JP3433486B2 - Geometric deviation calculator - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for calculating a geometric deviation, and is used, for example, in the evaluation of a geometrical tolerance given to a shape element of a mechanical part in the inspection of the part.

[0002]

2. Description of the Related Art When inspecting whether or not a partial shape element of a mechanical part satisfies a required function, the geometric deviation of the shape element is calculated and compared with a given allowable value to make a judgment. To do. At this time, the target of calculation of the geometric deviation is the entire actual shape of the shape element, but when using a coordinate measuring machine that is currently popular, it is time-consuming to measure the entire shape element. Is difficult from. Therefore, in general, coordinate values are sampled in a realistic range, real shape data having an infinite area is created from the obtained coordinate values by a shape evaluation algorithm, and the area specified for the real shape data is set. The geometric deviation is calculated based on the above.

FIG. 7 is a diagram for explaining a conventional technique. The side lengths Lx and Lz of the figure forming the rectangular area S1 and the respective directions are given to the actual shape data A1 created from the measured data of the shape elements, and this area S1 is used as the geometric deviation calculation target. The values of the lengths Lx and Lz are input by a keyboard or the like, and the respective directions are set in advance with an appropriate coordinate system C for the actual shape data A1 and the coordinate axes thereof are designated (X in FIG. 7). Axis and Z axis)
Etc.

[0004]

However, the work efficiency is low in the above method. Also, since it is difficult to specify the shape element area for shape elements other than rectangles, the geometric deviation calculated by the above method is compared with the geometric tolerance value given for the shape element. Therefore, it is not possible to judge the correctness of the processing.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a geometric deviation calculating apparatus capable of efficiently defining an applicable area according to a given geometrical tolerance.

[0006]

In order to solve the above-mentioned problems, the invention according to claim 1 is C which shows the shape of the work.
Display means for displaying AD data, and the displayed CA
Designation means for designating a boundary element that limits the area of the measurement point where the geometric deviation is measured for the D data;
First to store CAD data of the specified boundary element
A configuration is provided that includes a storage unit, a second storage unit that stores actual shape data obtained by actually measuring the measurement location, and a unit that calculates a geometric deviation from the first and second storage units. .

According to a second aspect of the present invention, a C indicating the shape of the work is shown.
Display means for displaying AD data and the displayed CA
Designation means for designating a boundary element that limits the area of the measurement point where the geometric deviation is measured for the D data;
First storage means for storing actual shape data obtained by actually measuring the boundary element, second storage means for storing actual shape data obtained by actually measuring the measurement location, and the first and second And a means for calculating the geometric deviation from the storage means.

[0008]

According to the present invention, the operator does not have to recognize the size of the region of the target shape element as a numerical value, and the operation procedure is simplified. Further, it is possible to deal with a shape element having a complicated outer shape, and it is possible to calculate a geometric deviation that can be determined as right or wrong by comparing with a given tolerance.

FIG. 1 is a block diagram of the principle of the present invention. The display means 10 displays the CAD data of the work. The display control means 12 controls the display means 10. Designating means 11
Specifies the shape element for which the geometric deviation is calculated in the CAD data displayed on the display unit 10 and the boundary element that limits the area for the shape element. Figure 3 is CA
It is a figure which shows the example of D data. This CAD data includes shape elements 50 that are geometrical deviation calculation targets, boundary elements 51 to 55 that limit the boundaries of regions, and shape elements 50 to 55.
Including design shape data corresponding to.

FIG. 4 is an explanatory diagram of the boundary element. Figure 4
In the example of (a), the plane elements 33 to 37 are the boundary elements for the plane element 32 whose area is limited. 32 'in the figure
˜37 ′ are plane shape data corresponding to the plane elements 32 to 37, respectively, and the plane shape data is defined by one point on the plane and a normal vector. The plane shape data 32 'is actual shape data created from the actual measurement data of the plane element 32, and the plane shape data 33' to 37 '.
Is actual shape data or design shape data of the plane elements 33 to 37. Real shape data 32 'and shape data 33'
Region 38 is defined by computing the intersection with ~ 37 '. In addition, FIG. 4B is an example in which the region is limited to the cylindrical axis element, and the actual shape data 39 ′ of the cylindrical axis element 39 which is the target of the geometric deviation calculation and the boundary elements 40 and
The area 42 is defined by the shape data 40 ′ and 41 ′ of one.

In FIG. 1, the first storage means 13 stores the shape data of the boundary element. Second storage means 1
Reference numeral 4 stores the actual shape data of the geometrical deviation calculation target shape element. The geometric deviation calculation means 15 defines a region from the shape data of the boundary element read from the first storage means and the actual shape data read from the second storage means, and calculates the geometric deviation.

[0012]

FIG. 2 is a block diagram of a geometric deviation calculating apparatus according to an embodiment of the present invention. The drawing conversion unit 21 receives the CAD data of the work for which the geometric deviation is calculated from the CAD system 20 in a standard format such as IGES, converts it into the CAD data used in the geometric deviation calculation device 31, and a CAD data file. Store in 22. The CAD data is displayed on the display 30 by the display control unit 26. The actual shape data corresponding to the geometric element and the boundary element for which the geometric deviation is calculated is created by the actual shape data creation unit 24 from the coordinate value data (shape measurement point sequence data) 23 measured by the coordinate measuring machine, It is stored in the shape data file 25. Memory 27
Corresponds to the first and second storage means 13 and 14 in FIG. 1, and reads the actual shape data stored in the actual shape data file 25. The mouse 29 corresponds to the designating means 11 in FIG. 1 and designates the shape element and the boundary element for which the geometric deviation is to be calculated in the CAD data displayed on the display 30. The processing unit 28 uses the shape data stored in the memory 27 to perform a region definition process and a geometric deviation calculation process. This corresponds to the geometric deviation calculation means 15 in FIG.

A method of defining an area in the geometric deviation calculating device having the above-mentioned configuration will be described. FIG. 5A shows shape data, and FIG. 5B shows a state in which the shape element is displayed on the display. First, on the display screen D, a pointer M whose display position is controlled by the mouse 29
The shape element A2 is designated by and the real shape data A2 ′ corresponding to the shape element A2 is read from the memory 27. This real shape data A2 ′ has an infinite area, and it is necessary to define the area in order to calculate the geometric deviation.

Next, for the shape element A2, the boundary elements B1 to B5 that limit the area where the geometric deviation is to be calculated are designated by the pointer M, and the shape data B1 'to B5 corresponding to the respective boundary elements B1 to B5. 'Is read from the second storage means (memory 27). As the shape data B1 ′ to B5 ′ read here, data created by several methods can be used. One is CAD data 22
Is the design shape data corresponding to the boundary elements B1 to B5 included in the above, and this is the plane shape data defined by one point on the plane and the normal vector. Another example is the actual shape data created by the actual shape data creating unit 24 from the measured data corresponding to the boundary elements B1 to B5, which is defined in the same format as the design shape data. In particular, when this real shape data is used, the area S2 is defined as an area more suited to the real shape area corresponding to the shape element A2.

Next, a method of calculating the geometric deviation will be described. First, for the shape data of the specified shape element, the area for which the geometric deviation is calculated is given from the shape data corresponding to the boundary element. That is, the real shape data A2 ′ defined by one point on the plane and the normal vector
And shape data B1 'to B5' defined in a similar format
Intersection lines L1 to L5 are calculated, and the coordinate values of the vertices P1 to P5 of the polygon formed by the intersection lines L1 to L5 are calculated. The points P1 to P5 calculated by this processing are all points on the real shape data A2 ', and the region can be defined by these coordinate values, and the target geometric deviation can be calculated. The calculated geometrical deviation can be displayed on the display 30 and compared with the geometrical tolerance value given to the geometrical element A2 to judge the correctness of the finish of the geometrical element.

In the present embodiment, only the case where both the geometric deviation calculation target element and the boundary element are planes have been described, but the present invention can also be applied to combinations of other shape elements. That is, when the target element is a straight line and the boundary element is a plane, the method of calculating the region is to calculate the end points of the straight line divided by the two planes. Further, in FIG. 5, the boundary elements B1 to
When B5 has real shape data as straight line elements, a plane including each straight line and perpendicular to the shape element A2 can be calculated and used as shape data B1 ′ to B5 ′.

A flow chart of the operation of the apparatus according to the embodiment described above is shown in FIG. First, the geometric element for which the geometric deviation is calculated and the boundary element of the geometric element are displayed on the display (43). The geometric element for which the geometric deviation is calculated is designated by the mouse (44). The shape data corresponding to the shape element designated at 44 is read from the second storage means 14 (45). The boundary element displayed at 43 is designated by the mouse (46). The shape data corresponding to the boundary element designated at 46 is read from the first storage means 13 (47). From the shape data read in 45 and 47, the area for calculating the geometric deviation is calculated (48). The geometric deviation is calculated from the area calculated in 48 (49).

As described above, according to this embodiment, the area for calculating the geometric deviation can be defined and the given allowable tolerance can be defined only by designating the display element by the designating means such as the mouse. It becomes possible to calculate the geometric deviation that can be determined as correct by comparing with.

[0019]

As described above, according to the present invention,
The shape element displayed on the display means is designated, and the area of the target shape element is defined by an internal calculation using the shape data corresponding thereto. As a result, the operator does not need to be aware of the size of the area as a numerical value, and the operation procedure is simplified. Further, it is possible to deal with a region of a shape element having a complicated outer shape, and it is possible to calculate a geometric deviation that can be judged as correct or false by comparing it with a given tolerance.

[Brief description of drawings]

FIG. 1 is a block diagram of the principle of the present invention.

FIG. 2 is a configuration diagram of a geometric deviation calculation device according to an embodiment of the present invention.

FIG. 3 is a diagram showing CAD data.

FIG. 4 is a diagram illustrating boundary elements.

FIG. 5 is a diagram showing a region defining method of the present invention. (A) shows shape data, and (B) shows CAD data displayed on the display device.

FIG. 6 is a flowchart of the operation of the geometric deviation calculation apparatus according to the embodiment of the present invention.

FIG. 7 is a diagram illustrating a conventional technique. (A) shows shape data, and (B) shows a view of (A) viewed from the Y-axis direction.

[Explanation of symbols]

10 Display means 11 designation means 12 Display control means 13 First storage means 14 Second storage means 15 Geometric deviation calculation means 26 Display control unit 27 memory 28 Processing Department 29 mice 30 display 31 Geometric deviation calculation device

─────────────────────────────────────────────────── ─── Continuation of the front page (56) Reference JP-A-7-77420 (JP, A) JP-A-63-206608 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) G01B 21/00 G06F 17/50

Claims (2)

(57) [Claims] 1. Display means for displaying CAD data indicating the shape of a work, and designation for designating a boundary element for limiting the area of a measurement point for which geometric deviation is measured with respect to the displayed CAD data. Means for storing CAD data of the specified boundary element,
Storage means; second storage means for storing actual shape data obtained by actually measuring the measurement point; and means for calculating geometric deviation from the first and second storage means. A device for calculating the geometric deviation. 2. Display means for displaying CAD data indicating the shape of a work, and designation for designating a boundary element for limiting the area of a measurement point for which geometric deviation is measured with respect to the displayed CAD data. Means, first storage means for storing real shape data obtained by actually measuring the boundary element, second storage means for storing real shape data obtained by actually measuring the measurement location, and first And a means for calculating the geometric deviation from the second storage means, the geometric deviation calculating device.