Currently, when processing parts on various milling and boring machines, in the conditions of the main and repair production, special tools are used. One such tool is a boring cutter.
It is used for making holes of large and small diameters to various depths. This boring is used in the details of the automotive industry, general engineering and instrumentation (gearboxes, cylinder liners, bearings, and so on).
Cutter design
It consists of a carbide rod soldered into a steel shank, which has a flat working part. Currently, there are many new models of this device. Thanks to innovations in these tools, chip outflows from the boring area were much improved. However, in any case, the boring cutter has a rod and a working part - a head. Therefore, the design of this tool is not complicated.
The rod has a rectangular or circular cross section. It is usually made of high-quality carbon
steel of grade 45. The rear part of the shank is used for fastening in the mandrel, and the head is used to install the cutting part, which, depending on size and modification, has the form of a plate or insert and is made of
high-speed steel P9, P18, P6M5. Slightly less common are these elements made of hard alloy (VK8, T5K10, T15K6) or mineral ceramics.
Boring Cutter - Sharpening
This process is not complicated if there is special equipment. This is done on the grinding machine. The result is the required cutting geometry. The head of this tool is sharpened along with the cutting insert. The front, rear, and plan angles are formed. The choice of tool geometry is made taking into account the properties of the processed material and processing modes.
Process features
The specificity of boring, especially of small diameters, is difficult chip control. The work is carried out in a closed area, chips accumulate, get off, as a result of which the cutting process is hindered, heat dissipation worsens and the treated surface can be damaged. To solve this problem, cutting fluid (coolant) is used. It removes heat and flushes chips into special chipbreaking grooves on the front surface of the cutting part of the cutter. This is important in this case. The specified groove is a well with a rounded bottom. As a result of the use of chip control elements, it is possible to avoid the formation of drainage chips, which are woven into “beards” and block the operation of the tool, as a result of which the boring cutter can fail.
Fixture mounting
A boring cutter is installed in mandrels having sockets for installing the corresponding holder profile. They come in different types. They also have a tapered shank according to GOST. The boring cutter is fixed mechanically. When processing deep holes or small diameters, adapter mandrels are used. They are selected so that it can be installed in the cone of the spindle of the machine. Short cantilever mandrels allow you to install two cutters at the same time and work as a combined tool, which increases productivity when finishing large holes. This is convenient in this case. Also, the processing of holes is performed on universal machines where a boring lathe cutter is used. It differs from the usual specified tool in the size of the holder and the method of attachment. Mandrels are not used here. The shank of the cutter has a massive cross section (25x25, 32x25, 40x40 mm) and is mounted in the tool holder with screws.