Machine tool pull pins are tensioning elements between the spindle and tool shank of CNC machine tools for boring and milling. The types of pull pins are diverse, and the standards used vary. How to select the correct pull pins for CNC machine tools? Here is a brief introduction for everyone.
Pull Pin Standard
The national standard GB 10945-89 "7:24 taper tool shanks for automatic tool change machines - Types 40, 45, and 50 taper shank pullers" is formulated with reference to the standard ISO 7388/2-1984, with the same overall dimensions, and is divided into two types: Type A pullers have a tightening angle of 15 ° and are coded "LDA"; The inclined angle of the tensioning surface of the type B pull pin is 45 °, and the code is "LDB". Both have through-holes for coolant circulation.
There are two types of pull pins in the German standard DIN 6988-1987: type A and type B, with through holes in type A; Type B does not have through holes, but has annular grooves for sealing rings to prevent coolant leakage from the tail. The inclined angle of the tension surface of both pull pins is 15 °.
The pull pin in Japanese standard JIS B 6339:1988 has only one form, with a diagonal angle of 15 ° on the tension surface of the pull pin, and is coded "XXP". The standard MAS-403 of the Japan Machinery Industry Association has two types of pull pins: type I and type II: the inclined angle of the tension surface of the type I pull pin is 30 °; The inclined angle of the tensioning surface of the type II pull pin is 45 °. When using, it should be noted that the head length of these two types of pull pins is smaller than the head diameter of the pull pin in JIS B 6339:1998 standard, and the neck length is longer. The code is "PxxT".
The American standard AMSE B 5.50-1994 has only one form of pull pin, with a tightening surface angle of 45 ° and no centering cylinder between the flange and the thread. The thread shall be UNC system thread. To facilitate user use, domestic manufacturers have also changed to corresponding metric thread, while other dimensions remain unchanged.
Selection of pull pins
There are many types of pull nails, so it is recommended to select them according to your machine tool manual when purchasing them. Most machine tool manufacturers will provide rivet drawings in the machine tool manual (different machine tools require different rivet drawings, so don't make the wrong choice),
It is also possible to directly measure and later determine the pull pin provided by the machine tool, mainly including the angle of the pull pin head, the distance from the reference plane to this angle, and the thread type.