JP2017044605A - Contactless inner surface shape measurement device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a contactless inner surface shape measurement device that enables highly accurate measurement.SOLUTION: A measurement unit 14 of a contactless inner surface shape measurement device 1 is arranged so as to be inserted into a measurement hole P of a measurement object. The measurement unit 14 comprises: a light emitting unit 40 that emits measurement light Lof; a right-angle mirror 42 that reflects the measurement light Lof emitted from the light emitting unit 40 in a direction perpendicular to a reference axis 14a; and a motor 44 that rotates the right-angle mirror 42 around the reference axis 14a to rotate an irradiation direction of the measurement light Lof.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a non-contact inner surface shape measuring apparatus, and more particularly to a non-contact inner surface shape measuring apparatus that measures the shape dimension of a cylindrical inner surface or a deep hole inner surface in a non-contact manner.

  Patent Documents 1 and 2 disclose measuring devices that measure the shape of the inner surface of the hole to be measured or the inner diameter of the hole in a non-contact manner.

  According to these measuring apparatuses of Patent Documents 1 and 2, a reflecting member such as a prism is inserted into the hole to be measured, and the reflected light is detected by irradiating the inner surface of the hole through the reflecting member. To do. Thereby, the position (distance from the specific position) of the measurement point irradiated with the laser beam is measured. Further, the inner surface shape of the hole, the inner diameter of the hole, and the like are measured by rotating the reflecting member around a predetermined rotation axis and changing the measurement direction around the rotation axis.

JP 2014-126396 A JP 2008-304407 A

  However, Patent Documents 1 and 2 involve not only the rotation of the reflection member but also the rotation of other optical members, so the rotation mechanism for rotating the reflection member is large-scale, and the accuracy is reduced. It is an inviting factor.

  This invention is made | formed in view of such a situation, and it aims at providing the non-contact inner surface shape measuring apparatus in which a highly accurate measurement is possible.

  In order to achieve the above object, a non-contact inner surface shape measuring device according to one aspect of the present invention irradiates measurement light, which is an inner surface of a measurement hole, from a measurement unit inserted into a measurement hole that is a measurement object. This is a non-contact inner surface shape measuring device that measures the shape of the measurement inner surface in a non-contact manner, and the measurement unit measures the reference axis along the insertion direction of the measurement unit into the measurement hole and the direction along the reference axis. A light emitting portion that emits light, and a traveling direction changing member that is disposed to face the light emitting portion, changes the traveling direction of the measuring light emitted from the light emitting portion, and emits the measuring light toward the measurement inner surface And a driving means for rotating the traveling direction changing member around the reference axis, and a guide portion that contacts the measurement inner surface and supports the measurement portion inside the measurement hole.

  According to this embodiment, it is possible to rotate the irradiation direction of the measurement light around the reference axis only by rotating the traveling direction changing member such as the reflecting member by the driving unit, and measure the shape of the entire circumference of the measurement inner surface. be able to. Therefore, since the rotation mechanism for rotating the traveling direction changing member can be simplified, the rotational motion error is small and the weight is small, so that bending due to its own weight is small and vibration is small. Thereby, improvement of measurement accuracy can be aimed at. Also, high-speed rotation is possible, and the measurement time can be shortened.

  In addition, since the measurement unit is supported inside the measurement hole by the guide unit, measurement can be performed in a stable posture, and measurement accuracy can be improved.

  In the non-contact inner surface shape measuring apparatus according to another aspect of the present invention, the traveling direction changing member may be a reflecting member having a reflecting surface that obliquely intersects the reference axis.

  In the non-contact inner surface shape measuring apparatus according to still another aspect of the present invention, the light emitting portion is disposed on the distal end side in the insertion direction relative to the traveling direction changing member, and emits the measurement light toward the proximal end side in the insertion direction. It can be set as the mode to do.

  In the non-contact inner surface shape measuring apparatus according to still another aspect of the present invention, the guide portion may be disposed on the distal end side and the proximal end side in the insertion direction of the measurement portion.

  In the non-contact inner surface shape measuring apparatus according to still another aspect of the present invention, the traveling direction changing member may be an aspect in which the periphery around the reference axis is surrounded by a transparent cylinder.

  In the non-contact inner surface shape measuring apparatus according to still another aspect of the present invention, a wavelength swept light source, a branching unit for branching light emitted from the wavelength swept light source into measurement light and reference light that pass through different optical paths, Guide light for guiding the measurement light to the light emitting portion, and return light from the measurement point irradiated with the measurement light emitted from the light emitting portion via the traveling direction changing member, the traveling direction changing member, the light emission Light detection means for detecting interference light between the return light and the reference light returning via the guide means and the interference light detected by the light detection means at each rotation angle of the reflecting member rotated by the drive means. By detecting the position of the measurement point based on this, it is possible to adopt an aspect including an inner surface shape detection unit that detects the shape of the measurement inner surface.

  In the non-contact inner surface shape measuring apparatus according to still another aspect of the present invention, the wavelength swept light source may be configured to change the wavelength within a range of 1200 nm to 1600 nm.

  According to the present invention, highly accurate measurement is possible.

Non-contact inner surface shape measuring apparatus to which the present invention is applied Configuration diagram showing the internal structure of the measuring device Graph illustrating time variation of wavelength of laser beam output from wavelength swept light source Configuration diagram showing the measurement part in the state inserted in the measurement hole The figure which showed the state which inserted the measurement part in the taper-shaped measurement hole The figure used for explanation of other embodiments of the measurement unit Flow chart showing measurement procedure of non-contact inner surface shape measuring device The figure which showed the measurement data obtained by measuring the inner peripheral surface of a cylindrical hole The figure which showed the measurement data obtained by measuring the internal gear The figure which showed measurement data of Drawing 9 with other forms The figure which illustrated interference intensity distribution which shows magnitude to the quantity of return light of measurement light

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

  FIG. 1 is an overall configuration diagram of a non-contact inner surface shape measuring apparatus to which the present invention is applied.

  As shown in the figure, the non-contact inner surface shape measuring apparatus 1 is a measurement data (interference signal) for obtaining the shape of the inner surface (hereinafter referred to as measurement inner surface S) of a hole to be measured (hereinafter referred to as measurement hole P). ) And the operation of each part of the measurement device 10, and various calculation processes are performed based on the measurement data acquired by the measurement device 10 to determine the shape of the measurement inner surface S and the inner diameter of the measurement hole P. And a control processing device 16 that calculates information related to the shape of the measurement inner surface S.

  The control processing device 16 includes an input means for an operator to input information and an output means for outputting (displaying, printing, etc.) information. Further, the entire control processing device 16 or all or part of the functions related to measurement may be incorporated in the measurement device 10 (the measurement device main body 12 described below).

  Further, the measurement inner surface S is not limited to a circular cross-sectional shape perpendicular to the axis of the measurement hole P but can also be a polygon or a complex shape.

  The measuring device 10 is connected to the measuring device main body 12 arranged outside the measuring hole P and the measuring device main body 12 via a cable or the like (electric cable and optical fiber) and is inserted into the measuring hole P. Part 14.

  FIG. 2 is a configuration diagram showing the internal structure of the measuring apparatus 10.

  The measurement apparatus 10 shown in the figure has a configuration of a wavelength sweep interference type displacement sensor. In the measurement apparatus main body 12, a wavelength sweep light source 20 and a circulator 22 connected to the wavelength sweep light source 20 via an optical fiber 30 are provided. And a photodetector 24 connected to the circulator 22 via an optical fiber 32.

  On the other hand, in the measuring unit 14, a light emitting unit 40 connected to the circulator 22 of the measuring apparatus main body 12 via an optical fiber 34, a right angle mirror 42 as a reflecting member disposed opposite to the light emitting unit 40, and a right angle mirror The motor 44 and the rotary encoder 46 which are connected to 42 and omitted as an integral part are shown.

  According to this measuring apparatus 10, coherent light (laser light) obtained by sweeping (changing) the wavelength at a constant period in the range of a constant wavelength band is emitted from the wavelength swept light source 20. The light emitted from the wavelength swept light source 20 is transmitted to the circulator 22 through the optical fiber 30.

  FIG. 3 is a graph illustrating the time change of the wavelength of the laser light output from the wavelength swept light source 20, where the horizontal axis indicates time (time) and the vertical axis indicates the wavelength. As shown in the figure, the wavelength is repeatedly changed in the range of about 1200 nm to about 1600 nm, and the frequency of the change is set to a value in the range of about 1 kHz to about 100 kHz.

  Here, the use of the wavelength band of about 1200 nm to about 1600 nm is excellent in terms of high-speed measurement, avoidance of natural light noise, and eye-safe (friendly to eyes). In particular, since it is eye-safe, there is no problem even if the amount of light is 20 mW or more in order to improve measurement sensitivity.

  In FIG. 2, the light transmitted to the circulator 22 is propagated only to the optical fiber 34 by the circulator 22 and is transmitted to the light emitting unit 40 via the optical fiber 34.

  A part of the light transmitted to the light emitting unit 40 is reflected at the end face 36 of the optical fiber 34 at the connection portion between the optical fiber 34 and the light emitting unit 40, and the rest is transmitted to the light emitting unit 40.

  Here, the end face 36 of the optical fiber 34 is a branching part that branches the light from the wavelength swept light source 20 into the measurement light Lof and the reference light Lr, and the reference light Lr in the interferometer is generated by the light reflected by the end face 36. Then, the measurement light Lof in the interferometer is generated by the light transmitted through the end face 36.

  The reference light Lr reflected by the end face 36 of the optical fiber 34 returns directly to the optical fiber 34 and is transmitted to the circulator 22.

  On the other hand, the light transmitted through the end face 36 of the optical fiber 34 is emitted from the light emitting unit 40 as the measurement light Lof. The light emitting unit 40 converts the measurement light Lof emitted from the end face 36 of the optical fiber 34 from diverging light to parallel light or condensed light, or reflects the measurement light L reflected from the measurement inner surface S (return light Lor). A collimator lens that collects the light and enters the optical fiber 34 from the end face 36.

  The measurement light Lof emitted from the light emitting unit 40 travels along the predetermined reference axis 14a of the measuring unit 14 (on the reference axis 14a), and then is reflected by the inclined surface that is the reflecting surface of the right-angle mirror 42. It proceeds in a direction perpendicular to the reference axis 14a.

  The reflection direction of the measurement light Lof by the reflection surface is not limited to the direction perpendicular to the reference axis 14a as long as it is directed toward the measurement inner surface, and the reflection member has a reflection surface that exhibits the same action as the right-angle mirror 42. If so, the right-angle mirror 42 is not necessary. Furthermore, it is not limited to the reflecting member, and any traveling direction changing member that changes the traveling direction of the measuring light Lof emitted from the light emitting unit 40 and emits the measuring light Lof toward the measuring inner surface S may be used.

  Moreover, the measurement part 14 is arrange | positioned so that the reference axis 14a may become substantially coaxial with the axial center of the measurement hole P as shown in FIG.

  The reference axis 14a is an axis along the direction (insertion direction) in which the measurement unit 14 is inserted into the measurement hole P, and the insertion direction side of the measurement unit 14 is the distal end side, and the opposite side to the insertion direction is the proximal end side. To do.

  The measurement light Lof that has traveled in the direction perpendicular to the reference axis 14a is applied to the measurement inner surface S. Then, a part or all of the measurement light scattered (reflected) on the measurement inner surface S travels back as an optical path through the optical path 34 as the return light Lor and enters the optical fiber 34 via the right angle mirror 42 and the light emitting unit 40.

  The return light Lor incident on the optical fiber 34 is transmitted to the circulator 22 via the optical fiber 34.

  The above-described reference light Lr and measurement light return light Lor transmitted to the circulator 22 via the optical fiber 34 are propagated only to the optical fiber 32 by the circulator 22, and the photodetector 24 is transmitted via the optical fiber 32. Is incident on.

  Interference light between the measurement light reflected by the measurement inner surface S (return light Lor) and the reference light Lr reflected by the end face 36 of the optical fiber 34 enters the photodetector 24, and the interference is caused by the photodetector 24. The intensity of light is detected as an interference signal that is an electrical signal. Then, the interference signal is given to the control processing device 16.

  In the control processing device 16, information on the position of the measurement point irradiated with the measurement light (return light) on the measurement inner surface S based on the interference signal obtained from the photodetector 24, that is, the measurement point from the reference axis 14a. The distance is calculated as distance information.

  Further, the right angle mirror 42 of the measurement unit 14 is rotated at least 360 degrees (one rotation) or more around the reference axis 14a by the motor 44 connected thereto. The rotation of the right angle mirror 42 may be a rotation within a specific angle range of less than 360 degrees, or may be a plurality of rotations.

  As a result, the irradiation direction (measurement direction) of the measurement light Lof emitted from the light emitting unit 40 and reflected by the inclined surface of the right-angle mirror 42 rotates around the reference axis 14a, and the measurement direction becomes the entire circumferential direction around the reference axis 14a. Be changed. That is, the measurement light Lof is radially scanned with respect to the measurement inner surface S.

  In addition, since only the right-angle mirror 42 is rotated, the rotational motion error is small and the vibration is small, so that the measurement accuracy is hardly lowered due to the rotational operation for radial scanning of the measurement light. For example, high-accuracy measurement on the order of microns is possible.

  Furthermore, since only the right-angle mirror 42 is rotated, the right-angle mirror 42 can be rotated at high speed, and the measurement time can be shortened.

  On the other hand, the rotation angle of the right angle mirror 42 of the measurement unit 14 is detected by the rotary encoder 46, and information on the rotation angle is given to the control processing device 16. Information on the rotation angle detected by the rotary encoder 46 corresponds to information on an angle related to the direction around the reference axis 14a in the measurement direction.

  Thereby, in the control processing device 16, information on the distance to the measurement inner surface S detected based on the interference signal from the photodetector 24 and information on the rotation angle from the rotary encoder 46 when the distance is detected. Measurement data indicating the shape (position) of the measurement inner surface S on the scanning surface where the position of each measurement point is detected and the measurement light is scanned based on (information on the angle about the reference axis 14a in the measurement direction). can get.

  Note that the measurement accuracy can be improved by rotating the right angle mirror 42 a plurality of times, detecting the position of the same point on the measurement inner surface S a plurality of times, and averaging.

  As described above, the measurement apparatus 10 of the above embodiment shows one form of an interferometer that detects the interference light between the reference light and the measurement light, and an interferometer having another configuration may be adopted. For example, a configuration generally known as a Michelson interferometer may be used.

  Next, a specific configuration of the measurement unit 14 will be described. FIG. 4 is a configuration diagram illustrating the measurement unit 14 in a state of being inserted into the measurement hole P. As described above, the insertion direction side of the measurement unit 14 into the measurement hole P is the distal end side, and the opposite side to the insertion direction is the proximal end side.

  As shown in the figure, the measurement unit 14 includes a first support unit 50 on which the light emitting unit 40 is supported, and a second support unit 52 disposed on the base end side of the first support unit 50, The right angle mirror 42 is rotatably supported, and is disposed between a second support portion 52 on which the motor 44 and the rotary encoder 46 are supported, and between the first support portion 50 and the second support portion 52. A transparent cylinder 54 that integrally connects the first support portion 50 and the second support portion 52, and provided on the distal end side of the first support portion 50 and the proximal end side of the second support portion 52, and measures the measurement portion 14. The first guide portion 56 and the second guide portion 58 that are guided to the hole P, and the base end side of the second guide portion 58 are connected, and the measurement portion 14 is pushed and pulled with respect to the measurement hole P to reduce the insertion amount. An insertion pipe 60 to be adjusted.

  The first support part 50 is a cylindrical member 70 having an outer diameter that is cylindrical, and has a cylindrical member 70 whose axial center is arranged substantially coaxially with the reference axis 14 a of the measurement part 14. The light emitting portion 40 is supported at a central portion along the axis of the cylindrical member 70.

  Further, the proximal end side of the light emitting portion 40 to which the optical fiber 34 is connected is accommodated and held inside the cylindrical member 70, and the distal end side of the light emitting portion 40 from which the measurement light Lof is emitted is the cylindrical member 70. It is arranged so as to protrude from the base end surface to the base end side (base end side in the measurement unit 14). In addition, the front end side of the light emission part 40 shows the end surface side from which the measurement light Lof is emitted from the light emission part 40, and a collimator lens, for example, is disposed at the front end part of the light emission part 40.

  As a result, the measurement light Lof transmitted from the optical fiber 34 to the light emitting portion 40 is emitted from the light emitting portion 40 from the distal end side to the proximal end side of the measuring portion 14 and substantially coaxial with the reference axis 14a. Go on top. 2 and 4, the direction of the light emitting unit 40 is reversed, and accordingly, the direction of the right angle mirror 42 is also reversed.

  The second support portion 52 is a columnar member 72 having an outer diameter that is a columnar shape, similar to the first support portion 50, and the columnar member 72 whose axial center is arranged substantially coaxially with the reference axis 14 a of the measurement unit 14. Have.

  A motor 44 is housed and held inside the cylindrical member 72, and a rotating shaft member 74 that is rotatably supported by the cylindrical member 72 along the axis of the cylindrical member 72 is connected to the rotating shaft 44 a of the motor 44. Is done. Then, the right angle mirror 42 is fixed to the tip of the rotating shaft member 74.

  The right angle mirror 42 is disposed at a position facing the tip (end surface from which the measurement light is emitted) of the light emitting unit 40 on the tip side (tip side in the measurement unit 14) of the tip surface of the cylindrical member 72, and The inclined surface which is a reflection surface is a position where the reference axis 14a intersects, and the inclined surface intersects the reference axis 14a obliquely (approximately 45 degrees).

  As a result, the right angle mirror 42 rotates around the reference axis 14 a by the rotation of the rotation shaft 44 a of the motor 44. Then, the measurement light Lof emitted from the light emitting unit 40 is reflected by the inclined surface of the right angle mirror 42 and irradiated in a direction perpendicular to the reference axis 14a, and the irradiation direction rotates around the reference axis 14a as a measurement direction. . Note that the irradiation direction of the measurement light Lof does not necessarily have to be a direction perpendicular to the reference axis 14a as long as it includes a component perpendicular to the reference axis 14a.

  In addition, the rotary encoder 46 is accommodated and held in the cylindrical member 72 and connected to the rotary shaft member 74. As a result, information on the rotation angle of the right-angle mirror 42 is detected by the rotary encoder 46 as information indicating an angle related to the direction around the reference axis 14a in the measurement direction via the rotation shaft member 74.

  Since the light emitting portion 40 is disposed on the tip side of the right-angle mirror 42, the scanning surface (measurement region) on which the measurement light Lof reflected and irradiated by the right-angle mirror 42 rotating around the reference axis 14a is scanned. ) Crosses the optical fiber 34. However, the optical fiber 34 can be extremely thin (thinner than the beam diameter of the measurement light), and the optical fiber 34 can be hardly affected by the measurement.

  The transparent cylinder 54 is formed in a cylindrical shape by a transparent member that transmits the wavelength of the measurement light Lof, and the distal end of the transparent cylinder 54 is fixed to the periphery of the base end surface of the columnar member 70 of the first support portion 50. Is fixed to the peripheral edge of the front end surface of the cylindrical member 72 of the second support portion 52.

  Thereby, the columnar member 70 of the first support part 50 and the columnar member 72 of the second support part 52 are integrally connected via the transparent cylinder 54.

  The right-angle mirror 42 is surrounded by a transparent cylinder 54 around the reference axis 14a. Since the transparent cylinder 54 has a characteristic of transmitting the wavelength of the measurement light Lof, it is emitted from the light emitting section 40 via the right-angle mirror 42. The measured measurement light Lof is applied to the measurement inner surface S without being blocked by the transparent cylinder 54. Then, the measurement light (return light Lor) reflected by the measurement inner surface S passes through the transparent cylinder 54 without being blocked by the transparent cylinder 54 and enters the light emitting unit 40 via the right angle mirror 42.

  The transparent cylinder 54 only needs to be formed of a material that is highly transmissive with respect to the wavelength of the measurement light Lof, and light having a wavelength of about 1200 nm to about 1600 nm, which is the wavelength of the measurement light Lof in the present embodiment. A transparent member such as a member whose front and back surfaces are polished with plastic (acrylic) or glass material can be used.

  Further, the columnar member 70 of the first support part 50 and the columnar member 72 of the second support part 52 may be connected by a plurality of small-diameter rod-shaped members or the like instead of the transparent cylinder 54.

  The first guide portion 56 and the second guide portion 58 have the same configuration as each other, a fixed shaft member 80 disposed coaxially with the reference shaft 14a, and a connecting member 82 fixed to the distal end of the fixed shaft member 80. And a pair of guide rollers 84 provided at positions symmetrical to the fixed shaft member 80 (reference shaft 14a).

  The first guide portion 56 is connected to the distal end side of the first support portion 50 by fixing the base end of the fixed shaft member 80 to the distal end surface of the columnar member 70 of the first support portion 50. The second guide portion 58 is connected to the proximal end side of the second support portion 52 by fixing the distal end surface of the connecting member 82 to the proximal end surface of the second support portion 52.

  Each guide roller 84 has the same structure and includes a disk-shaped roller member 86. When only one guide roller 84 of the first guide portion 56 is described with reference numerals, the guide roller 84 is fixed to the roller member 86, the arm member 88 that rotatably supports the roller member 86, and the connecting member 82. And a support member 90 that rotatably supports the arm member 88.

  Both of the rotation shaft of the roller member 86 and the rotation shaft of the arm member 88 have a direction perpendicular to the same plane including the reference shaft 14a.

  Further, the arm member 88 is biased in a direction in which the roller member 86 is separated from the reference shaft 14a by a biasing member (not shown).

  By the first guide portion 56 and the second guide portion 58, each roller member 86 is pressed (pressed) against the measurement inner surface S when the measurement portion 14 is inserted into the measurement hole P. The reference axis 14a of the measurement unit 14 is arranged substantially coaxially with the axis of the measurement hole P.

  The guide rollers 84 of the first guide portion 56 and the second guide portion 58 are provided not only at two locations in the direction around the reference axis 14a but also at three or more locations at equal intervals, for example, and at least three rollers on the measurement inner surface S. The member 86 may be pressed.

  In the present embodiment, guide portions such as the first guide portion 56 and the second guide portion 58 are provided on the distal end side and the proximal end side of the measurement portion 14, but the arrangement of the guide portions is not limited thereto. Not exclusively.

  The insertion pipe 60 is connected to the base end of the fixed shaft member 80 of the second guide portion 58, and its axis is arranged substantially coaxially with the reference shaft 14a.

  When the operator holds the insertion pipe 60, the operator can insert the measurement hole P from the distal end side of the measurement unit 14, and by pushing and pulling the insertion pipe 60, the measurement unit 14 for the measurement hole P can be inserted. The amount of insertion can be adjusted. That is, the position of the scanning surface (measurement position) where the measurement light is irradiated (scanned) to the measurement inner surface S, and the position of the scanning surface in the direction along the axis of the measurement hole P is pushed by the insertion pipe 60. It can be adjusted by pulling operation.

  Further, the insertion pipe 60 and the fixed shaft member 80 to which the insertion pipe 60 is connected are hollow inside, and a signal line (electric wire) connected to the motor 44 and the rotary encoder 46 is inserted into the inside. Be placed. Then, a cable in which these signal lines are covered with an exterior is extended from the proximal end of the insertion pipe 60, and the cable is connected to the control processing device 16.

  Accordingly, a drive signal (electric power) for driving the motor 44 is supplied from the control processing device 16, and rotation angle information detected by the rotary encoder 46 is given to the control processing device 16.

  The wiring path of the signal line connected to the motor 44 and the rotary encoder 46 is not limited to this aspect, and may be any aspect, and may not be inserted through the fixed shaft member 80. The inside of the insertion pipe 60 may not be inserted.

  Further, the optical fiber 34 connected to the light emitting unit 40 has a columnar end opposite to one end connected to the light emitting unit 40 inside the columnar member 70 of the first support unit 50. The member 70 extends from the inside to the outside and is connected to the measuring apparatus main body 12. At this time, the wiring path of the optical fiber 34 is inserted through at least one of the cylindrical member 72 of the second support portion 52, the fixed shaft member 80 of the second guide portion 58, and the insertion pipe 60. Alternatively, the signal line of the motor 44 may be combined with a single cable and connected to the control processing device 16 or the measurement device main body 12.

  4 shows a state in which the measurement part 14 is inserted into the measurement hole P having a substantially constant inner diameter. FIG. 5 shows a state in which the measurement part 14 is inserted into the measurement hole P having a tapered measurement inner surface S. . As shown in the figure, the roller member 86 is moved to a position where the guide roller 84 of the first guide portion 56 and the second guide portion 58 of the measurement portion 14 comes into pressure contact with the tapered measurement inner surface S. Thereby, the reference axis 14a of the measurement unit 14 is arranged substantially coaxially with the axis of the measurement hole P.

  Note that the measurement light emitted from the light emitting unit 40 through the right angle mirror 42 in a direction perpendicular to the reference axis 14a is obliquely irradiated to the measurement inner surface S, but the light scattered on the measurement inner surface S is returned light. Since it enters into the light emission part 40 through the right-angle mirror 42, it can measure.

  In the measurement unit 14 described above, a part of the optical fiber 34 including a portion intersecting the scanning surface of the measurement light Lof is optically connected without a cable, and the measurement light Lof emitted from the light emission unit 40 is applied to the optical fiber 34. You may make it not be irradiated.

  For example, as shown in FIG. 6, the optical fiber 34 is divided into two optical fibers 34a and 34b, and a cableless portion 34c through which light propagates in the atmosphere is provided. The cableless portion 34c is arranged so as to be around the outer peripheral portion of the transparent cylinder 54, and the end portion 35a of the optical fiber 34a and the end portion 35b of the optical fiber 34b are respectively connected to the columnar member 72 of the second support portion 52 and the first member. It is fixed to the columnar member 70 of the support part 50. In each of the end portions 35a and 35b, the light emitted from the optical fibers 34a and 34b to the cableless portion 34c is converted into parallel light, and the light incident from the cableless portion 34c is collected to collect the optical fibers 34a and 34b. A collimator lens to be entered is disposed.

  Note that the cableless portion 34 c may be disposed inside the transparent cylinder 54.

  Next, the measurement procedure of the non-contact inner surface shape measuring apparatus 1 will be described using the flowchart of FIG.

  First, in step S <b> 10, the operator holds the insertion pipe 60 and inserts the measurement unit 14 into the measurement hole P from the distal end side. Then, the insertion pipe 60 is pushed and pulled to adjust and set the measurement position in the direction along the axis of the measurement hole P. Then, the process proceeds to step S12.

  In step S <b> 12, the control processing device 16 turns on the wavelength sweep light source 20 of the measurement device main body 12 and emits the measurement light Lof from the light emission unit 40 of the measurement unit 14. Further, the motor 44 is driven to rotate the right angle mirror 42. Then, an interference signal from the photodetector 24 is acquired, and information on the distance to the measurement point on the measurement inner surface S irradiated with the measurement light Lof is acquired (calculated) based on the interference signal. Thereafter, the process proceeds to step S14.

  In step S14, the control processing device 16 acquires information on the rotation angle from the rotary encoder 46 of the measurement unit 14, and the rotation angle (an angle related to the direction around the reference axis 14a in the measurement direction) and the measurement point acquired in step S12. Is associated with the distance. Then, the process proceeds to step S16.

  In step S16, the control processing device 16 determines whether or not the right angle mirror 42 is rotated once by the motor 44, that is, whether or not the measurement direction is rotated once around the reference axis 14a. If it is YES, it will transfer to Step S20, and if it is NO, it will return to Step S12 and will repeat processing of Step S12-Step S16.

  In step S16, it may be determined whether or not the right angle mirror 42 has been rotated by a predetermined angle range, instead of whether or not the right angle mirror 42 has been rotated once.

  In addition, the control processing device 16 provides the distance information to the measurement point every time the right-angle mirror 42 rotates by a predetermined angle Δθ, for example, the angle Δθ is, for example, when the number of measurement points is X The measurement data for the number of measurement points obtained by dividing 360 degrees by the angle Δθ is obtained.

  On the other hand, in step S20 when YES is determined in step S16, the shape information (position information) of the measurement inner surface S on the scanning surface of the measurement light is obtained based on the distance information at each rotation angle associated in step S14. Get and save. Further, the shape information of the measurement inner surface S is displayed on output means such as a monitor. Then, the process proceeds to step S22.

  In step S22, the operator determines whether or not to perform measurement at a different measurement position. And when it determines with YES, it returns to step S10 and starts from adjustment of the measurement position by pushing-pull operation of the insertion pipe 60. FIG. If NO is determined, the measurement is terminated.

  The measurement data (and output screen to a monitor etc.) obtained by the above non-contact inner surface shape measuring apparatus 1 are illustrated.

  The measurement data in FIG. 8 shows the shape data of the measurement inner surface S measured when a cylindrical hole having an inner diameter of about 98 mm is used as the measurement hole P and the inner peripheral surface thereof is used as the measurement inner surface S.

  As shown in the figure, the measurement data is plotted as a large number of measurement points x in the polar coordinate graph, the center O of the graph corresponds to the position of the reference axis 14a, and the angular coordinates and radial coordinates of each measurement point x. Indicates the angle around the reference axis 14a and the distance from the reference axis 14a at each measurement point irradiated with the measurement light on the measurement inner surface S.

  Further, based on the measurement data as shown in FIG. 8, the inner diameter of the measurement hole P can be obtained as an actual measurement value. In the same figure, the measurement value of the inner diameter of the measurement hole P is 97.991 mm ± 0.0055 mm. It is shown that there is.

  The measurement data of FIG. 9 shows the shape data of the measured inner surface S measured when the hole in which the internal gear is formed is the measurement hole P and the internal gear is measured as the measurement inner surface S.

  As in FIG. 8, the measurement data is plotted as a large number of measurement points x in the polar graph, and it can be seen from the measurement data in FIG.

  Further, based on the measurement data as shown in FIG. 9, the diameters of the tip circle and the root circle can be obtained as actual measurement values. They are shown to be 115.998 mm ± 0.017 mm and 124.975 mm ± 0.044 mm, respectively.

  Further, as shown in FIG. 10, the whole or a part of the measurement data can be displayed with the horizontal coordinate and the vertical axis representing the angle coordinate and the radial coordinate (radius) in FIG.

  When the interference signal detected by the light detector 24 of the measurement apparatus 10 is analyzed, an interference intensity distribution indicating the magnitude of the amount of return light of the measurement light with respect to the distance from the reference axis 14a as shown in FIG. can get. The measurement point irradiated with the measurement light on the measurement inner surface S forms a maximum point a in the interference intensity distribution, and the distance indicated by the maximum point a indicates the distance to the measurement point x.

  On the other hand, when return light is generated also on the inner and outer surfaces of the transparent cylinder 54, the measurement light is measured on the inner and outer surfaces of the transparent cylinder 54 in addition to the maximum point a formed by the measurement points on the measurement inner surface S in the interference intensity distribution. There are also local maximum points b and c formed by the passing points through which the distances pass, and the distances indicated by the local maximum points b and c indicate the distances between the inner surface and the outer surface of the transparent cylinder 54.

  According to this, the difference in the distance (thickness of the transparent cylinder 54) between the passing point of the inner surface and the outer surface of the transparent cylinder 54 directly derived from the interference intensity distribution of FIG. This is a value represented by the optical path length in the atmosphere, and is different from the actual thickness of the transparent cylinder 54 in the real space. Therefore, the distance to the measurement point directly derived from the interference intensity distribution of FIG.

  On the other hand, by correcting the thickness of the transparent cylinder 54 directly derived from the interference intensity distribution of FIG. 11 to the actual thickness in real space based on the refractive index of the transparent cylinder 54 and the refractive index of the atmosphere, The distance to the measurement point can be measured with higher accuracy.

  Further, the thickness of the transparent cylinder 54 derived from the interference intensity distribution of FIG. 11 is represented by the optical path length in the atmosphere where the thickness is calculated based on the known thickness and the known refractive index of the transparent cylinder 54. The distance to each point of the interference intensity distribution may be corrected so as to match.

  As described above, in the measurement unit 14 according to the above-described embodiment, the light emitting unit 40 is disposed on the distal end side with respect to the right-angle mirror 42. However, the configuration is not limited thereto, and the light emitting unit 40 is proximal to the right-angle mirror 42. It is good also as a structure arrange | positioned at the side.

  Further, the non-contact inner surface shape measuring apparatus 1 of the above embodiment is based on the measurement principle of the wavelength sweep interference type displacement sensor, but even if it is different from this measurement principle, it is inserted into the measurement hole P. The present invention can be applied to any device that measures the shape of the measurement inner surface S in a non-contact manner by irradiating the measurement inner surface S with measurement light from the measurement unit.

DESCRIPTION OF SYMBOLS 1 ... Non-contact inner surface shape measuring apparatus, 10 ... Measuring apparatus, 12 ... Measuring apparatus main body, 14 ... Measuring part, 14a ... Reference axis, 16 ... Control processing apparatus, 20 ... Wavelength sweep light source, 22 ... Circulator, 24 ... Light detection 30, 32, 34 ... optical fiber, 40 ... light emitting part, 42 ... right angle mirror, 44 ... motor, 46 ... rotary encoder, 50 ... first support part, 52 ... second support part, 54 ... transparent cylinder, 56 ... 1st guide part, 58 ... 2nd guide part, 60 ... Insertion pipe, 70, 72 ... Cylindrical member, 84 ... Guide roller, 86 ... Roller member, P ... Measurement hole, S ... Measurement inner surface

Claims (7)

A non-contact inner surface shape measuring device that measures the shape of the measurement inner surface in a non-contact manner by irradiating measurement light to a measurement inner surface that is an inner surface of the measurement hole from a measurement portion inserted into a measurement hole that is a measurement object ,
The measuring unit is
A reference axis along the insertion direction of the measurement part into the measurement hole;
A light emitting portion for emitting measurement light in a direction along the reference axis;
A traveling direction changing member that is disposed to face the light emitting portion, changes the traveling direction of the measuring light emitted from the light emitting portion, and emits the measuring light toward the measurement inner surface;
Driving means for rotating the traveling direction changing member around the reference axis;
A guide part that contacts the measurement inner surface and supports the measurement part inside the measurement hole;
A non-contact inner surface shape measuring apparatus.   The non-contact inner surface shape measuring apparatus according to claim 1, wherein the traveling direction changing member is a reflecting member having a reflecting surface obliquely intersecting the reference axis.   3. The non-contact inner surface according to claim 1, wherein the light emitting portion is disposed on a distal end side in the insertion direction with respect to the traveling direction changing member, and emits the measurement light toward a proximal end side in the insertion direction. Shape measuring device.   The non-contact inner surface shape measuring device according to claim 1, 2, or 3, wherein the guide portion is disposed on a distal end side and a proximal end side in the insertion direction of the measurement portion.   The non-contact inner surface shape measuring apparatus according to claim 1, wherein the traveling direction changing member is surrounded by a transparent cylinder around the reference axis. A wavelength swept light source;
Branching means for branching light emitted from the wavelength swept light source into measurement light and reference light that pass through different optical paths;
Guiding means for guiding the measurement light to the light emitting section;
Return light from the measurement point irradiated with the measurement light emitted from the light emitting part via the traveling direction changing member, via the traveling direction changing member, the light emitting part, and the guiding means Light detecting means for detecting interference light between the return light returning and the reference light;
Inner surface shape detection for detecting the shape of the measurement inner surface by detecting the position of the measurement point based on the interference light detected by the light detection device at each rotation angle of the reflecting member rotated by the driving device. Means,
The non-contact inner surface shape measuring apparatus according to claim 1, comprising:   The non-contact inner surface shape measuring apparatus according to claim 6, wherein the wavelength swept light source changes a wavelength within a range of 1200 nm to 1600 nm.

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