Screw thread machining method

Screw thread machining method

Screw thread machining method

1. Screw thread types:

A: Triangle thread (60 degree): combination / lock

B: useful triangular thread (55 degree): combination / lock

C: trapezoidal thread (30 or 29 degrees): Power Transmission

D: side thread (90 degrees): Power Transmission

Processed within ﹑ external thread, there are mainly two types of cutting and rolling process.

1) screw thread cutting tool generally refers to forming or abrasive workpiece processing thread, there are mainly turning ﹑ ﹑ Tapping Milling Grinding ﹑ ﹑ ﹑ sets of grinding and wire cutting, etc. cyclone. Turning ﹑ thread milling and grinding, the workpiece per a turn, the machine drive chain cutter or grinding wheel to ensure Tool ﹑ accurate and uniform along the workpiece axis to move a lead. In tapping or threading, the cutting tool (tap or die) for relative rotation with the workpiece by the first thread groove formed to guide the cutting tool (or workpiece) for axial movement.

2) screw thread milling in the thread milling cutter with a disc cutter for milling or comb. Disc cutter is mainly used for milling and other artifacts on the worm screw ﹑ trapezoidal external threads. Comb-shaped cutter for milling outside the common thread in ﹑ and taper thread, as is multi-blade milling products, their work was part of the length is greater than the length of processing threads, so just rotate the workpiece transfer can be 1.25 ~ 1.5 completion of the processing, productivity is high. Screw pitch precision milling is generally up to 8 ~ 9, the surface roughness is R 5 ~ 0.63 microns. This method is suitable for mass production of threaded parts, or the general accuracy of the rough before grinding.

3) screw thread grinding is mainly used in the thread grinder hardened workpiece precision thread grinding wheel according to different sub-section shape of single and multi-line grinding wheel grinding wheel two. Single pitch wheel grinding can achieve an accuracy of 5 to 6, the surface roughness of R 1.25 ~ 0.08 micron, wheel dressing more convenient. This method is suitable for grinding precision screw thread gauges ﹑ ﹑ ﹑ small quantities of worm thread grinding the workpiece and the precision hob. Multi-line was divided into vertical grinding wheel grinding method and cut into the ground and French. Vertical grinding method was grinding wheel is smaller than the width of thread length, vertical grinding wheel can move one or several trips to the final size of the thread mill. Cut fey thread grinding wheel width was less than the length of the radial cut into the surface grinding wheel, workpiece transfer of about 1.25 mill can turn a good, high productivity, but lower precision, wheel dressing is rather complicated. Cut into the grinding method suitable for large-volume tap relief grinding and grinding some of the fastening thread.

4) screw thread grinding soft materials such as cast iron nut-type or screw type of thread lapping tool, the workpiece has been processed on the thread pitch error of the area there were pros and cons to the rotating grinding to improve pitch accuracy. Hardening of the internal thread grinding method is often used to eliminate distortion and improve accuracy.