JPH06195405A - Graphic display method - Google Patents

Abstract

PURPOSE:To prevent interference caused by not considering the variation in dimensions of parts by displaying the width of a graphic outline line segment with a width including a dimension tolerance. CONSTITUTION:This method executes interference-check by comparing the X-address of a line part DC (a2+r) and that of a line segment EF (a3-t) as objects by considering the dimension tolerance of the parts. When the line segment is an oblique line, the method executes interference check by comparing addresses including the dimensional tolerance of points C and F. Display in this case includes dimensional tolerance and when an operator indicates display including the tolerance of only a part I, the outline of the part I is displayed by a thick line corresponding to the tolerance. Thereby, the operator can view the dimensional tolerance of the parts as the width of the outline and furthermore, a dimensional tolerance quantity and the interval between the parts are displayed as numerical information so that a mistake by a designer can be prevented.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a graphic display method in a CAD system, and more particularly to a graphic display method for displaying the dimensional tolerances of parts included in the width of the graphic outline.

[0002]

2. Description of the Related Art In designing mechanical products in recent years, a so-called CAD system using a computer is widely used.
For example, a display unit for inputting a figure, a transparent tablet arranged on the front surface of the display unit, a stylus pen for inputting a figure or the like on the tablet, a microprocessor for figure processing, a memory for storing figure data and a processing program, etc. Part, screen frame buffer memory to write display data,
It is composed of a monitor unit composed of a 21-inch color CRT for displaying a drawing on a monitor and a display control unit for controlling these. In the CAD system configured as described above, the operator draws an arbitrary figure with the stylus pen while looking at the grid on the transparent tablet, and the microprocessor controls the display control unit according to the processing program stored in the storage unit. The drawing is displayed on the display unit and the monitor unit.

In recent CAD systems, interference check using three-dimensional data is performed in order to prevent design errors due to interference of a plurality of components (overlapping of component arrangement) due to erroneous arrangement of components constituting a product. It is being appreciated. A method using two-dimensional data has been developed for this interference check, and for example, a method using the following procedure has been developed. With respect to the part to be checked, the outline of the part is obtained for each projection surface such as the front surface, the plane surface, and the side surface, and the outline is extracted. The two parts are paired and the overlap of each projection plane is checked, and if an overlap location is detected on any of the projection planes, this is taken as an interference candidate. Further, the positional correspondence between a plurality of projection planes is checked from the interference candidates, and the range where the overlapping portions match is narrowed down as interference candidates. It is determined whether or not there is interference by utilizing the characteristics of each component type. Other than this, for example, a method of previously determining whether or not two objects interfere (collide) with each other is disclosed in, for example, JP-A-64-72.
209.

[0004]

Although the CAD system for checking the interference of the parts can detect the interference of the parts on the design drawing, the size of the actual product only by the interference check based on the reference value of the figure outline. Since the tolerance is not taken into consideration, there is a problem that the parts may interfere with each other at the stage of assembling the parts. Especially C
In the AD system, since it is easy to enlarge the figure, it is displayed as if there is a space between the parts in the drawing, and the outline of the part is drawn even in a narrow area where handwriting is not possible. There is a problem that interference may occur due to dimensional tolerance.

An object of the present invention is to eliminate the above-mentioned problems caused by the prior art, to visually confirm the dimensional tolerance of parts on a display screen, and to check the interference caused by the dimensional variation of parts on a CAD system. It is to provide a graphic display method capable of performing

[0006]

In order to achieve the above-mentioned object, a graphic display method of a graphic processing system according to the present invention calculates a dimension tolerance value of an outline line segment of the graphic to determine a width of the graphic outline line segment. The first feature is to display with a width including a tolerance.

Further, in the graphic display method according to the present invention, the dimension tolerance value of the contour line segment of the graphic is calculated, and the width of the graphic contour line segment is displayed with a width including the dimension tolerance. The second feature is to check the interference of each projection of the line segment and warn the operator when the interference is detected.

[0008]

According to the graphic display method according to the first feature,
By displaying the width of the figure outline line with a width that includes the dimensional tolerance, the operator can visually check whether or not the figures overlap, so that the variation in the dimensions of parts cannot be taken into consideration. The generated interference can be prevented. Further, according to the graphic display method according to the second feature, the graphic processing system checks the interference, which is the overlap between the outline drawings of the outlines of the plurality of component graphics, and warns the operator when the interference is detected. As a result, the operator can be easily alerted and the interference can be further prevented.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below in detail with reference to the drawings. The hardware configuration of the CAD system to which this embodiment is applied is as shown in FIG. 8, a display unit 15 for displaying an input graphic, a transparent tablet 13 arranged in front of the display unit 15, and an arbitrary transparent tablet 13. A stylus pen 2 for drawing a drawing by designating a position; a microprocessor 11 for inputting a coordinate position on the transparent tablet 13 designated by the stylus pen 2 as an input signal 12 for graphic processing; A storage unit 10 for storing graphic data processed by the microprocessor 11 and a processing program, and coordinate conversion for performing coordinate conversion of the graphic data for display by the microprocessor 11 and calculating a line segment width including a dimensional tolerance described later. And a screen frame buffer memory 8 for writing display data by the conversion unit 9 into a frame at a predetermined position. And a display control unit 7 for display control of the display data in the memory 8 on the display unit 15 and the monitor 6. The coordinate conversion unit is unique to this embodiment and is composed of an ordinary adder and a complementer, and performs coordinate conversion as shown in [Formula 1] to [Formula 4] described later.
In addition, a high-precision grid is arranged on the transparent tablet 13 as an index for figure input, and when the screen of the display unit 15 is viewed through the tablet 13, the grid of the grid blocks the view of the figure itself. Therefore, in this system, the monitor unit 6 is separately provided.

In the CAD system thus constructed, the operator draws an arbitrary figure with the stylus pen 2 while looking at the grid on the transparent tablet 13, and the microprocessor 11 is stored in the storage unit 10. The drawing is displayed by instructing the display controller 15 and the monitor 6 to display the drawing via the coordinate conversion unit 9 and the screen frame buffer memory 8 according to the processing program.

A high-precision A1 size color CRT is used for the display section, and a transparent tablet equipped with a high-precision grid is provided on the screen of the display section. Drawing on this display unit is performed by picking an arbitrary drawing point 14 on the high-precision grid 1 with the stylus pen 2 as shown in FIG. 1A, and a figure 3 along the grid line as shown in FIG. be painted. In this display screen 4, the horizontal axis is X and the vertical axis is Y, and the address of the intersection is (0,
0), the address of the image point 14 is represented as (m, n), and considering the case of drawing a rectangular part a and a square part b, as shown in FIG. By doing so, the figure is formed, and regarding the part B, the figure is formed by connecting the square vertices EFGH.

This part (i) sets the address of each vertex to A (a
₁ , b ₁ ), B (a ₁ , b ₂ ), C (a 2, b ₂ ), D
Assuming that (a ₂ , b ₁ ), the addresses of the respective vertices and the points forming the line segment connecting the vertices vertically and horizontally emit light,
It is displayed as a rectangle. For example, if the line segment AB is taken, the X address is a ₁ and the Y address is from b ₁ to b _2.
Each address up to is emitting light. Each of these line segments shows the outline of the component. As for the part B, the addresses of the vertices are E (a ₃ , b ₃ ), F (a ₃ , b ₄ ), G
The same thing can be said if (a ₄ , b ₄ ) and H (a ₄ , b ₃ ). Here, the reference point of the drawing of the part a is A, and the reference point of the drawing of the part b is G, and when the dimensional tolerances of the part a and the part b are taken into consideration, the part dimensional tolerance of the part is taken into consideration. Consider whether parts B cause interference. Note that only the X-axis direction will be described here to simplify the description.

Considering the part a, this is a rectangular part, and the reference point for drawing is A. Now line segment A
The length of D (same as the length of line segment BC) is the reference value P,
When the dimensional tolerance of the component a in the X-axis direction is + r, -s,
The address of the point D has a maximum value of (a ₂ + r, b ₁ ), and a minimum value of (a ₂ −s,
b ₁ ). That is, the address of the point D in consideration of the dimensional tolerance is the value shown in the following [Equation 1] regarding the maximum value and the minimum value.

[0014]

[Equation 1]

As a result, the address of the point D in consideration of the dimensional tolerance is arbitrary on the line segment connecting the two addresses (a ₂ + r, b ₁ ) and (a ₂ -s, b ₁ ) of the equation _1. It becomes the point.

Similarly, the address of the point C becomes the value shown in [Equation 2] regarding the maximum value and the minimum value, and the address of the point C in consideration of the dimensional tolerance is two addresses (a ₂ + r,
It is an arbitrary point on the line segment connecting (b ₂ ) and (a ₂ −s, b ₂ ).

[0017]

[Equation 2]

Therefore, the outline DC connecting the points D (a ₂ , b ₁ ) and C (a ₂ , b ₂ ) considering the dimensional tolerance of the component B in the X-axis direction is four points (a ₂ -s , B ₁ ), (a ₂ + r,
b ₁ ), (a ₂ + r, b ₂ ), (a _{2 −} s, b ₂ ) is an arbitrary point in the rectangle, and the above four addresses (a _{2 −} s, b ₁ ), ( a ₂ + r, b ₁ ), (a ₂ + r,
b ₂ ), (a ₂ −s, b ₂ ) respectively at points D ₁ , D ₂ , C ₂ ,
Let us call it C _1, and FIG. 4 shows an example of a graphic display method including the width of the outline in consideration of the dimensional tolerances + r and −s. Figure 4
FIG. 4A shows an example in which the insides of the rectangles D ₁ , D ₂ , C ₂ and C ₁ are displayed as filled thick lines, and FIG. 4B shows the rectangle D 1.
_This is an example in which the insides of ₁ , D ₂ , C ₂ , and C ₁ are hatched and displayed. In FIG. 4C, the outline DC, the broken line D ₁ C ₁ connecting the minimum values of the dimension tolerance, and the dimension tolerance of Dashed line connecting maximum values D ₂ C ₂
And are displayed as three lines. The display method including the line segment width due to this tolerance is not limited to these, and may be another display method such as changing the display color / blinking the maximum and minimum width line segments.

Next, considering the part b, this is a square part, and the reference point for drawing is G. Line segment E
The length of H (same as the length of the line segment FG) is the reference value Q,
The dimensional tolerance of the X-axis direction of the component (b) + t, When -u, respectively the point E, the address of the point _{F (a 3, b 3)} , (a 3,
b ₄ ). Considering the dimensional tolerance of the part B in the X-axis direction in the same manner as for the part B, the outline EF connecting the points E and F has four points (a ₃ -t, b ₃ ), (a ₃ +
u, b ₃ ), (a ₃ + u, b ₄ ), (a ₃ −t, b ₄ ) are connected to form a rectangular shape. The above four symbols are E ₁ ,
Let us denote them as E ₂ , F ₂ , and F ₁ .

Here, a method of checking interference of parts according to the present embodiment will be described. This interference check is performed on the front surface of the part to be checked as described in the above-mentioned conventional technique.
Obtain the outline of the part for each plane such as plane and side, extract the outline including the dimensional tolerance, check the overlap in units of the projection plane with two parts as a pair, and if the overlapping parts are detected on all the projection planes. , This is a candidate for interference. When inspecting the interference between the parts B and B in the X-axis direction of the figure shown in FIG. 3, in the conventional method, the X address (a
₂ ) and the X address (a ₃ ) of the line segment EF were compared, but in reality there are dimensional tolerances in the parts, causing interference even if a ₂ <a ₃ on the address. There was a possibility. In the present embodiment, taking into account the dimensional tolerances of the parts, the X address (a ₂ + r) of the line segment D ₂ C ₂ and the X address (a ₃ −t) of the line segment E1F1 are compared and interfered. Check. If the line segment is an oblique line, the interference check is performed by comparing the addresses including the dimensional tolerances of the points C and F. As described above, the interference check according to the present embodiment determines the presence or absence of the interference by taking into consideration the dimensional tolerance of the component even if the dimensional tolerance varies in the most adverse direction. This judgment is made in front of the part,
This CAD system displays the warning on the display unit 15 and / or the monitor unit 16 when the interference is detected for each projection surface such as the side surface or the flat surface.

Further, the display in the present embodiment is a display including the dimensional tolerance as shown in FIG. 4, and for example, when the operator gives an instruction to display the tolerance including only the component a,
As shown in FIG. 5, the outline of the part a is displayed by a thick line corresponding to the tolerance. This allows the operator to visually check the dimensional tolerance of the component as the width of the outline. Further, by displaying the dimensional tolerance amount and the component interval as numerical information, it is possible to prevent mistakes by the designer.

In the above embodiment, the example is shown only in the X-axis direction, but the same operation can be performed also in the Y-axis direction to process as two-dimensional data. Further, for example, for the part a, the drawing reference point was set to A and the dimensional tolerance was taken into consideration. However, the center point of the part a can also be used as the drawing reference point. In this case, the address of the point A is
It becomes the range of the maximum value and the minimum value like [Equation 3]. That is, the address of the point A taking the dimensional tolerance into consideration is an arbitrary point on the line segment connecting the two addresses (a ₁ -r / 2, b 1) and (a ₁ + s / 2, b ₁ ). .

[0023]

[Equation 3]

Similarly, the address of the point D is also in the range of the maximum value and the minimum value as shown in the following [Equation 4], and the address of the point D in consideration of the dimensional tolerance is two addresses (a ₂ − s /
2, b ₁ ) and (a ₂ + r / 2, b ₁ ) on the line segment.

[0025]

[Equation 4]

Therefore, the line segment AB considering the dimensional tolerance is taken into consideration.
The X address of the line segment CD is between (a ₁ -r / 2) and (a ₁ + s / 2), and the X address of the line segment CD is (a ₂ -s / 2) and (a ₂ +).
r / 2). In this way, when the drawing reference point is changed to another position, the address range corresponding to the drawing reference point is calculated in the same manner as above,
It is possible to display by including the dimensional tolerance in the width of the contour line forming the figure. Further, in the above-mentioned embodiment, the shape of the component is rectangular for the sake of simplicity of explanation. However, even when the shape of the component is other than rectangular, the dimensional tolerance includes the width in the contour line forming the figure by the same method. It goes without saying that it can be displayed.

Although the CAD system sets the dimensional tolerance and performs the display and the interference check in the above embodiment, the dimensional tolerance required in the actual product design depends on the kind of parts and the line segment length. Since it is different, the designer may set the tolerance. Hereinafter, a processing method in which the designer specifies the dimensional tolerance will be described with reference to FIGS. 6 and 7. FIG. 6 is a diagram showing a processing flow in the CAD system, and FIG. 7 is a diagram showing a blank tolerance table 5 according to dimensional tolerances and line lengths required for drawing parts. First, the tolerance table 5 will be described. This table shows (I) (II) (III)
Is the degree of tolerance required by the type of part. For example, (I) is the tolerance of parts that require precise machining accuracy, and (II)
Is a tolerance that requires normal processing accuracy, and (III) is a tolerance that does not require so much processing accuracy, such as a rubber foot. For example, a part that requires precise processing accuracy is 4 mm long
While the following tolerance is ± 0.1 mm, it shows that the tolerance of parts of the same length that does not require so much machining accuracy is ± 0.3 mm.

The process flow in the CAD system will now be described. In this process procedure, the operator draws a figure using the stylus pen (step 61).
Next, the reference line is set, for example, line segment A in the example of part B in FIG.
D is drawn (step 62), and then the specified tolerance value is input from the keyboard or the like with reference to the tolerance table of FIG. 7 (step 63). When this tolerance value is input, the CAD system calculates the dimensional tolerance of the line segment AD using the above-mentioned mathematical expression, and displays the contour line including the tolerance range in the line segment width (step 65). Similarly, line segments AB and B
Drawing of C and DC or an outline including a tolerance range is displayed, and a graphic display including a dimensional tolerance is performed as in the case of component a shown in FIG. 5, for example. Similarly, a graphic display including a dimensional tolerance is also performed for component B. To do. Further, as in the above-described embodiment, the apparatus checks the interference of each component for each projection surface, and when the interference is detected on any of the projection surfaces, the operator is given a warning display to that effect. This warning may be a warning sound or a color display. By the graphic display including the dimensional tolerance, the operator can easily visually confirm whether or not the input plural graphics interfere with each other, and the interference check can be performed by the apparatus itself as in the above-described embodiment. it can.

Although all the tolerance values may be displayed on the outline of the displayed graphic, if all the tolerance values are displayed, the drawing becomes complicated, so that only a specific tolerance value is displayed. good. Further, in the above example, the case of inputting the tolerance value with the keyboard has been described, but the blank tolerance table 5 is displayed on a part of the display unit and the operator inputs the designated tolerance value with the stylus pen. You can also do it.

[0030]

As described above, according to the graphic display method of the present invention, by displaying the width of the graphic outline line segment with the width including the dimensional tolerance, it is possible for the operator to visually check whether or not the graphics overlap each other. It is possible to prevent interference caused by not taking into consideration the dimensional variation of parts. Further, according to the graphic display method according to the present invention, the graphic processing system checks the interference, which is the overlap for each of the projection views of the outline line segments of the multi-component graphic, and warns the operator when the interference is detected. The operator can be easily alerted to further prevent interference.

[Brief description of drawings]

FIG. 1 is a diagram for explaining a graphic input method.

FIG. 2 is a front view of a display screen.

FIG. 3 is a front view of a drawn component.

FIG. 4 is a diagram showing a display example in which a dimensional tolerance according to the present invention is included in a width of a contour line.

FIG. 5 is a diagram showing a display example of a component including a dimensional tolerance in the width of an outline according to the present invention.

FIG. 6 is a flowchart showing a graphic drawing and dimensional tolerance input procedure according to an embodiment of the present invention.

FIG. 7 is a diagram showing an example of a tolerance table applied to this embodiment.

FIG. 8 is a diagram showing a configuration of a CAD system according to the present embodiment.

[Explanation of symbols]

1 ... Grid, 2 ... Stylus pen, 3 ... Graphic, 4 ... Display screen, 5 ... Tolerance table, 6 ... Display part, 7 ... Display control part, 8 ... Screen frame buffer memory, 9 ... Coordinate conversion part, 10 ... storage unit, 11 ... microprocessor, 12 ... input signal, 1
3 ... Transparent tablet, 14 ... Drawing point.

Claims (2)

[Claims] 1. A graphic display method of a graphic processing system for displaying a plurality of graphics on a display unit, wherein a dimension tolerance value of a contour line segment of the graphic is calculated, and a width of the contour line segment of the graphic is calculated as a dimension tolerance. A graphic display method characterized by displaying with the included width. 2. A graphic display method of a graphic processing system for displaying a plurality of graphics on a display unit, wherein a dimension tolerance value of an outline line segment of the graphic is calculated, and a width of the outline line segment of the graphic is calculated as a dimension tolerance. A graphic display method characterized by displaying an included width and checking for interference, which is an overlap between projections of contour lines of multiple component graphics, and alerting the operator when interference is detected.