A forming die for a wing trailing edge

Abstract

The utility model discloses a kind of forming mould of wing trailing edge, specifically relates to wing trailing edge mould technical field, comprising: mould main body, the mould main body outer end is fixed with connecting flange;Bottom fixed frame, the bottom fixed frame is fixed in mould main body and connecting flange bottom end, heating cavity is opened between the bottom fixed frame and mould main body bottom end, the distance of each point in the heating cavity inside to the each point of mould main body bottom end is same, the bottom end of mould main body is fixed with multiple reinforcing support plate, multiple reinforcing support plate bottom end is fixedly connected with heating cavity inner end, one communication port is opened in the middle of multiple reinforcing support plate.The utility model successfully solves the core technical problem that temperature field is not uniform in hot-pressing tank forming of large, complex profile wing trailing edge, provides a kind of special forming mould capable of manufacturing high quality, high precision, high performance composite material component.

Description

Technical Field

[0001] This utility model relates to the field of wing trailing edge mold technology, specifically to a wing trailing edge forming mold. Background Technology

[0002] The trailing edge of an airfoil is a critical component for its aerodynamic performance, characterized by its thinness, sharpness, high curvature, and extremely high precision requirements. Airfoil trailing edges are typically manufactured using composite materials (such as carbon fiber prepreg), and the main molding process determines the type of mold. Autoclave molding is the most common method. The mold requires only one surface (usually a lower mold / concave mold), and the auxiliary material is placed on the prepared blank, then the entire part is placed into the autoclave. The part is cured by vacuuming and the high temperature and pressure inside the autoclave.

[0003] Currently, in actual use, the autoclave molding mold for the trailing edge of the wing has a large cavity curvature. Therefore, during the heating and curing process, it is difficult to maintain a uniform curing temperature field at the thinner edges and in the middle, which will affect the final curing quality. Utility Model Content

[0004] The purpose of this invention is to provide a molding die for the trailing edge of an airfoil to address the aforementioned shortcomings in the technology.

[0005] To achieve the above objectives, this utility model provides the following technical solution: a molding die for the trailing edge of an airfoil, comprising: The mold body has a connecting flange fixedly provided at its outer end; A bottom fixing frame is fixedly installed on the bottom end of the mold body and the connecting flange. A heating cavity is opened between the bottom fixing frame and the bottom end of the mold body. The vertical distance from each point inside the heating cavity to each point on the bottom end of the mold body is the same. Multiple reinforcing support plates are fixedly installed on the bottom end of the mold body. The bottom ends of the multiple reinforcing support plates are fixedly connected to the inner end of the heating cavity. A communication port is opened in the middle of the multiple reinforcing support plates. A hot oil inlet pipe is fixedly installed inside the communication port. One end of the hot oil inlet pipe passes through one end of the bottom fixed frame and extends to the outside of the bottom fixed frame. Multiple oil outlet holes are opened at the outer end of the hot oil inlet pipe. The multiple oil outlet holes are staggered with multiple reinforcing support plates. A control valve is fixedly installed on the end of the hot oil inlet pipe that extends to the outside of the bottom fixed frame.

[0006] Preferably, one end of the hot oil inlet pipe is connected to an external hot oil conveying device.

[0007] Preferably, the mold body, bottom fixing frame, and reinforcing support plate are made of Invar steel.

[0008] Preferably, a vacuum groove is provided at the top of the connecting flange, and a vacuum connector is fixed at the edge of the connecting flange. One end of the vacuum connector is connected to the inside of the vacuum groove, and the other end of the vacuum connector is connected to an external vacuum pump.

[0009] Preferably, a release cloth is laid on the top of the mold body and the connecting flange.

[0010] Preferably, a breathable felt is laid on the top of the release fabric.

[0011] Preferably, a vacuum bag film is laid on the outside of the breathable felt, and the vacuum bag film covers the breathable felt, the release cloth and the edge of the connecting flange.

[0012] Preferably, the vacuum bag film is sealed and bonded to the outer edge of the connecting flange by a sealing strip.

[0013] The technical effects and advantages provided by this utility model in the above technical solution are as follows: 1. Achieves extremely high temperature uniformity, effectively improving curing quality: This invention constructs a highly efficient uniform temperature heating system by designing a heating cavity equidistant from the mold surface and utilizing staggered reinforcing support plates and a hot oil inlet pipe with oil outlet holes. The hot oil is forced to diffuse uniformly within the cavity, eliminating the "hot spots" and "cold spots" present in traditional heating methods on complex mold surfaces. This ensures that the trailing edge of the wing, from the thicker root to the extremely thin and highly curved edge, maintains a highly uniform curing temperature field (temperature difference can be controlled within ±2.5°C). This fundamentally avoids defects such as inconsistent resin curing, internal stress, and deformation caused by uneven temperature, significantly improving the mechanical properties and dimensional stability of the molded parts.

[0014] 2. Excellent material compatibility and structural stability: The mold body, bottom fixing frame, and reinforcing support plate are all made of Invar steel. The extremely low coefficient of thermal expansion of Invar steel is highly compatible with carbon fiber composite materials, allowing the mold and parts to expand and contract synchronously during heating and cooling. This greatly reduces thermal stress caused by the difference in the coefficients of thermal expansion between the two materials, thus ensuring the surface accuracy of the parts, especially the thin-walled rear edge, and preventing springback or torsional deformation of the parts after demolding.

[0015] 3. A perfect combination of rigidity and heating efficiency: The reinforced support plate design serves a dual function. On one hand, as a robust skeletal structure, it significantly enhances the overall rigidity and stability of the mold when subjected to the enormous pressure (typically 0.4-0.8 MPa) within the autoclave, ensuring zero deformation of the mold surface during the process. On the other hand, it cleverly guides the flow path of the hot oil, dividing the expansive heating chamber into orderly flow channels, promoting both uniform heat exchange and improved heat transfer efficiency.

[0016] 4. Reliable vacuum system with thorough venting: A vacuum channel network is formed by connecting the vacuum groove on the connecting flange to the breathable felt covering the entire part. This design ensures that air and resin volatiles between the prepreg layers are completely removed during the curing process, effectively preventing quality problems such as bubbles and delamination inside the part, and guaranteeing the fiber volume content and interlayer bonding strength of the composite material. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this utility model. For those skilled in the art, other drawings can be obtained based on these drawings.

[0018] Figure 1 This is a schematic diagram of the overall structure of this utility model; Figure 2 This is a schematic diagram of the overall exploded structure of this utility model; Figure 3 This is a three-dimensional structural diagram of the mold body and connecting flange of this utility model; Figure 4 This is a three-dimensional structural diagram of the hot oil inlet pipe of this utility model.

[0019] Explanation of reference numerals in the attached figures: 1. Mold body; 2. Connecting flange; 3. Bottom fixing frame; 4. Heating chamber; 5. Reinforcing support plate; 6. Connecting port; 7. Hot oil inlet pipe; 8. Oil outlet; 9. Control valve; 10. Vacuum tank; 11. Vacuum connector; 12. Release cloth; 13. Breathable felt. Detailed Implementation

[0020] To enable those skilled in the art to better understand the technical solution of this utility model, the present utility model will be further described in detail below with reference to the accompanying drawings.

[0021] Refer to the instruction manual appendix Figure 1-4 As shown, the present invention provides a molding die for the trailing edge of an airfoil, which mainly consists of a die body 1, a connecting flange 2, a bottom fixing frame 3, a heating system and a vacuum system.

[0022] Mold Body and Materials: The mold body 1 is preferably made of Invar steel through precision casting and five-axis CNC milling. Its surface perfectly conforms to the aerodynamic shape of the wing trailing edge and is polished to a mirror finish. An integrally formed connecting flange 2 is provided around the mold body 1 to provide a working surface for the sealing of the vacuum bag system. The bottom fixing frame 3 is also made of Invar steel and is fixed to the bottom of the mold body 1 and the connecting flange 2 by welding or bolting, thus forming a closed heating chamber 4 between the bottom of the mold body 1 and the bottom fixing frame 3.

[0023] Uniform Temperature Heating System: The core improvement of this utility model lies in the uniform temperature heating system described above. A key feature of the heating chamber 4 is that the vertical distance from all points within its internal space to the bottom profile of the mold body 1 is the same. This means that the top profile of the heating chamber 4 is equidistant from the bottom profile of the mold body 1, creating a uniform heat exchange space. Inside the heating chamber 4, multiple reinforcing support plates 5, also made of Invar steel, are provided. These not only enhance the overall rigidity of the mold and prevent deformation under autoclave pressure, but also divide the heating chamber 4 into multiple flow channels. A common connecting port 6 is provided in the middle of the multiple reinforcing support plates 5.

[0024] A hot oil inlet pipe 7 passes through the connecting port 6, with one end passing through the bottom fixing frame 3 and connecting to an external hot oil circulation device, and the other end being a closed end. The hot oil inlet pipe 7 is located on a pipe section inside the heating chamber 4 and has multiple oil outlet holes 8. These oil outlet holes 8 are spatially staggered with multiple reinforcing support plates 5. When high-temperature hot oil is injected from the hot oil inlet pipe 7, it will spray out from each oil outlet hole 8. Due to the obstruction and guiding effect of the reinforcing support plates 5, the hot oil will be forced to flow evenly and meanderingly in each flow channel separated by the reinforcing support plates 5, eventually filling the entire heating chamber 4. Through the excellent thermal conductivity of Invar steel, the heat is evenly transferred to the entire mold body 1.

[0025] Vacuum system: A vacuum groove 10 is machined on the working plane of the connecting flange 2, surrounding the cavity of the mold body 1. A vacuum connector 11 is installed on the edge of the connecting flange 2. One end of the connector is connected to the vacuum groove 10, and the other end is connected to an external vacuum pump through a pipeline.

[0026] Molding and layup operation: In the actual molding of composite materials for the trailing edge of an airfoil, the operation is as follows: 1. First, apply a high-temperature release agent to the mold body 1 and the connecting flange 2.

[0027] 2. Then, according to the design, lay out composite materials such as carbon fiber prepreg.

[0028] 3. After the installation is completed, cover the parts with release cloth 12 and breathable felt 13 in sequence.

[0029] 4. Finally, cover the entire assembly (including the breathable felt 13, the release cloth 12, and the edge of the connecting flange 2) with a vacuum bag film, and seal the vacuum bag film tightly on the connecting flange 2 with a sealing strip, which should be located on the outside of the vacuum groove 10.

[0030] 5. Connect the tubing on the vacuum bag membrane to vacuum connector 11, and turn on the vacuum pump to check for leaks. After confirming that the seal is intact, the entire mold can be sent into the autoclave for the curing process. During the curing process, the hot oil circulation system and the autoclave are turned on simultaneously to heat and pressurize the composite material parts for curing.

[0031] In summary, this invention successfully solves the core technical problem of uneven temperature field at the trailing edge of large and complex airfoil during autoclave molding, and provides a special molding die capable of manufacturing high-quality, high-precision, and high-performance composite material components.

[0032] The foregoing description only illustrates certain exemplary embodiments of the present invention. Undoubtedly, those skilled in the art can modify the described embodiments in various ways without departing from the spirit and scope of the present invention. Therefore, the above drawings and descriptions are illustrative in nature and should not be construed as limiting the scope of protection of the claims of the present invention.

Claims

1. A molding die for the trailing edge of an airfoil, characterized in that, include: The mold body (1) has a connecting flange (2) fixedly provided at its outer end. Bottom fixing frame (3) is fixedly installed at the bottom of the mold body (1) and the connecting flange (2). A heating cavity (4) is provided between the bottom fixing frame (3) and the bottom of the mold body (1). The vertical distance from each point inside the heating cavity (4) to each point at the bottom of the mold body (1) is the same. Multiple reinforcing support plates (5) are fixedly installed at the bottom of the mold body (1). The bottom ends of the multiple reinforcing support plates (5) are fixedly connected to the inner end of the heating cavity (4). A connecting port (6) is opened in the middle of the multiple reinforcing support plates (5). A hot oil inlet pipe (7) is fixed inside the connecting port (6). One end of the hot oil inlet pipe (7) passes through one end of the bottom fixing frame (3) and extends to the outside of the bottom fixing frame (3). Multiple oil outlet holes (8) are opened at the outer end of the hot oil inlet pipe (7). The multiple oil outlet holes (8) are staggered with multiple reinforcing support plates (5). A control valve (9) is fixed on the end of the hot oil inlet pipe (7) that extends to the outside of the bottom fixing frame (3).

2. The forming mold for the trailing edge of a wing according to claim 1, characterized in that: One end of the hot oil inlet pipe (7) is connected to an external hot oil conveying device.

3. The forming mold for the trailing edge of a wing according to claim 1, characterized in that: The mold body (1), bottom fixing frame (3) and reinforcing support plate (5) are made of Invar steel.

4. The forming mold for the trailing edge of a wing according to claim 1, characterized in that: The top of the connecting flange (2) is provided with a vacuum groove (10), and a vacuum connector (11) is fixed at the edge of the connecting flange (2). One end of the vacuum connector (11) is connected to the inside of the vacuum groove (10), and the other end of the vacuum connector (11) is connected to an external vacuum pump.

5. The forming mold for the trailing edge of a wing according to claim 1, characterized in that: The top of the mold body (1) and the connecting flange (2) is covered with a release cloth (12).

6. The forming mold for the trailing edge of a wing according to claim 5, characterized in that: The top of the release fabric (12) is covered with a breathable felt (13).

7. The forming mold for the trailing edge of a wing according to claim 6, characterized in that: The breathable felt (13) is covered with a vacuum bag film, which covers the edges of the breathable felt (13), the release cloth (12) and the connecting flange (2).

8. The forming mold for the trailing edge of a wing according to claim 7, characterized in that: The vacuum bag film is sealed and bonded to the outer edge of the connecting flange (2) by a sealing strip.

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