JP2023126360A - Surface quality measuring device and correlation generating method - Google Patents

Abstract

To provide a surface quality measuring device and a correlation generating method capable of performing simple, low-cost adjustment of measuring forces.SOLUTION: A surface quality measuring device includes: a contact (202); an arm (204) on which the contact is mounted; arm support parts (222, 224) which support the arm in a swingable state with elastic members (220) at a swing fulcrum (212) of the arm; a measuring force applying part (206) which applies a measuring force to the contact through the arm by applying a force to the arm; a detection part (208) that detects a displacement of the contact through the arm; and a measuring force setting part which sets a measuring force based a correlation memory part which sores a correlation between a setting value of measuring force applying part and measuring force and based on the correlation.SELECTED DRAWING: Figure 5

Description

The present invention relates to a correlation generation method, a measuring force adjustment method, and a surface texture measuring device.

In a contact-type surface texture measurement detector, there is a contact that contacts the object to be measured, an arm that supports the contact, a swing support shaft that swingably supports the arm, and a sensor that detects the swing displacement of the arm. Lever-type detectors equipped with are widely used. In a lever-type detector, an elastic body such as a coil spring is used to apply a measuring force to press a contact against an object to be measured. The measuring force is adjusted using a measuring force adjustment mechanism. Setting accuracy was an issue with measurement power.

Patent Document 1 describes a contact type inner diameter measuring device that performs measurement by bringing a contactor into contact with an object to be measured. The device described in this document includes a contact at one end of a measurement arm that is swingably supported at a swing fulcrum, and uses a detector to detect displacement at the other end. The swinging fulcrum of the arm included in the device is constructed using a cross spring. Such a configuration enables highly accurate measurement with a constant measuring force.

Japanese Patent Application Publication No. 11-257905

However, if there are mechanical individual differences between devices, even if the settings of the measuring force applying mechanism are the same, the actual measuring force applied to the object to be measured may differ. For this purpose, it is necessary to actually measure the correlation between the setting of the measuring force applying mechanism and the measuring force for each device. A similar problem exists even when the arms, contacts, etc. are replaceable.

The present invention was made in view of the above circumstances, and an object of the present invention is to provide a correlation generation method, a measuring force adjustment method, and a surface texture measuring device that can perform simple measuring force adjustment at low cost. do.

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

In the correlation generation method according to the first aspect, an arm including a contact is swingably supported at a swing fulcrum using a plate-like elastic member, and an arm provided with a contact is supported on the opposite side of the contact across the swing fulcrum. This is a correlation generation method in surface texture measurement in which a measuring force is applied to a contact through the arm by applying a biasing force to the arm using a measuring force applying part, and the displacement of the contact is detected. and a detection step of detecting the displacement of the contact through the arm while changing the set value of the measuring force applying part corresponding to the biasing force with the contact not in contact with the workpiece, and the detection step of detecting the displacement of the contact through the arm. A calculation step of calculating the measuring force applied to the contact when displacement is detected based on the physical property values of the plate-like elastic member, and a set value of the measuring force applying section and the measuring force based on the calculation result of the calculation step. This is a correlation generation method including a creation step of creating a correlation with.

According to the first aspect, the displacement of the contact is detected with respect to the set values of the plurality of measuring force applying mechanisms, with the contact being in a non-contact state. Using the physical property values of the plate-like elastic member that supports the arm at the swing fulcrum from the detection results of the displacement of the contact, derive the correlation between the measurement force applied to the contact and the setting value of the measurement force application mechanism. . This makes it possible to generate a simple, low-cost correlation that is applied to adjusting the measuring force without requiring a measuring device or the like to actually measure the measuring force.

The concept of adjusting the measuring force may include concepts such as initial setting of the measuring force and configuration after the measuring force is set.

A second aspect is the correlation generation method of the first aspect, in which the measurement force is F _meas , the bending stiffness of the plate-shaped elastic member is B , the detected value of the displacement detection position in the arm is D , and the plate-shaped elastic member The length of is L, the distance from the swing fulcrum to the displacement detection position is L _arm , and the distance from the swing fulcrum to the contact is L _tip , F _meas = B x D/(L x L _arm x L _tip ) A configuration may also be adopted in which a measurement force derived using the above is applied.

According to the second aspect, the bending stiffness B of the plate-like elastic member, the detected displacement value D of the contact, the length L of the plate-like elastic member, the distance L from the swing fulcrum to the displacement detection position on the _arm , and the swing Using the distance L _tip from the dynamic fulcrum to the contact, the measurement force F _meas can be derived from the detected displacement value D of the contact.

The measuring force adjustment method according to the third aspect is a measuring force adjusting method that adjusts the measuring force using the correlation created by the correlation generation method described in the first aspect, wherein the measuring force value is input. a determination step of determining the set value of the measuring force applying section corresponding to the value of the measuring force by referring to the correlation; and a determining step of determining the setting value of the measuring force applying section that corresponds to the value of the measuring force; This is a measurement force adjustment method including an adjustment step of operating a force application unit to adjust the measurement force applied to the contact.

According to the third aspect, it is possible to adjust the measuring force using the correlation described in the first aspect.

In the fourth aspect, the measuring force adjustment method of the third aspect may include a correlation selection step of selecting a correlation according to the measurement condition from a plurality of correlations.

According to the fourth aspect, the measurement force can be adjusted according to the measurement conditions.

A surface texture measuring device according to a fifth aspect includes a contact, an arm to which the contact is attached, and an arm support portion that swingably supports the arm using a plate-like elastic member at a swing fulcrum of the arm. A measuring force applying section that applies a measuring force to the contact through the arm by applying a biasing force to the part of the arm opposite to the contact across the swing fulcrum, and a measuring force applying section that applies a measuring force to the contact through the arm. It is equipped with a detection section that detects displacement, and a correlation storage section that stores the correlation between the set value of the measurement force applying section and the measurement force, and the correlation is stored with the contactor not in contact with the workpiece. , detects the displacement of the contact while changing the set value of the measuring force applying part corresponding to the biasing force, and based on the detected displacement value and the physical property value of the plate-shaped elastic member, when the displacement is detected, the contact This is a surface texture measuring device that calculates a measuring force to be applied, and applies a correlation between a set value of a measuring force applying unit and the measuring force that is generated based on the calculation result.

According to the fifth aspect, it is possible to adjust the measuring force using the correlation described in the first aspect.

According to the present invention, the displacement of the contact is detected with respect to the setting values of the plurality of measuring force applying mechanisms, with the contact being in a non-contact state. Using the physical property values of the plate-like elastic member that supports the arm at the swing fulcrum from the detection results of the displacement of the contact, derive the correlation between the measurement force applied to the contact and the setting value of the measurement force application mechanism. . This makes it possible to generate a simple, low-cost correlation that is applied to adjusting the measuring force without requiring a measuring device or the like to actually measure the measuring force.

FIG. 1 is an overall configuration diagram of a roundness measuring device according to an embodiment. FIG. 2 is a functional block diagram of the roundness measuring device shown in FIG. FIG. 3 is a flowchart showing the procedure of a measuring force adjustment method applied to the roundness measuring device shown in FIG. FIG. 4 is a conceptual diagram of a lever type detector. FIG. 5 is a schematic diagram showing a configuration example of a detector applied to the roundness measuring device shown in FIG. 1. FIG. 6 is a schematic diagram showing the relationship between the set value of the measuring force applying mechanism and the detected value of the displacement sensor. FIG. 7 is a detailed explanatory diagram of the rotational moment generated by the leaf spring. FIG. 8 is an explanatory diagram of calculation of the measuring force generated by the leaf spring. FIG. 9 is an explanatory diagram of calculation of the measuring force acting on the contact. FIG. 10 is a graph showing the detected value of the displacement sensor with respect to the set value of the measuring force applying mechanism. FIG. 11 is a graph showing the measuring force versus the set value of the measuring force applying mechanism. FIG. 12 is a schematic diagram of a leaf spring applied to the swing fulcrum of the arm. FIG. 13 is a schematic diagram of a cross spring applied to the swing fulcrum of the arm. FIG. 14 is a schematic diagram of a detection unit including a replaceable contact. FIG. 15 is a schematic diagram of a detection unit having different shapes of contacts. FIG. 16 is a schematic diagram when the contactor is attached at different angles to the arm.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In this specification, the same reference numerals are given to the same components, and overlapping explanations are omitted as appropriate.

[Roundness measuring device]
[Overall configuration of roundness measuring device]
FIG. 1 is an overall configuration diagram of a roundness measuring device according to an embodiment. A roundness measuring device 10 shown in the figure measures the roundness of a cylindrical workpiece 9. The workpiece 9 to be measured may have a disk shape, a cylindrical shape, or the like.

The roundness measuring device 10 includes a base 11. The base 11 is a support stand that supports each part of the roundness measuring device 10. A support stand is synonymous with a base. The roundness measuring device 10 includes a table 13. The table 13 is sometimes called a stage.

The table 13 has a disc shape and is attached to the upper surface of the base 11. The table 13 is rotatably supported using the base 11 at a position of a rotation shaft 22 that passes through the center of the table 13 and extends in the vertical direction. The inclination of the table 13 with respect to the reference plane is adjusted so that it is parallel to the reference plane in the horizontal direction.

Here, the term "upward" in this specification refers to a vertically upward direction. Further, the term "downward" refers to a vertically downward direction.

A workpiece 9 is placed on the upper surface of the table 13. The workpiece 9 is placed on the upper surface of the table 13 so that the center of the shape of the part to be measured coincides with the rotation axis. FIG. 1 shows an example in which the outer peripheral surface of a cylindrical workpiece 9 is the part to be measured, and the workpiece 9 is placed so that the central axis of the cylinder coincides with the rotation axis 22 of the table 13.

The roundness measuring device 10 includes a motor 14 . Motor 14 is arranged inside base 11 . The rotation shaft of the motor 14 is connected to the rotation shaft of the table 13 via a drive transmission mechanism. The motor 14 rotates the table 13 around the rotating shaft 22 . The drive transmission mechanism may include gears. Note that illustration of the drive transmission mechanism is omitted.

The roundness measuring device 10 includes a column 15, a carriage 16, a horizontal arm 17, and a detector 18. The column 15 is the upper surface of the base 11 and is arranged on the side of the base 11 in the horizontal direction. Column 15 is a pillar extending in the vertical direction.

The carriage 16 is supported using the column 15 so as to be movable up and down. A horizontal arm 17 is attached to the carriage 16 so as to be movable in the horizontal direction. A detector 18 is attached to the tip of the horizontal arm 17.

The detector 18 includes a contactor 18A and a displacement sensor. Note that in FIG. 1, illustration of the displacement sensor is omitted. The displacement sensor is illustrated in FIG. 2 using the reference numeral 18B. The detector 18 detects the displacement of the contactor 18A moving along the direction indicated by the symbol A. Detector 18 outputs a detection signal representing the displacement of contactor 18A. The detection signal is transmitted to the control device 19.

The detector 18 includes a measuring force applying mechanism. The measuring force applying mechanism applies a measuring force corresponding to the set value of the measuring force to the contactor 18A. Note that in FIG. 1, illustration of the measuring force applying mechanism is omitted. The measuring force applying mechanism is illustrated in FIG. 2 using the reference numeral 56.

The roundness measuring device 10 includes a control device 19. The control device 19 is connected to a display device 19A and an input device 19B. A display device such as a liquid crystal display can be used as the display device 19A. The input device 19B may include a keyboard and a mouse. A touch panel type display device may be applied to the display device 19A so that the display device 19A and the input device 19B can be used together.

[Description of control device]
FIG. 2 is a functional block diagram of the roundness measuring device shown in FIG. The control device 19 includes a detection signal acquisition section 40 and a signal processing section 42. The detection signal acquisition unit 40 acquires the detection signal transmitted from the detector 18. The detection signal acquisition unit 40 stores the detection results using the detection signal storage unit 44. The signal processing unit 42 generates a measurement result of the workpiece 9 using the detection signal of the detector 18. The signal processing section 42 stores the measurement results using the measurement result storage section 46.

The control device 19 includes a display control section 48 . The display control unit 48 controls the display device 19A. The signal processing section 42 transmits an electrical signal representing the measurement result to the display control section 48. The display control unit 48 converts the electrical signal representing the measurement result into a display signal applied to the display device 19A, and transmits the display signal to the display device 19A. The display device 19A displays the measurement results of the detector 18 represented by the display signal transmitted from the display control unit 48.

The control device 19 includes a measuring force application control section 50, a measuring force setting section 52, and a table storage section 54. The measuring force applying control section 50 controls the operation of the measuring force applying mechanism 56 included in the detector 18 . The measuring force setting unit 52 sets a measuring force that is a control parameter of the measuring force applying mechanism 56.

The table storage unit 54 stores a measuring force setting table 58 that shows the correlation between the setting value of the measuring force applying mechanism 56 and the measuring force applied to the contact. The measuring force applying control section 50 controls the operation of the measuring force applying mechanism 56 based on the setting value of the measuring force setting section 52. Note that the table storage section 54 shown in the embodiment corresponds to an example of a correlation storage section. Details of the operation control of the measuring force applying mechanism 56 will be described later.

The control device 19 includes a drive control section 60. The drive control unit 60 controls the operation of the drive mechanism 62 based on the control parameters of the drive mechanism 62. Drive mechanism 62 may include motor 14 shown in FIG. 1, a motor that operates carriage 16, and a motor that operates horizontal arm 17.

The control device 19 includes an input section 64 . The input unit 64 acquires an input signal transmitted from the input device 19B. The input section 64 transmits information corresponding to the input signal to each section of the control device 19. For example, when a set value of a control parameter is input using the input device 19B, the input unit 64 transmits the control parameter corresponding to the acquired input signal to the corresponding control unit.

The control device 19 includes a program storage section 66 . The program storage unit 66 stores various programs applied to the roundness measuring device 10 and the control device 19. An example of the program is a measuring force adjustment program used to adjust the measuring force applied to the contact.

[Hardware configuration of control device]
The control device 19 may be a computer. The control device 19 implements the functions of the roundness measuring device 10 by executing a prescribed program using hardware described below. As the hardware of each control unit, various types of processors can be applied. An example of a processor is a CPU (Central Processing Unit). The CPU executes programs and functions as various processing units.

FIG. 3 is a flowchart showing the procedure of a measuring force adjustment method applied to the roundness measuring device shown in FIG. In the measuring force setting step S10, the measuring force setting section 52 shown in FIG. 2 sets the measuring force applied to the measurement of the workpiece 9. Note that the measuring force setting step S10 described in the embodiment corresponds to an example of an inputting step of inputting the value of the measuring force. The measurement of the workpiece 9 described in the embodiment corresponds to an example of surface texture measurement.

The measuring force is determined according to the standard of the workpiece 9, measurement accuracy, measurement conditions of the contactor 18A, etc. The measuring force setting unit 52 sets the measuring force based on the measurement conditions applied to the measurement of the workpiece 9. After the measuring force setting step S10, the process advances to a measuring force setting information acquisition step S12. Note that the setting of the measuring force described in the embodiment corresponds to an example of inputting the value of the measuring force.

In the measuring force setting information acquisition step S12, the measuring force application control unit 50 acquires the input information of the measuring force set in the measuring force setting step S10. An example of the measuring force setting information is the setting value of the measuring force applying mechanism 56. Setting values of the measuring force applying mechanism 56 are shown in FIG. 6 using the symbol _SV . After the measuring force setting information acquisition step S12, the process advances to an operation parameter reading step S14.

In the operation parameter reading step S14, the measuring force application control section 50 reads out the operation parameters corresponding to the measuring force setting information from the measuring force setting table 58. After the operation parameter reading step S14, the process proceeds to the operation parameter setting step S16.

In the operation parameter setting step S16, the measuring force application control unit 50 sets the operation parameters of the measuring force application mechanism 56 read out in the operation parameter reading step S14. After the operation parameter setting step S16, the process advances to the measurement applying mechanism operation step S18. Note that the operation parameter reading step S14 and the operation parameter setting step S16 described in the embodiment correspond to an example of a component of the determination step.

In the measurement applying mechanism operating step S18, the measuring force applying control section 50 operates the measuring force applying mechanism 56 based on the operating parameters set in the operating parameter setting step S16. After the measurement applying mechanism operation step S18, the process proceeds to the adjustment completion confirmation step S20.

In the adjustment completion confirmation step S20, the measuring force applying control unit 50 determines whether the adjustment of the measuring force applying mechanism 56 is completed. The measuring force applying control unit 50 may determine whether the adjustment of the measuring force applying mechanism 56 is completed based on the detection result of a position sensor that detects the position of the measuring force applying mechanism 56.

In the adjustment completion confirmation step S20, if the measuring force applying control unit 50 determines that the adjustment of the measuring force applying mechanism 56 is not completed, the determination is No. In the case of No, the process proceeds to the measurement applying mechanism operation step S18, and the measurement applying mechanism operation step S18 and the adjustment completion confirmation step S20 are repeatedly performed until a Yes determination is made in the adjustment completion confirmation step S20.

On the other hand, in the adjustment completion confirmation step S20, if the measuring force applying control unit 50 determines that the adjustment of the measuring force applying mechanism 56 is completed, the determination is Yes. In the case of a Yes determination, the measuring force application control unit 50 ends the measuring force adjustment method.

Note that the measurement applying mechanism operation step S18 and the adjustment completion confirmation step S20 shown in the embodiment correspond to an example of the constituent elements of the adjustment step.

When the table storage section 54 shown in FIG. 2 stores a plurality of measuring force applying mechanisms 56, a table switching process may be performed in which the measuring force setting table 58 is switched according to the measurement conditions of the workpiece 9. In this aspect, after implementing the measurement condition acquisition step of acquiring the measurement conditions of the workpiece 9, the table switching step can be performed.

The control device 19 may cause the display device 19A to display identification information of the measurement force setting table 58 applied to the measurement value adjustment. That is, a measuring force setting table identification information displaying step may be performed to display the identification information of the measuring force setting table 58 applied to the measurement value adjustment.

The control device 19 may generate a new measurement force setting table 58. That is, in the operation parameter reading step S14, when there is no measuring force setting table 58 that matches the measurement conditions such as the type of arm and the mounting direction of the arm, when the contactor 202 is not in contact with the object to be measured 210, A table creation process can be carried out in which the detection value of the displacement sensor 208 is read out for each setting value of the measurement force, the measurement force is calculated from the detection value of the displacement sensor 208, and a new measurement force setting table 58 is created.

Note that the table creation process shown in the embodiment corresponds to an example of a correlation creation process. Each measuring force setting value shown in the embodiment corresponds to an example of each measuring force setting. According to this aspect, it becomes possible to perform measurement force adjustment for new measurement conditions.

When the control device 19 includes a plurality of measuring force setting tables 58, it can implement a table selection step of selecting the measuring force setting table 58 according to the measurement conditions. Note that the table selection process shown in the embodiment corresponds to an example of the correlation selection process. According to this aspect, the measurement force can be adjusted according to the measurement conditions.

[Description of common lever type detector]
FIG. 4 is a conceptual diagram of a lever type detector. The lever type detector 100 includes a contactor 102, an arm 104, a measuring force applying mechanism 106, and a displacement sensor 108. The lever type detector 100 detects irregularities on the surface of the object to be measured 110 by bringing the contact 102 into contact with the object to be measured 110 and relatively operating the contact 102 and the object to be measured 110 . Contactor 102 corresponds to contactor 18A shown in FIG. The object to be measured 110 corresponds to the workpiece 9 .

The arm 104 shown in FIG. 4 holds the contact 102 at its tip. The arm 104 is swingably supported using a swing fulcrum 112. The arrow line attached to the swing fulcrum 112 represents the swing direction of the arm 104.

The measuring force applying mechanism 106 adjusts the measuring force for pressing the contact 102 against the object to be measured 110 by applying a biasing force to the arm 104. The measuring force applying mechanism 106 includes an elastic body such as a coil spring 114 that generates a measuring force. One end of the coil spring 114 is connected to the arm 104. The other end of the coil spring 114 is connected to a lifting mechanism. The arrow line attached to the measuring force applying mechanism 106 represents the moving direction of the other end of the coil spring 114. Note that illustration of the elevating mechanism is omitted.

Displacement sensor 108 detects displacement at displacement detection position 116, which is the base end position of arm 104. The lever type detector 100 outputs an output signal representing the detection result of the displacement sensor 108. The measuring force applied to the object to be measured 110 is set and adjusted using the measuring force applying mechanism 106, and the setting accuracy of the measuring force ensures the measurement accuracy for measuring the surface texture of the object to be measured 110. This has become an issue.

For convenience of explanation, FIG. 4 shows an example in which the tip of the contact 102 faces downward; however, the lever-type detector shown in FIG. A mode in which the tip of the contactor 102 faces horizontally and a mode in which the tip of the contactor 102 faces upward may also be used. The same applies to the detector 200 etc. shown in FIG.

[Configuration example of a detector applied to the roundness measuring device according to this embodiment]
FIG. 5 is a schematic diagram showing a configuration example of a detector applied to the roundness measuring device shown in FIG. 1. The detector 200 includes a contactor 202, an arm 204, a measuring force applying mechanism 206, and a displacement sensor 208. The measuring force applying mechanism 206 includes a coil spring 214.

Contact 202 shown in FIG. 5 corresponds to contact 18A shown in FIG. The object to be measured 210 corresponds to the workpiece 9 . Reference numeral 212 represents a swinging fulcrum of the arm 204. Reference numeral 216 represents the displacement detection position of the arm 204.

In FIG. 5, the base end of the arm 204 is used as the displacement detection position 216, but the displacement detection position 216 may be any position of the arm 204 on the opposite side of the contactor 202 with respect to the swing fulcrum 212. obtain.

In the detector 200, a plate spring 220 is applied to a support member that swingably supports the arm 204. The midpoint of the leaf spring 220 becomes the swing fulcrum 212 of the arm 204. The arrow line attached to the arm 204 represents the direction in which the arm 204 swings. The leaf spring 220 is connected to the arm 204 using an arm connection member 222. The arm 204 is connected to the leaf spring 220 at a position closer to the contact 202 than the swing fulcrum 212 .

The leaf spring 220 is coupled to a frame 226 that supports the displacement sensor 208 using a frame coupling member 224 . The detector 200 uses the correlation between the set value of the measuring force applying mechanism 206 and the measuring force to measure the object to be measured 210 applying a prescribed measuring force.

Using the physical property values of the leaf spring 220, the measurement force is calculated from the detection value of the displacement sensor 208, and the correlation between the setting value of the measurement force applying mechanism 206 and the detection value of the displacement sensor 208 is derived.

The measuring force setting table 58 shown in FIG. 2 can be applied to the correlation between the setting value of the measuring force applying mechanism 206 and the measuring force. Note that the measuring force applying mechanism 206 corresponds to the measuring force applying mechanism 56 shown in FIG. 2. The calculation of the measuring force will be explained in detail below.

Note that the leaf spring 220 shown in the embodiment corresponds to an example of a component of an arm support section that supports an arm using a plate-like elastic member. Further, the plate spring 220 shown in the embodiment corresponds to an example of a plate-shaped elastic member. Furthermore, the measuring force applying mechanism 206 described in the embodiment corresponds to an example of a measuring force applying section.

[Explanation of deriving the correlation between the setting value of the measuring force applying mechanism and the measuring force]
FIG. 6 is a schematic diagram showing the relationship between the set value of the measuring force applying mechanism and the detected value of the displacement sensor. A detection step of detecting the detection value of the displacement sensor 208 for each set value S _V of the measuring force applying mechanism 206 is carried out according to the following procedure. FIG. 6 schematically shows the set value S _V of the measuring force applying mechanism 206. First, the contactor 202 is brought into a free state. That is, the contactor 202 is brought into a non-contact state with respect to the object to be measured 210 shown in FIG.

Next, the set value _SV of the measuring force applying mechanism 206 is determined. The set value S _V is the moving distance of the elevating mechanism included in the measuring force applying mechanism 206 with respect to the reference position. The moving distance when raising the elevating mechanism relative to the reference position is a positive value, and the moving distance when lowering the elevating mechanism relative to the reference position is a negative value. The arrow line attached to the measuring force applying mechanism 206 represents the elevation of the elevating mechanism.

The reaction force of the leaf spring 220 according to the set value S _V acts on the arm 204, and the rotational moment generated by the leaf spring 220 and the rotational moment generated by the measuring force applying mechanism 206 are balanced, and the swinging of the arm 204 is caused. Stand still.

Note that the arrow line attached to the tip end side of the swing fulcrum 212 of the arm 204 shown in FIG. 6 represents the rotational moment generated by the leaf spring 220. The arrow line attached to the connection position 204B of the coil spring 214 in the arm 204, which is the part of the arm on the opposite side of the contactor 202 across the swing fulcrum 212 of the arm 204, indicates the rotational moment generated by the measuring force applying mechanism 206. represent. The same applies to FIGS. 7 and 9.

The rotation moment generated by the leaf spring 220 is a moment of force acting on the connecting position 204A of the leaf spring 220 on the arm 204. The rotational moment generated by the measuring force applying mechanism 206 is a moment of force acting on the connecting position 204B of the coil spring 214 in the arm 204.

A detected value D of the displacement sensor 208 in a state where the swinging of the arm 204 is stationary is obtained. Using the physical property values of the leaf spring 220, the reaction force of the leaf spring 220 corresponding to the set value _SV of the measuring force applying mechanism 206 is calculated from the detected value D of the displacement sensor 208. From the reaction force of the leaf spring 220, it is possible to calculate the measurement force applied to the contact 202 that corresponds to the force generated by the leaf spring 220.

The set value _SV of the measuring force applying mechanism 206 is changed, and the measuring force is calculated for the plurality of set values _SV of the measuring force applying mechanism 206. Based on the calculation results, a correlation between the set value _SV of the measuring force applying mechanism 206 and the measuring force is derived. Note that the calculation of the measuring force described in the embodiment corresponds to an example of a calculation process. The correlation generation procedure described in the embodiment corresponds to an example of a correlation generation method. The calculation of the measuring force will be explained in detail below.

The contactor 202 and arm 204 illustrated using solid lines in FIG. 6 represent the case where the set value S _V of the measuring force applying mechanism 206 is any value other than zero. The contactor 202 and the arm 204 shown using dashed lines in the figure represent the case where the set value _SV of the measuring force applying mechanism 206 is zero. The detected value D of the displacement sensor 208 when the set value _SV of the measuring force applying mechanism 206 is zero is set as the reference value. In the following explanation, the reference value is assumed to be zero. The displacement at the displacement detection position 216 of the arm 204 is applied to the detection value D of the displacement sensor 208.

For the displacement of the displacement detection position 216 of the arm 204, the distance from the position of the displacement detection position 216 of the arm 204 when the set value S _V of the measuring force applying mechanism 206 is zero is applied. For the displacement of the displacement detection position 216 of the arm 204, a unit representing distance such as millimeter is used.

The symbol P _A represents the reaction force of the leaf spring 220. The reaction force _PA acts on the connecting position 204A of the leaf spring 220 on the arm 204. The symbol F _mf represents the force generated by the coil spring 214 . The force F _mf generated by the coil spring 214 makes an angle φ with respect to the arm 204 .

The symbol L represents the length of the leaf spring 220 along the longitudinal direction of the arm 204. The length L of the leaf spring 220 is the length of the elastically deformable portion of the leaf spring 220, and the length of the leaf spring 220 in a non-deformed state is applied. The length L of the leaf spring 220 is a fixed value.

[Calculation of rotational moment generated by a leaf spring]
FIG. 7 is a detailed explanatory diagram of the rotational moment generated by the leaf spring. The symbol L _arm is the distance from the swing fulcrum 212 of the arm 204 to the displacement detection position 216. The symbol θ is the angle of the arm 204 when the set value S _V of the measuring force applying mechanism 206 is an arbitrary value with respect to the arm 204 when the set value S _V of the measuring force applying mechanism 206 is zero.

The rotational moment generated by the reaction force of the leaf spring 220 is expressed as (L/2)× _PA using the length L of the leaf spring 220 and the reaction force _PA of the leaf spring 220. Note that, for convenience of calculation, the swing fulcrum 212 of the arm was set at the midpoint of the leaf spring 220. The midpoint of the leaf spring 220 is the midpoint of the elastically deformable portion of the leaf spring 220.

[Calculation of the measuring force generated by the leaf spring]
FIG. 8 is an explanatory diagram of calculation of the measuring force generated by the leaf spring. The displacement δ(x) at a position x distance from the base end 220A of the leaf spring 220 is δ(x)=(P×L×x ² )/[(6×B)×{3−(x/L )}].

Here, the force P generated by the leaf spring 220 has the same magnitude as the reaction force _PA of the leaf spring 220 shown in FIG. 7, and is directed in the opposite direction to the reaction force _PA of the leaf spring 220. B is the bending stiffness and is expressed as B=(b×t ³ ×E)/{12×(1−ν ² )}.

b is the width of the leaf spring 220. The width of the leaf spring 220 is the entire length of the leaf spring 220 in the width direction orthogonal to the direction of the length L of the leaf spring 220. t is the thickness of the leaf spring 220. E is the Young's modulus of the leaf spring 220. ν is the Poisson's ratio of the leaf spring 220.

The arm angle θ(x) of the detector 200 at a position x distance from the base end 220A of the leaf spring 220 is expressed as θ(x)={δ(x+dx)−δ(x)}/dx. That is, the arm angle θ(x) of the detector 200 is dδ(x)/dx, which is obtained by differentiating δ(x) with respect to x. The arm angle θ(x) of the detector 200 is expressed as θ(L)=(P×L ² )/(2×B) using the length L of the leaf spring 220 as a parameter.

Here, the arm angle θ(x) of the detector 200 shown in FIG. 8 is the angle θ shown in FIG. 7. In FIG. 8, the arm 204 is schematically shown using a dashed line. On the other hand, using the distance L _arm from the swing fulcrum 212 of the arm 204 to the displacement sensor 208 and the detection value D of the detector 200, the tangent of θ is expressed as tan(θ)=D/L _arm .

Applying the small angle approximation and solving the above equation for P with tan(θ)=θ, P(D)=(2×B×D)/(L ² ×L _arm ) is obtained. The force P generated by the leaf spring 220 is expressed as a function using the detection value D of the detector 200 as a parameter.

In P(D) above, the bending stiffness B of the leaf spring 220 and the length L of the leaf spring 220 are defined as physical property values of the leaf spring 220. Further, the distance L _arm from the swing fulcrum 212 of the arm 204 to the displacement sensor 208 is defined based on the mechanical specifications of the arm 204.

[Calculation of the measuring force acting on the contact]
FIG. 9 is an explanatory diagram of calculation of the measuring force acting on the contact. Let L _tip be the distance from the swing fulcrum 212 on the arm 204 to the position of the contact 202, and let F _meas be the measuring force acting on the contact 202.

The rotational moment generated by the measuring force applying mechanism 206 is expressed as (L/2)×P=B×D/(L×L _arm ). The rotational moment generated by the measuring force applying mechanism 206 is balanced by F _meas x L _tip . That is, F _meas acting on the contactor 202 is expressed as F _meas (D)=B×D/(L×L _arm ).

[Explanation of measuring force setting table]
FIG. 10 is a graph showing the detected value of the displacement sensor with respect to the set value of the measuring force applying mechanism. The horizontal axis of the graph shown in the figure is the set value _SV of the measuring force applying mechanism 206, and the vertical axis is the detected value D of the displacement sensor 208.

As the setting value S _V of the measuring force applying mechanism 206, the operating parameters of the moving mechanism for moving the coil spring 214 shown in FIG. 5 and the like can be applied. When the moving mechanism includes a control type motor such as a pulse motor, the number of pulses corresponding to the moving distance of the coil spring 214 can be applied as the control parameter.

The set value _SV of the measuring force applying mechanism 206 is changed, and the detection value D of the displacement sensor 208 is measured for a plurality of set values _SV . Processing such as linear interpolation and data extrapolation is performed on the plot representing the measured values, and the graph shown in FIG. 10 is generated.

FIG. 11 is a graph showing the measuring force versus the set value of the measuring force applying mechanism. The horizontal axis of the graph shown in FIG. 11 is the set value _SV of the measuring force applying mechanism 206, similar to the graph shown in FIG. The vertical axis of the graph shown in FIG. 11 is the measuring force F _meas acting on the contactor 202. The unit of the measuring force F _meas is millinewton.

The graph shown in FIG. 11 can be derived by applying the detected value D of the displacement sensor 208 shown in FIG. 10 to F _meas (D)=B×D/(L×L _arm ×L _tip ). The graph shown in FIG. 11 is an example of the measuring force setting table 58 shown in FIG. 2. The measuring force applying control section 50 shown in _FIG . The set value _SV of the measuring force applying mechanism 206 is read out, and the measuring force applying mechanism 206 is operated based on the set value _SV of the measuring force applying mechanism 206.

[Preferred embodiment of creating measurement force setting table]
<Extrapolation>
When detecting the detected value D of the displacement sensor 208 with respect to the set value S _V of the measuring force applying mechanism 206, there is a set value S _V of the measuring force applying mechanism 206 at which the detected value D of the displacement sensor 208 is outside the detection range. obtain. In such a case, the plot in the graph shown in FIG. 10 can be extrapolated to interpolate the set value S _V of the measuring force applying mechanism 206 corresponding to the detected value D of the displacement sensor 208 that is outside the detection range. For extrapolation of the plot, known approximation methods such as polynomial approximation may be applied.

<Linear characteristics>
The measuring force F _meas with respect to the set value S _V of the measuring force applying mechanism 206 has linear characteristics. This makes it possible to increase the accuracy of plot extrapolation. The linearity here is not limited to a strict linearity. Even if it is non-linear, a substantially linear method may be applied since it can obtain the same effect as a linear method.

<Update of measuring force setting table>
The measuring force setting table 58 can be generated and stored in the initial state of the roundness measuring device 10. The measuring force setting table 58 can be updated depending on the state of the detector 200 and the object to be measured 110. Updating here can include both a mode of rewriting an existing table and a mode of leaving the existing table and adding a new table.

When the measuring force setting table 58 is updated, it is preferable to store the updated information. That is, the roundness measuring device 10 may include an update information storage section that stores update information of the measuring force setting table 58. The update information may include information such as update date and time.

[Description of plate-shaped elastic member]
FIG. 12 is a schematic diagram of a leaf spring applied to the swing fulcrum of the arm. A single plate spring 300 shown in FIG. 12 is composed of a single plate having a flat plate shape. A single-plate leaf spring 300 shown in FIG. 12 is applied to the leaf spring 220 shown in FIG. 5 and the like.

The single-plate leaf spring 300 is supported on one side using a swing-side connecting member 302 and on the other side using a fixed-side swing member 304 . The swing-side connecting member 302 corresponds to the arm connecting member 222 shown in FIG. 5 and the like. The swing-side connecting member 302 is connected to the contactor 202 and the core shown in FIG. 5 and the like. The fixed side swinging member 304 corresponds to the frame connecting member 224. The fixed side swinging member 304 is connected to the main body side of the detector 200.

FIG. 13 is a schematic diagram of a cross spring applied to the swing fulcrum of the arm. The cross spring 320 shown in FIG. 13 has improved characteristics as a rotation bearing compared to the single plate spring 300 shown in FIG. 12.

The cross spring 320 shown in FIG. 13 is supported using a swing-side connecting member 322 and a fixed-side swing member 324. The function of the swing-side coupling member 322 is similar to that of the swing-side coupling member 302 shown in FIG. The function of the fixed side swinging member 324 is similar to that of the fixed side swinging member 304. Note that the cross spring 320 shown in FIG. 13 corresponds to an example of a plate-like elastic member.

[Effect]
[Zero point calibration of displacement sensor detection value]
In the operation of reading the detected value D of the displacement sensor 208 while changing the set value _SV of the measuring force applying mechanism 206, the set value SV of the measuring force applying mechanism 206 at which the detected value D of the displacement sensor 208 becomes _zero is detected. Thereby, the setting value S _V of the measuring force applying mechanism 206 at which the measuring force F _meas becomes neutral can be detected.

FIG. 14 is a schematic diagram of a detection unit including a replaceable contact. FIG. 15 is a schematic diagram of a detection unit having different shapes of contacts. FIG. 16 is a schematic diagram when the contactor is attached at different angles to the arm.

As shown in FIG. 14, in a detector 200A in which the contact 202A is replaced depending on the purpose of measurement, etc., the zero point of the detected value D of the displacement sensor 208 changes depending on the shape of the contact 202, etc. If the measuring force adjustment shown in this embodiment is not performed, it is necessary to directly measure the measuring force F _meas with respect to the state of the contactor 202A using a measuring device such as a scale.

In the detector 200A shown in FIG. 14, the contact 202A can be replaced with respect to the detector 200 shown in FIG. .

The detector 200B shown in FIG. 15 includes a detector 200B having a different shape and mass from the contact 202 provided in the detector 200 shown in FIG. , a change in rotational moment relative to the contactor 202 occurs.

The detector 200C shown in FIG. 16 has a different mounting angle of the contact 202C from the contact 202 provided in the detector 200 shown in FIG. A change in rotational moment relative to 202 occurs.

The detector 200A shown in FIG. 14, the detector 200B shown in FIG. 15, and the detector 200C shown in FIG. 16 use the measuring force setting table 58 shown in _FIG . The zero point of the detected value D of the sensor 208 can be calibrated.

[No need for a measuring device such as a scale to directly measure measuring force]
It is possible to adjust and calibrate the measuring force more easily at lower cost. Further, on-site work can be performed at the installation location of the roundness measuring device 10, and accurate calibration of the measuring force can be performed in the actual operating environment of the roundness measuring device 10. Moreover, the calibration value of the measurement force in the latest state can always be used. This increases the reproducibility of the measurement results of the roundness measuring device 10, making it possible to achieve high measurement accuracy.

[Eliminating the influence of individual differences in detectors, contacts, etc.]
If there are individual differences between the detector 200 and the contact 202, it is necessary to manage the correlation between the set value S _V of the measuring force applying mechanism 206 and the measuring force F _meas for each individual roundness measuring device 10. . In addition, individual management requires effort, and there is a concern that setting errors may occur.

In contrast, the roundness measuring device 10 shown in the present embodiment does not require the effort of individual management such as inputting serial numbers, suppresses the occurrence of setting errors, and reduces the processing period for individual management. obtain.

[Application example]
In this embodiment, as an example of a surface texture measuring device that measures the surface shape of the workpiece 9, a circularity measuring device 10 that measures the roundness, straightness, parallelism, squareness, etc. of the workpiece 9 will be exemplified. However, the present invention is not limited to this, and various surface texture measuring devices such as a surface roughness measuring device and a contour shape measuring device may be used.

In the embodiments of the present invention described above, constituent elements can be changed, added, or deleted as appropriate without departing from the spirit of the present invention. The present invention is not limited to the embodiments described above, and many modifications can be made within the technical idea of the present invention by those having ordinary knowledge in the field.

DESCRIPTION OF SYMBOLS 10... Roundness measuring device, 19... Control device, 19A... Display device, 48... Display control part, 50... Measuring force application control part, 54... Table storage part, 56, 206... Measuring force application mechanism, 58... Measurement Force setting table, 66...Program storage section, 200, 200A, 200B, 200C...Detector, 202, 202A, 202B, 202C...Contactor, 204...Arm, 208...Displacement sensor, 212...Swing fulcrum, 220...Plate Spring, 222...Arm connection member, 224...Frame connection member, 300...Single plate spring, 302, 322...Swing side connection member, 304, 324...Fixed side swing member, 320...Cross spring

Claims (5)

with a contactor,
an arm to which the contactor is attached;
an arm support section that swingably supports the arm using an elastic member at a swing fulcrum of the arm;
a measuring force applying unit that applies a measuring force to the contactor via the arm by applying a biasing force to the arm;
a detection unit that detects displacement of the contactor via the arm;
a correlation storage unit that stores a correlation between a setting value of the measurement force applying unit and the measurement force;
a measuring force setting unit that sets the measuring force based on the correlation;
A surface texture measuring device comprising: The surface texture measuring device according to claim 1, further comprising a correlation generation unit that generates the correlation according to the measurement conditions when the correlation according to the measurement conditions is not stored. The surface texture measuring device according to claim 1 or 2, wherein the correlation storage unit updates the correlation. The surface texture measuring device according to claim 3, further comprising an update information storage section that stores update information on the correlation. An arm provided with a contact is swingably supported at a swing fulcrum using an elastic member, and a biasing force is applied to the arm using a measuring force applying section to apply force to the contact via the arm. A method for generating a correlation in surface texture measurement in which a measuring force is applied to the contact and the displacement of the contact is detected, the method comprising:
a detection step of detecting displacement of the contactor via the arm while changing a set value of the measuring force applying unit corresponding to the biasing force while the contactor is not in contact with the workpiece;
a calculation step of calculating a measuring force to be applied to the contact when the displacement is detected, based on the detected displacement value and the physical property value of the elastic member;
a creation step of creating a correlation between the setting value of the measuring force applying unit and the measuring force based on the calculation result of the calculating step;
Correlation generation method including.

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