Composite fairing, assembly mold and molding method

Abstract

The application discloses a composite fairing, a combined die and a forming method, and the fairing comprises a connecting support, a supporting core material, a suction surface shell, a pressure surface shell, a left wing surface shell, a right wing surface shell and a tail wing; the supporting core material is arranged on the two sides of the connecting support, the suction surface shell covers the top of the supporting core material and the connecting support, and the pressure surface shell covers the bottom of the supporting core material and the connecting support; the left wing surface shell covers the leftmost side of the supporting core material, the right wing surface shell covers the rightmost side of the supporting core material, and the tail wing covers the rear end of the connecting support; the suction surface shell, the pressure surface shell, the left wing surface shell, the right wing surface shell and the tail wing are all carbon fiber reinforced resin matrix composite structural members. The application is applied to the field of fairing preparation, has high forming precision, can realize lightweight treatment of the fairing, and has a relatively simple preparation process.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of fairing preparation, in particular to a composite material fairing, a combined mold and a forming method. BACKGROUND

[0002] In order to ensure that the airflow flows along the set channel when the aircraft is flying, the fairing treatment is often needed. The traditional fairing is usually made of metal material, which is not only difficult to accurately form the curved surface shape, but also heavy, which is not conducive to the flight of the aircraft. SUMMARY

[0003] In view of the above deficiencies in the prior art, the present application provides a composite material fairing, a combined mold and a forming method, which not only has high forming precision, but also can realize the lightweight treatment of the fairing, and the preparation process is relatively simple.

[0004] To achieve the above purpose, the present application provides a composite material fairing, which is a wave-receiving body with a tail wing in a conical structure, comprising a connecting bracket, a supporting core material, a suction surface shell, a pressure surface shell, a left wing surface shell, a right wing surface shell and a tail wing.

[0005] The supporting core material is arranged on both sides of the connecting bracket, the suction surface shell covers the top of the supporting core material and the connecting bracket, and the pressure surface shell covers the bottom of the supporting core material and the connecting bracket.

[0006] The left wing surface shell covers the leftmost side of the supporting core material and is connected with the suction surface shell and the pressure surface shell, the right wing surface shell covers the rightmost side of the supporting core material and is connected with the suction surface shell and the pressure surface shell, and the tail wing covers the rear end of the connecting bracket.

[0007] The suction surface shell, the pressure surface shell, the left wing surface shell, the right wing surface shell and the tail wing are all carbon fiber reinforced resin matrix composite structural parts, the connecting bracket is a metal structural part, and the supporting core material is a foam material.

[0008] In one embodiment, the top of the left wing surface shell has a first left flange, and the bottom has a second left flange, and the top of the right wing surface shell has a first right flange, and the bottom has a second right flange.

[0009] The first left flange and the first right flange are clamped between the suction surface shell and the supporting core material, and the second left flange and the second right flange are clamped between the pressure surface shell and the supporting core material.

[0010] In one of the embodiments, the front end of the connecting bracket has a stopper, and the front and rear ends of the supporting core material abut against the stopper and the stop plate respectively.

[0011] The tail fin is connected with the outer wall of the stop plate.

[0012] In one of the embodiments, the suction surface shell is glued to the top of the connecting bracket and fixed by rivets, and the pressure surface shell is glued to the bottom of the connecting bracket and fixed by rivets.

[0013] The suction surface shell is glued to the top of the supporting core material and fixed by rivets at positions corresponding to the first left and right flanges, and the left and right airfoil surface shells and the supporting core material.

[0014] The pressure surface shell is glued to the bottom of the supporting core material and fixed by rivets at positions corresponding to the second left and right flanges, and the left and right airfoil surface shells and the supporting core material.

[0015] The left airfoil surface shell is glued to the stopper and the stop plate and fixed by rivets, the right airfoil surface shell is glued to the stopper and the stop plate and fixed by rivets, and the tail fin is glued to the stop plate and fixed by rivets.

[0016] To achieve the above-mentioned purpose, the application further provides a combined mold for forming the composite fairing, wherein the combined mold comprises a pressure surface forming mold, a suction surface forming mold, a left airfoil surface forming mold, a right airfoil surface forming mold and a tail fin forming mold.

[0017] The pressure surface forming mold has a first forming surface matched with the shape of the pressure surface shell, the suction surface forming mold has a second forming surface matched with the shape of the suction surface shell, the left airfoil surface forming mold has a third forming surface matched with the shape of the left airfoil surface shell, the right airfoil surface forming mold has a fourth forming surface matched with the shape of the right airfoil surface shell, and the tail fin forming mold has a fifth forming surface matched with the shape of the tail fin.

[0018] In one of the embodiments, the pressure surface forming mold and the suction surface forming mold have a rectangular structure.

[0019] The four corners of the pressure surface forming mold are provided with positioning insertion grooves, the four corners of the suction surface forming mold are provided with positioning insertion blocks, the positioning insertion grooves and the positioning insertion blocks are one-to-one corresponding and can be inserted and matched, and the first and second positioning connection holes coaxially assembled are arranged on the corresponding positioning insertion grooves and positioning insertion blocks.

[0020] In one embodiment, the pressure surface forming mold is provided with a first docking protrusion and a second docking protrusion respectively on the left and right sides of the first forming surface and located between the two positioning slots; the suction surface forming mold is provided with a third docking protrusion and a fourth docking protrusion respectively on the left and right sides of the second forming surface and located between the two positioning blocks.

[0021] The first docking protrusion and the third docking protrusion are provided with a third positioning connection hole and a fourth positioning connection hole that are coaxial after assembly. The second docking protrusion and the fourth docking protrusion are provided with a fifth positioning connection hole and a sixth positioning connection hole that are coaxial after assembly.

[0022] In one embodiment, a first assembly cavity is provided between the first mating protrusion and the left side of the first molding surface, and between the third mating protrusion and the left side of the second molding surface, for accommodating the left wing profile molding mold;

[0023] A second assembly cavity is provided between the second mating protrusion and the right side of the first molding surface, and between the fourth mating protrusion and the right side of the second molding surface, for accommodating the right wing profile molding mold;

[0024] After assembly, the left wing profile forming mold is located in the first assembly cavity. The upper and lower sides of the left wing profile forming mold abut against the suction surface forming mold and the pressure surface forming mold, respectively. At least one of the suction surface forming mold and the pressure surface forming mold is obliquely cut to the left wing profile forming mold.

[0025] After assembly, the right wing profile forming mold is located in the second assembly cavity. The upper and lower sides of the right wing profile forming mold abut against the suction surface forming mold and the pressure surface forming mold, respectively, and at least one of the suction surface forming mold and the pressure surface forming mold is obliquely cut to the right wing profile forming mold.

[0026] To achieve the above objectives, the present invention also provides a method for molding the above-mentioned composite material fairing, comprising the following steps:

[0027] Step 1: Using the above-mentioned combined mold, prepare the suction surface shell, pressure surface shell, left wing profile shell, right wing profile shell and tail wing, and demold only the tail wing;

[0028] Step 2: Use structural adhesive to bond the suction surface shell, pressure surface shell, left wing shell, right wing shell, tail wing, connecting bracket, and support core material into a fairing. During this process, the assembled and locked combined mold is used for auxiliary positioning to obtain a combined mold tooling with the fairing main blank.

[0029] Step 3, after the heating and curing of the combined mold tooling, the fairing main blank is demolded, rivets are fixed at the set positions of the fairing main blank, and finally the overall polishing is performed to obtain the composite fairing.

[0030] In one of the embodiments, step 2 specifically comprises:

[0031] Step 201, place the pressure surface forming die with the pressure surface shell on the ground or reference platform, and keep the pressure surface shell facing up;

[0032] Step 202, divide the support core material into three parts, namely support core material #1, support core material #2 and support core material #3, wherein the support core material #2 corresponds to the area between the first left flanging edge and the second left flanging edge on the left wing surface shell, the support core material #3 corresponds to the area between the first right flanging edge and the second right flanging edge on the right wing surface shell, and the support core material #1 corresponds to the remaining area;

[0033] Step 203, after scraping a layer of mixed structural adhesive on the bonding surface of the connecting bracket, support core material #1, support core material #2, support core material #3, pressure surface shell, left wing surface shell, right wing surface shell, suction surface shell and tail wing respectively, bond the connecting bracket #1, support core material and pressure surface shell, and bond the support core material #2 and left wing surface shell, and bond the support core material #3 and right wing surface shell;

[0034] Step 204, after removing the baffles on the left wing surface forming die corresponding to the first left flanging edge and the second left flanging edge, and removing the baffles on the right wing surface forming die corresponding to the first right flanging edge and the second right flanging edge, place the left wing surface forming die with the left wing surface shell and the support core material #2, and the right wing surface forming die with the right wing surface shell and the support core material #3 on the pressure surface forming die corresponding to the first assembly cavity and the second assembly cavity respectively;

[0035] Step 205, install the suction surface forming die with the suction surface shell on the pressure surface forming die, keep the plug-in cooperation of the positioning plug and the positioning slot, and the first and second butt protrusions align with the third and fourth butt protrusions respectively, and install bolts between the first and second positioning connection holes, the third and fourth positioning connection holes, and the fifth and sixth positioning connection holes, tighten the bolts to press the suction surface forming die downward, and drive the left wing surface forming die and the right wing surface forming die to extrude inward;

[0036] Step 206, bond the tail wing to the rear end of the connecting bracket, and install the tail wing baffle at the rear end of the pressure surface forming die and the rear end of the suction surface forming die, so that the tail wing is clamped between the connecting bracket and the tail wing baffle, and a combined mold tooling with a fairing main blank is obtained.

[0037] Compared with the prior art, the present application has the following beneficial technical effects:

[0038] 1. The present application can effectively guarantee the forming precision of the curved surface shape on the fairing, realize the lightweight treatment of the fairing, and the preparation process is relatively simple by adopting the carbon fiber reinforced resin matrix composite structural part as the suction surface shell, the pressure surface shell, the left wing profile shell, the right wing profile shell and the tail wing.

[0039] 2. The present application can not only form the suction surface shell, the pressure surface shell, the left wing profile shell, the right wing profile shell and the tail wing by using the combined mold, but also can assist the assembly of the suction surface shell, the pressure surface shell, the left wing profile shell and the right wing profile shell by using the combined mold, thereby effectively improving the assembly precision of the fairing. BRIEF DESCRIPTION OF DRAWINGS

[0040] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or the prior art description. Obviously, the drawings in the following description only some embodiments of the present application, and for those skilled in the art, other drawings can be obtained without creative labor on the basis of the drawings shown.

[0041] Figure 1 It is a forward explosion schematic view of the composite fairing in the embodiment 1 of the present application.

[0042] Figure 2 It is a back explosion schematic view of the composite fairing in the embodiment 1 of the present application.

[0043] Figure 3 It is a sectional view of the composite fairing in the embodiment 1 of the present application.

[0044] Figure 4 It is a forward axial view of the combined mold in the embodiment 2 of the present application.

[0045] Figure 5 It is a back axial view of the combined mold in the embodiment 2 of the present application.

[0046] Figure 6 It is an explosion schematic view of the combined mold in the embodiment 2 of the present application.

[0047] Figure 7 It is an axial view of the pressure surface forming mold in the embodiment 2 of the present application.

[0048] Figure 8 It is an axial view of the suction surface forming mold in the embodiment 2 of the present application.

[0049] Figure 9The isometric view of the left wing profile forming die in the embodiment 2 of the present application;

[0050] Figure 10 The isometric view of the right wing profile forming die in the embodiment 2 of the present application;

[0051] Figure 11 The schematic view of the bevel matching of the right wing profile forming die and the pressure surface forming die in the embodiment 2 of the present application.

[0052] The drawing number: connecting support 1, baffle 101, baffle plate 102, convex part 103, support core material 2, suction surface shell 3, pressure surface shell 4, left wing profile shell 5, first left flanging 501, second left flanging 502, right wing profile shell 6, first right flanging 601, second right flanging 602, tail fin 7, through hole 8, pressure surface forming die 9, first forming surface 901, positioning slot 902, first positioning connecting hole 903, first butt joint protrusion 904, second butt joint protrusion 905, third positioning connecting hole 906, fifth positioning connecting hole 907, suction surface forming die 10, second forming surface 1001, positioning plug 1002, second positioning connecting hole 1003, third butt joint protrusion 1004, fourth butt joint protrusion 1005, fourth positioning connecting hole 1006, sixth positioning connecting hole 1007, left wing profile forming die 11, third forming surface 1101, right wing profile forming die 12, fourth forming surface 1201, tail fin baffle 13.

[0053] The implementation, functional features and advantages of the present application will be further described with reference to the embodiments and the accompanying drawings. DETAILED DESCRIPTION

[0054] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work fall within the protection scope of the present application.

[0055] It should be noted that all the directionality indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present application are only used to explain the relative position relationship, movement condition, etc. between components in a certain specific posture (as shown in the drawings). If the specific posture changes, the directionality indications also change accordingly.

[0056] In addition, the descriptions such as "first", "second" and the like in the present application are only for the purpose of description and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first", "second" can explicitly or implicitly include at least one of the features. In the description of the present application, the meaning of "a plurality of" is at least two, for example, two, three, etc., unless otherwise explicitly specified and limited.

[0057] In the present application, unless otherwise explicitly specified and limited, the terms "connection", "fixation" and the like should be understood in a broad sense, for example, "fixation" can be fixed connection, or detachable connection, or integral; can be mechanical connection, or electrical connection, or physical connection or wireless communication connection; can be directly connected, or indirectly connected through intermediate medium, can be internal communication of two elements or interaction relationship between two elements, unless otherwise explicitly limited. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0058] In addition, the technical solutions of various embodiments of the present application can be combined with each other, but it must be based on the fact that a person skilled in the art can realize it, when the combination of technical solutions appears contradictory or cannot be realized, it should be considered that the combination of technical solutions does not exist, nor within the scope of protection required by the present application.

[0059] Embodiment 1

[0060] As Figures 1 to 2 The composite fairing disclosed in the present embodiment is a wave-receiving body with a tail wing in a conical structure, which comprises a connecting bracket 1, a supporting core material 2, a suction surface shell 3, a pressure surface shell 4, a left wing surface shell 5, a right wing surface shell 6 and a tail wing 7. Specifically, the supporting core material 2 is arranged on both sides of the connecting bracket 1, the suction surface shell 3 covers the top of the supporting core material 2 and the connecting bracket 1, and the pressure surface shell 4 covers the bottom of the supporting core material 2 and the connecting bracket 1. The left wing surface shell 5 covers the leftmost side of the supporting core material 2 and is connected with the suction surface shell 3 and the pressure surface shell 4, the right wing surface shell 6 covers the rightmost side of the supporting core material 2 and is connected with the suction surface shell 3 and the pressure surface shell 4, and the tail wing 7 covers the rear end of the connecting bracket 1. Among them, the connecting bracket 1 is a metal structural part, the supporting core material 2 is a foam material, and the suction surface shell 3, the pressure surface shell 4, the left wing surface shell 5, the right wing surface shell 6 and the tail wing 7 are all carbon fiber reinforced resin matrix composite structural parts. Using carbon fiber reinforced resin matrix composite structural parts as the suction surface shell 3, the pressure surface shell 4, the left wing surface shell 5, the right wing surface shell 6 and the tail wing 7 can not only effectively guarantee the forming precision of the curved surface shape on the fairing, but also realize the lightweight processing of the fairing, and the preparation process is relatively simple.

[0061] Reference Figure 3 The top of the left wing profile shell 5 has a first left flange 501 and the bottom has a second left flange 502. The top of the right wing profile shell 6 has a first right flange 601 and the bottom has a second right flange 602. After the fairing assembly is cured, the first left flange 501 and the first right flange 601 are clamped between the suction surface shell 3 and the support core 2, and the second left flange 502 and the second right flange 602 are clamped between the pressure surface shell 4 and the support core 2, thereby effectively improving the overall structural strength of the fairing.

[0062] In the specific implementation process, the front end of the connecting bracket 1 has a stopper 101 and the rear end has a stop plate 102. After the fairing assembly is cured, the front and rear ends of the support core 2 abut against the stopper 101 and the stop plate 102 respectively, and the empennage 7 is connected to the outer wall of the stop plate 102. In addition, the left and right sides of the stopper 101 and the top and bottom of the connecting bracket 1 are each provided with a protruding part 103, and the suction surface shell 3, the pressure surface shell 4, the left wing profile shell 5, and the right wing profile shell 6 are each provided with a through hole 8 at a position corresponding to the protruding part 103, for embedding the protruding part 103 at the corresponding position, so that the protruding part 103 can be exposed on the outer surface of the overall cover, so that the fairing can be connected to the external mechanism through the protruding part 103, avoiding direct rigid cooperation with the external mechanism through the suction surface shell 3, the pressure surface shell 4, the left wing profile shell 5, and the right wing profile shell 6.

[0063] In the specific implementation process, the connecting bracket 1 and the support core 2 are fixed by structural glue, the top of the suction surface shell 3 and the connecting bracket 1 are glued by structural glue and then fixed by rivets, and the bottom of the pressure surface shell 4 and the connecting bracket 1 are glued by structural glue and then fixed by rivets. The top of the suction surface shell 3 and the support core 2 are glued by structural glue and then fixed by rivets at positions corresponding to the first left flange 501 and the first right flange 601 and the left wing profile shell 5, the right wing profile shell 6, and the support core 2, and the bottom of the pressure surface shell 4 and the support core 2 are glued by structural glue and then fixed by rivets at positions corresponding to the second left flange 502 and the second right flange 602 and the left wing profile shell 5, the right wing profile shell 6, and the support core 2. The left wing profile shell 5 and the stopper 101 and the stop plate 102 are glued by structural glue and then fixed by rivets, the right wing profile shell 6 and the stopper 101 and the stop plate 102 are glued by structural glue and then fixed by rivets, and the empennage 7 and the stop plate 102 are glued by structural glue and then fixed by rivets, thereby effectively improving the overall structural strength of the fairing.

[0064] Example 2

[0065] As Figures 4 to 6The combination mold disclosed by the embodiment is used for forming the composite fairing in Example 1, and comprises a pressure surface forming mold 9, a suction surface forming mold 10, a left wing surface forming mold 11, a right wing surface forming mold 12, a tail wing forming mold and a tail wing baffle 13, which are used for assisting the assembly of the suction surface shell 3, the pressure surface shell 4, the left wing surface shell 5, the right wing surface shell 6 and the tail wing 7 while forming the suction surface shell 3, the pressure surface shell 4, the left wing surface shell 5, the right wing surface shell 6 and the tail wing 7, so as to effectively improve the assembly precision of the fairing.

[0066] Reference Figures 7 to 10 The pressure surface forming mold 9 is provided with a first forming surface 901 matched with the shape of the pressure surface shell 4, the suction surface forming mold 10 is provided with a second forming surface 1001 matched with the shape of the suction surface shell 3, the left wing surface forming mold 11 is provided with a third forming surface 1101 matched with the shape of the left wing surface shell 5, the right wing surface forming mold 12 is provided with a fourth forming surface 1201 matched with the shape of the right wing surface shell 6, and the tail wing forming mold is provided with a fifth forming surface matched with the shape of the tail wing 7.

[0067] In the specific implementation process, the pressure surface forming mold 9 and the suction surface forming mold 10 are in a rectangular structure as a whole, the four corner portions of the pressure surface forming mold 9 are provided with positioning insertion grooves 902, the four corner portions of the suction surface forming mold 10 are provided with positioning insertion blocks 1002, the positioning insertion grooves 902 and the positioning insertion blocks 1002 are one-to-one corresponding and can be inserted and matched, and the corresponding positioning insertion grooves 902 and the corresponding positioning insertion blocks 1002 are provided with first and second positioning connection holes 903, 1003 coaxial after assembly, so that the pressure surface forming mold 9 and the suction surface forming mold 10 can be assembled in alignment with each other, and the assembly and positioning of the suction surface shell 3 and the pressure surface shell 4 are completed.

[0068] Further preferably, the first and second butt protrusions 904, 905 are respectively arranged on the left and right sides of the first forming surface 901 of the pressure surface forming mold 9 and located between the two positioning insertion grooves 902, the third and fourth butt protrusions 1004, 1005 are arranged on the left and right sides of the second forming surface 1001 of the suction surface forming mold 10 and located between the two positioning insertion blocks 1002, the first and third butt protrusions 904, 1004 are provided with third and fourth positioning connection holes 906, 1006 coaxial after assembly, and the second and fourth butt protrusions 905, 1005 are provided with fifth and sixth positioning connection holes 907, 1007 coaxial after assembly, that is, the assembly precision of the pressure surface forming mold 9 and the suction surface forming mold 10 is further improved by using the first and second butt protrusions 904, 905 and the third and fourth butt protrusions 1004, 1005.

[0069] In this embodiment, the first abutting protrusion 904 and the left side of the first forming surface 901, and the third abutting protrusion 1004 and the left side of the second forming surface 1001 are provided with a first assembly cavity capable of accommodating the left wing surface forming die 11. The second abutting protrusion 905 and the right side of the first forming surface 901, and the fourth abutting protrusion 1005 and the right side of the second forming surface 1001 are provided with a second assembly cavity capable of accommodating the right wing surface forming die 12. After assembly, the left wing surface forming die 11 is located in the first assembly cavity, and the upper and lower sides of the left wing surface forming die 11 abut the suction surface forming die 10 and the pressure surface forming die 9, respectively. The right wing surface forming die 12 is located in the second assembly cavity, and the upper and lower sides of the right wing surface forming die 12 abut the suction surface forming die 10 and the pressure surface forming die 9, respectively. That is, during the alignment and assembly of the suction surface shell 3 and the pressure surface shell 4, the assembly and positioning of the left wing surface shell 5 and the right wing surface shell 6 are simultaneously achieved.

[0070] As a preferred embodiment, at least one of the suction surface forming die 10 and the pressure surface forming die 9 is mitered with the left wing surface forming die 11, and at least one of the suction surface forming die 10 and the pressure surface forming die 9 is mitered with the right wing surface forming die 12, that is, Figure 11 As shown, when the suction surface forming die 10 and the pressure surface forming die 9 approach each other, they can inwardly extrude the left wing surface forming die and the right wing surface forming die 12, thereby improving the assembly precision of the pressure surface forming die 9, the suction surface forming die 10, the left wing surface shell 5, and the right wing surface shell 6.

[0071] Embodiment 3

[0072] The present embodiment discloses a forming method of the composite fairing in embodiment 1, which mainly includes the following steps:

[0073] Step 1: using the combined die in embodiment 2 to prepare the suction surface shell, the pressure surface shell, the left wing surface shell, the right wing surface shell, and the tail wing, and only demolding the tail wing;

[0074] Step 2: using structural glue to bond the suction surface shell, the pressure surface shell, the left wing surface shell, the right wing surface shell, the tail wing, the connecting support, and the supporting core material into a fairing. In this process, the combined die after assembly and locking is used for auxiliary positioning to obtain a combined die tooling with a fairing main blank;

[0075] Step 3: after heating and curing the combined die tooling, demolding to obtain the fairing main blank, and riveting at the set position of the fairing main blank. Finally, overall polishing can obtain the composite fairing.

[0076] In the implementation process of step 1, the suction surface shell, the pressure surface shell, the left wing profile shell, the right wing profile shell and the tail wing are prepared by using the autoclave molding process. Taking the suction surface shell as an example, the specific preparation process includes the following steps:

[0077] Mold pretreatment: first, use 1000 sandpaper to slightly polish the second forming surface of the suction surface forming mold, then clean the second forming surface of the mold with anhydrous ethanol, then evenly brush high-temperature release agent on the second forming surface with a brush, wait for the high-temperature release agent to dry naturally, then clean the second forming surface with a clean towel, then perform the second high-temperature release agent treatment, and repeat the above process for a total of 6 times of high-temperature release agent treatment. After that, the mold pretreatment is completed. At room temperature of about 25 degrees, it takes about 30 minutes to perform the next high-temperature release agent treatment;

[0078] Brushing primer: brush a layer of resin matrix primer on the second forming surface of the pretreated suction surface forming mold. After brushing the resin matrix primer, carefully clean the debris left on the mold second forming surface during brushing. Wait for 4 hours before laying the next layer.

[0079] Prepreg layering: the first layer of skin prepreg is laid. First, draw the center lines of the front and back edges. Then, tear off the white paper on one side of the cut prepreg. Align the small edge center line and straighten it. Then, lay the prepreg from the small edge to the large edge. Use a horn scraper to flatten the prepreg from the laying direction and from the middle to the left and right directions. Then, check the surface carefully. There should be no bubbles or unevenness on the surface of the prepreg. Then, tear off the white paper on the other side of the prepreg. Cut a piece of polytetrafluoroethylene cloth to the size of the prepreg surface. Then, lay it flat on the surface of the first layer of prepreg. Wrap it with air-permeable felt. Place the mold in a vacuum bag and seal it. Extract the vacuum. After entering the oven, heat it to 50 degrees and keep it at that temperature for 1 hour. After taking it out of the oven, clean the polytetrafluoroethylene cloth and vacuum bag film on the surface of the prepreg. Use a horn scraper to flatten the uneven and bulging areas on the surface of the prepreg. Lay the fifth layer in the same way as the first layer. Extract the vacuum for 30 minutes after the fifth layer is completed. Repeat the process until the layering is complete. After the last layer of prepreg is laid, cut a piece of polytetrafluoroethylene cloth to the size of the prepreg surface. Then, lay it flat on the surface. Enter the large oven and heat it to 50 degrees. Keep it at that temperature for 1 hour.

[0080] Vacuum packaging: cut a piece of polytetrafluoroethylene cloth to the size of the prepreg. Then, lay it flat on the surface of the last layer of prepreg. Cut a piece of yellow high-temperature air-permeable felt to the size of the product. Lay it flat on the polytetrafluoroethylene cloth. Wrap the mold with yellow high-temperature air-permeable felt. Use two layers of yellow high-temperature air-permeable felt to wrap each corner to prevent the vacuum bag film from being damaged during vacuum extraction.

[0081] Curing and shaping: Put the mold as a whole on a metal flat plate, put the vacuum nozzle at the lower right corner of the mold, and surround the four sides with high-temperature adhesive tape. Put a thermocouple in front and back, and use the actual temperature of the thermocouple to heat and keep the product during curing. Seal the vacuum bag and vacuum seal. After the vacuum seal is qualified, push the platform car into the hot press tank for product curing. The curing system is as follows: 130 degrees for 2 hours, then 0.1 MPa pressure, the mold temperature reaches 160 degrees, then 0.2 MPa pressure, and 2 hours of pressure and temperature maintenance. After curing is completed, the suction surface forming mold with the suction surface shell is obtained.

[0082] The same operation steps as described above are used to obtain the pressure surface forming mold with the pressure surface shell, the left wing surface forming mold with the left wing surface shell, the right wing surface forming mold with the right wing surface shell, and the tail wing forming mold with the tail wing by using the pressure surface forming mold, the left wing surface forming mold, the right wing surface forming mold, and the tail wing forming mold, respectively. Then, the tail wing is demolded from the tail wing forming mold to obtain an independent tail wing part.

[0083] Before assembling the combined mold tool in step 2, the connecting bracket and the supporting core material need to be pretreated. The specific process is as follows:

[0084] The connecting bracket of titanium alloy material is cleaned with alcohol, and each part of the connecting bracket is roughened with a P80 abrasive belt to prevent poor adhesion of the glue to the titanium alloy. Titanium alloy material is installed on both ends of the connecting bracket.

[0085] The supporting core material is matched with the connecting bracket according to the requirements, and the excess supporting core material is polished to match the size of the connecting bracket.

[0086] The fairing is assembled by using the combined mold auxiliary positioning in step 2. The specific implementation process includes the following steps:

[0087] Step 201: Place the pressure surface forming mold with the pressure surface shell on the ground or reference platform, keep the pressure surface shell facing up, install the positioning baffle at the front and rear ends of the pressure surface forming mold, arrange two positioning screws on each of the two positioning baffles, temporarily do not tighten, and then clean the pressure surface forming mold as a whole.

[0088] Step 202: Divide the supporting core material into three parts, namely supporting core material #1, supporting core material #2, and supporting core material #3. The supporting core material #2 corresponds to the area between the first left flange and the second left flange on the left wing surface shell, the supporting core material #3 corresponds to the area between the first right flange and the second right flange on the right wing surface shell, and the supporting core material #1 corresponds to the remaining area.

[0089] Step 203, respectively, in the connecting bracket, support core material #1, support core material #2, support core material #3, pressure surface shell, left wing surface shell, right wing surface shell, suction surface shell, tail wing of the adhesive matching surface of the adhesive after scraping a layer of mixed structure, the connecting bracket, support core material #1 and pressure surface shell are bonded, and the support core material #2 and the left wing surface shell are bonded, the support core material #3 and the right wing surface shell are bonded, which specifically includes:

[0090] The connecting bracket and the pressure surface shell are bonded: first find a flat plate, mix the room temperature curing high temperature adhesive with the electronic scale, stir evenly with a spatula, scrape a layer of mixed structure adhesive on the bonding surface of the connecting bracket and the pressure surface shell, and control the thickness of the structure adhesive to be 5-10 mm, then align the front and rear ends of the connecting bracket and press down at the same time, then put the positioning baffle on the four positioning screws of the connecting bracket, and then clean the excess glue with a spatula, supplement the glue in the place where the glue is less, and clean the residual glue on the bonding surface with a dust-free cloth dipped in anhydrous ethanol. The bonding structure adhesive is a room temperature curing high temperature adhesive with a ratio of 100:20, and the curing time of the adhesive is 24 hours at room temperature. Since the temperature is relatively low, external heating is needed to assist the curing;

[0091] Support core material #1 bonding: the same structure adhesive and the same glue application method are used to bond the support core material #1 with the connecting bracket on both sides and the pressure surface shell;

[0092] Support core material #2 bonding: the same structure adhesive and the same glue application method are used to bond the support core material #2 with the left wing surface shell;

[0093] Support core material #3 bonding: the same structure adhesive and the same glue application method are used to bond the support core material #3 with the right wing surface shell;

[0094] Step 204, after removing the baffle corresponding to the first left flange and the second left flange on the left wing surface forming mold, and removing the baffle corresponding to the first right flange and the second right flange on the right wing surface forming mold, respectively, place the left wing surface forming mold with the left wing surface shell and the support core material #2, and the right wing surface forming mold with the right wing surface shell and the support core material #3 on the pressure surface forming mold corresponding to the first assembly cavity and the second assembly cavity, and bond the support core material #2, the support core material #3 and the support core material #1 with the same structure adhesive and the same glue application method;

[0095] Step 205, install the suction surface forming die with the suction surface shell on the pressure surface forming die, keep the corresponding positioning slot and the positioning plug inserted and matched, and the first and second butt protrusions aligned with the third and fourth butt protrusions respectively, and install the bolts between the corresponding first and second positioning connection holes, the third and fourth positioning connection holes, and the fifth and sixth positioning connection holes, tighten the bolts to press the suction surface forming die downward, and drive the left and right wing surface forming dies to extrude the excess structural glue, and ensure the overall profile accuracy of the fairing;

[0096] Step 206, bond the tail wing to the rear end of the connecting bracket, and install the tail wing baffle 13 at the rear end of the pressure surface forming die and the rear end of the suction surface forming die, so that the tail wing is clamped between the connecting bracket and the tail wing baffle, and the excess structural glue at the tail wing is extruded, thereby obtaining a combined mold tooling with a fairing main blank.

[0097] In the specific implementation process of step 3, the process of heating and curing is as follows: place the combined mold tooling in an oven and cure at 50 degrees for 24 hours.

[0098] In the specific implementation process of step 3, the process of riveting at the specified position of the fairing main blank is as follows: at the specified position of the fairing main blank, rivet a 5mm diameter rivet at an interval of 100-150mm. Preferably, structural glue is filled at the nut of the rivet to prevent the glue from flowing and creating voids when the product is turned over due to temporary uncured structural glue. After the structural glue is cured, the hole site is polished to be flush with the external surface of the product. If there is a lack of glue at the hole site, structural glue is used for filling, repairing, and subsequent curing and polishing. Finally, the whole is polished to remove excess edges, burrs, structural glue during bonding, etc., thereby obtaining a composite fairing.

[0099] The above description is only a preferred embodiment of the present application, and does not limit the protection scope of the present application. Any equivalent structural transformation based on the inventive concept of the present application, or direct / indirect application in other related technical fields is included in the protection scope of the present application.

Claims

1. A composite fairing, characterized by, The fairing is a conical structure with tail wings, comprising a connecting bracket, a supporting core material, a suction surface shell, a pressure surface shell, a left wing profile shell, a right wing profile shell and a tail wing. The supporting core material is arranged on both sides of the connecting bracket, the suction surface shell covers the top of the supporting core material and the connecting bracket, and the pressure surface shell covers the bottom of the supporting core material and the connecting bracket. The left wing profile shell covers the leftmost side of the supporting core material and is connected with the suction surface shell and the pressure surface shell, the right wing profile shell covers the rightmost side of the supporting core material and is connected with the suction surface shell and the pressure surface shell, and the tail wing covers the rear end of the connecting bracket. The suction surface shell, the pressure surface shell, the left wing profile shell, the right wing profile shell and the tail wing are all carbon fiber reinforced resin matrix composite structural members, the connecting bracket is a metal structural member, and the supporting core material is a foam material.

2. The composite fairing of claim 1, wherein, The top of the left wing profile shell is provided with a first left flange, and the bottom is provided with a second left flange, the top of the right wing profile shell is provided with a first right flange, and the bottom is provided with a second right flange. The first left flange and the first right flange are clamped between the suction surface shell and the supporting core material, and the second left flange and the second right flange are clamped between the pressure surface shell and the supporting core material.

3. The composite fairing of Claim 2, wherein, The front end of the connecting bracket is provided with a stopper, and the rear end is provided with a baffle, and the front end and the rear end of the supporting core material abut against the stopper and the baffle respectively. The tail wing is connected with the outer wall of the baffle.

4. The composite fairing of claim 3, wherein, The suction surface shell is glued to the top of the connecting bracket and fixed by rivets, and the pressure surface shell is glued to the bottom of the connecting bracket and fixed by rivets. The suction surface shell is glued to the top of the supporting core material and fixed by rivets at positions corresponding to the first left flange and the first right flange, and the left wing profile shell, the right wing profile shell and the supporting core material are fixed by rivets. The pressure surface shell is glued to the bottom of the supporting core material and fixed by rivets at positions corresponding to the second left flange and the second right flange, and the left wing profile shell, the right wing profile shell and the supporting core material are fixed by rivets. The left wing profile shell is glued to the stopper and the baffle and fixed by rivets, the right wing profile shell is glued to the stopper and the baffle and fixed by rivets, and the tail wing is glued to the baffle and fixed by rivets.

5. A combination mold characterized by, The forming of the composite fairing according to any one of claims 1 to 4, wherein the combined mold comprises a pressure surface forming mold, a suction surface forming mold, a left wing profile forming mold, a right wing profile forming mold and a tail wing forming mold. The pressure surface forming mold is provided with a first forming surface matched with the shape of the pressure surface shell, the suction surface forming mold is provided with a second forming surface matched with the shape of the suction surface shell, the left wing profile forming mold is provided with a third forming surface matched with the shape of the left wing profile shell, the right wing profile forming mold is provided with a fourth forming surface matched with the shape of the right wing profile shell, and the tail wing forming mold is provided with a fifth forming surface matched with the shape of the tail wing.

6. The combination mold according to claim 5, wherein The pressure surface forming die and the suction surface forming die are in a similar rectangular structure as a whole; Four corners of the pressure surface forming die are provided with positioning insertion grooves, four corners of the suction surface forming die are provided with positioning insertion blocks, the positioning insertion grooves and the positioning insertion blocks are one-to-one corresponding and can be inserted and matched, and first and second positioning connecting holes coaxial after assembly are arranged on the corresponding positioning insertion grooves and the positioning insertion blocks.

7. The modular mold of claim 6, wherein, First and second butt protrusions are arranged on the pressure surface forming die at positions corresponding to left and right sides of the first forming surface and between the two positioning insertion grooves, and third and fourth butt protrusions are arranged on the suction surface forming die at positions corresponding to left and right sides of the second forming surface and between the two positioning insertion blocks; The first and third butt protrusions are provided with third and fourth positioning connecting holes coaxial after assembly, and the second and fourth butt protrusions are provided with fifth and sixth positioning connecting holes coaxial after assembly.

8. The modular mold of claim 7, wherein, A first assembly cavity in which the left wing surface forming die can be arranged is arranged between the first butt protrusion and the left side of the first forming surface, and between the third butt protrusion and the left side of the second forming surface; A second assembly cavity in which the right wing surface forming die can be arranged is arranged between the second butt protrusion and the right side of the first forming surface, and between the fourth butt protrusion and the right side of the second forming surface; After assembly, the left wing surface forming die is located in the first assembly cavity, the upper and lower sides of the left wing surface forming die abut against the suction surface forming die and the pressure surface forming die respectively, and at least one of the suction surface forming die and the pressure surface forming die is mitered with the left wing surface forming die; After assembly, the right wing surface forming die is located in the second assembly cavity, the upper and lower sides of the right wing surface forming die abut against the suction surface forming die and the pressure surface forming die respectively, and at least one of the suction surface forming die and the pressure surface forming die is mitered with the right wing surface forming die.

9. A method of forming a fairing of composite material as claimed in any one of claims 1 to 4, characterised in that, The method comprises the following steps: Step 1: using the combined mold of any one of claims 5 to 8 to prepare a suction surface shell, a pressure surface shell, a left wing surface shell, a right wing surface shell, and a tail wing, and only demolding the tail wing; Step 2: using structural glue to bond the suction surface shell, the pressure surface shell, the left wing surface shell, the right wing surface shell, the tail wing, the connecting support, and the supporting core material into a fairing, and using the combined mold of claim 8 and the combined mold after assembly and locking for auxiliary positioning to obtain a combined mold tool with a fairing main blank; Step 3: after heating and curing the combined mold tool, demolding to obtain a fairing main blank, and riveting at a set position of the fairing main blank, and finally polishing to obtain the composite fairing.

10. The molding method according to claim 9, characterized by Step 2 specifically comprises: Step 201: placing the pressure surface forming die with the pressure surface shell on the ground or a reference platform, and keeping the pressure surface shell upward; Step 202, the support core material is divided into three parts, support core material #1, support core material #2 and support core material #3, wherein the support core material #2 corresponds to the area between the first left flanging and the second left flanging on the left wing surface shell, the support core material #3 corresponds to the area between the first right flanging and the second right flanging on the right wing surface shell, and the support core material #1 corresponds to the remaining area; Step 203, after scraping a layer of mixed structural adhesive on the bonding surface of the connecting bracket, the support core material #1, the support core material #2, the support core material #3, the pressure surface shell, the left wing surface shell, the right wing surface shell, the suction surface shell and the tail wing respectively, the connecting bracket #1, the support core material and the pressure surface shell are bonded, and the support core material #2 and the left wing surface shell are bonded, and the support core material #3 and the right wing surface shell are bonded; Step 204, after removing the baffles on the left wing surface forming mold corresponding to the first left flanging and the second left flanging, and removing the baffles on the right wing surface forming mold corresponding to the first right flanging and the second right flanging, the left wing surface forming mold with the left wing surface shell and the support core material #2 is placed on the pressure surface forming mold corresponding to the first assembly cavity and the second assembly cavity, and the right wing surface forming mold with the right wing surface shell and the support core material #3 is placed on the pressure surface forming mold corresponding to the first assembly cavity and the second assembly cavity; Step 205, the suction surface forming mold with the suction surface shell is installed on the pressure surface forming mold, and the positioning slot and the positioning block are inserted and matched, and the first butt protrusion and the second butt protrusion are aligned with the third butt protrusion and the fourth butt protrusion respectively, and the bolts are installed between the first positioning connecting hole and the second positioning connecting hole, the third positioning connecting hole and the fourth positioning connecting hole, and the fifth positioning connecting hole and the sixth positioning connecting hole, and the bolts are tightened to make the suction surface forming mold press downward and drive the left wing surface forming mold and the right wing surface forming mold to extrude inward; Step 206, the tail wing is bonded to the rear end of the connecting bracket, and the tail wing baffle is installed at the rear end of the pressure surface forming mold and the rear end of the suction surface forming mold, so that the tail wing is clamped between the connecting bracket and the tail wing baffle, and the combined mold tool with the fairing main blank body is obtained.

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