A molding method for the horizontal stabilizer of a small unmanned helicopter
The method for fabricating the horizontal tail of a small unmanned helicopter using composite materials employs processes such as pressure-sensitive tape, modeling clay, release film, and autoclave, which solves the problem of excessive weight of aluminum alloy and achieves a lightweight and high-strength composite material horizontal tail.
Patent Information
- Application Number
- CN202511471454.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2025-10-15
- Publication Date
- 2025-12-02
- Estimated Expiration
- 2045-10-15
AI Technical Summary
The horizontal stabilizer material of existing small unmanned helicopters is mainly aluminum alloy, which results in a relatively heavy weight. A composite material preparation method is needed to reduce weight and ensure high strength.
The horizontal tail of a small unmanned helicopter is made of composite materials. Through a multi-step molding method, including the use of pressure-sensitive tape, modeling clay, release film, adhesives and autoclaves, reliable bonding of each component is ensured, forming a horizontal tail composed entirely of composite materials.
A lightweight and high-strength composite material horizontal stabilizer was developed, providing more room for weight reduction while meeting the needs of small unmanned helicopters.
Smart Images
Figure CN120921715B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of composite material preparation technology, and in particular to a molding method for the horizontal tail of a small unmanned helicopter. Background Technology
[0002] Currently, small unmanned helicopters are widely used in urban traffic monitoring, agricultural and forestry seeding / spraying, and other fields. Composite materials, due to their advantages such as high specific strength, high specific stiffness, designability, and ease of large-area integral molding, have been applied in batches in areas such as wings and fuselage structures of small unmanned helicopters.
[0003] In the current technology, the horizontal tail material of small unmanned helicopters is mainly aluminum alloy. The weight of this type of joint is higher than that of composite material joints. In order to give small unmanned helicopters more room for weight reduction, it is urgent to use composite materials to prepare the molding method of the horizontal tail of small unmanned helicopters, so as to reduce the weight of the horizontal tail while ensuring high strength. Summary of the Invention
[0004] The purpose of this section is to outline some aspects of embodiments of the present invention and to briefly describe some preferred embodiments. Simplifications or omissions may be made in this section, as well as in the abstract and title of this application, to avoid obscuring the purpose of these documents; however, such simplifications or omissions should not be construed as limiting the scope of the invention.
[0005] In view of the problems existing in the above and / or existing helicopter horizontal stabilizer manufacturing processes, the present invention is proposed.
[0006] Therefore, the purpose of this invention is to provide a molding method for a small unmanned helicopter horizontal stabilizer. This invention can reliably produce a helicopter horizontal stabilizer composed entirely of composite materials, which is lightweight and high-strength.
[0007] To solve the above-mentioned technical problems, the present invention provides the following technical solution: a method for forming a horizontal stabilizer of a small unmanned helicopter, comprising the following steps:
[0008] S1. Prepare the first horizontal tail skin, the second horizontal tail skin, the first horizontal tail beam, the second horizontal tail beam, the horizontal tail adapter, the trailing edge foam of the horizontal tail, the first horizontal tail end foam, and the second horizontal tail end foam.
[0009] S2. Place the second flat tail skin on the surface of the second skin forming mold, and fix the edges with pressure-sensitive tape so that the second flat tail skin fits the second skin forming mold. Mark the positions of each flat tail beam and foam on the surface, and use release cloth to protect the non-adhesive areas around the perimeter.
[0010] S3. Place modeling clay on the upper and outer sides of the second flat tail skin, and cover the surface with a layer of release film. Place the first and second flat tail beams on the upper surface of the second flat tail skin according to the marked positions. Place each foam in the corresponding position on the outer side of the second flat tail skin. After bag making and pre-vacuuming, remove the first flat tail skin, beams and foam. According to the compaction of the modeling clay, apply a layer of adhesive to the bonding surface of the second flat tail skin. At the same time, apply a layer of adhesive to the bonding surfaces of the beams and foam cores. Place each foam and each flat tail beam according to the marked positions. Bag making and pre-vacuuming. After the pre-vacuuming is completed, unpack the bag, seal it, and transfer the mold to the autoclave for curing to form the second skin assembly.
[0011] S4. Use fasteners to fix the horizontal tail adapter to the first horizontal tail skin to form the first skin assembly.
[0012] S5. Place the second skin assembly on the surface of the second skin molding mold, and fix the edges with pressure-sensitive tape to make the second flat tail skin fit the second skin molding mold. Lay a layer of release film on the bonding surface of the second skin assembly, place modeling clay on the release film, place the assembled first skin assembly on the second skin assembly, and use sandbags to compact for a set time. Remove the first skin assembly and observe the compaction of the modeling clay on the surface. According to the compaction, apply adhesive to the bonding surfaces of the second skin assembly and the first skin assembly, and place the first skin assembly on the corresponding position on the upper surface of the second skin assembly.
[0013] S6. Transfer the second skin forming mold to the autoclave for curing;
[0014] S7. Use sandpaper to sand down any excess adhesive on the product edges.
[0015] As a further improvement of the present invention, the step of preparing the first flat-tail skin is as follows:
[0016] Prepare the first skin forming mold, which has an upward-facing first laying groove;
[0017] Prepreg is laid in the first laying groove according to the set layer sequence to form the first outer skin;
[0018] Two honeycomb cores spaced apart in the left-right direction are placed on the upper side of the first outer skin;
[0019] A first inner skin is laid on the upper side of the honeycomb core and the first outer skin outside the honeycomb core;
[0020] It is then packaged and placed in an autoclave for curing.
[0021] As a further improvement of the present invention, the step of preparing the second flat-tail skin is as follows:
[0022] Prepare the second skin forming mold, which has an upward-facing second laying groove;
[0023] In the second laying groove, the prepreg is laid in the set layup sequence to form the second outer skin;
[0024] Use laser projection to locate the honeycomb core area, and lay epoxy structural film in the corresponding area. After the film is laid, place the honeycomb core according to the laser projection, and lay epoxy structural film on the upper surface of the honeycomb core as well.
[0025] A second inner skin is laid on the upper side of the honeycomb core and on the upper side of the second outer skin outside the honeycomb core;
[0026] It is then packaged and placed in an autoclave for curing.
[0027] As a further improvement of the present invention, the step of preparing the first flat tail beam is as follows:
[0028] Prepare the first beam forming mold. The upper part of the first beam forming mold is provided with the first beam laying part. The left and right sides of the first beam laying part are flush with the left and right sides of the first beam forming mold.
[0029] Prepreg is laid on the outer edge of the first beam according to the set layering sequence. Vacuum pre-compacting is performed every 4 layers, and the pre-compacting time is not less than 15 minutes.
[0030] It is then packaged and placed in an autoclave for curing.
[0031] As a further improvement of the present invention, the step of preparing the second horizontal tail beam is as follows:
[0032] Prepare the second beam forming mold, which includes a base plate. The first laying part is fixed on the left and right sides of the base plate, and the second laying part is fixed on the upper side of the base plate. The left and right sides of the first laying part and the second laying part are flush.
[0033] Prepreg is laid along the outer edge of the first and second laying sections in the lay-up sequence. Vacuum pre-compacting is performed every 4 layers, and the pre-compacting time is not less than 15 minutes.
[0034] It is then packaged and placed in an autoclave for curing.
[0035] As a further improvement of the present invention, the steps for preparing the adapter are as follows:
[0036] Prepare the adapter molding mold, which includes insert one and insert two. Insert two can be detachably connected to the upper side of insert one. When insert two is connected to insert one, the bottom surface of insert two is attached to the upper surface of insert one. The outer perimeter of the interface between insert two and insert one at a set distance is the R area.
[0037] Prepreg is laid on the bottom surface of the insert according to the set layering sequence. Vacuum pre-compacting is performed every 4 layers, and the pre-compacting time is not less than 15 minutes.
[0038] Prepreg is laid on the upper part of the second insert according to the set layup sequence. Vacuum pre-compacting is performed every 4 layers, and the pre-compacting time is not less than 15 minutes.
[0039] Connect the second insert to the upper side of the first insert;
[0040] The carbon wire is made by twisting prepreg into carbon wire, wrapping a layer of adhesive film on the outside of the carbon wire, placing it on the core material tooling, and transferring it to the press for compaction. The initial pressure is 8MPa±0.1MPa. The mold is heated to 60℃±5℃ at a heating rate of no more than 1.5℃ / min. Under these conditions, the temperature and pressure are maintained for 0.5h±10min to make the core material.
[0041] Wrap the core material around the R area once, then vacuum and compact it.
[0042] Several layers of prepreg are laid on the side of the assembled insert one and insert two, then sealed and sent into an autoclave for curing.
[0043] During demolding, insert one and insert two are separated to complete the demolding of the part.
[0044] As a further improvement of the present invention, the adapter molding die also includes at least two positioning pins, at least two positioning countersunk holes are opened on the first insert, and several positioning holes corresponding to the positioning countersunk holes are opened on the second insert, and several positioning pins can be inserted into the corresponding positioning countersunk holes through the positioning holes.
[0045] As a further improvement of the present invention, before connecting the second insert to the upper side of the first insert, the following steps are also included.
[0046] Based on the recessed positioning holes and countersunk hole areas of the paving area, cut out the prepreg in the areas where the positioning holes and countersunk holes are located on insert one and insert two;
[0047] Place the second insert on top of the first insert, and use several locating pins to insert into the corresponding locating countersunk holes through the locating holes to complete the combination of the first insert and the second insert.
[0048] As a further improvement of the present invention, after the part is demolded, the prepared thin plate is taken out, the thin plate is glued, and the thin plate is glued to the downward-facing end of the part. The thin plate covers all the areas where the holes of the part are located, thus completing the preparation of the adapter.
[0049] Compared with the prior art, the present invention has the following technical effects: Before the bonding of each component in the second skin assembly and before the bonding of the first skin assembly and the second skin assembly, the present invention uses the step of placing and compacting modeling clay to verify that each area to be bonded needs to be bonded before bonding, and determines the bonding gap, thereby ensuring reliable bonding; The helicopter horizontal stabilizer prepared by the present invention is made entirely of composite materials, providing more space for weight reduction for small unmanned helicopters, while also having high strength; It can be applied to the preparation of helicopter horizontal stabilizers. Attached Figure Description
[0050] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. Wherein:
[0051] Figure 1 This is a three-dimensional structural diagram of the second skin forming mold in this invention.
[0052] Figure 2 This is a three-dimensional structural diagram of the first skin forming mold in this invention.
[0053] Figure 3 This is a three-dimensional structural diagram of the first beam forming mold in this invention.
[0054] Figure 4 This is a three-dimensional structural diagram of the second beam forming mold in this invention.
[0055] Figure 5 This is a three-dimensional structural diagram of insert two in the mold for the adapter.
[0056] Figure 6 This is a three-dimensional structural diagram of insert one in the mold for the adapter.
[0057] Figure 7 This is a three-dimensional structural diagram of the adapter molding die in this invention.
[0058] Figure 8 This is a top view of the second flat-tail skin in this invention.
[0059] Figure 9 for Figure 8 View from point AA.
[0060] Figure 10 for Figure 9 A magnified view of a section at point B in the middle.
[0061] Figure 11 This is a top view of the first flat-tail skin in this invention.
[0062] Figure 12 for Figure 11 The view at CC.
[0063] Figure 13 for Figure 12 A magnified view of a section at point D.
[0064] Figure 14 This is a three-dimensional structural diagram showing the first and second tail beams bonded together on the upper side of the second tail skin.
[0065] Figure 15 This is a three-dimensional structural diagram of the second skin assembly in this invention.
[0066] Figure 16 This is the three-dimensional structure of the first skin assembly in this invention. Figure 1 .
[0067] Figure 17 This is the three-dimensional structure of the first skin assembly in this invention. Figure 2 .
[0068] Figure 18 This is a three-dimensional structural diagram of the flat tail prepared using the present invention.
[0069] Figure 19 This is a three-dimensional structural diagram of the adapter in this invention.
[0070] Figure 20 This is a three-dimensional structural diagram of the core material tooling in this invention.
[0071] In the diagram: 100 Second skin forming mold, 101 First laying groove, 200 First skin forming mold, 201 Second laying groove, 300 First beam forming mold, 301 First beam laying section, 400 Second beam forming mold, 401 Base plate, 402 First laying section, 403 Second laying section, 500 Adapter forming mold, 501 Inlay 1, 501-1 Positioning countersunk hole, 502 Inlay 2, 502-1 Positioning hole, 502-2 Bottom surface, 600 Second skin assembly, 601 Flat tail leading edge foam, 602 First flat tail beam, 603 First flat tail end Foam for the first part, 604 second flat tail beam, 605 rear edge foam for the flat tail, 606 end foam for the second flat tail, 607 second flat tail skin, 607-1 second outer skin, 607-2 second honeycomb core, 607-3 first inner skin, 700 first skin assembly, 701 first planar skin, 701-1 first outer skin, 701-2 first honeycomb core, 701-3 first inner skin, 701-4 through opening, 702 adapter, 702-1 lower connecting part, 702-2 upper connecting part, 800 core material tooling, 801 core material groove, 900 space. Detailed Implementation
[0072] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.
[0073] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways different from those described herein, and those skilled in the art can make similar extensions without departing from the spirit of the invention. Therefore, the invention is not limited to the specific embodiments disclosed below.
[0074] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The phrase "in one embodiment" appearing in different places in this specification does not necessarily refer to the same embodiment, nor is it a single or selective embodiment that is mutually exclusive with other embodiments.
[0075] Example 1: Refer to Figures 1-4 and Figures 8 to 18 This is the first embodiment of the present invention, which provides a molding method for a small unmanned helicopter horizontal stabilizer. Using the present invention, a small unmanned helicopter horizontal stabilizer made of composite material can be reliably prepared, and the prepared product is lightweight and high-strength.
[0076] A method for forming the horizontal stabilizer of a small unmanned helicopter includes the following steps:
[0077] S1. Prepare the first horizontal tail skin, the second horizontal tail skin, the first horizontal tail beam, the second horizontal tail beam, the horizontal tail adapter, the leading edge foam of the horizontal tail, the trailing edge foam of the horizontal tail, the first end foam of the horizontal tail, and the second end foam of the horizontal tail.
[0078] S2. Place the second flat tail skin on the surface of the second skin forming mold, and fix the edges with pressure-sensitive tape so that the second flat tail skin fits the second skin forming mold. Mark the positions of each flat tail beam and foam on the surface, and use release cloth to protect the non-adhesive areas around the perimeter.
[0079] S3. Arrange modeling clay on the upper and outer sides of the second flat-tail skin, and cover the surface with a layer of release film. Place the first and second flat-tail beams on the upper surface of the second flat-tail skin according to the marked positions. Place each foam in the corresponding position on the outer side of the second flat-tail skin. After pre-vacuuming the bag, remove the first flat-tail skin, beams, and foam. Depending on the compaction of the modeling clay, apply a layer of adhesive to the bonding surface of the second flat-tail skin. At the same time, apply a layer of adhesive to the bonding surfaces of the beams and foam core. Place each foam and each flat-tail beam according to the marked positions. First, place the first... The first flat tail beam and the second flat tail beam are placed on the corresponding positions on the upper side of the second flat tail skin. The first flat tail beam is in front of the second flat tail beam and is connected to the second flat tail beam. The leading edge foam, trailing edge foam, first flat tail end foam and second flat tail end foam are respectively placed in front of the first flat tail beam, behind the second flat tail beam, on the left side of the first flat tail beam and the second flat tail beam, and on the right side of the first flat tail beam and the second flat tail beam. The bag is pre-extracted, the bag is unpacked after the pre-extraction is completed, and the mold is transferred to the autoclave for curing to form the second skin assembly.
[0080] S4. Use fasteners to fix the horizontal tail adapter to the first horizontal tail skin to form the first skin assembly.
[0081] S5. Place the second skin assembly on the surface of the second skin molding mold, and fix the edges with pressure-sensitive tape to make the second flat tail skin fit the second skin molding mold. Lay a layer of release film on the bonding surface of the second skin assembly, place modeling clay on the release film, place the assembled first skin assembly on the second skin assembly, and use sandbags to compact for a set time. Remove the first skin assembly and observe the compaction of the modeling clay on the surface. According to the compaction, apply adhesive to the bonding surfaces of the second skin assembly and the first skin assembly, and place the first skin assembly on the corresponding position on the upper surface of the second skin assembly.
[0082] S6. Transfer the second skin forming mold to the autoclave for curing;
[0083] S7. Use sandpaper to sand down any excess adhesive on the product edges.
[0084] The steps for preparing the first flat-tail skin are as follows:
[0085] Prepare the first skin forming mold (receive the first skin forming mold and apply release agent to the surface of the first skin forming mold). The first skin forming mold has an upward-facing first laying groove.
[0086] Using the CPD module of Catia software, the shape of each layer of prepreg is simulated and imported into the operating system of the automatic feeder. The prepreg is taken out of the cold storage 6 hours in advance to thaw and left to stand at room temperature until there is no moisture in the packaging bag. The thawed prepreg is placed on the tray of the automatic feeder and each piece is cut according to the program.
[0087] In the first laying groove, the prepreg is laid in the set layup sequence (specifically, lay 1 layer of [0] direction (parallel to the length of the skin) carbon fiber fabric epoxy prepreg (T300P200 / E1302), and then lay 2 layers of [45 / -45] carbon fiber unidirectional epoxy prepreg (T700 / E1302)) to form the first outer skin;
[0088] The aramid paper honeycomb core material (CNC2-1.83-48-3) was chamfered using a honeycomb chamfering template. After chamfering, the surface was cleaned and dehumidified in an autoclave at 70±5°C for 1 hour. The honeycomb core area was located using laser projection, and an epoxy structural film (LWF-2A) was applied to the corresponding area of the first outer skin. After the film was applied, the first honeycomb core was placed according to the laser projection, and an epoxy structural film (LWF-2A) was also applied to the upper surface of the first honeycomb core.
[0089] Two layers of [45 / -45] carbon fiber unidirectional epoxy prepreg (T700 / E1302) are laid on the upper side of the first honeycomb core and the first outer skin outside the first honeycomb core to form the first inner skin;
[0090] The material is then packaged, placed in an autoclave for curing, and once curing is complete, the preparation of the first flat-tail skin is finished.
[0091] The steps for preparing the second flat-tail skin are as follows:
[0092] Prepare the second skin forming mold, which has an upward-facing second laying groove;
[0093] Get carbon fiber unidirectional epoxy prepreg (T700 / E1302), carbon fiber fabric epoxy prepreg (T300P200 / E1302), epoxy structural film (LWF-2A), and aramid paper honeycomb core material (CNC2-1.83-48-3).
[0094] Using the CPD module of Catia software, the shape of each layer of prepreg is simulated and imported into the operating system of the automatic feeder. The prepreg is taken out of the cold storage 6 hours in advance to thaw and left to stand at room temperature until there is no moisture in the packaging bag. The thawed prepreg is placed on the tray of the automatic feeder and each piece is cut according to the program.
[0095] In the second laying tank, the prepreg is laid in the set layup sequence (laying 1 layer of [0] direction carbon fiber fabric epoxy prepreg (T300P200 / E1302), then laying 2 layers of [45 / -45] carbon fiber unidirectional epoxy prepreg (T700 / E1302)), vacuuming and pre-compacting, the pre-vacuuming time is ≥15min, and the pre-vacuuming time is calculated from the vacuum degree in the vacuum bag ≤-0.095MPa to form the second outer skin;
[0096] Use laser projection to locate the honeycomb core area, and lay epoxy structural film in the corresponding area. After the film is laid, place the second honeycomb core according to the laser projection, and lay epoxy structural film on the upper surface of the second honeycomb core as well.
[0097] Two layers of [45 / -45] carbon fiber unidirectional epoxy prepreg (T700 / E1302) are laid on the upper side of the second honeycomb core and the upper side of the second outer skin outside the second honeycomb core to form the second inner skin;
[0098] The components are packaged, placed in an autoclave for curing, and after curing, a through-hole is made on the second flat-tail skin to allow the upper part of the adapter to pass through (this is existing technology), thus completing the preparation of the second flat-tail skin.
[0099] The steps for preparing the first horizontal tail beam are as follows:
[0100] Prepare the first beam forming mold. The upper part of the first beam forming mold is provided with the first beam laying part. The left and right sides of the first beam laying part are flush with the left and right sides of the first beam forming mold.
[0101] Collect carbon fiber unidirectional epoxy prepreg (T700 / E1302).
[0102] Using the CPD module of Catia software, the shape of each layer of prepreg is simulated and imported into the operating system of the automatic feeder. The prepreg is taken out of the cold storage 6 hours in advance to thaw and left to stand at room temperature until there is no moisture in the packaging bag. The thawed prepreg is placed on the tray of the automatic feeder and each piece is cut according to the program.
[0103] Eight layers of carbon fiber unidirectional epoxy prepreg (T700 / E1302) are laid on the outer edge of the first beam laying section. The laying sequence is [45 / 0 / -45 / 0 / 0 / -45 / 0 / 45]. Vacuum pre-compaction is performed every four layers. The pre-compaction time is not less than 15 minutes. The pre-compaction time is calculated from the point when the vacuum degree in the vacuum bag is ≤-0.095MPa.
[0104] The material is then packaged, placed in an autoclave for curing, and once curing is complete, the first flat tail beam is finished.
[0105] The steps for preparing the second horizontal tail beam are as follows:
[0106] Prepare the second beam forming mold, which includes a base plate. The first laying part is fixed on the left and right sides of the base plate, and the second laying part is fixed on the upper side of the base plate. The left and right sides of the first laying part and the second laying part are flush.
[0107] Collect carbon fiber unidirectional epoxy prepreg (T700 / E1302).
[0108] Using the CPD module of Catia software, the shape of each layer of prepreg is simulated and imported into the operating system of the automatic feeder. The prepreg is taken out of the cold storage 6 hours in advance to thaw and left to stand at room temperature until there is no moisture in the packaging bag. The thawed prepreg is placed on the tray of the automatic feeder and each piece is cut according to the program.
[0109] Eight layers of carbon fiber unidirectional epoxy prepreg (T700 / E1302) are laid along the outer edge of the first and second laying parts. The laying sequence is [45 / 0 / -45 / 0 / 0 / -45 / 0 / 45]. Vacuum pre-compacting is performed every four layers. The pre-vacuuming time is not less than 15 minutes. The pre-vacuuming time is calculated from the point when the vacuum degree in the vacuum bag is ≤-0.095MPa.
[0110] The material is then packaged, placed in an autoclave for curing, and once curing is complete, the preparation of the second flat tail beam is finished.
[0111] In this invention, before bonding each component in the second skin assembly and before bonding the first and second skin assemblies, a step of placing and compacting modeling clay is used to verify that each area to be bonded needs to be bonded before bonding, and to determine the bonding gap, thereby ensuring reliable bonding. The helicopter horizontal stabilizer prepared by this invention is made entirely of composite materials, providing more space for weight reduction for small unmanned helicopters, while also possessing high strength.
[0112] Example 2: Figures 5-7 , Figure 19 and Figure 20 This is the second embodiment of the present invention, which provides a method for forming a horizontal stabilizer of a small unmanned helicopter, which further realizes the preparation of the adapter.
[0113] Specifically, the steps for preparing the adapter are as follows:
[0114] Prepare the adapter molding mold, which includes insert one, insert two and at least two positioning pins. Insert two can be detachably connected to the upper side of insert one. The structure is such that insert one has at least two positioning countersunk holes, insert two has several positioning holes that correspond one-to-one with positioning countersunk holes, and several positioning pins can be inserted into the corresponding positioning countersunk holes through the positioning holes. When insert two is connected to insert one, the bottom surface of insert two is in contact with the upper surface of insert one. The outer perimeter of the contact surface between insert two and insert one and above a set distance is the R area.
[0115] Prepare the core material fixture, with several core material grooves arranged on the upward-facing end of the core material fixture;
[0116] Prepreg is laid on the bottom surface of the insert according to the set layering sequence. Vacuum pre-compacting is performed every 4 layers, and the pre-compacting time is not less than 15 minutes.
[0117] Prepreg is laid on the upper part of the second insert according to the set layup sequence. Vacuum pre-compacting is performed every 4 layers, and the pre-compacting time is not less than 15 minutes.
[0118] Based on the recessed positioning holes and countersunk hole areas of the paving area, cut out the prepreg in the areas where the positioning holes and countersunk holes are located on insert one and insert two;
[0119] Place the second insert on top of the first insert, and use several positioning pins to insert into the corresponding positioning countersunk holes through the positioning holes to complete the combination of the first insert and the second insert. There is a gap at the joint of the first insert and the second insert.
[0120] The carbon wire is made by twisting prepreg into carbon wire, wrapping a layer of adhesive film on the outside of the carbon wire, placing the carbon wire in the core material groove, and pressing the carbon wire with a press. The initial pressure is 8MPa±0.1MPa. The mold is heated to 60℃±5℃ at a heating rate of no more than 1.5℃ / min. Under these conditions, the temperature and pressure are maintained for 0.5h±10min to produce a core material with the same shape as the gap.
[0121] Wrap the core material around the R area once, then vacuum and compact it to fill the gaps and improve the structural strength of the adapter.
[0122] Several layers of prepreg are laid on the side of the assembled insert one and insert two, then sealed and sent into an autoclave for curing.
[0123] During demolding, insert one and insert two are separated to complete the demolding of the part;
[0124] Take out the prepared thin plate, apply adhesive to the thin plate, and attach the thin plate to the bottom of the part. The thin plate covers all the areas where the holes of the part are located, thus completing the preparation of the adapter.
[0125] Prepared adapters such as Figure 19 As shown, the adapter includes a lower connecting part, and an upper connecting part is fixed to the upper side of the lower connecting part. When the adapter is connected to the first flat tail skin, after the upper connecting part passes through the through-hole, the upper side of the lower connecting part abuts against the lower side of the first flat tail skin, and the upper connecting part is fixedly connected to the first flat tail skin using fasteners.
[0126] When the first skin assembly is connected to the second skin assembly, such as Figure 14 As shown, there is a space between the first and second flat tail beams that is just enough to accommodate the lower connecting part, which is inserted into the space. The lower side of the first flat tail skin is glued to the upper side of the foam core.
[0127] In this application, the [0] direction is parallel to the length direction of the skin, the
[90] direction is perpendicular to the [0] direction, the 45° direction is the direction of the center line between [0] and
[90] , the [0] direction is the direction of the center line between 45 and -45°, and the ply direction is defined as conventional technology.
[0128] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.
Claims
1. A method for forming the horizontal stabilizer of a small unmanned helicopter, characterized in that: Includes the following steps, S1. Prepare the first horizontal tail skin, the second horizontal tail skin, the first horizontal tail beam, the second horizontal tail beam, the horizontal tail adapter, the trailing edge foam of the horizontal tail, the first horizontal tail end foam, and the second horizontal tail end foam. S2. Place the second flat tail skin on the surface of the second skin forming mold, and fix the edges with pressure-sensitive tape so that the second flat tail skin fits the second skin forming mold. Mark the positions of each flat tail beam and foam on the surface, and use release cloth to protect the non-adhesive areas around the perimeter. S3. Place modeling clay on the upper and outer sides of the second flat tail skin, and cover the surface with a layer of release film. Place the first and second flat tail beams on the upper surface of the second flat tail skin according to the marked positions. Place each foam in the corresponding position on the outer side of the second flat tail skin. After bag making and pre-vacuuming, remove the first flat tail skin, beams and foam. According to the compaction of the modeling clay, apply a layer of adhesive to the bonding surface of the second flat tail skin. At the same time, apply a layer of adhesive to the bonding surfaces of the beams and foam cores. Place each foam and each flat tail beam according to the marked positions. Bag making and pre-vacuuming. After the pre-vacuuming is completed, unpack the bag, seal it, and transfer the mold to the autoclave for curing to form the second skin assembly. S4. Use fasteners to fix the horizontal tail adapter to the first horizontal tail skin to form the first skin assembly. S5. Place the second skin assembly on the surface of the second skin molding mold, and fix the edges with pressure-sensitive tape to make the second flat tail skin fit the second skin molding mold. Lay a layer of release film on the bonding surface of the second skin assembly, place modeling clay on the release film, place the assembled first skin assembly on the second skin assembly, and use sandbags to compact for a set time. Remove the first skin assembly and observe the compaction of the modeling clay on the surface. According to the compaction, apply adhesive to the bonding surfaces of the second skin assembly and the first skin assembly, and place the first skin assembly on the corresponding position on the upper surface of the second skin assembly. S6. Transfer the second skin forming mold to the autoclave for curing; S7. Use sandpaper to sand down any excess adhesive on the edges of the product; The steps for preparing the adapter are as follows: Prepare the adapter molding mold, which includes insert one and insert two. Insert two can be detachably connected to the upper side of insert one. When insert two is connected to insert one, the bottom surface of insert two is attached to the upper surface of insert one. The outer perimeter of the interface between insert two and insert one at a set distance is the R area. Prepreg is laid on the bottom surface of the insert according to the set layering sequence. Vacuum pre-compacting is performed every 4 layers, and the pre-compacting time is not less than 15 minutes. Prepreg is laid on the upper part of the second insert according to the set layup sequence. Vacuum pre-compacting is performed every 4 layers, and the pre-compacting time is not less than 15 minutes. Connect the second insert to the upper side of the first insert; The carbon wire is made by twisting prepreg into carbon wire, wrapping a layer of adhesive film on the outside of the carbon wire, placing it on the core material tooling, and transferring it to the press for compaction. The initial pressure is 8MPa±0.1MPa. The mold is heated to 60℃±5℃ at a heating rate of no more than 1.5℃ / min. Under these conditions, the temperature and pressure are maintained for 0.5h±10min to make the core material. Wrap the core material around the R area once, then vacuum and compact it. Several layers of prepreg are laid on the side of the assembled insert one and insert two, then sealed and sent into an autoclave for curing. During demolding, insert one and insert two are separated to complete the demolding of the part.
2. The method for forming the horizontal stabilizer of a small unmanned helicopter as described in claim 1, characterized in that: The steps for preparing the first flat-tail skin are as follows: Prepare the first skin forming mold, which has an upward-facing first laying groove; Prepreg is laid in the first laying groove according to the set layer sequence to form the first outer skin; Two honeycomb cores spaced apart in the left-right direction are placed on the upper side of the first outer skin; A first inner skin is laid on the upper side of the honeycomb core and the first outer skin outside the honeycomb core; It is then packaged and placed in an autoclave for curing.
3. The method for forming the horizontal stabilizer of a small unmanned helicopter as described in claim 1, characterized in that: The steps for preparing the second flat-tail skin are as follows: Prepare the second skin forming mold, which has an upward-facing second laying groove; In the second laying groove, the prepreg is laid in the set layup sequence to form the second outer skin; Use laser projection to locate the honeycomb core area, and lay epoxy structural film in the corresponding area. After the film is laid, place the honeycomb core according to the laser projection, and lay epoxy structural film on the upper surface of the honeycomb core as well. A second inner skin is laid on the upper side of the honeycomb core and on the upper side of the second outer skin outside the honeycomb core; It is then packaged and placed in an autoclave for curing.
4. The method for forming the horizontal stabilizer of a small unmanned helicopter as described in any one of claims 1 to 3, characterized in that: The steps for preparing the first horizontal tail beam are as follows: Prepare the first beam forming mold. The upper part of the first beam forming mold is provided with the first beam laying part. The left and right sides of the first beam laying part are flush with the left and right sides of the first beam forming mold. Prepreg is laid on the outer edge of the first beam according to the set layering sequence. Vacuum pre-compacting is performed every 4 layers, and the pre-compacting time is not less than 15 minutes. It is then packaged and placed in an autoclave for curing.
5. The method for forming the horizontal stabilizer of a small unmanned helicopter as described in claim 1, characterized in that: The steps for preparing the second horizontal tail beam are as follows: Prepare the second beam forming mold, which includes a base plate. The first laying part is fixed on the left and right sides of the base plate, and the second laying part is fixed on the upper side of the base plate. The left and right sides of the first laying part and the second laying part are flush. Prepreg is laid along the outer edge of the first and second laying sections in the lay-up sequence. Vacuum pre-compacting is performed every 4 layers, and the pre-compacting time is not less than 15 minutes. It is then packaged and placed in an autoclave for curing.
6. The method for forming the horizontal stabilizer of a small unmanned helicopter as described in claim 1, characterized in that: The adapter molding die also includes at least two positioning pins. The first insert has at least two positioning countersunk holes, and the second insert has several positioning holes that correspond one-to-one with the positioning countersunk holes. Several positioning pins can be inserted into the corresponding positioning countersunk holes through the positioning holes.
7. The method for forming the horizontal stabilizer of a small unmanned helicopter as described in claim 6, characterized in that: Before attaching the second insert to the upper side of the first insert, the following steps are also included. Based on the recessed positioning holes and countersunk hole areas of the paving area, cut out the prepreg in the areas where the positioning holes and countersunk holes are located on insert one and insert two; Place the second insert on top of the first insert, and use several locating pins to insert into the corresponding locating countersunk holes through the locating holes to complete the combination of the first insert and the second insert.
8. The method for forming the horizontal stabilizer of a small unmanned helicopter as described in claim 7, characterized in that: After the part is demolded, the prepared thin plate is taken out, the thin plate is glued, and the thin plate is glued to the bottom end of the part. The thin plate covers all the areas where the holes of the part are located, thus completing the preparation of the adapter.
Citation Information
Patent Citations
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CN117429097A
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CN118288567A