JPH04329405A - Nc work data preparing method for press metal die - Google Patents

Abstract

PURPOSE:To obtain NC work data removing over cutting to the corner projecting parts of a lower die when obtaining upper die/lower die NC work data for sheet press work from a single work model using thee-dimensional copy measurement and digitizing. CONSTITUTION:When obtaining the NC work data for lower die by using inverted shape data 100, in regard to the corner projecting part, lower die corner projecting part data 400 including a dummy lower die apex 401 offsetting the corner projecting parts by a probe radius Rs portion are calculated from data before and behind a corner projecting part apex 100b of the inverted shape data. Next, in regard to the points except the corner projecting apex 100b, lower die NC work data 202 are obtained by an arithmetic processing with offsetting by the value equivalent to the total rodius value of a probe and tool fromthe inverter shape data. Then, lower die corner projecting part NC work data 202b are obtained by an arithmetic processing with offsetting the corner projecting parts of the lower die by the radius value of the machine tool from the lower die corner projecting part data.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention relates to a method for creating NC machining data for press dies, particularly for upper and lower molds based on shape data obtained by three-dimensional copying and digitizing methods and inverted shape data obtained by inverting this shape data. The present invention relates to an improvement in a method for obtaining NC machining data using arithmetic processing.

0002

[Prior art] In order to manufacture press molds, a hand-made workpiece model is 3D scanned and measured, the 3D coordinates of each measurement point are digitized, and the shape data obtained for each sampling point is processed. Machining data indicating the locus of a tool is obtained. A conventional device for obtaining NC machining data from such scanning measurement coordinate data through arithmetic processing is disclosed in, for example, Japanese Patent Application Laid-Open No. 135162/1983, which has the advantage that machining data can be easily obtained.

[0003] Also, from the shape data obtained by the above-mentioned scanning measurement and digitizing, it is possible to calculate the NC of both the upper mold and the lower mold.
Machining data is obtained only by calculation processing, and according to this conventional method, from a single workpiece model,
Upper mold and lower mold NC machining data can be obtained, and this is an extremely effective method for creating NC machining data for molds for pressing thin plates, such as press molds for machining outer panels of automobiles.

FIG. 4 shows the NC in such a conventional device.
The processing steps are shown. The workpiece model 10 is digitized at each sampling point by the three-dimensional measuring machine 11, and the measuring element 12 is set at a predetermined X with respect to the workpiece model 10.
Or while moving in the Y direction, the work model 10 at that time
The contact point with the is imported as the Z coordinate, and the shape data 100
is obtained. Shape data 100 obtained in this way
is further calculated by predetermined calculation processing, that is, by taking into account data such as the diameter of the gauge head 12 and the tool used for machining, and the thickness of the thin plate to be pressed, etc., the upper mold NC machining data 201 and the lower mold NC processing data are
The data is supplied to the NC processing machine 20 as processing data 202. The NC processing machine 20 uses a predetermined tool 21 to cut the upper mold 30.
Then, the lower mold 31 can be subjected to NC processing.

[0005] The conventional shape data 100 and NC machining data 201, 202 obtained by arithmetic processing.
The calculation procedure is shown in FIGS. 5 and 6.

In FIG. 5, the measuring tip 12 is traced and scanned on the surface of the workpiece model 10, the movement locus of the center point of the measuring tip 12 at this time is captured as shape data 100, and upper mold NC machining data 201 is obtained from this shape data 100. It shows how to find. As is well known, when the measuring tip 12 is moved along the workpiece model 10, the corner convex portion 1 of the workpiece model 10
0a, that is, for a protrusion having a non-rounded apex, the shape data 100 becomes shape data 100a consisting of a curved line as shown in the figure. On the other hand, as shown by reference numeral 10b, shape data 100 is used for the corner recessed part of the workpiece model 10.
Also has a vertex shape indicated by reference numeral 100b. In this way, the shape data 100 is displaced from the surface of the workpiece model 10 by the radius Rs of the probe 12, and the machining locus of the tool 21, that is, the NC machining data, must be determined in consideration of this amount of displacement. In the figure, the radius of the tool 21 is indicated by Rc, and as a result, the shape data 100
The NC machining data 201 for the upper die can be obtained by offsetting by the difference (Rc - Rs) between the radii Rs and Rc of the probe 12 and the tool 21, respectively. If the tool 21 is moved along the NC machining data 201 for the upper die, the workpiece model 10 will be placed on the workpiece 30.
It is possible to perform NC processing to create a shape that almost matches the surface of the . However, as mentioned above, the tool 21 has a minimum machining radius R
c, a machining residual portion 50 is produced in the corner recessed portion of the upper mold, as shown in black in the figure.

As described above, in the past, shape data 1 obtained by three-dimensional copying and digitizing
From the shape data 100, the desired NC machining data 201 for the upper mold can be easily obtained only by arithmetic processing, but furthermore, as shown in FIG. It can be obtained by the arithmetic processing of That is, it is the total radius value obtained by adding the probe radius Rs and the second half Rc to the shape data 100 (
The NC machining data 202 for the lower mold can be obtained by offsetting the NC machining data for the upper mold by Rc+Rs) to the opposite side from the NC machining data for the upper mold. Of course, the thickness of the thin plate to be pressed at this time is of course taken into account in the machining data for both molds.

As described above, conventionally, FIG.
The shape data 100 is made into inverted shape data as shown in FIG.
It becomes possible to obtain NC processing data for the lower die 31. However, when such inverted shape data is used, there is a problem that overshaving occurs when processing the lower mold 31.

This over-shaving is indicated by the reference numeral 51 in FIG. 6, and when such over-shaving occurs, the apex of the corner of the lower die in which the corner convex portion is to be obtained will be rounded, and the pressing process will be interrupted. In some cases, it has become impossible to achieve the desired angular pressing.

[0010] For the remaining part 50 of conventional machining, whether it is the upper mold or the lower mold, auxiliary machining is performed using other suitable machining processes such as ridge machining using a small diameter tool. By doing this, it is possible to remove the remaining machining portion 50, but once over-shaving 51 occurs as shown in FIG. 6, it is extremely difficult to recover from this.

[0011]

[Problem to be Solved by the Invention] Therefore, in the past, when such over-shaving occurred, extremely troublesome methods such as welding overlay on the corner convex portion and resharpening this by hand were required. It needed work.

[0012] The above-mentioned drawbacks are as follows:
This is generated by calculating the NC machining data of both the upper mold and the lower mold from the shape data 100 of .

FIG. 6 briefly explains the reason why such a problem occurs.

That is, if the corner convex apex 100b of the inverted shape data for the lower die is offset by the sum of the radii of both the measuring tip 12 and the tool 21 (Rc+Rs),
As mentioned above, the NC machining data 202 for the lower mold is obtained, but at this time, a perpendicular line is drawn from the corner convex apex 100b to the reverse machining data 100, and this perpendicular line is A machining trajectory of the tool 21 is obtained by connecting the inner regions 301 with circular arcs 200a.

However, the lower mold 31 actually required
The vertex of the corner convex portion is located at the position indicated by reference numeral 31a, and therefore,
Originally, for the NC machining data 202, the area within the perpendicular line drawn from the apex 31a of the lower mold 31 to the machining data 202, that is, the part indicated by reference numeral 302, is a circular arc 202 indicated by a broken line.
b, and as is clear from the figure, it is understood that the conventional arc 202a obtained only by arithmetic processing digs deeper into the lower mold 31 side than the originally required arc 202b, and as a result, the above-mentioned cutting 51 had occurred.

Therefore, in the past, such excessive cutting was accepted as an unavoidable situation, but in view of such conventional problems, the present invention is capable of accurately cutting the apex of the corner convex portion of the lower die. To provide an improved NC machining data creation method which enables press working with excellent squaring by importing it as NC machining data and thereby machining the corner convex part of a lower mold into a vertex without any modification. There is a particular thing.

[0017]

[Means for Solving the Problems] In order to achieve the above object, the present invention obtains shape data by three-dimensionally tracing a measuring element on a workpiece model, and calculates upper mold NC processing data from this shape data. Press mold NC processing data is obtained from the inverted shape data by calculation processing.
In the machining data creation method, for the corner convex part of the inverted shape data, lower mold corner convex part data including a pseudo lower mold apex offset from the data before and after the corner convex apex of the inverted shape data by the radius of the measuring tip is obtained. For areas other than the corner protrusions of the lower mold, lower mold NC machining data is calculated by offsetting only the total radius of the probe and tool from the inverted shape data, and for the lower mold corner protrusions, the above The present invention is characterized in that only the radius value of the tool is offset from the lower mold corner convex portion data, and the lower mold corner convex portion NC machining data is obtained through arithmetic processing.

[0018]

[Operation] Therefore, according to the present invention, NC machining data for the upper die can be easily obtained by calculation processing from a single shape data obtained by three-dimensional scanning measurement and digitizing, and at the same time, the shape data can be inverted. NC for lower mold from data
The machining data is obtained through arithmetic processing, and at this time, for the corner convex part of the lower mold, lower mold corner convex part data including the pseudo lower mold apex is once obtained, and based on this, the NC machining data of the lower mold is obtained. As a result, there is an advantage that the shape of the apex-cornered convex portion of the lower die can be formed as processing data during a series of shape data calculation processes.

[0019]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a diagram illustrating the lower mold NC machining data arithmetic processing operation of the present invention, which is similar to the conventional method shown in FIG. 6 described above.

In the present invention, the upper die NC machining data is obtained in exactly the same manner as the conventional method shown in FIG. 5, and the explanation thereof will be omitted. In FIG. 1, only the arithmetic processing for the corner convex portion 100b when obtaining large-scale Nc machining data for the inverted shape data 100 is characteristic of the present invention.

First, the vertex 1 of the corner convex part of the inverted shape data 100
Using the shape data 100 before and after 00b, that is, the minute straight line group data obtained by three-dimensional scanning measurement and digitizing for each sampling point, the pseudo lower mold apex 4 is
Lower mold corner convex portion data 400 including 01 is obtained.

That is, as is clear from FIG. 1, the inverted shape data 100 itself has an apex 100b of a convex corner, and from a group of straight lines before and after this apex 100b,
A straight line that is parallel to this and outside the inverted shape data 100 by the radius Rs of the measuring tip 12 is the lower mold corner convex apex data 40.
Set to 0. This straight line becomes two straight lines with different angles,
It is clear that the intersection of the two forms a pseudo lower mold apex 401.

Once the pseudo lower mold apex 401 is obtained in this way, the next step in the present invention is to divide the lower mold 31 into a region corresponding to the corner convex apex 401 and the other regions to form a lower mold NC. Arithmetic processing of processed data is performed.

For the parts other than the apex 401 of the lower mold corner convex portion, the tracing stylus 12 is determined from the inverted shape data 100 in the same manner as before.
Then, the lower die NC machining data is obtained by offsetting the total radius value (Rc+Rs) of the tool 21.

On the other hand, the area 302 corresponding to the corner convex apex 401 of the lower die is offset by the radius value Rc of the tool 21 from the lower die corner convex apex data 400 obtained in the first step. Lower mold corner convex part NC machining data 20
2b is obtained.

In practice, lower mold corner convex portion NC machining data 202
b may be performed not only on the region 302 in FIG. 1 but also on the region 301, or in the present invention, this lower mold corner convex NC machining data is performed only on the region 302, and the outside region is It can also be determined from the lower mold NC machining data itself.

FIG. 2 shows details of each processing means using a computer for creating NC machining data according to the present invention.

The shape data obtained by the three-dimensional scanning measurement and digitizing described above are digitally recorded in the shape memory means 50.

In the embodiment, for the upper mold, the upper mold NC machining data calculation means 51 is stored in the storage means 50.
The shape data 100 is read out and desired machining data calculations are performed. FIG. 3 shows a flowchart of the present invention, in which after the shape data is taken in (S10), it is determined in step S11 whether the upper mold is the upper mold or the lower mold.
The C processing data calculation means 51 performs an offset calculation of (Rc-Rs) shown in step S12. This upper mold NC
The processed data is stored in the NC processed data storage means 52 as digital data.

On the other hand, if it is determined in step S11 that it is a lower mold, the inverted shape data calculation means 53 performs an inversion calculation on the shape data 100 (S13), and the lower mold corner convex part data calculation means 54 further calculates the pseudo lower mold. Create lower mold corner convex part data including vertices.

In practice, this lower mold corner convex part data is sequentially processed by arithmetic processing according to the inverted shape data, and as shown in FIG. is determined (S14), and if it is determined to be a corner convex portion as described above, lower mold corner convex portion data is created (S15). And for this lower mold corner convex part,
As shown in step S16, the Rc offset is performed by the lower mold corner convex portion NC machining data calculation means 55.

On the other hand, if it is determined in step S14 that the part is not a corner convex part, the lower mold NC is used in the same way as the upper mold.
The processed data calculation means 56 performs an offset of (Rc+Rs) (S17). The lower mold NC machining data and the lower mold corner convex portion NC machining data thus obtained are then stored in the storage means 52 in the same manner as the upper mold NC machining data.

As described above, according to the present invention, for a corner convex portion having an apex of the lower die, the pseudo apex of the lower die is once determined, and this pseudo apex is used to obtain NC machining data for the corner convex portion of the lower die. is calculated, it is possible to reliably prevent over-cutting as in the conventional method.

[0035] It goes without saying that the upper mold and lower mold in the present invention can be reversed as desired.

[0036]

[Effects of the Invention] As explained above, according to the present invention,
Using a single shape data from 3D scanning measurement and digitizing, we can calculate the upper and lower dies for thin plate press processing through simple calculation processing, and we can create accurate shapes without over-cutting even the corner convex parts. It becomes possible to easily obtain NC machining data.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram showing a preferred embodiment of the NC machining data creation method according to the present invention.

FIG. 2 is a configuration diagram of processing means for executing the data creation method according to the present invention.

FIG. 3 is a flowchart showing the NC machining data creation method of the present invention.

FIG. 4 is an explanatory diagram of an NC processing process using conventional three-dimensional scanning measurement and digitizing.

FIG. 5 is an explanatory diagram showing conventional calculation processing of upper mold NC machining data.

FIG. 6 is an explanatory diagram showing conventional lower mold NC machining data calculation processing.

[Explanation of symbols]

10 Work model 12 Gauge head 21 Tool 30 Upper mold 31 Lower mold 100 Inverted shape data 202 Lower mold NC machining data 202b Lower mold corner convex NC machining data 401 Pseudo lower mold vertex

Claims (1)

[Claims] Claim 1: Shape data is obtained by three-dimensionally tracing a measuring head on a workpiece model, upper die NC machining data is obtained from this shape data through arithmetic processing, and lower die NC machining data is further arithmetic processed from the inverted shape data. Press mold NC required by
In the machining data creation method, for the corner convex part of the inverted shape data, lower mold corner convex part data including a pseudo lower mold apex offset from the data before and after the corner convex apex of the inverted shape data by the radius of the measuring tip is obtained. For areas other than the corner protrusions of the lower mold, lower mold NC machining data is calculated by offsetting the inverted shape data by the sum of the radii of the probe and tool, and for the lower mold corner protrusions, the lower A method for creating NC machining data for a press mold, characterized in that NC machining data for a lower die corner convex portion is obtained through calculation processing by offsetting only the radius value of the tool from the mold corner convex portion data.