JP2018165688A - Shape measurement device and shape measurement method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a shape measurement device and shape measurement method capable of measuring a shape of a workpiece with high accuracy and at high speed.SOLUTION: A shape measurement device includes: a reference plane on which a workpiece is installed; a distance detection unit configured to detect a distance from a reference position to a measuring point in a surface to be measured of the workpiece opposite to the reference position, for each of three or more reference positions on the same circumference with a measurement reference shaft vertical to the reference place as a center; and an analysis unit configured to acquire a shape of the workpiece, based on known positional information on individual reference positions to the measurement reference shaft, and the distance for each reference position detected by the distance detection unit.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a shape measuring apparatus and a shape measuring method for measuring the shape of a workpiece.

  2. Description of the Related Art Shape measuring apparatuses that measure various shapes such as roundness and dimensions (radius, diameter, etc.) of a columnar or cylindrical workpiece are known. For example, in Patent Document 1, three or more contact-type or non-contact-type distance meters are arranged on the outer peripheral surface or inner peripheral surface (surface to be measured) of a cylindrical workpiece, and the workpiece is relative to each distance meter. A shape measuring device that detects the outer diameter or inner diameter of a workpiece based on the result of detecting the distance to each peripheral surface with each distance meter while rotating is disclosed.

  In Patent Document 2, based on the result of detecting the distance to the outer peripheral surface with the optical sensor while disposing the optical sensor at a position facing the outer peripheral surface of the cylindrical workpiece and rotating the workpiece relative to the optical sensor. A shape measuring device for measuring the shape of the outer peripheral surface of a workpiece is disclosed. Further, the shape measuring device of Patent Document 2 has a configuration in which the optical sensor is step-moved to a plurality of positions in the longitudinal direction of the workpiece, and distance detection by the optical sensor is executed at each of the plurality of positions while rotating the workpiece. Thus, the diameter at each of a plurality of positions of the workpiece can be detected. Thereby, the shape measuring apparatus of patent document 2 can detect the cylindricity of a workpiece | work.

  In Patent Document 3, the shape of the workpiece (including the outer diameter) is used in a non-contact manner using a pair of two-dimensional laser type first displacement sensors for distance detection and a two-dimensional laser type second displacement sensor for shape measurement. ) Is measured.

  In Patent Document 4, while rotating a disk-shaped workpiece, a laser beam is emitted from a laser light source disposed on one surface side of the workpiece toward the circumferential edge of the workpiece, and the laser beam is applied to the workpiece. A shape measuring device for receiving light by a light receiving portion arranged on the other surface side of the above is disclosed. The shape measuring device of Patent Document 4 detects the shape of the circumferential edge of a workpiece based on the light amount distribution of the laser light received by the light receiving unit.

JP 2004-045206 A JP 2013-057020 A JP 2013-007749 A JP 2014-052257 A

  However, in the shape measuring apparatuses of Patent Document 1 and Patent Document 2, it is necessary to relatively rotate (relatively move) the workpiece with respect to a measuring unit such as a distance meter and an optical sensor. For this reason, it takes time to measure due to the limitation of the rotation speed, a measurement error occurs due to vibration during rotation, the position adjustment (centering) of the work is required, and the installation of a rotation mechanism complicates the device. Or the measurement of the shape of a workpiece that is difficult to rotate or fix becomes difficult.

  In the shape measuring apparatus of Patent Document 3, since a laser beam is irradiated to a workpiece from a large two-dimensional laser displacement sensor arranged outside the workpiece, for example, the inner diameter of a cylindrical workpiece cannot be measured. . Also, in the shape measuring device described in Patent Document 3, since it is necessary to rotate the workpiece relative to the two-dimensional laser displacement sensor, the same problems as those of the shape measuring devices in Patent Document 1 and Patent Document 2 described above occur. is there.

  The measuring apparatus of Patent Document 4 has a problem that only the circumferential edge of a disk-shaped workpiece can be measured. Further, the measuring device of Patent Document 4 also has the same problem as the measuring devices of Patent Document 1 and Patent Document 2 because the workpiece needs to be rotated.

  The present invention has been made in view of such circumstances, and an object thereof is to provide a shape measuring apparatus and a shape measuring method capable of measuring the shape of a workpiece with high accuracy and at high speed.

  The shape measuring apparatus for achieving the object of the present invention is provided for each reference position set at three or more on the same circumference centering on a measurement reference axis perpendicular to the reference plane and a reference plane on which the workpiece is placed. The distance detector detects the distance from the reference position to the measurement point in the measurement surface of the workpiece facing the reference position, the known position information of each reference position with respect to the measurement reference axis, and the distance detector detects An analysis unit that obtains the shape of the workpiece based on the distance for each reference position.

  According to this shape measuring apparatus, the shape of the workpiece can be measured by detecting the distance from each reference position to the measurement point in the measured surface of the workpiece facing each other without rotating (moving) the workpiece. Can do.

  In the shape measuring apparatus according to another aspect of the present invention, the reference positions are set at equal angular intervals on the same circumference around the measurement reference axis. As a result, the positions of the measurement points in the surface to be measured can be acquired at equal intervals, so that the shape of the workpiece can be measured with high accuracy regardless of the position, posture, and type (shape) of the workpiece.

  In the shape measuring apparatus according to another aspect of the present invention, the shape measuring device includes a repetition control unit that repeatedly operates the distance detection unit and the analysis unit a plurality of times, and the analysis unit obtains an average shape obtained by averaging the shapes of the workpieces obtained a plurality of times. . Thereby, since the influence of the error of distance detection is reduced, the shape of the workpiece can be measured with high accuracy.

  In the shape measuring apparatus according to another aspect of the present invention, for each reference position, a signal is incident on a measurement point facing the reference position from the reference position, and the reflected signal is detected individually for each measurement point. A distance detection unit that detects a distance for each reference position based on a signal detection result for each measurement point by the measurement unit. Thereby, the distance for each reference position can be detected in a non-contact manner without rotating (moving) the workpiece.

  In the shape measuring apparatus according to another aspect of the present invention, the signal is measurement light, and the direction of the optical axis of the measurement light incident on the measurement point from the reference position is measured in a plane including the reference position and the measurement reference axis. The direction is perpendicular to the reference axis. Thereby, the shape of the workpiece can be measured with high accuracy using the measurement reference axis as a reference.

  In the shape measuring apparatus according to another aspect of the present invention, when the workpiece is cylindrical or columnar and the measured surface is the outer peripheral surface of the workpiece, the reference position is set outside the outer peripheral surface. Thereby, the shape of the outer peripheral surface of a workpiece | work can be measured.

  In the shape measuring apparatus according to another aspect of the present invention, when the workpiece is cylindrical and the surface to be measured is the inner circumferential surface of the workpiece, the reference position is set inside the inner circumferential surface. Thereby, the shape of the internal peripheral surface of a workpiece | work can be measured.

  In the shape measuring apparatus according to another aspect of the present invention, when the workpiece is cylindrical and the surface to be measured is the inner circumferential surface of the workpiece, the reference position is 3 on the same circumference inside the inner circumferential surface. The measurement unit is a plurality of reflectors individually provided for each reference position, and a plurality of optical units arranged at intervals in a direction perpendicular to the reference plane, the same circle. A plurality of optical units individually arranged at positions on the circumference and facing the individual reflectors, and for each optical unit, the measurement light is emitted to the reflectors facing the optical unit; The measurement light incident from the opposing reflector is detected, and for each reflector, the measurement light incident from the optical unit facing the reflector is reflected and incident on the measurement point facing the reflector. The measurement light reflected by the The distance detection unit detects the distance for each reference position based on the size of the known distance between the reference position and the optical unit and the measurement light detection result for each optical unit. To do. Thereby, even when the diameter of the internal peripheral surface of a workpiece | work is a small diameter, the shape of this internal peripheral surface can be measured.

  In the shape measuring apparatus according to another aspect of the present invention, when the workpiece has a peripheral surface and the surface to be measured is a peripheral surface, the analysis unit determines the workpiece based on the position information and distance for each reference position. As the shape, the radius of the peripheral surface and the roundness of the peripheral surface are obtained. Thereby, the radius of a surrounding surface and the roundness of a surrounding surface can be measured as a shape of a workpiece.

  In the shape measuring apparatus according to another aspect of the present invention, the reference position is set to three or more on a plurality of the same circumference where the axial positions of the measurement reference axes are different, and the distance detection unit is provided for each reference position. Perform distance detection. The shape of the workpiece can be detected for each different axial position of the measurement reference axis.

  In the shape measuring apparatus according to another aspect of the present invention, when the workpiece is cylindrical or columnar and the surface to be measured is at least one of the outer circumferential surface and the inner circumferential surface of the workpiece, the analysis unit Based on the information and the distance for each reference position detected by the distance detection unit, the center position of the peripheral surface is obtained for each axial position, and the workpiece shape is measured with respect to the measurement reference axis based on the center position for each axial position. Find the tilt angle of the workpiece. Thereby, the inclination angle of the workpiece with respect to the measurement reference axis (reference plane) can be measured as the shape of the workpiece.

  In the shape measuring apparatus according to another aspect of the present invention, when the workpiece is cylindrical or columnar and the surface to be measured is at least one of the outer circumferential surface and the inner circumferential surface of the workpiece, the analysis unit Based on the information and the distance for each reference position detected by the distance detector, the radius of the peripheral surface is obtained for each axial position, and the straightness and cylindricity are calculated as the workpiece shape based on the radius for each axial position. Ask. Thereby, straightness and cylindricity can be measured as the shape of the workpiece.

  A shape measuring method for achieving the object of the present invention is a shape measuring method for measuring the shape of a workpiece placed on a reference plane, wherein 3 on the same circumference centered on a measurement reference axis perpendicular to the reference plane. For each of the reference positions set as described above, a distance detection step for detecting the distance from the reference position to the measurement point on the workpiece measurement surface facing the reference position, and known position information of each reference position with respect to the measurement reference axis And an analysis step for obtaining the shape of the workpiece based on the distance for each reference position detected in the distance detection step.

  The shape measuring apparatus and the shape measuring method of the present invention can measure the shape of a workpiece with high accuracy and high speed.

It is the schematic of the shape measuring apparatus of 1st Embodiment. It is the upper side figure and side view of the sensor head arrange | positioned on a reference plane. It is explanatory drawing which showed the emission direction of the measurement light radiate | emitted from each sensor head. It is the graph which showed an example of the detection result of the distance for every sensor head. It is a block diagram which shows the structure of a computer. It is explanatory drawing for demonstrating calculation of the shape of the workpiece | work by an analysis part. It is the graph which showed the relationship between the measurement precision of the shape (outer peripheral surface diameter) of a workpiece | work, and the number of channels of a sensor head. It is the graph which showed the relationship between the measurement precision of the average shape (diameter of an outer peripheral surface) of a workpiece | work, and the repetition frequency. It is a flowchart which shows the flow of the workpiece | work shape measurement by a shape measuring apparatus. It is the upper side figure and side view of the sensor head provided in the shape measuring apparatus of 2nd Embodiment. It is explanatory drawing for demonstrating the combination of 1st Embodiment and 2nd Embodiment. It is sectional drawing, such as a stage of 3rd Embodiment. It is a top view of the reference plane of the third embodiment. It is the front view which looked at each sensor head in Drawing 12 from the Z-axis direction lower side. It is a side view of the stage and sensor head which comprise the shape measuring apparatus of 4th Embodiment. It is sectional drawing in alignment with the 16A-16A line in FIG. 15, and sectional drawing in alignment with the 16B-16B line. It is explanatory drawing for demonstrating the center coordinate of the 1st measurement cross section used for calculation of the inclination of the central axis of a workpiece | work, and the center coordinate of a 2nd measurement cross section. It is explanatory drawing for demonstrating the inclination calculation of the central axis of a workpiece | work. It is explanatory drawing for demonstrating the modification of 4th Embodiment. It is a side view of the stage and sensor head which comprise the shape measuring apparatus of 5th Embodiment. FIG. 21 is a cross-sectional view taken along line 21A-21A in FIG. 20, a cross-sectional view taken along line 21B-21B, and a cross-sectional view taken along line 21C-21C.

[Shape Measuring Device of First Embodiment]
FIG. 1 is a schematic diagram of a shape measuring apparatus 10 according to the first embodiment. The shape measuring device 10 measures the shape of the cylindrical workpiece W. The shape of the workpiece W here includes dimensions such as the diameter (radius and diameter) of the peripheral surface of the workpiece W, the roundness of the workpiece W, the inclination of the workpiece W (fourth embodiment), and the workpiece. Various shapes and dimensions including straightness and cylindricity of W (fifth embodiment) are included.

  As shown in FIG. 1, the shape measuring apparatus 10 includes a stage 12 having a disk shape (or other shapes are possible), a multi-channel non-contact displacement meter 13, and a computer 14.

  The upper surface (horizontal plane) of the stage 12 serves as a reference plane 12a on which the workpiece W is placed. In the present embodiment, an axis that passes through the center of the reference plane 12a (may be other than the center) and is perpendicular to the reference plane 12a is the measurement reference axis A1. In the drawing, the center axis of the workpiece W coincides with the measurement reference axis A1, but the center axis of the workpiece W may be eccentric with respect to the measurement reference axis A1. That is, it is not necessary to center the workpiece W on the reference plane 12a.

  The non-contact displacement meter 13 corresponds to a measurement unit of the present invention, and includes an eight-channel (CH1 to CH8) sensor head 18, eight sensor position adjustment units 19, and a displacement meter body 20. . Note that the number of sensor heads 18 and sensor position adjustment units 19 (reference position P1 described later) may be increased or decreased as long as the number is 3 or more.

  FIG. 2 is a top view (upper stage) and a side view (lower stage) of the sensor head 18 disposed on the reference plane 12a. As shown in FIG. 2, the outer peripheral surface is located outside the outer peripheral surface (corresponding to the surface to be measured of the present invention) of the workpiece W placed on the reference plane 12a and facing the outer peripheral surface. Eight reference positions P1 are set in advance at equal angular intervals (45 °) on the same circumference (C1) with the measurement reference axis A1 as the center so as to surround. Specifically, the reference position P1 is an angular position on the same circumference (C1) represented by θi = (i−1) × (360/8) [i = 1 to 8] with the measurement reference axis A1 as the center. (0 °, 45 °, 90 °, 135 °, 180 °, 225 °, 270 °, 315 °).

  For example, a fiber collimator is used for the 8-channel sensor head 18. Each sensor head 18 is connected to the displacement meter main body 20 via a signal propagation cable (optical fiber cable) (not shown). Each sensor head 18 individually emits measurement light L (corresponding to a signal of the present invention) input from the displacement meter body 20 toward the workpiece W. Each sensor head 18 individually receives the measurement light L reflected by the workpiece W and outputs it individually to the displacement meter body 20.

  Each sensor position adjustment unit 19 is provided at a position corresponding to each reference position P1 on the reference plane 12a. Each sensor position adjustment unit 19 supports one sensor head 18 at the reference position P1. As a result, the 8-channel sensor heads 18 are arranged at the above-described reference positions P1, that is, arranged at equal angular intervals (equal angular positions) on the same circumference (C1) around the measurement reference axis A1.

  Each sensor position adjustment unit 19 performs position adjustment of the position of the supporting sensor head 18 in the three axial directions and posture adjustment (pan / tilt adjustment), so that the measurement light L emitted from the sensor head 18 is adjusted. The emission direction can be arbitrarily adjusted.

  FIG. 3 is an explanatory diagram showing the emission direction of the measurement light L emitted from each sensor head 18. As shown in FIG. 3, each sensor position adjustment unit 19 adjusts the position and orientation of the supporting sensor head 18, and sets the direction of the optical axis OA of the measurement light L emitted from the sensor head 18 as a reference. Adjustment is made in a direction D perpendicular to the measurement reference axis A1 in the plane F including the position P1 and the measurement reference axis A1. Thereby, the measurement light L parallel to the direction D is emitted from the sensor head 18 at each reference position P1 toward the measurement reference axis A1. As a result, the measurement light L individually emitted from each sensor head 18 (reference position P1) is individually incident on the measurement point P2 in the outer peripheral surface of the workpiece W facing each sensor head 18 (reference position P1). (See FIG. 2).

  In addition, since the position adjustment and attitude | position adjustment of the sensor head 18 for every sensor position adjustment part 19 are performed using a well-known jig, a method, a measuring instrument, etc., concrete description is abbreviate | omitted here.

  1 and 2, the measurement light L incident on the measurement points P2 facing each other from each sensor head 18 (reference position P1) is reflected toward the original sensor head 18 for each measurement point P2. Each sensor head 18 receives light individually. The measurement light L received by each sensor head 18 is individually input to the displacement meter main body 20 via a signal propagation cable (not shown) as described above.

  The displacement meter body 20 individually inputs the measurement light L to each sensor head 18 via a signal propagation cable (not shown) under the control of the computer 14, and the measurement light L received by each sensor head 18. Are individually detected (photoelectric conversion). Then, the displacement meter body 20 is based on the detection result of the measurement light L detected for each sensor head 18, and the distance from each sensor head 18 (reference position P1) to the measurement point P2 facing each other (hereinafter simply referred to as “sensor”). A distance for each head 18) is detected. That is, the displacement meter body 20 functions as a distance detection unit of the present invention. In addition, since the specific distance detection method is a well-known technique, specific description is abbreviate | omitted here.

  FIG. 4 is a graph showing an example of a distance detection result for each sensor head 18. Note that the horizontal axis in the figure is the angular position of the sensor head 18 of eight channels (CH1 to CH8) with the measurement reference axis A1 as the center.

  In an ideal state where the cross-sectional shape of the outer peripheral surface of the workpiece W in the XY-axis direction is a perfect circle and the center axis of the workpiece W coincides with the measurement reference axis A1, the distance for each sensor head 18 (reference position P1) is It becomes almost the same value. However, the cross-sectional shape of the workpiece W does not become a perfect circle due to a machining error. Furthermore, in this embodiment, the shape of the workpiece W is detected without performing centering to make the center axis of the workpiece W coincide with the measurement reference axis A1. Because it can, it is not centered. For this reason, as shown in FIG. 4, the sensor head 18 (reference position P1) corresponds to the roundness of the work W and the eccentricity (eccentric direction and amount) of the center axis of the work W with respect to the measurement reference axis A1. ) Varies in distance.

  The displacement meter body 20 outputs a distance detection signal indicating the detection result of the distance for each sensor head 18 to the computer 14.

  A displacement meter main body 20 and a display unit 14a are connected to the computer 14. The computer 14 controls the operation of the displacement meter body 20. Further, the computer 14 measures the shape of the workpiece W based on the distance detection signal for each sensor head 18 input from the displacement meter main body 20, and displays the measurement result on the display unit 14a. Various arithmetic processing devices may be used instead of the computer 14.

[Computer configuration]
FIG. 5 is a block diagram illustrating a configuration of the computer 14. As shown in FIG. 5, the computer 14 includes a control unit 25 and a storage unit 26. Although not shown, the control unit 25 includes various arithmetic units including a CPU (Central Processing Unit) or an FPGA (field-programmable gate array), a processing unit, a memory, and the like. The control unit 25 functions as a measurement control unit 28, an analysis unit 29, and a repetitive control unit 30 by executing a control program (not shown) read from the memory or the storage unit 26.

  The storage unit 26 stores the measurement result of the shape of the workpiece W input from the analysis unit 29 described later. The storage unit 26 stores in advance position information 32 indicating the position of each sensor head 18 (reference position P1) with respect to the measurement reference axis A1. The position information 32 includes, for example, the angular position of each sensor head 18 (reference position P1) on the same circumference (C1), the radius of the “circumference” on the same circumference (C1), and the like. ,It is included. The position information 32 is not particularly limited as long as the position of each sensor head 18 (reference position P1) with reference to the measurement reference axis A1 can be determined. For example, the position information 32 is based on an arbitrary origin of the reference plane 12a. The position coordinates of the measurement reference axis A1 and each sensor head 18 (reference position P1) may be used.

  The measurement control unit 28 obtains a distance detection signal for each sensor head 18 by the displacement meter body 20 (emission of the measurement light L from each sensor head 18, detection of the measurement light L received by each sensor head 18, and sensor head). 18) and the like. Further, the measurement control unit 28 outputs a distance detection signal for each sensor head 18 acquired from the displacement meter main body 20 to the analysis unit 29.

  The analysis unit 29 obtains the shape of the workpiece W based on the distance detection signal for each sensor head 18 acquired from the displacement meter body 20 and the above-described position information 32 acquired from the storage unit 26. In the present embodiment, the radius (diameter) and roundness of the outer peripheral surface of the workpiece W are obtained as the shape of the workpiece W.

  FIG. 6 is an explanatory diagram for explaining calculation (analysis) of the shape of the workpiece W by the analysis unit 29. The analysis unit 29 can determine the distance for each sensor head 18 based on the distance detection signal for each sensor head 18. Further, the analysis unit 29 determines, based on the position information 32, the angular position of each sensor head 18 (reference position P1) with respect to the measurement reference axis A1 and the radius of the “circumference” on the same circumference (C1). it can.

Therefore, as shown by a “dotted line” in FIG. 6, the analysis unit 29 is based on the distance detection signal for each sensor head 18 and the position information 32, and the outer peripheral surface of the workpiece W placed on the reference plane 12 a. It is possible to detect the position of each of the measurement points P2 (position based on the measurement reference axis A1). Thereby, the analysis unit 29 can obtain the center coordinates (x ₀ , y ₀ ) of the workpiece W and the radius R of the outer peripheral surface of the workpiece W.

For example, the number of sensor heads 18 (reference position P1) is “N” (N = 8 in this embodiment). As shown in the following [Equation 1], the distance to the measurement point P2 for each sensor head 18 is “r _i ”, and the angular position for each sensor head 18 is “θ _i ”. Thus, the position of each measurement point P2 in the outer peripheral surface of the workpiece W can be expressed by polar coordinates (r _i, θ _i). The analysis unit 29 then converts the polar coordinate values (r _i , θ _i ) of each measurement point P2 into coordinate values (x _i , y _i ) in the XY coordinate system using the following [Equation 2]. To do.

Next, the analysis unit 29 uses the equation represented by the following [Equation 3] based on the coordinate values (x _i , y _i ) of each measurement point P2 converted into the XY coordinate system, and the center coordinates ( x ₀ , y ₀ ) and the radius R of the outer peripheral surface of the workpiece W are calculated.

Based on the center coordinates (x ₀ , y ₀ ) of the workpiece W obtained as described above, the eccentricity (eccentric direction and eccentricity) of the center axis of the workpiece W with respect to the measurement reference axis A1 can be obtained. Therefore, the analysis unit 29 corrects the eccentricity of the center axis of the workpiece W with respect to the measurement reference axis A1 in the same manner as when the roundness of the workpiece W is obtained by a known least square center method. Specifically, the analysis unit 29 uses the coordinates (x _i , y _i ) of each measurement point P2 using the center coordinates (x ₀ , y ₀ ) of the workpiece W, as shown in the following [Equation 4]. Is corrected, and the corrected coordinate value (xa _i , ya _i ) of each measurement point P2 is calculated. Thereby, as indicated by the “solid line” in the figure, the position of each measurement point P2 after the eccentricity correction is calculated with respect to the measurement reference axis A1.

Next, based on the corrected coordinate values (xa _i , ya _i ) of each measurement point P2, the analysis unit 29, from the measurement reference axis A1 (origin) to each measurement point P2, as shown in the following [Equation 5]. The distance ra _i is calculated respectively. And the analysis part 29 uses the following [Equation 6] formula based on the calculation result of the distance ra _i to each measurement point P2, and the radius R calculated previously for every measurement point P2 with respect to the radius R. A variation δ _i of the distance ra _i is calculated. The variation δ _i for each measurement point P2 is a value that serves as an index of the roundness of the outer circumferential surface of the workpiece W. Therefore, the roundness (simple roundness) of the outer circumferential surface of the workpiece W is based on each variation δ _i. Is required. The roundness may be calculated by using a known method such as the least-square center method described above.

  Thus, the analysis unit 29 obtains the radius R (diameter) and the roundness of the outer peripheral surface of the workpiece W as the shape of the workpiece W based on the distance detection signal for each sensor head 18 and the position information 32. it can. Thereby, one-time shape measurement of the workpiece W is completed. The analysis unit 29 outputs the measurement result of the shape of the workpiece W [measurement result of radius R (diameter) and roundness] to the display unit 14 a and the storage unit 26.

  FIG. 7 is a graph showing the relationship between the measurement accuracy of the shape of the workpiece W (the diameter of the outer peripheral surface) and the number of channels of the sensor head 18. Here, assuming that there is a measurement error (detection error) of ± 0.1 μm for each sensor head 18, 500 times of simulations are performed to determine the variation in the diameter of the outer peripheral surface and the 2σ deviation for each number of channels. Looking for.

  As shown in FIG. 7, the variation in diameter is about 0.33 μm when the number of channels is the minimum number “3”, and gradually decreases as the number of channels increases. Also, the 2σ deviation in diameter is about 0.30 μm when the number of channels is the minimum number “3”, and gradually decreases as the number of channels increases. For this reason, even if there is a measurement error of ± 0.1 μm for each sensor head 18, the measurement results of the distance for each sensor head 18 are averaged by performing multi-channel measurement, thereby reducing variation and 2σ deviation. be able to. As a result, the shape of the workpiece W can be measured with high accuracy.

  Returning to FIG. 5, the repetition control unit 30 repeatedly operates the measurement control unit 28 (displacement meter body 20) and the analysis unit 29 a plurality of times. Thereby, the acquisition of the distance detection signal for each sensor head 18 by the displacement meter body 20 and the measurement control unit 28 and the calculation of the shape of the workpiece W by the analysis unit 29 are repeated a plurality of times. The number of repetitions can be set to a desired number by the user. Thereby, the detection result of the shape of the workpiece | work W for multiple times is obtained.

  After repeatedly calculating the shape of the workpiece W a plurality of times, the analysis unit 29 calculates the average value of the radius R (diameter) of the outer peripheral surface of the workpiece W as an average shape obtained by averaging the shapes of the workpiece W obtained a plurality of times. The average value of roundness is calculated. Then, the analysis unit 29 outputs the calculated result of the average shape of the workpieces W to the display unit 14a and stores it in the storage unit 26.

  FIG. 8 is a graph showing the relationship between the measurement accuracy of the average shape (the diameter of the outer peripheral surface) of the workpiece W and the number of repetitions. Here, it is assumed that there is a measurement error of ± 0.1 μm for each sensor head 18, and the outer peripheral surface for each number of repetitions is performed by performing 500 simulations under the conditions using the 8-channel sensor head 18. Variation in diameter and 2σ deviation were obtained. When the time required for one measurement is about 1 msec, the time required for 100 repetitions is about 100 msec.

  As shown in FIG. 8, the variation in the diameter of the outer peripheral surface of the workpiece W and the 2σ deviation decrease as the number of repetitions increases. For this reason, even if there is a measurement error of ± 0.1 μm for each sensor head 18, the measurement of the shape of the workpiece W is repeatedly performed a plurality of times, and the average shape of the workpiece W is calculated. The influence of 13 measurement errors can be reduced.

[Operation of the shape measuring apparatus of the first embodiment]
FIG. 9 is a flowchart showing a flow of measuring the shape of the workpiece W by the shape measuring apparatus 10 having the above configuration (the shape measuring method of the present invention). The setting of each reference position P1, the adjustment of the position and orientation of each sensor head 18, and the calibration of the non-contact displacement meter 13 are performed in advance. As shown in FIG. 9, first, the user places the workpiece W to be measured on the reference plane 12a (step S1). At this time, since it is not necessary to perform centering to make the center axis of the workpiece W coincide with the measurement reference axis A1, the measurement time can be shortened.

  Next, when the user performs a measurement start operation on the computer 14, the measurement light L is input from the displacement meter body 20 to each sensor head 18 under the control of the measurement control unit 28 of the control unit 25, and from each sensor head 18. The measurement light L is individually emitted toward the measurement point P2 in the outer peripheral surface of the workpiece W facing each other. Each sensor head 18 individually receives the measurement light L reflected at the measurement points P2 facing each other (step S2). As a result, the measurement light L received by each sensor head 18 is individually input to the displacement meter body 20.

  Next, in the displacement meter body 20, the detection of the measurement light L for each sensor head 18 and the detection of the distance for each sensor head 18 are sequentially performed, and then the sensor head from the displacement meter body 20 to the measurement control unit 28. A distance detection signal for every 18 is output (step S3, corresponding to the distance detection step of the present invention). The time required for one measurement is 1 to 10 msec. As a result, a distance detection signal for each sensor head 18 is input to the measurement control unit 28, and further input to the analysis unit 29 via the measurement control unit 28.

  Receiving the distance detection signal for each sensor head 18, the analysis unit 29 calculates the above [Equation 1] to [Equation 6] based on each distance detection signal and the position information 32 acquired from the storage unit 26. The shape of the work W [radius R (diameter) and roundness of the outer peripheral surface] is calculated (step S4, corresponding to the analysis step of the present invention). Thereby, the first shape measurement of the workpiece W is completed, and the measurement results are output from the analysis unit 29 to the display unit 14a and the storage unit 26, respectively.

  At this time, in this embodiment, since the shape of the workpiece W is measured using the 8-channel sensor head 18, the detection results for each sensor head 18 are averaged as shown in FIG. Variation and 2σ deviation can be reduced. As a result, the shape of the workpiece W can be measured with high accuracy.

  Next, the repetition control unit 30 repeatedly operates the measurement control unit 28 (displacement meter body 20) and the analysis unit 29 when the number of repetitions of shape measurement has not reached the predetermined number of times set by the user, The above-described processing from step S2 to step S4 is executed again (NO in step S5). Thereby, the shape of the workpiece W is calculated again by the analysis unit 29.

  Hereinafter, the processing from step S2 to step S5 described above is executed until the number of repetitions reaches the set number (YES in step S5). Thereby, the measurement result of the shape of the workpiece | work W for multiple times is obtained. Next, the analysis unit 29 calculates an average shape obtained by averaging the shapes of the workpieces W for a plurality of times, and outputs the calculation result to the display unit 14a and stores it in the storage unit 26 (step S6). Thus, by repeatedly performing shape measurement a plurality of times to obtain the average shape of the workpiece W, the influence of the measurement error for each sensor head 18 is reduced, and as shown in FIG. Variation and 2σ deviation can be reduced. As a result, the shape of the workpiece W can be measured with high accuracy.

[Effect of the first embodiment]
As described above, in the shape measuring apparatus 10 of the first embodiment, by using the non-contact displacement meter 13, from each sensor head 18 (reference position P1) to the measurement point P2 on the outer peripheral surface of the workpiece W facing each other. Can be detected in a batch without contact. Thereby, the shape of the workpiece | work W can be measured, without rotating the workpiece | work W relatively with respect to the sensor head 18 conventionally. For this reason, it is possible to shorten the measurement time, prevent the occurrence of measurement errors due to vibration during rotation, simplify the apparatus configuration by omitting the rotation mechanism, and measure the shape of the workpiece W that is difficult to rotate or fix. Is obtained. As a result, the shape of the workpiece W can be measured with high accuracy and at high speed.

[Shape Measuring Device of Second Embodiment]
FIG. 10 is a top view (upper stage) and a side view (lower stage) of the sensor head 18 provided in the shape measuring apparatus 10 of the second embodiment. In the first embodiment, the radius R (diameter) and roundness of the outer peripheral surface of the workpiece W are measured as the shape of the cylindrical workpiece W. However, in the shape measuring apparatus 10 of the second embodiment, the workpiece is measured. The radius R (diameter) and roundness of the inner peripheral surface of W (corresponding to the surface to be measured of the present invention) are measured.

  Note that the shape measuring apparatus 10 of the second embodiment has basically the same configuration as the shape measuring apparatus 10 of the first embodiment except that the arrangement of the sensor heads 18 is different, and thus the first embodiment. Those that are functionally or structurally identical are denoted by the same reference numerals and description thereof is omitted.

  As shown in FIG. 10, in the second embodiment, the same circle centering on the measurement reference axis A <b> 1 is located inside the inner peripheral surface of the workpiece W placed on the reference plane 12 a (a position facing the inner peripheral surface). Eight reference positions P1 are set in advance at equal angular intervals (45 °) on the circumference (C2). That is, in the second embodiment, eight reference positions P1 are set in an arrangement pattern similar to that of the first embodiment inside the inner peripheral surface of the workpiece W. Thereby, the 8-channel sensor heads 18 are arranged at equal angular intervals on the same circumference (C2) with the measurement reference axis A1 as the center.

  Each sensor position adjustment unit 19 of the second embodiment adjusts the position and orientation of the sensor head 18 that is supported, and the optical axis of the measurement light L emitted from the sensor head 18 as in the first embodiment. The direction of OA is adjusted to direction D (see FIG. 3). Accordingly, the measurement light L is emitted radially from the sensor head 18 at each reference position P1 with the measurement reference axis A1 as the center. As a result, the measurement light L individually emitted from each sensor head 18 (reference position P1) is individually applied to the measurement point P2 in the inner peripheral surface of the workpiece W that faces each sensor head 18 (reference position P1). Incident.

  Each sensor head 18 individually receives the measurement light L reflected at the measurement point P2 facing each sensor head 18. Then, the measurement light L received by each sensor head 18 is individually input to the displacement meter body 20.

  Similar to the first embodiment, the displacement meter main body 20 of the second embodiment detects the measurement light L for each sensor head 18 and detects the distance for each sensor head 18. Thereby, the distance from each sensor head 18 (reference position P1) to the measurement point P2 in the inner peripheral surface of the workpiece W facing each other is detected. Then, the displacement meter body 20 outputs a distance detection signal for each sensor head 18 to the computer 14.

  The computer 14 according to the second embodiment, based on the distance detection signal for each sensor head 18 input from the displacement meter main body 20 and the position information 32 acquired from the storage unit 26, similarly to the above [Numeric The radius R (diameter) and the roundness of the inner peripheral surface of the workpiece W are obtained using the formula 1 to the formula 6 below.

  Since the operation of the shape measuring apparatus 10 of the second embodiment is basically the same as that of the first embodiment shown in FIG. 9 described above, a specific description is omitted here. And according to the shape measuring apparatus 10 of 2nd Embodiment, the distance from each sensor head 18 (reference position P1) to the measurement point P2 in the internal peripheral surface of the workpiece | work W which opposes each is collectively without contact. Since it can detect, the effect similar to the said 1st Embodiment is acquired.

[Combination of the first embodiment and the second embodiment]
FIG. 11 is an explanatory diagram for explaining a combination of the first embodiment and the second embodiment. As shown in FIG. 11, the first embodiment and the second embodiment are combined to set the reference position P1 on the outer side of the outer peripheral surface of the work W and the inner side of the inner peripheral surface of the work W, respectively. The sensor head 18 may be disposed at the position P1. Thereby, the shape of the outer peripheral surface and inner peripheral surface of the workpiece | work W can be measured collectively.

[Shape Measuring Device of Third Embodiment]
Next, the shape measuring apparatus 10 according to the third embodiment of the present invention will be described. In the second embodiment, each sensor head 18 and each sensor position adjusting unit 19 are arranged inside the inner peripheral surface of the workpiece W. However, when the diameter of the inner peripheral surface of the workpiece W is a small diameter, each sensor The head 18 or the like cannot be disposed inside the inner peripheral surface of the workpiece W. Therefore, in the shape measuring apparatus 10 of the third embodiment, the shape of the inner peripheral surface of the workpiece W is measured without arranging the sensor heads 18 and the like inside the inner peripheral surface of the workpiece W.

  In addition, the shape measuring apparatus 10 of 3rd Embodiment is the said 1st except the point from which the arrangement | positioning of each sensor head 18 differs and the point provided with the reflector 35 (refer FIG. 12) instead of the sensor position adjustment part 19. FIG. The configuration is basically the same as that of the shape measuring apparatus 10 of the second embodiment. For this reason, the same functions or configurations as those of the above embodiments are denoted by the same reference numerals, and the description thereof is omitted.

  FIG. 12 is a cross-sectional view of the stage 12 and the like according to the third embodiment. FIG. 13 is a top view of the reference plane 12a of the third embodiment. FIG. 14 is a front view (bottom view) of each sensor head 18 in FIG. 12 as viewed from the lower side in the Z-axis direction.

  As shown in FIGS. 12 to 14, a substantially disc-shaped reflector holding portion 36 is provided in a region on the reference plane 12 a and inside the inner peripheral surface of the workpiece W. On the upper surface of the reflector holding portion 36, the reflector 35 is provided for each reference position P1 described above. Thus, the eight reflectors 35 are arranged at equal angular intervals on the same circumference (C2) with the measurement reference axis A1 as the center.

  Each reflector 35 is, for example, a mirror. Each reflector 35 reflects the measurement light L incident from above in the Z-axis direction toward the inner peripheral surface of the workpiece W in a direction parallel to the direction D (see FIG. 3). As a result, the measurement light L incident from above in the Z-axis direction is reflected toward the measurement point P2 in the inner peripheral surface of the workpiece W facing each reflector 35 (reference position P1). Each reflector 35 reflects the measurement light L incident from the measurement point P2 facing each other upward in the Z-axis direction.

  Each sensor head 18 of the third embodiment corresponds to an optical unit of the present invention, and is arranged with a space in the vertical direction (upward in the Z-axis direction) with respect to the reference plane 12a. Specifically, a disk-shaped sensor holding portion 37 parallel to the reference plane 12a is supported by a support portion (not shown) at a position above the reference plane 12a and facing each reflector 35. Yes. On the lower surface of the sensor holding portion 37, sensor heads 18 are provided at positions facing the respective reference positions P1 (each reflector 35).

  Each sensor head 18 emits measurement light L downward in the Z-axis direction. Thereby, the measurement light L is emitted from each sensor head 18 toward the reflector 35 (reference position P1) facing each other. Then, each measurement light L is reflected radially by the respective reflectors 35 toward the measurement points P2 facing each other.

  Next, the measurement light L individually incident on each measurement point P2 is individually reflected toward the original reflector 35 for each measurement point P2. The measurement light L incident on the reflectors 35 facing each other from each measurement point P2 is individually reflected by the reflectors 35 toward the sensor head 18 facing each other. Thereby, each sensor head 18 individually receives the measurement light L reflected by the reflectors 35 facing each other. Hereinafter, as in the above embodiments, the measurement light L received by each sensor head 18 is individually input to the displacement meter body 20.

  The displacement meter main body 20 of the third embodiment individually detects the measurement light L received by each sensor head 18. Next, the displacement meter main body 20 detects the sensor beam L based on the detection result of the measurement light L and the magnitude (symbol α) of the known distance (distance) between the reference position P1 and the sensor head 18. For each head 18, the distance from the reflector 35 (reference position P1) to the measurement point P2 facing the reflector 35 is detected.

  For example, the displacement meter main body 20 detects the optical path length of each measurement light L based on the detection result of the measurement light L for each sensor head 18, and subtracts the value of the interval from the detected optical path length, respectively. The distance to the measurement point P2 is detected for each position P1. Then, the displacement meter body 20 outputs a distance detection signal for each sensor head 18 to the computer 14.

  Since the subsequent processing is basically the same as that of the second embodiment, a detailed description thereof will be omitted.

  As described above, in the shape measuring apparatus 10 of the third embodiment, the inner side of the inner peripheral surface of the workpiece W is refracted by using the reflectors 35 arranged at the respective reference positions P1 to refract the optical path of the measuring light L. The shape of the inner peripheral surface of the workpiece W can be measured without disposing each sensor head 18 and each sensor position adjusting unit 19. Thereby, even when the diameter of the internal peripheral surface of the workpiece | work W is a small diameter, the shape of this internal peripheral surface can be measured. Further, the same effects as those in the above embodiments can be obtained.

[Shape Measuring Device of Fourth Embodiment]
Next, the shape measuring apparatus 10 according to the fourth embodiment of the present invention will be described. In each of the above embodiments, the radius R (diameter) and roundness of the inner and outer peripheral surfaces of the workpiece W are measured as the shape of the workpiece W. In the fourth embodiment, the inclination of the workpiece W with respect to the measurement reference axis A1. Measure the angle. Here, the inclination angle of the workpiece W is an inclination angle of the central axis A2 (see FIG. 15) of the workpiece W with respect to the measurement reference axis A1.

  FIG. 15 is a side view of the stage 12 and the sensor head 18 constituting the shape measuring apparatus 10 of the fourth embodiment. 16 is a cross-sectional view along the line 16A-16A in FIG. 15 (upper stage) and a cross-sectional view along the line 16B-16B in FIG. 15 (lower stage). The shape measuring apparatus 10 of the fourth embodiment has basically the same configuration as the shape measuring apparatus 10 of the first embodiment, except that two sets of 8-channel sensor heads 18 are provided. For this reason, the same functions or configurations as those of the first embodiment are denoted by the same reference numerals and description thereof is omitted.

  As shown in FIGS. 15 and 16, in the fourth embodiment, the measurement reference axis is located outside the outer circumferences of both the first measurement cross section CS1 and the second measurement cross section CS2 of the workpiece W perpendicular to the measurement reference axis A1. Eight reference positions P1 are set in advance at equal angular intervals on the same circumference (C1) with A1 as the center. The first measurement cross section CS1 and the second measurement cross section CS2 are different from each other in the axial position of the measurement reference axis A1. The height h of the first measurement section CS1 with respect to the second measurement section CS2 is a known value.

  Each sensor head 18 of the fourth embodiment is arranged and supported at each reference position P1 by a support member (not shown). As a result, at different axial positions of the measurement reference axis A1, the 8-channel sensor heads 18 are arranged at equal angular intervals on the same circumference (C1) with the measurement reference axis A1 as the center. Hereinafter, each sensor head 18 at the height position of the first measurement section CS1 is referred to as “first sensor head 18”, and each sensor head 18 at the height position of the second measurement section CS2 is referred to as “second sensor head 18”. "

  Further, the position and orientation of each sensor head 18 are adjusted so that the direction of the optical axis OA of the measurement light L to be emitted is parallel to the aforementioned direction D (see FIG. 3). Thereby, the measurement light L emitted from each first sensor head 18 is incident on the measurement point P2 on the outer periphery of the first measurement cross section CS1 facing each of the first sensor heads 18, and each measurement point P2 After being reflected toward the original first sensor head 18, the light is individually received by the original first sensor head 18. On the other hand, the measurement light L emitted from each second sensor head 18 enters each second sensor head 18 at a measurement point P2 on the outer periphery of each opposing second measurement cross section CS1, and at each measurement point P2. After being reflected toward the original second sensor head 18, the light is individually received by the original second sensor head 18.

  The displacement meter main body 20 of the fourth embodiment detects the measurement light L for each first sensor head 18, detects the measurement light L for each second sensor head 18, and detects the distance for each sensor head 18. Do. As a result, the displacement meter body 20 has a distance from the first sensor head 18 (reference position P1) to the measurement point P2 on the outer periphery of the first measurement section CS1 facing each other, and the second sensor head 18 (reference position P1). ) To the measurement point P2 on the outer periphery of the second measurement cross section CS2 facing each other. The displacement meter body 20 includes a distance detection signal for each first sensor head 18 (hereinafter referred to as a first distance detection signal), a distance detection signal for each second sensor head 18 (hereinafter referred to as a second distance detection signal), Are output to the computer 14, respectively.

  Each distance detection signal input to the computer 14 of the fourth embodiment is input to the analysis unit 29 via the measurement control unit 28 (see FIG. 5). Further, the storage unit 26 of the fourth embodiment stores position information 32 of each first sensor head 18 and each second sensor head 18.

  Based on the first distance detection signal and the second distance detection signal input from the displacement meter main body 20 and the position information 32 acquired from the storage unit 26, the analysis unit 29 of the fourth embodiment is used as the shape of the workpiece W. The inclination of the center axis A2 of the workpiece W with respect to the measurement reference axis A1 is obtained.

FIG. 17 shows the center coordinates V1 (x ₀₁ , y ₀₁ ) of the first measurement section CS1 and the center coordinates V2 (x ₀₂ , y ₀₂ ) of the second measurement section CS2 used for calculating the inclination of the center axis A2 of the workpiece W. It is explanatory drawing for demonstrating. FIG. 18 is an explanatory diagram for explaining the calculation of the inclination of the central axis A2 of the workpiece W.

As shown in FIG. 17, the analysis unit 29 uses the above [Equation 2] and [Equation 3] based on the first distance detection signal and the position information 32 as the center position of the first measurement cross section CS1. The coordinates V1 (x ₀₁ , y ₀₁ ) are obtained. Similarly, the analysis unit 29 obtains the center coordinates V2 (x ₀₂ , y ₀₂ ) as the center position of the second measurement section CS2 based on the second distance detection signal and the position information 32.

Next, as illustrated in FIG. 18, the analysis unit 29 is based on the center coordinates V1 (x ₀₁ , y ₀₁ ), the center coordinates V2 (x ₀₂ , y ₀₂ ), and the known height h (see FIG. 15). The inclination angle φ of the central axis A2 with respect to the measurement reference axis A1 is obtained using the following [Equation 7].

  As described above, the analysis unit 29 according to the fourth embodiment can obtain the inclination angle φ of the workpiece W as the shape of the workpiece W based on the first distance detection signal, the second distance detection signal, and the position information 32. Thereby, one-time shape measurement of the workpiece W is completed. In the same way as in the first embodiment, the measurement control unit 28 (displacement meter body 20) and the analysis unit 29 are repeatedly operated by the repetition control unit 30 a plurality of times, so that the average shape of the workpiece W can be obtained multiple times. An average value of the inclination angle φ is obtained.

  The subsequent processing is basically the same as that in the first embodiment, and a detailed description thereof will be omitted.

  As described above, in the shape measuring apparatus 10 according to the fourth embodiment, the distance from each first sensor head 18 (reference position P1) to the measurement point P2 on the outer periphery of the first measurement section CS1 facing each other, The distance from the second sensor head 18 (reference position P1) to the measurement point P2 on the outer periphery of the second measurement cross section CS2 facing each other can be collectively detected without contact. Thereby, the shape (inclination angle φ) of the workpiece W can be measured without rotating the workpiece W relative to each sensor head 18. As a result, the same effect as the first embodiment can be obtained.

  In the fourth embodiment, two sets of eight reference positions P1 having different axial positions of the measurement reference axis A1 are set. However, three or more sets are set and distance detection is performed for each reference position. You may obtain | require inclination-angle (phi) from the center coordinate of each three or more measurement cross sections.

[Modification of Fourth Embodiment]
FIG. 19 is an explanatory diagram for describing a modification of the fourth embodiment. In the fourth embodiment, the sensor heads 18 (the first sensor head 18 and the second sensor head) are arranged at all the reference positions P1, and the distance for each sensor head 18 is detected.

  On the other hand, as shown in FIG. 19, in the modification of the fourth embodiment, eight channels arranged on the same circumference (C1) with the same arrangement pattern as the reference position P1 around the measurement reference axis A1. A moving unit 40 that moves the sensor head 18 in the axial direction (Z-axis direction) of the measurement reference axis A1 is provided. The moving unit 40 moves each sensor head 18 to a plurality of axial positions corresponding to the reference position P1 along the Z-axis direction (for example, axial positions respectively corresponding to the first measurement section CS1 and the second measurement section CS2). Move in order.

  On the other hand, the measurement control unit 28 controls the displacement meter body 20, and each time the moving unit 40 moves each sensor head 18 to a new axial position, the measurement light L is input to each sensor head 18, and The detection of the measurement light L received by each sensor head 18 and the detection of the distance for each sensor head 18 are repeatedly executed. Accordingly, measurement is performed within the outer peripheral surface of the workpiece W facing each other from each sensor head 18 (for example, on the outer periphery of the first measurement cross section CS1 and the second measurement cross section CS2) for each different axial position of the measurement reference axis A1. The distance to the point P2 can be detected.

  Accordingly, also in the present modification, the inclination angle φ of the workpiece W can be obtained in the same manner as in the fourth embodiment, and thus the same effect as in the fourth embodiment can be obtained. Furthermore, in this modified example, the number of sensor heads 18 can be reduced, and the axial position and number of distance detection can be arbitrarily adjusted.

[Shape Measuring Device of Fifth Embodiment]
Next, the shape measuring apparatus 10 according to the fifth embodiment of the present invention will be described. In each of the above embodiments, as the shape of the workpiece W, the radius R (diameter) and roundness of the inner and outer peripheral surfaces of the workpiece W and the inclination angle φ are measured. In the fifth embodiment, the straightness of the workpiece W is measured. Measure degrees and cylindricity.

  FIG. 20 is a side view of the stage 12 and the sensor head 18 constituting the shape measuring apparatus 10 of the fifth embodiment. 21 is a cross-sectional view along line 21A-21A in FIG. 20 (upper stage), a cross-sectional view along line 21B-21B (middle stage), and a cross-sectional view along line 21C-21C (lower stage). The shape measuring apparatus 10 of the fifth embodiment includes a plurality of 8-channel sensor heads 18 and has basically the same configuration as the shape measuring apparatus 10 of the fourth embodiment. For this reason, the same functions or configurations as those in the fourth embodiment are denoted by the same reference numerals, and the description thereof is omitted.

  As shown in FIGS. 20 and 21, in the fifth embodiment, a plurality of measurement cross sections (a first measurement cross section CS1, a second measurement cross section CS2,... Nth measurement cross section CSN) of the workpiece W perpendicular to the measurement reference axis A1. 8 reference positions P1 are set in advance at equal angular intervals (C1) on the same circumference with the measurement reference axis A1 as the center. The measurement cross-sections CS1 to CSN are different from each other in the axial position of the measurement reference axis A1.

  Each sensor head 18 is arranged and supported at each reference position P1 by a support member (not shown), as in the fourth embodiment. Accordingly, eight sensor heads 18 are arranged at equal angular intervals on the same circumference (C1) with the measurement reference axis A1 as the center at different axial positions of the measurement reference axis A1. Hereinafter, each sensor head 18 at the height position of the first measurement section CS1 is referred to as “first sensor head 18”, and each sensor head 18 at the height position of the second measurement section CS2 is referred to as “second sensor head 18”. The sensor heads 18 at the height position of the Nth measurement cross section CSN are referred to as “Nth sensor heads 18”.

  As in the fourth embodiment, the position and orientation of each sensor head 18 are adjusted so that the direction of the optical axis OA of the emitted measurement light L is parallel to the aforementioned direction D. Thereby, the measurement light L individually emitted from each sensor head 18 is within the outer peripheral surface of the workpiece W facing each of the sensor heads 18 (on the outer periphery of the first measurement cross section CS1 to the Nth measurement cross section CSN). After entering the measurement point P2 and being reflected toward the original sensor head 18 at each measurement point P2, the original sensor head 18 individually receives light.

  The displacement meter body 20 of the fifth embodiment performs detection of the measurement light L for each sensor head 18 and distance detection for each sensor head 18. As a result, the displacement meter main body 20 is located within the outer peripheral surface of the workpiece W facing each of the sensor heads 18 (for the first measurement cross section CS1 to the Nth measurement cross section CSN) for each different axial position of the measurement reference axis A1. The distance to the measurement point P2 on the outer periphery can be detected. The displacement meter body 20 includes a distance detection signal for each first sensor head 18 (hereinafter referred to as a first distance detection signal), a distance detection signal for each second sensor head 18 (hereinafter referred to as a second distance detection signal),. A distance detection signal for each N sensor head 18 (hereinafter referred to as an Nth distance detection signal) is output to the computer 14.

  Each distance detection signal input to the computer 14 of the fifth embodiment is input to the analysis unit 29 via the measurement control unit 28 (see FIG. 5). Further, the storage unit 26 of the fifth embodiment stores position information 32 of the first sensor head 18 to the Nth sensor head 18.

  The analysis unit 29 of the fifth embodiment uses the straightness of the workpiece W and the cylinder as the shape of the workpiece W based on each distance detection signal input from the displacement meter body 20 and the position information 32 acquired from the storage unit 26. Find the degree.

First, the analysis unit 29 uses the above [Expression 2] and [Expression 3] based on the first distance detection signal to the Nth distance detection signal and the position information 32 to calculate the center of the first measurement cross section CS1. The coordinates V1 (x ₀₁ , y ₀₁ ), the center coordinates V2 (x ₀₂ , y ₀₂ ) of the second measurement section CS2,..., The center coordinates VN (x _0N , y _0N ) of the Nth measurement section CSN are obtained.

Next, the analysis unit 29 uses the following [Equation 8] equations based on the obtained center coordinates V1 (x ₀₁ , y ₀₁ ) to center coordinates VN (x _0N , y _0N ) for each measurement section. The radius R _0i of each measurement cross section with the center coordinate as the center is obtained.

Then, the analysis unit 29 obtains the difference between the maximum value and the minimum value of the radius R _0i of each measurement cross section obtained by the above [Equation 8] as the straightness of the workpiece W. Further, the analysis unit 29 obtains the diameter (D _0i , i = 1, 2,... N) of each measurement cross section based on the radius R _0i of each measurement cross section, and calculates the maximum value and the minimum value of the diameter of each measurement cross section. (Dmax−Dmin) is obtained as the cylindricity of the workpiece W. Thereby, the straightness and cylindricity of the workpiece W can be measured as the shape of the workpiece W.

  Thus, one-time shape measurement of the workpiece W is completed. In the same way as in the first embodiment, the measurement control unit 28 (displacement meter body 20) and the analysis unit 29 are repeatedly operated by the repetition control unit 30 a plurality of times, so that the average shape of the workpiece W can be obtained multiple times. The average value of straightness and the average value of cylindricity are obtained.

  The subsequent processing is basically the same as that in each of the above embodiments, and a specific description thereof will be omitted.

  As described above, in the shape measuring apparatus 10 of the fifth embodiment, from each sensor head 18 to the measurement point P2 in the outer peripheral surface of the workpiece W facing each other for each different axial position of the measurement reference axis A1. Distances can be detected in a batch without contact. Thereby, the shape (straightness and cylindricity) of the workpiece W can be measured without rotating the workpiece W relative to the sensor head 18. As a result, the same effect as the first embodiment can be obtained.

  As in the modified example of the fourth embodiment shown in FIG. 19, the eight channels arranged on the same circumference (C1) with the same arrangement pattern as the reference position P1 around the measurement reference axis A1. The distance may be detected for each axial position while the sensor head 18 is sequentially moved by the moving unit 40 to different axial positions of the measurement reference axis A1. Thereby, while the number of arrangement | positioning of the sensor head 18 can be reduced, the axial direction position and number which perform distance detection can be adjusted arbitrarily.

[Others]
You may combine the structure of each said embodiment suitably. Moreover, in the said 4th Embodiment and 5th Embodiment, distance detection to each measurement point P2 of the internal peripheral surface of the workpiece | work W is performed, or each measurement point P2 of both the outer peripheral surface and internal peripheral surface of the workpiece | work W is detected. The various shapes of the workpiece W may be measured by performing distance detection.

  In each of the above embodiments, the measurement light L individually received by each sensor head 18 is detected (photoelectric conversion) by the displacement meter body 20, but the measurement light L may be detected by each sensor head 18. Further, in the displacement meter body 20, instead of detecting the distance for each sensor head 18 based on the detection result of the measurement light L for each sensor head 18, the distance is detected by the computer 14, or instead of each sensor head 18. A known rangefinder (displacement meter) may be provided.

  The non-contact displacement meter 13 of each of the above embodiments detects the distance for each sensor head 18 using the measurement light L, but various non-contact type sensors using various signals (such as sound waves) other than the measurement light L. You may detect distance by a distance detection part. Further, instead of the non-contact type distance detecting unit, for example, a contact type distance detecting unit that performs distance detection with a probe provided in a known contact type three-dimensional measuring machine or roundness measuring machine or the like is used. May be.

  In each of the above embodiments, the sensor heads 18 (reference positions P1) are arranged on the same circumference with the measurement reference axis A1 as the center. The position is not particularly limited. In addition, in order to measure the shape of the workpiece W with high accuracy regardless of the position, posture, and type (shape) of the workpiece W, the position (distance and angular position) of the measurement point on the circumferential surface (surface to be measured) ) Are preferably obtained at equal intervals. Therefore, as shown in the above embodiments, the sensor heads 18 are preferably arranged at equiangular intervals on the same circumference with the measurement reference axis A1 as the center.

  In each of the above embodiments, the case where the shape of the cylindrical workpiece W is measured has been described as an example. However, the columnar workpiece W and a workpiece partially including a peripheral surface (such as an outer peripheral surface or an inner peripheral surface). The present invention can also be applied when measuring the shape of W. The present invention can also be applied to measuring the shape of various shapes of workpieces W having various shapes of measured surfaces.

  In each of the above embodiments, as the shape of the workpiece W, the radius R (diameter), the roundness, the inclination angle φ, the straightness, and the cylindricity are described as examples, but other shapes (including dimensions) are described. The present invention can also be applied to the measurement.

  DESCRIPTION OF SYMBOLS 10 ... Shape measuring apparatus, 12a ... Reference plane, 13 ... Non-contact displacement meter, 14 ... Computer, 18 ... Sensor head, 20 ... Displacement meter main body, 25 ... Control part, 29 ... Analysis part, 30 ... Repeat control part, 32 ... position information, 35 ... reflector

Claims (13)

A reference plane on which the workpiece is placed;
For every three or more reference positions set on the same circumference centered on the measurement reference axis perpendicular to the reference plane, from the reference position to the measurement point in the surface to be measured of the workpiece facing the reference position A distance detector for detecting the distance;
Based on the known position information of each of the reference positions with respect to the measurement reference axis and the distance for each of the reference positions detected by the distance detection unit, an analysis unit that obtains the shape of the workpiece,
A shape measuring apparatus comprising:   The shape measuring apparatus according to claim 1, wherein the reference positions are set at equiangular intervals on the same circumference around the measurement reference axis. A repetition control unit that repeatedly operates the distance detection unit and the analysis unit a plurality of times,
The shape measuring apparatus according to claim 1, wherein the analysis unit obtains an average shape obtained by averaging the shapes of the workpieces obtained a plurality of times. For each of the reference positions, a measurement unit that makes a signal incident on the measurement point facing the reference position from the reference position and individually detects the signal reflected at each measurement point,
The shape measurement apparatus according to claim 1, wherein the distance detection unit detects the distance for each reference position based on a detection result of the signal for each measurement point by the measurement unit. The signal is measurement light;
The direction of the optical axis of the measurement light incident on the measurement point from the reference position is a direction perpendicular to the measurement reference axis in a plane including the reference position and the measurement reference axis. Shape measuring device.   The said reference position is set to the outer side of the said outer peripheral surface when the said workpiece | work is cylindrical shape or column shape, and the said to-be-measured surface is an outer peripheral surface of the said workpiece | work. The shape measuring apparatus described.   The said reference position is set to the inner side of the said internal peripheral surface, when the said workpiece | work is cylindrical and the said to-be-measured surface is an internal peripheral surface of the said workpiece | work. Shape measuring device. When the workpiece is cylindrical and the measured surface is an inner peripheral surface of the workpiece,
The reference position is set to three or more on the same circumference inside the inner peripheral surface,
The measuring unit is
A plurality of reflectors individually provided for each of the reference positions;
A plurality of optical units arranged at intervals in a direction perpendicular to the reference plane, wherein the plurality of optical units are individually arranged at positions on the same circumference and facing the individual reflectors. And comprising
For each of the optical units, emitting the measurement light to the reflector facing the optical unit and detecting the measurement light incident from the reflector facing the optical unit,
For each reflector, the measurement light incident from the optical unit facing the reflector is reflected and incident on the measurement point facing the reflector, and the measurement light reflected at the measurement point is reflected. Reflected toward the optical unit facing the reflector,
The distance detection unit detects the distance for each reference position based on a known size of the interval between the reference position and the optical unit and a detection result of the measurement light for each optical unit. Item 6. The shape measuring apparatus according to Item 5. When the workpiece has a peripheral surface, and the measured surface is the peripheral surface,
The said analysis part calculates | requires the radius of the said surrounding surface, and the roundness of the said surrounding surface as a shape of the said workpiece | work based on the said positional information and the said distance for every said reference position. The shape measuring device described in 1. The reference position is set to 3 or more on a plurality of the same circumferences with different axial positions of the measurement reference axis,
The shape measuring apparatus according to claim 1, wherein the distance detection unit detects the distance for each reference position. When the workpiece is cylindrical or columnar and the surface to be measured is at least one of the outer circumferential surface and the inner circumferential surface of the workpiece,
The analysis unit obtains a center position of the circumferential surface for each axial position based on the position information and the distance for each reference position detected by the distance detection unit, and determines the center position for each axial position. The shape measuring apparatus according to claim 10, wherein an inclination angle of the workpiece with respect to the measurement reference axis is obtained as a shape of the workpiece based on a center position. When the workpiece is cylindrical or columnar and the surface to be measured is at least one of the outer circumferential surface and the inner circumferential surface of the workpiece,
The analysis unit obtains a radius of the peripheral surface for each axial position based on the position information and the distance for each reference position detected by the distance detection unit, and the radius for each axial position. The shape measuring apparatus according to claim 10, wherein straightness and cylindricity are obtained as the shape of the workpiece based on the above. In the shape measuring method for measuring the shape of the workpiece placed on the reference plane,
For every three or more reference positions set on the same circumference centered on the measurement reference axis perpendicular to the reference plane, from the reference position to the measurement point in the surface to be measured of the workpiece facing the reference position A distance detection step for detecting the distance;
An analysis step for determining the shape of the workpiece based on known position information of each of the reference positions with respect to the measurement reference axis and the distance for each of the reference positions detected in the distance detection step;
A shape measuring method comprising:

Images