Composite material forming device

Abstract

A composite material forming device is used for manufacturing composite material parts and comprises a first mold and a second mold which are matched with each other, and fiber fabric is wound or laid on the first mold. Wherein the second mold comprises a pre-compaction system, the pre-compaction system comprises a swing arm and a rolling shaft, one end of the swing arm is connected to a mold body of the second mold in a swing mode, and the rolling shaft is installed at the other end of the swing arm; the rolling shaft can be pushed by the swing arm to abut against the surface of the fiber fabric and roll along the surface of the fiber fabric. According to the device, the fiber fabric can be tightly pressed, the fitting degree of the fiber fabric and the mold is improved, and the quality defect of a finished product of a composite material part caused by improper deformation or bridging of the fiber fabric is reduced.

Description

Technical Field

[0001] The invention belongs to the field of composite materials, and in particular relates to a composite material forming device. Background Art

[0002] For large bypass ratio commercial aircraft engines, composite materials have the advantages of being lightweight and high-strength, and have a significant weight reduction effect. The use of composite materials to manufacture low-temperature end casings can effectively improve the economy of the engine. At present, composite material casings are generally manufactured by winding and paving fiber fabrics into preforms and then impregnating them with resin. When using fiber fabrics to manufacture large-curvature components including casings, the fiber fabrics need to be deformed by covering, twisting, winding, compacting, etc. to meet the molding requirements. When there are some large-angle areas on the mold, such as flange corners, R-angle areas of T-shaped ribs, etc., on the female mold of such structural molding molds, the preforms often deform out of place or bridge, resulting in defects such as local dry spots and resin-rich, which affect the overall quality of the finished product. Therefore, it is of great practical value to provide a composite material molding device that can make the fiber fabric fit tightly to a large-angle structural mold. Summary of the invention

[0003] The object of the present invention is to provide a composite material forming device, which can improve the fit between fiber fabric and mold.

[0004] According to an embodiment of the present invention, there is provided a composite material forming device for manufacturing composite material parts, the composite material forming device comprising a first mold and a second mold, wherein the first mold comprises a forming cavity, a fiber fabric is wound around or laid on the forming cavity, and the second mold provides a forming surface that matches the forming cavity. The second mold also comprises a pre-compacting system, the pre-compacting system comprises a swing arm and a roller; one end of the swing arm is rotatably fixed to the mold body of the second mold, and the other end is a swinging free end; the roller is installed at the other end of the swing arm, and can abut against the fiber fabric in the forming cavity of the first mold under the push of the swing arm, compress and roll along the surface of the fiber fabric.

[0005] The pre-compacting system can roll along the surface of the fiber fabric and compact the fiber fabric during the closing process of the second mold and the first mold, eliminating defects such as insufficient filling or bridging in the process of fiber fabric winding or covering, avoiding dry spots or resin-rich areas formed after resin infiltration, and thus improving the quality of the finished composite parts.

[0006] Furthermore, in some embodiments, the swing arm has a folded state. In the folded state, the swing arm swings to a position attached to the mold body of the second mold, and at least part of the swing arm provides at least part of the wall of the molding surface. The swing arm in the folded state participates in the surface molding of the composite material part, making the molding process coherent and the mold structure more compact.

[0007] Further, in some embodiments, the first mold includes a first plane and a second plane, the second plane is bent and protruded relative to the first plane; the swing arm includes a first section and a second section, the first section is connected to the mold body of the second mold, the first section and the second section are connected together through an intermediate shaft, and the second section can rotate around the intermediate shaft to allow the first section and the second section to form a conformal fit with the first plane and the second plane when the swing arm is in the folded state. The setting of the intermediate shaft allows the swing arm to bend, thereby allowing the pre-compacting system to be applied to the molding and manufacturing of composite materials with complex profiles such as flange edges.

[0008] Furthermore, in some embodiments, the intermediate shaft is provided with a control device, and the control device restricts the second segment from rotating before the roller rolls to the connection between the first plane and the second plane. The control device can control the rotation of the second segment to avoid the second segment rotating in advance, resulting in insufficient surface pressure of the fiber fabric.

[0009] Furthermore, in some embodiments, the control device is configured as a mechanical control device, an electric control device or a pneumatic control device.

[0010] Furthermore, in some embodiments, the intermediate shaft limits the angle between the second segment and the first segment to a range of θ-180°, where θ is the angle between the first plane and the second plane. Limiting the angle of rotation of the second segment allowed by the intermediate shaft is used to avoid insufficient pressure on the fiber fabric during the rolling process of the roller.

[0011] Furthermore, in some embodiments, the connection position between the first plane and the second plane is configured as a rounded corner. The rounded corner enables the roller to roll smoothly from the first plane to the second plane.

[0012] Furthermore, in some embodiments, the radius of the roller is smaller than the radius of the rounded corner. The roller radius is smaller than the rounded corner radius to prevent the roller from getting stuck when the angle between the first plane and the second plane is small.

[0013] Furthermore, in some embodiments, the angle between the first plane and the second plane is 90°.

[0014] Furthermore, in some embodiments, the composite material part is configured as a cylindrical part with a flange. The composite material forming device can be used to manufacture large cylindrical composite material parts such as aircraft engine casings.

[0015] Furthermore, in some embodiments, the second mold is configured in plurality. For a workpiece with a complex shape or a large volume, a plurality of second molds can be used to form the workpiece together.

[0016] Furthermore, in some embodiments, the second mold is equipped with a plurality of the pre-compacting systems. A single second mold can be equipped with a plurality of pre-compacting systems to accommodate a workpiece with a larger volume or a complex profile.

[0017] Furthermore, in some embodiments, the first mold and the second mold form an enlarged area on the outer peripheral side of the molding cavity to allow the roller and part of the swing arm to extend to be accommodated in the enlarged area after the first mold and the second mold are closed. The enlarged area of ​​the molding mold of the composite material part can be used to accommodate the roller and part of the swing arm that do not participate in the surface molding during the resin curing process to avoid affecting the surface profile of the part.

[0018] Furthermore, in some embodiments, a torque control device is provided at the connection position between the swing arm and the mold body of the second mold to provide torque so as to maintain the pressure provided by the roller on the fiber fabric.

[0019] Furthermore, in some embodiments, the torque provided by the torque control device is adjustable. The torque should be able to maintain the pressure of the roller on the surface of the fiber fabric, and the torque required to be provided varies with the change of the swing angle of the swing arm.

[0020] Furthermore, in some embodiments, the roller is configured as a hollow shaft, and a glue injection hole is provided on the roller. The glue injection hole can be used for resin injection during the molding process, so that the resin can more fully infiltrate the fiber fabric. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is a schematic structural diagram of a composite material forming device in one embodiment;

[0022] Figure 2a to Figure 2e This is a schematic diagram of the closing process of the first mold and the second mold of the composite material molding device in one embodiment;

[0023] Figure 3 This is a schematic diagram of a roller structure in one embodiment;

[0024] Figure 4 It is a schematic structural diagram of a composite material forming device in another embodiment;

[0025] Figure 5 FIG. 2 is a schematic diagram of the structure of a composite material forming device in an embodiment.

[0026] The purpose of the above drawings is to explain the present invention in detail so that those skilled in the art can understand the technical concept of the present invention, but it is not intended to limit the present invention. For the sake of simplicity, the above drawings only schematically illustrate the structures related to the technical features of the present invention, and do not strictly follow the actual scale to draw the complete structure and all details. DETAILED DESCRIPTION

[0027] The present invention is further described in detail below through specific embodiments in conjunction with the accompanying drawings.

[0028] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present invention. The phrase appearing in various locations in the specification does not necessarily refer to the same embodiment, nor is it limited to mutually exclusive independent or alternative embodiments. Those skilled in the art should be able to understand that the embodiments herein may be combined with other embodiments without causing structural conflicts.

[0029] In the description of this article, unless otherwise clearly specified and limited, the technical terms "installed", "connected", "connected" and the like should be understood in a broad sense, which can be a movable connection, a fixed connection or an integral connection. For ordinary technicians in this field, the specific meanings of the above terms in the embodiments of this application can be understood according to specific circumstances.

[0030] In the description of this document, terms indicating orientation or positional relationships, such as "up", "down", "left", "right", "horizontal", "vertical", "height", "length", and "width", are intended to accurately describe the embodiments and simplify the description, but are not intended to limit the parts or structures involved to have a specific orientation, be installed or operate in a specific orientation, and should not be construed as a limitation on the embodiments in this document.

[0031] In the description of this article, the terms "first", "second" and the like are only used to distinguish different objects, and cannot be understood as indicating relative importance or limiting the quantity, specific order or primary and secondary relationship of the described technical features. In the description of this article, the meaning of "plurality" is at least two.

[0032] One embodiment of the present invention provides a composite material forming device, the device as Figure 1As shown, it includes a first mold 1 as a bottom mold and a second mold 2 as an upper mold, wherein the first mold 1 is a female mold and the second mold 2 is a male mold. The first mold 1 has a molding cavity 14 with a groove-shaped cross section, including a horizontal first plane 11 and a second plane 12 vertically protruding relative to the first plane 11. The fiber fabric 3 is arranged on the first plane 11 and the second plane 12 in a draping or winding manner, wherein the first plane 11 is used to mold the main part of the composite material part, and the second plane 12 is used to mold the flange edge of the composite material part. The second mold 2 provides a molding surface that matches the molding cavity 14. The fiber fabric 3 can be woven by a combination of one or more materials such as carbon fiber, glass fiber, Kevlar fiber, polyimide fiber, silicon carbide fiber, etc. Since the fiber itself has a certain elasticity and hardness, at the corner position formed by the connection between the first plane 11 and the second plane 12, it is easy to have pores between the fiber fabric 3 and the first mold 1 due to problems such as inadequate deformation or bridging, and it is easy to form defects such as dry spots or resin-rich during the subsequent resin infiltration and curing process, affecting the quality of the finished product.

[0033] In order to solve the above problems, the composite material forming device is further provided with a pre-compacting system consisting of a swing arm 21 and a roller 22 on the second mold 2. One end of the swing arm 21 is connected to the mold body 20 of the second mold 2 through a rotating shaft 23, and the other end is a free swinging end, on which the roller 22 is installed. The roller 22 can abut against the surface of the fiber fabric 3 under the push of the swing arm 21, press and roll along the surface of the fiber fabric 3. The pressure applied by the roller 22 can press and compact the fiber fabric 3, eliminate the pores and bridges between the fiber fabric 3 and the first mold 1, and thus improve the quality of the finished composite material product.

[0034] In a preferred embodiment, the swing arm 21 has a folded state, in which the swing arm 21 swings to a position attached to the surface of the mold body 20 of the second mold 2, and a portion of the surface of the swing arm 21 is set as a molding surface 214 to assist in forming the surface structure 32 of the composite material part.

[0035] In a preferred embodiment, the swing arm 21 has a first section 211 and a second section 212 connected by an intermediate shaft 213. The first section 211 is connected to the mold body 20, and the second section 212 is connected to the roller 22. The intermediate shaft 213 allows the second section 212 to rotate relative to the first section 211, so that the first section 211 and the second section 212 can be conformally matched with the first plane 11 and the second plane 12 in the folded state.

[0036] In a further preferred embodiment, the intermediate rotating shaft 213 is provided with a control device (not shown), which can control the second segment 212 not to rotate around the first segment 211 before the roller 22 rolls to the connection position between the first plane 11 and the second plane 12, so as to avoid insufficient pressure applied by the roller 22 to the fiber fabric 3. In different embodiments, the control device can be set as a mechanical control device (such as a spring), an electric control device or a pneumatic control device.

[0037] In a preferred embodiment, the structure is as follows Figure 1 The composite material forming device shown in FIG. 1 shows a closing process of the first mold 1 and the second mold 2. Figure 2a to Figure 2e As shown:

[0038] First, if Figure 2a As shown in FIG. 1 , the middle rotating shaft 213 remains locked so that the swing arm 21 does not bend. As the second mold 2 is pressed downward in the direction indicated by the arrow 41, the roller 22 rolls along the surface of the fiber fabric 3 in the direction indicated by the arrow 42 under the push of the swing arm 21, and at the same time exerts a squeezing effect on the fiber fabric 3 until the roller 22 rolls to the connecting position of the first plane 11 and the second plane 12 as shown in FIG. Figure 2b shown.

[0039] In a preferred embodiment, the rotating shaft 23 is provided with a torque control device (not shown), which provides torque to maintain the roller 22 squeezing the fiber fabric 3. In different embodiments, the torque control device can adopt different schemes such as an electromagnetic torque control device and a pneumatic torque control device. In a further preferred embodiment, the torque provided by the torque control device is adjustable, and the torque can be adjusted according to the different angles of the swing arm 21, so that the roller 22 can uniformly provide squeezing effect on the fiber fabric 3. Specifically, in some embodiments, before the roller 22 contacts the fiber fabric 3, the torque provided by the torque control device is not less than the gravity torque of the swing arm 21; after the roller 22 contacts the fiber fabric 3, the torque provided by the torque control device is not less than the combined torque of the gravity of the swing arm 21, the pressure between the roller 22 and the fiber 3, and the friction force on the roller 22; at an appropriate time, such as when the roller 22 needs to start moving upward along the second plane 12, the torque provided by the torque control device can be reduced or removed. The torque provided by the torque control device can be in a damping form, or can be set to an active form that can drive the swing arm 21 to swing.

[0040] At this time, if Figure 2cAs shown, the second segment 212 starts to rotate, and the roller 22 rolls to the direction of the second plane 12. In a preferred embodiment, the connection position is set as a chamfer 13, and the support reaction force provided by the chamfer 13 enables the roller 22 to continue to move upward in the direction indicated by the arrow 43 to avoid getting stuck. In a further preferred embodiment, the radius of the roller 22 is smaller than the radius of the chamfer 13 to ensure that the roller 22 can smoothly roll from the first plane 11 to the second plane 12. Figure 2d In some embodiments, the rotation of the second segment 212 may be a passive rotation caused by the upward support reaction force provided by the chamfer 13 overcoming the locking force of the control device (such as a spring) of the intermediate shaft 213, or an active rotation caused by the control device (such as an electric control device or a pneumatic control device).

[0041] In a preferred embodiment, if Figure 2d As shown, between the first mold 1 and the second mold 2, an enlarged area 15 is formed on the outer peripheral side of the molding cavity 14, and part of the fiber fabric 3 is also present in the enlarged area 15. This part of the fiber fabric 3 is configured as a molding margin 33 at the edge of the composite material workpiece, which will be processed and removed after the molding process is completed. Figure 2e As shown, the swing arm 21 is fully closed, and the swing arm 21 reaches a folded state, and the molding surface 214 of the swing arm 21 presses the surface structure 32 of the fiber fabric 3. Then, resin is introduced to infiltrate and cure the fiber fabric 3, and the molding process between the composite materials is completed. In some embodiments, the diameter of the roller 22 is slightly larger than the gap width between the surface at the molding margin 33 and the second mold 2, so that when the first mold 1 and the second mold 2 are closed, the roller 22 can squeeze and fix the molding margin 33 area, further improving the structural stability of the fiber fabric 3 as a whole during the resin injection and curing process.

[0042] In a preferred embodiment, the structure of the roller 22 is as follows Figure 3 As shown, it is configured as a hollow shaft, the middle of which is set as a hollow pipe 221, and the circumferential surface of the roller 22 is provided with a glue injection hole 222. During the resin injection process, the resin can be injected into the hollow pipe 221 and flow out from the glue injection hole 222 to wet the fiber fabric 3, so as to further improve the resin impregnation effect.

[0043] In some embodiments, one or more load control devices are provided in the pre-compacting system, which can be provided at the roller 22 or at the intermediate shaft 213, the shaft 23, etc., to detect the pressure of the pre-compacting system and feed back to the control system, so as to ensure that the roller 22 provides sufficient pressure while avoiding the occurrence of non-designed deformation such as overpressure and tearing. The load control device can be mechanical, such as a spring, or an automated control system composed of a sensor, an electric or pneumatic device.

[0044] In some embodiments, according to the specific structure of the composite material part, the angle between the first plane 11 and the second plane 12 (i.e., the angle between the two plane surfaces measured at the connection position of the two planes) can also be configured to be greater than 90°. Correspondingly, in an optional embodiment, the intermediate shaft 213 limits the angle between the first segment 211 and the second segment 212 to be between θ and 180°. Wherein, θ is the angle between the first plane 11 and the second plane 12, and 180° means that the first segment 211 and the second segment 212 are in a straight line and the swing arm 21 is straight. Limiting the angle between the first segment 211 and the second segment 212 to not more than 180° can prevent the second segment 212 from bending in the opposite direction and causing it to get stuck; limiting the angle between the first segment 211 and the second segment 212 to be greater than θ can make the roller 22 maintain a certain pressure on the second plane 12. In an actual embodiment, the minimum angle between the first segment 211 and the second segment 212 can also be set to be slightly lower than θ, such as θ-5°.

[0045] In some relatively simple embodiments, the first mold may not have the second plane 12, and the composite material forming device may also be used to compact the fiber fabric 3. However, in relatively simple structures, the probability of defects in the fiber fabric 3 is relatively low.

[0046] In other embodiments, the swing arm 21 can be set to be non-foldable, and after the roller 22 abuts against the connection between the first plane 11 and the second plane 12 and compacts the fiber fabric 3, the swing arm 21 can be disassembled and the molding operation can be continued. However, the molding efficiency in these embodiments is low and extra working hours will be consumed.

[0047] In a preferred embodiment, if Figure 4 As shown, the first mold 1 with a circular cross-section structure corresponds to four second molds 2A, 2B, 2C, and 2D in a quarter-circular shape, which are used to manufacture cylindrical composite parts with flange structures at the ends, such as the engine casing of civil aircraft.

[0048] In some other optional embodiments, Figure 5 As shown, the surface of the first mold 1 is provided with two groups of first planes 11A, 11B and two groups of second planes 12A, 12B, and correspondingly, the second mold 2 is configured with two groups of swing arms 21A, 21B for compacting and molding the fiber fabric 3 .

[0049] In a preferred embodiment, the Figure 1 and Figure 4 The composite material forming device shown manufactures an aircraft engine casing having a flange structure, and the method is as follows:

[0050] First, the fiber fabric 3 is wound and laid in the mold cavity 14 of the first mold 1 , wherein the edge of the flange 31 has a processing allowance 33 .

[0051] Next, as shown in FIG2 , four quarter-circular second molds 2A, 2B, 2C and 2D are arranged on the circumference of the first mold 1. In other embodiments, the number of second molds can also be configured to be more. Each second mold 2 is provided with a pre-compacting system consisting of multiple groups of swing arms 21 and rollers 22 in the circumferential direction of the casing. Among them, the swing arms 21 are configured as a plate-like structure with an arc on the surface. In the folded state, each swing arm 21 can be closely laid on the surface of the fiber fabric 3 wound around the first mold 1 along the circumferential direction, and the gap size between the swing arms 21 should be controlled within an acceptable range so that the surface state of the finished casing meets the quality requirements. Similarly, since the flange 31 extends in the radial direction of the casing, as it moves away from the rotation center of the casing, the gap between the second segments 212 increases. When setting the number of circumferential swing arms, it should be considered that the gap between the second segments 212 of each adjacent swing arm 21 in the molding area of ​​the flange 31 should be able to make the flange 31 of the finished product meet the surface quality requirements. Increasing the total number of circumferential swing arms 21 can reduce the gap width between the second segments 212 of adjacent swing arms 21.

[0052] Then, if Figure 2a to Figure 2e As shown, after the swing arm 21 and the roller 22 are arranged in place, the first mold 1 and the second molds 2A, 2B, 2C, and 2D are controlled to close. During the closing process, the roller 22 rolls along the surface of the fiber fabric 3 and compacts the fiber fabric 3 (especially the fiber fabric 3 at the connection between the first plane 11 and the second plane 12). After the first mold 1 and the second mold 2 are closed, the length of the second segment 212 is slightly greater than the width of the flange 31, and the end of the second segment 212 and the roller 22 are received in the enlarged area 15 formed by the first mold 1 and the second mold 2, and the roller 22 squeezes and fixes the machining allowance 33.

[0053] Finally, glue injection and curing are carried out. In addition to the mold's own glue injection pipeline, such as Figure 3 As shown, resin can also be injected into the hollow pipe 221 of the roller 22, so that the resin can infiltrate the fiber fabric 3 through the injection holes 222 on the side of the roller 22. After the infiltration is completed, the resin is cured, then demolded, and fine machining is performed to remove the machining allowance 33 to complete the manufacture of the casing.

[0054] The purpose of the above embodiments is to further explain the present invention in detail in conjunction with the accompanying drawings so that those skilled in the art can understand the technical concept of the present invention. Within the scope of the claims of the present invention, the optimization or equivalent replacement of the part structure or method steps involved, and the combination of implementation methods in different embodiments without conflict of structure and principle, all fall within the protection scope of the present invention.

Claims

1. A composite material molding device for manufacturing composite material products, comprising a first mold and a second mold, wherein the first mold comprises a molding cavity, a fiber fabric is wound around or covered on the molding cavity, and the second mold provides a molding surface that matches the molding cavity, characterized in that: The second mold also includes a pre-compaction system, which includes a swing arm and a roller; one end of the swing arm is rotatably fixed to the mold body of the second mold, and the other end is a swinging free end; the roller is installed on the other end of the swing arm, and can abut against the fiber fabric in the molding cavity of the first mold under the push of the swing arm, press and roll along the surface of the fiber fabric.

2. The composite material forming device according to claim 1, characterized in that: The swing arm has a folded state. In the folded state, the swing arm swings to a position attached to the mold body of the second mold, and at least a portion of the swing arm provides at least a portion of the wall of the molding surface.

3. The composite material forming device according to claim 2, characterized in that: The first mold includes a first plane and a second plane, and the second plane is bent and protruded relative to the first plane; the swing arm includes a first section and a second section, the first section is connected to the mold body of the second mold, the first section and the second section are connected together through an intermediate rotating shaft, and the second section can rotate around the intermediate rotating shaft to allow the first section and the second section to be conformally matched with the first plane and the second plane when the swing arm is in the folded state.

4. The composite material forming device according to claim 3, characterized in that: The intermediate rotating shaft is provided with a control device, and the control device restricts the second segment from rotating before the roller rolls to the connection between the first plane and the second plane.

5. The composite material forming device according to claim 4, characterized in that: The control device is configured as a mechanical control device, an electric control device or a pneumatic control device.

6. The composite material forming device according to claim 3 or 4, characterized in that: The intermediate rotating shaft limits the angle range between the second segment and the first segment to θ-180°, where θ is the angle between the first plane and the second plane.

7. The composite material forming device according to claim 3 or 4, characterized in that: The connection position between the first plane and the second plane is configured as a rounded corner.

8. The composite material forming device according to claim 7, characterized in that: The radius of the roller is smaller than the radius of the rounded corner.

9. The composite material forming device according to claim 3 or 4, characterized in that: The angle between the first plane and the second plane is 90°.

10. The composite material forming device according to claim 9, characterized in that: The composite material part is configured as a cylindrical part with a flange.

11. The composite material forming device according to any one of claims 1 to 5, characterized in that: The second mold is provided in plurality.

12. The composite material forming device according to any one of claims 1 to 5, characterized in that: The second mold is equipped with a plurality of the pre-compacting systems.

13. The composite material forming device according to any one of claims 1 to 5, characterized in that: The first mold and the second mold form an enlarged area on the outer peripheral side of the molding cavity to allow the roller and part of the swing arm to extend to and be accommodated in the enlarged area after the first mold and the second mold are closed.

14. The composite material forming device according to any one of claims 1 to 5, characterized in that: A torque control device is provided at the connection position between the swing arm and the mold body of the second mold to provide torque so as to maintain the pressure provided by the roller on the fiber fabric.

15. The composite material forming device according to claim 14, characterized in that: The torque provided by the torque control device is adjustable.

16. The composite material forming device according to any one of claims 1 to 5, characterized in that: The roller is configured as a hollow shaft, and a glue injection hole is arranged on the roller.

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