Composite material double-pod rod preforming device and preforming method

Abstract

The invention provides a composite material double-pod rod preforming device and method. The preforming device comprises a support, a bottom die, a plurality of pressing rollers and a pressure applying assembly. The bottom die is connected to the support and provided with a transition curve molded surface. The multiple pressing rollers are arranged at intervals in the length direction of the bottom die and rotationally connected to the support, the pressing rollers and the transition curve molded surfaces are oppositely arranged, and the shape of the outer molded surface of each pressing roller corresponds to the shape of the transition curve molded surface opposite to the pressing roller; the pressure applying assembly is connected to the pressing roller; wherein the bottom mold is provided with a heating module, the composite material prepreg moves in the length direction of the bottom mold, and the pressure applying assembly is used for applying pressure to the composite material prepreg so that the top face of the composite material prepreg can be attached to the outer molded surface of the pressing roller, and the bottom face of the composite material prepreg can be attached to the transition curve molded surface. According to the preforming device, preforming of the composite material double-pod rod can be achieved, wrinkles and splitting of a laying layer can be avoided, redundant resin and bubbles in the composite material are removed, and the preforming quality is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of composite material preforming, and more particularly to a composite material double-pod rod preforming device and a preforming method. Background Art

[0002] Composite material double pod pole for aerospace deployable antenna (such as Figure 1 As shown) is a thin-walled support rod that can be rolled up and unfolded by its own elasticity (as shown Figure 2 As shown), it is being increasingly widely used in spacecraft due to its advantages such as light weight, high performance, small size and convenient transportation. The principle of winding and rewinding after flattening the end, combined with the advanced pultrusion technology of composite materials with no restrictions on the length of the product, is the main forming technology for achieving continuous forming of ultra-long double pod rods. This technology is to pass the prepared prepreg flat layer through the unwinding device 200, the preforming device 100, the forming and curing device 300, the forming traction and cooling device 400 and the cutting and polishing device 500 in sequence to prepare a half pod rod, which is then flattened and reeled into a roll by the reeling device 600. The whole process is completed by the forming traction and cooling device 400 step-by-step pulling of the prepreg flat layer from the unwinding direction to the rewinding direction (as shown in FIG. Figure 3 As shown). Preforming is an important component of advanced pultrusion technology. The main function of preforming is to guide the ply to gradually evolve from a plane into the shape of the final pultruded product. Existing pod rod preforming technologies include natural transition forming, preforming mold forming, and multi-stage deformation roller forming. Natural transition forming is the natural forming of the prepreg ply from the discharge roller to the curing molding die, without any external force constraints in between; preforming mold forming is to make a preforming mold from a straight line to the final product molding curve, and rely on the traction mold to make the prepreg ply slide on the preforming mold to form; multi-stage deformation roller forming is to set multiple levels of rollers on the preforming path. Each roller in the roller group is set according to the molding curve, and the traction mold is used to make the prepreg ply pass through the middle of the roller group to form the prepreg ply.

[0003] The preforming equipment in the prior art is prone to causing ply wrinkles during actual use and is unable to remove excess resin and bubbles in the composite material. Summary of the Invention

[0004] (1) Technical issues to be resolved The technical problem to be solved by the present invention is that the preforming equipment in the prior art is prone to cause ply wrinkles during actual use and is unable to eliminate excess resin and bubbles in the composite material.

[0005] (2) Technical solution To achieve the above object, the technical solution adopted by the present invention is: The present invention provides a composite material double-pod rod preforming device, comprising a bracket, a bottom mold, a plurality of pressing rollers and a pressure assembly; the bottom mold is connected to the bracket, and the bottom mold has a transition curve surface; a plurality of pressing rollers are arranged at intervals along the length direction of the bottom mold and are respectively rotatably connected to the bracket, the pressing rollers are arranged opposite to the transition curve surface, and the outer surface of each pressing roller corresponds to the shape of the transition curve surface opposite to it; the pressure assembly is connected to the pressing rollers; wherein, the bottom mold has a heating module, a composite material prepreg moves along the length direction of the bottom mold, and the pressure assembly is used to press the composite material prepreg so that the top surface of the composite material prepreg is in contact with the outer surface of the pressing roller, and the bottom surface of the composite material prepreg is in contact with the transition curve surface.

[0006] Preferably, the first end of the transition curve surface is a plane surface, the first end of the transition curve surface is a straight line surface, the second end of the transition curve surface is the outer contour boundary curve surface of the composite material double pod rod, and the transition curve surface gradually transitions from the straight line surface to the outer contour boundary curve surface of the composite material double pod rod along the length direction of the bottom mold.

[0007] Preferably, there are three pressure rollers, namely a fixed center pressure roller, an intermediate pressure roller and an end pressure roller. The fixed center pressure roller is arranged at the first end, the end pressure roller is arranged at the second end, and the intermediate pressure roller is arranged between the fixed center pressure roller and the end pressure roller.

[0008] Preferably, the pressure assembly includes a cylinder and a rotating frame, the pressure roller is rotatably connected to the rotating frame, the cylinder body of the cylinder is installed on the bracket, and the output end of the cylinder is connected to the rotating frame.

[0009] Preferably, the pressure assembly further includes a guide rod, the bracket is provided with a guide hole, the guide rod is passed through the guide hole and the end of the guide rod is connected to the rotating frame.

[0010] Preferably, the outer surface of the pressing roller is provided with a silicone soft film layer.

[0011] Preferably, it further comprises a plurality of pressure sensors and a control module, wherein the plurality of pressure sensors are arranged on the bottom mold, and the pressure sensors and the pressure-applying components are electrically connected to the control module.

[0012] Preferably, the heating module comprises a plurality of electric heating rods and thermocouples, and the plurality of electric heating rods and thermocouples are arranged at intervals along the length direction of the bottom mold.

[0013] Preferably, the pressure applied by the pressure-applying component ranges from 0 to 0.6 MPa.

[0014] The present invention also provides a composite material double-pod rod preforming method, which uses the composite material double-pod rod preforming device described in any one of the above technical solutions to preform the composite material double-pod rod. The composite material double-pod rod preforming method comprises the following steps: Heat the bottom mold to the required temperature; Composite material prepreg is unloaded at one end of the bottom mold; The pressure component drives the pressure roller to apply pressure to the composite material prepreg so that the top surface of the composite material prepreg is in contact with the outer surface of the pressure roller, and the bottom surface of the composite material prepreg is in contact with the transition curve surface; The composite material prepreg is pulled and moved along the length direction of the transition curve surface. During the movement of the composite material prepreg, the pressure roller squeezes the composite material prepreg to remove bubbles therein and cooperates with the transition curve surface to preform the composite material prepreg into a composite material double pod rod.

[0015] (3) Beneficial effects The above technical solution of the present invention has at least the following advantages: The pressure component can drive the pressure roller to press against the upper surface of the composite prepreg, and under the action of pressure, the lower surface of the composite prepreg is fitted with the transition curve surface. Under the action of traction, the composite prepreg moves, driving the pressure roller to rotate along its axis. The rotation of the pressure roller can squeeze the upper surface of the composite prepreg to remove excess resin and bubbles in the composite material. When the composite prepreg moves to the second end, under the constraint of the end pressure roller and the bottom mold surface, the composite prepreg is preformed into a composite double pod rod. According to the structural characteristics of the composite prepreg, the corresponding transition curve surface is designed. The longitudinal line lengths of the transition curve surface are equal, and the unfolded lengths of the cross-sectional curves of the transition curve surface are equal, so as to avoid lateral wrinkles and splitting of adjacent carbon fibers in the composite prepreg tape during the preforming process. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0017] Figure 1 It is a schematic diagram of the cross-sectional curve shape of the composite material double pod rod.

[0018] Figure 2 It is a structural diagram of a composite material double pod pole.

[0019] Figure 3Schematic diagram of the pultrusion process of composite double-pod rod.

[0020] Figure 4 It is a structural schematic diagram of a composite material double-pod rod preforming device provided by an embodiment of the present invention.

[0021] Figure 5 It is a structural schematic diagram of the bottom mold provided by an embodiment of the present invention.

[0022] The reference numerals in the figures are: 1. Bracket; 2. Bottom mold; 3. Pressure roller; 4. Pressure assembly 11. Guide hole; 21. Transition curve surface; 22. Heating module; 31. Centering pressure roller; 32. Intermediate pressure roller; 33. End pressure roller; 41. Cylinder; 42. Rotating frame; 43. Guide rod; 211. First end; 212. Second end. DETAILED DESCRIPTION

[0023] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0024] It should be noted that when an element is referred to as being “fixed to” or “disposed on” another element, it may be directly located on the other element or indirectly located on the other element. When an element is referred to as being “connected to” another element, it may be directly connected to the other element or indirectly connected to the other element.

[0025] It should be understood that the terms "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the present invention, and do not indicate that the device or element must have a specific orientation, be constructed and operate in a specific orientation. Therefore, it should not be understood as a limitation on the present invention.

[0026] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating relative importance or the number of technical features. In the description of the present invention, "plurality" means two or more, unless otherwise specifically defined. The following is a more detailed description of the specific implementation of the present invention in conjunction with specific embodiments: like Figure 4 and Figure 5As shown, an embodiment of the present invention provides a composite material double-pod rod preforming device, including a bracket 1, a bottom mold 2, a plurality of pressure rollers 3 and a pressure component 4; the bottom mold 2 is connected to the bracket 1, and the bottom mold 2 has a transition curve surface 21; the plurality of pressure rollers 3 are arranged at intervals along the length direction of the bottom mold 2 and are respectively rotatably connected to the bracket 1, the pressure rollers 3 are arranged opposite to the transition curve surface, and the outer surface of each pressure roller 3 corresponds to the shape of the transition curve surface opposite to it; the pressure component 4 is connected to the pressure roller 3; wherein the bottom mold 2 has a heating module 22, the composite material prepreg moves along the length direction of the bottom mold 2, and the pressure component 4 is used to pressurize the composite material prepreg so that the top surface of the composite material prepreg is in contact with the outer surface of the pressure roller 3, and the bottom surface of the composite material prepreg is in contact with the transition curve surface 21.

[0027] In one embodiment, the first end 211 of the transition curve profile 21 is a straight line, and the second end 212 of the transition curve profile 21 is the outer contour boundary curve profile of the composite double peapod rod. The transition curve profile 21 gradually transitions from a straight line to the outer contour boundary curve profile of the composite double peapod rod along the length of the base mold 2. The composite prepreg is unloaded at the first end 211 and then moved along the length of the transition curve profile under the traction of a traction device. During this movement, the pressing roller 3 presses the composite prepreg so that it is tightly aligned with the profile of the transition curve profile 21. Finally, the composite prepreg is preformed at the second end 211, so that the planar composite prepreg is finally preformed into the desired profile structure for making the composite double peapod rod.

[0028] In one embodiment, there are three pressure rollers 3, namely a fixed pressure roller 31, an intermediate pressure roller 32 and an end pressure roller 33. The fixed pressure roller 31 is arranged at the first end 211, the end pressure roller 33 is arranged at the second end 212, and the intermediate pressure roller 32 is arranged between the fixed pressure roller 31 and the end pressure roller 33. Specifically, the centering roller 31 can achieve centering and fixing of the composite material prepreg so that the axis of the composite material prepreg can be positioned and coincident with the axis of the transition curve profile. There can be multiple intermediate rollers 32, and the specific number can be determined according to actual usage requirements. Multiple intermediate rollers 32 are arranged at intervals along the length direction of the transition curve profile. In this embodiment, the number of intermediate rollers 32 is preferably one. The intermediate rollers 32 and the end roller 33 can press the composite material prepreg tightly against the transition curve profile. The intermediate rollers 32 and the end roller 33 constrain the shape of the upper profile of the composite material prepreg, and the transition curve profile constrains the shape of the lower profile of the composite material prepreg, so as to finally preform the composite material prepreg into the required profile structure for making a composite material double pod rod. The centering roller 31, the intermediate rollers 32 and the end roller 33 are arranged along the length direction of the bottom mold 2, and are used to expand the composite material prepreg along the width direction and constrain the center of the composite material prepreg when it is deformed. The centering roller 31 constrains the center of the composite material prepreg during its initial deformation, the intermediate roller 32 is used to expand the composite material prepreg along the width direction, and the end roller 33 is used to constrain the final shape of the composite material double peapod rod. The composite material prepreg first passes through the centering roller 31 to achieve precise centering of the composite material prepreg, ensuring that the composite material prepreg does not deviate during the pre-deformation process; then passes through the intermediate roller 32 to achieve gradual expansion along the width direction of the bottom mold during the preforming process; finally, passes through the end roller 33 to achieve the final shaping of the composite material prepreg, wherein the outer surface curve of each roller is consistent with the corresponding double peapod transition curve.

[0029] In one embodiment, the pressure assembly 4 includes a cylinder 41 and a rotating frame 42. The pressure roller 3 is rotatably connected to the rotating frame 42. The cylinder body of the cylinder 41 is mounted on the bracket 1, and the output end of the cylinder 41 is connected to the rotating frame 42. Specifically, the cylinder 41 includes but is not limited to a hydraulic cylinder and an electric cylinder. The pressure roller 3 can rotate on the rotating frame 42. The pressure roller 3 is raised and lowered by the cylinder 41. The operating pressure and stroke of the cylinder 41 are adjustable, which can effectively control the layup thickness of the composite prepreg and remove excess resin and bubbles in the layup.

[0030] In one embodiment, the pressure assembly 4 further includes a guide rod 43. The bracket 1 defines a guide hole 11. The guide rod 43 is inserted into the guide hole 11, and the end of the guide rod 43 is connected to the rotating frame 42. The length of the guide rod 43 is parallel to the thickness of the bottom mold. The guide rod 43 can guide the movement of the rotating frame 42 to ensure the stability of the movement of the pressure roller 3 and ensure that the force applied by the pressure roller 3 is parallel to the thickness of the bottom mold.

[0031] In one embodiment, the outer surface of the pressing roller 3 is provided with a silicone soft film layer. The outer surface of the pressing roller is covered with a silicone rubber soft mold of corresponding thickness, which can effectively eliminate the pressure difference caused by the bottom mold surface error and the thickness error of the composite material prepreg, so that the composite material prepreg is evenly compressed.

[0032] In one embodiment, the system further includes multiple pressure sensors (not shown) and a control module (not shown). The multiple pressure sensors are located on the base mold, and both the pressure sensors and the pressure-applying assembly are electrically connected to the control module. The pressure sensors detect the pressure applied by the pressure roller 3 to the composite prepreg, monitoring changes in the pressure value in real time. The control module receives feedback from the pressure sensors and adjusts the state of the pressure-applying assembly accordingly to keep the pressure generated by the pressure-applying assembly within a predetermined, reasonable range.

[0033] In one embodiment, the heating module 22 includes a plurality of electric heating rods and thermocouples, which are spaced apart along the length of the bottom mold 2. When the plurality of electric heating rods are in operation, the bottom mold can be heated, and the heat from the bottom mold is transferred to the composite material prepreg, thereby preheating the composite material prepreg and increasing the plasticity of the composite material prepreg so that the composite material prepreg can conform to the transition curve surface. The thermocouple is used to detect the temperature of the bottom mold 2 and feed the temperature back to the corresponding controller. The controller regulates the working state of the electric heating rods to control the temperature of the bottom mold within a preset range.

[0034] The present invention also provides a composite material double-pod rod preforming method, which uses any of the composite material double-pod rod preforming devices of the above embodiments to preform a composite material double-pod rod. The composite material double-pod rod preforming method includes the following steps: Heat the bottom mold to the required temperature; Composite material prepreg is unloaded at one end of the bottom mold; The pressure component 4 drives the pressure roller 3 to apply pressure to the composite material prepreg so that the top surface of the composite material prepreg is in contact with the outer surface of the pressure roller 3, and the bottom surface of the composite material prepreg is in contact with the transition curve surface 21; The composite material prepreg is pulled and moved along the length direction of the transition curve surface 21. During the movement of the composite material prepreg, the pressing roller 3 squeezes the composite material prepreg to remove bubbles therein and cooperates with the transition curve surface 21 to preform the composite material prepreg into a composite material double pod rod.

[0035] Furthermore, the longitudinal line lengths of corresponding points on multiple cross-sections along the length of the transition curve profile are equal, and the developed lengths of the curves of each cross-section of the transition curve profile are equal. Composite prepreg tapes comprise a resin matrix and carbon fibers (reinforcement) disposed within the resin matrix. Because carbon fibers are difficult to deform by stretching, if the path lengths of the longitudinal fibers of the composite prepreg tape vary from the start to the end of preforming, surface wrinkling and center offset can occur. Furthermore, the prepreg tape lacks transverse stiffness (the carbon fibers are spaced apart along the length). If the developed lengths of the transverse cross-section curves are unequal, adjacent fibers in the prepreg tape will wrinkle and split during the preforming process. Therefore, when designing the transition curve profile, it is important to ensure that the longitudinal line lengths are equal, as well as the developed lengths of the cross-section curves of the transition curve profile are equal, to avoid transverse wrinkling and splitting of adjacent carbon fibers in the composite prepreg tape during preforming. A design requirement for composite prepreg preforming is that the path lengths of the carbon fiber bundles involved in deformation are consistent from the starting point to the end point during deformation, meaning that the difference in line segment lengths at each reference point should be minimized. Each carbon fiber bundle must not be laterally squeezed or separated from its adjacent carbon fiber bundles during its path. Specifically, the double pod rod has a complex curved surface, with both concave and convex surfaces coexisting and multiple bends. Traditional preforming molds cannot ensure that the prepreg ply adheres to the preformed curved surface. To address this characteristic, this embodiment models and analyzes the deformation process of the preformed prepreg. By modeling and analyzing the changes in the curve of the surface in the longitudinal and cross-sectional directions, the prepreg ply is prevented from compressing in both the longitudinal and cross-sectional directions, and the tensile deformation is minimized, thereby achieving the purpose of preventing wrinkles and splitting.

[0036] The working principle of this embodiment is as follows: Before the double-peapod rod pultrusion preforming, the base mold 1 is heated to the required preforming temperature, and the fixed center pressure roller 31, the middle pressure roller 32 and the end pressure roller 33 are lifted upward by the cylinder 41 to facilitate the laying of the composite material prepreg on the base mold 1. During the double-peapod rod pultrusion forming process, the cylinder 41 drives the fixed center pressure roller 31, the middle pressure roller 32 and the end pressure roller 33 downward to lay the composite material prepreg on the base mold 1. During the double-peapod rod pultrusion forming process, the traction device pulls the double-peapod rod forward, and the fixed center pressure roller 31, the middle pressure roller 32 and the end pressure roller 33 roll along with the movement of the composite material prepreg. After the double-peapod rod pultrusion forming, the cylinder 41 lifts the fixed center pressure roller 31, the middle pressure roller 32 and the end pressure roller 33 upward to facilitate the removal of the composite material prepreg from the base mold 1. Among them, during the preforming process, the pressure component controls the movement of the central pressure roller, the middle pressure roller and the end pressure roller to press against the upper surface of the composite prepreg, and under the action of pressure, the lower surface of the composite prepreg is fit with the transition curve surface. The heating module of the bottom mold preheats the composite prepreg to improve the plasticity of the composite prepreg. Under the action of traction, the composite prepreg moves and drives the pressure roller to rotate along its axis. The rotation of the pressure roller can squeeze the upper surface of the composite prepreg to remove excess resin and bubbles in the composite material. When the composite prepreg moves to the second end, under the constraint of the end pressure roller and the surface of the bottom mold, the composite prepreg is preformed into a composite double pod rod.

[0037] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A composite material double pod rod preforming device, characterized in that: include: Bracket; A bottom mold is connected to the bracket, and the bottom mold has a transition curve surface; A plurality of pressing rollers are arranged at intervals along the length direction of the bottom mold and are respectively rotatably connected to the bracket, the pressing rollers are arranged opposite to the transition curved surface, and the outer surface of each pressing roller corresponds to the shape of the transition curved surface opposite to it; A pressure component connected to the pressure roller; In which, the bottom mold has a heating module, the composite material prepreg moves along the length direction of the bottom mold, and the pressure component is used to apply pressure to the composite material prepreg so that the top surface of the composite material prepreg fits with the outer surface of the pressing roller, and the bottom surface of the composite material prepreg fits with the transition curve surface.

2. The composite material double pod rod preforming device according to claim 1, characterized in that: The first end of the transition curve surface is a straight surface, the second end of the transition curve surface is the outer contour boundary curve surface of the composite material double peapod rod, and the transition curve surface gradually transitions from the straight surface to the outer contour boundary curve surface of the composite material double peapod rod along the length direction of the bottom mold.

3. The composite material double pod rod preforming device according to claim 2, characterized in that: There are three pressure rollers, namely a fixed center pressure roller, an intermediate pressure roller and an end pressure roller. The fixed center pressure roller is arranged at the first end, the end pressure roller is arranged at the second end, and the intermediate pressure roller is arranged between the fixed center pressure roller and the end pressure roller.

4. The composite material double pod rod preforming device according to claim 1, characterized in that: The pressure assembly includes a cylinder and a rotating frame, the pressure roller is rotatably connected to the rotating frame, the cylinder body of the cylinder is installed on the bracket, and the output end of the cylinder is connected to the rotating frame.

5. The composite material double pod rod preforming device according to claim 4, characterized in that: The pressure assembly further includes a guide rod. The bracket is provided with a guide hole. The guide rod is passed through the guide hole and the end of the guide rod is connected to the rotating frame.

6. The composite material double pod rod preforming device according to claim 1, characterized in that: The outer surface of the pressing roller is provided with a silicone soft film layer.

7. The composite material double pod rod preforming device according to claim 1, characterized in that: It also includes a plurality of pressure sensors and a control module. The plurality of pressure sensors are arranged on the bottom mold, and the pressure sensors and the pressure-applying components are electrically connected to the control module.

8. The composite material double pod rod preforming device according to claim 1, characterized in that: The heating module includes a plurality of electric heating rods and thermocouples, and the plurality of electric heating rods and thermocouples are arranged at intervals along the length direction of the bottom mold.

9. A composite material double pod rod preforming method, characterized in that: The composite material double-pod pole preforming device according to any one of claims 1 to 8 is used to preform a composite material double-pod pole, and the composite material double-pod pole preforming method comprises the following steps: Heat the bottom mold to the required temperature; Composite material prepreg is unloaded at one end of the bottom mold; The pressure component drives the pressure roller to apply pressure to the composite material prepreg so that the top surface of the composite material prepreg is in contact with the outer surface of the pressure roller, and the bottom surface of the composite material prepreg is in contact with the transition curve surface; The composite material prepreg is pulled and moved along the length direction of the transition curve surface. During the movement of the composite material prepreg, the pressure roller squeezes the composite material prepreg to remove bubbles therein and cooperates with the transition curve surface to preform the composite material prepreg into a composite material double pod rod.

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