JPH0133298B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field The present invention relates to a technique for finishing a curved surface of a press mold (workpiece) in press working, and more particularly to a method and apparatus for displaying mold deviation.

Prior Art In conventional press mold manufacturing, curved surfaces are finished by combining a model copied from a master (original model) with the workpiece. That is, the red glaze is applied to the surface of the model facing the workpiece, and by pressing the model and the workpiece together, the red glaze is adhered only to the protruding portions of the workpiece. This red shavings adhesion area is called the red contact area, and can be regarded as the area where there is a grinding allowance for the model. Skilled workers use a grinding tool to gradually finish the red contact area until there is no grinding allowance.

However, this conventional finishing only indicates that the red contact area is relatively sharp compared to other areas, and does not indicate the required amount of grinding as a numerical value. Therefore, the work must depend on the experience and skill of the operator, depending on the shape of the model and the red contact state of the entire workpiece. Therefore, it was difficult to finish with high precision. In addition, the worker visually checks the red contact area between the mating model and the workpiece, performs manual finishing using a grinding tool, and sequentially matches the workpiece shape to the reference model shape, so until the work is completed. requires a lot of man-hours.

In order to solve the drawbacks of the prior art, in the first application of the present application, the present applicant has developed a computer-based method for designing the standard shape of a workpiece, such as the exterior or body of an automobile, by press working. By comparing the calculated data with the data actually measured from the workpiece, the deviation between the two is calculated, the deviation is displayed in color on the display or on the workpiece, and the workpiece is finished according to the surface. We are proposing a technology that does this. According to this technique, the deviation from the reference shape can be expressed as a specific numerical value. Therefore, even if an operator is not skilled, he or she can accurately know the deviation and finish the mold quickly and reliably.

However, in the prior art, when actually measuring a press die, there is a problem in that deviation measurement cannot be performed correctly when the press die is tilted due to foreign matter such as dust on the surface plate on which the die is placed. That is, due to the inclination of the press mold, the measured data is data in a coordinate system different from that of the reference data, and even if the difference processing between the measured data and the reference data is performed, it is not possible to determine the correct deviation. In other words, it is impossible to determine whether the displayed deviation is due to the convex shape of the measured object being inclined with respect to the reference data, or whether it is caused by the unevenness of the measured object. It was difficult to evaluate the overall shape.

Problems to be Solved by the Invention The present invention has been made in view of the problems of the prior art, and even if the object to be measured is inclined with respect to the coordinates of the reference shape data, the reference data and measurement data can be The objective is to provide technology that can accurately grasp the deviation of

Means for Solving Problems The workpiece deviation display method according to the present invention stores reference shape data at multiple points of a workpiece to be finished, and changes the shape of the workpiece to points corresponding to the collection points of the reference data. , and calculate the deviation between the reference data and the actual measurement data at each point.
The color tone corresponding to the deviation of each point is displayed on the screen along with the contour shape of the workpiece, and the deviation that corrects the workpiece inclination is calculated and displayed from the inclination of the workpiece that is grasped from the tendency of the color tone as a whole on the screen. This consists of displaying the deviation. As shown in FIG. 1, the workpiece deviation display device according to the present invention includes a storage means 1 for storing reference data of the workpiece at a plurality of points, and an actual measurement of the workpiece at each point corresponding to the plurality of points. means 2 for measuring shape data; means 3 for calculating the deviation between reference data and actual measurement data of the workpiece at each point; and displaying the deviation together with the outer diameter of the workpiece in a color tone corresponding to the degree of deviation. a display means 4 for displaying a cursor on the display; a cursor moving means 6 for moving the cursor in a desired direction; means 7 for setting and inputting appropriate correction parameters for the reference data to eliminate the inclination of the workpiece at a plurality of points on the display designated by the cursor, and correcting the deviation using the input correction parameters. , means 8 for correcting the tone of the deviation displayed on the display screen.

Effects According to the method of the present invention, the coordinate system of the reference data is corrected according to the inclination of the workpiece, thereby making it possible to match the coordinate systems of the workpiece and the reference data. Therefore, accurate deviation measurement can be performed.

According to the device of the present invention, a cursor is displayed on the display, a plurality of points on the display screen are designated by an interactive method, the amount of coordinate correction due to the inclination of the workpiece is input, and from that value, each of the reference data is Calculating coordinate correction parameters. Therefore, the reference data coordinates are corrected to match the workpiece coordinates according to the inclination of the workpiece. Therefore, the deviation of the workpiece is accurately displayed on the display screen.

Embodiment In FIG. 2 showing the overall system configuration of the present invention, numeral 10 indicates a three-dimensional measuring machine as a whole, which has a base 12, on which a press die 14, which is a workpiece to be measured, is installed. Ru. There is a carrier 18 on the carriage 16, and attachment 1
9, the sensing end is attached as described below.
The carriage 16 is placed in a direction perpendicular to the plane of the paper, and the carrier 18
can be independently moved on the carriage 16 in the horizontal direction in the figure, and the attachment 19 can be independently moved in the vertical direction with respect to the carrier 18, thereby making it possible to perform three-dimensional measurements of the mold.

22 is a main computer that controls data input, controls the operation of the coordinate measuring machine, and also controls the display, and includes a central processing unit (CPU) 24 and a read-on memory (ROM) 2.
6. It is equipped with a random access memory (RAM) 28. The CPU 24 is connected to an interface 32 via a line 30, and the interface 32 controls the exchange of signals between the coordinate measuring machine 10 and the CPU 24. The CPU 24 is connected to an input device 34 such as a keyboard and a color display 36. The CPU 24 is further connected to an external storage device 38 such as a magnetic disk device. ROM2
4 contains a CPU that implements the flowchart described below.
24 control programs are stored, and the same
In accordance with this control program, the CPU 24 inputs data from the input device 34, performs mold measurement using the coordinate measuring machine 10, and displays deviations in color using the color display 36.

The three-dimensional measuring machine 10 has a sub-computer 4 for control.
0, and is connected to the main computer 10 via the interface 32. Similar to the main computer 22, the sub computer 40 also has a CPU 41,
It is composed of ROM42 and RAM43.

Next, the principle of contour line display of mold deviation in the present invention will be explained. In the three-dimensional coordinate system in FIG. 3, 200 is a shape (master) that is the prototype of the article to be manufactured. Each point p on this curved surface 200
can be specified by its coordinates x, y, z, and the curvature of the point p can be specified by each component i, j, k of a unit vector (vector perpendicular to the plane) N in the normal direction. If this article is an automobile part, the shape is determined by the appearance of the automobile or the design of the body. In this section, such a design is performed using an electronic computer. In any case, there is data that is used as a master when press-molding a certain part based on the exterior or body design of the automobile, and this data is stored in a computer.

In FIG. 4, 200 is such a master shape, and 200' is an actual workpiece. Now, regarding the comparison between the reference shape 200 and the workpiece shape 200', it is necessary to know the deviation between the two. In the present invention, a concept is adopted in which each point p ₁ , p ₂ , p _{3 ,} . That is, the sensing end 20 provided on the three-dimensional measuring machine is driven along a perpendicular vector N to each point (for example, p ₁ ) on the reference data shape 200, and the coordinates (x _' , y ′, z′). The deviation Δ1 is calculated from the coordinates of this point u ₁ and the coordinates of the point p ₁ on the master shape. For example, take the root mean square of the coordinates of points p ₁ and u ₁ ,
It is possible to convert each point into a scalar as a distance from the origin, and use the difference as a deviation. That is, the deviations Δ ₁ , ₂ , … _o are Δ ₁ , ₂ , … _o =√ ² + ² + ² −√′ ² +′ ² +′
² ...(1).

In this way, each point on the reference data shape 200
Actual shape 2 in the perpendicular direction for p ₁ , ₂ ,...n
The deviation with respect to the corresponding points u ₁ , ₂ , . . . n on 00 is calculated. The deviation calculated at each point is displayed at a predetermined position on the curved surface together with the workpiece outline on the color display 36 (FIG. 6). The operator can perform finishing appropriately by numerically determining the deviation based on the displayed color.

However, since the workpiece 200 is placed on the base 12 of the coordinate measuring machine and subjected to measurement, if the workpiece is tilted due to the presence of foreign matter such as dust, accurate measurement becomes impossible. That is, in FIG. 5, which shows the workpiece curved surface 200' and the reference shape curved surface 200 in FIG. 4, for example, if the workpiece is inclined by θ in the However, depending on the inclination of the workpiece, it takes a shape of 200". Therefore, the standard shape 2
The deviation from 00 is Δ ₁ −Δ ₁ ′, Δ ₂ −Δ ₂ ′, ...Δ _o −Δ _o ′
Errors like this are introduced. In the present invention, in order to eliminate errors caused by the inclination of the workpiece, the operator determines the inclination state of the workpiece while looking at the display screen, and interactively corrects the coordinates of the reference plane according to the inclination state using the keyboard. There is. That is, deviations are displayed in different colors depending on their magnitude, but if the workpiece is tilted, the tendency of the tilt can be understood from the color distribution on the screen. Then, by specifying three points on the screen and appropriately setting the amount of correction thereof, it is possible to calculate the coordinate correction parameter of the reference data due to the inclination. The method of such correction will be explained with reference to FIG. In FIG. 6, 50 is the outline of the workpiece, and deviations are displayed in colors depending on their magnitude. In the figure □＼,
□・, □×, ■, □/ are points of respective colors, and the deviations are assumed to decrease in this order. In this figure, the color display of the deviation has a regular tendency from small to large, which can be attributed to the work being tilted from the lower left to the upper right. In other words, the display screen corresponds to the x, y plane, and the degree to which the x, y plane of the workpiece is inclined relative to the x, y plane of the reference data is determined by the color on the screen. be able to. In other words, by specifying ω ₁ , ω ₂ , and ω ₃ for three points on the display, how much should each point be moved in the z direction perpendicular to the display screen to obtain the reference data relative to the tilt coordinate of the workpiece? It can be determined whether the coordinates can be matched. In this case, the three points w ₁ , w ₂ , and w ₃ can be selected from any three appropriately spaced points on the display screen, and in reality they are selected at positions outside the outline of the workpiece. , theoretically any point on the display screen is fine. In other words, since the display screen corresponds to the XY plane, by taking three appropriately spaced points at any point on the screen, each point determines the amount of coordinate transformation that can correct the inclination exactly. This is because there is a Z coordinate at . That is, FIG. 7 schematically shows such coordinate alignment, where the broken lines are the original coordinates, and the three points ω ₁ ,
The coordinates shown are converted into coordinates represented by solid lines by correcting ω ₂ and ω ₃ by 0, +1, and +2, respectively.

Once the amount of movement of the three points in the z direction is determined in this way, it is easy to convert this into a corresponding amount of movement parameter in the x, y, z coordinate system of the reference data, and this If the deviation is calculated again after correcting the reference data coordinates from the parameters, an accurate deviation calculation result can be obtained that corrects the error caused by the inclination of the workpiece.

Next, software for realizing the principles of the present invention as described above will be explained using a flowchart. A program for realizing this flowchart is stored in the ROM 26, 42 of the computer 22, 40.

FIG. 8 shows the main routine of the main computer. This routine enters execution at step 300, and at 302 the internal registers of the CPU 24,
RAM28 etc. are initialized, then CPU2
4 performs a command check from the keyboard 34, and executes each subroutine process from the keyboard 34.
This will be done in response to the command from 4.

The first process is press-type measurement, and the workpiece 14 to be measured is placed on the base 12 of the coordinate measuring machine 10. As explained in Figs. 3 and 4, the measurement of the workpiece is performed using each point p(x,
y, z) from the direction N perpendicular to the plane of that point. The coordinate values (x, y, z) and the components (i, j, k) of the perpendicular vector for each point p are stored in advance in the storage area 3 of the storage device 38 by a database computer.
8a. keyboard 3
The CPU confirms that there is a press type measurement command from 4.
When detected, the measurement at step 304 in Figure 8 is
If Yes, the program proceeds to 600 and calls the press mold measurement routine shown in FIG. When this routine starts, in step 601 the CPU 24 asks the interface 32 whether the coordinate measuring machine 10 is capable of measurement.
Judgment will be made based on the content. That is, the subcomputer 40 for the three-dimensional measuring machine writes a flag f of "1" or "0" in one bit of the interface 32, indicating whether or not measurement is possible. The CPU 24 can make the determination 601 by looking at the flag f. The process waits until a measurable flag is output from the three-dimensional measuring machine 10, and if Yes, the process proceeds to 602. 602, storage area 3 of external storage device 38
The coordinate values ₍ x, y,
z) and the component values of the perpendicular vector N (i, j, k)
is imported. In the next step 604, a measurement operating point is calculated. That is, the detection end 2 of the coordinate measuring machine
0 is once lowered from point q ₁ to point q ₂ on the surface perpendicular vector N at the selection point p ₁ of the master shape, and then driven in the direction of the surface perpendicular vector to point q ₃ inside the master shape 200, and press After contacting the mold 200 (point u ₁ ), it rises to q ₄ to complete the measurement of one point p ₁ on the press mold, which is the object to be measured. Each operating point q ₁ - q ₂ - q ₃ of such a series of sensing ends 20
- The calculation of q ₄ will be performed in 604 steps.

At 606, the operating point data calculated at 604 is sent to the interface 32. The three-dimensional measuring machine has the program shown in FIG. 12, and performs a loop until writing of the measurement operating point is completed. When reading becomes possible, the program advances to step 904 and transfers the data to the RAM 43. Proceed to step 906 and read the read data, i.e. the operating point.
Driving of the sensing end 20 is started according to q ₁ - q ₂ - q ₃ - q ₄ . When the sensing end 20 comes into contact with the workpiece (that is, when it comes to the _u1 point), the answer is 908, ``Yes'', and the data of the coordinates x', y', z' at that time are written to the interface 32, at 910. At the same time, a flag f' is written to the interface 32 indicating that the work has been contacted. When the detection end 20 reaches the final point (q ₄ ), the determination in 907 becomes Yes, and a permission command for measurement of the next point of the reference data is issued in 912. On the other hand, the main computer performs a loop in step 608 while constantly checking the presence or absence of this flag f'. When it comes into contact with the workpiece, the flag changes, so the judgment of 608 changes to Yes,
Proceed to step 610. At 610, the coordinates u ₁ (x', y', z') of the press mold at that time are read from the interface 32 as data. CPU in 612 steps
24 stores the read data in the second storage area 38b of the external storage device 38. In step 614, all points of the master shape (200 in Figure 7)
The contact points _{u 1 , 2 ,} .
It is determined whether the measurement of n(x', y', z') is completed, and if Yes, this routine ends at 616.

In the main routine of FIG. 8, when a deviation display command is input from the keyboard 34, 306
The result is Yes, and the subroutine shown in Figure 10 starts executing from step 700, and the CPU 2
4, the outline data of the workpiece in the workpiece reference data stored in the storage area 38a of the external storage device 38 is taken into the RAM 28 (step 4).
701). In the next step 702, this imported outline data is transferred to the video RAM address corresponding to the display coordinates on the screen of the display 36, and as a result, as shown in FIG.
0 is displayed. In the next 704 steps, the CPU
24 is one point of the master shape 200 (for example, the fourth
p ₁ ) and one point of the corresponding workpiece shape 200' in the direction of its perpendicular vector N ₁ (for example, u ₁ in FIG. 4)
and coordinate data are imported. In the next step 705, the coordinates x, y, and z of the basic data are corrected by the workpiece inclination correction parameters δ _x , δ _y , and δ _z . These correction parameters δ _x , δ _y , and δ _z are calculated by modifying the 3-point z value, which is input interactively by the operator while looking at the color deviation display on the display, as described later. Initially, δ _x , δ _y ,
Note that δ _z =0 is set.

In Figure 10, in the next step 706, the point
The difference between the coordinate values of p ₁ and u ₁ is scalarized as the difference between the root mean square values Δ ₁ (Equation (1)). In the next step 708, the color data is converted into color data representing the magnitude of the deviation according to the magnitude of this difference. For example, depending on the size of the deviation, red□＼
→Yellow□・→Green□×→Blue■→White□/etc. In step 710, the color data is stored in RAM.
28 color data areas. RAM28
This area corresponds to the color of the display coordinates on the display screen, and by setting a predetermined value in the RAM 28, that color will be displayed as shown in FIG. In 720, all points p ₁ , ₂ ,...n of master data
The deviation calculation and color display are repeated, and if it is determined that all points have been completed, this routine ends.

FIG. 6 schematically shows the display screen in a state where the deviation color display has been completed for all points of the reference data. □\, □・, □×, ■, □/ are different colors corresponding to the size of the deviation, for example 2.5mm,
They are 2mm, 1.5mm, 1mm, and 0.5mm. Normally, this indicates that there is an error in the size of each color between the workpiece and the master, but as explained in Figure 5, if the workpiece is tilted on the surface plate, the tilted amount will also be displayed. Since the deviation is calculated including this, it is necessary to subtract the slope from the calculation. By the way, deviations caused by the unevenness of the workpiece relative to the master occur at random locations on the workpiece surface, whereas inclinations occur regularly, so deviations can occur due to their respective causes. Deviations are discernible. Looking at the schematic display in Figure 6, the magnitude of the deviation changes regularly from a large value to a small value on the screen, and the workpiece is tilted from the bottom left to the top right of the step. is estimated. Since the color on the screen corresponds to the size of the deviation, the three points ω ₁ on the screen,
By specifying ω ₂ and ω ₃ , it is possible to determine how much the height at each point (in this case, the height in the z direction) needs to be corrected in order to match the standard data coordinates to the tilted workpiece. can.

At step 308 in Figure 8, when a coordinate correction command is input from the keyboard 34, the process branches to Yes.
A processing routine shown in FIG. 11 is called for matching reference data coordinates with inclined workpiece coordinates using an interactive method. 800 indicates the start of this routine, and 802 the CPU displays a cursor on the display screen. In the next 804, keyboard 34
Determine whether the upper cursor movement key is pressed. If Yes, branch to 806 and move the cursor. The cursor is moved to the correction point ω ₁ of the z value selected by the operator on the display screen as described in FIG.
This continues until the cursor comes to one of ω ₂ and ω ₃ . If the cursor movement key is not pressed at 804, advance to 808, and the cursor point at that time is z.
Determine whether the value is one of the correction points. If Yes
The process advances to 810 and an x mark is displayed on the screen (see Figure 6). In 812, there are three points ω ₁ , ω ₂ , which are the correction points of the z value.
Determine whether ω ₃ is displayed. If No, repeat the above process.

If it is determined Yes in step 812, then in step 814, the correction amounts z ₁ , z ₂ , z ₃ are calculated for the three selected points.
It is determined whether or not is input. If No, go to 816 and enter the data from the keyboard 34 (i.e., 0mm, +1mm, +2mm in the example in Figure 6)
is input. In step 818, input z ₁ ,
x in the standard shape data from the data of z ₂ and z ₃ ,
Correction parameters δ _x , δ _y , and δ _z for each y and z coordinate are calculated. That is, each point on the display screen is located on the x, y plane (sixth point) at the coordinates of the reference data.
(see figure). Move three points ω ₁ , ω ₂ , ω ₃ on the x, y plane to z ₁ in the z direction perpendicular to that plane,
When the coordinate system is tilted by moving z ₂ and z ₃ , the amount of deviation δ _x , δ y , and δ _z of each of the x, _y , and z components of the coordinate system is calculated.

After the correction parameters have been calculated in this manner, when a deviation display command is input from the keyboard 34, the subroutine call shown in FIG. 10 is performed again, and deviation display is started from step 700.
In step 705, δ _x , δ _y , and δ _z are calculated from the input correction values z ₁ , z ₂ , and z ₃ according to the inclination of the workpiece according to the routine shown in FIG. .
Therefore, the coordinates x, y, z of the reference data match the coordinates of the inclined workpiece. Therefore, the difference result calculated in 706 does not include the influence of the tilt of the workpiece. Therefore, in step 710, the difference between the workpiece measurement data and the reference shape data, that is, the deviation caused only by the workpiece unevenness, is accurately displayed on the display screen.

The operator then finishes grinding the workpiece according to the displayed deviation, and this finishing operation is maintained until the deviation disappears.

Effects of the Invention According to the invention, since the reference data coordinates are corrected according to the inclination of the workpiece, it is possible to accurately detect the irregularities of the workpiece. Conventionally, when a workpiece is tilted, re-measurement is performed, but the present invention eliminates the need for re-measurement, and enables quick and reliable shape evaluation.

[Brief explanation of drawings]

FIG. 1 is a diagram showing the configuration of the present invention, FIG. 2 is a block diagram of the control computer, FIG. 3 is a diagram explaining the configuration of reference data, FIG. 4 is a diagram explaining press mold measurement, and FIG. The figure is a diagram explaining the causes of errors in measurement data when the workpiece is tilted.
Fig. 6 is a diagram showing the color display of deviation on the display screen, Fig. 7 is a diagram explaining how to correct coordinates due to the inclination of the workpiece, and Figs. 8 to 12 are flow charts showing the software of the present invention. Chart diagram, 10... Three-dimensional measuring machine, 14... Press mold, 20...
Sensing end, 22...Main computer, 32...Interface, 38...External storage device, 40...Subcomputer.

Claims (1)

[Claims] 1. Memorize reference shape data at multiple points of a workpiece to be finished, measure the shape of the workpiece at points corresponding to the collection points of the reference data, and determine the reference shape data at each of those points. The deviation between the data and the measured data is calculated, and the color tone corresponding to the deviation at each point is displayed on the screen together with the contour shape of the workpiece. A workpiece deviation display method consisting of calculating the corrected deviation and displaying the corrected deviation. 2. A workpiece deviation display device consisting of the following elements: (a) A storage means for storing reference data of the workpiece at multiple points; (b) Actual measurement of the workpiece at each point corresponding to the plurality of points to measure its shape data. (c) A means for calculating the deviation between the standard data and the measured data of the workpiece at each point; (d) A display means for displaying the deviation together with the outer diameter of the workpiece in a color tone corresponding to the degree of deviation; (e) A display. (f) A cursor moving means for moving the cursor in a desired direction; means for setting and inputting appropriate correction parameters for reference data that eliminate the inclination of the workpiece at multiple points; (h) correcting the deviation according to the input correction parameters; A means of correcting the color tone.