Process method for forming large-thickness composite material preform
Through the single-sided blind seam suture technology, the multi-degree of freedom robotic arms of the lead needle and hook and thread components can be used to achieve efficient molding of large-thick composite prefabricated bodies, solving the problems of low efficiency and insufficient performance in traditional processes, and improving the Overall performance and production efficiency of composite materials.
Patent Information
- Application Number
- CN202411378802.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-30
- Publication Date
- 2025-01-14
AI Technical Summary
The prior art is difficult to achieve the mechanized preparation of large-thick carbon fiber three-dimensional composite prefabricated bodies, especially in terms of impact resistance and Z-directional properties, and the traditional process efficiency is low and it is difficult to ensure the consistency of product quality.
Using single-side blind seam suture technology, through the multi-degree-of-freedom robotic arms of the lead needle and hook and thread component, a continuous single-sided chain suture stitch is formed along a predetermined path, thereby realizing multi-layer splicing seam of the composite prefabricated body. Suitable for rectangular, annular and hollow composite prefabricated bodies, ensuring that sutures do not interfere, improving suture density and resistance to shear stress.
It realizes efficient forming of large-thick composite prefabricated bodies, improves the overall performance and structural reliability of the material, reduces production costs, adapts to various shapes and sizes of composite prefabricated bodies, and meets the needs of high-performance composite structural parts. , improves production efficiency and product consistency.
Smart Images
Figure CN119305215A_ABST
Abstract
Description
Technical Field
[0001] The invention belongs to the technical field of composite material preforms, and in particular relates to a process method for forming a composite material preform with a large thickness. Background Art
[0002] Carbon fiber three-dimensional composite preforms have great application potential in aerospace, automotive industry, energy equipment, sports equipment and other fields due to their excellent mechanical properties and lightweight characteristics. As a typical representative material, they are widely used in structural materials of aerospace and load-bearing structures of various military and civil aircraft. Carbon fiber three-dimensional composite preforms have many advantages, such as high quality and light weight, high strength and high stiffness, corrosion resistance, etc., but they also have many disadvantages, such as low impact resistance, low anti-delamination ability and unstable in-plane performance.
[0003] Since there is no fiber reinforcement in the Z direction between the layers of the carbon fiber three-dimensional composite material preform, the Z-direction performance is much different from the in-plane performance. When subjected to a large Z-direction load or shear load, the three-dimensional structure of the preform is prone to failure. Suture reinforcement technology is to connect the layers through sutures, introduce reinforcing fibers in the thickness direction, and sew the layers into a whole. In addition, there are other methods such as three-dimensional weaving and z-pin interlayer reinforcement, but due to the cumbersome process or damage to the preform, it is impossible to achieve mechanized preparation of thick three-dimensional composite material preforms.
[0004] Among the stitching reinforcement technologies, blind stitching technology, as a new type of preform connection method, has received widespread attention in recent years. It can complete stitching through single-sided cooperation without the need to operate from the other side of the preform. Compared with other methods, the stitching process is simpler, the production cost is lower, and the automation of mechanical equipment can be realized, which greatly improves the stitching efficiency and flexibility. In particular, for structures with limited internal space or difficult access, blind stitching technology provides an effective solution. This technology can complete high-quality stitching without destroying the overall structure of the preform, which is crucial to improving the overall performance of composite structural parts.
[0005] For example, annular composite preforms, as an important type of carbon fiber three-dimensional composite preforms, play a key role in annular components such as turbine engine blades, wind turbine blades, and high-performance tires. They not only need to have excellent fatigue resistance and high temperature resistance, but also need to maintain good formability and consistency under complex geometric shapes. Traditional methods for preparing annular composite preforms are mostly hand weaving, hand laying, etc., which are not only inefficient but also difficult to ensure the consistency of product quality. It can be seen that the existing domestic stitching devices and the process research proposed for blind stitching are unable to achieve the stitching of large thickness preforms.
[0006] Therefore, the research on the process method of forming thick composite preforms through single-sided blind stitching technology has important practical engineering significance. Summary of the invention
[0007] The problem to be solved by the present invention is to provide a process method for forming a thick composite material preform.
[0008] In order to solve the above technical problems, the technical solution adopted by the present invention is: a process method for forming a thick composite material preform, comprising the following steps: S1. Sewing two layers of composite material preforms, each with a thickness of H: the two layers of composite material preforms include a first preform located at a lower layer and a second preform located at an upper layer; S11, stacking the second preform and the first preform together, the thread guide needle carrying a single suture thread penetrates the second preform from the initial position of the thread guide needle above the second preform in an arc-shaped trajectory and then passes through the upper surface thickness h (h<H) of the first preform, until the end of the thread guide needle with the suture thread passes through the upper surface of the second preform and reaches the termination position of the thread guide needle and then begins to retreat along the original path; at the same time, the thread hooking component rotates horizontally from the initial position of the thread hooking component above the second preform until it reaches the termination position of the thread hooking component and then retreats along the original path; S12, during the retreat of the thread guide needle and the thread hooking component, the sutures on both sides of the thread guide needle body accumulate and form a thread loop; when the thread hooking component performs a horizontal rotational movement from the thread hooking component end position to the thread hooking component initial position, the thread loop formed by the thread guide needle is hooked, and then the thread loop is continued to move toward the thread hooking component initial position with the thread hooking component; S13, after the guide needle and the hooking thread component reach their respective initial positions, the multi-degree-of-freedom robotic arm drives the guide needle and the hooking thread component to move a fixed needle distance along the suture path direction, or the multi-axis linkage feeding workbench moves a fixed needle distance along the suture path direction, and after the movement, the guide needle carries the suture to puncture the second preform and the first preform again; S14, when the thread guide needle carries the suture through the second preform and the first preform, the needle tip of the thread guide needle passes through the old thread loop hooked by the thread hooking component last time, and then the thread guide needle continues to move toward the thread guide needle end position, and during the process of the thread hooking component rotating horizontally to the thread hooking component end position, the old thread loop is thrown out, and the thrown out old thread loop forms a thread loop locking knot with the passed suture; S15, the thread guide needle and the thread hook component retreat again, the suture at the end of the thread guide needle accumulates and forms a new thread loop; the thread hook component hooks the new thread loop formed by the thread guide needle, and then the thread guide needle and the thread hook component respectively carry the suture and the new thread loop and continue to move to their respective initial positions, completing a suturing cycle; S16, after multiple suturing cycles from step S11 to step S15, a continuous single-sided chain suturing stitch is formed; S17, after completing a unilateral chain stitching line, the multi-degree-of-freedom robotic arm drives the thread guide needle and the thread hook component or the multi-axis linkage feeding workbench to move a distance to continue the stitching work, until a plurality of unilateral chain stitching lines are formed, and the stitching preparation of the two-layer composite material preform is completed; S2. Splicing and stitching of multi-layer composite material preforms: S21, after the sewing of the two layers of composite material preforms is completed, a third preform is stacked on top of the two layers of composite material preforms that have been stitched; the stitching method is the same as step S1, and the stitching positions of the thread guide needle and the thread hook component must ensure that when the thread guide needle penetrates the newly stacked third preform and passes through the upper surface thickness h of the previously stitched second preform, it does not interfere with the single-sided chain stitching traces left after the previous stitching; The splicing and sewing process of S22, the fourth preform, the fifth preform, the Nth preform, and the N+1th preform is the same as step S21, ensuring that when the lead needle penetrates the N+1th preform and only passes through the upper surface thickness h of the Nth preform, it does not interfere with the single-sided chain stitch left by the Nth preform, until the sewing preparation of the multi-layer composite material preform seam material is completed.
[0009] Further, in step S1, when the composite material preform sewing material is rectangular, the sewing path is a radial path, and the single-sided chain stitch is a straight line.
[0010] Furthermore, in step S2, when the composite material preform seam is rectangular, after the sewing of two layers of composite material preform seams is completed, the multi-degree-of-freedom robotic arm drives the thread guide needle and the thread hook component back to the top of the sewing starting point, and then a layer of the third preform is stacked on top of the two layers of composite material preform seams that have been stitched; the multi-degree-of-freedom robotic arm drives the thread guide needle and the thread hook component or the multi-axis linked feeding workbench to translate along the stitched single-sided chain stitch line to achieve splicing and stitching in the same direction, ensuring that the thread guide needle does not interfere with the stitches left after the previous stitching when penetrating the newly stacked third preform and passing through a certain thickness of the upper surface layer of the second preform that has been stitched previously, and the stitching cycle and subsequent processes are the same as step S1.
[0011] Further, in step S2, when the composite material preform seam is rectangular, after the sewing of the two layers of composite material preform seam is completed, the multi-degree-of-freedom robotic arm drives the thread guide needle and the thread hook component back to the top of the sewing starting point, and rotates 90°, and then a layer of the third preform is stacked on top of the two layers of composite material preform seam that have been stitched; the multi-degree-of-freedom robotic arm drives the thread guide needle and the thread hook component or the multi-axis linked feeding workbench to translate in a direction perpendicular to the stitched single-sided chain stitch, to achieve warp and weft interlaced splicing and stitching, to ensure that the thread guide needle does not interfere with the stitches left after the previous stitching when penetrating the newly stacked third preform and passing through a certain thickness of the upper surface layer of the second preform that has been stitched previously; the stitching cycle and subsequent processes are the same as step S1.
[0012] Further, in step S1, when the composite material preform sewing material is in the shape of a hollow ring, the suturing path is a circular path, and the unilateral chain suturing stitch is in the shape of a ring.
[0013] Furthermore, when suturing through the circumferential path, the thread guide needle and the thread hook component are first fixed, and the composite material preform sewing material is placed on the multi-axis linkage feeding workbench, and the suturing is performed by diverging from the inner circle to the outer circle or contracting from the outer circle to the inner circle. When the multi-axis linkage feeding workbench drives the composite material preform sewing material to rotate a circle to complete the suturing, the rotation is stopped, and the multi-degree-of-freedom mechanical arm drives the thread guide needle and the thread hook component to move a fixed distance radially, and then the multi-axis linkage feeding workbench continues to rotate to complete the next circle of suturing. Until the whole circle of suturing is completed, a number of single-sided chain suture traces of circumferential path suturing are formed, and the splicing and suturing of the two layers of composite material preform sewing materials are completed. According to step S2, the thickness of the composite material preform is infinitely increased.
[0014] Further, in step S1, when the composite material preform sewing material is a hollow ring, the suturing path is a radial path, and the unilateral chain suturing stitch is a straight line.
[0015] Furthermore, when suturing through a radial path, the composite material preform is placed on a multi-axis linkage feeding workbench, the multi-axis linkage feeding workbench is kept stationary, and the multi-degree-of-freedom mechanical arm drives the thread guide needle and the thread hook component to sew radially from the inner circle to the outer circle. When the outer circle position is reached, the multi-axis linkage feeding workbench rotates an angle, and the multi-degree-of-freedom mechanical arm drives the thread guide needle and the thread hook component to sew radially from the outer circle to the inner circle until the composite material preform is sewed around the entire circle, forming a plurality of single-sided chain stitches of radial path suturing, and completing the splicing and suturing of the two layers of composite material preform. Then according to step S2, the thickness of the composite material preform is infinitely increased.
[0016] Further, in step S1, when the composite material preform sewing material is a hollow ring, the sewing path is a warp and weft path, and the unilateral chain sewing stitch is in a grid shape.
[0017] Furthermore, when sewing in the warp and weft directions, the composite material preform is placed on a multi-axis linkage feeding workbench and remains stationary, and the multi-degree-of-freedom mechanical arm drives the thread guide needle and the thread hook component to first sew in the weft direction in an S-shaped path, and after completing the weft sew of the entire circle, the warp sew begins until the entire circle is sewn, forming a number of single-sided chain sewed stitches of the warp and weft paths, and completing the splicing and sewing of the two layers of composite material preform sewing materials. Then, according to step S2, the thickness of the composite material preform is infinitely increased.
[0018] Furthermore, when the composite material preform is a hollow ring and the hollow space is relatively large, the multi-degree-of-freedom robotic arm drives the thread guide needle and the thread hook component to sew in the hollow space to achieve the sew of the inner wall and the outer wall of the ring-shaped composite material preform.
[0019] The wire guide needle has a constant radius of curvature, an embedding groove is provided on the inner side of the wire guide needle, and a wire passing groove is provided on the outer side of the wire guide needle; the wire hooking component is a horizontally arranged arc-shaped structure.
[0020] Wherein, in step S1, the thickness H of the seam material of the single-layer composite material preform is 2-8 mm; and the thickness h of the upper surface layer is 2-5 mm.
[0021] Among them, the guide needle and the wire hook component are installed on the single-sided curved needle suture head, and the rotation of the guide needle and the wire hook component is realized by driving the synchronous belt mechanism through a single servo motor. The single-sided curved needle suture head is installed on the flange at the end of the multi-degree-of-freedom robotic arm, and the multi-degree-of-freedom robotic arm drives the single-sided curved needle suture head to perform suturing work.
[0022] Due to the adoption of the above technical solution, the present invention has the following beneficial effects: The present invention is suitable for single-side stitching of composite material preforms, and for rectangular composite material preform seams, it can realize the stacking and splicing of multi-layer composite material preform seams. At the same time, the present invention has high flexibility and adaptability, is not limited by the stitching space, and for hollow annular composite material preform seams, it can be stitched through circumferential, radial, and longitude and latitude stitch planning.
[0023] In order to avoid interference between sutures and stitches, the stitch planning of the present invention can achieve an ideal suture density, increase suture thickness and shear stress resistance, and ensure product consistency.
[0024] The present invention can adapt to composite material preforms of various shapes and sizes, can realize unlimited increase in the thickness of composite material preforms, complete the Z-direction fastening of large-thickness composite material preforms, to meet the needs of high-performance composite material structural parts, not only maintain the integrity of the material, but also improve the integrity and reliability of the structure. The present invention gets rid of the dependence on needles in traditional puncture molding and the limitation of Z-direction stroke in shaft-rod molding, making the suture molding process simpler and helping to reduce costs. It can be seen that the present invention is highly operable, enhances the interlayer Z-direction performance, improves production efficiency and product consistency, and thus promotes the development and popularization of carbon fiber composite materials in practical applications, and provides more reliable and economical solutions for related industries. BRIEF DESCRIPTION OF THE DRAWINGS
[0025] The present invention will be described in detail below with reference to the accompanying drawings and in combination with examples, and the advantages and implementation methods of the present invention will become more obvious. The contents shown in the accompanying drawings are only used to explain the present invention and do not constitute any limitation to the present invention in any sense. In the accompanying drawings: Figure 1 It is a schematic diagram of the splicing and seaming of the two-layer rectangular composite material preform of the present invention.
[0026] Figure 2 It is a schematic diagram of the warp and weft interweaving and stitching of the three-layer rectangular composite material preform of the present invention.
[0027] Figure 3 It is a schematic diagram of seaming materials of a multilayer rectangular composite material preform of the present invention.
[0028] Figure 4 It is a schematic structural diagram of the multi-degree-of-freedom mechanical arm and the single-sided curved needle suturing head of the present invention.
[0029] Figure 5 It is a schematic diagram of the circumferential sewing path of the seam material of the annular composite material preform of the present invention.
[0030] Figure 6 It is a schematic diagram of the circumferential splicing and seaming of the seams of the two-layer annular composite material preform of the present invention.
[0031] Figure 7 It is a schematic diagram of the circumferential splicing and seaming of the seams of the multi-layer annular composite material preform of the present invention.
[0032] Figure 8 It is a schematic diagram of the radial stitching path of the seam material of the annular composite material preform of the present invention.
[0033] Fig. 9 It is a schematic diagram of radial splicing and seaming of seams of two-layer annular composite material preforms of the present invention.
[0034] Fig.10It is a schematic diagram of the circumferential splicing and seaming of the seams of the multi-layer annular composite material preform of the present invention.
[0035] Fig.11 It is a schematic diagram of the warp and weft sewing paths of the annular composite material preform of the present invention.
[0036] Fig.12 It is a schematic diagram of the warp and weft splicing of the seams of the two-layer annular composite material preform of the present invention.
[0037] Fig.13 It is a schematic diagram of the warp and weft splicing of the seams of the multi-layer annular composite material preform of the present invention.
[0038] Fig.14 It is a schematic diagram of the splicing and sewing of the inner wall and the outer wall of the annular composite material preform of the present invention.
[0039] 1. Guide needle; 2. Thread hook component; 3. New thread loop; 4. Old thread loop; 5. Single-sided chain stitch; 6. Composite material preform sewing material; 7. Multi-degree-of-freedom robotic arm; 8. Single-sided curved needle sewing head; 9. First preform; 10. Second preform; 11. Third preform. DETAILED DESCRIPTION
[0040] like Figures 1 to 14 As shown, the process for forming a thick composite material preform of the present invention comprises the following steps: S1. Stitching of two layers of composite material preforms 6, each with a thickness of H: The two-layer composite material preform sewing material 6 includes a first preform 9 located at the lower layer and a second preform 10 located at the upper layer; S11, stacking the second preform 10 and the first preform 9 together, the thread guide needle 1 carries a single suture from the initial position of the thread guide needle 1 above the second preform 10, penetrates the second preform 10 in an arc-shaped trajectory, and then passes through the upper surface thickness h (h<H) of the first preform 9, until the end of the thread guide needle 1 with the suture passes through the upper surface of the second preform 10 and reaches the terminal position of the thread guide needle 1, and then begins to retreat along the original path; at the same time, the thread hooking component 2 is horizontally rotated from the initial position of the thread hooking component 2 above the second preform 10, until it reaches the terminal position of the thread hooking component 2 and then retreats along the original path; S12, during the retreat of the thread guide needle 1 and the thread hooking component 2, due to the embedding groove provided on the thread guide needle 1, the friction between the stitches on both sides of the needle body of the thread guide needle 1 and the composite material preform 6 is uneven, and the stitches accumulate and form a thread loop; when the thread hooking component 2 performs a horizontal rotational movement from the end position of the thread hooking component 2 to the initial position of the thread hooking component 2, the thread loop with a good shape formed by the thread guide needle 1 is hooked, and then the thread loop is carried to continue to move toward the initial position of the thread hooking component 2; S13, after the lead needle 1 and the hook thread component 2 reach their respective initial positions, the PLC receives feedback, and the multi-degree-of-freedom robotic arm 7 drives the lead needle 1 and the hook thread component 2 to move a fixed needle distance a along the suture path direction, or the multi-axis linkage feeding workbench moves a fixed needle distance a along the suture path direction, and after the movement, the lead needle 1 carries the suture to puncture the second preform 10 and the first preform 9 again; S14, when the thread guide needle 1 carries the suture thread through the second preform 10 and the first preform 9, the needle tip of the thread guide needle 1 passes through the old thread loop 4 hooked by the thread hooking component 2 last time, and then the thread guide needle 1 continues to move toward the end position of the thread guide needle 1. During the process of the thread hooking component 2 rotating horizontally to the end position of the thread hooking component 2, the old thread loop 4 is thrown out, and the thrown out old thread loop 4 forms a thread loop lock knot with the passed suture thread; S15, the guide needle 1 and the hooking thread component 2 retreat again, the suture at the end of the guide needle 1 accumulates and forms a new thread loop 3; the hooking thread component 2 hooks the new thread loop 3 with a good shape formed by the guide needle 1, and then the guide needle 1 and the hooking thread component 2 respectively carry the suture and the new thread loop 3 and continue to move to their respective initial positions, completing a suturing cycle; S16, after multiple suturing cycles from step S11 to S15, a continuous single-sided chain suturing stitch 5 is formed; S17. After completing a single-sided chain stitch 5, the multi-degree-of-freedom robot arm 7 drives the thread guide needle 1 and the hook component 2 or the multi-axis linked feeding workbench to move a distance m to continue the stitching work until a number of single-sided chain stitches 5 are formed, completing the stitching preparation of the two-layer composite material preform stitching material 6.
[0041] S2. Splicing and sewing of the multilayer composite material preform 6: S21, after the sewing of the two layers of composite material preforms 6 is completed, a third preform 11 is stacked on the top of the two layers of composite material preforms 6 that have been stitched; the stitching method is the same as step S1, and the stitching position of the thread guide needle 1 and the thread hook component 2 must ensure that the thread guide needle 1 does not interfere with the single-sided chain stitch 5 left after the previous stitching when penetrating the newly stacked third preform 11 and passing through the upper surface thickness h of the previously stitched second preform 10; The splicing and sewing process of S22, the fourth preform, the fifth preform, the Nth preform, and the N+1th preform is the same as step S21, ensuring that the lead needle 1 does not interfere with the single-sided chain stitch 5 left by the Nth preform when penetrating the N+1th preform and only passing through the upper surface thickness h of the Nth preform, until the sewing preparation of the multi-layer composite material preform seam material 6 is completed.
[0042] like Figures 1 to 3 As shown, when the composite material preform seam material 6 is rectangular: In step S1 , when the composite material preform sewing material 6 is rectangular, the sewing path is a radial path, and the single-sided chain stitch 5 is a straight line.
[0043] In step S2, when the composite material preform sewing material 6 is rectangular, after the sewing of the two layers of composite material preform sewing material 6 is completed, the multi-degree-of-freedom robot arm 7 drives the thread guide needle 1 and the thread hook component 2 back to the top of the sewing starting point, and then a layer of the third preform 11 is stacked on the top of the two layers of composite material preform sewing material 6 that have been stitched; the multi-degree-of-freedom robot arm 7 drives the thread guide needle 1 and the thread hook component 2 or the multi-axis linked feeding workbench to translate a distance n along the stitched single-sided chain stitch 5 to achieve splicing and stitching in the same direction, ensuring that the thread guide needle 1 does not interfere with the stitches left after the previous stitching when penetrating the newly stacked third preform 11 and passing through a certain thickness of the upper surface layer of the second preform 10 that has been stitched before, and the stitching cycle and subsequent process are the same as step S1.
[0044] In step S2, when the composite material preform sewing material 6 is rectangular, after the sewing of the two layers of composite material preform sewing material 6 is completed, the multi-degree-of-freedom robot arm 7 drives the thread guide needle 1 and the thread hook component 2 back to the top of the sewing starting point, and rotates 90°, and then a layer of the third preform 11 is stacked on the top of the two layers of composite material preform sewing material 6 that have been stitched; the multi-degree-of-freedom robot arm 7 drives the thread guide needle 1 and the thread hook component 2 or the multi-axis linked feeding workbench to translate a distance n in a direction perpendicular to the stitched single-sided chain stitch 5 to achieve warp and weft interlaced splicing and stitching, ensuring that the thread guide needle 1 does not interfere with the stitches left after the previous stitching when penetrating the newly stacked third preform 11 and passing through a certain thickness of the upper surface layer of the second preform 10 that has been stitched before; the stitching cycle and subsequent processes are the same as step S1.
[0045] When the composite material preform seam material 6 is a hollow ring: like Figures 5 to 7 As shown, in step S1, when the composite material preform sewing material 6 is a hollow ring, the sewing path is a circular path, and the single-sided chain sewing stitch 5 is a ring.
[0046] Among them, when suturing through the circumferential path, the multi-degree-of-freedom mechanical arm 7, the thread guide needle 1 and the hook thread component 2 are first fixed, and the composite material preform sewing material 6 is placed on a multi-axis linkage feeding workbench (specifically a rotating workbench in this embodiment), and it can be suturing from the inner circle to the outer circle divergently, or it can be suturing from the outer circle to the inner circle contraction. When the multi-axis linkage feeding workbench drives the composite material preform sewing material 6 to rotate a circle to complete the suturing, it will stop rotating, and the multi-degree-of-freedom mechanical arm 7 drives the thread guide needle 1 and the hook thread component 2 to move a fixed distance in the radial direction, and then the multi-axis linkage feeding workbench continues to rotate to complete the next circle of sewing. Repeat the above steps to complete the whole circle of sewing, forming a number of single-sided chain suture stitches 5 of the circumferential path sewing, and completing the splicing and sewing of the two layers of composite material preform sewing material 6. The same method can be used to sequentially realize the sewing and molding preparation of multi-layer annular composite material preform sewing materials 6.
[0047] When the composite material preform seam material 6 is a hollow ring: like Figures 8 to 10 As shown, in step S1, when the composite material preform sewing material 6 is a hollow ring, the sewing path is a radial path, and the single-sided chain sewing stitch 5 is a straight line.
[0048] When suturing through a radial path, the composite material preform suturing material 6 is placed on a multi-axis linkage feeding workbench (specifically a rotating workbench in this embodiment), the multi-axis linkage feeding workbench is kept stationary first, and the multi-degree-of-freedom mechanical arm 7 drives the thread guide needle 1 and the thread hook component 2 to suturing radially from the inner circle to the outer circle. When the outer circle position is reached, the multi-axis linkage feeding workbench rotates an angle, and the multi-degree-of-freedom mechanical arm 7 drives the thread guide needle 1 and the thread hook component 2 to suturing radially from the outer circle to the inner circle. After reaching the inner circle position, the above steps are repeated until the composite material preform suturing material 6 is suturing around the entire circle, forming a number of single-sided chain stitches 5 suturing through the radial path, and completing the splicing and suturing of the two layers of composite material preform suturing material 6. The same method can realize the suturing and molding preparation of two-layer, five-layer, and multi-layer composite material preform suturing materials 6 in sequence.
[0049] When the composite material preform seam material 6 is a hollow ring: like Figures 11 to 13 As shown, in step S1, when the composite material preform sewing material 6 is a hollow ring, the sewing path is a warp and weft path, and the single-sided chain sewing stitch 5 is in a grid shape.
[0050] Among them, when suturing through the warp and weft paths, the composite material preform sewing material 6 is placed on a multi-axis linkage feeding workbench and remains stationary, and the multi-degree-of-freedom mechanical arm 7 drives the thread guide needle 1 and the hook thread component 2 to first sew along the weft path in an S-shaped path. After completing the whole-circle weft suturing, start the warp suturing, adjust the needle distance, and avoid interference with the stitches left by the weft suturing. Repeat the above steps to complete the whole circle of suturing, forming a number of single-sided chain suturing stitches 5 suturing in the warp and weft paths, completing the splicing and suturing of the two layers of composite material preform sewing material 6, and the same method can be used to realize the sewing and molding preparation of two-layer, five-layer, and multi-layer composite material preform sewing materials 6.
[0051] When the composite material preform seam material 6 is a hollow ring: like Fig.14 As shown, the inner and outer walls of the composite material preform sewing material 6 can also be sutured. When the hollow space in the composite material preform sewing material 6 is relatively large, the multi-degree-of-freedom robot arm 7, the guide needle 1 and the hook wire component 2 can suture in the hollow space, getting rid of the shortcomings of puncture molding being limited by the needle and shaft rod molding being limited by the Z-axis stroke.
[0052] The thread guide needle 1 has a constant radius of curvature, an embedding groove is formed inside the thread guide needle 1, and a thread passing groove is formed outside the thread guide needle 1; the thread hook component 2 is a horizontally arranged arc-shaped structure.
[0053] Among them, in step S1, the thickness H of the single-layer composite material preform sewing material 6 is 2-8mm; the thickness h of the upper surface layer is 2-5mm (if it is less than this thickness, the sewing effect of the lower preform is very poor, because this is the sewing thickness of the lower preform; and if it is greater than this thickness, it is limited by the curvature radius of the lead needle 1, and the sewing thickness can only be reduced, affecting the sewing effect).
[0054] The fixed needle distance a is 3-10mm; the moving distance m is 12-25mm.
[0055] Wherein, in step S2, the translation distance n is 2-5 mm, and the number of stitching layers of the composite material preform stitching material 6 does not exceed 100 layers.
[0056] Among them, the multi-degree-of-freedom robotic arm 7 can be used to drive the movement of the lead needle 1 and the hooking component 2, or the lead needle 1 and the hooking component 2 can be kept stationary while the feeding workbench moves in a multi-axis linkage manner; a corresponding stitch planning method is performed according to the shape of the three-dimensional composite material preform, so that a thicker three-dimensional composite material preform with simpler suturing process, higher suturing density and better suturing effect can be achieved.
[0057] like Figure 4As shown, the guide needle 1 and the thread hook component 2 are installed on a single-sided curved needle suture head 8, and the rotation of the guide needle 1 and the thread hook component 2 is realized by a single servo motor driving a synchronous belt mechanism. The single-sided curved needle suture head 8 is installed on a flange at the end of a multi-degree-of-freedom robotic arm 7, and the multi-degree-of-freedom robotic arm 7 drives the single-sided curved needle suture head 8 to perform suturing work.
[0058] Among them, the stitching is T300-6K carbon fiber.
[0059] The embodiments of the present invention are described in detail above, but the contents are only preferred embodiments of the present invention and cannot be considered to limit the scope of implementation of the present invention. All equivalent changes and improvements made within the scope of the present invention should still fall within the scope of the present invention.
Claims
1. A process for forming a thick composite material preform, characterized in that: The following steps are involved: S1. Sewing two layers of composite material preforms, each with a thickness of H: the two layers of composite material preforms include a first preform located at a lower layer and a second preform located at an upper layer; S11, the second preform and the first preform are stacked together, and the thread guide needle carries a single suture from the initial position of the thread guide needle above the second preform, penetrates the second preform in an arc-shaped trajectory, and then passes through the upper surface thickness h of the first preform, until the end of the thread guide needle with the suture passes through the upper surface of the second preform and reaches the termination position of the thread guide needle, and then begins to retreat along the original path; at the same time, the thread hooking component is horizontally rotated from the initial position of the thread hooking component above the second preform, until it reaches the termination position of the thread hooking component and then retreats along the original path; S12, during the retreat of the thread guide needle and the thread hooking component, the sutures on both sides of the thread guide needle body accumulate and form a thread loop; when the thread hooking component performs a horizontal rotational movement from the thread hooking component end position to the thread hooking component initial position, the thread loop formed by the thread guide needle is hooked, and then the thread loop is continued to move toward the thread hooking component initial position with the thread hooking component; S13, after the guide needle and the hooking thread component reach their respective initial positions, the multi-degree-of-freedom robotic arm drives the guide needle and the hooking thread component to move a fixed needle distance along the suture path direction, or the multi-axis linkage feeding workbench moves a fixed needle distance along the suture path direction, and after the movement, the guide needle carries the suture to puncture the second preform and the first preform again; S14, when the thread guide needle carries the suture through the second preform and the first preform, the needle tip of the thread guide needle passes through the old thread loop hooked by the thread hooking component last time, and then the thread guide needle continues to move toward the thread guide needle end position, and during the process of the thread hooking component rotating horizontally to the thread hooking component end position, the old thread loop is thrown out, and the thrown out old thread loop forms a thread loop locking knot with the passed suture; S15, the thread guide needle and the thread hook component retreat again, the suture at the end of the thread guide needle accumulates and forms a new thread loop; the thread hook component hooks the new thread loop formed by the thread guide needle, and then the thread guide needle and the thread hook component respectively carry the suture and the new thread loop and continue to move to their respective initial positions, completing a suturing cycle; S16, after multiple suturing cycles from step S11 to step S15, a continuous single-sided chain suturing stitch is formed; S17, after completing a unilateral chain stitching line, the multi-degree-of-freedom robotic arm drives the thread guide needle and the thread hook component or the multi-axis linkage feeding workbench to move a distance to continue the stitching work, until a plurality of unilateral chain stitching lines are formed, and the stitching preparation of the two-layer composite material preform is completed; S2. Splicing and stitching of multi-layer composite material preforms: S21, after the sewing of the two layers of composite material preforms is completed, a third preform is stacked on top of the two layers of composite material preforms that have been sewn together; the sewing method is the same as step S1; The splicing and sewing process of S22, the fourth preform, the fifth preform, the Nth preform, and the N+1th preform is the same as step S21, ensuring that when the lead needle penetrates the N+1th preform and only passes through the upper surface thickness h of the Nth preform, it does not interfere with the single-sided chain stitch left by the Nth preform, until the sewing preparation of the multi-layer composite material preform seam material is completed.
2. The process for forming a thick composite material preform according to claim 1, characterized in that: In step S1, when the composite material preform sewing material is rectangular, the sewing path is a radial path, and the single-sided chain stitch is a straight line.
3. The process for forming a thick composite material preform according to claim 2, characterized in that: In step S2, when the composite material preform seam is a rectangle, after the sewing of two layers of composite material preform seams is completed, the multi-degree-of-freedom robotic arm drives the thread guide needle and the thread hook component back to the top of the sewing starting point, and then a layer of the third preform is stacked on top of the two layers of composite material preform seams that have been sewn; the multi-degree-of-freedom robotic arm drives the thread guide needle and the thread hook component or the multi-axis linked feeding workbench to translate along the stitched single-sided chain stitch line to achieve splicing and sewing in the same direction.
4. The process for forming a thick composite material preform according to claim 2, characterized in that: In step S2, when the composite material preform seam is rectangular, after the sewing of two layers of composite material preform seams is completed, the multi-degree-of-freedom robotic arm drives the thread guide needle and the thread hook component back to the top of the sewing starting point, and rotates 90°, and then a layer of the third preform is stacked on top of the two layers of composite material preform seams that have been sewn; the multi-degree-of-freedom robotic arm drives the thread guide needle and the thread hook component or the multi-axis linked feeding workbench to translate in a direction perpendicular to the stitched single-sided chain stitch, so as to realize the warp and weft interlaced splicing and sewing.
5. The process for forming a thick composite material preform according to claim 1, characterized in that: In step S1, when the composite material preform sewing material is a hollow ring, the suture path is a circumferential path, and the unilateral chain suture stitch is a ring. When sewing through the circumferential path, the thread guide needle and the thread hook component are first fixed, and the composite material preform sewing material is placed on a multi-axis linkage feeding workbench, and sewed divergently from the inner circle to the outer circle or sewed contractively from the outer circle to the inner circle. When the multi-axis linkage feeding workbench drives the composite material preform sewing material to rotate one circle to complete the sew, the rotation is stopped, and the multi-degree-of-freedom robotic arm drives the thread guide needle and the thread hook component to move a fixed distance in the radial direction, and then the multi-axis linkage feeding workbench continues to rotate to complete the next circle of sew, until the whole circle of sew is completed, forming a number of unilateral chain suture stitches sewed in the circumferential path, and completing the splicing and sew of the two layers of composite material preform sewing materials.
6. The process for forming a thick composite material preform according to claim 1, characterized in that: In step S1, when the composite material preform sewing material is a hollow ring, the suture path is a radial path, and the unilateral chain suture stitch is a straight line. When sewing through the radial path, the composite material preform sewing material is placed on a multi-axis linkage feeding workbench, the multi-axis linkage feeding workbench is first kept stationary, and the multi-degree-of-freedom robotic arm drives the thread guide needle and the hook thread component to sew radially from the inner circle to the outer circle. When reaching the outer circle position, the multi-axis linkage feeding workbench rotates an angle, and the multi-degree-of-freedom robotic arm drives the thread guide needle and the hook thread component to sew radially from the outer circle to the inner circle until the composite material preform sewing is completed in a whole circle, forming a plurality of unilateral chain suture stitches sewed in the radial path, and completing the splicing and sew of the two layers of composite material preform sewing materials.
7. The process for forming a thick composite material preform according to claim 1, characterized in that: In step S1, when the composite material preform sewing material is a hollow ring, the suture path is a warp and weft path, and the unilateral chain suture stitch is in a grid shape. When sewing through the warp and weft paths, the composite material preform sewing material is placed on a multi-axis linked feeding workbench and remains stationary. The multi-degree-of-freedom robotic arm drives the thread guide needle and the hook thread component to first sew along the weft path in an S-shaped path. After completing the weft suturing of the entire circle, the warp suturing is started until the entire circle is sewn, forming a number of unilateral chain suture stitches sewed in the warp and weft paths, thereby completing the splicing and suturing of the two layers of composite material preform sewing materials.
8. The process for forming a thick composite material preform according to claim 1, characterized in that: When the composite material preform is a hollow ring and the hollow space is relatively large, the multi-freedom robot arm drives the thread guide needle and the thread hook component to sew in the hollow space to achieve the sew of the inner wall and the outer wall of the ring-shaped composite material preform.
9. The process for forming a thick composite material preform according to claim 1, characterized in that: The thickness H of the single-layer composite material preform seam material is 2-8 mm; the thickness h of the upper surface layer is 2-5 mm.
10. The process for forming a thick composite material preform according to any one of claims 1 to 9, characterized in that: The guide needle and the thread hook component are installed on a single-sided curved needle suture head, and the rotation of the guide needle and the thread hook component is realized by a single servo motor driving a synchronous belt mechanism. The single-sided curved needle suture head is installed on a flange at the end of a multi-degree-of-freedom robotic arm, and the multi-degree-of-freedom robotic arm drives the single-sided curved needle suture head to perform suturing work.