JPH10240790A - Method for instructing formation of fillet surface - Google Patents

Abstract

PROBLEM TO BE SOLVED: To save the trouble and operation time of a user and to evade a formation omission by allowing a CAD device to automatically form tentative fillet surfaces as to all couples of curved surfaces to be operated without sequentially instructing curved surfaces for which fillet surfaces are to be generated on a screen by the user. SOLUTION: A tentative fillet surface is formed in a shape A having couples of curved surfaces (F1 , F2 ), (F3 , F4 ).... The user after selecting an automatic tentative fillet surface formation command previously inputs the radius R of a tangential arc and a value for deciding a corner. After those are inputted, the CAD(computer-aided design) device finds common ridges E1 , E2 ... of the couples of curved surfaces (F1 , F2 ), (F3 , F4 )... to judge whether or not a couple of curved surfaces form a corner, then generates tangential arcs of all the curved surfaces with the radius R inputted previously by the user, and connects those tangential arcs to form and display a tentative fillet surface on a screen. Consequently, the final fillet surface is formed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for creating a fillet surface to be embedded in a corner of a previously created shape in order to perform a rounding process on the corner in a previously created shape in a design using a computer-aided design (CAD) apparatus. The present invention relates to a method for instructing the creation of a fillet surface, which is used when designating.

[0002]

2. Description of the Related Art FIG. 6 shows an example of a procedure for a fillet surface creation instruction performed in a conventional CAD apparatus. Shape A of the plurality of curved surfaces set shown in FIG. (F _31, F _32),
(F ₃₃ , F ₃₄ ),..., And a fillet surface is created on this. The user looks at the shape A displayed on the screen and sequentially designates points on the ridge lines E ₃₁ , E ₃₂ ,... Of each pair of curved surfaces, that is, intersections A ₃₁ , A ₃₂ ,. , Enter the radii R ₃₁ , R ₃₂ ,... Of the tangent arc at each intersection. After the above information is input by the user, the CAD device performs a calculation to create a fillet surface and displays it on the screen.

However, in this method, it is necessary to sequentially designate the ridge line and intersection of each set of curved surfaces, and the radius of the tangent arc, so that a more efficient method for creating a fillet surface for a complicated shape is required. A new way was needed.

[0004] As an improvement of the conventional fillet surface creation instruction method, for example, there is one described in JP-A-6-332990. According to this method, a user of the CAD apparatus can select any representative point among intersections between a common ridge line of a plurality of curved surfaces forming a set forming a corner in the previously created shape and each of the plurality of cut surfaces. And the radius of the tangent arc tangent to the curved surface at each cut surface is specified, and then the CAD apparatus obtains two straight lines tangent to the curved surface at the intersection at each cut surface, and the user first obtains the straight line. A temporary tangent arc that touches the designated radius is set, and these tangent arcs are smoothly connected to each other to create a temporary fillet surface. Thereafter, the user checks the positional relationship between the obtained temporary fillet surface and the curved surface, and makes corrections and the like as necessary.

However, in such a conventional method, the work of searching for a corner is performed visually while rotating the shape displayed on the screen, and an instruction for creating a fillet surface is also performed each time. Therefore, when the number of curved surfaces constituting the shape is large, or when the number of fillet surfaces to be created is large, there is a point to be improved such that the working time becomes longer and the omission of creation is more likely to occur.

[0006]

SUMMARY OF THE INVENTION The present invention relates to a method for creating and instructing a fillet surface using a CAD apparatus.
It is an object of the present invention to overcome the above-mentioned problems of the prior art.

That is, according to the first and second aspects of the present invention, when creating and instructing a fillet surface, a user of the CAD device does not individually instruct a curved surface for creating the fillet surface, and the CAD device performs the work. By automatically creating a tentative fillet surface for a pair of curved surfaces, which is a target of fillet surface creation, of all the curved surfaces constituting the target shape, shortening the work time, The purpose is to prevent omission in creation.

[0008] Further, the invention according to claims 3 and 4 relates to a program for creating a fillet surface in a CAD apparatus for realizing the invention according to claims 1 and 2.

[0009]

Means for Solving the Problems and Action / Effect The method according to the present invention is applied to a CAD apparatus for instructing creation of a fillet surface to be embedded in a corner formed by a plurality of curved surfaces in a previously created shape. An angle value for a user of the CAD apparatus to determine a corner in the created shape;
After entering the radius of the fillet surface to be created,
D apparatus first obtains a common ridge line between the two sets of curved surfaces for all the curved surfaces to be worked by the user, and then creates a temporary fillet surface out of the obtained common ridge lines. And determining whether the selected ridge is a corner by comparing the angle value input by the user with the angle formed by a set of curved surfaces sharing the ridge. Is performed, and when it is determined that the corner is a corner, a temporary fillet surface is formed and displayed on the corner with the value of the radius input by the user, and then the user of the CAD device displays the displayed fillet surface. About the positional relationship between the fillet surface and the set of the curved surfaces forming the same, and based on the result, at least one of correcting the fillet surface and adding a new instruction as necessary. I do.

According to this method, the CAD apparatus automatically sets a temporary fillet for all sets of curved surfaces to be worked without the user instructing a curved surface on which a fillet surface is to be created on the screen. You will create a surface. Therefore, it is possible to reduce the labor and work time of the user, and it is possible to prevent omission of creation.

In the method according to the present invention, a plurality of surfaces adjacent to each other by sharing the end points of the common ridge line among the temporary fillet surfaces created by the above-described procedure are stored as one set. It is characterized by the following. As a result, a plurality of temporary fillet surfaces can be handled in one process, so that more efficient work can be performed.

Further, by using a program for realizing the present method in a CAD device, the efficiency of the work for creating a fillet surface in a design using the CAD device can be improved.

[0013]

Preferred embodiments of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 shows the configuration of a CAD apparatus for creating a fillet surface using the method according to the present embodiment. This device is a central processing unit (CPU) that performs arithmetic processing
1, a memory 2 for storing programs and data, a keyboard 3 for a user to input programs and data, a printer 4 for outputting processing results and the like, an image display device (CRT) 5 for displaying characters, figures, etc. CRT5
The mark displayed on the screen is moved by the user's operation, and a mouse 6 for the user to give instructions to the CAD apparatus on the screen, an auxiliary storage device 7 comprising a recording medium for recording programs, data, etc. And a bus line 8 interconnecting them.

FIG. 2 is a flowchart showing a procedure for creating a fillet surface using the method according to the present embodiment. In this example, the fillet surface creation instruction method is
As shown in the figure, an automatic temporary fillet surface creation command, a fillet surface creation command A, a fillet surface change command,
The user selects any one of the five commands (commands) of the fillet surface information input command and the fillet surface creation command B. When an automatic temporary fillet surface creation command is input in step 11, a step
When an automatic temporary fillet plane creation procedure is executed in steps 12 to 19, and a fillet plane creation command A is input in step 21, the fillet plane creation procedure in steps 22 to 28 is executed. When a fillet plane change command is input in step 31, a fillet plane change procedure is executed in steps 32-38. Note that the temporary fillet surface may be created by inputting a fillet surface information input command in step 41 and individually creating an arbitrary set of curved surfaces in steps 42 to 48. Enter and step
The fillet surface creation procedure of steps 52 to 53 may be executed.

In order to instruct creation of a fillet plane in this method, an automatic temporary fillet plane creation command is selected in step 11 from a command selection waiting state.
Next, in step 12, the value of the radius R of the fillet surface to be created and the numerical value of the angle for determining whether the set of curved surfaces to be worked are corners capable of creating a fillet surface are input. I do. Here, the user may input an arbitrary value, or the input may be omitted. If the user omits the input, standard values for the work object and the manufacturing site are automatically input. Thereafter, when the user instructs the end of the input in step 13, the CAD apparatus creates a temporary fillet surface according to the following procedure.

First, in step 14, a common ridge line of a set of curved surfaces is determined for all the curved surfaces included in the shape to be worked. Here, the shape to be worked is the shape displayed on the screen when the user instructed the end of the input in step 13 or the shape specified by the user before the command was selected. Next, in step 15, it is checked whether or not a temporary fillet surface has been created for all the common ridge lines obtained in the previous step 14, and a range in which a temporary fillet surface has not been created is determined. Thereafter, in step 16, it is determined whether or not the range in which the temporary fillet surface has not been created is a corner portion.
Creates a temporary fillet surface with the radius R value specified by the user. Further, in step 18, it is determined whether or not the processing on all the common edges has been completed. If the processing has been completed, the process proceeds to the next step 19, and if not, the processing in steps 15 to 18 is repeated. In step 19, among the temporary fillet surfaces created up to the previous step, the end points of the common ridge line are coincident, that is, each fillet surface relating to a set of continuous curved surfaces adjacent to each other is stored as one group. Note that, here, a temporary fillet surface in which three or more end points coincide, for example, a branch shape is excluded. As described above, a temporary fillet surface is created.

After the temporary fillet surface is created by the above automatic temporary fillet surface creation command, a final fillet surface is created by the fillet surface creation command A shown in steps 21 to 28. First, when the user selects the fillet surface creation command A in step 21, a single input / group input menu and a repeat end menu are displayed on the screen in step 22. Here, the single input means to instruct creation of a fillet surface for each surface with respect to the previously created temporary fillet surface, and the group input refers to a command of the automatic temporary fillet surface creation command. Steps
This means that creation of a fillet surface is instructed with a single instruction for a plurality of temporary fillet surfaces stored as one group in step 19. The term "repetition end" means to end the repetition work for creating a final fillet surface for all the created temporary fillet surfaces. Here, the user selects and instructs whether to create the fillet surface in any of the above procedures.

Thereafter, in step 23, a temporary fillet surface for creating a final fillet surface is designated. Next steps
It is determined whether or not the group input is selected in 24, and if the group input is selected, in step 25,
It is considered that all other temporary fillet planes in the group to which the designated temporary fillet plane belongs are also designated. Further, in step 26, the user instructs another temporary fillet surface, or instructs repetition end, and if it is determined in step 27 that repetition end is instructed, in step 28, all the temporary fillet surfaces previously instructed are displayed. Create the final fillet face for it.

FIG. 3 is a diagram showing an example of a method for instructing the creation of a fillet surface in a CAD apparatus, and shows a shape A having a plurality of sets of curved surfaces (F ₁ , F ₂ ), (F ₃ , F ₄ ),. This is to create a temporary fillet surface. After selecting the automatic temporary fillet surface creation command in step 11 described above, the user only needs to input the value R of the radius of the tangent arc and the value for determining the corner in advance in the next step 12. After inputting these, the CAD apparatus sets the set of curved surfaces (F ₁ , F ₂ ), (F ₃ ,
F _4), ... common ridge E _1, E _2, and seek ..., after the set of the curved surface is determined whether angled portion, all surface with radius R prior to the user-entered set And a temporary fillet surface is created by connecting these tangent arcs and displayed on the screen. After that, the fillet plane creation command A is selected in the above-mentioned step 21 and the temporary fillet plane displayed on the screen is designated, so that the final fillet plane is formed.

[0021] Here, the following problems occur: the temporary fillet surface created by the automatic temporary fillet surface creation command is out of the created curved surface, and the value of the radius R is too large or too small for the curved surface. Sometimes. In this case, the user selects the fillet surface change command and changes the created temporary fillet surface before performing the processing using the fillet surface creation command A described above. First, a fillet plane change command is input in step 31 shown in FIG. 2, and in steps 32 to 33, the positions of all temporary fillet planes to be changed and a new radius value are input. Then CA
The device D finds a temporary arc and displays it on the screen. In step 35, it is determined whether or not the obtained arc is appropriate. If it is appropriate, in step 36, the position of the intersection of the changed curved surface and the radius of the arc are stored. Thereafter, it is determined in step 37 whether or not the change operation has been completed. If the operation has been completed, a temporary fillet surface is calculated again in step 38 and displayed on the screen again, and the process returns to a command selection waiting state. Thereafter, the operator may perform the processing using the fillet surface creation command A.

FIG. 4 is a diagram produced by the method according to the present invention.
With the automatic temporary fillet surface creation command for temporary fillet surface
Grouping and fillet creation command
9 shows an instruction procedure at C.A. The shape shown in Fig. 4 (a)
Form A has a temporary fillet surface SF ₁₁~SCIENCE FICTION₁₆Is formed
You. Where the temporary fillet surface SF₁₁And SF₁₂Is point A₁₁In each other
Contact with SF₁₂And SF₁₃Is A₁₂ ,SCIENCE FICTION₁₃And SF₁₄Is A₁₃ ,SCIENCE FICTION
₁₄And SF_FifteenIs A₁₄,SCIENCE FICTION_FifteenAnd SF₁₆Is A_Fifteen , And even SF₁₆And SF₁₁
Is A₁₆Are in contact with each other. Therefore, the temporary fillet
Bottom surface SF₁₁~SCIENCE FICTION₁₆Command for automatic temporary fillet surface creation
In step 19 of
With fillet surface creation command A, this shape
For A, create fillet surface in one process
be able to. That is, in step 23, for example, FIG.
Point P shown in (a)₁₁ You just need to instruct (pick).

On the other hand, in the shape B shown in FIG.
Three temporary fillet surface SF _21, SF ₂₇ also in the three temporary fillet surface SF ₂₄ - SF ₂₆ is also the point A _26, at point A _24,
SF ₂₈ is in contact. In this case, it is impossible to store all formed in a shape B of the temporary fillet surface SF ₂₁ - SF ₂₈ as one group. In this case, in step 19 of the automatic temporary fillet surface creation command, for example, SF _{21 to} SF ₂₅
And divided into two groups of SF ₂₆ - SF _28, in step 23 of the fillet surface creation command A, the point shown in FIG. 4 (b) P
₂₁ and P ₂₂ may be instructed.

FIG. 5 shows a procedure for determining whether or not a set of curved surfaces forms a corner in the method according to the present invention. First, in step 61, for each of the start point, end point, and middle point of one target common ridge line, the normal direction vectors ( _Vl , _Vr ) of adjacent curved surfaces are obtained. Next, at step 62, the angle θ formed between these pairs of V _l and V _r is determined. Further, in step 63, the value of θ is compared with the value of the determination angle previously input by the user, and if θ is larger, it is determined to be a corner.

As described above, according to the present invention, all sets of curved surfaces are automatically set without requiring the user to individually specify the set of curved surfaces to be worked and the radius of the arc of the fillet surface. , A temporary fillet surface is created, so that the working time can be shortened and the procedure can be simplified. Further, since there is no omission of instructions by the user, accurate work can be performed.

The present invention is not limited to the above-described example, but can be used for various graphic processing using a CAD device or the like.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of a CAD apparatus that performs an operation using a method for creating a fillet surface according to the present invention.

FIG. 2 is a flowchart showing a procedure for creating a fillet surface by the method according to the present invention.

FIG. 3 is a diagram showing an example of a temporary fillet surface creation instruction method according to the present method.

FIG. 4 is a diagram showing an example of a procedure for grouping created temporary fillet surfaces in a temporary fillet surface creation instruction method according to the present method.

FIG. 5 is a flowchart illustrating a processing procedure for determining whether a set of curved surfaces forms a corner and a positional relationship between the set of curved surfaces in the method.

FIG. 6 is a diagram showing an example of a fillet surface creation instruction method according to a conventional method.

[Explanation of symbols]

 1 CPU 2 Memory 3 Keyboard 4 Printer 5 CRT 6 Mouse 7 Auxiliary Storage 8 Bus Line

Claims (4)

[Claims] In a CAD apparatus, when instructing the creation of a fillet surface to be embedded in a corner formed by a plurality of curved surfaces in a previously created shape, a user of the CAD device specifies After inputting an angle value for determining a corner portion and a radius of a fillet surface to be created, the CAD apparatus firstly sets all two curved surfaces to be worked by the user into two sets. A common ridge line between curved surfaces is obtained, and then a range in which a temporary fillet surface is not created is selected from the obtained common ridge lines, and then, for the selected ridge line, an angle value input by the user and the ridge line It is determined whether or not the corner is a corner by comparing the angle formed by a set of curved surfaces sharing the same. If the corner is determined, the temporary fillet surface is determined by the value of the radius input by the user. Is formed on the corner and displayed Then, the user of the CAD apparatus examines the positional relationship between the fillet surface and the set of the curved surfaces forming the same with respect to the displayed temporary fillet surface, and based on the result, the fillet as necessary. A method for instructing creation of a fillet surface, wherein at least one of correcting a surface and adding a new instruction is performed. 2. The method according to claim 1, wherein, among the created temporary fillet surfaces, a plurality of surfaces adjacent to each other and continuous by sharing an end point of the common ridge line are stored as one set. Characteristic method of creating fillet surface. 3. A medium in which a program for creating a fillet surface to be embedded in a corner formed by a plurality of curved surfaces in a previously created shape is recorded in a CAD device, wherein the program is a program for the CAD device. After the user inputs an angle value for determining a corner portion in the created shape and a radius of a fillet surface to be created, the CAD apparatus firstly performs all operations to be performed by the user. For a set of curved surfaces, a common ridge line is obtained, and then, among the obtained common ridge lines, a range in which a temporary fillet surface is not created is selected, and then, for the selected ridge line, an angle value input by the user, It is determined whether or not it is a corner by comparing the angle formed by a set of curved surfaces sharing the ridge line, and when it is determined that the corner is a corner, a provisional value is obtained with the value of the radius input by the user. Fillet A surface is formed and displayed at the corner, and the user of the CAD apparatus examines a positional relationship between the fillet surface and the set of the curved surfaces that form the displayed temporary fillet surface, and as a result, A medium for recording a fillet surface creation instruction program, wherein at least one of the correction of the fillet surface and the addition of a new instruction are performed as necessary. 4. The medium storing the program according to claim 3, wherein the program creates a plurality of surfaces adjacent to each other by sharing an end point of the common ridge line among the created temporary fillet surfaces. Characterized by being stored as a set,
A medium recording a fillet surface creation instruction program.