1. Characteristics of indexable cutting tools for CNC lathes
Compared with general lathes, the indexable turning tools used in CNC lathes are generally not fundamentally different, and their basic structure and functional characteristics are the same. However, the machining process of CNC lathes is automatically completed, so the requirements for indexable turning tools are different from those used in general lathes.
2. Tool selection process of CNC lathe tools
The tool selection process of CNC lathe tool requires ten basic steps from the analysis of the processed part drawing to the selection of the tool. The tool selection process starts from the "part drawing" and passes through two paths to the last icon "selected tool" to complete the tool selection work.
Among them, the first route is: part drawing, influencing factors of machine tool, selection of tool bar, blade clamping system, selection of blade shape, mainly considering the situation of machine tool and tool; The second route is: influencing factors of the workpiece, selecting the material code of the workpiece, determining the chip breaking groove code or ISO chip breaking range code of the blade, and selecting the processing condition mask. This route mainly considers the situation of the workpiece. Only by combining the results of these two routes can the selected cutting tools be determined.
(1) Influencing factors of machine tool
In order to ensure the feasibility and economy of the processing scheme and obtain the best processing scheme, the following factors related to the machine tool must be determined before the tool selection:
1) Machine tool type: CNC lathe, turning center.
2) Tool accessories: shape and diameter of tool handle, left and right cutting tool handles.
3) Spindle power.
4) Workpiece clamping mode.
(2) Select tool bar
When selecting the cutter bar, the cutter bar with the largest size should be selected first, and the following factors should be considered at the same time:
1) Clamping mode.
2) Section shape of cutting layer, i.e. cutting depth and feed rate.
3) The overhang of the knife handle.
(3) Blade clamping system
1) Lever clamping system: lever clamping system is the most commonly used blade clamping method. Its characteristics are: high positioning accuracy, smooth chip cutting, simple operation, and can be used with other series of tool products.
2) Screw clamping system: features: suitable for small bore inner hole and long overhang processing.
(4) Select blade shape
1) Knife point angle: the size of the knife point angle determines the strength of the blade. On the premise that the structural shape of the workpiece and the rigidity of the system allow, the tool tip angle should be as large as possible. Usually this angle is between 35 degrees and 90 degrees.
2) Basic types of blades: blades can be divided into positive and negative types. Positive blade: for internal contour processing, small machine tool processing, poor rigidity of the process system and complex structural shape of the workpiece, positive blade should be preferred. Negative blade: for cylindrical processing, negative blade should be preferred when metal removal rate is high and processing conditions are poor.