JPH0962721A - Method for conversion from two-dimensional cad diagram to three-dimensional cad diagram - Google Patents

Abstract

PROBLEM TO BE SOLVED: To shorten the time required to generate a three-dimensional CAD drawing representing the three-dimensional shape of a pipe from a two-dimensional CAD drawing including the pipe. SOLUTION: A two-plane drawing of a two-dimensional CAD drawing representing a three-dimensional pipe structure formed by welding a straight pipe and (or) a curved pipe together is read in (S1), only pipe parts and the center line of the pipe parts are extracted (S2 and S3), and the pipe parts in two-plane drawings of the extracted pipe parts with the center lines are made to correspond to each other by making use of the center lines, thereby generating a three-dimensional CAD drawing (S4).

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a two-dimensional CAD (computer-aided) drawn in a triangular drawing method in advance for a shape having a pipe portion such as a motorcycle frame, a stand or an exhaust muffler. The present invention relates to a conversion method from a two-dimensional CAD diagram to a three-dimensional CAD diagram that allows a CAD system to easily create a three-dimensional CAD diagram (stereoscopic diagram) based on data related to a (design) diagram.

[0002]

2. Description of the Related Art Conventionally, two-dimensional CA drawn by a triangular drawing method.
When converting the D diagram into a three-dimensional CAD diagram, a two-dimensional CAD diagram in which dimensions are described is printed out, and the dimensions are manually picked up from the printed two-dimensional CAD diagram.
On the three-dimensional axes with a grid drawn on the display of the D system, the ridge lines and vertices related to the picked up dimensions are manually input, and the curved surface is spline-interpolated to perform a three-dimensional CAD diagram (3D diagram). ) And draw 3D CAD
Obtained the data related to the figure. By drawing a three-dimensional drawing,
The advantage is that the visibility of the product shape is improved, in other words, the product shape can be easily grasped.

[0003]

However, in the above-mentioned conventional method for converting a two-dimensional CAD diagram into a three-dimensional CAD diagram, the dimensions are visually read, and the vertices or the like relating to the read dimensions are read by a mouse or the like. Since it was a work method to specify and input on the screen using, for example,
Even with simple parts such as a motorcycle stand, it takes about several hours to generate a three-dimensional CAD drawing from a two-dimensional CAD drawing, and it takes a long time to create it. In this case, the input work is an inefficient work, and the labor of the CAD operator increases.

The present invention has been made in consideration of such a problem, and the time required to create a three-dimensional CAD diagram representing the three-dimensional shape of the pipe portion from the two-dimensional CAD diagram including the pipe portion is significantly shortened. Two-dimensional C that makes it possible to
It is an object to provide a method for converting an AD diagram into a three-dimensional CAD diagram.

[0005]

SUMMARY OF THE INVENTION According to the present invention, a two-dimensional CAD drawing including a pipe portion is selected from two-dimensional CAD drawings drawn by a trigonometric drawing method, and a two-dimensional C drawing including the selected pipe portion is selected.
The data related to the AD diagram is read into the CAD system, and the shape of the pipe registered in advance and the specifications of the center line registered in advance are referred to from the data related to the two-dimensional CAD diagram including the read pipe portion. Then, the pipe part and the center line of the pipe part are specified and extracted, and the parts other than the extracted pipe part with the center line are removed to obtain a two-dimensional CAD diagram of the two-view drawing of the extracted pipe part with the center line. It is characterized in that the pipe portion with the center line of each plan in the data is associated with the center line of each plan to create the data relating to the three-dimensional CAD diagram.

In this case, a straight pipe and / or
A two-dimensional drawing of a two-dimensional CAD diagram showing a three-dimensional pipe structure in which curved pipes are joined by welding or the like is read, only the pipe portion and the center line of this pipe portion are extracted, and the extracted center line The respective pipe portions in the two-sided view of the attached pipe portion are associated with the respective center lines, and 3
Since it is designed to create a two-dimensional CAD diagram, a two-dimensional C
It is possible to easily create a three-dimensional CAD diagram from the AD diagram.

Further, according to the present invention, the step of reading the two-dimensional CAD data of the pipe product drawing created by the triangular drawing method on the CAD system, and the element irrelevant to the product shape in the pipe product drawing are discriminated. And deleting the pipe product drawing, determining the product shape of the product forming the pipe product, classifying the product shape into a shape other than the pipe part and the pipe part, and extracting the pipe part,
It is characterized by including a step of taking correspondence between the two views of the extracted pipe portion and a step of synthesizing the corresponding pipe portion of the two views into a three-dimensional solid view.

In this case, the products are classified into a pipe portion and a portion other than the pipe portion (non-pipe portion), and a three-dimensional CAD drawing (three-dimensional drawing) is synthesized by taking correspondence between the two views of the pipe portion. Therefore, a three-dimensional CAD diagram (stereoscopic diagram) can be easily formed on the display.

[0009]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows the configuration of a CAD system 11 according to this embodiment.

The CAD system 11 is a central processing unit (hereinafter referred to as CPU) 1 having an arithmetic unit, a control unit and the like.
The CPU 12 includes an internal storage device 13 as a RAM (random access memory) and an OS (operating system) including a hard disk.
A main storage device 14 that stores a system program and an application program for converting a two-dimensional CAD diagram into a three-dimensional CAD diagram, and an optical disk or a hard disk. Drafting rule information 15a, product material information 15b, product shape The information 15c, the ambiguity 15d of two views, the ambiguity 15e of the designer, the knowledge database 15 that stores various information such as the (allowable) error table 15f, and a large amount of graphic data composed of an optical disk or a hard disk 2 A graphic database 20 in which the three-dimensional CAD data and the created three-dimensional CAD data are stored is connected.

Further, the CPU 12 is a central device for dialogue between the graphic output device 16 such as an XY plotter and the CAD system 11 and its user (operator), and serves as a display device used in conjunction with the input device. Display 1
7, a keyboard 18 as an input device, and a mouse, a light pen, a dial, and a function key (graphic processing and program switching) for an operator to point a specific position on the screen of the display 17 which is an input device.
Is connected to a pointing device 19 including the above.

The CAD system 11 is usually connected to a host computer (not shown) through a network so that data can be exchanged with another CAD system through the network.

Next, the processing of the CAD system 11 will be described in detail with reference to the flowchart of FIG. In the following description of the process, the control subject is C
Although it is the PU 12, it is complicated to refer to the CPU 12 each time, and therefore it is referred to only when it is particularly necessary.

Therefore, first, a two-dimensional CAD diagram (pipe product drawing) representing a three-dimensional pipe structure (in this embodiment, a motorcycle stand) which has been created in advance on the CAD system 11 and is about to be created. 2), the two views are read (step S1). Each of these two views is a drawing drawn by the triangular drawing method on the CAD system 11 and converted into two-dimensional CAD data. Further, these two views are, for example, a front view, a rear view, a top view, a bottom view,
From the right side view and the left side view, any two views in which the shape appears well are selected. The two-dimensional CAD data may be data created by another CAD system.

The step S1 will be described with reference to a specific example. Two-dimensional CAD data Dfa representing a front view displayed on the screen 21 of the display 17 (see FIG. 3).
(Referred to as front two-dimensional CAD data), two-dimensional CAD data Dsa indicating a side view (referred to as side two-dimensional CAD data), and two-dimensional CAD data Dba indicating a bottom view.
Of the three views including (bottom two-dimensional CAD data), in the present embodiment, the front two-dimensional CAD data Dfa and the side two-dimensional CAD data D having a good shape are shown.
Select sa and.

As can be seen from FIG. 3, the front two-dimensional C
The AD data Dfa and the side surface two-dimensional CAD data Dsa include a product shape and a dimension lead line other than the product shape, a dimension,
It includes elements that are not related to the product shape, such as finishing symbols, processing symbols such as welding, and other drawing information.

Therefore, next, the product shape is extracted (step S2). In this step S2, referring to the drawing rule information 15a and the like in the knowledge database 15, character / size information (straight line, curve) from the front two-dimensional CAD data Dfa and the side two-dimensional CAD data Dsa to which dimensions and the like are added. , Information other than circles and ellipses), welding marks, finish symbols, etc., which are unrelated to the product shape, are deleted, and the front two-dimensional CAD data Df of only the product shape is deleted.
b and side surface two-dimensional CAD data Dsb are extracted. This extraction operation is so-called AI (Artificial) which performs inference and pattern recognition based on the information in the knowledge database 15.
Intelligence) processing, etc.

The center line is not deleted during this extraction. In this embodiment, the center line is defined as an alternate long and short dash line with a line width of 0.1 mm, and is defined in the drawing regulation information 15a. By the process of step S2, the front face 2 with the center line relating to the product shape is almost instantly
It is possible to extract the two-dimensional CAD data Dfb and the side surface two-dimensional CAD data Dsb with the center line (see FIG. 5).

As can be seen from FIG. 4, the extracted front two-dimensional CAD data Dfb and side two-dimensional CAD data Dsb.
Includes the pipe portion 31f (3) which is necessary product shape information.
1s) and the center line 30f of the pipe, which is the necessary center line information.
In addition to (30s), a pipe part holding fitting 32f which is unnecessary product shape information other than the pipe part 31f (31s)
(32s) and unnecessary center line 33f other than the pipe center line 30f (30s) are included.

Therefore, next, the front face two-dimensional CAD data Dfc and the side face two-dimensional CAD data Dsc corresponding to the pipe portion 35f (35s) with the center line shown in FIG. 5 which is necessary information is extracted (step S3). In this case, the center line 30f (30s) of the pipe is the knowledge database 15
Judgment is made according to the (A) pipe center line judgment criterion stored in the drawing rule information 15a of FIG. Further, the pipe body is judged by (B) pipe outer contour line (contour line) judgment standard and (C) pipe radius judgment standard described below.

In the present invention, since the center line on the two-dimensional CAD diagram, to be precise, the center line related to the radius of the pipe is treated as a pipe, the center line extraction process is an important process. Is. (A) Pipe centerline judgment criteria a. A thin line (0.1 mm as an example), which is a straight line, a curved line, a circular arc, and an alternate long and short dash line of an ellipse is the center line of the pipe. b. The horizontal and vertical thin dashed line passing through the origin is not the centerline of the pipe. Based on this criterion, the unnecessary center line 33f in FIG. 4 is deleted (removed). (B) Criteria for determining the contour of the pipe a. It is parallel to the center line of the pipe (refer to the error table 15f for parallelism), and a thick line (0.6, for example).
mm, 0.4 mm) is the outline of the pipe. Based on this criterion, the pipe part holding fitting 32f (32s), which is unnecessary product shape information in FIG. 4, is deleted (removed). (C) Pipe radius judgment criteria a. The parallel distance between the center line of the pipe and the outer line of the pipe is the radius of the pipe. However, the product shape information 15c of the pipe is also collated, and it is determined that the pipe is regarded as a pipe in which the parallel intervals and the like do not match is not the pipe.

Next, the front dimension CAD data D shown in FIG. 5 representing the extracted pipe portion 35f (35s) with a center line.
Three-dimensional CAD data of the pipe structure, in other words, three-dimensional CAD drawing of the pipe structure is created from fc and the side surface two-dimensional CAD data Dsc (step S4).

FIG. 6 is a detailed flowchart relating to the creation of the three-dimensional CAD diagram in step S4.

In this case, first, as a preparation for three-dimensional CAD drawing, for each drawing, in this example, front two-dimensional CA.
For each of the D data Dfc and the side surface two-dimensional CAD data Dsc,
Tree structure data (plan tree structure data) is created by extracting the attributes of each pipe constituting the pipe structure (step S41).

FIG. 7 is a diagram provided for explaining a general structure of the plan view tree structure data T.

As can be seen from FIG. 7, a general pipe α
The plan view tree structure data T that represents is composed of radius data, center line data, plan view data, and connection portion data.

Here, when the center line is regarded as a set in which straight lines are connected to each other, the center line data has both ends of the straight lines from the origins OG _f and OG _s (see FIG. 3) for each plan. It is represented by the two-dimensional coordinate data of a point and the distance between the two-dimensional coordinate data in the X and Y directions. The end points are
When the center line is a straight line, (a part of) a circle, (a part of) an ellipse, or (a part of) a free curve, it means points at both ends.

As described above, the origin (for example, the (dimension) origin OG _{f of the} front view and the (dimension) origin OG of the side view are provided for each of the views.
_s }, and the origin of each floor plan, that is, the two-dimensional coordinate data of the end points from the origin in the local coordinate system and its 2
It is represented by the distance between the dimensional coordinate data. More specifically, when the coordinates of both end points of the center line in the plan view 1 are represented by (x1, y1) and (x2, y2), the distance D is the distance in the X direction Dx = (x2-x1). ) And the distance in the Y direction Dy = (y2-y1), while the coordinates of both end points of the center line in the plan view 2 are (x
a, ya), (xb, yb), the distance D
Are respectively Dx = (xb-xa) and Dy = (y
b-ya). This is because even if the origin of coordinates is different, the distance between the two views can be compared so that the pipes between the views can be associated with each other.

The local coordinate systems may have different positive and negative directions from the origin of the orthogonal XY axes, but it is premised that the mutual XY axes are parallel and the scales are the same.

In FIG. 7, the plan view data (also referred to as view data) is such as whether the pipe α belongs to the front view or the side view in the two-dimensional drawing drawn by the triangular drawing method. It is data that means whether it belongs to a plan (also called a view).

Further, the connection part data is the pipe α
The end point of the center line is data indicating which pipe (in the example in FIG. 7) the end point of the center line of the pipe has a rounded corner, that is, a so-called corner R connected by what mm. If the corner R is a circle, its radius is
In the case of an ellipse, the major axis of the ellipse is used, and in the case of a free curve, the radius of three-point circular arc approximation is used.

In this case, when another pipe exists at both ends of the center line of the pipe α, the other pipe name and the corner R are added in parallel to the description of the pipe β.

As will be described later by way of example, a straight pipe is connected to both end points of the pipe α when the center line 30f (30s) of the pipe is not a straight line but a circle, an ellipse or a part of a free curve. If so, the pipe α
The plan view tree structure data T for is not created.

FIG. 8 shows a part of the front tree structure data Tf created for the pipe structure represented by the front two-dimensional CAD data Dfc shown in FIG. In FIG. 8, since the straight pipe 1 and the straight pipe 3 are connected to both end points of the elliptical or free-form pipe 2, the plan tree structure data T is not created.

In FIG. 8, as an example, a straight pipe 3
Explaining the tree structure of, the straight pipe 3 having the radius r1 is connected to the straight pipe 1 with the corner R being R = R1 and is connected to the straight pipe 4 having the corner R being R = R2. I understand.

Next, on the basis of the front tree structure data Tf and the side tree structure data Ts of the pipe structure thus created, the two views of the pipe portion are associated with each other to correspond to the front view of the pipe structure. Tree structure data is created (step S42). Regarding this processing, first, general processing will be described, and thereafter, processing in a specific example will be described in detail.

FIG. 9 is a detailed flowchart of the general process of the associating step S42.

First, pipes having the same diameter (radius in this embodiment) on the tree structure data between the two views (views 1 and 2) are associated and classified (step S51).

Then, in the classification of step S51,
Further, the tree structure between the pipes between the floor plans 1 and 2 is created by subdividing according to the following rules.

In this case, first, in order to identify the pipe i among the pipes i in one of the plan views 1, the parameter i is set as i = 1 by considering i as a calculation parameter (step S52).

Next, paying attention to the pipe i in the plan view 1 (pipe i = pipe 1 in the first processing), the other pipe group in the plan view 2 is subjected to the following sieving (verification), When they match, the correspondence between the pipe i in plan view 1 and the pipe group in plan view 2 is taken (step S53). It should be noted that sieving means that the pipe i in the front view 1 and the pipe group in the front view 2 are collated by so-called brute force.

Next, the distance D between the end points of the center lines of the pipe i of the plan view 1 and the pipe a of the plan view 2 is calculated as an error table (see FIG.
Among them, those that match within the error tolerance defined by the knowledge database 15 are associated (step S5).
4).

As a result of the processing in step S54 shown in FIG.
As shown in A, the pipe i of the plan view 1 and the pipe a of the plan view 2 are shown.
Are associated with. In FIG. 10A, the origin OG1 of the local coordinate system of the plan view 1 and the X axis and the Y axis, and the origin OG2 of the local coordinate system of the plan view 2 and the X axis and the Y axis are also displayed. As described above, the origins OG1 and OG2 are two-dimensional CAs.
In general, they are arranged at different positions so that the dimension from the origin OG in FIG.

Next, the distance D between the end points of the center lines of the pipe i in the plan view 1 and the distances Da, Db between the end points of the center lines of the connected pipes a, b, c ... , Dc and the total distance Da + Db + Dc are matched with each other within an allowable error range (step S55).

By the processing of this step S55, FIG.
As shown in B, for example, the pipe i of the plan view 1 and the connected pipes a, b, and c of the plan view 2 are associated with each other.

Then, the distance D between the end points of the center lines of the pipe i in the plan view 1 is calculated as the distances Da, Db, Dc between the end points of the center lines of the independent pipes a, b, c ... .. are associated with each other (step S56).

That is, as shown in FIG. 10C, for example, the pipe a at the distance Da and the pipe b at the distance Db in the plan view 2 having a larger distance than the pipe i at the distance D in the plan view 1 are applicable. Pipe a and pipe b are separated by the distance D of pipe i.
It is called an independent pipe because it is not connected in series between the pipes.

Next, the distance D between the end points of the center line of the pipe i in the plan view 1 is the distance Da, Db between the end points of the center lines of the independent pipes a, b, c ... Those smaller than Dc ... Are associated (step S57). In this case, as shown in FIG. 10D, for example, as compared with the pipe i having the distance D in the plan view 1, the distance D in the plan view 2 having a smaller distance than the pipe i.
Pipe a of a corresponds to this.

By the processing of steps S53 to S57, the pipe a of the plan view 2 for the first pipe i = 1 of the plan view 1,
Since the correspondence with b, c ... Is completed in principle, next, the parameter i is set to i = i + 1 (step S58), and steps S53 to S57 for the pipe 2 in the plan view 1 are performed.
Is performed, and thereafter, the pipe i of the plan view 1 and the pipes a, b, c of the plan view 2 are sequentially associated until the last pipe i = n (step S59).

At the time when the processing up to step S59 is completed, unmatched pipes a, b, c in the plan view 2 are shown.
.. is present, the unprocessed pipes a, b, c, ... Correspond with the pipe i in FIG. 1, so that the same processes as those in steps S55 and S56 are performed. Performed as viewed from a, b, c (step S
60). This process occurs as shown in FIG. 11, for example, when it is seen in the plan view 2 that there are two pipes a and b, but in the plan view 1, one pipe i
The case where it can only be seen as is applicable.

Next, when there is an unmatched pipe in the plan 1 or 2, the unmatched pipe i in the plan 1 is associated with a horizontal line passing through the origin OG2 in the plan 2. For the pipes a, b, c, ... Of the plan view 2, a process for taking correspondence with the horizontal line passing through the origin OG1 of the plan view 1 is performed (step S61, see FIG. 10E). This processing occurs in a pipe whose both end points are not connected to other pipes, for example, the pipe i shown in the plan view 1 in FIG.

When the above-mentioned associating process in step S42, that is, the processes in steps S51 to S61 are completed, the pipe structure floor plan correspondence tree that correlates the pipes constituting the plan 1 and the pipes constituting the plan 2 The structural data Tv is completed.

FIG. 13 shows a general structure of the tree structure data Tv corresponding to the pipe structure front view completed in this way.

From FIG. 13, for example, a pipe having a radius of 1 has a pipe 1 and a pipe 2 in the front view 1, the pipes 1 and 2 in the front view correspond to the pipe 1, and the pipes a and b are corners. You can see that they are connected by R. Pipe 2 of floor plan 1
It can be seen that the pipe j in Fig. 2 corresponds to the. Further, it can be seen that the pipe i having the radius 2 in the plan view 1 and the pipe k having the radius 2 in the plan view 2 correspond to the pipe xxx, and these are connected at the corner R.

FIG. 14 is a diagram provided for explaining the creation of the pipe structure surface view correspondence tree structure data Tv for the specific example shown in FIGS. 5 and 8.

In this example, the plan view 1 corresponds to the side surface two-dimensional CAD data Dsc, and the plan view 2 corresponds to the front surface two-dimensional CAD data Dfc.

The following can be understood from the tree structure data Tv corresponding to the pipe structure surface view shown in FIG. (1) Pipe A in side view and pipes 1, 3, 4, in front view
The radii of 5 are the same and are radius r1. (2) Pipe 1 in the front view with respect to pipe A in the side view,
3, 4, 5 correspond. (3) In the pipes 1, 3, 4, 5, ... In the front view, the pipe 1 and the pipe 3 are connected, and the corner R of the connection is
R = R1. Further, the pipe 3 and the pipe 4 are connected, and the corner R of the connection is R = R2. Similarly, the pipe 4 and the pipe 5 are connected, and the corner R of the connection is R = R3.

By the end of step S61 shown in FIG. 9,
Step S42 shown in FIG. 6 ends. Therefore, next, the final processing in the general flowchart of FIG. 2, that is, the three-dimensional CAD drawing creation processing of the pipe portion is performed (FIG. 2).
Medium, step S4).

FIG. 15 shows a detailed flowchart of the process of step S4.

First, by the process of step S42 (the process described with reference to the flowchart of FIG. 9), the center lines of the pipes corresponding between the two drawings are combined on the three-dimensional coordinates (3D) (3D). Step S71).

FIG. 16 is a general diagram provided to explain this compositing process. This synthesizing process is performed in the XYZ orthogonal 3
In the axial coordinate system, for example, the center line 1c of the pipe 1 and the center line 2c of the pipe 2 are drawn on the YZ plane corresponding to the plan view 1, and the center line ac of the pipe a corresponding to the plan view 2 is drawn.
And draw the center line bc of the pipe b. Next, the width (length) of the center line 2c passing through the center line 2c of the pipe 2 on the plan view 1
And a plane 2p that is orthogonal to the plan view 1, a so-called center line 2
Draw a ruled plane formed by moving c. Similarly, view 2
A plane bp, which is a ruled plane by the center line bc passing through the center line bc of the upper pipe b and orthogonal to the plan view 2, is drawn.

The intersection line between the plane bp and the plane 2p is XY.
It is the center line Jc of the pipes 2 and b on the Z orthogonal three-axis coordinate system, that is, on the three-dimensional diagram.

Similarly, the center line 1c of the pipe 2 on the front view 1
Draw a plane not shown, which is a weaving plane with a center line 1c orthogonal to the plane view 1, and further pass through the center line ac of the pipe a on the plane view 2 and with a center line ac orthogonal to the plane view 2 A plane not shown, which is a ruled plane, is drawn. The intersecting line of these ruled planes becomes the center line Kc of the pipes 1 and a on the XYZ orthogonal triaxial coordinate system, that is, on the three-dimensional drawing.

When the corner R exists at the connecting portion between the center line Jc of the pipe J and the center line Kc of the pipe K synthesized on the three-dimensional coordinates (3D) shown in FIG. 16, the center line Jc on 3D is present. A corner R is drawn at the connecting portion between Kc and Kc (step S72).

Finally, the pipe J with the corner R attached
A wire frame model, a surface model, or a solid model relating to the pipe having a radius r1 is created on the center line Jc of (1) and the center line Kc of the pipe K on 3D by known CAD software (step S73).

FIG. 17 shows a CAD diagram after the three-dimensional processing for a specific example. That is, the pipe P3d that is obtained by synthesizing the front shape of the pipe represented by the front two-dimensional CAD data Dfc shown in FIG. 5 and the side surface shape of the pipe represented by the side two-dimensional CAD data Dsc by the processing from steps S71 to S73. The three-dimensional shape of is shown.

According to the above-described embodiment, the two-dimensional views of the two-dimensional CAD diagram showing the three-dimensional pipe structure in which the straight pipe and / or the curved pipe are joined by welding or the like are read. , A pipe portion and only the center line of this pipe portion are extracted, and each pipe in the two-view drawing of the extracted pipe portion with the center line is associated with each of the center lines to automatically generate a three-dimensional CAD diagram. I am trying to create it.

By processing in this way, for example, as shown in FIG.
The work of drawing the pipe P3d in the seven cases took about 6 hours in the past, but can be completed in about a few minutes or less. Therefore, the labor of the operator can be reduced. In the above-described embodiment, only the creation of the three-dimensional CAD drawing (three-dimensional drawing) for the pipe portion is described, but the additional shape of the pipe portion (for example, the pipe portion holding metal fitting 32f ( The present inventors have confirmed that the same procedure can be performed for s) and the like). The present invention is not limited to the above-described embodiments, and it goes without saying that various configurations can be adopted without departing from the gist of the present invention.

[0070]

As described above, according to the present invention, the product drawing by the two-dimensional CAD drawing constituted by the pipe drawn based on the triangular drawing method and the characteristics of the product and the drawing drawing method are known. The three-dimensional shape of the product is inferred from the base-processed product, so-called AI processing is also incorporated, and a three-dimensional CAD drawing (three-dimensional drawing) is automatically synthesized on the CAD system.

Therefore, it is possible to achieve an effect that the time for creating a three-dimensional CAD diagram representing the three-dimensional shape of the pipe from the two-dimensional CAD diagram including the pipe is significantly shortened.

Actually, the time is reduced by about 90% or more, and the labor of the operator is reduced.

[Brief description of drawings]

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

FIG. 2 is a schematic overall flow chart provided for explanation of creating a three-dimensional CAD diagram from a two-dimensional CAD diagram.

FIG. 3 is a diagram showing an example of a two-dimensional CAD diagram in which auxiliary symbols other than shapes such as dimensions are entered.

FIG. 4 is a diagram showing a two-dimensional CAD diagram in which auxiliary symbols are deleted from the two-dimensional CAD diagram shown in FIG.

5 is a diagram showing a two-dimensional CAD diagram in which parts other than the pipe part are deleted from the two-dimensional CAD diagram shown in FIG. 4 and only the pipe part is left.

FIG. 6 is a detailed flowchart of step S4 shown in FIG.

FIG. 7 is a diagram provided for explaining general tree structure data created for a pipe.

FIG. 8 is a diagram provided for explaining specific tree structure data created for a pipe.

9 is a detailed flowchart of step S42 shown in FIG.

FIG. 10 is a diagram which is used for explaining the association of the center lines of the pipes between the two views for explaining the process of the flowchart in FIG.

FIG. 11 is a diagram provided for explaining a difference in how a pipe is viewed on a front view and a side view such as a side view.

FIG. 12 is a diagram provided for explaining an example of a pipe in which an end point of a center line is not connected to another center line.

FIG. 13 is a diagram provided for a general description of associating pipes between drawings based on the pipe diameter.

FIG. 14 is a diagram provided for a specific description of associating pipes between the drawings based on the pipe diameter.

FIG. 15 is a detailed flowchart of step S4 shown in FIG.

FIG. 16 is a diagram provided for explaining a process of generating a shape of a center line on a three-dimensional coordinate system with reference to the center line of each plan.

FIG. 17 is a diagram showing an example of a three-dimensional CAD diagram (stereoscopic diagram) created from the two-view diagram shown in FIG. 5 according to this embodiment.

[Explanation of symbols]

11 ... CAD system 15 ... Knowledge database 21 ... Screen 1c ... Center line of pipe 1 2c ... Center line of pipe 2 ac ... Center line of pipe a bc ... Center line of pipe b Jc ... Center line of pipe J Kc ... Pipe K Center line 2p ... plane relating to pipe 2 bp ... plane relating to pipe b Dsa, Dsb, Dsc ... Side two-dimensional CAD data Dfa, Dfb, Dfc ... Front two-dimensional CAD data Tv ... Pipe structure floor plan correspondence tree structure data P3d ... 3D pipe

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kenichi Sueda 1-4-1 Chuo, Wako-shi, Saitama, Ltd. Inside Honda R & D Co., Ltd.

Claims (2)

[Claims] 1. A triangular drawing method 2 including a pipe portion.
By selecting two views of the two-dimensional CAD diagram, reading the data related to the two-dimensional CAD diagram including the selected pipe part on the CAD system, and reading the data related to the two-dimensional CAD diagram including the pipe part, By referring to the shape of the pipe registered in advance and the specifications of the center line registered in advance, the pipe portion and the center line of this pipe portion are specified and extracted, and other than the pipe portion with the extracted center line is extracted. 3D by correlating the pipe part with centerline of each plan in the data related to the two-dimensional CAD diagram of the two-view diagram of the pipe part with centerline extracted by removing the part with the centerline of each plan A method for converting a two-dimensional CAD diagram into a three-dimensional CAD diagram, which is characterized by creating data relating to a CAD diagram. 2. A step of reading two-dimensional CAD data of a pipe product drawing created by a triangular drawing method on a CAD system, and a step of discriminating and deleting an element irrelevant to the product shape from the pipe product drawing. And, regarding the pipe product drawing, determining a product shape of a product forming the pipe product, classifying the product into a pipe part and a shape other than the pipe part, and extracting the pipe part. And a step of synthesizing a correspondence between the drawings and a step of synthesizing the two-dimensional views of the pipe portion for which the correspondence is adopted into a three-dimensional solid view.
A method for converting a three-dimensional CAD diagram into a three-dimensional CAD diagram.