Thread milling.

With the progress of the times, NC industry in China's large and medium-sized machinery processing industry used more and more widely, some large parts of the thread processing, traditional thread turning and tap, die has been unable to meet the production needs. In the numerical control milling machine or machining center is widely used today, the three axis linkage machine tool for thread processing, changed the thread processing technology, and achieved good results.
Spiral milling inner hole
1 machining range
Large aperture blind holes or through holes, the twist drill processing is too slow or can not be processed, often choose spiral milling way. And because of the choice of the tool does not bring the bottom edge, so it is more suitable for small cut deep, high speed and large feed processing.
2 machining features
Spiral milling hole is based on the spiral cutting method based on the processing method, the helical milling hole has a characteristic: each spiral milling a week, the Z axis of the tool moves a lower cutting height.
3 choice of thread milling cutter
Choice of 16mm three edge milling cutter, cutting speed S=3000r/min, feed F=2500mm/min.
4 description
This method in helical milling holes is quite distinctive, the procedures for the preparation of the essence of is a knife height as a spiral line height compiled a subroutine, by calling the helix subroutine to complete the hole milling. The method is not affected by the milling cutter size and other factors, so it is ideal for the application of CNC milling machine and machining center.
5 application examples and procedures
As shown in Figure 1 of the parts diagram, processing thread M36 * 1.5mm bottom hole.
First, calculate the thread M36 * 1.5mm bottom diameter: nominal diameter -1.0825 * P * 1.5=33.75mm =36-1.0825 (pitch). Confirm that the parts of the processing blank is 80mm * 80mm * 30MM 45 steel, the selected tool for the 16mm three blade turning milling cutter, cutting speed S=3000r/min, feed F=2500mm/min. The arc import point is A (Figure 2), in the 0A section to establish the knife to fill, the arc export point is B, in the 0B section cancels the knife to fill.
Reference procedures are prepared as follows (this article relates to the reference procedures are used in the FANUC system).
The main procedure is as follows.
% (starting at the beginning of the program)
O0001; (main program name)
T1; (cutting tool for 16mm end milling cutter)
G80G40G69; (cancellation of fixed cycle, tool radius compensation and rotation instructions)
G90G54G00X0Y0M03S3000; (program initialization)
H01 G43Z50.0; (1 tool length compensation)
Z5.0; (fast moving point location)
G01Z0F50; (into).
G41D01G01X-6.875Y10.0; (D01=8.0, in the 0A section of the establishment of the knife up)
G03X-16.875Y0R10; (arc import R10)
M98P100L16; (call subroutine O100, call 16 times)
G90G03X-6.875Y-10R10.0; (the whole outline of a week)
G40G01X0Y0; (cancel)
G0Z50.0; (exit)
M05; (spindle stop)
M30; (the end of the program and the return of the program header)
% (end of program)
Subroutine is as follows.
% (starting at the beginning of the program)
O100; (subroutine)
G91G03I16.875Z-2.0F2500; (using the incremental coordinate values to write, each run a week of cutting tool in the Z axis direction of the downward movement of 2mm)
M99; (return to main program)
% (end of program)
The inner hole can be processed by the method of the spiral type lower cutter, and the cylindrical workpiece can be processed according to the programming idea.
Two. Single blade thread milling cutter
1 machining range
The same thread milling cutter can be milling left - hand thread and can be milling - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -.
2 machining features
Single blade thread milling cutter, machining is built on the basis of spiral cutting method based on the method of processing. The principle of milling thread is: one week of the thread milling cutter, the cutter motion in the direction of Z axis (single line is a pitch).
3 choice of thread milling cutter
Select 16mm single blade thread milling cutter, cutter speed S=1800r/min, feed rate F=300mm/min.
4 description
This method features in the thread milling, its programming the essence is a guide process of spiral wires woven into a subroutine, which is processed by the repeated calls of the helix subroutine, you can complete the entire thread milling. Using this method, the thread is not affected by the thread pitch and thread size, so it is widely used in the CNC milling machine and machining center.
5 application examples and procedures
Continue processing Figure 1 shows the work piece of the thread M36 * 1.5mm thread, as shown in Figure 3, the arc of the import point for the A, in the 0A section to establish a tool to fill, arc export point for B, in the 0B section of the abolition of the knife up. According to the idea of the processing thread procedure is as follows.
The main procedure is as follows.
% (starting at the beginning of the program)
O0002; (main program name)
T2; (2 tool for 16mm thread milling cutter)
G80G40G69; (cancellation of fixed cycle, tool radius compensation and rotation instructions)
G90G54G00X0Y0M03S1800; (program initialization)
G43Z50.0H02; (2 tool length compensation)
Z5.0; (fast moving point location)
G01Z0F50; (to Z0)
G42D02G01X-8Y-10.0; (D02=Rprg, the radius of the radius of the thread milling cutter programming value, in the 0A segment to build up the knife up)
G02X-18.0Y0R10; (arc import R10)
M98P200L14; (call subroutine O200, call 14 times)
G90G02X-8.0Y10R10.0; (arc derived R10)
G40G01X0Y0; (cancel)
G0Z50.0; (exit)
M05; (spindle stop)
M30; (the end of the program and the return of the program header)
% (end of program)
Subroutine is as follows.
% (starting at the beginning of the program)
O200; (subroutine)
G91G02I18.0Z-1.50F300; (using the incremental coordinate values to write, the cutting tool every week along the Z axis to move down a pitch P=1.5mm)
M99; (return to main program)
% (end of program)
The case is about the use of a single blade thread milling cutter plus