1. Reduce the quality of non-standard blades, reduce th […]
1. Reduce the quality of non-standard blades, reduce the number of non-standard blade components, and simplify the non-standard blade structure
In the structure of the cutter body, care should be taken to avoid and reduce the stress concentration. The grooves on the cutter body (including the cutter seat groove, the chip pocket and the keyway) may cause stress concentration and reduce the strength of the cutter body. Therefore, the through groove and the groove should be avoided as much as possible. The bottom of the groove has a sharp corner. At the same time, the structure of the cutter body should be symmetrical to the rotary shaft so that the center of gravity passes through the axis of the milling cutter. The clamping and adjustment structure of the blade and the tool holder should eliminate the play as much as possible, and the repeatability is required. Non-standard blades have been widely used, which greatly improves the rigidity and repeatability of the blade system, which is beneficial to the increase of the tool breaking limit speed. In addition, the diameter of the clip-on high-speed non-standard blade reveals a trend of smaller diameter and reduced number of teeth, which is also conducive to the improvement of tool strength and rigidity.
2. Improve the clamping method of non-standard blades
Simulation calculations and fracture test studies have shown that non-standard blade clamping methods do not allow for the usual frictional clamping, using a blade with a central hole, screw clamping, or a specially designed tool structure to prevent the blade from flying. . The clamping force of the blade seat and the blade is preferably in the same direction as the centrifugal force. At the same time, the pre-tightening force of the screw should be controlled to prevent the screw from being damaged in advance due to overload. For small diameter shank milling cutters, hydraulic chucks or thermal expansion shrink chucks are used for high precision and high stiffness.
3. Improve the dynamic balance of non-standard blades
Improving the dynamic balance of non-standard blades is of great help to improve the safety of high-speed milling cutters. Because the amount of unbalance of the blade creates an additional radial load on the spindle system, its magnitude is proportional to the square of the speed.