How to select cutting parameters for cutting tools in CNC machining?

The tool handle is a common connector. NC machining also has certain requirements for the stiffness and accuracy of the tool handle. What types of NC tool handles are there? Look what Sheng Anbei said!

Hydraulic TOOL HOLDER: This is to use hydraulic pressure to shrink the inner diameter of the Tool Holder to clamp the tool. It is more convenient to operate. Generally, a T-wrench is required. This is a relatively simple clamping method in the tool holder.

Milling cutter handle: this NC cutter handle compresses the main body of the NC cutter handle to shrink through the nut, so as to clamp the cutter. It has high rigidity and strong clamping force. It is also a tool with large clamping force in the cutter handle.

Side fixed tool handle: it is used to lock the cutting tool through the side fixed screws, mainly for rough machining such as drill bit and milling cutter flattened at the handle.

Spring Tool Holder: the taper spring jacket is used to gradually shrink in the process of axial movement to clamp the tool.

Which of these CNC tool handles do you often use? The use methods of various tool handles will be different. When selecting tool handles for machining, it is recommended to select them according to production needs.

The tool selection and cutting parameters determination in NC machining are completed in the state of human-computer interaction, which is in sharp contrast to ordinary machine tool machining. At the same time, it also requires programmers to master the basic principles of tool selection and cutting parameters determination, and see how to reasonably select cutting parameters?

Principle of reasonable selection of cutting parameters

During rough machining, productivity is generally improved, but economy and processing cost should also be considered; In semi finishing and finishing, the cutting efficiency, economy and processing cost should be considered on the premise of ensuring the processing quality.

The specific value shall be determined according to the machine tool manual, cutting parameter manual and experience. The following factors should be considered:

1. Cutting depth t. When the rigidity of machine tool, workpiece and tool allows, t is equal to machining allowance, which is an effective measure to improve productivity. In order to ensure the machining accuracy and surface roughness of parts, a certain allowance shall be reserved for finish machining. The finishing allowance of CNC machine tools can be slightly smaller than that of general machine tools (welcome to WeChat official account: industrial manufacturing).

2. Cutting width L. Generally, l is directly proportional to the tool diameter D and inversely proportional to the cutting depth. In the machining process of economical NC machine tools, the value range of L is generally L = (0.6 ~ 0.9) d.

3. Cutting speed v. Increasing V is also a measure to improve productivity, but V is closely related to tool durability. With the of V, the tool durability decreases sharply, so the choice of V mainly depends on the tool durability. In addition, the cutting speed is also closely related to the processing materials. For example, when milling alloy 30crni2mova with an end milling cutter, V can be about 8m / min; When milling aluminum alloy with the same end milling cutter, V it can be more than 200m / min.

4. Spindle speed n (R / min). The spindle speed is generally selected according to the cutting speed v. The calculation formula is: v = Πnd / 1000. The control panel of the NC machine tool is generally equipped with a spindle speed adjustment (magnification) switch, which can adjust the spindle speed by an integral multiple during the machining process.

5. Feed speed VF. VF shall be selected according to the machining accuracy and surface roughness requirements of parts and the materials of tools and workpieces. The increase of VF can also improve production efficiency. When the requirement of machined surface roughness is low, VF can be larger. During processing, VF can also be manually adjusted through the repair switch on the machine tool control panel, but the feed speed is limited by the equipment stiffness and feed system performance.