CNC machining method of mechanical parts

Wed May 25 16:26:54 CST 2022

1 . A numerical control machining method, comprising the following steps:

Provide the machining program curve P0 Pn required by the CNC machining equipment, and the machining program curve P0 Pn includes at least two

Micro-segment instruction points Pi and Pj;

Identify the continuous microsegment part Pi Pj;

The target processing curve is obtained from the continuous micro-segment part Pi Pj according to the deviation range:

If the continuous micro-segment part Pi Pj can be smoothly compressed into a spline curve that satisfies the machining accuracy, it constitutes a continuous micro-segment part

Divide the target processing curve corresponding to Pi Pj;

If the continuous micro-segment part Pi Pj cannot be smoothly compressed into a spline curve that meets the machining accuracy, reduce j to k until continuous

The micro-segment Pi Pk can be smoothly compressed into a spline curve that meets the machining accuracy, that is, the corresponding continuous micro-segment Pi Pk is obtained.

Sub-target processing curve;

Then smoothly compress the remaining micro-segment part Pk Pj in the same way to obtain the command point corresponding to the remaining micro-segment part Pk Pj.

Sub-target processing curve;

Connect all the sub-target processing curves in sequence to obtain the target processing curve of the continuous micro-segment part Pi Pj;

Among them, Pi is any micro-segment command point on the machining program curve P0 Pn, i≤k<j≤m, all positive integers.

2 . The numerical control machining method according to claim 1 , wherein the purpose of obtaining the continuous micro-segment parts Pi Pj

After marking the machining curve, the numerical control machining equipment processes the workpiece according to the target machining curve.

3 . The numerical control machining method according to claim 1 , wherein the method of identifying the continuous micro-segment parts Pi Pj

The law includes:

Compare the length between two adjacent micro-segment command points Pn, Pn+1 on the machining program curve P0 Pm with the preset micro-segment length

The threshold dmax is compared, and if the length between the two adjacent micro-segment instruction points is greater than the micro-segment length threshold dmax, then

Set the corresponding two two-micro-segment instruction points Pn, Pn-1 as the disconnection points of continuous micro-segments;

Compare the vector angle ∠Pn-1PnPn+1 formed by three adjacent micro-segment instruction points Pn-1, Pn, Pn+1 with the preset angle threshold

In comparison, if the vector angle is greater than the angle threshold, the programming point Pn corresponding to the intersection of the vector angle is set as continuous

the break point of the microsegment;

The starting point P0 and its adjacent breaking point Pn, the end point Pm and its adjacent breaking point Pn+1, or two adjacent breaking points

The continuous micro-segment portion between the opening points is identified as the continuous micro-segment portion Pi Pj, where n, m are positive integers, and n<i≤m or

where n<j≤m.

4 . The numerical control machining method according to claim 1 , wherein the continuous micro-segment portion Pi Pj is pressed smoothly

The steps of shrinking the spline to meet the machining accuracy include:

Obtain the node vector parameters corresponding to the micro-segment instruction points on the continuous micro-segment part Pi Pj;

The interpolation curve is constructed by 4 consecutive micro-segment instruction points on the continuous micro-segment part Pi Pj to calculate the relationship between these 4 micro-segments

The first-order tangent vector corresponding to the command point;

According to the micro-segment instruction point on the continuous micro-segment part Pi Pj, the node vector parameter corresponding to the micro-segment instruction point

number, and the first-order tangent corresponding to four consecutive micro-segment instruction points on the continuous micro-segment part Pi Pj, the continuous micro-segment part

Pi Pj is compressed into a first-order continuous smooth spline.