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CN-117512878-B - Single knitting forming device and method for three-dimensional preform

CN117512878BCN 117512878 BCN117512878 BCN 117512878BCN-117512878-B

Abstract

The invention discloses a device and a method for forming a three-dimensional preform by single knitting. The weaving and forming method of the device comprises the steps of moving output yarns in the guide array above the lower pore plate through the mechanical arm, compacting the prefabricated body downwards along the guide rail by the upper pore plate after one layer of the weaving is finished, weaving the prefabricated body with large thickness after multiple times of weaving and compacting, improving the dimensional precision of the prefabricated body component and improving the mechanical property of the prefabricated body. Compared with the prior art, the method realizes the weaving of the large-thickness preform, and solves the problems of low interlayer strength, easy layering and low impact toughness and damage tolerance of the preform in the thickness direction.

Inventors

  • SHAN ZHONGDE
  • GUO KEHONG
  • SUN ZHENG
  • WANG YONGLI
  • TAN CHENCHEN
  • Bian Jinshuai

Assignees

  • 南京航空航天大学

Dates

Publication Date
20260512
Application Date
20231108

Claims (7)

  1. 1. A three-dimensional preform single knitting forming device is characterized by comprising a yarn discharging mechanism (10), a guiding mechanism (20) and a compacting mechanism (30), wherein the yarn discharging mechanism (10) comprises a mechanical arm (101) and a hollow needle (102) at the tip of the mechanical arm, the guiding mechanism (20) comprises a plurality of guiding rods (201) and a guide rail (202), the compacting mechanism (30) comprises an upper pore plate (301), a lower pore plate (302) positioned below the upper pore plate (301), a first steel bar frame fixed on the lower side of the upper pore plate (301), a second steel bar frame fixed on the upper side of the lower pore plate (302), a top plate (308), a bottom plate (309) positioned below the top plate (308), a screw rod (307) penetrating through the top plate (308) from top to bottom, a motor (304), a screw rod lifter (305) connected with the motor (304) and a linkage shaft (306), the guiding rods (201) penetrate through the lower pore plate (302) and the second steel bar frame from bottom to top, the guide rail (202) penetrates through the upper pore plate (301) along the vertical direction, two ends of the guide rail (202) are fixed on the periphery of the bottom plate (303), the first steel bar frame and the second steel bar frame comprises a plurality of steel bars (201) penetrating through the hollow-shaped steel bar frames respectively, the yarn feeding mechanism comprises a hollow part, a guide rod array, a yarn discharging mechanism (10), a compacting mechanism (30), a mechanical arm (101), a plurality of guide rods (201) and a compacting mechanism (30), wherein the hollow part is matched with the guide rod array, the linkage shaft (306) is connected with the two screw rod lifters (305), the yarn discharging mechanism (10) outputs yarn between the guide rods (201) and moves along a guide rail (202), the mechanical arm (101) is a six-axis mechanical arm, the guide rods (201) are orderly arranged to form the guide array, and the compacting mechanism (30) realizes that the two screw rod lifters (305) simultaneously control screw rods (307) to rotate through the linkage shaft (306), so that the compacting mechanism (30) moves along the guide rail (202).
  2. 2. The three-dimensional preform single knitting forming device according to claim 1, characterized in that the yarn exit mechanism (10) is independent from the guiding mechanism (20) and the compacting mechanism (30).
  3. 3. The three-dimensional preform single knitting forming device of claim 1, characterized in that the hollow needle (102) of the robotic arm tip has yarn passing through it.
  4. 4. The three-dimensional preform single knitting forming device according to claim 1, characterized in that the guide rail (202) is provided with four and the screw (307) is provided with two.
  5. 5. The three-dimensional preform single knitting forming device of claim 1 wherein the hollowed-out portion has a shape conforming to an exterior shape to be achieved by the preform.
  6. 6. A weaving forming method using the three-dimensional preform single knitting forming device according to any one of claims 1 to 5, characterized by comprising the steps of: a) Calculating the diameter and the distance between the guide rods (201) according to the structure of the prefabricated body, forming holes on the upper pore plate (301) and the lower pore plate (302), and enabling the guide rods (201) to penetrate through the lower pore plate; b) According to the designed prefabricated body, the mechanical arm (101) is operated to enable the hollow needles (102) in the yarn outlet mechanism (10) to orderly move in the guide array, and meanwhile, yarn is output and wound on the guide rod (201); c) After one layer of knitting is completed, the mechanical arm (101) is lifted, the upper pore plate (301) is controlled to move downwards along the guide rail (202) and cover the lower pore plate (302), then the upper pore plate (301) is enabled to move upwards along the guide rail (202), the initial position is returned, and the compaction is completed repeatedly; d) Repeating the steps b) and c) until the weaving of the designed preform is completed; e) After the last compaction is finished, the upper pore plate (301) is pressed on the lower pore plate (302), the two steel bar frames (303) are fixed together, and then the two steel bar frames (303) and the guide rod (201) are taken down together; f) And removing the guide rod (201), and replacing the guide rod (201) with yarn at the original position of the preform to complete the knitting of the large-thickness preform.
  7. 7. The method of forming a three-dimensional preform single knit forming device according to claim 6 wherein said step b) moves the hollow needle (102) along 0 ° or 45 ° or 90 ° in the guide array.

Description

Single knitting forming device and method for three-dimensional preform Technical Field The invention relates to the technical field of weaving and forming of three-dimensional preforms, in particular to a device and a method for forming a single knitting of a three-dimensional preform. Background The digital single knitting forming system and equipment are suitable for preparing large-scale, variable-section, high-density and high-performance fiber composite material components, can realize fiber directional layout of single fibers and an overall preform structure, and realize three-dimensional structure weaving and forming of complex composite material preforms. At present, the three-dimensional woven preform forming equipment can only weave a few thinner preforms, is difficult to realize integrated forming aiming at a composite material component preform with larger thickness, is usually realized by adopting a multi-layer superposition and stitching method, and has the problems of low interlayer strength, easy layering, low impact toughness, low damage tolerance and low efficiency in the thickness direction of the preform, and has important influence on the dimensional accuracy and mechanical property of the preform component. Therefore, there is a need to design a single knitting forming device of a large thickness three-dimensional preform to solve the above-mentioned problems. Disclosure of Invention The invention aims to solve the problems, and provides a device and a method for forming a three-dimensional preform by single knitting, which solve the problems of low interlayer strength, easiness in layering and low impact toughness and damage tolerance of the preform in the thickness direction and can weave a preform with large thickness. The technical scheme includes that the three-dimensional preform single knitting forming device comprises a yarn discharging mechanism, a guiding mechanism and a compacting mechanism, wherein the yarn discharging mechanism comprises a mechanical arm and hollow needles at the tip of the mechanical arm, the guiding mechanism comprises a plurality of guiding rods and a guide rail, the compacting mechanism comprises an upper orifice plate, a lower orifice plate positioned below the upper orifice plate, a first steel rod frame fixed on the lower side of the upper orifice plate, a second steel rod frame fixed on the upper side of the lower orifice plate, a top plate, a bottom plate positioned below the top plate, a screw rod penetrating through the top plate from top to bottom, a motor, screw rod lifters connected with the motor and a linkage shaft, the guiding rods penetrate through the lower orifice plate and the second steel rod frame from bottom to top, the guide rail penetrates through the upper orifice plate in the vertical direction, two ends of the guide rail are fixed on the periphery of the top plate and the bottom plate, the steel rod frames comprise hollow rectangular parts, the guiding rods penetrate through the hollow parts, the hollow parts are matched with the guiding rod arrays, the linkage shaft is connected with the two screw rod lifters, and the yarn discharging mechanism outputs yarns along the guide rail between the guiding mechanisms. Further, the yarn outlet mechanism is independent of the guide mechanism and the compaction mechanism. Further, the mechanical arm is a six-axis mechanical arm. Further, the hollow needle at the tip of the mechanical arm is penetrated by yarns. Further, the plurality of guide bars are orderly arranged to form a guide array. Further, the guide rails are four, and the screw rods are two. Further, the compaction mechanism realizes that the two screw lifters simultaneously control the screw to rotate through the linkage shaft, so that the compaction mechanism moves along the guide rail. Further, the shape of the hollowed-out part is consistent with the external shape to be achieved by the preform. The weaving and forming method of the three-dimensional preform single-knitting forming device adopts the following technical scheme that: a) Calculating the diameter and the distance of the guide rods according to the structure of the prefabricated body, forming holes in the upper pore plate and the lower pore plate, and enabling the guide rods to penetrate through the lower pore plate; b) According to the designed preform, the mechanical arm is operated to enable the hollow needles in the yarn outlet mechanism to orderly move in the guide array, and simultaneously yarn is output and wound on the guide rod; c) After one layer of braiding is completed, the mechanical arm is lifted, the upper pore plate is controlled to move downwards along the guide rail and cover the lower pore plate, then the upper pore plate is enabled to move upwards along the guide rail, the original position is returned, and the compaction is completed repeatedly; d) Repeating the steps b) and c) until the weaving of the designed preform is completed; e) Aft