Three methods of machining threads in Machining Centers


The benefits of using CNC machining center to process workpieces have been deeply understood. For the operation and programming of CNC machining center, today I share with you the thread processing method. There are three ways of NC machining: thread milling method, tap machining, and thread picking machining method:

1.Thread milling method

Thread milling is the use of thread milling tools for the processing of large-hole threads, as well as the processing of threaded holes with difficult-to-machine materials. It has the following characteristics:

1. The tool is generally made of cemented carbide material, with fast speed, high thread precision for milling, and high processing efficiency;

2. The same pitch, whether it is a left-handed thread or a right-handed thread, can use one tool, reducing the cost of the tool;

3. The thread milling method is especially suitable for the thread processing of difficult-to-machine materials such as stainless steel and copper. It is easy to remove chips and cool, and can ensure the quality and safety of processing;

4. There is no tool front guide, which is more convenient to process blind holes with short threaded bottom holes or holes without undercuts.

Thread milling tools are divided into two types: machine-clamped carbide insert milling cutters and integral cemented carbide milling cutters. Machine-clamped tools can not only process holes whose thread depth is less than the length of the blade, but also can process holes whose thread depth is greater than the length of the blade. Holes; and solid carbide milling cutters are used to machine holes whose thread depth is less than the length of the tool;

Thread milling CNC programming attention points: so as not to cause damage to the tool or processing errors.

1. After the threaded bottom hole is processed first, use a drill to process small diameter holes, and use boring to process larger holes to ensure the accuracy of the threaded bottom hole;

2. The tool generally uses a 1/2 circle arc path to cut in and out to ensure the shape of the thread, and the tool radius compensation value should be brought in at this time.

2. Tap Machining Method

The tap processing method of CNC machining center is suitable for threaded holes with small diameters or low hole position accuracy requirements. Generally, the diameter of the threaded bottom hole drill is close to the upper limit of the diameter tolerance of the threaded bottom hole, which can reduce the machining allowance of the tap. , reduce the load of the tap, and also improve the service life of the tap.

Everyone should choose the appropriate tap according to the material to be processed. The tap is relative to the milling cutter and the boring cutter;

It is very sensitive to the material to be processed; taps are divided into through-hole taps and blind-hole taps. The front-end guide of through-hole taps is long for front chip removal. When processing blind holes, the processing depth of the thread cannot be guaranteed, and the front-end guide of blind holes is short. , for rear chip removal, so pay attention to the difference between the two; when using a flexible tapping chuck, pay attention to the diameter of the tap shank and the width of the square to be the same as that of the tapping chuck; the diameter of the tap shank for rigid tapping should be the same as that of the spring The jacket diameter is the same.

The programming of the tap machining method is relatively simple. It is a fixed mode. It is enough to add parameter values. It should be noted that the numerical control system is different, and the format of the subroutine is also different, so the representative meaning of the parameter value is different.

3.Pick Machining Method

The pick processing method is suitable for the processing of large threaded holes on box parts, or when there are no taps and thread milling cutters, this method is used to install a thread turning tool on the boring bar for boring threads. There are several precautions for the implementation of the pick-and-button processing method:

1. Start the spindle with a delay time to ensure that the spindle reaches the rated speed;

2. The sharpening of the hand-ground thread tool cannot be symmetrical, and the reverse tool cannot be used for retraction. The tool must be moved radially with the spindle orientation, and then the tool is retracted;

3. The toolbar must be precise and consistent with the position of the tool slot, otherwise, multi-tool bar processing cannot be used, resulting in the phenomenon of random buckles;

4. When picking the buckle, be careful not to pick it with one knife, even if it is a very thin button, otherwise it will cause tooth loss and poor surface roughness, so it should be picked with multiple knives;

5. Picking processing method is only suitable for single pieces, small batches, special pitch thread, and no corresponding tool, and the processing efficiency is low.

The picking method of CNC machining center is only a temporary emergency method. It is recommended that you process the tool by threading method, which can effectively improve the efficiency and quality of threading, reduce the processing cost and improve the efficiency of the machining center.

Post time: Sep-15-2022