Grooving and cutting are shown in fig. 3-42 and are unique turning applications.
The applications of cutting and grooving include cylindrical grooving, cylindrical cutting, inner hole grooving, end face grooving and tool withdrawal groove.
The groove shapes include narrow groove, wide groove, shallow groove, deep groove and forming groove.
For the application of cutting tools, each groove has some special requirements.
Fig. 3-42 machining diagram of cutting and grooving turning tool
In general, cylindrical grooves are easiest to machine because gravity and cutting fluid can help remove chips.
In addition, the cylindrical groove processing is visible to the operator, and the processing quality can be directly and relatively easy to check.
However, some potential obstacles in workpiece design or clamping must be avoided.
Generally speaking, the cutting effect is the best when the tool tip of the grooving tool is kept slightly below the center line.
The inner hole grooving is similar to the outer circle grooving, but the difference is that the application of cutting fluid and chip removal are more challenging.
For inner hole grooving, the best performance can be obtained when the tool tip position is slightly higher than the centerline.
In order to better machine the end groove, the tool must be able to move in the axial direction.
The machining effect is best when the tool tip position of the end grooving tool is slightly higher than the center line.
The cutters used for cutting and grooving are mainly grooving cutters for various turning.
The process features are:
(1) One main cutting edge and two auxiliary cutting edges participate in three-sided cutting at the same time.
The plastic deformation of the material to be cut is complex, the friction resistance is large, the feed rate is small, the cutting thickness is thin, the average deformation is large, and the unit cutting force increases.
The total cutting force and power consumption are large, generally about 20% larger than that of cylindrical turning, with poor heat dissipation and high cutting temperature.
(2) The cutting speed changes constantly in the machining process, especially when cutting off machining, the cutting speed changes from maximum to zero.
Cutting force and cutting heat are also changing.
(3) As the workpiece rotates and the cutting tool cuts in continuously, the Archimedes spiral surface is actually formed on the workpiece surface, which causes the actual front angle and back angle to change constantly, making the process more complex.
(4) Due to the narrow width of the cutting tool, its relative suspension and elongation, its rigidity is poor, and it is easy to vibrate, especially when cutting and cutting deep grooves.
Chip removal is also a crucial factor in the cutting process.
As the tool moves deeper, there is less chance of chip breaking in the restricted space.
The chip breaking groove of the blade is mainly used to form neat chips for smooth chip removal.
The result of poor performance in this respect is chip blockage, which will lead to poor surface quality and tool breakage.