Mon Jul 04 11:55:02 CST 2022
Grooving is an important processing method in turning processing. The characteristics of chip formation and discharge make it different in almost every aspect. Innovative insert design and coating can improve the efficiency and quality of grooving, but to complete the process successfully, some key points must be mastered. Here's a list of 10 essentials for processing.
It is important to understand the three main types of grooves: outer round grooves, inner bore grooves, and face grooves. The outer circular grooves are the easiest to work with because gravity and coolant help remove chips. In addition, the outer circular groove machining is visible to the operator and the machining quality can be checked directly and relatively easily. However, some potential obstacles in workpiece design or clamping must also be avoided. In general, the grooving tool works best when its tip is held just below the centerline.
The internal grooves are similar to the outer circular grooves, except that coolant applications and chip removal are more challenging. For inner hole grooves, the best performance is achieved when the tip position is slightly above the center line.
To process the grooves, the tool must be able to move in the axial direction, and the radius of the tool's back face must match the radius being machined. The machining effect is best when the tip position of the end face grooving tool is slightly higher than the center line.
In grooving processing, the design type and technical conditions of machine tools are also the basic elements to be considered. Some of the main performance requirements for the machine tools include: sufficient power to ensure that the tool runs within the correct speed range without stalling or jitter; High enough rigidity to complete the required cutting without chatter; High enough coolant pressure and flow to assist chip removal; High enough accuracy. In addition, in order to produce the correct groove shape and size, proper adjustment and calibration of the machine tool is also essential.
Proper selection and use of tools will determine the cost effectiveness of machining. The slotting cutter can process the workpiece geometry in two ways: one is to process the whole groove shape by a single cut; The second is to cut the final size of the groove step by step. After selecting the tool geometry, consider using a tool coating that improves chip removal.
Forming tools should be considered for bulk processing. By cutting all or most of the grooves in one cut, the forming tool can free up the tool position and shorten the machining cycle time. A disadvantage of non-insert forming tools is that if one of the teeth breaks or wears out faster than the others, the whole tool must be replaced. Another important factor to consider is the amount of machine tool power required to control the chip generation and form cutting.
Multi-function tool can generate tool path in axial and radial direction. In this way, the tool can not only machine the groove, but also the diameter of the turning, the interpolation machine radius, and the machine Angle. The tool can also carry out multi - direction turning. Once the insert is in the cutting, it moves axially from one end of the workpiece to the other, all the while maintaining contact with the workpiece. The use of multifunctional tools can spend more time cutting the workpiece, rather than for tool change or idle travel. The multi-function tool also helps to reduce the machining process of the whole workpiece.
Feed rate and cutting speed play a key role in groove machining. Incorrect feed rates and cutting speeds can cause chatter, reduce tool life and prolong machining cycle time. Factors that affect feed and cutting speed include workpiece material, grooving tool geometry, type and concentration of coolant, insert coating, and machine performance. In order to correct the problems caused by unreasonable feed and cutting speed, secondary machining is often required. While it is possible to list many sources of information on "optimal" feed rates and cutting speeds for a variety of tools, the most up-to-date and useful information usually comes from the tool manufacturer.
Coating can significantly prolong the life of carbide insertss. Because the coating provides a lubricating layer between the grooving tool and the chip, it can also shorten the processing time and improve the surface finish of the workpiece. Currently commonly used coatings include TiAlN, TiN, TiCN and so on. For best performance, the coating must match the material being processed.
Proper application of cutting fluid means providing sufficient cutting fluid at the cutting point where the slotting insert contacts the workpiece. The cutting fluid serves a dual function of cooling the cutting zone and aiding chip removal. Increasing the cutting fluid pressure at the cutting point is very effective for improving chip removal when machining the inner diameter grooves of blind holes. For the groove machining of some difficult materials (such as high toughness and high viscosity materials), high pressure cooling has obvious advantages.