A large-size single-side closed-angle H-beam forming die for aircraft and its preparation method

Abstract

A forming die for a large-sized, single-sided, closed-angle H-beam for aircraft and a preparation method thereof belong to the field of aviation composite material forming. The specific scheme is as follows: A forming die for a large-sized, single-sided, closed-angle H-beam for aircraft comprises a forming die and a pre-layout die. The forming die includes a frame base I, a form plate I, and a die body I. Form plate I is fixedly mounted on frame base I, and die body I is fixed on form plate I. The profile of die body I is consistent with the internal profile of the open-angle side of the H-beam. The pre-layout die includes a frame base II, form plate II, and die body II. Form plate II is fixedly mounted on frame base II, and die body II is fixed on form plate II. The profile of die body II is consistent with the internal profile of the closed-angle side of the H-beam. The pre-layout die is undercut above the forming die, and die body II is surface-matched and positioned with die body I. This invention solves the problems of the difficulty in forming large-sized, single-sided, closed-angle H-beam parts for aircraft and the difficulty in operator operation.

Description

Technical Field

[0001] The invention belongs to the field of aviation composite material forming, and in particular relates to a large-size single-side closed-angle H-beam forming die for aircraft and a preparation method thereof. Background Art

[0002] Carbon fiber composites have replaced many traditional materials. Their characteristics, such as low specific gravity, high specific strength and specific modulus, have led to their increasing use in aircraft. The development of modern high technology is inseparable from composite materials. Composite materials play a vital role in the development of modern science and technology and have become one of the important indicators of a country's scientific and technological advancement.

[0003] Composite parts are usually formed using vacuum bag autoclaves. The advantage of autoclaves is their flexibility in pressurizing composite parts. Usually, the part is laid on one side of the mold and then placed in a vacuum bag. Pressure is applied to the part to make it fit tightly against the mold, and the pressure on the part is further increased by vacuuming the bag. Large-sized closed-angle beam parts with composite central wings require high precision on the outer surface, so vacuum bag autoclave molding technology is used. Currently, the existing tooling has the following problems when forming large-sized single-sided closed-angle H-beams: the surface quality of the product is unqualified, there are defective delamination phenomena, there are wrinkles inside the product, and the pass rate is low; the positioning of the upper and lower molds of the tooling is inaccurate. There are errors in the product alignment; the tooling is too large, which is not conducive to lifting and transportation. Summary of the Invention

[0004] The present invention provides a large-sized single-sided closed-angle H-beam forming mold for aircraft and a preparation method thereof. In order to solve the problems of high precision, great difficulty in forming, and difficulty in operation for workers in the existing technology for large-sized single-sided closed-angle H-beam parts for aircraft, a new forming method and tooling structure are adopted to solve the above problems.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions:

[0006] A forming die for a large-sized, single-sided closed-angle H-beam for aircraft comprises a forming die and a pre-laying die. The forming die comprises a frame base I, a form plate I, and a die body I. The form plate I is fixedly arranged on the frame base I, and the die body I is fixed on the form plate I. The profile of the die body I is consistent with the internal profile of the open-angle side of the H-beam. The pre-laying die comprises a frame base II, a form plate II, and a die body II. The form plate II is fixedly arranged on the frame base II, and the die body II is fixed on the form plate II. The profile of the die body II is consistent with the internal profile of the closed-angle side of the H-beam. The pre-laying die is undercut above the forming die, and the surfaces of the die body II and the die body I are matched and positioned.

[0007] Furthermore, the forming mold further includes a plurality of positioning components I, and the pre-laying mold further includes a plurality of positioning components II. The plurality of positioning components I and the plurality of positioning components II are matched and fixedly connected accordingly.

[0008] Furthermore, the plurality of positioning components I are evenly distributed on the front and back sides of the phantom I, and the plurality of positioning components II are evenly distributed on the front and back sides of the phantom II.

[0009] Furthermore, rotating shafts are fixedly provided horizontally at the left and right ends of the frame base II.

[0010] Furthermore, the forming mold also includes two side plates, the shapes of the two side plates are the same as the edge strip shape of the H-beam, and the two side plates can be detachably fixed on the mold plate I and are respectively located on the front and rear sides of the mold body I.

[0011] Furthermore, the two side panels are composed of several inserts I that are spliced and fixed in sequence. The bottom of each insert I is provided with at least one slider mounting groove, and a slider is provided inside each slider mounting groove, and the slider protrudes from the slider mounting groove; the bottom of each insert I is provided with at least one demolding groove.

[0012] Furthermore, the mold body II is composed of a plurality of inserts II that are sequentially spliced and fixedly connected, and each insert II is provided with a draft angle along the length direction of the H-beam.

[0013] Furthermore, the side walls of the frame base I and the frame base II are provided with a plurality of lifting rings and / or a plurality of forklift slots, the bottoms of the frame base I and the frame base II are provided with casters, and the frames of the frame base I and the frame base II are provided with storage boxes.

[0014] A forming method using the single-side closed angle H-beam forming die comprises the following steps:

[0015] Step 1: Lay a layer of composite material prepreg on the mold body I of the forming mold, vacuum and compact it, then lay several layers of composite material prepreg in sequence to form the lower half of the 'C'-shaped beam, and vacuum once after laying two layers of composite material prepreg; Lay a layer of composite material prepreg on the mold body II of the pre-laying mold, vacuum and compact it, then lay several layers of composite material prepreg in sequence to form the upper half of the 'C'-shaped beam, and vacuum once after laying two layers of composite material prepreg;

[0016] Step 2: Place the pre-layout mold upside down on top of the forming mold and fix the two together to close the mold, fill the R corner with twist strips, and then lay the edge strips of the H-beam on the front and back sides of the forming mold;

[0017] Step 3: Remove the pre-laid formwork, place a soft formwork that is consistent with the inner profile of the closed angle side of the H-beam inside the upper half of the 'C' beam, and fix the edge strip surface to the formwork body I through the side panels;

[0018] Step 4: Place the forming mold into an autoclave for curing; after curing, demould to obtain a large-sized single-sided closed-angle H-beam for aircraft.

[0019] Furthermore, in step four, the curing step is to push the forming mold of the paste vacuum bag into the autoclave, connect the vacuum bag to the vacuum pipeline, increase the temperature to 120°C, increase the pressure to 0.6 MPa and keep the temperature and pressure for 120-180 minutes.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] 1. The present invention adopts the AIRPAD soft mold pressurization method to solve the quality problems of large closed angle products with step difference and rough surface and difficult demoulding.

[0022] 2. The use of AIRPAD soft mold and multi-stage positioning of the forming mold solves the problem of inaccurate positioning of large-size tooling and improves the forming quality of parts.

[0023] 3. A graphite copper plate slider is set at the bottom of the forming die insert, which can be used in an environment where it is difficult to refuel or in an oil-free environment for a long time. It has the characteristics of strong load-bearing capacity, impact resistance, high temperature resistance, and strong self-lubrication ability. It is convenient for large-size tooling parts to move and reciprocate, etc., reducing the difficulty and inconvenience of movement, making it more convenient for workers to operate the forming die insert and improving their production efficiency.

[0024] 4. The frame split structure is adopted to increase the overall strength of the frame, make the frame beautiful in appearance, and save manufacturing costs.

[0025] 5. The pre-laying mold and the forming mold are positioned with tapered pins, which can be quickly positioned, saving the staff's time and making the operation simple.

[0026] 6. The storage box allows you to intuitively see the number of detachable parts, which is convenient for inventory, prevents loss, and facilitates operation by staff. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a diagram showing the mold closing state of the forming mold and the pre-laying mold of the present invention;

[0028] Figure 2 It is a diagram showing the state of the forming mold and the pre-laying mold being separated from each other according to the present invention;

[0029] Figure 3 This is a front view of the forming die of the present invention;

[0030] Figure 4is a top view of the forming die of the present invention;

[0031] Figure 5 This is the axonometric drawing of the forming die frame base I;

[0032] Figure 6 This is the axonometric drawing of the forming die body I;

[0033] Figure 7 yes Figure 6 Partial enlarged view of forming die insert I;

[0034] Figure 8 This is the view of the forming die drilling jig I;

[0035] Figure 9 It is an axonometric view of the forming die storage box;

[0036] Figure 10 Cross-sectional view of the forming die and the pre-layout die positioning assembly in alignment;

[0037] Figure 11 This is the main view of the pre-form;

[0038] Figure 12 It is a top view of the pre-form;

[0039] Figure 13 This is the axonometric drawing of the pre-formwork frame base II;

[0040] Figure 14 This is the axonometric drawing of the pre-layout mold body II;

[0041] Figure 15 yes Figure 14 Partial enlarged view of pre-laying mold phantom II;

[0042] Figure 16 This is the axonometric drawing of the pre-layout mold positioning component II;

[0043] Figure 17 It is an axonometric view of a pre-molded storage box;

[0044] Figure 18 This is the main view of the soft mold forming die;

[0045] Figure 19 It is a top view of the soft mold forming die;

[0046] Figure 20 This is the axonometric drawing of the base of the soft mold forming mold frame III;

[0047] Figure 21 It is the axonometric drawing of the soft mold forming model plate III and mold body III;

[0048] Figure 22 This is a partial enlarged view of the drilling position of the soft mold of the soft mold forming mold;

[0049] Figure 23 It is the II axis diagram of the soft mold forming mold drilling mold;

[0050] Figure 24 Schematic diagram of the finished product of a large-sized single-sided closed-angle H-beam for aircraft;

[0051] In the figure: 1. forming mold, 2. pre-laying mold, 3. soft mold forming mold, 11. frame base I, 12. template I, 13. mold body I, 14. positioning component I, 15. side panel, 16. lifting ring, 17. caster, 18. storage box, 19. drilling jig I, 20. forklift slot, 21. frame base II, 22. template II, 23. mold body II, 24. positioning component II, 25. rotating shaft, 31. frame base III, 32. template III, 33. mold body III, 34. drilling jig II, 151. insert I, 152. slider mounting groove, 153. slider, 154. demoulding groove, 231. insert II, 232. draft angle. DETAILED DESCRIPTION

[0052] The technical solutions of the present invention will be clearly and completely described below in conjunction with the accompanying drawings and embodiments. Obviously, the described embodiments are only part of the embodiments of the invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention. Specific implementation method 1

[0054] A large-size, single-sided, closed-angle H-beam forming die for aircraft comprises a forming die 1 and a pre-laying die 2. The forming die 1 comprises a frame base I11, a formwork plate I12, and a die body I13. The formwork plate I12 is fixedly arranged on the frame base I11, and the die body I13 is fixed on the formwork plate I12. The profile of the die body I13 is consistent with the internal profile of the open-angle side of the H-beam. The pre-laying die 2 comprises a frame base II21, a formwork plate II22, and a die body II23. The formwork plate II22 is fixedly arranged on the frame base II21, and the die body II23 is fixed on the formwork plate II22. The profile of the die body II23 is consistent with the internal profile of the closed-angle side of the H-beam. When the pre-laying die 2 is inverted and arranged above the forming die 1, the die body II23 matches the surface of the die body I13 and is positioned. The mold body I13 is used to form the open angle side of the H-beam, and the mold body II23 is used to form the closed angle side of the H-beam. Both the mold body I13 and the mold body II23 are convex mold structures.

[0055] Furthermore, the forming mold 1 also includes a plurality of positioning components I14, and the pre-laying mold 2 also includes a plurality of positioning components II24. The plurality of positioning components I14 and the plurality of positioning components II24 are matched and fixedly connected accordingly.

[0056] Furthermore, the plurality of positioning assemblies I14 are evenly welded to the frame base I11 and located on the front and rear sides of the mold body I13. The plurality of positioning assemblies II24 are evenly welded to the frame base II21 and located on the front and rear sides of the mold body II23. The positioning assemblies I14 and II24 are used to quickly merge the forming mold 1 and the pre-laying mold 2 and correct their relative positions.

[0057] Furthermore, a rotating shaft 25 is fixed horizontally at both ends of the left and right sides of the frame base Ⅱ21, which is used to flip the pre-laying mold 2 and turn it upside down on the top of the forming mold 1, and then quickly locate the relative positions of the forming mold 1 and the pre-laying mold 2 through the positioning hole on the positioning component Ⅰ14 and the positioning pin on the positioning component Ⅱ24.

[0058] Furthermore, the forming die 1 includes two side panels 15, each shaped like the edge strips of the H-beam. Both panels 15 are detachably fixed to the form plate I 12 and positioned on the front and rear sides of the form body I 13. Composite prepreg is applied to form body I 13 of forming die 1 to form the lower half of the C-beam, while composite prepreg is applied to form body II 23 of pre-laying die 2 to form the upper half of the C-beam. After the lower and upper half C-beams are combined, the prepreg for the edge strips on both sides of the H-beam are applied. The side panels 15 are used to apply pressure to the edge strips during part forming.

[0059] Furthermore, the two side panels 15 are each composed of a number of inserts I 151 that are spliced and fixed in sequence. The bottom of each insert I 151 is provided with at least one slider mounting groove 152, and a slider 153 is provided inside each slider mounting groove 152. The slider 153 protrudes from the slider mounting groove 152. The slider 153 allows the insert I 151 to slide freely on the mold plate I 12, facilitating operation and avoiding repeated disassembly and assembly. The bottom of each insert I 151 is provided with at least one demolding groove 154. The size of the insert I 151 is 1 meter, and there are 16 of them in total. Preferably, the slider 153 is a graphite copper plate. A pad is provided inside the slider mounting groove 152, and the slider 153 is fixedly connected to the pad. The pad is used to adjust the relative height of the slider 153 relative to the slider mounting groove 152.

[0060] Furthermore, the mold body II 23 is composed of a plurality of inserts II 231 which are sequentially spliced and fixedly connected. Each insert II 231 is provided with a draft angle 232 along the length direction of the H-beam to ensure smooth demoulding.

[0061] Furthermore, the side walls of the frame base I11 and the frame base II21 are provided with a plurality of lifting rings 16 and / or a plurality of forklift slots 20 to facilitate the transfer and transportation of the forming mold 1 and the pre-laying mold 2. The bottoms of the frame base I11 and the frame base II21 are provided with casters 17. The frames of the frame base I11 and the frame base II21 are provided with storage boxes 18. The storage boxes 18 are welded with thin steel plates and are mainly used for storing and organizing detachable parts on tooling. The number of detachable parts can be intuitively seen, which is convenient for counting and preventing loss.

[0062] Preferably, the number of casters 17 provided at the bottom of the frame base I11 and the frame base II21 are four, respectively provided at the four corners of the bottom of the frame base I11 and the four corners of the bottom of the frame base II21, and the four casters include two universal casters and two fixed casters.

[0063] Preferably, the number of the lifting rings 16 provided on the side walls of the frame base I11 and the frame base II21 are both four, and the number of the forklift slots 20 are both four.

[0064] Furthermore, the frame base I11 and the frame base II21 are welded by square tubes and steel plates. The square tubes are arranged in an orderly manner horizontally and vertically, and reinforced square tubes are locally provided to ensure that they have sufficient strength and will not undergo plastic deformation during use and transportation, and will not affect the forming of parts.

[0065] Furthermore, a drilling jig Ⅰ19 is provided at the left and right ends of the mold body Ⅰ13. The drilling jig Ⅰ19 is made of CNC machined steel plates and is used for processing the process holes of the parts after the overall forming of the parts. The position of the drilling jig Ⅰ19 is configured to ensure that it has sufficient precision so that the hole position is accurate when it cooperates with other tooling.

[0066] Furthermore, the single-side closed-angle H-beam forming mold also includes a soft mold, the outer profile of which is consistent with the inner profile of the closed-angle side of the H-beam. After all prepregs are laid, the pre-layout mold 2 is removed and the soft mold is installed. The side panel 15 is provided with a plurality of oblong holes, and positioning pins are inserted through the oblong holes and the positioning holes of the soft mold to position the soft mold.

[0067] Furthermore, the soft mold is composed of a plurality of separate molds, which is convenient for assembly and disassembly.

[0068] Furthermore, the soft mold forming mold 3 of the soft mold includes a frame base III31, a mold plate III32 and a mold body III33. The mold plate III32 is fixed on the frame base III31, and the mold body III33 is fixed on the mold plate III32. The profile of the mold body III33 is consistent with the internal profile of the closed angle side of the H-beam. The side wall of the frame base III31 is also provided with a plurality of hanging rings 16 and / or a plurality of forklift slots 20. The interior of the frame base III31 is also provided with a storage box 18, and the bottom of the mold body III33 is also provided with a plurality of demolding grooves 154.

[0069] Furthermore, the mold body III 33 is formed by splicing and fixing a plurality of inserts III, and a demoulding groove 154 is provided at the bottom of each insert III.

[0070] The frame base III31 is welded with square tubes and steel plates. The square tubes are arranged in an orderly manner horizontally and vertically, and reinforced square tubes are locally set to ensure that it has sufficient strength and will not undergo plastic deformation during use and transportation, and will not affect the forming of parts. Four lifting rings 16 and two forklift slots 20 are arranged on the frame base III31 to facilitate the transfer and transportation of tooling; the mold plate III32 is fully welded to the top of the frame base III31, and the mold body III33 is connected to the mold plate III32 by screws and pins. Because the product has a large closed angle, several inserts III are set to facilitate demoulding, and a fixed drill jig II34 is set on the edge side of the insert III so that the soft mold can be positioned in the forming mold 1; the drill jig II34 is made of steel plate CNC processing and is used for the processing holes of the part after the overall forming of the part. The position of the drill jig II34 is configured to ensure that it has sufficient precision so that the hole position is accurate when it cooperates with other tooling. The storage box 18 is welded with thin steel plates and is mainly used for storing and organizing detachable parts on tooling. The number of detachable parts can be intuitively seen, which is convenient for counting and preventing loss. Specific implementation method 2

[0072] A forming method using the single-side closed angle H-beam forming die comprises the following steps:

[0073] Step 1: Lay the layers according to the layup diagram: lay a layer of composite material prepreg on the mold body I13 of the forming mold 1, vacuum and compact it, and then lay several layers of composite material prepreg in sequence to form the lower half of the 'C'-shaped beam, and vacuum once after laying two layers of composite material prepreg; lay a layer of composite material prepreg on the mold body II23 of the pre-laying mold 2, vacuum and compact it, and then lay several layers of composite material prepreg in sequence to form the upper half of the 'C'-shaped beam, and vacuum once after laying two layers of composite material prepreg; wherein the mold body I13 and the mold body II23 are both convex mold structures.

[0074] Step 2: The lower half 'C' beam and the upper half 'C' beam that have been laid are respectively packaged on the corresponding tooling and hot compacted. After the hot compaction of the lower half 'C' beam and the upper half 'C' beam is completed, the pre-laying mold 2 is inverted on top of the forming mold 1 and the two are fixedly connected by the positioning component I 14 and the positioning component II 24 to close the mold. After the assembly is completed, the R corners are filled with the twist strips that have been hot compacted, and then the edge strips of the H-beam are laid on the front and back sides of the forming mold 1 according to the drawings.

[0075] Step 3: After the laying is completed, remove the pre-laying mold 2, place a soft mold that is consistent with the internal surface of the closed angle side of the H-beam inside the upper half of the 'C' beam, and fix the edge surface to the mold body I13 through the side plate 15; adjacent inserts I151 need to be locked with bolts. After the inserts I151 are combined, the inserts I151 and the mold body I13 are positioned using locating pins through oblong holes and connected with bolts. The bolts do not need to be tightened. During curing, the edge surface of the part is pressurized by the pressure of the vacuum bag and the sliding of the slider.

[0076] Step 4: Place the single-sided closed-angle H-beam forming mold into an autoclave for curing; after curing, demould to obtain a large-sized single-sided closed-angle H-beam for aircraft.

[0077] Furthermore, in step four, the curing step is to push the forming mold of the paste vacuum bag into the autoclave, connect the vacuum bag to the vacuum pipeline, increase the temperature to 120°C, increase the pressure to 0.6 MPa and keep the temperature and pressure for 120-180 minutes.

[0078] Since there is a large closed angle on one side of the product, the upper half of the 'C' beam needs to be pre-laid and then transferred as a whole to the top of the forming mold 1.

[0079] Example 1

[0080] A large-size single-side closed-angle H-beam forming die for aircraft, comprising a forming die 1 and a pre-layout die 2.

[0081] The frame base Ⅰ11 in the forming mold 1 is made of Q235-AF and is fully welded by square steel pipe GB3094. The lifting ring mounting plate, caster assembly, positioning assembly Ⅰ14, and storage box 18 are welded to the square steel pipe. After welding, heat treatment is performed to relieve stress. The weld is cleaned after welding, and the finished parts of the lifting ring 16 and caster 17 are installed. Among them, the positioning assembly Ⅰ14 is made of Q235-AF and is fully welded to the frame base Ⅰ11. The positioning assembly Ⅰ14 is used to position with the tapered pin of the positioning assembly Ⅱ24 in the pre-laying mold 2 tooling; the mold body Ⅰ13 is welded to the template Ⅰ12, and the template Ⅰ12 is fully welded to the frame base Ⅰ11; the insert Ⅰ151 is connected to the template Ⅰ12 by screws and pins to ensure the correct installation position; then the slider 153 is installed on the slider mounting groove 152 by screws to facilitate the sliding of the insert Ⅰ151; the drilling mold Ⅰ19 is made of Q235-AF and is used to drill positioning holes after the product is solidified. Insert Ⅰ151 has a demoulding groove to facilitate demoulding.

[0082] The frame base II21 of the pre-laying mold 2 is made of Q235-AF and is fully welded with square steel pipe GB3094. The lifting ring mounting plate, caster assembly, template II22, storage box 18, etc. are welded to the square steel pipe. After welding, heat treatment is performed to relieve stress. After welding, the weld is cleaned, and the finished parts of the lifting ring 16 and caster 17 are installed. Among them, the tapered pin of the positioning component II24 is made of Q235-AF and is fully welded to the frame base I11. The tapered pin is used for positioning with the positioning component I14 in the forming mold 1 tooling. Position; the insert II 231 material is Q235-AF, and is connected to the template II 22 by screws and pins to ensure the correct installation position; to ensure that it can be demoulded, each insert II 231 has a draft angle increased along the length direction of the tooling to facilitate demoulding; the rotating shaft 25 material is 45#, and is installed to the left and right ends of the frame base II 21 by screws and pins. Its function is to transfer the pre-laying mold 2 tooling to the top of the forming mold 1 by flipping it after the pre-laying is completed, and position it in the correct position; then remove the pre-laying mold 2 tooling.

[0083] The frame base III31 of the soft mold forming mold 3 is made of Q235-AF and is fully welded from the square steel tube GB3094. The lifting ring mounting plate, template III32, storage box 18 and square steel tube are welded together. After welding, heat treatment is performed to relieve stress, the weld is cleaned after welding, and the lifting ring 16 finished product is installed; the insert III is made of Q235-AF. Since the product has a large closed angle and is easily damaged during demoulding, multiple inserts III are designed. Each insert III is detachable to ensure smooth demoulding without damaging the product. The insert III is fixed to the template III32 by screws and pins; the drilling jig II34 is made of Q235-AF and is used to drill positioning holes after the product is cured.

[0084] Before forming the H-beam, a soft mold must be manufactured using the soft mold forming die 3. The steps are as follows: A CNC blanking machine is used for blanking. The soft mold is placed on the closed corner side of the part. The soft mold is then broken into five sections. The soft mold is manually laid with three layers of 0.6mm prepreg and one layer of AIRPAD, which are then cured. Two layers of prepreg are broken at the corner radius. To ensure accurate positioning of the soft mold, positioning holes are designed in the soft mold forming die 3 to align it with the forming die 1 tooling.

[0085] 1. Move the assembled soft mold forming mold 3 tooling to the working position through the forklift slot 20 or the lifting ring 16, and use the blanking machine to unload the material, ensuring the unloading angle and dimensional accuracy. The AIRPAD soft mold is manually pasted according to the laying specifications. The soft mold is placed on the closed angle side of the part. The soft mold needs to be broken and divided into five sections. The soft mold is manually laid with 3 layers of 0.6mm tooling prepreg and 1 layer of AIRPAD for curing. The two layers of prepreg that do not fit the product are broken at their R corners. To ensure the accuracy of the soft mold position, the soft mold forming mold 3 is designed with positioning holes to position it with the forming mold 1 tooling. Prepreg is laid on the soft mold forming mold 3 tooling. The beam transition zone boundary and the part boundary are laid using laser projection to locate the layer boundary. Vacuum compaction is carried out according to the requirements of the process documents. The tooling is cleaned to prevent foreign matter from appearing on the tooling.

[0086] 2. After laying, package and prepare for curing. During curing, place non-porous isolation film, breathable felt, cover plate and vacuum bag on the surface of the parts in sequence. After completion, the parts will be packaged in the packaging area, vacuumed, kept warm and pressurized, and then put into the autoclave for curing. During the process, a complete vacuum leak check is carried out. The minimum vacuum is 0.08MPa. Before the leak check, the parts are connected to the vacuum system for at least 15 minutes, and the vacuum system is turned off. After 5 minutes, the vacuum gauge reading does not drop by more than 0.017MPa. Push the tooling for the pasted vacuum bag into the autoclave, connect the vacuum pipeline, increase the temperature to 120℃, increase the pressure to 0.6Mpa, and keep warm and pressurized for 120-180 minutes. The vacuum degree negative pressure reading is tested to drop by no more than 0.017MPa.

[0087] 3. After curing is completed, move the tooling indoors and ventilate to cool to room temperature;

[0088] 4. Drill holes for subsequent use;

[0089] 5. Demolding should be carried out strictly in accordance with the demolding direction to avoid problems such as violent demolding and reduce damage to parts during demolding. After demolding, the tooling should be assembled, oiled, rust-proofed and processed, and then stored for future use.

[0090] 6. After demolding is completed, trim and polish the edges of the soft mold, and then save it in the library for subsequent use;

[0091] 7. Move the assembled pre-laying mold 2 to the working position through the lifting ring 16 or casters 17, and manually paste the component beam products (the upper half of the 'C' beam on the closed angle side). Vacuum and pre-compact after each two layers.

[0092] 8. Move the assembled Forming Die 1 tooling to the working position using casters 17 or lifting rings 16. Lay out the layers according to the layup diagram. First, lay out the upper and lower half "C" beams. Formation Body I 13 and Formation Body II 23 are male mold structures. One half of the "C" beam is laid on Forming Die 1 tooling, and the other half is laid on Pre-laying Die 2. Vacuum the beam after laying the first layer. For hand-pasted beam parts, vacuum and pre-compact after every two layers. Transfer the pre-laid upper half of the "C" prepreg on Pre-laying Die 2 to Forming Die 1. During the transfer process, positioning assembly I 14 in Forming Die 1 coordinates with positioning assembly II 24 in Pre-laying Die 2 to ensure accurate positioning. After mold closing, heat-compacted twist strips are placed at the R corners. The edge strips are then laid out according to the drawings. Once the layup is complete, the pre-layout mold is removed, and a soft mold is placed on the closed-angle side of the part. Insert I 151 is then connected to mold plate I 12. Adjacent inserts I 151 are bolted together. After insert I 151 is assembled, oblong-hole bolts and locating pins are installed between insert I 151 and mold body I 13. The bolts do not need to be tightened. During curing, the vacuum bag pressure and the sliding movement of slider 153 apply pressure to the edge strips of the part. Finally, the packaging and bagging process is completed, and the tooling is cleaned to prevent the presence of foreign matter.

[0093] 9. After laying is completed, the package is ready for curing. During curing, a non-porous isolation film, breathable felt, cover plate and vacuum bag are placed on the surface of the part in sequence. After completion, the parts will be packaged in the packaging area, vacuumed, kept warm and pressurized before entering the autoclave for curing. During the process, a complete vacuum leak check is carried out. The minimum vacuum is 0.08MPa. Before the leak check, the parts are connected to the vacuum system for at least 15 minutes, and the vacuum system is turned off. After 5 minutes, the vacuum gauge reading does not drop by more than 0.017MPa. Push the tooling for the pasted vacuum bag into the autoclave, connect the vacuum pipeline, heat up to 120℃, increase the pressure to 0.6Mpa and keep warm and pressurized for 120-180 minutes. The vacuum degree negative pressure reading is tested to drop by no more than 0.017MPa.

[0094] 10. After curing is completed, move the tooling indoors and ventilate to cool to room temperature;

[0095] 11. Drill holes for subsequent use;

[0096] 12. Demolding should be carried out strictly in accordance with the demolding direction to avoid problems such as violent demolding and reduce damage to parts during demolding. After demolding, the tooling should be assembled, oiled, rust-proofed and processed, and then stored for future use.

[0097] 13. After demolding is completed, trim and polish the edges of the parts;

[0098] 14. Carry out surface treatment such as moisture-proof and anti-corrosion, and pass the inspection.

[0099] In addition, it should be understood that although this specification is described in terms of implementation methods, not every implementation method contains only one independent technical solution. This narrative method of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other implementation methods that can be understood by those skilled in the art.

Claims

1. A large-size, single-side closed-angle H-beam forming die for aircraft, characterized by: The invention comprises a forming die (1) and a pre-laying die (2), wherein the forming die (1) comprises a frame base I (11), a template I (12) and a die body I (13), wherein the template I (12) is fixedly arranged on the frame base I (11), and the die body I (13) is fixed on the template I (12), and the profile of the die body I (13) is consistent with the internal profile of the open angle side of the H-beam; the pre-laying die (2) comprises a frame base II (21), a template II (2 2) and mold body II (23), the mold plate II (22) is fixedly arranged on the frame base II (21), the mold body II (23) is fixed on the mold plate II (22), and the mold body II (23) has a profile consistent with the internal profile of the closed angle side of the H-beam; the pre-laying mold (2) is set upside down above the forming mold (1), and the mold body II (23) matches the surface of the mold body I (13) and is positioned; the forming mold (1) also includes a plurality of positioning groups Part I (14), the pre-laying mold (2) also includes a plurality of positioning components II (24), the plurality of positioning components I (14) and the plurality of positioning components II (24) are matched and fixedly connected; the forming mold (1) also includes two side panels (15), the shape of the two side panels (15) is the same as the edge strip shape of the H-beam, the two side panels (15) can be detachably fixed on the mold plate I (12) and are respectively located on the front and rear sides of the mold body I (13); the two side panels (15) are formed by splicing and fixing a plurality of inserts I (151) in sequence, the bottom of each insert I (151) is provided with at least one slider mounting groove (152), the interior of each slider mounting groove (152) is provided with a slider (153), and the slider (153) protrudes from the slider mounting groove (152); the bottom of each insert I (151) is provided with at least one demoulding groove (154).

2. The large-size, single-side closed-angle H-beam forming die for aircraft according to claim 1, characterized in that: The plurality of positioning components I (14) are evenly distributed on the front and rear sides of the phantom I (13), and the plurality of positioning components II (24) are evenly distributed on the front and rear sides of the phantom II (23).

3. The large-size, single-side closed-angle H-beam forming die for aircraft according to claim 1, characterized in that: Rotating shafts (25) are fixedly provided horizontally at the left and right ends of the frame base II (21).

4. The large-size, single-side closed-angle H-beam forming die for aircraft according to claim 1, characterized in that: The mold body II (23) is composed of a plurality of inserts II (231) that are sequentially spliced and fixedly connected, and each insert II (231) is provided with a draft angle (232) along the length direction of the H-beam.

5. The large-size, single-side closed-angle H-beam forming die for aircraft according to claim 1, characterized in that: The side walls of the frame base I (11) and the frame base II (21) are both provided with a plurality of lifting rings (16) and / or a plurality of forklift slots (20), the bottoms of the frame base I (11) and the frame base II (21) are both provided with casters (17), and the frames of the frame base I (11) and the frame base II (21) are both provided with storage boxes (18).

6. A forming method using the single-side closed angle H-beam forming die according to claim 1, characterized in that: The following steps are involved: Step 1: Lay a layer of composite material prepreg on the mold body I (13) of the forming mold (1), vacuumize and compact it, and then lay several layers of composite material prepreg in sequence to form the lower half of the 'C'-shaped beam, and vacuumize once after laying two layers of composite material prepreg; Lay a layer of composite material prepreg on the mold body II (23) of the pre-laying mold (2), vacuumize and compact it, and then lay several layers of composite material prepreg in sequence to form the upper half of the 'C'-shaped beam, and vacuumize once after laying two layers of composite material prepreg; Step 2: Place the pre-laying mold (2) upside down on the top of the forming mold (1) and fix the two together to close the mold, fill the R corner with twist strips, and then lay the edge strips of the H-beam on the front and back sides of the forming mold (1); Step 3: Remove the pre-laid mold (2), place a soft mold that is consistent with the internal profile of the closed angle side of the H-beam inside the upper half of the 'C' beam, and fix the edge strip surface to the mold body I (13) through the side plate (15); Step 4: Place the forming mold into an autoclave for curing; after curing, demould to obtain a large-sized single-sided closed-angle H-beam for aircraft.

7. The molding method according to claim 6, wherein: In step 4, the curing step is to push the forming mold of the paste vacuum bag into the autoclave, connect the vacuum bag to the vacuum pipeline, increase the temperature to 120°C, increase the pressure to 0.6Mpa and keep the temperature and pressure for 120-180 minutes.

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