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CN-121973474-A - Continuous pultrusion device for hollow composite material pipe with sandwich structure and working method thereof

CN121973474ACN 121973474 ACN121973474 ACN 121973474ACN-121973474-A

Abstract

A continuous pultrusion device for hollow composite material pipes with sandwich structures and a working method thereof belong to the technical field of composite material molding. The frame body is fixedly provided with a preformed plate and a closed die glue injection forming die, the preformed plate is coaxially positioned in front of an inlet of the closed die glue injection forming die, the preformed plate is matched with a feeding system, the middle parts of the preformed plate and the closed die glue injection forming die are coaxially inserted with an inner core rod which is horizontally arranged, one end of the inner core rod is fixed on the frame body, the other end of the inner core rod extends into the closed die glue injection forming die, and a traction and cutting system is arranged behind a discharge of the closed die glue injection forming die. According to the invention, the material friction force in the pultrusion process is reduced, the fiber damage is avoided, the accurate positioning of the carbon fiber-foam-carbon fiber sandwich structure is realized, the stability of the cross section size of the product is ensured, the interfacial peel strength is improved, the on-line composite forming problem of the structure is solved, and the production efficiency is improved.

Inventors

  • LI SHUMAO
  • LIN DONGSHENG
  • GAO JINPING

Assignees

  • 广联航宇(哈尔滨)新材料科技有限公司

Dates

Publication Date
20260505
Application Date
20260128

Claims (8)

  1. 1. The continuous pultrusion device for the hollow composite material pipe with the sandwich structure is characterized by comprising a frame body (3), a preformed plate (4), an inner core rod (5), a closed mold glue injection forming die (6), a traction and cutting system (10) and a feeding system, wherein the preformed plate (4) and the closed mold glue injection forming die (6) are fixed on the frame body (3), the preformed plate (4) is coaxially positioned in front of an inlet of the closed mold glue injection forming die (6), the preformed plate (4) is matched with the feeding system, the middle parts of the preformed plate (4) and the closed mold glue injection forming die (6) are coaxially inserted with an inner core rod (5) which is horizontally arranged, one end of the inner core rod (5) is fixed on the frame body (3), the other end of the inner core rod (5) extends into the closed mold glue injection forming die (6), and the traction and cutting system (10) is arranged behind a discharge of the closed mold glue injection forming die (6).
  2. 2. The continuous pultrusion device for hollow composite pipes with the sandwich structure according to claim 1, wherein the preformed plate (4) comprises a front plate (401) and a rear plate (402), the rear plate (402) is coaxially arranged between the front plate (401) and an inlet of a closed die injection molding die (6), an inner core rod through hole (403) is formed in the center of the front plate (401), an inner hole group and an outer hole group which are concentrically arranged with the inner core rod through hole (403) are sequentially arranged on the outer side of the inner core rod through hole (403), the inner hole group comprises a plurality of inner holes (404) which are uniformly distributed along the circumferential direction of the inner core rod through hole (403), the outer hole group comprises a plurality of outer holes (405) which are uniformly distributed along the circumferential direction of the inner core rod through hole (403), two arc-shaped guide sliding grooves (406) which are symmetrically arranged along the center of the front plate (401) are arranged between the inner hole group and the outer hole group, the outer hole (404) is used for guiding fiber bundles of inner layer carbon fibers to pass through, the outer layer carbon fibers are used for guiding the outer layer carbon fibers to pass through, the outer layer carbon fibers are used for being converted into a large-shaped like a foam, and the same plane, and the inner layer carbon fibers are used for being formed by the inner layer carbon fibers, and the inner layer carbon fibers are formed by the inner layer, and the carbon fibers are formed by the carbon fibers, and the carbon fibers.
  3. 3. The continuous pultrusion device for hollow composite pipes with the sandwich structure according to claim 2, wherein the feeding system comprises a double-layer creel (1) and a core material discharging frame (2), the double-layer creel (1) is used for placing inner-layer carbon fiber yarn groups and outer-layer carbon fiber yarn groups respectively, fiber yarns of the inner-layer carbon fiber yarn groups sequentially penetrate through an inner hole (404) and a through hole (407) and then enter an inlet of a closed-die glue injection molding die (6), fiber yarns of the outer-layer carbon fiber yarn groups sequentially penetrate through the through hole (407) of an outer hole (405) and then enter an inlet of the closed-die glue injection molding die (6), the core material discharging frame (2) is used for installing a flexible foaming paper roll, and flexible foaming paper of the flexible foaming paper roll sequentially penetrates through an arc-shaped guide chute (406) and the through hole (407) and then enters the inlet of the closed-die glue injection molding die (6).
  4. 4. A continuous pultrusion device for hollow composite pipes with sandwich structures according to claim 3 is characterized in that the closed-die glue injection molding die (6) comprises a glue injection cavity (7), a die cavity (8) and a heating system (9), wherein the glue injection cavity (7) is positioned at the front end of the die cavity (8), the glue injection cavity (7) is connected with a high-pressure glue injection machine and is used for receiving epoxy resin injected at high pressure, a plurality of discharging ends (701) of the glue injection cavity (7) are arranged along the pultrusion direction, each discharging end (701) is annular, the inner wall of the die cavity (8) is arranged in a ring shape and is communicated with the die cavity (8), the die cavity (8) is used for providing a closed space for material molding, and the heating system (9) is arranged below the die cavity (8) and comprises three sections of independent heating plates and is used for forming a gradient temperature field along the pultrusion direction in the die cavity (8) so as to provide temperature conditions for in-situ expansion of flexible foaming paper and curing of the epoxy resin.
  5. 5. The continuous pultrusion device for hollow composite tubes with sandwich structure according to claim 4, wherein three sections of the heating plates comprise: A first temperature zone (901), namely a glue injection zone, is used for reducing the viscosity of the epoxy resin, so that the epoxy resin fully infiltrates the carbon fiber bundles and the flexible foaming paper; A second temperature zone (902), namely an expansion triggering zone, for triggering the expansion of the flexible foaming paper to generate in-situ internal pressure; Wen Ousan (903), i.e., a cure molding zone, for rapid cross-linking curing of the epoxy.
  6. 6. The continuous pultrusion device for hollow composite pipes with sandwich structures according to claim 1, wherein the inner core rod (5) is a chromed steel rod.
  7. 7. A method of operating a continuous pultrusion device for hollow composite tubes having a sandwich structure according to any of the claims 1-6, characterized in that the method comprises the steps of: S1, sequentially passing inner-layer carbon fiber yarns through inner holes (404) corresponding to a preforming plate (4), sequentially passing outer-layer carbon fiber yarns through outer holes (405) corresponding to the preforming plate (4), sequentially passing flexible foam paper through arc-shaped guide-in sliding grooves (406) corresponding to the preforming plate (4), and forming an inner-layer carbon fiber-flexible foam paper-outer-layer carbon fiber dry preforming assembly taking an inner core rod (5) as a center; S2, starting a crawler tractor of a traction and cutting system (10), and simultaneously starting a high-pressure glue injection machine to inject epoxy resin into a glue injection cavity (7), wherein the epoxy resin forcedly permeates fiber bundles of inner-layer carbon fibers and outer-layer carbon fibers from outside to inside under the action of pressure and wraps flexible foaming paper, so that the primary infiltration of materials of each layer is realized; s3, entering the preformed assembly into a die cavity (8) along with traction force, and sequentially completing infiltration, in-situ expansion compaction and solidification in a gradient temperature field formed by a heating system (9); And S4, pulling out the closed mold glue injection molding mold (6) by a crawler tractor of the traction and cutting system (10) after the high-temperature curing of the molded pipe, and then automatically cutting off the molded pipe according to a set length by a cutting saw of the traction and cutting system (10) to obtain the finished carbon fiber hollow sandwich pipe.
  8. 8. The method according to claim 7, characterized in that the heating of the heating system (9) S3 comprises the steps of: S301, in a glue injection area, reducing the viscosity of epoxy resin to enable the epoxy resin to fully infiltrate carbon fiber bundles and flexible foaming paper; S302, in an expansion triggering area, the flexible foaming paper is heated, gasified and expanded, and the epoxy resin is not gel at the moment and still has fluidity, and because of the space limitation of a die cavity (8) and an inner core rod (5), the in-situ internal pressure generated by the expansion of the flexible foaming paper, namely radial expansion pressure, is converted into bidirectional extrusion force on an inner skin and an outer skin, the inner carbon fiber and the inner core rod are compacted inwards, the outer carbon fiber and the inner wall of the die cavity (8) are compacted outwards, the epoxy resin is pressed into fiber gaps, and meanwhile, a foam core layer is expanded to a preset thickness accurately; S302, in a curing forming area, the epoxy resin is rapidly crosslinked and cured, and the sandwich structure of the inner carbon fiber layer, the foam core layer and the outer carbon fiber layer is locked.

Description

Continuous pultrusion device for hollow composite material pipe with sandwich structure and working method thereof Technical Field The invention relates to a continuous pultrusion device for hollow composite material pipes with a sandwich structure and a working method thereof, belonging to the technical field of composite material molding. Background The pultrusion of hollow composite material pipe is a common continuous production process, and the traditional hollow composite material pipe pultrusion process mainly depends on a rigid inner core mold to support and position fiber materials so as to ensure the forming precision and structural integrity of the pipe. When manufacturing the sandwich structure pipe, the traditional technical scheme faces a plurality of technical pain points which are difficult to solve: Firstly, the friction moment is huge, the contact area between the material and the inner core die and the outer die is increased due to the introduction of the sandwich structure, so that the traction force required in the pultrusion process is greatly improved, the carbon fiber is easily damaged due to friction due to the excessively high traction force, and the mechanical property of the product is influenced; Secondly, the interlayer positioning precision is low, a prefabricated rigid foam ring cannot pass through a long-distance guide system, and in the continuous pultrusion process, concentricity of an inner layer carbon fiber, an outer layer carbon fiber and a foam layer is difficult to ensure, and the problems of interlayer deviation, uneven thickness and the like are easy to occur; thirdly, the interface bonding defect, the traditional process lacks an effective internal compaction mechanism, so that a glue-poor area or an air gap is easily generated between the inner carbon fiber skin and the foam core material, and the interface bonding strength and the overall structural stability of the sandwich structure are seriously affected. Disclosure of Invention In order to solve the problems in the background technology, the invention provides a continuous pultrusion device for hollow composite material pipes with a sandwich structure and a working method thereof. The technical scheme is that the continuous pultrusion device for the hollow composite material pipe with the sandwich structure comprises a frame body, a preformed plate, an inner core rod, a closed die glue injection forming die, a traction and cutting system and a feeding system, wherein the preformed plate and the closed die glue injection forming die are fixed on the frame body, the preformed plate is coaxially positioned in front of an inlet of the closed die glue injection forming die, the preformed plate is matched with the feeding system, the middle parts of the preformed plate and the closed die glue injection forming die are coaxially inserted with the inner core rod which is horizontally arranged, one end of the inner core rod is fixed on the frame body, the other end of the inner core rod extends into the closed die glue injection forming die, and the traction and cutting system is arranged behind a discharge of the closed die glue injection forming die. The pre-forming plate comprises a front plate and a rear plate, wherein the rear plate is coaxially arranged between the front plate and an inlet of a closed die glue injection forming die, an inner core rod through hole is formed in the center of the front plate, an inner hole group and an outer hole group which are concentrically arranged on the outer side of the inner core rod through hole are sequentially arranged on the inner side of the inner core rod through hole, the inner hole group comprises a plurality of inner holes which are uniformly distributed along the circumferential direction of the inner core rod through hole, the outer hole group comprises a plurality of outer holes which are uniformly distributed along the circumferential direction of the inner core rod through hole, two arc-shaped guide sliding grooves which are symmetrically arranged along the center of the front plate are arranged between the inner hole group and the outer hole group, the inner holes are used for guiding fiber bundles of an inner layer carbon fiber skin to pass through, the arc-shaped guide sliding grooves are used for guiding flexible foaming paper to be changed into a cambered surface shape from a plane shape, and through holes which are concentric with the inlet of the closed die glue injection forming die are formed in the center of the rear plate. The feeding system comprises a double-layer creel and a core material discharging frame, wherein the double-layer creel is used for placing an inner-layer carbon fiber yarn group and an outer-layer carbon fiber yarn group respectively, fiber yarns of the inner-layer carbon fiber yarn group sequentially pass through an inner hole and a through hole and then enter an inlet of a closed mold glue injection molding die, fiber yarns of