Steadfastness
According to DIN 6583, the stability refers to the ability of an active pair ( workpiece and tool ) to withstand certain machining processes .
The tool life is influenced by the cutting edge retention of the tool, the machinability of the material and the tool life conditions , i. H. the conditions that affect the machining process.
Stand conditions
The most important stand conditions are:
- Workpiece geometry and material
- Tool geometry and material ( cutting material )
- Cutting speed .
Further stand conditions are
- the static and dynamic rigidity of the machine tool
- the kinematics of the machining process
- the cutting conditions
- the environment
- the amount of cooling lubricant
- the thermal boundary conditions during processing .
Stand sizes
Stand sizes are according to DIN 6583
- the service life (most important)
- the tool life
- the standing quantity or the standing volume ,
which are achieved under certain standing conditions until a certain standing criterion occurs. The various stand sizes are therefore always assigned associated criteria and conditions.
Wear parameters are often used as standing criteria . Wear on machining tools is usually the width of wear measured, which is a measure for the free surfaces is wear, and with the scour depth, which is a measure for the crater wear on the rake face is. For example, this means that the service life until a wear mark width of 0.2 mm is reached at a cutting speed of 200 m / min is equal to 60 minutes.
The following values are usually used as permissible wear mark widths:
Wear mark width | High speed steel / carbide | Cutting ceramics |
---|---|---|
Roughing | 0.8 to 1.0 mm | 0.3 mm |
Finishing | 0.2 to 0.4 mm | 0.3 mm |
Other standing criteria besides wear are
- the cutting force
- the cutting performance
- the surface roughness on the workpiece
- the chip shape
- the chip temperature.
Relationship between the stand sizes
In some processes it is common to specify the tool life, which depends on the tool life .
When drilling and milling , the tool life is measured in the feed direction:
With:
- - Tool life in feed direction (Engl. Feed )
- - feed
- - speed ,
when planing and broaching in the cutting direction:
With
- - Tool life in the cutting direction (English cut )
- - cutting speed.
Sometimes the tool life is also given, which also depends on the tool life:
With
- - prime time .
In addition to the service life, the stability can generally also be specified by the conditions or criteria:
Here the cutting speed of a certain tool, at which a wear mark width of 0.2 mm is reached within 15 minutes, is equal to 200 m / min.
The value
however, indicates the cutting force for a cutting depth of 2 mm and a tool life of N = 500.
See also
Individual evidence
- ^ Fritz Klocke, Wilfried König: Manufacturing process 1. 8th edition. 2008, p. 259.
- ↑ a b c d Fritz Klocke, Wilfried König: Manufacturing process. 8th edition. Springer, 2008, p. 259 f.
- ^ Alfred Herbert Fritz, Günter Schulze: Manufacturing technology. 11th edition. Springer, 2015, p. 289 f.
- ↑ Berend Denkena, Hans Kurt Tönshoff: Spanen - basic. 3. Edition. Springer, 2011, p. 149.
- ↑ Herbert Schönherr: Machining production. Oldenbourg, 2002, p. 48.