Precautions for selecting toolholder of CNC machine tool
August 03, 2022
The method of selecting cutting tools and the selection of tool shanks of CNC machine tools directly affect the performance of the machine tools and the whole machining efficiency. If there are too few tool handles, the machine tool cannot realize some operations; Too many knife handles will affect the investment. Therefore, the selection of NC tool holders should pay attention to methods.
1. Structural form of toolholder
The structure of CNC machine tool tool shank is divided into integral type and modular type. The working part of the clamping tool of the integral tool handle is integrated with the handle for installation and positioning on the machine tool. This kind of tool handle has poor adaptability to the transformation of machine tools and parts. In order to adapt to the transformation of parts and machine tools, users must reserve knife handles of various specifications, so the utilization rate of knife handles is low. Modular tool system is a more advanced tool system. Each tool handle can be assembled through various series of modules. According to different processing parts and machine tools, different assembly schemes can be adopted to obtain a variety of tool handle series, so as to improve the adaptability and utilization of tool handles.
The selection of the structural form of the tool handle should take into account the 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 appropriate to equip with an integral tool handle, so that the tool is rigid and cheap (such as the end mill tool handle, spring collet tool handle and drill collet tool handle used for processing the outer contour of parts); ② When machining multi variety and small batch parts with frequently varying aperture and hole depth, modular tool handles should be selected to replace a large number of integral boring tool handles and reduce processing costs; ③ For many CNC machine tools, especially the spindle end of the machine tool and the tool changing manipulator are different, it is appropriate to choose modular tool handle. Since the intermediate module (extension rod) and working module (tool loading module) used by each machine tool can be used universally, the equipment investment can be greatly reduced and the utilization rate of tools can be improved.
2. Knife handle specification
Most NC tool shanks adopt 7:24 taper tool shanks, and adopt the corresponding type of pull nail tension structure to match with the machine tool spindle. The handle has various specifications, and the commonly used ones are No. 40, No. 45 and No. 50. At present, iso7388-1983, gb10944-1989, mas403-1982, ansi/asmeb5.50-1985, etc. are widely used in China. When selecting, the specification of the tool handle should be considered to adapt to the machine tool spindle and manipulator.
3. Specification and quantity of tool holder the integrated TSG tool system includes 20 kinds of tool handles, with hundreds of specifications. Users can select the variety and specification of tool handles according to the NC processing technology of typical parts processed, which can meet the processing requirements without causing backlog. Considering that a certain number of tool shanks are in preset or tool grinding while the CNC machine tool is working, the number of tool shanks is usually 2 ~ 3 times that of the required tool shanks.
4. Matching of cutter and toolholder
Pay attention to the matching between the tool holder and the tool, especially when selecting the tapping tool handle, pay attention to the size of the matched tap transmission square head. In addition, selecting a single edge boring tool on the NC machine tool can avoid scratching the workpiece during tool withdrawal, but attention should be paid to the position and direction of the tool tip relative to the keyway on the tool handle: some machine tools are required to be consistent with the keyway orientation, while others are required to be perpendicular to the keyway orientation.
