JP7026478B2 - Work inspection device and work inspection method - Google Patents

Description

The present invention relates to a technique for inspecting a work.

Conventionally, for workpieces such as cast products in which metal materials such as aluminum, zinc, and magnesium are cast with a mold, and resin molded products in which a resin material is molded with a mold, internal defects formed inside the work are non-destructive. Various devices for inspection have been proposed.

Patent Document 1 below discloses a technique for inspecting a cavities, which is one of internal defects, by photographing a cast product with an X-ray CT imaging device. This technique can inspect the cavities formed inside the casting regardless of its size by performing a specific filtering process on the 3D CT volume data obtained by CT imaging of the casting. Is to be.

Japanese Unexamined Patent Publication No. 2005-351875

By the way, it is known that the cavities generated inside the cast product include cavities caused by the structure of the casting die and cavities generated in response to minute changes in actual casting conditions. Has been done. When multiple castings are cast in the same mold, cavities generated in response to changes in casting conditions are randomly generated inside the casting, whereas cavities due to the structure of the casting mold are generated. Are concentrated in a generally common area inside the casting.

Therefore, if a plurality of samples cast in the same mold are photographed by the above-mentioned X-ray CT imaging device and the cavities included in the three-dimensional volume data obtained by the X-ray image can be accurately compared between the samples, cavities will occur. It is possible to associate the factors to be used with the structure of the mold. This makes it possible to reflect the occurrence of cavities in the structure of the mold, and the cost required for the development and improvement of expensive molds can be kept low.

However, it takes a lot of man-hours to manually aggregate the three-dimensional volume data of a plurality of samples and compare the cavities. Therefore, in order to keep the man-hours low, it is conceivable to combine the three-dimensional volume data of a plurality of samples on the system.

However, since the data capacity of the three-dimensional volume data per sample is large, it takes time to synthesize a plurality of three-dimensional volume data on the system. In particular, since a large number of samples are required to ensure the above association, it takes an enormous amount of time to synthesize the three-dimensional volume data of these samples on the system.
Therefore, it is difficult to compare the cavities between the samples within the limited development and improvement period of the mold. However, if the number of samples is reduced, the accuracy of the above association will be reduced, and it will be difficult to fulfill the original purpose of reflecting the occurrence of cavities in the structure of the mold.
Further, the above-mentioned defects can occur not only in a cast product obtained by casting a metal material with a mold, but also in a resin molded product obtained by molding a resin material with a mold.

The present invention has been made in view of the above problems, and is an object of the present invention to provide a work inspection technique capable of comparing internal defects of each of a plurality of works formed by the same mold in a short time. Is.

One aspect of the present invention is
A work inspection device (1 ) that inspects a plurality of workpieces (W) formed by the same mold (M).
A processing device (20 ) for processing each X-ray image (C) of the plurality of workpieces is provided.
The above processing device
A data extraction unit (23) that extracts internal defect voxel data (D2) related to internal defects (B, B1, B2) from the three-dimensional volume data (D1) obtained by the X-ray image.
The comparative image data (D3) obtained from the internal defect voxel data extracted by the data extraction unit for each of the plurality of workpieces is converted into the workpiece body data (Dw) showing the overall shape common to the plurality of workpieces. On the other hand, the data synthesizing unit (25) that synthesizes at the synthesizing position (P, P1, P2) which is the original position of the internal defect,
Based on the internal defect voxel data extracted by the data extraction unit, the same volume as the voxel aggregate from the digitized data (Dc) representing the voxel aggregates (A, A1, A2) constituting the internal defects. A data creation unit (24) that creates voxel data (Ds, Ds1, Ds2, Ds3) of a simple figure (S, S1, S2) having the above as image data for comparison.
Have,
The data synthesizing unit synthesizes the graphic voxel data created by the data synthesizing unit at the position of the center of gravity (G) of the voxel aggregate, which is the synthesizing position, with respect to the work body data. 1 ),
It is in.

Further, another aspect of the present invention is
It is a work inspection method for inspecting a plurality of workpieces (W) formed by the same mold (M).
Data extraction step (S10 6 ) to extract internal defect voxel data (D2) related to internal defects (B, B1, B2) from three-dimensional volume data (D1) obtained by X-ray images (C) of each of the plurality of workpieces. ) And
The comparative image data (D3) obtained from the internal defect voxel data extracted by the data extraction step for each of the plurality of works is applied to the work body data (Dw) showing the overall shape common to the plurality of works. The data synthesis step (S112 ) for synthesizing at the synthesis position (P, P1, P2) which is the original position of the internal defect, and
Based on the internal defect voxel data extracted by the data extraction step, the same volume as this voxel aggregate is obtained from the numerical data (Dc) representing the voxel aggregates (A, A1, A2) constituting the internal defects. A data creation step (S111) for creating voxel data (Ds, Ds1, Ds2, Ds3) of a simple figure (S, S1, S2) having as the above-mentioned comparative image data, and
Have,
In the data synthesis step, a work inspection method for synthesizing the graphic voxel data created by the data creation step at the position of the center of gravity (G) of the voxel aggregate, which is the synthesis position, with respect to the work body data .
It is in.

In the work inspection device or the work inspection method described above, internal defect voxel data relating to internal defects is extracted from the three-dimensional volume data obtained by the X-ray image of the work. The data capacity of this internal defect voxel data is smaller than that of the three-dimensional volume data of the work itself.
Therefore, compared to the case of synthesizing a plurality of three-dimensional volume data, the processing load when synthesizing the comparative image data obtained from the internal defect voxel data with the work body data on the system can be suppressed to a low level. .. Then, the occurrence status of internal defects can be compared among a plurality of works by comparing the comparison image data synthesized with respect to the work body data.
In this case, since the processing load for synthesizing the comparison image data is low, a series of processes from acquiring the X-ray images of each of the plurality of workpieces to comparing the internal defects contained in these X-ray images. Can be done in a short time.

As described above, according to the above aspect, it is possible to provide a work inspection technique capable of comparing the internal defects of each of a plurality of works formed by the same mold in a short time.
The reference numerals in parentheses described in the scope of claims and the means for solving the problem indicate the correspondence with the specific means described in the embodiments described later, and limit the technical scope of the present invention. It's not a thing.

The block diagram of the work inspection apparatus of Embodiment 1. FIG. The perspective view which shows the peripheral structure of the rotation base of the CT imaging apparatus in FIG. The flowchart of the work inspection method of Embodiment 1. The figure which shows typically the process of processing each X-ray image of a plurality of workpieces according to the flowchart of FIG. The figure which shows typically the 3D volume data by the X-ray image of a work. The figure which shows the voxel aggregate of the 1st cavities included in the 3D volume data of FIG. The figure which shows the voxel aggregate of the 2nd cavities included in the 3D volume data of FIG. The figure which shows the graphic voxel data created from the voxel aggregate of the 1st cavities of FIG. The figure which shows the graphic voxel data created from the voxel aggregate of the 2nd cavities of FIG. The figure which shows the appearance that a plurality of figure voxel data were combined with the work body data. FIG. 10 is a diagram showing a state in which voxels of each graphic voxel data are color-coded. The block diagram of the work inspection apparatus of reference form 1 . The flowchart of the work inspection method of reference form 1 .

Hereinafter, embodiments relating to the work inspection device and the work inspection method will be described with reference to the drawings.

In the drawings of the present specification, unless otherwise specified, the left-right direction of the work is indicated by an arrow X, the depth direction of the work is indicated by an arrow Y, and the height direction of the work is indicated by an arrow Z.

(Embodiment 1)
As shown in FIG. 1, the work inspection apparatus (hereinafter, also simply referred to as “inspection apparatus”) 1 of the first embodiment is an apparatus for inspecting a plurality of workpieces W formed by the same mold. In the present embodiment, the work W is assumed to be a cast product (die cast) made of a metal material such as aluminum, zinc, magnesium, and copper. A casting cavity B as an internal defect, which is a spatial defect, is generated in the work W during casting.

The inspection device 1 includes a CT imaging device 10, a processing device 20, an external storage device 30, and a display device 40.

The CT imaging device 10 is for photographing the work W using X-rays. The CT imaging device 10 rotates about the rotation axis L between the X-ray generator 11, the X-ray detector 12, and the X-ray generator 11 and the X-ray detector 12 for installing the work W. It has a rotating base 13 and a freely arranged rotation base 13. The CT imaging device 10 is also referred to as a "CT scanning device".

The X-ray generator 11 is a known device, and although the description of its structure is omitted, it is configured to generate X-rays by injecting electrons accelerated by a voltage into a metal. The X-ray detector 12 has a function of detecting X-rays, and is configured by an X-ray two-dimensional camera in the present embodiment. This X-ray two-dimensional camera is a flat panel detector (FPD) that uses CMOS, amorphous, or the like as a photographing element. The X-ray detector 12 is electrically and constantly connected to the processing device 20 via a connection means (not shown) such as an Ethernet (LAN) or a camera link.

In the CT imaging of the work W, the X-rays generated by the X-ray detector 12 pass through the work W installed on the rotation base 13 while being absorbed in energy, and then reach the X-ray detector 12. Then, the transmitted image at this time is detected by the X-ray detector 12. By performing CT imaging while rotating the rotation base 13, a plurality of two-dimensional X-ray images C can be obtained for one work W. These a plurality of X-ray images C are continuously transmitted from the X-ray detector 12 to the storage unit 21 of the processing device 20 via the above-mentioned connection means in the order in which they are photographed. This X-ray photographed image C can also be referred to as a "X-ray image" or a "X-ray photograph".

As shown in FIG. 2, it is preferable that the positioning jig 14 is attached to the rotary base 13. The positioning jig 14 is configured so that each of a plurality of workpieces W formed by the same mold M can be positioned at a common reference position Q. For this purpose, the positioning jig 14 includes a fixed leg 15 to which the rotation base 13 is fixed, a plate-shaped holding plate 16 arranged above the fixed leg 15, and is provided on the front surface of the holding plate 16. Is provided with two protrusions 17 for supporting the work W from below and two protrusions 18 that engage with the work W at a common reference position Q.

According to the positioning jig 14, for example, when the work W from the first work W1 to the nth work Wn formed by the same mold M is sequentially switched and CT imaging is performed, each work W is held. It can be easily positioned and set at the common reference position Q with respect to the plate 16.

Here, it is preferable that the holding plate 16 of the positioning jig 14 is configured to be inclined at an acute angle θ with respect to the vertical direction. According to this configuration, the work W set on the holding plate 16 is urged toward the front surface of the holding plate 16 by its weight, and is stably held by the holding plate 16.

Further, it is preferable that the positioning jig 14 is configured to be detachably attached to the rotation base 13 and is prepared for each type of work W. In this case, by replacing the positioning jig 14 as necessary, the positioning work of each work W can be easily performed when the work W is switched for each type and CT imaging is performed.

Instead of using the positioning jig 14 for positioning the plurality of works W, the absolute coordinates common to the plurality of X-ray images C may be specified in the processing on the processing device 20 side.

Returning to FIG. 1, the processing device 20 is configured by using a personal computer (hereinafter, referred to as “PC”) having a function of processing each X-ray image C of a plurality of work W.

In order to realize the function, the processing device 20 includes a storage unit 21, a reconstruction calculation unit 22, a data extraction unit 23, a data creation unit 24, a data synthesis unit 25, an overlap determination unit 26, and the like. It is provided with a hue setting unit 27. With respect to these elements constituting the processing device 20, a plurality of elements may be integrated into one element, or one element may be divided into a plurality of elements, if necessary.

The storage unit 21 has a function of temporarily storing a plurality of X-ray images C transmitted from the X-ray detector 12 of the CT imaging device 10. The storage unit 21 is composed of a memory on the motherboard of the PC. The processing device 20 is equipped with an external storage device 30 having the same function as the storage unit 21. The external storage device 30 is composed of at least one of a hard disk drive (HDD) and a solid state drive (SSD) having a capacity larger than that of the storage unit 21.

The reconstruction calculation unit 22 uses a CPU or GPU (image board) and CT reconstruction software to execute a reconstruction calculation for reconstructing a plurality of X-ray images C into three-dimensional volume data D1. It is configured.

The data extraction unit 23 has a function of extracting the cavities voxel data D2 relating to the cavities B, which is internal defect voxel data, from the three-dimensional volume data D1 reconstructed by the reconstruction calculation unit 22.

Here, the three-dimensional volume data D1 is created by performing a reconstruction operation on a plurality of X-ray images C. That is, the three-dimensional volume data D1 is the three-dimensional CT volume data directly created by the reconstruction operation. This three-dimensional volume data D1 is obtained for each work W. This three-dimensional volume data D1 is represented by a voxel aggregate that is an aggregate of voxels (minimum cubes (normal lattice)) that divide the three-dimensional space into diced pieces, and displays the density distribution of images in the three-dimensional space. It is represented by a three-dimensional data array. Specifically, data in which the amount of X-ray absorption is stored for each voxel is obtained, and one pixel value (value indicating the amount of X-ray absorption) is given to each voxel.

The data creation unit 24 obtains the quantified data Dc representing the voxel aggregate A constituting the cavities B based on the voxel data D2 extracted by the data extraction unit 23, and the voxel set is obtained from the quantified data Dc. It has a function of creating the figure voxel data Ds of the sphere S as a simple figure having the same volume as the body A as the comparison image data D3.

In the present embodiment, the quantified data Dc is composed of numerical values for specifying the position and size of the sphere S. Specific numerical data Dc includes the three-dimensional coordinates of the center of gravity G of the voxel aggregate A constituting the cavities B and the respective numerical values of the volume of the voxel aggregate A in the three-dimensional volume data D1. In this case, the value of the xyz coordinate of the center of gravity G of the voxel aggregate A and the volume value of the voxel aggregate A can be used. The volume value of the voxel aggregate A can also be expressed by the diameter value of the sphere S obtained from this volume value.

According to the data creation unit 24, the cavities B are re-voxelized as the graphic voxel data Ds of the sphere S by using the digitized data Dc. The process at this time can also be referred to as "re-voxelization" or "reverse voxelization".

In addition, instead of the sphere S which is a simple figure, other simple three-dimensional figures such as a prism such as a cube, a cone, and an ellipsoid are used to create figure boxel data Ds of these figures. You may do so. In short, a simple figure having a simpler shape than the cavities B (voxel aggregate A) having a complicated shape is sufficient.

The data synthesis unit 25 casts graphic voxel data Ds (comparative image data D3) obtained from the voxel data D2 extracted by the data extraction unit 23 for each of the plurality of works W with respect to the work body data Dw. It has a function of synthesizing at the synthesis position P which is the original position of the nest B, that is, the position of the center of gravity G of the voxel aggregate A.

Here, the work body data Dw is obtained by removing the three-dimensional volume data corresponding to the cavities B from the three-dimensional volume data D1 of any one of the plurality of works W.
Instead of this, CAD data indicating the overall shape of the work W can be used as the work body data Dw.

The overlap determination unit 26 has a function of determining the degree of overlap of a plurality of graphic voxel data Ds synthesized with respect to the work body data Dw by the data synthesis unit 25. Then, the hue setting unit 27 has a function of displaying the graphic voxel data Ds on the display device 40 with the hue preset in advance according to the degree of overlap determined by the overlap determination unit 26.

The display device 40 is configured as a PC display (monitor) capable of displaying information generated by processing data and images by the processing device 20, and is electrically connected to the processing device 20 via a connecting means (not shown). ing.

Next, an inspection method using the inspection apparatus 1 having the above configuration will be described with reference to FIGS. 3 to 11.

As shown in the flowchart of FIG. 3, a work inspection method for inspecting a plurality of workpieces W formed by the same mold M is achieved by sequentially executing the processes from step S101 to step S114. If necessary, another step may be added to this flowchart, or one step of this flowchart may be divided into a plurality of steps.

Step S101 is a step of setting one work W with respect to the rotation base 13 of the CT imaging device 10. In this step S101, it is preferable to use the above-mentioned positioning jig 14 (see FIG. 2) in order to easily position the work W. According to this step S101, the preparation before operating the CT imaging device 10 is executed.

Following step S101, step S102 is a step of operating the CT imaging device 10 to perform CT imaging of the work W. In this step S102, the rotation base 13 is rotationally driven around the rotation axis L in a state where the X-ray generator 11 and the X-ray detector 12 are operated. According to this step S102, the actual CT imaging of the work W is performed, and a plurality of X-ray images C of the work W are obtained.

Step S103 is a step of storing a plurality of X-ray images C of the work W obtained in step S102. According to this step S103, a plurality of X-ray images C are transmitted from the CT imaging device 10 to the storage unit 21 of the processing apparatus 20 and temporarily stored. In this step S103, a plurality of X-ray images C may be stored in the external storage device 30 in place of or in addition to the storage unit 21.

Step S104 is a step of reconstructing a plurality of X-ray images C into three-dimensional volume data D1. In this step S104, a plurality of radiographed images C temporarily stored in the storage unit 21 are read out, and these plurality of radiographed images C are reconstructed into a three-dimensional volume by the CT reconstruction software of the calculation unit 22. Reconstruct into data D1. This step S104 is executed for all the work W.

For example, as shown in FIG. 4, a plurality of radiographed images C1 for the first work W1 are reconstructed into three-dimensional volume data D1, and a plurality of radiographed images Cn for the nth work Wn are generated. It is reconstructed into the three-dimensional volume data D1.

Step S105 is a step of displaying the three-dimensional volume data D1 reconstructed in step S104 on the display device 40. According to this step S105, the user can observe each work W as a three-dimensional object on the display device 40, or can observe the cross section of each work W.

Here, as shown in FIG. 5, the three-dimensional volume data D1 is composed of an aggregate A (also referred to as “void”) of voxels a constituting the internal space. By classifying the brightness value of each voxel a based on the threshold value, a plurality of cavities B in the three-dimensional volume data D1 can be selected.

Step S106 is a data extraction step of extracting the cavities voxel data D2 relating to the cavities B from the three-dimensional volume data D1 obtained by the X-ray image C of each work W. This step S106 is executed by the data extraction unit 23 for the cavities B of all the works W.

For example, as shown in FIG. 5, the first cavity B1, which is one of the cavities B, is formed at the position P1 of the work W, and is a voxel aggregate which is one of the voxel aggregates A. It is composed of A1. Similarly, the second cavities B2, which is one of the cavities B, is formed at the position P2 of the work W, and is composed of the voxel aggregate A2, which is one of the voxel aggregates A.
Therefore, according to this step S106, these voxel aggregates A1 and A2 are extracted as the cavity voxel data D2 from the three-dimensional volume data D1.

Step S107 is a step of digitizing the cavity voxel data D2 extracted by step S106. Specifically, the digitized data Dc representing the voxel aggregate A is obtained. This step S107 is executed by the data creation unit 24 for the cavities B of all the workpieces W.

For example, as shown in FIGS. 4 and 6, for the cavities B1, the three-dimensional coordinates (x1, y1, z1) of the center of gravity G of the voxel aggregate A1 constituting the cavities B1 and the voxel aggregate A1 Each numerical value with the volume V1 is used as the numerical data Dc representing the voxel aggregate A1. In this case, the volume of the voxel aggregate A1 is derived from the number of voxels a constituting the voxel aggregate A1.

Similarly, as shown in FIGS. 4 and 7, for the cavities B2, the three-dimensional coordinates (x2, y2, z2) of the center of gravity G of the voxel aggregate A2 constituting the cavities B2 and the voxel aggregate A2. Each numerical value with the volume V2 of is used as the numerical data Dc representing the voxel aggregate A2. In this case, the volume of the voxel aggregate A2 is derived from the number of voxels a constituting the voxel aggregate A2.

The data capacity of the above-mentioned digitized data Dc is significantly smaller than the data capacity of the three-dimensional volume data D1 of the work W. For example, the data capacity of the three-dimensional volume data D1 is several gigabytes, whereas the data capacity of the digitized data Dc is several kilobytes.

Step S108 is a step of temporarily storing the digitized data Dc obtained in step S107 in the storage unit 21.

Step S109 determines whether or not the inspection number n of the work W has reached a predetermined number k. In this S109, if the number of inspections n reaches a predetermined number k (in the case of “Yes” in step S109), the process proceeds to step S110, and if not (in the case of “No” in step S109), the process proceeds to step S101. return. In addition, in order to improve the comparison accuracy of the cavities B of the work W, it is preferable that the predetermined number k at this time is at least about 30.

Step S110 is a step of reading the digitized data Dc from the storage unit 21.

Step S111 is a data creation step of creating graphic voxel data Ds of a sphere S having the same volume as the voxel aggregate A as comparative image data D3 based on the digitized data Dc read out in step 110. The graphic voxel data Ds are three-dimensional volume data of the sphere S, that is, a voxel aggregate. As a result, the cavities B are re-voxelized, and the graphic voxel data Ds of the sphere S are created. This step S111 can also be referred to as a "re-voxelization step" or a "reverse voxelization step". This step S111 is executed by the data creation unit 24 for the cavities B of all the workpieces W.

For example, as shown in FIGS. 4 and 8, for the cavities B1, the graphic voxel data Ds1 of the sphere S1 having the same volume as the voxel aggregate A1 is created as the comparative image data D3. Similarly, as shown in FIGS. 4 and 9, for the cavities B2, the graphic voxel data Ds2 of the sphere S2 having the same volume as the voxel aggregate A2 is created as the comparative image data D3.

In step S112, the graphic voxel data Ds created in step S111 are combined with the work body data Dw showing the overall shape common to the plurality of work W at the composite position P which is the original position of the cavities B (“integration”). It is also a data synthesis step. This step S112 is executed by the data synthesizing unit 25 for the cavities B of all the workpieces W.

For example, as shown in FIGS. 4 and 10, for the first cavities B1, the graphic voxel data Ds1 of the sphere S1 corresponding to the voxel aggregate A1 is used as the source of the cavities B1 in the work body data Dw. It is synthesized at the synthesis position P1 (see FIG. 5) which is the position of. This composite position P1 is the position of the center of gravity G of the voxel aggregate A1.

Similarly, for the second cavities B2, the graphic voxel data Ds2 of the sphere S2 corresponding to the voxel aggregate A2 is used as the composite position P2 (FIG. 5) which is the original position of the cavities B2 in the work body data Dw. See). This composite position P2 is the position of the center of gravity G of the voxel aggregate A2.

It is preferable to display the state in which the graphic voxel data Ds are combined with the work main body data Dw on the PC display which is the display device 40. In this case, since both the work body data Dw and the graphic voxel data Ds are three-dimensional volume data, the user can observe the cross section of the work W.

Step S113 is an overlap determination step for determining the degree of overlap of a plurality of graphic voxel data Ds synthesized with respect to the work body data Dw in step S112. This step S113 is executed by the overlap determination unit 26 for the cavities B of all the workpieces W.

According to this step S113, the degree of overlap of the graphic voxel data Ds for the plurality of work W can be determined. In the present embodiment, the number of overlaps of voxels a of each graphic voxel data Ds that overlaps with the voxels a of the work body data Dw (hereinafter, referred to as “voxel overlap number”) is determined as the degree of overlap. Information related to this overlapping number is stored in the storage unit 21.

Step S114 is a hue setting step of displaying the graphic voxel data Ds on the display device 40 with the hue set in advance according to the degree of overlap determined by step S113. This step S114 is executed by the hue setting unit 27 for the cavities B of all the workpieces W.

In this step S114, for example, the work body data Dw is displayed in a base color such as black or white, while the voxel a having a relatively large number of voxel overlaps in each figure voxel data Ds has a relatively small number of voxel overlaps. Display in a color that is more noticeable than voxels. According to this step S114, the user can visually recognize the occurrence status of the cavities B in each work W and the occurrence probability of the cavities B in all the works W.

Here, an example of a display mode of the number of voxel overlaps of the graphic voxel data Ds will be described with reference to FIG.

In the example shown in FIG. 11, one graphic voxel data Ds1 that overlaps only with the work body data Dw, two graphic voxel data Ds2 that overlap with the work body data Dw and overlap with each other, and 3 that overlap with the work body data Dw and overlap with each other. Two figure voxel data Ds3 and are shown. In this case, the number of voxel overlaps of the voxel a belonging to the first region R1 is "1", the number of voxel overlaps of the voxel a belonging to the second region R2 is "2", and the number of voxel overlaps of the voxel a belonging to the third region R3 is "1". The number of voxel overlaps is "3".

Therefore, in one display mode, the voxel a in the second region R2 is displayed in a hue more conspicuous than the voxel a in the first region R1, and the voxel a in the third region R3 is displayed in a hue more conspicuous than the voxel a in the second region R2. It can be displayed in a conspicuous hue. At this time, the hue of voxel a may be continuously changed between the regions, or the hue of voxel a may be changed stepwise between the regions.

For example, when the number of work W is 30, the number of voxel overlaps can be a numerical value from 1 to 30. Therefore, when the hue displayed on the PC display of the display device 40 consists of a combination of R (red), G (green), and B (blue), and each of RGB has 8-bit (256 gradations) information, RGB By appropriately setting the respective gradations and combining them with each other, the hue of the boxel a between 1 and 30 can be changed continuously or stepwise.

In addition, instead of the display form in which the voxels a are color-coded according to the number of voxel overlaps as described above, the display form in which the voxels a are color-coded according to parameters other than the number of voxel overlaps such as the overlap density and the overlap area of the voxels a. Alternatively, a display form in which the figure voxel data Ds are color-coded according to the number of overlaps of the figure voxel data Ds can be adopted.

Further, when the graphic voxel data Ds displayed on the display device 40 is selected by a selection means such as a mouse, the number of voxel overlaps of the voxels a at the selected position is numerically displayed on the display device 40. preferable. As a result, the user can not only qualitatively grasp the number of voxel overlaps of the voxels a by the difference in hue, but also quantitatively grasp the number by numerical values.

Next, the operation and effect of the above-mentioned first embodiment will be described.

According to the first embodiment, the cavities voxel data D2 relating to the cavities B is extracted from the three-dimensional volume data D1 obtained by the X-ray image C of each work W. Further, the graphic voxel data Ds is created by using the quantified data Dc obtained by quantifying the cavities voxel data D2. The digitized data Dc at this time has a smaller data capacity than the three-dimensional volume data D1 of the work W itself. For example, the data capacity of the digitized data Dc can be suppressed to several kilobytes with respect to the three-dimensional volume data D1 having a data capacity of several gigabytes.
Therefore, compared to the case of synthesizing a plurality of three-dimensional volume data D1, the processing load when synthesizing the graphic voxel data Ds obtained from this digitized data Dc with respect to the work body data Dw on the system can be suppressed to a low level. Can be done. Then, the generation state of the cavities B can be compared among the plurality of works W by comparing the graphic voxel data Ds synthesized with respect to the work body data Dw.
In this case, since the processing load for synthesizing the graphic voxel data Ds is low, from the acquisition of the X-ray images C of each of the plurality of works W to the comparison of the cavities B contained in these X-ray images C. A series of processes can be performed in a short time.

As described above, according to the first embodiment, it is possible to compare the cavities B of the plurality of workpieces W formed by the same mold M in a short time.

Further, according to the first embodiment, the probability of occurrence of the cavities B can be grasped by determining the degree of overlap (the number of voxel overlaps) in which a plurality of graphic voxel data Ds synthesized with respect to the work body data Dw overlap each other. .. In particular, by displaying the graphic voxel data Ds on the display device 40 in a hue set in advance according to the number of voxel overlaps, the user can visually recognize the locations where the cavities B are concentrated among the plurality of work Ws. can.

As a result, the user can determine that the cavities B that are concentrated in a substantially common area inside the plurality of workpieces W are caused by the structure of the mold M, and the cavities B are generated. Factors can be associated with the structure of the mold M. On the other hand, this casting cavity B can be distinguished from internal defects that randomly occur in response to minute changes in actual casting conditions. As a result, it becomes possible to reflect the generation state of the cast cavity B in the structure of the mold M, and the cost required for the development and improvement of the expensive mold M can be kept low.

Further, according to the first embodiment, by using the three-dimensional volume data D1 of any one of the plurality of work Ws as the work body data Dw, the graphic voxel data Ds is synthesized with the work body data Dw. It is possible to observe the cross section of the work W.

Hereinafter, other embodiments related to the above-described first embodiment will be described with reference to the drawings. In other embodiments, the same elements as those in the first embodiment are designated by the same reference numerals, and the description of the same elements will be omitted.

( Reference form 1 )
As shown in FIG. 12, the work inspection device 101 of the reference embodiment 1 is different from the work inspection device 1 of the first embodiment only in the configuration of the processing device 120.

The processing device 120 includes a storage unit 21, a reconstruction calculation unit 22, a data extraction unit 23, a data synthesis unit 25, an overlap determination unit 26, and a hue setting unit 27. That is, the processing device 120 does not include an element corresponding to the data creation unit 24 of the processing device 20 of the first embodiment.
Other configurations are the same as those in the first embodiment.

As shown in FIG. 13, the inspection method using the work inspection apparatus 101 of the reference embodiment 1 is achieved by sequentially executing the processes from step S201 to step S212. If necessary, another step may be added to this flowchart, or one step of this flowchart may be divided into a plurality of steps.

Here, the processing from step S201 to step S206 and the processing of step S208 are the same as the processing from step S101 to step S106 and the processing of step S108 (see FIG. 3) of the first embodiment. Therefore, in the following, only the processing of the other steps will be described.

Step S207 is a step of temporarily storing the cavities voxel data D2 extracted by step S206 in the storage unit 21. In this case, the cavity voxel data D2 is stored as the three-dimensional coordinates of all the voxels a constituting the voxel aggregate A.

Step S209 is a step of reading the cavities voxel data D2 from the storage unit 21.

Step S210 is a data synthesis step of synthesizing the cavities voxel data D2 read in step S209 at the synthesis position P, which is the original position of the cavities B, with respect to the work body data Dw. In this case, the cast cavity voxel data D2 itself becomes the comparison image data D3. This step S210 is executed by the data synthesizing unit 25 for the cavities B of all the workpieces W.

Step S211 is an overlap determination step for determining the degree of overlap (the number of overlaps of voxels a) in which a plurality of cavities voxel data D2 synthesized with respect to the work body data Dw in step S210 overlap each other. This step S211 is executed by the overlap determination unit 26 for the cavities B of all the workpieces W.

Step S212 is a hue setting step for displaying the cast cavity voxel data D2 on the display device 40 with a preset hue according to the degree of overlap determined by step S210. This step S212 is executed by the hue setting unit 27 for the cavities B of all the workpieces W.

According to the reference form 1 , since the voxel data D2 of the cavities B (the voxel aggregate A of the cavities B) is synthesized with respect to the work body data Dw in that shape, the cavities B after synthesis on the display device 40. Can be displayed with high accuracy. As a result, the user can observe the actual shape of the cavities B instead of the simple spherical shape as in the first embodiment.

Further, the data capacity of the cavities voxel data D2 synthesized with respect to the work body data Dw is larger than the digitized data Dc in the first embodiment, but the volume of the cavities B is considerably small, so that the work W 3 The data capacity of the three-dimensional volume data D1 is still significantly lower than this data capacity.
Therefore, the processing load for synthesizing the cavities voxel data D2 is low, and from the acquisition of the X-ray images C of each of the plurality of works W to the comparison of the cavities B contained in these X-ray images C. A series of processes can be performed in a short time.

Further, the data creation unit 24 of the first embodiment, the digitization step such as step S107, and the data creation step such as step S111 can both be omitted.

Other than that, it has the same effect as that of the first embodiment.

The present invention is not limited to the above-mentioned typical embodiments, and various applications and modifications can be considered as long as the object of the present invention is not deviated. For example, the following embodiments to which the above embodiments are applied can also be implemented.

In the above embodiment, the case where the processing device 20 includes at least three elements of the reconstruction calculation unit 22, the overlap determination unit 26, and the hue setting unit 27 has been illustrated, but instead, all of these three elements have been exemplified. Is omitted (hereinafter referred to as "first configuration"), only the reconstruction calculation unit 22 is omitted (hereinafter referred to as "second configuration"), and only the hue setting unit 27 is used. Adopting an omitted configuration (hereinafter referred to as "third configuration") or a configuration in which both the overlap determination unit 26 and the hue setting unit 27 are omitted (hereinafter referred to as "fourth configuration"). You can also.

For example, in the case of the first configuration, the three-dimensional volume data D1 of each work W is stored in the storage unit 21 in advance, and the three-dimensional volume data D1 is read out from the storage unit 21 by the data extraction unit 23 to read the three-dimensional volume data D1. Voxel data D2 may be extracted from the data D1. Further, by displaying the state in which the comparison image data D3 is synthesized with respect to the work main body data Dw on the display device 40, the user can compare the cavities B of the plurality of works W with each other.

Further, in the case of the second configuration, the three-dimensional volume data D1 of each work W is stored in the storage unit 21 in advance, and the three-dimensional volume data D1 is read out from the storage unit 21 by the data extraction unit 23 to read the three-dimensional volume data D1. Voxel data D2 may be extracted from the data D1.

Further, in the case of the third configuration, the storage unit 21 can store numerical information indicating the degree of overlap, which is determined by the overlap determination unit 26, without color-coding the degree of overlap of the comparison image data D3. can.

Further, in the case of the fourth configuration, by displaying the state in which the comparison image data D3 is combined with the work main body data Dw on the display device 40, the user can use the cavities B of each of the plurality of works W. You can compare each other.

In the above embodiment, the case where the image processing is performed by the processing device 20 while the work W is photographed by the CT imaging device 10 has been illustrated. Instead, the image processing by the processing device 20 is performed by the CT imaging device for the work W. It can also be executed at a timing different from the operation of shooting at 10.

In the above embodiment, the case where the X-ray detector 12 of the CT imaging device 10 is always connected to the processing device 20 has been illustrated, but instead, the CT imaging device 10 and the processing device 20 are separated from each other. It can also be used in the state of being made.

In the above embodiment, the case where the cavities inside the work W are inspected as the cavities B is illustrated, but it is also possible to inspect the spatial cavities B such as cracks in addition to the cavities.

In the above embodiment, the case where the X-ray is used to obtain the X-ray image of the work W has been illustrated, but instead, the work W is X-rayed using radiation other than X-rays such as gamma rays. You may try to get an image.

In the above embodiment, the case of inspecting a plurality of cast products (die casts) cast from a metal material with the same mold M has been illustrated, but this inspection technique was molded from a resin material with the same mold. It can also be applied to a technique for inspecting a plurality of resin molded products.

1,101 Work inspection equipment (inspection equipment)
10 CT imaging device 11 X-ray generator 12 X-ray detector 13 Rotation base 14 Positioning jig 20,120 Processing device 22 Reconstruction calculation unit 23 Data extraction unit 24 Data creation unit 25 Data synthesis unit 26 Overlap discrimination unit 27 Hua set Part 40 Display device a Voxel A, A1, A2 Voxel aggregate B, B1, B2 Casting cavity (internal defect)
C X-ray image D1 3D volume data D2 Voxel data of cavities (internal defect voxel data)
D3 Comparison image data Dc quantified data Ds, Ds1, Ds2, Ds3 Graphic voxel data (comparison image data)
Dw Work body data G Center of gravity M Mold P, P1, P2 Composite position Q Common reference position S, S1, S2 Sphere (simple figure)
W, W1, Wn Work S106, S206 Data extraction step S111 Data creation step S112, S210 Data synthesis step S113, S211 Overlap discrimination step S114, S212 Hue setting step

Claims (9)

A work inspection device (1 ) that inspects a plurality of workpieces (W) formed by the same mold (M).
A processing device (20 ) for processing each X-ray image (C) of the plurality of workpieces is provided.
The above processing device
A data extraction unit (23) that extracts internal defect voxel data (D2) related to internal defects (B, B1, B2) from the three-dimensional volume data (D1) obtained by the X-ray image.
The comparative image data (D3) obtained from the internal defect voxel data extracted by the data extraction unit for each of the plurality of workpieces is converted into the workpiece body data (Dw) showing the overall shape common to the plurality of workpieces. On the other hand, the data synthesizing unit (25) that synthesizes at the synthesizing position (P, P1, P2) which is the original position of the internal defect,
Based on the internal defect voxel data extracted by the data extraction unit, the same volume as the voxel aggregate from the digitized data (Dc) representing the voxel aggregates (A, A1, A2) constituting the internal defects. A data creation unit (24) that creates voxel data (Ds, Ds1, Ds2, Ds3) of a simple figure (S, S1, S2) having the above as image data for comparison.
Have,
The data synthesizing unit synthesizes the graphic voxel data created by the data synthesizing unit at the position of the center of gravity (G) of the voxel aggregate, which is the synthesizing position, with respect to the work body data. 1 ) . The processing apparatus according to claim 1 , further comprising an overlap determination unit (26) for determining the degree of overlap of a plurality of the comparison image data synthesized with respect to the work body data by the data composition unit. Work inspection device. The processing apparatus has a hue setting unit (27) for displaying the comparison image data on the display device (40) with a hue preset according to the degree of overlap determined by the overlap determination unit. 2. The work inspection device according to 2. The work body data is any one of claims 1 to 3 , wherein the 3D volume data corresponding to the internal defect is excluded from the 3D volume data of any one of the plurality of works. The work inspection device described in. The work inspection device according to any one of claims 1 to 4 , wherein the processing device has a reconstruction calculation unit (22) that reconstructs the X-ray image into the three-dimensional volume data. A CT imaging device (10) for obtaining the above-mentioned X-ray image is provided.
The CT imaging device is a rotation base (13) rotatably arranged between the X-ray generator (11), the X-ray detector (12), and the X-ray generator and the X-ray detector. Any one of claims 1 to 5 , wherein a positioning jig (14) capable of positioning each of the plurality of workpieces at a common reference position (Q) is attached to the rotation base. The work inspection device described in. It is a work inspection method for inspecting a plurality of workpieces (W) formed by the same mold (M).
Data extraction step (S10 6 ) to extract internal defect voxel data (D2) related to internal defects (B, B1, B2) from three-dimensional volume data (D1) obtained by X-ray images (C) of each of the plurality of workpieces. ) And
The comparative image data (D3) obtained from the internal defect voxel data extracted by the data extraction step for each of the plurality of works is applied to the work body data (Dw) showing the overall shape common to the plurality of works. The data synthesis step (S112 ) for synthesizing at the synthesis position (P, P1, P2) which is the original position of the internal defect, and
Based on the internal defect voxel data extracted by the data extraction step, the same volume as this voxel aggregate is obtained from the numerical data (Dc) representing the voxel aggregates (A, A1, A2) constituting the internal defects. A data creation step (S111) for creating voxel data (Ds, Ds1, Ds2, Ds3) of a simple figure (S, S1, S2) having as the above-mentioned comparative image data, and
Have,
A work inspection method in which, in the data synthesis step, the graphic voxel data created by the data creation step is synthesized with respect to the work body data at the position of the center of gravity (G) of the voxel aggregate, which is the synthesis position . The work inspection method according to claim 7, further comprising an overlap determination step (S113 ) for determining an overlap degree in which a plurality of the comparative image data synthesized with respect to the work body data by the data composition step overlap each other. The work according to claim 8 , further comprising a hue setting step (S114 ) for displaying the comparison image data on the display device (40) with a hue set in advance according to the degree of overlap determined by the overlap determination step. Inspection method.

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