Identify the type of trench
It is important to identify three main trench types: outer circular grooves, inner grooves, and end face grooves.
Outer grooves are easiest to machine because gravity and coolant can help remove chips. In addition, the outer groove machining is visible to the operator and the machining quality can be checked directly and relatively easily. However, some potential obstacles in the design or clamping of the workpiece must also be avoided.
In general, the cutting effect is best when the tip of the grooving tool is kept slightly below the centerline. The inner bore grooving is similar to the outer diameter grooving, except that coolant application and chip evacuation are more challenging.
For grooves in bores, the best performance is obtained when the tip is positioned slightly above the centerline. To machine the face groove, the tool must be able to move in the axial direction, and the rake radius of the tool must match the radius to be machined. The machining effect is best when the tip position of the end groove cutter is slightly higher than the centerline.
Machine tool design and technical conditions
In grooving processing, the design type and technical conditions of the machine tool are also basic elements to be considered.
Some of the main performance requirements for the machine include: having enough power to keep the tool running in the correct speed range without stalling or jitter; It has high enough rigidity to complete the required cutting processing without flutter; Having a sufficiently high coolant pressure and flow rate to help chip evacuation; There is a high enough accuracy.
In addition, proper commissioning and calibration of the machine are essential in order to machine the correct groove shape and size.
Understand the material properties of the workpiece
Familiarity with some of the properties of the workpiece material, such as tensile strength, work hardening characteristics, and toughness, is essential to understand how the workpiece affects the tool.
When machining different workpiece materials, different combinations of cutting speed, feed, and tool characteristics are required. Different workpiece materials may also require specific tool geometries to control chips or specific coatings to extend tool life.
Choose a forming tool
When machining large batches, forming tools should be considered. The forming tool produces all or most of the groove shape in a single cut, freeing up the tool position and reducing the machining cycle time.
One disadvantage of non-blade forming tools is that if one of the teeth breaks or wears out faster than the others, the entire tool must be replaced. An important factor to consider is the mechanical power required to control the chips generated by the tool and the forming cut.
The role of feed and cutting speed
Feed and cutting speed plays a key role in trench machining. Incorrect feeds and cutting speeds can cause flutter, reduce tool life and extend machining cycle times. Add WeChat: Yuki7557 Send a macro program tutorial, and the factors affecting the feed and cutting speed include the workpiece material, tool geometry, coolant type, and concentration, insert coating, and machine performance.
In order to correct problems caused by unreasonable feed and cutting speed, secondary machining is often required. While there are many sources of information on "optimal" feeds and cutting speeds for a wide range of tools, the most up-to-date and useful information usually comes from the tool manufacturer.
Select the tool coating
The coating can significantly increase the life of the carbide insert. Since the coating provides a lubricating layer between the tool and the chip, it also reduces machining time and improves the surface finish of the workpiece. At present, commonly used coatings include TiAlN, TiN, TiCN, etc. For optimal performance, the coating must be matched to the material being processed.
Use the correct processing sequence
Proper planning of the optimal machining sequence needs to consider a variety of factors, such as the change of workpiece strength before and after trench machining because after the trench is machined, the strength of the workpiece will be reduced. This may prompt the operator to adopt a lower-than-optimal feed and cutting speed in the next operation to reduce flutter, and reducing cutting data can lead to longer machining times, shorter tool life, and unstable cutting performance.
Another factor to consider is whether the next process will push the burr into the already machined groove.
As a rule of thumb, consider starting from the point farthest from the tool chuck after outside and inside diameter turning, and then machining grooves and other structural features.
