Processing technology range of the hottest CNC mil

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The processing range of CNC milling machine

milling is one of the most commonly used processing methods in machining. It mainly includes plane milling and contour milling, and it can also drill, expand, ream, bore, spot facer and thread processing for parts. NC milling is mainly suitable for the processing of the following types of parts

1. Plane parts

plane parts refer to parts whose machining surface is parallel or perpendicular to the horizontal plane, and the angle between the machining surface and the horizontal plane is a certain value. This kind of machining surface can be expanded into a plane

the three parts shown in Figure 4.1 are plane parts. Among them, the curved contour surface a is perpendicular to the horizontal plane and can be processed by cylindrical end mills. The side B of the boss forms a certain angle with the horizontal plane, and this kind of processing surface can be processed with a special angle forming milling cutter. For the inclined plane C, when the size of the workpiece is small, the inclined plate can be used for leveling and processing; When the size of the workpiece is large and the slope of the inclined plane is small, it is also commonly processed by the line cutting method. At this time, the fixed fingers or slight fracture blade traces on the face when cutting will be left on the processing surface, which should be removed by the clamp repair method

a) contour surface a b) contour surface B C) contour surface C

figure 4.1 plane parts

2. Ruled surface parts

ruled surface parts refer to surface parts generated by straight lines moving according to a certain law. As shown in Figure 4.2, the machined surface of the part is a ruled surface. When the ruled surface changes from section (1) to section (2), the included angle between it and the horizontal plane changes uniformly from 3 ° 10 'to 2 ° 32', and from section (2) to section (3), it changes uniformly to 1 ° 20 ', and finally to section (4), the bevel angle changes uniformly to 0 °. The machining surface of ruled surface parts cannot be expanded into a plane

when machining ruled surface parts with 4-axis or 5-axis NC milling machine, the connection between the machining surface and the circumference of the milling cutter is a robust data processing function, and the moment of contact is a straight line. This kind of parts can also be processed approximately by using the line cutting method on the three-axis NC milling machine

Figure 4.2 ruled surface 3. Solid surface parts whose machining surface is spatial surface are called solid surface parts. The machined surface of this kind of parts cannot be developed into a plane. Generally, the ball end milling cutter is used for cutting, and the machined surface is always in point contact with the milling cutter. If other cutters are used for processing, it is easy to produce. Due to the different shape and size of bolt fasteners, the need for large load, and the need for high temperature experiments, the difficulty of tensile experiments of metal bolt fasteners is increased, resulting in interference and milling damage to the adjacent surface. Generally, three-dimensional NC milling machines are used to process three-dimensional curved surface parts, and the following two processing methods are adopted

(1) line cutting processing method uses a three-axis CNC milling machine for two axis half coordinate control processing, that is, line cutting processing method. As shown in Figure 4.3, the ball end milling cutter performs linear interpolation along the curve of the XY plane. When a curve is processed, it feeds along the X direction Δ X reprocesses another adjacent curve, so the plane curve is used to approach the whole surface in turn. Distance between two adjacent curves Δ X shall be selected according to the requirements of surface roughness and the radius of ball end milling cutter. The ball radius of ball end milling cutter should be selected as large as possible to increase the rigidity of the cutter, improve the heat dissipation and reduce the surface roughness value. When machining concave arcs, the radius of the ball head of the milling cutter must be less than the minimum radius of curvature of the machined surface

figure 4.3 line cutting processing method

(2) three axis linkage processing adopts three-axis CNC milling machine, that is, spatial linear interpolation. For example, semi spherical shape can be processed by line cutting method or three coordinate linkage method. At this time, the CNC milling machine uses the spatial linear interpolation of X, y and Z coordinate linkage to realize spherical processing, as shown in Figure 4.4. Figure 4.4 three coordinate linkage processing

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