1
Understanding the Types of Trenches
It is important to understand the three main types of grooves: cylindrical grooves, bore grooves, and face grooves. Cylindrical grooves are the easiest to machine because gravity and coolant facilitate chip evacuation. In addition, the processing of cylindrical grooves is visible to the operator and the processing quality can be checked directly and relatively easily. But some potential obstacles during part design or clamping must also be avoided. Generally speaking, the best cutting results are obtained when the tip of the grooving tool is held slightly below the center line.
Internal grooving is similar to external radial grooving, except that coolant application and chip removal are more difficult. For interior grooving, best performance is achieved when the tool tip is positioned slightly above the centerline. To machine end grooves, the tool must be able to move in the axial direction and the flank radius of the tool must match the radius to be machined. The machining effect is optimal when the tip position of the end face grooving tool is slightly higher than the center line.
2
Machine tools and processing applications
When grooving, the type of design and technical conditions of the machine tool are also fundamental factors to consider. Some of the key performance requirements for machine tools include: having enough power to ensure the tool operates in the correct speed range without stalling or shaking; have sufficiently high rigidity to perform the required cut without chattering; to facilitate chip removal; it has sufficiently high accuracy. Additionally, in order to machine the correct shape and size of the grooves, proper debugging and calibration of the machine tool is also crucial.
3
Understand the material properties of the workpiece
Knowledge of certain properties of the part material, such as tensile strength, work hardening characteristics, and toughness, is essential to understanding how the part affects the tool. Machining different part materials requires different combinations of cutting speeds, feeds and tool characteristics. Different workpiece materials may also require specific tool geometries to control chipping or use specific coatings to extend tool life.
4
Correct choice of tools
Proper tool selection and use will determine the profitability of machining. The grooving tool can process the workpiece geometry in two ways: one is to machine the entire groove shape in one plunge; the other is to rough out the final groove size in stages via multiple plunges. After selecting a tool geometry, consider tool coatings that improve chip evacuation.
5
Forming tools
When machining large quantities, form tools should be considered. Forming tools process all or most of the groove shape in a single pass, freeing up tool space and shortening machining cycle time. A disadvantage of insertless form cutters is that if one of the teeth breaks or wears out more quickly than the others, the entire cutter must be replaced. An important factor to also consider is the machine power required to control the chips generated by the tool and form the cut.
6
Choose a single-point multi-tool
Versatile tool usage can generate tool paths in both axial and radial directions. In this way, the tool can not only machine grooves, but also turn diameters, interpolate radii and machine angles. The tool can also perform multi-directional turning. Once the insert enters the cut, it moves axially from one end of the part to the other, while maintaining contact with the part. Using multifunctional tools allows you to spend more time cutting the workpiece, rather than changing tools or making unnecessary movements. Multifunctional tools also help reduce the number of machining steps required for the entire part.
7
Use the correct processing sequence
Reasonable planning of the best processing sequence requires consideration of many factors, such as the change in workpiece strength before and after groove processing, because the workpiece strength will decrease after the first groove processing . This may cause the operator to use lower than optimal feeds and cutting speeds in the next operation to reduce vibration, while decreasing cutting parameters may result in longer machining times, shorter tool life and unstable cutting performance. Another factor to consider is whether the next operation will push the burr into the groove that was machined. As a general rule, consider starting at the farthest point from the tool holder and then machining the grooves and other structural features after completing the OD and ID lathes.
8
Use the correct processing sequence
Cutting feed and speed play a key role in grooving. Incorrect feeds and cutting speeds can cause vibration, reduce tool life and extend machining cycle times. Factors that affect feeds and cutting speeds include workpiece material, tool geometry, coolant type and concentration, insert coatings, and machine tool performance. In order to correct problems caused by unreasonable feeds and cutting speeds, secondary processing is often necessary. Although there are many sources of information on “optimal” cutting feeds and speeds for a variety of different cutting tools, the most current and practical information usually comes from the cutting tool manufacturer. cut.
9
Select the blade coating
Coatings can significantly increase the life of carbide inserts. 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. Currently commonly used coatings include TiAlN, TiN, TiCN, etc. For optimal performance, the coating must be adapted to the material to be treated.
10
cutting fluid
Proper cutting fluid application means providing adequate cutting fluid to the cutting point where the grooving insert contacts the workpiece. The cutting fluid plays the dual role of cooling the cutting zone and facilitating chip evacuation. When machining internal grooves of blind holes, increasing the cutting fluid pressure at the cutting point is very effective in improving chip evacuation. For groove processing of some difficult-to-machine materials (such as high toughness and high viscosity materials), high pressure cooling has obvious advantages.
The concentration of water-soluble oil-based coolant is also essential for grooving difficult-to-machine materials. Although the typical coolant concentration range is 3% to 5%, in order to improve the lubricity of the coolant and provide a protective layer for the tool tip, you can also experiment with effect of increasing the concentration of the coolant (up to 30%). .
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