JP2000039302A - Profile measuring instrument - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the profile measuring instrument which can be improved in operability and measurement efficiency. SOLUTION: The profile measuring instrument is equipped with a keyboard 45 for inputting the surface property level and measurement precision level of a body to be measure; a measurement condition setting table 48 which previously contains reference intrusion quantities, and measurement speeds corresponding to the surface property levels and measurement precision levels of bodies to be measured; and a host computer 44 which reads the reference intrusion quantity and measurement speed corresponding to the surface property level and measurement precision level of the body to be measured out of the measurement condition setting table 48, on condition that the surface property level and measurement precision level of the body to be measured are inputted and places a three-dimensional measuring instrument A in operation according to the reference intrusion quantity and measurement speed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a scanning probe which is moved relative to a workpiece while pressing the scanning probe against the surface of the workpiece with a predetermined measurement pressure. The present invention relates to a scanning measurement device that measures a contour shape.

[0002]

2. Description of the Related Art A scanning measurement in which a scanning probe and an object to be measured are relatively moved while pressing the scanning probe against the surface of the object to be measured at a predetermined measurement pressure, and the surface contour shape of the object to be measured is measured from the relative movement locus. A scanning probe is attached to a device, for example, a coordinate measuring machine, and the scanning probe is moved along the surface shape of the measured object while pressing the scanning probe against the surface of the measured object at a predetermined measurement pressure. There has been known a scanning measurement device for measuring a surface contour shape of an object to be measured.

[0003] When performing a scanning measurement in this type of scanning measurement apparatus, taking into account the required measurement accuracy,
First, it is necessary to specify a measurement pressure of the scanning probe, specifically, a reference press-in amount proportional to the measurement pressure and a measurement speed of the scanning. In general, it is advantageous to increase the reference indentation for high-speed measurement and to decrease the reference indentation for high-accuracy measurement.

This is because, in the former case, the larger the reference pushing amount, the better the followability to the surface of the object to be measured (the probe follows a rapid change in the curvature of the surface of the object without detaching). In the latter case, the current pushing amount or the deviation from the specified cross section or track is
When the allowable width set at a certain ratio to the reference indentation is exceeded, the measurement speed is automatically reduced,
This is because the push-in amount and the deviation amount are controlled so as to return within the allowable range. In the end, the former is “high-speed and low-accuracy”, and the latter is “high-accuracy and low-speed”.

[0005] Since this constraint is known, the measurer first selects "high-speed low-accuracy" or "high-accuracy low-speed" depending on the object to be measured.
Then, an appropriate reference indentation amount and measurement speed were specified.

[0006]

However, in the scanning measurement, since the scanning behavior is affected by the surface properties of the object to be measured, the measurer can determine the appropriate reference indentation amount and measurement speed suitable for the measurement accuracy. Setting a specific numerical value is extremely complicated, and in most cases, the default value specified for each scanning probe is used. For this reason, a measurement error may occur and the scanning measurement may not be performed. In addition, high-accuracy scanning measurement may not be performed, or the measurement may take a long time even though the accuracy is low.

SUMMARY OF THE INVENTION An object of the present invention is to solve such a conventional drawback and to provide a scanning measurement apparatus capable of improving usability and measurement efficiency.

[0008]

The scanning measuring apparatus of the present invention has a moving mechanism for relatively moving the scanning probe and the object to be measured, and moves the scanning probe to the surface of the object to be measured by the moving mechanism. In a scanning measurement device that relatively moves a scanning probe and an object to be measured while pressing with pressure, and measures a surface contour shape of the object to be measured from the relative movement trajectory,
An input means for inputting a surface texture level and a measurement accuracy level of the DUT; a measurement condition setting table in which measurement pressures and measurement speeds corresponding to the respective surface texture levels and the respective measurement accuracy levels of the DUT are stored in advance; .. Corresponding to the surface texture level and the measurement accuracy level of the DUT input from the measurement condition setting table on condition that the surface texture level and the measurement accuracy level of the DUT are input from the input means. Control means for reading out the measured pressure and the measured speed and operating the moving mechanism based on the measured pressure and the measured speed.

According to such a configuration, when the measurer inputs the surface texture level and the measurement accuracy level of the measured object using the input means, the surface texture of the measured object is input from the measurement condition setting table. The measurement pressure and the measurement speed corresponding to the level and the measurement accuracy level are read, and the moving mechanism is operated based on the measurement pressure and the measurement speed. In other words, in the past, it was difficult to specify the specific values of the measurement pressure and the measurement speed, but by simply inputting the surface texture level and the measurement accuracy level of the measured object, which can be easily specified in an image, the scanning measurement was performed. Since the measurement pressure and measurement speed, which are one of the conditions, are automatically determined, the usability of the operator can be improved, and if low accuracy is required, high-speed scanning measurement can be performed automatically. Efficiency can be greatly improved.

In the above, since the measurement pressure is proportional to the reference pushing amount of the copying probe to the object to be measured, the measuring pressure may be defined by the reference pushing amount. Also, the steps of the surface texture level and the measurement accuracy level of the object to be measured are arbitrary, but if it is too large, it becomes complicated for the measurer to select, and conversely, if it is too small, an appropriate reference indentation amount and measurement are performed. Since it is difficult to obtain a speed, the surface property level of the object to be measured is classified into at least two or more steps according to the magnitude of friction on the surface of the object to be measured, and the measurement accuracy level is divided into at least three or more steps according to the measurement accuracy. It is desirable to have been.

[0011] In addition, the control means, when performing the scanning measurement by operating the moving mechanism, measures when the pushing amount of the scanning probe exceeds a predetermined allowable width with respect to the reference pushing amount. It is preferable to have a function for making an error. This eliminates the need to continue useless measurement work, which is efficient. At this time, if the control unit operates the moving mechanism at a measurement speed reduced by one rank in the measurement condition setting table when a measurement error occurs, the control unit automatically sets an appropriate measurement speed. The scanning measurement can be continued with. In this case, if the automatic continuation of the scanning measurement is performed under the condition that the automatic retry is specified from the input unit, the post-processing when the measurement error occurs is automatically performed, or the surface texture level or the measurement may be performed. It is possible to select the accuracy level re-input processing.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is an overall perspective view showing an embodiment of a scanning measurement apparatus according to the present invention. The measuring apparatus according to the present embodiment includes a coordinate measuring machine A as a moving mechanism for relatively moving the scanning probe P and the workpiece W in a three-dimensional direction, and controls the driving of the coordinate measuring machine A and performs three-dimensional measurement. A controller B for taking in relative movement data between the scanning probe P and the workpiece W provided from the measuring machine A, a CMM operating via the controller B, and a scanning probe from the CMM A P and DUT W
And a host system C that processes relative movement data and the like to obtain the surface contour shape of the workpiece W.

The coordinate measuring machine A has a base 21, a table 22 mounted on the base 21 and on which an object to be measured W is mounted on an upper surface, and is movable on the table 22 in the front-rear direction (Y-axis direction). A slider 24 provided to be movable in the left-right direction (X-axis direction) along the X beam 23A of the gate-shaped frame 23;
The slider 24 includes a Z-axis spindle 25 provided to be vertically movable (Z-axis direction) and a scanning probe P provided at a lower end of the Z-axis spindle 25.

Here, as the copying probe P, for example, a copying probe disclosed in Japanese Patent Publication No. 4-77242 proposed by the present applicant can be used. As shown in FIGS. 2 and 3, a base 110 detachably attached to the lower end of the Z-axis spindle 25;
A Y slider 120 provided to be slidable in the Y-axis direction with respect to the base 110;
X slider 130 slidably provided in the axial direction
A Z slider 140 provided on the X slider 130 so as to be able to move up and down in the Z axis direction, and a stylus 15 provided on the Z slider 140 and having a contact ball 151 at a lower end.
0, a neutral position holding means 160 for holding the stylus 150 at a neutral position in the X, Y, and Z axes, and a displacement detecting means 170 for detecting the amount of displacement of each of the sliders 120, 130, 140. .

[0015] As shown in FIG.
A hollow section 111 having a rectangular cross section penetrating in the axial direction is provided. The Y slider 120 is, as shown in FIG.
A pair of slide members 121A, 1 penetrating through ten hollow portions 111 and slidable in the Y-axis direction in the hollow portions 111.
21B, and rectangular frames 122 and 123 disposed outside the base 110 in the width direction and connected to both ends of the pair of slide members 121A and 121B. This allows the Y slider 120 to slide in the Y-axis direction while being guided by the base 110. As shown in FIG. 6, the X slider 130 is a slide member housed in the hollow portion 111 of the base 110 and slidable in the X-axis direction while being sandwiched between the slide members 121A and 121B of the Y slider 120. 131 and the base 11
0 and a main body 133 having a rectangular hollow portion 132 connected to both ends of the slide member 131 and penetrating in the Z-axis direction. The Z slider 140 is, as shown in FIG.
The main body 142 is housed in the hollow portion 132 so as to be able to ascend and descend and has a hollow cylindrical portion 141 therein, and a stylus mounting member 143 attached to the lower end of the main body 142 and having the stylus 150 on the lower surface.

The neutral position holding means 160 includes an XY origin return means 161 for returning the stylus 150 to the origin in the XY plane in a non-contact state in which no pressing force is applied to the stylus 150 from an object or the like, and a stylus. And Z origin return means 166 for returning 150 to the origin on the Z axis. The XY origin return means 161 includes a rod-shaped wire spring 162. The wire spring 162 has an upper end screwed to the base 110 via a nut member 163 so as to be able to adjust a vertical position, and a lower end of the wire spring 162 with respect to a hollow cylindrical portion 134 attached to the lower surface of the X slider 130. An axially slidable ball 165 is provided. The Z origin return means 166 is constituted by a coil spring 167 whose upper end is locked by the Z slider 140 and whose lower end is locked by the hollow cylindrical portion 134.

The displacement detecting means 170 includes a Y sensor 171 for detecting the displacement of the Y slider 120 and the X sensor
An X sensor 172 for detecting an amount of displacement of the slider 130,
Z sensor 17 for detecting the amount of displacement of the Z slider 140
3 is provided. The Y sensor 171 is composed of a scale 171A provided on the upright portion of the upper end of the Y slider 120, and a detector 171B provided on the base 110 so as to face the scale 171A. X sensor 172
Is composed of a scale 172A provided on the base 110 and a detector 172B provided on the protruding portion of the X slider 130 so as to face the scale 172A. The Z sensor 173 includes a scale 173A provided on the X slider 130 and a detector 173B provided on the Z slider 140 so as to face the scale 173A.

Therefore, after the scanning probe P is attached to the Z-axis spindle 25, the stylus 150 of the scanning probe P is moved along the surface of the workpiece W while keeping the stylus 150 in contact with the surface of the workpiece W. , Each sensor 171, 1
72, 173, the sliders 120, 130, 14
The displacement amount of 0, that is, the pushing amount of the stylus 150 is output. Here, when the moving mechanism of the coordinate measuring machine A is adjusted so that the pushing amount becomes the reference pushing amount specified in advance, the contact ball 151 at the tip of the stylus 150 is adjusted.
Are pressed while being pressed against the surface of the workpiece W by the reference pressing amount.

As shown in FIG. 8, the host system C includes a CPU 41, a ROM 42 storing a driving program, a data processing program, and the like, and a host computer 44 as control means having a RAM 43 storing data and the like. To the host computer 44, a keyboard 45, a display device 46, a printer 47, and the like as input means are connected, and the controller B is connected. The RAM 43 is provided with a measurement condition setting table 48 in addition to an area for storing various data. The measurement condition setting table 48
As shown in FIG. 9, the surface property level (large,
Medium, small) and measurement accuracy level (high accuracy, slightly high accuracy,
Corresponding to medium precision, slightly low precision, and low precision), reference depression amounts D1 to D15 and measurement speeds V1 to V15 are stored. More specifically, for each surface texture level (large, medium, small) in which the surface texture of the workpiece W is classified into three levels according to the magnitude of friction (surface roughness), the measurement accuracy is classified into five levels. The reference indentation amounts D1 to D15 and the measurement speeds V1 to V15 are stored corresponding to the accuracy levels (high accuracy, slightly high accuracy, medium accuracy, slightly low accuracy, low accuracy).

From the keyboard 45, the surface texture level (large, medium, small), the measurement accuracy level (high accuracy, slightly high accuracy, medium accuracy, slightly low accuracy, low accuracy) of the object W to be measured and the automatic retry are displayed. Presence or absence is entered. When the surface texture level and the measurement accuracy level of the DUT W are input from the keyboard 45, the host computer 44 reads the input surface texture level and the measurement of the DUT W from the measurement condition setting table 48. The reference push-in amount and the measurement speed corresponding to the accuracy level are read, and an allowable width ratio (allowable width ratio of the push-in amount and the shift amount) preset for the reference push-in amount is selected. The measurement speed and the allowable width ratio are given to the controller B together with the copying start command. When a measurement error occurs during scanning measurement, a measurement condition setting table 48 is set on condition that automatic retry is specified in advance by the keyboard 45.
Of the measurement speeds is selected, and the measurement speed is instructed to the controller B.

Next, the operation of the present embodiment will be described with reference to the flowchart of FIG. At the time of measurement, the measurer places the object W on the table 22 of the coordinate measuring machine A.
Is set, first, the surface texture level, the measurement accuracy level, and the presence / absence of automatic retry are selected and input using the keyboard 45 of the host system C (S
1). For example, the surface texture level is large, medium, or small depending on the level of friction (surface roughness) on the surface of the workpiece.
Select one of the small. As for the measurement accuracy level, one of high accuracy, slightly high accuracy, medium accuracy, slightly low accuracy, and low accuracy is selected.

Then, the host computer 44, based on the measurement condition setting table 48,
The reference indentation amount and the measurement speed corresponding to the surface texture level and the measurement accuracy level of the object are read out, and the allowable width ratio corresponding to the reference indentation amount is selected, and these (the standard indentation amount, the measurement speed and the allowable width ratio) are copied. Command to the controller B together with the start command (S
2). Thereby, the controller B operates the coordinate measuring machine A based on the given reference press-in amount and measurement speed (S3).

At this time, if the copying probe P has excessively cut into the workpiece W or has been separated, that is, if an error has occurred, the copying operation is stopped and whether or not automatic retry is specified. Check (S4
S5). If the automatic retry is specified, the measurement speed is reduced by one rank in the measurement condition setting table 48 (S
6) Instruct the controller B of the reduced measurement speed, reference press-in amount, and allowable width ratio. If the automatic retry is not specified, the input of the surface texture level, the measurement accuracy level, and the presence / absence of the automatic retry is performed from the keyboard 45 from the beginning.

Therefore, according to the present embodiment, when the surface texture level and the measurement accuracy level of the workpiece W are input from the keyboard 45, the surface texture level of the workpiece input from the measurement condition setting table 48 is input. And the reference push-in amount and the measurement speed corresponding to the measurement accuracy level are read out, and the coordinate measuring machine A is operated based on the reference push-in amount and the measurement speed.
By simply inputting the surface texture level and the measurement accuracy level of the workpiece W, the reference indentation amount and the measurement speed are automatically determined, so that the usability of the measurer can be improved.

When low accuracy is required, high-speed scanning measurement is possible, so that measurement efficiency can be greatly improved. For example, when measuring with an inner diameter of about 50 mm, when the measurement speed is 3 mm / s and 25 mm / s,
The measurement time can be reduced to 以下 or less.

Further, even if the pushing amount of the scanning probe P exceeds the allowable width set in advance with respect to the reference pushing amount and a measurement error occurs, if an automatic retry is first designated on the keyboard 45, Since the three-dimensional measuring machine A is operated at a measurement speed that is one rank lower than the measurement speed in the measurement condition setting table 48, the scanning measurement can be automatically continued at an appropriate speed.

In the above embodiment, the scanning probe P
The scanning probe P was moved while controlling the amount of pushing into the surface of the object to be measured W to be the reference pushing amount. For example, a force detector such as a piezoelectric element was provided at the base of the stylus 150, and this force was applied. A detector detects a force (measurement pressure) acting on the stylus 150 in the X, Y, and Z-axis directions (measurement pressure), and moves the scanning probe P while controlling the measurement pressure to be a preset measurement pressure. You may.

In the above embodiment, the surface texture level is divided into three levels of large, medium, and small, and the measurement precision level is divided into five levels of high precision, slightly high precision, medium precision, slightly low precision, and low precision. However, it is not limited to this. The surface property level is preferably divided into at least two or more steps, and the measurement accuracy level is preferably divided into at least three or more steps.

Further, in the above-described embodiment, the three-dimensional measuring machine A having a structure in which the scanning probe P moves in the X, Y, and Z-axis directions with respect to the workpiece W is used. A three-dimensional measuring machine having a structure in which the workpiece W moves in the X, Y, and Z axis directions with respect to the probe P may be used. In short, any mechanism may be used as long as the scanning probe P and the workpiece W can move relative to each other in a three-dimensional (or two-dimensional) direction.

[0030]

According to the scanning measuring apparatus of the present invention, the measuring pressure or the reference indentation amount and the measuring speed are automatically determined only by inputting the surface texture level and the measuring accuracy level, thereby improving the usability of the measurer. And the measurement efficiency can be greatly improved.

[Brief description of the drawings]

FIG. 1 is an overall perspective view showing an embodiment of a scanning measurement apparatus according to the present invention.

FIG. 2 is a cross-sectional view of the copying probe according to the embodiment.

FIG. 3 is a sectional view taken along line III-III of FIG. 2;

FIG. 4 is a perspective view showing a base of the copying probe shown in FIGS. 2 and 3;

FIG. 5 is a perspective view showing a Y slider of the copying probe shown in FIGS. 2 and 3;

FIG. 6 is a perspective view showing an X slider of the copying probe shown in FIGS. 2 and 3;

FIG. 7 is a perspective view showing a Z slider of the copying probe shown in FIGS. 2 and 3;

FIG. 8 is a block diagram of a host system in the embodiment.

FIG. 9 is a diagram showing a measurement condition setting table in the embodiment.

FIG. 10 is a flowchart showing a measurement procedure of the embodiment.

[Description of Signs] 44 Host computer (control means) 45 Keyboard (input means) 48 Measurement condition setting table A Coordinate measuring machine (moving mechanism) P Copying probe W DUT

Claims (6)

[Claims] A moving mechanism configured to relatively move the scanning probe and the object to be measured; the moving mechanism presses the scanning probe against a surface of the object to be measured with a predetermined measurement pressure, and moves the scanning probe and the object to be measured. Relative movement of the object and measuring the surface contour shape of the object from the relative movement trajectory; and input means for inputting a surface texture level and a measurement accuracy level of the object to be measured. A measurement condition setting table in which a measurement pressure and a measurement speed corresponding to the surface texture level and each measurement accuracy level are stored in advance, provided that the surface texture level and the measurement accuracy level of the measured object are input from the input unit, Read out the measurement pressure and measurement speed corresponding to the surface texture level and measurement accuracy level of the measured object input from the measurement condition setting table, And a control means for operating the moving mechanism based on the measurement pressure and the measurement speed. 2. The scanning measurement apparatus according to claim 1, wherein the measurement pressure is defined by a reference pressing amount of the scanning probe with respect to an object to be measured. 3. The scanning measurement apparatus according to claim 2, wherein the surface property level of the object to be measured is divided into at least two or more stages according to the magnitude of friction of the surface of the object to be measured, and the measurement accuracy level is measured. At least 3 depending on accuracy
A scanning measurement device characterized by being divided into stages or more. 4. The scanning measurement device according to claim 2, wherein the control unit is configured to operate the moving mechanism to perform the scanning measurement, so that a pushing amount of the scanning probe becomes equal to a reference pushing amount. A scanning measurement device having a function of setting a measurement error when a predetermined allowable width is exceeded. 5. The scanning measurement device according to claim 4, wherein the control unit controls the moving mechanism at a measurement speed that is one rank lower in the measurement condition setting table when a measurement error occurs. A scanning measurement device characterized by being operated. 6. The scanning measurement apparatus according to claim 4, wherein the control unit sets the measurement speed to the measurement condition on the condition that an automatic retry is designated from the input unit when a measurement error occurs. A scanning measurement apparatus characterized in that the moving mechanism is operated at a measurement speed one rank lower in a setting table.