JP2015222235A - X-ray diffraction measurement method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make an incident angle of an X-ray with respect to a measurement object be a setting value accurately even though the measurement object has a complex shape.SOLUTION: By sticking a leveling instrument LV or a leveling instrument LH to a measurement spot of a measurement object OB to adjust the posture of the measurement object OB, the measurement spot of the measurement object OB is made horizontal. Then, from an X-ray diffraction measurement apparatus which can accurately adjust an angle to a gravity direction of the optical axis of an X-ray with respect to the measurement spot or which has the angle to the gravity direction of the optical axis of the X-ray fixed to a setting value, the X-ray is emitted and the generated diffraction light of the X-ray is received to image a diffraction ring.

Description

  The present invention relates to an X-ray diffraction measurement in which an X-ray diffraction ring is formed by irradiating a measurement object with X-rays and diffracted by the measurement object. The present invention relates to a method for adjusting a position and a distance from an X-ray irradiation point to an X-ray diffraction ring forming plane.

  Conventionally, as shown in Patent Document 1, for example, an X-ray diffraction ring (on the surface of an imaging plate having photosensitivity by irradiating a measurement object with X-rays at a predetermined angle and diffracting the measurement object with X-rays ( (Hereinafter referred to as a diffractive ring) and irradiating the formed diffractive ring while scanning with a laser beam to read the shape of the diffractive ring. X-ray diffractometers that measure residual stress are known. The method for calculating the residual stress by the cos α method using the shape of the diffractive ring is shown in, for example, Patent Document 2 below. For calculating the residual stress, in addition to the shape of the diffractive ring, the lattice spacing and the like A known parameter, a distance L from the X-ray irradiation point to the imaging plate (diffraction ring forming plane), and an incident angle ψ to the X-ray measurement object are required. If the measurement object is a rectangular parallelepiped shape, as shown in Patent Document 1, an X-ray diffraction measurement apparatus is set so that the angle of the optical axis of the X-ray with respect to the stage plane on which the measurement object is placed always becomes a set value. If the height of the surface of the measurement object when the distance L becomes the set value is obtained in advance, both the distance L and the incident angle ψ can be set to the set value. That is, the distance L and the incident angle ψ can be set to the set values by moving the stage plane in the normal direction and adjusting the height of the surface of the measurement object to the set height.

JP 2012-225796 A JP-A-2005-241308

  However, when the measurement object has a complicated shape such as a gear, it is difficult to set the incident angle ψ to the set value. In addition, it is difficult to adjust the position of the measurement object so that X-rays are radiated to the intended location of the measurement object with high accuracy and to set the distance L with high accuracy.

  The present invention has been made to solve this problem, and its purpose is to perform measurement in X-ray diffraction measurement in which a measurement object is irradiated with X-rays and a diffraction ring is formed by X-rays diffracted by the measurement object. An object of the present invention is to provide a method that can accurately set the incident angle of X-rays to a measurement object even if the object has a complicated shape. Furthermore, a method capable of accurately setting the X-ray irradiation position on the measurement object and a method for accurately setting the distance from the X-ray irradiation point on the measurement object to the diffraction ring forming plane. Is to provide.

  In order to achieve the above object, the present invention is characterized by a stage on which a measurement object to be measured is placed, a stage posture changing mechanism that makes an inclination angle of the stage an arbitrary angle, and an X toward the measurement object. An X-ray emitter that emits a line, and X-rays emitted from the X-ray emitter toward the measurement object, and X-ray diffracted light generated at the measurement object is emitted from the X-ray emitter An X-ray diffraction measurement system comprising a diffraction ring forming means for receiving light on an imaging plane perpendicular to the X-ray optical axis and forming a diffraction ring as an image of X-ray diffracted light on the imaging plane was used. In the X-ray diffractometry method, the measurement object is measured at a measurement point at a measurement point, a flat part that can be attracted to another object at the tip of the long part, and a horizontal part when the flat part is perpendicular to the direction of gravity. Attach a level with a display that shows that there is a flat surface A diffracting ring is formed by means of a diffracting ring forming step, a measuring object posture adjusting step for adjusting the tilt angle of the stage so that the display unit of the spirit level is horizontal by operating the stage posture changing mechanism, and a diffraction ring forming means. A diffractive ring forming step.

  According to this, since the measurement location of the measurement object can be made perpendicular to the gravity direction, that is, horizontal by the measurement object posture adjustment step, the gravity direction of the optical axis of the X-ray emitted from the X-ray emitter If the angle with respect to can be adjusted to an appropriate angle, or if the angle is fixed to be an appropriate angle, the incident angle of X-rays can be accurately set to a set value.

  Another feature of the present invention is that the diffraction measurement system includes a stage position changing mechanism for setting the position of the stage with respect to the X-ray emitter and the imaging plane, and no X-rays are 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 emitted from the X-ray emitter, to the object to be measured. The object is to perform a measurement object position adjustment step of adjusting the position of the stage so that visible light is emitted from the emitter and the stage position changing mechanism is operated to adjust the irradiation point of the visible light to the measurement object. .

  According to this, by adjusting the position of the stage so that the visible light irradiation point becomes the measurement location in the measurement object position adjusting step, the X-ray irradiation position on the measurement target is accurately set to the intended position. Can do.

  Another feature of the present invention is that the diffraction measurement system forms an image of a measurement object in an area including an irradiation point of visible light, and an image formed by the imaging lens. A camera that has an imager and outputs an imaging signal representing a captured image; and a display that inputs an imaging signal output from the camera and displays the image captured by the imager on a screen. When the distance from the visible light irradiation point on the measurement object to the surface on which the diffraction ring is formed is a predetermined distance, the position of the irradiation point imaged by the imager on the image is set as the irradiation point reference position, and the imaging signal And a display for displaying on the screen independently from the image displayed by the step, and the measuring object position adjusting step further includes a step of adjusting the irradiation point of visible light displayed on the display to match the irradiation point reference position. Also to adjust .

  According to this, in addition to adjusting the irradiation point of visible light to be a measurement location in the measurement object position adjustment step, the irradiation point of visible light displayed on the display unit matches the irradiation point reference position. By adjusting, the distance from the X-ray irradiation point on the measurement object to the imaging plane (diffraction ring forming plane) can be accurately set to a set value.

  Another feature of the present invention is that the X-ray diffraction measurement system includes a housing including at least an X-ray emitter and an imaging plane, and a housing connected to the housing so that the posture of the housing is an arbitrary posture. An attitude change mechanism, and an inclination detection means for detecting an angle that can be calculated with respect to the direction of gravity of the optical axis of the X-ray emitted from the X-ray emitter and set in the housing, and before the diffraction ring forming step Further, from the X-ray emitter on the basis of the housing posture adjustment step for adjusting the posture around the direction perpendicular to the gravity direction of the housing by operating the housing posture changing mechanism, and the angle detected by the tilt detecting means An incident angle acquisition step of acquiring an incident angle of the emitted X-ray with respect to the measurement object is performed.

  According to this, if the attitude of the casing including the X-ray emitter and the imaging plane is adjusted by the casing attitude adjustment step until the incident angle acquired by the incident angle acquisition step reaches the set value, The incident angle can be accurately set to a set value. Therefore, the set value of the incident angle of X-rays can be set to various values.

1 is an overall schematic diagram of an X-ray diffraction measurement system including an X-ray diffraction measurement device used in the practice 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 process drawing when measuring the residual stress of a measurement object using an X-ray diffraction measurement system. It is the external view which looked at the level from the upper direction and the horizontal direction. It is the figure which showed a mode that the attitude | position of a measuring object was adjusted using the level of FIG. (A) is a figure for demonstrating the position adjustment of the stage of the X, Y, Z-axis direction, (B) is a figure which shows the captured image at the time of the said position adjustment.

  A configuration of an X-ray diffraction measurement system including an X-ray diffraction measurement apparatus used in an embodiment of the present invention will be described with reference to FIGS. This X-ray diffraction measurement system irradiates the measurement object OB with X-rays in order to measure and evaluate the residual stress of the measurement object OB, and also emits diffraction emitted from the measurement object OB by X-ray irradiation. The shape of the diffraction ring formed by X-rays is detected. The X-ray diffraction measurement device is connected to the tip of the arm type moving device, and can adjust the position and posture with respect to the measurement object OB. The apparatus for setting the measurement object OB includes an arm mechanism, a three-axis movement mechanism, and a tilt mechanism around two axes, leveling the measurement point of the measurement object OB, and measuring the X-ray diffraction measurement apparatus. The position of the object OB can be adjusted. In the present embodiment, the measurement object OB is an iron gear.

  The X-ray diffraction measurement apparatus includes an X-ray emitter 10 that emits X-rays, a table 16 for mounting an imaging plate 15 on which a diffraction ring is formed by diffracted X-rays, and a table drive mechanism 20 that rotates and moves the table 16. And a laser detector 30 for measuring the shape of the diffraction ring formed on the imaging plate 15, and these X-ray emitter 10, imaging plate 15, table 16, table driving mechanism 20 and laser detector 30. And a housing 50 to be used. The X-ray diffraction measurement system includes an object setting device 60 on which a measurement object OB is set, a computer device 90, and a high-voltage power supply 95 together with the X-ray diffraction measurement device. The housing 50 also includes various circuits that are connected to the X-ray emitter 10, the table 16, the table driving mechanism 20, and the laser detection device 30 to control operation and input detection signals. In FIG. 1, various circuits indicated by a two-dot chain line shown outside the casing 50 are accommodated within a two-dot chain line in the casing 50. In FIG. 1 and FIG. 2, circuit boards, electric wires, fixtures, air cooling fans, and the like are omitted.

  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. One of the side walls is provided with a connection portion (not shown) connected to the support arm 51, and the connection portion is rotatable about the vertical direction of the paper surface of FIGS. The support arm 51 is a tip of an arm type moving device (not shown), and by operating the arm type moving device, the housing 50 (X-ray diffraction measuring device) can be in an arbitrary position and posture. Thereby, the position and attitude | position of the housing | casing 50 (X-ray-diffraction measuring apparatus) can be adjusted with respect to the measurement object OB.

  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. ) One end of an arm mechanism 69 is fixed in the vicinity of the corner of the upper surface of the stage 61, and the other end of the arm mechanism 69 is fixed to a fixed plate PL having a square surface. The arm mechanism 69 of the fixed plate PL is The surface opposite to the fixed surface is made of a magnet. Therefore, as shown in FIGS. 1 and 2, if the measurement object OB is made of iron or stainless steel, the measurement object OB is set on the object setting device 60 by being adsorbed to the surface of the fixed plate PL. can do. The arm mechanism 69 has a plurality of joints, and can roughly adjust the position and posture of the fixed plate PL, that is, the set measurement object OB. Further, in the object setting device 60, the height adjusting mechanism 63, the first to fifth plates 64 to 68, and the stage 61 are respectively placed on the installation plate 62 formed in a flat plate shape placed on the installation surface. It is placed in order from top to bottom. 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 around the Y 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 Y axis with respect to the second plate 65, that is, the inclination angle of the stage 61 around the Y axis is changed. An operation element 66a is assembled to the third plate 66, and the fourth plate 67 is rotated about the X 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 X axis relative to the third plate 66, that is, the inclination angle of the stage 61 around the X 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. In other words, the object setting device 60 can roughly adjust the position and orientation of the measurement object OB by the arm mechanism 69, and can finely adjust the position and orientation of the measurement object OB by the operation elements 65a to 68a. Since the stage moving mechanism of the present invention is a mechanism that can change the position of the measurement object OB with respect to the X-ray diffraction measurement apparatus, the object setting apparatus 60 moves in the X-axis, Y-axis, and Z-axis directions. In addition to the mechanism, it also refers to a moving mechanism of an arm type moving device.

  The X-ray emitter 10 is formed in a long shape, extends in the left-right direction in the figure in the upper part of the housing 50 and is fixed to the housing 50, and supplies a high voltage from a high-voltage power supply 95. The X-ray control circuit 71 controls the X-ray to emit downward in FIG. The side wall of the housing 50 is substantially parallel to the optical axis of the emitted X-ray, and the bottom wall 50a is substantially perpendicular to the optical axis of the emitted X-ray. Therefore, when the bottom wall 50a is parallel to the surface of the measurement object OB, the emitted X-rays are perpendicular to the surface of the measurement object OB. When the connecting wall 50d is made parallel to the surface of the measurement object OB, the emitted X-ray is an angle formed by the connection wall 50d and the bottom wall 50a with respect to the normal of the surface of the measurement object OB (for example, 30 to 30). 45 degrees).

  The X-ray control circuit 71 is controlled by a controller 91 that configures a computer device 90 to be described later, and a high-voltage power supply 95 is supplied to the X-ray emitter 10 so that X-rays with a certain intensity are emitted from the X-ray emitter 10. The drive current and the drive voltage supplied from are controlled. 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. Thereby, the temperature of the X-ray emitter 10 is kept constant.

  The table driving mechanism 20 includes a moving stage 21 below the X-ray emitter 10. The moving stage 21 is in the plane formed by the optical axis of the X-ray emitted from the X-ray emitter 10 and the normal line of the measurement object OB by the feed motor 22 and the screw rod 23, and the X-ray light. It can move in the direction perpendicular to the axis. The feed motor 22 is fixed in the table driving mechanism 20 and cannot move with respect to the housing 50. The screw rod 23 extends in a direction perpendicular to the optical axis of the X-ray emitted from the X-ray emitter 10, and one end thereof is connected to the output shaft of the feed motor 22. The other end portion of the screw rod 23 is rotatably supported by a bearing portion 24 provided in the table drive mechanism 20. The moving stage 21 is sandwiched between a pair of opposed plate-like guides 25 and 25 fixed in the table driving mechanism 20, respectively, and can move along the axial direction of the screw rod 23. ing. That is, when the feed motor 22 is driven forward or backward, the rotational motion of the feed motor 22 is converted into the linear motion of the moving stage 21. An encoder 22 a is incorporated in the feed motor 22. The encoder 22a outputs a pulse train signal that alternately switches between a high level and a low level to the position detection circuit 72 and the feed motor control circuit 73 each time the feed motor 22 rotates by a predetermined minute rotation angle.

  The position detection circuit 72 and the feed motor control circuit 73 start to operate in response to a command from the controller 91. Immediately after the start of measurement, the feed motor control circuit 73 drives the feed motor 22 to move the moving stage 21 to the feed motor 22 side. When the pulse train signal output from the encoder 22a is not input, the position detection circuit 72 outputs a signal indicating that the movement stage 21 has reached the movement limit position to the feed motor control circuit 73, and sets the count value to “0”. Set to. When the feed motor control circuit 73 receives a signal indicating that the movement limit position has been reached from the position detection circuit 72, the feed motor control circuit 73 stops outputting the drive signal to the feed motor 22. The above movement limit position is set as the origin position of the moving stage 21. Therefore, the position detection circuit 72 outputs a position signal representing “0” when the movable stage 21 moves in the upper left direction in FIGS. 1 and 2 and reaches the movement limit position, and the movement stage 21 moves to the movement limit position. When moving to the lower right, the pulse train signal from the encoder 22a is counted, and a signal indicating the movement distance x from the movement limit position is output as a position signal.

  When the feed motor control circuit 73 receives a set value indicating the position of the moving stage 21 from the controller 91, the feed motor control circuit 73 drives the feed motor 22 in the forward or reverse direction according to the set value. The position detection circuit 72 counts the number of pulses of the pulse signal output from the encoder 22a. Then, the position detection circuit 72 calculates the current position (movement distance x from the movement limit position) of the movement stage 21 using the counted number of pulses, and outputs it to the controller 91 and the feed motor control circuit 73. The feed motor control circuit 73 drives the feed motor 22 until the current position of the moving stage 21 input from the position detection circuit 72 matches the position of the moving destination input from the controller 91.

  Further, the feed motor control circuit 73 inputs a set value indicating the moving speed of the moving stage 21 from the controller 91. Then, the moving speed of the moving stage 21 is calculated using the number of pulses per unit time of the pulse signal input from the encoder 22a, and the calculated moving speed of the moving stage 21 becomes the moving speed input from the controller 91. The feed motor 22 is driven.

  The upper ends of the pair of guides 25 are connected by a plate-like upper wall 26. A through hole 26 a is provided in the upper wall 26, and the center position of the through hole 26 a faces the center position of the emission port 11 of the X-ray emitter 10. The line enters the table driving mechanism 20 through the emission port 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 formed 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 having an output shaft 27a whose center of rotation is the position of the central axis of the exit port 11 and the through holes 26a, 21a. The output shaft 27a is formed in a cylindrical shape and has a through-hole 27a1 having a circular cross section with the center of rotation as the central axis. On the opposite side of the spindle motor 27 from the output shaft 27a, a through hole 27b having the central position of the through hole 27a1 as a central axis is provided. A cylindrical passage member 28 for reducing the inner diameter of a part of the through hole 27b is fixed on the inner peripheral surface of the through hole 27b.

  An encoder 27c similar to the encoder 22a is incorporated in the spindle motor 27. The encoder 27c outputs, to the spindle motor control circuit 74 and the rotation angle detection circuit 75, a pulse train signal that is alternately switched between a high level and a low level every time the spindle motor 27 rotates by a predetermined minute rotation angle. 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.

  The spindle motor control circuit 74 and the rotation angle detection circuit 75 start to operate in response to a command from the controller 91. The spindle motor control circuit 74 inputs a setting value representing the rotational speed of the spindle motor 27 from the controller 91. Then, the rotational speed of the spindle motor 27 is calculated using the number of pulses per unit time of the pulse signal input from the encoder 27c, and the calculated rotational speed becomes the rotational speed (set value) input from the controller 91. A drive signal is supplied to the spindle motor 27. The rotation angle detection circuit 75 counts the number of pulses of the pulse train signal output from the encoder 27c, calculates the rotation angle of the spindle motor 27, that is, the rotation angle θp of the imaging plate 15 using the count value, and sends it to the controller 91. Output. The rotation angle detection circuit 75 sets the count value to “0” when the index signal output from the encoder 27c is input. That is, the position where the index signal is input is the position where the rotation angle is 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. This position is a line because it is at each radial position.

  The table 16 is formed in a circular shape, and is fixed to the tip of the output shaft 27 a of the spindle motor 27. The center axis of the table 16 coincides with the center axis of the output shaft of the spindle motor 27. The table 16 has a protrusion 17 that is provided integrally and protrudes downward from the center of the lower surface, and a thread is formed on the outer peripheral surface of the protrusion 17. The central axis of the protrusion 17 coincides with the central axis of the output shaft 27 a of the spindle motor 27. An imaging plate 15 is attached to the lower surface of the table 16. The imaging plate 15 is a circular plastic film whose surface is coated with a phosphor. A through-hole 15a is provided at the center of the imaging plate 15. By passing the protrusion 17 through the through-hole 15a and screwing a nut-shaped fixture 18 on the outer peripheral surface of the protrusion 17, the 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 projecting portion 17 and the fixture 18 are also provided with through holes 16a, 17a and 18a, respectively. The central axis of the through holes 16a, 17a and 18a is the same as the central axis of the table 16, and the through hole 18a. Is smaller than the through holes 16a and 17a, and is the same as the inner diameter of the passage member 28 described above. Accordingly, the X-ray emitted from the output shaft 27a of the spindle motor 27 passes through the through holes 16a, 17a, and 18a, and the measurement object is positioned below and outside via the circular hole 50c1 provided in the notch wall 50c. It is emitted toward OB. In this case, since the inner diameter of the passage member 28 and the inner diameter of the through hole 18a are small, the X-rays that have entered the through holes 27b, 27a1, 16a, and 17a through the passage member 28 are slightly diffused, but the through hole 18a. X-rays emitted from the light become parallel light parallel to the axis of the through hole 27a1 and are emitted from the circular hole 50c1. The inner diameter of the circular hole 50c1 is large in order to guide the diffracted light from the measurement object OB to the imaging plate 15.

  The imaging plate 15 is driven by the feed motor 22 and moves together with the moving stage 21, the spindle motor 27, and the table 16 from the origin position to the diffraction ring imaging position for imaging the diffraction ring. As described above, the measurement object OB is irradiated with the X-rays emitted from the X-ray emitter 10 at the diffraction ring imaging position. In addition, the imaging plate 15 is driven by the feed motor 22 while being driven by the spindle motor 27 and rotated, together with the moving stage 21, the spindle motor 27, and the table 16, in the diffraction ring reading region for reading the imaged diffraction ring, And move in the diffractive ring erasing region to erase the diffractive ring. In this case, in the movement of the imaging plate 15, the central axis of the imaging plate 15 is the optical axis of the X-ray emitted from the X-ray emitter 10 and the position (line) at a rotation angle of 0 ° in the imaging plate 15. In a state maintained in a plane formed by the X-ray, it moves in a direction perpendicular to the optical axis of the X-ray.

  The laser detection device 30 detects the intensity of light incident from the imaging plate 15 by irradiating the imaging plate 15 that images the diffraction ring with laser light. The laser detection device 30 is sufficiently separated from the measurement object OB and the imaging plate 15 at the diffraction ring imaging position toward the feed motor 22. That is, when the imaging plate 15 is at the diffraction ring imaging position, the X-ray diffracted by the measurement object OB is not blocked by the laser detection device 30. The laser detection device 30 includes a laser light source 31, a collimating lens 32, a reflecting mirror 33, a dichroic mirror 34, and an objective lens 36.

  The laser light source 31 is controlled by the laser driving circuit 77 to emit laser light that irradiates the imaging plate 15. The laser drive circuit 77 is controlled by the controller 91 and controls and supplies a drive signal so that laser light having a predetermined intensity is emitted from the laser light source 31. The laser drive circuit 77 inputs a light reception signal output from the photodetector 42 described later, and controls a drive signal output to the laser light source 31 so that the intensity of the light reception signal becomes a predetermined intensity. Thereby, the intensity of the laser light applied to the imaging plate 15 is kept constant.

  The collimating lens 32 converts the laser light emitted from the laser light source 31 into parallel light. The reflecting mirror 33 reflects the laser light converted into parallel light by the collimating lens 32 toward the dichroic mirror 34. The dichroic mirror 34 transmits most of the laser light incident from the reflecting mirror 33 (for example, 95%) as it is. The objective lens 36 focuses the laser light incident from the dichroic mirror 34 on the surface of the imaging plate 15. The optical axis of the laser light emitted from the objective lens 36 is in a plane formed by the optical axis of the X-ray emitted from the X-ray emitter 10 and the position (line) at the rotation angle 0 ° in the imaging plate 15. The direction parallel to the optical axis of the X-ray, that is, the direction perpendicular to the moving direction of the moving stage 21.

  A focus actuator 37 is assembled to the objective lens 36. The focus actuator 37 is an actuator that moves the objective lens 36 in the optical axis direction of the laser light. The objective lens 36 is located at the center of the movable range when the focus actuator 37 is not energized.

  When the laser beam condensed by the objective lens 36 is irradiated on the surface of the imaging plate 15 where the diffraction ring is imaged, a photo-stimulated luminescence phenomenon occurs. That is, after imaging the diffraction ring, when the imaging plate 15 is irradiated with laser light, the phosphor of the imaging plate 15 is light corresponding to the intensity of the diffracted X-ray and has a wavelength shorter than the wavelength of the laser light. To emit. The reflected light of the laser light irradiated and reflected on the imaging plate 15 and the light emitted from the phosphor pass through the objective lens 36, and most of the light emitted from the phosphor is reflected by the dichroic mirror 34. Most of the reflected light of the laser beam is transmitted. In the reflection direction of the dichroic mirror 34, a condenser lens 38, a cylindrical lens 39, and a photodetector 40 are provided. The condensing lens 38 condenses the light incident from the dichroic mirror 34 on the cylindrical lens 39. The cylindrical lens 39 causes astigmatism in the transmitted light. The photodetector 40 is composed of four divided light receiving elements composed of four light receiving elements having the same square shape divided by dividing lines, and the light incident on the light receiving areas A, B, C, and D arranged in the clockwise direction. A detection signal having a magnitude proportional to the intensity is output to the amplifier circuit 78 as a light reception signal (a, b, c, d).

  The amplifying circuit 78 amplifies the light reception signals (a, b, c, d) output from the photodetector 40 with the same amplification factor to generate light reception signals (a ′, b ′, c ′, d ′), Output to the focus error signal generation circuit 79 and the SUM signal generation circuit 80. In this embodiment, focus servo control based on the astigmatism method is used. The focus error signal generation circuit 79 generates a focus error signal by calculation using the amplified light reception signals (a ′, b ′, c ′, d ′). That is, the focus error signal generation circuit 79 calculates (a ′ + c ′) − (b ′ + d ′) and outputs the calculation result to the focus servo circuit 81 as a focus error signal. The focus error signal (a ′ + c ′) − (b ′ + d ′) represents the amount of deviation of the focal position of the laser beam from the surface of the imaging plate 15.

  The focus servo circuit 81 is controlled by the controller 91, generates a focus servo signal based on the focus error signal, and outputs the focus servo signal to the drive circuit 82. The drive circuit 82 drives the focus actuator 37 according to the focus servo signal to displace the objective lens 36 in the optical axis direction of the laser light. In this case, the focus servo signal is generated so that the value of the focus error signal (a ′ + c ′) − (b ′ + d ′) is always a constant value (for example, zero), so that the laser is applied to the surface of the imaging plate 15. The light can be continuously collected.

  The SUM signal generation circuit 80 adds the received light signals (a ′, b ′, c ′, d ′) to generate a SUM signal (a ′ + b ′ + c ′ + d ′) and outputs it to the A / D conversion circuit 83. To do. 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 light is substantially constant, the intensity of the SUM signal corresponds to the intensity of light generated by the stimulated emission. That is, the intensity of the SUM signal corresponds to the intensity of the diffracted X-ray incident on the imaging plate 15. The A / D conversion circuit 83 is controlled by the controller 91, receives the SUM signal from the SUM signal generation circuit 80, converts the instantaneous value of the input SUM signal into digital data, and outputs the digital data to the controller 91.

  Further, the laser detection device 30 includes a condenser lens 41 and a photodetector 42. The condenser lens 41 is a part of the laser light emitted from the laser light source 31, and condenses the laser light reflected without passing through the dichroic mirror 34 on the light receiving surface of the photodetector 42. The photodetector 42 is a light receiving element that outputs a light receiving signal corresponding to the intensity of light collected on the light receiving surface. Therefore, the photodetector 42 outputs a light reception signal corresponding to the intensity of the laser light emitted from the laser light source 31 to the laser driving circuit 77.

  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. The LED drive circuit 84 is controlled by the controller 91 and supplies a drive signal for generating visible light having a predetermined intensity to the LED light source 43.

  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 X-ray emitter 10 and the upper wall 26 of the table driving mechanism 20. The plate 45 is fixed to the output shaft 46a of the motor 46 fixed in the housing 50 at the other end upper surface, and is in a plane parallel to the upper wall 26 of the table driving mechanism 20 by the rotation of the motor 46. Rotate. Stopper members 47 a and 47 b are provided on the upper wall 26 of the table driving mechanism 20. When the plate 45 is rotated in the direction D <b> 1 in FIG. 4, the LED light source 44 is connected to the X-ray emitter 10. The rotation of the plate 45 is restricted so that it stops at a position (position A) opposite to the exit hole 11 and the through hole 26 a of the upper wall 26 of the table drive mechanism 20. On the other hand, when the plate 45 is rotated in the direction D2 in FIG. 4, the stopper member 47b is formed between the emission port 11 of the X-ray emitter 10 and the through hole 26a of the upper wall 26 of the table driving mechanism 20. The rotation of the plate 45 is restricted so that it stops at a position (B position) that is not blocked. 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. LED light is diffused visible light, and when the plate 45 is in the A position, a part of the plate 45 passes through the through holes 26a and 21a, the passage of the passage member 28 and the through hole 27b, and the output shaft 27a of the spindle motor 27. Is incident on the through hole 27a1 and emitted from the through holes 16a, 17a, 18a and the circular hole 50c1 of the notch wall 50c. Also in the case of this LED light, since the inner diameter of the passage member 28 and the inner diameter of the through hole 18a are small, the X-rays that have entered the through holes 27b, 27a1, 16a, and 17a through the passage member 28 are slightly diffused. The LED light emitted from the through hole 18a becomes parallel light parallel to the axis of the through hole 27a1, and is emitted from the circular hole 50c1. Therefore, the LED light source 44, the passage member 28, the through hole 18a, and the like constitute the visible light emitter of the present invention that emits parallel light, which is visible light, to the measurement object OB.

  The motor 46 includes an encoder 46b similar to the encoders 22a and 27a. The encoder 46b generates a pulse train signal that alternately switches between a high level and a low level each time the motor 46 rotates by a predetermined minute rotation angle. 86. When a rotation direction and a rotation start instruction 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 specified 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 cutout wall 50 c of the housing 50, and an imager 49 is provided inside the housing 50. The image pickup device 49 is composed of a CCD light receiver or a CMOS light receiver in which a large number of image pickup devices are arranged in a matrix, and receives a light reception signal (image pickup signal) having a magnitude corresponding to the intensity of light received by each image pickup device. For each output to the sensor signal extraction circuit 87. The imaging lens 48 and the image pickup device 49 pick up an image of a region centered on the emission point of the LED light on the measurement object OB located at a position set with respect to the imaging plate 15. That is, the imaging lens 48 and the imager 49 function as a digital camera that images the measurement object OB. The position set with respect to the imaging plate 15 means that a vertical distance L from the X-ray and LED light emission point (irradiation point) to the imaging plate 15 on the measurement object OB is a predetermined distance Lo that is determined in advance. It is a position. In this case, the depth of field by the imaging lens 48 and the imaging device 49 is set in a range before and after the emission point. The sensor signal extraction circuit 87 outputs the intensity data of the light reception signal (imaging signal) from each imaging device of the imaging device 49 to the controller 91 together with the data indicating the position (that is, the pixel position) of each imaging device. Therefore, the controller 91 outputs image data representing an image in the vicinity of the irradiation point P1 including the LED light irradiation point P1 (see FIG. 8) on the measurement object OB.

  Further, the optical axis of the imaging lens 48 is adjusted so as to be included in a plane including the optical axis of the X-ray emitted from the X-ray emitter 10 and a line having a rotation angle of 0 ° of the imaging plate 15. The point at which the optical axis of the imaging lens 48 and the optical axes of the X-rays and LED light irradiated to the measurement object OB intersect with each other is determined by the X in the measurement object OB at the position set with respect to the imaging plate 15. It is an irradiation point of a line and LED light. Therefore, when the measurement object OB is in a set position with respect to the imaging plate 15 and the LED light from the LED light source 44 is irradiated onto the measurement object OB, the optical axis of the imaging lens 48 is imaged. An image of the irradiation point of the LED light is formed at a point intersecting the container 49. Conversely, a point where the optical axis of the imaging lens 48 intersects the image sensor 49 is displayed in the captured image created by the image data output from the sensor signal extraction circuit 87, and the LED light in the captured image is displayed. By adjusting the position and orientation of the X-ray diffraction measurement apparatus (housing 50) so that the irradiation point P1 is adjusted to this point, the measurement object OB can be set to a position set with respect to the imaging plate 15.

  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. In addition to the image including the irradiation point P1 imaged by the imaging device 49 on the display screen, the display device 93 emits the LED light when the measurement object OB is at a position set with respect to the imaging plate 15. A mark indicating the point at which P1 is imaged is also displayed. This mark will be described later in detail. 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.

  A tilt sensor 56 is attached to the casing 50, and the tilt angle in two directions, ie, a setting direction parallel to the side wall of the casing 50 and a direction perpendicular to the direction (subtract 90 ° from the angle formed by each direction and the gravity direction). The signal corresponding to the angle) is output to the inclination sensor signal extraction circuit 88. When the viewpoint is changed, the tilt sensor 56 outputs a signal corresponding to the setting direction perpendicular to the rotation axis of the connection portion of the support arm 51 to the housing 50 and the tilt angle in the rotation axis direction. When a command is input from the controller 91, the tilt sensor signal extraction circuit 88 converts the signal output from the tilt sensor 56 into digital data and outputs the digital data at a set time interval. Thus, when the operator inputs a command for displaying the tilt angle from the input device 92, the controller 91 starts to input two tilt angle data. The controller 91 stores in advance an angle formed by the optical axis of the X-ray emitted from the X-ray emitter 10 and a setting direction parallel to the side wall of the housing 50. The controller 91 inputs data every time data is input. Further, from the inclination angle in the setting direction parallel to the side wall of the casing 50, the inclination angle in the direction perpendicular to the side wall of the casing 50, and the angle stored in advance, the gravity direction and the optical axis of the X-ray are The formed angle A is calculated and displayed on the display device 93. If the measurement location is perpendicular to the gravitational direction, that is, if it is horizontal, the angle A is the X-ray incident angle. Further, the inclination angle in the direction perpendicular to the side wall of the housing 50 is displayed as it is on the display device 93 as the angle B. The angle B is an angle formed by a plane including the optical axis of the X-ray and the line of the imaging plate 15 having a rotation angle of 0 ° with the direction of gravity. When the angle B is 0 °, the rotation is performed when the measurement location is horizontal. The line with an angle of 0 ° coincides with the position of the rotation angle of 0 ° in the diffraction ring. Further, the direction of the line intersecting the horizontal plane and the plane parallel to the side wall of the housing 50 and the direction in which the vertical axis direction of the captured image displayed on the display device 93 is projected onto the horizontal plane are calculated from the shape of the diffraction ring. This is the direction of measurement of residual compressive stress.

  The position and posture of an iron gear that is a measurement object OB with respect to the X-ray diffraction measurement device (housing 50) are described below using an X-ray diffraction measurement system including the X-ray diffraction measurement device configured as described above. A specific method for adjusting the residual stress of the measurement object OB after adjusting and irradiating X-rays will be described. This residual stress is measured by operating the X-ray diffraction measurement system by turning on the power supply, and then, as shown in FIG. 5, position and orientation adjustment step S1, diffraction ring imaging step S2, diffraction ring reading step S3, diffraction This is performed by executing the ring elimination step S4 and the residual stress calculation step S5.

  First, the position / orientation adjustment step S1 will be described. An operator causes a gear, which is an object to be measured OB, to be adsorbed to a fixed plate PL connected to the stage 61 by an arm mechanism 69 so that X-rays are irradiated to the measurement location. Next, the position and orientation of the X-ray diffraction measurement device (housing 50) are adjusted by operating an arm type moving device connected to the housing 50 of the X-ray diffraction measurement device, so that approximately the X-ray diffraction The irradiation point and the irradiation direction are the intended position and direction, and the distance from the X-ray irradiation point to the imaging plate 15 is set to a set value. Next, the operator inputs a tilt angle display command from the input device 92, causes the display device 93 to display the angles A and B described above, and operates the arm type moving device, so that the angle B becomes 0 °. Thus, the posture of the X-ray diffraction measurement apparatus (housing 50) is adjusted so that the angle A becomes the set X-ray incident angle.

  Next, the operator sets the level LV or level LH shown in FIG. 6 at the measurement location of the measurement object OB. The level LV and the level LH will be described below. The level LV is composed of an inclination confirmation part 101, a long part 102, and a suction part 103, and confirms that the micro-plane of the set location is perpendicular to the direction of gravity, that is, horizontal. is there. The inclination confirmation unit 101 is the same as a general level, and enters the center of a circle 105 on which a bubble 104 is drawn when the bottom surface of a suction unit 103 to be described later is perpendicular to the direction of gravity, that is, horizontal. Indicates that it is horizontal. A columnar elongated portion 102 is formed from the bottom surface portion of the inclination confirmation portion 101, the tip portion thereof is tapered, and a columnar suction portion 103 made of a magnet is attached to the tip. If the measurement object OB is iron or stainless steel, the adsorption unit 103 is adsorbed on the surface of the measurement object OB. Therefore, the posture of the measurement object OB is adjusted with the adsorption unit 103 adsorbed to the measurement object OB. If it is confirmed that the inclination confirmation unit 101 is horizontal, the portion adsorbed on the measurement object OB becomes horizontal. Similarly, the level LH includes an inclination confirmation part 111, a long part 112, and a suction part 113, and confirms that the minute plane of the set location is horizontal. The inclination confirmation unit 111 is the same as a general level, and when the bottom surface of the adsorption unit 113 described later is horizontal, the bubble 114 enters the center of the drawn circle 115 to indicate that it is horizontal. There is a plate-like long portion 112 from the side surface portion of the inclination confirmation portion 111, and a columnar adsorption portion 113 made of a magnet is attached to the surface of the tip portion opposite to the inclination confirmation portion 111 side. If the measurement object OB is iron or stainless steel, the adsorption unit 113 adsorbs to the surface of the measurement object OB. Therefore, the posture of the measurement object OB is adjusted with the adsorption unit 113 adsorbed to the measurement object OB. If it confirms that it is horizontal by the inclination confirmation part 111, the location made to adsorb | suck to the measuring object OB will become horizontal.

  Whether the level LV or the level LH is set at the measurement location of the measurement object OB may be appropriately determined depending on the shape of the measurement object OB and the measurement location. When the measurement object OB is a gear as in the present embodiment, as shown in FIG. 7, when it is a position between gear teeth, a level LV is set, and at the position of the gear teeth. In some cases, the level LH may be set.

  Next, the arm mechanism 69 is operated while looking at the inclination confirmation portions 101 and 111 of the set level LV or level LH so that the measurement location becomes almost horizontal. Thereafter, the operation elements 65a and 66a of the object setting device 60 are operated to rotate the stage 61 about the X axis and the Y axis, respectively, and the tilt confirmation units 101 and 111 of the set level LV or level LH. To indicate horizontal. By this adjustment, the measurement location becomes horizontal, and the incident angle of the X-ray with respect to the plane parallel to the measurement location becomes the set value. Further, the direction of the line in which the plane parallel to the side wall of the casing 50 and the horizontal plane intersect, and the direction in which the vertical axis direction of the captured image displayed on the display device 93 is projected on the horizontal plane are the measurement direction of the residual compressive stress. Become.

  Next, the operator operates the input device 92 to instruct the controller 91 to start position adjustment by irradiating LED light. In response to this instruction, the controller 91 controls the feed motor control circuit 73 to move the imaging plate 15 to the diffraction ring imaging position (state shown in FIGS. 1 and 2). Further, the controller 91 controls the rotation control circuit 86 to rotate the motor 46 in the direction D1 in FIG. 4 until the rotation of the plate 45 is stopped by the stopper member 47a, thereby rotating the plate 45 to the A position. In this state, the LED light source 44 is positioned opposite to the through hole 26 a provided in the upper wall 26 of the table driving mechanism 20.

  Thereafter, the controller 91 controls the LED drive circuit 85 to turn on the LED light source 44. When the LED light source 44 is turned on, part of the LED light that is emitted and diffused from the LED light source 44 passes through the through hole 26a, the passage member 28, the through holes 27b, 27a1, 16a, 17a, and 18a. And emitted from the fixture 18. In this case, the inner diameters of the passage member 28 and the through hole 18a are small, and the X-ray emitted from the through hole 18a is parallel light parallel to the axis of the through hole 27a1. The LED light, which is parallel light, is emitted to the outside from a circular hole 50c1 provided in the notch wall 50c of the housing 50, and is irradiated onto the measurement object OB.

  Next, the controller 91 instructs the sensor signal extraction circuit 87 to input an image pickup signal from the image pickup device 49, and 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. The controller 91 outputs this imaging signal to the display device 93 and causes the display device 93 to display an image near the irradiation position of the LED light imaged by the imaging device 49. In this case, the image displayed on the display device 93 includes an image of the LED light irradiation point P1 on the measurement object OB in the vicinity of the LED light irradiation position. In addition, the controller 91 has the optical axis of the imaging lens 48 intersecting the image pickup device 49 independently of the image displayed by the image pickup signal from the image pickup device 49 including the irradiation point P1 imaged by the image pickup device 49. A cross mark is displayed at a position on the captured image corresponding to the position to be performed.

  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 imaging point 49 captures the irradiation point P1 when the distance L from the LED light irradiation point to the imaging plate 15 on the measurement object OB is the predetermined distance Lo. . The Y-axis direction of the cross mark is the irradiation direction of the LED light and the X-ray, and the direction in which the Y-axis direction is projected onto the surface of the measurement object OB is the residual stress measurement direction.

  While viewing the captured image displayed on the display device 93, the operator operates the operating elements 67a and 68a of the object setting device 60 to move the stage 61, that is, the measurement object OB in the X-axis direction and the Y-axis direction, respectively. Then, the irradiation point on the screen, that is, the irradiation position of the LED light is set as the measurement position of the measurement object OB. Further, by operating the operation element 63a, the stage 61, that is, the measurement object OB is moved in the Z-axis direction (that is, the height direction) so that the irradiation point P1 coincides with the cross point of the cross mark. The distance from the irradiation point on the object OB to the imaging plate 15 is set to a predetermined distance. FIG. 8 shows the state of this operation and the captured image displayed on the display device 93. Even if the irradiation point P1 is set as the measurement location of the measurement object OB by adjusting the movement of the stage 61 in the X-axis direction and the Y-axis direction, the irradiation point P1 is thereafter positioned at the cross point of the cross mark. When the movement adjustment of the stage 61 in the Z-axis direction is performed, the irradiation point P1 (irradiation position) is slightly shifted in the Y-axis direction of the measurement object OB. Therefore, these position adjustments are repeatedly performed.

  By this adjustment, the X-ray irradiated to the measurement object OB becomes a measurement location, and the distance from the X-ray irradiation point to the imaging plate 15 becomes a predetermined distance. Further, by the adjustment performed before the position adjustment by irradiating the LED light, the incident angle of the X-ray is already as set, and the measurement direction of the residual compressive stress is the target direction.

  Next, the operator operates the input device 92 and instructs the controller 91 to end the adjustment. In response to this instruction, the controller 91 controls the LED drive circuit 85 to turn off the LED light source 44 and controls the sensor signal extraction circuit 87 to stop the input of the imaging signal from the imaging device 49 and the imaging signal controller 91. And the rotation control circuit 86 is controlled to rotate the motor 46 in the direction D2 in FIG. 4 until the rotation of the plate 45 is stopped by the stopper member 47b, thereby rotating the plate 45 to the B position. . With the rotation of the plate 45, the X-ray from the X-ray emitter 10 can enter a through hole 26 a provided in the upper wall 26 of the table driving mechanism 20.

  In the next diffraction ring imaging step S2, the operator uses the input device 92 to input the material of the measurement object OB (in this embodiment, iron), and instructs the controller 91 to start measuring the residual stress. As a result, the controller 91 first controls the spindle motor control circuit 74 with the imaging plate 15 in the imaging position, rotates the imaging plate 15 at a low speed, and inputs the index signal from the encoder 27c. The rotation of 15 is stopped. As a result, the position where the laser beam is irradiated at the start of reading of the diffraction ring in the diffraction ring reading step S3 to be described later becomes a position with a rotation angle of 0 °.

  Next, the controller 91 controls the X-ray control circuit 71 to cause the X-ray emitter 10 to start emitting X-rays. After a predetermined time has elapsed, the controller 91 controls the X-ray control circuit 71 to control the X-ray emitter 10. X-ray emission is stopped. As a result, the X-rays emitted from the X-ray emitter 10 are emitted to the outside through the through holes 26a and 21a, the passage member 28, the through holes 27b, 27a1, 16a, 17a, and 18a, and the circular hole 50c1, and measured. The measurement location of the object OB is irradiated for a predetermined time. By irradiating the measurement object OB with X-rays for a predetermined time, diffracted X-rays are generated from the measurement location of the measurement object OB, and a diffraction ring is imaged on the imaging plate 15.

  After such a diffractive ring imaging step S2, the controller 91 executes the diffractive ring reading step S3 of FIG. 5 either automatically or by an instruction from the operator using the input device 92. 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 of the imaging plate 15 is a position where the center of the objective lens 36, that is, the irradiation position of the laser beam is slightly inside the circle of the diffraction ring reference radius Ro. In this case, the position signal output from the position detection circuit 72 represents the moving distance x that the moving stage 21 has moved from the state in which the moving stage 21 is at the movement limit position, and the moving stage 21, that is, the table 16 (imaging plate 15). ) Is at the movement limit position, the distance from the center of the table 16 (imaging plate 15) to the center position of the objective lens 36 is a predetermined value. Therefore, the movement of the imaging plate 15 to the reading start position is performed using the position signal from the position detection circuit 72.

  The diffraction ring reference radius Ro is the radius of the diffraction ring formed on the imaging plate 15 by X-ray irradiation to the measurement object OB when the residual stress of the measurement object OB is “0”. It depends on the diffraction angle Θx of X-rays on the object OB and the distance L from the imaging plate 15 to the measurement object OB. The X-ray diffraction angle Θx is determined by the material of the measurement object OB, and the distance L is a predetermined distance Lo set in advance by the adjustment in the X-ray incident angle adjustment step S1. Therefore, if the diffraction angle Θx is stored in advance for each material of the measurement object OB, the controller 91 sets the diffraction ring reference radius Ro to Ro = Lo · tan (by using the material of the input measurement object OB. It is automatically calculated by the calculation of 2Θx). Note that, when the residual stress of the measurement object OB of the same material is repeatedly measured, it can be used repeatedly without calculating the diffraction ring reference radius Ro.

  Next, the controller 91 causes the spindle motor control circuit 74 to control the rotation of the spindle motor 27 so that the imaging plate 15 rotates at a predetermined constant rotation speed. Further, the laser driving circuit 77 is controlled to start irradiation of the imaging plate 15 with laser light from the laser light source 31. Thereafter, the controller 91 instructs the focus servo circuit 81 to start focus servo control, and causes the focus servo circuit 81 to start focus servo control. Therefore, the objective lens 36 is driven and controlled in the optical axis direction so that the focus of the laser light is aligned with the surface of the imaging plate 15.

  Next, the controller 91 operates the rotation angle detection circuit 75 and the A / D conversion circuit 83 to start inputting the rotation angle θp from the reference position of the spindle motor 27 (imaging plate 15) from the rotation angle detection circuit 75. At the same time, the controller 91 starts to output the digital data of the instantaneous value I of the SUM signal from the A / D conversion circuit 83. Next, the controller 91 controls the feed motor control circuit 73 to rotate the feed motor 22 to move the imaging plate 15 from the reading start position to the lower right direction in FIGS. 1 and 2 at a constant speed. Thereby, the irradiation position of the laser beam starts to move relative to the imaging plate 15 from the position slightly inside the diffraction ring reference radius Ro toward the outside at a constant speed. This slightly inside position is a position slightly inside the position where the radius of the captured diffraction ring may deviate from the diffraction ring reference radius Ro. 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 inputs the digital data of the instantaneous value I of the SUM signal via the A / D conversion circuit 83, and from the rotation angle detection circuit 75. The rotation angle θp and the movement distance x from the position detection circuit 72 are input, and the digital data of the instantaneous value I of the SUM signal is obtained from the center of the imaging plate 15 based on the rotation angle θp from the reference position and the movement distance x. The laser beam is sequentially stored in correspondence with the radial distance r (radius value r) of the irradiation position of the laser beam. Also in this case, the distance from the center of the table 16 (imaging plate 15) to the center position of the objective lens 36 in a state where the moving stage 21, that is, the table 16 (imaging plate 15) is at the movement limit position, is a predetermined value determined in advance. Therefore, the radius value r is calculated using the movement distance x. As a result, regarding the irradiation position of the laser beam rotating in a spiral shape, data representing the instantaneous value I, the rotation angle θp, and the radius value r of the SUM signal is sequentially stored and accumulated for each predetermined rotation angle.

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 r _α and a SUM signal intensity value I _α corresponding to the peak of the curve are stored. This is to obtain the intensity distribution of the diffracted X-rays in the radial direction for each rotation angle α of the diffraction ring, and to calculate the radius value r _{α at the} location where the intensity of the diffracted X-rays reaches the peak and the intensity I _α corresponding to the intensity of the diffracted X-ray. This is the processing that is required. Then, the radius value r _α and the intensity I _α are acquired at all the rotation angles θp (rotation angle α), and the instantaneous value I of the SUM signal to be detected is sufficiently smaller than the intensity I _α (for example, 1/10 or less). At this point, the data representing the instantaneous value I, the rotation angle θp, and the radius value r of the SUM signal is detected and stored for each predetermined rotation angle. Thereby, the intensity distribution (data group of instantaneous value I, rotation angle θp, and radius value r) corresponding to the intensity of diffracted X-rays in the diffraction ring and the shape of the diffraction ring (radius value r _α for each rotation angle _α ) are obtained. It is detected.

  Thereafter, the controller 91 stops the focus servo control by the focus servo circuit 81 and stops the irradiation of the laser light from the laser light source 31 by the laser drive circuit 77. Further, the controller 91 stops the operation of the A / D conversion circuit 83 and the rotation angle detection circuit 75 and also stops the operation of the feed motor 22 by the feed motor control circuit 73. Thereby, the diffraction ring reading step S3 is completed. In this state, the operation of the position detection circuit 72 and the rotation of the imaging plate 15 are continued as before.

  After such a diffraction ring reading step S3, the controller 91 executes the diffraction ring elimination step S4 of FIG. 5 either automatically or by an instruction from the operator using the input device 92. In this diffraction ring erasing step, the controller 91 controls the feed motor control circuit 73 to move the imaging plate 15 to the erasing start position in the diffraction ring erasing 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. . Also in this case, as in the case of the reading start position, the imaging plate 15 is moved using the position signal from the position detection circuit 72.

  Next, the controller 91 controls the LED drive circuit 84 to start the irradiation of the LED light to the imaging plate 15 by the LED light source 43 and also controls the feed motor control circuit 73 to move the imaging plate 15 to 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. The erasure end position is a position where the center of the LED light from the LED light source 43 is outside the diffraction ring reference radius Ro by the same distance as the erasure start position. Thereby, the LED light from the LED light source 43 is irradiated spirally on the imaging plate 15 from the erase start position to the erase end position, and the diffraction ring formed by the diffraction X-rays is erased.

  Next, 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 visible light from the LED light source 43. The controller 91 stops the operation of the position detection circuit 72 and also controls the spindle motor control circuit 74 to stop the rotation of the imaging plate 15 by the spindle motor 27. Thereby, the diffraction ring erasing step S4 ends.

After such a diffraction ring elimination step S4, the controller 91 performs the residual stress calculation step S5 of FIG. 5 either automatically or according to an instruction from the operator using the input device 92. The residual stress calculation step S5 may be performed in parallel with the diffraction ring elimination step S4. The residual stress calculation step S5 is a calculation process by a program performed by the controller 91 using the shape of the diffraction ring (radius value r _α for each rotation angle _α ) obtained in the diffraction ring reading step S3. Since the calculation method in this calculation process is described in detail in [0026] to [0044] of Japanese Patent Laid-Open No. 2005-241308 shown as Patent Document 2 in the background art, it is omitted. A set value of the X-ray incident angle ψ and a set value of the distance L from the X-ray irradiation point to the imaging plate 15 are used together with the shape data. Therefore, since the incident angle ψ and the distance L are adjusted with the above-described adjustment method with high accuracy, the residual stress (residual compressive stress and residual shear stress) can be calculated with high accuracy.

  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 this, the intensity distribution image of the diffraction ring (image obtained from the data group of the instantaneous value I, the rotation angle θp and the radius value r with the instantaneous value I as the brightness), and the measurement conditions such as the incident angle ψ and the distance L May be displayed. The operator can evaluate the degree of fatigue of the measurement object OB by looking at the result.

  As can be understood from the above description, in the above-described embodiment, the long portions 102 and 112 and the suction portion that can be sucked to another object at the tip of the long portions 102 and 112 are measured at the measurement object OB. 103 and 113 and level levels LV and LH including inclination confirmation units 101 and 111 indicating that the planes of the suction units 103 and 113 are horizontal when the planes of the suction units 103 and 113 are perpendicular to the direction of gravity. By operating the arm level 69 and the operation elements 65a and 66a, the inclination angle of the stage 61 is adjusted so that the inclination confirmation parts 101 and 111 of the level elements LV and LH are horizontal. After performing a measurement object posture adjustment step to be adjusted, diffraction ring imaging by X-ray irradiation, diffraction ring reading, and residual stress calculation are performed. According to this, since the measurement location of the measurement object OB can be made perpendicular to the direction of gravity, that is, horizontal by the measurement object attitude adjustment step, the optical axis of the X-ray emitted from the X-ray emitter 10 can be adjusted. If the angle with respect to the direction of gravity can be adjusted to an appropriate angle, the incident angle of X-rays can be set to a set value with high accuracy.

  In the above embodiment, the X-ray diffraction measurement apparatus rotates the operating elements 67a, 68a, and 63a of the object setting device 60 that sets the position of the stage 61 with respect to the X-ray emitter 10 and the imaging plate 15 to an arbitrary position. LED light with the same optical axis as the X-rays emitted from the X-ray emitter 10 in a state in which the X-rays are not emitted from the X-, Y- and Z-axis moving mechanisms An LED light source that emits light to the measurement object is provided, and before the diffraction ring imaging by X-ray irradiation, LED light is emitted from the LED light source, and the movement mechanism in the X, Y, and Z axis directions of the object setting device 60 is operated. Thus, the position of the stage 61 is adjusted so that the irradiation point of the LED light on the measurement object OB becomes the measurement location. According to this, by adjusting the position of the stage 61 so that the LED light irradiation point becomes a measurement location, the X-ray irradiation position on the measurement object can be accurately set to the intended position.

  In the above embodiment, the X-ray diffraction measurement apparatus forms an image of the measurement object in the region including the irradiation point of the LED light, and the image formed by the imaging lens 48. A camera that has an imager 49 that captures an image and outputs an imaging signal representing the captured image, and a display device that inputs an imaging signal output from the camera and displays the image captured by the imager on the screen 93, when the distance from the LED light irradiation point on the measurement object OB to the imaging plate 15 is a predetermined distance, the position on the image of the irradiation point imaged by the imager 49 is set as a cross point of the cross mark. And a display device 93 that displays on the screen independently of the image displayed by the imaging signal, and further illuminates the visible light displayed on the display device 93 when adjusting the position of the measurement object. Point is adjusted to be consistent with the cross point of the cross mark. According to this, in addition to adjusting the irradiation point of the LED light to be a measurement location, the measurement object is adjusted by adjusting the irradiation point of the LED light displayed on the display device 93 to match the cross point. The distance from the X-ray irradiation point in OB to the imaging plate 15 can be set to a set value with high accuracy.

  Further, in the above-described embodiment, the housing 50 of the X-ray diffraction measurement device, the arm-type moving device that is connected to the housing 50 of the X-ray diffraction measurement device and makes the posture of the housing 50 an arbitrary posture, and the housing A tilt sensor 56 and a tilt sensor signal extraction circuit 88 that detect an angle that is set on the body 50 and that can calculate the angle of the optical axis of the X-ray emitted from the X-ray emitter 10 with respect to the direction of gravity are provided. Prior to imaging of the diffraction ring, the arm type moving device is operated to adjust the attitude of the casing 50 of the X-ray diffraction measurement device around the direction perpendicular to the gravity direction, and the tilt sensor 56 and the tilt sensor signal extraction circuit Based on the angle detected by 88, the incident angle of the X-ray emitted from the X-ray emitter 10 to the measurement object OB is calculated and displayed on the display device 93. According to this, the X-ray incident angle can be accurately set to the set value by adjusting the attitude of the housing of the X-ray diffraction measurement apparatus until the incident angle displayed on the display device 93 reaches the set value. it can. Therefore, the set value of the incident angle of X-rays can be set to various values.

  The implementation of the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the object of the present invention.

  In the above-described embodiment, the tip of the level used to adjust the measurement location of the measurement object OB horizontally is a columnar adsorption portion made of a magnet, but it adheres closely to the minute plane of the measurement location of the measurement object. Any material may be used as long as it has a flat surface to be adsorbed. For example, it may be adhering in close contact with a suction cup. In addition, the inclination confirmation part that confirms the level of the spirit level is the one that enters the center of the circle in which bubbles are drawn when it is horizontal, as in a general spirit level. It may be of a different type. For example, a system that emits laser light to a horizontal plane and detects the light receiving position of the reflected laser light may be used.

  Further, in the above embodiment, the X-ray diffraction measurement apparatus is configured to be able to change the position and posture by the arm type moving device. However, the X-ray diffraction measurement apparatus is fixed to the stand and the stand is moved. Although the position of the device and the posture around the gravity direction can be changed, the posture around the direction perpendicular to the gravity direction may be fixed. According to this, although the incident angle of X-rays is fixed to one set value, the cost of the apparatus can be reduced by the amount that the arm type moving device and the tilt sensor 56 are unnecessary. Further, if the measurement object OB is limited and the position and orientation of the X-ray diffraction measurement device with respect to the measurement object OB are not greatly changed, the X-ray diffraction measurement device is fixed to a fixed facility, The position and orientation of the measurement object OB may be adjusted only by the setting device 60.

  In the above embodiment, the position and posture of the measurement object OB are adjusted by the object setting device 60 after adjusting the position and posture of the casing 50 of the X-ray diffraction measurement device by the arm type moving device. It was. However, the measurement location of the measurement object OB is horizontal, the X-ray irradiation point becomes the measurement location, and the distance L from the X-ray irradiation point to the imaging plate 15 and the X-ray incident angle ψ are set values. Therefore, the order of adjustment can be changed as appropriate. For example, the position of the measurement object OB is adjusted to level the measurement location, and then the LED light is irradiated to illuminate the position and orientation of the housing 50 of the X-ray diffraction measurement apparatus. The LED light irradiation point may be adjusted to approximately the measurement location, and finally the position of the measurement object OB may be adjusted so that the LED light irradiation point becomes the measurement location and the distance L becomes the set value.

  In the above-described embodiment, the arm type moving device and the object setting device 60 are used to adjust the position of the housing 50 of the X-ray diffraction measurement device and the position of the measurement object OB. Even if only one of the adjustments is possible, the present invention can be implemented. For example, when the object setting device 60 is configured such that only the posture of the measurement object OB can be adjusted, the measurement object OB is adjusted so that the measurement location of the measurement object OB is horizontal, and then the housing 50 of the X-ray diffraction measurement apparatus. Is adjusted so that the irradiation point of the LED light becomes the measurement location, and the distance L and the incident angle ψ become the set values.

  Moreover, in the said embodiment, the position of a measuring object is adjusted using LED light with the same optical axis as the emitted X-ray, and the camera which images the irradiation point vicinity of LED light, and the X-ray irradiation point Is the measurement position, and the distance from the X-ray irradiation point to the imaging plate 15 is set to a set value. However, when the X-ray diffraction measurement device is fixed, the measurement location of the measurement object OB is predetermined. The object setting device 60 may be moved so that the LED light and the camera are eliminated. As a method of setting the measurement location of the measurement object OB to a predetermined position, a method using laser beams that intersect at a predetermined position can be considered.

  In the above-described embodiment, imaging is performed from the X-ray irradiation point by matching the LED light irradiation point P1 with the cross point of the cross mark in the captured image generated and displayed based on the signal output from the imager 49. The distance L to the plate 15 is set to the set distance Lo. However, if the distance L can be obtained with high accuracy, the residual stress can be calculated with high accuracy. Instead, the relationship between the LED light irradiation point position in the captured image and the distance L can be obtained with high accuracy in advance. Alternatively, the relationship curve is stored in the controller 91, the captured image created based on the signal output from the imager 49 is processed to obtain the irradiation point position of the LED light, and the stored relationship table or relationship curve The distance L may be calculated from According to this, adjustment of a position and a posture can be made easier.

  In the above embodiment, the cross mark is displayed 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. However, the measurement object OB is displayed on the imaging plate 15. Since the position where the image of the LED light irradiation point is formed can be accurately displayed in the captured image when it is at the set position, the position where the optical axis of the imaging lens 48 intersects the image sensor 49 is sufficient. It does not have to be. In this case, when the measurement object OB is at a position set with respect to the imaging plate 15, the position on the captured image where the image of the LED light irradiation point is formed is detected, and a cross mark is displayed at that position. You just have to do it. Note that, as the light passing through the center of the imaging lens 48 is further away from the optical axis of the imaging lens 48, the formed spot becomes larger. Therefore, the optical axis of the imaging lens 48 is the same as that of the imaging device 49. It is preferable to be in the vicinity of the intersecting position.

  In the above embodiment, the LED light source 44 is moved on the optical axis of the X-ray by the plate 45, the motor 46, and the stopper member 47a to irradiate the measurement object OB with the LED light. However, instead of this, any structure may be used as long as it can emit visible parallel light having the same optical axis as that of 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.

  Further, in the above embodiment, the passage member 28 having a small inner diameter is provided in the through hole 27 b of the spindle motor 27 and the inner diameter of the through hole 18 a of the fixture 18 is reduced to reduce the LED light emitted from the LED light source 44. Although parallel light having a cross-sectional diameter is obtained, another structure may be used as long as visible parallel light having a small cross-sectional diameter can be obtained. For example, by increasing the axial length of the passage member 28, parallel light having a small cross-sectional diameter may be obtained from the LED light from the LED light source 44. Further, a collimator lens and an expander lens are arranged near the laser light source that emits visible laser light, and the optical axis of the emitted laser light with a small cross-sectional diameter is the through hole 27a1 of the output shaft 27a of the spindle motor 27. It may be made to coincide with the central axis line.

  In the above embodiment, after the diffraction ring is formed on the imaging plate 15, the intensity distribution corresponding to the intensity of the diffracted X-rays in the diffraction ring is detected by laser irradiation from the laser irradiation device 30 and light intensity detection. If the diffraction ring is erased by irradiating the LED light, and the intensity distribution can be detected by forming the diffraction ring, what method is used to form the diffraction ring and detect the intensity distribution? Also good. 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. You may make it detect the intensity distribution in a diffraction ring. Further, instead of the X-ray CCD having the same area 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. You may make it detect the intensity distribution in a diffraction ring from a scanning position.

  In the above embodiment, the X-ray diffraction measurement apparatus is an apparatus capable of forming a diffraction ring and distributing the intensity corresponding to the intensity of the diffraction X-ray, that is, reading the diffraction ring, erasing the diffraction ring, and calculating the residual stress. However, if it takes a long time for the measurement, the X-ray diffraction measurement device is a device that only forms a diffraction ring, and the imaging plate 15 on which the diffraction ring is formed is detached from the table 16 and set in another device. The reading of the diffraction ring, the elimination of the diffraction ring, and the calculation of the residual stress may be performed by another apparatus. Further, the residual stress may be calculated by another apparatus.

DESCRIPTION OF SYMBOLS 10 ... X-ray emitter, 15 ... Imaging plate, 15a, 16a, 17a, 18a, 21a, 26a, 27a1, 27b ... Through-hole, 16 ... Table, 18 ... Fixing tool, 20 ... Table drive 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 ... connecting wall, 51 ... support arm, 56 ... tilt sensor, 60 ... object setting device, 61 ... stage, 63a, 65a, 66a, 67a, 68a ... operator, 90 ... computer device, 91 ... Controller, 92 ... input apparatus, 93 ... display, 95 ... high voltage power supply, OB ... measurement object, PL ... fixing plate, LV ... Level, LH ... Level

Claims (4)

A stage on which an object to be measured is placed; a stage posture changing mechanism that makes an inclination angle of the stage an arbitrary angle;
An X-ray emitter for emitting X-rays toward the measurement object;
X-ray radiated from the X-ray emitter toward the measurement object, and X-ray diffracted light generated at the measurement object is applied to the optical axis of the X-ray emitted from the X-ray emitter. X-ray diffraction measurement using an X-ray diffraction measurement system comprising a diffraction ring forming means for receiving light on an imaging plane perpendicular to the imaging plane and forming a diffraction ring as an image of the X-ray diffracted light on the imaging plane. In the method
At the measurement location of the measurement object, a long part, a flat part that can be attracted to another object at the tip of the long part, and a display that indicates that the flat part is horizontal when it is perpendicular to the direction of gravity And a spirit level mounting step for mounting the level by adsorbing the flat surface,
A measurement object posture adjustment step of adjusting the tilt angle of the stage so that the display unit of the level is horizontal by operating the stage posture changing mechanism,
And a diffraction ring forming step of forming a diffraction ring by the diffraction ring forming means. The X-ray diffraction measurement method according to claim 1,
The diffraction measurement system includes:
A stage position changing mechanism for arbitrarily setting the position of the stage with respect to the X-ray emitter and the imaging plane;
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. Equipped with
Before the diffractive ring forming step, visible light is emitted from the visible light emitter, and the stage position changing mechanism is operated so that the irradiation point of the visible light on the measurement object becomes a measurement location. An X-ray diffraction measurement method comprising performing a measurement object position adjustment step for adjusting a position. In the X-ray-diffraction measuring device method of Claim 2,
The diffraction measurement system includes:
An imaging lens that forms an image of a measurement object in an area including the irradiation point of the visible light, and an imager that captures an image formed by the imaging lens, and represents the captured image A camera that outputs an imaging signal;
A display for inputting an imaging signal output from the camera and displaying an image captured by the imaging device on a screen, wherein the diffraction ring is formed from an irradiation point of the visible light on a measurement object When the distance to the surface to be captured is a predetermined distance, the position on the image of the irradiation point imaged by the imaging device is used as the irradiation point reference position, and is displayed on the screen independently of the image displayed by the imaging signal. And an indicator
In the X-ray diffraction measurement method, the measurement object position adjusting step further adjusts the irradiation point of the visible light displayed on the display so as to coincide with the irradiation point reference position. In the X-ray-diffraction measuring method of Claim 2 or Claim 3,
The X-ray diffraction measurement system includes:
A housing including at least the X-ray emitter and the imaging plane;
A housing posture change mechanism connected to the housing and making the posture of the housing an arbitrary posture;
An inclination detecting means for detecting an angle that is set in the housing and capable of calculating an angle of the optical axis of the X-ray emitted from the X-ray emitter with respect to the gravity direction;
Before the diffraction ring formation step,
A housing posture adjustment step of adjusting the posture around a direction perpendicular to the gravitational direction of the housing by operating the housing posture changing mechanism;
An X-ray diffraction measurement method comprising: an incident angle acquisition step of acquiring an incident angle of an X-ray emitted from the X-ray emitter to an object to be measured based on an angle detected by the tilt detection means. .