JP5946259B2 - Measuring device, measuring method and touch probe - Google Patents

Description

  The present invention relates to a measuring apparatus and a measuring method, and more particularly, to a device for measuring an object to be measured using a touch probe.

  The present invention also relates to a touch probe, and more particularly to a device for measuring a concave surface of an object to be measured.

  The present invention also relates to a calibration gauge, and more particularly, to a calibration gauge used before measuring an object to be measured using a touch probe.

  Conventionally, as shown in FIG. 11, the shape of an object to be measured (for example, a workpiece) W is measured using a touch probe 403 in which a stylus 401 extends linearly.

  However, in the touch probe 403 shown in FIG. 11, when the touch probe 403 is moved so as to measure the shape of the concave portion W1 of the workpiece W, the stylus 401 before the probe 405 of the touch probe 403 contacts the concave portion W1 of the workpiece W. May contact the convex part W2 existing around the concave part W1, and the concave part W1 of the workpiece W may not be measured.

  In order to solve such a problem, as shown in FIG. 12, it is known that the tip portion of the stylus is branched in a “ten” shape. A measuring element 405 is arranged at the tip of each tip side portion 407 of these styluses.

  In addition, as a document related to the above-described conventional technique, for example, see Patent Document 1 can be cited.

  Conventionally, as shown in FIGS. 11 and 12, the shape of an object to be measured (for example, a workpiece) W is measured using a touch probe.

  11 and FIG. 12, reference numeral W1 indicates a concave portion of the workpiece W, reference numeral W2 indicates a convex portion of the workpiece W, reference numeral 401 indicates a stylus, and reference numeral 403 indicates The reference numeral 405 (405A, 405B) indicates a measuring element, and the reference numeral 407 (407A, 407B) indicates a tip side portion of the stylus 401.

  Further, before measuring the workpiece W, in order to improve the measurement accuracy of the workpiece W, calibration is performed using a calibration gauge having a hemispherical portion (a concave portion or a convex portion).

  In addition, as a document related to the above-described conventional technique, for example, see Patent Document 1 can be cited.

JP 2006-349411 A

  However, when the touch probe 403 shown in FIG. 12 is used, the tip side portion (one tip side portion of the four tip side portions) 407A of the stylus 401 faces or a slight crossing angle with this direction. There is a problem in that the concave portion W1 of the workpiece W can be measured only in the direction intersecting with.

  That is, in the touch probe 403 shown in FIG. 12, the four tip side portions 407 intersect at an angle of 90 ° to form a “ten” shape.

  Then, one tip side portion 407A (measuring element 405A) of the four tip side portions 407 is moved in the direction of arrow A12 shown in FIG. 12 (the extending direction of the axis of the tip side portion 407A), and the workpiece is moved. The measurement of the concave portion is performed. At this time, the direction of the arrow A12 and the direction of the normal vector of the measurement location of the recess W1 of the workpiece W (location where the measuring element 405A abuts) coincide with each other.

  By the way, when the direction of the normal vector is the direction indicated by the arrow A12a in FIG. 12 (the direction intersecting the arrow A12 at an angle of about 45 °), the touch probe 403 (measurement is performed in the direction of the arrow A12a). 405A, the tip side portion 407A) needs to be moved, and by this movement, the tip side portion 407B or tip side portion 407C (measurement piece 405B or measurement piece 405C) adjacent to the tip side portion 407A is moved to the workpiece W. A situation occurs in which the concave portion W1 of the workpiece W cannot be measured due to contact with the convex portion W2 around the concave portion W1 of the workpiece.

  The present invention has been made in view of the above problems, and a measuring apparatus (measuring apparatus for measuring object) and a measuring method (measuring object to be measured) that can avoid the occurrence of a situation where the concave portion of the object to be measured cannot be measured as much as possible. The object is to provide a measuring method).

  Further, when the touch probe 403 shown in FIG. 12 is used, the tip side portion (one tip side portion of the four tip side portions) 407A of the stylus 401 is facing or a slight crossing angle with this direction. There is a problem in that the concave portion W1 of the workpiece W can be measured only in the direction intersecting with.

  That is, in the touch probe 403 shown in FIG. 12, the four tip side portions 407 intersect at an angle of 90 ° to form a “ten” shape.

  Then, one tip side portion 407A (measuring element 405A) of the four tip side portions 407 is moved in the direction of arrow A12 shown in FIG. 12 (the extending direction of the axis of the tip side portion 407A), and the workpiece is moved. The measurement of the concave portion is performed.

  At this time, the direction of the arrow A12 and the direction of the normal vector of the measurement location of the recess W1 of the workpiece W (location where the measuring element 405A abuts) coincide with each other. By the way, when the direction of the normal vector is the direction indicated by the arrow A12a in FIG. 12 (the direction intersecting the arrow A12 at an angle of about 45 °), the touch probe 403 (measurement is performed in the direction of the arrow A12a). 405A, the tip side portion 407A) needs to be moved, and by this movement, the tip side portion 407B or tip side portion 407C (measurement piece 405B or measurement piece 405C) adjacent to the tip side portion 407A is moved to the workpiece W. A situation occurs in which the concave portion W1 of the workpiece W cannot be measured due to contact with the convex portion W2 around the concave portion W1 of the workpiece.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a touch probe that can avoid the occurrence of a situation in which the concave portion of the object to be measured cannot be measured as much as possible.

The invention according to claim 1 comprises a measured object installation body on which the measured object is installed, and a spindle that is rotatably provided in the casing about a predetermined axis. A head in which the casing can be moved and positioned relative to the object to be measured, a housing integrally installed on the spindle, a stylus main body protruding from the housing, and the stylus A stylus having a spherical probe provided at the tip of the main body, and when the housing is installed on the spindle, the stylus main body is viewed from a direction orthogonal to the central axis of the housing. when viewed, semicircular Joma other quarter circle shape is also properly has a touch probe which is an elongated rod-shaped with 2/3 yen shape, the housing is installed in the spindle In a state where the placed touch probe is index-positioned using the spindle, the housing is moved relative to the measured object installation body, and the installed measurement object installed on the measured object installation body A measuring object measuring apparatus configured to measure the shape of the installed object to be measured by bringing the measuring element into contact with the object.

According to a second aspect of the present invention, there is provided a calibration gauge installation body according to the first aspect, wherein a calibration gauge is installed and the calibration gauge installation body is movable and positioned relative to the housing. And configured to calibrate using the installed calibration gauge installed on the calibration gauge installation body before measuring the shape of the installed object to be measured with the installed touch probe. cage, the calibration gauge is a predetermined first plane draws one of the virtual curve of a predetermined shape, when moved by a predetermined distance in a direction perpendicular to the virtual curve to said predetermined one plane, A calibration surface is provided with a two-dimensional curved surface that is a curved surface represented by the locus of the virtual curve, and the calibration , Said installation already touch probe Indekkkusu positioning a measuring device of the object that is configured to the calibration.

According to a third aspect of the present invention, in the measurement object measuring apparatus according to the first aspect, a calibration gauge is installed, and the calibration gauge is installed so as to be movable and positionable relative to the housing of the head. And having a body configured to calibrate using the installed calibration gauge installed on the calibration gauge installation body before measuring the shape of the installed object to be measured with the installed touch probe. are, stylus main body of the touch probe is located is the measuring element before the end, in the installation already touch probe, the central axis of the rotation center axis of the spindle housing coincides with each other and, the calibration gauge, draws one of the virtual curve of a predetermined shape in a predetermined one plane, the virtual track When a predetermined distance is moved in a direction orthogonal to the predetermined plane, a two-dimensional curved surface that is a curved surface represented by the locus of the virtual curve is provided as a calibration curved surface, A predetermined one direction in the measured object is an X-axis direction, a predetermined one direction orthogonal to the X-axis direction is a Y-axis direction, and a predetermined one orthogonal to the X-axis direction and the Y-axis direction When the direction is the Z-axis direction, the installed calibration gauge has the moving direction of the virtual curve on the calibration curved surface in the X-axis direction, and the calibration is performed on the installed object to be measured. A predetermined point to be measured is determined, and components in the three-axis directions of the X-axis direction, the Y-axis direction, and the Z-axis direction in the normal vector at the predetermined point to be measured are obtained. A component in the Y-axis direction and a component in the Z-axis direction of the normal vector, and a component in the Y-axis direction of the normal vector at the predetermined measurement point and a component in the Z-axis direction. A predetermined temporary measurement point that is equal to the component is determined, the spindle is rotated by an amount corresponding to the component in the X-axis direction of the normal vector at the predetermined measured point, and the Y-axis direction of the normal vector The touch probe is positioned by positioning the probe at a predetermined distance from the temporary measurement point in the direction of the temporary normal vector formed by the component and the component in the Z-axis direction. And the measuring element in the direction of the provisional normal vector and in the direction approaching the installed calibration gauge, with respect to the installed calibration gauge. The measurement object is configured to move relative to each other and bring the measuring element into contact with the temporary measurement point.

According to a fourth aspect of the present invention, in the method for measuring an object to be measured, a stylus comprising a housing, a stylus main body protruding from the housing, and a spherical measuring element provided at the tip of the stylus main body. with the door, touch the stylus body portion, when viewed from a direction perpendicular to the center axis of the housing, semicircular Joma others also are properly quarter circle shape which is in an elongated rod-shaped with 2/3 £ shaped An index positioning stage in which the probe is rotated and index-positioned about the central axis of the housing, and the touch probe is index-positioned in the index positioning stage, and the housing is moved to the device under test. A measuring stage for measuring the shape of the object to be measured with the touch probe. It is a method for measuring the object to be measured.

According to a fifth aspect of the present invention, in the method for measuring an object to be measured according to the fourth aspect, a calibration step of performing calibration using a calibration gauge before indexing the housing in the index positioning step is performed. a, the calibration gauge is a predetermined first plane draws one of the virtual curve of a predetermined shape, when the virtual curve has moved a predetermined distance in a direction perpendicular to said one predetermined plane the 2-dimensional curved surface is a curved surface represented by the locus of the virtual curve, provided with a curved calibration, the calibration step, around the central axis of the housing by rotating the housing the touch probe In the measurement method of the object to be measured, which is the stage where the index is positioned and the calibration is performed. That.

According to a sixth aspect of the present invention, in the method for measuring an object to be measured according to the fourth aspect, a calibration step of performing calibration using a calibration gauge before indexing the housing in the index positioning step is performed. a, the calibration gauge is a predetermined first plane draws one of the virtual curve of a predetermined shape, when the virtual curve has moved a predetermined distance in a direction perpendicular to said one predetermined plane the 2-dimensional curved surface is a curved surface represented by the locus of the virtual curve, provided with a curved calibration, the stylus main body of the touch probe is located is the measuring element before the end, the touch the probe contact with the central axis of the housing and the axis of rotation center of the spindle of the measuring device of the object to be measured coincides with each other A predetermined direction in the object to be measured is an X-axis direction, a predetermined direction orthogonal to the X-axis direction is a Y-axis direction, and a predetermined direction orthogonal to the X-axis direction and the Y-axis direction is set. Assuming that one direction is the Z-axis direction, the calibration gauge is such that the moving direction of the virtual curve on the calibration curved surface is the X-axis direction. A point to be measured is determined, and components in the three-axis directions of the normal vector at the predetermined point to be measured, ie, the X-axis direction, the Y-axis direction, and the Z-axis direction, are calculated. The component in the Y-axis direction and the component in the Z-axis direction of the normal vector are equal to the component in the Y-axis direction and the component in the Z-axis direction of the normal vector at the predetermined measurement point. And the spindle is rotated by an amount corresponding to the X-axis direction component of the normal vector at the predetermined measured point, and the Y-axis component and the Z-axis direction of the normal vector Positioning the touch probe in a direction away from the temporary measurement point by a predetermined distance in the direction of the temporary normal vector formed by the component of Relative to the calibration gauge installed in the calibration gauge installation body in the direction of the temporary normal vector and in the direction approaching the calibration gauge installed in the calibration gauge installation body. It is a measuring method of the to-be-measured object which is the step which moves to (2) and makes the said measurement element contact | abut to the said temporary measurement point, and performs the said calibration.

The invention according to claim 7 includes a housing, a stylus main body protruding from the housing, and a spherical measuring element provided at a tip of the stylus main body, and the stylus main body is when viewed from a direction perpendicular to the center axis of the housing, the semicircular Joma others also are properly quarter circle shape is a touch probe which is an elongated rod-shaped with 2/3 yen shape.

The invention according to claim 8, in the touch probe according to claim 7, before kissing stylus body portion is positioned is the measuring element before the end, the rotation center of the spindle of the measuring device of the object to be measured In this touch probe, the shaft and the central axis of the housing coincide with each other.

  According to the present invention, it is possible to avoid as much as possible the occurrence of a situation where the concave portion of the object to be measured cannot be measured.

  In addition, according to the present invention, it is possible to provide a calibration gauge that is accurate and easy to manufacture.

It is a figure which shows schematic structure of the measuring apparatus which concerns on embodiment of this invention, (a) is a front view, (b) is a side view (IB arrow view in (a)). It is explanatory drawing when measuring the free-form surface of a to-be-measured object. It is a figure explaining the calibration using a calibration gauge, (b) is the IIIB arrow directional view in (a). It is a figure which shows the structure of the system which implements the calibration method of a calibration cage and the measuring apparatus using the calibration cage. It is a perspective view of the calibration gauge which concerns on a modification. (A) is a front view of the calibration gauge which concerns on a modification, (b) is a VIB arrow directional view in (a). It is a figure explaining the calibration using the calibration gauge which concerns on a modification, (b) is a figure which shows the VIIB-VIIB cross section in (a). It is a figure explaining the calibration using the calibration gauge which concerns on a modification. It is a figure which shows the IX-IX cross section in Fig.3 (a), and is a figure corresponding to the calibration shown in FIG. It is a figure which shows the touch probe which concerns on a modification. It is a figure which shows the conventional aspect in the case of measuring a to-be-measured object using a touch probe. It is a figure which shows the conventional aspect in the case of measuring a to-be-measured object using a touch probe.

  A measuring apparatus (measuring object measuring apparatus) 201 according to an embodiment of the present invention is used, for example, as a machine tool (for example, a CNC triaxial machine) such as a portal machine tool that cuts a workpiece W with a tool. And the tool (tool) is configured to be replaceable. Then, by attaching a touch probe instead of a tool, it is possible to measure an object to be measured (for example, a workpiece processed by the tool itself). The measuring device 201 may be a dedicated machine that exclusively measures the object to be measured.

  Hereinafter, for convenience of explanation, one horizontal direction is defined as an X-axis direction, another horizontal direction that is orthogonal to the X-axis direction is defined as a Y-axis direction, and the X-axis direction and the Y-axis direction. A direction (vertical direction; vertical direction) orthogonal to the Z axis direction.

  As shown in FIG. 1, the measuring apparatus 201 includes a bed 203. A pair of columns 205 extends upward from both sides of the bed 203 (intermediate portion in the X-axis direction and both end portions in the Y-axis direction). The pair of columns 205 are integrally provided on the bed 203.

  A beam 207 is provided at the upper ends of the pair of columns 205. The beam 207 is provided integrally with the pair of columns 205, and the pair of columns 205 and the beam 207 form a gate-shaped portion.

  The beam 207 is provided with a Y-axis table 209. The Y-axis table 209 is supported by the beam 207 via a linear guide bearing (not shown), and under the control of the computer numerical controller (CNC) 20 by an actuator such as the Y-axis servo motor 32 shown in FIG. It can be moved and positioned with respect to the bed 203 in the Y-axis direction.

  The Y-axis table 209 is provided with a Z-axis table (not shown). The Z-axis table is supported by the Y-axis table 209 via a linear guide bearing (not shown), and is controlled by the CNC 20 with respect to the Y-axis table 209 by an actuator such as the Z-axis servo motor 33 shown in FIG. It can be moved and positioned in the Z-axis direction.

  A head 213 is provided on the Z-axis table. The head 213 includes a housing 215 and a spindle (rotating body) 217. The housing 215 is integrally provided on the Z-axis table.

  The spindle 217 (main shaft 51) is provided inside the housing 215. Further, the spindle 217 rotates with respect to the housing 215 around the central axis C axis. The C axis is an axis extending in the Z axis direction through the center of the head 213 (spindle 217). The spindle 217 is rotationally driven and rotationally positioned by an actuator such as a servo motor 37 shown in FIG. 4 under the control of the CNC 20.

  The servo motor 37 is a so-called built-in type (a type in which the stator is provided in the housing 215 and the rotor is integrated with the spindle 217). The repeated rotational positioning accuracy of the spindle 217 is 1 / It is about 10000 ° (0.36 ″).

  An X-axis table 219 is provided on the upper surface of the bed 203. The X-axis table 219 is mounted on and supported by the bed 203 via a linear guide bearing (not shown). The X-axis table 219 is controlled by the CNC 20 by an actuator such as the X-axis servo motor 31 shown in FIG. Therefore, it can be moved and positioned in the X-axis direction.

  Thereby, the housing 215 of the head 213 can be moved and positioned relative to the X-axis table 219 in the X-axis direction, the Y-axis direction, and the Z-axis direction.

  The head 213 is positioned away from the X-axis table 219 and above the X-axis table 219, and a workpiece (object to be measured) W is integrally formed on the X-axis table 219 by a fixture (not shown). It is to be installed.

  The lower end side portion of the spindle 217 protrudes from the lower end of the housing 215 of the head 213, and a tool is integrally installed at the lower end of the spindle 217. Then, with the workpiece W installed on the X-axis table 219, the spindle 217 is rotated under the control of the CNC 20, and the head 213 (housing 215) is moved relative to the X-axis table 219. The workpiece W is cut by appropriately moving. The surface formed by processing is, for example, a three-dimensional curved surface.

  Further, after the cutting process is completed, the tool is replaced with the touch probe 60, and the spindle 217 is rotated and positioned under the control of the CNC 20, and the head 213 (housing 215) is moved relative to the X-axis table 219. By appropriately moving, the shape of the workpiece W is measured.

  When performing the above-described processing and measurement, the workpiece W may be rotatable and positionable around the A axis (a predetermined axis parallel to the X axis) and the B axis (a predetermined axis parallel to the Y axis). .

  Next, the control system of the measuring apparatus 201 will be described in detail.

  As shown in FIG. 4, the control system of the measuring apparatus 201 includes a CAD / CAM machine 10 and a computer numerical controller (CNC) 20.

  The CAD / CAM machine 10 and the CNC 20 are connected so as to be capable of bidirectional communication by communication means 40 such as serial communication by RS2324 or the like, LAN, or the Internet. Note that the CAD / CAM machine 10 and the CNC 20 may exchange data offline.

  The CAD / CAM machine 10 is a dedicated computer or a general-purpose personal computer. The CAD / CAM machine 10 includes a man-machine interface, and by executing a computer program, a CAD / CAM data creation unit 11, a measurement program creation unit 12, a normal vector data extraction unit 13, and a calibration The execution program creation unit 14 is embodied.

  The CAD / CAM data creation unit 11 creates a numerical control machining program from the shape data, curved surface data (surface data), shape data, and curved surface data of the object to be measured (machined portion).

  The measurement program creation unit 12 creates a shape accuracy measurement program that performs shape accuracy measurement of the object to be measured. The shape accuracy measurement program uses the arbitrary coordinate position of the free-form surface (surface) of the object to be measured as the measurement point, and based on the data indicating the normal vector of the surface of the object at the measurement point, the normal vector direction from the measurement point Set the position offset by a predetermined amount, and move the touch probe so that the probe probe center is located at the offset position, and move the touch probe in the direction of the normal vector of the measurement point from the offset position. A computer language in which the CNC 20 can execute a procedure for bringing a probe probe close to and in contact with the surface of the object to be measured, and obtaining a movement amount from the offset position to the contact position with the surface of the object to be measured or a quantity value equivalent thereto. It is described.

  The shape accuracy measurement program sequentially designates a plurality of measurement points S1, S2, S3... On the surface of the object to be measured by means of three orthogonal coordinate values (Xs, Ys, Zs), and each measurement point S1. , S2, S3... Describe the normal vector of the surface of the object to be measured. That is, the shape accuracy measurement program designates the measurement points S1, S2, S3... On the surface of the object to be measured, and the coordinate values (Xs, Ys, Zs) of the three orthogonal axes, and the designated measurement points S1, S2. , S3 has normal vector data of the surface of the object to be measured at each measurement point S1, S2, S3.

  The normal vector of the surface of the object to be measured at the measurement points S1, S2, S3... Is defined by the vectors i, j, and k in the X-axis, Y-axis, and Z-axis directions from the curved surface creation formula, The tangential plane inclination angle (for example, the intersection angle between the tangential plane and the XY plane) B and the horizontal angle (for example, the intersection line that is the intersection of the tangential plane and the XY plane) at the measurement points S1, S2, S3. There is a way to define it by the angle of intersection (C) with the X axis. Here, by using the latter, the command format is expressed as follows. The command format is represented by “G *** _ X *** _ Y *** _ Z *** _ B *** _ C ***”.

  When the object to be measured is a workpiece having a free-form surface shape machined by a CNC triaxial machine like a mold, the data indicating the normal vector (inclination angle B and horizontal angle C) is free. For machining of a curved surface shape, it can be obtained from CAD / CAM curved surface data for creating a numerical control machining program used in a CNC triaxial machine.

  Thus, the measurement program creation unit 12 obtains data indicating the normal vector (inclination angle B and horizontal angle C) from the CAD / CAM curved surface data created by the CAD / CAM data creation unit 11.

  Here, the shape accuracy measurement of the object to be measured by the shape accuracy measurement program will be described with reference to FIG.

  A touch probe 60 having a spherical or hemispherical measuring element 61 is used as a three-dimensional shape measuring instrument, and the measured point (measurement point) S is located in the normal vector direction Ns based on the acquired normal vector data. The offset position Psof that has been quantitatively offset is set, and the touch probe 60 is moved so that the center Tc of the measuring element 61 is positioned at the offset position Psof (measurement object W installed on the X-axis table 219 of the measuring device 201). On the other hand, the touch probe 60 installed on the head 213 (spindle 217) of the measuring apparatus 201 is moved), and the touch probe 60 is moved from the offset position Psof to the normal vector direction Ns of the measurement point S. The contact 61 is brought into close contact with the surface of the workpiece (for example, workpiece) W. The amount of movement from the offset position Psof to the position of contact with the surface of the workpiece W or a quantity value equivalent thereto is obtained.

  Since the design coordinate values (Xs, Ys, Zs) of the measurement point S and the coordinate values (Xsof, Ysof, Zsof) of the offset position Psof are known values, the offset position Psof and the measurement point S when the error is zero The distance in the normal vector direction, that is, the quantity value in the thickness direction is a known value, and the difference value between this known value (measurement reference value) and the measured value is directly the thickness of the measurement point S on the free-form surface f. The shape accuracy in the thickness direction is expressed as a quantity.

  By performing a comparison operation to determine whether or not the difference value is within a preset error tolerance value, OK or NG is output for each measurement point S, or the difference value is divided stepwise to obtain an error level. (VALUE) 0 to N can be output.

  When the workpiece W is a workpiece having a free-form surface shape machined by a CNC triaxial machine (for example, a measuring device 201 that is also used as a machine tool), as shown in FIG. The probe 60 is attached to the main spindle 51 (spindle 217) of the CNC triaxial machine, and the free-form surface shape can be measured in the automatic mode on the CNC triaxial machine using the CNC 20 of the CNC triaxial machine.

  As a result, the CNC triaxial machine can function as a surface measurement CMM (Coordinated Measuring Machine) having a BC axis automatic offset function (normal vector automatic offset function).

  This shape accuracy measurement can be equally performed even with a servo-controlled three-dimensional measurement dedicated machine having an orthogonal three-axis axis control system such as a surface straight measurement CMM provided with a BC axis automatic offset function.

  The normal vector data extraction unit 13 of the CAD / CAM machine 10 uses the shape accuracy measurement program created by the measurement program creation unit 12 to measure the surface of the measurement object at each measurement point (measurement point) S1, S2, S3. Extract normal vector data.

  When the normal vector at the measurement point S is defined by the curved surface inclination angle B and the horizontal angle C, the normal vector data extraction unit 13 determines each measurement point S1, S2, S3,. Each measurement point S1, S2, S3... (B *** _ C ***) is extracted from each command format (G *** _ X *** _ Y ** _ Z ** _ B *** _ C **).

  Note that only one (B ** _ C **) is valid, and the same (B ** _ C **) is not duplicated.

  If the normal vector of the surface of the object to be measured at the measurement points S1, S2, S3,... Is defined by vectors i, j, k in the X axis, Y axis, and Z axis directions, The line vector data extraction unit 13 extracts vectors i, j, and k in the X-axis, Y-axis, and Z-axis directions.

  The calibration execution program creation unit 14 creates a calibration execution program. For each normal vector data (for example, B ** _ C **) extracted by the normal vector data extraction unit 13, the calibration execution program calibrates the measuring apparatus only with respect to the normal vector direction indicated by the normal vector data. Describes the command to execute the action.

  As shown in FIG. 4, the calibration execution program has the center of the probe 61 of the touch probe 60 with respect to a calibration gauge (calibration gauge) 100 installed at a predetermined position (predetermined coordinate position). With respect to the concave spherical surface 101 of the calibration gauge 100, the extracted normal vector data (for example, B ** _ C **) is positioned at an offset position Pcof offset by a predetermined amount in the normal vector direction Nc. The touch probe 60 is moved, and the touch probe 60 is moved in the normal vector direction Nc from the offset position Pcof by three-axis synchronous control (three-axis simultaneous control) of the X, Y, and Z axes. 60 measuring elements 61 are brought into close contact with the concave spherical surface 101 of the calibration gauge 100 and turned off. The Tsu Miyako position Pcof than obtaining the quantity value of the movement amount or its equivalent to the contact position between the concave spherical surface 101 of the calibration gauge 100 procedures are those described in available computer language execution CNC20.

  The CNC 20 is capable of three-axis synchronous control of the X axis, the Y axis, and the Z axis. The input / output unit 21, the program execution unit 22, the X axis control unit 23, the Y axis control unit 24, and the Z axis And an axis control unit 25. Further, the CNC 20 includes a C-axis control unit 27 so that C-axis control is possible (the spindle 217 can be freely rotated and positioned). The C axis may or may not be capable of 4-axis synchronous control for all of the X, Y, and Z axes.

  The program execution unit 22 executes a numerical control machining program, a shape accuracy measurement program, and a calibration execution program by user designation. Regardless of which program is executed, the program execution unit 22 generates an X-axis command, a Y-axis command, and a Z-axis command by the X-axis control unit 23, the Y-axis control unit 24, and the Z-axis control unit 25. The axis command is output to the X-axis servo motor 31, the Y-axis servo motor 32, and the Z-axis servo motor 33. When executing the shape accuracy measurement program and the calibration execution program, in addition to each axis command, a C axis command is generated by the C axis control unit 27, and the generated axis command is used as a C axis servo motor. Output to 37.

Position detectors 34, 35, 36, and 38 such as rotary encoders are connected to the X-axis servo motor 31, the Y-axis servo motor 32, the Z-axis servo motor 33, and the C-axis servo motor 37, respectively. The position detectors 34, 35, and 36 detect the motor positions of the servo motors 31 to 33 for each axis. The motor position signals of the position detectors 34, 35, 36, and 38 are input to the CNC 20 as position signals for feedback servo control, shape accuracy measurement, and calibration.

  In addition, the position signal at the time of each control can also use the output signal of a linear sensor by providing a linear sensor with respect to each axis in the X-axis, the Y-axis, and the Z-axis.

  At the time of measuring the shape accuracy and at the time of calibration, the spindle 51 of the CNC three-axis machine is moved by the X-axis servomotor 31, the Y-axis servomotor 32, and the Z-axis servomotor 33 and rotated by the C-axis servomotor 37. The touch probe 60 is attached to the (spindle 217) instead of the tool. An on / off signal indicating contact of the probe 61 of the touch probe 60 is input to the CNC 20 via the programmable logic controller (PLC) 26.

  Calibration for measuring the shape accuracy by the touch probe 60 is performed by the program execution unit 22 of the CNC 20 executing the calibration execution program.

  This calibration is performed by measuring the offset position displaced from the surface of the object to be measured at the measurement points S1, S2, S3... Specified in the normal vector direction Nc of the surface of the object to be measured and the measuring point S1, This is calibration of a measuring device that measures the surface shape accuracy by measuring the distance in the normal vector direction Nc from the surface of the object to be measured at S2, S3, and so on, at each measurement point S1, S2, S3,. Calibration is performed only for the normal vector direction Nc of the surface of the object to be measured.

  In this embodiment, calibration is performed by attaching a calibration gauge 100 having a hemispherical concave spherical surface 101 to a predetermined machine coordinate position (attached to a predetermined position on the X-axis table 219 of the measuring apparatus 201), and measuring the shape accuracy. On the same machine.

  As shown in FIG. 3, this calibration is performed, for example, with respect to the calibration gauge 100, the center of the probe 61 of the touch probe 60 is one point of the concave spherical surface 101 of the calibration gauge 100 (measurement points S1, S2, S3). The touch probe 60 is moved together with the main shaft 51 by the X-axis servo motor 31, the Y-axis servo motor 32, and the Z-axis servo motor 33 so as to be positioned at an offset position Pcof offset by a predetermined amount in the normal vector direction Nc with respect to. In addition, the spindle 217 is rotationally positioned by the C-axis servomotor 37 and the touch probe 60 is moved from the offset position Pcof in the normal vector direction Nc of the one point to move the probe 61 of the touch probe 60. Approaches the concave spherical surface 101 of the calibration gauge 100 It is tactile, to calibrate the measuring device 201 seeking the quantity value of the movement amount or its equivalent to the contact position between the concave spherical surface 101 of the calibration gauge 100 from the offset position Pcof.

  Since the shape dimension of the calibration gauge 100 is known, the distance in the normal vector direction from the offset position Pcof to any one point of the concave spherical surface 101 of the calibration gauge 100 is known, and this distance and the above-described movement amount The difference value of the measured values is taken into the CNC 20 as a calibration difference value, and the shape accuracy measurement by the CNC 20 is tuned.

  Then, as a guarantee of the calibration result, the calibration reflecting the calibration difference value is performed in the same manner, and the above calibration is repeated until the calibration difference value falls within the allowable value.

  In this calibration, calibration is performed in the direct method with the same phase as the normal vector direction of the actual measurement points S1, S2, S3... Thus, the calibration for guaranteeing a high shape accuracy measurement result is performed accurately and in a short time without unnecessarily increasing the number of calibration points.

  The calibration gauge 100 used in this embodiment is a mortar-shaped calibration gauge having a hemispherical concave spherical surface 101 as shown in FIG. The calibration gauge 100 has a cylindrical portion 102 having a height (axial length) h with the same radius as the radius of the concave spherical surface 101 concentrically with the concave spherical surface 101 on the opening end side of the concave spherical surface 101. The calibration gauge 100 has a vertical plane (for example, a plane orthogonal to the Y-axis direction) 103 around the open end of the cylindrical portion 102.

  In this calibration gauge 100, the offset position Pcof can be set to one point of the center point Gc of the concave spherical surface 101 in any normal vector direction calibration.

  As a result, the program description for setting the offset position Pcof can be simplified, and the total path length of the touch probe 60 in calibration can be made shorter than when a calibration gauge using a convex spherical surface is used. This also shortens the time required for calibration.

  Further, in the calibration gauge using the convex spherical surface, the spherical probe 61 of the touch probe 60 is not satisfactorily seated with respect to the convex spherical surface, and the phenomenon that the probe 61 slides with respect to the convex spherical surface is likely to occur. If it is 101, the probe 61 sits better with respect to the concave spherical surface 101, and the calibration accuracy of the touch probe 60 is not lowered due to slipping.

The offset position Pcof, that is, the coordinates (Xcof, Ycof, Zcof) of the center point Gc of the concave spherical surface 101 of the calibration gauge 100 is set by the CNC 20 using the touch probe 60 and automatic centering of the inner diameter portion by the G code. By executing the (orthogonal two-way approach) macro program, the cylindrical portion 102 of the calibration gauge 100 is automatically centered to obtain coordinate values (Xcof, Ycof), and the touch probe 60 is used. by the average insert height h min than values rather discount measures the Z-axis position of the orthogonal four horizontal upper surface 103, can be acquired coordinate values (Zcof).

  As a result, the use of the concave spherical calibration gauge 100 facilitates the setting of the offset position Pcof, which also reduces the time required for calibration.

  The calibration gauge 100 has a hemispherical convex spherical surface 104 in addition to the hemispherical concave spherical surface 101. In the calibration gauge 100, the concave spherical surface 101 and the convex spherical surface 104 can be selectively used depending on whether the surface of the object to be measured at the measurement point is concave or convex.

  Here, the measuring apparatus 201 will be described in more detail.

  As shown in FIG. 1, the measuring apparatus 201 includes a measured object installation body (X-axis table) 219 and a head 213.

  An object to be measured W having a curved outer surface (free curved surface; a three-dimensional curved surface such as a spherical surface) is integrally installed on the object to be measured installation body 219.

  The head 213 includes a housing 215 and a spindle 217 that is rotatably provided on the housing 215 around a predetermined axis (C axis). The housing 215 is movable and positionable relative to the measured object installation body 219 in the X axis direction, the Y axis direction, and the Z axis direction.

  A touch probe 60 is installed at the lower end of the spindle 217. The touch probe 60 includes a housing 221 and a stylus 223 as shown in FIG.

  The stylus 223 includes an elongated rod-like stylus main body 225 and a spherical measuring element 61. The stylus main body 225 protrudes from the housing 221 in, for example, at least one of a curved shape and a bent shape. The measuring element 61 is provided integrally with the stylus main body 225 at the tip of the stylus main body 225.

  In a state where the housing 221 is installed integrally with the spindle 217, the stylus 223 extends downward from the housing 221. When the housing 221 is integrally installed on the spindle 217, at least one of the stylus main body 225 and the measuring element 61 is separated from the rotation center axis C1 of the spindle 217 (is present at an offset position). Is configured to).

  Here, the 1st aspect which concerns on the form of the touch probe 60 is illustrated (refer FIG. 2).

  The stylus main body 225 is made of an elongated cylindrical material (for example, a cylindrical material whose height is sufficiently large to about 5 to 100 times the outer diameter) at an intermediate portion (for example, the central portion) in the longitudinal direction. By bending and bending by a predetermined angle θ (for example, 90 °), a straight base end portion 227 and a straight tip end portion 229 are provided to form an “L” shape. The measuring element 61 is provided at the distal end of the distal end side portion 229. The center of the measuring element 61 is located on an extension line of the central axis CH of the distal end side portion 229.

  When the touch probe 60 is installed on the spindle 217 (in the installed touch probe), the rotation center axis C of the spindle 217 and the center axis of the proximal end portion 227 of the stylus main body 225 coincide with each other (spindle 217). The central axis of the base end side portion 227 of the stylus main body 225 exists on the extension line of the rotation central axis C of the stylus).

  When the touch probe 60 is installed on the spindle 217, the center axis CH of the tip side portion 229 of the stylus main body 225 is, for example, orthogonal to the rotation center axis C of the spindle 217, and the tip side portion 229 of the stylus main body 225 is. However, it extends in a direction away from the rotation center axis C of the spindle 217 (the base end side portion 227 of the stylus main body 225).

  The first aspect is an example in which when the touch probe 60 is installed on the spindle 217, the distal end portion 229 of the stylus main body 225 and the probe 61 are separated from the rotation center axis C of the spindle 217. It is.

  The 2nd aspect which concerns on the form of the touch probe 60 is illustrated (not shown).

  The stylus body is formed by bending a long and narrow cylindrical material (for example, a cylindrical material whose height is sufficiently large to about 5 to 100 times the outer diameter) in this longitudinal direction, for example, a semicircle It is in the form of a shape. That is, the central axis of the stylus body is semicircular.

  When the touch probe is installed on the spindle, the base end of the center axis of the stylus body intersects the extension line of the spindle rotation center axis, and the tip of the center axis of the stylus body part is also an extension line of the rotation center axis of the spindle. And the center of the probe exists on the extension line of the rotation center axis of the spindle. On the other hand, the intermediate portion in the longitudinal direction of the stylus main body is separated from the rotation center axis of the spindle. Therefore, even if the spindle is rotated when the touch probe is installed on the spindle, the center position of the probe does not change and exists at a fixed position. On the other hand, when the spindle is rotated when the touch probe is installed on the spindle, the position of the intermediate portion in the longitudinal direction of the stylus main body changes, and when the spindle is rotated once, the locus of the central axis of the stylus main body becomes spherical. Become.

  The second aspect is an example in which only the stylus main body is separated from the rotation center axis of the spindle when the touch probe is installed on the spindle.

  A third aspect relating to the form of the touch probe will be listed (not shown).

  In the third aspect, the length of the stylus main body is shorter or longer than the second aspect. Therefore, the stylus body is, for example, a ¼ circle or a 2/3 circle.

  When the touch probe is installed on the spindle, the base end of the central axis of the stylus body intersects the extension line of the rotation center axis of the spindle, and parts other than the base end of the stylus main body are separated from the rotation center axis of the spindle. In addition, the center of the probe is also away from the rotation center axis of the spindle.

  The third aspect is an example where the stylus main body and the measuring element are separated from the rotation center axis of the spindle when the touch probe is installed on the spindle.

  The 4th aspect which concerns on the form of a touch probe is illustrated (not shown).

  The stylus main body is not bent and is formed in an elongated cylindrical shape (for example, a cylindrical material whose height is sufficiently large to about 5 to 100 times the outer diameter). The measuring element is provided at the tip of the stylus main body. The center of the probe is located on an extension line of the central axis of the stylus main body.

  When the touch probe is installed on the spindle, the base end of the center axis of the stylus body intersects the extension line of the rotation center axis of the spindle, but the center axis of the stylus body part is relative to the rotation center axis of the spindle. The center of the measuring element is away from the center axis of rotation of the spindle. Therefore, when the spindle is rotated when the touch probe is installed on the spindle, the position of the stylus body changes, and when the spindle is rotated once, the locus of the central axis of the stylus body becomes a conical side surface.

  The fourth aspect is an example where the stylus main body and the measuring element are separated from the rotation center axis of the spindle when the touch probe is installed on the spindle.

  In the first to third aspects described above, the stylus body is bent in an “L” shape or curved in an arc shape, but other shapes (for example, “U” shape) May be bent, may be curved in another shape (for example, an elliptical arc shape), or may be configured to include both bending and bending.

  Further, in the first to fourth aspects described above, the stylus main body is not branched, and the stylus main body is in the form of one material as it is or bent or curved, It is desirable that only one measuring element is provided at the tip of one stylus body.

  In addition, the measurement device 201 controls the head in a state where the installed touch probe 60 in which the housing 221 is installed on the spindle 217 is index-positioned by index-positioning the spindle 217 under the control of the control device (for example, CNC 20). The housing 215 of 213 is moved relative to the measured object installation body 219 (parallel movement that does not change its posture in at least one of the X-axis direction, the Y-axis direction, and the Z-axis direction), It is configured to measure the shape (curved outer surface; measured portion) of the installed measurement object W installed on the measurement object installation body 219 with the installed touch probe 60.

  The touch probe 60 is in a predetermined posture at a predetermined position with respect to the housing 221 when no force is applied to the stylus 223 in the same manner as a commercially available touch probe. Then, when the probe 61 comes into contact with the workpiece W, the probe 61 (stylus 223) is pushed by the workpiece W, and the attitude of the stylus 223 (the position of the probe 61) is very small with respect to the housing 221. It is designed to be slightly displaced. The measuring device 201 detects the slight start of the displacement of the stylus 223 to obtain the position of the housing 221 of the touch probe 60 when the measuring member 61 comes into contact with the object W to be measured. It is possible to obtain the position of the part of the object W to be in contact with. Further, the measuring device 201 is configured to measure the shape of the workpiece W by obtaining a plurality of positions of the portion of the workpiece W with which the measuring element 61 contacts.

  As already understood, in the measuring apparatus 201, when the measuring element 61 of the touch probe 60 is brought into contact with the concave portion W1 of the workpiece W to measure the shape of the concave portion W1 of the workpiece W, the concave portion In order to avoid interference between the stylus main body portion 225 and the portion (protrusion position protruding from the concave portion W1) W2 existing around W1, at least one of the stylus main body portion 225 and the probe 61 is attached to the spindle 217. The spindle 217, which is separated from the rotation center axis C and on which the touch probe 60 is installed, is index-positioned (see FIGS. 2, 9, etc.).

  In addition, the measurement apparatus 201 is provided with a calibration gauge installation body (for example, an object installation body; X-axis table) 219. Calibration gauges 100 and 150 (see FIGS. 3 and 5 etc.) are integrally installed on the calibration gauge installation body 219. The calibration gauge installation body 219 is in the X axis direction and the Y axis direction with respect to the housing 215 of the head 213. It is relatively movable and positionable in the Z-axis direction.

  Then, the measurement device (measurement object shape measurement device) 201 controls the X-axis table before measuring the shape of the installed measurement object W with the installed touch probe 60 under the control of the control device (for example, the CNC 20). The calibration is performed using the installed calibration gauges 100 and 150 installed in 219.

  The calibration gauge 100 may have a hemispherical surface as shown in FIG. 3, but the calibration (calibration according to the modified example) 150 used here is a two-dimensional one as shown in FIG. A curved surface is provided as a calibration curved surface 151.

2-dimensional curved surface is in a predetermined first plane draws one of the virtual curve of a predetermined shape, said predetermined one plane (curve extending without themselves a start and end points intersect) the virtual curve It is a curved surface represented by the locus of the virtual curve when it moves linearly in a direction orthogonal to the predetermined distance. As the two-dimensional curved surface, for example, a part of the side surface of the cylinder can be listed.

  The calibration gauge 150 is used when the installed touch probe 60 is indexed and calibrated.

  In this calibration, the probe 61 of the installed touch probe 60 exists away from the rotation center axis C of the spindle 217 as described above. The extending direction of the rotation center axis C of the spindle 217 is, for example, a direction (for example, orthogonal) that intersects the moving direction of the virtual curve (the direction orthogonal to the predetermined plane; for example, the X-axis direction). Direction; Y-axis direction). The calibration is configured to move the measuring element 61 of the installed touch probe 60 in the direction of the normal vector at a predetermined point in the calibration curved surface 151.

  An example of calibration will be described in more detail.

  As described above, the shape measurement (measurement of the position of the measurement point using the measuring apparatus 201) of the set object W to be measured is performed in the direction of the normal vector from the measurement point to the measurement point. The center of the probe 61 of the installed touch probe 60 is separated by a predetermined distance, the probe 61 of the installed touch probe 60 is moved in the direction of the normal vector of the measured point from the measured point, and installed. The measuring probe 61 of the touch probe 60 is configured to be in contact with the point to be measured.

  As described above, the stylus main body 225 of the touch probe 60 has a linear base end part 227 and a linear part intersecting the base end part 227 at a predetermined angle (for example, 90 °). The tip 61 is formed in an “L” shape (may be “H” or “Le”), and the probe 61 is positioned at the tip of the tip side portion 229. doing.

  In the installed touch probe 60, the rotation center axis C of the spindle 217 and the center axis of the base end side portion 227 of the stylus main body portion 225 coincide with each other, and the center axis CH of the distal end side portion 229 of the stylus main body portion 225. Intersects with the rotation center axis C of the spindle 217 at a predetermined angle (for example, 90 °), and the distal end portion 229 of the stylus main body 225 is connected to the rotation center axis C of the spindle 217 (the base end of the stylus main body 225). It extends in a direction away from the side part 227).

  A predetermined one direction in the set object W to be measured is defined as an X-axis direction, a predetermined one direction orthogonal to the X-axis direction is defined as a Y-axis direction, and a predetermined one perpendicular to the X-axis direction and the Y-axis direction is defined as the predetermined one direction. Let the direction be the Z-axis direction. In the installed calibration gauge 150, the moving direction of the virtual curve on the calibration curved surface 151 (the virtual curve forming the calibration curved surface 151 formed of a two-dimensional curved surface) is the X-axis direction.

  Under such conditions, calibration is performed as follows.

  First, a predetermined measurement point in the set object to be measured W is determined, and components in the three-axis directions of the normal vector at the predetermined measurement point in the X-axis direction, the Y-axis direction, and the Z-axis direction are obtained. .

  Subsequently, the Y-axis direction component and the Z-axis direction component of the normal vector, which are temporary measurement points existing in the calibration curved surface 151 in the installed calibration gauge 150, are set as predetermined measurement points (installation points). A predetermined temporary measurement point (calibration measured point) that is equal to the Y-axis direction component and the Z-axis direction component of the normal vector at the predetermined measured point of the measured object W).

  Subsequently, the spindle 217 (installed touch probe 60) is rotated by an amount corresponding to the X-axis direction component of the normal vector at a predetermined measurement point of the installed object to be measured W, and the tip of the stylus main body 225 is rotated. The side portion 229 is index-positioned, and in the direction of the provisional normal vector formed by the Y-axis direction component and the Z-axis direction component of the normal vector, a predetermined measurement point from the provisional measurement point of the installed calibration gauge 150 The installed touch probe 60 is positioned by positioning the probe 61 of the installed touch probe 60 at a distance.

  Subsequently, the stylus 61 (spindle 217) is calibrated in the direction of the tentative normal vector in the direction approaching the calibration gauge (installed calibration gauge) 150 installed in the calibration gauge installation body 219. The probe 61 moves relative to the calibration gauge 150 installed on the calibration gauge installation body 219 and linearly, thereby bringing the probe 61 into contact with the temporary measurement point. As a result, calibration is performed.

  Here, the calibration gauge 150 will be described in more detail (see FIGS. 5, 6, and 7).

The virtual curve forming the two-dimensional curved surface (calibration curved surface 151) of the calibration gauge 150 includes a first semicircular arc 153 and a second semicircular arc 153 that is separated from the first semicircular arc 153. A semicircular arc 155 is provided. That is, the calibration curved surface 151 of the calibration gauge 150 includes a half of the first cylindrical side surface and a half of the second cylindrical side surface. Incidentally, as the calibration curved surface 151, half of the first cylindrical side surface of the concave half of a convex-shaped second cylindrical side may be configured to have at least one.

  The second semicircular arc 155 has a predetermined point C1 (see FIG. 6A) existing outside the semicircle formed by the first semicircular arc 153 as a first point. The semi-circular arc 153 is positioned 180 °.

  Furthermore, the first semicircular arc 153 and the second semicircular arc 155 have a positional relationship as described below.

First, a first semicircle (a semicircle of the arc 153 of the first semicircle) and a second semicircle (a second semicircle of the second semicircle) formed by dividing the circle into two equal parts by a predetermined diameter of the circle. Semicircle of arc 155). The second semicircle is moved from the first semicircle by a predetermined distance in a direction perpendicular to the extending direction of the predetermined diameter within the plane on which the circle is drawn. Release. A radius of the circle in the extending direction of the predetermined diameter with respect to the first semicircle in a plane on which the second semicircle is separated from the first semicircle by a predetermined distance. Move a predetermined distance greater than. By such a movement, the first semicircle and the second semicircle are in a predetermined positional relationship apart from each other. A first semicircular arc 153 positional relationship between the second semicircular arcs 155 have a relationship between the first arc and the second arc of semicircle semicircular.

  A concave calibration curved surface 157 is formed by the first semicircular arc 153, and a convex calibration curved surface 159 is formed by the second semicircular arc 155.

  Next, the rotation of the spindle 217 by an amount corresponding to the component in the X-axis direction of the normal vector at the measurement point of the workpiece to be measured W will be described in more detail.

  First, a case where the normal vector at the measurement point of the installed object to be measured W does not include a component in the X-axis direction will be described with reference to FIG. In FIG. 7, for convenience of explanation, the normal vector at the measurement point of the object to be measured W does not include the Z-axis direction component, but may include the Z-axis direction component. It can be considered in the same manner as the following explanation.

  When the normal vector at the measurement point of the object to be measured W does not include the component in the X-axis direction, the central axis CH of the tip side portion 229 in the stylus main body 225 of the touch probe 60 is in the Y-axis direction. The head 213 (installed) is positioned so that the touch probe 60 is indexed around the C axis so as to extend, and the center of the probe 61 is positioned at the center of the first semicircular arc 153 of the installed calibration gauge 150. The housing 221) of the finished touch probe 60 is positioned.

Subsequently, calibration is performed by moving the installed touch probe 60 in the Y-axis direction and bringing the probe 61 into contact with the calibration gauge 150 (the calibration curved surface 151 of the first semicircular arc 153). If the normal vector at the measurement point of the object to be measured W also includes a component in the Z-axis direction, the installed touch probe 60 is inclined with respect to the Y-axis direction and the Z-axis direction. Calibration may be performed by linearly moving (obliquely with respect to the Y-axis direction).

  Next, the case where the normal vector at the measurement point of the object to be measured W that has been installed includes a component in the X-axis direction will be described with reference to FIGS. 8 and 9. In FIG. 8, as in the case of FIG. 7, for convenience of explanation, the normal vector at the measurement point of the object to be measured W does not include the component in the Z-axis direction. Even if the component in the axial direction is included, it can be considered in the same manner as described in FIG.

  FIG. 9 is a diagram showing the calibration gauge 100. For the sake of explanation, the calibration gauge 100 will be referred to as an object W to be measured. Assuming that a point to be measured on the object W to be measured is SW, a normal vector at this point to be measured SW has a component in the X-axis direction and a component in the Y-axis direction, and intersects the Y-axis at an angle θA. Yes.

  When the calibration for the measurement point SW shown in FIG. 9 is performed using the calibration gauge 100 shown in FIG. 3, the installed touch probe 60 is moved to the arrow (measurement point SW) as shown in FIG. The calibration is performed by moving as indicated by an arrow in the direction opposite to the normal vector in FIG.

  On the other hand, when the calibration for the measurement point SW shown in FIG. 9 is performed using the calibration gauge 150 shown in FIG. 5 or FIG. 6, as shown in FIG. Index positioning is performed around the C axis so that the central axis CH of the tip side portion 229 of the stylus main body 225 of the touch probe 60 intersects the Y axis at an angle θA, and an arrow (what is an arrow extending in the Y axis direction? The calibration is performed by moving as shown by the reverse arrow.

The distance between the center of the probe 61 and the calibration curved surface 151 shown in FIG. 8 is, for example, the distance between the center of the probe 61 and the calibration curved surface shown in FIG. It is assumed that it is equal to the radius of the recess. Further, after the calibration shown in FIG. 8, by an angle θA counterclockwise from the state shown in FIG. 8, and positioning by rotating an installed touch probe 60, as shown in Figure 9, the measurement target object W It is desirable to measure the shape.

  By the way, when measuring the workpiece W, in FIG. 9, the central axis CH of the distal end side portion 229 in the stylus main body 225 of the installed touch probe 60 extends in the Y-axis direction. The center axis CH of the distal end side portion 229 may extend obliquely with respect to the Y axis (not illustrated but inclined by an angle θB). Calibration in this case (calibration in the mode shown in FIG. 8) is, for example, an angle θA plus an angle θB.

  Next, the operation of the measuring apparatus 201 will be described.

  As an initial state, it is assumed that an object to be measured (for example, a processed workpiece processed by the measuring apparatus 201) W is installed on the X-axis table 219, and the touch probe 60 is installed on the spindle 217 of the head 213. .

  In the initial state, the measurement point of the workpiece W is determined under the control of the CNC 20 or the like (the measurement point may be determined in advance), and the housing 221 (spindle) is centered on a predetermined axis (C axis). 217) is rotated to index-position the installed touch probe 60 (index positioning stage).

  Subsequently, in a state in which the touch probe 60 is index-positioned in the index positioning stage, the housing 221 is moved relative to the object W to be measured, and the shape of the object W to be measured (curved outer surface; Part) with the touch probe 60 (measurement stage).

  When calibration is performed in the measurement apparatus 201, the calibration gauges 150 and 100 are calibrated before the housing 221 is index-positioned at the index positioning stage and the workpiece W is measured using the touch probe 60 at the measurement stage. Calibrate using (calibration stage).

  The calibration stage is a stage in which the housing 221 is rotated about a predetermined axis (C axis), the touch probe 60 is indexed and calibrated.

To further illustrate, the calibration preparative stage, to determine the predetermined measured point in the object to be measured W, 3 axes of the X-axis direction and the Y-axis direction and the Z-axis direction in the normal vector at the predetermined measured point A component in the direction is obtained. For example, the component in the Y-axis direction and the component in the Z-axis direction of the normal vector existing in the calibration curved surface 151 in the calibration gauge 150 are the normal vector at a predetermined measurement point. A predetermined temporary measurement point that is equal to the Y-axis direction component and the Z-axis direction component is determined, and the spindle 217 is rotated by an amount corresponding to the X-axis direction component of the normal vector at the predetermined measurement point, The probe 61 is positioned at a predetermined distance from the temporary measurement point in the direction of the temporary normal vector formed by the Y-axis direction component and the Z-axis direction component of the normal vector. By positioning, the installed touch probe 60 is positioned, and the probe 61 (spindle 217) is in the direction of the tentative normal vector and in the direction approaching the calibration gauge 150 installed in the calibration gauge installation body. The calibration is performed by moving linearly relative to the calibration gauge 150 installed in the calibration gauge installation body and bringing the probe 61 into contact with the temporary measurement point.

  According to the measuring apparatus 201, the housing 215 of the head 213 is moved relative to the measured object installation body 219 in a state where the installed touch probe 60 in which the stylus 223 is displaced from the axis C is index-positioned. Since the configuration of the object to be measured W is configured to be measured, it is possible to avoid the occurrence of a situation where the concave portion W1 of the object to be measured W cannot be measured as much as possible.

That is, FIGS. 11 and 12 (as before), as also shown in an attempt to measure the shape of the recess W1 of the workpiece W in the form, the convex portion of the Sutaitasu body portion workpiece W as described above ( A situation occurs in which the measuring element does not reach the concave portion W1 due to contact with the convex portion around the concave portion W1) W2.

  On the other hand, as shown in FIG. 2, the stylus body 225 is bent at an intermediate portion in the longitudinal direction, and the touch probe 60 is indexed with the C axis as a rotation center. Therefore, when measuring the shape of the concave portion W1 of the workpiece W, the opportunity to avoid the situation where the stylus comes into contact with the convex portion W2 around the concave portion W1 is increased as compared with the conventional case.

Further, according to the measuring apparatus 201, the installed touch probe 60 is indexed and calibrated, so that the calibration curved surface 151 formed by the two-dimensional curved surface is used to perform the calibration of the three-dimensional curved surface. can and Turkey to perform the calibration.

  According to the calibration gauge 150, the calibration curved surface 151 is not a three-dimensional curved surface such as a spherical surface but a two-dimensional curved surface (cylindrical side surface curved surfaces 157 and 159). Is simplified, and it is possible to obtain a calibration gauge 150 that is accurate and easy to manufacture.

Meanwhile, as are shown in FIG. 10, to divide the housing 221 into the proximal housing 231 and distal housing 233, and the axis CX to the pivot center, the head housing member 233 with respect to proximal housing 231 The touch probe 60 may be configured to be rotationally positioned. Thereby, the extending direction of the axis CA of the stylus 223 can be inclined.

60 Touch probe 61 Measuring element 100, 150 Calibration gauge 151 Curved surface for calibration 203 Head 215 Case 217 Spindle 219 Object installation object (X-axis table; calibration gauge installation object)
221 Housing 223 Stylus 225 Stylus body part 227 Base end side part 229 Tip side part C Rotation center axis (predetermined axis)
W measuring device

Claims (8)

A measured object installation body on which the measured object is installed; and
A housing and a spindle provided on the housing so as to be rotatable about a predetermined axis are provided, and the housing is movable and positionable relative to the measured object installation body. Head,
A housing integrally provided with the spindle, a stylus including a stylus main body protruding from the housing, and a spherical measuring element provided at a tip of the stylus main body, when installed on the spindle, the stylus body portion, when viewed from a direction perpendicular to the center axis of the housing, semicircular Joma other quarter circle shape is also properly in an elongated rod-shaped with 2/3 £ shaped Touch probe and
And moving the housing relative to the measured object installation body in a state where the installed touch probe in which the housing is installed on the spindle is index-positioned using the spindle, An object to be measured is configured to measure the shape of the object to be measured by bringing the measuring element into contact with the object to be measured installed on the object object to be measured. measuring device. In the measuring apparatus of the to-be-measured object of Claim 1,
A calibration gauge is installed and has a calibration gauge installation body that is movable and positionable relative to the housing.
Before measuring the shape of the installed object to be measured with the installed touch probe, it is configured to perform calibration using an installed calibration gauge installed on the calibration gauge installation body,
The calibration gauge draws one virtual curve having a predetermined shape on a predetermined plane, and moves the virtual curve by a predetermined distance in a direction orthogonal to the predetermined plane. A two-dimensional curved surface that is a curved surface represented by the locus of is provided as a calibration curved surface,
The measurement object measuring apparatus is characterized in that the calibration is configured such that the installed touch probe is indexed and the calibration is performed. In the measuring apparatus of the to-be-measured object of Claim 1,
A calibration gauge is installed, and has a calibration gauge installation body that is movable and positionable relative to the housing of the head.
Before measuring the shape of the installed object to be measured with the installed touch probe, it is configured to calibrate using the installed calibration gauge installed on the calibration gauge installation body,
The stylus main body of the touch probe has the probe located at the tip,
In the installed touch probe, the rotation center axis of the spindle and the center axis of the housing coincide with each other,
The calibration gauge draws one virtual curve having a predetermined shape on a predetermined plane, and moves the virtual curve by a predetermined distance in a direction orthogonal to the predetermined plane. A two-dimensional curved surface that is a curved surface represented by the locus of is provided as a calibration curved surface,
A predetermined direction in the set object to be measured is defined as an X-axis direction, a predetermined one direction orthogonal to the X-axis direction is defined as a Y-axis direction, and a predetermined direction orthogonal to the X-axis direction and the Y-axis direction If the one direction is the Z-axis direction, the installed calibration gauge has the moving direction of the virtual curve on the calibration curved surface is the X-axis direction,
The calibration is
Determining a predetermined measurement point in the measured object to be measured, and determining a component in a triaxial direction of the X-axis direction, the Y-axis direction, and the Z-axis direction in a normal vector at the predetermined measurement point;
A component in the Y-axis direction and a component in the Z-axis direction of the normal vector that are present in the calibration curved surface of the installed calibration gauge and a component in the Y-axis direction of the normal vector at the predetermined measurement point Determine a predetermined temporary measurement point that is equal to the component in the Z-axis direction,
The spindle is rotated by an amount corresponding to the X-axis direction component of the normal vector at the predetermined measurement point, and the temporary vector is formed by the Y-axis component and the Z-axis component of the normal vector. In the direction of the normal vector, by positioning the probe at a predetermined distance from the temporary measurement point, the installed touch probe is positioned,
The probe is moved relative to the installed calibration gauge in the direction of the temporary normal vector and close to the installed calibration gauge, and the probe is moved to the temporary measurement. An apparatus for measuring an object to be measured, wherein the apparatus is configured to perform contact with a point. In the measurement method of the object to be measured,
A stylus including a housing, a stylus main body protruding from the housing, and a spherical measuring element provided at a tip of the stylus main body, and the stylus main body is orthogonal to the central axis of the housing to when viewed from the direction, the touch probe semicircle Joma others also are properly quarter circle shape which is in an elongated rod-shaped with 2/3 yen shaped, rotating the housing around the central axis of the housing An index positioning stage for index positioning;
In a state where the touch probe is index-positioned in the index positioning step, the housing is moved relative to the object to be measured, and a measuring step of measuring the shape of the object to be measured with the touch probe;
A method for measuring an object to be measured, comprising: In the measuring method of the to-be-measured object of Claim 4,
A calibration step of performing calibration using a calibration gauge before indexing the housing in the index positioning step;
The calibration gauge draws one virtual curve having a predetermined shape on a predetermined plane, and moves the virtual curve by a predetermined distance in a direction orthogonal to the predetermined plane. A two-dimensional curved surface that is a curved surface represented by the locus of is provided as a calibration curved surface,
The method of measuring an object to be measured is characterized in that the calibration step is a step of rotating the housing about a central axis of the housing, index-positioning the touch probe, and performing the calibration. In the measuring method of the to-be-measured object of Claim 4,
A calibration step of performing calibration using a calibration gauge before indexing the housing in the index positioning step;
The calibration gauge draws one virtual curve having a predetermined shape on a predetermined plane, and moves the virtual curve by a predetermined distance in a direction orthogonal to the predetermined plane. A two-dimensional curved surface that is a curved surface represented by the locus of is provided as a calibration curved surface,
The stylus main body of the touch probe has the probe located at the tip,
In the touch probe, the center axis of rotation of the spindle of the measuring device for the object to be measured and the center axis of the housing coincide with each other,
A predetermined one direction in the object to be measured is an X-axis direction, a predetermined one direction orthogonal to the X-axis direction is a Y-axis direction, and a predetermined one is orthogonal to the X-axis direction and the Y-axis direction. When the direction is the Z-axis direction, the calibration gauge has the moving direction of the virtual curve on the calibration curved surface is the X-axis direction,
The calibration step includes
Determining a predetermined point to be measured in the object to be measured, and obtaining a component in a triaxial direction of an X axis direction, a Y axis direction, and a Z axis direction in a normal vector at the predetermined point to be measured;
A component in the Y-axis direction and a component in the Z-axis direction of the normal vector that are present in the calibration curved surface in the calibration gauge are the component in the Y-axis direction of the normal vector at the predetermined measurement point and the Z-axis. Determine a predetermined provisional measurement point equal to the direction component,
The spindle is rotated by an amount corresponding to the X-axis direction component of the normal vector at the predetermined measurement point, and the temporary vector is formed by the Y-axis component and the Z-axis component of the normal vector. In the direction of the normal vector, by positioning the probe at a predetermined distance from the temporary measurement point, the installed touch probe is positioned,
With respect to the calibration gauge installed in the calibration gauge installation body in the direction of the temporary normal vector and in the direction approaching the calibration gauge installed in the calibration gauge installation body The method of measuring an object to be measured is a stage in which the calibration is performed by moving the probe relative to the temporary measurement point. A housing;
A stylus body projecting from the housing;
A spherical measuring element provided at the tip of the stylus body,
Has, that the stylus body portion, when viewed from a direction perpendicular to the center axis of the housing, semicircular Joma others that can properly be quadrant-shaped has an elongated rod-shaped with 2/3 £ shaped Touch probe characterized by. The touch probe according to claim 7,
The stylus body has the probe located at the tip,
Touch probe to the rotational center axis of the spindle of the measuring device of the object to be measured and the center axis of the housing and wherein the match each other.

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