Structure of Cutting Tools

  • The structure of various CNC cutting tools is composed of clamping part and working part. The clamping part and working part of the whole structure cutter are made on the cutter body; The working part (cutter tooth or blade) of the cutter with inlaid tooth structure is inlaid on the cutter body.

    There are two types of tool clamping parts: with hole and with handle. The tool with hole is set on the spindle or spindle of the machine tool by the inner hole, and the torsional moment is transmitted by the axial key or end key, such as cylindrical milling cutter, sleeve face milling cutter, etc.

    There are three kinds of tools with handles: rectangular handle, cylindrical handle and conical handle. Turning tools and planers are generally rectangular shank; The tapered shank bears axial thrust by taper and transmits torque by friction; Cylindrical shank is generally suitable for small twist drills, end mills and other tools. When cutting, the friction generated by clamping is used to transfer the torque. Many tools with handles are made of low alloy steel, while the working part is made of high speed steel by butt welding the two parts.

    The working part of the tool is the part that produces and processes chips, including the blade, the structure that breaks or rolls the chips, the space for chip removal or storage, the channel of cutting fluid and other structural elements. The working part of some cutting tools is the cutting part, such as turning tool, planer, boring tool and milling tool; The working part of some cutting tools includes cutting part and calibration part, such as drill, reamer, broach and tap. The function of the cutting part is to remove the chip with the blade, and the function of the calibration part is to polish the machined surface and guide the tool.

    There are three kinds of structure of tool working part: integral type, welding type and mechanical clamping type
    The overall structure is to make a cutting edge on the cutter body;
    The welding structure is to braze the blade to the steel body;
    There are two mechanical clamping structures, one is to clamp the blade on the tool body, the other is to clamp the brazed cutter head on the tool body.

    Cemented carbide cutting tools are generally made into welding structure or mechanical clamping structure; All ceramic cutting tools adopt mechanical clamping structure. The geometric parameters of the cutting part have a great influence on the cutting efficiency and machining quality. Increasing the rake angle can reduce the plastic deformation of the rake face when extruding the cutting layer, and reduce the friction resistance of the chip flowing through the front, so as to reduce the cutting force and cutting heat. However, increasing the rake angle will reduce the strength of the cutting edge and the heat dissipation volume of the cutter head.

    When selecting the angle of cutting tool, we need to consider the influence of many factors, such as workpiece material, cutting tool material, processing properties (rough and finish machining), etc., which must be reasonably selected according to the specific situation. Generally speaking, the tool angle refers to the marking angle for manufacturing and measurement. In actual work, due to the different installation position of the tool and the change of cutting movement direction, the actual working angle and marking angle are different, but the difference is usually very small.