1
Basic classification of cutting tools
Depending on the end geometry:
1) Flat bottom cutter
2) Flat bottom R angle milling cutter
3) Ball end mill
4) Integrated indexable end mill
2
Basic geometry of cutting tools
3
Geometric precision of cutting tools
For cutting tools used for finishing, the cutting edges must have very good contour accuracy.
Several possible tool contour deviations:
1) Accurate overview;
2) The grinding process is not precise enough, resulting in irregular chips on the blade;
3) Radius deviation due to imprecise grinding process.
If the precision of the workpiece is very high, you should purchase a standard certified tool from the tool manufacturer.
4
Ensure the minimum radial runout error of the tool
Assuming that the maximum overhang length of the tool holder and tool system does not exceed the specified value, in order to ensure that the spindle can work accurately, the radial runout error of the tool should be detected at the tool holder and cutting edge respectively. If the radial runout error is too large, it will cause severe vibration of the spindle.
5
How to choose the right cutting tool
1) Analyze the specific processing conditions, such as spindle and machine tool performance, tool clamping system, lubrication method, etc. ;
2) Analyze the material properties of the workpiece;
3) Analyze the processing surface quality, processing accuracy requirements, costs, etc. ;
4) Comprehensively consider various factors and make the optimal choice.
6
Method for calculating high-speed cutting processing parameters
Three important formulas:
Several important terms and processing parameters in the high-speed cutting process
1. Cutting speed Vc
Definition of cutting speed: Vc=N*p*Deff/1000
Vc refers to the appropriate cutting speed value suitable for high-speed processing of a certain workpiece material under the conditions of a specific tool. It refers to the linear speed of the tool.
How to correctly set the cutting speed Vc value:
Provided by tool supplier;
Refer to existing experimental data;
Establish your own database through a large number of cutting experiments.
The Vc value is an important basis for correctly setting other cutting parameters!
Effect of cutting speed on surface roughness:
Comparison of the color of iron shavings produced at different cutting speeds:
2. Effective diameter of the Deff tool
Effective tool diameter and calculation of effective tool diameter.
3. Feeding by fz blade
Definition of blade feed:
How to correctly adjust the feed per edge of the tool:
Supplied by cutting tool suppliers;
Refer to experimental data obtained by others;
Obtained through numerous cutting experiments.
Whether or not the edge feed is set correctly has an extremely important impact on the reasonable distribution of the cutting load on the tool.
4. Axial and radial feed ap& ae
Calculation of axial feed:
Depending on the spindle, tool and material, actual results will be affected.
The influence of Ae and Fz on softness▼
Methods for calculating cutting parameters in high-speed machining
Adjusting processing parameters
Three important formulas:
(1) Principles for defining processing parameters
1) When machining at high speed, the processing parameters need to be optimized and cannot be adjusted at will;
2) The cutting speed Vc value must be correctly set;
3) The blade feed fz must be adjusted correctly.
A reasonable value can maximize the cutting performance of the tool to the limit, make full use of the tool, and improve the quality and processing efficiency. This will not affect tool life, thereby reducing costs and enabling true high-speed machining;
(2) Treatment test
Test the tool’s ability to cut S136. The tools used in this experiment are as follows:
1) Diameter: 10 mm
2) Number of blades: 6
3) Front angle: -13°
4) Coating: TiAlN
Test items:
in conclusion:
1) When Vc increases from 150 to 250, the noise improves significantly;
2) Different Vc values have different colors of iron filings, which proves that the processing temperature is different;
3) Changes in Fz will also affect the cutting temperature.
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