JPH09292909A - Flat part and standing wall part dividing method and recording medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for dividing an envelope (offset face) showing the moving pattern of a tool into a flat part and a standing wall part at the time of working to manufacture an object in the same form as a model through the use of the tool. SOLUTION: The envelope of the fixed point of the tool at the time when the tool comes into contact with each face of the model is prepared (S2), two-dimensional grid points at a regular intervals are set within a working area (S2), each of the set grid point is projected to the envelope (S4), the coordinate of the projected point is obtained (S5), the height of the flat part at the envelope is specified based on the inclination of the mesh consisting of the four projected points on the envelope (S6) and a contour path combining points at the same height at the envelope is calculated (S7). Then a pair of contour paths between which the height of the specified flat part exists are extracted from the calculated paths (S8) to divide the envelope by making the part inserted between the extracted contour paths the flat part (S9) and making the other part the standing wall part (S10). An equal-interval projection path working processing is given to the flat part and a contour working processing is given to the standing wall part.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention divides data of an envelope surface for controlling the movement of a tool into a flat portion and a standing wall portion when a tool having the same shape as a model is machined and manufactured. On how to do.

[0002]

2. Description of the Related Art In order to automatically machine and manufacture a product having the same shape as a model composed of a plurality of surfaces using a tool of an NC machine for simultaneous three-axis machining, a model obtained by CAD is used. The three-dimensional processing data is obtained in advance by adding the shape data including the dimension information of the tool to the shape data of (3). And
The movement of the tool is controlled in accordance with the three-dimensional machining data to produce the same shape as the model.

As a method for creating such three-dimensional processed data, the following method has been generally used. First, an offset surface is created for each surface that constitutes the model in consideration of the size and shape of the tool.
In this case, the envelope surface drawn by the fixed point of the tool when the tool virtually contacts each surface of the model is the offset surface. For example, when the shape of the end portion where the tool is machined is a hemisphere, the envelope surface drawn by a fixed point (center of the hemisphere) separated from each point on the model surface by the radius of the hemisphere is used as the offset surface. Then, the information on the offset surface becomes the three-dimensional machining data that controls the movement of the tool.

By the way, when an object having the same shape as the model is machined and manufactured, a flat portion (a portion substantially perpendicular to the direction in which the tool comes into contact with and separates from the workpiece) and a standing wall portion (a portion other than the flat portion). And, the processing method by the tool is different.

FIG. 6 is a perspective view showing an example of a model M having a plurality of surfaces. In FIG. 6, the Z-axis direction is the direction in which the tool approaches and separates from the object to be processed, and the portion of the surface that is substantially perpendicular to the Z-axis, that is, substantially parallel to the XY plane, is the flat portion, The remaining part becomes the standing wall. FIG. 7 (view seen from the X-axis direction) and FIG. 8 (view seen from the Z-axis direction) show division patterns of the flat portion and the standing wall portion with respect to the model M shown in FIG. In FIG. 7, the area marked with A is the flat portion, and the area marked with B is the standing wall portion,
In FIG. 8, a white region indicates a flat portion A, and a hatched region indicates a standing wall portion B.

In the processing method for a flat portion, the height of the tool (position in the Z direction) is fixed, and the obtained offset surface (XY
Set a movement path at equal intervals on a plane parallel to the plane, and control the movement of the tool according to the movement path. FIG. 9 shows an example of the movement of the tool T with respect to the object Q to be processed during the flat portion processing. On the other hand, in the machining method for the standing wall portion, information (contour line path) connecting points of the same height (Z direction position) on the offset surface is obtained, and the movement of the tool is controlled according to the obtained plurality of contour line paths. FIG. 10 shows an example of the movement of the tool T with respect to the object Q to be machined when machining the standing wall. In this way, by changing the processing method for each of the flat portion and the standing wall portion, an object having the same shape as the model can be produced accurately and efficiently.

[0007]

However, when it is not possible to distinguish which region is the flat portion or the standing wall portion in the model, it is impossible to switch the processing method in this way. Therefore, conventionally, an operator involved in the fabrication process separates the flat portion from the standing wall portion by visual judgment on the model. However, even if the model having a simple shape can determine the flat portion / standing wall portion, the model having a complicated shape has a large number of boundaries, and the determination is difficult.

Since it is the information of the offset surface (envelope surface of the tool fixed point) that becomes the three-dimensional machining data that actually controls the movement of the tool, it is important to divide the flat portion / standing wall portion on the offset surface. is there. There is a gap between the boundary of the flat portion / standing wall portion in the model and the boundary of the flat portion / standing wall portion in the offset surface in consideration of the shape of the tool. FIG.
Is a schematic diagram showing this deviation. A solid line C shows the surface of the model M, and a broken line D shows an offset surface representing the fixed point locus of the tool T. As shown in FIG. 11, the flat portion / standing wall boundary position C1 in the model M and the flat portion / standing wall boundary position D1 in the offset surface D are set to the radius of the hemispherical tip of the tool T. It is off by a corresponding amount. It is difficult for the operator to consider such a shift, and the operator can only specify the boundary in the model, and it is practically impossible to specify the boundary between the flat portion / standing wall portion in the offset surface when machining with the tool. It was possible.

As described above, in the conventional method, in the model having a complicated shape, the flat portion / standing wall portion cannot be divided into regions on the offset surface, and even if it is possible, the division result is not accurate.

If the flat portion and the standing wall portion cannot be divided into regions, either one of the working method suitable for the flat portion and the working method suitable for the standing wall portion is performed over the whole area, Alternatively, both the processing method suitable for the flat portion and the processing method suitable for the standing wall portion are performed throughout.
The former method has a problem in that the whole is not finished cleanly, and the latter method has a problem in that the machining efficiency is very poor due to many unnecessary movements of the tool. Under such circumstances, it is desired to develop a method for dividing the flat portion and the standing wall portion on the offset surface.

The present invention has been made in view of the above circumstances, and provides a flat portion / standing wall portion dividing method capable of easily and accurately automatically dividing a flat portion and a standing wall portion on an offset surface. The purpose is to

Another object of the present invention is to accurately divide an offset surface into a flat portion and a standing wall portion so that an object having the same shape as the model can be accurately and efficiently processed and produced. A part / standing wall part dividing method is provided.

Yet another object of the present invention is to provide a recording medium having a computer program recorded thereon, which can realize the above-described flat portion / standing wall portion dividing method.

[0014]

According to the flat part / standing wall part dividing method of the present invention, a tool virtually contacts an object having the same shape as a model having a plurality of surfaces with each surface of the model. When machining the tool by moving it while repeatedly contacting and separating it from the envelope surface according to the data of the envelope surface drawn by the fixed points defined in relation to the tool, the envelope surface and the envelope surface of the tool Is a method of dividing into a flat portion that is a portion whose angle formed by the contacting and separating direction of the angle is from a right angle to a predetermined angle and a standing wall portion that is a portion other than the flat portion. Setting grid points,
Projecting each set grid point onto the envelope surface in the contact / separation direction; and specifying a position in the contact / separation direction of a flat portion of the envelope surface based on the position of a projection point on the envelope surface. , A step of calculating a plurality of paths connecting points having the same position in the approaching and separating direction in the data of the envelope surface, and two adjacent paths with the position of the designated flat portion among the calculated paths. Extracting the path,
A step of determining a portion sandwiched by the extracted paths as a flat portion and the other portion as a standing wall portion, and dividing the portion.

In the recording medium according to the present invention, an object having the same shape as a model having a plurality of surfaces is drawn by a fixed point defined in relation to the tool when the tool virtually contacts each surface of the model. When moving the tool according to the data of the enveloping surface while repeatedly moving the tool to and from the enveloping surface,
The enveloping surface is a flat portion that is a portion in which the angle between the enveloping surface and the direction of contact with and separating from the enveloping surface of the tool is a range from a right angle to a predetermined angle, and a standing wall portion that is a portion other than the flat portion. A recording medium in which a computer program for dividing is recorded, the method comprising: setting two-dimensional grid points at regular intervals; projecting each set grid point onto the envelope surface in the approaching and separating direction; A step of designating the position of the flat portion of the envelope surface in the contacting / separating direction based on the position of the projection point in, and a plurality of paths connecting points at which the position of the contacting / separating direction in the data of the envelope surface is the same. The step of calculating and the step of extracting two adjacent paths between the calculated paths with the position of the specified flat portion in between, the portion sandwiched by the extracted paths is set as the flat portion, and the other portion is set up. Wall and decision Characterized in that are recorded thereon a computer program comprising the steps of: to split.

1 to 3 are schematic views showing the concept of the method of the present invention. Note that the following processing is performed according to the software program, and when the model shape data and the dimension / shape data of the tool to be used are input, the computer follows the software program as follows. , The envelope surface is divided into a flat portion and a standing wall portion.

In FIG. 1, M is a model having a plurality of faces. First, a network N having _n two-dimensional lattice points P _{1 to} P _n at regular intervals is set so as to cover the processing area in the model M. In addition, one plane is designated from all the planes forming the model M, a fixed point of the tool when the tool contacts the designated plane is considered, and an envelope surface (offset surface) is created in consideration of the locus of this fixed point. . In FIG. 1, the envelope surface S ′ for one surface S in the model M is shown by a chain line. Such a process is similarly performed for all the faces of the model M to create an envelope face.

Next, all envelopes from one grid point of the network N are
Project in the Z direction on the plane and project to that grid point.
Obtain the three-dimensional coordinate data of the shadow point. All such processing
For all grid points. Note that multiple surfaces overlap
In the region where one grid point (eg grid point P in FIG._j)
On the other hand, some projection points are determined, but in this case, in the network N
Closest projection point (highest projection point in Z direction)
(For example, the grid point P _jIn the case of the envelope S '
Selected projection point) to obtain its three-dimensional coordinate data.
Create machined surface data based on the obtained coordinate data
You.

Next, the inclination of the mesh formed by the four projected points on the envelope surface is examined to specify the height of the flat portion of the envelope surface. In this case, specifically, when the angle between the Z axis and the plane parallel to the two diagonal lines of the mesh of the quadrangle is detected as the inclination of the mesh, and the angle is larger than a predetermined value. Further, the height of the mesh (position in the Z direction) is defined as the height of the flat portion of the envelope surface. This process is performed for all meshes and the heights of all flat parts are specified. FIG. 2 is a schematic diagram of the envelope surface D viewed from the X-axis direction. Specifically, in the example shown in FIG. 2, the heights of the three flat portions a, b, and c are designated.

Further, a plurality of contour line paths connecting points of equal height on the envelope surface D are calculated. The calculated contour path is shown in FIG. Specifically, in the example shown in FIG. 3, nine contour line paths p1 to p9 are calculated. From these contour line paths, a set of two contour line paths having the height of the flat portion on the envelope surface D therebetween is extracted. Specifically, the height a of the flat portion a
For, extract the contour paths p1 and p2 between which
For the height b of the flat part, the contour path p between them
4 and p5 are extracted, and with respect to the height c of the flat portion, contour line paths p8 and p9 that intervene between them are extracted.

The area sandwiched between each of the two contour lines extracted is defined as a flat portion. In addition, the area other than the flat portion is used as the standing wall portion. Therefore, specifically, between p1 and p2, p4,
Between p5 and between p8 and p9 is determined as a flat portion, and between p2 and p4 and between p5 and p8 is determined as a standing wall portion.

When the flat portion and the standing wall portion are divided as described above, all of the envelope surface for controlling the movement of the tool must be divided into either the flat portion or the standing wall portion. It can be done without the flat part and the standing wall part overlapping.
Accurate division can be realized.

[0023]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be specifically described below with reference to the drawings showing the embodiments thereof.

FIG. 4 is a flow chart showing the procedure of the flat portion / standing wall portion dividing method of the present invention. In FIG.
Only step S1 is a process performed by the worker, and the remaining steps S2 to S10 are processes realized by software in the computer. First, model information and tool information are input (step S1). The model information includes information such as a machining area, a surface to be machined, and machining conditions. In addition, the information on the tool includes information such as the size and shape of the end portion of the tool which is in contact with the processing surface and is actually processed.

Next, offset surfaces for all the machined surfaces of the model are created based on the input shape information of the end portion of the tool (step S2). In this case, the envelope surface of the tool fixed point when the tool is in contact with each surface to be processed is the offset surface. Specifically, if the end of the tool that is in contact with the machining surface is hemispherical, the center of this hemisphere is the fixed point of the tool, and the trajectory of that fixed point (separated from the machining surface by the radius of this hemisphere) is the envelope. It becomes the surface (offset surface). In this step, the offset surfaces are created for all the processed surfaces without considering the overlapping of the surfaces and the gaps.

Then, two-dimensional lattice points at regular intervals are set within the same size as the processing area (step S3). That is, the processed area is expressed as a net having a certain fineness. The length of the fixed interval in this case may be an arbitrary value.

Next, each grid point is projected in the Z direction (height direction) to obtain projection points for all offset planes (step S4). The coordinate data of the projection point on each grid point is obtained (step S5). That is, all the grid points of the net are projected on the offset plane to obtain the coordinate data of the highest point. For a grid point where only one projection point can be obtained without overlapping surfaces, the coordinate data of the projection point is obtained as it is. On the other hand, there are a plurality of projection points for the lattice points where the surfaces overlap. In such cases, Z
The projection point at the highest position in the direction is selected, and the coordinate data of the selected projection point is obtained. Then, one offset surface is obtained from the obtained coordinate data of each projection point. In this case, the coordinate data of points other than the projection points corresponding to the grid points are obtained by linearly interpolating the obtained coordinate data of the plurality of projection points.

Next, the inclination of the mesh formed by the four projected points on the offset surface is checked, and the height of the flat portion of the offset surface is designated based on the inclination (step S6).
Specifically, the angle formed by the Z-axis and the plane parallel to the two diagonal lines of the mesh of the square that is surrounded by the four projected points on the offset plane is detected. When the detected angle is larger than a predetermined value, the height of the mesh (the position in the Z direction) is set as the height of the flat portion of the offset surface.

Next, a plurality of contour paths connecting points at the same height on the offset plane are calculated (step S
7). Set a set of two contour lines that pass between the heights of the specified flat areas, by as many sets as the number of heights of the specified flat areas.
Extract from the calculated contour path (step S
8).

The extracted contour line path is set as a boundary between the flat portion and the standing wall portion, and the area sandwiched between the pair of extracted contour line paths is determined as the flat portion (step S9). Then, the area other than the flat portion, that is, all the areas not determined as the flat portion are determined as the standing wall portions (step S10).

After dividing the flat portion and the standing wall portion as described above, the height component (Z-axis component) of these boundary information is removed to obtain planar (XY plane) region information. Then, processing data is created using this area information. In other words, for the area corresponding to the flat portion, processing data is created by setting moving paths at equal intervals on the offset surface, and for the area corresponding to the standing wall portion, a plurality of contour line paths are set. Create processing data.

By using different machining methods for the flat portion and the standing wall portion, the tool is moved according to the machining data thus created to perform the machining process on the object to be machined, and the object having the same shape as the model is manufactured. . FIG. 5 shows that the offset surface has a flat portion A.
And the standing wall portion B, the tool T is moved with respect to the workpiece Q. In the flat portion A, for example, passes at even intervals are projected on the XY plane and subjected to processing to finish a portion close to the plane. On the other hand, in the standing wall portion B, contour line processing is performed to finish the portion close to the standing wall.

Since the flat portion A and the standing wall portion B only have to be subjected to the processing treatments that match them, there is no waste in the processing treatments. Further, since the flat portion A and the standing wall portion B can be accurately divided, each portion can be finished neatly.

[0034]

As described above, according to the present invention, when the tool is moved in accordance with the three-dimensional machining data and the object having the same shape as the model is machined and manufactured, the flat portion and the standing wall portion can be easily and accurately automated. It can be divided.

Further, according to the present invention, the flat portion and the standing wall portion can be accurately separated without any gaps or overlaps. Therefore, when processing data suitable for each portion is created according to the division result, the model An object having the same shape as can be accurately and efficiently manufactured.

[Brief description of drawings]

FIG. 1 is a schematic view showing a concept (shading) of a flat portion / standing wall portion dividing method of the present invention.

FIG. 2 is a schematic diagram showing a concept (designating the height of a flat portion) of the flat portion / standing wall portion dividing method of the present invention.

FIG. 3 is a schematic view showing a concept (contour line path and flat portion / standing wall portion division) of the flat portion / standing wall portion dividing method of the present invention.

FIG. 4 is a flowchart showing a procedure of a flat portion / standing wall portion dividing method of the present invention.

FIG. 5 is a schematic view showing a state in which an object having the same shape as a model using a tool is machined and manufactured.

FIG. 6 is a perspective view showing an example of a model having a plurality of surfaces.

FIG. 7 is a front view showing the model shown in FIG. 6 classified into a flat portion and a standing wall portion.

FIG. 8 is a plan view showing the model shown in FIG. 6 classified into a flat portion and a standing wall portion.

FIG. 9 is a schematic diagram showing an example of movement of a tool in flat part processing.

FIG. 10 is a schematic diagram showing an example of movement of a tool in machining a standing wall portion.

FIG. 11 is a schematic diagram showing a state in which the boundary position of the flat portion / standing wall portion is different between the model and the offset surface.

[Explanation of symbols]

 A flat part B standing wall part C model surface D offset surface (envelope surface) M model Q object to be processed T tool a, b, c height of flat part p1 to p9 contour line path

Claims (2)

[Claims] 1. An object having the same shape as that of a model having a plurality of surfaces is drawn according to data of an envelope surface drawn by a fixed point defined in relation to the tool when the tool virtually contacts each surface of the model. When the tool is moved and processed while repeating contact and separation with respect to the envelope surface, the angle between the envelope surface and the direction of contact and separation of the tool with the envelope surface is within a range from a right angle to a predetermined angle. A method of dividing into a flat portion that is a portion and a standing wall portion that is a portion other than the flat portion,
Setting two-dimensional grid points at regular intervals; projecting each set grid point on the envelope surface in the approaching / separating direction; and flattening the envelope surface based on the position of projection points on the envelope surface. A position in the contacting / separating direction of the part, a step of calculating a plurality of paths connecting points having the same position in the contacting / separating direction in the data of the envelope surface, and specifying from the calculated paths And a step of extracting two adjacent paths with the position of the flat portion interposed therebetween, and a step of determining a portion sandwiched by the extracted paths as a flat portion and other portions as standing wall portions and dividing the flat portion. A method for dividing a flat portion / standing wall portion, characterized by: 2. An object having the same shape as that of a model having a plurality of surfaces is formed according to data of an envelope surface drawn by a fixed point defined in relation to the tool when the tool virtually contacts each surface of the model. When the tool is moved and processed while repeating contact and separation with respect to the envelope surface, the angle between the envelope surface and the direction of contact and separation of the tool with the envelope surface is within a range from a right angle to a predetermined angle. A recording medium for recording a computer program for dividing into a flat portion which is a portion and a standing wall portion which is a portion other than the flat portion, the step of setting two-dimensional lattice points at regular intervals, and each set lattice Projecting a point onto the envelope surface in the approaching / separating direction; specifying the position in the approaching / separating direction of the flat portion of the envelope surface based on the position of the projected point on the envelope surface; To the data of A step of calculating a plurality of paths connecting points having the same position in the contact and separation directions, and a step of extracting two adjacent paths from the calculated paths with a position of a designated flat portion therebetween. A recording medium for recording a computer program including a step of determining a portion sandwiched by the extracted paths as a flat portion and determining the other portion as a standing wall portion and dividing the portion.