CN106738505A - A kind of manufacturing method of composite material forming mold with composite structure - Google Patents

Abstract

A manufacturing method of a composite material forming die with a composite structure belongs to the technical field of composite material forming, and particularly relates to a manufacturing method of a composite material forming die with a composite structure. Aiming at the problems of low forming precision, high manufacturing cost and short service life of a large-scale and precise composite material part forming die, the invention processes a composite material die bracket according to a die digital model and performs assembly connection on the bracket; according to the CAD (computer aided design) digital model of the mold profile, utilizing an additive manufacturing method to stack and process the mold metal profile and the bracket assembly layer by layer; roughly machining the die profile and the assembly assembled by the profile and the bracket by using a numerical control machine; the molded surface of the die is assembled and connected with the bracket through the self-locking component; and performing surface finish machining on the assembled die to manufacture the composite material forming die with the composite structure. The invention is suitable for manufacturing the composite material forming die with a composite structure.

Description

A kind of manufacturing method of composite material forming mold with composite structure

technical field

The invention belongs to the technical field of composite material forming, and in particular relates to a manufacturing method of a composite material forming mold with a composite structure.

Background technique

Composite materials are more and more used in aircraft structural parts due to their advantages of high specific stiffness, high specific strength, light weight, good invisibility, fatigue resistance and corrosion resistance, such as Boeing B787 and Airbus A350, and The manufacture of composite material parts presents a trend of larger size and more complex shape, so higher requirements are put forward for the manufacturing quality of composite material parts. Due to the solidification and molding characteristics of composite parts, their quality, especially deformation control, depends to a large extent on the quality of the molding die.

Among them, the carbon fiber composite material mold has the characteristics of high molding precision with the thermal expansion coefficient consistent with the parts, but its high manufacturing cost, easy damage, short service life, and the disadvantages of difficult demoulding and difficult repair restrict its large-scale application. Metal material molds such as Invar steel have the characteristics of high temperature resistance, wear resistance, and long service life. Compared with carbon fiber composite material molds, the advantages of long service life are significant, but the weight of large-scale and complex metal molds is too large, which affects the transportation carrying capacity and The size requirements of the autoclave equipment are too high, and the existing manufacturing methods have problems such as poor precision and high cost. The existing manufacturing process of large-size and complex-shaped molds is: forming of thick plates in blocks, assembly and welding of mold surfaces and brackets, tailor-welding of block-shaped mold surfaces, rough machining and finishing of mold surfaces, etc. Among them, the surface forming is mainly roll bending (or stamping) forming plus water and fire correction, and the welding is manual argon arc welding. For the forming process of thick plates with complex curvatures and tailor welding of long welds on forming profiles, quality problems such as out-of-tolerance appearance and air leakage at welds are likely to occur, which require rework and repair. At the same time, the milling of thick plates with profiles is large high cost. On the other hand, the mold surface processed by the existing method will be solidified once processed and cannot be changed. This will cause great inconvenience to the initial research and development of composite structural parts. It is impossible to repair the mold shape according to the springback deformation of the part. Can be reworked with new molds.

Therefore, in view of the existing metal mold processing and manufacturing process, which are easy to appear in the complex curvature thick plate forming control, poor welding quality stability of long welds, etc., as well as the problems of short service life, difficult repair and high manufacturing cost of carbon fiber composite molds, there is an urgent need Improving the existing mold manufacturing methods, so as to ensure the quality of the mold, how to scientifically and effectively realize the high-precision molding and low-cost manufacturing of composite material molds is an urgent problem to be solved in the design and manufacture of composite material molds.

Contents of the invention

The technical problem to be solved by the present invention is to propose a method for manufacturing a composite material molding die with a composite structure for the problems of low forming precision, high manufacturing cost and short service life of large-scale and precision composite material part molding dies. The method is effective Improve the manufacturing accuracy of composite parts, improve the service life and ensure product quality.

A kind of manufacturing method of the composite material molding die with composite structure described in the present invention, the concrete steps of this method are:

Step 1. Process the composite material mold bracket according to the mold digital model, and assemble and connect the bracket;

Step 2. According to the CAD digital model of the mold surface, the metal surface of the mold and the assembly components of the mold surface and the bracket are processed layer by layer by using the additive manufacturing method;

Step 3, use the CNC machine tool to rough the mold surface and the assembly of the mold surface and the bracket;

Step 4, the mold surface and the bracket are assembled and connected through self-locking components;

Step 5: Finishing the surface of the assembled mold to complete the manufacture of the composite material forming mold with a composite structure.

The advantages and beneficial effects that the present invention has:

1) The mold with metal profile and composite material bracket structure can shorten the manufacturing cycle of the mold and reduce the cost of mold manufacturing;

2) Complicated surface additive manufacturing can be formed at one time, with high forming precision, avoiding the problems of poor forming control accuracy of thick plates and high requirements for forming equipment in the traditional manufacturing process, and avoiding the tailor-made welding of the shape in the traditional manufacturing process Difficulty in positioning, and the problem of air leakage defects;

4) The composite material used for the bracket can reduce the weight of the mold, and is close to the thermal expansion coefficient of the Invar steel surface, reducing the deformation caused by the difference in thermal expansion coefficient between the mold surface and the bracket;

5) The self-locking structural assembly can solve the problem of connecting the metal profile and the composite material bracket, avoiding the problems of difficult assembly of the mold profile and the bracket and heavy welding workload in the traditional manufacturing process;

6) The composite structure mold can correct and repair the mold surface according to the process requirements, avoiding the characteristics that the solidification of the single carbon fiber composite structure mold surface cannot be changed.

Description of drawings

Fig. 1 is a flowchart of the present invention;

Fig. 2 is the carbon fiber composite material bracket described in Embodiment 5;

Fig. 3 is the CAD model of the mold profile described in Embodiment 5;

Fig. 4 is the schematic diagram of manufacturing the Invar steel profile described in the fifth embodiment;

Fig. 5 is a schematic diagram of the self-locking structure of the connection between the mold surface and the bracket described in the fifth embodiment;

Fig. 6 is a schematic diagram of the final assembled flat tail root fairing mold described in the fifth embodiment.

detailed description

The specific embodiment one, in conjunction with Fig. 1 illustrates this embodiment, a kind of manufacturing method of the composite material forming mold with composite structure described in this embodiment, the concrete steps of this method are:

Step 1. Process the composite material mold bracket according to the mold digital model, and assemble and connect the bracket;

Step 2. According to the CAD digital model of the mold surface, the metal surface of the mold and the assembly components of the mold surface and the bracket are processed layer by layer by using the additive manufacturing method;

Step 3, use the CNC machine tool to rough the mold surface and the assembly of the mold surface and the bracket;

Step 4, the mold surface and the bracket are assembled and connected through self-locking components;

Step 5: Finishing the surface of the assembled mold to complete the manufacture of the composite material forming mold with a composite structure.

Specific embodiment 2. This embodiment is a further description of the manufacturing method of a composite material forming mold with a composite structure described in specific embodiment 1. The additive manufacturing method described in step 2 includes laser additive methods, electronic Beam additive methods and arc (TIG or MIG) additive methods.

The mold surface additive manufacturing method described in this embodiment includes but not limited to laser additive, electron beam additive, arc (TIG or MIG) additive and other methods.

If the designer needs to change the size before the mold starts to be processed, it is only necessary to update the CAD digital model of the additive manufacturing program; if the mold needs to be changed in size during or after processing, then it is necessary to mill out the excess at the changed part The material is manufactured according to the new digital model additive, and then the subsequent processing is carried out.

For the damage caused on the surface of the mold during use, you can also refer to the above method for repairing.

Specific embodiment three. This embodiment is a further description of the manufacturing method of a composite material forming mold with a composite structure described in specific embodiment one or two. The mold surface described in step two is carbon fiber composite material, Invar steel or nickel alloy.

Embodiment 4. This embodiment is a further description of the manufacturing method of a composite material forming mold with a composite structure described in Embodiment 1. In step 3, the use of a numerical control machine tool to control the mold profile and the profile and The specific method for the rough machining of the components assembled by the bracket is as follows: the lower surface of the profile is milled with an end mill, and the axial depth of milling is less than 3 mm.

Embodiment 5. This embodiment is a further description of the manufacturing method of a composite material forming mold with a composite structure described in Embodiment 1 or 4. In step 5, perform surface finishing on the assembled mold The best method is: milling the surface of the mold surface with an end mill, the milling axial depth of cut is less than 0.8mm, and then milling with a ball end milling cutter to the theoretical shape of the mold, the final contour error of the mold is less than 0.4mm.

Concrete embodiment, take flat tail wing root fairing form mold as example, in conjunction with accompanying drawing and specific embodiment, the present invention is further described:

1) As shown in Figure 2, use the traditional method to process the carbon fiber composite material bracket, and assemble and connect the bracket;

2) As shown in Figure 3, according to the CAD model of the mold surface, the layered processing is carried out, and the scanning path of each layer is produced by the computer, and the Invar steel surface and the Invar steel surface and the carbon fiber support are formed by stacking layer by layer along the scanning path Assembling connected components;

3) As shown in Figure 4, laser additive forming, electron beam additive forming, arc (TIG or MIG) additive forming and other methods can be used to manufacture Invar steel profiles. Number 1 in the figure is the working head of additive manufacturing equipment , label 2 is the mold surface;

4) Figure 5 is a schematic diagram of the self-locking structure connecting the mold surface and the bracket, in which number 3 is the back assembly component of the Invar steel mold surface, through which the mold surface and the bracket are assembled and connected, and number 4 is the mold carbon fiber bracket upper components.

5) Figure 6 is a schematic diagram of the finally assembled flat tail root fairing mold.

6) If due to design changes or process adjustments, it is necessary to partially correct the processed mold surface, then perform CNC milling on the corrected parts to meet the requirements, and then repeat step 3) to carry out local additive manufacturing forming, and finally realize the part. Shape adjustments.

To sum up, the manufacturing method of the mold for composite material molding of the composite structure provided by the present invention can realize the precise and rapid manufacturing of the mold with complex shape and high dimensional accuracy.

The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the present invention. Any modifications, equivalent replacements and improvements made within the spirit and principles of the present invention should be included in the protection of the present invention. within range.

Claims (5)

1. a kind of manufacture method of the composite material shaping mould with composite construction, it is characterised in that the specific step of the method Suddenly it is：

Step one, according to mould digital-to-analogue, machining composite material mould rack, and assembly connection is carried out to support；

Step 2, successively piled up using increasing material manufacturing method according to die face CAD digital-to-analogues process Mold Metal type face and Type face and support assembling assembly；

Step 3, roughing is carried out to the component that die face and type face and support are assembled using Digit Control Machine Tool；

Step 4, die face and support carry out assembly connection by self-locking component；

Step 5, the mould to assembling carry out the finishing of type face, complete the composite material shaping mould with composite construction Manufacture.

2. a kind of manufacture method of composite material shaping mould with composite construction according to claim 1, its feature It is that the increasing material manufacturing method described in step 2 includes that laser gain material method, electron beam increase material method and electric arc increases material method.

3. the manufacture method of a kind of composite material shaping mould with composite construction according to claim 1 and 2, it is special Levy and be, the die face described in step 2 is carbon fibre composite, Invar steel or nickel alloy.

4. a kind of manufacture method of composite material shaping mould with composite construction according to claim 1, its feature It is that rough machined tool is carried out to the component that die face and type face are assembled with support using Digit Control Machine Tool described in step 3 Body method is：Using the lower surface in end mill(ing) cutter milling type face, milling axial direction cutting-in is less than 3mm.

5. the manufacture method of a kind of composite material shaping mould with composite construction according to claim 1 or 4, it is special Levy and be, pair mould for assembling described in step 5 carries out type face method for finishing manufactured and is：End is first used in die face upper surface Milling cutter milling, milling axial direction cutting-in is less than 0.8mm, is then machined to the theoretical profile of mould, mould with rose cutter milling again Final profile degree error is less than 0.4mm.