JP5032031B2 - Contact probe and shape measuring device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a contact probe reduced in load applied onto a measuring object surface. <P>SOLUTION: This contact probe is provided with: the probe 310 having a contact part 312 contacting with the measuring object surface in its tip; a detecting sensor for detecting a displacement of the probe 310; a support plate 420 of an elastic plate arranged substantially orthogonally to an axial direction of the probe 310, and for supporting a base end side of the probe 310; and a stylus displacing means 440 for displacing the probe 310. The stylus displacing means 440 is provided with actuators 441-443 for applying stresses onto the support plate 420 to change elastic deformation amounts of the support plate 420 in respective points. <P>COPYRIGHT: (C)2007,JPO&amp;INPIT

Description

  The present invention relates to a contact probe and a shape measuring device. For example, the present invention relates to a shape measuring apparatus that measures the shape of an object to be measured with a contact probe.

  Measuring devices that scan the surface of the object to be measured and measure the surface properties and three-dimensional shape of the object to be measured are known, such as a roughness measuring machine, a contour shape measuring machine, a roundness measuring machine, and a three-dimensional measuring machine. It has been known. A contact probe is used as a displacement sensor that detects the surface of the object to be measured based on the minute displacement of the contact part when the contact part contacts the surface of the object to be measured (Patent Document 1).

FIG. 21 shows a configuration of the coordinate measuring machine 10 using a contact probe.
The three-dimensional measuring machine 10 includes a contact probe 11 and a drive mechanism 12 that moves the contact probe 11 three-dimensionally along the surface of the object to be measured. As shown in FIG. 22, the contact probe 11 includes a stylus 13 having a contact portion 14 at a distal end, and a sensor main body 15 that supports the proximal end of the stylus 13. The sensor main body 15 supports the stylus 13 so as to be displaceable within a certain range in the xp, yp, and zp directions, and detects the amount of displacement of the stylus 13.

Touch detection is an example of detecting the surface of the object to be measured with such a contact probe.
In the touch measurement, first, the contact probe 11 is moved by the drive mechanism 12 to bring the contact portion 14 into contact with the measurement point on the surface of the object to be measured. Then, the contact probe 11 is moved in the direction in which the contact portion 14 is pushed into the object to be measured, and the contact portion 14 and the surface of the object to be measured are detected when a predetermined push amount (reference push amount) is detected as the displacement of the contact portion 14. Detects contact with. When the contact between the contact portion 14 and the surface of the object to be measured is detected, the coordinates of the contact portion 14 are sampled to measure the surface of the object to be measured. After sampling the coordinates of the contact portion 14, the contact probe 11 is separated from the object to be measured by a touchback operation, and the contact portion 14 is brought into contact with the next measurement point again. Such a touch measurement is repeatedly executed to measure the surface of the object to be measured.

JP 2000-39302 A

However, when the contact portion 14 is pushed into the surface of the object to be measured by a predetermined amount, contact between the contact portion 14 and the surface of the object to be measured is detected. Overtravel occurs due to the inertia of the drive mechanism, and the contact exceeds the predetermined amount. The part 14 is pushed into the surface of the object to be measured.
Thus, when overtravel occurs and the contact portion 14 is pushed too much into the surface of the object to be measured beyond a predetermined amount, a large load is applied to the stylus 13 as well as a problem of damaging the surface of the object to be measured.

Furthermore, in order to improve the measurement accuracy, it is necessary to make the contact portion 14 minute. However, if the contact portion 14 is made small, the pressure per unit area increases, so that the surface of the object to be measured is severely damaged. Problem arises.
For this reason, it has been difficult to perform high-precision measurement and reduce the load on the surface of the object to be measured in contact measurement.

  An object of the present invention is to provide a contact probe and a shape measuring apparatus that have a small load on the surface of the object to be measured.

The contact probe according to the present invention is arranged such that a probe having a contact portion in contact with the surface of the object to be measured, a detection sensor for detecting displacement of the probe, and an axial direction of the probe are substantially orthogonal to each other. a support plate for supporting the base end side of the measuring element a plate of elastic material with, and a measuring element displacement means for displacing the measuring element, the support plate, the third position is not in a straight line A narrow region connecting a portion where the base end side of the probe is fixed and another portion between the cut line and a portion where the base end side of the probe is fixed. The probe displacement means is arranged in the narrow region , applies stress to the narrow region , and determines the position and / or angle of the portion to which the proximal end side of the probe is fixed. changing to the portion, displace the measuring element in any direction And wherein the obtaining Bei a stress applying means for.
Such a stress applying means is a piezoelectric actuator that is configured by laminating a plurality of thin plates of piezoelectric elements, the height of which is changed by application of voltage, and is disposed on the lower surface of the narrow region , What pushes up a narrow area | region by predetermined amount is employable.
Alternatively, as the stress applying means, the narrow stretch amount on the front and back surfaces of the region is constituted by affixed different plate material, bimorph actuator elastically deforming the narrow region by the stress from the front and back by applying a voltage It is good.

In such a configuration, when the contact portion of the probe contacts the surface of the object to be measured, force acts on the contact portion from the surface of the object to be measured. Then, since the measuring element is supported by a portion of the support plate, which is an elastic body, supported through three or more narrow regions not on a straight line , the proximal end side is fixed to this portion and this portion. The measuring element is displaced by an amount corresponding to the force received from the surface of the object to be measured. At this time, the support plate is an elastic plate and supports the probe in a state of being arranged substantially orthogonal to the axial direction of the probe, so that the support plate moves up and down or tilts in an arbitrary direction. By doing so, the three-dimensional displacement of the measuring element is allowed. The displacement of the probe due to contact with the surface of the object to be measured is detected by a detection sensor. For example, when the displacement of the probe reaches a predetermined amount (reference push amount) set in advance, contact between the contact portion and the surface of the object to be measured is detected. When the stress applying means provided on the support plate is driven, stress is applied to the support plate at each point, and the support plate is elastically deformed at each point.

Here, since the stress with respect to the support plate is applied to three or more narrow regions not on a straight line, the inclination angle of the support plate is uniquely determined by these three points. When the probe is supported by the support plate, the probe is displaced together with the inclination angle of the portion where the proximal end of the probe of the support plate is fixed due to elastic deformation of the narrow region. By determining the angle by adjusting the stress from the stress applying means, the displacement of the measuring element is uniquely determined.

According to such a configuration, in addition to the displacement of the probe due to the pressing force when contacting the surface of the object to be measured, the probe can be displaced by driving the probe displacement means.
For example, in touch measurement, contact is detected when the contact portion is pushed down to a predetermined amount, and touch back is performed immediately after contact detection. However, inertia works on the drive mechanism that relatively moves the contact probe and the object to be measured. In addition, the touchback operation cannot be performed immediately, and the contact probe may be pushed too much into the surface of the object to be measured more than the reference amount.

In this regard, in the present invention, since the measuring element displacing means is provided, the measuring element is moved from the surface of the object to be measured by the measuring element displacing means regardless of the operation of the driving mechanism for relatively moving the contact probe and the object to be measured. It can be displaced in the direction of separation. Then, since the contact portion is not excessively pushed into the surface of the object to be measured, the surface of the object to be measured that is the object of measurement is not damaged.
In particular, when the contact portion is made minute in order to improve the measurement accuracy, the contact pressure per unit area increases, so that the risk of damaging the surface of the object to be measured increases. Since the contact portion is not pushed into the surface of the object to be measured, it is possible to measure with high accuracy by the minute contact portion and to prevent the surface of the object to be measured from being damaged.

In addition, even when this contact probe is used for scanning measurement, it is possible to reduce friction that is a problem in scanning measurement.
For example, when the contact portion is moved along the surface of the object to be measured, the contact portion is displaced by driving the measuring element displacing means so as to reduce the pushing amount at a predetermined cycle. When scanning measurement is performed with the indentation amount kept constant, distortion occurs in the probe due to the friction between the contact part and the surface of the object to be measured, but the probe is displaced slightly by the probe displacement means. The indentation pressure can be reduced by reducing the amount. Then, the strain energy accumulated in the probe can be periodically released.

  Thus, according to the present invention, since the measuring element can be displaced by the measuring element displacing means, the indentation pressure between the contact portion and the surface of the object to be measured is decreased at a desired timing to measure the surface of the object to be measured or the measurement. Child damage can be prevented.

Further, since the stress applying means constituting the measuring element displacing means applies stress at three or more points of the supporting plate, the supporting plate can be inclined in any direction, and the measuring element can be displaced in an arbitrary direction. it can. Accordingly, the contact portion can be displaced in a direction away from the surface of the object to be measured regardless of the directionality in which the contact portion contacts the surface of the object to be measured.

The stress applying means is an actuator that elastically deforms the support plate at each location of the support plate and changes the position and / or angle of the surface of the support plate that supports the base end of the measuring element. An example of such an actuator is a configuration in which a pressing force is applied to the support plate when the top portion appears or disappears or the entire portion expands and contracts.
Examples of such a configuration include a piezoelectric actuator in which piezoelectric elements are stacked, a magnetostrictive actuator, an electrostatic actuator, an ultrasonic actuator, and the like.
Or as such an actuator, the bimorph type structure which stuck the board | plate material (or thin film) which can control an expansion-contraction amount on the front and back of a support plate may be sufficient.

With the configuration described above, since the response is fast, an operation such as separating the measuring element from the surface of the object to be measured can be executed at a desired timing.
For example, a drive mechanism that moves the contact probe relative to the object to be measured is difficult to stop suddenly because it is affected by inertia, but before the contact portion is pushed beyond a specified amount due to the quick response of the stress applying means. The contact portion can be separated from the surface of the object to be measured.
Therefore, it is possible to reliably prevent the surface of the object to be measured and the measuring element from being damaged.

  In the present invention, the support plate is a circle centered at a point through which the axis of the probe passes, and the stress applying means is arranged at equal intervals on a virtual circle centered on the center point of the support plate. It is preferable that

In such a configuration, the axis of the probe passes through the center of the support plate, and the support plate is circular. Accordingly, by supporting the probe with this support plate, there is no anisotropy, and even when the probe is displaced in an arbitrary direction, the displacement of the probe with respect to the same stress can be made the same.
In addition, since the stress applying means is arranged at equal intervals on a virtual circle centered on the center point of the support plate, the measuring element can be displaced in any direction without anisotropy.

The detection sensor includes a light source, a light sensor that receives light and outputs a light reception signal corresponding to the amount of light received through photoelectric conversion, and an incident position of the light emitted from the light source on the light sensor. It is preferable to include an optical shift means for shifting according to the displacement.
The light shift means can be configured by a reflection mirror that is attached to the support plate and tilts together with the support plate.

  Here, it is preferable that the light incident position on the optical sensor changes greatly with a slight displacement of the probe. For example, the distance from the axis of the probe to the variable portion of the support plate is shortened, and the reflection mirror ( It is preferable to increase the distance from the light shift means) to the optical sensor, and to increase the light incident angle from the light source to the reflection mirror (light shift means).

If the distance from the axis of the probe to the variable portion of the support plate is small, the change in the angle of the support plate with respect to the displacement of the probe becomes large, so that the minute displacement of the probe can be detected with high sensitivity.
Further, if the distance from the reflection mirror to the optical sensor is long, the lever ratio of the light lever increases, so that the minute displacement of the probe can be detected with high sensitivity.

  The shape measuring apparatus of the present invention includes the contact probe, a drive mechanism that moves the contact probe relative to the object to be measured, and contacts or separates the contact probe from the surface of the object to be measured. A driving sensor for detecting a driving amount of the driving mechanism; an operation control unit for driving and controlling the driving mechanism and the probe displacement means; and a detection surface of the object to be measured based on detection values by the detecting sensor and the driving sensor. An analysis means for analyzing the shape, wherein the operation control unit sets in advance a displacement of the contact part caused by a measurement pressure received from the surface of the object to be measured by the contact part in contact with the surface of the object to be measured. A contact detection unit that detects contact between the surface of the object to be measured and the contact part when the reference pressing amount is reached, and contact between the contact part and the surface of the object to be measured is detected by the contact detection unit. And a probe drive controller that drives the probe displacement means to displace the probe in a direction in which the contact pressure between the contact portion and the surface of the object to be measured decreases. .

In such a configuration, the contact probe is moved relative to the object to be measured by the driving mechanism, and the contact portion comes into contact with the surface of the object to be measured. Then, when the contact portion is pushed into the surface of the object to be measured and the displacement of the contact portion reaches a preset reference push amount, the contact detection unit detects that the contact portion has come into contact with the surface of the object to be measured. Is done.
In this way, the coordinate values of the surface of the object to be measured are acquired by sampling the detection values of the drive sensor and the detection sensor when the contact between the contact part and the surface of the object to be measured is detected by the contact detection unit. When the contact between the contact portion and the surface of the object to be measured is detected by the contact detection unit, the contact probe is touched back from the surface of the object to be measured by the driving mechanism in order to move to the next measurement point.

However, the operation of the drive mechanism cannot be changed suddenly due to inertia due to the weight of the drive mechanism itself and the weight of the contact probe, and the contact probe is continuously moved toward the surface of the object to be measured. It will end up.
Here, when the contact is detected by the contact detection unit, the probe displacement control unit is driven by the probe drive control unit. Then, the probe is displaced in a direction in which the contact pressure between the contact portion and the surface of the object to be measured is reduced by the probe displacement means. Then, after touch back by the drive mechanism, the contact probe is moved to the next measurement point.

  According to such a configuration, when the contact between the contact portion and the surface of the object to be measured is detected, the measuring element is displaced toward the direction of retreating from the surface of the object to be measured by the measuring element displacement means. Therefore, even when the drive mechanism is affected by inertia, the contact portion is not pushed more than the reference push amount into the surface of the object to be measured. Therefore, the contact portion is not excessively pushed into the surface of the object to be measured, and damage to the surface of the object to be measured and the probe is prevented.

  When displacing the probe in the direction in which the contact pressure between the contact portion and the surface of the object to be measured decreases, the contact portion may be separated from the surface of the object to be measured until the contact portion is separated from the surface of the object to be measured. Alternatively, the contact portion may be displaced in a direction in which the contact pressure decreases within a range in which the contact portion is not separated from the surface of the object to be measured.

  Also, for example, when measuring one surface in the V-groove, if the contact portion is retracted from the surface of the object to be measured, the contact portion comes into contact with the other surface of the V-groove, and the predetermined retracting operation is impossible. This situation is also expected. Thus, it is desirable to stop the measurement operation when an abnormality is detected during the evacuation operation. Thereby, it is possible to avoid the contact probe from being damaged or being unable to be measured.

  In the present invention, the probe drive control unit includes a normal vector calculation unit that calculates a normal direction of the surface of the object to be measured at the contact point based on the displacement of the contact unit detected by the detection sensor, and the normal line A distribution amount calculation unit that calculates the driving amount of each stress applying means necessary to displace the contact portion in the direction of the normal vector calculated by the vector calculation unit, and the distribution amount calculation unit It is preferable to include a stress applying drive unit that drives each stress applying means in accordance with the driving amount of each stress applying means.

In such a configuration, when the contact portion is detected to be in contact with the surface of the object to be measured, the probe is controlled by the probe drive control unit so that the contact pressure between the contact portion and the surface of the object to be measured decreases. However, first, the normal vector calculation unit calculates the normal vector of the surface of the object to be measured at the contact point.
Here, when the contact portion is pushed into the surface of the object to be measured and a pressing force is applied to the surface of the object to be measured, the contact portion is displaced by the reaction force from the surface of the object to be measured. Therefore, when the displacement of the contact portion is (Δx, Δy, Δz), the vector in the normal direction of the surface of the object to be measured at the contact point is (Δx, Δy, Δz).

  Next, the drive amount of each stress applying means necessary for displacing the contact portion in the direction of the normal vector is calculated by the distribution amount calculation unit. Then, a control signal such as a control voltage is output from the stress applying drive unit to each stress applying means according to the calculated driving amount of each stress applying means, and each stress applying means is driven. Then, the amount of elastic deformation at each point of the support plate is changed by driving each stress applying means, and the inclination angle of the support plate is changed. The measuring element is displaced with the inclination angle of the support plate, and the contact portion is displaced in the normal direction of the surface of the object to be measured.

  The shape measuring apparatus of the present invention includes the contact probe, a drive mechanism that relatively moves the contact probe along the surface of the object to be measured, a drive sensor that detects a drive amount of the drive mechanism, the drive mechanism, and the measurement An operation control unit that drives and controls a child displacement unit; and an analysis unit that analyzes a shape of the surface of the object to be measured based on the detection sensor and a value detected by the drive sensor, and the operation control unit includes: A probe excitation control unit is provided to drive the probe displacement means to vibrate the contact portion in the normal direction of the surface of the object to be measured.

In such a configuration, the scanning measurement is executed by moving the contact probe along the surface of the object to be measured by the driving mechanism.
In this scanning measurement, first, the probe displacement means is driven by the control signal from the probe excitation controller, and the probe is vibrated. At this time, the vibration direction of the contact portion is the normal direction of the surface of the object to be measured. For example, the contour data of the object to be measured is set and inputted in advance prior to the measurement operation, and the normal direction of the surface of the object to be measured at each measurement point is calculated in advance based on the contour data and the measurement path of the scanning measurement. The contact portion is vibrated in the calculated normal direction. The contact probe is moved along the surface of the object to be measured by the drive mechanism in a state where the contact portion is vibrated in the normal direction of the surface of the object to be measured. Then, since the contact portion vibrates, the contact portion moves following the surface of the object to be measured while tapping. When the displacement of the contact part including the vibration of the contact part is detected by the detection sensor, the contact between the contact part and the surface of the object to be measured is detected when the amplitude of the vibration of the contact part is suppressed to a predetermined level. As an example. The displacement of the contact portion is detected by the detection sensor and the drive amount of the drive mechanism is detected by the drive sensor, whereby measurement data is obtained. Based on the measurement data, the surface shape of the object to be measured is analyzed by the analyzing means.

According to such a configuration, since the contact portion taps the surface of the object to be measured in the copying measurement, the contact time between the contact portion and the surface of the object to be measured is shortened, and the friction between the contact portion and the surface of the object to be measured is extremely reduced. Can be small.
Conventionally, since the scanning measurement was performed with the contact portion pushed into the surface of the object to be measured by a predetermined amount, the friction force acting between the contact portion and the surface of the object to be measured damages the measuring element and the surface of the object to be measured. There was a problem.
In this respect, according to the present invention, since the friction between the contact portion and the surface of the object to be measured is reduced, the surface of the object to be measured is not damaged by the measurement.

  Further, since the probe is supported by the support plate so as to be displaceable in any direction in three dimensions, the contact portion can be vibrated in any direction in three dimensions by driving the probe displacement means. Therefore, in any direction when contacting the surface of the object to be measured, it is possible to perform the copying measurement while vibrating the contact portion in the normal direction of the surface of the object to be measured. Further, when the scanning measurement is performed by tapping as described above, the contact portion is vibrated by the probe displacement means, so that the operation of the drive mechanism for moving the contact probe may be the same as that of the conventional scanning measurement. Accordingly, the scanning measurement operation command is not different from the conventional one and is very simple.

In addition, about the vibration frequency which vibrates a contact part, it is preferable to avoid all the natural frequencies of a contact probe. In the contact probe, a natural frequency exists in each direction. For example, a natural frequency of the vibration of the probe is present in the vertical direction.
If the natural frequency of the probe is used when the contact portion is vibrated three-dimensionally in an arbitrary direction, the probe is resonated at the natural frequency, and longitudinal vibration is also generated. As a result, the surface of the object to be measured cannot be accurately tapped by vibrating the contact portion in an arbitrary direction. Therefore, by avoiding natural frequencies in all directions, the contact portion can be vibrated only in the intended direction.

DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments of the present invention will be illustrated and described with reference to reference numerals attached to respective elements in the drawings.
(First embodiment)
1st Embodiment which concerns on the shape measuring apparatus of this invention is described with reference to FIGS.
As a first embodiment, a measurement system 100 as a shape measuring apparatus using a contact probe 300 is shown in FIG.
FIG. 2 is a block diagram of the measurement system 100.

  The measurement system 100 includes a coordinate measuring machine 200 that moves the contact probe 300, an operation unit 110 having a joystick 111 that is manually operated, a motion controller (operation control unit) 500 that controls the operation of the coordinate measuring machine 200, A host computer 600 that operates the coordinate measuring machine 200 via the motion controller 500 and processes the measurement data acquired by the coordinate measuring machine 200 to determine the size and shape of the object W to be measured, and the measurement conditions and the like are input. Input means 120 for outputting, and output means 130 for outputting the measurement result.

  The three-dimensional measuring machine 200 includes a contact probe 300, a surface plate 210, a drive mechanism 220 that is erected on the surface plate 210 and moves the contact probe 300 three-dimensionally, and a drive that detects the drive amount of the drive mechanism 220. Sensor 230.

The configuration of the contact probe 300 will be described.
FIG. 3 is a perspective view showing the configuration of the contact probe 300.
FIG. 4 is a cross-sectional view of the contact probe 300 cut in the vertical direction.
For the following explanation, the z-axis is taken in the vertical direction of the paper in FIG. 4, the x-axis is taken in the horizontal direction of the paper, and the y-axis is taken in the vertical direction of the paper.

  The contact probe 300 includes a measuring element 310 that is displaced by contact pressure when it abuts on the surface S of the object to be measured, and a sensor main body 400 that supports the measuring element 310 so as to be displaceable and detects the displacement of the measuring element 310. .

The measuring element 310 includes a stylus 311 and a contact portion 312 provided at the tip of the stylus 311.
The base end of the stylus 311 is attached to the sensor main body 400, and the measuring element 310 is supported in a state of hanging from the sensor main body 400.
Note that a direction along the axis of the stylus 311 in a reference state in which the measuring element 310 is not displaced is referred to as a center line direction A.

  The sensor main body 400 includes a cylindrical housing part 410 having an open lower end surface and a storage space 411 therein, a support plate 420 that supports the proximal end side of the measuring element 310 on the lower end side of the housing part 410, and a measuring element. Displacement detection means (detection sensor) 430 for detecting the displacement of 310 and stylus displacement means (measurement element displacement means) 440 for displacing the stylus 311 by deforming the support plate 420 are provided.

The housing part 410 includes a support plate 420, a displacement detection unit 430, and a stylus displacement unit 440 in an internal storage space 411.
A flexible sheet material 412 that closes the opening and prevents intrusion of dust and the like into the inside is disposed on the lower end side of the housing portion 410. The measuring element 310 is disposed in a state where the sheet material 412 is inserted.

The support plate 420 is a circular metal plate, and a peripheral end portion is fixed to the housing portion 410. The measuring element 310 is attached and fixed to the lower surface side of the support plate 420 via the reinforcing plate 421 at the center of the support plate 420.
Here, FIG. 5 is a top view of the support plate 420.
The support plate 420 has three cut lines 422, and the three cut lines 422 are provided symmetrically with the center C1 of the support plate 420 as the center of point symmetry. Each incision line 422 has a circular arc part 423 and a straight line part 424, and is bent in a substantially square shape. Then, the three cut lines 422 are arranged around the center C1 of the support plate 420, and the straight line part 424 of the other cut line 422 is positioned inside the arc part 423 of the one cut line 422. The support plate 420 can be displaced in the vertical direction at the cut line 422, and the measuring element 310 is swingably supported by attaching the measuring element 310 to the center of the supporting plate 420.

The displacement detection means 430 includes a reflection mirror (light shift means) 431 that is displaced according to the displacement of the probe 310, an illumination optical system 432 that emits light toward the reflection mirror 431, and reflected light from the reflection mirror 431. An optical sensor 433 for receiving light.
The reflection mirror 431, the illumination optical system 432, and the optical sensor 433 are arranged along the center line A.

  The reflection mirror 431 is disposed substantially at the center of the support plate 420 on the upper surface side of the support plate 420. When the measuring element 310 is displaced, the center of the support plate 420 is displaced together with the measuring element 310. Therefore, the reflecting mirror 431 is also displaced according to the displacement of the measuring element 310, and the position and angle of the reflecting surface are changed.

  The illumination optical system 432 includes two light sources 432A and 432B that emit light. The two light sources 432A and 432B are spaced apart in the x direction with the optical sensor 433 interposed therebetween. The light sources 432 </ b> A and 432 </ b> B emit light toward the reflection mirror 431, and the posture is such that the light reflected by the reflection mirror 431 is incident on the center of the optical sensor 433 in a reference state where the probe 310 is not displaced. Adjusted.

In FIG. 4, the light sources 432 </ b> A and 432 </ b> B cause light to enter the reflection mirror 431 at an incident angle θ. As the light sources 432A and 432B, for example, LEDs can be used. The two light sources 432A and 432B emit modulated light that is amplitude-modulated at different frequencies.
In FIG. 3 and FIG. 4, for example, a modulated light Sa amplitude-modulated at a frequency fa is emitted from a light source 432A disposed on the −x side, and amplitude modulated at a frequency fb from a light source 432B disposed on the + x side. The modulated light Sb thus emitted is emitted. (However, fa ≠ fb)

The optical sensor 433 receives light from the reflection mirror 431 and outputs a light reception signal by photoelectric conversion.
FIG. 6 is a view of the optical sensor 433 as viewed from the light receiving surface side.
The optical sensor 433 is divided into four by dividing lines along the x-axis and the y-axis, and includes first to fourth light receiving units 434 to 437. Here, the light receiving unit disposed at the position (+ y, −x) is referred to as a first light receiving unit 434, the second light receiving unit 435 is disposed at the position (+ y, + x), and (−y, + x) The light receiving unit disposed at the position is referred to as a third light receiving unit 436, and the light receiving unit disposed at the position (−y, −x) is referred to as a fourth light receiving unit 437.

The stylus displacement means 440 includes three actuators (stress applying means) 441 to 443 disposed between the support plate 420 and the lower end edge of the housing portion 410 on the lower surface side of the support plate 420.
The actuators 441 to 443 are configured by laminating a plurality of thin plates of piezoelectric elements, and the height changes depending on the application of voltage. The support plate 420 is provided with three cut lines 422. When the support plate 420 is deformed between the arc part 423 of one cut line 422 and the straight line part 424 of the other cut line 422, each actuator 441- 443 is disposed on the lower surface side of a narrow region sandwiched between the arc portion 423 and the straight portion 424. The arrangement positions of the actuators will be described with reference to FIG. 5 seen through from the upper surface side of the support plate 420. The three actuators 441 to 443 are centered on the center point C1 of the support plate 420 in the perspective view (FIG. 5). Are arranged at intervals of 60 degrees on the circumference of the circle.

Here, in terms of angles measured from the + X axis, actuators 441 to 443 are disposed at the 60 degree position, the -60 degree position, and the -180 degree position, respectively.
The actuator at the 60 degree position is referred to as the first actuator 441, the actuator at the -60 degree position is referred to as the second actuator 442, and the actuator at the -180 degree position is referred to as the third actuator 443.
When a voltage is applied to the actuators 441 to 443, the top portions of the actuators 441 to 443 push up the narrow region to deform the support plate 420. Then, the angle of the probe 310 supported by the support plate 420 changes. Since three actuators 441 to 443 are provided, the angle of the surface of the support plate 420 can be changed to an arbitrary angle by controlling the voltage applied to each of the actuators 441 to 443. That is, the angle of the stylus 311 can be changed to an arbitrary angle by the three actuators 441 to 443.

  Two drive mechanisms 220 are provided so as to have a height in the Zm direction that is substantially perpendicular to the surface plate 210 from both side ends of the surface plate 210 and to be slidable in the Ym-axis direction along the side edge of the surface plate 210. A beam support 221, a beam 222 supported on the upper end of the beam support 221 and having a length in the Xm direction, a column 223 provided on the beam 222 so as to be slidable in the Xm direction, and having a guide in the Zm axis direction, And a spindle 224 that is slidable in the Zm-axis direction in the column 223 and holds the contact probe 300 at the lower end.

  Here, the machine coordinate system is defined by the Xm-axis direction, the Ym-axis direction, and the Zm-axis direction of the drive mechanism 220.

Although not shown in detail, the drive sensor 230 includes a Ym-axis sensor that detects movement of the beam support 221 in the Ym direction, an Xm-axis sensor that detects movement of the column 223 in the Xm direction, and a Z of the spindle 224. And a Zm-axis sensor that detects movement in the direction.
The detection result by the drive sensor 230 is output to the host computer 600 via the motion controller 500.

The operation unit 110 includes a joystick 111 as a manual operation member that is provided on the operation panel so as to be swingable and manually operates the movement of the contact probe 300.
Although not particularly illustrated, the operation unit 110 includes a detection unit that detects an operation of the joystick 111 such as an inclination angle of the joystick 111, and a signal from the detection unit is output to the motion controller 500.

  The motion controller 500 counts the drive signal of the drive mechanism 220 by counting the pulse signal output from the drive control unit 510 and the drive sensor 230 in accordance with commands from the host computer 600 and the operation unit. A drive counter 520 for measuring, a probe signal processing unit 530 for processing a signal from the contact probe 300 to calculate a displacement amount of the contact part 312, and a probe for displacing the contact part 312 in the normal direction of the surface S of the object to be measured A drive control unit 540, and a contact detection unit 550 that detects contact between the contact unit 312 and the surface S of the object to be measured are provided.

The drive control unit 510 outputs a control signal to the drive mechanism 220 based on commands from the host computer 600 and the operation unit, and drives the drive mechanism 220 to bring the contact unit 312 into contact with the measurement point.
Although not shown in detail, the drive counter 520 includes a Ym-axis counter that counts output from the Ym-axis sensor, an Xm-axis counter that counts output from the Xm-axis sensor, and a Zm-axis that counts output from the Zm-axis sensor. And a counter.
The measured drive amount of the drive mechanism 220 is output to the host computer 600.

The probe signal processing unit 530 will be described.
FIG. 7 is a diagram illustrating a configuration of the probe signal processing unit 530.
The probe signal processing unit 530 separates the modulated light signals Sa and Sb from the received light signals output from the light receiving units 434 to 437, and extracts the original signals from the modulated light signals Sa and Sb. The demodulating circuit unit 532 restores the signals fa and fb, and the arithmetic processing unit 533 that calculates the displacement of the contact unit 312 based on the signal demodulated by the demodulating circuit unit 532.

Four band-pass filter units 531 are provided according to the four light receiving units 434 to 437. Each band-pass filter unit 531 includes a band-pass filter 531A having a center frequency of fa and a band-pass having a center frequency of fb. The filter 531B and two band pass filters are provided.
Similarly, four demodulation circuit units 532 are provided according to the four bandpass filter units 531, and each demodulation circuit unit 532 includes a demodulation circuit 532A that demodulates the original signal fa from the modulated light Sa, and a modulated light Sb. And a demodulating circuit 532B for demodulating the original signal fb.
Examples of the demodulation circuit include a peak hold circuit and a smoothing circuit.

  With these four demodulation circuit units 532, four signal sets composed of combinations of fa and fb are obtained. The arithmetic processing unit 533 calculates the displacement of the contact unit 312 based on the four signal sets. That is, the arithmetic processing unit 533 obtains the shift amounts of the two light beams on the optical sensor 433 from the four signal sets, and calculates the displacement amount of the contact portion 312 from the displacement amounts of the two light beams.

  The probe drive control unit 540 includes a normal vector calculation unit 541 that calculates the normal direction of the surface S of the measurement object at the contact point based on the displacement of the contact unit 312 calculated by the probe signal processing unit 530, and a normal line A distribution amount calculation unit 542 that calculates the drive amount of each actuator 441 to 443 for displacing the contact unit 312 in the direction of the normal vector calculated by the vector calculation unit 541 and the actuators 441 to 443 are driven to be covered. An actuator driving unit (stress applying driving unit) 543 that displaces the contact portion 312 in the normal direction of the surface S of the measurement object.

The normal vector calculation unit 541 calculates the normal direction of the measurement object surface S based on the displacement of the contact part 312 when the contact part 312 contacts the measurement object surface S.
When the contact probe 300 is moved by the drive mechanism 220 and the contact portion 312 comes into contact with the measurement point on the surface S of the object to be measured, the movement of the contact probe 300 is continued by the drive mechanism 220 to a predetermined pushing amount. When the contact probe 312 is further pushed into the measurement object surface S from the state where the contact part 312 is in contact with the measurement object surface S, the contact part 312 is displaced with respect to the sensor main body 400 of the contact probe 300. Become. The displacement amount of the contact part 312 at this time is calculated by the probe signal processing part 530.
Here, when the contact portion 312 is pushed into the object surface S to apply a pressing force to the object surface S, the contact portion 312 is displaced by the reaction force from the object surface S.
Therefore, when the displacement of the contact portion 312 is (Δx, Δy, Δz), the normal direction of the surface S of the object to be measured at the contact point is a vector (Δx, Δy, Δz), and the normal vector N is It is expressed by a formula.

  The normal vector N calculated by the normal vector calculation unit 541 is output to the distribution amount calculation unit 542.

The distribution amount calculation unit 542 calculates the drive amounts of the three actuators 441 to 443 necessary for displacing the contact unit 312 in the direction of the normal vector N.
The three actuators 441 to 443 are disposed on the lower surface of the support plate 420, and the inclination of the support plate 420 changes to a predetermined angle by pushing up the narrow area of the support plate 420 by a predetermined amount by each actuator 441 to 443. .
When the inclination angle of the support plate 420 changes, the angle of the stylus 311 changes, so that the contact portion 312 is displaced in a predetermined direction. That is, the distribution amount calculation unit 542 calculates the tilt angle of the support plate 420 when the contact portion 312 is displaced in the direction of the normal vector N, and then is necessary for tilting the support plate 420 to the calculated tilt angle. The driving amounts of the actuators 441 to 443 are calculated. The calculated driving amounts of the actuators 441 to 443 are output to the actuator driving unit 543.

The actuator driving unit 543 drives the actuators 441 to 443 by applying a control voltage to each of the three actuators 441 to 443.
At this time, the actuator drive unit 543 applies a predetermined voltage to each of the actuators 441 to 443 according to each drive amount calculated by the distribution amount calculation unit 542.

  The contact detection unit 550 monitors the displacement data of the contact unit 312 output from the probe signal processing unit 530. When the displacement data of the contact unit 312 reaches the reference indentation amount, the contact unit 312 and the surface S of the object to be measured S are detected. Detects contact with. The contact detection unit 550 generates a contact detection signal when detecting the contact between the contact unit 312 and the surface S of the object to be measured, and outputs the contact detection signal to the probe drive control unit 540 and the host computer 600.

  The host computer 600 is set with a memory (storage device) 610 for storing measurement conditions set and inputted by the input means 120, and a data sampling unit 620 for sampling data from the drive counter 520 and the probe signal processing unit 530. The movement vector command unit 630 for instructing the moving direction and moving speed for moving the contact probe 300 to the measured point, the shape analysis unit 640 for analyzing the shape of the workpiece W, the arithmetic device and the storage device (ROM, RAM) And a bus 660 that connects a central processing unit (CPU) 650 that executes a predetermined program, processes data, and the like, and a memory 610, a movement vector command unit 630, a data sampling unit 620, a shape analysis unit 640, and a central processing unit 650. And.

  The memory 610 stores measurement conditions and the like set and input from the input unit 120, and includes contour data based on design data of the object W to be measured, and an amount Δr (reference pushing amount) for pushing the contact portion 312 into the object W to be measured. ) And measurement points.

  The data sampling unit 620 samples the driving amount of the driving mechanism 220 counted by the driving counter 520 and the displacement amount of the contact unit 312 calculated by the probe signal processing unit 530. The data sampling unit 620 samples the count value of the drive counter 520 and the displacement of the contact unit 312 by the probe signal processing unit 530 when the displacement of the contact unit 312 reaches a predetermined pushing amount. That is, the drive amount of the drive mechanism 220 and the displacement amount of the contact portion 312 are sampled with a cue that the contact detection signal has been generated.

The movement vector command unit 630 generates a vector command for moving the contact probe 300 in a direction in which the contact unit 312 contacts the measurement point based on the contour data set in the memory 610 and the measurement point.
The generated vector command is output to drive control unit 510.
The movement vector command unit 630 receives the contact detection signal from the data sampling and moves the contact probe 300 to the next measurement point.
At this time, the movement vector command unit 630 generates a vector command of a touchback operation for separating the contact unit 312 from the measured object surface S, touches the contact unit 312 from the measured object surface S, and then continues. The vector command for moving the contact probe 300 to the next measurement point is generated.

The shape analysis unit 640 analyzes the shape of the measurement object surface S based on the data sampled by the data sampling unit 620.
When data is sampled in a state where the contact portion 312 is pushed by a predetermined reference push amount, the measured object surface is corrected by correcting the push amount and the radius of the contact portion 312 in the normal direction of the measured object surface S. The position of S is calculated.

Next, the operation of the first embodiment will be described.
First, the operation when the probe 310 of the contact probe 300 is displaced will be described with reference to FIGS.

FIG. 8 is a diagram illustrating a state where the contact portion 312 is displaced in the + Z direction.
When stress acts on the contact portion 312 from the −Z direction to the + Z direction, the measuring element 310 is pushed up in the + Z direction. Then, the support plate 420 is displaced up and down in the notch of the support plate 420, and the displacement of the measuring element 310 in the + Z direction is allowed. Alternatively, when the three actuators 441 to 443 all push up the narrow region of the support portion by an equal amount, the center portion of the support plate 420 is displaced in the + Z direction, and the probe 310 together with the center portion of the support plate 420 is moved in the + Z direction. It is displaced to.
Then, when the center of the support plate 420 is displaced in the + Z direction together with the measuring element 310, the reflection mirror 431 is displaced in the + Z direction.

  Lights Sa and Sb emitted from the light sources 432A and 432B are incident on the reflection mirror 431 and then reflected by the reflection mirror 431. As a result, the reflection position is displaced in the + Z direction by the displacement of the reflection mirror 431 in the + Z direction. . Then, in the light reflected by the reflection mirror 431, the light Sa from the light source 432A is shifted to the −X side and the light Sb from the light source 432B is on the + X side, compared to when the measuring element 310 is located at the reference position. shift. FIG. 9 shows a light beam received by the optical sensor 433 at this time.

Next, a case where the contact portion 312 is displaced in the X direction will be described with reference to FIGS. 10 and 11.
FIG. 10 is a diagram illustrating a state in which the contact portion 312 is displaced (swinged) in the + X direction.
When stress acts on the contact portion 312 from the −X direction to the + X direction, the measuring element 310 swings in the + X direction. At this time, when the support plate 420 is cut, the support plate 420 is displaced upward in the + X direction, and is displaced downward in the −X direction so that the support plate 420 is elastically deformed, so that the displacement of the probe 310 in the X direction is allowed. Is done. Alternatively, when the first actuator 441 and the second actuator 442 are driven to push up the support plate 420, the + X side of the center portion of the support plate 420 is displaced upward, the center of the support plate 420 is inclined, and the measuring element 310 is tilted. Displacement in the + X direction. As the support plate 420 is elastically deformed, the reflection mirror 431 is inclined and the reflection surface is inclined toward the −X direction.

  The light emitted from the light sources 432A and B enters the reflection mirror 431 and then is reflected by the reflection mirror 431. The reflection direction of the light is in the −X direction due to the inclination of the reflection mirror 431 in the −X direction. Displace. Then, the reflected light from the reflecting mirror 431 is shifted to the −X side on the optical sensor 433 as compared to when the measuring element 310 is located at the reference position (see FIG. 11).

Next, a case where the contact portion 312 is displaced in the Y direction will be described with reference to FIGS.
FIG. 12 is a diagram illustrating a state where the contact portion 312 is displaced in the + Y direction.
When stress is applied to the contact portion 312 from the −Y direction to the + Y direction, the probe 310 swings in the + Y direction. At this time, when the support plate 420 is cut, the support plate 420 is displaced upward in the + Y direction, and is displaced downward in the −Y direction, so that the support plate 420 is elastically deformed, so that the displacement of the probe 310 in the + Y direction is allowed. Is done. Alternatively, mainly by driving the first actuator 441 and pushing up the support plate 420, the + Y side of the support plate 420 is displaced upward, the center of the support plate 420 is inclined, and the measuring element 310 is displaced in the + Y direction. As the support plate 420 is elastically deformed, the reflection mirror 431 is inclined and the reflection surface is inclined toward the −Y direction.

  The light emitted from the light sources 432A and B enters the reflection mirror 431 and then is reflected by the reflection mirror 431. The reflection direction of the light is in the −Y direction due to the inclination of the reflection mirror 431 in the −Y direction. Displace. Then, the reflected light from the reflection mirror 431 is shifted to the −Y side on the optical sensor 433 as compared to when the measuring element 310 is located at the reference position (see FIG. 13).

Next, when stress is applied to the contact portion 312 from an arbitrary direction, or the first to third actuators 441 to 443 are driven by a predetermined amount, respectively, and the contact portion 312 is displaced three-dimensionally in an arbitrary direction. Consider the case.
The reflection mirror 431 moves up and down and tilts along with the elastic deformation of the support plate 420 when the contact portion 312 is displaced three-dimensionally. Then, the light Sa and Sb emitted from the light sources 432A and B are reflected by the reflection mirror 431, and the incident points of the light Sa and Sb on the optical sensor 433 are displaced. At this time, the following expressions hold for the displacement (ΔXa, ΔYa) of the light Sa and the displacement (ΔXb, ΔYb) of the light Sb.

Here, it is assumed that the shift amount of the light Sa on the optical sensor 433 is (ΔXa, ΔYa), and the shift amount of the light Sb is (ΔXb, ΔYb). Further, the incident angle of light from the light sources 432A and 432B to the reflection mirror 431 is θ. In the reference state (the state in which the contact portion 312 is not displaced), the distance from the stylus 311 to the light reflection position on the reflection mirror is La, and the vertical distance from the optical sensor 433 to the reflection mirror 431 is L.
The displacement of the reflection mirror 431 in the Z direction is dz. The rotation angle around the x axis of the reflection mirror 431 (or contact portion 312) is θx, and the rotation angle around the y axis of the reflection mirror 431 (or contact portion 312) is θy.

  When the length of the stylus 311 is Ls, the following relationship is established between the coordinates (x, y, z) of the contact portion 312 and the posture and position (θy, θx, dz) of the reflecting mirror 431. .

  The above formula is summarized as follows.

  The displacement amount (x, y, z) of the contact portion 312 is obtained by the simultaneous equations of (Equation 9) to (Equation 12).

Further, the vertical displacement amount and the tilt angle of the reflection mirror 431 when the displacement of the contact portion 312 is (x, y, z) can be calculated geometrically.
Since the driving amounts of the actuators 441 to 443 required for moving the reflecting mirror 431 up and down by a predetermined amount can be calculated geometrically, the contact portion 312 is displaced by (x, y, z). It is possible to calculate the driving amount of each actuator 441 to 443 necessary for the above.

Next, with reference to the flowchart in FIG. 14 and the operation example in FIG. 15, an operation for touch-measuring an object to be measured according to the first embodiment will be described.
First, when touch-measuring an object to be measured, measurement conditions are input in ST100. For example, the measurement conditions are input by the input unit 120 such as a keyboard, and the input conditions are stored in the memory 610. Examples of the measurement conditions include shape data of the object to be measured, a reference pushing amount for detecting contact, a measurement point, and the like.

  Next, in ST110, the movement vector command unit 630 generates a movement vector command, and the generated movement vector command is output to the drive control unit 510. The movement vector command unit 630 generates a movement vector for moving the contact probe 300 to the measurement point based on the shape data of the measurement object set in the memory 610 and the measurement point.

Upon receiving the movement vector command, in ST120, drive control of the drive mechanism 220 is performed by the drive control unit 510, and the contact probe 300 is moved by the drive mechanism 220 (see FIG. 15A).
By driving the drive mechanism 220 based on the movement vector command, the contact probe 300 moves to the measurement point, and the contact portion 312 comes into contact with the measurement point (see FIG. 15B). Then, the contact portion 312 is pushed into the measurement point (see FIG. 15C).

When the contact portion 312 is pushed into the measurement point in ST120, the contact portion 312 is displaced by the reaction force from the surface S of the object to be measured, as described with reference to FIGS. At this time, as described with reference to FIGS. 8 to 13, the light reception signal from the sensor unit is processed by the probe signal processing unit 530, whereby the displacement of the contact unit 312 is calculated.
The calculated displacement of the contact portion 312 is output to the contact detection portion 550.

The contact detection unit 550 monitors the displacement of the contact unit 312 and compares the reference push amount set in the memory 610 with the displacement amount of the contact unit 312. Then, when the displacement amount of the contact portion 312 reaches the reference indentation amount, contact between the contact portion 312 and the surface S of the object to be measured is detected in ST130. When the contact between the contact portion 312 and the surface S of the object to be measured is detected, the contact detection portion 550 generates a contact detection signal.
The contact detection signal is output to the probe drive control unit 540 and the movement vector command unit 630.

Upon receiving the contact detection signal, in ST140, the data sampling unit 620 calculates the drive amount of the drive mechanism 220 counted by the drive counter 520 and the displacement amount of the contact unit 312 calculated by the probe signal processing unit 530. Sampling.
Data sampled by the data sampling unit 620 is sent to the shape analysis unit 640.

The contact detection signal generated by the data sampling unit 620 is sent to the probe drive control unit 540. In response to the contact detection signal, the probe drive control unit 540 performs the retracting operation (ST150 to ST180) of the contact unit 312.
First, in ST150, the normal vector calculation unit 541 calculates the normal vector of the surface S of the measurement object at the contact point.
The normal vector is calculated by equation (1).
The calculated normal vector N is output to the distribution amount calculation unit 542.

In ST160, based on the calculated normal vector N, the distribution amount calculation unit 542 calculates the drive amounts of the three actuators 441 to 443, respectively.
That is, the driving amounts of the actuators 441 to 443 necessary for moving the contact portion 312 in the direction of the normal vector N are calculated. The calculated drive amounts of the actuators 441 to 443 are output to the actuator drive unit 543.

In ST170, the actuator driving unit 543 applies a predetermined voltage to each of the actuators 441 to 443 in accordance with each driving amount calculated by the distribution amount calculating unit 542. Then, in ST180, the retracting operation of the contact portion 312 is performed (see FIG. 15D). That is, when a control voltage is applied to the actuators 441 to 443 by the actuator driving unit 543, the actuators 441 to 443 are driven by a predetermined amount, and the inclination of the support plate 420 changes to a predetermined angle.
As the support plate 420 is inclined, the angle of the stylus 311 changes, and the contact portion 312 is displaced in the direction of the normal vector N.

  In response to the contact detection signal, a touchback operation is performed in ST180. That is, when the contact detection signal is output to the movement vector command unit 630, the movement vector command unit 630 generates a vector command for the touchback operation in response to the contact detection signal. Then, based on the vector command for the touchback operation, the drive control unit 510 controls the drive mechanism 220 to move the contact probe 300 away from the contact point (see FIG. 15E).

When the touchback operation is completed, it is determined in ST200 whether all the measurement points set in the memory 610 have been measured. When all the measurement points have been measured (ST200: YES), the shape analysis unit 640 performs shape analysis of the object to be measured based on the sampled data.
In ST200, when all the measurement points have not been measured (ST200: NO), movement to the next measurement point is started (ST220).
Then, ST110 to ST200 are repeatedly executed until the measurement is completed for all measurement points.

According to such 1st Embodiment, there can exist the following effects.
(1) Since the stylus displacing means 440 is provided, in addition to the displacement of the probe 310 due to the pressing force when it comes into contact with the object surface S, the probe 310 is driven by the actuators 441 to 443. Can be displaced. Therefore, regardless of the operation of the drive mechanism 220 that moves the contact probe 300 and the object to be measured relative to each other, the stylus displacing means 440 can displace the measuring element 310 in a direction to separate the object from the surface S to be measured. Therefore, the contact portion 312 is not excessively pushed into the object surface S to be measured, so that the surface of the object to be measured that is the object of measurement is not damaged.

(2) Since the actuators 441 to 443 apply stress at the three points of the support plate 420, the support plate 420 can be tilted in any direction, and the measuring element 310 can be displaced in any direction. Therefore, the contact portion 312 can be displaced in a direction away from the measurement object surface S regardless of the directionality in which the contact portion 312 contacts the measurement object surface S.

(3) Since the actuators 441 to 443 have a quick response, the measuring element 310 can be separated from the surface S of the object to be measured at a desired timing. In the drive mechanism 220, it is difficult to stop suddenly because it is affected by inertia. However, since the response of the actuators 441 to 443 is fast, the contact portion from the surface S to be measured before the contact portion 312 is pushed beyond a predetermined amount. 312 can be spaced apart. Therefore, it is possible to reliably prevent the surface of the object to be measured S and the measuring element 310 from being damaged.

(4) Since the axis of the probe 310 passes through the center of the support plate 420 and the support plate 420 is circular, the probe 310 is supported by the support plate 420 to be different from the probe 310. The displacement of the probe 310 with respect to the same stress can be made the same even when the probe 310 is displaced from an arbitrary direction without giving directionality. Further, since the actuators 441 to 443 are arranged at equal intervals on a virtual circle centered on the center point of the support plate 420, the measuring element 310 can be displaced in any direction without anisotropy.

(Second Embodiment)
Next, a second embodiment of the present invention will be described with reference to FIGS.
The basic configuration of the second embodiment is the same as that of the first embodiment, but there is a difference in the point that the scanning measurement is performed in the second embodiment.
FIG. 16 is a block diagram illustrating a configuration of the second embodiment.
In FIG. 16, the motion controller 500 includes a probe excitation control unit 560, and the host computer 600 includes a scanning vector command unit 670.

The probe vibration control unit 560 applies a control voltage to the actuators 441 to 443 of the contact probe 300 to drive the actuators 441 to 443 to vibrate the contact unit 312.
At this time, the contact portion 312 measures the surface of the object to be measured S, and the vibration direction of the contact portion 312 is measured at the contact point where the contact portion 312 contacts the surface of the object to be measured S during the scanning measurement. This is the normal direction.
Here, the contact detection unit 550 detects contact between the contact unit 312 and the surface of the object to be measured S when the contact unit 312 is pressed by a predetermined reference pressing amount. The amplitude of the vibration of 312 is larger than the reference pushing amount.
The vibration frequency of the contact portion 312 is a vibration frequency that avoids any natural frequency that constitutes the contact probe 300.
In addition, the normal direction of the surface S of the object to be measured is calculated by the shape analysis unit 640 based on the contour data of the object to be measured set and input to the memory 610, and is output to the probe excitation control unit 560.

  The scanning vector command unit 670 generates a scanning vector that causes the contact probe 300 to move along the surface S of the object to be measured based on the contour data of the object to be measured set and input to the memory 610 and the measurement path of the copying measurement. The generated scanning vector is output to the drive control unit 510.

An operation for copying and measuring the surface S of the object to be measured according to the second embodiment having such a configuration will be described with reference to FIG.
FIG. 17 is a diagram illustrating a state in which the surface S of the object to be measured is measured by the contact probe 300.
As shown in FIG. 17, the contact probe 300 is moved along the measurement object surface S.
A scanning vector that causes the contact probe 300 to move along the surface S of the object to be measured is output from the scanning vector command unit 670 to the drive control unit 510, and the drive mechanism 220 is driven and controlled based on the scanning vector command.
When the contact probe 300 moves along the workpiece surface S, the actuators 441 to 443 are driven by the control signal from the probe vibration control unit 560 to vibrate the probe 310. When the probe 310 is vibrated, the vibration direction of the contact portion 312 is the normal direction of the surface S of the object to be measured. That is, for example, in (B) in FIG. 17, the normal direction of the surface S of the object to be measured is the axial direction of the stylus 311, so the measuring element 310 is vibrated in the axial direction of the stylus 311. On the other hand, for example, in FIG. 17C, the surface S of the object to be measured is inclined, and the normal direction of the surface S of the object to be measured is a direction intersecting the stylus 311. The contact portion 312 is vibrated in the normal direction of the object surface S.

  When the surface of the object to be measured S is scanned in a state where the contact portion 312 is vibrated as described above, when the contact portion 312 and the surface of the object to be measured S contact with each other, the vibration of the contact portion 312 is suppressed by a predetermined amount or more. Contact between the contact portion 312 and the surface S of the object to be measured is detected by the contact detection portion 550. When the contact detection unit 550 detects contact between the contact unit 312 and the surface S of the object to be measured, the drive amount of the drive mechanism 220 and the displacement of the contact unit 312 calculated by the drive counter 520 and the probe signal processing unit 530 are detected. Sampled. This data sampling is performed by the data sampling unit 620. When all of the preset scanning measurement paths are measured, the sampled data is sent to the shape analysis unit 640, and the shape analysis of the surface S of the object to be measured is performed by the shape analysis unit 640.

According to 2nd Embodiment provided with such a structure, there can exist the following effects.
(5) Since the contact part 312 taps the object surface S in the scanning measurement, the contact time between the contact part 312 and the object surface S is shortened, and the friction between the contact part 312 and the object surface S is reduced. It can be made extremely small. Further, since the friction between the contact portion 312 and the object surface S to be measured is reduced, the object surface S to be measured is not damaged by the measurement.

It should be noted that the present invention is not limited to the above-described embodiment, and modifications, improvements, and the like within the scope that can achieve the object of the present invention are included in the present invention.
For example, in the first embodiment, the stylus displacing means 440 has been described as an example in which the three actuators 441 to 443 are disposed between the support plate 420 and the lower end edge of the housing portion 410. As shown in FIGS. 18 and 19, a bimorph type structure in which plate materials (or thin films) with different amounts of expansion and contraction are attached to the front and back surfaces of the support plate 420 may be used. Such bimorph actuators 441 to 443 can be formed by depositing film-like elements 444 on the front and back of the support plate 420. Then, as shown in FIG. 19, by applying a voltage to the front and back membrane elements 444, the support plate 420 can be elastically deformed by the stress from the front and back.

In the first embodiment, when contact between the contact portion 312 and the object surface S is detected in touch measurement, the stylus displacing means 440 moves the contact portion 312 in a direction away from the object surface S. In this case, the displacement amount of the contact portion 312 by the stylus displacing means 440 may be as small as 1 μm or less, and the contact portion 312 is displaced so that the contact portion 312 is completely separated from the surface S of the object to be measured. It does not have to be.
For example, as shown in FIG. 20, after detecting contact between the contact portion 312 and the object surface S in the state of FIG. 20A, the contact portion 312 is moved to the object surface S in FIG. When the retracting operation is performed, the contact portion 312 does not retract so much that the contact portion 312 is separated from the measured object surface S, and the contact portion 312 and the measured object surface S are not retracted as shown in FIG. The contact portion 312 may be retracted within a range where the contact is maintained. Even in this case, the contact pressure between the contact portion 312 and the surface of the object to be measured S decreases, so that damage to the probe 310 and the surface of the object to be measured S can be prevented.

In the second embodiment, the vibration amplitude of the contact portion 312 is greater than the reference push amount. However, the vibration amplitude of the contact portion 312 may be smaller than the reference push amount.
As described above, when the contact portion 312 is vibrated with an amplitude smaller than the reference pressing amount, the contact portion 312 maintains contact without being separated from the surface S of the object to be measured, but the contact pressure periodically decreases. The load on the measuring element 310 and the surface S of the object to be measured can be reduced.

In the first embodiment, the contact portion 312 is retracted from the surface S of the object to be measured using the actuators 441 to 443 constituting the stylus displacement means 440. However, the actuators 441 to 443 may be used as active bumpers. . When the probe 310 is supported by a support plate 420 that is a leaf spring, the probe 310 vibrates at a natural frequency determined by the weight and the elastic constant of the support plate 420 and the probe 310.
Here, when the probe 310 vibrates at the natural frequency, if the actuators 441 to 443 are driven to cancel the vibration of the probe 310, the vibration of the probe 310 is suppressed, and the optical sensor. The upper light receiving position is stabilized. As a result, the detection accuracy of the probe displacement is improved. In order to cancel the vibration of the probe 310, the actuators 441 to 443 are driven at timings that are the natural frequencies of the support plate 420 and the probe 310 and slightly shifted in phase from the vibration of the probe 310. Can be mentioned.

  The present invention can be used for a contact probe and a shape measuring apparatus.

The figure which shows the measurement system as a shape measuring apparatus using a contact probe in 1st Embodiment. The block diagram which shows the structure of a measurement system in 1st Embodiment. The perspective view which shows the structure of a contact probe in 1st Embodiment. FIG. 3 is a cross-sectional view of the contact probe cut in the vertical direction in the first embodiment. The top view of a support plate in a 1st embodiment. The figure which looked at the optical sensor from the light-receiving surface side in 1st Embodiment. The figure which shows the structure of a probe signal process part in 1st Embodiment. The figure which shows the state which the contact part displaced in + Z direction in 1st Embodiment. The figure which shows the light beam received with an optical sensor, when a contact part is displaced to + Z direction. The figure which shows the state which the contact part displaced (oscillated) in + X direction. The figure which shows the light beam received with an optical sensor when a contact part is displaced to + X direction. The figure which shows the state which the contact part displaced to + Y direction. The figure which shows the light beam received with an optical sensor, when a contact part is displaced to + Y direction. 5 is a flowchart illustrating a procedure of a measurement operation in the first embodiment. The figure which shows the mode of measurement operation | movement in 1st Embodiment. The block diagram which shows the structure of 2nd Embodiment. The figure which shows a mode that the surface of a to-be-measured object is copied and measured with a contact probe in 2nd Embodiment. The figure which shows the modification of a stylus displacement means. The figure which shows the modification of a stylus displacement means. The figure which shows the modification at the time of carrying out retracting operation | movement of a contact part. The figure which shows the structure of the three-dimensional measuring machine using a contact probe. The figure which shows the structure of a contact probe.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... CMM, 11 ... Contact probe, 12 ... Drive mechanism, 13 ... Stylus, 14 ... Contact part, 15 ... Sensor main part, 100 ... Measurement system, 110 ... Operation part, 111 ... Joystick, 120 ... Input means , 130 ... output means, 200 ... coordinate measuring machine, 210 ... surface plate, 220 ... drive mechanism, 221 ... beam support, 222 ... beam, 223 ... column, 224 ... spindle, 230 ... drive sensor, 300 ... contact probe , 310 ... measuring element, 311 ... stylus, 312 ... contact part, 400 ... sensor body part, 410 ... housing part, 411 ... storage space, 412 ... sheet material, 420 ... support plate, 421 ... reinforcing plate, 422 ... score line 423 ... arc portion, 424 ... linear portion 430 ... displacement detection means, 431 ... reflection mirror, 432A ... light source, 432B ... light 432, illumination optical system, 433, optical sensor, 434, first light receiving section, 435, second light receiving section, 436, third light receiving section, 437, fourth light receiving section, 440, stylus displacement means, 441, first. Actuator, 442 ... 2nd actuator, 443 ... 3rd actuator, 444 ... Element, 500 ... Motion controller, 510 ... Drive controller, 520 ... Drive counter, 530 ... Probe signal processor, 531A ... Band pass filter, 531B ... Band Pass filter, 531 ... Band pass filter unit, 532A ... Demodulation circuit, 532B ... Demodulation circuit, 532 ... Demodulation circuit unit, 533 Arithmetic processing unit, 540 ... Probe drive control unit, 541 ... Normal vector calculation unit, 542 ... Distribution amount Calculation unit, 543 ... actuator driving unit, 550 ... contact detection unit, 560 ... probe excitation Control unit, 600 ... host computer, 610 ... memory, 620 ... data sampling unit, 630 ... motion vector instruction unit, 640 ... shape analysis unit, 650 ... central processing unit, 660 ... bus, 670 ... scanning vector command unit.

Claims (7)

A probe having a contact portion at the tip that contacts the surface of the object to be measured;
A detection sensor for detecting displacement of the probe;
A support plate that is an elastic plate disposed substantially orthogonal to the axial direction of the probe and supports the proximal end of the probe;
A measuring element displacing means for displacing the measuring element,
The support plate is provided with cut lines at three or more positions that are not on a straight line, and the base end side of the probe is fixed between the cut line and a portion where the base end side of the probe is fixed. A narrow region is formed to connect the formed part and the other part,
The probe displacement means is disposed in the narrow region , applies stress to the narrow region , and determines the position and / or angle of the portion where the proximal end side of the probe is fixed with respect to the other portion. varying the contact probe, wherein the obtaining Bei stress applying means for displacing the measuring element in any direction. The contact probe according to claim 1,
The stress applying means is configured by laminating a plurality of thin plates of piezoelectric elements, and is a piezoelectric actuator whose height is changed by application of voltage,
The piezoelectric actuator, the is disposed on the lower surface of the narrow region, the contact probe, characterized in that push up the narrow region by a predetermined amount. The contact probe according to claim 1,
It said stress applying means, amount of expansion and contraction in the front and back surfaces of the narrow region is constituted by affixed different plate material, is a bimorph type actuator to elastically deform the narrow region by the stress from the front and back by applying a voltage A contact probe characterized by that. The contact probe according to any one of claims 1 to 3,
The support plate is a circle centered at a point through which the axis of the probe passes.
The contact probe characterized in that the stress applying means are arranged at equal intervals on a virtual circle centered on the center point of the support plate. The contact probe according to any one of claims 1 to 4,
A drive mechanism for moving the contact probe relative to the object to be measured to bring the contact probe into contact with or away from the surface of the object to be measured;
A drive sensor for detecting a drive amount of the drive mechanism;
An operation control unit for driving and controlling the drive mechanism and the probe displacement means;
Analyzing means for analyzing the shape of the surface of the object to be measured based on the detection values by the detection sensor and the drive sensor,
The operation controller is
The contact with the surface of the object to be measured when the displacement of the contact caused by the measurement pressure received from the surface of the object to be measured reaches a preset reference pushing amount. A contact detection unit for detecting contact with the unit,
Direction in which contact pressure between the contact portion and the surface of the object to be measured is reduced by driving the measuring element displacing means when contact between the contact portion and the surface of the object to be measured is detected by the contact detector. And a probe drive control unit for displacing the measuring element. In the shape measuring apparatus according to claim 5,
The probe drive controller is
A normal vector calculation unit for calculating a normal direction of the surface of the object to be measured at the contact point based on the displacement of the contact part detected by the detection sensor;
A distribution amount calculation unit that calculates a driving amount of each stress applying means necessary to displace the contact portion in the direction of the normal vector calculated by the normal vector calculation unit;
A shape measuring apparatus comprising: a stress applying drive unit that drives each stress applying unit in accordance with the driving amount of each stress applying unit calculated by the distribution amount calculating unit. The contact probe according to any one of claims 1 to 4,
A drive mechanism for relatively moving the contact probe along the surface of the object to be measured;
A drive sensor for detecting a drive amount of the drive mechanism;
An operation control unit for driving and controlling the drive mechanism and the probe displacement means;
Analyzing means for analyzing the shape of the surface of the object to be measured based on the detection values by the detection sensor and the drive sensor,
The operation controller is
A shape measuring apparatus comprising: a probe excitation control unit that drives the probe displacement means to vibrate the contact portion in a normal direction of the surface of the object to be measured.

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