The selection of CNC tool and the determination of cutting amount are important contents in the CNC machining process. It not only affects the machining efficiency of CNC machine tools, but also directly affects the machining quality. The development of CAD/CAM technology makes it possible to directly use CAD design data in CNC machining, especially the connection between DNC system microcomputer and CNC machine tool, so that the whole process of design, process planning and programming is completed on the computer, generally not Need to export a special process file.
At present, many CAD/CAM software packages provide automatic programming functions. These softwares generally prompt the process planning related problems in the programming interface, such as tool selection, machining path planning, cutting usage setting, etc., programmers only need to set up relevant The parameters of the NC program can be automatically generated and transferred to the CNC machine for processing.
Therefore, the tool selection and cutting amount determination in NC machining is completed under the human-computer interaction state, which is in sharp contrast with the ordinary machine tool processing. At the same time, the programmer must also master the basic principles of tool selection and cutting amount determination. When programming, fully consider the characteristics of CNC machining, and can correctly select the cutting tool and the cutting amount.
Types and characteristics of commonly used tools for CNC machining CNC machining tools must adapt to the high speed, high efficiency and high degree of automation of CNC machine tools. Generally, they should include general-purpose tools, universal connecting shanks and a small number of special shanks. The shank is to be connected to the tool and mounted on the power head of the machine, so it has been standardized and serialized. There are several ways to classify CNC tools. According to the tool structure can be divided into:
Integral;
Inlaid type, using welding or machine clamp type connection, the machine clamp type can be divided into two types: non-indexing and indexable;
Special types, such as composite tools, shock absorbing tools, etc.
According to the materials used to manufacture the tool, it can be divided into:
High speed steel cutter;
Carbide tool;
Diamond cutter
Other material tools, such as cubic boron nitride tools, ceramic tools, etc.
From the cutting process can be divided into:
Turning tools, such as outer circle, inner hole, thread, cutting tool, etc.;
Drilling tools, including drill bits, reamers, taps, etc.;
Boring tool
Milling tools, etc.
In order to meet the requirements of CNC machine tools for tools that are durable, stable, easy to adjust, and changeable, in recent years, machine-clampable indexable tools have been widely used, reaching 30% to 40% of the entire CNC tool in number, metal removal The amount accounts for 80% to 90% of the total.
Compared with the tools used on ordinary machine tools, CNC tools have many different requirements, mainly including the following features:
Good rigidity (especially roughing tools), high precision, anti-vibration and small thermal deformation;
Good interchangeability, easy to change the knife quickly;
High life, stable and reliable cutting performance;
The size of the tool is easy to adjust to reduce the tool change time;
The tool should be able to reliably break chips or crumbs to facilitate the removal of chips;
Serialization and standardization for programming and tool management.
Next page
