JP7259198B2 - Surface shape measuring device - Google Patents

Description

The present invention relates to a contact-type surface shape measuring apparatus for measuring the surface shape of an object to be measured, such as surface roughness and contour shape.

Conventionally, the probe and the object to be measured are relatively moved while the probe is in contact with the surface of the object to be measured, and the displacement of the probe caused by the undulations on the surface of the object to be measured is converted into an electric signal and detected. 2. Description of the Related Art A surface shape measuring device for measuring the surface shape of an object is known (see Patent Documents 1 and 2). In addition, a contact (equivalent to a probe) provided at the tip of the stylus is brought into contact with the object to be measured, and a strain gauge detects the amount of distortion of the stylus due to the stress from the object to be measured. 2. Description of the Related Art A device that calculates a displacement amount and measures the surface shape of an object to be measured is known (see Patent Document 3).

JP 2007-303837 A JP 2016-191631 A JP-A-2005-55345

The contact-type surface shape measuring apparatus has the following problems [1] to [3].

[1] If the measurement surface of the workpiece, which is the object to be measured, has scratches, dust, or a singular point, the probe may jump or, after jumping, collide with the workpiece vigorously, depending on the driving speed, resulting in damage to the workpiece. Surface shape may not be traced correctly.

[2] When measuring the shape of a work having a steep surface to be measured, depending on the drive speed and the stiffness of the probe, the probe may bend and correct measurement results may not be obtained.

[3] When there is disturbance such as wind or vibration during measurement, it is difficult to determine whether the abnormality in the measured value is due to the shape of the workpiece or due to the disturbance.

If correct measurement results cannot be obtained for the reasons [1] to [3] above, it is preferable to change the measurement conditions and perform measurement again, or exclude abnormal measurement data from the calculation. However, conventional equipment does not have a mechanism for verifying whether the measurement result is correct or abnormal, or a function for automatically coping when an abnormality occurs. It was necessary to perform work by judging the graph of shape) by human eyes.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a surface profile measuring apparatus capable of confirming whether or not a measurement result is proper and obtaining a correct measurement result. With the goal.

In order to achieve the above objects, the following inventions are provided.

A surface shape measuring apparatus according to a first aspect of the present invention includes a detector that detects displacement of a probe, and relative movement that relatively moves the object to be measured and the detector while the probe is in contact with the object to be measured. and a weighing scale that detects a measuring force, which is the pressing force of the stylus against the object to be measured, as a weight acting in the direction of gravity.

According to the first aspect, the weighing scale detects the load (measuring force) acting on the object to be measured by the contact of the stylus with the object to be measured. The magnitude of the measuring force detected by the weighing scale may change due to bouncing or collision of the gauge head, disturbance, or deflection of the gauge head. According to the first aspect, it is possible to determine the validity of the measurement result based on the information on the measuring force obtained from the weighing scale.

In the surface shape measuring apparatus according to the second aspect of the present invention, in the first aspect, the weighing scale is used to monitor the measuring force during the operation of measuring the surface shape of the object to be measured based on detection of displacement by the detector. be done.

According to the second aspect, the measuring force can be observed in real time during the surface shape measuring operation.

A surface profile measuring device according to a third aspect of the present invention is, in the first aspect or the second aspect, in a state in which the object to be measured is placed on the weighing scale, the measuring element is moved relative to the object to be measured while being in contact with the object to be measured. The surface shape of the object to be measured is measured by relatively moving the object to be measured and the detector by means of a mechanism and detecting the displacement of the stylus with the detector.

In any one of the first to third aspects of the surface profile measuring device according to the fourth aspect of the present invention, the weighing scale has a resolution capable of measuring a measuring force of 0.75 millinewtons [mN] or less. Have.

A surface profile measuring apparatus according to a fifth aspect of the present invention is, in any one aspect of the first aspect to the fourth aspect, wherein the weighing scale for measuring the surface roughness as the surface profile of the object to be measured is an electromagnetic Or it is a tuning fork weighing scale.

According to a sixth aspect of the present invention, there is provided a surface shape measuring apparatus according to any one of the first to fourth aspects, wherein the weighing scale for measuring the contour shape as the surface shape of the object to be measured is a load cell type or It is a tuning fork weighing scale.

A surface shape measuring apparatus according to a seventh aspect of the present invention is, in any one aspect of the first to sixth aspects, a base, a column erected on the upper part of the base, a column supported by the column, and a length of the column and a drive unit as a relative movement mechanism for moving the detector in a direction orthogonal to the direction.

A surface shape measuring apparatus according to an eighth aspect of the present invention, in any one of the first to seventh aspects, is characterized in that during the operation period of relative movement between the object to be measured and the detector by the relative movement mechanism, A measuring force monitoring unit is provided for monitoring the measuring force based on the obtained information.

A surface shape measuring apparatus according to a ninth aspect of the present invention is the eighth aspect, wherein the measuring force monitoring unit includes a displacement detection signal indicating the displacement detected by the detector and a weight detection signal indicating the measuring force detected by the weighing scale. and a signal processor that simultaneously acquires

In the eighth or ninth aspect of the surface shape measuring apparatus according to the tenth aspect of the present invention, the measuring force monitoring unit detects an abnormality in the measuring force based on the detection result of the measuring force detected by the weighing scale. .

In the tenth aspect, the surface shape measuring apparatus according to the eleventh aspect of the present invention excludes from the calculation, among the measurement data acquired via the detector, the measurement data corresponding to the location where the abnormality in the measuring force is detected. and an analysis processing unit that performs data analysis.

A surface profile measuring apparatus according to a twelfth aspect of the present invention, in the tenth aspect, further comprises a control section that causes re-measurement when an abnormality in the measuring force is detected.

A surface shape measuring apparatus according to a thirteenth aspect of the present invention is, in any one of the first to twelfth aspects, a first The measurement result output unit displays the graph in association with a second graph showing detection data of the measurement force acquired using the weighing scale.

For example, a display device and/or a printer may be employed as the measurement result output unit.

According to the present invention, it is possible to verify the validity of the measurement result based on the force information obtained from the weighing scale, and to obtain the correct measurement result.

1 is an external view of a surface profile measuring device according to an embodiment of the present invention; FIG. 1 is a block diagram showing an outline of a control system of a surface profile measuring device according to an embodiment of the present invention; FIG. FIG. 10 is a diagram schematically showing a state in which the probe has jumped up from the measurement surface during measurement; It is an example of a graph of a measurement shape and a graph of a detected measurement force when bounce and collision of the probe or disturbance occurs. FIG. 10 is a diagram schematically showing how the probe is bent due to the shape of the workpiece; FIG. 5 is an explanatory diagram schematically showing an example of the relationship between the deflection of the probe due to the shape of the workpiece and the detected measuring force; FIG. 10 is an explanatory diagram schematically showing another example of the relationship between the deflection of the probe due to the workpiece shape and the detected measuring force; It is a figure which shows the structural example of an electromagnetic weighing scale. It is a figure which shows the structural example of a load cell-type weighing scale. It is a figure which shows the structural example of a tuning fork type weighing scale. 3 is a block diagram showing functions of the data processing device; FIG. 4 is a flow chart showing a first example of the flow of measurement processing by the surface shape measuring device according to the embodiment of the present invention; FIG. 13 is a flow chart showing a flow of analysis processing (step S127) in FIG. 12; FIG. 6 is a flow chart showing a second example of the flow of measurement processing by the surface shape measuring device according to the embodiment of the present invention; 9 is a flow chart showing a third example of the flow of measurement processing by the surface shape measuring device according to the embodiment of the present invention;

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

<<Structure of Surface Profile Measuring Device>>
FIG. 1 is an external view of a surface profile measuring device according to an embodiment of the present invention. The surface shape measuring apparatus 10 includes a base 12, a column 14 erected on the upper part of the base 12, a driving unit 16 attached to the column 14, a detector 18, and a stylus 20 attached to the detector 18. and a weighing scale 24 for detecting the measuring force of the probe 20 acting on the workpiece W. The surface shape measuring apparatus 10 also includes an input device 26 for giving various instructions such as input of measurement conditions, and a display device 28 for displaying measurement results and the like.

A work W is placed on the weighing scale 24 . The work W may be placed directly on the weighing scale 24, or may be set on the weighing scale 24 via a work holder (not shown).

The column 14 is an elevating mechanism that moves the driving unit 16 and the detector 18 in the vertical direction (Z-axis direction) in FIG. The Z-axis direction corresponds to the longitudinal direction of the column 14 . The column 14 includes a ball screw (not shown) arranged along the Z-axis direction and a lifting motor (not shown). A rotating shaft of the lifting motor is connected to a ball screw. The drive unit 16 moves in the Z-axis direction by rotating the ball screw with the power of the lifting motor. The detector 18 supported by the driving portion 16 moves along with the driving portion 16 in the Z-axis direction. The height (position in the Z-axis direction) of the probe 20 can be adjusted by the vertical movement of the column 14 .

The driving unit 16 is a mechanism for driving the detector 18 and the probe 20 along the X-axis direction perpendicular to the Z-axis direction, and supports the detector 18 movably along the X-axis direction (not shown). It includes a motor (not shown) that serves as a power source for generating a mechanism and driving force. A linear motor may be used as the power source for the drive unit 16 .

When measuring the surface shape of the work W, the probe 20 is brought into contact with the surface of the work W, and the detector 18 and the probe 20 are moved in the X-axis direction by the drive unit 16, whereby the workpiece W and the probe 20 are moved. 20 are moved relative to each other. The drive unit 16 is an example of a “relative movement mechanism”. The probe 20 is displaced following the shape of the surface of the work W. As shown in FIG.

The detector 18 includes a transducer (not shown) that converts the amount of displacement of the stylus 20 into an electrical signal. The transducer may, for example, be configured with a differential transformer. The probe 20 is pressed against the workpiece W in a direction parallel to the direction of gravity, that is, in the Z-axis direction. The pressing force of the stylus 20 against the workpiece W is called measuring force. A pressing force in a direction parallel to the direction of gravity acts on the work W due to the contact between the work W and the probe 20 .

The weight scale 24 detects the magnitude of the component of the measurement force acting on the workpiece W in the direction of gravity as weight.

FIG. 2 is a block diagram showing an overview of the control system of the surface shape measuring apparatus 10. As shown in FIG. The surface shape measuring device 10 includes a control device 30 and a data processing device 32 . The control device 30 includes an amplifier (not shown) that supplies driving power to a motor (not shown) built in the driving section 16 . The control device 30 also includes an amplifier (not shown) that supplies driving power to a lifting motor (not shown) provided in the column 14 (see FIG. 1).

The control device 30 centrally controls the operation of the surface shape measuring device 10 . The control device 30 includes, for example, various arithmetic processing circuits including a CPU (central processing unit) and a storage device such as a memory. The control device 30 functions as a control section by executing a predetermined program stored in advance. The functionality of controller 30 may be implemented using one or more processors. The processor can have various circuit forms such as a CPU, a programmable logic device (PLD) such as an FPGA (Field Programmable Gate Array), and an ASIC (Application Specific Integrated Circuit).

A controller 30 is connected to the drive 16 and the detector 18 . The control device 30 is also connected to a data processing device 32 . The detector 18 and weigh scale 24 are connected to a data processor 32 . A signal (displacement detection signal) output from the detector 18 is input to the data processor 32 . A signal (weight detection signal) output from the weighing scale 24 is input to the data processing device 32 .

The data processing device 32 includes a processor that processes data obtained through the detector 18 and the weighing scale 24 and performs various calculations, and a storage device such as a memory that stores various information such as measurement data. The data processing device 32 may be configured using a computer.

The data processing device 32 analyzes the surface shape of the object to be measured based on the displacement detection signal obtained from the detector 18 . The data processor 32 monitors the measuring force during the measuring operation in real time based on the weight detection signal obtained from the weighing scale 24 .

Data processing device 32 is connected to input device 26 and display device 28 . Input device 26 and display device 28 function as a user interface. The input device 26 may be, for example, operation buttons, a joystick, a keyboard, a mouse, a touch panel, or an appropriate combination thereof. By operating the input device 26, the user can input various instructions such as measurement conditions and analysis conditions.

The display device 28 may be, for example, a liquid crystal display or an organic electro-luminescence (OEL) display. The display device 28 can display various types of information such as measurement result information. A printer (not shown) may also be connected to the data processing device 32 . Also, the control device 30 may include the functions of the data processing device 32 . For example, each function of the control device 30 and the data processing device 32 may be realized by one computer.

<<Overview of Operation of Surface Profile Measuring Device 10>>
The outline of the operation of the surface shape measuring apparatus 10 configured as described above is as follows.

A workpiece W is placed on the weighing scale 24 and the probe 20 is brought into contact with the workpiece W. - 特許庁The initial measuring force at the start of measurement is adjusted to a predetermined reference measuring force (for example, 0.75 millinewtons [mN]). By moving the probe 20 in the X-axis direction while the probe 20 is in contact with the work W, the surface shape of the work W is measured. Simultaneously with the surface shape measurement, the value of the weighing scale 24 is detected to monitor the measuring force in real time.

Depending on the workpiece W, there may be protrusions on the measurement surface, or the measurement surface may be steeply inclined. Due to the shape of the workpiece W itself, such as such protrusions and steep slopes, the stylus 20 may bounce or bend. Moreover, the stylus 20 may bounce under the influence of disturbances such as wind and vibration in the measurement environment. When the probe 20 bounces, the probe 20 instantly separates from the workpiece W, so that the weight corresponding to the measuring force of the probe 20 is not applied.

Further, when the stylus 20 bounces and then collides with the workpiece W vigorously, the weight of the colliding stylus 20 is applied more than the prescribed measuring force of the stylus 20 .

Further, when the probe 20 is bent due to the shape of the work W, the force corresponding to the bending of the probe 20 is added to the value of the weighing scale 24 .

During measurement, the value of the weighing scale 24 is monitored, and when the value of the weighing scale 24 momentarily indicates an abnormal value (when an abnormality is detected momentarily), bounce or collision of the probe 20, Alternatively, it determines that it is the influence of the disturbance, and selects, for example, one of the countermeasures 1 to 3 shown below.

[Countermeasure 1] Carry out the measurement to the end, and exclude the measurement data corresponding to the abnormal point from the calculation of the data analysis.

[Countermeasure 2] Interrupt the measurement and perform the measurement again.

[Countermeasure 3] Interrupt the measurement, change the measurement conditions, and then perform the measurement again.

Further, if the value of the weighing scale 24 continuously indicates an abnormal value during measurement (when an abnormality is continuously detected), it is determined that the stylus 20 is bent. Select countermeasure 4 shown in .

[Countermeasure 4] The value of the weighing scale 24 is fed back to the measuring force adjustment mechanism of the detector 18 to automatically adjust the measuring force so that the probe 20 does not bend. As for the measuring force adjusting mechanism, for example, a known configuration such as the measuring force adjusting mechanism described in Patent Document 2 can be adopted.

Further, in place of or in combination with the above countermeasures 1 to 4, when outputting the measurement result of the surface shape, a graph of the measurement force is additionally provided to the user together with the graph of the measurement shape showing the measurement result. This is useful for confirming/verifying that measurements have been properly performed without bounces, collisions, or disturbances.

It should be noted that it may be configured such that the user can select a desired countermeasure from the input device 22 regarding whether or not to adopt each of the countermeasures 1 to 4 described above.

FIG. 3 is a diagram schematically showing how the stylus 20 jumps up from the measurement surface during measurement. FIG. 4 is an example of a measurement shape graph and a measurement force graph obtained when the probe 20 bounces and collides or a disturbance occurs. A graph G1 shown in the upper part of FIG. 4 is a graph of the measured shape detected by the detector 18. FIG. The horizontal axis represents the position in the X-axis direction, and the vertical axis represents the position or displacement in the Z-axis direction. A graph G2 shown in the lower part of FIG. 4 is a graph of the measuring force detected by the weighing scale 24. The horizontal axis represents time or position in the X-axis direction, and the vertical axis represents the magnitude of force.

The measurement force is detected at the same time as the shape is measured, and the position in the X-axis direction can be calculated from the drive speed of the probe 20 in the X-axis direction during measurement and the time. The shape measurement data obtained from the detection result of the detector 18 and the measurement force data obtained from the weighing scale 24 can be grasped by associating (associating) the data with each other based on the corresponding position (or time) relationship. can.

In the graph G2 shown in the lower part of FIG. 4, the portion surrounded by the circle indicated by symbol A is the portion where an abnormality in the measuring force was detected. In the graph G1 shown in the upper part of FIG. 4, the portion surrounded by the circle indicated by the symbol B is the portion of the measurement data corresponding to the abnormal portion of the measuring force.

For example, when the processing of [Countermeasure 1] described above is selected, the measurement data in the circled portion indicated by symbol B is automatically excluded from the calculation.

FIG. 5 is a diagram schematically showing how the probe 20 is bent due to the shape of the workpiece. FIG. 6 is an explanatory diagram schematically showing an example of the relationship between the deflection of the probe 20 caused by the workpiece shape and the detected measuring force. The upper part of FIG. 6 shows the relationship between the workpiece shape and the bending of the probe 20, and the lower part shows a graph of the measuring force detected by the weighing scale. A measuring force indicated by a dashed line in the graph indicates a predetermined reference measuring force.

FIG. 7 is an explanatory diagram schematically showing another example of the relationship between the deflection of the probe 20 caused by the workpiece shape and the detected measuring force. The upper part of FIG. 7 shows the relationship between the workpiece shape and the deflection of the probe 20, and the lower part shows a graph of the measuring force detected by the weighing scale.

As illustrated in FIGS. 6 and 7, when the probe 20 is bent due to the workpiece shape, a measuring force reflecting the amount of bending is observed. As is clear from comparing the graph G2 shown in the lower part of FIG. 4 with the graphs shown in the lower part of FIG. 6 and the lower part of FIG. , the abnormal state of the measuring force becomes continuous. On the other hand, abnormalities in the measuring force due to bouncing or collision of the stylus 20, disturbances, etc. are momentary, as shown in the graph G2 shown in the lower part of FIG.

In this way, it is possible to monitor the measuring force during measurement, detect anomalies in the measuring force, and determine the cause of the anomaly depending on whether it is a momentary anomaly or a continuous anomaly. .

《Example of weight scale》
Weighing scales include electromagnetic type, load cell type, and tuning fork type.

<Example 1>
For roughness measurements, for example, the standard measurement force is 0.75 millinewtons [mN], so the scale should read 75 grams force [gf] or less. That is, when performing roughness measurement, it is preferable to use a weighing scale having a resolution capable of measuring a measuring force of 0.75 mN or less. Therefore, an electromagnetic type or a tuning fork type with high resolution is suitable.

<Example 2>
In the case of contour measurement with a relatively large measuring force, with a standard measuring force of about 2 millinewtons [mN] to 30 millinewtons [mN], a high-response load cell type or tuning fork type is suitable, giving priority to measurement speed. .

<Example 3>
The load cell system using a strain gauge itself is a weighing scale suitable for heavy workpieces, but weighing scales capable of weighing heavy weights have lower resolution (the minimum readable weight difference increases). , it may be difficult to detect the measuring force with a load cell type weighing scale for a heavy workpiece. It is preferable to use an electromagnetic weighing scale for heavy workpieces. If it is an electromagnetic type, it can be used to detect a measuring force of 75 weight grams [gf] or less for a workpiece weighing about 10 kilograms [kg].

<Structure example of an electromagnetic weighing scale>
FIG. 8 is a diagram showing a structural example of an electromagnetic weighing scale. The electromagnetic weighing scale 50 includes a weighing pan 51 on which the workpiece W is placed, a Roberval mechanism 52, a force coil 53, and a magnet . The Roberval mechanism 52 is a parallelogram four-bar link mechanism in which four links (nodes) 52A, 52B, 52C, and 53D are connected by joints (joints) 55A, 55B, 55C, and 55D. Two links 52A, 52C are rotatably supported by fulcrums 56A, 56C.

Of the two vertical links 52B and 52D that face left and right across the fulcrums 56A and 56B, one link 52B supports the weighing pan 51, and the other link 52D supports the force coil 53. . A combination of the force coil 53 and the magnet 54 constitutes an electromagnetic force generator. The load applied to the weighing pan 51 and the electromagnetic force generated by applying current to the force coil 53 are balanced, and the load applied to the weighing pan 51 is calculated from the amount of electricity required to generate the electromagnetic force that is in the balanced state. It is configured to

<Example of structure of load cell weighing scale>
FIG. 9 is a diagram showing a structural example of a load cell weighing scale. A load cell weighing scale 60 includes a weighing pan 61 on which a workpiece W is placed, a strain body 62 , and a strain gauge 63 attached to the strain body 62 . The weighing pan 61 is supported on one end of the strain generating body 62, and the other end is fixed to a fixing portion (not shown). The strain body 62 is deformed by the load applied to the weighing pan 61 . The strain gauge 63 expands and contracts with the deformation of the strain generating body 62 and outputs an electric signal corresponding to the amount of expansion and contraction. The load cell weight scale 60 is configured to calculate the load applied to the weighing pan 61 based on the electrical signal obtained from the strain gauge 63 .

<Structure example of tuning fork weighing scale>
FIG. 10 is a diagram showing a structural example of a tuning fork weighing scale. The tuning fork weighing scale 70 includes a weighing pan 71 on which a workpiece W is placed, a lever 72 for transmitting the load applied to the weighing pan 71, a tuning fork vibrator 73 connected to the lever 72, a fulcrum of the lever 72 and the tuning fork vibrator 73. and a support block 74 that supports the . A piezoelectric element (not shown) for generating vibration and a piezoelectric element (not shown) for detecting vibration are attached to the tuning fork vibrator 73 . The tuning fork vibrator 73 changes its frequency according to the magnitude of the load applied to both ends.

When a load is applied to the weighing pan 71, a tensile load is applied to the tuning fork vibrator 73 via the lever 72, and the frequency changes. This change in frequency is detected by a piezoelectric element for vibration detection, and the load applied to the weighing pan 71 is calculated based on the electrical signal obtained from the piezoelectric element.

<<Processing function of data processor>>
FIG. 11 is a block diagram showing processing functions of the data processing device. The data processing device 32 includes a displacement detection signal acquisition unit 81, a weight detection signal acquisition unit 82, a shape measurement data generation unit 83, a measurement force detection data generation unit 84, a storage unit 85, a measurement force abnormality detection unit 86, and an analysis processing unit 87. , a display control unit 88 and a data output unit 89 . The functions of these units are realized by a combination of hardware and software of the data processing device 32. FIG. Various processors including the CPU and/or FPGA of the data processing device 32 include a displacement detection signal acquisition unit 81, a weight detection signal acquisition unit 82, a shape measurement data generation unit 83, a measurement force detection data generation unit 84, and a measurement force abnormality detection unit. 86 , an analysis processing unit 87 , a display control unit 88 and a data output unit 89 . Also, the memory of the data processing device 32 can function as the storage unit 85 .

The displacement detection signal acquisition section 81 is an interface that takes in the displacement detection signal output from the detector 18 . The displacement detection signal acquisition unit 81 may be a signal input terminal or a communication interface. The displacement detection signal output from the detector 18 is sent to the shape measurement data generation section 83 via the displacement detection signal acquisition section 81 .

The shape measurement data generator 83 generates shape measurement data indicating the surface shape of the workpiece W based on the displacement detection signal acquired via the displacement detection signal acquisition unit 81 .

The shape measurement data generated by the shape measurement data generating section 83 is stored in the storage section 85 .

The weight detection signal acquisition unit 82 is an interface that takes in the weight detection signal output from the weighing scale 24 . The weight detection signal acquisition unit 82 may be a signal input terminal or a communication interface. The weight detection signal output from the weighing scale 24 is sent to the measurement force detection data generation section 84 via the weight detection signal acquisition section 82 .

The measuring force detection data generating section 84 generates measuring force detection data indicating the measuring force acting on the workpiece W based on the weight detection signal acquired via the weight detection signal acquiring section 82 . Measuring force detection data and shape measurement data are obtained substantially simultaneously by parallel processing or parallel processing of the measurement force detection data generation unit 84 and the shape measurement data generation unit 83 . The measurement force detection data generated by the measurement force detection data generation section 84 is stored in the storage section 85 .

The storage unit 85 includes a shape measurement data storage unit 85A and a measuring force detection data storage unit 85B. The shape measurement data storage unit 85A is a storage area for storing shape measurement data. The measuring force detection data storage unit 85B is a storage area for storing measuring force detection data. The storage unit 85 also includes a storage area for storing calculation results by the analysis processing unit 87 .

The measuring force abnormality detection unit 86 detects an abnormality of the measuring force based on the measuring force detection data detected by the weighing scale 24 during measurement. For example, the measuring force abnormality detection unit 86 determines whether or not the measuring force detected by the weighing scale 24 is within an allowable range of a predetermined reference measuring force. is detected, it is determined that the measurement force is abnormal.

When the measuring force abnormality detection section 86 detects an abnormality in the measuring force, the analysis processing section 87 receives a signal (calculation exclusion command signal) that instructs the analysis processing section 87 to exclude the shape measurement data corresponding to the abnormal location from the calculation. to output According to the calculation exclusion command signal from the measurement force abnormality detection section 86, the analysis processing section 87 can analyze the data by excluding from the calculation the shape measurement data corresponding to the location where the measurement force abnormality is detected.

Further, the measuring force abnormality detection section 86 may output a re-measurement command signal for commanding re-measurement when an abnormality in the measuring force is detected. The remeasurement command signal is sent to control device 30 (see FIG. 2) via data output section 89 . Control device 30 can perform remeasurement according to the remeasurement command signal.

The analysis processing unit 87 is an arithmetic processing unit that performs data analysis of shape measurement data. Based on the shape measurement data stored in the storage unit 85, the analysis processing unit 87 analyzes, for example, profile curves such as roughness curves, cross-sectional curves, and undulation curves, load curves, probability density functions, arithmetic mean roughness, maximum height Various parameters such as height, maximum peak height, maximum valley depth, average height, root-mean-square height, and root-mean-square slope can be obtained. A calculation result by the analysis processing unit 87 is stored in the storage unit 85 .

The display control unit 88 generates a signal indicating the content displayed by the display device 28 . The calculation result by the analysis processing section 87 can be displayed on the display device 28 via the display control section 88 . Information on the measuring force stored in the measuring force detection data storage unit 85B can be displayed on the display device 28 via the display control unit 88. FIG. For example, the display device 28 can simultaneously or selectively display graphs G1 and G2 as shown in FIG. By displaying the graph G1 and the graph G2 in association with each other, the user can confirm the validity of the measured shape data. The display device 28 is an example of a "measurement result output unit". Graph G1 shown in the upper part of FIG. 4 is an example of the "first graph". A graph G2 shown in the lower part of FIG. 4 is an example of a “second graph”.

The data output unit 89 is an output interface for outputting various data to the outside of the data processing device 32 . The data output unit 89 may be a communication interface or a signal output terminal. The data processing device 32 is connected to the control device 30 (see FIG. 2) via the data output section 89 .

The data processing device 32 may also be connected to a printer (not shown) via the data output section 89 . Furthermore, the data output unit 89 may include a media interface to which an external storage medium such as a memory card (not shown) is attached.

The data output to the outside through the data output unit 89 can include, for example, measurement result information including calculation results by the analysis processing unit 87, measurement force detection data, remeasurement command signals, and the like.

11, a displacement detection signal acquisition unit 81, a weight detection signal acquisition unit 82, a shape measurement data generation unit 83, a measurement force detection data generation unit 84, a storage unit 85, and a measurement force abnormality detection unit 81 mounted on the data processing device 32. The circuit configuration including the section 86 functions as a measurement force monitoring section 90 that monitors the measurement force in real time during measurement. The measuring force monitoring unit 90 monitors the measuring force based on the information obtained from the weighing scale 24 during the relative movement operation period between the workpiece W and the detector 18 . The data processing device 32 is an example of a "signal processing device that simultaneously acquires a displacement detection signal indicating the displacement detected by the detector and a weight detection signal indicating the measuring force detected by the weighing scale".

<<Operation Example 1 of Surface Profile Measuring Device 10>>
FIG. 12 is a flow chart showing a first example of the flow of measurement processing by the surface shape measuring apparatus 10. As shown in FIG.

First, an operator (user) places a work W on the weighing scale 24 (step S101). The operation of placing the work W on the weighing scale 24 may be automated using a handling robot or the like.

After that, in order to cancel the weight of the work W, the value of the weighing scale 24 is reset to 0 (step S102). The process of step S102 may be performed based on a user's operation, or may be automatically performed by the data processing device 32 and/or the control device 30. FIG.

Next, the measurement conditions are set based on the information input by the user or automatically set by the program (step S103).

After the preparation for measurement is completed, the control device 30 starts shape measurement (step S104).

The data processing device 32 acquires a weight detection signal from the weighing scale 24 (step S110) and acquires a displacement detection signal from the detector 18 (step S120).

The data processing device 32 generates measurement force detection data from the weight detection signal acquired from the weighing scale 24, and stores it in the storage unit 85 (step S111). The data processing device 32 also generates shape measurement data from the displacement detection signal acquired from the detector 18, and stores it in the storage unit 85 (step S121).

The data processing device 32 determines whether or not the measuring force indicated by the measuring force detection data is abnormal (step S112), and proceeds to step S126 if no abnormality is detected.

In step S126, the data processing device 32 determines whether or not the shape measurement of the designated measurement length has been completed. If the shape measurement of the designated measurement length has not been completed (No in step S126), the process returns to steps S110 and S120 to continue the measurement.

When an abnormality in the measuring force is detected in step S112, the data processor 32 further determines whether the abnormality is momentary or continuous (step S113). If it is determined in step S113 that there is a "momentary abnormality", the process proceeds to step S126 to continue the measurement.

On the other hand, if it is determined in step S113 that there is a "continuous abnormality", the process proceeds to step S14 to perform automatic adjustment control of the measuring force. The control device 30 performs feedback control of the measuring force adjustment mechanism using the measuring force detection data so that the measuring force is kept within a predetermined allowable range (for example, within ±10%).

Steps S110 to S126 are repeated until the shape measurement of the designated measurement length is completed.

When the shape measurement of the designated measurement length is completed (Yes in step S126), the data processor 32 analyzes the obtained shape measurement data (step S127).

FIG. 13 is a flow chart showing the flow of analysis processing (step S127).

In step S201, the data processing device 32 determines whether or not there is an abnormal portion of the measuring force based on the measuring force detection data. If there is no abnormal portion, the process proceeds to step S204 to analyze the shape measurement data.

On the other hand, if the determination result in step S201 is Yes, that is, if there is a location where the measuring force is abnormal, the process proceeds to step S202.

In step S202, the data processing device 32 compares the shape measurement data and the measuring force detection data, and performs processing for excluding the shape measurement data of the abnormal portion from the calculation (step S203). After that, the process proceeds to step S204 to analyze the shape measurement data. The processing of step S204 is performed by the analysis processing unit 87 described with reference to FIG.

Then, the data processing device 32 stores the calculation result by the analysis processing section 87 in the storage section 85 and outputs it to the display device 28 or the like.

After step S205, the process returns to the flow chart of FIG. 12 and ends the measurement process.

<<Operation Example 2 of Surface Profile Measuring Device 10>>
FIG. 14 is a flow chart showing a second example of the flow of measurement processing by the surface shape measuring apparatus 10. As shown in FIG. In FIG. 14, steps common to those in the flowchart shown in FIG. 13 are given the same step numbers, and overlapping descriptions are omitted. Differences from FIG. 13 will be described.

The flowchart shown in FIG. 14 includes a step of moving to remeasurement (step S115) when the determination result of step S113 is "instantaneous abnormality".

The re-measurement in step S115 may be performed by returning to the measurement start position, or by changing the measurement start position and repeating the measurement from the beginning. You may go back and partially redo the measurements.

Note that when the measurement is redone from the beginning, the measurement may be performed again after changing the measurement conditions such as changing the measuring force.

The analysis process (step S127) in the flowchart shown in FIG. 14 may be performed by performing the flowchart of FIG. 13, or by omitting steps S201 to S203 of the flowchart of FIG. 13 and performing steps S204 and S205. .

<<Operation Example 3 of Surface Profile Measuring Device 10>>
FIG. 15 is a flow chart showing a third example of the flow of measurement processing by the surface shape measuring apparatus 10. As shown in FIG. In FIG. 15, steps common to those in the flowchart shown in FIG. 13 are given the same step numbers, and overlapping descriptions are omitted.

In the example shown in FIG. 15, after the measuring force detection data and shape measurement data are generated in steps S111 and S121, the process proceeds to step S126, and the measurement for the designated measurement length is performed.

Then, after acquiring all the shape measurement data for the designated measurement length and making the determination in step S126 as Yes, the process proceeds to step S130 to determine whether or not there is an abnormal portion of the measuring force. make a judgment.

When the data processing device 32 determines that there is a portion where the measuring force is abnormal in step S130 (Yes in step S130), the data processing device 32 proceeds to re-measurement operation (step S131). In this remeasurement operation, the process returns to step S104 and the measurement is restarted from the beginning. Alternatively, the re-measurement operation may return to step S103 and reset the measurement conditions.

When the data processing device 32 determines that there is no location where the measuring force is abnormal in step S130 (No in step S130), the data processing device 32 performs analysis processing (step S132). For the analysis processing in step S132, steps S201 to S203 in the flowchart of FIG. 13 may be omitted and steps S204 and S205 may be performed.

<<Advantages of the Surface Profile Measuring Device 10>>
The surface profile measuring device 10 according to the embodiment of the present invention has the following advantages.

(1) Based on information on the measuring force detected by the weighing scale, it is possible to detect an abnormality in the measuring force due to the impact of bounce or collision of the probe, disturbance, or bending of the probe.

(2) It is possible to obtain an appropriate measurement result by comparing a portion where the measuring force is abnormal with the shape measurement data and automatically excluding the shape measurement data of the abnormal portion from the calculation.

(3) In addition, when an abnormality in the measuring force is detected, re-measurement can be performed, or re-measurement can be performed by changing the measurement conditions.

(4) Based on information on the measuring force detected by the weighing scale, it is possible to automatically distinguish whether there is an abnormality in the workpiece or the influence of disturbance or the like.

<<Modification 1>>
In the above-described embodiment, the stylus 20 has a stylus pointing downward, and the measuring force acts on the workpiece W in the direction of gravity. For example, the technology of the present disclosure is also effective when measuring the lower surface of a workpiece with the probe pointing upward, or when measuring the upper surface (top surface) of the inner peripheral surface of a cylindrical workpiece. is. In this case, the measurement force acting on the work is an upward force in the direction opposite to the direction of gravity.

<<Modification 2>>
The deflection amount of the probe 20 is calculated from the information of the measuring force detected by the weight scale 24, the deflection amount of the probe 20 is converted into the displacement amount of the probe 20, and the displacement detection signal value (measurement value) is obtained. may be corrected.

<<Modification 3>>
The means for processing the information of the measuring force detected by the weighing scale 24 is not limited to the data processing device (signal processing device) provided in the surface shape measuring device 10, but an external processing device configured separately from the surface shape measuring device. It may be a device (an external device attached externally). For example, the weight detection signal of the weighing scale 24 is output to an external device, and the external device performs various processes such as generation and storage of measurement force detection data, detection of abnormalities in measurement force, and analysis of shape measurement data. You may

<<Other application examples>>
The present invention is applicable not only to surface roughness measuring devices, but also to various surface shape measuring devices such as contour shape measuring devices, roundness measuring devices, and three-dimensional coordinate measuring devices. As used herein, the term "surface profile measuring device" includes concepts of various devices such as a surface roughness measuring device, a contour shape measuring device, a roundness measuring device, and a three-dimensional coordinate measuring device. In addition, the term surface roughness measuring device or contour shape measuring device refers to a surface roughness and contour shape integrated measuring device that can simultaneously measure surface roughness and contour shape, and a surface roughness and contour shape integrated measuring device that can selectively measure surface roughness or contour shape. It includes the concept of a complex surface roughness/contour measurement system.

Although the embodiments of the present invention have been described above, the present invention is not limited to the above examples, and of course various improvements and modifications may be made without departing from the gist of the present invention. .

DESCRIPTION OF SYMBOLS 10... Surface profile measuring apparatus 12... Base 14... Column 16... Drive part 18... Detector 20... Probe 22... Input device 24... Weighing scale 26... Input device 28... Display device 30... Control device 32... Data processing device 50 Electromagnetic weight scale 53 Force coil 54 Magnet 60 Load cell weight scale 62 Strain generating body 63 Strain gauge 70 Tuning fork weight scale 73 Tuning fork vibrator 83 Shape measurement data generator 84 Measurement force detection Data generation unit 85 Storage unit 86 Measurement force abnormality detection unit 87 Analysis processing unit 90 Measurement force monitoring unit

Claims (11)

a detector that detects the displacement of the stylus;
a relative movement mechanism for relatively moving the object to be measured and the detector while the stylus is in contact with the object to be measured;
a weighing scale that detects a measuring force, which is the pressing force of the stylus against the object to be measured, as a weight acting in the direction of gravity;
a measuring force monitoring unit that monitors the measuring force based on information obtained from the weighing scale during an operation period of relative movement between the object to be measured and the detector by the relative movement mechanism;
with
The measuring force monitoring unit detects an abnormality in the measuring force based on a detection result of the measuring force detected by the weighing scale,
surface shape measurement, wherein, when the measuring force monitoring unit detects an abnormality in the measuring force, the cause of the abnormality in the measuring force is determined based on whether the abnormality in the measuring force is instantaneous or continuous; Device. 2. The surface shape measuring apparatus according to claim 1, wherein said weighing scale is used to monitor said measuring force during operation of measuring the surface shape of said object based on detection of said displacement by said detector. With the object to be measured placed on the weighing scale, the object to be measured and the detector are relatively moved by the relative movement mechanism while the probe is brought into contact with the object to be measured. 3. The surface shape measuring apparatus according to claim 1, wherein the surface shape of the object to be measured is measured by detecting the displacement of by the detector. 4. The surface shape measuring apparatus according to any one of claims 1 to 3, wherein the weight scale has a resolution capable of measuring a measuring force of 0.75 millinewtons [mN] or less. 5. The surface shape measuring apparatus according to claim 1, wherein the weighing scale for measuring the surface roughness as the surface shape of the object to be measured is an electromagnetic weighing scale or a tuning fork weighing scale. 5. The surface shape measuring apparatus according to claim 1, wherein the weighing scale for measuring the contour shape as the surface shape of the object to be measured is a load cell or tuning fork weighing scale. a base;
a column erected above the base;
a drive unit as the relative movement mechanism that is supported by the column and moves the detector in a direction perpendicular to the longitudinal direction of the column;
The surface profile measuring device according to any one of claims 1 to 6, comprising: 8. The measuring force monitoring unit according to any one of claims 1 to 7, wherein the measuring force monitoring unit includes a signal processing device that simultaneously acquires a displacement detection signal indicating the displacement detected by the detector and a weight detection signal indicating the measuring force detected by the weighing scale. The surface profile measuring device according to any one of claims 1 to 3. 2. From claim 1, comprising an analysis processing unit that analyzes data by excluding from calculation the measurement data corresponding to a location where an abnormality in the measuring force is detected among the measurement data acquired via the detector. 9. The surface profile measuring device according to any one of 8. The surface shape measuring apparatus according to any one of claims 1 to 8, further comprising a control unit that performs re-measurement when an abnormality in the measuring force is detected. A first graph indicating shape measurement data of the surface shape of the object to be measured obtained using the detector corresponds to a second graph indicating detection data of the measuring force obtained using the weighing scale. 11. The surface shape measuring apparatus according to any one of claims 1 to 10, further comprising a measurement result output unit for displaying the result.

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