JP6761703B2 - Measured object measuring device and measured object measuring method - Google Patents

Description

The present invention relates to a device for measuring an object to be measured and a method for measuring an object to be measured, and relates to a device for measuring an object to be measured by bringing a ball body into contact with the object to be measured.

Conventionally, in precision machining, the function of centering the work and measuring the work on the machine has been very important.

In a precision processing machine (for example, a machining center for precision metal processing), one of a plurality of tools may be replaced with a touch probe to measure a workpiece (measurement object).

The touch probe detects the position (center position) of the tip sphere when the work and the tip sphere (ball body) of the touch probe come into contact with each other, and the moving direction of the tip sphere when the tip sphere comes into contact with the work (the position of the tip sphere). The work is measured from the moving direction with respect to the object to be measured) and the coordinates (center position of the tip sphere).

Here, for example, Patent Document 1 can be listed as a patent document relating to the conventional technique.

Japanese Patent No. 5817379

By the way, the tip sphere (ball body) of the touch probe is not a point but a sphere (not only the position information), and has a size (position information and volume) in a three-dimensional space. There is.

Therefore, as shown in FIGS. 11 and 12, when the object W to be measured has a simple shape such as a quadrangular prism or a cylinder, if the probe 101 (tip sphere 103) is moved toward the center thereof, the tip sphere 103 can be moved. It is easy to apply it perpendicularly to the surface of the object W to be measured. Then, the actual measurement position (contact position W1 between the tip sphere 103 and the object to be measured W) is obtained by adding or subtracting the value of the radius R of the tip sphere 103 to the coordinates of the center of the tip sphere 103 at the time of contact. Then, it can be easily obtained.

However, when the surface of the object to be measured has a complicated three-dimensional shape such as an aspherical surface as shown in FIG. 4, the contact angle of the tip sphere at the time of contact is unknown, and the tip sphere and the object to be measured There is a problem that the contact position and the like cannot be easily obtained.

The present invention has been made in view of the above problems, and even if the surface of the object to be measured has a complicated three-dimensional shape, the contact position between the tip sphere and the object to be measured can be easily obtained. It is an object of the present invention to provide an object measuring device and a method for measuring an object to be measured.

The invention according to claim 1 is to bring the ball into contact with the object to be measured three times or more by moving the ball from a standby position away from the object to be measured in a predetermined direction approaching the object to be measured. The object to be measured is measured by using the ball body contacting step performed a plurality of times and the positions of a plurality of positions of the ball body when the ball body is brought into contact with the object to be measured a plurality of times in the ball body contacting step. When each of the waiting positions in the ball body contacting step is viewed from the predetermined one direction, each of the waiting positions has a value or diameter of the diameter of the ball body. The balls are separated by a smaller value, and the ball contact step is a step of performing the contact at least four times, and when each of the standby positions is viewed from the predetermined one direction, at least four of the standby positions The center of the ball body at the other one of the four standby positions is located inside the triangle formed at the center of the ball body at the three standby positions. The measurement step is the intersection of one extension line extending in the Z-axis direction including the center of the ball body at the one standby position located inside the triangle and the surface of the object to be measured. A subject including a step of measuring at least one of the positions, the positions of the contact points when the ball body comes into contact with the object to be measured by moving from one of the standby positions located inside the triangle. This is a method for measuring an object to be measured.

According to a second aspect of the invention, the object to be measured measuring method according to claim 1, the values of the three sides each of the length of the triangle is 1/3 times to the value of the diameter of the ball member A method of measuring an object to be measured that is within the range of 1 times.

The invention described in claim 3 is the measured object measuring method according to claim 2, wherein a triangular three sides each of length values measured object is equal to one another measurement method.

The invention according to claim 4 is the method for measuring an object to be measured according to any one of claims 1 to 3, wherein the ball body abutting step is performed a plurality of times and the measurement is performed in the measuring step. This is a method for measuring an object to be measured, in which the outer shape of the object to be measured is obtained by repeating the above process a plurality of times by changing the standby position.

The invention according to claim 5 is the method for measuring an object to be measured according to any one of claims 1 to 4, wherein the ball body is subjected to a plurality of times of 4 times or more in the ball body contact step. When abutting the object to be measured, when viewed from the predetermined one direction, each of the center positions of the ball body in a plurality of − (minus) one abutments hits the circumference of a predetermined circle. This is a method for measuring an object to be measured, which is located at a point of distribution and the center position of the ball body in the remaining one contact is located at the center of the circle .

The invention according to claim 6 detects the position of the ball body moving portion that moves the ball body relative to the object to be measured and the position of the ball body when the ball body comes into contact with the object to be measured. The ball body detecting unit and the ball body are moved from a standby position away from the object to be measured in a predetermined direction approaching the object to be measured to bring the ball into contact with the object to be measured three times or more. The ball body detection is performed so as to control the ball body moving portion and detect the positions of a plurality of positions of the ball body when the ball body is brought into contact with the object to be measured a plurality of times. It also has a control unit that controls the unit and measures the object to be measured by using the positions of a plurality of positions of the ball when the ball is brought into contact with the object to be measured a plurality of times. When each of the standby positions is viewed from the predetermined direction, the control unit is separated from each other by a value of the diameter of the ball or a value smaller than the diameter of the ball, and the contact is made. Is performed at least four times, and when each of the standby positions is viewed from the predetermined one direction, inside the triangle formed at the center of the ball body at three of the four standby positions. The center of the ball at the other one of the four standby positions is located and includes the center of the ball at one of the standby positions located inside the triangle. The ball is moved to the object to be measured by moving from the position of the intersection of one extension line extending in the Z-axis direction and the surface of the object to be measured and the one standby position located inside the triangle. It is an object measuring device configured to measure at least one of the positions of contact points when a body comes into contact with the body.

The invention described in claim 7 is the measured object measuring apparatus according to claim 6, the value of the three sides each of the length of the triangle is 1/3 times to the value of the diameter of the ball member It is an object measuring device to be measured that is within the range of 1 times.

The invention according to claim 8, wherein in the section 6 to the measuring object measuring apparatus according to any one of claims 7, values of the three sides each of the length of the triangle is equal to each other This is an object measuring device.
The invention according to claim 9 is the object measuring device according to any one of claims 6 to 7, wherein the control unit makes the ball body abutting a plurality of times to obtain the ball body. Measurement of the object to be measured to determine the outer shape of the object to be measured by repeating the detection of the positions of a plurality of positions of the ball body when the object is brought into contact with the object to be measured a plurality of times by changing the standby position. It is a device.
The invention according to claim 10 is the object measuring device according to any one of claims 6 to 7, wherein the control unit measures the ball body four times or more a plurality of times. When abutting an object, each of the center positions of the ball body in a plurality of − (minus) one abutments when viewed from the predetermined one direction appropriately distributes the circumference of a predetermined circle. The object to be measured device is located at the center of the circle, and the center position of the ball body in the remaining one contact is located at the center of the circle.

According to the present invention, even if the surface of the object to be measured has a complicated three-dimensional shape, it is possible to easily obtain the contact position between the tip sphere and the object to be measured.

It is a figure which shows the schematic structure of the object measurement apparatus which concerns on embodiment of this invention. FIG. 2 is a view on arrow II in FIG. It is a block diagram of the object measurement apparatus which concerns on embodiment of this invention. It is a figure which shows the measurement state of the object to be measured using the touch probe. It is a figure which shows the detail of the measurement state of the object to be measured using the touch probe. It is a VI arrow view in FIG. It is a figure which shows the calculation formula used in the object measurement method which concerns on embodiment of this invention. It is a figure which shows the calculation formula used in the object measurement method which concerns on embodiment of this invention. It is a figure which shows the measurement method of the object to be measured which concerns on the modification. It is a figure which shows the measurement method of the object to be measured which concerns on the modification. It is a figure which shows the measurement method of the object to be measured when the object to be measured is a square columnar, and (b) is the XIB arrow view in (a). It is a figure which shows the measurement method of the object to be measured when the object to be measured is columnar.

The method for measuring an object to be measured (method for measuring an object to be measured) according to the embodiment of the present invention is performed by, for example, the measuring device for the object to be measured (measured object measuring device) 1 shown in FIG.

The object to be measured device 1 may be a dedicated machine for measuring the object to be measured 3, but a general-purpose precision processing machine (for example, a machining center for precision metal machining) is used as the object to be measured device 1. To. In the precision processing machine 1, one of the plurality of tools is replaced with a touch probe 5 to measure the object to be measured (work) 3.

Here, for convenience of explanation, one horizontal predetermined direction is defined as the X-axis direction, and the other predetermined horizontal direction perpendicular to the X-axis direction is defined as the Y-axis direction. The direction (vertical direction) orthogonal to the direction and the Y-axis direction is defined as the Z-axis direction.

As shown in FIGS. 1 and 2, the touch probe 5 includes a housing (touch probe housing) 7 and a stylus 9. The stylus 9 includes an elongated rod body portion 11 and a spherical ball body (tip ball) 13 provided at the tip of the rod body portion 11.

The portion of the stylus 9 on the proximal end side (upper portion) is embedded in the touch probe housing 7 and is supported by the touch probe housing 7.

The stylus 9, for example, projects downward from the lower end of the touch probe housing 7 so that the ball body 13 is located at the lower end of the rod body portion 11 and the central axis of the rod body portion 11 extends in the vertical direction. ..

The stylus 9 is slightly movable with respect to the touch probe housing 7 in the Z-axis direction, around the A-axis parallel to the X-axis, and around the B-axis parallel to the Y-axis.

In the normal state (when no external force is applied to the stylus 9), the stylus 9 protrudes most downward with respect to the touch probe housing 7, and the central axis of the rod body portion 11 extends in the Z-axis direction (so that the stylus 9 protrudes most downwardly). It is urged by an urging part (not shown) so that it has a basic posture.

Then, the touch probe 5 is moved with respect to the object to be measured 3, and when the ball body 13 abuts on the object to be measured 3 and an external force acts on the stylus 9, it moves in the Z-axis direction and is parallel to the X-axis. The stylus 9 moves very slightly with respect to the touch probe housing 7 in at least one of rotation around the A axis and rotation around the B axis parallel to the Y axis.

Further, when the touch probe 5 starts the very slight movement due to the contact (when the ball body 13 comes into contact with the object 3 to be measured and starts moving from the basic posture), the touch probe 5 gives a contact signal (contact signal). It is designed to be emitted to the outside. After that, when the touch probe 5 separates from the object to be measured 3, the touch probe 5 returns to the basic posture.

As shown in FIGS. 1 and 2, the object measuring device 1 includes a base body (bed) 15, an X-axis moving body 17, a Y-axis moving body 19, a Z-axis moving body 21, a head housing 23, and a spindle. It includes a rotating body 25.

The X-axis moving body 17 is mounted on the base body 15 and is engaged with the base body 15 so as to be movable in the X-axis direction, and the X-axis servomotor 27 (see FIG. 3) or the like is used. The actuator makes it possible to move and position the base body 15 in the X-axis direction.

An object to be measured 3 (not shown in FIGS. 1 and 2) is integrally installed at a predetermined position on the upper surface of the X-axis moving body 17 by using a fixed object to be measured (not shown). It has become so.

The Y-axis moving body 19 is mounted on the base body 15 and is engaged with the base body 15 so as to be movable in the Y-axis direction, such as a Y-axis servomotor 29 (see FIG. 3). The actuator makes it possible to move and position the base body 15 in the Y-axis direction.

The Z-axis moving body 21 is located above the X-axis moving body 17 and the object 3 to be measured installed on the X-axis moving body 17, and is engaged with the Y-axis moving body 19 on the side of the Y-axis moving body 19. It fits and is movable in the Z-axis direction with respect to the Y-axis moving body 19. Further, an actuator such as a Z-axis servomotor 31 (see FIG. 3) makes it possible to move and position the Y-axis moving body 19 in the Z-axis direction.

The head housing 23 is located above the X-axis moving body 17 and the object to be measured 3 installed on the X-axis moving body 17, and is integrally provided on the Z-axis moving body 21. The spindle rotating body 25 is provided in the head housing 23 so as to rotate about a central axis extending in the Z-axis direction as a rotation center.

Then, an actuator such as a spindle servomotor 33 (see FIG. 3) makes it possible to rotate and position the Z-axis moving body 21.

The lower end of the spindle rotating body 25 slightly protrudes downward from the head housing 23, and a workpiece integrally installed on the upper surface of the X-axis moving body 17 is processed at the lower end of the spindle rotating body 25. A touch probe 5 (touch probe housing 7) for measuring the object to be measured 3 integrally installed on the upper surface of the tool or the X-axis moving body 17 is integrally installed.

With this configuration, when the rotation of the spindle rotating body 25 is stopped and the spindle rotating body 25 is fixed to the head housing 23, the object to be measured 3 is integrally installed on the X-axis moving body 17. On the other hand, the touch probe housing 7 integrally installed on the spindle rotating body 25 can be moved and positioned in the X-axis direction, the Y-axis direction, and the Z-axis direction.

Further, in the object measuring device 1 to be measured, for example, the position of the X-axis moving body 17 is detected by a detector (not shown) such as a rotary encoder provided on the rotary output shaft of the X-axis servomotor 27. Can be done.

Similarly, the position of the Y-axis moving body 19 can be detected by a detector (not shown) such as a rotary encoder provided on the rotary output shaft of the Y-axis servomotor 29, and the Z-axis servomotor 31 can be detected. The position of the Z-axis moving body 21 can be detected by a detector (not shown) such as a rotary encoder provided on the rotary output shaft of the above.

The object measuring device 1 to be measured will be further described.

The object measuring device 1 measures the positions of the ball moving portion 35 that moves the ball 13 relative to the object 3 and the ball 13 when the ball 13 comes into contact with the object 3. It is configured to include a ball body detection unit 37 for detecting (X, Y, Z coordinates) and a control unit 39.

As is already understood, the ball body moving unit 35 includes, for example, an X-axis moving body 17, a Y-axis moving body 19, a Z-axis moving body 21, a head housing 23, a spindle rotating body 25, and an X-axis servomotor 27. The Y-axis servomotor 29 and the Z-axis servomotor 31 are configured in the above-described manner.

In the ball body detection unit 37, the ball body 13 of the touch probe 5 installed on the spindle rotating body 25 comes into contact with the object to be measured 3 installed on the X-axis moving body 17, and the touch probe 5 contacts the contact signal. The position of the ball body 13 can be determined by detecting the position of the X-axis moving body 17, the position of the Y-axis moving body 19, and the position of the Z-axis moving body 21 with each of the above detectors when the above is emitted to the outside. It is configured to detect. At this time, the spindle rotating body 25 is fixed to the head housing 23.

The control unit 39 includes a CPU 41 and a memory 43, and controls the ball body moving unit 35 and the ball body detecting unit 37 as shown below.

The ball body (the ball body of the touch probe 5 installed on the spindle rotating body 25 fixed to the head housing 23) 13 is the object to be measured (the object to be measured installed on the X-axis moving body 17) 3. Therefore, for example, it is positioned at a standby position away from the upper side. Then, by moving the object to be measured 3 from this standby position in a predetermined direction (for example, downward in the Z-axis direction), the contact with the object to be measured 3 is repeated three or more times. The ball body moving unit 35 is controlled so as to perform the above.

Further, the ball body detecting unit 37 detects the positions of a plurality of positions of the ball body 13 (for example, the position of the center of the ball body 13; coordinates) when the ball body 13 is brought into contact with the object 3 to be measured a plurality of times. 3 is controlled, and the object 3 to be measured is measured by using the positions of a plurality of positions of the ball body 13 when the ball body 13 is brought into contact with the object 3 to be measured a plurality of times.

When the standby positions (contact positions) are viewed from the Z-axis direction (in the Z-axis direction), the standby positions are slightly separated from each other without being positioned on a straight line.

Further, in the object to be measured device 1, the control unit 39 has a plurality of extension lines extending in the Z-axis direction including the center of the ball body 13 at each standby position, and the surface of the object to be measured 3. The object 3 to be measured is measured by finding the position (coordinates) of at least one of the plurality of intersections.

In addition to or in addition to the above-mentioned measurement mode, the control unit 39 determines the position (coordinates) of at least one of the plurality of contact points (contact points) between the ball body 13 and the object to be measured 3. By measuring (calculating), the object to be measured 3 may be measured.

Further, the control unit 39 makes the contact at least four times, and when each standby position is viewed from the Z axis, one of the plurality of standby positions is one of the plurality of standby positions. It may be located inside a plurality of other standby positions.

For example, the center of the ball 13 at the other one of the four standby positions is located inside the polygon formed at the center of the ball 13 at the three standby positions of the four standby positions. You may be.

In this case, the control unit 39 is the intersection of one extension line extending in the Z-axis direction including the center of the ball body 13 at one standby position located inside the triangle and the surface of the object 3 to be measured. Position (coordinates), at least one of the positions (coordinates) of the contact point when the ball body comes into contact with the object 3 to be measured by moving from one standby position located inside the triangle ( It may be configured to calculate).

Further, in the object measuring device 1, the control unit 39 abuts the ball body 13 a plurality of times to bring the ball body 13 into contact with the object 3 a plurality of times, and the positions of the ball body 13 at a plurality of positions. By repeating (for example, the position of the center of the ball body 13; coordinates) a plurality of times by changing (shifting) the standby position and covering the surface of the object 3 to be measured. , The outer shape of the object to be measured 3 may be determined.

Next, the operation of the object measuring device 1 (measurement method) will be described.

The object measuring device 1 to be measured is operated by, for example, an operation program stored in advance in the memory 43. The output unit 45 shown in FIG. 3 can display the operation program, and the input unit 47 shown in FIG. 3 can change the operation program.

As an initial state, the object to be measured 3 is integrally installed at a predetermined position on the X-axis moving body 17, and the touch probe 5 (touch probe housing 7) is integrally installed on the spindle rotating body 25. The spindle rotating body 25 is fixed to the head housing 23 so as not to rotate, and the touch probe 5 is located above the object to be measured 3 and away from the object to be measured 3 in a standby position. And.

First, the ball body 13 is brought into contact with the object to be measured 3 or more three times or more by linearly moving the ball 13 from a standby position away from the object to be measured 3 downward on the Z axis approaching the object to be measured 3. Repeat the process (ball contact process).

The object to be measured 3 is measured by using the positions of a plurality of positions of the ball body 13 (for example, the position of the center of the ball body 13; coordinates) when the object 3 is brought into contact with the object 3 a plurality of times in the ball body contact step. (Measurement process).

As described above, when each standby position (each contact position) in the ball body contact process is viewed in the Z-axis direction, the respective standby positions are slightly separated from each other without being positioned in a straight line. ing.

Further, in the measurement step, at least one intersection of each of the plurality of extension lines extending in the Z-axis direction including the center of the ball body 13 at each standby position and the surface of the object 3 to be measured is at least one. (Coordinates), and at least one of the positions (coordinates) of at least one of the plurality of contact points (contact points) between the ball body 13 and the object 3 to be measured is measured (calculated).

explain in detail. In the ball body contact step, the positions (three positions) of the ball body 13 are detected by bringing the ball body 13 into contact with the object to be measured 3 three times, for example, as shown below.

First, in the first contact, the ball body 13 is moved downward on the Z axis from the first standby position P1 (see FIG. 6) to bring the ball body 13 into contact with the object to be measured 3 (FIG. 5). reference). After that, the ball body 13 is moved upward on the Z axis to be separated from the object to be measured 3, slightly moved in the X-axis direction and the Y-axis direction, and slightly separated from the first standby position P1. It is located at the standby position P2 (see FIG. 6).

Subsequently, in the second contact, the ball body 13 is moved in the Z-axis direction (the same direction as the direction in the first contact) from the second standby position P, and is the same as in the first contact. , The ball body 13 is brought into contact with the object to be measured. After that, by moving the ball body 13 upward on the Z axis, the ball body 13 is separated from the object to be measured 3 and slightly moved in the X-axis direction and the Y-axis direction to perform the first standby positions P1 and the second. It is positioned at a third standby position P3 (see FIG. 6) slightly away from the standby position P2.

Subsequently, in the third contact, the ball body 13 is moved in the Z-axis direction (the same direction as the direction in the contact between the first and second times) from the third standby position P3, and the first and second times are made. The ball body 13 is brought into contact with the object to be measured 3 in the same manner as the second contact.

When the above three standby positions P1, P2, and P3 are viewed from the Z-axis direction, as shown in FIG. 6, the central positions O1, O2, and O3 of the ball body 13 at each of the standby positions P1, P2, and P3 are triangles 49. It is located at the top of. In FIG. 6, the value of the length of each of the three sides of the triangle 49 is larger than the value of the diameter of the ball body 13 (for example, about 1 mm), but it is actually desirable that the value is smaller. ..

The value of the length of each of the three sides of the triangle 49 may be in the range of 1 to 10 times the diameter of the ball body 13, or 1/3 to 1 times. It may be. Further, the values of the lengths of the three sides of the triangle 49 may be equal to each other.

The standby positions P1, P2, and P3 are slightly separated from each other when viewed from the Z-axis direction, and are viewed from a direction intersecting the Z-axis direction (for example, the X-axis direction which is an orthogonal direction). Sometimes they may be far apart from each other.

In the measurement step, for example, as shown below, Z includes the center of the ball body 13 when the ball body 13 comes into contact with the object 3 to be measured (at the time of the first contact) by moving from the standby position P1. The position (x-coordinate, y-coordinate, z-coordinate) of the intersection 53 between the extension line 51 (see FIG. 5) extending in the axial direction and the surface of the object 3 to be measured is obtained.

Further, to be described in more detail, the position of the center CP ₁ of the ball body 13 at the time of the first contact of the ball body 13 with the object to be measured 3 in the ball body contact step (first center position; FIG. 7A). The CP ₁ (x ₁ , y ₁ , z ₁ )) indicated by) and the center CP ₂ of the ball body 13 at the time of the second contact of the ball body 13 with the object to be measured 3 in the ball body contact step. The position (second center position; CP ₂ (x ₂ , y ₂ , z ₂ ) shown in FIG. 7 (a)) and the ball body 13 in the ball body contact step to the third object to be measured 3 Three center positions (coordinates) from the position of the center CP ₃ of the ball body 13 at the time of contact (third center position; CP ₃ (x ₃ , y ₃ , z ₃ ) shown in FIG. 7 (a)). (A ₁ x + b ₁ y + c ₁ z + d ₁ = 0; see FIG. 7 (b)).

Since the ball body 13 moves only in the Z-axis direction, the x-coordinate and y-coordinate of the center position CP ₁ of the ball body 13 at the contact position are the x of the center position O1 of the ball body 13 at the standby position. Equal to coordinates and y-coordinates. Similarly, the x-coordinate and y-coordinate of the center position CP ₂ are equal to the x-coordinate and y-coordinate of the center position O2 at the standby position, and the x-coordinate and y-coordinate of the center position CP ₃ are the center position at the standby position. It is equal to the x-coordinate and y-coordinate of O3.

The plane equation (a ₁ x + b ₁ y + c ₁ z + d ₁ = 0) is a vector from the position of the first center CP _{1 to} the position of the second center CP ₂ (vector CP ₁₂ shown in FIG. 8 (b)). , The outer product (outer product vector (p, q, r)) with the vector (vector CP ₁₃ shown in FIG. 8 (b)) extending from the position of the first center CP _{1 to} the position of the third center CP ₃ and the first It can be determined from the position of the center CP ₁ of ₁ , and can also be determined from the three points of the first center position CP ₁ , the second center position CP ₂ , and the third center position CP ₃ .

Find the cosine (cos θ; see FIG. 7 (d)) of the intersection angle θ between the found plane (a ₁ x + b ₁ y + c ₁ z + d ₁ = 0) and the XY plane (z = 0; see FIG. 7 (c)). .. From the obtained cos θ and the radius R of the ball body 13, the correction value (Zc = R / cos θ) of the Z-axis coordinates is obtained.

From the position of the center CP ₁ of the ball body 13 at the _first contact position (center coordinates; x ₁ , y ₁ , z ₁ ) and the correction value Zc of the Z-axis coordinate, the ball at the first contact The intersection 53 position of one extension line 51 extending in the Z-axis direction including the center CP _{1 of the} body 13 (the center O1 of the ball body 13 at the first standby position P1) and the surface of the object 3 to be measured. (Coordinates of intersection 53; x ₁ , y ₁ , z ₁ −R / cos θ) is obtained. The direction in which the ball body 13 approaches the object to be measured 3 side from the standby position P1 is a minus (−) direction.

Similarly, the position of the intersection of the extension line including the center of the ball 13 and extending in the Z-axis direction and the surface of the object 3 at the time of the second contact of the ball 13 with the object 3 to be measured ( The x-coordinate, y-coordinate, and z-coordinate) are obtained, and the extension line extending in the Z-axis direction including the center of the ball body 13 at the time of the third contact of the ball body 13 with the object to be measured and the object to be measured 3 The position of the intersection with the surface of the (x coordinate, y coordinate, z coordinate) may be obtained.

That is, from the center position CP ₂ (center coordinates; x ₂ , y ₂ , z ₂ ) of the ball body 13 at the time of the second contact and the correction value of the Z-axis coordinate, the ball at the second contact intersection between one extension and the object to be measured 3 surfaces including the center position CP ₂ of the body 13 extends in the Z-axis direction (intersection of _{coordinates; x 2, y 2, z} 2 -R / cosθ ) May be obtained, or from the correction value of the center position CP ₃ (center coordinates; x ₃ , y ₃ , z ₃ ) of the ball body 13 and the Z-axis coordinate at the time of the third contact, the third time. The intersection position of one extension line extending in the Z-axis direction including the center position CP ₃ of the ball body 13 at the contact of the object 3 with the surface of the object to be measured (coordinates of the intersection; x ₃ , y ₃ , ₃ , z _3- R / cos θ) may be obtained.

When determining the position (coordinates) of the contact point 55 between the ball body 13 and the object to be measured 3 in the measurement step, for example, the following is performed.

In the same manner as described above, the first center position CP ₁ (see FIG. 8A) and the second center position CP ₂ (see FIG. 8A) of the ball body 13 in the ball body contact step. And the third center position CP ₂ (see FIG. 8A), the plane including the three center positions (coordinates) is obtained.

An equation of a straight line including the center of the ball body 13 at the first contact, orthogonal to the obtained plane ((xx _L ) / L = (yy _M ) shown in FIG. 8 (c)). Find / M = (zz _N ) / N).

The equation of the straight line and the equation of the surface of the ball body 13 at the first contact ((xx ₁ ) ² + (yy ₁ ) ² + (zz) shown in FIG. 8 (d)). ₁ ) _{Find the} coordinates M ₀₁ (x _M1 , y _M1 , z _M1 ) and M ₀₂ (x _M2 , y _M2 , z _M2 ) shown in FIG. 8 (e) of the two intersections with ² = R ² ). However, it is assumed that z _M1 <z _M2 .

Of the two coordinates obtained, the one with the smaller Z-axis coordinate is the coordinate (x _M1 ) of the contact point (contact point) 55 between the object 3 to be measured and the ball body 13 at the first contact. y _M1 , z _M1 ).

Similarly, the coordinates of the contact point between the ball body 13 and the object to be measured 3 for the second time and the coordinates of the contact point between the ball body 13 and the object to be measured 3 for the third time may be obtained.

As described above, in the ball body contact step, the ball body 13 may be brought into contact with the object 3 to be measured at least four times. In this case, when each standby position of the ball body 13 before the contact (may be each position of the ball body 13 at the time of contact) is viewed from the Z-axis direction, one of the plurality of standby positions is on standby. The position is located inside the other standby positions of the plurality of standby positions.

For example, the center of the ball 13 at the other one of the four standby positions is located inside the polygon formed at the center of the ball 13 at the three standby positions of the four standby positions. ing.

Further, in the above measurement step, the position of the intersection of one extension line including the center of the ball body 13 and extending in the Z-axis direction at one standby position located inside and the surface of the object 3 to be measured ( Coordinates), at least one of the positions (coordinates) of the contact points when the ball body 13 comes into contact with the object 3 by moving from one standby position located inside is measured (calculated). The position of the intersection and the position of the contact point in the contact from the three standby positions may be measured.

When the ball body is brought into contact with the object to be measured four or more times in the ball body contact step, the position of the center of the ball body 13 at each standby position when the ball body is brought into contact with the object to be measured a plurality of times is set. When viewed from the Z-axis direction, it is sufficient that a triangle is formed at the center of the ball body 13 in 3 out of 4 times.

For example, when the contact is performed four times, a quadrangle (including one having an internal angle of more than 180 °) is formed by connecting the positions of the centers of the ball bodies 13 in order when viewed from the Z-axis direction. It is usually done (three or more points do not exist on one straight line), but the position of the center of the ball body exists on one straight line in three out of four times. In this mode, only a triangle may be formed.

When the ball body 13 is brought into contact with the object 3 to be measured four or more times in the ball body contact step, the plane (a1x + b1y + c1z + d1 = 0; see FIG. 7B) and the straight line are subjected to the least squares method. ((Xx _L ) / L = (yy _M ) / M = (zz _N ) / N; see FIG. 8 (c)).

Further, when the ball body is brought into contact with the object 3 to be measured four times in the ball body contact step, the position of the center of the ball body 13 at each standby position when the ball body is brought into contact with the object 3 four times is viewed from the Z-axis direction. And, as shown in FIG. 9, each of the center positions of the ball body 13 in the contact of 3 times out of 4 times is located at each of the 3 vertices of the equilateral triangle, and out of 4 times. It is desirable that the center position of the ball body 13 in the remaining one contact is located at the center of the equilateral triangle. Then, it is desirable to obtain the coordinates and the like of the contact point in the remaining one contact.

The outer shape of the object to be measured may be determined by the method of measuring the object to be measured.

That is, the surface of the object to be measured 3 to be measured is covered by changing (shifting) the standby position to perform the contact a plurality of times in the ball body contact process and perform the measurement in the above measurement process. As described above, the outer shape of the object to be measured 3 may be obtained by repeating the process a plurality of times.

According to the measurement method of the object to be measured, when each standby position in the ball body contact process is viewed from a predetermined direction, each of the standby positions is slightly separated from each other without being positioned in a straight line. Since the measurement of the object 3 to be measured is performed by using the positions of a plurality of positions of the ball body 13 when the object 3 is brought into contact with the object 3 a plurality of times in the ball contact step, and finding a plane including the positions of the plurality of points. Even if the surface of the object to be measured 3 has a complicated three-dimensional shape, the contact position between the ball body 13 and the object to be measured 3 can be easily obtained by correction using the plane.

Further, according to the measurement method of the object to be measured, in the measurement step, a plurality of extension lines including the center of the ball body 13 at the standby position and extending in the Z-axis direction and a plurality of surfaces of the object 3 to be measured. Since the position (coordinates) of at least one of the intersections is obtained, only the coordinates of the Z axis need to be corrected, and the measurement of the object 3 to be measured can be further facilitated.

Further, in the measurement step, the position (coordinates) of at least one contact point among the plurality of contact points (contact points) between the ball body 13 and the object to be measured 3 is obtained, so that the ball body 13 and the object to be measured 3 are used. You can get the coordinates of the actual contact point of.

Further, according to the method of measuring the object to be measured, in the measurement process, one extension line including the center of the ball body 13 at one standby position located inside and extending in the Z-axis direction and the object to be measured 3 The position (coordinates) of the intersection with the surface of the object and the position (coordinates) of the contact point when the ball body 13 abuts on the object 3 to be measured by moving from one standby position located inside is measured. Therefore, the plane in contact with the measurement point (the point on the surface of the object to be measured 3) can be accurately determined.

Further, according to the method of measuring the object to be measured, the outer shape of the object 3 to be measured 3 is obtained by repeating the process of abutting a ball body a plurality of times in the ball contact process and measuring in the measurement process a plurality of times by changing the standby position. Since the shape is determined, the shape of the entire object 3 to be measured 3 can be obtained over a wide range (for example, the whole).

By the way, if the object to be measured device 1 is a precision processing machine and the object to be measured 3 installed in the precision processing machine 1 is a work that requires further finishing after rough processing, the object to be measured 3 is By determining the outer shape of the work 3, it is possible to easily grasp the accuracy of installing the work 3 on the precision processing machine 1 and the finishing allowance of the work 3.

Further, in the ball body contact step, when the ball body is brought into contact with the object 3 to be measured four or more times a plurality of times- (minus) once when viewed from the Z-axis direction, as shown in FIG. Each of the center positions of the ball body 13 at the contact of the ball is located at a position where the circumference of the circle CZ is equally distributed, and the center position of the ball body 13 at the remaining one contact is the center of the circle CZ. It is desirable to be located at.

Further, in the object measuring device 1, the touch probe 5 installed on the spindle rotating body 25 has the X-axis direction, the Y-axis direction, and the Z-axis with respect to the object 3 installed on the X-axis moving body 17. In addition to being freely movable and positioning in the direction, it is also rotatable around the A axis extending in the X-axis direction and rotatable around the B axis extending in the Y-axis direction. Good.

1 Measured object measuring device 3 Measured object 13 Ball body 35 Ball body moving part 37 Ball body detecting part 39 Control part 51 Extension line 53 Intersection point 55 Position of this contact point O1, O1, O3 Center of ball body P1, P2, P3 Standby position

Claims (10)

A ball body contact step in which the ball body is brought into contact with the object to be measured three or more times by moving the ball body from a standby position away from the object to be measured in a predetermined direction approaching the object to be measured. When,
It has a measurement step of measuring the object to be measured by using the positions of a plurality of positions of the ball when the ball is brought into contact with the object to be measured a plurality of times in the ball contact step.
When each of the standby positions in the ball body contact step is viewed from the predetermined one direction, each of the standby positions is separated from each other by a value of the diameter of the ball body or a value smaller than the diameter .
The ball body contact step is a step of performing the contact at least four times, and when each standby position is viewed from the predetermined one direction, the ball body contact step is at three of the standby positions out of at least four standby positions. Inside the triangle formed at the center of the ball body, the center of the ball body at the other one of the four standby positions is located.
The measurement step is an intersection of one extension line extending in the Z-axis direction including the center of the ball body at one standby position located inside the triangle and the surface of the object to be measured. The step of measuring at least one of the positions of the contact points when the ball body comes into contact with the object to be measured by moving from one of the standby positions located inside the triangle. , A method for measuring an object to be measured. In the method for measuring an object to be measured according to claim 1,
The 3 three sides the value of the length of each of the prismatic, DUT measurement method characterized in that it is in the range of 1/3 to 1 times the diameter of the ball member. In the method for measuring an object to be measured according to claim 2,
Measured object measured how the value of the three sides each of the length of the triangle is equal to or has become equal to each other. In the method for measuring an object to be measured according to any one of claims 1 to 3.
The subject is characterized in that the outer shape of the object to be measured can be obtained by repeating the process of abutting a ball body a plurality of times in the ball body abutting step and performing measurement in the measuring step a plurality of times by changing the standby position. Measurement method. In the method for measuring an object to be measured according to any one of claims 1 to 4.
In the ball body contact step, when the ball body is brought into contact with the object to be measured four times or more a plurality of times, a plurality of- (minus) one contact is performed when viewed from the predetermined one direction. Each of the center positions of the ball body in the above is located at a position where the circumference of a predetermined circle is uniformly distributed, and the center position of the ball body in the remaining one contact is the center of the circle. A method for measuring an object to be measured, which is characterized by being located in. A ball body moving part that moves the ball body relative to the object to be measured,
A ball body detecting unit that detects the position of the ball body when the ball body comes into contact with the object to be measured, and a ball body detecting unit.
By moving the ball body from a standby position away from the object to be measured in a predetermined direction approaching the object to be measured, the ball is brought into contact with the object to be measured three or more times. The ball body detection unit is controlled so as to control the ball body moving unit and detect the positions of a plurality of positions of the ball body when the ball body is brought into contact with the object to be measured a plurality of times. It has a control unit for measuring the object to be measured by using the positions of a plurality of positions of the ball when the ball is brought into contact with the object to be measured a plurality of times.
When each of the standby positions is viewed from the predetermined one direction, the control unit is separated from each other by a value of the diameter of the ball body or a value smaller than the diameter , and the contact with the control unit. Is performed at least four times, and when each of the standby positions is viewed from the predetermined one direction, inside the triangle formed at the center of the ball body at three of the four standby positions. The center of the ball body in the other one of the four standby positions is located.
The position of the intersection of one extension line including the center of the ball body and extending in the Z-axis direction at the one standby position located inside the triangle and the surface of the object to be measured, said 3. It is configured to measure at least one of the positions of the contact points when the ball body comes into contact with the object to be measured by moving from one of the standby positions located inside the polygon. A featured object measuring device. In the object measuring device according to claim 6,
The value of the three sides each of the length of the triangle is, the ball having a diameter of the workpiece measuring apparatus characterized that it is 1/3 the range to 1 times the value. In the object measuring device according to any one of claims 6 to 7.
The triangle of the three sides each of the workpiece measuring apparatus length value is equal to or has become equal to each other. In the object measuring device according to any one of claims 6 to 7.
The control unit changes the standby position to detect the positions of a plurality of positions of the ball body when the ball body is brought into contact with the object to be measured a plurality of times and the ball body is brought into contact with the object to be measured a plurality of times. A device for measuring an object to be measured, characterized in that the outer shape of the object to be measured is obtained by repeating the process a plurality of times. In the object measuring device according to any one of claims 6 to 7.
When the control unit abuts the ball body on the object to be measured four times or more a plurality of times, the ball is abutted a plurality of times − (minus) once when viewed from the predetermined one direction. Each of the center positions of the body is located at a position where the circumference of a predetermined circle is equally distributed, and the center position of the ball body in the remaining one contact is located at the center of the circle. An object measuring device to be measured, which is characterized in that it is configured as follows.

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