JP2980820B2 - Method of creating shape data for mold processing - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a CAD system.
The present invention relates to a mold processing shape data creating method for creating mold machining shape data in which a fillet surface is formed between respective surface surfaces constituting a determined mold surface model.

[0002]

2. Description of the Related Art Conventionally, in order to manufacture a product having a complicated shape, shape data is created using a CAD system, and NC processing data for processing a mold is obtained from the shape data. A mold is created based on the data, and a product is manufactured from the mold.

In this case, a wire frame model for a product is first created from the shape data, and then a surface model is created by setting a surface to the wire frame model. Then, a fillet surface is set to smoothly connect the respective curved surfaces (surface surfaces) constituting the surface model. For example, Japanese Patent Application Laid-Open No. Sho 58-1
The method described in JP-A-60041 is known.

In this method, two connected curved surfaces are offset by a predetermined amount in a direction for forming a fillet surface,
An arc tangent to each of the curved surfaces with the obtained intersection of the two curved surfaces as the center is defined as a component line of the fillet surface, and a surface composed of a set of the component lines is generated as a fillet surface.

[0005]

In the prior art, as shown in FIG. 32, a curved surface A1 (points a1, a1
2, a3, a4) and the curved surface A2 (points a2, a5, a
Fillet plane B (points a7, a3)
8, a9, and a10), but the phase relationship between the curved surfaces A1, A2 and the fillet surface B is not set.

Here, the phase relationship is information indicating how the curved surfaces A1, A2 and the fillet surface B are connected. For example, when the outlines of the curved surfaces A1 and A2 are D1 to D7, the phase relationship indicating that these are connected by the outline D3 is a loop relationship between the curved surfaces A1 and A2 set as shown in FIG. Can be obtained from the configuration.

In this case, the outline D8 of the fillet surface B
From the loop configuration set for D11, a phase relationship indicating that the curved surfaces A1 and A2 are connected by the outlines D8 and D9 of the fillet surface B cannot be obtained. Therefore, in the phase relationship set as shown in FIG.
As shown in FIG. 32, a part of the unnecessary curved surfaces A1 and A2 (the range of the points a7, a2, a3, and a10 and the point a
2, a8, a9, and a3) coexist with the fillet surface B.

Therefore, conventionally, in order to set a phase relationship between the curved surfaces A1, A2 and the fillet surface B, a curved surface A1 ^* composed of outlines D1, D21, D8, D41 is used ^.
As shown in FIG. 34, the operator sets a loop configuration to give a phase relationship to the curved surface A2 ^* composed of the contour lines D9, D52, D6, and D72. By using the phase relationship set in this way, it is possible to recognize the shape data composed of the curved surfaces A1 ^* and A2 ^* and the fillet surface B.

[0009] However, such a work is not only extremely time-consuming, but also takes a long time to understand the shape of a complicatedly curved surface and fillet surface. Has a problem that accurate shape data cannot be obtained.

SUMMARY OF THE INVENTION The present invention solves the above-mentioned problem. In a CAD system, a mold system can easily generate mold processing shape data having a topological relationship from a surface surface and a fillet surface set with respect to the surface surface. It is an object of the present invention to provide a method for creating shape data for mold processing that can be created.

[0011]

In order to achieve the above object, the present invention provides a method of forming a fillet surface between respective surface surfaces constituting a surface model of a mold set on a CAD system. mold to create a mold for processing shape data
In the processing shape data creating method, a first step of finding an intersection between the outermost region line of the surface surface and the outermost region line of the fillet surface, and a normal vector of the surface surface or the fillet surface at the intersection A second step of obtaining; a third step of obtaining a tangent vector of the outermost region line of the fillet surface passing through the intersection on the surface surface; and obtaining an outer product vector of the normal vector and the tangent vector. 4 steps,
Selecting, as a new surface surface, a region located in the direction of the outer product vector from among the regions of the surface surface separated by the outermost region line of the fillet surface on the surface surface passing through the intersection; a step, that consists characterized.

[0012]

According to the present invention, the outermost region line of the fillet surface dividing the surface surface is determined, and the normal vector at the intersection of the outermost region line of the fillet surface and the outermost region line of the surface surface is determined. A region in the direction of the cross product vector obtained from the normal vector and the tangent vector of the outermost region line of the fillet surface is selected from the surface surface as a new surface surface. In this case, since the unnecessary area does not exist in the selected new surface surface, the phase relationship can be easily set for this surface surface. By performing this operation on all surface surfaces, shape data having a topological relationship can be easily created.

[0013]

FIG. 1 shows a CAD system 1 to which the present invention is applied.
FIG. 3 is a block diagram showing a configuration of a 0. CAD system 10
Has a central processing unit for performing graphic calculation, display control, database management, etc., and a large-capacity storage device 14 capable of storing and updating a large amount of graphic information.
And a graphic-compatible display device 16 which is a central device for the interaction between the CAD system 10 and the operator.
And a keyboard 18 as an input device and a tablet 2
0, a mouse 22, a light pen 24, an external auxiliary storage device (CMT) 26, and an XY plotter 28 as a graphic output device.

The controller 1 of the CAD system 10
2 has many programs as shown in FIG. Each program can be classified into the following modules according to the functions to be shared.

(A) An operating system 30 and a control module 32 for controlling the processing of the controller 12 and the flow of information.

(B) An input module 34 that assists various input devices, for example, an input operation corresponding to the keyboard 18 to be performed smoothly.

(C) An input interpretation module 36 for interpreting the input information according to a command instruction format.

(D) A display module 38 for managing display information and performing display processing according to commands.

(E) A command module 40 for performing graphic processing according to a command composed of sub-modules corresponding to the instruction.

(F) CAD held in the database 42
A database operation module 44 for efficiently searching and storing a large amount of information necessary for the system 10;

(G) A macro module 48 for executing a macro program 46 which is an automatic design program.

(H) An external system interface 50 for exchanging information with other CAD systems and performing interlocking processing.

Further, in order to maintain expandability and maintainability, the controller 12 has a system control file 52 for storing the configuration and standard values of the CAD system 10 and a command control for storing operability of each command and a program control procedure. Auxiliary files such as a file 54 and a display control file 56 for storing the model and configuration of the display device 16 are prepared. Other auxiliary components include a graphics processing library 58 for performing graphics processing and a display library 6 for displaying on the display device 16.
0, a program such as a drawing utility 62 for outputting the processing result to the XY plotter 28, and a data exchange utility 64 for coupling with another CAD system.

Next, each module will be briefly described. The control module 32 integrates programs into modules and intervenes between the modules to centrally manage the control in the system and standardize the calling procedure.
Its functions are start, end, abnormal processing, execution control of each module, recording of execution history, debugging, special processing with the operating system 30, and the like.

The input module 34 provides the operator with a comfortable input procedure in accordance with the unified specifications of various input devices. The functions are input promotion for instructing an operator on the type of information to be input, an input method and an input device, selection of an input device, conversion of input information to a standard type, and the like.

The input interpretation module 36 unifies the input information interpretation method and the result display, thereby supporting various input instruction methods, improving input operability, and maintaining the expandability of the system. Its function is to interpret the input information and display the result of the interpretation.

The display module 38 processes various display operation requests in a unified manner, and manages a display device, controls display, manages display information, and manages a display state.

The command module 40 centrally manages the format of input arguments, calls a processing program according to a command, and processes a result, and maintains maintainability and expandability of the system.

The database operation module 44 standardizes the request method from other modules and provides recovery means when a failure occurs. Its functions are management and operation of the use state of the database 42, processing when a failure occurs, and the like.

The external system interface 50 standardizes information exchange with other systems, and makes effective use of the CAD system 10. The functions are information exchange with an external system and operation control of an external program.

The macro module 48 controls the execution of the CAD system 10 according to the created macro program 46. Its function is to translate and execute the macro program 46.

Next, a description will be given of a method of forming a fillet surface with respect to a surface model in the CAD system 10 having the above-described programs and forming shape data for generating NC machining data.

FIG. 3 shows an overall flowchart for creating the shape data, and FIGS. 4 to 11 are explanatory diagrams of the processing procedure.

First, data constituting the surface model shown in FIG. 4 is read from the mass storage device 14 (FIG. 1). This surface model includes, for example, ridge lines R1 to R4.
Curved surfaces (surface surfaces) S1 to
S4, and each of the curved surfaces S1 to S4 is formed as shown in FIG.
3 has a phase relationship as shown in FIG. Therefore, fillet surfaces F1 to F4 are set for the ridgelines R1 to R4 between the curved surfaces S1 to S4 as shown in FIG. 5 (step S100).

FIG. 12 is a subroutine for creating the fillet plane F1, and FIG. 13 is an explanatory diagram thereof. First, a plane Hn passing through the point R1n on the ridge line R1 and orthogonal to the ridge line R1 is obtained (step S200). Then, the intersection lines K1n, K1 between the plane Hn and the curved surfaces S1, S2
2n, the intersection lines K1n and K2n are offset by the radius rn on the plane Hn, and the center Cn of the arc An is determined (step S201). Then, an arc An having a radius rn is obtained from the center Cn (step S202). After the above processing is performed on all the planes Hn set at predetermined intervals between the end points R1s and R1e of the ridge line R1 (step S2).
03), outlines g1 and g2 formed by smoothly connecting points where each arc An comes into contact with the curved surfaces S1 and S2, and the end point R1.
outlines g3, g composed of arcs An corresponding to s, R1e
4 is obtained (step S204). Lastly, a fillet plane F1 is created by setting a plane using, for example, the Coons formula in a region surrounded by these outlines g1 to g4 and defined by the circular arcs An (step S1). S205). The other fillet surface F2
To F4 are similarly created.

Here, each of the fillet surfaces F1 to F4 created as described above has a ridge line R1 as shown in FIG.
R4 are superimposed on each other in the vicinity of the point Q where they meet, and a smooth curved surface cannot be obtained as it is.
Therefore, a connecting surface that smoothly connects these fillet surfaces F1 to F4 is created.

First, as shown in FIG.
An intersection (point P2) between the outer line of No. 1 (corresponding to the outer line g2 in FIG. 13) and the outer line of the fillet surface F2 is obtained (step S101). Since this point P2 is on the curved surface S2, it can be easily obtained as an intersection of the two outlines. Next, the contact point on the curved surface S1 of the arc (corresponding to the arc An in FIG. 13) on the fillet surface F1 passing through the point P2 is determined as the point P1 (step S1).
102). Similarly, after the intersection (point P3) of the outline of the fillet surface F2 and the outline of the fillet surface F3 is determined (step S103), the contact point on the curved surface S4 of the arc on the fillet surface F3 passing through the point P3 is obtained. Is obtained as a point P4 (step S104). And points P1, P2
A new fillet surface F1 ^* is created by cutting the fillet surface F1 by an arc between them, and a new fillet surface F3 ^* is created by cutting the fillet surface F3 by an arc between the points P3 and P4 (FIG. 6, Step S10
5).

Next, the point P obtained as described above
An outline L1 that smoothly connects the points P1 and P4, and points P2 and P
3 is determined (step S).
106).

FIGS. 14 and 15 are subroutines for obtaining the outline L1, and FIGS. 16 to 18 are explanatory diagrams thereof. First, the fillet plane F1 passing through the point P1
^The unit tangent vector V1 for the outline g5 of the fillet plane F3 ^* passing through the point P4 is determined along with the unit tangent vector V1 for the outline g1 of ^* (step S300). Next, using the unit tangent vectors V1, V4 and the coordinate values of the points P1, P4, outlines g1 and g
A temporary contour line C0 that smoothly connects No. 5 is obtained (step S301). In this case, the temporary outline C0 is the outline g1,
Since it is set based only on the condition in contact with g5, FIG.
As shown in FIG. 7, generally, it does not coincide with the target outline L1.

Then, a unit normal vector VV1 passing through the point P1 and orthogonal to the curved surface S1 and a unit normal vector VV4 passing through the point P4 and orthogonal to the curved surface S4 are obtained (step S302). The projection vector VV is obtained by combining the line vectors VV1 and VV4 (step S303). Then, using the projection vector VV, the temporary contour line C0 is projected onto the curved surface S1, the curved surface S4, and the fillet surface F4, so that the projected curve C1,
Find C2 and C3 (FIG. 17, step S30)
4). The projection curve C1 is set between a point P1 which is an end point of the fillet plane F1 ^* and a point P5 which is an end point on the ridge line R4, and the projection curve C2 is an end point of the point P5 and the end point of the fillet plane F3 ^* . The projection curve C3 is set between a certain point P4 and the projection curve C3 is set between points P6 and P7 on the fillet plane F4 (see FIG. 17). An outline L1 is obtained by setting the connection relationship between the projection curves C1 to C3 obtained as described above according to a subroutine shown in FIG. 15 (step S305).

First, the projection curve including the point P1 is defined as a start curve C
s (projection curve C1), and the projection curve including the point P4 is set as the final curve Ce (projection curve C2) (step S).
400). Next, the start curve Cs (projection curve C1)
Is set as a transfer check target that moves from the outline g1 shown in FIG. 17, and a flag is set on the start curve Cs (projection curve C1) as shown in (1) of FIG. 18 (step S401). Next, it is determined whether or not the current transfer check target is the final curve Ce (projected curve C2) (step S402). If it is not the final curve Ce, i = 1 is set (step S403), and the projected curve Ci has already been set. It is determined whether or not a transfer check has been set, that is, whether or not a flag has been set (step S40).
4). Since a flag has already been set for the projection curve C1, i = i + 1 is set (step S405), and the flag of the projection curve Ci is checked (step S404). In this case, no flag is set for the projection curve C2 (see (1) in FIG. 18). Therefore, it is determined whether or not the projection curve C2 is smoothly connected to the projection curve C1 previously set as the transfer check target (step S406). In this case, the projection curve C2 corresponds to the point P5
Since the projection curve C1 is not smoothly connected to the projection curve C1, i = i + 1 is set (step S405), and the process of step S404 is repeated. In this case, no flag is set for the projection curve C3 (see FIG. 1).
8 (1)), the process of step S406 is performed. Since the projection curve C3 is smoothly connected to the projection curve C1 previously set as the transfer check target, the projection curve C3 is set as the transfer check target (step S407), and (2) in FIG. As shown in
The flag of the projection curve C3 is set. Then, the processing from step S402 is repeated. In step S402, since the current transfer check target is the projection curve C3 and not the final curve Ce, the processing from step S403 is performed. In this case, in step S406,
Since the projection curve C2 is smoothly connected to the projection curve C3 previously set as the transfer target (step S406), the projection curve C2 is set as the transfer check target (step S407), and (3) in FIG. The flag of the projection curve C2 is set as shown in FIG. And
The process of step S402 is performed again. At this time, since the transfer check target matches the final curve Ce, FIG.
Based on the flags set in the order shown in FIG.
→ C3 → C2 are linked in this order (step S408), and an outline L1 is set. The outline L2 can be set in the same manner.

As described above, without setting the phase relationship such as which curved surface is connected to which curved surface with respect to each of the curved surfaces S1 to S4 and the fillet surfaces F1 to F4,
The outline L1 can be automatically set on the plurality of curved surfaces S1, S4 and the fillet surface F4.

Next, the points P1, P2 on the fillet surface F1 ^*
An outline g4 set between them, an outline g6 set between the points P3 and P4 of the fillet plane F3 ^* , and a connection plane C () surrounded by the outlines L1 and L2 set as described above. (See FIG. 8), the outline L1,
Constituent points are generated at predetermined intervals on L2 (FIG. 3, step S107). The method of generating the constituent points will be described with reference to the flowchart shown in FIG. 19 and the explanatory diagrams shown in FIGS.

First, as shown in FIG.
A plurality of constituent points Kn ^* and Kn are set on the contour lines L1 and L2 according to the curvatures of L1 and L2 (step S50).
0). Next, the curve lengths l ₁ , l _{2 of} the respective outlines L1, L2
Is obtained (step S501). And the curve length l
_1, and l _2, points P1, P2 and the component points Kn ^*, Kn
The distance between k _n ^*, the distance ratio between _{^{k n k n * / l 1}} , k n /
l ₂ is obtained (step S502). Next, n = 1 (step S503), and the distance ratio k _n ^* / l ₁ , k
If _n / l ₂ is not within the predetermined range, i.e., when not satisfied _{^{k n * / l 1 ≒ k}} n / l 2 conditions (step S504), for example, the point P1 composing point Kn ^* and the New point Km between
^* Is added (step S505). The above operation is performed for all constituent points (steps S506 and S507), and a set of corresponding constituent points (for example, constituent points Kn ^* and Km in FIG. 21) is set. Thus, each contour line L
1, the same number of component points and substantially the same interval are set on L2.

Here, for example, as shown in FIG. 22, when the shape of the outline g4 and the shape of the outline g6 forming the connection surface C are significantly different from each other, such as an S-shape and an inverted S-shape, these outlines are not considered. When the curved surface of the direct connection surface C is generated using the boundary conditions on the lines g4 and g6, there is a possibility that the consistency at the central portion is deteriorated.

In order to avoid such inconvenience, in this embodiment, the connecting surface C having the constituent points set as described above is used.
Is divided into three regions B1, B2, and B3 (FIG. 22, step S108). Then, i = 1 (step S
109), after generating a curved surface of the central region B1 (Bi = B1) (steps S110, S111, S112), using the curved surface information of the region B1, the regions B2 and B3 (B
A curved surface of i = 2, 3) is generated (step S113).
In this case, the difference between the shape of the outline g4 and the shape of the outline g6 is absorbed by the outlines g7 and g8 constituting the central region B1, and the connection surface C that smoothly connects the fillet surfaces F1 ^* and F3 ^*. Can be obtained.

Therefore, first, according to the subroutine shown in FIG. 23 and the explanatory diagrams of FIGS. 24 and 25, the constituent points Kn ^* , which are a set obtained in step S107 for the area B1, are set.
A case where the curve RR (B1) is set between Km will be described.

First, the region B1 is located on the outer lines L1 and L2.
Is defined by the contour line L with respect to the constituent points Kn ^* and Km which form a pair between the points P8 and P9 and between the points P10 and P11.
1, unit tangent vectors Vt1 and Vt2 for L2 are obtained (step S600). Next, a combined vector Va of the unit tangent vectors Vt1 and Vt2 is determined (step S601), and a unit direction vector Vh from the constituent point Kn ^* to the constituent point Km is determined (step S60).
2). Then, an outer product vector Vb of the unit direction vector Vh and the composite vector Va is obtained (step S6).
03) Further, a cross product vector Vp of the cross product vector Vb and the unit direction vector Vh is obtained (step S6).
04). Next, the outer product vector Vp and the constituent point Kn ^*
And the outer product vector Vv1 of the normal vector Vu1 at the constituent point Km and the outer product vector Vv2 of the outer product vector Vp are obtained (step S605). Note that these cross product vectors Vv
1, Vv2, as shown in FIG. 24, constituent points Kn ^*, K
represents the tangent vector of the curve RR (B1) at m.

Using the tangent vectors (outer product vectors Vv1, Vv2) obtained as described above, a curve RR (B1) consisting of a Bezier curve is obtained. In this case, FIG.
As shown in the figure, control points Q1 and Q2 are set on an extension of the outer product vectors Vv1 and Vv2, and the control points Q1 and Q2 are set.
The distances q ₁ and q ₂ to are obtained based on the following equation (1) (step S606). Then, the control points Q1, Q
2 is used to generate a curve RR (B1) (step S6).
07). In the equation (1), r ₁ and r ₂ represent the distance between the intersection O of the unit tangent vectors Vt 1 and Vt ₂ and each of the constituent points Kn ^* and Km, and θ is a sector O−Kn ^* −.
Represents the central angle of Km.

Q _i = 4 · (1−cos (θ / 2)) · r _j / 3 · sin (θ / 2) (1) (θ ≠ 0, j = 3-i) By performing the processing for all the constituent points forming the set of B1 (step S111 in FIG. 3), the area B
1, all the curves RR (B1) are set, and thereby the area B1 is determined.

When the area B1 is determined, next, the area B2
Is set for the curve RR (B2). In this case, based on FIGS. 26 and 27, the constituent points K1 and K
Description will be made assuming that a curve RR (B2) is set between the three.

First, similarly to the processing in steps S600 to S605, the curve RR (B2) for the constituent point K3
A direction vector Vw3 is obtained. On the other hand, the vector Vw1 in the direction of the curve RR (B2) with respect to the component point K1 is the area B1 obtained in step S607 adjacent to the component point K1.
Is set as shown in FIG. 27 by using the constituent point K2 on the curve RR (B1). That is, constituent points K1 to K
3 is generated, and the tangent at the constituent point K1 of the arc R is set to the vector Vw1 in the direction of the curve RR (B2). Then, the set vectors Vw1, Vw3
Is used, all the curves RR (B2) on the area B2 are set in the same manner as in steps S606 and S607, and the area B2 is determined. The area B3 can be determined in the same manner as the area B2.

When the connection plane C composed of the areas B1 to B3 is determined as described above, the data is temporarily output to the mass storage device 14 (step S114), and the fillet plane intersecting with the connection plane C is output. F2 and F4 are cut using the data of the connection plane, and fillet planes F2 ^* and F2
4 ^* is created (FIG. 9, step S115). In this case, a phase relationship having a loop configuration is set for each of the fillet surfaces F1 ^{* to} F4 ^* and the connection surface C, as in the case shown in FIG. Then, the data composed of these fillet planes F1 ^{* to} F4 ^* and the connecting plane C is output to the mass storage device 14 as fillet plane data (FIG. 10, step S116).

In the above-described embodiment, a case has been described in which a connecting surface C capable of smoothly connecting the mutually overlapping fillet surfaces F1 to F4 is created. For example, a previously set fillet surface is designed. In the case of being cut off by a change or the like, the present invention can be similarly applied when creating a connecting surface connecting these fillet surfaces.

Finally, by synthesizing the surface model data shown in FIG. 4 and the fillet plane data, FIG.
1, full fillet model data including the fillet planes F1 ^{* to} F4 ^* , the connecting plane C, and the curved planes S1 ^{* to} S4 ^* is generated (step S117).

By the way, fillet planes F1 ^{* to} F4 ^* ,
Since no phase relationship is set between the connection surface C and the curved surfaces S1 ^{* to} S4 ^* , as described with reference to FIG.
The data related to S4 will be included. Therefore, a method of creating shape data consisting only of necessary data by removing unnecessary data will be described with reference to flowcharts shown in FIGS. 28 and 29 and FIGS. 30 and 31.

First, the outermost region line Fr of the fillet model (see FIG. 10) composed of the fillet surfaces F1 ^{* to} F4 ^* and the connecting surface C is extracted (step S700), and the outermost region line Fr and the curved surfaces S1 to S4 are extracted. The intersections e1 to e8 (see FIG. 9) of the surface model (see FIG. 4) composed of are all calculated (step S701). Next, a phase relationship is set for the curved surfaces S1 ^{* to} S4 ^* with reference to the intersections e1 to e8 (step S702).

In this case, at the intersection ei of interest, the outermost region line Fr (outline g1, g2,
g3), it is determined whether or not the differential coefficients of the two outermost region lines (outline g1 and g3) connected at the intersection ei are discontinuous (step S8).
00, S801, S802), if discontinuous, curved surface S1
Unit tangent vector Ve of the outermost region line (outline g1) above
i is obtained (step S803). The direction of the unit tangent vector Vei depends on the fillet plane F1 ^{* of} interest ^.
Is set in advance by a loop configuration which is a phase relationship set in the above. Next, the unit normal vector Vni to the curved surface S1 or the fillet surface F1 ^{* at} the intersection ei
Is obtained (step S804). Then, an outer product of the unit normal vector Vni and the unit tangent vector Vei is obtained as a determination vector Vgi (step S80).
5).

Here, the judgment vector Vgi is a curved surface S divided by an outline g1 of the fillet surface F1 ^*.
1 is used to determine a curved surface S1 ^* , which is an effective part of 1. That is, in FIG. 30, among the contours of the curved surface S1 divided at the intersection ei, the contour on the curved surface S1 ^* side is represented by f1.
^* , The remainder is f1, and the tangent vectors of the outlines f1 ^* and f1 at the intersection ei and the determination vector Vg
Find the inner product with i. Then, the contour line f1 ^* whose inner product is a positive value is selected as an effective part (step S8).
06). As a result, the side including the contour lines f1 ^* and g1 is selected as the curved surface S1 ^* , and a loop configuration having a phase relationship as shown in FIG. 34 is set for this part (step S807). This loop configuration can be automatically set because the outline is determined.

The same processing can be performed for the intersection e (i + 1). In this case, the fillet face F1 ^*
Unit tangent vector Ve (i +
Direction of 1), the loop structure against the fillet surface F1 ^*, to be set to the opposite unit tangent vector Vei, curved S2 ^* of outline f2 ^* is selected as the effective portion. As a result, the curved surface S2 including the contour f2 ^{* *} is selected.

On the other hand, in step S802, FIG.
As shown in the figure, when the outermost region lines (outline g9, g10) of the fillet surface F at the intersection ei are not broken,
The outermost region line of the fillet surface F has a plurality of curved surfaces S5 and S5.
If it is set across six, any outline g
9 and g10 are also on the curved surfaces S5 and S6, so that a common unit tangent vector Vgi is obtained (step S808), and the effective portion can be determined.

The above processing is performed for all the intersections e1 to e8 (step S809), whereby the fillet surfaces F1 ^{* to} F4 ^* having a phase relationship, the connecting surface C, and the curved surface S1 are obtained.
^* To S4 ^* shape data is a full fillet model data consisting of can be created (step S70
3).

The shape data created in this way is
After being converted into NC processing data, the data is transferred to an NC controller (not shown), and processing of a mold for forming a product is performed. In this case, since the NC processing data includes a fillet surface that smoothly connects the curved surfaces of the surface model, a mold having a desired shape can be automatically and accurately created.

In the embodiment described above, the intersection (point P2) of the fillet surfaces F1 and F2, the fillet surfaces F2 and F3
The point (point P3) is determined, and the connection plane C is set between the fillet planes F1 and F3 using the points P2 and P3. However, the points P2 and P3 are set at arbitrary positions. Of course, the present invention can be applied to a case where a connecting surface is set between the two fillet surfaces F1 and F3.

[0065]

As described above, according to the present invention, the CAD system
Fillet between mold surface faces set on the system
When forming a surface, before it is divided by the fillet surface
The effective area of the serial surface plane, can be selected automatically based on the outermost area line of the fillet surface. In this case, since the unnecessary area does not exist in the selected new surface surface, the phase relationship can be easily set for this surface surface. As a result, mold processing shape data having a phase relationship can be easily created.

[Brief description of the drawings]

FIG. 1 is a configuration block diagram of a CAD system to which the present invention is applied.

FIG. 2 is a software configuration diagram of a controller shown in FIG. 1;

FIG. 3 is an overall processing flowchart for creating shape data.

FIG. 4 is an explanatory diagram of a surface model.

FIG. 5 is an explanatory diagram of a fillet surface set in the surface model shown in FIG. 4;

FIG. 6 is an explanatory diagram of a fillet surface cut by another fillet surface.

FIG. 7 is an explanatory diagram of an outline of a connection surface set between fillet surfaces.

FIG. 8 is an explanatory diagram of a connecting surface set between fillet surfaces.

FIG. 9 is an explanatory diagram of a fillet surface set on a surface model.

FIG. 10 is an explanatory diagram of fillet model data.

FIG. 11 is an explanatory diagram of a model obtained by synthesizing a surface model and a fillet model.

FIG. 12 is a flowchart of a process for creating a fillet surface.

FIG. 13 is an explanatory diagram of a process of creating a fillet surface.

FIG. 14 is a flowchart for obtaining a projection curve forming an outline of a connection surface.

FIG. 15 is a flowchart for connecting projection curves and obtaining an outline of a connection plane;

FIG. 16 is an explanatory diagram of a process for creating a projection curve.

FIG. 17 is an explanatory diagram of a process of creating a projection curve.

FIG. 18 is an explanatory diagram of a process for creating a projection curve.

FIG. 19 is a flowchart of a process for setting a constituent point on an outline of a connection surface.

FIG. 20 is an explanatory diagram of a process of setting constituent points on an outline of a connection surface.

FIG. 21 is an explanatory diagram of a process of setting constituent points on an outline of a connection surface.

FIG. 22 is an explanatory diagram of an area obtained by dividing a connection plane.

FIG. 23 is a flowchart for generating a curve connecting the constituent points of the central area obtained by dividing the connecting plane.

FIG. 24 is an explanatory diagram of a process of generating a curve that connects constituent points of a central region obtained by dividing a connecting surface.

FIG. 25 is an explanatory diagram of a process of generating a curve connecting the constituent points of the central area obtained by dividing the connection plane.

FIG. 26 is an explanatory diagram of a process of generating a curve that connects constituent points of both end regions obtained by dividing a connecting surface.

FIG. 27 is an explanatory diagram of a process of generating a tangent vector of a curve in the region at both ends obtained by dividing the connection surface.

FIG. 28 is a flowchart for synthesizing surface model data and fillet surface data.

FIG. 29 is a flowchart for determining an effective area on a surface and setting a phase relationship;

FIG. 30 is an explanatory diagram for determining an effective area on a surface surface.

FIG. 31 is an explanatory diagram for determining an effective area on a surface surface.

FIG. 32 is an explanatory diagram when a fillet surface is set between curved surfaces.

FIG. 33 is an explanatory diagram of a loop configuration set on the curved surface and the fillet surface shown in FIG. 32;

FIG. 34 is an explanatory diagram in a case where the loop configuration shown in FIG. 33 is modified and a phase relationship is set between a curved surface and a fillet surface.

[Explanation of symbols]

Reference Signs List 10 CAD system 12 Controller 14 Large-capacity storage device 16 Display device C Connecting surface F1 to F4 Fillet surface R1 to R4 Edge line S1 to S6 Curved surface

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Ayumu Nakajima 1-10-1 Shinsayama, Sayama-shi, Saitama Honda Engineering Co., Ltd. (72) Inventor Koji Hara 1-10-1 Shin-Sayama, Sayama-shi, Saitama Honda Engineering (56) References JP-A-61-265675 (JP, A) JP-A-1-2555972 (JP, A) JP-A-4-114204 (JP, A) JP-A-4-114206 (JP, A) A) Study on CSG representation of fillet Joma, et al. Journal of Japan Society for Precision Engineering, Vol. 170-176 (1988) (58) Fields investigated (Int. Cl. ⁶ , DB name) G06F 17/50 G06T 1/00 G06T 17/00 G05B 19/4097 JICST file (JOIS)

Claims (1)

(57) [Claims] 1. A mold to create a mold machining shape data to form the fillet surface between the surface planes constituting the server <br/> Fes model of the set mold on CAD system processing
In the method for creating shape data for use , a first step of determining an intersection between an outermost region line of the surface surface and an outermost region line of the fillet surface; and determining a normal vector of the surface surface or the fillet surface at the intersection. A second step, a third step of obtaining a tangent vector of the outermost region line of the fillet plane passing through the intersection on the surface, and a fourth step of obtaining an outer product vector of the normal vector and the tangent vector And selecting, as a new surface surface, a region located in the direction of the outer product vector from the surface surface region divided by the outermost region line of the fillet surface on the surface surface passing through the intersection. fifth step and the mold machining shape data creating method characterized by comprising the to be.