SU916096A1 - Method of working variable pitch threads - Google Patents

Description

The invention relates to mechanical engineering and can be used for machining variable pitch, screws, screws, worms and other products on turning, milling and other machines.

There is a known method for machining threads, according to which the shaping of the thread of a variable pitch to the workpiece is reported to rotate with a variable in accordance with the law of pitch change with angular speed, and the cutting tool is rectilinear ¹⁰ moving along the axis of the product with a constant speed of SI.

The main drawback of the known method is the constancy tartaric speed ^'5 tovogo tool movement that causes low tool life and the inability to optimal processing conditions.

Chain invention - increase stoy- ²⁰ bone tools by maintaining optimum speed helical movement over the whole thread cutting.

2

'To achieve the goal, when machining threads of variable pitch, the speed of movement of the workpiece and the tool is simultaneously changed in accordance with the dependencies:

H

AND

where V is the speed of movement of the shaping, mm / s;

1% - the frequency of rotation of the workpiece, rev / s;

K, - tool movement speed, mm / s;

- diameter of the workpiece, mm;

C - thread pitch, mm (variable

guise).

The speed of the screw movement of the tool relative to the workpiece, which is equal to the cutting speed during turning and the resultant feed during thread milling, represents the geometric sum of the peripheral speed of the workpiece and a speed of 916096

ν ₄ axial displacement of the tool, i.e.

where wee ^ -ipu ⁵

Therefore V "

^oti """·"

For the exact shaping of the thread being machined, the relation ν = Π | Η is obligatory. _; and the dependence of the rotational speed of the workpiece _<5 ki on the thread pitch to simplify the implementation can be set approximately.

With a variable pitch H of the thread being cut, for example, according to the law H ~ But + (&) where At is the initial pitch of the thread, £ (si) _{m is} some function of the angle <11 of the workpiece, the values and Vy have the opposite character * changes (increase and decreasing V ”when machining a thread with decreasing pitch ₂₅ or increasing λ / ΐ *. and decreasing when machining a thread with incremental pitch), while the speed of the screw movement of the tool relative to the workpiece is kept constant throughout the entire section of the cut thread. This allows you to process * ya optimal cutting conditions and thereby improve tool life and productivity.

The most simple way is implemented on machines with numerical control.

Claims (1)

Claim The method of processing threads of variable pitch, in which the workpiece is reported to rotate around its axis, and the cutting tool is matched with it in accordance with the law of pitch change linear motion along this axis, characterized in that, in order to increase the cutting tool durability by maintaining optimal cutting speed throughout the entire section of the thread being cut, the speeds of movement of the workpiece and the tool are simultaneously changed in accordance with the dependencies: where ¥ is the speed of movement of the shaping, mm / s; U - the frequency of rotation of the workpiece, rev / s; \ 7ts - tool movement speed, mm / s; cG is the diameter of the workpiece, mm; C - thread pitch, mm (variable).