Vacuum composite material mold pressing injection molding co-curing process method and mold

Abstract

The invention provides a vacuum composite material mold pressing, injection molding and co-curing process method and a mold, and multiple procedures including vacuum mold pressing, injection molding and high-temperature and high-pressure co-curing in manufacturing of carbon fiber composite material parts can be completed only by using one set of mold. The defects that in the prior art, stations, die tools and temperature and pressure environments need to be repeatedly replaced among different working procedures are overcome, the machining precision is improved through the continuous forming process, and the temperature and pressure conditions in the process are easier to control. In cooperation with existing automatic equipment such as automatic composite material paving, vacuum adsorption tools and multi-axis numerical control milling, the production efficiency of such products can be greatly improved, and the labor and equipment cost is effectively reduced, so that the capacity requirement of high-performance vehicle parts is met.

Description

Technical Field

[0001] The invention belongs to the technical field of carbon fiber composite material automobile parts processing, and specifically relates to a vacuum composite material compression molding co-curing process method and a mold. Background Art

[0002] At present, driven by the continuous improvement of the automotive industry's requirements for lightweight indicators and the trend of high-performance models from different manufacturers being launched one after another, carbon fiber composite materials are increasingly used in the manufacture of automotive parts due to their many advantages such as excellent lightness, high strength and stiffness, good weather resistance and corrosion resistance. Combining them with steel or aluminum alloy materials can achieve a better balance between the strength and lightness of the body. The existing automotive parts processing technology using carbon fiber composites requires a lot of manpower in multiple processes such as paving, vacuum compaction, curing, finishing and polishing, resulting in serious low production efficiency and production capacity that cannot meet actual needs. In addition, in the existing process, the composite material pressing and injection molding processes still need to be carried out separately, and the molds and workstations need to be replaced and the temperature and pressure of each process need to be adjusted separately. After repeated heating and cooling, due to the differences in the expansion coefficients and shrinkage rates of the composite materials and plastics, the bonding strength at the interface of the two materials will be insufficient, which is easy to induce peeling or gaps. At the same time, step-by-step forming is not conducive to improving efficiency. Therefore, how to provide a composite material parts forming process with good forming effect, high efficiency and low cost is a technical problem that urgently needs to be solved in this field. Summary of the invention

[0003] In view of this, in order to solve the technical problems existing in the art, the present invention provides a vacuum composite material compression molding co-curing process method, which specifically includes the following steps:

[0004] Step 1: Mold manufacturing: manufacturing a mold for performing multiple processes including molding, injection molding and co-curing; the mold is composed of a concave lower mold and a convex upper mold;

[0005] Step 2: Prefabricated board manufacturing: cutting the carbon fiber prepreg according to the designed shape and size to obtain a carbon fiber composite material prefabricated board;

[0006] Step 3: Laying the prefabricated board: Lay the carbon fiber composite material prefabricated board on the surface of the concave mold, and ensure that the carbon fiber composite material prefabricated board is flat and wrinkle-free;

[0007] Step 4: Vacuum molding: merge the convex upper mold and the concave lower mold, and use an external vacuum pump connected to the concave lower mold to vacuum the mold, so that the carbon fiber composite material prefabricated board and the mold are closely fitted, and the upper and lower molds are kept pressed continuously during the process;

[0008] Step 5, injection molding: the upper mold of the male mold guides the injection molding material heated to a molten state to be injected into the mold to form one or more structural reinforcements on the carbon fiber composite material prefabricated plate;

[0009] Step 6: Co-curing treatment: The external heating device passes heat transfer oil to the concave lower mold and the convex upper mold to form a uniform and stable heating environment in the mold, so that the carbon fiber composite material and the injection molding material are cured at the set temperature and pressure at the same time to form an integral component;

[0010] Step 7: Demolding and post-processing: After the mold has cooled, separate the concave lower mold and the convex upper mold. After the component is demoulded and taken out, perform necessary post-processing including trimming and inspection to obtain the final component product.

[0011] Furthermore, when executing step three, it also includes setting embedded parts on the carbon fiber composite material prefabricated board to form corresponding connection and fastening structures on the carbon fiber composite material prefabricated board by injection molding.

[0012] Furthermore, a plurality of reinforcing ribs with an inverted T-shaped cross section are specifically formed on the carbon fiber material prefabricated plate through injection molding in step five, or a strip-shaped or grid-shaped reinforcement structure formed by connecting a plurality of reinforcing members into one body.

[0013] Furthermore, the injection molding material is specifically selected from any one of polyetheretherketone (PEEK), polyamide (PA), polycarbonate (PC), and polypropylene (PP) and is used alone or mixed with chopped fiber reinforcement.

[0014] Correspondingly, the present invention also provides a vacuum composite material compression molding and co-curing process mold for executing the above method, which is composed of a concave lower mold and a convex upper mold;

[0015] The lower die of the concave die is provided with a vacuum flow channel consisting of a plurality of ventilation branches, a sealing ring and a plurality of oil guide holes; the vacuum flow channel is connected to the vacuum pump, and the sealing ring is used to maintain and adjust the pressure and sealing performance in the die;

[0016] The upper mold of the male mold is provided with an injection gate, a plurality of injection material flow channels and an oil guide hole connected with the injection gate; the injection gate is connected with the injection material feeding device, and the injection material in a molten state can be injected into the mold through the injection material flow channels under the action of the feeding device;

[0017] The oil guide holes on the concave lower die and the convex upper die are connected to the external heating device to form a uniform and stable heating environment inside the mold through the circulation of heat-conducting oil.

[0018] The vacuum composite molding, injection molding and co-curing process method and mold provided by the present invention can complete multiple processes including vacuum molding, injection molding, high temperature and high pressure co-curing in the manufacturing of carbon fiber composite parts with only one set of molds, avoiding the disadvantages of the existing process of repeatedly replacing tooling and molds and adjusting the temperature and pressure environment between different processes. The continuous forming process improves the processing accuracy and makes the temperature and pressure conditions in the process easier to control. In conjunction with existing automated equipment such as automatic composite material laying, vacuum adsorption tooling, multi-axis CNC milling, etc., the present invention can greatly improve the production efficiency of such products and effectively reduce labor and equipment costs, thereby meeting the production capacity requirements of high-performance automotive parts. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 A schematic diagram of the structure of the mold provided by the present invention;

[0020] Figure 2 A schematic diagram of a finished component having an inverted T-shaped reinforcement rib manufactured by the method of the present invention;

[0021] Figure 3 A schematic diagram of a front hood cover of an automobile manufactured by the method of the present invention;

[0022] Figure 4 A perspective view of a front hood cover of an automobile manufactured by the method of the present invention;

[0023] Figure 5 It is a schematic diagram of an optional connection and fastening structure including embedded parts on a front hood cover of an automobile;

[0024] Figure 6 The figure is a schematic diagram of a car using the front hood cover.

[0025] Explanation of the accompanying numbers: 1-convex upper mold, 2-concave lower mold, 3-carbon fiber composite material prefabricated plate, 4-oil guide hole, 5-vacuum flow channel, 6-sealing ring, 7-structural reinforcement, 8-injection molding gate, 9-rectangular grid rib reinforcement structure, 10-honeycomb grid reinforcement structure, 11-long strip reinforcement rib, 12-embedded parts. DETAILED DESCRIPTION

[0026] The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0027] In the description of the present invention, it should be noted that the terms "upper", "lower", "inside", "outside", etc. indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as a limitation on the present invention.

[0028] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0029] The vacuum composite material compression molding and injection molding co-curing process provided by the present invention is as follows: Figure 1 As shown, the specific steps include:

[0030] Step 1: Mold manufacturing: manufacturing a mold for performing multiple processes including molding, injection molding and co-curing; the mold is composed of a concave lower mold 2 and a convex upper mold 1;

[0031] Step 2: Prefabricated board manufacturing: cutting the carbon fiber prepreg according to the designed shape and size to obtain a carbon fiber composite material prefabricated board 3;

[0032] Step 3: Laying the prefabricated board: Lay the carbon fiber composite material prefabricated board on the surface of the concave mold, and ensure that the carbon fiber composite material prefabricated board is flat and wrinkle-free; manual laying can be used in the specific operation, or automatic wire laying or tape laying equipment can be used to further improve efficiency;

[0033] Step 4: vacuum molding: the convex upper mold 1 and the concave lower mold 2 are combined, and the mold is vacuumed by an external vacuum pump connected to the concave lower mold 2, so that the carbon fiber composite material prefabricated plate 3 is closely fitted to the mold, and the upper and lower molds are kept pressed continuously during the process;

[0034] Step 5, injection molding: the male mold 1 guides the injection molding material heated to a molten state to be injected into the mold to form one or more structural reinforcement members 7 on the carbon fiber composite material prefabricated plate 3;

[0035] Step 6, co-curing treatment: an external heating device passes heat transfer oil to the concave lower mold 2 and the convex upper mold 1 to form a uniform and stable heating environment in the mold, so that the carbon fiber composite material and the injection molding material are cured at the set temperature and pressure at the same time to form an integral component;

[0036] Step 7, demoulding and post-processing: After the mold is cooled, separate the concave lower mold 2 and the convex upper mold 1, demould the component and take it out, use vacuum adsorption tooling and multi-axis CNC milling equipment to perform necessary finishing and post-processing, and obtain the final component product after passing the inspection.

[0037] In a preferred embodiment of the present invention, when executing step three, it also includes setting embedded parts, such as bolts, nuts, angle pieces, etc. on the carbon fiber composite material prefabricated board, for forming corresponding connecting and fastening structures on the carbon fiber composite material prefabricated board by injection molding.

[0038] In a preferred embodiment of the present invention, the following is specifically formed on the carbon fiber material prefabricated plate by injection molding in step five: Figure 1 , 2 The cross section shown is a plurality of reinforcing ribs in an inverted T shape, or as shown in Figure 3 The strip-shaped or grid-shaped reinforcement structure shown is composed of multiple reinforcement members connected into one.

[0039] In a preferred embodiment of the present invention, the injection molding material specifically selects any one of high-performance plastics such as polyetheretherketone (PEEK), polyamide (PA), polycarbonate (PC), polypropylene (PP) and the like, which can provide excellent mechanical properties, heat resistance and corrosion resistance; or short-cut fiber reinforcement can be mixed therein to further improve the strength and stiffness of the injection molding material and enhance the mechanical properties of the product.

[0040] Correspondingly, the present invention also provides a vacuum composite material compression molding co-curing process mold for executing the above method, which is composed of a concave lower mold 2 and a convex upper mold 1;

[0041] The lower die 2 of the concave die is provided with a vacuum flow channel 5 composed of a plurality of ventilation branches, a sealing ring 6 and a plurality of oil guide holes 4; the vacuum flow channel 5 is connected to the vacuum pump, and the sealing ring 6 is used to maintain and adjust the sealing inside the die;

[0042] The upper mold 1 of the male mold is provided with an injection gate 8, a plurality of injection material flow channels and an oil guide hole connected to the injection gate 8; the injection gate 8 is connected to the injection material feeding device, and the injection material in a molten state can be injected into the mold through the injection material flow channels under the action of the feeding device;

[0043] The oil guide holes on the concave lower die 2 and the convex upper die 1 are both connected to the external heating device, so as to form a uniform and stable heating environment inside the mold through the circulation of heat-conducting oil.

[0044] Figure 3-5A car front hood cover manufactured based on the present invention is actually manufactured. A rectangular grid reinforcement structure 9, a honeycomb grid reinforcement structure 10 and a long strip reinforcement rib 11 are formed at different positions on the cover through the above process, and a fastening structure with an embedded corner piece 12 is formed at the central position. Several openings on the cover can be formed in the cutting step of the carbon fiber composite material prefabricated board. The component obtained by the present invention can achieve a higher surface finish while ensuring the processing accuracy, structural strength and other indicators, thereby further meeting the aesthetic requirements of the product. Figure 6 The figure shows the overall visual effect of the automobile front hood cover after installation on the vehicle.

[0045] It should be understood that the size of the serial numbers of the steps in the embodiment of the present invention does not mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiment of the present invention.

[0046] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A vacuum composite molding injection co-curing process method, characterized in that: The specific steps include: Step 1: Mold manufacturing: manufacturing a mold for performing multiple processes including molding, injection molding and co-curing; the mold is composed of a concave lower mold and a convex upper mold; Step 2: Prefabricated board manufacturing: cutting the carbon fiber prepreg according to the designed shape and size to obtain a carbon fiber composite material prefabricated board; Step 3: Laying the prefabricated board: Lay the carbon fiber composite material prefabricated board on the surface of the concave mold, and ensure that the carbon fiber composite material prefabricated board is flat and wrinkle-free; Step 4: Vacuum molding: merge the convex upper mold and the concave lower mold, and use an external vacuum pump connected to the concave lower mold to vacuum the mold, so that the carbon fiber composite material prefabricated board and the mold are closely fitted, and the upper and lower molds are kept pressed continuously during the process; Step 5, injection molding: The convex upper mold guides the injection molding material heated to a molten state to be injected into the mold to form one or more structural reinforcements on the carbon fiber composite material prefabricated plate; Step 6: Co-curing treatment: The external heating device passes heat transfer oil to the concave lower mold and the convex upper mold to form a uniform and stable heating environment in the mold, so that the carbon fiber composite material and the injection molding material are cured at the set temperature and pressure at the same time to form an integral component; Step 7: Demolding and post-processing: After the mold has cooled, separate the concave lower mold and the convex upper mold. After the component is demoulded and taken out, perform necessary post-processing including trimming and inspection to obtain the final component product.

2. The method according to claim 1, characterized in that: When executing step three, it also includes setting embedded parts on the carbon fiber composite material prefabricated board to form corresponding connection and fastening structures on the carbon fiber composite material prefabricated board by injection molding.

3. The method according to claim 1, characterized in that: Through the injection molding in step five, a plurality of reinforcing ribs with an inverted T-shaped cross section are specifically formed on the carbon fiber material prefabricated plate, or a strip-shaped or grid-shaped reinforcement structure formed by connecting a plurality of reinforcing members into one body.

4. The method according to claim 1, characterized in that: The injection molding material is specifically selected from any one of polyetheretherketone, polyamide, polycarbonate, and polypropylene, used alone or mixed with chopped fiber reinforcement.

5. A vacuum composite compression molding co-curing process mold for performing the method according to any one of claims 1 to 4, characterized in that: It consists of a concave lower die and a convex upper die; The lower die of the concave die is provided with a vacuum flow channel consisting of a plurality of ventilation branches, a sealing ring and a plurality of oil guide holes; the vacuum flow channel is connected to the vacuum pump, and the sealing ring is used to maintain and adjust the pressure and sealing performance in the die; The upper mold of the male mold is provided with an injection gate, a plurality of injection material flow channels and an oil guide hole connected with the injection gate; the injection gate is connected with the injection material feeding device, and the injection material in a molten state can be injected into the mold through the injection material flow channels under the action of the feeding device; The oil guide holes on the concave lower die and the convex upper die are connected to the external heating device to form a uniform and stable heating environment inside the mold through the circulation of heat transfer oil.

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