JPH04149708A - Nc controller - Google Patents

Abstract

PURPOSE:To obtain high-accuracy, smooth NC data which has small tolerance by obtaining a smooth interpolated curve from an extracted dot group and then extracting division points, and restructuring dot group data. CONSTITUTION:The NC controller is provided with a curve arithmetic means 5 which interpolates the dot group extracted from free curved surface data 2 for machining into the curve according to a desired interpolation expression and a division point extracting means 6 which extracts >=1 point on the interpolated curve between dots, and the dot group and division point group are interpolated with straight lines to generate NC data for a working machine. In the NC controller 4, the curve arithmetic means 5 performs curve interpolation so as to reproduce a smooth track from continuous points in the given dot group data. The division point extracting means 6 find point coordinates on the interpolation curve between points by using an expression showing the interpolated curve. An NC data generating means 7 finds movement data by linear interpolation from the results. Consequently, the data is smaller in run length than data obtained by interpolating the original dot group data linearly and the high-accuracy, smooth machining of the working machine is performed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to mold data smoothing processing applied to an NC control device for processing mold data of a machine tool.

[Conventional technology]

Conventional mold machining involves obtaining point cloud data from free-form surface data for machining in CAD, sending it to an NC weight device, and performing linear interpolation to generate all NC data that approximates the CAD data. .

FIG. 2 shows a block diagram of a conventional NC device. CA
DI has the shape to be processed as free-form surface data 2. From there, the point cloud data extraction means 3 extracts a point cloud, and at that time, the point cloud is determined so that the difference (tolerance) between the actual machined surface and the straight line between the two extracted points is a certain value. ing. The NC control device 4 generates NC data by linear interpolation between two consecutive points, and the processing machine 13 performs cutting according to this NC data to obtain a mold that approximates the CAD data.

[Problem to be solved by the invention]

As mentioned above, in conventional NC control devices, free-form surfaces are approximated by linear interpolation of point group data. It is safe to reduce the distance between two points in the point cloud data, but in order to achieve this, it is necessary to memorize a huge amount of point cloud data. Memory is safe, ■ It takes time to extract point cloud data from CA ■))) The amount of movement of the machine per block per hour during machining is reduced, so data communication takes longer to process. This poses a problem that processing efficiency may decrease due to the possibility of loss.

[Means for solving all 5 yen 1 problems] In order to solve all the problems mentioned above, the present invention provides an NCC method for generating NCC pigs for processing machines based on free-form surface data for machining T.
In the C control device, a curve calculating means interpolates to a curve using an interpolation formula of the point group extracted from the free-form surface data for machining + i''fT, and a point north of 1 of the interpolated curve of the 7-point booth is extracted. It is an object of the present invention to provide an NC control device which is equipped with division point extraction means and NC data generation means for generating all NC data for a processing machine using the above-mentioned point group and division point group all linear interpolation L2. It is something to do.

[Effect]

The curve calculation unit approximates the point cloud data obtained from the free-form surface data of CAD to reproduce smoother curve data.The division point extraction means extracts points on this curve and uses the point cloud data Rebuild point cloud data with less tolerance.

The NC data generation means performs linear interpolation on the reconstructed point group to obtain N
Generate all C data.

〔Example〕

FIG. 1 is a block diagram of the NC device of the present invention. C
A point cloud data extraction means 3 extracts point cloud data from the free-form surface data 2fJ of A and DI.

This is sent to the NC control device 4 by A communication. NC control device #
4, a curve calculation means 5 performs curve interpolation in order to reproduce a smoothed locus from continuous points among the given point group data. For example, consecutive ← Seri, Ta, 3 points P(0), P
Using (1) and P(2), cubic function ■)・-at'-
+1) Considering the cost of interpolating with t21-ct poison, (
〒4〒〒〒〒〒〒、When the increment between three points is clear, the interpolation curve P is as follows. The total (i-t), 12b, and t3 line connections (n) are found from the previous interpolation t'. ) Change the t value in the above formula and find the point coordinates of the interpolation curve between P(0) and Pf1 point.For example, when dividing into 4, t is 025.0
Find the P value at 5.075. From this bundle, the NC data generation means 7 generates the movement data "2P(025)-PIOI,
P(0,5)-P(0,25), P(0,75)-P
(0,5) and Pt1.1-P(0,75) are obtained by surface line interpolation. Since this data has a smaller tolerance than that obtained by linearly interpolating the original point group data, the processing machine can produce tMJ and 1iil with direct accuracy and smoothness.

In addition, in this embodiment, the interpolation formula is; cubic formula (P-at
'→bt'+ct'D')k has been described above, but the interpolation curve is not limited to this, and the interpolation curve may be obtained using a be, ゛, - function, circular interpolation, or the like.

[Effects of the Invention] As explained above in detail, the present invention makes it possible to obtain smooth NC data with a small positioning accuracy.

[Brief explanation of the drawing]

Fig. 1 is a block diagram of the NCC device related to misfire]]11, Fig. 2 is a block diagram of the conventional NCC device: The fourth section in the figure is an explanatory diagram of the curve calculation means, and FIG. 5 is an explanation of the division point extraction means. 1-CAD, 2. Free-form surface data, 3. Point group 6.
...Dividing point extraction means, ...NC data generation means, ...processing machine.

Claims (1)

[Claims] In an NC control device that generates NC data for a processing machine based on free-form surface data for processing, a curve calculation means for interpolating a point group extracted from the free-form surface data for processing into a curve using a desired interpolation formula; The present invention is characterized by comprising: division point extraction means for extracting one or more points on the interpolation curve; and NC data generation means for linearly interpolating the point group and the division point group to generate NC data for a processing machine. NC control device.