1、 CNC precision machining sequence

When the mold is large and deep, soft machining is used for rough and semi finish machining before quenching, and hard machining is used for finish machining after quenching; Small, shallow molds can be milled once after quenching. If the mold wall is very thin and the mold cavity is deep, electrical machining is used.

If the mold cavity has a large and flat bottom surface, use an integrated milling cutter for rough machining, and then use a round nose milling cutter to clear the corners. The cutting force and heat dissipation effect of the integrated milling cutter are very good. The round nose milling cutter is more efficient than the flat bottom cutter in processing parts that require back chipping and is not prone to edge breakage

2、 Selection of nc precision machining tools

When CNC precision machining hardened molds, the correct selection of milling cutters is important. Generally, it is a good choice to choose tools with a high rigidity cutter body design, high temperature resistance, wear-resistant coating, and superhard materials for production. The high-speed and high hardness H series introduced by Zhongshan Ailang Precision Tools achieve high-speed and high hardness machining below HRC 70. In addition, the rigidity of the tool is very important. In order to increase the rigidity of small diameter milling cutters, the diameter of the tool shank is made much larger than the diameter of the tool, in order to improve the machining smoothness and extend the tool life; The overhang length of the tool holder should be as short as possible. On the other hand, selecting a new coating allows the tool to withstand higher cutting temperatures, such as the acidification temperature of the Tisin and Cygnus-X coatings of 1300 ℃, the surface hardness of Hv3700, and the coating thickness of 4um. Therefore, they are more suitable for high-speed and hardened mold processing

3、 Selection of Tool Handles and Tool Clamping for CNC Precision Machining

The knife handle should have dynamic balance or select a sintered knife handle, and the shape of the knife handle should adapt to the structure of the mold. Generally, there should be a half degree gap between the milling cutter and the side of the workpiece. For example, if the side of the workpiece is a 3 ° bevel, the shape of the tool shank should be made to be 5/2 to obtain great rigidity. If the side surface of the workpiece is a 90 ° straight surface, the tool handle should adopt a thin neck structure.

Fixing a milling cutter is very important, which involves factors such as the tolerance of the shank, the fit between the shank and the cutter holder, and the radial runout after installation. For this reason, the manufacturing tolerance of the tool shank should be from -0.0025mm to -0.005mm, or a heat shrinkable clamp should be used to clamp the tool.

4、 Selection of NC Precision Machining Machine Tools and Key Points of NC Programming

Good results can only be achieved by using a machine tool with good rigidity and high accuracy. When programming for machining high hardness molds, spiral interpolation should be used to insert the path of the tool into the mold, so that the cutting process is more stable. In situations where lateral or spiral cutting cannot be used, oblique wave cutting should be used to avoid axial cutting. The programming also determines the size of the radial tool path and the cutting depth.