JP2017032325A - Bending tester for X-ray observation - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable internal observation of a test piece during a bending test.SOLUTION: A bending test machine 50 comprises an upper frame 53a and a lower frame 53b on which fulcrum support members 55a and 55b for supporting fulcrums 54a and 54b are movably provided. The upper frame 53a and the lower frame 53b are each constituted of an L-shaped member and a flat plate and form a substantially U-shape in a side view and that are vertically placed to have a gap therebetween on an X-ray optical axis connecting an X-ray irradiation part and an X-ray detector. One load frame is constituted by connecting the upper frame 53a and the lower frame 53b by a connection holding member 61 and an indenter 57. A load direction is a direction parallel to a stage surface of a rotation stage, which is a moving direction of a pushing member 62. The member placed on the X-ray optical axis is constituted of an X-ray transmissive member.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a bending test machine for X-ray observation for non-destructively observing changes in a test piece in a bending test in which a bending load is applied to the test piece.

  In a material test in which a test force is applied to a test piece to clarify characteristics such as the strength of the material, X-ray fluoroscopy and CT imaging may be performed in order to observe the internal fracture state of the test piece. An industrial X-ray fluoroscopy / CT apparatus rotates with an X-ray source, an X-ray detector disposed opposite to the X-ray source, and a specimen placed between the X-ray source and the X-ray detector. A stage is provided, and by performing X-ray fluoroscopy while rotating the stage, a three-dimensional structure inside the specimen can be observed (see Patent Document 1). As a testing machine that can be installed on the stage of such an X-ray CT apparatus and perform X-ray fluoroscopy and CT imaging during a material test, a material for a tensile test as described in Patent Document 2 can be used. A testing machine has been proposed.

  In the tensile test, since both ends of the test piece are gripped by the grips disposed on the top and bottom, in the material testing machine for the tensile test described in Patent Document 2, the base on which the bottom grip is disposed and A test piece provided with a tensile load between the upper gripper and the lower gripper by disposing a cylindrical member made of an X-ray transparent material between the pneumatic cylinder connected to the upper gripper Can be observed from all directions at 360 degrees with X-rays.

JP 2005-351879 A JP 2005-195414 A

  FIG. 6 is a schematic diagram illustrating a state in which the conventional bending tester 150 is installed in the X-ray CT apparatus. A conventional bending test machine 150 includes a base 151, a pair of support columns 152 erected on the base 151, a cross head 153 horizontally mounted on the pair of support columns 152, and a cylinder type disposed on the cross head 153. By pressing an indenter 157 attached to the piston rod 156 of the actuator 155 into a test piece TP attached to a base 151 and supported by a pair of support bases 154 having fulcrums formed at the tips. Configured to perform a bending test.

  When such a bending tester 150 is installed on the stage 113 of the X-ray CT apparatus and a bending test is performed, members such as an indenter 157 and a support base 154 made of metal or the like are X as shown in FIG. There is a problem that the line transmission is hindered, and the shape of the member portion is reflected in the X-ray image, and CT imaging of the test piece TP using the fluoroscopic images from 360 degrees different directions cannot be performed. In the case of a bending test, in the configuration of a testing machine in which the test force load direction is perpendicular to the surface of the stage 113 of the X-ray CT apparatus, the base 151 is similar to a material testing machine that performs a tensile test of Patent Document 2. Even if the gap between the head and the cross head 153 is made of, for example, an X-ray transparent material such as acrylic resin or polycarbonate resin, the indenter 157 and the support base 154 obstruct X-ray transmission, and the test piece TP near the indenter The internal structure cannot be observed. In addition, although it is conceivable that both the indenter 157 and the support base 154 are made of an X-ray transparent material, even if it does so, the fact that there are many members on the X-ray optical axis itself is for X-ray CT imaging. Is disadvantageous. In addition, the arrangement shown in FIG. 6 is not highly recommended from the standpoint of the fixed stone that the sample should be arranged so that the length in the X-ray optical axis direction is as short as possible in X-ray CT imaging.

  For this reason, conventionally, a bending test is performed with a bending tester installed separately from the X-ray CT apparatus, and the test piece is removed from the bending tester during the test, and the test piece is placed on the stage of the X-ray CT apparatus. The X-ray CT imaging of 360 degrees is carried out, and then the operation of attaching to the bending tester is repeated, and the change over time of the internal fracture of the test piece subjected to the bending load is examined. It was.

  However, when the test piece removed from the bending test machine in the middle of the test is mounted on the bending test machine again, it is difficult to bring the indenter into contact with the same place of the test piece before removing from the test machine. Since the bending load could not be applied to the same part of the piece, the accuracy of the test was impaired. For this reason, there has been a demand for a bending tester capable of performing X-ray fluoroscopy and CT imaging during the test without removing the test piece from the bending tester.

  The present invention has been made to solve the above-described problems, and an object thereof is to provide an X-ray observation bending tester capable of observing the inside of a test piece during a bending test.

  The invention according to claim 1 is a bending test machine for X-ray observation installed on a stage arranged between an X-ray source and an X-ray detector arranged to face each other, and the X-ray source And a pair of upper and lower members connected to each other by a connection holding member made of an X-ray transparent material to form a gap on the X-ray optical axis connecting the X-ray detector and the X-ray detector. A first fulcrum support having a frame that functions as a load frame for applying a bending load to a test piece mounted on the optical axis, and a first fulcrum that is movably disposed inside the frame and abuts the test piece A first member that is made of a member and an X-ray transparent material and is held so as to be movable back and forth with respect to the frame; The fulcrum support member of the A push-in member to be moved and an X-ray transparent material, fixed at a position facing the push-in member in the frame, and moving the first fulcrum support member through the push-in member. And a second fulcrum support member having a second fulcrum that comes into contact with the test piece from the opposite side of the surface with which the first fulcrum comes into contact.

  According to a second aspect of the present invention, in the bending test machine for X-ray observation according to the first aspect, the pushing member has a hollow cylindrical shape.

  According to a third aspect of the present invention, in the bending test machine for X-ray observation according to the first or second aspect, a force detector is provided between the second fulcrum support member and the frame.

  According to the invention of claim 1 to claim 3, comprising a frame in which a pair of members are vertically arranged so that a gap is formed on the X-ray optical axis connecting the X-ray source and the X-ray detector, Since the pushing member and the second fulcrum support member are made of an X-ray transparent material, an area where no member that blocks X-ray transmission is arranged in a certain area around the X-ray optical axis is provided. Thus, it becomes possible to perform internal observation of the test piece in a state in which a bending load is applied by the bending tester.

  According to invention of Claim 2, it becomes possible to prevent the fall of the X-ray transmittance by the thickness of a pushing member because the pushing member was made into the hollow cylindrical shape.

  According to the third aspect of the present invention, the test force can be measured by arranging the force detector.

1 is a schematic diagram of an X-ray CT system to which a bending tester for X-ray observation according to the present invention is applied. 1 is a perspective view of a bending test machine 50 for X-ray observation according to a first embodiment of the present invention. It is a sectional side view of the bending test machine 50 for X-ray observation which concerns on 1st Embodiment of this invention. It is a sectional side view of the bending test machine 70 for X-ray observation which concerns on 2nd Embodiment of this invention. It is a sectional side view schematic diagram of the bending test machine 80 for X-ray observation which concerns on 3rd Embodiment of this invention. It is a schematic diagram explaining the case where the conventional bending test machine 150 is installed in the X-ray CT apparatus.

  Embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a schematic diagram of an X-ray CT system to which a bending test machine 50 for X-ray observation according to the present invention is applied.

  This X-ray CT system includes an X-ray irradiation unit 11, an X-ray detector 12, and a rotary stage 13. In this X-ray CT system, the bending tester 50 is installed on the rotary stage 13 disposed between the X-ray irradiating unit 11 and the X-ray detector 12 arranged opposite to each other. Non-destructive internal observation of the test piece TP in a state where it is attached and a bending load is applied is performed.

  The X-ray irradiation unit 11 includes an X-ray tube as an X-ray source therein, and generates X-rays corresponding to the tube voltage and tube current supplied from the high voltage generator 15 from the X-ray tube. The high voltage generator 15 is controlled by an X-ray control unit 16, and the X-ray control unit 16 is connected to a personal computer PC in which control software for controlling the entire X-ray CT system is installed. The X-ray detector 12 is a combination of an image intensifier (II) and a CCD camera, or an FPD (Flat Panel Detector), which is connected to a personal computer PC via a CT image reconstruction calculation device 18. Connected. Note that the X-ray detector 12 is configured to be detachable from the rotary stage 13 in order to enlarge or reduce the fluoroscopic imaging region. The rotary stage 13 can also be separated from the X-ray irradiation unit 11.

  The rotary stage 13 rotates around a rotation axis R in the z-axis direction orthogonal to the x-axis along the X-ray optical axis L connecting the X-ray irradiation unit 11 to the X-ray detector 12, and by the stage drive mechanism 14. It is possible to move in the horizontal and vertical directions in the x, y and z axis directions. The stage drive mechanism 14 is connected to the personal computer PC via the stage control unit 17.

  In X-ray CT imaging, a test piece TP is attached to a bending test machine 50 installed on the rotary stage 13 to apply a bending load. Next, the rotation stage 13 is rotated about the rotation axis R while irradiating the X-ray from the X-ray irradiation unit 11 toward the test piece TP. Then, X-rays transmitted from 360 degrees around the test piece TP are detected by the X-ray detector 12, and the X-ray transmission data is taken into the CT image reconstruction calculation device 18.

  The CT image reconstruction calculation device 18 is configured by a computer including a ROM, a RAM, a hard disk, and the like as a storage device that stores programs, detection data of the X-ray detector 12, and a CPU as a calculation device. . In the CT image reconstruction calculation device 18, a tomographic image (CT image) of the test piece TP sliced along a plane along the xy plane is constructed using the acquired X-ray transmission data of the test piece TP for 360 degrees. Is done. The CT image is transmitted from the CT image reconstruction calculation device 18 to the personal computer PC, and is used for three-dimensional imaging by a three-dimensional image construction program installed in the personal computer PC.

  The personal computer PC is connected with a display device 23 such as a liquid crystal display and an input device 22 including a keyboard 22a and a mouse 22b. The keyboard 22a and the mouse 22b are used for input by an operator in various operations. The display device 23 displays the CT image transmitted from the CT image reconstruction calculation device 18 to the personal computer PC, and displays a three-dimensional image constructed using the CT image. The function of the CT image reconstruction calculation device 18 may be integrated with the personal computer PC and realized by a single computer as a computer peripheral device or software.

  Next, details of the bending tester 50 will be described. FIG. 2 is a perspective view of a bending test machine 50 for X-ray observation according to the first embodiment of the present invention, and FIG. 3 is a sectional view thereof.

  The bending tester 50 includes an upper frame 53a and a lower frame 53b as members constituting a frame that becomes a load frame. The upper frame 53a and the lower frame 53b have a substantially U-shape formed of an L-shaped member and a flat plate in a side view, and connect the X-ray irradiation unit 11 (X-ray source) and the X-ray detector 12. It is divided up and down so that a gap is formed on the X-ray optical axis L. The shapes of the upper frame 53a and the lower frame 53b are symmetrical except for differences such as fine attachment holes. The lower frame 53b is connected to a support column 52 erected on a base 51 fixed to the rotary stage 13, and the upper frame 53a is connected to the lower frame 53b by a connection holding member 61 so as to be vertically opposite. Yes. The connection holding member 61 is made of an X-ray transmissive material. Further, since the upper frame 53a and the lower frame 53b are not on the path of X-rays, they may be made of a material that hardly transmits X-rays. For example, aluminum or other suitable metal can be used. By using a metal material, it is possible to make the frame so rigid that it can withstand a test force applied as a bending test.

  The fulcrum support member 55a has a fulcrum 54a, and is disposed on the inner side of the upper frame 53a so as to face the inner side (lower side in FIG. 3), and in the load axis direction (left-right direction in FIG. 3) with respect to the upper frame 53a. Can be moved to. Further, the fulcrum support member 55b has a fulcrum 54b, which is disposed inside the lower frame 53b so as to face the inside (upper side in FIG. 3), and is movable in the load axis direction with respect to the lower frame 53b. The fulcrum support member 55a and the fulcrum support member 55b are connected to each other by a plate member 59, and can move integrally in the load axis direction. The plate member 59 is made of an X-ray transmissive material. Also, the fulcrum support member 55a and the fulcrum support member 55b, and the fulcrum 54a and the fulcrum 54b can be made of aluminum or other appropriate metal, like the upper frame 53a and the lower frame 53b.

  The connection holding member 61 has a hollow cylindrical shape with a flange, and a female screw is formed in the hollow hole. A hollow cylindrical push-in member 62 having a male screw formed on the outer periphery is screwed into the hole. The tip that protrudes into the region surrounded by the upper frame 53a and the lower frame 53b through the gap between the upper frame 53a and the lower frame 53b of the pushing member 62 is the fulcrum support member 55a on the upper frame 53a side and the lower frame 53b side. The fulcrum support member 55b is in contact with a plate member 59 that connects the fulcrum support member 55b. That is, the push-in member 62 is disposed so as to be able to advance and retreat with respect to the frame through a gap in the middle portion of the upper and lower frames, and pushes the fulcrum support member 55a and the fulcrum support member 55b via the plate member 59. Yes. The pushing member 62 is made of an X-ray transmissive material.

  An indenter 57 is disposed at a position facing the pushing member 62 surrounded by the upper frame 53a and the lower frame 53b. The indenter 57 is attached so as to be bridged in the gap between the upper frame 53a and the lower frame 53b so that the contact end with the test piece TP faces the pushing member 62 side. That is, the contact end of the indenter 57 with the test piece TP is connected to the upper frame 53a so that the load axis, which is the direction in which a bending load is applied to the test piece TP, is parallel to the stage surface (xy plane). It will be arranged in the gap between the lower frame 53b. The indenter 57 also functions to connect the upper frame 53a and the lower frame 53b in the same manner as the connection holding member 61 described above. The indenter 57 is made of an X-ray transparent material.

  In this bending test machine 50, the upper frame 53a and the lower frame 53b are connected by the connection holding member 61 and the indenter 57 to form one frame, which functions as a load frame for applying a bending load to the test piece TP. doing. The load direction is the moving direction of the push-in member 62 and is parallel to the stage surface of the rotary stage 13. The intermediate gap between the frames (a pair of the upper frame 53a and the lower frame 53b) in the present invention only needs to have a width corresponding to the observation region of the test piece TP, and on the side where the connection holding member 61 is disposed. Any width that allows the pushing member 62 to be inserted and moved is acceptable. In this embodiment, since the flat plate on the side where the indenter 57 is disposed in the upper frame 53a and the lower frame 53b is removable, the indenter 57 can be easily attached.

  In this bending test machine 50, the upper frame 53a, the lower frame 53b, the fulcrum support members 55a and 55b, and the fulcrum 54a are provided in order to give the tester main body strength sufficient to withstand the test force applied to the test piece TP in the bending test. , 54b are made of metal. On the other hand, a gap is provided between the upper frame 53a and the lower frame 53b, and the indenter 57, the plate member 59, the connection holding member 61, and the pushing member 62 are made of an X-ray transparent material, so that the X-ray optical axis L A member that prevents the transmission of X-rays is not arranged in the visual field range around the. As a result, when the rotary stage 13 is rotated around the rotation axis R, reflection of members other than the test piece TP and the indenter 57 in the visual field range is eliminated, and the test piece TP during the bending test from the 360 degree direction. X-ray fluoroscopy and CT imaging are possible. And since it becomes possible to perform CT imaging while applying a bending load to the test piece TP by the bending tester 50, it becomes possible to observe the change over time of the internal fracture of the test piece TP more accurately.

  As the X-ray transparent material constituting the indenter 57, the plate member 59, the connection holding member 61, and the pushing member 62, an acrylic resin, a polycarbonate resin, or the like is used. Here, the X-ray transmissive material may be any material that does not affect the degree of X-ray absorption of the material when performing CT image observation of the sample or fluoroscopic observation from a predetermined direction using X-rays. Further, in this bending tester 50, the pushing member 62 has a hollow cylindrical shape, and the thickness of the indenter 57 in the load direction is thin enough not to impair the pressing force on the test piece TP. A decrease in X-ray transmittance can be reduced.

  When the test piece TP is mounted on the bending test machine 50, it is inserted between the fulcrums 54a and 54b and the indenter 57. Then, the pusher member 62 is turned and pushed into the inner region surrounded by the upper frame 53a and the lower frame 53b, and the fulcrum support member 55b on the upper frame 53a side and the fulcrum support member 55b on the lower frame 53b side through the plate member 59. Are moved to slide toward the indenter 57. Thereby, the test piece TP is clamped by the three points of the fulcrums 54 a and 54 b and the indenter 57.

  Further, when the pushing member 62 is turned and the pushing member 62 is pushed, the fulcrum support member 55a on the upper frame 53a side and the fulcrum support member 55b on the lower frame 53b side move closer to the indenter 57. That is, a bending load is applied to the test piece TP by moving to the indenter 57 side with the fulcrums 54a and 54b in contact with the test piece TP. In this way, the pressing force generated when the pressing member 62 is pressed is a bending load between the test piece TP and the indenter 57 via the plate member 59, the fulcrum support members 55a and 55b, and the fulcrums 54a and 54b. Works. In the X-ray CT system, the rotating stage 13 is rotated while a bending load is applied to the test piece TP to irradiate the X-ray from the X-ray irradiation unit 11, and the periphery of the contact area of the test piece TP with the indenter 57 360 degree transmission images are collected. Then, a tomographic image of the test piece TP is generated by the CT image reconstruction calculation device 18 using the collected transmission images.

  As the push-in operation of the push-in member 62 in the bending test machine 50, X-rays from the X-ray irradiation unit 11 at a predetermined timing (for example, every 10 minutes in time or after each CT image reconstruction calculation is completed). Irradiation is stopped, and the operator manually rotates the push-in member 62 and pushes it in a predetermined amount (for example, 5 mm). As a whole of the bending test, this manual push-in operation and CT imaging are repeated. Further, instead of the manual pushing operation, it may be pushed at a predetermined speed by a motor or the like. At this time, when the motor is used as the power for the pushing operation of the pushing member 62 and the power transmission member between the motor and the pushing member 62 is on the X-ray optical axis L, the power transmission member is transmitted through the X-ray. Preferably, it is made of a functional material.

  In the first embodiment described above, the fulcrum 54a and the fulcrum 54b correspond to the first fulcrum of the present invention, and the fulcrum support member 55a and the fulcrum support member 55b correspond to the first fulcrum support member. The indenter 57 corresponds to the second fulcrum support member of the present invention, and the tip of the indenter 57 corresponds to the second fulcrum. Further, in the first embodiment described above, the fulcrum support member 55a and the like and the indenter 57 may be interchanged. That is, the indenter 57 may be disposed at a position where the indenter 57 is moved by the pushing member 62, and the fulcrum support member 55a and the fulcrum support member 55b may be fixed to the frame. In this case, the indenter 57 becomes the first fulcrum support member of the present invention, and the fulcrum support member 55a and the like become the second fulcrum support member.

  Next, a bending test machine for X-ray imaging according to another embodiment will be described. FIG. 4 is a side sectional view of a bending test machine 70 for X-ray observation according to the second embodiment of the present invention. In addition, about the member same as the bending test machine 50 which concerns on 1st Embodiment mentioned above, the same code | symbol is attached | subjected and detailed description is abbreviate | omitted. Note that the fulcrum support member 55a and the like and the indenter 57 may be interchanged as in the first embodiment.

  The bending test machine 70 includes a load cell 71 as a force detector. In the bending test machine 50 according to the first embodiment, the upper frame 53a and the lower frame 53b are on the opposite sides of the upper frame 53a and the lower frame 53b on the side where the connection holding member 61 and the pushing member 62 are disposed. The indenter 57 is disposed by being directly bolted to both the upper frame 53a side and the lower frame 53b side at a position where a gap is formed between them. In this bending tester 70, the upper frame 53a is disposed. The load cell 71 is disposed between the lower frame 53 b and the indenter 57.

  The two load cells 71 are arranged at equal intervals with respect to the center of the indenter 57 (the contact point between the indenter 57 and the test piece TP), so that half of the load applied to the indenter 57 is reduced to each load cell. 71 will be detected. Each of the load cells 71 is connected to the personal computer PC, and the detection values of the two load cells 71 are added together by an arithmetic device in the personal computer PC and displayed as a test force value on the display device 23.

  In the bending test machine 70 according to the second embodiment, since the test force during the test can be measured, the bending strength can be obtained while performing the internal observation of the test piece TP by X-rays.

  FIG. 5 is a schematic side sectional view of a bending test machine 80 for X-ray observation according to a third embodiment of the present invention. In addition, about the member same as the bending test machine 50 which concerns on 1st Embodiment mentioned above, the same code | symbol is attached | subjected and detailed description is abbreviate | omitted.

  The bending test machine 50 according to the first embodiment and the bending test machine 70 according to the second embodiment described above are equipped with an indenter 57 for performing a three-point bending test. The bending test machine according to the third embodiment. 80 is attached with an indenter 87 for a four-point bending test in place of the indenter 57. Thus, in the bending test machines 50, 70, 80 of the present invention, the indenters 57, 87 can be detached from the upper frame 53a and the lower frame 53b. It can be easily replaced. Of course, as in the second embodiment described above, the test force may be detected by interposing a load cell between the indenter 87 and the upper frame 53a and between the indenter 87 and the lower frame 53b. is there.

  In the third embodiment, the fulcrum 54a and the fulcrum 54b correspond to the first fulcrum of the present invention, and the fulcrum support member 55a and the fulcrum support member 55b correspond to the first fulcrum support member. The indenter 87 corresponds to the second fulcrum support member of the present invention, and the two protrusions of the indenter 87 correspond to the second fulcrum. The fulcrum support member 55a and the indenter 87 may be interchanged. That is, the indenter 87 may be disposed at a position where the indenter 87 is moved by the pushing member 62, and the fulcrum support members 55a and 55b may be fixed to the frame.

  In the above-described embodiment, the bending test machines 50, 70, 80 according to the present invention are installed on the rotary stage 13, and the X-ray CT system that performs X-ray CT imaging has been described as an example. Even in an X-ray fluoroscopic system in which the stage on which 80 is installed does not rotate, the bending tester 50, 70, 80 of the present invention is installed and the inside of the test piece TP to which a bending load is applied is observed from a predetermined direction. Is also possible. Also in this case, in the bending tester according to the present invention, observation is not hindered because only the X-ray transmissive material exists on the X-ray optical axis.

DESCRIPTION OF SYMBOLS 11 X-ray irradiation part 12 X-ray detector 13 Rotation stage 14 Stage drive mechanism 15 High voltage generator 16 X-ray control part 17 Stage control part 18 CT image reconstruction calculation apparatus 22 Input apparatus 23 Display apparatus 50 Bending test machine 51 Base 52 support 53a upper frame 53b lower frame 54a fulcrum 54b fulcrum 55a fulcrum support member 55b fulcrum support member 57 indenter 59 plate member 61 connection holding member 62 push-in member 70 bending test machine 71 load cell 80 bending test machine 87 indenter

Claims (3)

A bending test machine for X-ray observation installed on a stage arranged between an X-ray source and an X-ray detector arranged opposite to each other,
In order to form a gap on the X-ray optical axis connecting the X-ray source and the X-ray detector, an intermediate portion is formed by a pair of upper and lower members connected by a connection holding member made of an X-ray transparent material. A frame functioning as a load frame for applying a bending load to the test piece mounted on the X-ray optical axis;
The first fulcrum support member having a first fulcrum that is movably disposed inside the frame and has a first fulcrum in contact with the test piece, and an X-ray transmissive material are held to be movable forward and backward with respect to the frame. A pushing member for moving the first fulcrum support member along the load direction by contacting the first fulcrum support member in the frame through the gap;
The first fulcrum is made of a material that is made of an X-ray transmissive material and fixed to a position facing the push-in member in the frame, and the first fulcrum support member moves through the push-in member. A second fulcrum support member having a second fulcrum that abuts against the test piece from the opposite side of the abutting surface;
A bending test machine for X-ray observation characterized by comprising: In the bending test machine for X-ray observation according to claim 1,
The pushing member is a bending test machine for X-ray observation having a hollow cylindrical shape. In the bending test machine for X-ray observation according to claim 1 or claim 2,
A bending test machine for X-ray observation, comprising a force detector between the second fulcrum support member and the frame.

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