Molding methods and molding systems for composite material components

Abstract

A molding method for composite material components, relating to the field of manufacturing methods for composite material components, includes the following steps: obtaining a woven preform with an enlarged edge region at its edge; wrapping the enlarged edge region with fabric and compacting it to locally increase the fiber content within the enlarged edge region of the woven preform, obtaining a wrapped preform; placing the wrapped preform in the cavity of a molding die having multiple injection ports and outlet ports; adding a resin distribution device between some of the injection ports and the wrapped preform; providing distribution holes along two intersecting directions on the resin distribution device; injecting resin into the cavity through some of the injection ports and via the resin distribution device, while simultaneously injecting resin into the cavity through the remaining injection ports; after resin injection, performing high-temperature curing to obtain a molded blank and demolding the molded blank. The above molding method can obtain high-quality composite material components. A molding system for composite material components is also provided.

Description

Technical Field

[0001] This invention relates to a method for manufacturing composite material components, and more specifically to a method for manufacturing aircraft engine components. Background Art

[0002] 3D woven preforms refer to fiber fabrics with normal reinforcing fibers woven by a specific textile machine or by hand. Fiber raw materials include, but are not limited to, carbon fiber, aramid fiber, and polyimide fiber. 3D woven composites are generally molded using resin transfer molding (RTM), a liquid molding process for resin-based composites. The basic process involves pouring liquid resin into a closed mold containing the fiber reinforcement, i.e., the woven preform, allowing the resin to fully impregnate the dry fiber reinforcement. After a specific curing process and demolding, a (near) net-size component with excellent surface quality is obtained.

[0003] In aero-engines, the above methods can be used to manufacture components such as fan blades or casings. Taking fan blades as an example, the fan blade is the largest rotor component of an aero-engine and also the first blade of the fan booster stage. The fan blade is mounted on the fan disk and provides most of the thrust to the engine by drawing in air. For three-dimensional woven composite fan blades, the woven preform of the blade needs to be manufactured and processed according to the shape and geometry of the blade. Then, it is placed into the blade forming mold, and resin is poured into the mold through the RTM process. After curing, it is demolded to form the blade blank body.

[0004] Before being placed into the mold, the woven blade preform undergoes a complex deformation process involving twisting and shearing to achieve the desired blade outline shape. During this process, the internal geometry of the blade preform changes, leading to variations in the permeability distribution across different regions. Permeability characterizes the ease with which a liquid flows within it, and changes in permeability distribution directly affect the resin flow process during the RTM (Resin Tolerance Molding) process. The mold filling process during RTM is crucial for the quality of the formed blade.

[0005] For example, the woven preform of the blade undergoes a complex pre-deformation process in the molding die, and the internal structure of the woven preform undergoes irregular and continuous changes, which leads to continuous changes in the permeability of each area of ​​the woven preform. This directly affects the resin filling and flow trajectory during the RTM process of the blade, and affects the molding quality of the woven preform.

[0006] For example, if the edges of the woven preform for blades are in a loose, broken yarn state, with low fiber content and permeability, the resin is likely to preferentially flow through this area and form a rapid flow channel, resulting in an envelope area and molding defects such as bubbles and dry spots. This can lead to molding failure and affect the mechanical properties of the blade. Furthermore, the structure of the blade preform is relatively loose at the edges, such as the bottom or side of the tenon, the leading and trailing edges of the blade, and the blade tip. During the RTM process, the resin may "scour" the woven preform in these areas, thereby changing or damaging the internal structure of the preform and affecting the performance of the molded blade. This is especially true when the resin injection pressure is high and the flow rate is large, as the preform in the inlet area is more prone to deformation due to resin scouring.

[0007] Furthermore, woven composite parts typically use toughened resin as the matrix. During the RTM process, the resin needs to be heated to a certain temperature to achieve a low viscosity. For example, resin PR520 requires heating to 165°C to meet the requirements. At this temperature, the resin has a limited process window; the resin viscosity increases with the duration of heat treatment at this temperature, resulting in a lower filling rate at the same injection pressure, potentially leading to filling failure, especially for larger composite parts. Failure to complete the process within the window will severely impact the molding quality of the composite parts. Summary of the Invention

[0008] One object of the present invention is to provide a molding method for composite material parts, which can reduce the probability of defects in composite material parts during the RTM process and improve the molding quality of composite material parts.

[0009] The molding method for achieving the above objectives includes the following steps: obtaining a woven preform with an enlarged edge region at its edge; wrapping the enlarged edge region with fabric and compacting it to locally increase the fiber content of the enlarged edge region of the woven preform, thereby obtaining a wrapped preform; placing the wrapped preform in the inner cavity of a molding die having multiple injection ports and outlet ports; adding a resin diversion device between some of the injection ports and the wrapped preform; setting diversion holes along two intersecting directions on the resin diversion device; injecting resin into the inner cavity through some of the injection ports and via the resin diversion device, while simultaneously injecting resin into the inner cavity through the remaining injection ports; after the resin injection is completed, performing high-temperature curing to obtain a molded blank and demolding the molded blank.

[0010] In one or more embodiments, a cavity is provided on the inflow side of the resin distribution device to ensure that surface injection is formed when resin is injected into the cavity.

[0011] In one or more embodiments, the height of the cavity ranges from 1 to 5 mm.

[0012] In one or more embodiments, the resin diversion device is a multi-row uniform array porous structure or a non-uniform porous structure.

[0013] In one or more embodiments, the resin diversion device is a stacked metal wire structure.

[0014] In one or more embodiments, the porosity of the wire stack structure ranges from 70% to 90%.

[0015] In one or more embodiments, the width of the enlarged edge region ranges from 15 to 30 mm.

[0016] In one or more embodiments, the number of wrapping layers of the fabric is such that the fiber content at the edge of the woven preform does not exceed 65%.

[0017] In one or more embodiments, the fabric is made of one or more of aramid fibers and polyimide fibers.

[0018] In one or more embodiments, the number and distribution of the injection ports and the outlet ports, as well as the resin injection pressure and resin flow rate of each injection port, are obtained by simulation calculation.

[0019] In one or more embodiments, the resin injection pressure for injecting resin into the cavity varies with the injection time in a gradient manner.

[0020] In one or more embodiments, the opening and closing of each of the glue inlet and outlet ports, the resin injection pressure for injecting resin into the inner cavity, and the resin flow rate are adjusted in real time by a control component.

[0021] In one or more embodiments, the injection port and the dispensing port are inclined.

[0022] Another object of the present invention is to provide a molding system for composite material parts, including a molding die and a resin distribution device. The molding die provides an inner cavity, a plurality of injection ports and an outlet port, the inner cavity having an enlarged cavity for an enlarged edge region of a woven preform; the resin distribution device is disposed between a portion of the injection ports and the inner cavity, having distribution slots distributed along two intersecting directions.

[0023] In one or more embodiments, the molding system has a cavity on the inflow side of the resin distribution device.

[0024] In the above-mentioned molding method for composite material parts, by wrapping and compacting the enlarged edge area of ​​the woven preform with fabric, it can be ensured that the fiber content in this edge area is higher than that in other areas after mold closing. This avoids the formation of rapid flow channels at the edge during molding, which can lead to defects such as bubbles and dry spots. It also prevents the preform from being misaligned or shifted during mold closing, thus avoiding affecting the formation of the internal structure of the net size area of ​​the part. In addition, by adding a resin diversion device between some injection ports and the wrapped preform, the resin flow rate during mold filling can be reduced, forming a "surface injection" effect. This prevents the resin from eroding the edge of the preform, thereby obtaining a high-quality composite material part. Attached Figure Description

[0025] The above and other features, properties and advantages of the present invention will become more apparent from the following description taken in conjunction with the accompanying drawings and embodiments, wherein:

[0026] Figure 1 This is a schematic diagram of a woven prefabricated structure;

[0027] Figure 2 This is a schematic diagram of the molding die;

[0028] Figure 3 This is a schematic diagram of the woven blade preform placed inside the cavity;

[0029] Figure 4 This is a schematic diagram of an embodiment of the inlet and outlet of a molding die;

[0030] Figure 5 This is a schematic diagram of another embodiment of the inlet and outlet of the molding die;

[0031] Figure 6 This is a schematic diagram of another embodiment of the inlet and outlet of the molding die;

[0032] Figure 7 This is a schematic diagram of the first embodiment of the resin diversion device;

[0033] Figure 8 This is a schematic diagram of a second embodiment of the resin diversion device;

[0034] Figure 9 This is a schematic diagram of the third embodiment of the resin diversion device;

[0035] Figure 10 This is a schematic diagram of the fourth embodiment of the resin diversion device;

[0036] Figure 11 This is a schematic diagram of an embodiment of the resin injection pressure variation at the injection port;

[0037] Figure 12This is a flowchart of a molding method for composite material parts.

[0038] Explanation of reference numerals in the attached figures

[0039] 10 Woven prefabricated bodies

[0040] 10' Wrapped Precast Body

[0041] 11 Leaf tip area

[0042] 12. Leading edge area of ​​the blade

[0043] 13 Leaf blade area

[0044] 14. Trailing edge area of ​​the blade

[0045] 15. Tenon area

[0046] 16 Diversion Hole Slots

[0047] 17 Pores

[0048] 18. Zoom in on the edge region

[0049] 19 dividing line

[0050] 20 Molding molds

[0051] 21 upper mold

[0052] 22 Lower mold

[0053] 23. Inner cavity

[0054] 31. Fabrics

[0055] 33 Resin Diversion Device

[0056] 331 First Resin Diversion Device

[0057] 332 Second Resin Diversion Device

[0058] 333 Third Resin Diversion Device

[0059] 334 Fourth Resin Diversion Device

[0060] 34 Cavity

[0061] 35 Opening

[0062] 36 Amplifying cavity

[0063] 41 Glue outlet

[0064] 42 Injection port

[0065] 72 Second Stage

[0066] 73 Third Stage Detailed Implementation

[0067] The present invention will be further described below with reference to specific embodiments and accompanying drawings. More details are set forth in the following description in order to provide a full understanding of the present invention. However, the present invention can obviously be implemented in many other ways different from those described herein. Those skilled in the art can make similar extensions and derivations based on actual application situations without departing from the spirit of the present invention. Therefore, the scope of protection of the present invention should not be limited by the content of this specific embodiment.

[0068] It should be noted that these and other accompanying drawings are merely examples and are not drawn to scale, and should not be construed as limiting the scope of protection of the present invention.

[0069] The molding method will now be described using an example of a fan blade as a composite material component. It should be noted that this molding method is not only applicable to three-dimensional woven composite fan blades, but also to any composite material component employing RTM molding technology, such as composite fan housings, guide vanes, and other engine composite material components. The molding method and corresponding mold design shall follow this method without exceeding the scope of this disclosure.

[0070] like Figure 1 As shown, the woven preform 10 of the fan blade is divided into tenon area 15, blade leading edge area 12, blade trailing edge area 14, blade tip area 11, and blade body area 13. Based on the external surface structure and thickness distribution of the fan blade, the woven preform 10 is woven to different thicknesses at different locations. During the forming process, the edges of the woven preform 10 are mostly areas of broken yarns, resulting in a looser structure and lower fiber content.

[0071] Reference Figure 2 As shown, after the woven preform 10 is placed in the molding mold 20, liquid resin is injected into the inner cavity 23 of the molding mold 20. The resin fully impregnates the fiber reinforcement in the woven preform 10. After curing and demolding, a blade blank with a high surface finish can be formed. To enhance the impact resistance of the blade, toughened epoxy resin, such as PR520 resin, is generally used. The molding mold 20 can be referenced. Figure 2 and Figure 3 As shown, the mold consists of two parts: an upper mold 21 and a lower mold 22. After the upper mold 21 and the lower mold 22 are closed, they form an inner cavity 23, which is used to place the woven preform 10. The mold body can be made of materials such as stainless steel, aluminum alloy, and ceramic to ensure that the surface finish of the inner cavity 23 meets the requirements of the composite material component.

[0072] Continue to refer to Figure 4As shown, the molding die 20 is also provided with a certain number of injection ports 42 and outlet ports 41. Liquid resin is injected into the inner cavity 23 through the injection ports 42 and flows out through the outlet ports 41. In some embodiments, the injection ports 42 are provided in the leading edge region 12 and the trailing edge region 14 of the blade. The injection ports 42 located in the leading edge region 12 and the trailing edge region 14 of the blade can also be used as venting ports for the resin filling process according to actual process needs, so as to discharge residual gas in the mold.

[0073] Based on the above description of the RTM process, this disclosure relates to a molding method for composite material parts, which can effectively improve the molding quality of composite material parts. It should be noted that the above description of the RTM process is for ease of understanding of the molding method involved in this disclosure and does not necessarily constitute prior art.

[0074] Reference Figure 11 The schematic diagram of the steps illustrates that in this forming method, a woven preform 10 is first obtained through step 81, with an enlarged edge region 18 left at the edge of the woven preform 10. To facilitate subsequent processing after blade forming, the woven preform 10 has an enlarged edge region 18 at the blade edge relative to the net size of the blade. The thickness and woven layer distribution of the enlarged edge region 18 are consistent with the woven structure of the woven preform body in that region.

[0075] Reference Figure 3 As shown, in some embodiments, the width of the enlarged edge region 18 is designed to be 15-30 mm, forming a boundary line 19 with the blade body, thus providing a certain manufacturing allowance for later adjustments to the blade blank. By setting the enlarged edge region 18, the size of the woven preform 10 is slightly larger than the final molded size of the composite material component. After obtaining the molded blank through the RTM process, the enlarged edge region 18 can be trimmed off by methods such as machining to obtain the final molded fan blade.

[0076] Then, in step 82, the enlarged edge region 18 is wrapped with fabric 31 and compacted to locally increase the fiber content of the enlarged edge region of the woven preform 10, thus obtaining the wrapped preform 10'. That is, the woven preform 10 wrapped with fabric 31 is called the wrapped preform 10'.

[0077] In some embodiments, the wrapping method may employ appropriate adhesives to bond and fix the wrapping fabric 31 and the enlarged edge region 18 of the woven preform 10, thereby obtaining the wrapping preform 10'.

[0078] In some embodiments, the material of fabric 31 is one or more of aramid fiber and polyimide fiber, and can be plain weave, satin weave, twill weave, etc. The wrapping area of ​​fabric 31 must be strictly controlled within the enlarged edge area 18 of the blade woven preform 10, and must not exceed the boundary line 19 between the blade body and the enlarged edge area 18, thereby avoiding affecting the fabric structure and thickness distribution of the blade body. In addition, the number of wrapping layers of fabric 31 should be appropriate, and the fiber content of the wrapping area can be calculated based on its areal density.

[0079] In some embodiments, the number of wrapping layers of fabric 31 is such that the fiber content at the edge of the woven preform 10 does not exceed 65%, so as to avoid excessive fiber content from affecting the mold closing of the molding die 20.

[0080] By wrapping and compacting the enlarged edge region 18 with fabric 31, it can be ensured that the fiber content in the enlarged edge region 18 is higher than that in other areas of the woven preform 10 after mold closing. This avoids resin scouring the edge of the preform during molding and the formation of rapid flow channels at the edge, thus preventing defects such as air bubbles caused by the formation of an envelope area at the resin flow front due to differences in resin flow velocity. Therefore, wrapping and compacting the enlarged edge region 18 can prevent the formation of rapid flow channels at the edge of the preform, improving the molding quality of the composite material part. At the same time, the increased fiber content at the edge of the enlarged edge region 18 also results in the region bearing a greater clamping force during mold closing, increasing the clamping force of the upper mold 21 and lower mold 22 on the enlarged edge region 18, thereby increasing the friction between the enlarged edge region 18 and the mold closing surface of the inner cavity 23, which has the effect of fixing the wrapped preform 10' and preventing the wrapped preform 10' from being misaligned or shifted during the blade mold closing process, thus affecting the formation of the internal structure of the composite material part.

[0081] After obtaining the preform 10', proceed to step 83, placing the preform 10' into the cavity 23 of the molding die 20 which has multiple injection ports 42 and dispensing ports 41.

[0082] The distribution pattern of the prefabricated body 10' is as follows: Figures 4 to 6 As shown, the preform 10' is located inside the inner cavity 23, and the inner cavity 23 is connected to the glue injection port 42 and the glue outlet 41.

[0083] In some embodiments, the number and distribution of injection ports 42 and outlet ports 41 are obtained by simulation calculation in step 85. That is, the number and distribution of injection ports 42 and outlet ports 41 are determined by the RTM process simulation tool after simulating and parametrically analyzing the resin filling process.

[0084] For example, using resin injection process simulation software (PAM-RTM) can simulate the resin filling flow and potential defect generation under isothermal or non-isothermal conditions. Therefore, the resin injection process simulation software can obtain a suitable arrangement scheme of injection port 42 / exit port 41 in advance before the test begins, ensuring that a successful composite material part can be obtained under this parameter design. This avoids iterative design of mold and molding process scheme through trial and error in actual tests, thereby effectively reducing the early manufacturing cost and cycle of the part and improving the success rate of RTM process.

[0085] Because the resin injection window is limited, for composite parts with low permeability or large dimensions, to ensure the molding process is completed within the resin process window, in some embodiments, multiple injection ports 42 are used to reduce resin injection time and effectively lower the molding time of composite parts. This is particularly effective in meeting the requirement of a shorter resin process window, ensuring high-quality molded composite parts. For example, injection ports 42 can be provided in the tenon area 15, the leading edge area 12, and the trailing edge area 14 of the blade to achieve resin injection in multiple directions.

[0086] exist Figures 4 to 6 In the illustrated embodiment of the fan blade molding, the diameters of the injection port 42 and the outlet port 41 are set within the range of 3mm to 6mm. This ensures successful molding of the fan blade while avoiding insufficient wetting of the preform due to excessive resin flow. The diameters of the injection port 42 and the outlet port 41 include, but are not limited to, the above-mentioned limitations. In the molding process of other composite material components such as engine casings, the diameters of the injection port 42 and the outlet port 41 are determined according to the actual component size and resin flow requirements.

[0087] In some embodiments, the dispensing port 42 and the dispensing port 41 are symmetrically distributed; Figure 4 and Figure 5 In other embodiments shown, the dispensing nozzle 42 and the dispensing nozzle 41 are asymmetrically distributed. Furthermore, in Figure 6 In the illustrated embodiment, the injection port 42 and the outlet 41 can also be inclined to increase the resin flow rate and ensure that the resin flow pressure and flow rate meet the design standards.

[0088] The configuration schemes for the glue inlet 42 and the glue outlet 41 include, but are not limited to, the above-described embodiments. In other embodiments, other schemes suitable for RTM process obtained by simulation calculation based on the permeation characteristics of the woven preform 10 can be applied to this disclosure without exceeding the scope of this disclosure.

[0089] After the preform 10' is placed in the inner cavity 23 of the molding mold 20, step 83 is continued. A resin diversion device 33 is added between the partial injection port 42 and the preform 10'. Diversion holes 16 are provided on the resin diversion device 33 along two intersecting directions to divert and dilute the resin flow at the injection port 42.

[0090] exist Figures 4 to 6 In the illustrated embodiment, since the blade tenon area 15 is located at the edge of the woven preform 10 and has a relatively loose structure, and the glue injection port 42 of the tenon area 15 is the main glue injection port, the resin injection pressure at this location is relatively high. In order to prevent the woven preform 10 in this area from deforming under the action of resin scouring and affecting the internal structure, a resin diversion device 33 is added to the glue injection port 42 and the tenon area 15 that wraps the preform 10'. The diversion holes 16 set in the two intersecting directions can effectively reduce the resin flow rate in the glue injection port 42, thereby reducing the scouring effect on the composite material component and thus avoiding changes or damage to the internal structure of the woven preform 10, which would affect the performance of the blade after molding.

[0091] The resin diversion device 33 can be set at the injection port 42 where the resin injection pressure is high, or it can be set at multiple injection ports 42 as needed, so as to adjust the resin flow rate and flow pressure, thereby reducing the scouring of the composite material parts.

[0092] In some embodiments, the resin diversion device 33 is made of an elastomer such as rubber, and its overall dimensions are designed according to the cavity dimensions of the molding die 20 and the dimensions of a specific area of ​​the composite material component. Its width and thickness can be consistent with these dimensions, or slightly larger than the cavity dimensions of the area of ​​the woven preform 10 to be contacted. For example, in... Figures 4 to 6 In the embodiment shown, the width and thickness of the resin diversion device 33 are consistent with the dimensions of the blade tenon area 15 to avoid affecting the mold closing.

[0093] Based on the above embodiments, a cavity 34 is provided on the inflow side of the resin diversion device 33. By providing a cavity 34 on the resin inflow side, the resin flowing in at high pressure and high flow rate can be buffered when passing through the cavity 34, thereby effectively reducing the resin flow rate.

[0094] Furthermore, the cavity 34 is combined with two intersecting directions where flow-diverting slots 16 are provided. Resin within the cavity 34 can continue to flow out through the flow-diverting slots 16, transforming the single-point injection from the injection port 42 into surface injection of resin through multiple flow-diverting slots 16. It should be noted that intersecting directions refer to any two mutually perpendicular directions, for example... Figure 7The resin diversion device 33 shown has multiple rows of diversion holes 16 arranged along the length and width directions of a plane, that is, the length and width directions form the aforementioned intersecting directions. The distribution of the diversion holes 16 includes, but is not limited to, the length and width directions. Those skilled in the art should understand that the diversion holes 16 can be arranged along any two intersecting directions in a plane to form a porous structure.

[0095] Unlike point injection formed by a single slit or line injection formed by a single row of slits, the multi-row array of distribution slits 16, distributed in at least two directions, can increase the resin injection range, thereby achieving the effect of surface injection. Surface injection can further reduce the resin flow rate, reduce the scouring effect on the woven preform 10, and at the same time produce a better flow formation effect, allowing the resin to flow evenly to the surface of the woven preform 10, thereby improving the molding quality of the composite material parts.

[0096] An embodiment of cavity 34 is described below. Figure 4 As shown, cavity 34 is disposed between resin distribution device 33 and the inner wall of inner cavity 23. That is, one end of resin distribution device 33 is in contact with the bottom of the tenon of the preform 10', and the other end is not in contact with the bottom of inner cavity 23 of molding mold 20. Cavity 34 is formed by the gap left at the bottom. Resin distribution device 33 and cavity 34 are independent of each other. After resin enters cavity 34 through injection port 42 and is buffered, it enters resin distribution device 33 to continue to distribute, so as to reduce resin flow rate.

[0097] To effectively reduce the flow rate, the resin diversion device 33 includes various embodiments, wherein the diversion orifice 16 is provided on the resin diversion device along two intersecting directions. For example... Figure 7 The first resin distribution device 331 shown is a multi-row uniform array porous structure. Each distribution hole 16 has the same size and is uniformly arranged in a multi-row array along the length and width directions of the resin distribution device 33. The diameter of the distribution holes 16 is set to 1-5mm. The spacing of each distribution hole 16 can be designed according to actual needs to ensure that the flow rate of resin flowing out along the distribution holes 16 meets the requirements to form a uniform surface injection effect without exceeding a certain range, thereby avoiding erosion at the edge of the preform 10'.

[0098] For example Figure 8 The second resin distribution device 332 shown is a non-uniform porous structure, with the dimensions of each distribution orifice 16 being unevenly distributed, and the specific dimensions being determined according to the resin injection requirements. As the resin flows through the unevenly distributed distribution orifices 16, the outflow velocity and flow rate are inconsistent across each orifice 16, thus effectively adjusting the resin flow.

[0099] Another example Figure 9 The third resin diversion device 333 shown is a stacked metal wire structure. The metal wires are stacked or piled up in any geometric structure to form the third resin diversion device 333. After the resin enters through the injection port 42, it passes through the pores 17 formed by the stacking or piling of the metal wires and then comes into contact with the preform 10'. The pores 17 can further slow down and divert the flow of the resin, reduce the erosion of the preform 10', and improve the molding quality of the engine parts.

[0100] In the fabrication of the fan blades, the diameter of the metal wires used in the resin distribution device 33 with stacked metal wires is no greater than 1 mm, and the porosity of the stacked metal wire structure ranges from 70% to 90%. This is to satisfy the surface injection effect while avoiding excessive resistance to resin flow due to excessively low porosity. In other embodiments, the optimal porosity range is determined by the specific dimensions of the manufactured component and the requirements for resin flow rate and volume.

[0101] exist Figure 10 In the fourth resin diversion device 334 shown, the cavity 34 is located inside the fourth resin diversion device 334, that is, the resin diversion device 33 and the cavity 34 are not independent of each other, but are set as an integral structure. The fourth resin diversion device 334 includes an opening 35 communicating with the injection port 42. The cavity 34, the opening 35 and the diversion hole 16 are interconnected. The resin flows into the opening 35 from the injection port 42 and then enters the cavity, which can effectively reduce the resin flow rate at the injection port 42, and at the same time change the resin point injection to surface injection, reducing the scouring effect on the preform at that time.

[0102] Based on the above embodiments, the height of the cavity 34 ranges from 1 to 5 mm, which effectively reduces the resin flow rate at the injection port 42 while ensuring the surface injection effect on the composite material component.

[0103] While several embodiments of the resin diversion device have been described above, other embodiments may have more details in many respects than the above embodiments, and at least some of these details may have diverse variations, such as the size and shape design of the diversion orifice 16, the material selection of the resin diversion device 33, and the height of the cavity 34. Therefore, the above description should not be regarded as a limitation on the resin diversion device.

[0104] After adding the resin diversion device 33, step 83 continues. Resin is injected into the inner cavity 23 through part of the injection port 42 and via the resin diversion device 33, while resin is injected into the inner cavity 23 through the remaining injection ports 42, thereby injecting the resin into the inner cavity 23 of the molding mold 20. Due to the different permeability at various points of the woven preform 10, the resin flows at different speeds at various points of the woven preform 10. This problem can be effectively solved by adjusting the resin injection pressure and resin flow rate at each injection port 42.

[0105] In addition to using the resin diversion device 33 to divert resin and adjust the resin flow rate, the resin injection pressure and resin flow rate of each injection port 42 can also be set according to actual needs. For example, the resin injection pressure and resin flow rate of each injection port 42 can be obtained through simulation calculation in step 86 to ensure that the resin flow speed at each point of the woven preform 10 remains uniform, thereby ensuring that the resin flow front advances as a whole without forming an envelope zone. By referring to the process simulation optimization results, the resin injection pressure and resin flow rate of each injection port 42 can be adjusted to the optimal solution, thereby avoiding the influence of different resin flow speeds at each point of the woven preform 10 on the molding quality.

[0106] For example, Figure 11 In one embodiment shown, based on simulation results, it is determined that the resin injection pressure for injecting resin into the inner cavity 23 varies with the injection time in a gradient manner. For example, in the second stage 72, the resin injection pressure remains at a stable value, which takes into account the preform molding requirements of this injection stage to facilitate stable resin injection. However, in the third stage 73, the resin injection pressure remains at another stable value to meet the molding requirements of the encapsulated preform 10' in another injection stage.

[0107] By controlling the resin flow rate within the preform 10', molding defects caused by the resin enveloping unfilled areas of the blade during the molding process can be avoided, thereby improving the blade molding quality. The distribution of injection pressure with injection time includes, but is not limited to, the embodiments described above. For example, in other embodiments, the resin injection pressure can also be set to a fluctuating value.

[0108] Considering that excessively high resin injection pressure places high demands on the load-bearing capacity of the molding die 20, the resin injection pressure is set within the range of 0.2 MPa to 0.4 MPa during the fan blade molding process. The resin injection pressure includes, but is not limited to, the above range. In other embodiments, the magnitude of the resin injection pressure is jointly determined by the molding die and the specific dimensions of the molded part.

[0109] In addition, the opening and closing of each glue inlet 42 and glue outlet 41, the resin injection pressure for injecting resin into the inner cavity 23, and the resin flow rate are adjusted in real time by the control component.

[0110] For example, the control unit can be configured to open each injection port 42 sequentially, or to open or close each injection port 42 in a specific order as needed to achieve resin injection. The opening sequence of each injection port 42 can be arbitrarily opened or closed by the control unit according to the optimized process scheme; it can be opened or closed sequentially, or one or more of them can be opened or closed simultaneously. At the same time, the control unit adjusts the resin injection pressure and resin flow rate of each injection port 42 in real time according to the resin injection requirements, thereby ensuring that the resin flow rate remains uniform throughout the woven preform 10, avoiding the formation of molding defects such as bubbles and dry spots, and completing the mold filling process more quickly to meet the requirement of a short resin process window.

[0111] After the die-casting process is completed, proceed to step 84. After resin injection is completed, high-temperature curing is performed to obtain a molded blank. The molded blank is then demolded to obtain a high-quality composite material part with a high surface finish.

[0112] Based on the above introduction to the molding method of composite material parts, we can also understand a molding system for composite material parts used in RTM process, which includes molding die 20 and resin distribution device 33.

[0113] The molding die 20 provides an inner cavity 23, multiple injection ports 42, and an outlet port 41. The inner cavity 23 has an enlarged cavity 36 for the enlarged edge region 18 of the clamping woven preform. (Refer to...) Figure 3 As shown, the enlarged cavity 36 is used to clamp the enlarged edge region 18 after the fabric is wrapped, thereby preventing the woven preform 10 from moving within the inner cavity 23. A resin diversion device 33 is disposed between a portion of the injection port 42 and the inner cavity 23, and has diversion slits 16 distributed along two intersecting directions. After the resin flows through the diversion slits 16, the flow velocity and pressure are effectively reduced, decreasing erosion of the preform's edges. Furthermore, the diversion slits 16 distributed along the two intersecting directions transform point injection of resin into surface injection, allowing the resin to flow evenly onto the surface of the woven preform 10, thereby improving the molding quality of the composite material component.

[0114] Furthermore, the molding system has a cavity 34 on the inflow side of the resin distribution device 33. By providing a cavity 34 on the resin inflow side, the cavity 34 can effectively disperse the resin flowing in from the injection port 42, reducing the scouring effect of the resin on loose edges of the preform, such as blade tenons, thus preventing deformation in these areas. At the same time, it forms a surface injection of the preform area, improving the resin injection effect and reducing the formation of defects.

[0115] While the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the invention. Any variations and modifications can be made by those skilled in the art without departing from the spirit and scope of the invention. Therefore, any modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of the present invention, without departing from the scope of the invention, fall within the protection scope defined by the claims of the present invention.

Claims

1. A molding method for composite material parts, characterized in that, Includes the following steps: Obtain a woven preform, leaving an enlarged edge region at the edge of the woven preform; The enlarged edge region is wrapped with fabric and compacted to locally increase the fiber content of the enlarged edge region of the woven preform, thereby obtaining a wrapped preform. The preform is placed in the inner cavity of a molding die with multiple injection ports and outlet ports. A resin diversion device is added between some of the injection ports and the preform. Diversion holes are provided on the resin diversion device in two intersecting directions. Resin is injected into the inner cavity through some of the injection ports and the resin diversion device. At the same time, resin is injected into the inner cavity in multiple directions through the remaining injection ports. A cavity is provided on the inflow side of the resin diversion device to ensure that surface injection is formed when resin is injected into the inner cavity. After the resin is injected, it is cured at high temperature to obtain a molded blank and then the molded blank is demolded. The resin injection pressure for injecting resin into the inner cavity varies with the injection time in a gradient manner.

2. The molding method for composite material parts as described in claim 1, characterized in that, The height of the cavity ranges from 1 to 5 mm.

3. The molding method for composite material parts as described in claim 1, characterized in that, The resin diversion device is a multi-row uniform array porous structure or a non-uniform porous structure.

4. The molding method for composite material parts as described in claim 1, characterized in that, The resin diversion device is a stacked metal wire structure.

5. The molding method for composite material parts as described in claim 4, characterized in that, The porosity of the stacked metal wire structure ranges from 70% to 90%.

6. The molding method for composite material parts as described in claim 1, characterized in that, The width of the enlarged edge region ranges from 15 to 30 mm.

7. The molding method for composite material parts as described in claim 1, characterized in that, The number of wrapping layers of the fabric is such that the fiber content at the edge of the woven preform does not exceed 65%.

8. The molding method for composite material parts as described in claim 1, characterized in that, The fabric is made of one or more of aramid fibers and polyimide fibers.

9. The molding method for composite material parts as described in claim 1, characterized in that, The number and distribution of the injection ports and outlets, as well as the resin injection pressure and resin flow rate at each injection port, are obtained through simulation calculations.

10. The molding method for a composite material component as described in claim 1, characterized in that, The opening and closing of each of the glue inlet and outlet ports, the resin injection pressure for injecting resin into the inner cavity, and the resin flow rate are adjusted in real time by the control component.

11. The molding method for the composite material component as described in claim 1, characterized in that, The glue injection port and the glue outlet are set at an angle.

12. A molding system for composite material components, characterized in that, For performing the molding method as described in any one of claims 1-11, the system comprises: The molding die provides an inner cavity, multiple injection ports and outlet ports, the inner cavity having an enlarged cavity for an enlarged edge region of the woven preform; and A resin diversion device is disposed between part of the injection port and the inner cavity, and has diversion holes distributed along two intersecting directions.

13. The molding system for composite material parts as described in claim 12, characterized in that, The molding system has a cavity on the inflow side of the resin distribution device.

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