1. Classification of commonly used toolholders for CNC machine tools
Compared with ordinary processing methods, CNC machining has stricter requirements on tool rigidity, precision, durability and dynamic balance performance. The selection of tools should focus on the analysis of the structure and processability of the workpiece, combined with the processing capabilities of the CNC machine tool, the workpiece material and the process content.
The commonly used tool holders for CNC machining are mainly divided into drilling tool holders, boring tool holders, milling tool holders, thread tool holders and straight shank tool holders (end milling cutter holders and spring chuck holders).
2. Selection of commonly used toolholders for CNC machine tools
Tool handle structure
The structure of tool holders for CNC machine tools is divided into two types: integral and modular. The integral tool holder has a working part that clamps the tool and a handle that is used to install and position the tool on the machine tool. This type of tool holder has poor adaptability to the changes of machine tools and parts. In order to adapt to the changes of parts and machine tools, users must reserve tool holders of various specifications, so the utilization rate of tool holders is low. The modular tool system is a more advanced tool system, and each tool holder can be assembled through various serialized modules. According to different processing parts and machine tools, different assembly schemes can be adopted to obtain a variety of tool holder series, thereby improving the adaptability and utilization rate of tool holders.
The selection of toolholder structure should take into account both advanced technology and economic rationality: ① For some simple tools that are used repeatedly for a long time and do not need to be assembled, it is advisable to equip them with integral toolholders, so that the tools have good rigidity and are cheap (such as end mill toolholders, spring chuck toolholders and drill chuck toolholders for machining the outer contour of parts); ② When machining multi-variety and small batch parts with frequently changing hole diameters and hole depths, modular toolholders should be used to replace a large number of integral boring toolholders to reduce processing costs; ③ For CNC machine tools, especially when the machine tool spindle ends and tool change manipulators are different, modular toolholders should be used. Since the intermediate modules (connecting rods) and working modules (tool loading modules) used by various machine tools can be used universally, equipment investment can be greatly reduced and tool utilization can be improved.
Tool handle specifications
Most of the CNC tool holders are: conical tool holders, and use the corresponding type of rivet tensioning structure to match the machine tool spindle. The holder has various specifications, and the commonly used ones are No., No. and No. At present, ISO-, GB-, MAS-, ANSI/ASMEB.-, etc. are widely used in my country. When choosing, the specifications of the holder should be considered to be compatible with the machine tool spindle and manipulator.
Specifications and quantity of tool handle
The integrated TSG tool system includes hundreds of toolholders. Users can select toolholders according to the CNC machining process of typical parts to be processed, which can meet the processing requirements without causing backlogs. Considering that a certain number of toolholders are in pre-adjustment or tool grinding while the CNC machine tool is working, the number of toolholders is usually twice the required number.
Matching of knife and handle
Pay attention to the matching of the tool holder and the tool, especially when choosing a tapping tool holder, pay attention to the size of the tap drive square head. In addition, using a single-edge boring tool on a CNC machine tool can avoid scratching the workpiece when the tool is withdrawn.