WO2019130373A1

WO2019130373A1 - X-ray in-line detection method and device

Info

Publication number: WO2019130373A1
Application number: PCT/JP2017/046300
Authority: WO
Inventors: 定岡　紀行; 中野　博之
Original assignee: 株式会社日立製作所
Priority date: 2017-12-25
Filing date: 2017-12-25
Publication date: 2019-07-04

Abstract

The purpose of the present invention is to provide an in-line detection method and device with which a measurement evaluation of detailed information such as the three-dimensional shape, volume, and position of an internal defect can be realized when performing in-line detection of an internal defect of a mass-produced cast product. The present invention is configured such that a plurality of imaging units each comprising an X-ray source and a two-dimensional detector are continuously disposed (1-a,2-a) (1-b,2-b) (1-c,2-c) (1-d,2-d). A conveyance mechanism (8) moves a pedestal (6), which holds a rotation table (5) that rotates a specimen (4), between the imaging units. At each imaging unit, the specimen (4) is rotated by the rotation table (5) to acquire a projection image at a fixed angular pitch, an initial image capture start position in the circumferential direction at each imaging unit is moved by an amount equivalent to the fixed angular pitch, and the projection images obtained by each imaging unit are sequentially added so as to perform three-dimensional image reconstruction, and thereby the presence of an internal defect is determined.

Description

X-ray in-line inspection method and apparatus

The present invention relates to an X-ray in-line inspection method and apparatus for continuously nondestructively imaging an internal state in a production line of a complex-shaped mass production machine component.

In the soundness and quality inspection in the production line of mass-produced machine parts represented by automobile casting parts, 100% inspections are required in order to enhance the reliability. In the inspection of mass production machine parts, dimension and shape measurement are the main evaluation items. However, in mass production cast products, in addition to the dimensional inspection, it is important to detect internal defects that may occur during the casting process. Although it is possible to measure from an optical system captured image represented by a laser range finder or a camera in dimension shape measurement on the outside of the product, it is necessary to measure the inside of the product nondestructively in the evaluation of internal defects in mass-produced castings. is there. The most effective measurement means for nondestructive inspection inside the product is X-ray transmission image and CT image measurement. Although the presence or absence of internal defects can be measured to some extent even by ultrasonic waves, it is difficult to handle a three-dimensional complex shaped article such as a cast part since it is necessary to bring the probe into contact with the product itself.

In the X-ray transmission image and CT image measurement, the target object may be placed between the X-ray source and the detector, and the internal state measurement evaluation without contact can be performed on the target object. In the X-ray transmission image and CT image measurement, not only internal defect measurement but also internal complicated three-dimensional shape and dimension measurement that can not be measured from the outside can be evaluated from the captured image.

In addition to mass-produced castings, in assembly products, it may be necessary to evaluate the soundness of the internal state without removing the outer casing. Also in this case, X-ray transmission image and CT image measurement become effective measurement means.

In 100% inspection in these production lines, products are produced continuously in a short time, so it is necessary to measure the physical quantity necessary for soundness evaluation continuously at short time intervals to determine the presence or absence of soundness . In order to evaluate the presence or absence of an internal defect continuously and in a short time by X-ray transmission image imaging, it is necessary to rotate the object to be examined 360 degrees and to determine with a large angle pitch and the minimum number of transmission images. For example, assuming that the pitch is 30 degrees, the presence or absence of a defect inside the object is determined from 12 projected images. In this case, there is a high probability that the presence or absence of an internal defect can be determined, but it is difficult to quantitatively evaluate the three-dimensional shape, volume, and position of an internal defect with little information. On the other hand, in the production line of mass-produced castings, if it is possible to quantitatively evaluate the shape, volume, position and other characteristics of the generated internal defects inline, optimization of casting conditions can be performed inline, leading to significant loss cost reduction There is sex.

Japanese Patent Application Laid-Open No. 60-73443

Conventionally, internal defect inspection in mass-produced castings has been carried out by destructive inspection by extraction, acoustic evaluation by tapping sound, etc., and when performing 100% inspection in a production line, transmission image imaging at a limited angle is performed The presence or absence of internal defects is determined by visual inspection of the image. For example, in a small automobile part made of aluminum, a target object is placed on a turntable between an X-ray source and a two-dimensional detector, and 12 transmission images are taken every 30 degrees while being rotated 360 degrees all around The presence or absence of internal defects is visually determined from these transmission images. The imaging time is reduced and can be used in mass production lines because of transmission image imaging with a limited small angular pitch.

In this case, although the presence or absence of internal defects can be determined, the detailed characteristics of internal defects such as the three-dimensional shape, volume, and three-dimensional position of the generated defect can be quantitatively evaluated only from the limited transmission image. difficult. On the other hand, in the in-line inspection at the time of manufacture, if the detailed characteristics of the generated defect can be evaluated in addition to the presence or absence of the internal defect of the target object, the adjustment optimization of the casting process conditions becomes possible in line. In this case, by detecting the occurrence of internal defects at the initial stage of occurrence and adjusting and optimizing the casting process conditions, it becomes possible to prevent the continuous occurrence of internal defects in the manufacturing line.

If three-dimensional CT imaging is performed, characteristics such as the three-dimensional shape, volume, etc. of internal defects can be evaluated, but a projection image at a detailed angular pitch for performing three-dimensional CT image reconstruction is required. . For example, when 3600 projected images are taken at a pitch of 0.1 degree, it takes 300 times more time than in the case of taking 12 transmission images, which can not be realized on a production line.

Further, in Patent Document 1, there is provided a transport path for transporting an object, and a radiation source for emitting fan beam radiation having a narrow predetermined spread angle along a predetermined plane so as to face via the transport path. And a plurality of multi-channel detectors having a two-dimensional resolution for detecting the fan beam radiation, and a plurality of pedestals for performing the traverse scan while holding the radiation source and the detectors Are arranged side by side on a conveyance path via a predetermined interval, and the conveyance path is intermittently traveled at a predetermined pitch, and the gantry is traversed and scanned when the travel is stopped. Radiation transmission data is collected, and when the object passes through each gantry, transmission data by radiation projection from each direction in the cross section of the object is obtained, and these are subjected to image reconstruction The radiation tomography apparatus is described for use.

In the apparatus of the above-mentioned document 1, an angular range portion of a part of the entire circumferential direction of the subject is one radiation detector unit integrated with a gantry and a multi-channel detector having two-dimensional resolution for detecting fan beam radiation. Get only projection data. Therefore, the projected images in the entire circumference are not aligned unless all the imaging units arranged in series in the transport path pass, and three-dimensional image reconstruction is possible only after all the imaging units have passed. Therefore, in the case of determining the presence or absence of the internal defect of the subject, the determination can be made after all of the plurality of imaging units have passed. Further, in the configuration of the same apparatus, the radiation transmission region needs to transmit not only the object but also the transport path member itself. Therefore, a strong radiation source that transmits not only the subject but also the transport path components at the same time is required. Furthermore, since the transport path component is also transmitted simultaneously, the scattered radiation generated in these areas becomes image noise, and the internal defect determination accuracy after image reconstruction is degraded.

Therefore, the object of the present invention is made against the background as described above, and in the in-line internal defect inspection of mass-produced cast products, presence or absence of internal defect and internal defect of target object within manufacturing tact time X-ray in-line inspection method and apparatus for realizing measurement evaluation of detailed information such as three-dimensional shape, volume, position, etc., when there exist.

For the above purpose, in the present invention, in the X-ray in-line inspection method using a two-dimensional detector, an X-ray source and a transport mechanism, a plurality of imaging units consisting of a two-dimensional detector and an X-ray source are continuously arranged. A pedestal for holding a rotary table for rotating the subject, and a transport mechanism for moving between these imaging units, the imaging unit comprising the respective two-dimensional detector and the X-ray source, rotating the subject with the rotary table The projection image of fixed angle pitch is acquired, the initial imaging start position in the circumferential direction in each imaging unit is moved by a fixed angle pitch, and the projection images obtained by each imaging unit are sequentially added to reconstruct a three-dimensional image To determine the presence or absence of internal defects.

According to the present invention, in the in-line internal defect inspection of a mass-produced cast product, if there is an internal defect and an internal defect of the target object within the manufacturing tact time, the three-dimensional shape, volume, position, etc. It becomes possible to provide an X-ray in-line inspection method and apparatus for realizing measurement and evaluation of detailed information.

FIG. 1 is an entire configuration diagram of an X-ray in-line inspection apparatus according to a first embodiment. FIG. 6 is a bird's-eye view of each imaging unit of the X-ray in-line inspection apparatus according to the first embodiment. FIG. 2 is an imaging flowchart of the X-ray in-line inspection apparatus according to the first embodiment. It is an example of the imaging transmission image by the X-ray in-line inspection apparatus by Example 1. FIG. It is an example of the projection image imaging start axis by the X-ray in-line inspection apparatus according to the first embodiment. FIG. 7 is an entire configuration diagram of an X-ray in-line inspection apparatus according to a second embodiment.

Hereinafter, embodiments of the present invention will be described using the drawings.

FIG. 1 is an entire configuration diagram of an X-ray in-line inspection apparatus according to a first embodiment for imaging a target product on a manufacturing line and evaluating internal defects with an X-ray in-line inspection method and apparatus. Fig. 6 shows a bird's-eye view of each imaging unit of the X-ray in-line inspection apparatus according to the first embodiment, showing an X-ray imaging implementation part of the apparatus; Further, FIG. 3 shows an imaging flow diagram of the X-ray in-line inspection apparatus according to the first embodiment showing a processing flow of imaging, image reconstruction, and internal defect determination using the apparatus of the embodiment shown in FIGS. ing.

As shown in FIG. 1, in the X-ray in-line inspection apparatus of the present embodiment, a mechanism for moving the transport pedestal 6 on which the rotary table 5 for installing and rotating the target subject 4 is installed on the rectangular transport path 8 have.

First, a plurality of subjects 4 to be examined are placed on the preparation stage 15. One subject 4 is placed on the rotary table 5 on the transport pedestal 6 waiting on the transport path 8 from the loading preparation stage 15 by the loading robot 12 of the subject 4. The subject 4 installed on the transport pedestal 6 moves on the transport path 8 together with the transport pedestal 6 to a position where the X-ray source 1-a (radiation source) and the two-dimensional detector 2-a face each other. , There pause for CT imaging.

An X-ray source 1-a for generating X-rays and a two-dimensional detector 2-a for detecting X-rays transmitted through the object 4 are provided on one of the long side portions of the rectangular conveyance path 8 It is arranged at the opposite position across 8. After stopping, cone beam X-rays are emitted from the X-ray source 1-a, and the irradiated X-rays pass through the inside of the subject 4 and are attenuated to be opposed to the X-ray source 1-a. The light is incident on the detection element of the detector 2-a and converted into a digital signal by the signal processing circuit 3-a. The X-rays generated by the cone beam pass through the entire region of the subject 4, and the X-ray attenuation amount reflecting the shape, material, and internal condition of the subject 4 is measured by each detection element of the two-dimensional detector 2-a. A projected image of one angle is obtained. Furthermore, while the rotary table 5 is made to go around, a projection image is taken at a constant angular pitch in the circumferential direction. A full 360 ° rotation is performed to capture a projected image in all directions. The obtained projection image is sent to the image reconstruction computer 10, where a three-dimensional image reconstruction processing operation is performed to generate a CT image of the object 4 to be examined. From the obtained CT image, the presence or absence of an internal defect is determined. As a result of the determination, the subject 4 determined to have an internal defect is taken out from the rotary table 5 and paid out from the transport path 8 as an NG product.

If it is judged as an OK product with no defect, then it moves on the transport path 8 together with the transport pedestal 6 while being installed on the transport pedestal 6, and the X-ray source 1-b And the two-dimensional detector 2-b move to the opposite position where it is paused again for CT imaging.

At this position, the start angle position in the circumferential direction on the rotary table at the start of imaging was shifted by a fixed angle from the position when imaged by the X-ray source 1-a and the two-dimensional detector 2-a in front Start imaging from the position. At the start of imaging, cone beam X-rays are emitted from the X-ray source 1-b, and the irradiated X-rays are transmitted through the inside of the subject 4 and attenuated to be opposed to the X-ray source 1-b 2 The light is incident on the detection element of the dimensional detector 2-b and converted into a digital signal by the signal processing circuit 3-b. The X-ray generated by the cone beam passes through the entire region of the subject 4 and the X-ray attenuation amount reflecting the shape, material and internal condition of the subject 4 is measured by each detection element of the two-dimensional detector 2-b. A projected image of one angle is obtained. While the rotary table 5 makes a round, a projection image is taken at a constant angular pitch in the circumferential direction.

Here, projection image data obtained by the imaging unit comprising the X-ray source 1-a and the two-dimensional detector 2-a in the previous stage is composed of the X-ray source 1-b and the two-dimensional detector 2-b. An image reconstruction process is performed by adding to the projection image data obtained by the imaging unit to generate a CT image. From the obtained CT image, the presence or absence of an internal defect is determined. As a result of the determination, the subject 4 determined to have an internal defect is taken out from the rotary table 5 and paid out from the transport path 8 as an NG product. If it is determined that the product is an OK product with no defect, then it moves on the transport path 8 along with the transport pedestal 6 while being installed on the transport pedestal 6, and the X-ray source 1-c And the two-dimensional detector 2-c move to the opposite position, where it is paused again for CT imaging.

At this position, the start angle position in the circumferential direction on the rotary table at the start of imaging is further shifted by a fixed angle from the position when imaged by the X-ray source 1-b and the two-dimensional detector 2-b in front. Start imaging from the new position. At the start of imaging, cone beam X-rays are emitted from the X-ray source 1-c, and the irradiated X-rays are transmitted through the inside of the subject 4 and attenuated to be opposed to the X-ray source 1-c 2 The light is incident on the detection element of the dimensional detector 2-c and is converted into a digital signal by the signal processing circuit 3-c. The X-ray generated by the cone beam passes through the entire region of the subject 4 and the X-ray attenuation amount reflecting the shape, material and internal condition of the subject 4 is measured by each detection element of the two-dimensional detector 2-c. A projected image of one angle is obtained. While the rotary table 5 makes a round, a projection image is taken at a constant angular pitch in the circumferential direction.

Here, from the projection image data obtained by the imaging unit consisting of the X-ray source 1-a at the second preceding stage and the two-dimensional detector 2-a, and from the X-ray source 1-b at the former stage and the two-dimensional detector 2-b Image reconstruction processing is performed by adding the projection image data obtained by the imaging unit and the projection image data obtained by the imaging unit consisting of the X-ray source 1-c and the two-dimensional detector 2-c. And generate a CT image. From the obtained CT image, the presence or absence of an internal defect is determined. As a result of the determination, the subject 4 determined to have an internal defect is taken out from the rotary table 5 and paid out from the transport path 8 as an NG product. If it is judged as an OK product with no defect, then it moves on the transport path 8 together with the transport pedestal 6 while being installed on the transport pedestal 6, and the X-ray source 1-d And the two-dimensional detector 2-d move to the opposite position where it is paused again for CT imaging.

At this position, the start angle position in the circumferential direction on the rotary table at the start of imaging is further shifted by a fixed angle from the positions when imaged by the X-ray source 1-c and the two-dimensional detector 2-c in front. Start imaging from the new position. At the start of imaging, cone beam X-rays are emitted from the X-ray source 1-d, and the irradiated X-rays are transmitted through the inside of the subject 4 and attenuated to be opposed to the X-ray source 1-d 2 The light is incident on the detection element of the dimensional detector 2-d and converted into a digital signal by the signal processing circuit 3-d. The X-ray generated by the cone beam passes through the entire region of the subject 4 and the X-ray attenuation amount reflecting the shape, material, and internal condition of the subject 4 is measured by each detection element of the two-dimensional detector 2-d. A projected image of one angle is obtained. While the rotary table 5 makes a round, a projection image is taken at a constant angular pitch in the circumferential direction.

Here, projection image data obtained by the imaging unit consisting of the X-ray sources 1-a, 1-b, 1-c and the two-dimensional detectors 2-a, 2-b, 2-c up to that point are An image reconstruction process is performed by adding to the projection image data obtained by the imaging unit including the X-ray source 1-d and the two-dimensional detector 2-d described above, and a CT image is generated. The subject 4 whose imaging has been completed moves on the transport path 8 along with the transport pedestal 6 to the OK product / NG product final dispensing position while being placed on the transport pedestal 6. At this position, an OK product is classified into an OK product stage 13 and an NG product into an NG product stage 14 based on the determination result based on the captured CT image by the final dispensing robot 11. The transport base 6 from which the subject 4 has been dispensed again moves to the subject 4 loading position, and the next robot 4 places the next subject 4 from the loading preparation stage 15 to the standby position on the transport path 8 by the loading robot 12. It is installed on the rotating table 5 on the moved transfer pedestal 6.

The series of operations described above are continuously executed continuously. The imaging units comprising the X-ray sources 1-a, 1-b, 1-c and 1-d and the two-dimensional detectors 2-a, 2-b, 2-c and 2-d operate in synchronization with each other. In the present embodiment, CT imaging is performed by simultaneously irradiating a cone beam X-ray of four subjects 4 with each imaging unit. Therefore, shield plates 9-a, 9-b and 9-c are provided between the imaging units in order to prevent scattered radiation from the adjacent X-ray guns. As shown in FIG. 2, the shielding plates 9-a, 9-b, 9-c have a gate-shaped structure, and a space through which the transport pedestal 6 on which the subject 4 is installed can pass through the transport path 8. The shutter is raised only when the transport pedestal 6 on the transport path 8 moves, and a passable space appears. During imaging in which the X-ray sources 1-a, 1-b, 1-c, 1-d are emitting X-rays, the shutter is closed to prevent scattered radiation. Further, positioning pins 7-a and 7-b are provided on these transfer pedestals 6 in order to align the projected images of the respective imaging units. In these processes, the projection images of the respective units are added on the basis of the projection images of the positioning pins 7-a and 7-b in the process of adding the encircling question in each imaging unit.

FIG. 2 shows a bird's-eye view of an X-ray imaging implementation portion of the X-ray in-line inspection system apparatus in the present embodiment. In order to install and irradiate an X-ray source adjacent to each other, shielding plates 9-a, 9-b and 9-c are provided between the imaging units in order to prevent the inflow of scattered radiation from the adjacent X-ray tube. The shielding plates 9-a, 9-b, 9-c are provided with through holes for passing the subject on the belt conveyor. Further, positioning pins 7-a and 7-b are provided on the transport pedestal 6 for imaging the subject with each imaging unit, so as to be reflected in the projected images of the subject. When adding each projection image in each imaging unit, projection image data is read with reference to the positioning pin imaging position.

FIG. 3 shows the processing flow of the imaging method using the present embodiment. In the present embodiment, first, at S100, the robot subjects the subject to be inspected to the loading table on the transport pedestal 6 on the apparatus. Next, in step S101, with the subject 4 of the product to be inspected installed on the rotary table 5 of the transport pedestal 6, the entire transport pedestal 6 is moved on the belt conveyor 8 to the first imaging unit position. Install. The first imaging unit position is an intermediate position where the X-ray source 1-a and the two-dimensional detection element array unit 2-a are opposed to each other, and the subject 4 installed on the rotary table 5 of the transport pedestal 6 is the X-ray source The entire area is included within the cone beam irradiation angle range of 1-a. Next, in S102, the subject on the rotary table 5 is rotated for a whole week at a constant angle pitch to obtain a projection image at a constant angle pitch.

In the present embodiment shown in FIG. 3, 900 projected images are obtained at a pitch of 0.4 degrees. Thus, constant angle pitch projection data (1) 101 is obtained. FIGS. 4A, 4B, 4C, and 4D show examples of acquired projected images at angle pitches of 0 degrees, 90 degrees, 180 degrees, and 270 degrees, respectively.

Next, in S103, a three-dimensional image reconstruction calculation is performed using the constant angle pitch projection data (1) 101. By this reconstruction process, a three-dimensional CT image of the subject 4 is generated.

In S104, the obtained three-dimensional CT image of the subject 4 is compared with the CT image of the healthy subject 4 having no internal defect, and the soundness evaluation is performed based on the presence or absence of the internal defect. If it is determined in S105 that there is no internal defect, the movement to the next adjacent imaging unit position in S107 is performed. If it is determined in S105 that there is an internal defect, in S118, internal defect characteristic quantities such as the three-dimensional shape, volume, position, etc. of the internal defect are calculated from the three-dimensional CT image. Thereafter, the target product is discharged from the belt conveyor 8 in S119, and the subject 4 does not move to the next imaging unit adjacent to the target conveyor unit, and the empty rotary table 5 and the transfer pedestal 6 in which the subject 4 is not installed. Only move to the adjacent imaging unit.

After moving to the next imaging unit position adjacent in S107, the X-ray source 1-b and the two-dimensional detection element array unit 2-b are placed on the rotary table 5 of the transport pedestal 6 at an intermediate position facing each other. The subject 4 is temporarily fixed at a position including the entire area within the cone beam irradiation angle range of the X-ray source 2-a. After the second imaging unit position is set, the rotation table is rotated by a designated angle as a projection image acquisition start position setting in S108. In this embodiment, it is rotated in the direction of 0.1 degree division to be a projection image acquisition start position. FIG. 4B shows the projection image acquisition start position at the second imaging unit position and the imaging projection image angle at a constant angle pitch after that.

The projection image acquisition start axis 20 in the first imaging unit is rotated by 0.1 degree to the projection image acquisition start instruction in the second imaging unit, and the axis 22 of the projection image income start position in the second imaging unit The projection image is acquired at a pitch of 0.5 degrees from the axis 22 of the projection image income start position in this second imaging unit. Therefore, while the projection image acquisition angle at the first imaging unit is 0 degrees, 0.5 degrees, 1.0 degrees, 1.5 degrees,..., The projection at the second imaging unit The image acquisition angles are 0.1 degrees, 0.6 degrees, 1.1 degrees, 1.6 degrees, and so on. Next, a projection image of the entire circumference is acquired at the angular pitch interval designated in S109, which is 0.5 degrees in this embodiment, and a total of 900 projection images are obtained. As a result, constant angle pitch projection data from the second imaging unit 102 is obtained.

Next, in S110, three-dimensional image reconstruction is performed by adding the first projection image angle pitch data (1) of 101 to the constant angle pitch projection data by the second imaging unit of 102. Therefore, in the three-dimensional image reconstruction here, 0 degrees, 0.1 degrees, 0.5 degrees, 0.6 degrees, 1.0 degrees, 1.1 degrees, 1.5 degrees, 1.6 degrees ... and the reconstruction is performed from the total of 1,800 projected images. By this reconstruction process, a three-dimensional CT image of the subject 4 is generated. In S111, the obtained three-dimensional CT image of the subject 4 is compared with the CT image of the healthy subject 4 having no internal defect, and the soundness evaluation is performed based on the presence or absence of the internal defect.

If it is determined in S112 that there is no internal defect, the movement to the next adjacent imaging unit position in S107 is performed. If it is determined in S113 that there is an internal defect, in S120, internal defect characteristic quantities such as the three-dimensional shape, volume, position, etc. of the internal defect are calculated from the three-dimensional CT image. After that, the target product is dispensed from the belt conveyor 8 in S121, and the subject 4 is not moved to the next imaging unit adjacent to it, and the empty rotary table 5 and the transport pedestal 6 in which the subject 4 is not installed. Only move to the adjacent imaging unit.

The operations from S107 to S114 are repeated in the second, third and fourth imaging units in this embodiment. FIG. 5C shows the projection image pickup start axis 24 in the N-th image pickup unit and the projection image pickup axis 25 at a constant angular pitch thereafter. After the third imaging unit, image reconstruction is performed with a total of 2700 projected images, and after the fourth imaging unit, a total of 3600 projected images. For the subject 4 imaged by all of the first to fourth imaging units, image reconstruction is performed using 3600 projected images at a pitch of 0.1 degree in the circumferential direction. In the present embodiment, four imaging units are configured, but if a plurality of N are arranged, it is possible to increase the projected image imaging pitch in one imaging unit and shorten the imaging time.

Further, in the present embodiment, in order to carry out the reconstruction for each imaging unit and to carry out the internal defect determination, it is possible to determine the relatively large internal defect at the initial stage of the plurality of imaging units. Therefore, it is possible to suppress imaging data to the necessary minimum.

The second embodiment will be described with reference to FIG. Even if not only X-rays but also neutrons are used as a radiation source for acquiring a projection image of the subject 4, similar effects can be obtained with the same configuration. In FIG. 6, instead of the X-ray source, small neutron sources 26-a, 26-b, 26-c, 26-d (radiation sources) and 2D detectors 27-a, 27-b, 27- for neutron detection are used. An example using c, 27-d is shown.

According to the present invention, in the in-line internal defect inspection of a mass-produced cast product, if there is an internal defect and an internal defect of the target object within the manufacturing tact time, the three-dimensional shape, volume, position, etc. It is possible to provide an X-ray in-line inspection method and apparatus for realizing measurement and evaluation of detailed information. Further, not only cast products but also general machine parts can be visualized on a production line by nondestructive visualization of the internal structure, which can lead to quality improvement of these machine parts.

The present invention is not limited to the embodiments described above, but includes various modifications. For example, the embodiments described above are described in detail in order to explain the present invention in an easy-to-understand manner, and are not necessarily limited to those having all the configurations described. Also, part of the configuration of one embodiment can be replaced with the configuration of another embodiment, and the configuration of another embodiment can be added to the configuration of one embodiment. In addition, with respect to a part of the configuration of each embodiment, it is possible to add, delete, and replace other configurations.

1-a, 1-b, 1-c, 1-d: X-ray source 2-a, 2-b, 2-c, 2-d: two-dimensional detector 3-a, 3-b, 3-c , 3-d: signal processing circuit 4: inspection zone 5: rotation table 6: transfer base 7-a, 7-b: positioning pin 8: belt conveyor 9-a, 9-b, 9-c: shield plate 10: Image reconstruction computer 11: Dispensing robot 12: Entry robot 13: OK stage 14: NG stage 15: entry preparation stage 16: 2D element array detector unit according to the first embodiment is used Transmission image simulation image (irradiation angle θ = 0 degrees)
17: Transmission image simulation image (irradiation angle θ = 90 degrees) when using the two-dimensional element array detector unit according to the apparatus configuration of the first embodiment
18: Transmission image simulation image (irradiation angle θ = 180 degrees) when using the two-dimensional element array detector unit according to the apparatus configuration of the first embodiment
19: Transmission image simulation image (irradiation angle θ = 270 degrees) when using the two-dimensional element array detector unit according to the apparatus configuration of the first embodiment
20: Axis 21 of projection image imaging start position in the first imaging unit according to the apparatus configuration of the first embodiment: Axis 22 of projection image imaging at a constant angular pitch in the first imaging unit according to the apparatus configuration of the first embodiment Axis 23 of projection image imaging start position in the second imaging unit according to the apparatus configuration of Embodiment 1 Axis 24 of projection image imaging at a constant angular pitch in the second imaging unit according to the apparatus configuration of Embodiment 1: Axis 25 of projection image imaging start position in the Nth imaging unit according to the apparatus configuration of the first embodiment: axis 26-a of projection image imaging at a constant angular pitch in the Nth imaging unit according to the apparatus configuration of the first embodiment , 26-b, 26-c, 26-d: compact neutron source 27-a, 27-b, 27-c, 27-d: 2D detector for neutron detection

Claims

A radiation source for emitting radiation;
A detector for detecting the radiation transmitted through a subject to be imaged;
A drive mechanism for moving the object between the radiation source and the detector;
A signal processing circuit that digitizes the amount of radiation transmission measured by the detector;
In an X-ray in-line inspection method in an X-ray in-line inspection apparatus comprising an arithmetic device which forms an image based on a signal of the signal processing circuit,
A plurality of imaging units including the radiation source and the detector are continuously arranged, and the imaging start circumferential direction position of the imaging target object is moved at a constant angular interval for each imaging unit, and imaging is performed for each imaging unit An X-ray in-line inspection method comprising: sequentially adding a projected image to reconstruct an image; calculating an internal defect shape; and determining the presence or absence of an internal defect.
A radiation source for emitting radiation;
A detector for detecting the radiation transmitted through a subject to be imaged;
A drive mechanism for moving the object between the radiation source and the detector;
A signal processing circuit that digitizes the amount of radiation transmission measured by the detector;
In an X-ray in-line inspection apparatus comprising an arithmetic device which forms an image based on a signal of the signal processing circuit,
A plurality of imaging units comprising the radiation source and the detector are continuously arranged.
The drive mechanism moves the imaging start circumferential direction position of the imaging target object for each imaging unit at a constant angular interval,
The X-ray in-line inspection apparatus according to claim 1, wherein the arithmetic unit reconstructs an image by sequentially adding captured and projected images for each imaging unit, calculates an internal defect shape, and determines the presence or absence of an internal defect.
In the X-ray in-line inspection apparatus according to claim 2,
It has a scattered radiation prevention plate between adjacent imaging units,
The drive mechanism has a movable pedestal provided with a rotary table on a conveyance pedestal,
The X-ray in-line inspection apparatus according to the present invention, wherein the transfer base has a positioning pin which is an index of coordinate alignment at the time of projection image addition.
In the X-ray in-line inspection apparatus according to claim 2,
The detector uses a two-dimensional element array as a detection element, and uses a semiconductor detector or a scintillator detector.
In the X-ray in-line inspection apparatus according to claim 2,
An X-ray in-line inspection apparatus characterized by using a small neutron source as the radiation source.