and the rotation of the tilting plate around the Y-axis on the lifting plate. This adjusts the variable cross-section prefabricated body to be stitched to its initial position. The controller detects whether the variable cross-section prefabricated body has rotated into position. If not, it further adjusts the angles of the three degrees of freedom until the variable cross-section prefabricated body is in the initial position. If it is in position, the next step is performed.

[0101] S5, Sewing and Feeding The controller starts the lead wire mechanism. When the lead wire mechanism completes a work cycle and reaches the upper limit position again, the controller controls the sliding plate of the four-degree-of-freedom worktable to move along the X-axis on the base and the preform fixture to rotate around the X-axis on the flip plate, adjusting the two degrees of freedom of feeding.

[0102] During the sewing process, the pressing mechanism is responsible for pressing down the seam of the prefabricated sewing material, the thread guiding mechanism is responsible for piercing the prefabricated sewing material and introducing the top thread into the lower surface of the prefabricated sewing material to form a thread loop; the threading mechanism is responsible for hooking and expanding the thread loop and feeding in the bobbin; and the tension control mechanism is responsible for controlling the tension of the sewing thread to form a stable stitch.

[0103] S6, Looping Action After the four-degree-of-freedom worktable moves one stitch length, the controller determines whether the four-degree-of-freedom worktable has moved to the limit position. If it has reached the limit position, the four-degree-of-freedom worktable and the sewing machine head stop working. If it has not reached the limit position, the next sewing cycle begins. This process is repeated until continuous sewing is completed.

[0104] This invention addresses the stitching requirements of composite material preforms with hollow cylindrical and hollow conical shapes by innovatively developing a dedicated stitching head and designing a matching conical preform clamp and a four-degree-of-freedom feeding table for clamping and moving the stitching material, thus forming a set of special stitching equipment suitable for high-performance fiber conical sleeve variable cross-section preforms.

[0105] The special sewing equipment of the present invention can realize the relative movement of the preform with the sewing machine head by clamping the conical preform clamp and moving the four-degree-of-freedom feeding table. Furthermore, the required stitching path can be obtained by controlling the movement trajectory of the four-degree-of-freedom feeding table through a set program, thereby ensuring the sewing effect.

[0106] The special sewing equipment of this invention uses a double-sided sewing method to sew high-performance fiber conical sleeve variable cross-section preforms. Using an improved lockstitch process, the knot between the top and bottom threads is placed on the surface of the sewing material. The stress generated by the improved lockstitch is on the surface of the sewing material, without affecting the interlayer performance of the preform.

[0107] The special stitching equipment of this invention can stitch together large-thickness, high-performance composite material preforms with irregular cross-sections and a thickness of 5-40 mm, thereby enhancing the mechanical properties of the composite material preforms. See also... Figure 13 and Figure 14 As shown, Figure 13 This is a schematic diagram showing the structure of the conical preform sewn by the special sewing equipment of the present invention. Figure 14 This is a cross-sectional view showing the conical preform sewn by the special sewing equipment of the present invention.

[0108] The special sewing equipment of the present invention is not limited to a thickness of 40mm, but can also be applied to the sewing of 100mm thick conical sleeve variable cross-section prefabricated bodies, as well as cylindrical, frustum conical rotating bodies and irregular cross-section annular bodies.

[0109] The special sewing equipment of this invention improves the automation level of high-performance fiber conical sleeve variable cross-section preform sewing technology, expands the application range of composite material preforms, and can effectively improve the working efficiency of preform processing, reduce costs, and improve economic benefits.

[0110] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, the phrase "comprising an element defined as..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0111] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

[0112] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A special sewing device for high-performance fiber conical sleeve variable cross-section prefabricated bodies, characterized in that, It consists of a sewing machine head, a conical preform clamp, and a four-degree-of-freedom feeding table. The four-degree-of-freedom feeding table is located below the front end of the sewing machine head, and the conical preform clamp is mounted on the four-degree-of-freedom feeding table. The conical preform clamp is used to hold the sewing material, and the four-degree-of-freedom feeding table is used to move the sewing material through the conical preform clamp to obtain the required stitching path. The sewing machine head is used to sew the sewing material located on the conical preform clamp. The sewing machine head includes a thread guiding mechanism, a thread threading mechanism, a tension control mechanism, a pressing mechanism, an upper spindle, a drive mechanism, and a frame. The thread guiding mechanism, thread threading mechanism, tension control mechanism, pressing mechanism, upper spindle, and drive mechanism are all mounted on the frame. The thread guiding mechanism is used to pierce the sewing fabric and introduce the top thread into the lower surface of the fabric to form a thread loop. The thread threading mechanism is used to hook and enlarge the thread loop and feed in the bobbin thread. The tension control mechanism is used to control the tension of the sewing thread to form a stable stitch. The pressing mechanism is used to press down on the sewing joint of the fabric. The drive mechanism is used to directly or indirectly drive the thread guiding mechanism, thread threading mechanism, tension control mechanism, and pressing mechanism to move via the upper spindle. The four-degree-of-freedom feeding table includes a table base, on which a sliding plate is mounted, moving along the X-axis under the drive of a first servo motor. A lifting plate is mounted on the sliding plate, moving along the Z-axis under the drive of a second servo motor. A tilting plate is mounted on the lifting plate, rotating around the Y-axis under the drive of a third servo motor. A fourth servo motor is mounted on the tilting plate to drive the conical preform fixture to rotate around the X-axis. The upper surface of the tilting plate has a first arc-shaped recess and a second arc-shaped recess to facilitate the rotation of the conical preform fixture. The conical preform... The body clamp is used to hold the variable cross-section irregular prefabricated body to be sewn and drive it to rotate around the X-axis; the flipping plate is used to drive the variable cross-section irregular prefabricated body to be sewn to rotate around the Y-axis; the lifting plate is used to drive the variable cross-section irregular prefabricated body to be sewn to move along the Z-axis; the sliding plate is used to drive the variable cross-section irregular prefabricated body to be sewn to move along the X-axis; the first servo motor, the second servo motor, the third servo motor, and the fourth servo motor are all under the comprehensive control of the controller, thereby realizing the linkage of the sliding plate, the lifting plate, the flipping plate, and the conical prefabricated body clamp; The conical preform fixture includes a turntable rotatably supported on the first arc-shaped concave platform and a conical support body disposed between the first and second arc-shaped concave platforms. The left end of the turntable is connected to the fourth servo motor. A conical pressure sleeve is disposed at the center of the right side of the turntable. The conical tip of the conical support body is aligned with the conical pressure sleeve. The open end of the conical support body is rotatably supported on the second arc-shaped concave platform. The circumference of the open end of the conical support body and the circumference of the turntable are fixedly connected by four parallel connecting columns. Two gripper structures are disposed on the circumference of the open end of the conical support body. Arc-shaped moving plates are disposed on both sides of the conical support body. The two arc-shaped moving plates are synchronously moved outward or inward on both sides of the conical support body through a spacing adjustment mechanism. The main body of the conical support is a conical cylinder. The upper surface of the conical cylinder has a fan-shaped gap for the sewing machine head to pass through during sewing. The open end of the conical cylinder has a semi-circular ring plate for installing the gripper structure and for connecting the connecting column. The two sides of the conical cylinder have sliding groove holes for the arc-shaped moving plate to move outward or inward. The lower surface of the conical cylinder has clearance holes for the spacing adjustment mechanism to be installed on the flip plate. The two arc-shaped movable plates are respectively movably embedded in the left and right sliding groove holes. The spacing adjustment mechanism includes a T-shaped bracket, a lead screw, a lead screw nut, a worm gear, and a worm, all located in the conical support body. The bottom of the T-shaped bracket is fixedly connected to the chassis through the clearance hole. The worm is rotatably mounted on the top of the T-shaped bracket. The two ends of the lead screw are respectively threaded to the inner surfaces of the left and right arc-shaped movable plates through the corresponding lead screw nuts. The worm gear is fixedly sleeved on the lead screw and meshes with the worm.

2. The special sewing equipment for high-performance fiber conical sleeve variable cross-section prefabricated bodies according to claim 1, characterized in that: The tension control mechanism includes a tension control cam, a tension rod, and a roller. The tension control cam is located at the front end of the upper spindle. A tension adjustment groove is formed on the circumferential surface of the tension control cam. The trajectory of the tension adjustment groove undulates along the axial direction of the tension control cam. The roller is rolled within the tension adjustment groove. The tension rod is L-shaped. The long side of the tension rod is the thread take-up portion, which extends forward and has a thread-passing eye at its front end. The short side of the tension rod is the adjustment portion, and a tension rod pin is provided at the end of the adjustment portion. One end of the tension rod pin is rotatably connected to the roller, and the other end is rotatably connected to the frame.

3. The special sewing equipment for high-performance fiber conical sleeve variable cross-section prefabricated bodies according to claim 2, characterized in that: The lead wire mechanism includes a needle bar connecting rod seat, a needle bar connecting rod, a needle bar slider, a needle bar, and a needle. The needle bar connecting rod seat is disposed on the front end face of the tension control cam. One end of the needle bar connecting rod is hinged to one side of the front surface of the needle bar connecting rod seat via an upper pin. The other end of the needle bar connecting rod is hinged to the outer surface of the needle bar slider via a lower pin. The needle bar is fixed vertically downward in the needle bar slider, and the needle is disposed at the bottom end of the needle bar.

4. The special sewing equipment for high-performance fiber conical sleeve variable cross-section prefabricated bodies according to claim 1, characterized in that: The threading mechanism includes a swing shaft eccentric wheel, a swing shaft connecting rod, a swing shaft, a clamping plate, a lower main shaft connector, a lower main shaft slider, a lower main shaft, and a swing hook. The swing shaft eccentric wheel is located at the rear of the upper main shaft. The upper end of the swing shaft connecting rod is hinged to the swing shaft eccentric wheel, and the lower end of the swing shaft connecting rod is hinged to the center hole of the swing shaft. The swing shaft is parallel to the upper main shaft, and the rear end of the swing shaft is hinged to the frame. The clamping plate is located at the front end of the swing shaft. The lower main shaft slider is located at the front end of the swing shaft through two clamping plates. The rear end of the lower main shaft is hinged to the lower main shaft slider through the lower main shaft connector. The lower main shaft is parallel to the upper main shaft, and the swing hook is located at the front end of the lower main shaft.

5. The special sewing equipment for high-performance fiber conical sleeve variable cross-section prefabricated bodies according to claim 4, characterized in that: The threading mechanism is externally provided with a threading mechanism base. The frame is provided with threaded holes, and the threading mechanism base is fixedly connected to the frame by bolts. The cross-section of the threading mechanism base is hollow and circular. The threading mechanism base includes a shuttle cover, a swing hook guide ring seat, and a needle plate. The shuttle cover is fixed to the front end of the threading mechanism base. The swing hook guide ring seat is installed inside the circular cavity of the threading mechanism base. The needle plate is installed on the top of the threading mechanism base.

6. The special sewing equipment for high-performance fiber conical sleeve variable cross-section prefabricated bodies according to claim 1, characterized in that: The pressing mechanism includes a pressing and lifting eccentric wheel, a pressing and lifting connecting rod, a pressing and lifting adjusting crank, a pressing and lifting shaft, a pressing and lifting crank, a pressing and lifting front connecting rod, a rocking plate, a small rocking connecting rod, an inner pressing and clamping rod, a small pressure foot, a clamping rod sliding block, a clamping rod, and a large pressure foot. The pressing and lifting eccentric wheel is located at the front of the upper main shaft. One end of the pressing and lifting connecting rod is hinged to the pressing and lifting eccentric wheel, and the other end of the pressing and lifting connecting rod is hinged to the pressing and lifting adjusting crank by screws. The pressing and lifting adjusting crank is fixedly connected to the rear end of the pressing and lifting shaft, and the front end of the pressing and lifting shaft is connected to the pressing and lifting... The upper end of the crank is fixedly connected, the lower end of the pressure lifting crank is hinged to the upper end of the pressure lifting front connecting rod, the lower end of the pressure lifting front connecting rod is hinged to the lower left end hole of the swinging rocker, the upper right end hole of the swinging rocker is hinged to the upper end of the swinging small connecting rod, the lower end of the swinging small connecting rod is hinged to the upper end of the inner pressure pressing rod, the small pressure foot is located at the bottom end of the inner pressure pressing rod, the upper left end hole of the swinging rocker is hinged to the pressing rod sliding block, the pressing rod is fixedly connected to the pressing rod sliding block, the large pressure foot is located at the bottom end of the pressing rod, and the small pressure foot is located in the large pressure foot.

7. The special sewing equipment for high-performance fiber conical sleeve variable cross-section prefabricated bodies according to claim 1, characterized in that: The drive mechanism includes an upper spindle drive motor, a transmission belt, a drive pulley, and a driven pulley. The upper spindle drive motor is mounted on the frame, the drive pulley is mounted on the output shaft of the upper spindle drive motor, the driven pulley is mounted at the rear end of the upper spindle, and the transmission belt is wound between the drive pulley and the driven pulley.

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