What matters should be paid attention to when processing fiber bottom die by precision carving machine?

When the carving machine processes the fiber bottom die, it is necessary to focus on the four core dimensions of fiber material characteristics, equipment parameter setting, processing technology control and safety protection. The specific matters are as follows:

Material pretreatment

Fiber bottom die (such as carbon fiber and glass fiber) is brittle and layered, so it is necessary to confirm the flatness of the material before processing to avoid processing deviation caused by warping; If there is film covering or impurities on the surface of the material, it needs to be cleaned first to prevent the tool from slipping when cutting.

Flexible fixtures (such as vacuum sucker and rubber batten) should be selected during clamping to avoid material edge collapse and delamination caused by excessive rigid clamping force; The clamping force should be uniform to ensure that the material has no displacement during processing.

Tool selection and parameter setting

Carbide coated knives or diamond coated knives are preferred for cutting tools, which have high hardness and good wear resistance and can reduce the wear of fiber materials on the blade; Avoid using ordinary high-speed steel tools to prevent the tool from being passivated too quickly, which will lead to the fuzzing of the machined surface.

Milling parameters should be adapted to the characteristics of fiber materials: the cutting speed is suggested to be controlled at 15,000-24,000 r/min, and the feed speed should not be too fast (800-1,500 mm/min) to avoid fiber tearing caused by excessive feed; The cutting depth should not exceed 0.5mm at a time, and layered cutting is adopted to reduce the tool load and the risk of material edge collapse.

Processing technology control

The machining path planning should follow the principle of "rough carving first and then fine carving": most of the allowance is removed in the rough carving stage, and small feed and high rotation speed are adopted in the fine carving stage to ensure the dimensional accuracy and surface smoothness of the bottom die; When carving the outline, choose the forward milling method as far as possible to reduce the pull between the cutter and the fiber and avoid the edge fuzzing.

In the process of machining, it is necessary to continuously blow with high-pressure air gun or cool with a small amount of cutting fluid. On the one hand, the fiber dust generated by cutting should be cleaned to prevent the dust from adhering to the machined surface and affecting the accuracy; On the other hand, the tool temperature is reduced to avoid material softening or tool coating falling off caused by high temperature.

Avoid continuous processing of the same position for a long time, prevent local overheating from causing carbonization and delamination of fiber materials, and set the interval of segmented processing to allow cooling time for tools and materials.

Dust and safety protection

Fiber dust (especially carbon fiber dust) is easy to float and has conductivity, which not only pollutes precision parts such as equipment guide rails and screw rods, but also may cause harm to human respiratory tract. When processing, the dust collection system of the equipment should be turned on, and the operators should wear dust masks and protective glasses.

After the processing is completed, clean the dust on the workbench, guide rail and spindle of the equipment with high-pressure air gun in time, and check the lubrication system of the equipment regularly to prevent the dust from entering and causing the parts to wear.

Precision detection and post-processing

After machining, use calipers, micrometers and other tools to detect the dimensional tolerance and flatness of the bottom die to confirm whether it meets the requirements of the drawings; If there are slight burrs on the surface, it can be polished gently with fine sandpaper with moderate attention to avoid damaging the fiber structure.

If the bottom die has the need of subsequent bonding and assembly, it is necessary to clean the machined surface to remove dust and oil pollution, so as to ensure the stability of subsequent processes.