1. Definition
Climb milling: means that the cutting speed direction of the tool is the same as the moving direction of the workpiece.
Up-milling: means that the cutting speed direction of the tool is opposite to the moving direction of the workpiece.
2. Discrimination method
When milling the outer contour of the workpiece, programming and programming in the clockwise direction along the outer contour of the workpiece is down milling; programming and feeding along the outer contour of the workpiece in the counterclockwise direction is reverse milling; when milling the inner contour of the workpiece, programming along the inner contour of the workpiece Feeding and programming in the counterclockwise direction is called down milling, programming and feeding in the clockwise direction along the inner contour of the workpiece is called reverse milling.
picture
3. Characteristics of down milling and up milling
1. During down milling, the cutting thickness of each tool gradually changes from small to large. When the cutter tooth first contacts the workpiece, the cutting thickness is zero. Only when the cutter tooth slides a certain distance on the cutting surface left by the previous cutter tooth and the cutting thickness reaches a certain value, the cutter tooth actually starts cutting. Up milling causes the cutting thickness to gradually change from large to small, and the sliding distance of the cutter teeth on the cutting surface is also very small. Moreover, during down milling, the distance traveled by the cutter teeth on the workpiece is also shorter than that during up milling. Therefore, under the same cutting conditions, the tool is prone to wear when up milling is used.
2. During up milling, since the horizontal cutting force direction of the milling cutter acting on the workpiece is opposite to the feed movement direction of the workpiece, the worktable screw rod and the nut can always keep one side of the thread in close contact. This is not the case in down milling. Since the direction of the horizontal milling force is consistent with the direction of the feed movement of the workpiece, when the force of the cutter teeth on the workpiece is large, the worktable will shift due to the gap between the worktable screw and the nut. This not only destroys the stability of the cutting process, affects the processing quality of the workpiece, but also damages the tool in severe cases.
3. During up milling, due to the large friction between the cutter teeth and the workpiece, the cooling and hardening of the machined surface is more serious.
4. During down milling, the cutter teeth start cutting from the surface of the workpiece every time, so it is not suitable for processing workpieces with hard skin.
5. The average cutting thickness during down milling is large, the cutting deformation is small, and the power consumption is less than that of up-milling (when milling carbon steel, power consumption can be reduced by 5%, and when milling difficult-to-machine materials, it can be reduced by 14%).
