JP2018084488A - Three-dimensional measuring machine measurement method and three-dimensional measuring machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a three-dimensional measuring machine measurement method and three-dimensional measuring machine that can attain a measurement result of a measurement factor enabling processing errors of the measurement factor by a processing machine to be highly accurately obtained.SOLUTION: In a work, a first measurement reference point and second measurement reference points are provided that serve as a reference of a work coordinate system, and a measurement factor is processed with a first processing reference point offset from the first measurement reference point and a second processing reference point offset from the second measurement reference point as a reference position. A three-dimensional measuring machine measurement method has: a first relative position calculation step of calculating a first relative position of the first processing reference point with respect to the first measurement reference point; a second relative position calculation step of calculating a second relative position of the second processing reference point with respect to the second measurement reference point; and a correction work coordinate setting step of setting a correction work coordinate correcting a work coordinate on the basis of the first relative position calculated in the first relative position step, and the second relative position calculated in the second relative position calculation step.SELECTED DRAWING: Figure 7

Description

  The present invention relates to a measuring method of a coordinate measuring machine and a coordinate measuring machine for measuring coordinate values of workpiece measurement points.

  Conventionally, it has a drive unit that displaces the position and orientation (position and orientation) of the probe, and this probe is brought into contact with the measurement point of a measurement element such as a circular hole in the workpiece, which is the measurement object, to obtain the coordinate value of the measurement point. A three-dimensional measuring machine that measures and measures the position, size, shape, and the like of a measurement element based on the measurement result is known (see Patent Document 1 and Patent Document 2).

  In such a three-dimensional measuring machine, prior to the measurement of the workpiece measurement element, the workpiece coordinate system indicating the origin and coordinate axes (defined on the workpiece) based on the workpiece is set (see Patent Document 3). ). The work coordinate system setting process includes a space correction process, an origin setting process, and a reference axis setting process.

FIG. 20 is an explanatory diagram of a general space correction process. In FIG. 20, the three axes X ₀ Y ₀ Z ₀ orthogonal to each other are the reference axes of the machine coordinate system unique to the coordinate measuring machine, and the reference numeral 100 is the origin of the machine coordinate system. As shown in FIG. 20, in the space correction step, coordinate values of three or more arbitrary points on the plane 104 are measured by the probe of the coordinate measuring machine, and the plane 104 of the workpiece 102 and the reference Z are measured based on these coordinate values. The intersection 106 with the _zero axis and the normal vector 108 of the plane 104 are determined.

Next, the coordinate measuring machine makes the reference Z ₀ axis parallel to the normal vector 108 of the plane 104. As a result, the X ₀ Y ₀ Z ₀ coordinate system indicated by the solid line in the drawing is spatially corrected to the X ₁ Y ₁ Z ₁ coordinate system indicated by the short broken line in the drawing.

Next, the coordinate measuring machine translates the origin 100 to the intersection 106. Thereby, the X ₁ Y ₁ Z ₁ coordinate system is spatially corrected to the X ₂ Y ₂ Z ₂ coordinate system indicated by the long broken line in the drawing. Through the above-described spatial correction process, the Z-axis direction of the work coordinate system and the origin 100 of the Z-axis of the work coordinate system are set.

  FIG. 21 is an explanatory diagram of a general origin setting process. As shown in FIG. 21, in the origin setting step, the first measurement reference hole 110 formed on the plane 104 by the probe is measured. Specifically, the coordinate values of a plurality of measurement points on the inner peripheral surface of the first measurement reference hole 110 necessary for the center measurement of the first measurement reference hole 110 are measured by the probe. The three-dimensional measuring machine obtains the center 112 of the first measurement reference hole 110 based on the measurement result of the coordinate value of each measurement point.

Next, the coordinate measuring machine translates the origin 100 of the Z axis to the center 112 of the first measurement reference hole 110. As a result, the X ₂ Y ₂ Z ₂ coordinate system indicated by the solid line in the figure is corrected to the X ₃ Y ₃ Z ₃ coordinate system indicated by the broken line in the figure. Through the above origin setting process, the origin of the XY axes of the workpiece coordinate system CS (see FIG. 22) is set as the origin of the X ₃ Y ₃ Z ₃ coordinate system.

  FIG. 22 is an explanatory diagram of a general reference axis setting process. As shown in FIG. 22, in the reference axis setting step, the second measurement reference hole 114 formed on the plane 104 by the probe is measured. Specifically, the coordinate values of a plurality of measurement points on the inner peripheral surface of the second measurement reference hole 114 necessary for the center measurement of the second measurement reference hole 114 are measured by the probe. The three-dimensional measuring machine obtains the center 116 of the second measurement reference hole 114 based on the measurement result of the coordinate value of each measurement point.

Then, the coordinate measuring machine, rotating the _{X 3} axis origin of the XY axes in the workpiece coordinate system CS (center 112 of the first measurement reference hole 110) as a fulcrum, to a position passing through the center 116 of the second measurement reference hole 114 Let Here sign α in the drawing indicates an angle to rotate the X ₃ axis. As a result, the X ₃ Y ₃ coordinate system indicated by the solid line in the figure is corrected to the X ₄ Y ₄ coordinate system indicated by the broken line in the figure. Through the above reference axis setting process, the X ₄ Y ₄ coordinate system is set as the direction of the XY axes of the workpiece coordinate system CS.

Thus, by going through the space correction process and the origin setting step and the reference axis setting step, X ₄ axis is the X-axis of the work coordinate system CS, Y ₄ axis is the Y-axis workpiece coordinate system CS, Z ₃ axes is the Z-axis of the work coordinate system CS. This completes the setting of the workpiece coordinate system CS. After setting the workpiece coordinate system CS, the coordinate values of the respective measurement points of the workpiece 102, for example the first circular hole 118 and the second circular hole 120, are measured by a three-dimensional measuring machine, and the first circular hole is measured. The position, size, shape, and the like of 118 and the second circular hole 120 are measured.

JP 2007-33052 A Japanese Patent Laid-Open No. 7-139936 JP-A-7-270152

  Incidentally, the first circular hole 118 and the second circular hole 120 which are the measurement elements of the workpiece 102 shown in FIGS. 20 to 22 described above are processed (formed) into the workpiece 102 by a processing machine with a drill or the like. Specifically, the processing machine has a table that supports the workpiece 102, and a first pin and a second pin for projecting the workpiece 102 to the table are projected from the table. Then, the first measurement reference hole 110 of the workpiece 102 is inserted into the first pin, and the second measurement reference hole 114 of the workpiece 102 is inserted into the second pin, whereby the workpiece 102 is positioned on the table. 1 processes the first circular hole 118 and the second circular hole 120 in the workpiece 102.

  At this time, there are respective dimensions between the first pin and the first measurement reference hole 110 (first measurement reference point) and between the second pin and the second measurement reference hole 114 (second measurement reference point). A backlash (gap) occurs due to the tolerance. Therefore, rattling of the workpiece 102 is prevented by offsetting the first measurement reference hole 110 with respect to the first pin and the second measurement reference hole 114 with respect to the second pin in one direction. In this state, the processing machine processes the first circular hole 118 and the second circular hole 120 in the workpiece 102.

  As described above, the actual processing of the first circular hole 118 and the second circular hole 120 by the processing machine is performed based on the centers 112 and 116 of the first measurement reference hole 110 and the second measurement reference hole 114, respectively. Instead, by the above-described shifting operation, the center axis (the first processing reference point and the second processing reference point) of each of the first pin and the second pin is used as a reference. Accordingly, the measurement result of the first circular hole 118 and the second circular hole 120 by the three-dimensional measuring machine includes a deviation amount that is a first relative position between the center 112 of the first measurement reference hole 110 and the center of the first pin, In addition, a shift amount that is a second relative position between the center 116 of the second measurement reference hole 114 and the center of the second pin, that is, a deviation error is included. For this reason, the measurement result of the three-dimensional measuring machine reflects both the processing error (error from the design value) of the first circular hole 118 and the second circular hole 120 by the processing machine and the above-described offset error. (See FIGS. 16 and 17 described later). As a result, the processing error of the processing machine (measurement result based on the first processing reference point and the second processing reference point) cannot be obtained accurately from the measurement result of the CMM, and compatibility with the processing machine is possible. There is a problem that a measurement result that maintains the above cannot be obtained.

  The present invention has been made in view of such circumstances, a measuring method of a three-dimensional measuring machine capable of obtaining a measurement result of a measuring element capable of obtaining a processing error of the measuring element by a processing machine with high accuracy, and An object is to provide a three-dimensional measuring machine.

  A measuring method of a CMM for achieving the object of the present invention is a measuring method of a CMM that measures a measuring element processed into a workpiece with a CMM, and the workpiece is based on the workpiece. The first measurement reference point and the second measurement reference point, which serve as a reference for the workpiece coordinate system, are set when the workpiece coordinate system is set and measurement is performed by a coordinate measuring machine, and the measurement element is offset from the first measurement reference point The first processing reference point and the second processing reference point offset from the second measurement reference point are processed as reference positions, and the first relative position of the first processing reference point with respect to the first measurement reference point The first relative position calculation step for calculating the first relative position calculation step, the second relative position calculation step for calculating the second relative position of the second machining reference point with respect to the second measurement reference point, and the first relative position calculation step. Relative position and second relative position calculation Based on the second relative position calculated in step has a correcting work coordinate system setting step of setting a correction work coordinate system obtained by correcting the work coordinate system, the.

  According to the measuring method of this coordinate measuring machine, by setting the corrected workpiece coordinate system, errors caused by offsetting the workpiece when machining the measuring element on the workpiece are measured by the measuring result of the coordinate measuring machine. Can be excluded from.

  In the measuring method of the coordinate measuring machine according to another aspect of the present invention, a position and orientation acquisition step of acquiring the position and orientation of the workpiece in the coordinate measuring machine, and the measurement point in the measuring element is measured by the coordinate measuring machine In the coordinate value acquisition step of acquiring the coordinate value of the measurement point represented by the machine coordinate system of the coordinate measuring machine, the correction work coordinate system set in the correction work coordinate system setting step, and the position and orientation acquisition step A coordinate value conversion step of converting the coordinate value of the measurement point acquired in the coordinate value acquisition step into a coordinate value represented in the corrected workpiece coordinate system based on the acquired position and orientation of the workpiece. This corrects the offset error caused by shifting the workpiece when the workpiece is processed by the processing machine, and the measurement result of the measurement element that reflects the processing error of the processing machine with high accuracy, that is, compatible with the processing machine. The measurement result which maintained the property is obtained.

  In the measurement method of the coordinate measuring machine according to another aspect of the present invention, the offset direction of the first machining reference point with respect to the first measurement reference point is the same as the offset direction of the second machining reference point with respect to the second measurement reference point. Direction. When machining a measuring element on a workpiece by a processing machine, when the workpiece is offset to prevent the workpiece from rattling, the offset error caused by workpiece offset can be eliminated from the measurement results of the CMM. it can.

  In the measuring method of the three-dimensional measuring machine according to another aspect of the present invention, the processing machine for processing the measuring element on the workpiece includes a first pin and a second pin that are projected in the first direction and used for positioning the workpiece. The workpiece is provided with a first measurement reference hole having a diameter larger than that of the first pin and inserting the first pin, and a second measurement reference hole having a diameter larger than that of the second pin and into which the second pin is inserted. In the state where the first pin is inserted into the first measurement reference hole and the second pin is inserted into the second measurement reference hole, and the work is offset in the second direction perpendicular to the first direction, The measuring element is processed by the processing machine, the first measurement reference point is the center of the first measurement reference hole, the second measurement reference point is the center of the second measurement reference hole, and the first processing reference point is the first pin. The second processing reference point is the central axis of the second pin. Even when the workpiece is offset when the measuring element is processed into the workpiece by the processing machine, the offset error due to the offset of the workpiece can be excluded from the measurement result of the coordinate measuring machine.

  In the measuring method of the coordinate measuring machine according to another aspect of the present invention, the first relative position calculating step acquires the center coordinates of the first measurement reference hole and the radius value of the first pin, and acquires the first measurement. The first relative position is calculated based on the center coordinate of the reference hole and the radius value of the first pin, and the second relative position calculation step acquires the center coordinate of the second measurement reference hole and the radius value of the second pin. The second relative position is calculated based on the acquired center coordinates of the second measurement reference hole and the radius value of the second pin. Thereby, the first relative position and the second relative position can be calculated.

  In the measuring method of the coordinate measuring machine according to another aspect of the present invention, the first relative position calculating step acquires the center coordinates of the first measuring reference hole by actual measurement using the three-dimensional measuring machine or the first measuring reference hole. Obtained from the design information, the second relative position calculating step obtains the center coordinates of the second measurement reference hole by actual measurement by a three-dimensional measuring machine or from the design information of the second measurement reference hole. Thereby, the first relative position and the second relative position can be calculated without actually measuring the center coordinates of the first measurement reference hole and the center coordinates of the second measurement reference hole.

  A three-dimensional measuring machine for achieving the object of the present invention is a three-dimensional measuring machine for measuring a measurement element machined into a workpiece. The workpiece is set with a workpiece coordinate system based on the workpiece to perform a three-dimensional measurement. A first measurement reference point and a second measurement reference point, which are used as a reference for the workpiece coordinate system when measuring with a machine, are provided, and the measurement elements are a first machining reference point offset from the first measurement reference point and a second measurement reference point. A first relative position calculation unit that is processed using the second processing reference point offset from the reference point as a reference position, and calculates a first relative position of the first processing reference point with respect to the first measurement reference point; A second relative position calculation unit that calculates a second relative position of the second machining reference point with respect to the second measurement reference point, a first relative position calculated by the first relative position calculation unit, and a second relative position calculation unit Based on the second relative position. Comprising a correction workpiece coordinate system setting unit for setting a correction work coordinate system obtained by correcting the click coordinates, the.

  In a coordinate measuring machine according to another aspect of the present invention, a position and orientation acquisition unit that acquires the position and orientation of a workpiece in the coordinate measuring machine, and a measurement point in the measuring element measured by the coordinate measuring machine. Coordinate value acquisition unit that acquires the coordinate value of the measurement point that is the coordinate value of the measurement point that is expressed in the machine coordinate system of the coordinate measuring machine, and the corrected work coordinate set by the correction work coordinate system setting unit Coordinate value conversion unit that converts the coordinate value of the measurement point acquired by the coordinate value acquisition unit into the coordinate value represented in the corrected work coordinate system based on the system and the position and orientation of the workpiece acquired by the position and orientation acquisition unit And comprising.

  The measuring method and the three-dimensional measuring machine of the present invention can obtain the measurement result of the measuring element that can obtain the processing error of the measuring element by the processing machine with high accuracy.

It is an external appearance perspective view of a three-dimensional measuring machine. It is explanatory drawing for demonstrating the process of the 1st circular hole and 2nd circular hole to the workpiece | work by a processing machine. The first relative position of the first measurement reference hole with respect to the first pin and the second of the second measurement reference hole with respect to the second pin when the work is shifted to the arrow A1 direction side (the (−) direction side of the Y axis). It is the schematic diagram which showed the relative position. It is sectional drawing of the workpiece | work along the Y-axis direction in FIG. It is an external appearance perspective view of a probe head. It is a functional block diagram of a computer. It is a flowchart which shows the flow of the correction | amendment workpiece | work coordinate system setting process in which a workpiece | work coordinate system setting part sets a correction | amendment workpiece | work coordinate system. It is explanatory drawing for demonstrating the process of step S2A and step S2B of FIG. It is explanatory drawing for demonstrating the process of step S2C to step S2E of FIG. It is explanatory drawing for demonstrating the process of step S3A of FIG. It is explanatory drawing for demonstrating the process of step S3B of FIG. It is explanatory drawing for demonstrating the process of step S3C and step 3D of FIG. It is explanatory drawing for demonstrating before execution of the process of step S3E of FIG. It is explanatory drawing for demonstrating after execution of the process of step S3E of FIG. It is a flowchart which shows the flow of the measurement process of the workpiece | work by a three-dimensional measuring machine. It is explanatory drawing for demonstrating the effect of the coordinate measuring machine of this embodiment. It is a top view of the workpiece | work of the lower stage of FIG. It is explanatory drawing for demonstrating the process by the processing machine in other embodiment. It is explanatory drawing for demonstrating the measurement by the coordinate measuring machine in other embodiment. It is explanatory drawing of a general space correction process. It is explanatory drawing of a general origin setting process. It is explanatory drawing of a general reference axis setting process.

  FIG. 1 is an external perspective view of the coordinate measuring machine 10. The three-dimensional measuring machine 10 measures the position, size, shape, and the like of the measurement element of the workpiece 102 (see FIG. 2) while displacing the position and orientation of the probe 12a. In the present embodiment, the first circular hole 118 and the second circular hole 120 of the work 102 shown in FIG. 2 are measured as measurement elements, but the work 102 to be measured and the type (shape) of the measurement element are particularly limited. Not done. Note that the X axis, the Y axis, and the Z axis in FIG. 1 are machine coordinate systems determined based on the machine coordinate origin inherent in the coordinate measuring machine 10.

  FIG. 2 is an explanatory diagram for explaining processing (formation) of the first circular hole 118 and the second circular hole 120 on the workpiece 102 by the processing machine 121. As shown in FIG. 2, a first measurement reference hole 110 and a second measurement reference hole 114 such as a knock hole are processed in the workpiece 102 in advance. In the present embodiment, the first measurement reference hole 110 and the second measurement reference hole 114 are through holes, but may be non-through holes.

  The processing machine 121 includes a table 122 on which the workpiece 102 is set, and a processing unit such as a drill (not shown) that processes the first circular hole 118, the second circular hole 120, and the like on the workpiece 102. On the table 122, the 1st pin 124 and the 2nd pin 126 are protrudingly provided by the Z-axis direction (1st direction of this invention) shown in FIG. When processing the workpiece 102 with the processing machine 121, the first pin 124 is inserted into the first measurement reference hole 110 and the second pin 126 is inserted into the second measurement reference hole 114. The workpiece 102 is positioned at a predetermined processing position.

  At this time, the first measurement reference hole 110 is formed to have a slightly larger diameter than the first pin 124, and the second measurement reference hole 114 is formed to have a slightly larger diameter than the second pin 126. For this reason, at the time of machining, the workpiece 102 on the table 122 is biased (biased, offset) to one direction side (arrow A1 direction side of the present invention, the second direction of the present invention) shown in FIG. As a result, the first measurement reference hole 110 is offset toward the arrow A1 direction with respect to the first pin 124, and the second measurement reference hole 114 is also offset toward the arrow A1 direction with respect to the second pin 126. The workpiece 102 can be positioned on the table 122 without backlash. In this state, the first circular hole 118 and the second circular hole 120 are processed in the workpiece 102 by a processing unit (not shown) of the processing machine 121.

  FIG. 3 shows the first relative position of the first measurement reference hole 110 with respect to the first pin 124 and the second pin 126 when the workpiece 102 is shifted to the arrow A1 direction side [Y-axis (−) direction side]. FIG. 6 is a schematic diagram showing a second relative position of a second measurement reference hole 114. 4 is a cross-sectional view of the workpiece 102 along the Y-axis direction in FIG.

  As shown in FIGS. 3 and 4, the center 112 of the first measurement reference hole 110 (corresponding to the first measurement reference point of the present invention) and the center 116 of the second measurement reference hole 114 (the second measurement reference of the present invention). "Corresponding to a point" is a measurement reference point that becomes a measurement reference in the CMM 10 described later. Note that the above-described workpiece coordinate system CS (see FIG. 22) is set based on these centers 112 and 116.

  On the other hand, the central axis 128 of the first pin 124 (corresponding to the first processing reference point of the present invention) and the central axis 130 of the second pin 126 (corresponding to the second processing reference point of the present invention) are the processing machine 121. This is a processing reference point that becomes a reference position when processing at.

  When the workpiece 102 is shifted to the arrow A1 direction side, the center axis 128 of the first pin 124 with respect to the center 112 of the first measurement reference hole 110 is the arrow A2 direction side opposite to the arrow A1 direction side [Y axis (+) Direction side], and the center axis 130 of the second pin 126 is also offset to the arrow A2 direction side with respect to the center 116 of the second measurement reference hole 114. That is, the central axes 128 and 130 are offset in the same offset direction.

  Then, the amount of deviation a in the Y-axis direction indicating the first relative position of the center axis 128 of the first pin 124 with respect to the center 112 of the first measurement reference hole 110 is equal to both the first measurement reference hole 110 and the first pin 124. Generated by dimensional tolerance of diameter. Further, the amount of deviation b in the Y-axis direction indicating the second relative position of the central axis 130 of the second pin 126 with respect to the center 116 of the second measurement reference hole 114 is equal to both the second measurement reference hole 114 and the second pin 126. Generated by dimensional tolerance of diameter. Therefore, when the above-described workpiece coordinate system CS (see FIG. 22) is set and the first circular hole 118 and the second circular hole 120 are measured by the three-dimensional measuring machine 10, the measurement result includes In addition to processing errors due to the processing machine 121 (errors from the design values of the first circular hole 118 and the second circular hole 120), the shift amounts a and b caused by the offset of the workpiece 102 appear as offset errors.

  Therefore, in the coordinate measuring machine 10 of the present embodiment, as will be described in detail later, deviation amounts a and b, which are deviation errors caused by the deviation of the workpiece 102, are obtained, and the deviation error is based on the obtained deviation amounts a and b. Measurement results of the first circular hole 118 and the second circular hole 120 that do not include, that is, a measurement result that is compatible with the processing machine 121 is obtained.

  Returning to FIG. 1, the coordinate measuring machine 10 includes a gantry 14, a surface plate 16 provided on the gantry 14, and a right Y carriage 18 </ b> R and a left Y carriage 18 </ b> L erected on both ends of the surface plate 16. And an X guide 20 that connects the upper portions of the right Y carriage 18R and the left Y carriage 18L. The portal frame 22 is configured by the right Y carriage 18R, the left Y carriage 18L, and the X guide 20.

  Sliding surfaces on which the right Y carriage 18R and the left Y carriage 18L slide along the Y axis direction are formed on the upper surface and side surfaces of both end portions of the surface plate 16 in the X axis direction. The right Y carriage 18R and the left Y carriage 18L are provided with air bearings (not shown) at positions facing the sliding surface of the surface plate 16. As a result, the right Y carriage 18R and the left Y carriage 18L can move in the Y-axis direction together with the X guide 20.

  An X carriage 24 is attached to the X guide 20. The X guide 20 is formed with a sliding surface along which the X carriage 24 slides along the X-axis direction. The X carriage 24 is provided with an air bearing (not shown) at a position facing the sliding surface of the X guide 20. As a result, the X carriage 24 is movable in the X-axis direction.

  A Z carriage 26 is attached to the X carriage 24. The X carriage 24 is provided with a Z-axis direction air bearing (not shown) for guiding the Z carriage 26 in the Z-axis direction. Thus, the Z carriage 26 is held by the X carriage 24 so as to be movable in the Z-axis direction. The probe head 12 is attached to the lower end of the Z carriage 26.

  FIG. 5 is an external perspective view of the probe head 12. As shown in FIG. 5, the probe head 12 is, for example, a 5-axis simultaneous control probe head provided with a stepless positioning mechanism, and holds the proximal end of the contact probe 12a. The proximal end of the stylus 12b is attached to the distal end of the probe 12a. A contact 12c is attached to the tip of the stylus 12b. The stylus 12b and the contact 12c constitute a probe for the probe 12a. The type of the probe 12a is not particularly limited.

  The probe head 12 is provided with a first drive unit 28 (see FIG. 6) such as a motor that rotates the probe 12a around two rotation axes θ1 and θ2 (see FIG. 1) orthogonal to each other. . As a result, the rotation angle φ around the rotation axis θ1 of the probe 12a and the rotation angle θ around the rotation axis θ2 of the probe 12a can be adjusted steplessly, so that the posture of the stylus 12b can be arbitrarily set. Can be displaced (rotated).

  Returning to FIG. 1, although not shown in the coordinate measuring machine 10, a Y-axis drive unit that moves the portal frame 22 in the Y-axis direction and an X-axis drive that moves the X carriage 24 in the X-axis direction. And a second drive unit 30 (see FIG. 6) including a Z-axis drive unit that moves the Z carriage 26 in the Z-axis direction. Thereby, the probe head 12 and the probe 12a can be moved in the XYZ triaxial directions. The first drive unit 28 and the second drive unit 30 allow the position and orientation of the probe 12a to be freely displaced, and the probe 12a can be arbitrarily displaced (moved and rotated).

  A Y-axis direction position detection linear scale (not shown) is provided at the end of the surface plate 16 on the right Y carriage 18R side. The X guide 20 is provided with an X-axis direction position detecting linear scale (not shown), and the Z carriage 26 is provided with a Z-axis direction position detecting linear scale (not shown).

  The right Y carriage 18R is provided with a Y-axis direction position detection head (not shown) that reads a Y-axis direction position detection linear scale. The X carriage 24 includes an X-axis direction position detection head (not shown) that reads an X-axis position detection linear scale, and a Z-axis position detection head (not shown) that reads a Z-axis position detection linear scale. )). Further, the probe head 12 is provided with a rotation angle detector (not shown) such as a rotary encoder that detects the rotation angles θ and φ of the probe 12a. The three-dimensional measuring machine 10 is configured so that the contact 12c at the tip of the probe 12a has the first circular hole 118 and the second circular hole of the workpiece 102 based on the detection result of the XYZ axial direction detection head and the detection result of the rotation angle detection unit. The coordinate values in the XYZ axis directions of the respective measurement points when the respective 120 measurement points (inner peripheral surface, etc.) are contacted are detected.

  The coordinate measuring machine 10 includes a drive controller 32 that controls the first drive unit 28 and the second drive unit 30 to control the movement of the probe head 12, that is, the displacement of the position and orientation of the probe 12a (stylus 12b). ing. Here, the coordinate measuring machine 10 has an automatic measurement mode in which measurement is performed automatically and a manual measurement mode in which measurement is performed manually. Accordingly, in the automatic measurement mode, the drive controller 32 controls the first drive unit 28 and the second drive unit 30 under the control of the computer 34 described later to displace the position and orientation of the probe 12a.

  Further, the drive controller 32 is provided with a probe operation unit 32a such as a joystick for manually operating the displacement of the position and orientation of the stylus 12b. Accordingly, in the manual measurement mode, the drive controller 32 controls the first drive unit 28 and the second drive unit 30 according to the operation input to the probe operation unit 32a, thereby displacing the position and orientation of the probe 12a.

  The drive controller 32 is connected to a contact detection sensor (not shown) of the probe 12a, an XYZ axial direction detection head (not shown) (not shown), and a rotation angle detection unit (not shown). Yes. The drive controller 32 detects the XYZ axial direction detection head at the moment when the contact detection sensor detects that the contact 12c of the probe 12a has contacted the measurement points of the first circular hole 118 and the second circular hole 120 of the workpiece 102. And the detection result of each of a rotation angle detection part is acquired, and the coordinate value of the XYZ-axis direction of each measurement point of the 1st circular hole 118 and the 2nd circular hole 120 is detected. The coordinate value of each measurement point is output from the drive controller 32 to the computer 34.

  The computer 34 is connected to the drive controller 32 via a various communication interface 36 (see FIG. 1) such as a LAN (Local Area Network) so that data communication is possible.

  A software program 34 a is installed in the computer 34. By executing the software program 34a, the computer 34 sets, for example, a correction work coordinate system CSH (see FIG. 6) described later, generation of a correction matrix MH (see FIG. 6), and on the surface plate 16. Various measurement operations including acquisition of the position and orientation of the workpiece 102 and acquisition of coordinate values of the measurement points of the first circular hole 118 and the second circular hole 120 are executed.

  Further, the computer 34 drives and controls the first drive unit 28 and the second drive unit 30 (see FIG. 6) via the drive controller 32 when the coordinate measuring machine 10 is in the automatic measurement mode, and the probe 12a. The measurement points of the first circular hole 118 and the second circular hole 120 are automatically measured.

  The display unit 38 is connected to the computer 34. The computer 34 causes the display unit 38 to display various information in the coordinate measuring machine 10, for example, a measurement position by the probe 12a, an operation instruction, and the like.

[Computer functions]
FIG. 6 is a functional block diagram of the computer 34. As shown in FIG. 6, the control unit 40 including a CPU (Central Processing Unit) or FPGA (field-programmable gate array) (not shown) of the computer 34 and a memory (not shown) includes the software described above. The wear program 34a is executed. Accordingly, the control unit 40 includes a display control unit 42, a storage unit 43, a design information acquisition unit 44, a work coordinate system setting unit 45, a position / orientation acquisition unit 46, a coordinate value acquisition unit 47, and a coordinate value. It functions as the conversion unit 48 and the measurement result acquisition unit 50.

  The display control unit 42 controls the display on the display unit 38. In addition to the software program 34a described above, the storage unit 43 stores various information necessary for measurement by the coordinate measuring machine 10 such as a part program 49 and a corrected work coordinate system CSH, which will be described in detail later.

  The design information acquisition unit 44 acquires design information 51 of the workpiece 102 to be measured from outside via various interfaces (communication interfaces) not shown. The design information 51 is, for example, CAD (computer aided design) data of the workpiece 102, and is information indicating design values of the first measurement reference hole 110 and the second measurement reference hole 114. When the design information 51 of the workpiece 102 to be measured exists outside (server or the like), the design information acquisition unit 44 acquires the design information 51 corresponding to the workpiece 102 to be measured from the outside, and this design Information 51 is output to the work coordinate system setting unit 45.

  Further, the design information acquisition unit 44 acquires the radius value Pin_R1 of the first pin 124 and the radius value Pin_R2 of the second pin 126 from the outside, and outputs the acquired radius values Pin_R1 and Pin_R2 to the work coordinate system setting unit 45. To do. The radius values Pin_R1 and Pin_R2 are nominal values (average values) obtained by actually measuring the radii of the first pin 124 and the second pin 126, for example. The design information acquisition unit 44 may acquire information that can calculate the radius values Pin_R1 and Pin_R2 such as the diameter values of the first pin 124 and the second pin 126, for example, instead of the radius values Pin_R1 and Pin_R2.

<Correction work coordinate system setting process>
The workpiece coordinate system setting unit 45 calculates the shift amounts a and b generated by the processing machine 121 described above, and based on the shift amounts a and b, the center 112 of the first measurement reference hole 110 and the second measurement reference hole. The corrected work coordinate system CSH is corrected by correcting the work coordinate system CS (see FIG. 22) with the center 116 of 114 as a reference. That is, the workpiece coordinate system setting unit 45 corresponds to a corrected workpiece coordinate system setting unit of the present invention.

  FIG. 7 is a flowchart showing the flow of a corrected work coordinate system setting process in which the work coordinate system setting unit 45 sets the corrected work coordinate system CSH. As shown in FIG. 7, in the corrected work coordinate system setting step, the space correction setting step (step S1), the origin setting step (step S2), and the reference axis setting step (step S3) are executed in order.

  Before the start of the space correction step (step S1), the probe 12a attached to the probe head 12 of the coordinate measuring machine 10 is calibrated. Omitted.

In the space correction step (step S1), as described with reference to FIG. 20, the operator operates the probe operation unit 32a to probe three or more points on the plane 104 (see FIG. 20) of the workpiece 102 with the probe 12a. . As a result, coordinate values of a plurality of points on the plane 104 are input to the work coordinate system setting unit 45 via the drive controller 32. Then, the workpiece coordinate system setting unit 45 obtains the plane 104, the intersection point 106, and the normal vector 108 described above and translates the origin 100 of the machine coordinate system to the intersection point 106 to set the origin of the Z axis. . Thereby, the space correction step (step S1) is completed, and the X ₀ Y ₀ Z ₀ coordinate system (see FIG. 20) is spatially corrected to the X ₂ Y ₂ Z ₂ coordinate system (see FIG. 20).

  The origin setting step (step S2) executes a total of five steps (processes) from step S2A to step S2E.

  FIG. 8 is an explanatory diagram for explaining the steps S2A and S2B of FIG. FIG. 9 is an explanatory diagram for explaining steps S2C to S2E in FIG.

As shown in FIG. 8, in step S2A, the operator operates the probe operation unit 32a to probe a plurality of measurement points on the inner peripheral surface of the first measurement reference hole 110 with the probe 12a. Note that the circle indicated by R1a in the drawing is the outline of the first measurement reference hole 110 drawn by the design radius value R1a of the first measurement reference hole 110. By the above probing, coordinate values of a plurality of measurement points of the first measurement reference hole 110 are input to the work coordinate system setting unit 45 via the drive controller 32. Thereby, the workpiece coordinate system setting unit 45 obtains an actual measurement value of the first center coordinates (x1o ₁ , y1o ₁ ) of the center 112 of the first measurement reference hole 110 in the X ₂ Y ₂ axes.

When the design information 51 of the workpiece 102 to be measured is input from the design information acquisition unit 44 described above to the workpiece coordinate system setting unit 45, the workpiece coordinate system setting unit 45 receives the first measurement standard from the design information 51. The first center coordinates (x1o ₁ , y1o ₁ ) of the hole 110 are acquired. Specifically, by acquiring the position and orientation of the workpiece 102 on the surface plate 16 by a method to be described in detail later, the workpiece coordinate system setting unit 45 obtains the position and orientation acquisition result of the workpiece 102 and the design information 51. Based on the above, the first center coordinates (x1o ₁ , y1o ₁ ) can be acquired.

Next, in step S2B, the operator of the _{Y 2} axis of the first center coordinate of the measurement point of the first measurement reference hole 110 by the probe 12a by operating the probe operation portion _{32a (x1o 1, y1o 1)} (-) direction The first measurement point 113 on the (+) direction side opposite to the side is probed a plurality of times. Thus, the coordinate value of the first measurement point 113 is input to the work coordinate system setting unit 45 via the drive controller 32, and the work coordinate system setting unit 45 sets the coordinate value (x1 ₁ , y1 ₁ ) of the first measurement point 113. = (X1o ₁ , y1o ₁ + R1) [R1: nominal value] is acquired. Thereby, the radius R1 of the first measurement reference hole 110 is obtained.

As shown in FIG. 9, in step S2C, the workpiece coordinate system setting unit 45 acquires the radius value Pin_R1 of the first pin 124 from the design information acquisition unit 44 described above. Next, in step S2D, the workpiece coordinate system setting unit 45 shifts the radius value Pin_R1 of the first pin 124 from the coordinate values (x1 ₁ , y1 ₁ ) of the first measurement point 113 to the (−) direction side of the Y axis. The central coordinates (x1 ₂ , y1 ₂ ) = (x1o ₁ , y1 ₁ −Pin_R1) [Pin_R1: nominal value] of the central axis 128 of the first pin 124 are calculated. As a result, a shift amount a indicating the first relative position of the central axis 128 of the first pin 124 that is the first processing reference point with respect to the center 112 of the first measurement reference hole 110 that is the first measurement reference point is calculated. That is, step S2D corresponds to the first relative position calculation step of the present invention. In this case, the work coordinate system setting unit 45 also functions as a first relative position calculation unit of the present invention.

Then, in step S2E, work coordinate system setting unit 45, the origin 100 (see FIG. 20) of the _{Z 2} axes set in space correction process in step S1 described above, the center coordinates _(x1 2 of the first pin 124, The origin is moved parallel to y1 ₂ ). As a result, the shift amount a between the center 112 of the first measurement reference hole 110 and the center axis 128 of the first pin 124 is corrected, and the X ₂ Y ₂ Z ₂ coordinate system (see FIG. 20) becomes X ₃ Y ₃ Z. Correction is made to a _three- coordinate system (see FIG. 21). Thus, the origin setting process (step S2) is completed.

  In the reference axis setting step (step S3), a total of five steps (processes) from step S3A to step S3E are executed.

  FIG. 10 is an explanatory diagram for explaining the step S3A of FIG. FIG. 11 is an explanatory diagram for explaining the step S3B of FIG. FIG. 12 is an explanatory diagram for explaining steps S3C and 3D in FIG. FIG. 13 is an explanatory diagram for explaining before the execution of the step S3E of FIG. FIG. 14 is an explanatory diagram for explaining after execution of the process of step S3E of FIG.

As shown in FIG. 10, in step S3A, the operator operates the probe operation section 32a and the probe 12a uses the probe 12a to measure a plurality of measurement points (the edge of the second measurement reference hole 114). ). Note that the circle indicated by R2a in the drawing is the outline of the second measurement reference hole 114 drawn by the design radius value R2a of the second measurement reference hole 114. By the above-described probing, coordinate values of a plurality of measurement points of the second measurement reference hole 114 are input to the work coordinate system setting unit 45 via the drive controller 32. Thereby, the workpiece coordinate system setting unit 45 obtains an actual measurement value of the second center coordinates (x2o ₁ , y2o ₁ ) of the center 116 of the second measurement reference hole 114 in the X ₂ Y ₂ axes.

When the design information 51 is input from the design information acquisition unit 44 described above to the work coordinate system setting unit 45, the work coordinate system setting unit 45 reads the second center of the second measurement reference hole 114 from the design information 51. The coordinates (x2o ₁ , y2o ₁ ) are acquired. In this case, by obtaining the position and orientation of the workpiece 102 on the surface plate 16 as described above, the workpiece coordinate system setting unit 45 can obtain the result of obtaining the position and orientation of the workpiece 102 and the design information 51. Based on the second center coordinates (x2o ₁ , y2o ₁ ).

As shown in FIG. 11, in step S3B, the operator operates the probe operation unit 32a, and the probe 12a uses the probe 12a to measure the Y ₃ axis of the second central coordinate (x2o ₁ , y2o ₁ ) among the measurement points of the second measurement reference hole 114. The second measurement point 115 on the (+) direction side is probed a plurality of times. As a result, the coordinate value of the second measurement point 115 is input to the work coordinate system setting unit 45 via the drive controller 32, and the work coordinate system setting unit 45 sets the coordinate value (x2 ₁ , y2 ₁ ) of the second measurement point 115. = (X2o ₁ , y2o ₁ + R2) [R2: nominal value] is acquired. Thereby, the radius R2 of the second measurement reference hole 114 is obtained.

As shown in FIG. 12, in step S3C, the work coordinate system setting unit 45 acquires the radius value Pin_R2 of the second pin 126 from the design information acquisition unit 44 described above. Next, in step S3D, the workpiece coordinate system setting unit 45 shifts the radius value Pin_R2 of the second pin 126 from the coordinate values (x2 ₁ , y2 ₁ ) of the second measurement point 115 to the (−) direction side of the Y axis. The center coordinates (x2 ₂ , y2 ₂ ) = (x2o ₁ , y2 ₁ −Pin_R2) (Pin_R2: nominal value) of the center axis 130 of the second pin 126 are calculated. Thereby, a deviation amount b indicating the second relative position of the central axis 130 of the second pin 126 that is the second processing reference point with respect to the center 116 of the second measurement reference hole 114 that is the second measurement reference point is calculated. That is, step S3D corresponds to the second relative position calculation step of the present invention. In this case, the work coordinate system setting unit 45 also functions as a second relative position calculation unit of the present invention.

As shown in FIGS 13 and 14, in step S3E, work coordinate system setting unit 45, so that the _{X 3} axis of FIG. 13 through the center coordinates _(x2 2, y2 ₂₎ the second pin 126, Using the origin of X ₃ Y ₃ axes [center coordinates (x 1 ₂ , y 1 ₂ )] as a fulcrum, the X ₃ axis is rotated as shown in FIG. Set. As a result, the direction of the XY axis of the corrected work coordinate system CSH becomes a direction in which the deviation amount b between the center 116 of the second measurement reference hole 114 and the center axis 130 of the second pin 126 is corrected, and X ₃ Y in FIG. _{The three} coordinate system is corrected to the X ₄ Y ₄ coordinate system of FIG. This completes the reference axis setting step (step S3).

Through the above steps, the workpiece coordinate system setting unit 45 sets a corrected workpiece coordinate system CSH in which the workpiece coordinate system CS (see FIG. 22) is corrected based on the shift amounts a and b (step S4). That, _{X 4} axis of FIG. 14 is set to the X-axis of the correction workpiece coordinate system CSH, _{Y 4} axis of FIG. 14 is set to the Y-axis of the correction workpiece coordinate system CSH, _{Z 3} axes of Figure 21 are corrected work coordinates is set to the Z-axis of the system CSH, the intersection of the center coordinates _(x1 2, y1 ₂₎ and _{Z 3} axes in FIG. 14 (see FIG. 21) is set to the origin of the correction work coordinate system CSH. Then, the workpiece coordinate system setting unit 45 stores the setting information of the corrected workpiece coordinate system CSH in the storage unit 43 (see FIG. 6).

  In addition, when the work coordinate system setting unit 45 acquires the design information 51 and the radius values Pin_R1 and Pin_R2 from the design information acquisition unit 44, the workpiece coordinate system setting unit 45 performs all the processes from the above-described steps S1 to S3 by calculation processing. The correction work coordinate system CSH can be set. In this case, the corrected work coordinate system CSH can be set by the off-line computer 34 without performing a probing operation by the operator.

<Acquisition of workpiece position and orientation>
Returning to FIG. 6, the position / orientation acquisition unit 46 of the workpiece 102 set on the surface plate 16 before the measurement of the first circular hole 118 and the second circular hole 120 of the workpiece 102 by the coordinate measuring machine 10 is started. Get position and orientation. The position and orientation acquisition unit 46, first controls the display control unit 42, Z upper surface (not shown) is a top orthogonal to the Z ₃ axes of the workpiece 102 is the side surface perpendicular to the Y ₄ axes of the workpiece 102 Y side (not shown), and is displayed on the display unit 38 a display prompting the probing for X side is a side that is perpendicular to the X ₄ axis of the workpiece 102 (not shown).

  Next, the operator operates the probe operation unit 32a to probe any three or more points on the Z upper surface of the workpiece 102 with the probe 12a. The posture of the probe 12a at this time is a posture parallel to the Z-axis at the start of measurement (initial state). Then, the result of the probing measurement on the Z upper surface is input to the position / orientation acquisition unit 46 via the drive controller 32.

  In addition, the operator operates the probe operation unit 32a to probe any two or more points on the Y side surface of the workpiece 102 with the probe 12a without rotating the posture of the probe 12a. The result of the Y-side probing measurement is input to the position / orientation acquisition unit 46 via the drive controller 32. The position / orientation acquisition unit 46 determines the Y origin and X axis orientation of the workpiece 102 on the surface plate 16 based on the results of the probing measurement of the Z upper surface and the Y side surface.

  Then, the operator operates the probe operation unit 32a to probe any one or more points on the X side surface of the workpiece 102 with the probe 12a without rotating the posture of the probe 12a. The result of the probing measurement on the X side is input to the position / orientation acquisition unit 46 via the drive controller 32. The position / orientation acquisition unit 46 determines the X origin of the workpiece 102 on the surface plate 16 and the directions of the Y axis and the Z axis based on the probing measurement results of the Z upper surface, the Y side surface, and the X side surface. Thereby, the position / orientation acquisition unit 46 can acquire the position / orientation of the workpiece 102 on the surface plate 16, and the acquisition result of the position / orientation of the workpiece 102 is sent to the coordinate value acquisition unit 47 and the coordinate value conversion unit 48. Output each.

  Note that the method for measuring the position and orientation of the workpiece 102 set on the surface plate 16 of the coordinate measuring machine 10 is not limited to the above-described method. For example, a method of analyzing an image obtained by imaging the workpiece 102 on the surface plate 16 with a camera provided in the coordinate measuring machine 10 or a detection result of a position sensor and a posture sensor provided in the workpiece 102 is acquired. The position and orientation of the workpiece 102 may be acquired using various methods such as a method for performing the above.

<Part program>
The part program 49 stored in the storage unit 43 is a coordinate value indicating the measurement path of the probe 12a, that is, the positions of the measurement points of both the first circular hole 118 and the second circular hole 120 that are measurement elements of the workpiece 102. , A measurement order of measurement points, a measurement posture (orientation) of the probe 12a for each measurement point, and the like, and are used for measurement control by a coordinate value acquisition unit 47 described later. The measurement path of the probe 12a is a measurement path based on the corrected work coordinate system CSH. Therefore, if the position and orientation of the workpiece 102 on the surface plate 16 are known, the first circular hole 118 and the second circular hole 120 can be automatically measured according to the part program 49.

  Although not shown, the control unit 40 functions as a part program creation unit that creates the part program 49 based on the corrected work coordinate system CSH stored in the storage unit 43. Since a specific method for creating the part program 49 is known, a specific description is omitted here.

<Acquisition of coordinate values of measurement points of measurement elements (first circular hole 118 and second circular hole 120)>
The coordinate value acquisition unit 47 controls the measurement by the coordinate measuring machine 10, that is, the measurement of the first circular hole 118 and the second circular hole 120 which are measurement elements of the workpiece 102. The coordinate value acquisition unit 47 is based on the position and orientation information of the workpiece 102 input from the position and orientation acquisition unit 46 and the part program 49 read from the storage unit 43, and the first circular hole 118 and the second circular hole 120. Execute measurement at each measurement point. Note that the known probe 12a is calibrated before starting measurement at each measurement point.

  For example, when the automatic measurement mode is set, the coordinate value acquisition unit 47 is based on the position and orientation information of the workpiece 102 input from the position and orientation acquisition unit 46 and the part program 49 via the drive controller 32. The first drive unit 28 and the second drive unit 30 are driven. Thereby, each measurement point of the first circular hole 118 and the second circular hole 120 can be probed by the probe 12a in the order determined by the part program 49.

  On the other hand, when the manual measurement mode is set, the coordinate value acquisition unit 47 controls the display control unit 42 based on the position / orientation information of the workpiece 102 and the part program 49, and the first circular hole 118 and Information indicating the position of each measurement point of the second circular hole 120, the measurement order, and the like is displayed on the display unit 38. The operator operates the probe operation unit 32 a according to the display content of the display unit 38 and probes each measurement point of the first circular hole 118 and the second circular hole 120 in the order determined by the part program 49 by the probe 12 a.

  And the coordinate value acquisition part 47 acquires the coordinate value of each measurement point of the 1st circular hole 118 and the 2nd circular hole 120 via the drive controller 32 in any of automatic measurement mode and manual measurement mode, The acquired coordinate value is output to the coordinate value conversion unit 48.

<Coordinate value conversion>
The coordinate value conversion unit 48 converts the coordinate values of the respective measurement points of the first circular hole 118 and the second circular hole 120 input from the coordinate value conversion unit 48, that is, the coordinate values expressed in the machine coordinate system, to the corrected work coordinates. Conversion into coordinate values expressed in the system CSH.

  Specifically, the coordinate value conversion unit 48 is expressed in a machine coordinate system based on the position and orientation information of the workpiece 102 input from the position and orientation acquisition unit 46 and the corrected workpiece coordinate system CSH read from the storage unit 43. A correction matrix 55 (also referred to as a conversion matrix or a conversion matrix) for converting the coordinate values to be converted into coordinate values represented by the correction work coordinate system CSH is generated. Each parameter of the correction matrix 55 includes a positional deviation amount between the origin of the machine coordinate system and the origin of the corrected workpiece coordinate system CSH, and a rotational deviation amount between the reference axis of the machine coordinate system and the reference axis of the corrected workpiece coordinate system CSH. To be determined.

  Therefore, the coordinate value conversion unit 48 converts the coordinate values of the measurement points of the first circular hole 118 and the second circular hole 120 input from the coordinate value conversion unit 48 using the correction matrix 55, thereby converting the coordinate values. Then, the coordinate value of each measurement point represented by the corrected work coordinate system CSH is acquired. Then, the coordinate value conversion unit 48 outputs the coordinate value of each measurement point after the coordinate value conversion to the measurement result acquisition unit 50.

<Acquisition of measurement results>
The measurement result acquisition unit 50 determines the positions and dimensions of the first circular hole 118 and the second circular hole 120 in the workpiece 102 based on the coordinate values of each measurement point after the coordinate value conversion input from the coordinate value conversion unit 48. Measurement results such as shape and shape are acquired. The measurement result is displayed on the display unit 38 by the display control unit 42 and stored in the storage unit 43.

[Operation of CMM]
FIG. 15 is a flowchart showing a flow of measurement processing of the workpiece 102 by the coordinate measuring machine 10 having the above-described configuration (measurement method of the coordinate measuring machine of the present invention). As shown in FIG. 15, first, the operator sets the workpiece 102 to be measured on the surface plate 16 of the coordinate measuring machine 10 (step S10).

  Next, the corrected work coordinate system setting step described with reference to FIG. 7 is executed, the corrected work coordinate system CSH of the work 102 is set by the work coordinate system setting unit 45, and the corrected work coordinate system is stored in the storage unit 43. CSH is stored (step S11).

  The parts used for measuring each measurement point of the first circular hole 118 and the second circular hole 120 of the workpiece 102 by a part program creation unit (not shown) based on the corrected workpiece coordinate system CSH stored in the storage unit 43. After the program 49 is created, the part program 49 is stored in the storage unit 43.

  After setting and storing the corrected work coordinate system CSH, the operator operates the probe operation unit 32a to probe the Z surface, Y side surface, and X side surface of the workpiece 102 set on the surface plate 16 with the probe 12a. Execute. Thereby, the position and orientation acquisition unit 46 acquires the position and orientation of the workpiece 102 on the surface plate 16 (step S12, corresponding to the position and orientation acquisition step of the present invention).

  Then, the position / orientation acquisition unit 46 outputs the acquisition result of the position / orientation of the workpiece 102 to the coordinate value acquisition unit 47 and the coordinate value conversion unit 48, respectively. As a result, the coordinate value conversion unit 48 generates the correction matrix 55 based on the position and orientation information of the workpiece 102 input from the position and orientation acquisition unit 46 and the corrected work coordinate system CSH stored in the storage unit 43. (Step S13).

  Next, measurement control of each measurement point of the first circular hole 118 and the second circular hole 120 by the coordinate value acquisition unit 47 is started. For example, in the case of the automatic measurement mode, the coordinate value acquisition unit 47 performs the first operation via the drive controller 32 based on the position and orientation information of the workpiece 102 from the position and orientation acquisition unit 46 and the part program 49 in the storage unit 43. The drive unit 28 and the second drive unit 30 are driven. As a result, the measurement points of the first circular hole 118 and the second circular hole 120 are probed by the probe 12 a in the order determined by the part program 49.

  On the other hand, in the manual measurement mode, the coordinate value acquisition unit 47 controls the display control unit 42 based on the position / orientation information of the workpiece 102 and the part program 49 to measure the measurement points and the second points of the first circular hole 118. Information indicating the position, measurement order, and the like regarding the measurement point of the circular hole 120 is displayed on the display unit 38. Then, the operator operates the probe operation unit 32a according to the display content of the display unit 38, and the measurement points of the first circular hole 118 and the measurement points of the second circular hole 120 are determined by the part program 49 by the probe 12a. Probing in order.

  When the probing in the automatic measurement mode or the manual measurement mode is executed, the coordinate value acquisition unit 47 obtains the coordinate values of the measurement points of the first circular hole 118 and the second circular hole 120 via the drive controller 32. (Step S14, corresponding to the coordinate value acquisition process of the present invention). Then, the coordinate value acquisition unit 47 outputs the acquired coordinate values of each measurement point to the coordinate value conversion unit 48.

  Next, the coordinate value conversion unit 48 generates the coordinate values represented in the machine coordinate system of the respective measurement points of the first circular hole 118 and the second circular hole 120 input from the coordinate value conversion unit 48 previously generated. Coordinate values are converted using the matrix 55, and the coordinate values of each measurement point represented by the corrected work coordinate system CSH are output to the measurement result acquisition unit 50 (step S15, corresponding to the coordinate value conversion process of the present invention).

  Then, the measurement result acquisition unit 50, based on the coordinate values of each measurement point represented by the corrected workpiece coordinate system CSH input from the coordinate value conversion unit 48, the workpieces 102 of the first circular hole 118 and the second circular hole 120. Measurement results such as the position, size, and shape are acquired (step S16). The measurement result is displayed on the display unit 38 by the display control unit 42 and stored in the storage unit 43.

  When measuring various measurement elements of the same type of workpiece 102, or when measuring various measurement elements of the workpiece 102 for which the corrected workpiece coordinate system CSH has been created and stored in the past, step S11 is performed. Can be omitted.

[Effect of CMM of this embodiment]
As described above, the coordinate measuring machine 10 according to the present embodiment calculates the above-described deviation amount “a” indicating the first relative position and the above-described deviation amount “b” indicating the second relative position. Then, a corrected work coordinate system CSH obtained by correcting the work coordinate system CS is set, and the coordinate values of the measurement points of the first circular hole 118 and the second circular hole 120 are measured. Thereby, in the coordinate measuring machine 10 of this embodiment, the 1st circular hole 118 and 2nd circle which correct | amended the offset error produced at the time of the process of the processing machine 121, and reflected the processing error by the processing machine 121 with high precision. A measurement result of the hole 120, that is, a measurement result that is compatible with the processing machine 121 is obtained.

  FIG. 16 is an explanatory diagram for explaining the effect of the coordinate measuring machine 10 of the present embodiment. Here, in the upper part of FIG. 16, the center 112 of the first measurement reference hole 110 and the center axis 128 of the first pin 124 coincide, and the center 116 of the second measurement reference hole 114 and the center axis 130 of the second pin 126. This is an example in which the first circular hole 118 and the second circular hole 120 are processed by the processing machine 121 in the ideal state in which.

  In the ideal state shown in the upper part of FIG. 16, the center 112 (first measurement reference point) and the center axis 128 (first processing reference point) coincide with each other, and the center 116 (second measurement reference point) and the center axis 130 ( 2nd processing reference point). Therefore, the first circular hole 118 and the second circular hole 120 are positions defined by the design radius values R1a and R2a with the first measurement reference point and the second measurement reference point serving as the reference of the workpiece coordinate system CS as reference positions. To be processed. As a result, even when the workpiece coordinate system CS (see FIG. 22) is set and the coordinate values of the measurement points of the first circular hole 118 and the second circular hole 120 are measured, the above-described offset error is the coordinate value. It does not appear in the measurement results.

  On the other hand, the lower part of FIG. 16 is an example in which the first circular hole 118 and the second circular hole 120 are processed by the processing machine 121 in the actual state where the workpiece 102 is shifted to the arrow A1 direction side in the processing machine 121. . FIG. 17 is a top view of the work 102 in the lower stage of FIG.

  In the actual state shown in the lower part of FIG. 16 and FIG. 17, the above-described deviation amounts a and b (see FIG. 3) occur. For this reason, the first circular hole 118 and the second circular hole 120 are displaced by a displacement amount b with respect to the first measurement reference point and a first processing reference point that is displaced by a displacement amount a with respect to the second measurement reference point. Processing is performed at a position defined by the design radius values R1a and R2a with the displaced second processing reference point as a reference position. As a result, when the conventional workpiece coordinate system CS is set and the coordinate values of the measurement points of the first circular hole 118 and the second circular hole 120 are measured, the measured values R1m and R2m include the deviation amounts a and b. The offset error Re corresponding to is included.

  Therefore, there is a gap between the measured values R1m and R2m obtained by actual measurement and the measured values R1s and R2s obtained by measurement using the first machining reference point and the second machining reference point of the processing machine 121 as reference positions. Occurs. That is, the shift amounts a and b due to the shift when the processing machine 121 is processed appear in the measured values R1m and R2m of the coordinate measuring machine 10 as a shift error Re. For this reason, the processing error of the processing machine 121 (the error between the measured values R1s and R2s and the design radius values R1a and R2a), in other words, in the processing machine 121 based on the first processing reference point and the second processing reference point. The measured values R1s and R2s cannot be accurately determined.

  On the other hand, when the correction work coordinate system CSH is set and the coordinate values of the measurement points of the first circular hole 118 and the second circular hole 120 are measured as in the present embodiment, the above-described offset error Re is not included. Measurement values R1s and R2s are obtained. For this reason, the processing error of the processing machine 121 can be obtained with high accuracy from the measured values R1s and R2s of the coordinate measuring machine 10.

  Further, for example, when the positional degrees of the first circular hole 118 and the second circular hole 120 are obtained, this positional degree is an error between the center 112 (center 116) and the center axis 128 (center axis 130), that is, as described above. This is twice the displacement amount a and b. For this reason, when the measurement error of the coordinate measuring machine 10 is set to E, in the method of measuring by setting the conventional workpiece coordinate system CS, the influence on the position is {(R1-Pin_R1) + E} ×. 2 = {a + E} × 2, {(R2-Pin_R2) + E} × 2 = {b + E} × 2. On the other hand, in the method of performing measurement by setting the corrected work coordinate system CSH as in the present embodiment, the shift amounts a and b (deviation error) can be excluded from the measurement results of the coordinate measuring machine 10. . For this reason, the processing error of the processing machine 121 can be determined with high accuracy from the measurement result.

[Others]
The workpiece 102 to be measured by the three-dimensional measuring machine 10 is not limited to the workpiece 102 described in the above embodiments, but the positions of the first measurement reference hole 110 and the second measurement reference hole 114 and the measurement elements. The positions of the first circular hole 118 and the second circular hole 120 may be different from the positions shown in the above embodiments. For example, as shown in FIGS. 18 and 19 below, the first measurement reference hole 110 and the second measurement reference hole 114, and the first circular hole 118 and the second circular hole 120 are formed on different surfaces of the workpiece 102. May be.

  FIG. 18 is an explanatory diagram for explaining processing by the processing machine 121 in another embodiment, and FIG. 19 is an explanatory diagram for explaining measurement by the coordinate measuring machine 10 in another embodiment. As shown in FIGS. 18 and 19, for example, a first measurement reference hole 110 (second measurement reference hole 114) and a first circular hole 118 (second circular hole 120) are formed on different surfaces of the workpiece 102. In such a case, the posture of the workpiece 102 at the time of measurement by the coordinate measuring machine 10 may be made different from the posture at the time of machining by the processing machine 121 using the jig 80. That is, the workpiece 102 is fixed by the jig 80 in such a posture that the probe 12a can probe both the first measurement reference hole 110 (second measurement reference hole 114) and the first circular hole 118 (second circular hole 120). It may be supported on the board 16.

  Further, the shape (type) of the workpiece 102 may be changed as appropriate, and the present invention can also be applied to a case where a measurement element other than a circular hole is measured.

  In the above embodiment, the coordinate value acquisition unit 47 acquires the coordinate value of each measurement point according to the part program 49 described in the corrected work coordinate system CSH, and the coordinate value conversion unit 48 converts the coordinate value of the machine coordinate system to the corrected work coordinate. Although the coordinate values of the system CSH are converted, the present invention is not limited to this. For example, after the coordinate value acquisition unit 47 acquires the coordinate value of each measurement point according to the part program 49 described in the workpiece coordinate system CS, the coordinate value conversion unit 48 converts the coordinate value of the machine coordinate system to the coordinate of the workpiece coordinate system CS. You may perform the 1st coordinate value conversion process converted into a value, and the 2nd coordinate value conversion process which converts the coordinate value of the workpiece | work coordinate system CS into the coordinate value of the correction | amendment workpiece | work coordinate system CSH.

  In the above embodiment, the first measurement reference hole 110 and the second measurement reference hole 114 have been described as examples of the first measurement reference point and the second measurement reference point of the present invention. Other first measurement reference points and second measurement reference points that can be used may be provided on the workpiece 102. In the above embodiment, the first pin 124 and the second pin 126 have been described as examples as the first processing reference point and the second processing reference point of the present invention. However, the reference when performing processing by the processing machine 121 is described. Other first processing reference points and second processing reference points that may be positions may be adopted.

  In the above-described embodiment, the center axis 128 of the first pin 124 and the center axis 130 of the second pin 126 are offset in the same direction by shifting the work 102. For example, the work 102 is placed on the upper surface (the upper surface of the table 122). On the other hand, when the backlash is suppressed by rotating around the axis of the vertical rotation axis, the center axes 128 and 130 are offset in different directions. Even in this case, the corrected work coordinate system CSH can be set by calculating the above-described deviation amounts a and b.

  In the above embodiment, the portal moving type three-dimensional measuring machine 10 has been described as an example. However, the present invention can be applied to various types of three-dimensional measuring machines, and probes used in the three-dimensional measuring machine 10. The type of 12a is not particularly limited, and for example, a non-contact type probe may be used. In the above embodiment, the coordinate measuring machine 10, the drive controller 32, and the computer 34 are separate bodies, but the coordinate measuring machine 10, and at least one of the drive controller 32 and the computer 34 are integrated. May be.

  The coordinate measuring machine according to the present invention includes a corrected work coordinate system CSH based on the measurement results (coordinate values) acquired from other coordinate measuring machines, the design information 51 and the radius values Pin_R1 and Pin_R2 acquired from the outside. Including the setting of the position and orientation of the workpiece 102, the acquisition of coordinate values, the conversion of coordinate values, and the like, that is, the configuration including only the computer 34 is included.

  DESCRIPTION OF SYMBOLS 10 ... CMM, 16 ... Surface plate, 28 ... 1st drive part, 30 ... 2nd drive part, 34 ... Computer, 38 ... Display part, 40 ... Control part, 44 ... Design information acquisition part, 45 ... Workpiece Coordinate system setting unit 46 ... Position and orientation acquisition unit 47 ... Coordinate value acquisition unit 48 ... Coordinate value conversion unit 49 49 Part program 51 Design information 102 Workpiece 110 110 First measurement reference hole 112 116 ... center, 114 ... second measurement reference hole, 118 ... first circular hole, 120 ... second circular hole, 124 ... first pin, 126 ... second pin, 128, 130 ... center axis

Claims (8)

In a measuring method of a CMM that measures a measuring element processed into a workpiece with a CMM,
The workpiece is provided with a first measurement reference point and a second measurement reference point that serve as a reference for the workpiece coordinate system when a workpiece coordinate system is set with the workpiece as a reference and measurement is performed by the coordinate measuring machine. The measurement element is processed with a first processing reference point offset from the first measurement reference point and a second processing reference point offset from the second measurement reference point as a reference position,
A first relative position calculating step of calculating a first relative position of the first processing reference point with respect to the first measurement reference point;
A second relative position calculating step of calculating a second relative position of the second processing reference point with respect to the second measurement reference point;
A corrected work coordinate system obtained by correcting the work coordinate system based on the first relative position calculated in the first relative position calculation step and the second relative position calculated in the second relative position calculation step. Correction workpiece coordinate system setting process to be set,
A measuring method for a three-dimensional measuring machine. A position and orientation acquisition step of acquiring the position and orientation of the workpiece in the coordinate measuring machine;
A coordinate value acquisition step of measuring a measurement point in the measurement element with the coordinate measuring machine and acquiring a coordinate value of the measurement point represented by a machine coordinate system of the coordinate measuring machine;
Based on the corrected workpiece coordinate system set in the corrected workpiece coordinate system setting step and the position and orientation of the workpiece acquired in the position and orientation acquisition step, the measurement point acquired in the coordinate value acquisition step A coordinate value conversion step of converting the coordinate value into a coordinate value represented in the corrected work coordinate system;
The measuring method of the coordinate measuring machine according to claim 1, comprising:   The three-dimensional according to claim 1 or 2, wherein an offset direction of the first machining reference point with respect to the first measurement reference point and an offset direction of the second machining reference point with respect to the second measurement reference point are the same direction. Measuring method of measuring machine. A processing machine for processing the measurement element on the workpiece includes a first pin and a second pin that are provided in a first direction and are used for positioning the workpiece,
The workpiece has a first measurement reference hole having a diameter larger than that of the first pin and the first pin being inserted therein, and a second measurement reference hole having a diameter larger than that of the second pin and the second pin being inserted therein. Formed,
The workpiece is shifted in a second direction perpendicular to the first direction, with the first pin inserted into the first measurement reference hole and the second pin inserted into the second measurement reference hole. In this state, the measuring element is processed by the processing machine,
The first measurement reference point is a center of the first measurement reference hole, the second measurement reference point is a center of the second measurement reference hole, and the first machining reference point is a central axis of the first pin. The measuring method of the coordinate measuring machine according to claim 3, wherein the second processing reference point is a central axis of the second pin. The first relative position calculating step acquires the center coordinate of the first measurement reference hole and the radius value of the first pin, and acquires the acquired center coordinate of the first measurement reference hole and the radius value of the first pin. And calculating the first relative position based on
The second relative position calculating step acquires the center coordinate of the second measurement reference hole and the radius value of the second pin, and acquires the acquired center coordinate of the second measurement reference hole and the radius value of the second pin. The measurement method of the coordinate measuring machine according to claim 4, wherein the second relative position is calculated based on: In the first relative position calculating step, the center coordinate of the first measurement reference hole is acquired by actual measurement by the coordinate measuring machine or acquired from the design information of the first measurement reference hole,
The three-dimensional according to claim 5, wherein the second relative position calculating step acquires the center coordinates of the second measurement reference hole by actual measurement by the three-dimensional measuring machine or from design information of the second measurement reference hole. Measuring method of measuring machine. In a three-dimensional measuring machine that measures measuring elements processed into workpieces,
The workpiece is provided with a first measurement reference point and a second measurement reference point that serve as a reference for the workpiece coordinate system when a workpiece coordinate system is set with the workpiece as a reference and measurement is performed by the coordinate measuring machine. The measurement element is processed with a first processing reference point offset from the first measurement reference point and a second processing reference point offset from the second measurement reference point as a reference position,
A first relative position calculator that calculates a first relative position of the first machining reference point with respect to the first measurement reference point;
A second relative position calculator that calculates a second relative position of the second machining reference point with respect to the second measurement reference point;
Based on the first relative position calculated by the first relative position calculation unit and the second relative position calculated by the second relative position calculation unit, a corrected work coordinate system is set by correcting the work coordinate system. Correction work coordinate system setting section,
CMM equipped with. A position and orientation acquisition unit for acquiring the position and orientation of the workpiece in the coordinate measuring machine;
The coordinate value of the measurement point obtained by measuring the measurement point in the measurement element with the coordinate measuring machine, and the coordinate value of the measurement point expressed in the machine coordinate system of the coordinate measuring machine A coordinate value acquisition unit for acquiring
Based on the corrected workpiece coordinate system set by the corrected workpiece coordinate system setting unit and the position and orientation of the workpiece acquired by the position and orientation acquisition unit, the coordinate value of the measurement point acquired by the coordinate value acquisition unit is obtained. , A coordinate value conversion unit that converts the coordinate value expressed in the corrected work coordinate system;
The coordinate measuring machine according to claim 7, comprising:

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