Surface property measurement device

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

Technical Field

[0001] The present invention relates to a correlation relationship generation method, a measurement force adjustment method, and a surface property measurement device.

Background Art

[0002] In a contact-type detector for measuring surface properties, a lever-type detector including a contactor that contacts an object to be measured, an arm that supports the contactor, a swing support shaft that swingably supports the arm, and a sensor that detects the swing displacement of the arm is widely used. In the lever-type detector, an elastic body such as a coil spring is used to apply a measurement force for pressing the contactor against the object to be measured. The measurement force is adjusted using a measurement force adjustment mechanism. The setting accuracy of the measurement force has been a problem.

[0003] Patent Document 1 describes a contact-type internal diameter measuring instrument that performs measurement by bringing a contactor into contact with an object to be measured. The device described in the document includes a contactor at one end of a measurement arm swingably supported at a swing fulcrum, and detects the displacement of the other end using a detector. The swing fulcrum of the arm provided in the device is configured using a cross spring. Such a configuration enables measurement with a constant and high-precision measurement force.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, when there are mechanical individual differences between devices, even if the settings of the measurement force application mechanism are the same, the measurement force actually applied to the object to be measured may be different. Therefore, it is necessary to actually measure the correlation between the setting of the measurement force application mechanism and the measurement force for each device. The same problem exists even when the arm, the contactor, etc. are replaceable.

[0006] The present invention has been made in view of such circumstances, and an object thereof is to provide a correlation relationship generation method, a measurement force adjustment method, and a surface property measurement apparatus capable of performing low-cost and simple adjustment of measurement force.

Means for Solving the Problems

[0007] In order to achieve the above object, the following invention aspects are provided.

[0008] The correlation relationship generation method according to the first aspect is a correlation relationship generation method in surface property measurement in which an arm having a contact is swingably supported using a plate-shaped elastic member at a swing fulcrum, and a biasing force is applied to a portion of the arm on the side opposite to the contact across the swing fulcrum by using a measurement force applying portion, thereby applying a measurement force to the contact via the arm, and detecting a displacement of the contact. The method includes a detection step of detecting the displacement of the contact via the arm while changing the set value of the measurement force applying portion corresponding to the biasing force in a state where the contact is non-contact with the work, a calculation step of calculating the measurement force applied to the contact when the displacement is detected based on the detected value of the displacement and the physical property value of the plate-shaped elastic member, and a creation step of creating a correlation relationship between the set value of the measurement force applying portion and the measurement force based on the calculation result of the calculation step.

[0009] According to the first aspect, with the contact being non-contact, the displacement of the contact is detected for the set values of a plurality of measurement force applying mechanisms. From the detection result of the displacement of the contact, a correlation relationship between the set value of the measurement force applying mechanism and the measurement force applied to the contact is derived using the physical property value of the plate-shaped elastic member that supports the arm at the swing fulcrum. Thereby, it is possible to generate a correlation relationship applicable to low-cost and simple measurement force adjustment without the need for a measurement device or the like that actually measures the measurement force.

[0010] The concept of measurement force adjustment may include concepts such as the initial setting of the measurement force and the configuration after the measurement force is set.

[0011] The second aspect is the correlation relationship generation method according to the first aspect, wherein the correlation relationship is such that the measurement force is F measLet B be the bending strength of the plate-like elastic member, D be the detected value at the displacement detection position in the arm, L be the length of the plate-like elastic member, and L be the distance from the swing fulcrum to the displacement detection position. arm Let L be the distance from the swing fulcrum to the contact. tip Then, F meas = B×D / (L×L arm ×L tip ) may be applied as a configuration in which the measuring force derived using this formula is applied.

[0012] According to the second aspect, using the bending strength B of the plate-like elastic member, the detected value D of the displacement of the contact, the length L of the plate-like elastic member, and the distance L from the swing fulcrum to the displacement detection position in the arm arm and the distance L from the swing fulcrum to the contact tip it is possible to derive the measuring force F meas from the detected value D of the displacement of the contact.

[0013] The measuring force adjustment method according to the third aspect is a measuring force adjustment method for adjusting the measuring force using the correlation created by the correlation generation method described in the first aspect, including an input step of inputting the value of the measuring force, a determination step of referring to the correlation and determining the set value of the measuring force applying unit corresponding to the value of the measuring force, and an adjustment step of operating the measuring force applying unit based on the set value of the measuring force applying unit determined in the determination step to adjust the measuring force applied to the contact.

[0014] According to the third aspect, it is possible to adjust the measuring force using the correlation described in the first aspect.

[0015] The fourth aspect may be configured to include a correlation selection step of selecting a correlation according to the measurement conditions from a plurality of correlations in the measuring force adjustment method of the third aspect.

[0016] According to the fourth aspect, it is possible to perform adjustment of the measuring force according to the measurement conditions.

[0017] The surface property measuring device according to the fifth aspect includes a contact, an arm to which the contact is attached, an arm support portion that supports the arm swingably using a plate-like elastic member at the swing fulcrum of the arm, and a measurement force applying portion that applies a measurement force to the contact via the arm by applying a biasing force to a portion of the arm on the side opposite to the contact across the swing fulcrum, a detection portion that detects the displacement of the contact via the arm, and a correlation relationship storage portion that stores the correlation relationship between the set value of the measurement force applying portion and the measurement force. The correlation relationship is obtained by detecting the displacement of the contact while changing the set value of the measurement force applying portion corresponding to the biasing force with the contact non-contact with the workpiece, calculating the measurement force applied to the contact when the displacement is detected based on the detected value of the displacement and the physical property value of the plate-like elastic member, and applying the correlation relationship between the set value of the measurement force applying portion generated based on the calculation result and the measurement force.

[0018] According to the fifth aspect, it is possible to adjust the measurement force using the correlation relationship described in the first aspect.

Effect of the Invention

[0019] According to the present invention, with the contact being non-contact, the displacement of the contact is detected for the set values of a plurality of measurement force applying mechanisms. From the detection result of the displacement of the contact, the correlation relationship between the measurement force applied to the contact with respect to the set value of the measurement force applying mechanism is derived using the physical property value of the plate-like elastic member that supports the arm at the swing fulcrum. Thereby, it is possible to generate a correlation relationship applicable to measurement force adjustment that is simple and low-cost without the need for a measuring device or the like that actually measures the measurement force.

Brief Description of the Drawings

[0020]

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DETAILED DESCRIPTION OF THE INVENTION

[0021] 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 assigned to the same components, and duplicate descriptions are omitted as appropriate.

[0022] [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. The roundness measuring device 10 shown in the figure measures the roundness of a cylindrical workpiece 9. The workpiece 9 to be measured can be applied with a disk shape, a cylindrical shape, or the like.

[0023] The roundness measuring device 10 includes a base 11. The base 11 is a support base that supports each part of the roundness measuring device 10. The support base is synonymous with the base. The roundness measuring device 10 includes a table 13. The table 13 may be called a mounting table.

[0024] The table 13 is disk-shaped and is attached to the upper surface of the base 11. The table 13 is rotatably supported by using the base 11 at a position of a rotation axis 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 as to be parallel to the horizontal reference plane.

[0025] Here, the term "upward" in this specification represents the vertically upward direction. Also, the term "downward" represents the vertically downward direction.

[0026] The upper surface of the table 13 is where the workpiece 9 is placed. The workpiece 9 is placed on the upper surface of the table 13 so that the shape center of the measurement target portion coincides with the rotation axis. FIG. 1 shows an example in which the outer peripheral surface of the cylindrical workpiece 9 is the measurement target portion and the workpiece 9 is placed so that the central axis of the cylinder coincides with the rotation axis 22 of the table 13.

[0027] The roundness measuring device 10 includes a motor 14. The motor 14 is disposed inside the base 11. The rotation axis of the motor 14 is connected to the rotation axis of the table 13 via a drive transmission mechanism. The motor 14 rotates the table 13 with the rotation axis 22 as the rotation center. The drive transmission mechanism may include gears. Note that the illustration of the drive transmission mechanism is omitted.

[0028] The roundness measurement device 10 includes a column 15, a carriage 16, a horizontal arm 17, and a detector 18. The column 15 is on the upper surface of the base 11 and is arranged on the side of the base 11 in the horizontal direction. The column 15 is a column extending in the vertical direction.

[0029] The carriage 16 is supported by using the column 15 so as to be movable up and down. The carriage 16 has a horizontal arm 17 attached thereto so as to be movable in the horizontal direction. The tip of the horizontal arm 17 has the detector 18 attached thereto.

[0030] The detector 18 includes a contact 18A and a displacement sensor. In FIG. 1, the 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 contact 18A moving along the direction indicated by the reference letter A. The detector 18 outputs a detection signal representing the displacement of the contact 18A. The detection signal is transmitted to the control device 19.

[0031] 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 contact 18A. In FIG. 1, the illustration of the measuring force applying mechanism is omitted. The measuring force applying mechanism is illustrated in FIG. 2 using the reference numeral 56.

[0032] The roundness measurement device 10 includes a control device 19. The control device 19 has a display device 19A and an input device 19B connected thereto. The display device 19A may be a display device such as a liquid crystal display. The input device 19B may be 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 also serves as the input device 19B.

[0033] 〔Description of the control device〕 Figure 2 is a functional block diagram of the roundness measuring device shown in Figure 1. The control device 19 includes a detection signal acquisition unit 40 and a signal processing unit 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 result 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 unit 42 stores the measurement result using the measurement result storage unit 46.

[0034] The control device 19 includes a display control unit 48. The display control unit 48 controls the display device 19A. The signal processing unit 42 transmits an electrical signal representing the measurement result to the display control unit 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 result of the detector 18 represented by the display signal transmitted from the display control unit 48.

[0035] The control device 19 includes a measurement force application control unit 50, a measurement force setting unit 52, and a table storage unit 54. The measurement force application control unit 50 controls the operation of the measurement force application mechanism 56 provided in the detector 18. The measurement force setting unit 52 sets the measurement force, which is a control parameter of the measurement force application mechanism 56.

[0036] The table storage unit 54 stores a measurement force setting table 58 showing the correlation between the set value of the measurement force application mechanism 56 and the measurement force applied to the contact. The measurement force application control unit 50 controls the operation of the measurement force application mechanism 56 based on the set value of the measurement force setting unit 52. Note that the table storage unit 54 shown in the embodiment corresponds to an example of a correlation storage unit. Details of the operation control of the measurement force application mechanism 56 will be described later.

[0037] The control device 19 includes a drive control unit 60. The drive control unit 60 controls the operation of the drive mechanism 62 based on the control parameters of the drive mechanism 62. The drive mechanism 62 may include the motor 14 shown in Figure 1, a motor that operates the carriage 16, and a motor that operates the horizontal arm 17.

[0038] The control device 19 includes an input unit 64. The input unit 64 acquires an input signal transmitted from the input device 19B. The input unit 64 transmits information corresponding to the input signal to each part 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.

[0039] The control device 19 includes a program storage unit 66. The program storage unit 66 stores various programs applied to the roundness measuring device 10 and the control device 19. As an example of a program, a measuring force adjustment program used for adjusting the measuring force applied to the contact is mentioned.

[0040] 〔Hardware Configuration of Control Device〕 The control device 19 can apply a computer. The control device 19 uses the hardware described below to execute a prescribed program to realize the functions of the roundness measuring device 10. The hardware of each control unit can apply various processors. An example of a processor is a CPU (Central Processing Unit). The CPU executes a program and functions as various processing units.

[0041] Figure 3 is a flowchart showing the procedure of the measuring force adjustment method applied to the roundness measuring device shown in Figure 1. In the measuring force setting step S10, the measuring force setting unit 52 shown in Figure 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 input step for inputting the value of the measuring force. The measurement of the workpiece 9 described in the embodiment corresponds to an example of surface property measurement.

[0042] The measuring force is determined according to the specifications of the workpiece 9, the measurement accuracy, and the measurement conditions such as the contact 18A. 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, it proceeds to the measuring force setting information acquisition step S12. Note that the setting of the measuring force described in the embodiment corresponds to an example of the input of the value of the measuring force.

[0043] 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. As an example of the measuring force setting information, the set value of the measuring force application mechanism 56 is cited. The set value of the measuring force application mechanism 56 is shown in FIG. 6 using the symbol S V After the measuring force setting information acquisition step S12, the process proceeds to the operation parameter reading step S14.

[0044] In the operation parameter reading step S14, the measuring force application control unit 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.

[0045] 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 proceeds to the measurement application 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 the components of the determination step.

[0046] In the measurement application mechanism operation step S18, the measuring force application control unit 50 operates the measuring force application mechanism 56 based on the operation parameters set in the operation parameter setting step S16. After the measurement application mechanism operation step S18, the process proceeds to the adjustment completion confirmation step S20.

[0047] In the adjustment completion confirmation step S20, the measuring force application control unit 50 determines whether or not the adjustment of the measuring force application mechanism 56 is completed. The measuring force application control unit 50 may determine whether or not the adjustment of the measuring force application mechanism 56 is completed based on the detection result of the position sensor that detects the position of the measuring force application mechanism 56.

[0048] In the adjustment completion confirmation step S20, if the measurement force application control unit 50 determines that the adjustment of the measurement force application mechanism 56 is not completed, it is a No determination. In the case of No, it proceeds to the measurement force application mechanism operation step S18, and the measurement force application mechanism operation step S18 and the adjustment completion confirmation step S20 are repeatedly executed until a Yes determination is made in the adjustment completion confirmation step S20.

[0049] On the other hand, in the adjustment completion confirmation step S20, if the measurement force application control unit 50 determines that the adjustment of the measurement force application mechanism 56 is completed, it is a Yes determination. In the case of a Yes determination, the measurement force application control unit 50 ends the measurement force adjustment method.

[0050] Note that the measurement force application mechanism operation step S18 and the adjustment completion confirmation step S20 shown in the embodiment correspond to an example of the components of the adjustment step.

[0051] When the table storage unit 54 shown in FIG. 2 stores a plurality of measurement force application mechanisms 56, a table switching step of switching the measurement force setting table 58 according to the measurement conditions of the workpiece 9 may be performed. In such an aspect, the table switching step can be performed after performing a measurement condition acquisition step of acquiring the measurement conditions of the workpiece 9.

[0052] The control device 19 may cause the display device 19A to display the identification information of the measurement force setting table 58 applied to the measurement value adjustment. That is, a measurement force setting table identification information display step of displaying the identification information of the measurement force setting table 58 applied to the measurement value adjustment may be performed.

[0053] 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 measurement force setting table 58 that matches the measurement conditions such as the type of the arm and the mounting direction of the arm, and when the contact 202 is in a non-contact state with the object to be measured 210, the detection value of the displacement sensor 208 is read for each set value of the measurement force, the measurement force is calculated from the detection value of the displacement sensor 208, and a table creation step of creating a new measurement force setting table 58 can be performed.

[0054] Note that the table creation process shown in the embodiment corresponds to an example of the correlation relationship creation process. Each set value of the measurement force shown in the embodiment corresponds to an example of each setting of the measurement force. According to such an aspect, it is possible to perform adjustment of the measurement force for new measurement conditions.

[0055] When the control device 19 includes a plurality of measurement force setting tables 58, it can perform a table selection process of selecting the measurement 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 relationship selection process. According to such an aspect, it is possible to perform adjustment of the measurement force according to the measurement conditions.

[0056] [Description of a general lever-type detector] FIG. 4 is a conceptual diagram of a lever-type detector. The lever-type detector 100 includes a contact 102, an arm 104, a measurement force applying mechanism 106, and a displacement sensor 108. The lever-type detector 100 brings the contact 102 into contact with the object to be measured 110, relatively operates the contact 102 and the object to be measured 110, and detects the unevenness on the surface of the object to be measured 110. The contact 102 corresponds to the contact 18A shown in FIG. 1. The object to be measured 110 corresponds to the workpiece 9.

[0057] 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.

[0058] The measurement force applying mechanism 106 adjusts the measurement force that presses the contact 102 against the object to be measured 110 by applying a biasing force to the arm 104. The measurement force applying mechanism 106 includes an elastic body such as a coil spring 114 that generates a measurement 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 an elevating mechanism. The arrow line attached to the measurement force applying mechanism 106 represents the moving direction of the other end of the coil spring 114. Note that the illustration of the elevating mechanism is omitted.

[0059] The displacement sensor 108 detects the displacement of the displacement detection position 116, which is the proximal end position of the arm 104. The lever-type detector 100 outputs an output signal representing the detection result of the displacement sensor 108. The measurement force applied to the object to be measured 110 is set and adjusted using the measurement force applying mechanism 106. However, the setting accuracy of the measurement force poses a problem in ensuring the measurement accuracy for measuring the surface properties of the object to be measured 110.

[0060] For the sake of explanation, FIG. 4 illustrates a mode in which the tip of the contact 102 faces downward. However, similar to the detector 18 shown in FIG. 1, the lever-type detector shown in FIG. 4 may also have a mode in which the tip of the contact 102 faces horizontally and a mode in which the tip of the contact 102 faces upward. The same applies to the detector 200 shown in FIG. 5 and the like.

[0061] 〔Configuration Example of Detector Applied to Circularity Measuring Apparatus According to Present Embodiment〕 FIG. 5 is a schematic diagram showing a configuration example of a detector applied to the circularity measuring apparatus shown in FIG. 1. The detector 200 includes a contact 202, an arm 204, a measurement force applying mechanism 206, and a displacement sensor 208. The measurement force applying mechanism 206 includes a coil spring 214.

[0062] The contact 202 shown in FIG. 5 corresponds to the contact 18A shown in FIG. 1. The object to be measured 210 corresponds to the workpiece 9. Reference numeral 212 represents the swing fulcrum of the arm 204. Reference numeral 216 represents the displacement detection position of the arm 204.

[0063] In FIG. 5, a mode in which the proximal end of the arm 204 is set as the displacement detection position 216 is applied. However, the displacement detection position 216 can be any position on the arm 204 on the side opposite to the contact 202 with respect to the swing fulcrum 212.

[0064] The detector 200 has a leaf spring 220 applied to a support member that swingably supports an arm 204. The midpoint of the leaf spring 220 serves as the swing fulcrum 212 of the arm 204. The arrow line attached to the arm 204 indicates the swing direction of the arm 204. 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 on the side of the contact 202 rather than the swing fulcrum 212.

[0065] The leaf spring 220 is connected to a frame 226 that supports a displacement sensor 208 using a frame connection member 224. The detector 200 performs measurement of a measurement object 210 to which a specified measurement force is applied, using the correlation between the set value of the measurement force applying mechanism 206 and the measurement force.

[0066] 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 set value of the measurement force applying mechanism 206 and the detection value of the displacement sensor 208 is derived.

[0067] The correlation between the set value of the measurement force applying mechanism 206 and the measurement force can apply the measurement force setting table 58 shown in FIG. 2. Note that the measurement force applying mechanism 206 corresponds to the measurement force applying mechanism 56 shown in FIG. 2. Hereinafter, the calculation of the measurement force will be described in detail.

[0068] Note that the leaf spring 220 shown in the embodiment corresponds to an example of a component of an arm support portion that supports an arm using a plate-shaped elastic member. Further, the leaf spring 220 shown in the embodiment corresponds to an example of a plate-shaped elastic member. Furthermore, the measurement force applying mechanism 206 described in the embodiment corresponds to an example of a measurement force applying portion.

[0069] 〔Explanation of Derivation of Correlation between Set Value of Measurement Force Applying Mechanism and Measurement Force〕 FIG. 6 is a schematic diagram showing the relationship between the set value of the measurement force applying mechanism and the detection value of the displacement sensor. According to the following procedure, a detection step of detecting the detection value of the displacement sensor 208 for each set value S V of the measurement force applying mechanism 206 is performed. In FIG. 6, the set value S VIt is schematically illustrated. First, the contact 202 is set to the free state. That is, the contact 202 is set to a non-contact state with respect to the object to be measured 210 shown in FIG. 5.

[0070] Next, the set value S of the measurement force applying mechanism 206 V is determined. The set value S V is the moving distance with respect to the reference position of the lifting mechanism provided in the measurement force applying mechanism 206. The moving distance when the lifting mechanism is lifted with respect to the reference position is set as a positive value, and the moving distance when the lifting mechanism is lowered with respect to the reference position is set as a negative value. The arrow line attached to the measurement force applying mechanism 206 represents the upward movement of the lifting mechanism.

[0071] The reaction force of the leaf spring 220 corresponding 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 measurement force applying mechanism 206 are balanced, and the swing of the arm 204 stops.

[0072] Note that the arrow line attached to the position on the tip 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 on the arm 204, which is the portion of the arm on the side opposite to the contact 202 with the swing fulcrum 212 of the arm 204 interposed therebetween, represents the rotational moment generated by the measurement force applying mechanism 206. The same applies to FIGS. 7 and 9.

[0073] The rotational moment generated by the leaf spring 220 is the moment of the force acting on the connection position 204A of the leaf spring 220 on the arm 204. The rotational moment generated by the measurement force applying mechanism 206 is the moment of the force acting on the connection position 204B of the coil spring 214 on the arm 204.

[0074] The detected value D of the displacement sensor 208 in the state where the swing of the arm 204 has stopped is acquired. Using the physical property values of the leaf spring 220, the set value S of the measurement force applying mechanism 206 is obtained from the detected value D of the displacement sensor 208 VCalculate the reaction force of the leaf spring 220 corresponding thereto. It is possible to calculate the measurement force applied to the contact 202 corresponding to the force generated by the leaf spring 220 from the reaction force of the leaf spring 220.

[0075] The set value S of the measurement force applying mechanism 206 V is changed, and the measurement force is calculated for the set values S of the plurality of measurement force applying mechanisms 206 V Based on the calculation results, the correlation between the set value S of the measurement force applying mechanism 206 V and the measurement force is derived. Note that the calculation of the measurement force described in the embodiment corresponds to an example of the calculation process. The procedure for generating the correlation described in the embodiment corresponds to an example of the correlation generation method. Hereinafter, the calculation of the measurement force will be described in detail.

[0076] The contact 202 and the arm 204 illustrated by the solid line in FIG. 6 represent the case where the set value S of the measurement force applying mechanism 206 V is any value other than zero. The contact 202 and the arm 204 illustrated by the dashed-dotted line in the same figure represent the case where the set value S of the measurement force applying mechanism 206 V is zero. The detected value D of the displacement sensor 208 when the set value S of the measurement force applying mechanism 206 V is zero is used as a reference value. In the following description, the reference value is set to zero. The detected value D of the displacement sensor 208 is applied to the displacement of the displacement detection position 216 of the arm 204.

[0077] The displacement of the displacement detection position 216 of the arm 204 is the distance with respect to the position of the displacement detection position 216 of the arm 204 when the set value S of the measurement force applying mechanism 206 V is zero. The displacement of the displacement detection position 216 of the arm 204 uses a unit representing a distance such as millimeters.

[0078] The symbol P A represents the reaction force of the leaf spring 220. The reaction force P A acts on the connection 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 generated by the coil spring 214 mfforms an angle φ with respect to the arm 204.

[0079] 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 portion of the leaf spring 220 that can be elastically deformed, and the length of the leaf spring 220 in its undeformed state is applied. The length L of the leaf spring 220 is a fixed value.

[0080] [Calculation of the rotational moment generated by the 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 setting value S V of the measuring force imparting mechanism 206 is an arbitrary value, relative to the arm 204 when the setting value S V of the measuring force imparting mechanism 206 is zero.

[0081] The rotation moment generated by the reaction force of the leaf spring 220 is expressed as (L / 2)×P A using the length L of the leaf spring 220 and the reaction force P A of the leaf spring 220. For the sake of convenience of calculation, the swing fulcrum 212 of the arm is set to the midpoint of the leaf spring 220. The midpoint of the leaf spring 220 is the midpoint of the part of the leaf spring 220 that can be elastically deformed.

[0082] [Calculation of the measuring force generated by a leaf spring] Figure 8 is an explanatory diagram of the calculation of the measuring force generated by a leaf spring. The displacement δ(x) at a position where the distance from the base end 220A of the leaf spring 220 is x is expressed as δ(x)=(P×L×x 2 ) / [(6×B)×{3-(x / L)}].

[0083] Here, the force P generated by the leaf spring 220 has the same magnitude as the reaction force P A of the leaf spring 220 shown in Figure 7, and is directed in the opposite direction to the reaction force P A of the leaf spring 220. B is the bending stiffness, and is expressed as B=(b×t 3 ×E) / {12×(1-ν 2 )}.

[0084] b is the width of the leaf spring 220. The width of the leaf spring 220 is the total length of the leaf spring 220 in the width direction orthogonal to the length L direction 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.

[0085] The arm angle θ(x) of the detector 200 at a position where the distance from the proximal end 220A of the leaf spring 220 is x 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 the derivative of 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.

[0086] 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-dotted 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 tan(θ) = D / L arm and is expressed as such.

[0087] Applying the small angle approximation and setting tan(θ) = θ, solving the above formula for P, we obtain P(D) = (2 × B × D) / (L 2 × L arm ). 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.

[0088] In the above P(D), the flexural strength 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. Also, 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.

[0089] 〔Calculation of the measuring force acting on the contact〕 FIG. 9 is an explanatory diagram of the calculation of the measurement force acting on the contact. The distance from the swing fulcrum 212 in the arm 204 to the position of the contact 202 is L tip Let the measurement force acting on the contact 202 be F meas Let it be.

[0090] The rotational moment generated by the measurement force applying mechanism 206 is (L / 2)×P = B×D / (L×L arm ) is expressed as. The rotational moment generated by the measurement force applying mechanism 206 is F meas ×L tip balances. That is, F acting on the contact 202 meas is, F meas (D)=B×D / (L×L arm ) is expressed as.

[0091] 〔Explanation of the measurement force setting table〕 FIG. 10 is a graph showing the detection value of the displacement sensor with respect to the setting value of the measurement force applying mechanism. The horizontal axis of the graph shown in the figure is the setting value S of the measurement force applying mechanism 206 V and the vertical axis is the detection value D of the displacement sensor 208.

[0092] The setting value S of the measurement force applying mechanism 206 V can apply the operation parameters of the moving mechanism that moves the coil spring 214 shown in FIG. 5 and the like. When the moving mechanism includes a controlled motor such as a pulse motor, the control parameter can apply the number of pulses corresponding to the moving distance of the coil spring 214.

[0093] By changing the setting value S of the measurement force applying mechanism 206 V and measuring the detection value D of the displacement sensor 208 for a plurality of setting values S V . By performing processes such as linear interpolation and data extrapolation on the plots representing the measured values, the graph shown in FIG. 10 is generated.

[0094] FIG. 11 is a graph showing the measurement force with respect to the setting value of the measurement force applying mechanism. The horizontal axis of the graph shown in FIG. 11 is, as in the graph shown in FIG. 10, the setting value S of the measurement force applying mechanism 206 VIt is as follows. The vertical axis of the graph shown in FIG. 11 is the measuring force F acting on the contact 202 meas It is as follows. The measuring force F meas is in millinewtons.

[0095] 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 unit 50 shown in FIG. 2 refers to the measuring force setting table 58 and, as the operation parameter of the measuring force applying mechanism 206 corresponding to the measuring force F meas set using the measuring force setting unit 52, reads the set value S V of the measuring force applying mechanism 206, and operates the measuring force applying mechanism 206 based on the set value S V of the measuring force applying mechanism 206.

[0096] 〔Desirable Embodiment for Creating Measuring 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 may be a set value S V of the measuring force applying mechanism 206 for which the detected value D of the displacement sensor 208 is outside the detection range. 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 outside the detection range. Extrapolation of the plot can apply a known approximation method such as polynomial approximation.

[0097] 〈Linear Characteristic〉 The measuring force F V with respect to the set value S meas of the measuring force applying mechanism 206 has a linear characteristic. Thereby, the accuracy of extrapolation of the plot can be improved. The linearity referred to here is not limited to strict linearity. A substantial linearity that can obtain the same effect as linearity even if it is non-linear may be applied.

[0098] <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 according to the state of the detector 200 and the object to be measured 110. The update here can include either a mode of rewriting the existing table or a mode of leaving the existing table and adding a new table.

[0099] When the measuring force setting table 58 is updated, it is preferable to store the update information. That is, the roundness measuring device 10 may include an update information storage unit that stores the update information of the measuring force setting table 58. The update information may include information such as the update date and time.

[0100] 〔Explanation of Plate-shaped Elastic Member〕 FIG. 12 is a schematic diagram of a leaf spring applied to the swing fulcrum of the arm. The single-plate leaf spring 300 shown in FIG. 12 is composed of a single plate having a flat plate shape. The leaf spring 220 shown in FIG. 5 etc. has the single-plate leaf spring 300 shown in FIG. 12 applied thereto.

[0101] One side of the single-plate leaf spring 300 is supported by using the swing-side connecting member 302, and the other side is supported by using the fixed-side swing member 304. The swing-side connecting member 302 corresponds to the arm connecting member 222 shown in FIG. 5 etc. The swing-side connecting member 302 has the contact 202 and the core shown in FIG. 5 etc. connected thereto. The fixed-side swing member 304 corresponds to the frame connecting member 224. The fixed-side swing member 304 is connected to the main body side of the detector 200.

[0102] 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 rotary bearing compared to the single-plate leaf spring 300 shown in FIG. 12.

[0103] The cross spring 320 shown in FIG. 13 is supported by using a swing side connecting member 322 and a fixed side swing member 324. The function of the swing side connecting member 322 is the same as that of the swing side connecting member 302 shown in FIG. 12. The function of the fixed side swing member 324 is the same as that of the fixed side swing member 304. Note that the cross spring 320 shown in FIG. 13 corresponds to an example of a plate-shaped elastic member.

[0104] [Function and Effect] [Zero Point Calibration of Displacement Sensor Detection Value] Setting value S of the measuring force applying mechanism 206 V In the operation of reading the detection value D of the displacement sensor 208 while changing the setting value S of the measuring force applying mechanism 206, the setting value S of the measuring force applying mechanism 206 at which the detection value D of the displacement sensor 208 becomes zero V is detected. Thereby, the setting value S of the measuring force applying mechanism 206 at which the measuring force F meas becomes neutral V can be detected.

[0105] FIG. 14 is a schematic diagram of a detection unit including a replaceable contact. FIG. 15 is a schematic diagram of a detection unit with different shapes of contacts. FIG. 16 is a schematic diagram when the mounting angle of the contact with respect to the arm is different.

[0106] In the detector 200A that replaces the contact 202A according to the purpose of measurement or the like as shown in FIG. 14, the zero point of the detection value D of the displacement sensor 208 changes according to the shape of the contact 202. When the measuring force adjustment shown in this embodiment is not performed, it is necessary to directly measure the measuring force F meas using a measuring device such as a scale with respect to the state of the contact 202A.

[0107] The detector 200A shown in FIG. 14 can replace the contact 202A with respect to the detector 200 shown in FIG. 5 and so on, and a change in the rotational moment with respect to the contact 202 occurs according to the mass of the contact 202A.

[0108] The detector 200B shown in FIG. 15 is provided with a detector 200B having a different shape and mass from the contact 202 provided in the detector 200 shown in FIG. 5 and the like. Depending on the mass and shape of the contact 202B, a change in the moment of rotation with respect to the contact 202 occurs.

[0109] The detector 200C shown in FIG. 16 has a different mounting angle of the contact 202C with respect to the contact 202 provided in the detector 200 shown in FIG. 5 and the like. Depending on the mounting angle of the contact 202C, a change in the moment of rotation with respect to the contact 202 occurs.

[0110] The detector 200A shown in FIG. 14, the detector 200B shown in FIG. 15, and the detector 200C shown in FIG. 16 use the measurement force setting table 58 shown in FIG. 2 to calibrate the zero point of the detection value D of the displacement sensor 208 with respect to the setting value S of the measurement force applying mechanism 206 V It becomes possible.

[0111] [Measurement device such as a scale for directly measuring the measurement force is not required] The measurement force can be adjusted and calibrated at a lower cost and more simply. In addition, on-site work can be performed at the installation location of the roundness measuring device 10, and accurate calibration of the measurement force is possible in the actual operating environment of the roundness measuring device 10. In addition, the calibration value of the measurement force in the always up-to-date state can be used. As a result, the reproducibility of the measurement results of the roundness measuring device 10 is improved, and high-precision measurement can be realized.

[0112] [Elimination of the influence of individual differences such as detectors and contacts] When there are individual differences between the detector 200 and the contact 202, it is necessary to manage the correlation between the setting value S of the measurement force applying mechanism 206 V and the measurement force F meas for each individual of the roundness measuring device 10. In addition, individual management is troublesome, and there is a concern about the occurrence of setting errors and the like.

[0113] On the other hand, the roundness measuring device 10 shown in the present embodiment does not require the trouble of individual management such as serial number input, and can suppress the occurrence of setting errors and the like and reduce the processing period of individual management.

[0114] 〔Application Example〕 In this embodiment, as an example of a surface property measuring device for measuring the surface shape of the workpiece 9, a roundness measuring device 10 for measuring roundness, straightness, parallelism, perpendicularity, etc. of the workpiece 9 has been described as an example. However, the present invention is not limited to this, and various surface property measuring devices such as a surface roughness measuring device and a contour shape measuring device may also be used.

[0115] The embodiments of the present invention described above can be appropriately modified, added to, or deleted in terms of the constituent elements without departing from the gist of the present invention. The present invention is not limited to the embodiments described above, and many modifications can be made by those having ordinary knowledge in the art within the technical idea of the present invention.

Explanation of Reference Numerals

[0116] 10... Roundness measuring device, 19... Control device, 19A... Display device, 48... Display control unit, 50... Measuring force application control unit, 54... Table storage unit, 56, 206... Measuring force application mechanism, 58... Measuring force setting table, 66... Program storage unit, 200, 200A, 200B, 200C... Detector, 202, 202A, 202B, 202C... Contact, 204... Arm, 208... Displacement sensor, 212... Oscillation fulcrum, 220... Leaf spring, 222... Arm connecting member, 224... Frame connecting member, 300... Single-plate leaf spring, 302, 322... Oscillation side connecting member, 304, 324... Fixed side oscillation member, 320... Cross spring

Claims

1. A contact and an arm to which the contact is attached; an arm support portion that supports the arm so that the arm can swing using an elastic member at a swing fulcrum of the arm; a measuring force applying unit that applies a measuring force to the contact via the arm by applying a biasing force to the arm; a detection unit that detects a displacement of the contact via the arm; a correlation storage unit for storing a correlation between a set value of the measuring force application unit and the measuring force; a measuring force setting unit that sets the measuring force based on the correlation; A surface texture measuring device comprising:

2. The surface texture measuring device according to claim 1 , further comprising a correlation generating unit that generates the correlation according to the measurement conditions when the correlation according to the measurement conditions is not stored.

3. The surface texture measuring device according to claim 1 , wherein the correlation storage unit updates the correlation.

4. The surface texture measuring device according to claim 3 , further comprising an updated information storage unit that stores updated information of the correlation.

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