Composite material storage box forming mold and manufacturing method thereof

Abstract

The invention discloses a composite material storage box forming mold and a manufacturing method thereof, and belongs to the technical field of composite material forming molds. An end socket connecting block, an end socket cylinder section connecting ring, a split type cylinder body assembly, a cap-shaped reinforcing rib and the like are manufactured in parallel and assembled to obtain the composite material storage box forming mold. The self-weight of the mold is greatly reduced while the outer molded surface of the combined mold is guaranteed, the mold filling and demolding processes are simplified, the end socket is left in the product after the product is formed, the strength and rigidity of the storage box are improved, and a stable connecting port can be provided.

Description

Technical Field

[0001] The invention relates to a composite material tank forming mould and a manufacturing method thereof, belonging to the technical field of composite material forming moulds. Background Art

[0002] Resin-based composite materials are increasingly used in aviation, aerospace and other fields due to their low density, high specific strength and modulus, and good fatigue resistance. Pressure vessels are indispensable energy storage systems in vehicles such as aircraft and new energy vehicles. In pursuit of extreme lightweight, the use of composite materials has gradually increased. Traditional composite pressure vessels use metal or plastic linings to wrap or lay continuous fibers on the surface of the lining. After molding, the lining remains inside the container to act as a sealing layer. The latest concept of Type V pressure vessels is to achieve extreme weight reduction and eliminate the obvious lining layer, which directly allows continuous fiber composite materials to bear the load and have a sealing effect. This brings huge challenges to the laying, molding, demolding, and sealing assembly of fiber-reinforced composite materials. The commonly used soluble core mold is too heavy when facing the large size of the molding tank, and its own deformation control is difficult to guarantee. Traditional metal material molding molds also face difficulties such as heavy weight, complex assembly, and thermal expansion mismatch. Summary of the invention

[0003] The purpose of the present invention is to provide a molding die suitable for a continuous fiber reinforced resin-based composite tank and a manufacturing method thereof. The molding die is assembled and disassembled through structures such as a barrel, a head, and a connecting ring. While ensuring the overall mold rigidity, the mold's own weight is greatly reduced, the mold assembly difficulty and operation risks are reduced, and the molding efficiency of the composite tank is improved.

[0004] To achieve the above purpose, the technical solution adopted by the present invention is as follows:

[0005] A composite material tank forming die, comprising a large end head connection block, a split-flap barrel assembly, a small end head connection block, a flange connection block, a large end head barrel section connection ring, a small end head barrel section connection ring and a hat-shaped reinforcing rib;

[0006] The flange connection blocks are located at both ends of the forming mold;

[0007] The outer edge of the large end head connection block is connected to the large end head barrel section connection ring, and the inner edge is connected to the flange connection block, together forming a forming support for the large end head area of ​​the tank;

[0008] The outer edge of the small end head connection block is connected to the small end head barrel section connection ring, and the inner edge is connected to the flange connection block, together forming a forming support for the small end head area of ​​the tank;

[0009] The split-type barrel assembly is composed of several blocks. The blocks are thin-skinned long strips with hat-shaped reinforcement ribs inside along the length of the tank. The split-type barrel assembly is located between the large head barrel section connecting ring and the small head barrel section connecting ring. The head end of each block of the split-type barrel assembly is connected to the large head barrel section connecting ring, and the tail end is connected to the small head barrel section connecting ring.

[0010] Preferably, the storage tank may be a cylindrical body structure or a body structure with a conical angle.

[0011] Preferably, a support plate nut is provided on the outer side of the large head barrel section connecting ring, and the various blocks of the split barrel assembly are mechanically connected in sequence by screws, and a draft angle is left in the connecting area.

[0012] Preferably, a support plate nut is provided on the outer side of the small head barrel section connecting ring, and the various blocks of the split barrel body assembly are mechanically connected in sequence by screws, and a draft angle is left in the connecting area.

[0013] Preferably, each segment of the split barrel assembly is provided with connecting flanges around it, and through holes and support plate nuts are sequentially provided on the flanges to connect adjacent segments and the large head barrel section connecting ring and the small head barrel section connecting ring.

[0014] Preferably, the main material of the molding mold is a fiber-reinforced resin-based composite material, the fiber is continuous carbon fiber, and the resin is a high-temperature curing epoxy resin or bismaleimide resin; wherein the component materials of the cap-shaped reinforcement ribs are a carbon fiber composite material skin and a PMI foam core.

[0015] A method for manufacturing a composite material tank forming mold comprises the following steps:

[0016] 1) Using a metal negative mold, the unidirectional prepreg is laid in the order of plying to the corresponding position of the metal negative mold surface, after vacuum bag packaging, it is cured and formed in an autoclave, and after demoulding, the surface of the bonding area between it and the large and small head barrel section connection rings is machined to obtain the large end head connection block and the small end head connection block respectively;

[0017] 2) Using a metal female mold, the unidirectional prepreg is laid in the order of plying to the corresponding position of the mold surface, after vacuum bag packaging, it is cured and formed in an autoclave, and after demoulding, the block blank of the split-flange barrel assembly is obtained, and the inner surface is polished to roughness with sandpaper, cleaned and set aside;

[0018] 3) Fixing the block blank on the mold, laying a film on the surface where it fits with the hat-shaped reinforcement rib, placing the foam sandwich core machined into a corresponding shape at the corresponding position, laying unidirectional prepreg on its surface according to the plying order, vacuum bagging the whole, curing and molding in an autoclave, demoulding and reshaping to obtain the petal-type barrel assembly block with the hat-shaped reinforcement rib;

[0019] 4) Punch the obtained blocks with the support plate nut installation holes and the screw installation holes respectively, install the support plate nuts at the corresponding positions, and mechanically connect all the blocks together by screws in sequence according to the assembly sequence to form a split-flap barrel assembly;

[0020] 5) Using a metal male mold, the unidirectional prepreg is laid in the order of plying to the corresponding position of the mold surface, after vacuum bag packaging, it is cured and formed in an autoclave, and after demoulding, the surface of the bonding area between it and the large and small end head connection blocks is machined to obtain a large end head barrel section connection ring and a small end head barrel section connection ring, which are respectively fixed to the corresponding positions of the assembled split-flap barrel assembly, and screw holes and support plate nut installation holes are punched, and the large and small end head barrel section connection rings are removed, and the corresponding support plate nuts are installed;

[0021] 6) Clean the fitting surfaces of the large and small head barrel section connecting rings and the large and small end head connecting blocks, apply paste glue, bond the large head barrel section connecting ring to the large end head connecting block, and bond the small head barrel section connecting ring to the small end head connecting block, fillet and seal the corner area, and let it stand at room temperature to solidify;

[0022] 7) Fix the split-type barrel assembly with a bracket, fix the cured large and small end head connection blocks on the large and small ends of the split-type barrel assembly respectively, and connect the split-type barrel assembly with the large and small end head barrel section connection rings with screws;

[0023] 8) The metal flange connection block is installed at the corresponding positions of the large and small end head connection blocks by screws to obtain the composite material tank forming mold.

[0024] Preferably, the plying form in step 1) is (0 / +45 / 90 / -45 / -45 / 90 / +45 / 0) n , where n is a positive integer according to the shape and requirements of the tank product.

[0025] Preferably, in step 2), the plying pattern of the segments of the split barrel assembly is (0 / +45 / 0 / -45 / 90 / -45 / 0 / +45 / 0) n , where n is a positive integer according to the shape and requirements of the tank product.

[0026] Preferably, in step 3), the foam is PMI foam with a compressive strength greater than 2.2 MPa, and the prepreg is alternately laid at 0° and ±45°, wherein the proportion of 0° is not less than 60%.

[0027] Preferably, in step 4), appropriate screws and support plate nuts should be selected according to the size of the product and should comply with aviation industry standards.

[0028] Preferably, in step 4), the gap between the petal-type barrel assembly after assembly should be less than 0.1 mm, and the step difference between the petal-type barrel assembly should be less than 0.1 mm.

[0029] Preferably, in step 5), the plying form of the large and small end cap barrel section connecting rings is (0 / +45 / 90 / -45 / -45 / 90 / +45 / 0) n Where n is a positive integer according to the shape and requirements of the tank product, and the tolerance range of the fitting surface after machining should be controlled within the range of (-0.3, -0.1) mm.

[0030] Preferably, in step 6), a room temperature curing paste structural adhesive is selected for bonding, the thickness of the adhesive layer is 0.1 to 0.2 mm, and the room temperature curing time is not less than 24 hours.

[0031] Preferably, in step 7), the gap between the split barrel assembly and the large and small end head connection blocks after assembly should be no more than 0.1 mm, the large and small end head connection blocks should be no higher than the split barrel assembly, and the sinking depth should be within the range of (-0.5, 0) mm.

[0032] The beneficial effects of the present invention compared with the prior art are as follows:

[0033] (1) The molding mold of the present invention adopts carbon fiber reinforced resin-based composite materials, which greatly reduces the overall weight. Compared with traditional metal molds, the bending deformation caused by its own weight is smaller. This can not only reduce the difficulty of mold installation and demoulding, but also greatly reduce the danger of operation.

[0034] (2) Compared with the soluble core mold, the molding mold of the present invention has the advantage of being reusable. After the molding is completed, no excess material remains when the mold is disassembled, and the mold structure is simple, the molding surface precision is high, and the manufacturing cost is low. In addition, the block structure of the mold split-flange barrel assembly includes a hat-shaped reinforcement rib along the axial direction, which effectively enhances the structural rigidity with less weight increase.

[0035] (3) The thermal expansion coefficient of the mold of the present invention is very small compared with the composite material to be molded, and the size of the composite material tank can be accurately controlled. The connection and assembly of the mold petal block and the core mold do not rely on metal connecting rods, but are all connected and supported by the head barrel section connecting ring and the head connecting block, which reduces the number of mold parts and facilitates the guarantee of surface accuracy.

[0036] (4) The shaft size of the molding die used in the process of laying or winding is smaller, and the bending deformation caused by the die itself is extremely small and almost negligible. This is more friendly to the chuck and transmission system of the winding machine and laying machine, and significantly extends their service life.

[0037] (5) If the molding die of the present invention is partially damaged, it can be easily dismantled and replaced, and the replacement component can be quickly manufactured using the original metal mold, thereby improving production efficiency.

[0038] (6) After the mold of the present invention is formed, the head connection block and the head barrel section connection ring will remain inside the product and do not need to be removed. They not only serve as a head reinforcement structure, but also provide a stable connection interface for subsequent internal anti-sway plates and other equipment of the tank, reducing the need for secondary bonding or mechanical connection. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 It is an overall schematic diagram of a composite material tank forming mold of the present invention.

[0040] Figure 2 It is a partial assembly schematic diagram of a composite material tank forming mold of the present invention.

[0041] Figure 3 The present invention is a block schematic diagram of a split-flap barrel assembly in a composite material tank forming mold.

[0042] Figure 4 The present invention is a schematic overall cross-sectional view of a composite material tank forming die. DETAILED DESCRIPTION

[0043] In order to make the various technical features and advantages or technical effects in the above technical solutions of the present invention more obvious and easy to understand, they are described in detail below in conjunction with embodiments.

[0044] The present invention provides a composite material tank forming die. The composite material tank can be a cylindrical barrel structure or a barrel structure with a conical angle. Figure 1-4 Taking the example shown, the molding mold includes a large end head connection block 1, a split barrel assembly 2, a small end head connection block 3, a flange connection block 4, a large head barrel section connection ring 5, a small head barrel section connection ring 6, a hat-shaped reinforcement rib 7 and connecting fasteners.

[0045] The large end head connection block 1 is used to connect the large end head barrel section connection ring 5 and the flange connection block 4, together forming the forming support of the large end head area of ​​the tank. The opening size of the large end head connection block 1 must be larger than the cross-sectional area of ​​the largest block in the split-flap barrel assembly 2, and the large end head connection block must ensure its own airtightness. After the product is formed, the large end head connection block remains in the product as a part of the product head to play a reinforcing role.

[0046] The split barrel assembly 2 is composed of several blocks, each block is a thin-skinned long strip, and there are hat-shaped reinforcement ribs 7 inside along the length direction of the tank. Each block is provided with connecting flanges around it, and through holes and support plate nuts are sequentially arranged on the flanges to connect adjacent blocks and the large head barrel section connecting ring 5 and the small head barrel section connecting ring 4. The principle of the block division of the split barrel assembly 2 is to divide the cross-sectional circle along the length direction in the radial direction evenly, and the number of blocks is as small as possible, but it is necessary to ensure that the cross-sectional area of ​​the largest block is smaller than the opening size of the large end head connecting block. Among them, one block needs to be demolded centripetally along the radial direction first, and its two side flanges have positive draft angles, and the remaining blocks are adjacent flange designs that are pressed in sequence.

[0047] The small end head connection block 3 is used to connect the small end head barrel section connection ring 6 and the flange connection block 4, together forming the forming support of the small end head area of ​​the tank. The small end head connection block must ensure its own airtightness. After the product is formed, the small end head connection block remains in the product as a part of the product head to play a reinforcing role.

[0048] The flange connection blocks 4 are located at both ends of the mold and are used to connect the large end head connection block 1 and the small end head connection block 3 with the transmission system such as the rotating rod or the support rod during wire laying or winding. After the tank is formed, it can also be connected to the cover or conversion joint and other devices.

[0049] The large head barrel section connecting ring 5 is a circular ring with a cross-section similar to an "L" shape. It is used to connect the large end head connecting block 1 and the various blocks of the split barrel assembly 2. A support plate nut is arranged on the outside thereof, and the various blocks of the split barrel assembly are mechanically connected in sequence by screws. A draft angle of about 2 to 5° is left in the connecting area, which can enable the blocks of the split barrel assembly 2 to be demolded centripetally.

[0050] The small head barrel section connecting ring 6 is a circular ring with a cross-section similar to an "L" shape. It is used to connect the small end head connecting block 3 and the various blocks of the split barrel assembly 2. A support plate nut is arranged on the outside thereof, and the various blocks of the split barrel assembly are mechanically connected in sequence by screws. A draft angle of about 2 to 5° is left in the connecting area, which can enable the blocks of the split barrel assembly 2 to be demolded centripetally.

[0051] The main material of the forming mold is a fiber-reinforced resin-based composite material, the fiber is continuous carbon fiber, and the resin is a high-temperature curing epoxy resin or bismaleimide resin. The hat-shaped reinforcement rib 7 is a reinforcement structure of the blocks in the split-type barrel assembly 2, which is composed of a carbon fiber composite material skin and a PMI foam sandwich, which increases the axial strength and rigidity of the blocks of the split-type barrel assembly.

[0052] The present invention also provides a method for manufacturing a composite material tank forming mold, which comprises the following steps:

[0053] 1. Molding of large end cap connection block 1 and small end cap connection block 3: Use a metal female mold to lay the unidirectional prepreg in the form of (0 / +45 / 90 / -45 / -45 / 90 / +45 / 0) n (where n is a positive integer according to the shape and requirements of the tank product) is laid in sequence to the corresponding positions of the metal negative model surface, packaged in a vacuum bag, and solidified in an autoclave. After demoulding, a machining center is used to machine the surface of the fitting area between it and the large and small head barrel section connecting rings 5 ​​and 6 to obtain the large end head connecting block 1 and the small end head connecting block 3 respectively.

[0054] 2. Block molding of the split barrel assembly 2: Use a metal female mold to mold the unidirectional prepreg according to (0 / +45 / 0 / -45 / 90 / -45 / 0 / +45 / 0) n The layers are laid in the order of (where n is a positive integer according to the shape and requirements of the tank product) to the corresponding positions of the mold surface, packaged in a vacuum bag, and solidified in an autoclave. After demoulding, the block blanks are obtained. The inner surface is polished to roughness with sandpaper, cleaned and set aside.

[0055] 3. Forming of the hat-shaped reinforcement rib 7: Fix the block blank in step 2 on the mold, lay a film on the surface where it fits with the hat-shaped reinforcement rib, place the foam core machined into the corresponding shape in the corresponding position, and choose PMI foam with a compressive strength greater than 2.2MPa. Lay unidirectional prepreg on its surface in the order of plying, wherein the prepreg is selected to be laid alternately at 0° and ±45°, of which 0° accounts for no less than 60%. The whole is packaged in a vacuum bag, cured and formed in an autoclave, and after demolding and shaping, a split-flap barrel assembly block with a hat-shaped reinforcement rib 7 is obtained.

[0056] 4. According to steps 2 and 3, all the required blocks of the split barrel assembly 2 and the hat-shaped reinforcement ribs 7 are formed and set aside.

[0057] 5. Assemble the split barrel assembly 2 in blocks: punch the support plate nut mounting holes and screw mounting holes on the blocks formed in step 4 respectively, select appropriate screws and support plate nuts according to the size of the product, which should comply with aviation industry standards, install the support plate nuts in the corresponding positions, and mechanically connect all the blocks together with screws in accordance with the assembly sequence to form the split barrel assembly 2. The gap between the split barrel assembly 2 blocks after assembly should be less than 0.1mm, and the step difference between the blocks should be less than 0.1mm.

[0058] 6. Forming of the large end-end barrel section connecting ring 5 and the small end-end barrel section connecting ring 6: Use a metal male mold to mold the unidirectional prepreg according to (0 / +45 / 90 / -45 / -45 / 90 / +45 / 0) n(where n is a positive integer according to the shape and requirements of the tank product) is laid in sequence to the corresponding positions of the mold surface, packaged in a vacuum bag, and cured in an autoclave. After demoulding, a machining center is used to machine the surface of the fitting area between it and the large and small end head connecting blocks 1 and 3. The tolerance range of the fitting surface after machining should be controlled within (-0.3, -0.1) mm. The large head barrel section connecting ring 5 and the small head barrel section connecting ring 6 are obtained respectively, and they are fixed to the corresponding positions of the split barrel body assembly 2 assembled in step 5, and screw holes and support plate nut mounting holes are punched out. The large head barrel section connecting ring 5 and the small head barrel section connecting ring 6 are removed, and the corresponding support plate nuts are installed.

[0059] 7. Bond the large head barrel section connecting ring 5 to the large end head connecting block 1, and the small head barrel section connecting ring 6 to the small end head connecting block 3: clean the fitting surfaces of the large and small head barrel section connecting rings 5, 6 and the large and small end head connecting blocks 1, 3, apply paste glue, and bond the large head barrel section connecting ring 5 to the large end head connecting block 1, and the small head barrel section connecting ring 6 to the small end head connecting block 3 respectively. Select room temperature curing paste structural glue with a glue layer thickness of 0.1 to 0.2 mm, fillet and seal the corner area, and let it stand at room temperature for curing for not less than 24 hours.

[0060] 8. Assemble the split barrel assembly 2 with the large end head connection block 1 and the small end head connection block 3: fix the split barrel assembly 2 assembled in step 5 with a bracket, fix the large end head connection block 1 and the small end head connection block 3 cured in step 7 to the large and small ends of the split barrel assembly 2 respectively, use screws to connect the split barrel assembly 2 with the large head barrel section connecting ring 5 and the small head barrel section connecting ring 6, the gap between the split barrel assembly 2 and the large end head connection block 1 and the small end head connection block 3 after assembly should be no more than 0.1mm, the large end head connection block 1 and the small end head connection block 3 should not be higher than the split barrel assembly 2, and the sinking depth is (-0.5,0)mm.

[0061] 9. Install the flange connection block 4: install the metal flange connection block 4 at the corresponding positions of the large end head connection block 1 and the small end head connection block 3 by screws, and install it as a whole at the corresponding position of the winding machine or the automatic wire laying machine transmission device to obtain a composite material molding mold.

[0062] A specific embodiment is provided below:

[0063] Example 1

[0064] The present embodiment specifically discloses a composite material tank forming mold, wherein the split barrel assembly 2 of the mold has a barrel section length of 2m, a large end head connection block 1 has a diameter of 1.2m, a small end head connection block 3 has a diameter of 1m, a barrel cone angle of 2.86°, a manhole inner diameter of 440mm for the large end head connection block 1, a manhole inner diameter of 304mm for the small end head connection block 3, an elliptical head curve, a split block wall thickness of 3mm for the split barrel assembly 2, a large end head connection block 1 has a wall thickness of 2mm, a small end head connection block 1 has a wall thickness of 2mm, a large head barrel section connection ring 5 has a wall thickness of 2mm, a lap side chord length of 86mm, a connection side length of 50mm, a small head barrel section connection ring 6 has a wall thickness of 2mm, a lap side chord length of 86mm, a connection side length of 50mm, a cap-shaped stiffener 7 has a skin thickness of 1.5mm, and the foam has a density of 110kg / m 3 PMI foam, compressive strength 3.2MPa.

[0065] Except for the flange connection block 4 which is made of aluminum alloy and the hat-shaped reinforcement rib 7 which is made of PMI foam, the rest of the molding die materials are T700 grade carbon fiber reinforced high temperature epoxy resin composite materials.

[0066] The big end head connection block 1 is used to connect the big end head barrel section connection ring 5 and the flange connection block 4, together forming a forming support for the big end head area of ​​the tank. The big end head connection block 1 has an opening inner diameter of 440 mm, which is larger than the cross-sectional size of the largest block in the petal-type barrel assembly 2. The big end head connection block 1 is bagged and evacuated to -0.09 MPa, and the pressure drop does not exceed 5 kPa within 10 minutes, meeting the airtightness requirements.

[0067] The split barrel assembly 2 is composed of 9 blocks, each block is a thin-skinned long strip, and there are hat-shaped reinforcement ribs 7 inside along the length of the tank. Each block is provided with connecting flanges around it, and through holes and support plate nuts are sequentially arranged on the flanges to connect adjacent blocks and the large head barrel section connecting ring 5 and the small head barrel section connecting ring 4. The maximum block cross-sectional size of the split barrel assembly 2 is 424mm, which is smaller than the opening size of the large end head connecting block 1. It can be demolded centripetally along the radial direction first, and its two side flanges have a positive draft angle of 10°. The remaining blocks are adjacent flange designs that are pressed in sequence.

[0068] The small end head connection block 3 is used to connect the small end head barrel section connection ring 6 and the flange connection block 4, together forming a forming support for the small end head area of ​​the tank. The small end head connection block 3 is bagged and evacuated to -0.09MPa, and the pressure drop does not exceed 5kPa within 10 minutes, meeting the airtightness requirements.

[0069] The flange connection blocks 4 are located at both ends of the mold and are used to connect the large end head connection block 1 and the small end head connection block 3 with the transmission system such as the rotating rod or the support rod during automatic wire laying. The cover and the conversion joint can be connected after the tank is formed.

[0070] The large head barrel section connecting ring 5 is a circular ring with a cross-section similar to an "L" shape. It is used to connect the large end head connecting block 1 and the various blocks of the split barrel assembly 2. A support plate nut is arranged on the outside thereof, and the various blocks of the split barrel assembly are mechanically connected in sequence by screws. A 3° draft angle is left in the connecting area, which can enable the blocks of the split barrel assembly 2 to be demoulded centripetally.

[0071] The small head barrel section connecting ring 6 is a circular ring with a cross-section similar to an "L" shape. It is used to connect the small end head connecting block 3 and the various blocks of the split barrel assembly 2. A support plate nut is arranged on the outside thereof, and the various blocks of the split barrel assembly are mechanically connected in sequence by screws. A 3° draft angle is left in the connecting area, which can enable the blocks of the split barrel assembly 2 to be demoulded centripetally.

[0072] The hat-shaped reinforcement rib 7 is a block reinforcement structure in the split barrel assembly 2, and is composed of a T700 grade carbon fiber reinforced high temperature epoxy resin composite material skin and a PMI foam core.

[0073] This embodiment also discloses a method for manufacturing a composite material tank forming mold, comprising the following steps:

[0074] 1. Molding of large end cap connection block 1 and small end cap connection block 3: Both adopt metal female molds, lay the unidirectional prepreg in the form of (0 / +45 / 90 / -45 / -45 / 90 / +45 / 0) 3 The layers are laid in the order of layers, and are laid to the corresponding positions of the metal negative model surface in sequence. After vacuum bag packaging, they are cured and formed in an autoclave at 0.6MPa. After demoulding, a five-axis machining center is used to machine the surface of the fitting area between it and the head barrel section connecting ring to obtain the large end head connecting block 1 and the small end head connecting block 3 respectively.

[0075] 2. Block molding of the split barrel assembly 2: Use a metal female mold to mold the unidirectional prepreg according to (0 / +45 / 0 / -45 / 90 / -45 / 0 / +45 / 0) 2 The layers are laid in the corresponding position of the mold surface in sequence, packaged in a vacuum bag, and solidified in an autoclave at 0.6MPa. After demoulding, the divided blanks are obtained. Use 100-mesh sandpaper to grind the inner surface until it is rough, clean it and set it aside.

[0076] 3. Forming of the hat-shaped reinforcement rib 7: fix the block blank in step 2 on the mold, lay medium-temperature curing epoxy film on the contact surface between it and the hat-shaped reinforcement rib, place the foam core machined into the corresponding shape at the corresponding position, the foam is PMI foam with a compressive strength of 3.2MPa, and lay unidirectional prepreg on its surface in the laying order of [0 / +45 / 0 / 0 / -45 / 0 / 0 / -45 / 0 / 0 / +45 / 0], vacuum bag the whole package, and cure and shape it in an autoclave at 0.4MPa. After demolding and shaping, the petal-type barrel assembly block with the hat-shaped reinforcement rib 7 is obtained.

[0077] 4. According to steps 2 and 3, all the required blocks of the split barrel assembly 2 and the hat-shaped reinforcement ribs 7 are formed and set aside.

[0078] 5. Assemble the split barrel assembly 2 in blocks: punch the blocks formed in step 4 with M5 support plate nut mounting holes and screw mounting holes respectively, with a nail spacing of 25 mm. Install the support plate nuts in the corresponding positions. According to the assembly sequence, mechanically connect all the blocks together with M5 screws to form the split barrel assembly 2. The gap between the split barrel assembly 2 blocks after assembly is 0 to 0.08 mm, and the step difference between the blocks is less than 0.1 mm.

[0079] 6. Forming of the large end-end barrel section connecting ring 5 and the small end-end barrel section connecting ring 6: Use a metal male mold to mold the unidirectional prepreg according to (0 / +45 / 90 / -45 / -45 / 90 / +45 / 0) 3 The layers are laid in sequence to the corresponding positions of the mold surface, packaged in a vacuum bag, and cured in an autoclave at 0.6MPa. After demoulding, a five-axis machining center is used to machine the surface of the fitting area between it and the large and small end head connecting blocks. The tolerance of the fitting surface after machining is (-0.25, -0.1) mm. The large head barrel section connecting ring 5 and the small head barrel section connecting ring 6 are obtained respectively, and they are fixed to the corresponding positions of the split-flap barrel assembly 2 assembled in step 5, and M5 screw holes and support plate nut mounting holes are punched. The large head barrel section connecting ring 5 and the small head barrel section connecting ring 6 are removed, and the corresponding support plate nuts are installed.

[0080] 7. Bond the large head barrel section connecting ring 5 to the large end head connecting block 1, and the small head barrel section connecting ring 6 to the small end head connecting block 3: Clean the fitting surfaces of the head barrel section connecting ring and the large and small end head connecting blocks, apply room temperature curing epoxy paste glue, and bond the large head barrel section connecting ring 5 to the large end head connecting block 1, and the small head barrel section connecting ring 6 to the small end head connecting block 3 respectively. The thickness of the glue layer should be controlled at 0.1-0.2mm, fillet and seal the corner area, and let it stand at room temperature for curing for 48 hours.

[0081] 8. Assemble the split barrel assembly 2 with the large end head connection block 1 and the small end head connection block 3: fix the split barrel assembly 2 assembled in step 5 with a bracket, fix the large end head connection block 1 and the small end head connection block 3 cured in step 7 to the large and small ends of the split barrel assembly 2 respectively, use M5 screws to connect the split barrel assembly 2 with the large head barrel section connecting ring 5 and the small head barrel section connecting ring 6, the gap between the split barrel assembly 2 and the large end head connection block 1 and the small end head connection block 3 after assembly is 0-0.08mm, and the sinking depth of the large end head connection block 1 and the small end head connection block 3 relative to the split barrel assembly 2 is (-0.5, -0.1)mm.

[0082] 9. Install the flange connection block 4: Install the metal flange connection block 4 at the corresponding positions of the large end head connection block 1 and the small end head connection block 3 through M8 screws, and install it as a whole at the corresponding position of the winding machine or the automatic wire laying machine transmission device to obtain a composite material molding mold.

[0083] Although the present invention has been disclosed as above by way of embodiments, it is not intended to limit the present invention. Appropriate modifications or equivalent substitutions of the technical solutions of the present invention made by ordinary technicians in the field should all be included in the protection scope of the present invention. The protection scope of the present invention shall be based on what is defined in the claims.

Claims

1. A composite material tank forming mold, characterized in that: It includes a large end head connection block, a split-flap barrel assembly, a small end head connection block, a flange connection block, a large end head barrel section connection ring, a small end head barrel section connection ring and a hat-shaped reinforcement rib; The flange connection blocks are located at both ends of the forming mold; The outer edge of the large end head connection block is connected to the large end head barrel section connection ring, and the inner edge is connected to the flange connection block, together forming a forming support for the large end head area of ​​the tank; The outer edge of the small end head connection block is connected to the small end head barrel section connection ring, and the inner edge is connected to the flange connection block, together forming a forming support for the small end head area of ​​the tank; The split-type barrel assembly is composed of several blocks. The blocks are thin-skinned long strips with hat-shaped reinforcement ribs inside along the length of the tank. The split-type barrel assembly is located between the large head barrel section connecting ring and the small head barrel section connecting ring. The head end of each block of the split-type barrel assembly is connected to the large head barrel section connecting ring, and the tail end is connected to the small head barrel section connecting ring.

2. The molding die according to claim 1, characterized in that: A support plate nut is provided on the outside of the large head barrel section connecting ring, and the various blocks of the split barrel body assembly are mechanically connected in sequence by screws, and a draft angle is left in the connection area; a support plate nut is provided on the outside of the small head barrel section connecting ring, and the various blocks of the split barrel body assembly are mechanically connected in sequence by screws, and a draft angle is left in the connection area.

3. The molding die according to claim 1, characterized in that: Each segment of the split barrel assembly is provided with connecting flanges around it, and through holes and support plate nuts are arranged in sequence on the flanges to connect adjacent segments and the large head barrel section connecting ring and the small head barrel section connecting ring.

4. The molding die according to claim 1, characterized in that: The main material of the molding mold is a fiber-reinforced resin-based composite material, the fiber is continuous carbon fiber, and the resin is a high-temperature curing epoxy resin or bismaleimide resin; the component materials of the cap-shaped reinforcement ribs are a carbon fiber composite material skin and a PMI foam core.

5. A method for manufacturing a composite material tank forming mold, characterized in that: The following steps are involved: 1) Using a metal negative mold, the unidirectional prepreg is laid in the order of plying to the corresponding position of the metal negative mold surface, after vacuum bag packaging, it is cured and formed in an autoclave, and after demoulding, the surface of the bonding area between it and the large and small head barrel section connection rings is machined to obtain the large end head connection block and the small end head connection block respectively; 2) Using a metal female mold, the unidirectional prepreg is laid in the order of plying to the corresponding position of the mold surface, after vacuum bag packaging, it is cured and formed in an autoclave, and after demoulding, the block blank of the split-flange barrel assembly is obtained, and the inner surface is polished to roughness with sandpaper, cleaned and set aside; 3) Fixing the block blank on the mold, laying a film on the surface where it fits with the hat-shaped reinforcement rib, placing the foam sandwich core machined into a corresponding shape at the corresponding position, laying unidirectional prepreg on its surface according to the plying order, vacuum bagging the whole, curing and molding in an autoclave, demoulding and reshaping to obtain the petal-type barrel assembly block with the hat-shaped reinforcement rib; 4) Punch the obtained blocks with the support plate nut installation holes and the screw installation holes respectively, install the support plate nuts at the corresponding positions, and mechanically connect all the blocks together by screws in sequence according to the assembly sequence to form a split-flap barrel assembly; 5) Using a metal male mold, the unidirectional prepreg is laid in the order of plying to the corresponding position of the mold surface, after vacuum bag packaging, it is cured and formed in an autoclave, and after demoulding, the surface of the bonding area between it and the large and small end head connection blocks is machined to obtain a large end head barrel section connection ring and a small end head barrel section connection ring, which are respectively fixed to the corresponding positions of the assembled split-flap barrel assembly, and screw holes and support plate nut installation holes are punched, and the large and small end head barrel section connection rings are removed, and the corresponding support plate nuts are installed; 6) Clean the fitting surfaces of the large and small head barrel section connecting rings and the large and small end head connecting blocks, apply paste glue, bond the large head barrel section connecting ring to the large end head connecting block, and bond the small head barrel section connecting ring to the small end head connecting block, fillet and seal the corner area, and let it stand at room temperature to solidify; 7) Fix the split-type barrel assembly with a bracket, fix the cured large and small end head connection blocks on the large and small ends of the split-type barrel assembly respectively, and connect the split-type barrel assembly with the large and small end head barrel section connection rings with screws; 8) The metal flange connection block is installed at the corresponding positions of the large and small end head connection blocks by screws to obtain the composite material tank forming mold.

6. The manufacturing method according to claim 5, characterized in that: The ply pattern in step 1) is (0 / +45 / 90 / -45 / -45 / 90 / +45 / 0) n , where n is a positive integer according to the shape and requirements of the tank product; In step 2), the ply pattern of the split barrel assembly is (0 / +45 / 0 / -45 / 90 / -45 / 0 / +45 / 0) n , where n is a positive integer according to the shape and requirements of the tank product; Step 5) The layup form of the connecting rings of the medium, large and small head tube sections is (0 / +45 / 90 / -45 / -45 / 90 / +45 / 0) n Where n is a positive integer according to the shape and requirements of the tank product, and the tolerance range of the fitting surface after machining is controlled within the range of (-0.3, -0.1) mm.

7. The manufacturing method according to claim 5, characterized in that: In step 3), the foam is PMI foam with a compressive strength greater than 2.2 MPa, and the prepreg is alternately laid at 0° and ±45°, with 0° accounting for no less than 60%.

8. The manufacturing method according to claim 5, characterized in that: In step 4), the gap between the petal-type barrel assembly after the blocks are assembled is less than 0.1 mm, and the step difference between the blocks is less than 0.1 mm.

9. The manufacturing method according to claim 5, characterized in that: In step 6), a room temperature curing paste structural adhesive is selected for bonding, the thickness of the adhesive layer is 0.1 to 0.2 mm, and the room temperature curing time is not less than 24 hours.

10. The manufacturing method according to claim 5, characterized in that: In step 7), the gap between the split barrel assembly and the large and small end head connection blocks after assembly is no more than 0.1 mm, the large and small end head connection blocks are no higher than the split barrel assembly, and the sinking depth is within the range of (-0.5, 0) mm.

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