A method for manufacturing a continuous fiber composite material spring, a production line and a spring
By wrapping the thermoplastic film outside the continuous fiber bundle and applying circumferential spiral extrusion pressure, the problem of dripping and deformation of the matrix material during the manufacturing spring of the continuous fiber composite material is solved, and a high-density and low-cost production process is achieved, ensuring that Production continuous and dimensional accuracy.
Patent Information
- Application Number
- CN202010130469.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2020-02-28
- Publication Date
- 2024-12-17
- Estimated Expiration
- 2040-02-28
AI Technical Summary
In the prior art, during the manufacturing spring of continuous fiber composite material, a large amount of matrix material drips during the conveying of fiber bundles to be cured due to multiple infiltrating the matrix material, resulting in a decrease in the resin content of the product, pollution of the production line, difficulty in mold removal and high cleaning costs. , and thermoplastic coating has problems of deformation or cracking, making it difficult to achieve continuous production.
The thermoplastic film is wound outside the initial continuous fiber bundle, and a circumferential spiral extrusion pressure is applied through the spiral extrusion tube to form the fiber bundle to be cured, avoiding the dripping of the matrix material, improving the fiber density and dimensional accuracy, reducing the cleaning process, and reducing production costs. .
Effectively control the resin content, reduce the cleaning process, improve fiber density and dimensional accuracy, avoid deformation of thermoplastic materials, achieve continuous production, and reduce production costs.
Smart Images
Figure CN113320125B_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the application field of continuous fiber composite materials, and in particular to a method for manufacturing a continuous fiber composite material spring, a production line suitable for continuous fiber composite material springs, and a spring made of continuous fiber composite materials. Background Art
[0002] In the prior art, springs are made of continuous fiber composite materials. The fibers / rovings are impregnated with matrix materials and then twisted into fiber bundles. The fibers are heated and cured in a spring forming and curing mold to form springs. During the winding process of the fibers being applied to the spring core, they are impregnated with matrix materials (such as resin) for multiple times, thereby forming wet fiber bundles to be cured. The fiber bundles to be cured are then wound on the spring forming and curing mold using spiral grooves corresponding to the geometry and size of the spring and heated and cured.
[0003] At present, the main disadvantage of this method is that due to multiple impregnations, a large amount of matrix material will drip during the transportation of the fiber bundle to be cured, resulting in a reduction in the resin content of the product and serious contamination of the spring production line.
[0004] In particular, it causes the fiber bundle to be cured to adhere to the parts of the spring forming and curing mold, which makes it extremely difficult to demould the spring forming, and also pollutes the spiral groove of the spring forming and curing mold, which causes the fiber bundle to be cured to adhere to the parts of the spring forming and curing mold, and the product size cannot be effectively controlled, resulting in a large tolerance. In addition, the matrix material bonded to the spiral groove in the spring forming and curing mold is difficult to remove, and it will also incur high cleaning costs. Within a certain production cycle, it will lead to a long downtime for cleaning, so it is impossible to achieve a continuous production process.
[0005] In the patent application with application number: CN201380072982.9 and application name: Apparatus and method for manufacturing springs from continuous fiber composite materials, the following problems exist: In the process of manufacturing springs from existing continuous fiber composite materials, thermoplastic plastics are coated on the outside of the fiber bundles to be cured, which cannot ensure a smooth and uniform surface and will cause dripping of the thermoplastic plastics, causing environmental pollution and cleaning costs. At the same time, the presence of matrix material will also cause the coated thermoplastic material to be unable to form an effective wrapping on the surface of the fiber bundles to be cured. At the same time, when the fiber bundles to be cured are cured and formed by passing through the spring forming and curing mold, high-temperature curing will undoubtedly cause deformation or cracking of the thermoplastic material.
[0006] If a metal plate is used to cover the outer surface of the fiber bundle to be cured, there are many problems such as insufficient softness, waste of resources, high production cost, poor elasticity, and difficulty in unwinding. Summary of the invention
[0007] Technical problem to be solved by the present invention: The purpose of the present invention is to solve the deficiencies in the prior art and to provide a method for manufacturing continuous fiber composite springs which is clean and hygienic, has low production costs, and does not affect the original properties of the cured fiber bundles.
[0008] Technical solution of the present invention: A method for manufacturing a continuous fiber composite spring according to the present invention comprises the following steps:
[0009] Step 1: coating a fiber bundle consisting of continuous fibers with a matrix material to form an initial continuous fiber bundle;
[0010] Step 2: wrapping a layer of thermoplastic film around the initial continuous fiber bundle to form a continuous fiber bundle to be pressurized;
[0011] Step 3: applying a circumferential spiral extrusion force on the continuous fiber bundle to be pressurized to form a continuous fiber bundle to be solidified;
[0012] Step 4: feeding the to-be-cured continuous fiber bundle into a spring forming and curing mold for curing and forming.
[0013] Furthermore, the circumferential spiral extrusion force is applied by a spiral extrusion tube; when the continuous fiber bundle to be pressurized passes through the spiral extrusion tube, the continuous threaded protrusions in the spiral extrusion tube generate a circumferential spiral extrusion force on the continuous fiber bundle to be pressurized entering the tube, and the thermoplastic film and fiber filaments originally wrapped around the continuous fiber bundle to be pressurized are pressed along the spiral line toward the axial direction of the continuous fiber bundle to be pressurized, and the original straight-line movement of the continuous fiber bundle to be pressurized is changed into spiral movement through extrusion.
[0014] Furthermore, the initial continuous fiber bundle comprises: multiple fiber bundles are drawn out from the initial tension creel, impregnated in an impregnation tank, and then passed through a winding machine and a second winding creel to form an initial continuous fiber bundle of a multi-axial continuous fiber composite material.
[0015] The present application also includes a production line suitable for continuous fiber composite springs, including an initial tension yarn frame, a first impregnation device, a bidirectional fiber winding machine, a second winding yarn frame, a second impregnation device and a spring forming and curing mold placed in sequence; between the second impregnation device and the spring forming and curing mold, a film winding machine and a circumferential spiral extruder are provided; the circumferential spiral extruder includes a spiral extrusion tube; a plurality of continuous threaded protrusions are evenly distributed on the inner wall of the spiral extrusion tube, and the two adjacent threaded protrusions form a spiral groove in the spiral extrusion tube.
[0016] Furthermore, the spiral extruded tube includes a fixed Hough tube and a movable Hough tube that matches the fixed Hough tube to form a closed cylindrical tube.
[0017] Furthermore, the cross section of the pattern protrusion is trapezoidal.
[0018] Furthermore, the spring forming and curing mold is arranged on a multi-head mold rotator, and the multi-head mold rotator can be provided with a plurality of spring forming and curing molds.
[0019] The present application also includes a spring made of a continuous fiber composite material. The continuous fiber bundle used to make the spring is compressed by a circumferential spiral extrusion force before solidification and molding, and a continuous and uninterrupted indentation is left on the spring after solidification.
[0020] The beneficial effects of the present invention compared with the prior art are as follows:
[0021] 1. Wrapping a thermoplastic film around the continuous fiber bundle to be cured directly wraps the fiber bundle to be cured, thereby preventing the matrix material from dripping and adhering to the spring forming and curing mold, effectively controlling the resin content of the product, greatly reducing the cleaning process, and reducing the production links; at the same time, the process of wrapping the thermoplastic film around the fiber bundle to be cured will produce secondary tightening of the fiber bundle to be cured, reducing the gaps and bubbles between the fiber filaments constituting the continuous fiber bundle to be cured, and increasing the density of the continuous fiber composite spring after curing; at the same time, the fiber bundle wrapped with the thermoplastic film will further squeeze the fiber bundle to be cured after circumferential spiral extrusion, further increasing the density of the continuous fiber bundle to be cured, and at the same time, the thermoplastic film and the continuous fiber bundle to be cured can be further compressed, at this time, the thermoplastic film wrapped around the fiber bundle to be cured can also prevent the fiber bundle to be cured from bursting and scattering under stress, thereby improving the external dimensional accuracy of the product.
[0022] 2. The existing twisting and tightening adopts a screwing method to fix one end of the fiber bundle and grasp the fiber bundle at the other end to drive the fiber bundle to rotate and apply a tightening force to the fiber bundle. The rotation is transmitted to the rear end through the fiber bundle body, which will cause the front fiber bundle to be subjected to large force and the rear fiber bundle to be subjected to small force. At the same time, the magnitude of the force is not easy to control during the tightening process, and excessive force will also cause fiber breakage in the fiber bundle. Moreover, since the continuous fiber bundle is a soft linear material before solidification and molding, conventional twisting, twisting and tightening will inevitably cause compression in the length direction. After processing and molding, there will be difficult to eliminate internal stress. Before the continuous fiber composite material spring is formed, this method uses a circumferential spiral extrusion force to force the continuous fiber filaments to be pressed toward the axis of the continuous fiber bundle, and the original straight line travel is changed to a spiral travel through extrusion. The sleeve method is used to apply an overall circumferential spiral extrusion force to a section of the continuous fiber bundle to be pressurized that passes through the spiral extrusion tube. The magnitude of the force is uniform, and there will be no local uneven force phenomenon, so there will be no compression in the length direction, resulting in the problem of being unable to eliminate internal stress.
[0023] 3. After the fiber bundles are cured through the spiral extrusion tube, the surface will have a unique indentation, which can enhance the recognition of the product. At the same time, the indentation can be changed according to the shape of the inner thread protrusion of the spiral extrusion tube, which is highly variable and can be applied to the production of different requirements and different products. BRIEF DESCRIPTION OF THE DRAWINGS
[0024] Figure 1 It is a schematic diagram of the overall structure of the spring production line of the present invention;
[0025] Figure 2 is a cross-sectional schematic diagram of a spiral extruded tube;
[0026] Figure 3 It is a schematic cross-sectional view of the spring of the present invention.
[0027] Explanation of reference numerals: 1-initial tension yarn rack; 2-first impregnation device; 3-bidirectional winding machine; 4-second winding yarn rack; 5-yarn collector; 6-second impregnation device; 7-guide control rubber sleeve; 8-film winding machine; 9-circumferential spiral extruder; 91-spiral extrusion tube; 92-spiral groove; 93-threaded protrusion; 10-rotating traction machine; 11-multi-head mold rotator; 12-spring forming and curing mold; 13-curing and heating device; 14-rotating demoulding mechanism; 15-control cabinet; 16-spring; 17-indentation. DETAILED DESCRIPTION
[0028] In order to deepen the understanding of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings. The embodiments are only used to explain the present invention and do not constitute a limitation on the protection scope of the present invention.
[0029] like Figure 1-Figure 3 The embodiment of a continuous fiber composite material spring production line of the present invention is shown, comprising the following steps:
[0030] In the first step, the continuous fiber is drawn out from an initial tension creel 1 with tension control according to design requirements and is impregnated through a first impregnation device 2 .
[0031] In the second step, the bidirectional winding machine 3 forms the initial fiber bundles after impregnation into a certain angle spacing and staggered transverse continuous fibers (to improve the density and stability of the fibers in the final molded product, thereby enhancing the tensile strength and fatigue resistance of the product).
[0032] In the third step, the longitudinal fibers are drawn out from the second winding yarn frames 4 on both sides, and are coated on the outer surface of the transverse continuous fibers through the yarn collector 5 (increasing the contact area between the transverse interlaced fibers and the longitudinal fibers, improving the stability of the grid formed by the longitudinal and transverse fibers, thereby enhancing the toughness and fatigue resistance of the product).
[0033] The fourth step is to enter the second impregnation device 6 to re-impregnate the transverse continuous fibers covering the longitudinal fibers, and then enter the guide control glue 7 for extrusion and compaction, which improves the surface smoothness of the product and forms a fiber bundle to be cured, which is convenient for the subsequent winding and control of the film winding machine 8.
[0034] In the fifth step, the film winding machine 8 winds the film tape onto the fiber bundle to be cured.
[0035] The sixth step is to enter the circumferential spiral extruder 9; the circumferential spiral extruder 9 is provided with a spiral extrusion tube and a rapid heating device. When the fiber bundle to be cured passes through, the fiber bundle to be cured wrapped in the film belt is longitudinally twisted under the joint action of the rotary traction machine 10 and the spiral extrusion tube 91. While twisting, the matrix material is heated and quickly forms a pre-gel layer inside the winding film, which fits tightly with the winding film, thereby ensuring that the surface of the final product is smooth and the surface wear resistance is improved.
[0036] Among them, the fiber bundle to be cured wrapped with a film belt passes through a fixed spiral extrusion tube 91, and the fiber bundle to be cured will move along the spiral groove 92. The continuous threaded protrusions 93 will squeeze the surface of the fiber bundle to be cured, thereby increasing the fiber density and forming special indentations 17 on the fiber surface. At the same time, the rear rotary traction machine 10 pulls and rotates to tighten the fiber bundle to be cured, which is a twisting process.
[0037] The heating temperature of the base material is controlled at about 120℃. Because of the rapid heating, only the colloid on the surface can quickly form a gel layer, while the colloid inside has a large content and slow heat transfer, so it has little effect on the inside. Therefore, it will not affect the entire product. In addition, the gel layer has a certain elasticity and will not break, which will not affect the mold winding.
[0038] In the seventh step, a driving mechanism is provided on the rotary traction machine 10, which can longitudinally pull the fiber and simultaneously play a tensioning role for the spring forming and production on the subsequent mold. Under the control of the electrical control cabinet 15, the traction speed and the spring production speed are ensured to be coordinated.
[0039] In the eighth step, six sets of spring forming and curing molds 12 are arranged on the multi-head mold rotator 11, one set of spring forming and curing molds 12 stays in the waiting position for production, and the other five sets of spring forming and curing molds 12 are heated and cured, rotating and working alternately. Each time the spring forming and curing mold 12 rotates to the waiting position, the solidified spring product is first demolded under the action of the rotating demoulding mechanism 14, and then the next product is produced.
[0040] The ninth step is curing and heating: the curing and heating device 13 is arranged on the periphery of the multi-head mold rotator 11, which can heat the products that are not in the position to be formed. At the same time, a heating device is also arranged in the mold cavity of the spring forming and curing mold 12, so that the products can be heated and cured from both inside and outside, thereby improving production efficiency.
[0041] The tenth step is to repeat the mold rotation, heating, and demoulding to ensure continuous production.
[0042] like Figure 3 , which is a schematic cross-sectional view of the spring of the present invention. During the manufacturing process, 12 continuous thread protrusions are evenly distributed on the inner wall of the spiral extrusion tube, so 12 indentations 17 are provided on the body of the spring 16, and the cross section of the thread protrusion is a trapezoid.
[0043] The present invention is clean and hygienic, has low production cost, and does not affect the original properties of the cured fiber bundle. The existing twisting and tightening method uses a screwing method to fix one end of the fiber bundle and grab the fiber bundle at the other end to drive the fiber bundle to rotate and apply a tightening force to the fiber bundle. The rotation is transmitted to the rear end through the fiber bundle body, which will cause an uneven phenomenon that the front fiber bundle is subjected to a large force and the rear fiber bundle is subjected to a small force. At the same time, the size of the force is not easy to control during the tightening process, and excessive force will also cause the fibers in the fiber bundle to break. In addition, since the continuous fiber bundle is a soft linear material before being solidified and formed, it will be twisted and twisted by conventional methods. Tightening will inevitably cause contraction in the length direction, and after processing and forming, there will be internal stress that is difficult to eliminate; before the continuous fiber composite material spring is formed, the present method uses circumferential spiral extrusion force to force the continuous fiber filaments to be pressed toward the axis of the continuous fiber bundle, and changes the original straight-line movement into spiral movement through extrusion; a sleeve method is used to apply an overall circumferential spiral extrusion force to a section of the continuous fiber bundle to be pressurized that passes through the spiral extrusion tube. The force is uniform in size and will not cause local uneven force. Therefore, there will be no contraction in the length direction, which will cause the problem of being unable to eliminate internal stress.
[0044] Since the thermoplastic film is wrapped around the fiber bundle to be cured, the fiber bundle to be cured is directly wrapped to prevent the matrix material from dripping and adhering to the spring forming curing mold; at the same time, the process of the thermoplastic film being wrapped around the fiber bundle to be cured will produce secondary tightening of the fiber bundle to be cured, reduce the gaps between the fiber filaments constituting the fiber bundle to be cured, and increase the density of the fiber bundle after curing; at the same time, the fiber bundle wrapped with the thermoplastic film will be further squeezed after circumferential spiral extrusion, further increasing the density of the fiber bundle to be cured, and at the same time, the thermoplastic film and the fiber bundle to be cured can be further compressed. At this time, the thermoplastic film wrapped around the fiber bundle to be cured can also prevent the fiber bundle to be cured from bursting and scattering under stress. Secondly, the fiber bundle to be cured after the spiral extrusion tube will have a unique indentation on the surface, which can enhance the recognition of the product. At the same time, the indentation can be changed according to the shape of the inner thread protrusion of the spiral extrusion tube, which is highly variable and can be applied to the production of different requirements and different products.
[0045] The above specific implementation methods are only for illustrating the technical concept and structural features of the present invention, and the purpose is to enable relevant persons familiar with this technology to implement it. However, the above content does not limit the protection scope of the present invention. Any equivalent changes or modifications made according to the spirit of the present invention should fall within the protection scope of the present invention.
Claims
1. A production line suitable for continuous fiber composite springs, comprising an initial tension creel, a first impregnation device, a bidirectional fiber winding machine, a second winding creel, a second impregnation device and a spring forming and curing mold placed in sequence; characterized in that: Between the second impregnation device and the spring forming and curing mold, a film winding machine, a circumferential spiral extruder and a rotary traction machine are provided; the circumferential spiral extruder comprises a spiral extrusion tube; the inner wall of the spiral extrusion tube is evenly distributed with a plurality of continuous thread protrusions, and two adjacent thread protrusions form a spiral groove in the spiral extrusion tube; The spiral extruded tube comprises a fixed Hough tube and a movable Hough tube matching the fixed Hough tube to form a closed cylindrical tube; the cross section of the threaded protrusion is a trapezoid; The spring forming and curing mold is arranged on a multi-head mold rotator, and the multi-head mold rotator is provided with a plurality of spring forming and curing molds; One set of spring forming and curing molds stays in the waiting position for production, while the other spring forming and curing molds are heated and cured, rotating and working alternately; each time the spring forming and curing mold rotates to the waiting position, the solidified spring product is demoulded under the action of the rotating demoulding mechanism, and then the next product is produced; The curing heating device is arranged on the periphery of the multi-head mold rotator, which can heat the products that are not in the position to be formed. At the same time, a heating device is also arranged in the mold cavity of the spring forming and curing mold to heat and cure the products from both inside and outside.
2. The production line for continuous fiber composite springs according to claim 1, characterized in that :Including steps: Step 1: coating a fiber bundle consisting of continuous fibers with a matrix material to form an initial continuous fiber bundle; Step 2: wrapping a layer of thermoplastic film around the initial continuous fiber bundle to form a continuous fiber bundle to be pressurized; Step 3: applying a circumferential spiral extrusion force on the continuous fiber bundle to be pressurized to form a continuous fiber bundle to be solidified; Step 4: feeding the to-be-cured continuous fiber bundle into a spring forming and curing mold for curing and forming.
3. The production line for continuous fiber composite springs according to claim 2, characterized in that : The circumferential spiral extrusion force is applied by the spiral extrusion tube; when the continuous fiber bundle to be pressurized passes through the spiral extrusion tube, the continuous threaded protrusions in the spiral extrusion tube generate circumferential spiral extrusion force on the continuous fiber bundle to be pressurized entering therein, and the thermoplastic film and fiber filaments originally wrapped outside the continuous fiber bundle to be pressurized are pressed along the spiral line toward the axial direction of the continuous fiber bundle to be pressurized, and the original straight-line movement of the continuous fiber bundle to be pressurized is changed into spiral movement through extrusion.
4. The production line for continuous fiber composite springs according to claim 2, characterized in that The initial continuous fiber bundle includes: multiple fiber bundles on the initial tension creel are drawn out, impregnated in an impregnation tank, and then passed through a winding machine and a second winding creel to form an initial continuous fiber bundle of a multi-axial continuous fiber composite material.