Graph the error sketch map of axis of X of deviate of point of a knife of 1 lathe tool

When the treatment on numerical control lathe is spherical, appearance error influencing factor and eliminate a method to be as follows.

- The error that axes of main shaft of deviate of lathe tool point of a knife causes and eliminate a method (it is exemple) with the ball inside the car. If the graph is shown 1 times, ∆Y is the distance of axis of X of lathe tool deviate, dt is diameter of theory of A-A section plane, d needs ball diameter for place, r=D/2 amount to accuses radius of interpolation of circular arc of lathe cutting tool. On A-A section plane curve of interpolation of cutting tool circular arc shows long axis to be kind of ellipse of D1 for D, short axis, its error is for D=D-D1=D-2[(D/2)2-∆Y2]½(1) in actual production, product blueprint should put forward to be machined commonly ball diameter precision. If machine ball bearing precision to be in commonly ± 0.005mm less than, namely D=0.01mm. To assure this precision, must control ∆Y. By type (1) knows ∆Y= ± ½(2Dd-d2)½(2)

Graph sketch map of 2 pairs of knives

Set D=80mm, when machining ball bearing, computational earning | ∆Y | ≤ 0.63mm. If pursue,to knife method 2 are shown. The numerical value on dial gauge is ∆Y value namely. The influence of error of the centre of a circle of interpolation of cutting tool circular arc and eliminate a method (with the car inside spherical for exemple) show 3 times like the graph, ∆X is the distance of axis of Y of deviate of the centre of a circle of interpolation of cutting tool circular arc, d needs ball diameter for place, d1 is XOY plane to go up to machine a diameter actually: D/2 is radius of interpolation of cutting tool circular arc. Visible, on XOY plane, error D=D1-D=2∆X: On XOZ plane, the elliptical ball that shows long axis diameter to be D for diameter of D1, short axis, its errorD=D1-D=2∆XCompare a law to remove the effect of error of the centre of a circle of interpolation of cutting tool circular arc with pointwise.

Graph the centre of a circle of interpolation of circular arc of 3 cutting tool affects sketch map (inside spherical)

(A)2∆X>0, to compensation ∆X

(B)∆X<0, lose to compensation ∆X

Graph 4 cutting tool compensate sketch map

Thick car sets D to need for place inside ball diameter, 1 ～ 1.5mm stays when thick car surplus of half fine vehicle, namely A1=D-(1 ～ 1.5) . internal diameter of thick car ball A1 of diameter of interpolation of the circular arc in real measure and program is compared, get error of center of main shaft of deviate of the centre of a circle of interpolation of cutting tool circular arc to be 2∆X. Be like 2∆X>0, criterion direction of edge X axis to compensation ∆X, be like 2∆X<0, lose along X axis direction to 4) of compensation ∆X(graph. Half thick car leaves surplus of 0.5mm fine vehicle, namely A2=D-0.5, measure next, quite, method of cutting tool compensatory is Alexandrine, give place to need till the car inside spherical.

Spherical principle is same inside car spherical outside surface and car, compensation way is same, what what differ is cutting tool installation way is opposite.

Because pace of numerical control lathe enters electromotor pulse equivalent to be able to be amounted to 0.01, 0.005, 0.001mm, precision of curve of circular arc interpolation is in accordingly ± 0.01, ± 0.005, ± 0.001mm, the basis is machined spare parts demand, choose corresponding numerical control lathe, can satisfy production to need actually.