When machining parts, CNC lathes are the most indispensable process when cutting the workpiece. At the same time, the grooving on the workpiece is also the most common. The efficiency of cutting and grooving is inseparable from the rigidity of the machine tool. The rigidity of the spindle of the CNC lathe and the rigidity of the turret are the main reasons that affect the vibration of the workpiece. The cutting method in cutting and grooving is also the most critical.
Next, let’s split from the cutting method how to improve the efficiency of cutting and grooving workpiece processing.
1. Cutting grooves on CNC lathes
1) The common method of car groove. The common methods of turning grooves on the surface of the workpiece are the outer groove, the inner groove and the end face groove.
2) The choice of turning tool. Generally, high-speed steel grooving tools are used for grooving.
3) The method of car slot. For rectangular grooves with low turning precision and narrow widths, a grooving tool with a tool width equal to the groove width can be used, and the straight forward method can be used to turn out at one time.
Rectangular grooves with high turning precision requirements are generally turned into two times. Turning a wider groove can be cut by multiple straight forwards, leaving a certain amount of finishing allowance on both sides of the groove, and then finishing to the size according to the groove depth and groove width. Turning smaller arc-shaped grooves is generally turned with a forming turning tool; turning larger arc-shaped grooves can be turned with both hands, and use a template to check and trim. Turning smaller trapezoidal grooves is generally done with a forming turning tool; turning larger trapezoidal grooves is usually done by turning the straight groove first, and then using the trapezoidal knife straight approach or left-right cutting method.
4) Inspection and measurement of rectangular grooves. Grooves with low accuracy requirements are generally measured with steel rulers and calipers. For grooves with high precision requirements, micrometers, templates, plug gauges and vernier calipers can be used for inspection and measurement.
2. Cutting off by CNC lathe. A cutting knife is used for cutting. The shape of the cutting knife is similar to that of a grooving knife, but it is easy to break due to its narrow head. Cutting knives include high-speed steel cutting knives, cemented carbide cutting knives, elastic cutting knives, reverse cutting knives and other types.
There are several cutting methods for CNC lathes:
1) Straight forward method. The cutting knife feeds and cuts perpendicular to the axis of the workpiece. This method is highly efficient, but it has higher requirements for the sharpening and clamping of the lathe and the cutting knife, otherwise it will easily cause the cutter head to break.
2) Borrowing a knife from left to right. In the case of insufficient rigidity of the tool, workpiece, and lathe, the borrowing method can be used to cut the workpiece. This method refers to the repeated reciprocating movement of the cutting knife in the axial direction, followed by radial feed on both sides, until the workpiece is cut off.
3) Reverse cutting method. The reverse cutting method means that the workpiece is reversed and the turning tool is clamped in reverse. This cutting method is suitable for cutting larger diameter workpieces. Its advantages are: because the cutting force acting on the workpiece is consistent with the gravity direction of the spindle (downward), the spindle is not easy to jump up and down, and the workpiece is relatively stable when cutting the workpiece, and the chips are discharged downwards, and will not be blocked in the cutting groove. Smooth chip evacuation.