JP2017032284A - X-ray diffraction measuring device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an X-ray diffraction measuring device that accurately detects an incident angle even if the incident angle of X-rays into a measurement object is made any angle.SOLUTION: An X-ray diffraction measuring device radiates parallel visible light of which the optical axis is the same as that of outgoing X-rays, forms a radiation point on an X-ray radiation place of a measurement object OB, and projects a pattern which has a certain shape when projected on a plane vertical to the optical axis of visible light around the radiation point. It photographs an area including the radiation point and the pattern with a camera composed of an image formation lens 48 and an imaging device 49, analyzes the shape of a pattern in the photographed image, and thereby calculates the incident angle of the X-rays into the measurement object OB.SELECTED DRAWING: Figure 8

Description

  The present invention relates to an X-ray diffraction measurement apparatus that irradiates a measurement object with X-rays and detects the shape of an X-ray diffraction ring formed by the X-rays diffracted by the measurement object.

  Conventionally, for example, as shown in Patent Document 1, an X-ray diffraction ring (hereinafter referred to as a diffraction ring) is formed by X-rays diffracted by a measurement object by irradiating the measurement object with X-rays at a predetermined incident angle. There is known an X-ray diffraction measurement apparatus that forms a diffraction ring, detects the shape of the formed diffraction ring, performs analysis by a cos α method, and measures a residual stress of a measurement object. The apparatus disclosed in Patent Document 1 includes an X-ray emitter, a diffraction ring imaging means such as an imaging plate, a diffraction ring reading means such as a laser detection device and a laser scanning mechanism, and a diffraction ring erasing means such as an LED irradiator. Are provided in one housing. An imaging step of imaging the diffraction ring on the imaging plate by diffracted X-rays generated by irradiating the measurement object with X-rays, and irradiating the imaging plate with laser light from a laser detection device while irradiating the diffraction ring A reading process for detecting the shape of the diffraction grating and an erasing process for erasing the diffraction ring by irradiating the LED light can be performed continuously. If this X-ray diffractometer is used, the residual stress of the measurement object can be measured in a short time. In addition, when the measurement object has various shapes, the X-ray irradiation point (residual stress measurement point) can be a target point, from the X-ray irradiation point to the imaging means necessary for calculating the residual stress. As an X-ray diffraction measurement apparatus capable of setting the X-ray incident angle with respect to the measurement object and the X-ray incident angle to the measurement object, there is an apparatus disclosed in Patent Document 2. The apparatus shown in Patent Document 2 includes an LED light irradiation function that irradiates LED light having the same optical axis as that of the X-ray irradiated to the measurement object, and an imaging function that images the vicinity of the irradiation point of the LED light. Before X-ray diffraction measurement, the measurement object is irradiated with LED light to image the vicinity of the irradiation point of the LED light, and the LED light irradiation point becomes the target measurement location, and the LED light on the imaging screen And the light receiving point of the reflected light of the LED light are set to the set positions. If this X-ray diffraction measurement apparatus is used, the position and orientation of the measurement object relative to the X-ray diffraction measurement apparatus can be adjusted in a short time.

JP 2012-225796 A JP 2014-98677 A

  However, the X-ray diffractometer shown in Patent Document 2 can set the incident angle of X-rays to the measurement object only to a very limited value at which a light receiving point of LED light is generated on the imaging screen. There is a problem that it cannot be set. Specifically, depending on the measurement object, the X-ray incident angle may be set to an appropriate value other than the set value so that the diffraction ring is clearly formed. When measurement is performed, the incident angle of X-rays cannot be detected with accuracy, and as a result, there is a problem that the measurement accuracy of residual stress calculated from the shape of the diffraction ring is poor.

  The present invention has been made to solve this problem, and an object of the present invention is to perform X-ray diffraction measurement capable of accurately detecting the incident angle even if the incident angle of the X-ray with respect to the measurement object is set to an arbitrary angle. To provide an apparatus.

  In order to achieve the above object, the present invention is characterized by an X-ray emitter that emits X-rays toward an object to be measured, and an X-ray emitted from the X-ray emitter toward the object to be measured. The diffracted X-rays generated at the measurement object are received by an imaging surface perpendicular to the optical axis of the X-rays emitted from the X-ray emitter, and are diffracted X-ray images on the imaging surface. In an X-ray diffraction measurement apparatus having a diffraction ring formation detecting means for forming a diffraction ring and detecting the shape of the diffraction ring, the X-ray output from the X-ray emitter is not emitted from the X-ray emitter. A visible light emitter for emitting visible light, which is parallel light having the same optical axis as the X-ray, to the measurement object, and an irradiation point formed on the measurement object by the visible light emitted from the visible light emitter A pattern with a fixed shape is projected around the surface of the lens when projected onto a plane perpendicular to the optical axis of visible light. A pattern projection means, an imaging lens for imaging an image of a measurement object in an area including the irradiation point and pattern of visible light, and an imager for imaging an image formed by the imaging lens. A camera that outputs an imaging signal that represents the captured image, an image creation unit that creates an image by inputting the imaging signal output by the camera, and an X-ray emitter from the shape of the pattern in the image created by the image creation unit And an incident angle calculating means for calculating an incident angle of the X-ray emitted from the object to be measured.

  According to this, when the visible light is emitted to the measurement object by the visible light emitter, the pattern is projected onto the measurement object by the pattern projection unit, and the camera is operated to create the image by the image creation unit. The angle calculation means can calculate the incident angle of the outgoing X-ray on the measurement object from the shape of the pattern in the image. That is, even if the incident angle of the X-ray with respect to the measurement object is an arbitrary angle, the incident angle can be detected with high accuracy. In addition, since the incident angle of the emitted X-ray is calculated from the shape of the pattern, the incident angle of the emitted X-ray can be detected in real time by using a computer, and the incident angle of the emitted X-ray can be easily set to the value desired by the operator Thus, the position and orientation of the measurement object can be adjusted.

  Another feature of the present invention is that the optical axis of the X-ray emitted from the X-ray emitter and the diffraction ring formation detecting means are based on the circumferential direction based on the pattern shape in the image created by the image creating means. There is provided a reference plane inclination angle calculating means for calculating an angle formed by the normal direction of the plane including the line to be positioned with the surface of the measurement object.

  According to this, the plane including the optical axis of the X-rays emitted from the X-ray emitter calculated by the reference plane tilt angle calculation means and the line that the diffraction ring formation detection means serves as the reference position in the circumferential direction. The position of the measurement object relative to the X-ray diffractometer is set so that the reference plane tilt angle is 0 ° while checking the value of the normal direction angle with the surface of the measurement object (hereinafter referred to as the reference plane tilt angle). And the posture can be adjusted. That is, in order to improve the accuracy of the residual stress calculated from the shape of the diffraction ring detected by the diffraction ring formation detection means, it is necessary to detect the incident angle of the emitted X-ray after setting the reference plane tilt angle to 0 °. However, if the reference plane inclination angle can be detected in real time, the position and orientation of the measurement object can be easily adjusted so that the reference plane inclination angle becomes 0 °. Note that the line used as the reference position in the circumferential direction is a line having a rotation angle of 0 ° when the position in the imaging surface is expressed by the rotation angle and the radius when the calculation is performed by the cos α method. This will be described later.

  Another feature of the present invention is that the pattern projection means projects a pattern in which two sets of parallel lines intersect when projected onto a plane perpendicular to the optical axis of visible light. According to this, it is possible to accurately calculate the incident angle of the outgoing X-ray and the reference plane tilt angle from the quadrangular shape formed by the two sets of parallel lines.

  In addition, another feature of the present invention is that the visible light emitter has an emission port that emits visible light that is substantially parallel light while shielding a peripheral portion in the cross section of the visible light. Is provided with a plurality of cylindrical lenses that pass visible light that does not pass through the emission port. According to this, it is possible to project a pattern in which two sets of parallel lines intersect only by providing two sets of cylindrical lenses arranged and fixed in parallel around the periphery of the emission port, thereby suppressing an increase in the cost of the apparatus. Can do. In particular, if the X-ray diffraction measurement apparatus is the apparatus disclosed in Patent Document 2 of the prior art document, an arithmetic processing program is installed in the controller as an incident angle calculation means and a reference plane inclination angle calculation means, and X-ray and visible light are installed. The present invention can be realized only by arranging and fixing a plurality of cylindrical lenses around the exit port of the light source, and does not increase the cost of the apparatus. The optical axis of the X-ray emitted from the X-ray emitter and the optical axis of the visible light are the same, but the X-ray does not pass through the cylindrical lens, and therefore does not affect the X-ray diffraction measurement.

1 is an overall schematic diagram showing an X-ray diffraction measurement system including an X-ray diffraction measurement apparatus used in an embodiment of the present invention. It is an enlarged view of the X-ray-diffraction measuring apparatus of FIG. It is a fragmentary sectional view which expands and shows the part through which the X-ray passes in the X-ray-diffraction measuring apparatus of FIG. It is an expansion perspective view of the plate part of FIG. It is the figure which looked at the fixing tool which attaches an imaging plate to a table from the upper direction. It is sectional drawing of the location of the cylindrical lens of the fixing jig of FIG. It is an enlarged view of the cylindrical lens attached to the fixing jig of FIG. It is a figure which matches and shows the incidence | injection and imaging | photography state of LED light seen from the X-axis direction, and the picked-up image of the pattern formed in the measuring object surface. It is a figure which matches and shows the incidence | injection and imaging | photography state of LED light seen from the Y-axis direction, and the picked-up image of the pattern formed in the measuring object surface.

  A configuration of an X-ray diffraction measurement system including an X-ray diffraction measurement apparatus according to an embodiment of the present invention will be described with reference to FIGS. Note that this X-ray diffraction measurement system differs from the X-ray diffraction measurement system disclosed in Patent Document 2 of the prior art document in the vicinity of the visible light irradiation point (LED light irradiation point) of the measurement object. A function of projecting a pattern in which two sets of parallel lines intersect with each other, an arrangement of a unit to which the LED light source 44 is attached, and an X-ray incident angle and a reference plane inclination angle (emitted X-ray light) A point having a program for calculating an angle formed by a normal direction of a plane including an axis and a line having a rotation angle of 0 ° of the imaging plate 15 with a minute plane around the X-ray irradiation point of the measurement object. The configuration is the same. Therefore, the part already demonstrated by the X-ray-diffraction measuring system shown by patent document 2 is only demonstrated briefly.

  In this X-ray diffraction measurement system, the measurement object OB is set on the object setting device 60, X-ray diffraction measurement is performed, and the residual stress of the measurement object OB is measured. The object setting device 60 includes a triaxial movement mechanism and a biaxial tilt mechanism, and can adjust the position and orientation of the measurement object OB with respect to the X-ray diffraction measurement apparatus. When performing X-ray diffraction measurement of the measurement object OB using this X-ray diffraction measurement system, first, the object setting device 60 is operated to determine the X-ray irradiation point and the X-ray irradiation direction on the measurement object OB. The target measurement position and direction, the distance from the X-ray irradiation point to the imaging plate 15 (hereinafter referred to as the distance IP-OB) becomes the set value, the reference plane tilt angle becomes 0 °, and X-ray incidence Make sure that the angle is the desired value. Then, X-ray diffraction measurement is performed by irradiating the measurement object OB with X-rays. In the present embodiment, the measurement object OB is an iron plate member.

  The X-ray diffraction measurement apparatus includes an X-ray emitter 10, a table 16 to which the imaging plate 15 is attached, a table driving mechanism 20 that rotates and moves the table 16, a laser detection device 30 that detects a diffraction ring, and the like. I have. The X-ray diffraction measurement system includes an object setting device 60, a computer device 90, and a high-voltage power supply 95 together with the X-ray diffraction measurement device. Various types of circuits for controlling operation and inputting detection signals are connected to the above-described apparatus and mechanism, and are shown in FIG. Various circuits indicated by the dotted line are accommodated in a two-dot chain line in the housing 50.

  The casing 50 is formed in a substantially rectangular parallelepiped shape, and includes a bottom wall 50a, a front wall 50b, a rear wall 50e, a top wall 50f, a side wall (not shown), and corners of the bottom wall 50a and the front wall 50b. It is formed to have a notch wall 50c and a connecting wall 50d provided so as to be cut out from the front side to the back side of the sheet. The notch wall 50c is composed of a flat plate perpendicular to the bottom wall 50a and a parallel plate, and the connecting wall 50d is perpendicular to the side wall and has a predetermined angle with the bottom wall 50a. This predetermined angle is, for example, 30 to 45 degrees. A handle 51 for carrying the housing 50 is provided on the upper surface wall 50f. A fixing tool that is fixed to the support rod 52 is provided on a side wall on the back side of the casing 50 in the figure, and the casing 50 has a notch portion wall 50 c that faces the upper surface of the object setting device 60. Further, it is fixed to the support rod 52 in the illustrated inclined state. The support rod 52 is erected and fixed on an installation plate 53 formed in a flat plate shape placed on the installation surface.

  The object setting device 60 includes a so-called goniometer, and moves the stage 61 in the X, Y, and Z axis directions of FIGS. 1 and 2, respectively, and rotates (tilts) around the illustrated X axis and Y axis. ) In the object setting device 60, a height adjusting mechanism 63, first to fifth plates 64 to 68, and a stage 61 are arranged on the installation plate 62 formed on the installation surface in a flat plate shape from above. Are placed in order. The height adjustment mechanism 63 has an operation element 63a, and moves the first plate 64 up and down (that is, moves in the Z-axis direction) relative to the installation plate 62 by rotating the operation element 63a. By changing the vertical distance between the first plates 64, the height of the first plate 64, that is, the height of the stage 61 is changed.

  An operating element 65a is assembled to the second plate 65, and the third plate 66 is rotated about the X axis with respect to the second plate 65 by a rotation operation of the operating element 65a via a mechanism (not shown). The inclination angle of the third plate 66 around the X axis relative to the second plate 65, that is, the inclination angle of the stage 61 around the X axis is changed. An operation element 66a is assembled to the third plate 66, and the fourth plate 67 is rotated around the Y axis with respect to the third plate 66 by a rotation operation of the operation element 66a via a mechanism (not shown). The inclination angle of the fourth plate 67 around the Y axis relative to the third plate 66, that is, the inclination angle of the stage 61 around the Y axis is changed. An operating element 67a is assembled to the fourth plate 67, and the fifth plate 68 is moved in the X-axis direction with respect to the fourth plate 67 by a rotation operation of the operating element 67a. The position of the fifth plate 68 in the X-axis direction with respect to the fourth plate 67, that is, the position of the stage 61 in the X-axis direction is changed. An operation element 68a is assembled to the fifth plate 68, and the stage 61 is moved in the Y-axis direction with respect to the fifth plate 68 by a rotation operation of the operation element 68a. The position of the fifth plate 68 in the Y axis direction, that is, the position of the stage 61 in the Y axis direction is changed. Further, the operating elements 67a and 68a can indicate the moving position with a scale, and the operating elements 65a and 66a can indicate the rotation angle (inclination angle) with the scale.

  The X-ray emitter 10 extends in the left-right direction in the figure at the upper part in the case 50 and is fixed to the case 50. The X-ray emitter 10 is supplied with a high voltage from a high-voltage power supply 95 and receives X-rays at the bottom. Emits in the direction. When the X-ray control circuit 71 receives a command from the controller 91, the X-ray emitter 10 emits X-rays having a constant intensity so that a driving current supplied from the high-voltage power supply 95 to the X-ray emitter 10 and Control drive voltage. In addition, the X-ray emitter 10 includes a cooling device (not shown), and the X-ray control circuit 71 also controls a drive signal supplied to the cooling device.

  The table driving mechanism 20 is fixed to the housing 50 and includes a moving stage 21 below the X-ray emitter 10. The moving stage 21 is sandwiched between a pair of opposed plate-like guides 25, 25 in the table driving mechanism 20, and is output by a feed motor 22, a screw rod 23, and a bearing portion 24 fixed to the table driving mechanism 20. It moves in a plane parallel to the side wall of the housing 50 including the X-ray optical axis and in a direction perpendicular to the optical axis of the outgoing X-ray. An encoder 22a is incorporated in the feed motor 22, and the encoder 22a outputs a pulse train signal that alternately switches between a high level and a low level each time the feed motor 22 rotates by a predetermined minute rotation angle. And output to the feed motor control circuit 73.

  The position detection circuit 72 and the feed motor control circuit 73 operate according to commands from the controller 91. Immediately after the start of measurement, the feed motor control circuit 73 outputs a drive signal to the feed motor 22 so as to move the moving stage 21 toward the feed motor 22, and the position detection circuit 72 indicates that the moving stage 21 has reached the movement limit position. When the pulse train signal is no longer input from the encoder 22a, a signal indicating that the drive signal is stopped is output to the feed motor control circuit 73, and the count value is set to “0”. Thus, the feed motor control circuit 73 stops outputting the drive signal. This movement limit position becomes the origin position of the moving stage 21, and the position detection circuit 72 thereafter counts the pulse train signal from the encoder 22a every time the moving stage 21 moves, and adds or subtracts the count value depending on the moving direction. The movement distance x from the movement limit position is output as a position signal. When the feed motor control circuit 73 inputs the destination position of the moving stage 21 from the controller 91, the feed motor 22 is driven forward or backward until the position signal input from the position detection circuit 72 becomes equal to the input destination position. To do. Further, when the moving speed of the moving stage 21 is input from the controller 91, the feed motor control circuit 73 calculates the moving speed of the moving stage 21 using the number of pulses per unit time of the pulse train signal input from the encoder 22a. The feed motor 22 is driven so that the calculated movement speed becomes the input movement speed.

  The upper ends of the pair of guides 25, 25 are connected by a plate-like upper wall 26, and a through hole 26 a is provided in the upper wall 26, and the center position of the through hole 26 a is the emission of the X-ray emitter 10. Opposite the center position of the mouth 11, the outgoing X-rays enter the table drive mechanism 20 through the outgoing opening 11 and the through hole 26a. In a state where an imaging plate 15 to be described later is in the diffraction ring imaging position (the state shown in FIGS. 1 to 3), a through hole is provided at a position facing the through hole 26a of the moving stage 21 as shown in an enlarged view in FIG. 21a is formed. The moving stage 21 is assembled with a spindle motor 27 whose center of rotation is the position of the central axis of the emission port 11 and the through holes 26a, 21a. The output shaft 27a of the spindle motor 27 is cylindrical and has a circular cross section. Have A through hole 27b is provided on the opposite side of the output shaft 27a of the spindle motor 27, and a cylindrical passage member 28 for reducing the inner diameter of a part of the through hole 27b is provided on the inner peripheral surface of the through hole 27b. Is fixed.

  An encoder 27c is incorporated in the spindle motor 27. The encoder 27c controls a pulse train signal that alternately switches between a high level and a low level every time the spindle motor 27 rotates by a predetermined minute rotation angle. It outputs to the circuit 74 and the rotation angle detection circuit 75. Furthermore, the encoder 27c outputs an index signal that switches from the low level to the high level for a predetermined short period of time for each rotation of the spindle motor 27 to the controller 91 and the rotation angle detection circuit 75.

  When the rotation speed is input from the controller 91, the spindle motor control circuit 74 outputs a drive signal so that the rotation speed calculated from the number of pulses per unit time of the pulse train signal input from the encoder 27c becomes the input rotation speed. Output to the spindle motor 27. The rotation angle detection circuit 75 counts the number of pulses of the pulse train signal input from the encoder 27c, calculates the rotation angle θp from the count value, and outputs it to the controller 91. In addition, when the index signal is input from the encoder 27c, the rotation angle detection circuit 75 resets the count value to “0”. This is the position at a rotation angle of 0 °. Note that the position of the imaging plate 15 at a rotation angle of 0 ° means that the laser beam is irradiated when an index signal is input when a diffraction ring formed on the imaging plate 15 is read by laser irradiation from a laser detection device 30 described later. It is a position that has been. Since this position is at each radial position of the imaging plate 15, it is a line. A plane including the line with the rotation angle of 0 ° and the optical axis of the outgoing X-ray is hereinafter referred to as a reference plane. As described above, the angle formed by the normal direction of the reference plane and the minute plane around the X-ray irradiation point of the measurement object is referred to as the reference plane tilt angle.

  The table 16 has a circular shape and is fixed to the tip of the output shaft 27 a of the spindle motor 27. The table 16 has a protruding portion 17 that protrudes downward from the central portion of the lower surface, and a thread is formed on the outer peripheral surface of the protruding portion 17. An imaging plate 15 is attached to the lower surface of the table 16. A through hole 15 a is provided in the center of the imaging plate 15, and the projection 17 is passed through the through hole 15 a, and a nut-shaped fixture 18 is screwed onto the outer peripheral surface of the projection 17, thereby imaging plate 15. Is fixed between the fixture 18 and the table 16. The fixture 18 is a cylindrical member, and a thread corresponding to the thread of the protrusion 17 is formed on the inner peripheral surface.

  The table 16, the protruding portion 17, and the fixture 18 are also provided with through holes 16 a, 17 a, and 18 a, respectively. That is, the emitted X-rays are emitted through the through holes 26a and 21a, the passage member 28, the through holes 27b, 27a1, 16a, 17a, and 18a. The X-ray emitted from the hole 18a becomes parallel light parallel to the axis of the through hole 27a1, and is emitted from the circular hole 50c1 of the housing 50.

  Further, when the fixture 18 is viewed from the circular hole 50c1 side, as shown in FIG. 5, the cylindrical lens 19 is point-symmetric around the through hole 18a with the center of the through hole 18a as the center of symmetry at an interval of about 90 °. The arrangement is fixed so as to be. FIG. 6 is an enlarged view of the cross section of the through hole 18a portion of the fixture 18. As shown in FIG. 6, the fixture 18 has a through hole 18b around the through hole 18a. Is arranged and fixed at the upper end of the through hole 18b. As shown in FIG. 7, the cylindrical lens 19 has a curvature in a cross section perpendicular to the longitudinal direction. When the cylindrical lens 19 is arranged and fixed to the fixture 18, the cross section perpendicular to the radial direction of the fixture 18 is curved. have. Therefore, when visible light is irradiated with the same optical axis as the outgoing X-ray, the light converges only in the vertical direction in the radial direction of the fixture 18 and then diffuses. This point will be described in detail in the description of LED light emitted on the same optical axis as that of the emitted X-ray. Since X-rays hardly pass through the glass, the emitted X-rays are not emitted from the cylindrical lens 19 but emitted only from the through hole 18a.

  The imaging plate 15 moves to the diffraction ring imaging position together with the moving stage 21, the spindle motor 27, and the table 16, and also includes a diffraction ring reading area for reading the imaged diffraction ring described later, and a diffraction ring erasing area for erasing the diffraction ring. Move to. In this movement, the central axis of the imaging plate 15 is maintained in a plane formed by the optical axis of the outgoing X-ray and the position (line) at a rotation angle of 0 ° in the imaging plate 15, and the optical axis of the outgoing X-ray. Move in a direction perpendicular to.

  The laser detection device 30 irradiates the imaging plate 15 that images the diffraction ring with laser light, and detects the intensity of the light emitted from the imaging plate 15. The laser detection device 30 is sufficiently separated from the imaging plate 15 at the diffraction ring imaging position toward the feed motor 22 so that the X-ray diffracted by the measurement object OB is not blocked by the laser detection device 30. . The laser detection device 30 is an optical head including a laser light source 31, a collimating lens 32, a reflecting mirror 33, a dichroic mirror 34, an objective lens 36, and the like, and has the same configuration as that used for recording and reproduction of an optical disc. When a command is input from the controller 91, the laser drive circuit 77 outputs a drive signal to the laser light source 31 so that the intensity of the signal input from the photodetector 42 becomes a predetermined intensity. Laser light with a constant intensity is emitted from the laser light source 31. The photodetector 42 reflects a small amount by a dichroic mirror 34 to be described later, and outputs a signal having an intensity corresponding to the intensity of the laser beam received through the condenser lens 41, but the ratio of reflection at the dichroic mirror 34 is constant. Therefore, it can be considered that a signal having an intensity corresponding to the intensity of the emitted laser light is output. The collimating lens 32 collimates the laser light, the reflecting mirror 33 reflects the laser light toward the dichroic mirror 34, and the dichroic mirror 34 transmits most of the incident laser light (for example, 95%) as it is. The objective lens 36 focuses the laser light on the surface of the imaging plate 15. A focus actuator 37 is assembled to the objective lens 36. The focus of the laser light always matches the surface of the imaging plate 15 by a focus servo described later.

  When the focused laser beam is applied to the portion of the imaging plate 15 where the diffraction ring is imaged, a photo-stimulated luminescence phenomenon occurs, which depends on the intensity of the diffracted X-rays at the time of imaging the diffraction ring. Light is generated. The light generated by the stimulated light emission has a wavelength shorter than the wavelength of the laser light and passes through the objective lens 36 together with the reflected light of the laser light. However, most of the light is reflected by the dichroic mirror 34, Most are transparent. The light reflected by the dichroic mirror 34 enters the photodetector 40 via the condenser lens 38 and the cylindrical lens 39. The photodetector 40 includes a four-part light receiving element including four light receiving elements having the same square shape, and outputs four light receiving signals (a, b, c, d) to the amplifier circuit 78. The cylindrical lens 39 is used to cause astigmatism.

  The amplification circuit 78 amplifies the four received light signals (a, b, c, d) and outputs them to the focus error signal generation circuit 79 and the SUM signal generation circuit 80. The focus error signal generation circuit 79 generates a focus error signal in the astigmatism method and outputs the focus error signal to the focus servo circuit 81. The focus servo circuit 81 starts to operate when a command is input from the controller 91, generates a focus servo signal based on the input focus error signal, and outputs the focus servo signal to the drive circuit 82. The drive circuit 82 drives the focus actuator 37 in accordance with the input focus servo signal to displace the objective lens 36 in the direction of the optical axis of the laser beam, so that the focal point of the laser beam is always on the surface of the imaging plate 15. Match.

  The SUM signal generation circuit 80 adds the four received light reception signals to generate a SUM signal and outputs it to the A / D conversion circuit 83. The intensity of the SUM signal is equivalent to the intensity of a small amount of laser light reflected by the imaging plate 15 and reflected by the dichroic mirror 34 and the intensity of light generated by the stimulated emission. Since the intensity of the reflected laser beam is substantially constant, the intensity of the SUM signal corresponds to the intensity of the light generated by the stimulated emission. That is, the intensity of the SUM signal corresponds to the intensity of diffracted X-rays in the imaged diffraction ring. When a command is input from the controller 91, the A / D conversion circuit 83 converts the instantaneous value of the input SUM signal into digital data and outputs it to the controller 91.

  Further, an LED light source 43 is provided adjacent to the objective lens 36. The LED light source 43 is controlled by the LED drive circuit 84 to emit visible light and erase the diffraction ring imaged on the imaging plate 15. When the LED drive circuit 84 receives a command from the controller 91, the LED drive circuit 84 supplies the LED light source 43 with a drive signal for generating visible light having a predetermined intensity.

  The X-ray diffraction measurement apparatus has an LED light source 44. As shown in FIGS. 2 to 4, the LED light source 44 is fixed to the lower surface of one end portion of the plate 45 disposed between the moving stage 21 and the lower surface of the upper wall 26 of the table driving mechanism 20. The plate 45 is fixed to an output shaft 46 a of a motor 46 fixed in the moving stage 21, and rotates in a plane parallel to the lower surface of the upper wall 26 by the rotation of the motor 46. The moving stage 21 is provided with stopper members 47a and 47b. When the plate 45 is rotated in the direction D1 in FIG. 4, the LED light source 44 causes the through hole 26a of the upper wall 26 and the moving stage 21 to move. The rotation of the plate 45 is regulated so that it stops at a position (position A) facing the through hole 21a. On the other hand, the stopper member 47b is a position (B position) where the plate 45 does not block between the through hole 26a of the upper wall 26 and the through hole 21a of the moving stage 21 when the plate 45 is rotated in the direction D2 in FIG. The rotation of the plate 45 is restricted so as to be stationary. In other words, the A position is a position where the plate 45 is in the state shown in FIGS. 2 and 3, and the LED light emitted from the LED light source 44 enters the passage of the passage member 28 provided in the through hole 27 a 1 of the spindle motor 27. This is the incident position. The B position is a position where X-rays emitted from the X-ray emitter 10 are not blocked by the plate 45. The LED light source 44 emits LED light according to a drive signal from an LED drive circuit 85 that is controlled by the controller 91. Although the LED light is a diffusing visible light, when the plate 45 is at the A position, a part of the light is emitted from the through hole 18a through the same path as the outgoing X-ray, so that the through hole 27a1 is the same as the outgoing X-ray. Becomes parallel light parallel to the axis. Hereinafter, this parallel light is referred to as parallel LED light, and a minute circular irradiation trace formed at a location where the parallel LED light is received is referred to as an irradiation point.

  Further, as described above, there are four through holes 18b around the through hole 18a, and the cylindrical lens 19 is arranged and fixed at the upper end thereof, so that the LED light is emitted also through the cylindrical lens 19. . Although the LED light is visible light that diffuses, only the LED light that has entered the through-hole 18b is incident on the cylindrical lens among the LED light that has entered the passage of the passage member 28, so that it is the same as the LED light emitted from the through-hole 18a. The LED light incident on the cylindrical lens 19 is also parallel light. As described above, since the cylindrical lens 19 has a curvature in the radial section of the fixture 18, the LED light emitted from the cylindrical lens 19 converges in the vertical direction of the fixture 18 in the radial direction. A line irradiation trace is formed at a location where the LED light is diffused and received. Hereinafter, LED light emitted from the cylindrical lens 19 is referred to as diffused LED light, and an irradiation trace of a line formed at a location where the diffused LED light is received is referred to as an irradiation line. Since four cylindrical lenses 19 are arranged and fixed around the through hole 18a at an interval of 90 °, four irradiation lines are formed around the irradiation point of the LED light so as to form a square. On the light receiving surface perpendicular to the optical axis of the emitted X-ray (parallel LED light), an irradiation line is formed so as to form a square centering on the irradiation point, but the optical axis of the emitted X-ray (parallel LED light) If the degree and direction of inclination of the light receiving surface with respect to the square change, the shape of the quadrangle changes accordingly. Therefore, the incident angle of the outgoing X-ray and the reference plane tilt angle can be obtained by photographing the irradiation line from a position fixed with respect to the optical axis of the outgoing X-ray (parallel LED light) and analyzing the photographed image. . This point will be described in detail later. The optical axis of the diffused LED light is substantially parallel to the optical axis of the parallel LED light, but the through hole 18b is located outside the through hole 18a, so that the component in the vertical direction of the optical axis of the parallel LED light is small although it is minute. Have. Therefore, the quadrangle formed by the four irradiation lines formed on the light receiving surface perpendicular to the optical axis of the emitted X-ray (parallel LED light) has a larger distance IP-OB (distance from the X-ray irradiation point to the imaging plate 15). It is small but large. However, since this enlargement ratio is small, if the distance IP-OB is approximately constant, the square can be regarded as constant.

  The motor 46 includes an encoder 46b. The encoder 46b outputs a pulse train signal that alternately switches between a high level and a low level to the rotation control circuit 86 every time the motor 46 rotates by a predetermined minute rotation angle. When a rotation direction and a rotation start command are input from the controller 91, the rotation control circuit 86 outputs a drive signal to the motor 46 to rotate the motor 46 in the indicated direction. When the input of the pulse train signal from the encoder 46b is stopped, the output of the drive signal is stopped. Thereby, the plate 45 can be rotated to the A position and the B position, respectively.

  An imaging lens 48 is provided on the notch wall 50 c of the housing 50, and an imager 49 is provided inside the housing 50. The image pickup device 49 is constituted by a CCD light receiver or a CMOS light receiver, and outputs a signal having an intensity corresponding to the light reception intensity of each image pickup device to the sensor signal extraction circuit 87. The imaging lens 48 and the imager 49 function as a digital camera that captures an image of an area around the irradiation point and irradiation line of the LED light on the measurement object OB at a position set with respect to the imaging plate 15. To do. The position set with respect to the imaging plate 15 is a position where the distance IP-OB is a predetermined distance determined in advance. In this case, the depth of field by the imaging lens 48 and the imager 49 is set in a range before and after the irradiation point. The sensor signal extraction circuit 87 outputs the signal intensity data for each image pickup device of the image pickup device 49 to the controller 91 together with data for knowing the position (that is, pixel position) of each image pickup device.

  Further, the optical axis of the imaging lens 48 is included in the reference plane, and the point where the optical axis and the optical axes of the X-rays and parallel LED light irradiated to the measurement object OB intersect with the imaging plate 15. The measurement object OB at the set position is adjusted to be an irradiation point of X-rays and parallel LED light. Further, when the incident angle of the X-ray and the parallel LED light with respect to the measurement object OB is a set value, the optical axis of the imaging lens 48 and the normal direction at the irradiation point of the X-ray and parallel LED light of the measurement object OB The angle formed by is equal to the incident angle. Therefore, when the distance IP-OB becomes a set value and parallel LED light is irradiated at the incident angle set on the measurement object OB, the LED light irradiation point in the captured image and the measurement object OB are reflected. The light receiving point of the LED light occurs at the same position. Since the parallel LED light applied to the measurement object OB is parallel light, scattered light and reflected light that is reflected as substantially parallel light are generated at the irradiation point, but the incident light enters the imaging lens 48 out of the scattered light. The light is imaged at the position of the image pickup device 49 to form an image of the irradiation point, and the reflected light incident on the image forming lens 48 is collected by the image forming lens 48 and received by the image pickup device 49 to form an image of the light receiving point. . When the distance IP-OB is the set value and the incident angle of the parallel LED light on the measurement object OB is the set value, the optical axis of the scattered light incident on the imaging lens 48 and the optical axis of the reflected light are either Since this coincides with the optical axis of the imaging lens 48, the image of the irradiation point and the image of the light receiving point are in the same position. Since the X-ray diffraction measurement system has a function of detecting the incident angle of X-rays with respect to the measurement object OB, it is essential that the distance IP-OB be a set value. It is not essential to set the incident angle of light at the measurement object OB to a set value.

  The computer device 90 includes a controller 91, an input device 92, and a display device 93. The controller 91 is an electronic control unit mainly including a microcomputer including a CPU, ROM, RAM, a large capacity storage device, and the like, and executes various programs stored in the large capacity storage device to perform an X-ray diffraction measurement device. Control the operation of The input device 92 is connected to the controller 91 and is used by an operator to input various parameters, work instructions, and the like. The display device 93 includes the position and orientation of the X-ray diffraction measurement device (housing 50) with respect to the measurement location of the measurement object OB, in addition to the image including the irradiation point and the light receiving point imaged by the imaging device 49 on the display screen. A mark for properly setting is also displayed. Further, the display device 93 visually notifies the operator of various setting situations, operating situations, measurement results, and the like. The high voltage power supply 95 supplies the X-ray emitter 10 with a high voltage and current for X-ray emission.

  Next, using the X-ray diffraction measurement system including the X-ray diffraction measurement apparatus configured as described above, after adjusting the position and orientation of the measurement object OB relative to the X-ray diffraction measurement apparatus, A specific method for performing X-ray diffraction measurement will be described. The operator places the measurement object OB on the stage 61 of the object setting device 60, transports the X-ray diffraction measurement device (housing 50) to the vicinity of the measurement object OB, and then turns on the power and turns on X. Activate the line diffraction measurement system. Thereafter, the X-ray diffraction measurement is performed in the order of the position / orientation adjustment step S1, the diffraction ring imaging step S2, the diffraction ring reading step S3, the diffraction ring elimination step S4, and the residual stress calculation step S5. The portions already described in detail in 2 are only briefly described.

  The position and orientation adjustment step S1 is a step of adjusting the position and orientation of the measurement object OB with respect to the X-ray diffraction measurement apparatus (housing 50). First, the operator operates some of the five operators 63a, 65a, 66a, 67a, 68a of the object setting device 60 to determine the position of the measurement object OB relative to the X-ray diffraction measurement device (housing 50). By adjusting the posture, the X-ray irradiation point and the X-ray incident direction on the measurement object OB are approximately set to the target measurement position and direction, and the distance IP-OB becomes a set value. Next, the operator inputs to adjust the position and orientation from the input device 92. With this input, the controller 91 outputs a command to each circuit, moves the imaging plate 15 to the diffraction ring imaging position (the state shown in FIGS. 1 to 3), and drives the motor 46 to rotate the plate 45 to the A position. The LED light source 44 is turned on. Thereby, parallel LED light and diffused LED light are emitted to the outside from the circular hole 50c1 of the housing 50, and an irradiation point and an irradiation line are formed in the vicinity of the target measurement position of the measurement object OB. Further, the controller 91 causes the image pickup signal from the image pickup device 49 to be output from the sensor signal extraction circuit 87 to the controller 91, and causes the display device 93 to display an image of the irradiation point and the vicinity of the irradiation line created from this image pickup signal. At this time, the displayed image includes a cross mark at a position on the captured image corresponding to the position where the optical axis of the imaging lens 48 intersects the image pickup device 49 independently of the image created by the imaging signal. Is displayed.

  In this case, the cross point of the cross mark is located at the center of the screen of the display device 93, the X-axis direction of the cross mark corresponds to the horizontal direction of the screen, and the Y-axis direction of the cross mark corresponds to the vertical direction of the screen. The cross point of the cross mark is a position where the irradiation point is imaged when the distance IP-OB is the set value, and at the same time, the distance IP-OB is the set value, and the parallel LED light measurement object OB. When the incident angle at is a set value, this is the position at which the light receiving point is imaged. The Y axis of the cross mark corresponds to a line where the reference plane intersects the imaging organ 49, and the Y axis direction of the cross mark is the irradiation direction of the parallel LED light and the X-ray, and this direction is projected onto the measurement object OB. The measured direction is the measurement direction of the residual normal stress.

  In addition, the controller 91 stores image data created from the imaging signal at a set time interval, and calculates the incident angle and reference plane tilt angle of the emitted X-ray (parallel LED light) from the irradiation line image in the stored image data. Calculation and display on the display device 93 are performed. Hereinafter, this calculation method will be described. FIG. 8 shows two irradiation lines above and below four irradiation lines when the angle of the plane of the measurement object OB with respect to the optical axis of the emitted X-ray (parallel LED light) is changed around the normal direction of the reference plane. These are a figure when the position imaged by the imager 49 is viewed on a reference plane, and an irradiation point and four irradiation lines in the captured image. In FIG. 8, the angle of the plane of the measurement object OB with respect to the optical axis of 30 °, 60 °, 90 ° and outgoing X-ray (parallel LED light) is changed in the order of (a) to (c). That is, the incident angle of the emitted X-ray (parallel LED light) is changed to 60 °, 30 °, and 0 °. The reference plane inclination angle is set to 0 ° for easy understanding. The quadrangle formed by the four irradiation lines formed on the measurement object OB is a square when the incident angle is 0 °, and becomes a rectangle whose side parallel to the reference plane becomes longer as the incident angle increases. Since there are places where the distance from the imaging lens 48 is different, the far side is small and the near side is long, as shown in the figure. That is, the optical axis direction of the imaging lens 48 substantially coincides with the normal direction of the measurement object OB, that is, the distance from the imaging lens 48 on the opposite sides of the quadrangle by the four irradiation lines is equal (a). Although the quadrangle is a rectangle, the optical axis direction of the imaging lens 48 is a trapezoid in (b) and (c) where the normal direction of the measurement object OB does not coincide. However, as can be seen from the figure, regardless of the square shape, the interval Wt between the upper and lower two irradiation lines becomes smaller as the incident angles become 60 °, 30 °, and 0 °, and the interval Wt and the incident angle become smaller. There is a 1: 1 relationship. This is because the position where the straight line connecting the position of the upper and lower two irradiation lines and the center of the imaging lens intersects with the imager 49, that is, the interval between the imaging positions of the upper and lower two irradiation lines is 60 °, 30 °. It can also be understood from the fact that the smaller the angle, the smaller the angle, 0 °. Therefore, if the relationship between the spacing Wt and the incident angle is stored in the form of a relational table or a relational expression, the image data is processed to obtain the spacing Wt between the upper and lower two irradiation lines, whereby the outgoing X-ray (parallel LED The incident angle of light) can be calculated.

  FIG. 8 shows the case where the optical axis of the imaging lens 48 intersects the irradiation point of the outgoing X-ray (parallel LED light), that is, the distance IP-OB becomes a set value. When the distance IP-OB is deviated from the set value, the irradiation point moves from the vicinity of the center of the irradiation line, and the relationship between the interval Wt and the incident angle also changes. However, if the distance IP-OB is near the set value, this relationship can be regarded as almost constant, and the distance IP-OB is set to the set value by matching the irradiation point with the cross point of the cross mark. Therefore, the relationship between the interval Wt and the incident angle to be stored only needs to be that when the distance IP-OB is a set value.

  FIG. 8 is a diagram in which the incident angle is changed by setting the reference plane inclination angle to 0 °. However, in actuality, the reference plane inclination angle rarely becomes 0 ° without adjustment, so that four irradiation lines are used. The quadrangle is not a trapezoid, and the upper and lower irradiation lines are not parallel. However, even if the reference plane tilt angle is not 0 °, the optical plane of the imaging lens 48 is included in the reference plane, so that two upper and lower irradiation lines of the four irradiation lines in FIG. The view of the imaged position on the reference plane does not change. That is, even if the upper and lower irradiation lines are not parallel, the relationship between the interval Wt and the incident angle in the Y-axis portion of the captured image (corresponding to the line where the reference plane intersects the imager 49) is the same relationship. . Therefore, if the image data is processed to obtain the interval Wt in the Y-axis part, the incident angle can be calculated from the relation table or relational expression. Since the original incident angle is an angle formed by the optical axis of the outgoing X-ray (parallel LED light) and the normal line at the X-ray irradiation point, the incident angle calculated when the reference plane tilt angle is not 0 ° is , Not the original incident angle, but the incident angle when the measuring object OB is rotated around a line where the reference plane and the plane of the measuring object OB intersect to set the reference plane tilt angle to 0 °. However, since the reference plane tilt angle is adjusted to be 0 °, there is no problem even if the displayed incident angle is the above value.

  Here, a method for obtaining the relationship between the interval Wt and the incident angle will be described. First, the X-axis direction of the X-ray diffraction measurement apparatus shown in FIG. 2 and the X-axis direction of the object setting apparatus 60 are made parallel. This is done as follows. The inclination of the object setting device 60 around the X-axis and the Y-axis is set to 0 (the scales of the operating elements 65a and 66a are set to 0), and a block having a uniform thickness with a mark on the stage 61 is placed on the X-ray. Activate the camera function of the diffractometer. Next, the operating elements 63a, 67a, and 68a are rotated so that the mark comes near the center of the captured image. Next, when the operator 67a is rotated to move the mark in the X-axis direction, the object setting device 60 or the X-ray diffraction measurement device is placed so that the mark in the captured image moves in the X-axis direction of the captured image. Change the way. Since the X-axis direction of the X-ray diffraction measurement apparatus is the normal direction of the reference plane, the rotation axis when the stage 61 is tilted by the operation element 65a is thus parallel to the normal direction of the reference plane. Next, as described above, the parallel LED light and the diffused LED light are emitted, and the operation elements 63a and 65a to 68a are operated so that the irradiation point and the light receiving point coincide with the cross point of the cross mark of the captured image. As a result, the reference plane and the plane of the block placed on the stage 61 become perpendicular, and the incident angle of the parallel LED light to the block becomes a set value. Next, a command is input from the input device 93 to cause the controller 91 to process the image data and obtain and store the interval Wt between the upper and lower two irradiation lines. Thus, the relationship between the set value of the incident angle and the interval Wt is obtained. Next, the operator 65a is rotated while reading the scale, and by changing the value of the scale by ΔΘ, the stage 61 is tilted by ΔΘ and input from the input device 93 to cause the controller 91 to process the image data. The interval Wt is obtained and stored. Thus, the relationship between the incident angle (setting value + ΔΘ) and the interval Wt is obtained. Thereafter, by repeatedly storing the interval Wt in the controller 91 every time ΔΘ is changed, the relationship between the interval Wt and the incident angle can be obtained. Whether this relationship is stored in the form of a relation table or in the form of a relational expression may be appropriately selected.

  Next, a method for calculating the reference plane tilt angle will be described. FIG. 9 shows the positions where the left and right irradiation lines of the four irradiation lines are imaged by the imager 49 when the angle of the plane of the measurement object OB with respect to the reference plane is changed. It is the figure at the time of seeing from the direction of the line which the plane of OB crosses, and the figure of the irradiation point in a picked-up image, and four irradiation lines. FIG. 9A is a diagram in which the incident angle of the emitted X-ray (parallel LED light) is 30 °, the angle of the plane of the measurement object OB with respect to the reference plane is 90 °, that is, the reference plane inclination angle is 0 °. Yes, the same state as in FIG. FIG. 9B is a diagram in which the reference plane inclination angle is 20 ° from the state of (a), and FIG. 9C is a diagram in which the reference plane inclination angle is 40 ° from the state of (a). As can be seen from FIG. 9, the interval between the two left and right irradiation lines changes only slightly even when the reference plane inclination angle increases to 0 °, 20 °, and 40 °. The difference in distance from the imaging lens 48 varies greatly. For this reason, the shape of the quadrangle formed by the four irradiation lines becomes worse in the degree of left-right symmetry as the reference plane tilt angle increases. This is that the difference between Θa and Θb and the difference between Θc and Θd are large at the inner angles Θa, Θb, Θc, and Θd formed by the four irradiation lines shown in FIG. 9A. That is, there is a 1: 1 relationship between the difference between Θa and Θb, or the difference between Θc and Θd and the reference plane tilt angle. Accordingly, if the difference between Θa and Θb, or the difference between Θc and Θd and the reference plane tilt angle is stored in the form of a relational table or relational expression, the image data is processed and the difference between Θa and Θb, or Θc By calculating the difference between Θd and Θd, the reference plane tilt angle can be calculated.

  The relationship between the difference between Θa and Θb, or the difference between Θc and Θd and the reference plane tilt angle is different for each incident angle of the outgoing X-ray (parallel LED light). Or it is necessary to memorize a relational expression. When calculating the reference plane inclination angle, it is necessary to use a relation table or relational expression of the incident angle closest to the incident angle obtained by the above-described method. However, the reference plane inclination angle is a value that should be 0 ° by adjusting the posture of the measurement object. If the reference plane inclination angle is 0 ° regardless of the incident angle, Θa = Θb and Θc = Θd. It is not necessary to accurately detect the reference plane tilt angle. Therefore, it is only necessary to store a relational table or relational expression at the incident angles of several outgoing X-rays (parallel LED light) that have greatly different values.

  Here, a method of obtaining the difference between Θa and Θb and the relationship between the difference between Θc and Θd and the reference plane tilt angle will be described. First, as described in the method for obtaining the relationship between the interval Wt and the incident angle, a block having a uniform thickness with a mark placed on the stage 61 is placed, and the X-axis direction of the X-ray diffraction measurement apparatus shown in FIG. And the X-axis direction of the object setting device 60 are made parallel. In this way, the Y-axis direction of the object setting device 60 is parallel to the reference plane, and the rotation axis when the stage 61 is tilted by the operation element 66a is parallel to the reference plane. Next, as described in the above-described method for obtaining the relationship between the interval Wt and the incident angle, the irradiation point and the light receiving point are matched with the cross point of the cross mark of the captured image. Next, a command is input from the input device 92, the image data is processed by the controller 91, and the difference between Θa and Θb and the difference between Θc and Θd are obtained and stored. Thus, the difference between Θa and Θb and the difference between Θc and Θd when the incident angle is a set value and the reference plane tilt angle is 0 ° are obtained. These differences are all zero. Next, the operator 66a is rotated while reading the scale, the stage 61 is tilted by ΔΘ by changing the value of the scale by ΔΘ, input from the input device 93, and the difference between Θa and Θb to the controller 91, and The difference between Θc and Θd is obtained and stored. Thus, the difference between Θa and Θb and the difference between Θc and Θd when the incident angle is the set value and the reference plane tilt angle is ΔΘ are obtained. After that, every time ΔΘ is changed, if the controller 91 stores the difference between Θa and Θb and the difference between Θc and Θd repeatedly, the difference between Θa and Θb when the incident angle is a set value, and Θc and The relationship between the difference in Θd and the reference plane tilt angle is obtained. Then, the operator 65a is rotated while reading the scale, and the incident angle is set to (set value + Θs) by changing the scale value by Θs, and the incident angle is set to (set value + Θs) by performing the same operation as described above. ), The difference between Θa and Θb, and the difference between Θc and Θd and the reference plane tilt angle are obtained. If this is carried out with several Θs with greatly different values, the difference between Θa and Θb, and the difference between Θc and Θd and the reference plane tilt angle at the incident angles of several outgoing X-rays (parallel LED light). A relationship can be sought. Whether this relationship is stored in the form of a relation table or in the form of a relational expression may be appropriately selected.

  Returning to the description of the position / orientation adjustment step S1, the operator looks at the captured image displayed on the display device 93, the numerical value of the incident angle of X-rays (parallel LED light), and the numerical value of the reference plane inclination angle, By operating the five operators 63a, 65a, 66a, 67a, 68a of the set device 60, the position and orientation of the measurement object OB are adjusted, and the irradiation point of the LED light on the captured image is the position of the measurement object OB. The target measurement position and the cross point of the cross mark are matched, the displayed reference plane tilt angle is 0 °, and the X-ray (parallel LED light) incident angle is adjusted to the target value. . If it is determined that X-rays are incident on the measurement object OB at a set incident angle, the displayed incident angle and reference plane tilt angle values are ignored, and the light receiving point matches the cross point of the cross mark. You may adjust as follows.

  When the adjustment of the position and orientation of the measurement object OB is finished, the operator inputs the end of the position and orientation adjustment from the input device 92. As a result, the controller 91 stores the incident angle ψ of the X-rays (parallel LED light) displayed on the display device 93. Then, a command is output to each circuit, the LED light source 44 is turned off, the output of the imaging signal is stopped, the motor 46 is driven, and the plate 45 is rotated to the B position. As a result, the X-ray from the X-ray emitter 10 can enter the through hole 21 a of the moving stage 21.

  In the next diffraction ring imaging step S2, the operator inputs the material of the measurement object OB (in this embodiment, iron) from the input device 92, and inputs the start of measurement. Accordingly, the controller 91 controls the spindle motor control circuit 74 to rotate the imaging plate 15 at a low speed, and stops the rotation of the imaging plate 15 when the index signal is input from the encoder 27c. Thereby, the diffraction ring is imaged on the imaging plate 15 in a state where the rotation angle is 0 ° at the time of reading the diffraction ring. Next, the controller 91 controls the X-ray control circuit 71 to cause the X-ray emitter 10 to start emitting X-rays. Thereby, the diffraction ring is imaged on the imaging plate 15 by the diffracted X-rays generated at the X-ray irradiation point in the measurement object OB. Then, after a predetermined time has elapsed, the X-ray control circuit 71 is controlled to cause the X-ray emitter 10 to stop emitting X-rays.

  Next, the controller 91 executes the diffraction ring reading step S3 automatically or by operator input. The controller 91 controls the feed motor control circuit 73 to move the imaging plate 15 to the reading start position in the diffraction ring reading region. The reading start position is a position where the irradiation position of the laser beam is slightly inside the circle with the diffraction ring reference radius Ro. The diffraction ring reference radius Ro is the radius of the diffraction ring formed on the imaging plate 15 when the residual stress of the measurement object OB is “0”, and the X-ray diffraction angle 2Θx of the measurement object OB. (Θx is a Bragg angle) and the distance L from the X-ray irradiation point to the imaging plate 15 are calculated by the following formula: Ro = L · tan (2Θx). The X-ray diffraction angle 2Θx is determined by the material of the measurement object OB, and the distance L is adjusted to a set value. Therefore, if the diffraction angle 2Θx is stored in advance for each material of the measurement object OB, the measurement is performed. The diffraction ring reference radius Ro can be calculated by inputting the material of the object OB.

  Next, the controller 91 controls the spindle motor control circuit 74 to rotate the spindle motor 27 at a predetermined rotation speed, and controls the laser drive circuit 77 to irradiate the imaging plate 15 with laser light from the laser detection device 30. The focus servo circuit 81 is controlled to start focus servo. Further, the rotation angle detection circuit 75 is controlled to start the output of the rotation angle θp of the spindle motor 27 (imaging plate 15), and the A / D conversion circuit 83 is controlled to output the data of the instantaneous value I of the SUM signal. , And the feed motor control circuit 73 is controlled to rotate the feed motor 22 to move the imaging plate 15 from the reading start position in the lower right direction in FIGS. 1 and 2 at a constant speed. Thereby, the irradiation position of the laser beam starts to rotate relatively spirally on the imaging plate 15. Thereafter, every time the imaging plate 15 rotates by a predetermined small angle, the controller 91 outputs the data of the instantaneous value I of the SUM signal output from the A / D conversion circuit 83 and the rotation angle θp output from the rotation angle detection circuit 75. And the data of the movement distance x output from the position detection circuit 72 are input and stored in correspondence with each other. The moving distance x is stored after being converted into a radial distance r (radius value r) of the laser beam irradiation position. As a result, the data representing the instantaneous value I, the rotation angle θp, and the radius value r of the SUM signal are sequentially stored for each predetermined rotation angle with respect to the irradiation position of the laser beam rotating in a spiral.

  In parallel with the storing operation for each predetermined rotation angle of the data representing the instantaneous value I, the rotation angle θp, and the radius value r of the SUM signal, the controller 91 sets the instantaneous value I of the SUM signal with respect to the radius value r for each rotation angle θp. A curve is created, and a radius value rα and a SUM signal intensity value Iα corresponding to the peak of the curve are stored. This is a process of obtaining the intensity distribution of the diffracted X-rays in the radial direction for each rotation angle α of the diffraction ring, and obtaining the radius value rα and the intensity Iα corresponding to the intensity of the diffracted X-rays where the intensity of the diffracted X-rays reaches a peak. It is. Then, the radius value rα and the intensity Iα are acquired at all the rotation angles θp (rotation angle α), and when the instantaneous value I of the SUM signal to be detected becomes sufficiently smaller than the intensity Iα, the data storage is finished. . As a result, the intensity distribution corresponding to the intensity of the diffracted X-rays in the diffraction ring is detected by the data group of the instantaneous value I, the rotation angle θp and the radius value r, and the shape of the diffraction ring is detected by the radius value rα for each rotation angle α. It will be done. Thereafter, the controller 91 outputs a command to each circuit, stops the focus servo, stops the irradiation of the laser beam, stops the operation of the A / D conversion circuit 83 and the rotation angle detection circuit 75, and Stop operation. The rotation of the imaging plate 15 is continued.

  Next, the controller 91 executes the diffraction ring elimination step S4 automatically or by operator input. The controller 91 controls the feed motor control circuit 73 to move the imaging plate 15 to the erase start position in the diffraction ring erase region. The erasing start position of the imaging plate 15 is a position where the center of the LED light output from the LED light source 43 is further inside than the reading start position with respect to the circle having the diffraction ring reference radius Ro. Next, the controller 91 controls the LED drive circuit 84 to irradiate the imaging plate 15 with the LED light from the LED light source 43 and controls the feed motor control circuit 73 so that the imaging plate 15 is moved from the erasing start position. The feed motor 22 is rotated so as to move at a constant speed in the lower right direction in FIGS. 1 and 2 to the erase end position. The erase end position is a position where the center of the LED light is outside the diffraction ring reference radius Ro by the same distance as the erase start position. Thereby, LED light is irradiated spirally on the imaging plate 15, and the imaged diffraction ring is erased.

  When the imaging plate 15 reaches the erasing end position, the controller 91 controls the feed motor control circuit 73 to stop the movement of the imaging plate 15 and controls the LED drive circuit 84 to stop the irradiation of the LED light to detect the position. The operation of the circuit 72 is stopped, and the spindle motor control circuit 74 is controlled to stop the rotation of the spindle motor 27 (imaging plate 15).

  Next, the controller 91 executes the residual stress calculation step S5 automatically or by operator input. This is based on the cos α method using the data of the radius value rα for each rotation angle α which is the shape of the diffraction ring, the set value L of the distance from the X-ray irradiation point to the imaging plate 15 and the X-ray incident angle ψ. This is a calculation process for calculating the residual stress by the calculation used. This calculation is a well-known technique and is described in detail in, for example, Japanese Patent Laid-Open No. 2005-241308 [0026] to [0044], and thus the description thereof is omitted. When the calculation of the residual stress is completed, the controller 91 displays the calculation result of the residual stress on the display device 93. In addition to the residual stress, measurement conditions such as the distance L from the X-ray irradiation point to the imaging plate 15, the incident angle ψ of the X-ray, and the shape curve of the diffraction ring (curve obtained from the radius value rα for each rotation angle α) The intensity distribution image of the diffraction ring (the instantaneous value Iα is converted into the lightness, and the image created from the data group of the lightness, the rotation angle θp and the radius value r corresponding to the instantaneous value Iα) may be displayed. . By looking at the result, the operator can evaluate the fatigue level of the measurement object OB, evaluate the processing result by shot peening, and the like.

  As can be understood from the above description, in the above embodiment, the X-ray emitter 10 that emits X-rays toward the target measurement object OB, and the X-ray emitter 10 toward the measurement object OB. X-rays are emitted, and the diffracted X-rays generated at the X-ray irradiation spot of the measurement object OB are reflected on the imaging plate 15 that intersects the optical axis of the X-rays emitted from the X-ray emitter 10 perpendicularly. It includes an X-ray diffraction measurement device that receives a light and forms a diffraction ring as an image of a diffraction X-ray on the imaging plate 15 and detects the shape of the diffraction ring, a table driving mechanism 20 and various circuits. In the X-ray diffraction measurement system, LED light that is parallel light having the same optical axis as that of the X-ray emitted from the X-ray emitter 10 in a state where the X-ray is not emitted from the X-ray emitter 10 is measured. Output to object OB LED light emitters comprising passages such as the LED light source 44 and the passage member 28, the through hole 27b, and the irradiation point formed on the measurement object OB by the LED light emitted from the LED light emitters. A pattern projector comprising an LED light source 44 for projecting a pattern having a fixed shape when projected onto a plane perpendicular to the optical axis, a passage such as the passage member 28 and the through hole 27b, the through hole 18b of the fixture 18 and the cylindrical lens 19; An imaging lens 48 that forms an image of the measurement object OB in an area including the LED light irradiation point and the pattern, and an image pickup device 49 that picks up an image formed by the imaging lens 48. A camera that outputs an imaging signal representing a captured image, an image creation program of a controller 91 that creates an image by inputting an imaging signal output by the camera, and a controller And an incident angle calculation program of the controller 91 for calculating the incident angle of the X-ray emitted from the X-ray emitter 10 on the measurement object OB from the shape of the pattern in the image created by the one image creation program. .

  According to this, the LED light is emitted to the measurement object by the LED light emitter, the pattern is projected onto the measurement object by the pattern projector, the camera is operated, and the image is created by the image creation program of the controller 91. For example, the incident angle calculation program of the controller 91 can calculate the incident angle of the outgoing X-ray on the measurement object OB from the pattern shape in the image. That is, even if the incident angle of the X-ray with respect to the measurement object OB is an arbitrary angle, the incident angle can be accurately detected. Since the incident angle of the outgoing X-ray is calculated from the shape of the pattern, the controller 91 can calculate and display the incident angle of the outgoing X-ray in real time, and the operator can easily determine the incident angle of the outgoing X-ray. The position and orientation of the measurement object OB can be adjusted so as to be a value.

  In the above-described embodiment, the X-ray optical axis emitted from the X-ray emitter 10 and the rotation angle of the imaging plate 15 are set to 0 ° from the pattern shape in the image created by the image creation program of the controller 91. A reference plane inclination angle calculation program of the controller 91 is provided for calculating an angle formed by the normal direction of the plane including the line with the surface of the measurement object OB.

  According to this, while confirming the value of the reference plane inclination angle calculated by the reference plane inclination angle calculation program of the controller 91, the position and orientation of the measurement object OB are adjusted so that the reference plane inclination angle becomes 0 °. can do. That is, in order to improve the accuracy of the residual stress imaged on the imaging plate 15 and calculated from the shape of the diffraction ring detected by the laser detector 30 or the like, the outgoing X-ray is set after setting the reference plane tilt angle to 0 °. However, since the reference plane tilt angle can be calculated and displayed in real time, the position and orientation of the measurement object OB can be easily adjusted so that the reference plane tilt angle is 0 °. can do.

  Moreover, in the said embodiment, the pattern projector which consists of LED light source 44, channel | paths, such as the channel | path member 28, the through-hole 27b, the through-hole 18b of the fixing tool 18, and the cylindrical lens 19, is a plane perpendicular | vertical to the optical axis of LED light. Projecting a pattern in which two parallel irradiation lines intersect. According to this, it is possible to accurately calculate the incident angle of the outgoing X-ray and the reference plane tilt angle from the quadrangular shape formed by the two sets of parallel irradiation lines.

  In the above embodiment, the LED light emitter has a through-hole 18a that emits LED light, which is substantially parallel light, while shielding the peripheral portion in the cross section of the LED light, and the pattern projector has the through-hole 18a. And a plurality of cylindrical lenses 19 that allow LED light that does not pass through the through hole 18a to pass therethrough. According to this, only by providing two sets of cylindrical lenses 19 arranged and fixed in parallel around the through-hole 18a, a pattern in which two sets of parallel irradiation lines intersect can be projected, thereby increasing the cost of the apparatus. Can be suppressed. Although the optical axis of the X-ray emitted from the X-ray emitter 10 and the optical axis of the LED light are the same, the X-ray does not pass through the cylindrical lens 19 and therefore does not affect the X-ray diffraction measurement.

  In carrying out the present invention, the present invention is not limited to the above embodiment, and various modifications can be made without departing from the object of the present invention.

  In the above embodiment, the irradiation line is formed on the surface of the measurement object OB by making the substantially cylindrical LED light incident on the convex cylindrical lens 19 and emitting the diffused LED light. As long as is formed, other lenses may be used. For example, a concave cylindrical lens may be used, or a rod lens may be used. The cylindrical lens described in the claims includes all lenses that can form an irradiation line on the surface of the measurement object OB.

  Further, in the above embodiment, a pattern in which a quadrangle with four irradiation lines is formed is projected on the surface of the measurement object OB. However, if the incident angle of the emitted X-ray can be accurately calculated, Any pattern may be projected. For example, a perfect circle pattern may be projected, and the incident angle and the reference plane tilt angle may be calculated from the major axis and minor axis length of the oval pattern generated in the captured image and the direction of the major axis. In addition, only the pattern that becomes the upper and lower irradiation lines in the captured image is projected, the incident angle of the X-ray is calculated in the same manner as in the above embodiment, and the reference plane inclination angle is calculated from the degree of deviation of the upper and lower irradiation lines from parallel. You may make it do.

  Moreover, in the said embodiment, the through-hole 18b is created in the fixing tool 18, and the cylindrical lens 19 is arrange | positioned and fixed to the upper end, and when irradiated with LED light, an irradiation line is set around the irradiation point of the measuring object OB. Was formed. However, any pattern projection method may be used as long as the pattern can be projected so that the pattern when projected onto the plane perpendicular to the optical axis of the emitted X-ray is constant. For example, if it is not necessary to consider the cost of the apparatus, a plurality of irradiators that irradiate line light may be arranged around the opening 50c1.

  In the above embodiment, the controller 91 includes a calculation program for calculating the incident angle of the outgoing X-ray and a calculation program for calculating the reference plane tilt angle. However, the measurement object OB is limited to a surface whose surface is substantially parallel to the surface of the stage 61, and the reference plane of the X-ray diffraction measurement apparatus (the optical axis of the emitted X-ray and the rotation angle of the imaging plate 15 is 0). When the tilt angle around the Y axis of the object setting device 60 is 0, the plane including the line of ° is perpendicular to the surface of the stage 61, and the normal direction of the reference plane is that of the object setting device 60. Since the reference plane inclination angle is always 0 ° as long as it is parallel to the X-axis direction, only the calculation program for calculating the incident angle of the emitted X-ray may be provided.

  In the above-described embodiment, the X-ray diffraction measurement apparatus is an apparatus that images the diffraction ring on the imaging plate 15 and detects the shape of the diffraction ring by laser irradiation from the laser detection apparatus 30 and light intensity detection. However, any type of apparatus may be used as long as the shape can be detected by imaging the diffraction ring. For example, instead of the imaging plate 15, an X-ray CCD having a plane as wide as the imaging plate 15 is provided, and when X-ray irradiation from the X-ray emitter 10 is performed, an electric signal output from each pixel of the X-ray CCD is used. A device that detects the intensity distribution of diffracted X-rays in the diffraction ring may be used. Further, instead of the X-ray CCD having the same plane as the imaging plate 15, the X-ray CCD having a small size is scanned while detecting the position, and the electric signal output from each pixel of the X-ray CCD and the X-ray CCD. A device that detects the intensity distribution of the diffracted X-rays in the diffraction ring from the scanning position in FIG. In addition, a device using a scintillation counter that detects fluorescence emitted from the scintillator with a photomultiplier tube (PMT) instead of the X-ray CCD may be used.

  In the above embodiment, the controller 91 is provided with a calculation program for calculating the residual stress from the shape of the diffraction ring. However, if the X-ray diffraction measurement may take time, the X-ray diffraction measurement system can obtain the shape of the diffraction ring, and input the diffraction ring data to another computer device to calculate the residual stress. You may do it. In this case, as a method for inputting diffraction ring data to another computer device, various methods such as a method through a recording medium and a method of transferring using a net line or the like are conceivable. Also, some or all of the calculations may be performed artificially.

  In the above embodiment, the position and orientation of the measurement object OB relative to the X-ray diffraction measurement apparatus are adjusted by the three-direction moving mechanism and the two-direction rotation mechanism of the object set 60. Any configuration may be used as long as the position and orientation of the measurement object OB with respect to the line diffraction measurement apparatus can be adjusted. For example, the stage 61 on which the measurement object OB is placed may be fixed, and the X-ray diffraction measurement device may be connected to an arm type moving device or the like so that the position and posture of the X-ray diffraction measurement device can be adjusted. The object set 60 may be left as it is, and the position and posture of both the X-ray diffraction measurement apparatus and the measurement object OB may be adjusted by connecting the X-ray diffraction measurement apparatus to an arm type moving device or the like.

  Moreover, in the said embodiment and modification, the LED light source 44 is moved on the optical axis of a X-ray with the plate 45, the motor 46, and the stopper member 47a, and parallel LED light and diffused LED light are irradiated to the measurement object OB. The structure to be. However, instead of this, any structure may be used as long as it can irradiate visible parallel light and diffused light having the same optical axis as the emitted X-ray. For example, the beam splitter may be disposed on the optical axis of the outgoing X-ray, and the LED light may be reflected by the beam splitter so that the outgoing X-ray and the optical axis are the same.

  In the embodiment and the modification, the passage member 28 having a small inner diameter is provided in the through hole 27b of the spindle motor 27, and the inner diameters of the through holes 18a and 18b of the fixture 18 are reduced to be emitted from the LED light source 44. LED light can be used to obtain parallel light with a small cross-sectional diameter and diffused light with a narrow width. However, if visible parallel light with a small cross-sectional diameter and diffused light with a narrow width can be obtained, a different structure can be used. Good. For example, a collimator lens and an expander lens are disposed near a laser light source that emits visible laser light, and the optical axis of the laser light having a small cross-sectional diameter is set to the central axis of the through hole 27a1 of the output shaft 27a of the spindle motor 27. They may be made to coincide and enter the through holes 18 a and 18 b of the fixture 18.

DESCRIPTION OF SYMBOLS 10 ... X-ray emitter, 15 ... Imaging plate, 15a, 16a, 17a, 18a, 18b, 21a, 26a, 27a1, 27b ... Through-hole, 16 ... Table, 17 ... Projection part, 18 ... Fixing tool, 19 ... Cylindrical Lens 20, table driving mechanism 21, moving stage 22, feed motor 23, screw rod 27, spindle motor 28, passage member 30, laser detector 31, laser light source 36, objective lens 44 ... LED light source, 45 ... plate, 46 ... motor, 47a, 47b ... stopper member, 48 ... imaging lens, 49 ... imaging device, 50 ... housing, 50a ... bottom wall, 50c ... notch wall, 50d ... connection Wall, 51 ... handle, 52 ... support rod, 53 ... installation plate, 60 ... object setting device, 61 ... stage, 63a, 65 , 66a, 67a, 68a ... operator, 90 ... computer device, 91 ... controller, 92 ... input apparatus, 93 ... display, 95 ... high voltage power supply, OB ... measurement object

In order to achieve the above object, the present invention is characterized by an X-ray emitter that emits X-rays toward an object to be measured, and an X-ray emitted from the X-ray emitter toward the object to be measured. The diffracted X-rays generated at the measurement object are received by an imaging surface perpendicular to the optical axis of the X-rays emitted from the X-ray emitter, and are diffracted X-ray images on the imaging surface. In an X-ray diffraction measurement apparatus having a diffraction ring formation detecting means for forming a diffraction ring and detecting the shape of the diffraction ring, the X-ray output from the X-ray emitter is not emitted from the X-ray emitter. A visible light emitter that emits visible light, which is parallel light having the same optical axis as that of the X-ray, to the measurement object, and in the cross-section of visible light that is substantially parallel light. a visible light emitting device having an emission opening for emitting the dark peripheral portion is emitted from the visible light emitting device Around the irradiation point formed in the measurement object by visible light, a pattern projection unit when projected onto a plane perpendicular to the optical axis of the visible light are two sets of parallel lines to project a pattern crossing the exit port A pattern projecting means for projecting a pattern by a plurality of cylindrical lenses that are provided around the screen and pass visible light that does not pass through the emission port, and forms an image of the measurement object in the region including the irradiation point of the visible light and the pattern An imaging lens and an imager that captures an image formed by the imaging lens, and a camera that outputs an imaging signal representing the captured image, and an imaging signal output by the camera are input to create the image The incident angle for calculating the incident angle of the X-ray emitted from the X-ray emitter at the measurement object from the image creating means and the pattern shape in the image created by the image creating means It lies in the fact that includes a means out.

According to this, when the visible light is emitted to the measurement object by the visible light emitter, the pattern is projected onto the measurement object by the pattern projection unit, and the camera is operated to create the image by the image creation unit. The angle calculation means can accurately calculate the incident angle of the outgoing X-ray on the measurement object from the quadrangular shape formed by the two sets of parallel lines that are the shape of the pattern in the image. That is, even if the incident angle of the X-ray with respect to the measurement object is an arbitrary angle, the incident angle can be detected with high accuracy. In addition, since the incident angle of the emitted X-ray is calculated from the shape of the pattern, the incident angle of the emitted X-ray can be detected in real time by using a computer, and the incident angle of the emitted X-ray can be easily set to the value desired by the operator. Thus, the position and orientation of the measurement object can be adjusted. Further, only by providing two sets of cylindrical lenses arranged and fixed in parallel around the exit port, a pattern in which two sets of parallel lines intersect can be projected, and the cost of the apparatus can be suppressed. In particular, if the X-ray diffraction measurement apparatus is the apparatus disclosed in Patent Document 2 of the prior art document, a calculation processing program is installed in the controller as an incident angle calculation unit, and a plurality of X-ray diffraction measurement apparatuses are installed around the X-ray and visible light emission openings. The present invention can be realized only by arranging and fixing the cylindrical lens, and the cost of the apparatus is not increased. The optical axis of the X-ray emitted from the X-ray emitter and the optical axis of the visible light are the same, but the X-ray does not pass through the cylindrical lens, and therefore does not affect the X-ray diffraction measurement.

Claims (4)

An X-ray emitter that emits X-rays toward a target measurement object;
The X-ray emitter emits X-rays toward the measurement object, and the diffracted X-rays generated at the measurement object are perpendicular to the optical axis of the X-ray emitted from the X-ray emitter. An X-ray diffraction measurement apparatus comprising: a diffraction ring forming detection unit configured to detect a shape of the diffraction ring while forming a diffraction ring that is an image of the diffraction X-ray on the imaging surface. In
Visible light emission in which visible light, which is parallel light having the same optical axis as that of the X-ray emitted from the X-ray emitter, is emitted to the measurement object in a state where X-rays are not emitted from the X-ray emitter. And
Pattern projection for projecting a pattern having a certain shape when projected onto a plane perpendicular to the optical axis of the visible light around an irradiation point formed on the measurement object by visible light emitted from the visible light emitter Means,
An imaging lens that forms an image of an object to be measured in an area including the irradiation point of the visible light and the pattern; and an imager that captures an image formed by the imaging lens. A camera that outputs an imaging signal representing an image;
Image creating means for creating an image by inputting an imaging signal output by the camera;
Incident angle calculating means for calculating an incident angle of the X-ray emitted from the X-ray emitter at the measurement object from the shape of the pattern in the image created by the image creating means, X-ray diffraction measurement device. The X-ray diffraction measurement apparatus according to claim 1,
From the shape of the pattern in the image created by the image creating means, an optical axis of X-rays emitted from the X-ray emitter, and a line that is used as a reference position in the circumferential direction by the diffraction ring formation detecting means An X-ray diffraction measurement apparatus comprising: a reference plane tilt angle calculating unit that calculates an angle formed by a normal direction of a plane including the surface of the measurement object. In the X-ray diffraction measuring apparatus according to claim 1 or 2,
The X-ray diffraction measuring apparatus, wherein the pattern projecting unit projects a pattern in which two sets of parallel lines intersect when projected onto a plane perpendicular to the optical axis of the visible light. In the X-ray-diffraction measuring apparatus of Claim 3,
The visible light emitter has an emission port that emits visible light that is substantially parallel light while shielding a peripheral portion in the cross section of the visible light,
The X-ray diffraction measurement apparatus, wherein the pattern projection unit includes a plurality of cylindrical lenses that are provided around the exit port and allow visible light that does not pass through the exit port to pass therethrough.