JPS60112105A - Numerical control system - Google Patents

Abstract

PURPOSE:To relieve the load of a computer and also to execute simply and quickly the correspondence to partial correction at processing by executing the 2nd processing in an NC machine as a cutting path formed at the 1st processing as an input data. CONSTITUTION:The cut path data formed by a cut path forming section 20 is inputted to the NC machine together with additional information required for processing at first. A boundary curve required to localize a cut curved face is inputted by utilizing a manual data input 50 in this case, the boundary curve is formed by a boundary curve forming processing section 60 and the data is stored in a buffer memory together with a plane code and additional information. A data processing section 70 of the NC machine reads sequentially the cut path data, it is decoded by a decoder, only the cut path data in the effective cut region is extracted and edited and the data in the buffer is revised. Each NC data of the buffer memory is converted into a pulse train corresponding to the cutter moving amount at an interpolation circuit 90 and the pulse drives an NC machine tool 110 via a servo system circuit 100.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a partial area machining method when cutting a workpiece such as a mold using an NC machine tool.

[Background of the invention]

When cutting a workpiece such as a mold using an NC machine tool, the shape of the workpiece is usually divided into multiple basic shapes (generally curved surfaces, hereinafter referred to as curved surfaces), and each The cutting process is performed for each curved surface, and the cutting movement control data (hereinafter referred to as cutting path) of the processing tool (hereinafter referred to as cutter) is processed.
) is being created. In general, when processing a mold made of a two-dimensional shape, the shape itself is complex, and the mold structure is also complicated, so it is necessary to process it by dividing it into many curved surfaces, and each curved surface is In many cases, these surfaces exist in an interrelated relationship with each other, and so-called interference wall processing, which is inevitably a mutual problem between multiple curved surfaces, increases, and even if a large-scale computer is used, an enormous amount of calculation time is required. Moreover, because conventional NC devices only output the 7'cNC command to an NC tape, decipher it as input data, and execute it, it is possible to generate the final finished shape in advance for all curved surfaces with complete fidelity. For example, even in the case where a plurality of partial shapes such as cylinders are interconnected on a curved surface, it is necessary to create a cutting path including detailed shapes. Therefore, for example, in the case of partially modifying the shape of one of a plurality of interference surfaces that serve as interference walls for the target cutting surface, 4, for the corresponding cutting surface,
It is necessary to calculate the cutting angle and angle again and create the NCC chip 1, which is not efficient.

To explain this gap a little more concretely, for example, in NC cutting of a model shape 10 as shown in FIGS. Considering the case of calculating,
The curved surfaces 12 and 13 will be processed as interference wall curved surfaces. Here, for example due to a design change, the shape of the curved surface 15 is changed to 1. As shown in FIG. 2, when modifying the shape of the curved surface 14, recalculation is required even though the shape of the white oil 111 is the same. Moreover, the work of re-outputting NC tapes due to such shape corrections is by no means rare, but actually quite common, and the increase in the amount of work cannot be ignored. Also, CAD/CAM
As the introduction of this progresses, the shape data created in upstream processes such as layered design will be shared in all processes, which will inevitably increase the opportunities for shape changes such as adding partial corrections. The impact on downstream processes such as the mold processing department is extremely large.In addition, it generally affects the departments that use computers to create NC tapes and the machine tools that perform actual machining using the NC tapes. Since the person in charge is different from the operator, the NC tape re-output work as described above occurs frequently.This not only increases the load on the computer, but also causes the work to go back to the upstream process each time, making the work difficult. There is also the problem that the time and waiting time etc. increase, which inevitably increases the total number of man-hours in the mold manufacturing process.

Engraving of the specification (no change in content) [Object of the invention] The object of the present invention is to process a workpiece such as Venus by using a computer to
When CC cutting is performed, each curved surface constituting the workpiece shape is separated into the first process of creating cutting marks and the second process of dividing the curved surface into partial areas using planar curves. Using the cutting path created in step 1 as input data,
To realize a partial area machining method and its control device that allows an NC device to execute a second process, thereby reducing the load on a computer and easily and quickly responding to partial corrections during machining. It is in.

[Summary of the invention]

As one basic shape constituting the workpiece shape, curved surface A has an interrelated relationship with curved surface B and curved surface C, and curved surface A has curved surface B,
The shape that is segmented by C, ie, the XY plane or the YZ plane.

When one of the ZX planes is used as a projection surface, the parallel projection curve of the member of curved surface A and curved surfaces B and C is the same plane as the parallel projection curve of the contour lines of curved surfaces B and C. It becomes a curve, and due to its plane curve, the curved surface A
Assume a shape that is divided into multiple regions. Here, curved surface A is the target curved surface for cutting processing, and when creating a cutting path to carve curved surface A, NC cutting processing is performed assuming that curved surfaces B and C do not exist, and cutting to process the entire area of curved surface A. The path is calculated and outputted to, for example, an NC tape 3. Thus, the above-mentioned N
Before reading the C tape as input data and performing NC machining on curved surface A, first, the above-mentioned plane curve information that is divided into curved surface A' by curved surface B and curved surface C, and additional information such as machining area designation are sent from the NC device. is input, curve data is generated using this plane curve with curved surface A as the boundary curve between the cutting area and the non-cutting area, and is stored in a buffer together with additional information. After that, the cutting pass data is sequentially read from the NC tape, and the intersection point calculation process between each cutting pass and the curve data is performed. For cutting passes where there is no intersection, if the cutting pass is in the cutting area (hereinafter referred to as "cutting") (referred to as mode) cuts, that is, inputs the input
The data is passed from the data processing section of the NC device to the interpolation circuit, and is controlled to move randomly as is well known, and if it is in a non-cutting area (hereinafter referred to as non-cutting mode), it is skipped as unnecessary data. Also, if there is an intersection, the cutting path is divided into two at that intersection, and in cutting mode, among the two divided cutting paths,
Cuts up to the intersection, converts to non-cutting mode, and skips the cutting path after the other intersection. Also, if you are in non-cutting mode, you can easily skip past the intersection points and change to cutting mode. J
L, te, and the other perform cutting processing. However, in this case, the previous cutter position, i.e., if there are several cutting areas, a cutting path that skips over the non-cutting area from the end of the previous cutting area to its intersection, usually rapid cutting, +S, newly generated 1. After that, I decided to cut with the cutting chips after the intersection point. By performing the above-described processing on the entire cutting nose, partial area machining of the curved surface A can be realized. The basic idea of the present invention is to perform simple arithmetic processing on two-dimensional graphic data using a well-known NC system.
By applying the voltage to the device, the result and 1. The goal is to realize a partial area processing function for three-dimensional shapes. That is, each cutting pan is usually created using three-dimensional line segment data, but in this method, as described above, it is only necessary to process it on the projection plane, so the third axis coordinate value that coincides with the projection direction is Since there is no need for area determination processing, it can be treated as two-dimensional data, and the object of the present invention can also be achieved by limiting the plane elements constituting the boundary curve to simple geometric shapes, such as line segments and circles. Therefore, it is basically a process to find the intersection of two-dimensional line segments or line segments and circles or Fl arcs, so if the initial machining shape is, for example, a three-dimensional free-form surface, However, there is no need to use a large-sized machine, and by adding a comparatively simple calculation tube forming system using a microprocessor to the NC equipment ff4, the three-dimensional shape partial thin cutting method of the present invention can be provided. Here, we have explained an example in which cutting path data for machining the entire area of curved surface A is input into an NC device using an NC tape, but of course the same applies to an NC device equipped with a flexible disk reader. The so-called C that directly controls the NC machine tool with
When this method is realized as an NC device, similar partial area processing becomes possible by outputting the cutting path to, for example, a magnetic disk.

[Embodiments of the invention]

First, an example of how to effectively utilize the present invention will be described using functional explanatory diagrams of the present invention shown in FIGS. 1 to 5. The shapes shown in FIGS. 1 to 3 are modeled workpiece shapes that have the same basic shape but have slightly different partial shapes. That is, the basic shape 10 in each case is composed of a curved surface 11 and a curved surface 12, and as a partial shape of this basic shape 10, a curved surface 15. In Figure 2, the curved surface 14.
In FIG. 3, a curved surface 15 and a curved surface 16 are respectively added. In such a case, in the partial area machining method according to the present invention, for example, considering the case where the cutting curved surface 11 in FIG. Cylindrical curved surface 1 that becomes a circle
3 is ignored, a cutting pass for machining the entire area of the cutting curved surface 11 is generated in advance, outputted to NC tape, etc.
3 is a non-cutting area. During machining, the projection plane from the NC device is set to XY thousand planes, and the cutting curved surface 11 is set as a non-cutting area.
Partial area processing can be performed by inputting a circle of radius R+ that partializes as a boundary curve. Therefore, in the case of the shape shown in FIG. 2, by specifying a rectangular curve on the XY plane of the prismatic curved surface 14 as the boundary curve, and in the case of the shape shown in FIG. The same NC tape can be used for both the curved surfaces 15 and 16 of the cylindrical shape (by specifying the circular curve data on the XY plane as multiple separate boundary curves, it is possible to When processing, or
For example, when partially correcting the shape shown in FIG. 1 to the shape shown in FIG. 2, this can be done effectively and quickly.

In addition, as shown in Fig. 4, if it is composed of only the basic shape 10, it is of course possible to use the above-mentioned NCC chive as is as in the conventional method, and furthermore, as shown in Fig. 5, cutting Even if there is a hole-shaped curved surface 17 that does not act as an interference wall with respect to the curved surface 11, and conversely cuts into the cutting curved surface 11 in the depth direction, when machining the cutting curved surface 11, it is usually like the curved surface 17. Since the hole-shaped portion has already been machined, the cutting pass in that area will be an empty cut, resulting in wasted machining time.

Therefore, in order to shorten the machining time, it is necessary to make the 17° C. portion of the curved surface into a non-cutting area, and this is one example of an effective application of the partial area machining method of the present invention at a machining site.

Next, the overall system configuration diagram and processing method of the partial area processing method according to the present invention for realizing the above-mentioned functions will be explained. FIG. 6 is an overall system configuration diagram as an embodiment of the partial area processing method of the present invention.

In other words, along with additional information necessary for NC machining such as cutting conditions, etc., the machining machine tool can be used directly or once converted into NC tape 30 or flexible disk 40, etc.
Input to C device. At this time, when performing partial area machining of the cutting curved surface according to the present invention, manual data input MDI such as a keyboard attached to the NC device is used in advance.
50t-, the boundary curve information necessary for segmenting the cutting surface is inputted, and the boundary curve creation processing unit 6o generates the boundary curve, and uses the predetermined information along with additional information such as its plane code and area code. Store it in buffer memory. Explanatory diagrams of this input data are shown in FIGS. 7 to 10. That is, the boundary curve information includes geometric data of the curve and additional data for area processing, and the geometric data includes the starting point P5 when the component of the curve is a line segment as shown in FIG. The end point P is specified, and in the case of a circular arc as shown in FIG. 8, the center point Pe and radius R are also specified. The additional data mainly includes the designation of the curve definition plane, that is, the projection plane of the cutting curved surface, and the designator boundary curve offset designation of the area mode of the cutting start point that designates the machining area.
For example, in the case of Figure 9, the definition plane is the XY plane, the area mode is the cutting mode because the cutting start point PI is the cutting area, and the offset specification is when moving the cutter to the boundary curve as shown in the example of path j. In the case of a path amount, specify an offset to the right from the starting point P of the boundary curve toward the end point P6, and in the case of a path, specify an offset to the left.

Also, in the case of a curve composed of multiple elements as shown in Figure 10, the geometric data of element 1- and element 2 should be specified consecutively, and additional circles should be generated at the edges between the elements. If so, specify the radius rl of the additional circle between the geometric data of each element. In the case of FIG. 10, a circular arc element with a starting point of Q1 and an ending point of Q2 is added, and the end point of element 1 and the starting point of element 2 are changed, so that a boundary curve consisting of three elements is finally created. FIG. 11 is a diagram showing the processing procedure of the boundary curve creation processing section 60. In FIG. 11, first, the curve data input processing unit 61 reads the boundary curve information inputted from NhlD Iso, and as for the geometric data, each component data of the curve is sequentially transferred to the work area, and the number of elements and additional circle processing are performed. The data is set, and the additional data is converted into specific plane codes, area codes, and onset codes. The additional circle processing unit 62 generates all additional circles with the specified radius between each element, and creates one boundary [tb m
The processing procedure for generating this additional circle, which is created as a take, is performed as follows, for example. Figure 12 shows element 1 and element 2.
An example will be shown in which an additional circle 1 with a radius rl is generated between 0 and an additional circle 1 with a radius r2 is generated between an element 2 and an element line segment 3.

In this case, first of all, an additional circle is added to the point Pa side of the bifurcated point of circle 1 and circle 2, which is closer to the starting point P8, and then the relationship between the intersection point Pc of circle 2 and line segment 3 with respect to circle 1 is determined. By selecting the additional circle that circumscribes circle 1, the two inscribed circles are removed, and from the relationship between starting point P8 and circle 2, of the remaining two circles, additional circle 1 that circumscribes circle 2 is finally selected. 0 and 2 within the lung can be generated by performing the same processing by considering the intersection Pa as Ps. The boundary curve data created in this way is processed by the element division processing unit 6.
In step 6, the contact points Q1 to Q04 between each element and the inside of the lung are divided into element data constituting the boundary curve, and as a result, a boundary curve composed of five elements indicated by arrows is created. Next, the standard form creation processing unit 64 determines whether each element is a line segment element or a circular element, and converts it into a specific standard form. 1st
3 and 14 show examples of standard forms of line segment elements and circular elements. In this case, the formula for the standard shape is, in the case of a line segment element, the starting point P
If the first coordinate of s is Xs and the second coordinate Ys, then in the case of a circular element, the first coordinate of the center point is XC,
If the second coordinate is Yc, it can be expressed as follows. Here, U is a parameter having a value of O≦U≦1. Furthermore, the offset processing section 65 uses the standard shape data to offset the standard shape data by the value of the cutter radius to the left or right in the defining direction of the boundary curve, that is, from the start point to the end point, using a well-known method. change.

Finally, the boundary curve output processing unit 66 outputs the plane code and the area code to a predetermined buffer memory, and also sequentially outputs the number of elements of the boundary curve and standard form data 'fr of each element.

On the other hand, the data processing unit 70 of the NC device sequentially reads the cutting path data, decodes it with a decoder, and sorts numerical information such as the amount of cutter movement of each coordinate axis of the NC machine tool into respective predetermined buffer memories. Then, the partial area processing unit 80 performs intersection calculation processing and area determination processing between each cutting pass data and the standard form data of the boundary curve, and extracts and edits only the cutting pass data within the valid cutting area. and update the corresponding data in the buffer.

The processing section J1m of the partial area processing section 80 is shown in FIG.

Hereinafter, the processing procedure will be explained using FIG. 15 and FIG. 16 explaining a specific example of the processing. In Fig. 16, cutting path i is divided into two boundary curves, curve 1 and curve 2, and P1 to Ps are each cutting point of cutting path l, and the first cutting point Ps is in the cutting area. Assume that there is. First, as an initialization process, the plane coordinate system is set to the XY plane, and the initial value of the area mode is set to cutting mode. Next, a line segment of the cutting path (hereinafter referred to as a path line segment) is created using the two cutting points PH+P2'ff of the cutting path data.

At this time, since each cutting point is generally three-dimensional data,
The first coordinate value and the second coordinate value are determined by changing to the set plane coordinate system. In the case of the XY plane, coordinate transformation is not necessary, so the formula for the path line segment can generally be expressed as follows. Here, dxj I dyj l dzzj
is the increment value of each coordinate component Ω between the jth cutting point and the j+ith cutting point, and the parameter uj is 0≦ujku1
shall take the value of . Next, in order to check whether this intersection line intersects with the boundary curve, for all elements of the boundary curve, if it is a circular element like curve 1, then equation (2) and (3)
) Formula 9 If it is a line segment element like curve 2, use formulas (1) and (3) to calculate the intersection point. This intersection can be easily found from the conditions that the parameters are 0≦U≦1 and 0≦uj≦1.

Thereafter, area determination processing is performed depending on the presence or absence of an intersection to determine whether the path line segment is to be subjected to cutting processing or non-cutting processing.

Here, cutting processing involves resetting the value of the corresponding cutting point in the buffer memory where each coordinate value of the cutting point is stored.
The path line segment is passed to the interpolation circuit as valid data to perform cutter movement control, and the non-cutting process is to delete the path line segment from the buffer as unnecessary data.

Similarly, for all path segments, the path segments are P2P
3. P3P4. By sequentially creating P7 and P8 and reversing the intersection calculation and region determination, the intended partial region processing can be realized. That is, if there is no intersection, if it is in cutting mode, the path line segment (in this case, for example, PIP2 is applicable. The same applies hereinafter) will be processed for cutting, and if it is in non-cutting mode, it will be processed as a straight path line segment (P3P4), ffi delete. Also, if an intersection exists, in cutting mode, convert the path segment (PzPa) into a path segment (shoulder) up to the intersection and perform the cutting process, and then reverse the area mode and switch to non-cutting mode. change.

In the case of one-way valve cutting mode, among the path line segments (P4P5), the path line segment (P4Q2) up to the intersection is deleted and a new cutting path that jumps between non-cutting areas, that is, between QI and QZ is generated. Add it to the buffer, convert the area mode to cutting mode, and add the path line segment after the intersection (Q2 Ps
) is the cutting process. The same goes for the cutting point P6 and after, and the path line segment Ps Ps becomes the cutting process, and the path line segment Pa P
Since it has an intersection with the 7-point curve 2, cut PeQ3,
Q3P7 is deleted, and path line segment P7P8 is also deleted. In this way, in the case of the present invention, in principle, the same area determination process is simply executed repeatedly for all cutting points on the curved surface, regardless of the number of boundary curves.
As is well known, each NC data stored in a predetermined buffer memory is converted into a pulse train corresponding to the cutter movement amount by an interpolation circuit 90, and then converted into a pulse train by a servo system circuit 100. D-A
By performing the conversion and driving the NC machine tool 110, the intended partial area machining can be realized.

〔Effect of the invention〕

(b) When performing NC machining of each curved surface that constitutes the shape of the workpiece of a new functional mold, etc., use the cutting path data output to NC tape, etc. to specify a planar curve to partialize the cut curved surface during machining. By doing so, the NC device realizes a partial area processing function of a curved surface that uses the plane curve as a boundary curve between a cutting area and a non-cutting area.

e→Economical and simplified It is possible to quickly respond to partial corrections of shapes at the processing site, which reduces the need to re-output NC tapes, reducing large-scale calculation time and calculation costs. can. Furthermore, the number of times of feedback to upstream processes such as the NC tape production department is reduced, so the man-hours of the entire mold manufacturing process are reduced. Another advantage is that the same NC tape can be used for NC machining of similar shapes.

[Brief explanation of drawings]

Figures 1 to 5 are functional explanatory diagrams of the present invention, Figure 6 is an overall configuration diagram of a system that realizes the partial area processing method of the present invention, and Figures 7 to 10 are diagrams that illustrate the curved surface of the present invention. An explanatory diagram of the input data of the boundary curve to be segmented, FIG. 11 is a diagram showing the processing procedure of the boundary curve creation processing section of the present invention, and FIG. FIGS. 15 and 14 are diagrams showing standard form data of the elements constituting the boundary curve, and FIGS. 15 and 16 are diagrams showing a method for generating the inside of the lung. It is an explanatory diagram of the processing procedure of the section. 20... Cutting path creation section 60... NC tape 40
...Flexible disk 50...Manual data input 60...Boundary curve creation processing section 61...Curve data input processing section 62...Internal processing section 66...Element division processing section 6
4... Standard form creation processing section 65... Offset processing section 66... Boundary curve output processing section 70... Data processing section 80... Partial area processing processing section 110... NC milling cutter 1. ) Figure 1 <b) Figure 2 Figure 6 Figure 12fI Figure 13 Figure 14 Procedural amendment (method) Indication of the case 1981 Patent Application No. 219412 Title of the invention
Relationship between the person making the numerical control method correction Patent applicant name (510, 1 stock accounting) Representing Hitachi Manufacturing
Subject of Administrator's Amendment 1 Column for detailed description of the specification/invention. Contents of amendment

Claims (1)

[Claims] Numerical side @ (hereinafter referred to as NC): NC cutting path data for cutting a part shape consisting of two-dimensional or three-dimensional shapes by a machine tool is input into the NC device from an NC tape or magnetic recording medium and the movement of the tool is controlled. In the NC method of controlling and machining the part shape, the NC device specifies two-dimensional curve data in a specific plane that defines the machining area, and uses the curve data as a boundary curve between the cutting area and the non-cutting area. 7, and performs intersection calculation processing and area determination processing with the above-mentioned all cutting path data, thereby extracting only the cutting passes that exist in the cutting region divided by the above-mentioned boundary curve, and also connecting the cutting passes. An NC method is characterized in that it is possible to realize partial area machining of a part shape by newly generating a cutting path.