RTM (Resin Transfer Molding) forming mold for carbon fiber product

Abstract

The utility model discloses an RTM (Resin Transfer Molding) forming mold of a carbon fiber product, which comprises a front mold plate provided with a forming groove and a rear mold plate provided with a forming table, and after the front mold plate and the rear mold plate are assembled, the forming groove and the forming table are matched to form a forming cavity; the forming groove comprises a product forming part and a leftover material forming part arranged on the periphery of the product forming part. The front mold plate is provided with a plurality of material pressing rods and a lifting driving device, and the lifting driving device is used for driving the material pressing rods to stretch out and retract from the end face of the leftover material forming part; according to the utility model, the stability and the reliability of product quality are improved, the forming period is shortened, the production efficiency is improved, and the dimensional accuracy and the consistency of products are ensured.

Description

Technical Field

[0001] The utility model relates to the technical field of composite material molding, in particular to an RTM molding die for carbon fiber products. Background Art

[0002] There is a big gap between my country and European and American countries in composite automobile manufacturing technology and research. With the development of automobile lightweight molding technology, it has gradually become a trend to replace traditional sheet metal parts with new composite parts in automobile applications. Composite materials have attracted widespread attention in the automotive industry due to their excellent performance. Among them, composite material molding technology has always been the focus of research. From the initial hand lay-up process, low-pressure RTM process, fiber winding process to the current new RTM process, the emergence and application of each new process is the advancement of composite material molding research. Traditional hand lay-up process and low-pressure RTM process have advantages in producing small batches and simple equipment configuration and low manufacturing cost in early sample research and development, so they are favored by small and medium-sized enterprises.

[0003] However, the traditional hand lay-up process and low-pressure RTM process have problems such as low automation, poor product consistency, low efficiency, bubbles, dry spots, etc., which are not suitable for standardized and mass production of automotive parts. In the RTM molding process, the design of the mold is very important, which directly affects the molding quality, production efficiency and cost of the product. Therefore, an improved mold design is needed. Summary of the invention

[0004] The purpose of the utility model is to provide an RTM molding die for carbon fiber products in view of the problems existing in the prior art, thereby improving the quality stability and reliability of the products, shortening the molding cycle, improving the production efficiency, and ensuring the dimensional accuracy and consistency of the products.

[0005] In order to achieve the above purpose, the technical solution adopted by the utility model is:

[0006] A RTM molding die for carbon fiber products comprises a front template provided with a molding groove and a rear template provided with a molding table. After the front template and the rear template are combined, the molding groove and the molding table cooperate to form a molding cavity; the molding groove comprises a product molding part and a scrap molding part arranged around the product molding part; the front template is provided with a plurality of press rods and a lifting drive device, and the lifting drive device is used to drive the press rods to extend and retract from the end face of the scrap molding part.

[0007] Furthermore, the product forming part is a front-to-back and left-to-right symmetrical structure, and the four pressing rods are symmetrically distributed in pairs on the front and back sides of the product forming part.

[0008] Furthermore, the lifting drive device includes four first oil cylinders and an oil collecting block, the movable part of each first oil cylinder is connected to one of the pressing rods, the first oil cylinders are connected to the oil collecting block through a pipeline, and the oil collecting block is used to distribute the hydraulic oil to each of the first oil cylinders.

[0009] Furthermore, the back of the front template is connected to a heat insulation board, the heat insulation board is connected to a square iron, the square iron is connected to a panel, the first oil cylinder and the oil collecting block are respectively fixed to the back of the front template, the front template is provided with four first through holes, and the pressing rods are movably arranged inside the first through holes in a one-to-one corresponding manner.

[0010] Furthermore, the front template is also provided with two second oil cylinders and two air blowing vacuum rods, and the air blowing vacuum rods are symmetrically arranged on both sides of the scrap forming part; the movable part of each second oil cylinder is connected to one air blowing vacuum rod respectively, and the second oil cylinder is used to drive the air blowing vacuum rod to extend and retract from the end face of the scrap forming part, and the air blowing vacuum rod is connected to the air pump through a pipeline.

[0011] Furthermore, a nozzle is provided in the front template, one end of the nozzle is connected to the product forming part, and the other end is connected to the injection molding machine through a pipeline.

[0012] Furthermore, a plurality of pressure plates are provided on the edge of the end face of the rear template, and the pressure plates are used to contact and bear pressure with the end face of the front template when the film is closed; a gasket is provided between the pressure plate and the rear template, and the thickness of the product molding can be adjusted by adjusting the thickness of the gasket.

[0013] Furthermore, the rear template is provided with a plurality of air holes, one end of the air hole extends to the end surface of the forming table, and the other end is connected to an air pump through a pipeline.

[0014] Compared with the prior art, the beneficial effects of the utility model are:

[0015] 1. Provide an RTM molding mold to improve product quality stability and reliability, shorten the molding cycle, and improve production efficiency;

[0016] 2. Before mold closing, the press rod is kept in the ejection state, which helps to pre-tighten the carbon fiber preform during the mold closing process. The pre-tightening effect of the press rod can reduce the displacement of the carbon fiber cloth when the mold is closed, ensure the accurate position of the carbon fiber cloth in the mold, and help improve the dimensional accuracy and consistency of the product;

[0017] 3. The automated press rod and lifting drive device can reduce manual operation, speed up mold closing and demoulding, and improve efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is a schematic structural diagram of an RTM molding die in one embodiment of the present application;

[0019] Figure 2 This is a schematic diagram of the structure of the hydraulic system in the front template in one embodiment of the present application;

[0020] Figure 3 This is a schematic diagram of the structure of the rear template in one embodiment of the present application;

[0021] Figure 4 This is a schematic diagram of the structure of the front template in one embodiment of the present application;

[0022] In the figure: 1, forming groove; 101, product forming part; 102, scrap forming part; 2, front template; 3, forming table; 4, rear template; 5, front template; 6, pressing rod; 7, first oil cylinder; 8, oil collecting block; 9, heat insulation board; 10, square iron; 11, panel; 12, second oil cylinder; 13, air blowing vacuum rod; 14, nozzle; 15, pressure plate; 16, air top hole; 17, product; 18, scrap. DETAILED DESCRIPTION

[0023] The following will be combined with the drawings in the utility model to clearly and completely describe the technical solution of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0024] In the description of the present utility model, it should be noted that the terms "center", "upper", "lower", "vertical", "horizontal", "inner", "outer", etc. indicate the orientation or position relationship based on the orientation or position relationship shown in the drawings, or the orientation or position relationship in which the utility model product is usually placed when in use, which is only for the convenience of describing the utility model and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present utility model. In addition, the terms "first", "second", "third", etc. are only used to distinguish the description, and cannot be understood as indicating or implying relative importance.

[0025] In addition, the terms "horizontal", "vertical" and the like do not mean that the components are required to be absolutely horizontal or suspended, but can be slightly tilted. For example, "horizontal" only means that its direction is more horizontal than "vertical", and does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0026] In the description of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "set", "install", "connect", and "connect" 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 direct connection, or an indirect connection 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.

[0027] like Figures 1 to 4 As shown, an RTM molding mold for carbon fiber products includes a front template 2 provided with a molding groove 1 and a rear template 4 provided with a molding table 3. After the front template 2 and the rear template 4 are combined, the molding groove 1 and the molding table 3 cooperate to form a molding cavity; the molding groove 1 includes a product molding part 101 and a scrap molding part 102 arranged around the product molding part 101; the front template 5 is provided with a plurality of pressing rods 6 and a lifting drive device, and the lifting drive device is used to drive the pressing rods 6 to extend and retract from the end face of the scrap molding part 102.

[0028] The working process of the above scheme is:

[0029] Step 1: Mold preparation: RTM mold is made of steel and has a smooth surface.

[0030] Step 2: wax the mold or spray the mold release agent; wipe the new RTM mold clean with alcohol, apply the special mold release agent more than 3 times, apply the mold release agent every 10 minutes, and the pores on the mold surface must be completely filled and the finish must be maintained; before molding the carbon fiber product preform blank, spray the external mold release agent that matches the resin properties;

[0031] Step 3: Lay out the twill and unidirectional fabric of carbon fiber products; according to the product layer design requirements, the preformed blank of carbon fiber products is processed in the early stage, and the unidirectional fabric and twill fabric of appropriate size are cut out, the unidirectional fabric in the middle, and the twill fabric on the top and bottom layers;

[0032] Step 4, press mold closing; after placing the twill cloth and the unidirectional cloth, enter the mold closing step. Before mold closing, the press rod 6 is always in the ejection state. During the mold closing process, the press rod 6 contacts the carbon fiber cloth in advance until the mold closing is completed, and the press rod 6 returns;

[0033] Step 5, vacuum pressure maintenance: after the front template 2 and the rear template 4 are closed and locked, the molding cavity is vacuumed and pressure maintained;

[0034] Step 6: Inject the matrix resin into the molding cavity. Before the resin is injected, the resin, curing agent, and internal mold release agent need to be preheated and degassed. After reaching the set temperature value, the injection work is performed.

[0035] Step 7: Pressure-maintaining and curing: Complete the resin injection and filling work in a short time, and then maintain pressure and cure;

[0036] Step 8: Product forming; when the set curing cycle is reached, the mold on the press opens and the product is cured;

[0037] Step 9: Blowing and demoulding: Mechanical ejection and demoulding are performed through the air ejection structure and the blowing joint built into the mold;

[0038] Step 10: Place it on the cooling tool to cool and then cut off the scraps.

[0039] The above-mentioned RTM molding mold solves the problems of insufficient molding strength, bubble phenomenon, and dry spots in the traditional hand lay-up process, improves product quality stability and reliability, shortens the molding cycle, and improves production efficiency.

[0040] Among them, a special improvement is that a plurality of press rods 6 and lifting drive devices are arranged in the front template 2. Before mold closing, the press rod 6 is always in the ejection state. During the mold closing process, the press rod 6 contacts the carbon fiber cloth in advance until the mold closing is completed, and the press rod 6 is retracted;

[0041] The advantages of the invention are that, first, before the mold is closed, the press rod 6 is kept in the ejection state, which helps to pre-press the carbon fiber preform during the mold closing process. The pre-pressing effect of the press rod 6 can reduce the displacement of the carbon fiber cloth when the mold is closed, ensure the accurate position of the carbon fiber cloth in the mold, and help to improve the dimensional accuracy and consistency of the product;

[0042] Second, the automated press rod 6 and lifting drive device can reduce manual operations and speed up mold closing and demoulding.

[0043] In some embodiments, the product forming part 101 is a front-to-back symmetrical and left-to-right symmetrical structure, and the four press rods 6 are symmetrically distributed in pairs on the front and back sides of the product forming part 101. The product forming part 101 adopts a front-to-back symmetrical and left-to-right symmetrical design in order to manufacture a carbon fiber product with central symmetry. The four press rods 6 are symmetrically distributed in pairs on the front and back sides of the product forming part 101, ensuring that uniform pressure is applied to the carbon fiber preform during the mold closing process.

[0044] In some embodiments, the lifting drive device includes four first oil cylinders 7 and an oil collecting block 8, the movable part of each first oil cylinder 7 is connected to a press rod 6, the first oil cylinder 7 is connected to the oil collecting block 8 through a pipeline, and the oil collecting block 8 is used to distribute the hydraulic oil to each first oil cylinder 7. The oil collecting block 8 is designed with multiple channels and interfaces to ensure that the hydraulic oil can be evenly and accurately distributed to each first oil cylinder 7; by controlling the flow and pressure of the hydraulic oil provided by the oil collecting block 8 to the first oil cylinder 7, the ejection and retraction of the press rod 6 are accurately controlled to adapt to the opening and closing process of the mold.

[0045] In some embodiments, the back of the front template 2 is connected to a heat insulation board 9, the heat insulation board 9 is connected to a square iron 10, the square iron 10 is connected to a panel 11, the first oil cylinder 7 and the oil collecting block 8 are respectively fixed to the back of the front template 2, the front template 2 is provided with four first through holes, and the press rods 6 are movably arranged inside the first through holes one by one. The heat insulation board 9 is connected to the back of the front template 2 to isolate heat during the resin curing process, prevent the mold from overheating, and ensure the stability and life of the mold; the square iron plays a supporting and fixing role, providing a stable installation platform for the oil cylinder and the oil collecting block.

[0046] In some embodiments, the front template 2 is further provided with two second oil cylinders 12 and two air-blowing vacuum rods 13, and the air-blowing vacuum rods 13 are symmetrically arranged on both sides of the scrap forming part 102; the movable part of each second oil cylinder 12 is respectively connected to a air-blowing vacuum rod 13, and the second oil cylinder 12 is used to drive the air-blowing vacuum rod 13 to extend and retract from the end surface of the scrap forming part 102, and the air-blowing vacuum rod 13 is connected to the air pump through a pipeline. The air-blowing vacuum rod 13 is connected to the air pump through a pipeline to perform vacuuming and blowing operations; before the resin is injected, the air-blowing vacuum rod 13 performs a vacuuming operation to remove the air and volatiles in the mold cavity to prepare for the resin injection; after the resin is injected, the air-blowing vacuum rod 13 can perform a blowing operation to help the resin better impregnate the carbon fiber material and ensure that the resin flows evenly.

[0047] In some embodiments, a nozzle 14 is provided in the front mold plate 2, one end of the nozzle 14 is connected to the product molding part, and the other end is connected to the injection machine through a pipeline. The function of the nozzle 14 is to ensure that the resin can directly and evenly enter the product molding part 101.

[0048] In some embodiments, a plurality of pressure plates 15 are provided at the edge of the end surface of the rear template 4. The pressure plates 15 are used to contact and bear pressure with the end surface of the front template 2 when the film is closed. A gasket is provided between the pressure plate 15 and the rear template. By adjusting the thickness of the gasket, the thickness of the product can be adjusted. The replacement and adjustment of the gasket is quick and easy, and can quickly adapt to the production of products with different thickness requirements. The gasket is a low-cost component, and using the gasket to adjust the thickness can save mold costs.

[0049] In some embodiments, the rear template 4 is provided with a plurality of air holes 16, one end of the air hole 16 extends to the end surface of the molding table 3, and the other end is connected to the air pump through a pipeline. When the product is cured, the air pump is started, and compressed air flows into the air hole 16 through the pipeline to lift the molded product from the molding table 3. The demoulding action of the air hole 16 can be integrated into the automatic control system to realize the automation of the demoulding process.

[0050] Although the 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 RTM molding die for a carbon fiber product, characterized in that: It comprises a front template (2) provided with a molding groove (1) and a rear template (4) provided with a molding platform (3); after the front template (2) and the rear template (4) are combined, the molding groove (1) and the molding platform (3) cooperate to form a molding cavity; The forming tank (1) comprises a product forming portion (101) and a scrap forming portion (102) arranged around the product forming portion (101); The front template (2) is provided with a plurality of pressing rods (6) and a lifting drive device, wherein the lifting drive device is used to drive the pressing rods (6) to extend from and retract into the end surface of the scrap forming portion (102).

2. The RTM molding die for carbon fiber products according to claim 1, characterized in that: The product forming part (101) is a front-to-back and left-to-right symmetrical structure, and the four pressing rods (6) are symmetrically distributed in pairs on the front and back sides of the product forming part (101).

3. The RTM molding die for carbon fiber products according to claim 1, characterized in that: The lifting drive device comprises four first oil cylinders (7) and an oil collecting block (8), the movable part of each of the first oil cylinders (7) is connected to one of the pressing rods (6), the first oil cylinders (7) are connected to the oil collecting block (8) via a pipeline, and the oil collecting block (8) is used to distribute hydraulic oil to each of the first oil cylinders (7).

4. The RTM molding die for carbon fiber products according to claim 3, characterized in that: The back of the front template (2) is connected to a heat insulation board (9), the heat insulation board (9) is connected to a square iron (10), the square iron (10) is connected to a panel (11), the first oil cylinder (7) and the oil collecting block (8) are respectively fixed to the back of the front template (2), the front template (2) is provided with four first through holes, and the pressing rods (6) are movably arranged inside the first through holes in a one-to-one corresponding manner.

5. The RTM molding die for carbon fiber products according to claim 1, characterized in that: The front template (2) is also provided with two second oil cylinders (12) and two air blowing vacuum rods (13), and the air blowing vacuum rods (13) are symmetrically arranged on both sides of the scrap forming part (102); the movable part of each second oil cylinder (12) is connected to one of the air blowing vacuum rods (13), and the second oil cylinder (12) is used to drive the air blowing vacuum rods (13) to extend and retract from the end face of the scrap forming part (102), and the air blowing vacuum rods (13) are connected to an air pump through a pipeline.

6. The RTM molding die for carbon fiber products according to claim 1, characterized in that: A nozzle (14) is provided in the front template (2); one end of the nozzle (14) is connected to the product forming part, and the other end is connected to the injection machine through a pipeline.

7. The RTM molding die for carbon fiber products according to claim 1, characterized in that: A plurality of pressure plates (15) are provided at the edge of the end surface of the rear template (4), and the pressure plates (15) are used to contact and bear pressure with the end surface of the front template (2) when the film is closed; a gasket is provided between the pressure plate (15) and the rear template (4), and the thickness of the product molding can be adjusted by adjusting the thickness of the gasket.

8. The RTM molding die for carbon fiber products according to claim 1, characterized in that: The rear template (4) is provided with a plurality of air holes (16), one end of the air hole (16) extends to the end surface of the forming table (3), and the other end is connected to an air pump through a pipeline.

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