JP2012237661A - Measurement auxiliary tool and diameter measuring method using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a measurement auxiliary tool which can measure the spatial coordinates of a peripheral surface on an opposite side from the viewpoint of a laser tracker about an annular measuring object, and enables even one person to easily measure a diameter because the measurement auxiliary tool is easy to be handled during measurement.SOLUTION: A measurement auxiliary tool 20 includes a target installation part 21 for installing a target Tg, and a moving mechanism part 22 for moving the target installation part 21 in the circumferential direction of a measuring object W. The moving mechanism part 22 has a first circumferential surface contact member 26 for coming into rotational contact with an outer circumferential surface Wa being a measuring object circumferential surface of the measuring object W, a second circumferential surface contact member 27 for coming into rotational contact with an inner circumferential surface Wb of the measuring object W, and an end surface contact member 28 for coming into rotational contact with a top end surface Wc of the measuring object W. The first circumferential surface contact member 26 freely rotates around an axis O1 in a vertical direction going through the center of the target installation part 21. A rotation driving source 41 for rotating the first or second circumferential surface contact member 26, 27 is provided.

Description

  The present invention relates to a measurement auxiliary instrument that is used auxiliary in measuring the spatial coordinates of an object such as a product, a building, or a natural object in the industrial and measurement fields, and a diameter measurement method using the same.

Laser tracking technology that controls the direction of the laser beam used as a guide with a biaxial motor to follow a moving target to obtain spatial coordinates (three-dimensional position information) of the target has long been known. In this laser tracking technology, it is possible to know the spatial direction (angle) of a moving target using a biaxial encoder attached to each motor. The target is generally a retro-reflector or simply a reflector that uses three mirrors orthogonal to each other. In any case, the reflector can return light in the incident direction.
Further, a technique for measuring a distance with a laser has been established. For example, a laser interferometer can measure a distance of several meters with a resolution of a nanometer unit.

  A device that combines the above two technologies is a laser tracker (for example, Patent Document 1), which measures the distance from the device to the target and the spatial angle with a laser interferometer and an encoder, respectively. The spatial position of the target with reference to the apparatus is specified from the measured value. Attempts have been made to measure the diameters of inner and outer rings of bearings using this laser tracker. The measurement is performed according to the following procedure.

(1) A laser tracker is installed in the vicinity of an object to be measured (bearing inner ring, outer ring, etc.).
(2) The target is brought into contact with the outer peripheral surface or inner peripheral surface of the measurement object.
(3) Laser light is emitted from the laser tracker toward the target, and the light reflected by the target is received again by the laser tracker. The spatial coordinates (three-dimensional position information) of the target are obtained from the encoder value and the laser interferometer value at this time.
(4) The above operations (2) and (3) are repeated at least three times to obtain three or more spatial coordinates, and the diameter of the measurement object is calculated therefrom.

JP 2009-2728 A

  In the above conventional diameter measuring method, as shown in FIG. 9, when the target Tg is on the opposite side (back side) of the measuring object W as seen from the laser tracker 1, the laser beam Lb is simply applied from the laser tracker 1 to the target Tg. The laser beam Lb is blocked by the measurement object W only by being emitted, and measurement is impossible. However, measurement can be performed by providing a commercially available measurement auxiliary instrument (for example, a target adapter manufactured by BRUNSON) between the measurement target W and the target Tg.

  However, the measurement aids that are currently on the market must be moved manually from the first measurement location to the final measurement location by hand. Therefore, the measurement worker has to acquire the spatial coordinate data while moving the measurement auxiliary instrument, and the burden on the measurement worker is very large.

The object of the present invention is to make it possible to measure the spatial coordinates of the circumferential surface on the opposite side as viewed from the laser tracker with respect to an annular measuring object. It is to provide a measurement aid that can be measured.
Another object of the present invention is to provide a measuring method capable of easily measuring the diameter of an annular measuring object even by one person.

  The measurement auxiliary instrument of the present invention is installed in a posture in which the central axis is along the vertical direction using a laser tracker that irradiates a target provided on the measurement object with laser light and obtains the spatial coordinates of the target from the reflected light. It is used as an auxiliary when measuring the outer diameter or inner diameter of an oval measuring object. The measurement auxiliary instrument includes a target installation unit on which the target is installed, and a moving mechanism unit that moves the target installation unit in the circumferential direction of the measurement object, and the movement mechanism unit is located below the target installation unit. In addition, the first rotating shaft is provided to be rotatable about a first rotation center axis in the vertical direction passing through the center of the target installation portion, and is in contact with one of the inner peripheral surface and the outer peripheral surface of the measurement object. A measurement object to be rotated around a second rotation center axis in the vertical direction at a position opposed to the circumference contact member and the first circumference contact member in the radial direction across the measurement object. The second peripheral surface contact member that is in rolling contact with the other peripheral surface of the object, and the height between the target installation portion and the first and second peripheral surface contact members are along the radial direction of the measurement object. Provided to be rotatable around the third rotation center axis And the end face contact member rolling contact with the upper end surface of the measurement object, and having a moving rotary drive source for rotating the first or second peripheral surface contact member.

  In the measurement auxiliary instrument having this configuration, the first circumferential surface contact member is in contact with the measurement target circumferential surface of the measurement object, and the second circumferential surface contact member is a circumference opposite to the measurement target circumferential surface of the measurement target. It is installed on the measurement object so as to be in contact with the surface and the end surface contact member is in contact with the upper end surface of the measurement object. For example, when the measurement target peripheral surface of the measurement object is the outer peripheral surface, the first peripheral surface contact member is brought into contact with the outer peripheral surface, the second peripheral surface contact member is brought into contact with the inner peripheral surface, The measurement object is sandwiched between the peripheral surface contact member and the second peripheral surface contact member.

  A target is installed in the target installation part of the measurement object, the target is irradiated with laser light from a laser tracker installed in the vicinity of the measurement object, and the spatial coordinates of the target are obtained from the reflected light. Since the positional relationship between the target and the first circumferential surface contact member is known in advance, the spatial coordinates of the contact point of the first circumferential surface contact member on the measurement target circumferential surface of the measurement object are derived from the spatial coordinates of the target. It is.

  Since the target is installed in the target installation part located above the measurement object, even when the measurement auxiliary instrument is located on the opposite side as viewed from the laser tracker, the laser light emitted from the laser tracker is Hit the target without being blocked by. For this reason, the laser tracker can measure not only the surface on the near side but also the spatial coordinates of the opposite surface as viewed from the laser tracker.

  In order to obtain the diameter of the measurement object, three or more spatial coordinates having different circumferential positions on the measurement object circumferential surface are measured. In that case, the target installation portion is moved to the target circumferential position by rotating the first or second peripheral surface contact member by driving the rotational drive source for movement. At this time, the first peripheral surface contact member is the measurement target peripheral surface, for example, the outer peripheral surface, the second peripheral surface contact member is the peripheral surface opposite to the measurement target peripheral surface, for example, the inner peripheral surface, and the end surface contact member is The upper end surface is rolled. The spatial coordinates of the target are acquired while changing the circumferential position of the target installation part, and the diameter of the measurement target circumferential surface is calculated from the acquired three or more spatial coordinates. Since the operation of changing the circumferential position of the target installation portion is not performed manually but by driving a rotational drive source for movement, the measurement worker can concentrate on acquiring the spatial coordinates of the target.

In the present invention, an infrared communication type or wireless communication type operation device for remotely controlling the driving of the rotational drive source for movement may be provided.
For example, if the operation device is installed near the laser tracker, the measurement worker does not move, and the target tracker is circumferentially moved using the operation device to acquire the spatial coordinates of the target using the laser tracker. The operation efficiency can be improved, and the work efficiency is improved.

In this invention, the rotational drive for movement is performed so that the operation of changing the circumferential position of the target installation portion and the operation of acquiring the spatial coordinates of the target by the laser tracker are performed a plurality of times in association with each other. A controller for controlling the source and the laser tracker may be provided.
With this configuration, when measuring the spatial coordinates of multiple locations with different circumferential positions on the measurement target circumferential surface, the operation of changing the circumferential position of the target installation unit and the spatial coordinates of the target by the laser tracker All of the acquired operations can be performed by automatic control.

  In this invention, the target installation part is rotatable about a direction change axis coaxial with the first rotation center axis with respect to the moving mechanism part, and rotates the target installation part about the direction change axis. From the rotational drive source for changing the direction, the circumferential position of the measurement location in the measurement object, the diameter of the measurement object, and the information on the distance between the laser tracker and the measurement object, the target emits laser light from the laser tracker. Calculating means for calculating the direction around the direction changing axis of the target installation section that is optimal for reflecting the light, and driving the direction changing rotary drive source so as to obtain the direction obtained by the calculating means Output means for outputting a command to be executed may be provided.

  In order to reflect the laser beam from the laser tracker back in the same direction, the target is provided with a reflecting mirror that is recessed in a conical shape with respect to the spherical surface. This reflection mirror has a limit to the angle at which laser light can be incident. If the target installation unit is fixed with respect to the moving mechanism unit, when measuring spatial coordinates at multiple locations in the circumferential direction of the measurement target, depending on the position of the target installation unit in the circumferential direction, laser light may be applied to the reflection mirror. Cannot be incident.

  When the measurement auxiliary instrument has the above-described configuration, the calculation means calculates the optimum direction around the direction change axis of the target installation unit from each information, and based on the calculation result, the output means determines the rotation drive source for direction change. A command to drive is issued, and the target installation unit is rotated around the direction changing axis so that the target installation unit is in an optimum orientation. As a result, the laser beam from the laser tracker can be reflected and returned in the same direction by the reflection mirror regardless of the position of the target installation portion in the circumferential direction.

  The diameter measuring method of this invention uses the said laser tracker and the measurement auxiliary | assistant instrument of any one of Claim 1 thru | or 4, The annular surface whose outer peripheral surface or inner peripheral surface is a measurement object peripheral surface A measurement method for measuring a diameter of the measurement target peripheral surface of the measurement target, wherein the measurement auxiliary instrument is connected to the first peripheral surface contact member in a state where the laser tracker is installed in the vicinity of the measurement target. Is in contact with the measurement object peripheral surface of the measurement object, the second peripheral surface contact member is in contact with the peripheral surface of the measurement object opposite to the measurement target peripheral surface, and the end surface contact member is measured. A process of installing the object in contact with an upper end surface of the object, a process of installing a target on the target installation part of the measurement auxiliary tool, a process of obtaining a spatial coordinate of the target by the laser tracker, and the rotation for movement Drive source Rotating the first or second peripheral surface contact member to change the circumferential position of the target installation part, and obtaining the spatial coordinates of the target; and the target installation part The process of changing the position in the circumferential direction is repeated three times or more, and the diameter of the measurement target circumferential surface is calculated from the acquired three or more spatial coordinates.

By repeating the process of acquiring the spatial coordinates of the target and the process of changing the circumferential position of the target installation part three or more times, spatial coordinates of three or more circumferential directions of the measurement target circumferential surface can be obtained. As described above, by using a measurement auxiliary tool, the laser tracker can measure the spatial coordinates of the circumferential surface on the opposite side as viewed from the laser tracker with respect to the annular measuring object. The spatial coordinates of a plurality of arbitrarily determined circumferential positions on the measurement object peripheral surface of the measurement object can be measured. By calculating the spatial coordinates of three or more points obtained in this way, the diameter of the measurement target circumferential surface is obtained.
The operation of changing the circumferential position of the target installation unit is not performed manually but by driving a rotational drive source for movement. Therefore, the measurement worker can concentrate on acquiring the spatial coordinates of the target and can easily measure the diameter of the measurement target peripheral surface of the measurement target even by one person.

  The measurement auxiliary instrument of the present invention is installed in a posture in which the central axis is along the vertical direction using a laser tracker that irradiates a target provided on the measurement object with laser light and obtains the spatial coordinates of the target from the reflected light. When measuring the outer diameter or inner diameter of an annular measurement object, a measurement auxiliary instrument used as an auxiliary, the target installation part on which the target is installed, and the target installation part on the circumference of the measurement object A moving mechanism unit that moves in a direction, and the moving mechanism unit is provided below the target installation unit so as to be rotatable around a first rotation center axis in the vertical direction passing through the center of the target installation unit, A first peripheral surface contact member that is in rolling contact with one of the inner peripheral surface and the outer peripheral surface of the measurement object, and a radial direction with the measurement object sandwiched between the first peripheral surface contact member and the first peripheral surface contact member A second circumferential surface contact member that is rotatably provided around the second rotation center axis in the vertical direction and is in contact with the other circumferential surface of the measurement object, the target installation portion, and the first And an end surface contact member that is rotatably provided around the third rotation center axis along the radial direction of the measurement object and is in contact with the upper end surface of the measurement object. And a rotational drive source for movement for rotating the first or second peripheral surface contact member, and therefore, the spatial coordinates of the peripheral surface on the opposite side as viewed from the laser tracker with respect to the annular measurement object are measured. It is easy to handle during measurement, and one person can easily measure the diameter.

  The diameter measuring method of this invention uses the said laser tracker and the measurement auxiliary | assistant instrument of any one of Claim 1 thru | or 4, The annular surface whose outer peripheral surface or inner peripheral surface is a measurement object peripheral surface A measurement method for measuring a diameter of the measurement target peripheral surface of the measurement target, wherein the measurement auxiliary instrument is connected to the first peripheral surface contact member in a state where the laser tracker is installed in the vicinity of the measurement target. Is in contact with the measurement object peripheral surface of the measurement object, the second peripheral surface contact member is in contact with the peripheral surface of the measurement object opposite to the measurement target peripheral surface, and the end surface contact member is measured. A process of installing the object in contact with an upper end surface of the object, a process of installing a target on the target installation part of the measurement auxiliary tool, a process of obtaining a spatial coordinate of the target by the laser tracker, and the rotation for movement Drive source Rotating the first or second peripheral surface contact member to change the circumferential position of the target installation part, and obtaining the spatial coordinates of the target; and the target installation part In order to calculate the diameter of the measurement target circumferential surface from three or more acquired spatial coordinates, the process of changing the position in the circumferential direction is repeated three times or more. Even one person can easily measure.

It is a partially broken side view which shows the use condition of the measurement auxiliary tool concerning 1st Embodiment of this invention. It is a perspective view of a laser tracker and a measuring object. It is a top view which shows movement operation | movement of the measurement auxiliary instrument. It is a partially broken side view which shows the use condition of the measurement auxiliary tool concerning 2nd Embodiment of this invention. It is the figure which added the block diagram of a control system to the partially broken side view which shows the use condition of the measurement auxiliary tool concerning 3rd Embodiment of this invention. It is the figure which added the block diagram of a control system to the partially broken side view which shows the use condition of the measurement auxiliary tool concerning 4th Embodiment of this invention. It is a figure which shows the relationship between a target and the incident angle of a laser beam. It is a figure which shows the change of direction of the target installed in the target installation part of the measurement holding instrument. FIG. 3 is a perspective view of a laser tracker and a measurement object in a state different from FIG. 2.

  FIG. 1 is a partially broken side view showing a use state of a measurement auxiliary instrument according to a first embodiment of the present invention. The measurement auxiliary instrument 20 is an instrument used as an auxiliary to the laser tracker 1 (FIG. 2) for measuring the spatial coordinates of the measurement target W. In particular, the measurement target W is an annular shape like a bearing ring. Used in cases.

First, the laser tracker 1 will be described with reference to FIG.
The laser tracker 1 is a device that follows the movement of the target Tg installed on the measurement target W and obtains the spatial coordinates of the measurement target W. The target Tg is installed in a stationary state at one position of the measurement object W or the measurement auxiliary instrument 20 (FIG. 1) fixed in position to the measurement object W. In FIG. 2, the target Tg is directly installed on the measurement target W. As the target Tg, for example, a spherical retro reflector is used. However, it is not limited to a spherical retro reflector.

  The laser tracker 1 mainly includes a laser light source 2a, a length measuring device 2b, a light receiving unit 3, an angle adjustment unit 4, a control unit 5, and a calculation unit 6.

  The laser light source 2a irradiates the target Tg with the laser light Lb, and the length measuring device 2b measures the distance to the target Tg using the laser light Lb reflected by the target Tg. As the length measuring device 2b, for example, a length measuring device including an interferometer or an absolute distance meter is used. In this example, the laser light source 2 a and the length measuring device 2 b are integrated to constitute the laser length measuring device 2. The laser length measuring device 2 is accommodated in a cylindrical casing 7.

  The light receiving unit 3 recognizes the position information of the reflected light of the laser light Lb, and is configured by, for example, a semiconductor position detecting element (abbreviated as PSD) or a quadrant photodiode. The light receiving unit 3 is also accommodated in the casing 7.

  The angle adjusting unit 4 includes a half mirror 8, a θ-axis motor 9, a θ-axis encoder 10, a ψ-axis motor 11, a ψ-axis encoder 12, and a mirror 13. The θ axis in the θ axis motor 9 and the ψ axis in the ψ axis motor 11 are orthogonal to each other. The θ axis is disposed in parallel with the axis of the casing 7.

  A rotating body 14 is supported on the upper end of the casing 7 so as to be angularly displaceable about the θ axis. The rotating body 14 is rotationally driven by the θ-axis motor 9. The angular displacement of the rotating body 14 is detected by the θ-axis encoder 10. The ψ-axis motor 11 and the ψ-axis encoder 12 are supported on the upper part of the rotating body 14 via a concave frame 15. The mirror 13 is supported on a rotating shaft 11 a that is rotated by a ψ-axis motor 11. The mirror 13 is angularly displaced by the rotational drive of the ψ-axis motor 11. The angular displacement of the mirror 13 is detected by the ψ-axis encoder 12. Note that a hole h through which laser light (including reflected light) Lb passes is formed in the upper end portion of the casing 7, the rotating body 14, and the frame 15.

  The laser light Lb emitted from the laser light source 2a passes through the half mirror 8, is reflected by the mirror 13, and then reaches the target Tg. The laser light Lb reflected from the target Tg, that is, the reflected light passes through substantially the same path, returns to the irradiation source laser tracker 1, is reflected by the half mirror 8 in the casing 7, and reaches the light receiving unit 3.

  Based on the signal from the light receiving unit 3, the control means 5 controls each driver of the θ-axis motor 9 and the ψ-axis motor 11 so that the reflected light reaching the light receiving unit 3 always returns to the center of the light receiving unit 3 (see FIG. (Not shown). Based on this command, the θ-axis motor 9 and the ψ-axis motor 11 cause the mirror 13 to be angularly displaced about the θ-axis and the ψ-axis that are orthogonal to each other. As a result, the mirror 13 is always directed in an appropriate direction.

  A part of the laser beam Lb returned to the laser tracker 1 enters the length measuring device 2b without being reflected by the half mirror 8. The length measuring device 2b receives the reflected light of the laser light Lb, and measures the distance to the target Tb from the laser light Lb projected by the laser light source 2a and the received reflected light.

  The computing means 6 obtains the spatial coordinates (three-dimensional position information) of the target Tg from the measured distance value measured by the length measuring instrument 2b and the measured values of the θ-axis encoder 10 and the ψ-axis encoder 12.

  Next, the measurement auxiliary instrument 20 will be described with reference to FIG. The measurement auxiliary instrument 20 operates a target installation unit 21 where the target Tg is installed, a movement mechanism unit 22 that moves the target installation unit 21 in the circumferential direction of the measurement target W, and a movement of the movement mechanism unit 22. And an operating device 23 for performing the operation.

  The illustrated target Tg is spherical, and has a reflecting mirror 24 that is recessed in a conical shape with respect to the spherical surface. The apex of the cone is located at the center of the target Tg, and the angle formed by two buses located on opposite sides of the side surface of the cone is 90 °. Thereby, the reflection mirror 24 reflects the laser beam Lb from the laser tracker 1 and returns it in the same direction.

  The target installation part 21 is a member for installing the target Tg, and has a conical recess 21a on the upper surface on which the target Tg is placed. By simply placing the target Tg on the recess 21a, the target Tg can be accurately positioned and installed.

  The moving mechanism unit 22 has a horizontal reference table 25, and the target installation unit 21 is fixed to the upper surface of one end of the reference table 25. A first peripheral surface contact member 26, a second peripheral surface contact member 27, and an end surface contact member 28 are provided below the reference table 25.

  The first circumferential surface contact member 26 is rotatably supported via a rolling bearing 31 at the lower end of a pole 30 that extends downward from a position immediately below the target installation portion 21 on the lower surface of the reference table 25. The rotation center axis (first rotation center axis) O <b> 1 of the first circumferential surface contact member 26 is a vertical axis that passes through the center of the target installation portion 21. The first peripheral surface contact member 26 is brought into contact with the measurement target peripheral surface which is either the outer peripheral surface Wa or the inner peripheral surface Wb of the measurement target W. In FIG. 1, the outer peripheral surface Wa is a measurement target peripheral surface.

  The second peripheral surface contact member 27 is attached to the lower end of the rotary shaft 33 rotatably supported by the reference base 25 via the rolling bearing 32 so as to rotate integrally with the rotary shaft 33. The pole 30 and the rotating shaft 33 are located at both ends of the reference table 25, respectively. The rotation center axis (second rotation center axis) O2 of the second peripheral surface contact member 27 is also a vertical axis. The second peripheral surface contact member 27 is brought into rolling contact with a peripheral surface that is not the measurement target peripheral surface of the measurement target W, for example, the inner peripheral surface Wb. The second peripheral surface contact member 27 is made of a material that does not slip with the measurement object W, for example, a rubber material. Although not shown, it is desirable to provide an urging means for urging the second circumferential surface contact member 27 toward the first circumferential surface contact member 26.

  The end surface contact member 28 is disposed below the center portion of the reference base 25 and at a height between the target installation portion 21 and the first and second peripheral surface contact members 26 and 27, and 2 is rotatable around a horizontal third rotation center axis O3 orthogonal to the two rotation center axes O1 and O2. Specifically, a pair of support members 35 are provided depending on the lower surface of the reference table 25, and an end surface contact member 28 is attached to a support shaft 34 provided across the pair of support members 35. The support shaft 34 may be rotatable with respect to the support member 35, or the end surface contact member 28 may be rotatable with respect to the support shaft 34. The end surface contact member 28 is brought into rolling contact with the upper end surface Wc of the measuring object W.

  The upper end of the rotary shaft 33 is connected to an output shaft (not shown) of a moving rotational drive source 41 fixed to the reference base 25 by a mounting member 40. The rotational drive source 41 for movement consists of an electric motor etc., and is connected to the said operating device 23 via the wiring 42. FIG. When the drive switch 23 a of the operation device 23 is turned ON, electricity is supplied from the operation device 23 to the moving rotational drive source 41 via the wiring 42.

  A method for measuring the diameter of the annular measuring object W using the laser tracker 1 and the measurement auxiliary member 20 will be described. As shown in FIG. 1, the measurement target W is, for example, an inner ring or an outer ring of a bearing, and the outer peripheral diameter ΦD2 is measured. The measurement is performed by the following method.

(1) The laser tracker 1 is installed in the vicinity of the measurement object W. (2) The measurement auxiliary instrument 20 is brought into contact with the outer peripheral surface Wa where the first peripheral surface contact member 26 is the measurement target peripheral surface of the measurement target W. The second circumferential surface contact member 27 is in contact with the inner circumferential surface Wb and the end surface contact member 28 is in contact with the upper end surface Wc. At this time, the third rotation center axis O3 that is the rotation center axis of the end surface contact member 28 is along the radial direction of the measurement target W. The second peripheral surface contact member 27 is urged toward the first peripheral surface contact member 26 by the urging means or the like, and the first peripheral surface contact member 26 and the second peripheral surface contact member 27 The measurement object W is sandwiched.

(3) The target Tg is installed on the target installation unit 21 of the measurement auxiliary instrument 20.
(4) The laser beam Lb is emitted from the laser tracker 1 to the target Tg, and the spatial coordinates (three-dimensional position information) of the target Tg are acquired.

  (5) The drive switch 23a of the operating device 23 is turned on to drive the rotational drive source 41 for movement. Thereby, as shown in FIG. 3, the second circumferential surface contact member 27 rotates and moves along the inner circumferential surface Wb of the measurement object W, and the entire measurement auxiliary instrument 20 moves in the circumferential direction. At this time, the first peripheral surface contact member 26 rolls on the outer peripheral surface Wa, and the end surface contact member 28 rolls on the upper end surface Wc. Although the first peripheral surface contact member 26 is pressed against the outer peripheral surface Wa of the measurement object W, the first peripheral surface contact member 26 is passively rotated via the rolling bearing 31. No scratches due to friction are generated on the outer peripheral surface Wa.

  (6) If the measurement auxiliary instrument 20 is moved to the target circumferential position by the process of (5) above, the spatial coordinates of the target Tg are acquired at that position. Similarly, the movement of the measurement auxiliary instrument 20 and the acquisition of spatial coordinates are repeated to acquire three or more spatial coordinates. Since the operation of changing the circumferential position of the target installation unit 21 is not performed manually but by driving the rotational drive source 41 for movement, the measurement worker can concentrate on acquiring the spatial coordinates of the target Tg.

(7) The diameter ΦD1 at the position of the target Tg is calculated from the acquired three or more spatial coordinates.
(8) By subtracting the radial offset amount L of the target Tg with respect to the measurement object W from the diameter ΦD1 obtained in (7), the outer peripheral diameter ΦD2 of the measurement object W is obtained (Formula 1).
ΦD2 = ΦD1- (2 × L) Equation 1

  Since the target Tg is installed in the target installation unit 21 positioned above the upper end surface contact member 22, the target Tg is emitted from the laser tracker 1 even when the measurement auxiliary instrument 20 is positioned on the opposite side as viewed from the laser tracker 1. The laser beam Lb strikes the target Tg without being blocked by the measurement object W. Therefore, the laser tracker 1 can measure not only the surface on the near side as seen from the laser tracker 1 but also the spatial coordinates of the opposite surface.

  In the above measurement example, the measurement target peripheral surface of the annular measurement target W is the outer peripheral surface Wa and the outer peripheral diameter ΦD2 is measured, but the inner peripheral diameter is measured using the measurement target peripheral surface as the inner peripheral surface Wb. You can also. In that case, the measurement auxiliary instrument 20 is installed such that the first peripheral surface contact member 26 is in rolling contact with the inner peripheral surface Wb and the second peripheral surface contact member 27 is in contact with the outer peripheral surface Wa. Others are the same as the case of measuring the outer diameter.

  FIG. 4 shows a second embodiment of the present invention. The measurement assisting instrument 20 remotely controls the driving of the rotational drive source 41 for movement by using the operation device 23 as an infrared communication type or a wireless communication type. For example, if the operating device 23 is installed near the laser tracker 1, the measurement worker does not move while staying near them, and acquires the spatial coordinates of the target Tg using the laser tracker 1. The operation device 23 can be used to perform the operation of moving the target installation unit 21 in the circumferential direction, and the work efficiency is improved.

  FIG. 5 shows a third embodiment of the present invention. The measurement auxiliary instrument 20 moves so that the operation of changing the circumferential position of the target installation unit 21 and the operation of acquiring the spatial coordinates of the target Tg by the laser tracker 1 are performed a plurality of times in association with each other. A control device 44 for controlling the rotary drive source 41 and the laser tracker 1 is provided. The control device 44 may be provided in a laser tracker control device (not shown) that performs overall control of the laser tracker 1 or may be provided separately from the laser tracker control device.

  When the control device 44 is provided, an operation for changing the circumferential position of the target installation unit 21 when measuring the spatial coordinates of a plurality of locations at different circumferential positions on the measurement target circumferential surface of the measurement target W, and All of the operations for acquiring the spatial coordinates of the target Tg by the laser tracker 1 can be performed automatically.

  FIG. 6 shows a fourth embodiment of the present invention. The measurement assisting device 20 is configured such that the target installation unit 21 can change the direction around the direction changing axis O4 that is coaxial with the first rotation center axis O1. Specifically, a rotating shaft 46 having an orientation changing axis O4 as a center is rotatably supported on the reference base 25 via a rolling bearing 47, and the target installation portion 21 is mounted on the rotating shaft 46. ing. A belt wheel (not shown) is provided on the outer periphery of the rotation shaft 46, and the belt 48 wound around the belt wheel is driven by a rotation driving source 49 for changing the direction such as a motor installed on the reference table 25. Then, the direction of the target installation unit 21 is changed. The direction changing rotation drive source 49 is supplied with electricity from the operation device 51 connected via the wiring 50.

The operating device 51 is connected to a direction change control device 52. The direction change control device 52 includes a calculation unit 53 and an output unit 54. The calculation means 53 is a means for calculating the direction (rotation angle) around the direction change axis O4 of the target setting portion 21 that is the optimal direction for the target Tg to reflect the laser beam Lb from the laser tracker 1, From the information of the circumferential position (angle) α of the measurement location in the measurement object W, the diameter ΦD of the measurement object W, and the distance β between the laser tracker 1 and the measurement object W shown in FIG. 21 is calculated (Formula 2). Among the above pieces of information, information on the circumferential position α is supplied from the rotational drive source 41 for movement. Other information may be input to the direction change control device 52 in advance, or may be supplied from the outside of the direction change control device 52.
γ = tan−1 [(D / 2 × sin α) / {β + (D / 2 × cos α)}] Equation 2
The output means 54 outputs to the operating device 51 so that the orientation obtained by the computing means 53 is obtained, and rotationally drives the orientation changing rotational drive source 49.

  Since the reflecting mirror 24 of the target Tg has a conical shape recessed with respect to the spherical surface, the angle at which the laser beam Lb from the laser tracker 1 can be incident is limited as shown in FIG. For example, FIGS. 9A and 9B can enter, but FIG. 5C cannot enter. Therefore, when the target installation unit 21 is fixed with respect to the moving mechanism unit 22, depending on the position of the target installation unit 21 in the circumferential direction when measuring spatial coordinates at a plurality of locations in the circumferential direction of the measurement target W. Therefore, the reflection mirror 24 cannot enter the laser beam Lb.

  Therefore, the direction changing control device 52 calculates the optimum direction around the direction changing axis O4 of the target setting unit 21 from each information, and the target setting unit 21 is driven by the changing rotary drive source 49 based on the calculation result. Is rotated around the direction changing axis 4 to control the direction of the target installation portion 21. That is, as shown in FIG. 8, the target Tg always receives the laser beam Lb in front of the reflection mirror 24. Thereby, the laser beam Lb from the laser tracker 1 can be reflected and returned in the same direction by the reflection mirror 24 regardless of the position of the target installation portion 21 in the circumferential direction.

DESCRIPTION OF SYMBOLS 1 ... Laser tracker 20 ... Measurement auxiliary instrument 21 ... Target installation part 22 ... Movement mechanism part 23 ... Operation apparatus 26 ... 1st surrounding surface contact member 27 ... 2nd surrounding surface contact member 28 ... End surface contact member 41 ... For movement Rotation drive source 44 ... control device 53 ... calculating means 54 ... output means Lb ... laser beam O1 ... first rotation center axis O2 ... second rotation center axis O3 ... third rotation center axis O4 ... direction changing axis Tg ... Target W ... measurement object Wa ... outer peripheral surface (measurement target peripheral surface)
Wb ... Inner peripheral surface Wc ... Upper end surface

Claims (5)

Using a laser tracker that irradiates the target provided on the measurement object with laser light and obtains the spatial coordinates of the target from the reflected light, an annular measurement object that is installed in a posture along the vertical direction is used. A measuring aid used as an auxiliary when measuring the outer diameter or inner diameter,
A target installation unit on which the target is installed, and a moving mechanism unit that moves the target installation unit in the circumferential direction of the measurement target;
The moving mechanism section is
Below the target installation part, it is rotatably provided around a first rotation center axis in the vertical direction passing through the center of the target installation part, and is either one of the inner peripheral surface and the outer peripheral surface of the measurement object. A first circumferential surface contact member that is in rolling contact with
The other peripheral surface of the measurement object is provided at a position opposed to the first peripheral surface contact member in the radial direction with the measurement object interposed therebetween so as to be rotatable around the second rotation center axis in the vertical direction. A second peripheral surface contact member that is in rolling contact with
Provided at a height between the target installation portion and the first and second peripheral surface contact members so as to be rotatable around a third rotation center axis along the radial direction of the measurement object. An end surface contact member that is in rolling contact with the upper end surface;
A measurement auxiliary instrument comprising: a rotational drive source for movement for rotating the first or second peripheral surface contact member.   The measurement auxiliary instrument according to claim 1, further comprising an infrared communication type or wireless communication type operation device for remotely controlling driving of the moving rotational drive source.   In claim 1 or claim 2, the operation of changing the circumferential position of the target installation unit and the operation of acquiring the spatial coordinates of the target by the laser tracker are performed a plurality of times in association with each other. A measurement auxiliary instrument provided with a control device for controlling the rotational drive source for movement and the laser tracker.   4. The target installation unit according to claim 1, wherein the target installation unit is rotatable about a direction changing axis coaxial with the first rotation center axis with respect to the moving mechanism unit. A rotation drive source for changing the direction around the direction change axis, the circumferential position of the measurement location in the measurement object, the diameter of the measurement object, and the distance between the laser tracker and the measurement object A calculation means for calculating a direction around the direction changing axis of the target installation unit, which is an optimum direction for the target to reflect the laser beam from the laser tracker, and a direction obtained by the calculation means. And an output means for outputting a command for driving the rotation drive source for changing the direction. The measurement object of an annular measurement object whose outer peripheral surface or inner peripheral surface is a measurement object peripheral surface using the laser tracker and the measurement auxiliary instrument according to any one of claims 1 to 4. A diameter measuring method for measuring a diameter of a peripheral surface,
In a state where the laser tracker is installed in the vicinity of the measurement object, the measurement auxiliary instrument is configured such that the first peripheral surface contact member is in contact with the measurement target peripheral surface of the measurement target and the second peripheral surface. A process in which the contact member is in contact with the peripheral surface of the measurement object opposite to the measurement object peripheral surface, and the end surface contact member is in contact with the upper end surface of the measurement object;
Installing a target on the target installation part of the measurement aid;
Obtaining a spatial coordinate of the target by the laser tracker;
And rotating the first or second circumferential surface contact member by driving the rotational drive source for movement, and changing the circumferential position of the target installation portion,
The process of acquiring the spatial coordinates of the target and the process of changing the circumferential position of the target installation part are repeated three or more times, and the diameter of the measurement target circumferential surface is calculated from the acquired three or more spatial coordinates. Diameter measuring method characterized by

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