Demolding device and forming method for composite material reinforced nest part

Abstract

The invention provides a demolding device for a composite material reinforced nest part, which comprises a demolding block, a demolding block, a demolding block, a demolding block, a demolding block and a demolding block, and is characterized in that the demolding block can separate the composite material reinforced nest part from a forming tool; the outer hexagon screw is arranged on the demolding block; wherein pulling force is applied to the outer hexagon screw, and the demolding block drives the composite material reinforcing nest piece to be separated from the forming tool; meanwhile, the invention further provides a forming method of the composite material reinforced nest part. The invention provides a forming method and a demoulding device of a composite material reinforcing nest, which are simple in structure, are verified by actual production pressure test, are simple in demoulding, and solve the problem of product defects caused by flanging hole stripping of a composite material.

Description

Technical Field

[0001] The present application belongs to the technical field of composite materials, and in particular relates to a demoulding device and a forming method for a composite material reinforced nest. Background Art

[0002] Advanced composite materials with high strength and high modulus carbon fiber have been widely used in aircraft, such as aircraft doors, wall panels, partitions, fairings, etc. These products are mostly thin-walled parts. In order to increase the strength and rigidity of local areas, reinforcement pockets are added to the wall panels, partitions and fairings. However, demolding at the reinforcement pockets of wall panels, partitions and fairings after curing usually causes tearing of the reinforcement pockets.

[0003] In order to solve the problem that the reinforcement socket is damaged during the demoulding process, the present invention provides a forming method and a demoulding device for a composite material reinforcement socket. Summary of the invention

[0004] Purpose of the invention: The present invention solves the problem of tearing of the reinforcing nest during demoulding, and proposes a forming method and demoulding device for a composite material reinforcing nest.

[0005] In a first aspect, the present application provides a demoulding device for a composite material reinforced nest, the device comprising:

[0006] De-module, which can separate the composite reinforcement nest from the forming tooling;

[0007] An external hexagon screw is arranged on the stripping module; wherein, when a pulling force is applied to the external hexagon screw, the stripping module is detached from the molding tool with the composite material reinforcement nest.

[0008] Preferably, the stripping module is adapted to the shape of the composite reinforcement socket.

[0009] Preferably, a preset gap is provided between the end surface of the stripping module and the flange of the composite material reinforcement nest; the end surface of the stripping module is connected to the composite material reinforcement nest through prepreg;

[0010] The preset gap is used for cutting the prepreg at a later stage.

[0011] Preferably, the thickness of the stripping module is greater than the lowermost end of the flange of the composite material reinforcement socket.

[0012] In a second aspect, the present application also provides a method for forming a composite material reinforced nest, the method comprising:

[0013] Parts curing;

[0014] After the temperature of the bag removal tooling drops below 60°C, cut off the vacuum nozzle, remove the bag, tighten the hexagonal screws to remove the module, lift the reinforcing nest, and achieve demoulding.

[0015] Preferably, the part curing comprises:

[0016] Put the mold into the autoclave, evacuate to -0.09MPa, test the vacuum leakage, and require the drop value to be no more than 0.017MPa within 5 minutes. Close the autoclave after passing the test;

[0017] Vacuum - above 0.09MPa, start heating to 93±5℃ at a rate of 0.5-4℃ / min, the air temperature should not exceed 98℃; at the same time, increase the pressure to 340-400KPa at a rate of 27KPa / min, and close the vacuum when the pressure reaches 100KPa;

[0018] When the temperature reaches 93±5℃, maintain it for 30-60 minutes, and continue to increase the pressure to 480-510KPa at a rate of 27KPa / min; at the same time, increase the temperature to 177±5℃ at a rate of 0.5-4℃ / min, and the air temperature cannot exceed 182℃, and maintain it for 120-360 minutes;

[0019] Evacuate to at least -0.08MPa, reduce the pressure to 300KPa, and at the same time cool down to below 60℃ at a rate not exceeding 4℃ / min; when the temperature is below 60℃, release the pressure in the tank.

[0020] Preferably, the method further comprises:

[0021] Draw lines according to the cutting lines of the parts, use a pneumatic cutting machine to make rough cuts according to the drawn lines, leave a 0.5-1mm margin relative to the cutting line or drawn line, use a grinder to repair the edge burrs and the remaining margin, then use 400# sandpaper to gently grind off the burrs around the edges and grind off the remaining margin.

[0022] Preferably, before the part is solidified, the process further includes: layering and bag making.

[0023] Beneficial technical effects of this application:

[0024] The present invention provides a forming method and demoulding device for a composite material reinforcement socket, which has a simple structure, is verified by actual production pressure test, and is easy to demould, thereby solving the problem of product defects caused by demoulding of flanging holes in composite materials. The device is suitable for demoulding of flanging holes of different thicknesses and the same hole size, and can be used as a universal flanging hole demoulding tool to reduce tooling investment costs. In addition, the demoulding device for the composite material reinforcement socket has a low equipment cost and can be promoted for large-scale use. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1is a partial cross-sectional view of a composite material reinforcement nest provided in an embodiment of the present application;

[0026] Figure 2 It is an axonometric view of a composite material reinforcement nest device provided in an embodiment of the present application;

[0027] Figure 3 is a cross-sectional view of a composite material reinforced nest device provided in an embodiment of the present application;

[0028] Among them, 1-removal module; 2-hexagonal screw; 3-forming tooling; 4-reinforcement socket. DETAILED DESCRIPTION

[0029] The present application provides a method for forming a composite material reinforcement socket, the forming method comprising the following steps:

[0030] Step 1: Picking Materials

[0031] Collect the required prepreg materials from the material custodian according to the material specifications given in the parts manufacturing instructions, and collect the required surface film, foam glue, film and other materials and corresponding materials from the material custodian.

[0032] Step 2: CNC cutting

[0033] Extract the blanking program in the blanking machine according to the CNC blanking name in the blanking process, use the corresponding unfolded digital model written on the instruction, enter the corresponding unfolded digital model into the CNC software for CNC blanking, sort the cut pieces, and check the blanking pieces according to the number of material pieces marked on the CNC blanking.

[0034] Step 3: Lay-up tooling preparation

[0035] 3.1. Receiving tooling: The tooling preparation personnel will deliver the tooling to the demolding area, and the production team will check and receive the tooling according to the instruction material delivery list page and the tooling label.

[0036] 3.2. Tool cleaning: Use an air gun and a copper scraper to clean the residual glue tumors on the tool surface, blocks, and holes, wipe them dry with white cotton cloth, and wipe the tool with a dry cloth in one hand. Wipe the tool longitudinally according to the above steps for the second time, and then wipe crosswise. Change the rag after each wipe, and use white cotton cloth soaked in 180# aviation gasoline to clean it thoroughly (blocks, screws, pins, etc. can be soaked). Before the solvent evaporates, wipe the surface of the tool with a clean and dry white cotton cloth in time.

[0037] 3.3. Brushing mold release agent on tooling: Use a temperature gun to test the surface temperature of the tooling. The surface temperature of the tooling shall not be lower than 16°C and not higher than 40°C. Use paper tape (TESA4309) to isolate the area for the putty strip around the surface of the tooling. The paper tape is preferably covered on the imprint of the original sealing strip. The new tooling paper tape should cover at least 100mm outside the margin line. Pour an appropriate amount of mold release agent on the rag, fully soak the rag, twist the rag lightly, and no dripping is allowed. Apply the mold release agent alternately horizontally and vertically. When brushing in the same direction, it must be one-way and no reciprocating is allowed.

[0038] Step 4: Lay Up

[0039] 4.1 Preparation for laying: Check the requirements of the clean room according to the instructions, verify the instructions, check the tooling, check the materials, prepare the tools, and prepare the equipment: turn on the laser projector and install the laser target head to use the laser projection data of the laying parts.

[0040] 4.2 First layer laying:

[0041] 4.2.1 Cut pieces comparison: Place the prepreg cut pieces on the tooling according to the positions indicated in the layup book / drawing for comparison, and check the size, direction and other information of the cut pieces;

[0042] 4.2.2 Remove the protective film of the cut pieces: remove the protective film on the back of the prepreg cut pieces. There is inkjet text on the front, including part drawing number, material brand, ply number and other information;

[0043] 4.2.3 Laying: Determine the laying reference edge according to the instruction, based on the tooling line or laser projection. After aligning the reference edge, gradually lay the pieces from the reference edge to the other side of the cut piece. Pay attention to laying flat. It is recommended to roll along the fiber direction to facilitate the removal of bubbles and compact the prepreg. For shorter parts (less than 1m), the unidirectional cloth laying angle deviation is ±3°; the fabric laying angle deviation is ±5°. If the part is longer (greater than 1m), the angle control deviation is larger, and the process should be strictly controlled by the linear dimension of ±1°; the fabric laying direction tolerance is ±5°, and the ply boundary position tolerance is ±3mm. If wrinkles appear at the corner of the reinforcement nest, the ply is allowed to be cut, but each layer of cloth should not be cut at the same place, and should be staggered as much as possible by 15mm-30mm. When the cloth turns outward from the inner turn, there may be a lack of cloth, forming a V-shaped cut, then the cloth in the same direction should be cut and laid, with an overlap width of 15mm-25mm. The film boundary size exceeds the honeycomb boundary size by 0-10 mm.

[0044] 4.3 Pre-compaction: Tear off the protective paper tape on the tooling, make a vacuum bag for pre-compaction, and pre-compact after the first layer is laid. The pressure in the vacuum bag is kept below -0.085Mpa, and the pre-compaction time is more than 5 minutes.

[0045] Pre-compacting is carried out after every 3 to 5 layers are completely laid, the pressure in the vacuum bag is maintained below -0.085Mpa, and the pre-compacting time is more than 5 minutes.

[0046] 4.4 Laying of the remaining layers: Continue laying the remaining layers in the same manner as above.

[0047] Step 5: Bag Making

[0048] 5.1 Cleaning of the sealing putty strip area: Tear off the protective paper tape pasted on the sealing putty strip area, and wipe the sealing putty strip bonding area with a clean rag;

[0049] 5.2 Paste the sealing putty strip: Paste the sealing putty strip around the tooling (the bonding area of ​​the sealing putty strip is outside the part margin line, and there should be no through holes that penetrate the tooling surface in the sealing area;

[0050] 5.3 Laying the isolation film: Cut the isolation film for bag making according to the isolation film cutting size in the material preparation page, and then fix the isolation film on the tooling with a small piece of putty or pressure-sensitive tape, and fix it with blue tape;

[0051] 5.4 Arrange the surface breathable felt: cut the breathable felt according to the size of the breathable felt in the material preparation page, lay the breathable felt flat on the surface of the part, cover the surface of the isolation film (at least 25mm larger than the isolation film area, and can extend to the edge of the sealing putty strip), and arrange the shape of the part to prevent bridging. If necessary, fix it with pressure-sensitive tape to prevent movement;

[0052] 5.5 Arrange the vacuum nozzle: collect the vacuum nozzle, wipe the vacuum nozzle with a clean rag dipped in machine solvent outside the cleaning room, fix the vacuum nozzle with single-sided pressure-sensitive tape to prevent the vacuum nozzle from falling sideways during vacuuming, and the pressure-sensitive tape should be pasted around the base of the vacuum nozzle to prevent local bridging and bag explosion. Wrap a circle of sealing putty strips around the wrapped vacuum nozzle to prevent air leakage;

[0053] 5.6 Vacuum bag sealing: Cut the vacuum bag according to the vacuum bag cutting size on the material preparation page. When using scissors to cut the vacuum bag, avoid puncturing the vacuum bag with the blade or the tip of the knife to cause air leakage. Use scissors to open a small hole of φ5-8mm in the vacuum bag at the vacuum nozzle position, expose the vacuum nozzle to the vacuum bag, and evacuate the vacuum bag until the vacuum bag is in a tidy state. Use sealing putty strips to seal around the vacuum nozzle to avoid air leakage. Do not wear sharp objects during packaging. After tightening the vacuum bag, insert a vacuum gauge on the vacuum nozzle to ensure that the vacuum gauge is not blocked. Use demoulding cloth or sealing putty strips to stick the excess bag to avoid the vacuum bag from lifting up during curing.

[0054] Step 6: Curing the Parts

[0055] Put the mold into the autoclave, evacuate to -0.09MPa, test the vacuum leakage, and require that the drop value should not exceed 0.017MPa within 5 minutes. Close the tank after passing the test; evacuate above -0.09MPa, and start heating to 93±5℃ at a rate of 0.5-4℃ / min, and the air temperature should not exceed 98℃; at the same time, increase the pressure to 340-400KPa at a rate of 27KPa / min, and when the pressure reaches 100KPa, close the vacuum. When the temperature reaches 93±5℃, keep it for 30-60 minutes (usually 45 minutes). Continue to increase the pressure to 480-510KPa at a rate of 27KPa / min, and at the same time, increase the temperature to 177±5℃ at a rate of 0.5-4℃ / min, and the air temperature should not exceed 182℃, and keep it for 120-360 minutes (usually 180 minutes). Evacuate at least -0.08MPa. Reduce the pressure to 300KPa and cool to below 60℃ at a rate of no more than 4℃ / min. When the temperature is below 60℃, release the pressure in the tank.

[0056] Step 7: Demolding

[0057] After the temperature of the bag removal tooling drops below 60°C, cut off the vacuum nozzle, remove the bag, tighten the hexagonal screws to remove the module, lift the reinforcing nest, and achieve demoulding.

[0058] Step 8: Cutting Edges

[0059] Draw lines according to the cutting lines of the parts, use a pneumatic cutting machine to make rough cuts according to the drawn lines, leave a 0.5-1mm margin relative to the cutting line or drawn line, use a grinder to repair the edge burrs and the remaining margin, then use 400# sandpaper to gently grind off the burrs around the edges and grind off the remaining margin.

[0060] In other embodiments of this application, please refer to 1. Figure 2 and Figure 3 The present application provides a demoulding device for a composite material reinforcement socket, which is composed of a demoulding module 1 and an external hexagonal screw 2.

[0061] The prepreg is spread all over the demolding module. After the part is solidified, the hexagonal screw is tightened on the demolding module, and the demolding module is lifted upwards with force. The demolding module drives the part to be separated from the molding tool 3 to achieve demolding. After demolding, the demolding module and the excess carbon fiber are cut off along the product score line.

[0062] Furthermore, the thickness of the prepreg laid over the stripping module is equal to the thickness of the flanging hole layer.

[0063] Furthermore, the length of the stripping module is L, the length of the flanging hole is L1, and L=L1+2

[0064] Furthermore, the height of the stripping module is H=10 mm.

[0065] Furthermore, the material of the de-module is Q235A.

[0066] Furthermore, the number of the external hexagonal screws is determined according to the size of the flanging hole.

[0067] The present invention provides a forming method and demoulding device for a composite material reinforcement socket, which has a simple structure, is verified by actual production pressure test, and is easy to demould, thereby solving the problem of product defects caused by demoulding of flanging holes in composite materials. The device is suitable for demoulding of flanging holes of different thicknesses and the same hole size, and can be used as a universal flanging hole demoulding tool to reduce tooling investment costs. In addition, the demoulding device for the composite material reinforcement socket has a low equipment cost and can be promoted for large-scale use.

Claims

1. A demoulding device for a composite material reinforced nest, characterized in that: The device comprises: De-module, which can separate the composite reinforcement nest from the forming tooling; An external hexagon screw is arranged on the stripping module; wherein, when a pulling force is applied to the external hexagon screw, the stripping module is detached from the molding tool with the composite material reinforcement nest.

2. The device according to claim 1, characterized in that The stripping module is adapted to the shape of the composite material reinforcement socket.

3. The device according to claim 2, characterized in that A preset gap is provided between the end surface of the stripping module and the flange of the composite material reinforcement nest; the end surface of the stripping module is connected to the composite material reinforcement nest through prepreg; The preset gap is used for cutting the prepreg at a later stage.

4. The device according to claim 3, characterized in that The thickness of the stripping module is greater than the lowermost end of the flange of the composite material reinforcement socket.

5. A method for forming a composite material reinforced nest, characterized in that: The method comprises: Parts curing; After the temperature of the bag removal tooling drops below 60°C, cut off the vacuum nozzle, remove the bag, tighten the hexagonal screws to remove the module, lift the reinforcing nest, and achieve demoulding.

6. The method according to claim 5, characterized in that The part curing comprises: Put the mold into the autoclave, evacuate to -0.09MPa, test the vacuum leakage, and require the drop value to be no more than 0.017MPa within 5 minutes. Close the autoclave after passing the test; Vacuum - above 0.09MPa, start heating to 93±5℃ at a rate of 0.5-4℃ / min, the air temperature should not exceed 98℃; at the same time, increase the pressure to 340-400KPa at a rate of 27KPa / min, and close the vacuum when the pressure reaches 100KPa; When the temperature reaches 93±5℃, maintain it for 30-60 minutes, and continue to increase the pressure to 480-510KPa at a rate of 27KPa / min; at the same time, increase the temperature to 177±5℃ at a rate of 0.5-4℃ / min, and the air temperature cannot exceed 182℃, and maintain it for 120-360 minutes; Evacuate to at least -0.08MPa, reduce the pressure to 300KPa, and at the same time cool down to below 60℃ at a rate not exceeding 4℃ / min; when the temperature is below 60℃, release the pressure in the tank.

7. The method according to claim 5, characterized in that The method further comprises: Draw lines according to the cutting lines of the parts, use a pneumatic cutting machine to make rough cuts according to the drawn lines, leave a 0.5-1mm margin relative to the cutting line or drawn line, use a grinder to repair the edge burrs and the remaining margin, then use 400# sandpaper to gently grind off the burrs around the edges and grind off the remaining margin.

8. The method according to claim 5, characterized in that Before the parts are solidified, the steps include: layering and bag making.

Images