JP2019168356A - Surface shape measuring device - Google Patents

Abstract

To provide a surface shape measuring device which can determine whether the result of a measurement is appropriate and can obtain a correct measurement result.SOLUTION: A surface shape measuring device 10 according to an aspect of the present invention includes: a detector 18 for detecting a displacement of a gauge head 20; a relative movement mechanism for relatively moving a measurement target object and the detector 18 while the gauge head 20 is being in contact with the measurement target object; and a weight scale 24 for detecting a measurement force as the force which the gauge head is applying against the measurement target object as a weight which acts in the direction of gravity.SELECTED DRAWING: Figure 2

Description

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

  Conventionally, by moving the measuring element and the measured object relative to each other while the measuring element is in contact with the surface of the measured object, the displacement of the measuring element caused by the undulation of the surface of the measured object is changed to an electrical signal and detected. 2. Description of the Related Art Surface shape measuring devices that measure the surface shape of an object to be measured are known (see Patent Documents 1 and 2). In addition, a contact (corresponding to a measuring element) provided at the tip of the stylus is brought into contact with the object to be measured, and the amount of distortion of the stylus due to the stress from the object to be measured is detected with a strain gauge. An apparatus for measuring the surface shape of an object to be measured by calculating a displacement amount is known (see Patent Document 3).

JP 2007-303837 A JP, 2006-191631, A JP 2005-55345 A

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

  [1] When there are scratches, dust, or singular points on the measurement surface of the workpiece that is the object to be measured, depending on the driving speed, the measuring element may bounce, or it may collide with the workpiece vigorously after the bounce. The surface shape may not be traced correctly.

  [2] When measuring a workpiece shape in which the measurement surface is a steep slope, depending on the driving speed and the rigidity of the probe, the probe may be bent and a correct measurement result may not be obtained.

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

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

  The present invention has been made in view of such circumstances, and provides a surface shape measuring device that can confirm whether or not a measurement result is appropriate and can obtain a correct measurement result. With the goal.

  In order to achieve the above object, the following invention is provided.

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

  According to the first aspect, the load (measuring force) acting on the object to be measured when the probe contacts the object to be measured is detected by the weigh scale. The magnitude of the measuring force detected by the weigh scale can change due to the bounce or collision of the measuring element, disturbance, or bending of the measuring element. According to the 1st aspect, the validity of a measurement result can be judged based on the information of the measuring force obtained from a weight scale.

  A surface shape measuring apparatus according to a second aspect of the present invention is the surface shape measuring apparatus according to the first aspect, wherein the weighing scale is used for monitoring a measuring force during a measuring operation of the surface shape of the object to be measured based on the detection of the displacement by the detector. It is done.

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

  A surface shape measuring apparatus according to a third aspect of the present invention is the surface shape measuring apparatus according to the first aspect or the second aspect, in a state in which the object to be measured is placed on the weighing scale while the measuring element is in contact with the object to be measured. The surface shape of the measurement object is measured by moving the measurement object and the detector relative to each other by the mechanism and detecting the displacement of the probe with the detector.

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

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

  In the surface shape measuring apparatus according to the sixth aspect of the present invention, the weight meter in the case of measuring the contour shape as the surface shape of the object to be measured in any one of the first to fourth aspects is a load cell type or It is a tuning fork type weighing scale.

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

  The surface shape measuring apparatus according to the eighth aspect of the present invention is the surface shape measuring apparatus according to any one of the first aspect to the seventh aspect, wherein the surface shape measuring device includes A measurement force monitoring unit that monitors the measurement force based on the obtained information is provided.

  The surface shape measuring apparatus according to the ninth aspect of the present invention is the surface shape measuring apparatus according to 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 weigh scale. And a signal processing device that simultaneously acquires

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

  In the tenth aspect, the surface shape measuring apparatus according to the eleventh aspect of the present invention excludes, from the calculation, measurement data corresponding to a location where a measurement force abnormality is detected, from measurement data acquired via a detector. And an analysis processing unit for performing data analysis.

  A surface shape measuring apparatus according to a twelfth aspect of the present invention includes, in the tenth aspect, a control unit that performs remeasurement when a measurement force abnormality is detected.

  A surface shape measuring apparatus according to a thirteenth aspect of the present invention is the first aspect of the first aspect showing the shape measurement data of the surface shape of the object to be measured acquired using the detector in any one of the first to twelfth aspects. A measurement result output unit is provided that displays the graph and a second graph indicating the detection data of the measurement force acquired using the weighing scale in association with each other.

  For example, a display device and / or a printer can 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 information on the measuring force obtained from the weight scale, and to obtain a correct measurement result.

It is an external view of the surface shape measuring apparatus which concerns on embodiment of this invention. It is a block diagram which shows the outline | summary of the control system of the surface shape measuring apparatus which concerns on embodiment of this invention. It is a figure which shows typically a mode that the measuring element jumped up from the measurement surface during the measurement. It is an example of the graph of the measurement shape obtained when the measurement element bounces and collides, or disturbance occurs, and the graph of the measurement force detected. It is a figure which shows typically a mode that the measuring element bent according to the workpiece | work shape. It is explanatory drawing which shows typically an example of the relationship between the bending of the measuring element resulting from a workpiece | work shape, and the measuring force detected. It is explanatory drawing which shows typically the other example of the relationship between the bending of the measuring element resulting from a workpiece | work shape, and the measuring force detected. 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 scale. It is a figure which shows the structural example of a tuning fork type weighing scale. It is a block diagram which shows the function of a data processor. It is a flowchart which shows the 1st example of the flow of the measurement process by the surface shape measuring apparatus which concerns on embodiment of this invention. It is a flowchart which shows the flow of the analysis process (step S127) in FIG. It is a flowchart which shows the 2nd example of the flow of the measurement process by the surface shape measuring apparatus which concerns on embodiment of this invention. It is a flowchart which shows the 3rd example of the flow of the measurement process by the surface shape measuring apparatus which concerns on embodiment of this invention.

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

<< Configuration of surface shape measuring device >>
FIG. 1 is an external view of a surface shape measuring apparatus according to an embodiment of the present invention. The surface shape measuring apparatus 10 includes a base 12, a column 14 erected on the top of the base 12, a drive unit 16 attached to the column 14, a detector 18, and a probe 20 attached to the detector 18. And a weigh scale 24 for detecting the measuring force of the probe 20 acting on the workpiece W. The surface shape measuring device 10 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.

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

  The column 14 is an elevating mechanism that moves the drive 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). The rotating shaft of the lifting motor is connected to a ball screw. When the ball screw is rotated by the power of the lifting motor, the drive unit 16 moves in the Z-axis direction. The detector 18 supported by the drive unit 16 moves in the Z-axis direction together with the drive unit 16. The height (position in the Z-axis direction) of the measuring element 20 can be adjusted by the lifting / lowering operation of the column 14.

  The drive unit 16 is a mechanism that drives the detector 18 and the measuring element 20 along the X-axis direction orthogonal to the Z-axis direction, and moves (not shown) that supports the detector 18 movably along the X-axis direction. A mechanism and a motor (not shown) serving as a power source for generating a driving force are included. The power source of the drive unit 16 may be a linear motor.

  When measuring the surface shape of the workpiece W, the measuring element 20 is brought into contact with the surface of the workpiece W, and the detector 18 and the measuring element 20 are moved in the X-axis direction by the drive unit 16, thereby the workpiece W and the measuring element. 20 is 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 workpiece W.

  The detector 18 includes a transducer (not shown) that converts the displacement of the probe 20 into an electrical signal. For example, the transducer may have a configuration using a differential transformer. The probe 20 is pressed against the workpiece W from a direction parallel to the direction of gravity, that is, the Z-axis direction. The pressing force of the probe 20 against the workpiece W is referred to as a measuring force. A pressing force in a direction parallel to the direction of gravity acts on the workpiece W due to the contact between the workpiece W and the probe 20.

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

  FIG. 2 is a block diagram showing an outline of the control system of the surface shape measuring apparatus 10. 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 drive unit 16. The control device 30 also includes an amplifier (not shown) that supplies driving power to an elevator motor (not shown) provided on the column 14 (see FIG. 1).

  The control device 30 performs overall control of 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 unit by executing a predetermined program stored in advance. The function of the control device 30 can be realized using one or more processors. The processor can have various circuit forms such as a CPU, a programmable logic device (PLD) such as a field programmable gate array (FPGA), and an application specific integrated circuit (ASIC).

  The control device 30 is connected to the drive unit 16 and the detector 18. The control device 30 is connected to the data processing device 32. The detector 18 and the weighing scale 24 are connected to the data processing device 32. A signal (displacement detection signal) output from the detector 18 is input to the data processing device 32. Further, 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 acquired via each of 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 processing device 32 monitors the measurement force during the measurement operation in real time based on the weight detection signal obtained from the weigh scale 24.

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

  The display device 28 may be, for example, a liquid crystal display or an organic EL (organic electro-luminescence: OEL) display. Various kinds of information such as measurement result information can be displayed on the display device 28. In addition, a printer (not shown) may be connected to the data processing device 32. The control device 30 may include the function of the data processing device 32. For example, the functions of the control device 30 and the data processing device 32 may be realized by a single computer.

<< Outline 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.

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

  Depending on the workpiece W, a protrusion may exist on the measurement surface, or the measurement surface may be steeply inclined. Due to the shape of the workpiece W itself such as protrusions or steep inclinations, the measuring element 20 may jump or bend. Further, the probe 20 may bounce under the influence of disturbance such as wind and vibration in the measurement environment. When the measuring element 20 bounces, the measuring element 20 is instantaneously separated from the workpiece W, so that the weight of the measuring force of the measuring element 20 is not applied.

  Further, when the measuring element 20 jumps and vigorously collides with the work W, the weight of the collision is more than the prescribed measuring force of the measuring element 20.

  Further, when the measuring element 20 is bent due to the shape of the workpiece W, the force corresponding to the bending of the measuring element 20 is included in the value of the weigh scale 24.

  During the measurement, the value of the weigh scale 24 is monitored, and when the value of the weight scale 24 shows an abnormal value instantaneously (when an abnormality is detected instantaneously), the measuring element 20 bounces or collides, Or it judges that it is the influence by disturbance and selects any one of the countermeasures 1-3 shown below, for example.

  [Countermeasure 1] The measurement is performed to the end, and the measurement data corresponding to the abnormal portion is excluded from the data analysis calculation.

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

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

  In addition, if the value of the weighing scale 24 continuously shows an abnormal value during measurement (when an abnormality is continuously detected), it is determined that the probe 20 is bent, for example, Countermeasure 4 shown in FIG.

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

  Further, when outputting the measurement result of the surface shape instead of or in combination with the above countermeasures 1 to 4, a graph of the measurement force is added to the user along with the measurement shape graph indicating the measurement result and provided to the user. Thus, it is useful for confirmation / verification that the measurement can be properly performed without any splashing, collision or disturbance.

  It should be noted that the adoption of each of the countermeasures 1 to 4 may be configured so that the user can select a desired countermeasure from the input device 22.

  FIG. 3 is a diagram schematically showing a state in which the probe 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 when a disturbance occurs. A graph G1 shown in the upper part of FIG. 4 is a graph of the measurement shape detected by the detector 18. 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 G <b> 2 shown in the lower part of FIG. 4 is a graph of the measuring force detected by the weigh scale 24. The horizontal axis represents time or the position in the X-axis direction, and the vertical axis represents the magnitude of force.

  The detection of the measuring force is performed simultaneously with the measurement of the shape, and the position in the X-axis direction can be calculated from the driving speed of the probe 20 in the X-axis direction and the time at the time of measurement. The shape measurement data obtained from the detection result of the detector 18 and the measurement force data obtained from the weight scale 24 can be grasped by associating (corresponding) the data to each other in relation to the corresponding position (or time). it can.

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

  For example, when the above-mentioned [Countermeasure 1] process is selected, the measurement data of the portion surrounded by a circle indicated by the symbol B is automatically excluded from the calculation.

  FIG. 5 is a diagram schematically showing a state in which the probe 20 is bent due to the workpiece shape. 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 measurement force. The upper part of FIG. 6 shows the relationship between the workpiece shape and the deflection of the measuring element 20, and the lower part shows a graph of the measuring force detected by the weigh scale. A measuring force indicated by a broken line in the graph indicates a predetermined 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 measurement 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 weigh 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. When the graph G2 shown in the lower part of FIG. 4 is compared with the graphs shown in the lower part of FIG. 6 or the lower part of FIG. 7, the probe 20 is bent or floated due to the workpiece shape. In this case, the abnormal state of the measuring force becomes continuous. On the other hand, the abnormality in the measuring force due to the jumping, collision, disturbance or the like of the probe 20 is instantaneous 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 an abnormality in the measuring force, and determine the cause of the abnormality depending on whether it is an instantaneous abnormality or a continuous abnormality. .

<Example of weighing scale>
The weigh scale includes an electromagnetic type, a load cell type, a tuning fork type, and the like, and it is preferable to use them properly depending on the work to be measured and the purpose.

<Example 1>
For example, in roughness measurement, the standard measuring force is 0.75 millinewton [mN], so the weigh scale needs to read 75 grams or less [gf] or less. That is, when measuring the roughness, it is preferable to use a weigh scale having a resolution capable of measuring a measuring force of 0.75 mN or less. Therefore, a high resolution electromagnetic type or tuning fork type is suitable.

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

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

<Example structure of electromagnetic weighing scale>
FIG. 8 is a diagram illustrating a structure example of an electromagnetic weighing scale. The electromagnetic weighing scale 50 includes a weighing pan 51 on which the workpiece W is placed, a roval mechanism 52, a force coil 53, and a magnet 54. The Roverval mechanism 52 is a parallelogram four-joint link mechanism in which four links (joints) 52A, 52B, 52C, and 53D are connected by joints (joints) 55A, 55B, 55C, and 55D. Two links 52A and 52C are rotatably supported by fulcrums 56A and 56C.

  Of the two vertical links 52B and 52D facing left and right across the fulcrums 56A and 56B, the weighing pan 51 is supported by one link 52B, and the force coil 53 is supported by the other link 52D. . The combination of the force coil 53 and the magnet 54 constitutes an electromagnetic force generator. The load applied to the weighing pan 51 is balanced with the electromagnetic force generated by flowing a current through the force coil 53, and the load applied to the weighing pan 51 is calculated from the amount of electricity required to generate the electromagnetic force in the balanced state. It is the composition to do.

<Structure example of load cell type weighing scale>
FIG. 9 is a diagram illustrating a structure example of a load cell type weigh scale. The load cell type weigher 60 includes a weighing pan 61 on which the 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 at 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 a load applied to the weighing pan 61. The strain gauge 63 expands and contracts with the deformation of the strain body 62 and outputs an electrical signal corresponding to the amount of expansion and contraction. The load cell type weigher 60 is configured such that a load applied to the weighing pan 61 is calculated based on an electric signal obtained from the strain gauge 63.

<Example structure of tuning fork type weigh scale>
FIG. 10 is a diagram showing a structural example of a tuning fork type weigh scale. The tuning fork weight scale 70 includes a weighing pan 71 on which the workpiece W is placed, an insulator 72 that transmits a load applied to the weighing pan 71, a tuning fork vibrator 73 connected to the insulator 72, a fulcrum of the insulator 72, and a tuning fork vibrator 73. And a support block 74 for supporting. The tuning fork vibrator 73 is provided with a vibration generating piezoelectric element (not shown) and a vibration detecting piezoelectric element (not shown). The tuning fork vibrator 73 changes in 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 insulator 72, and the frequency changes. This change in frequency is detected by a piezoelectric element for vibration detection, and a load applied to the weighing pan 71 is calculated based on an electric signal obtained from the piezoelectric element.

<< Processing function of data processing device >>
FIG. 11 is a block diagram illustrating processing functions of the data processing apparatus. 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. 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. The memory of the data processing device 32 can function as the storage unit 85.

  The displacement detection signal acquisition unit 81 is an interface that captures 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 unit 83 via the displacement detection signal acquisition unit 81.

  The shape measurement data generation unit 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 generation unit 83 is stored in the storage unit 85.

  The weight detection signal acquisition unit 82 is an interface that captures the weight detection signal output from the weigh 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 weight scale 24 is sent to the measurement force detection data generation unit 84 via the weight detection signal acquisition unit 82.

  The measurement force detection data generation unit 84 generates measurement force detection data indicating the measurement force acting on the workpiece W based on the weight detection signal acquired via the weight detection signal acquisition unit 82. By the 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 and the shape measurement data are obtained substantially simultaneously. The measurement force detection data generated by the measurement force detection data generation unit 84 is stored in the storage unit 85.

  The storage unit 85 includes a shape measurement data storage unit 85A and a measurement force detection data storage unit 85B. The shape measurement data storage unit 85A is a storage area for storing shape measurement data. The measurement force detection data storage unit 85B is a storage area for storing measurement force detection data. In addition, the storage unit 85 includes a storage area for storing a calculation result by the analysis processing unit 87.

  The measurement force abnormality detection unit 86 detects an abnormality in the measurement force based on the measurement force detection data detected by the weigh scale 24 during measurement. For example, the measurement force abnormality detection unit 86 determines whether or not the measurement force detected by the weigh scale 24 is within the predetermined reference measurement force tolerance range, and the measurement force is below or above the tolerance range. Is detected, it is determined that the measuring force is abnormal.

  The measurement force abnormality detection unit 86 instructs the analysis processing unit 87 to exclude the shape measurement data corresponding to the abnormal part from the calculation when the measurement force abnormality is detected (calculation exclusion command signal). Is output. The analysis processing unit 87 can perform data analysis by excluding the shape measurement data corresponding to the location where the measurement force abnormality is detected from the calculation in accordance with the calculation exclusion command signal from the measurement force abnormality detection unit 86.

  In addition, the measurement force abnormality detection unit 86 may output a remeasurement command signal for instructing re-measurement when the measurement force abnormality is detected. The remeasurement command signal is sent to the control device 30 (see FIG. 2) via the data output unit 89. The 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 the shape measurement data. The analysis processing unit 87 is based on the shape measurement data stored in the storage unit 85, for example, a contour curve such as a roughness curve, a cross-sectional curve, a waviness curve, a load curve, a probability density function, an arithmetic mean roughness, a maximum height Various parameters such as maximum peak height, maximum valley depth, average height, root mean square height, root mean square slope, and the like can be obtained. The 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 unit 87 can be displayed on the display device 28 via the display control unit 88. In addition, the measurement force information stored in the measurement force detection data storage unit 85 </ b> B can be displayed on the display device 28 via the display control unit 88. For example, the display device 28 can display the graphs G1 and G2 as shown in FIG. 4 simultaneously or selectively. By displaying the graph G1 and the graph G2 in association with each other, the user can confirm the validity of the measurement shape data. The display device 28 is an example of a “measurement result output unit”. The graph G1 shown in the upper part of FIG. 4 is an example of the “first graph”. The 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 unit 89.

  In addition, the data processing device 32 may be connected to a printer (not shown) via the data output unit 89. Further, 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 may include, for example, measurement result information including a calculation result by the analysis processing unit 87, measurement force detection data, a remeasurement command signal, and the like.

  In FIG. 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 mounted on the data processing device 32. The configuration of the circuit including the unit 86 functions as a measurement force monitoring unit 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 weigh scale 24 during the operation period of relative movement 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 a displacement detected by a detector and a weight detection signal indicating a measurement force detected by a weight scale”.

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

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

  Thereafter, in order to cancel the weight of the workpiece W, the value of the weigh scale 24 is reset to 0 (step S102). The process of step S <b> 102 may be performed based on a user operation, or may be automatically performed in the data processing device 32 and / or the control device 30.

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

  After 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 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 weight scale 24 and stores it in the storage unit 85 (step S111). Further, the data processing device 32 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 measurement force indicated by the measurement force detection data is abnormal (step S112). If no abnormality is detected, the data processing device 32 proceeds to step S126.

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

  In step S112, when an abnormality in the measuring force is detected, the data processing device 32 further determines whether it is an instantaneous abnormality or a continuous abnormality (step S113). If it is determined in step S113 that there is an “instantaneous abnormality”, the process proceeds to step S126 and measurement is continued.

  On the other hand, if it is determined in step S113 that it 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 measurement force adjusting mechanism so that the measurement force falls within a predetermined allowable range (for example, within ± 10%) using the measurement force detection data.

  Steps S110 to S126 are repeated until shape measurement for the specified measurement length is completed.

  When the shape measurement for the specified measurement length is completed (Yes in step S126), the data processing device 32 performs an analysis process on the obtained shape measurement data (step S127).

  FIG. 13 is a flowchart showing the flow of the analysis process (step S127).

  In step S201, the data processing device 32 determines whether or not there is an abnormal portion of the measurement force based on the measurement force detection data. If there is no abnormal location, the process moves 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 portion where the measurement force is abnormal, the process proceeds to step S202.

  In step S202, the data processing device 32 collates the shape measurement data and the measurement force detection data, and performs a process of excluding the shape measurement data of the abnormal part from the calculation (step S203). Then, it transfers to step S204 and analyzes shape measurement data. The process in 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 unit 87 in the storage unit 85 and outputs it to the display device 28 or the like.

  After step S205, the process returns to the flowchart of FIG.

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

  The flowchart illustrated in FIG. 14 includes a step of shifting to an operation of remeasurement (step S115) when the determination result of step S113 is “instantaneous abnormality”.

  The re-measurement in step S115 may return to the measurement start position or change the measurement start position and start the measurement again from the beginning. Alternatively, the measurement position may be slightly before the point where the abnormality is detected. You may go back and partially redo the measurement.

  When measurement is performed again from the beginning, the measurement may be re-measured after changing the measurement conditions such as changing the measurement force.

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

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

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

  And after acquiring all the shape measurement data for the designated measurement length and the determination in step S126 is Yes, the process proceeds to step S130 to determine whether there is an abnormal portion of the measurement force. Make a decision.

  If it is determined in step S130 that there is a portion having an abnormal measurement force (Yes in step S130), the data processing device 32 proceeds to a remeasurement operation (step S131). In this re-measurement operation, the process returns to step S104 and the measurement is repeated from the beginning. Alternatively, the remeasurement operation may return to step S103 to reset the measurement conditions.

  If the data processing device 32 determines in step S130 that there is no abnormal measuring force (No in step S130), the data processing device 32 performs an analysis process (step S132). In the analysis process of 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 Surface Profile Measuring Device 10 >>
The surface shape measuring apparatus 10 according to the embodiment of the present invention has the following advantages.

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

  (2) It is possible to collate a portion having an abnormal measurement force with the shape measurement data, automatically exclude the shape measurement data of the abnormal portion from the calculation, and obtain an appropriate measurement result.

  (3) When an abnormality in the measuring force is detected, remeasurement can be performed, or remeasurement can be performed by changing measurement conditions.

  (4) Based on the information of the measuring force detected by the weight scale, it is possible to automatically determine whether the workpiece is abnormal or an influence due to disturbance or the like.

<< Modification 1 >>
In the above-described embodiment, the example has been described in which the probe 20 has a downward stylus and the measurement force acts on the workpiece W in the direction of gravity. However, the weigh scale 24 only needs to be able to detect the measurement force. For example, the technique of the present disclosure is effective even when measuring the lower surface of the workpiece with the probe facing upward, or when measuring the upper surface (top surface) of the inner peripheral surface of the cylindrical workpiece. It is. In this case, since the measurement force acting on the workpiece is an upward force in the direction opposite to the gravity direction, the force acting in the direction opposite to the gravity direction is read from the weight detection signal of the weigh scale 24.

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

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

《Other application examples》
The present invention is not limited to a surface roughness measuring device, but can be applied to various surface shape measuring devices such as a contour shape measuring device, a roundness measuring device, and a three-dimensional coordinate measuring device. In this specification, the term “surface shape measuring device” includes the concept 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. The terms surface roughness measuring device or contour shape measuring device can selectively measure surface roughness and contour shape, as well as surface roughness and contour shape integrated measuring device that can measure surface roughness and contour shape simultaneously. The concept of a complex surface roughness / contour shape combined measuring device is included.

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

DESCRIPTION OF SYMBOLS 10 ... Surface shape measuring device 12 ... Base 14 ... Column 16 ... Drive part 18 ... Detector 20 ... Measuring element 22 ... Input device 24 ... Weight scale 26 ... Input device 28 ... Display device 30 ... Control device 32 ... Data processing device 50 ... Electromagnetic weight meter 53 ... Force coil 54 ... Magnet 60 ... Load cell type weight meter 62 ... Straining body 63 ... Strain gauge 70 ... Tuning fork weight meter 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 (13)

A detector for detecting the displacement of the probe;
A relative movement mechanism for relatively moving the object to be measured and the detector in a state where the measuring element is in contact with the object to be measured;
A weigh scale for detecting a measuring force, which is a pressing force of the measuring element against the object to be measured, as a weight acting in the direction of gravity;
A surface shape measuring device comprising:   The surface shape measuring apparatus according to claim 1, wherein the weight scale is used to monitor the measurement force during a measurement operation of the surface shape of the object to be measured based on detection of the displacement by the detector.   With the measurement object placed on the weighing scale, the measurement object is moved relative to the measurement object by the relative movement mechanism while the measurement element is in contact with the measurement object. 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 the object by the detector.   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 millinewton [mN] or less.   The surface shape measuring apparatus according to any one of claims 1 to 4, wherein the weighing scale in the case of measuring the surface roughness as the surface shape of the object to be measured is an electromagnetic or tuning fork type weighing scale.   The surface shape measuring apparatus according to any one of claims 1 to 4, wherein the weighing scale in the case of measuring a contour shape as a surface shape of the object to be measured is a load cell type or tuning fork type weighing scale. Base and
A column erected on top of 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 shape measuring device according to any one of claims 1 to 6.   The measurement force monitoring unit that monitors the measurement 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. The surface shape measuring apparatus as described in any one of Claims.   The said measurement force monitoring part contains the signal detection apparatus which acquires simultaneously the displacement detection signal which shows the displacement which the said detector detected, and the weight detection signal which shows the measurement force which the said weight meter detected. Surface shape measuring device.   The surface shape measuring device according to claim 8 or 9, wherein the measuring force monitoring unit detects an abnormality of the measuring force based on a detection result of the measuring force detected by the weighing scale.   The measurement processing unit according to claim 10, further comprising: an analysis processing unit that performs data analysis by excluding the measurement data corresponding to a location where the abnormality in the measurement force is detected from the measurement data acquired via the detector. The surface shape measuring apparatus as described.   The surface shape measuring apparatus according to claim 10, further comprising a control unit that performs re-measurement when an abnormality in the measuring force is detected.   Corresponding to the first graph showing the shape measurement data of the surface shape of the measurement object acquired using the detector, and the second graph showing the detection data of the measurement force acquired using the weighing scale The surface shape measuring apparatus according to any one of claims 1 to 12, further comprising a measurement result output unit that is attached and displayed.

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