Prepreg hole making method

Abstract

The invention belongs to the technical field of composite material manufacturing, and relates to a prepreg hole making method, which comprises the following steps of: 1, establishing a positioning sample plate process model by using a product digital model according to design requirements; 2, outputting unfolding blanking data of the positioning sample plate process model; 3, selecting a proper prepreg mark, and generally selecting the prepreg with the mark consistent with that of the prepreg on the outermost layer of the product; fourthly, blanking is conducted on the expanded blanking data through a numerical control blanking machine, and a positioning sample plate real object is formed; fifthly, the positioning sample plates are pasted to the surface of the pre-drilled soaked material according to the related placement sequence and position information of the positioning sample plates; sixthly, according to different laying layer thicknesses of the prepreg, adaptive drill bits of different models are selected; 7, setting the speed of the drill bit, and keeping uniform low speed; and manual drilling is carried out according to the hole site spacing marked by the positioning sample plate. According to the method provided by the invention, the drilling position can be quickly found, the accuracy and consistency of the manual drilling position are ensured, and meanwhile, the special drill bit is adopted, so that the phenomena of damage and stress concentration of the composite material in a local area are effectively avoided.

Description

Technical Field

[0001] The invention belongs to the technical field of composite material manufacturing, and relates to a prepreg hole making method, in particular to a prepreg manual drilling method with high efficiency and high precision positioning. Background Art

[0002] The main purpose of drilling holes in composite materials usually involves connection, assembly and process requirements. In aircraft structures, drilling is the last step in connection and assembly, ensuring that structural parts can be connected together accurately and effectively. In addition, drilling also involves specific process requirements.

[0003] At present, the drilling of carbon fiber composite materials is mainly done manually. Manual drilling allows operators to drill holes in complex structures or irregularly shaped materials without the use of large or fixed mechanical equipment. However, the accuracy of manual drilling is often lower than that of mechanical drilling because the operator's skills and experience directly affect the accuracy and consistency of drilling; and compared with automated drilling equipment, manual drilling is slower.

[0004] As a modern processing method, robot automatic drilling has advanced positioning and sensing technology, which can achieve precise positioning. Compared with traditional manual drilling, robot automatic drilling has a higher processing speed, significantly improves production efficiency, reduces manual participation, and reduces the labor intensity of operators. However, the purchase and installation costs of robot automatic drilling equipment are high, and the operation process is relatively complicated, requiring professional technicians to operate and maintain. More advanced automatic drilling equipment combined with the robot end-hole actuator can realize the robot's positioning of the hole and the adjustment of the hole-making tool posture during drilling processing, improving work efficiency and drilling quality.

[0005] The purpose of drilling holes in prepreg is to achieve structural connection, meet assembly needs and comply with specific process requirements. However, due to the specific wettability and viscosity of prepreg, deviations are more likely to occur during manual drilling. Summary of the invention

[0006] The purpose of the present invention is to address the possibility that the fibers and matrix of the prepreg may be damaged during the drilling process, especially in the case of improper operation or unreasonable selection of process parameters. Such damage may affect the overall strength and stiffness of the composite material and reduce its bearing capacity. In order to reduce the impact of prepreg drilling on the performance of the composite material, a series of measures need to be taken, such as optimizing the drilling process parameters and improving the drilling positioning accuracy. To this end, the present invention provides a method for efficiently and accurately positioning prepreg holes by manual drilling, which can quickly locate the drilling position and ensure the accuracy and consistency of the manual drilling position. At the same time, a special drill bit is used to effectively avoid the composite material from being damaged in local areas and the occurrence of stress concentration.

[0007] Technical solution: To achieve the above purpose, the present invention adopts a process to increase the auxiliary drilling positioning reference to ensure the accuracy of the drilling position; at the same time, a special drill bit is provided, and a prepreg hole making method is specifically proposed, comprising the following steps:

[0008] Step 1: Based on the design requirements, use the product digital model to establish the positioning sample process model;

[0009] Step 2: Output the positioning sample process model and expand the blanking data;

[0010] Step 3: Choose the appropriate prepreg grade, generally choose the prepreg that is consistent with the prepreg grade of the top layer of the product;

[0011] Step 4: Cut the unfolded blanking data through a CNC blanking machine to form a physical positioning sample;

[0012] Step 5: Use the relevant placement order and position information of the positioning template to stick the positioning template on the surface of the pre-drilled dip material;

[0013] Step 6: Select different types of drill bits according to the different layer thicknesses of prepreg;

[0014] Step 7: Set the drill speed and maintain a uniform low speed; perform manual drilling according to the hole spacing marked on the positioning template.

[0015] Furthermore, holes with unequal spacing are opened on both sides of the positioning template.

[0016] Furthermore, the positioning template is made of wet prepreg, has good conformability, and can be attached to the surface of the product.

[0017] Furthermore, a notch is designed on the positioning template to facilitate accurate positioning of the drill bit during the drilling process.

[0018] Furthermore, a placement position mark is provided on the positioning template.

[0019] Furthermore, in the second step, the positioning sample process model is output using Fibersim software to expand the cutting data.

[0020] Furthermore, the drill speed is set to 0-400r / min.

[0021] Furthermore, the drill bit adopts a two-stage structure, with a drill bit with a smaller diameter at the front end and a drill bit with a larger diameter at the rear end.

[0022] The advantages of the present invention are:

[0023] Manual drilling of prepreg is characterized by high flexibility. Since it is a manual operation, the position of the drilling can be flexibly adjusted according to specific needs and on-site conditions. In addition, the prepreg itself has excellent mechanical properties and chemical stability, which can ensure the quality and effect of drilling to a certain extent.

[0024] Compared with automated or semi-automated drilling equipment, manual drilling has certain limitations in speed and accuracy. However, drilling holes in composite materials does not involve connection and assembly requirements, and only meets process requirements. Manual drilling can be fully realized, and it also reduces production costs to a large extent. At the same time, the use of prepreg positioning templates to replace traditional drilling tools fundamentally eliminates the heavy and complex metal drilling tools. The use of light and simple positioning templates can quickly and accurately locate the hole position; when drilling holes manually, use a suitable drill bit and select it according to the thickness of the composite material to ensure the accuracy and efficiency of the drilling. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 This is a schematic diagram of the drilling positioning template of the present invention.

[0026] Figure 2 It is a schematic diagram of the drill bit structure of the present invention. DETAILED DESCRIPTION

[0027] 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.

[0028] The drilling method proposed in the present invention is used to perform drilling on a prepreg of a certain type of machine, and specifically comprises the following steps:

[0029] Step 1: Use the product digital model to establish the positioning template process model based on the design requirements, with the hole spacing of 60mm on one side and 30mm on the other side. At the same time, the process model contains information such as the placement and order of the positioning template; Figure 1 The positioning template structure shown has holes with equal spacing on both sides. The S-H mark on the positioning template indicates the placement position of the positioning template (the trailing edge of the upper wing surface); 01 indicates the placement order of the positioning template; 30 and 60mm indicate the hole spacing;

[0030] Step 2: Use Fibersim software to output the positioning sample process model and expand the cutting data;

[0031] Step 3: Select the prepreg with the same grade as the prepreg on the surface of the product to prevent the introduction of other impurities;

[0032] Step 4: Cut the unfolded blanking data through a CNC blanking machine to form a physical positioning sample;

[0033] Step 5: Use the relevant placement order and position information of the positioning template to stick the positioning template on the surface of the prepreg with pre-drilled holes; to prevent the isolation film of the prepreg from being brought into the hole during the drilling process, it is recommended to peel off the isolation film, that is, the positioning template is in direct contact with the product prepreg. The prepreg can provide good adhesion and the positioning template is not easy to slide;

[0034] Step 6: Select different types of matching drill bits according to the different layer thicknesses of prepreg; the right drill bit can ensure stability and safety during operation.

[0035] Step 7: Set the drill speed to 0-400r / min. Slowly press the electric drill switch during operation to maintain a uniform low speed. Figure 2 As shown, Φ2 represents the hole diameter; SR0.5 represents the ball radius; 3.5 represents the length of the small diameter drill tip; 15 and 40 represent different thicknesses of the prepreg material of the workpiece, that is, the drilling depth;

[0036] Step 8: Perform manual drilling according to the hole spacing marked on the positioning template. Although manual drilling is slightly more time-consuming than automated equipment, it is a very efficient option when there is no need to meet high requirements for hole position and accuracy. Operators can flexibly adjust according to actual conditions to ensure that the processing process is fast and accurate.

[0037] The above specific implementation methods or cases are only used to explain the technical solutions of the present invention, and are not intended to limit the present invention. Any parts not described in detail are regarded as conventional technical means in the art. A person of ordinary skill in the art should understand that based on the design concept of the present application, the technical solutions described in the aforementioned implementation methods should be adaptively modified, or some or all of the technical features therein should be replaced by equivalents. These modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for making holes in prepreg, characterized in that: The steps include: Step 1: Based on the design requirements, use the product digital model to establish the positioning sample process model; Step 2: Output the positioning sample process model and expand the blanking data; Step 3: Select the prepreg with the same grade as the prepreg on the surface of the product; Step 4: Cut the unfolded blanking data through a CNC blanking machine to form a physical positioning sample; Step 5: Use the relevant placement order and position information of the positioning template to stick the positioning template on the surface of the pre-drilled dip material; Step 6: Select different types of drill bits according to the different layer thickness of prepreg; Step 7: Set the drill speed and maintain a uniform low speed; perform manual drilling according to the hole spacing marked on the positioning template.

2. A method for making holes in prepreg according to claim 1, characterized in that: There are holes with unequal spacing on both sides of the positioning template.

3. A method for making holes in prepreg according to claim 1 or 2, characterized in that: The positioning template is made of wet prepreg.

4. A method for making holes in prepreg according to claim 3, characterized in that: A notch is designed on the positioning template to facilitate accurate positioning of the drill bit during drilling.

5. A method for making holes in prepreg according to claim 4, characterized in that: The positioning template is provided with placement position markings.

6. A method for making holes in prepreg according to claim 1, characterized in that: In the second step, Fibersim software is used to output the positioning sample process model and expand the cutting data.

7. A method for making holes in prepreg according to claim 1, characterized in that: The drill bit adopts a two-stage structure, with a drill bit with a smaller diameter at the front end and a drill bit with a larger diameter at the rear end.

8. A method for making holes in prepreg according to claim 7, characterized in that: The drill speed is set to 0-400r / min.

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