JP2012063229A - Surface property measuring apparatus and computer program for surface property measurement - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a surface property measuring apparatus capable of simply, quickly and accurately measuring surface roughness or waviness of a curved surface in an article having the curved surface, and to provide a computer program for surface property measurement which is applied to the surface property measuring apparatus.SOLUTION: A surface property measuring apparatus 100 includes a work support 101, an imaging apparatus 102, a backlight illumination device 103, and a computer apparatus 110. The work support 101 supports a ball stud 90 to be an object to be measured. The imaging apparatus 102 images a contour of a ball part 92 in the ball stud 90. The backlight illumination device 103 applies light to the imaging apparatus 102 through the contour of the ball part 92 in the ball stud 90 set on the work support 101. The computer apparatus 110 controls the operation of the imaging apparatus 102 and the backlight illumination device 103 by executing the surface property measuring program to measure the surface roughness of the ball part 92.

Description

  The present invention relates to a surface texture measuring device for measuring the roughness or waviness of a surface to be measured having a curved surface, and a computer program for measuring the surface texture applied to the surface texture measuring device.

  Conventionally, in an article having a curved surface that requires smooth rotation and sliding, such as a ball of a steel ball of a bearing or a ball stud, the surface roughness of the curved surface is measured during the manufacturing process of the article. Yes. In general, the surface roughness is measured using a contact-type or non-contact-type surface roughness measuring device in relation to the measured curved surface of the object to be measured.

  For example, Patent Document 1 below discloses a so-called contact-type surface roughness measuring machine that detects irregularities of a measured curved surface by bringing a stylus into contact with the measured curved surface of the measured object and displacing it. Patent Document 2 below discloses a so-called non-contact type surface roughness measuring device that detects unevenness of a measured curved surface using a change in intensity of reflected light of a laser beam irradiated on the measured curved surface of a measured object. It is disclosed. Further, in Patent Document 3 below, a measured image is obtained by comparing a captured image obtained by capturing the measurement surface in a state where light is irradiated in a ring shape on the measured curved surface of the measured object with reference image information (determination data file). A non-contact type surface roughness measuring machine that detects unevenness of a curved surface is disclosed.

JP 05-164506 A JP-A-10-170247 JP 02-208504 A

  However, the contact-type surface roughness measuring device described in Patent Document 1 has a problem that the measurement accuracy of the surface roughness tends to be lowered by external vibration transmitted to the surface roughness measuring device. In particular, at the manufacturing site where the object to be measured is manufactured, the stylus that comes into contact with the surface to be measured is vibrated by vibrations generated from various mechanical devices and the like, and the measurement accuracy of the surface roughness is likely to decrease. In addition, in the non-contact type surface roughness measuring apparatus using the laser beam described in Patent Document 2, various information about the object to be measured such as the material, curvature, and CAD data of the object to be measured is necessary. It is necessary to strictly adjust the irradiation angle of the laser beam to be irradiated and the position of the light receiving element that receives the reflected light. That is, the non-contact type surface roughness measuring apparatus described in Patent Document 2 has a problem that the measurement work for measuring the surface roughness is extremely complicated and takes time. Further, in the non-contact type surface roughness measuring apparatus described in Patent Document 3, the light irradiation position and the imaging position for the object to be measured must be strictly positioned and reference image information to be compared The (determination data file) must be prepared in advance, and there is a problem that the measurement work for measuring the surface roughness is extremely complicated.

  SUMMARY OF THE INVENTION The present invention has been made to address the above problems, and its purpose is to provide a surface texture measuring device that can easily and accurately measure the roughness or undulation of a curved surface of an article having a curved surface in a short time. An object of the present invention is to provide a computer program for measuring surface properties applied to the surface texture measuring device.

  In order to achieve the above object, a feature of the present invention according to claim 1 is that, in a surface texture measuring device for measuring the roughness or undulation of the surface of the measurement object having a curved surface, a workpiece support means for supporting the measurement object , Using the workpiece imaging means for outputting contour captured image information obtained by imaging the contour of the curved surface of the measurement object supported by the workpiece supporting means, and the same contour using image information representing the contour portion of the curved surface included in the contour captured image information And an image processing means for calculating the surface roughness or undulation.

  In this case, for example, as shown in claim 2, the image processing means detects the edge of the object to be measured from the contour image information and obtains the measurement surface curve, and the measurement object using the measurement surface curve. It is good to provide the surface property calculation means which calculates the roughness or waviness of the surface of the outline in a thing.

  According to the characteristic of the present invention according to claim 1 configured as described above, the surface texture measuring device captures the contour of the curved surface of the object to be measured and acquires the contour captured image information, and the acquired contour captured image. Using the information representing the contour portion of the curved surface included in the information, the roughness or waviness of the surface of the contour is calculated. Thereby, the roughness or undulation of the curved surface of the object to be measured can be measured easily and accurately in a short time while suppressing the influence of external vibration transmitted to the surface texture measuring device.

  In another aspect of the present invention according to claim 3, in the surface texture measuring device, the image processing means further includes contour shape specifying means for specifying the contour of the object to be measured using the measurement surface curve, and measurement. Measurement surface curve correction means for correcting the measurement surface curve by removing the specified contour component from the surface curve, and the surface property calculation means uses the measurement surface curve corrected by the measurement surface curve correction means. The object is to calculate the roughness or waviness of the contour surface of the object to be measured.

  According to another aspect of the present invention according to claim 3 configured as described above, the surface texture measuring device specifies the contour of the object to be measured using the measurement surface curve obtained by detecting the edge of the object to be measured. In addition, the measurement surface curve is corrected by removing the shape component of the specified contour from the measurement surface curve. Thereby, the surface texture measuring apparatus can measure the surface roughness or the waviness surface texture by excluding the influence of the surface shape component of the object to be measured included in the change of the measurement surface curve. For example, when the contour shape of the curved surface of the object to be measured is an arc shape, the occupancy ratio of the roughness component or the swell component is improved by excluding the influence of the arc shape component from the measurement surface curve change. The roughness or undulation of the curved surface of the object to be measured can be measured by the measurement surface curve. Thereby, the measurement precision of surface property can be improved.

  According to another aspect of the present invention according to claim 4, in the surface texture measuring apparatus, the image processing means further extracts a roughness curve from the measurement surface curve corrected by the measurement surface curve correction means. A curve extracting means is provided, and the surface property calculating means is to calculate the roughness of the surface of the contour of the object to be measured using the roughness curve.

  According to another aspect of the present invention according to claim 4 configured as described above, the surface texture measuring device extracts a roughness curve from the corrected measurement surface curve to obtain the surface roughness of the contour of the object to be measured. Is calculated. That is, if the measurement surface curve that represents the surface roughness of the contour of the object to be measured includes noise and contour swell components during contour imaging in addition to the roughness component, the measurement surface curve that includes these components From this, only the roughness component representing the surface roughness of the contour of the object to be measured is extracted to calculate the surface roughness. In this case, for example, by using a low-pass filter (LPF) that removes noise components during contour imaging or a high-pass filter (HPF) that removes waviness components of the contour, the surface roughness of the contour is determined from the measured surface curve. The representing roughness component can be extracted. Thereby, the measurement precision of surface roughness can be improved.

  Another feature of the present invention according to claim 5 resides in that the surface texture measuring device further includes illumination means for irradiating light toward the imaging means via the contour of the object to be measured.

  According to another aspect of the present invention according to claim 5 configured as described above, the surface texture measuring apparatus includes an illuminating unit that irradiates light toward the imaging unit via the contour of the object to be measured. As a result, the brightness difference between the information representing the contour portion in the contour captured image information obtained by capturing the contour of the object to be measured and the information representing the other portion is clarified, so that the contour portion included in the contour captured image information is represented. Information can be extracted with high accuracy, and the roughness or undulation of the contour surface of the object to be measured can be calculated. Thereby, the measurement precision of surface property can be improved.

  According to another aspect of the present invention according to claim 6, in the surface texture measuring device, the display means for displaying the result of the roughness or swell of the contour surface of the measured object calculated by the image processing means. It is in having.

  According to another feature of the present invention according to claim 6 configured as described above, the surface texture measuring apparatus displays the result of the roughness of the contour surface of the measured object calculated by the image processing means. It has. Thereby, the operator who measures the surface texture of the curved surface of the object to be measured can visually recognize the measurement result of the surface texture early.

  In addition, the present invention can be implemented not only as an invention of a surface texture measuring device but also as an invention of a computer program for measuring surface roughness applied to the surface roughness measuring device.

  Specifically, for example, as shown in claim 7, the surface roughness or waviness of the curved surface is calculated using contour captured image information obtained by imaging the contour of the curved surface of a measurement object having a curved surface. A computer program for surface property measurement to be executed by a computer device, wherein the computer device uses an edge detection step for obtaining a measurement surface curve by detecting an edge of the object to be measured from contour image information, and using the measurement surface curve It is preferable to execute a surface property calculation step for calculating the roughness or waviness of the contour surface of the object to be measured.

  In this case, as shown in claim 8, in the computer program for surface property measurement, a contour shape specifying step for specifying a contour in the measurement object using the measurement surface curve, and the contour specified from the measurement surface curve A measurement surface curve correction step for correcting the measurement surface curve by removing the components of the measurement surface, and the surface property calculation step uses the measurement surface curve corrected by the measurement surface curve correction step. It is preferable to calculate the roughness or undulation of the surface.

  In this case, as shown in claim 9, the computer program for measuring surface properties further includes a roughness curve extraction step for extracting a roughness curve from the measurement surface curve corrected by the measurement surface curve correction step, In the surface property calculation step, the roughness of the surface of the contour of the object to be measured may be calculated using the roughness curve. Also by these, the same effect as the surface texture measuring device can be expected.

It is the block diagram which showed typically the whole structure of the surface texture measuring apparatus which concerns on one Embodiment of this invention. It is the top view which showed roughly the whole structure of the workpiece support stand shown in FIG. It is a flowchart of the surface property measurement program which the computer apparatus shown in FIG. 1 performs. It is explanatory drawing which shows the example of the captured image of the outline of the ball | bowl part which the imaging device shown in FIG. 1 imaged. (A), (B) is a figure for demonstrating the process of obtaining a measurement surface curve from the contour picked-up image information which an imaging device outputs, (A) is the process of detecting an edge from the picked-up image of the outline of a ball | bowl part. It is explanatory drawing shown typically, (B) is explanatory drawing which shows typically the process which removes and correct | amends the component regarding the contour shape of a ball | bowl part with respect to a measurement surface curve. It is explanatory drawing which shows typically the process in which the component regarding the outline shape of a ball | bowl part is removed and correct | amended with respect to a measurement surface curve. (A) is explanatory drawing which shows typically the example of the cross-sectional curve P, (B) is explanatory drawing which shows the example of the roughness curve R typically, (C) The example of the waviness curve W is shown. It is explanatory drawing shown typically.

  Hereinafter, an embodiment of a surface texture measuring device according to the present invention will be described with reference to the drawings. FIG. 1 is a block diagram schematically showing the overall configuration of a surface texture measuring apparatus 100 according to the present invention. Note that each drawing referred to in the present specification is schematically represented by exaggerating some of the components in order to facilitate understanding of the present invention. For this reason, the dimension, ratio, etc. between each component may differ. The surface texture measuring device 100 is a measuring device for measuring the roughness of the surface of an article having a curved surface, specifically, a ball portion 92 of a ball stud 90 constituting a ball joint (not shown).

  Here, the ball stud 90 which is a measurement target of the surface roughness in the surface texture measuring device 100 according to the present invention will be briefly described. The ball stud 90 is a machine that forms a ball joint (not shown) for movably connecting shaft-shaped components to each other in a suspension mechanism (suspension device) or a steering mechanism (steering device) in a vehicle such as an automobile. It is a part. The ball joint 90 mainly includes a cylindrical bearing seat in which a substantially spherical ball portion 92 formed at the tip of a shaft-shaped ball stud 91 is held in a bottomed cylindrical housing (not shown). (Not shown) is accommodated in a slidable state.

(Configuration of surface texture measuring apparatus 100)
The surface texture measuring apparatus 100 includes a workpiece support base 101. The work support base 101 is a jig for supporting the imaging device 102 (described later) in the tangential direction of the spherical surface of the ball stud 90 that is the target of surface roughness measurement. In the present embodiment, the workpiece support base 101 supports the ball stud 90 in a substantially horizontal state. The workpiece support base 101 has a concave portion 101b having a shape corresponding to the shape of one half along the axial direction of the ball stud 90 on the upper surface of the base portion 101a formed of a steel material in a rectangular parallelepiped shape, and the ball stud 90 in the concave portion 101b. Relief portions 101c for inserting the operator's hand when fitted are formed and configured. That is, the work support base 101 corresponds to the work support means according to the present invention.

  An imaging device 102 is provided above the ball portion 92 of the ball stud 90 set on the work support base 101. The imaging device 102 is an optical mechanical device for imaging a part of the contour of the ball portion 92 in the ball stud 90 set on the workpiece support base 101. The imaging device 102 is controlled by a computer device 110 to be described later, and images the contour of the ball portion 92 in the ball stud 90 from the tangential direction of the same contour, and the contour captured image representing the captured image of the captured contour of the ball portion 92. Information is output to the computer device 110. In the present embodiment, the imaging apparatus 102 is configured using a CCD (Charge Coupled Device) image sensor having a number of pixels of 1280 × 1024 pixels and a visual field of 3.2 mm (when using a double lens) as a light receiving element. That is, the imaging device 102 corresponds to a workpiece imaging unit according to the present invention.

  A backlight illumination device 103 is provided below the imaging device 102. The backlight illuminating device 103 is an illuminating device that irradiates light toward the imaging device 102 through the outline of the ball portion 92 of the ball stud 90 set on the work support base 101. The backlight illumination device 103 is controlled to be turned on / off by the computer device 110. In the present embodiment, the backlight illumination device 103 is configured with an LED that emits red visible light as a light source. That is, the backlight illumination device 103 corresponds to the illumination unit according to the present invention. As long as the backlight illumination device 103 is a light source that can accurately capture the contour of the ball portion 92 by the imaging device 102, the color to be emitted and the type of the light source itself are not limited.

  The computer device 110 is configured by a microcomputer including a CPU, ROM, RAM, hard disk, and the like, and performs imaging by executing the surface property measurement program shown in FIG. 3 in accordance with instructions from the input device 111 including a keyboard and a mouse. The operations of the device 102 and the backlight illumination device 103 are controlled. In addition, the computer device 110 includes a display device 112 formed of a liquid crystal display, and appropriately displays an operating state of the computer device 110, an execution state of the surface texture measurement program, an execution result, a captured image by the imaging device 102, and the like. That is, in the present embodiment, the computer apparatus 110 is assumed to be a personal computer for personal use (so-called personal computer).

(Operation of the surface texture measuring device 100)
The operation of the surface texture measuring apparatus 100 configured as described above will be described. First, an operator who measures the surface roughness of the ball portion 92 in the ball stud 90 operates the input device 111 of the computer device 110 to cause the computer device 110 to perform the surface roughness measurement process for the ball portion 92 of the ball stud 90. Is executed. In response to this instruction, the computer apparatus 110 starts execution of the surface property measurement program shown in FIG. 3 in step S100, and executes measurement preparation processing in step S102. Specifically, the computer device 110 controls the standby state in which the imaging device 102 and the backlight illumination device 103 are started to start imaging and lighting immediately.

  Next, in step S <b> 104, the computer apparatus 110 determines whether an instruction to end the surface roughness measurement process is input from the operator via the input apparatus 101. In this case, the computer apparatus 110 continues to determine “No” in this determination process until the operator gives an instruction to end the surface roughness measurement process, and proceeds to step S106. On the other hand, when the operator gives an instruction to end the surface roughness measurement process, the computer apparatus 110 determines “Yes” in this determination process and proceeds to step S122.

  Next, in step S <b> 106, the computer apparatus 110 determines whether or not an instruction to start the surface roughness measurement process is input from the operator via the input apparatus 101. In this case, the computer apparatus 110 continues to determine “No” in this determination process until the operator gives an instruction to start the surface roughness measurement process, and returns to step S104. On the other hand, when an instruction to start the surface roughness measurement process is input from the operator, the computer apparatus 110 determines “Yes” in this determination process and proceeds to step S108.

  That is, when there is a ball stud 90 that is machined and needs to be measured for surface roughness, the operator sets the ball stud 90 on the work support base 101 and then operates the input device 111 to operate the computer. The apparatus 110 is instructed to start the surface roughness measurement process. In this case, the operator fits the stud portion 91 of the ball stud 90 into the recess 101 a of the work support base 101. Accordingly, the ball stud 90 is supported by the work support base 101 in a state where the ball part 92 protrudes from the left side surface portion of the work support base 101 in the longitudinal direction and the end of the ball part 92 is positioned within the field of view of the imaging device 102. The

  Next, the computer apparatus 110 performs an imaging process in step S108. Specifically, the computer device 110 controls the operations of the imaging device 102 and the backlight illumination device 103, respectively, so that the contour of the ball portion 92 of the ball unit 92 is synchronized with the light emission of the backlight illumination device 103. Image capture is executed. As a result, as shown in FIG. 4, the contour of the ball portion 92 in the ball stud 90 is imaged, and contour captured image information representing the captured image is output to the computer device 110. 4 and 5, the captured image of the ball portion 92 is denoted by the same reference numeral as that of the ball portion 92, and “OL” is appended to the captured image of the contour of the ball portion 92.

  In this case, the captured image of the ball portion 92 represented by the contour captured image information is represented by gray processing. That is, the captured image of the ball part 92 represented by the contour captured image information is represented by a gray value in a gray scale of 0 (white) to 255 (black). Specifically, the captured image of the ball part 92 is captured. Due to the illumination by the backlight illumination device 103 at the time, the outer portion of the ball portion 92 is represented by a light gray value close to white, and the ball portion 92 is represented by a dark gray value close to black.

  Next, the computer apparatus 110 performs an edge detection process in step S110. The edge detection process in step S110 is a process for detecting and specifying a portion representing the contour of the ball portion 92 represented by the contour captured image information. This edge detection process is an edge detection process in the prior art, that is, specifies a pixel (also referred to as “pixel”) in which the luminance (brightness of the image) in the contour captured image information changes sharply. More specifically, as shown by a broken line arrow in FIG. 5A, the computer apparatus 110 shows contour captured image information representing a ball portion 92 having a high gray value for each 1280 pixels in the illustrated horizontal direction in the contour captured image information. A pixel whose luminance changes discontinuously toward the outermost pixel of the contour captured image information representing the outside of the ball portion 92 having a low gray value from the outermost pixel is detected and specified. As a result, as shown in FIG. 5B, a measurement surface curve SL composed of 1280 pixel groups representing the contour of the ball portion 92 is obtained. That is, the edge detection process in step S110 corresponds to the edge detection means according to the present invention. In FIG. 5B, the pixel group constituting the measurement surface curve SL is shown roughly (less).

  Next, the computer apparatus 110 performs a contour shape specifying process in step S112. The contour shape specifying process in step S112 is a process for specifying the contour shape of the ball portion 92 in order to remove the component related to the contour shape of the ball portion 92 from the measurement surface curve SL. Specifically, the computer apparatus 110 calculates an arc constituting the contour of the ball portion 92 by the least square method using the measurement surface curve SL, and calculates the center position CP of the arc. That is, the contour shape specifying process in step S112 corresponds to the contour shape specifying means according to the present invention.

  Next, the computer apparatus 110 performs the correction process of the measurement surface curve SL in step S114. The contour shape specifying process in step S114 is a process for removing components related to the contour shape of the ball portion 92 from the measurement surface curve SL. Specifically, the computer device 110 calculates the distance of each pixel constituting the measurement surface curve SL with respect to the center position CP of the arc constituting the contour of the ball portion 92 calculated in step S112. Then, the computer apparatus 110 arranges the pixels constituting the measurement surface curve SL along the reference BL line at positions separated from the calculated center position CP from the common base line BL. Thereby, as shown in FIG. 6, the component regarding the outline shape of the ball | bowl part 92 is removed from measurement surface curve SL. That is, the correction process of the measurement surface curve SL in step S114 corresponds to the measurement surface curve correction unit according to the present invention.

  Next, the computer apparatus 110 performs a roughness curve extraction process in step S116. The roughness curve extraction process in step S116 is a process for extracting a component relating to the roughness of the contour surface of the ball portion 92 from the measurement surface curve SL. That is, in the measurement surface curve SL representing the contour portion of the ball portion 92, in addition to the component representing the arc-shaped contour of the ball portion 92, the component relating to the surface roughness of the contour of the ball portion 92 and the contour surface of the ball portion 92 Ingredients related to swell are included. In addition to the components related to the contour shape of the ball portion 92, the measurement surface curve SL representing the contour portion of the ball portion 92 includes components caused by the imaging processing by the imaging device 102, specifically various noise components. It is included. Therefore, in the roughness curve extraction process in step S116, only the component related to the surface roughness of the contour of the ball portion 92 is extracted from the measured surface curve SL including the component related to the surface roughness, the component related to the waviness, and the component related to the noise. To do.

  Specifically, the computer apparatus 110 performs a filtering process that allows only a specific frequency component to pass through the measurement surface curve SL. More specifically, the computer apparatus 110 uses a λs contour curve filter that is a low-pass filter (low-pass filter) that cuts (cuts off) a short wavelength component shorter than the cutoff value λs (2.5 to 25 μm). A λc contour curve filter that is a high-pass filter (high-pass filter) that removes a noise component from the measurement surface curve SL and cuts (blocks) a long wavelength component longer than the cutoff value λc (0.08 to 8 mm) is used. To remove the waviness component from the measured surface curve SL.

  That is, the computer apparatus 110 extracts only the component related to the surface roughness of the contour of the ball portion 92 from the measurement surface curve SL by the band pass filter having the cutoff values λs to λc as the pass band. By removing the noise component from the measurement surface curve SL, a cross-sectional curve P is obtained as shown in FIG. 7A. By removing the waviness component from the cross-sectional curve P, the process shown in FIG. As shown, a roughness curve R is obtained. That is, the roughness curve extraction process in step S116 corresponds to the roughness curve extraction means according to the present invention.

  Next, the computer apparatus 110 calculates the roughness of the contour surface of the ball portion 92 in step S118. Specifically, the computer device 110 calculates the average of the sum of the peak height and the valley depth for each reference length within the evaluation length of the roughness curve R in the roughness curve R calculated in step S116. It is calculated as the roughness of 92 contour surfaces. That is, in the present embodiment, the length of the roughness curve R imaged by the imaging device 102 (that is, the field of view of the imaging device 102) is 3.2 mm, so the evaluation length of the roughness curve R is 3. 2 mm. On the other hand, the reference length is set to 0.8 mm because the feed amount (cutting pitch) of the cutter when the ball portion 92 is cut by cutting is 0.8 mm / rev. In other words, one peak and one valley exist within the standard length of 0.8 mm.

  Therefore, the controller apparatus 110 calculates the sum of the peak height and the valley depth for each reference length of 0.8 mm with respect to the roughness curve R of the evaluation length of 3.2 mm, and calculates the average value of this sum. (In this embodiment, the total sum is divided by 4). That is, the contour surface roughness calculation process in step S118 corresponds to the surface roughness calculation means according to the present invention. Note that such a method for calculating the surface roughness is different from the method for calculating the surface roughness in the current JIS standard (Japanese Industrial Standard). However, according to experiments by the present inventors, the surface roughness value calculated by the surface roughness calculation method in this embodiment and a contact-type surface roughness measuring machine (not shown) according to JIS standards. The correlation coefficient with the surface roughness measurement result of the ball part 92 in the ball stud 90 is about 0.96.

The contour surface roughness calculation process in step S118 is different from the surface roughness calculation method in the current JIS standard (Japanese Industrial Standard) as described above. However, in the calculation processing of the roughness of the contour surface in step S118, the calculation method of the surface roughness in JIS standard (Japanese Industrial Standard) is not excluded. That is, the contour surface roughness calculation process in step S118 may be performed by calculating parameters that can evaluate the contour surface roughness of the ball portion 92. For example, the ten-point average roughness Rz _jis , the arithmetic average roughness Of course, it may be Ra, square root roughness Rq, centerline average roughness Ra75, maximum height roughness Rz, and the like.

Next, the computer apparatus 110 displays the pass / fail judgment result of the roughness of the contour surface of the ball portion 92 in step S120. Specifically, the computer apparatus 110 calculates the 10-point average roughness Rz _jis calculated in step S118 by comparing with the evaluation 10-point average roughness Rz _jis preset in the surface roughness measurement program. If the ten-point average roughness Rz _jis is less than the evaluation ten-point average roughness Rz _jis , the display device 112 displays the word “pass” on the assumption that the surface roughness of the ball portion 92 is within the reference value. . On the other hand, when the calculated ten-point average roughness Rz _jis is equal to or greater than the evaluation ten-point average roughness Rz _jis , the computer device 110 determines that the surface roughness of the ball portion 92 is outside the reference value on the display device 112 Display the word “Fail”.

  Therefore, the operator determines “good” or “bad” of the ball stud 90 as the measurement target according to the display content displayed on the display screen of the display device 112. According to the experiments by the present inventors, the time from the instruction to start the surface roughness measurement process by the operator in step S106 to the pass / fail determination display in step S120 is about 1 second. This is much faster than the response time of about 55 seconds by the contact-type surface roughness measuring device according to the prior art. Further, the current JIS standard (Japanese Industrial Standard) stipulates that the surface roughness measuring machine is a contact type. However, the surface roughness measurement result of the ball portion 92 in the ball stud 90 by the surface texture measuring device 100 according to the present invention and the ball stud 90 by a contact type surface roughness measuring machine (not shown) according to JIS standard. The correlation coefficient with the measurement result of the surface roughness of the ball portion 92 is about 0.96 as described above. That is, the surface texture measuring apparatus 100 according to the present invention has a measurement accuracy substantially the same as that of a contact-type surface roughness measuring machine according to JIS standards.

  After executing the display processing of the pass / fail determination result of the contour surface roughness of the ball portion 92 in step S120, the computer apparatus 110 returns to step S104. Thereby, the computer apparatus 110 again waits for an instruction to end the surface roughness measurement work and an instruction to start the surface roughness measurement process. When the operator finishes the surface roughness measurement work of the ball stud 90, the operator operates the input device 111 to instruct the computer device 110 to end the surface roughness measurement process. In response to this instruction, the computer apparatus 110 determines “Yes” in the determination process of step S104 and proceeds to step S122. Next, in step S122, the computer apparatus 110 stops the measurement end processing, specifically, the operations of the imaging apparatus 102 and the backlight illumination apparatus 103, respectively. In step S124, the computer apparatus 110 ends the execution of the surface texture measurement program.

  As can be understood from the above operation, according to the above embodiment, the surface texture measuring device 100 captures the contour of the ball portion 92 in the ball stud 90 that is the object to be measured and acquires contour captured image information, The surface roughness of the contour is calculated using information representing the contour portion of the ball portion 92 included in the acquired contour captured image information. Thereby, the surface roughness of the ball portion 92 in the ball stud 90 can be measured easily and accurately in a short time while suppressing the influence of external vibration transmitted to the surface texture measuring device 100.

  Furthermore, in carrying out the present invention, the present invention is not limited to the above embodiment, and various modifications can be made without departing from the object of the present invention. In addition, in each modification shown below, the code | symbol corresponding to the same component as said each embodiment is attached | subjected, and the description is abbreviate | omitted.

  For example, in the above-described embodiment, the surface texture measuring device 100 represents the contour captured image information obtained by capturing the contour of the ball portion 92 in the ball stud 90 by gray processing, and represents the gray value of 256 gradations. However, the contour captured image information is not necessarily limited to the above-described embodiment as long as it is image data obtained by capturing the contour of the ball portion 92 and data in a format that can identify the contour in the edge processing. For example, the contour captured image information may be constituted by monochrome image information composed of binary information of white and black, or may be composed of color image information composed of RGB.

  Moreover, in the said embodiment, the surface texture measuring apparatus 100 comprised the imaging device 102 with the CCD image sensor. However, the imaging device 102 can be widely used as long as it is an optical element that outputs an electrical signal corresponding to the image formed on the light receiving surface to the computer device 140. For example, the imaging device 102 can be configured using various imaging elements such as a CMOS (Complementary Metal Oxide Semiconductor) image sensor in addition to the CCD image sensor.

  In the above embodiment, the surface texture measuring device 100 includes the backlight illumination device 103 that emits light toward the imaging device 102. However, the backlight illuminating device 103 makes it easy to detect the edge by increasing the difference in brightness in the edge detection processing in step S110 in the surface property measurement program, and obtains the measurement surface curve SL with high accuracy. That is, the backlight illumination device 103 (illuminating means) is not necessarily required as long as the measurement surface curve SL can be obtained with high accuracy. For example, instead of the backlight illuminating device 103, a plate body configured with a color (for example, black) in which a difference in brightness with the metal color of the ball stud 90 is clear may be arranged. The imaging device 102 may be provided with a flash device such as a flash. When the backlight illumination device 103 is provided, it may be a light source that emits light other than infrared light, such as a fluorescent lamp, an incandescent lamp, an LED illumination, or a halogen lamp.

  Moreover, in the said embodiment, in order to display the surface roughness measurement result of the ball stud 90, the display apparatus 112 was comprised with the liquid crystal display. However, the display device 112 is not necessarily limited to the above embodiment as long as the operator can recognize the surface roughness measurement result of the ball stud 90. For example, the display device 112 can be configured by a rotating device or a printing device that prints measurement result information instead of or in addition to a liquid crystal display. In addition to visual display means such as the display device 112, the measurement result may be displayed with a sound such as a buzzer.

  In the above-described embodiment, in the surface property measurement program, components related to the contour shape of the ball portion 92 are removed from the measurement surface curve SL by executing the processes of step S112 and step S114. However, the processing for removing the component related to the contour shape of the ball portion 92 from the measurement surface curve SL is performed when the shape along the measurement direction of the surface roughness of the object to be measured is a linear shape, for example, an outer periphery of a cylinder or a cylindrical shape. When the surface roughness of the surface is measured along the axial direction, it can be omitted.

  In the above embodiment, in the surface texture measurement program, the roughness curve R extraction process is executed in step S118. However, the process of extracting the roughness curve R is not always necessary when the noise component and the undulation component can be ignored from the measurement surface curve SL and the cross-sectional curve P. That is, the surface roughness of the contour of the ball portion 92 may be calculated using the measurement surface curve SL and the cross-sectional curve P as the roughness curve R.

  In the above embodiment, in the surface texture measurement program, the roughness curve R extraction process is executed in step S118. However, the surface texture measurement program may measure the waviness state of the contour shape of the ball portion 92 instead of or in addition to the process of extracting the roughness curve R in step S118. Specifically, the computer apparatus 110 uses a λs contour curve filter that is a low-pass filter (low-pass filter) that cuts (cuts off) a short wavelength component shorter than the cutoff value λc (0.08 to 8 μm). A high-pass filter that removes noise components and roughness components from the surface curve SL and cuts (cuts off) long wavelength components longer than the cutoff value λf (n × λf (n = number of reference lengths)) ( A frequency component longer than the waviness component is removed from the measurement surface curve SL using a λf contour curve filter which is a high-pass filter.

  That is, the computer apparatus 110 extracts only the component related to the undulation of the contour of the ball portion 92 from the measurement surface curve SL by the band pass filter having the cutoff values λc to λf as the pass band. By the process of extracting the undulation component from the measurement surface curve SL, the computer apparatus 110 obtains the filtered undulation curve W as shown in FIG. Thereby, the state of the waviness of the contour shape of the worker and the ball portion 92 can be measured.

  In the above embodiment, the surface texture measuring apparatus 100 uses the ball stud 90 as the object to be measured. However, the surface texture measuring apparatus 100 according to the present invention can widely measure any object to be measured having a curved surface. For example, it is possible to measure the roughness and undulation of the surface of a cylindrical body or columnar body having a curved surface, and a spherical body having a spherical surface.

SL: measurement surface curve, P: cross section curve, R: roughness curve, W: filtered wave curve,
90 ... ball stud, 91 ... stud part, 92 ... ball part,
DESCRIPTION OF SYMBOLS 100 ... Surface texture measuring device 101 ... Work support stand 102 ... Imaging device 103 ... Backlight illumination device 110 ... Computer device 111 ... Input device 112 ... Display device

Claims (9)

In the surface texture measuring device for measuring the roughness or undulation of the surface of the object having a curved surface,
Workpiece support means for supporting the object to be measured;
Workpiece imaging means for outputting contour captured image information obtained by imaging the contour of the curved surface of the object to be measured supported by the workpiece support means;
An image processing means for calculating roughness or undulation of the surface of the contour using image information representing the contour portion of the curved surface included in the contour captured image information. In the surface texture measuring apparatus according to claim 1,
The image processing means includes
Edge detection means for detecting the edge of the object to be measured from the contour image information and obtaining a measurement surface curve;
A surface texture measuring device comprising: a surface texture calculating means for calculating roughness or waviness of the surface of the contour of the object to be measured using the measurement surface curve. In the surface texture measuring apparatus according to claim 2,
The image processing means further includes
Contour shape specifying means for specifying the contour of the object to be measured using the measurement surface curve;
Measurement surface curve correction means for correcting the measurement surface curve by removing the identified contour component from the measurement surface curve,
The surface texture calculation unit calculates the roughness or waviness of the surface of the contour of the object to be measured using the measurement surface curve corrected by the measurement surface curve correction unit. . In the surface texture measuring apparatus according to claim 3,
The image processing means further includes
A roughness curve extracting means for extracting a roughness curve from the measured surface curve corrected by the measured surface curve correcting means,
The surface texture calculating device calculates the roughness of the contour surface of the object to be measured using the roughness curve. The surface texture measuring device according to any one of claims 1 to 4, further comprising:
An apparatus for measuring surface texture, comprising: illumination means for irradiating light toward the imaging means through the contour of the object to be measured. In the surface texture measuring device according to any one of claims 1 to 5, further,
A surface texture measuring apparatus comprising: display means for displaying a result of surface roughness or undulation of the contour of the object to be measured, calculated by the image processing means. A computer program for measuring surface properties that is executed by a computer device that calculates the roughness or undulation of the surface of the curved surface using contour captured image information obtained by imaging the contour of the curved surface of a measurement object having a curved surface. ,
In the computer device,
An edge detection step of obtaining a measurement surface curve by detecting an edge of the object to be measured from the contour captured image information;
A computer program for measuring a surface property, comprising: executing a surface property calculating step of calculating a surface roughness or undulation of the contour of the object to be measured using the measurement surface curve. The computer program for measuring surface properties according to claim 7, further comprising:
A contour shape identifying step for identifying the contour of the object to be measured using the measurement surface curve;
A measurement surface curve correction step for correcting the measurement surface curve by removing the identified contour component from the measurement surface curve,
In the surface property calculation step, the surface roughness or waviness of the contour of the object to be measured is calculated using the measurement surface curve corrected by the measurement surface curve correction step. Computer program for property measurement. The computer program for measuring surface properties according to claim 8, further comprising:
A roughness curve extraction step for extracting a roughness curve from the measurement surface curve corrected by the measurement surface curve correction step;
The computer program for measuring surface properties, wherein the surface property calculating step calculates the surface roughness of the contour of the object to be measured using the roughness curve.

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