End mill with gradient edge geometry and grinding method thereof

A grinding method of an end mill with a gradient edge geometry, applied to a tool, wherein the tool comprises a cutter head, a cutting blade, an edge, and an end blade, and the grinding method comprises:

• step S1:
• for a same to-be-machined part, performing an actual machining experiment by end mills with different gradient edge geometries under a same cutting condition, so as to acquire cutting state data of each of the end mills with the different gradient edge geometries on the same to-be-machined part, wherein the gradient edge geometries each comprise an edge width and an edge angle;
• and the cutting state data comprises a cutting load parameter, a cutting temperature parameter, and a cutting vibration amplitude parameter applied to an edge:
• sequentially marking the edge width and the edge angle as RKd and RKj, and setting a preliminary range of the edge width as 0.1 mm≤RKd≤0.5 mm;
• setting a range of the edge angle as 10°≤RKj≤40°;
• according to a parameter range of the gradient edge geometry, selecting end mills with different edge geometries, and preparing the end mills with the different gradient edge geometries in a grinding process;
• measuring, by a force sensor in real time, the cutting load parameter applied to the tool in a cutting process of each end mill, wherein the cutting load parameter comprises a main cutting force and a side cutting force;
• monitoring, by an infrared thermal imager or an embedded thermocouple sensor, the cutting temperature parameter of the edge of the tool;
• and
• recording, by a three-dimensional (3D) vibration sensor, the cutting vibration amplitude parameter of the tool in the cutting process;
• step S2:
• according to experimental verification or evaluation of an expert panel, setting a lifetime evaluation criterion for the end mills with the different gradient edge geometries in the step S1, wherein the lifetime evaluation criterion is used for setting a reference value and an alert threshold for each parameter comprised in the cutting state data, and the alert threshold falls within a range of 0% to 100%;
• generating a preliminary adjustment strategy for the gradient edge geometry based on the reference value and the alert threshold;
• and adjusting the gradient edge geometry of the end mill based on the preliminary adjustment strategy;
• wherein the lifetime evaluation criterion comprises a cutting load parameter evaluation criterion, a cutting temperature parameter evaluation criterion, and a cutting vibration amplitude parameter evaluation criterion:
• sequentially marking the cutting load parameter, the cutting temperature parameter and the cutting vibration amplitude parameter as CL, CT and CV, sequentially marking the main cutting force and the side cutting force comprised in the cutting load parameter as CLm and CLs, sequentially marking an alert threshold of the cutting load parameter, an alert threshold of the cutting temperature parameter and an alert threshold of the cutting vibration amplitude parameter as a first alert threshold, a second alert threshold, and a third alert threshold, and adjusting the first alert threshold, the second alert threshold and the third alert threshold by the expert panel through experimental data;
• and
• sequentially marking an edge width and an edge angle adjusted through the preliminary adjustment strategy as RKd(t+1) and RKj(t+1), wherein t+1 in the RKd(t+1) and the RKj(t+1) is time when an actual cutting experiment in the following step S3 is performed;
• step S3:
• performing the actual cutting experiment by an adjusted end mill, and continuously monitoring the cutting state data in the actual cutting experiment;
• step S4:
• comparing the cutting state data obtained in the step S3 with a corresponding reference value and a corresponding alert value in the step S2 for analysis, and from the cutting load parameter, the cutting temperature parameter and the cutting vibration amplitude parameter, selecting a parameter exceeding an alert threshold set for the corresponding reference value;
• step S5:
• performing combined analysis on the cutting load parameter, the cutting temperature parameter and the cutting vibration amplitude parameter comprised in the cutting state data in the step S3 to generate an adjustment index, wherein the adjustment index is used for providing a fine adjustment strategy for the gradient edge geometry of the end mill according to the cutting state data selected in the step S4;
• and adjusting the gradient edge geometry of the end mill based on the fine adjustment strategy;
• and
• step S6:
• repeating the step S3 to the step S5, until the cutting load parameter, the cutting temperature parameter and the cutting vibration amplitude parameter comprised in the cutting state data each meet a corresponding lifetime evaluation criterion.