JP2006337108A - Worked surface evaluator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a non-contact type worked surface evaluator for giving a highly reliable measurement result, having no restraint imposed thereon as to a measuring object, and moreover, being used for evaluating roughness, etc. of a member surface in a relatively short period of time. <P>SOLUTION: This evaluator is equipped with: a light source for substantially vertically projecting light from a back surface of a replica, which corresponds to a surface reverse to a reflective surface, toward the reflective surface, with the replica having the reflective surface for reflecting the conditions of the worked surface; a microscope for receiving, by its light receiving surface, transmitted light projected and transmitted by the replica; a domain/shape determination part 501 for determining a domain where transmitted light of intensity not less than a prescribed value reaches out of a domain where transmitted light reaches on the receiving surface; and a roughness determination part 503 for determining the roughness of the worked surface based on the domain of the receiving surface determined by the determination part 501. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a machined surface evaluation apparatus that evaluates the surface of a machined object, and more particularly to a machined surface evaluation apparatus that evaluates a machined surface in a non-contact manner.

Currently, in the field of machining and the like, the surface of metal parts is polished. The state of the metal part surface affects the performance and appearance of the finished machine. For this reason, higher processing accuracy is required for the accuracy of polishing processing.
By the way, as the processing accuracy of polishing increases, the technique for measuring the state of the polished surface (processed surface) also tends to increase in accuracy. Many of the current measurement techniques measure the scale of unevenness as roughness, and the main measurement methods include contact-type roughness measurement with a stylus on the processing surface, optical interference and optical cutting. There is a non-contact type roughness measurement method used.

In the roughness measurement, a sample member called a replica that reproduces the unevenness of the processed surface is sometimes measured instead of directly measuring the processed surface. Such a measuring method is called a replica measuring method, and is often applied to the case of measuring a processed surface of a structure or a large part.
Generally, a replica reproduces a processed surface by transferring the processed surface. For this reason, the reproduced surface has irregularities obtained by inverting the irregularities of the base processing surface. If there is a problem in measuring the surface of the processed surface with the irregularities reversed, the replica surface may be further transferred to create a measurement sample, and this surface may be measured by a contact or non-contact method.

As a conventional technique for measuring the surface roughness by the replica method, for example, Patent Document 1 is cited. Further, Patent Document 2 describes that a replica is created in order to inspect a defect at a rotor assembly position of a turbine blade, and a replica surface is measured by a non-contact measurement method using laser light.
Japanese Patent Laid-Open No. 5-220811 JP 2003-294716 A

  However, in the roughness measurement method using a stylus, the measurement accuracy changes depending on the pressure applied by the needle to the surface, and the measurement accuracy tends to increase when a relatively high pressure is applied. However, depending on the pressure, the surface may be damaged, and there is a risk that accurate roughness cannot be measured. In addition, the roughness measurement method using a stylus has a drawback in that it takes a relatively long time to measure because the height needs to be measured at a plurality of consecutive points in order to measure the roughness.

The roughness measurement method using light cutting can measure the surface roughness to about μm depending on the projection method of the slit light to be irradiated. However, in such a measurement method, the measurement accuracy varies depending on the projection angle of the slit light, and thus there may be cases where a measurement value with sufficient reliability cannot be obtained.
Furthermore, in the roughness measurement method using optical interference, the surface to be measured is preferably a member having a roughness of 1 μm or less and a relatively high reflectance. For this reason, the material of the measurement object and the replica are limited.
The present invention has been made in view of the above-described points. High reliability is obtained in the measurement results, the measurement target is not limited, and the state of the member surface is set within a relatively short time. An object of the present invention is to provide a non-contact type processing surface evaluation apparatus that can be evaluated.

  In order to solve the above problems, the machined surface evaluation apparatus according to claim 1 uses a substantially transparent sample member having a reflecting surface that reflects the state of the machined surface of the object to be evaluated, and the state of the machined surface. And a light irradiating means for irradiating the sample member with light substantially perpendicularly from the back surface corresponding to the surface opposite to the reflecting surface to the reflecting surface, and irradiating with the light irradiating means. A light receiving means for receiving the transmitted light transmitted through the sample member at a light receiving surface, and a range of transmitted light having a strength greater than or equal to a predetermined intensity in a range in which the transmitted light spreads on the light receiving surface of the light receiving means. Roughness determining means for determining the roughness of the processed surface on the basis thereof.

  According to such an invention, light is irradiated substantially perpendicularly from the back surface of the reflecting surface that reflects the state of the processed surface, so that adjustment and setting of the light irradiation direction and the like are simplified, and the reliability of the measurement result is increased. Can do. In addition, the transmitted light that has been irradiated and transmitted through the reflecting surface is received by the light receiving surface, and the roughness of the processed surface is determined based on the range in which the received transmitted light spreads. It is possible to provide a machined surface evaluation apparatus that can evaluate the roughness of the surface of a member machined in a relatively short period of time without being restricted, and can evaluate the roughness without contact.

  Further, the machined surface evaluation apparatus according to claim 2 uses a substantially transparent sample member having a reflecting surface that reflects the machined surface state of the object to be evaluated, and machined surface evaluation for evaluating the machined surface state. A light irradiating means for irradiating the sample member with light substantially perpendicularly from the back surface, which is the surface opposite to the reflecting surface, to the reflecting surface; A light receiving unit that receives the transmitted light through the light receiving surface; and a surface shape determining unit that determines the shape of the unevenness of the processing surface based on the shape of the range in which the transmitted light spreads on the light receiving surface of the light receiving unit. It is characterized by.

  According to such an invention, light is irradiated substantially perpendicularly from the back surface of the reflecting surface that reflects the state of the processed surface, so that adjustment and setting of the light irradiation direction and the like are simplified, and the reliability of the measurement result is increased. Can do. In addition, since the transmitted light that has passed through the reflecting surface after being irradiated is received by the light receiving surface, and the unevenness of the processed surface is determined based on the shape of the range in which the received transmitted light spreads, the reflectance of the measurement target In addition, it is possible to provide a machined surface evaluation apparatus that is capable of non-contacting evaluation of the unevenness state of the surface of a member that is processed within a relatively short time without being limited by the surface condition.

Further, the machined surface evaluation apparatus according to claim 3 has machining method information indicating in advance the shape of the range in which transmitted light spreads on the light receiving surface of the light receiving unit and the machining method in association with each other, and the surface shape determining unit Comprises a processing method determining means for determining a processing method for processing the processed surface by comparing the shape of the range in which transmitted light spreads on the light receiving surface of the light receiving means and the processing method information.
According to such an invention, the method of processing the member surface can be automatically determined by comparing the shape of the range in which the transmitted light spreads with the processing method information.

According to a fourth aspect of the present invention, there is provided the machined surface evaluation apparatus previously having roughness information that associates a range in which the transmitted light spreads on the light receiving surface of the light receiving unit with roughness, and the transmitted light is transmitted on the light receiving surface of the light receiving unit. Roughness determination means for determining the roughness of the processed surface by comparing the expanded range with the roughness information is provided.
According to such an invention, since the roughness of the processed surface is determined based on the range in which the transmitted light that has been received spreads, there is no limitation on the reflectance or surface condition of the measurement target, and it is relatively short. The roughness which is the state of the surface of the member processed over time can be evaluated without contact.

  The processing surface evaluation apparatus according to claim 5, wherein the roughness information is information for associating a range in which transmitted light spreads on a light receiving surface of the light receiving unit with a roughness for each processing method. The determining means determines the roughness of the processing surface by comparing the roughness information corresponding to the processing method determined by the processing method determining means with a range in which transmitted light spreads on the light receiving surface of the light receiving means. Characterize

The processing surface evaluation apparatus according to claim 6, wherein the roughness information includes a range in which transmitted light having an intensity greater than or equal to a predetermined value in a range in which transmitted light spreads on a light receiving surface of the light receiving unit. The roughness determination unit is configured to correlate the range in which transmitted light having an intensity equal to or greater than the predetermined value spreads on the light receiving surface of the light receiving unit against the roughness information. The roughness is determined.
According to such an invention, transmitted light having a predetermined intensity or less can be excluded from the information for determining the roughness of the processed surface. For this reason, the influence which disturbance light etc. have on roughness determination can be reduced, and the reliability of roughness determination can be improved.

The processing surface evaluation apparatus according to claim 7, wherein the light irradiation unit irradiates spot light having a substantially uniform intensity distribution on the reflection surface of the irradiation light.
According to such an invention, characteristics such as the intensity distribution of the irradiated light are not affected by the measurement result, and the state of the processed surface can be accurately evaluated.

The processing surface evaluation apparatus according to claim 8, wherein the sample member reflects a surface obtained by further transferring a surface obtained by transferring the processing surface or a surface obtained by transferring the processing surface. It is characterized by being a replica.
According to such an invention, it is possible to evaluate a target surface that cannot be measured by bringing a processing surface evaluation device into the site of a structure or the like using a replica that accurately reproduces the shape of the processing surface. In addition, when a replica obtained by further transferring a surface obtained by transfer is used, the processed surface can be evaluated using a replica that accurately reproduces the left / right / upper / lower relationship of the unevenness of the processed surface.

Embodiments 1 and 2 of the machined surface evaluation apparatus according to the present invention will be described below with reference to the drawings.
(Embodiment 1)
1 and 2 are diagrams for explaining the basic measurement principle of the processing surface evaluation apparatus according to the first embodiment. FIG. 1 is a diagram for explaining the basic configuration, and FIG. FIG. 2 is a diagram for explaining a phenomenon that occurs in the configuration shown in FIG.
The configuration shown in FIG. 1 includes the screen 105, the replica 104 installed at a predetermined distance L from the screen 105, the He—Ne laser 103 for irradiating the replica 104 with light, and the light transmitted through the replica 104. The digital camera 101 shoots the light reception state on the screen 105. In such a configuration, the rear surface of the replica 104 is irradiated with light and transmitted, and the state of the processed surface of the object is evaluated.

The replica 104 is a substantially transparent sample member having a surface that reflects the state of the processing surface of the object, and has a surface (reflection surface) 104a that reflects the state of the processing surface of the object, and a back surface 104b. ing. The replica 104 is substantially transparent, and the surface of the back surface 104b is a flat surface except for the example shown in FIG. Details of the replica 104 will be described later.
When the replica 104 is irradiated with the spot light Ps using the He—Ne laser 103 as a light source from the back surface 104b of the replica, the spot light Ps is transmitted through the replica 104 from the back surface 104b toward the reflecting surface 104a. Then, as shown in FIG. 2, the transmitted light Pt is generated by diffusing or partially scattering on the reflecting surface 104a. The transmitted light Pt forms an image on the screen 105 serving as a light receiving surface. FIG. 3 shows an example in which an image formed by the transmitted light Pt on the screen 105 is taken by the digital camera 101.

When the reflecting surface 104b is a diffraction grating, as shown in FIG. 2, the angle β at which the transmitted light Pt is emitted is expressed by the following equation (1). Moreover, Formula (2) is materialized by Snell's law. Expression (3) is established by Expression (1) and Expression (2). According to Expression (3), it is understood that the incident light incident on the replica 104 becomes light having a wavelength λ having an angle β and an intensity depending on the cross-sectional shape of the groove of the diffraction grating.
Sain β = mλ / d Equation (1)
(Sainβ = Nmλ / d)
n · Sain θβ = Sain (θβ + β) Equation (2)
θβ = tan (Nmλ / (n− (1- (Nmλ) ² ) ^1/2 ) Equation (3)
However,
β: angle formed by diffracted light and diffraction grating normal line N: number of diffraction gratings per 1 mm m: diffraction order (m = 0, ± 1, 2,...)
λ: wavelength of spot light n: refractive index of replica θβ: blaze angle

  The replica 104 of the first embodiment is a substantially transparent flat plate member made of silicon having a thickness of 20 mm, and the back surface 104b and the reflecting surface 104a are along the direction of the arrow A shown in FIG. And has a long rectangular shape. In the first embodiment, the direction indicated by the arrow A in the following description is referred to as the vertical direction of the replica 104, and the direction orthogonal to the arrow A is referred to as the side of the replica 104. The replica 104 shown in FIG. 2 has a sawtooth groove (blazed diffraction grating) in the horizontal direction on the reflecting surface 104a.

  3A, 3 </ b> B, 3 </ b> C, and 3 </ b> D, the state of the transmitted light Pt obtained when the reflecting surface of the replica 104 a is irradiated with the spot light Ps depends on the shape of the reflecting surface 104 a. It is the figure which showed that. FIG. 3A shows transmitted light Pt obtained when the back surface 104b and the reflecting surface 104a of the replica 104 are both smooth surfaces. The light transmitted through the smooth reflecting surface 104a has a circular cross section perpendicular to the traveling direction of the zero-order light shown in FIG.

  FIG. 3B shows the transmitted light Pt obtained when the spot light Ps is applied to the replica having the smooth back surface 104b and the reflecting surface 104a having a lateral groove. Further, (c) is obtained when the rear surface 104b and the reflecting surface 104a both have grooves, and the spot light Ps is irradiated to the replica in which the vertical and horizontal directions of the grooves are different between the rear surface 104b and the reflecting surface 104a. The transmitted light Pt, (d) shows the transmitted light Pt obtained when the spot light Ps is irradiated onto a replica having a smooth back surface 104b and a reflecting surface 104a having a longitudinal groove.

  According to the example shown in FIG. 3, it can be seen that the transmitted light Pt forms a long image in a direction orthogonal to the direction of the groove on the back surface 104b or the reflecting surface 104a. The inventors of the present invention determine the roughness of the processed surface based on the range in which the light transmitted through the reflecting surface 104a spreads on the light receiving surface using the above points, and the shape of this range on the light receiving surface. Based on this, the shape of the unevenness on the processed surface (irregular shape) is determined. In addition, uneven | corrugated shape shall mean the presence or absence of the groove | channel on the processing surface, and the direction where a groove | channel extends, for example.

  As described above, the shape of the light receiving range of transmitted light reflects the shape of fine irregularities on the processed surface. Further, the irregularities on the surface of the processed metal or the like often have different shapes depending on the processing method. The inventors of the present invention pay attention to this point, and store data indicating the shape of the light receiving range indicating the uneven shape of the processed surface processed by a predetermined processing method. Then, the processing surface evaluation apparatus according to the first embodiment is used to determine the processing method for processing the processing surface on which the replica is based, by comparing the light receiving range of the transmitted light transmitted through the replica to be evaluated with the stored data. Configured.

  FIG. 4 is a diagram for explaining the configuration of the machined surface evaluation apparatus according to the first embodiment. The processed surface evaluation apparatus irradiates the replica 104 with light from a light source 403 that irradiates light perpendicularly (incidence angle 0) from the back surface 104b and the light source 403, passes through the replica 104, and reflects from the reflecting surface 104a. A microscope 108 is provided as a light receiving means for receiving the emitted transmitted light. The light source 403 irradiates spot light having a uniform intensity distribution on the reflection surface 104a, and for example, a laser light source can be used. Further, the microscope 108 includes a light receiving surface 108a made of an image pickup device such as a CCD (Charge Coupled Device), and the transmitted light is received by the light receiving surface 108a.

In the first embodiment, a light emitting red diode (λ = 660 nm) having a diameter of 0.5 mm is used as the light source 403. The microscope 108 captures an image formed by the received transmitted light at a magnification of 50 times. In the first embodiment, the distance L between the reflecting surface 104a and the microscope 108 is 90 mm.
The processing surface evaluation apparatus according to the first embodiment includes a personal computer (PC) 109. The PC 109 is a surface shape determining unit that determines the shape of the unevenness of the processed surface based on the shape of the range in which the transmitted light spreads on the light receiving surface 108a of the microscope 108. It functions as a roughness determination means for determining the roughness of the processed surface based on the range of transmitted light having an intensity equal to or greater than the intensity of.
In the first embodiment, the PC 109 controls the entire processing surface evaluation apparatus, and the PC 109 outputs a control signal to the light source 403 so that the light source 403 is turned on / off.

  FIG. 5 is a functional block diagram for explaining the configuration of the PC 109. As shown in the figure, the PC 109 includes a range / shape determination unit 501 that determines the shape of a range where transmitted light spreads on the light receiving surface 108a. The range / shape determination unit 501 receives the image data dp of the image of the replica 104 to be evaluated, which is captured by the microscope 108, specifies the light reception range of transmitted light based on the image data dp, and determines the shape of the range. It is the structure which determines.

In the first embodiment, the image data dp is directly input to the display control unit 504 together with the range / shape determination unit 501, and is displayed on the display 109a as an analysis image.
The light receiving range of the transmitted light can be acquired by, for example, counting the bright spots that indicate the transmitted light or determining the area occupied by the bright spots. In the first embodiment, when calculating the light receiving range, only bright spots having an intensity of a predetermined value or more on the light receiving surface 108a are used for counting or calculating the area, and transmitted light having an intensity of a predetermined value or more spreads. The range is the light receiving range. In the first embodiment, the luminance of 200 or more is set as a predetermined value in the display 109a.

  Further, the PC 109 includes a processing method determination unit 502 that determines a processing method for processing the processing surface that is the basis of the replica based on the result of the comparison by the range / shape determination unit 501. The processing surface evaluation apparatus according to the first embodiment includes processing method data 505 corresponding to, for example, the graph shown in FIG. . The processing method data 505 is data measured in advance by the processing surface evaluation apparatus of the first embodiment, and is stored in the processing surface evaluation apparatus prior to evaluation of the processing surface. The machining data 505 of the first embodiment includes machining method data 505a to 505g for a plurality of machining methods such as lapping and electric discharge machining, for example.

  The processing method determination unit 502 is configured to sequentially read the processing method data 505a to 505g and contrast the shape of the light receiving range determined by the range / shape determination unit 501 with the processing method data 505a to 505g. Then, as a result of the comparison, when the processing method data that matches the shape of the light receiving range is specified, the replica 104 is created based on the processing surface processed by the processing method corresponding to the specified processing method data. Judge that it is.

The data comparison in the processing method determination unit 502 is performed by comparing the processing method data 505a to 505g and the shape of the light receiving range with, for example, pattern matching or image density distribution.
In addition, the PC 109 includes roughness determination data 506 that indicates the range in which the transmitted light spreads on the light receiving surface 108a and the roughness of the processed surface in association with each other. The roughness determination data 506 is data measured in advance by the processing surface evaluation apparatus according to the first embodiment, and is stored in the processing surface evaluation apparatus prior to the evaluation of the processing surface.

Further, the machined surface evaluation apparatus of the first embodiment has roughness determination data 506 that associates the range in which the transmitted light spreads on the light receiving surface 108a with the roughness of the reflecting surface 104a of the replica 104. The machining data 506 of the first embodiment includes roughness data 506a to 506g for each machining method for a plurality of machining methods such as lapping and electric discharge machining, for example.
The PC 109 compares the roughness determination data corresponding to the processing method determined by the processing method determination unit 502 among the roughness data 506a to 506g and the roughness of the processing surface by comparing the range in which the transmitted light spreads. A roughness determination unit 503 is provided.

The roughness determination unit 503 reads roughness determination data corresponding to the machining method determined by the machining method determination unit 502 among the roughness determination data 506a to 506g. Then, the data of the light receiving range received from the range / shape determining unit 501 is compared with the read roughness determination data to determine the roughness of the processed surface.
The above configuration can also be realized by density displacement measurement software. The density displacement measurement software can measure the density of an arbitrary region of the image over time. Since the image data of the transmitted light has a density according to the light intensity, it is possible to measure the intensity of the transmitted light and the distribution of the intensity, and even the change over time of the intensity by using density displacement measurement software. it can. Since the concentration displacement measurement software is a well-known software program, further explanation is omitted.

  The machined surface evaluation apparatus of Embodiment 1 having the above-described configuration operates as follows. That is, the processing surface evaluation apparatus according to the first embodiment starts the operation when the operator operates the PC 109 to start a program for evaluating the processing surface. At this time, the PC 109 controls the light source 403 to emit light. The emitted light passes through the replica 104 from the back surface 104b of the replica 104 and exits from the reflecting surface 104a. Then, the light is received by the light receiving surface 108a.

  The microscope 108 captures the received light, generates analysis image data dp, and inputs it to the PC 109. The range / shape determination unit 501 counts bright spots that are equal to or greater than a predetermined value in the generated image data, and determines the light reception range indicated by the analysis image and its shape. Data indicating the shape of the range obtained as a result of the determination is compared with the processing method data 505 in the processing method determination unit 502, and a processing method for processing the processing surface on which the replica 104 is based is determined.

  Further, the range obtained as a result of the determination is sent to the roughness determination unit 503. The roughness determination unit 503 determines the roughness of the processed surface by comparing the sent range with the roughness determination unit 506. In the first embodiment having a plurality of processing method data and roughness determination data, the roughness determination unit 503 corresponds to the roughness determined by the processing method determination unit 502 among the roughness determination data 506a to 506g. The thickness determination data is used for determining the roughness of the processed surface.

With the above operation, the method of processing the processed surface that is the basis of the replica 104 and the determination of the roughness of the processed surface are completed. The result of the determination is displayed on the display 109a via the display control unit 504.
Next, the processing method data 505 and the roughness determination data 506 used in the first embodiment will be described more specifically. In the first embodiment, a replica of a metal surface processed by a plurality of processing methods is generated in order to generate the processing method data 505 and the roughness determination data 506.

  The replica was created as follows. That is, in Embodiment 1, a metal surface was processed by a plurality of processing methods, and a mold was created for each of the surfaces. Then, liquid silicon is poured into the mold. Since liquid silicon is excellent in fluidity, it is a member known to easily flow into fine gaps and be capable of precise molding, and can accurately reproduce irregularities on the metal processing surface.

The solidified liquid silicon is removed from the mold and becomes a replica for each processing method. The replica created in the first embodiment has a flat plate shape with a thickness of 20 mm, and one surface of the flat plate is a reflecting surface, and a surface positioned opposite to the reflecting surface is a back surface.
In Embodiment 1, replicas were created for the following processing methods by the above-described method. In the following, a replica having a reflecting surface that reflects the machining surface machined by the following machining method will be described with the name of the machining method, for example, a lap machining replica, an electric discharge machining replica, etc. To do.
・ Lapping ・ Hand finishing (paper, file)
・ Electric discharge machining ・ Precision casting ・ Grinding ・ Shaping

  In the first embodiment, the created replica is imaged by the processing surface evaluation apparatus of the first embodiment to create an analysis image. The created analysis image is stored as processing method data 505a to 505g for each processing method. Furthermore, in the first embodiment, bright spots with a luminance of 200 or more appearing in the processing method data 505 to 505g are counted, and a graph in which the counted value is associated with the roughness of the processing surface is stored as roughness determination data 506a to 506g. is doing.

6A, 6B, and 6C are views showing processing method data for lapping among the above-described processing methods. FIG. 6A is an analysis image of a replica having a maximum height Ry of 0.2 μm. (B) is an analysis image of a replica having a maximum height Ry of 0.4 μm, and (c) is a replica of a maximum height Ry of 0.8 μm. Each processing method data includes analysis image data and the roughness shown in FIGS. 6 (a) to 6 (c). The roughness shown in FIG. 6 and FIG. 7 shown later is a value obtained by measuring the reflection surface of the replica by a known measurement method such as a probe method.
As shown in FIGS. 6A to 6B, the light receiving range approaches a circular shape to an elliptical shape as the reflecting surface of the replica becomes rough. Such a phenomenon occurs because streaky irregularities (grooves) are generated on the processed surface as the surface roughness of the processed surface processed by lapping is increased.

FIG. 7 is a diagram showing lapping roughness determination data based on the processing method data shown in FIG. 6, and can be created by processing an analysis image, which is processing method data, with density displacement measurement software or the like. In the first embodiment, as illustrated in FIG. 6, a plurality of replicas having different roughnesses are created for lapping, and a plurality of replicas are evaluated to obtain a light receiving range corresponding to the plurality of roughnesses. The vertical axis of the graph indicates the number of pixels (density object pixels) having a luminance of 200 or more, and the horizontal axis indicates the roughness of the reflecting surface of the replica. In the first embodiment, the density object pixel number and the roughness are measured a plurality of times in order to increase the reliability of the measurement value, and the difference in the plot of the graph represents the difference in the number of measurements.
As shown in FIG. 7, the number of density object pixels tends to increase as the roughness of the reflecting surface becomes rough. The reason for this is that when the reflecting surface 104a is rougher, the degree of light diffusion becomes larger, and the range (light receiving range) for receiving the transmitted light on the light receiving surface 108a becomes larger.

  FIG. 8 and FIG. 9 are diagrams for explaining such a phenomenon. FIG. 8 shows a processed surface having a maximum height Ry of 0.2 μm (FIG. 8B) and a processed surface shown in FIG. FIG. 8 shows an analysis image (FIG. 8A) of the reflection surface reflecting the above. FIG. 9 shows a processed surface (FIG. 9B) having a maximum height Ry of 0.8 μm and an analysis image (FIG. 9A) of a reflecting surface reflecting the processed surface shown in FIG. 9B. ing. As apparent from FIGS. 8B and 9B, there is no groove on the processed surface with the maximum height Ry of 0.2 μm, and a groove is generated in the vertical direction of the screen on the processed surface with the maximum height of Ry 0.8 μm. I understand that

As described with reference to FIG. 3, the light transmitted through the replica is diffracted by the grooves on the reflecting surface, and forms a long image in the direction perpendicular to the grooves. That is, on the processed surface that is lapped, a groove is generated as the surface roughness becomes rough, and the shape of the light receiving range becomes an elliptical shape.
With such a processing method, in the machined surface evaluation apparatus according to the first embodiment, for example, based on the shape in which the light receiving range is a circle or an ellipse, The shape of the unevenness can be determined. In the processing surface evaluation apparatus of the first embodiment, the light receiving range can be obtained from the number of density object pixels, and the roughness of the processing surface can be determined based on this value.

  Next, processing method data and roughness determination data of other processing methods will be described. FIGS. 10A, 10 </ b> B, 10 </ b> C, 10 </ b> D, and 10 </ b> E are processing method data for manual polishing (hand-finished paper) using sandpaper (paper). According to FIGS. 10A to 10E, even in the case of hand-finished paper, a phenomenon occurs in which the shape of the light receiving range extends in the horizontal direction as the roughness becomes rough, and a vertical groove in the drawing is formed on the reflecting surface. It can be seen that has occurred.

FIG. 11 is a diagram showing roughness determination data of hand-finished paper based on the processing method data shown in FIGS. The vertical axis of the graph represents the number of density object pixels having a luminance of 200 or more, and the horizontal axis represents the roughness of the replica according to the luminance. According to the graph shown in FIG. 10, it can be seen that the light receiving range is increased and the number of density object pixels is increased as the roughness of the reflecting surface is increased even in hand-finished paper.
It can also be seen that with hand-finished paper, the variation in the results obtained from the first measurement to the third measurement is small. For this reason, it can be said that the hand-finished paper is a processing method suitable for the present invention because a highly reliable result is obtained when evaluated by the processing surface evaluation apparatus of the first embodiment.

  12 (a), (b), (c), (d), (e), (f), (g), and (h) are all machining method data of electric discharge machining. In electric discharge machining, a machining electrode and a workpiece are set in an insulating liquid, a small gap is provided between the machining electrode and the workpiece, and an electric arc is generated by applying a voltage. This is a processing method for removing the melted and melted portion. According to FIGS. 12A to 12H, in the electric discharge machining, the light receiving range tends to increase as the roughness increases, but the shape of the light receiving range does not extend in the vertical or horizontal direction. From these results, it can be seen that the machining surface evaluation apparatus of Embodiment 1 does not generate grooves even when the surface becomes rough in electric discharge machining.

  FIG. 13 is a diagram showing roughness determination data for electric discharge machining based on the machining method data shown in FIGS. The vertical axis of the graph represents the number of density object pixels having a luminance of 200 or more, and the horizontal axis represents the roughness of the replica according to the luminance. According to the graph shown in FIG. 13, it can be seen that in the electric discharge machining, the density object pixel number decreases as the reflection surface roughness increases. The reason for this is considered that the diffusion of light increases due to the roughened surface, and the light having a luminance of 200 or more is reduced among the observed light.

  FIGS. 14 (a), (b), (c), (d), (e), (f), (g), (h), and (i) are all processing methods data for precision casting. The precision casting refers to a casting having particularly good dimensional accuracy, such as a lost wax method (investment mold method). According to FIGS. 14A to 14I, in precision casting, although the light receiving range tends to become wider and sparse as the roughness becomes rougher, the shape of the light receiving range extends in the vertical or horizontal direction. Absent. From these results, it can be seen that the machined surface evaluation apparatus of Embodiment 1 has no grooves on the metal surface manufactured by precision casting regardless of the surface roughness.

  FIG. 15 is a diagram showing the precision casting roughness determination data based on the processing method data shown in FIGS. The vertical axis of the graph represents the number of density object pixels having a luminance of 200 or more, and the horizontal axis represents the roughness of the replica according to the luminance. According to the graph shown in FIG. 15, in precision casting, when the roughness of the reflecting surface increases, the number of density object pixels once increases and then decreases. Then, it can be seen that the number of density object pixels increases again when the surface becomes rougher. Such a phenomenon increases the number of density object pixels by increasing the diffusion of transmitted light due to the increased surface roughness. However, when the surface is further roughened, the amount of light emitted from the replica is reduced and the number of density object pixels is reduced. Further, when the surface unevenness is further increased, the uneven surface is smooth, and thus the amount of transmitted light increases and the number of density object pixels increases again.

16A, 16B, 16C, 16D, 16E, and 16F are all grinding method data. Grinding is a processing method of cutting a workpiece with a grindstone. According to FIGS. 16 (a) to 16 (f), it can be seen that in the grinding process, the light receiving range extends laterally as the roughness increases, and vertical grooves are formed as in the lapping process described above. .
FIG. 17 is a diagram showing roughness determination data for grinding based on the processing method data shown in FIGS. The vertical axis of the graph represents the number of density object pixels having a luminance of 200 or more, and the horizontal axis represents the roughness of the replica according to the luminance. According to the graph shown in FIG. 17, in the grinding process, the number of density object pixels increases with the roughness of the reflecting surface 104a, and approaches a certain value when the maximum height Ry is larger than about 12 μm. I understand.

18 (a), (b), (c), (d), and (e) are all processing method data for hand-finishing file processing. Hand-finished file processing is a surface processing method by manual file.
FIG. 19 is a diagram showing grinding roughness determination data based on the machining method data shown in FIGS. The vertical axis of the graph represents the number of density object pixels having a luminance of 200 or more, and the horizontal axis represents the roughness of the replica according to the luminance. According to FIGS. 18A to 18E and FIG. 19, the length of the light receiving range extends in the lateral direction as the surface becomes rough up to the maximum height Ry of 3.2 to 6.3 μm. However, it can be seen that when the surface is further roughened to the maximum height Ry of about 12.5 μm, the length of the light receiving range is shortened and the number of density object pixels is reduced. Such a phenomenon is considered to occur when the number of density object pixels changes not only due to the roughness of the processed surface but also due to the influence of the groove interval and the groove surface shape.

20 (a), (b), (c), (d), and (e) are all machining method data for shaping. Shape machining refers to a machining method in which a surface is cut by combining a linear cutting motion of a tool and a linear feed motion of a workpiece. Further, FIG. 21 is a diagram showing roughness determination data for the shaping process based on the machining method data shown in FIGS. The vertical axis of the graph represents the number of density object pixels having a luminance of 200 or more, and the horizontal axis represents the roughness of the replica according to the luminance.
According to FIGS. 20A to 20E and FIG. 21, the number of density object pixels changes from increasing to decreasing with the maximum height Ry of 12.5 μm as a boundary. Such a phenomenon is considered to be due to the fact that light having a luminance of 200 or more is not emitted from the replica although the light receiving range is increased.

  In the processing surface evaluation apparatus of Embodiment 1 provided with the processing method data and roughness determination data described above, the replica to be measured is lapping, hand-finished paper, hand-finishing file, electric discharge machining, precision casting, grinding, It can be determined which of the shaping methods is used. Furthermore, the roughness of the reflecting surface 104a of the replica can be measured by comparing the light receiving range with the roughness determination data corresponding to the determined processing method.

Since the processing surface evaluation apparatus according to the first embodiment described above irradiates light substantially perpendicularly from the back surface of the reflection surface, it is relatively easy to obtain sufficient accuracy required for the installation angle of the light source 403 and the assembly of the optical system. be able to.
Further, the processing surface evaluation apparatus according to the first embodiment determines the roughness of the processing surface based on the range in which the transmitted light transmitted through the replica spreads, and automatically determines the uneven shape of the processing surface based on the shape of the range. Can be determined. For this reason, it is possible to evaluate the state of the surface of the member processed in a non-contact manner within a relatively short time without being limited by the reflectance and the surface state of the measurement target.

  Furthermore, the machined surface evaluation apparatus of Embodiment 1 is not limited to the configuration described above. That is, in the first embodiment, the number of density object pixels having a luminance of 200 or more is counted in the graph shown in FIG. However, the threshold value of luminance when counting as the number of density object pixels is not limited to 200 or more, and may be an arbitrary value.

In the present embodiment, the processing surface evaluation apparatus irradiates one point on the reflection surface 104a with the light source 403 to acquire an analysis image. However, the means for scanning the light source 403 with the reflection surface 104a is a processing surface evaluation. It is also possible to measure the straight line roughness on the reflecting surface 104a provided in the apparatus.
Furthermore, the processing surface evaluation apparatus according to the first embodiment is not limited to the one that stores only the processing method information about the processing method exemplified in the first embodiment, and processing by any other processing method is possible. The method information may be stored. Furthermore, even for the same machining method, machining information and roughness information are stored in the machining surface evaluation device for each jig and machining condition, and the roughness of the machining surface is more accurately compared with the measurement results. It can be measured.

  In the first embodiment, a plate-like replica having a smooth reflecting surface 104b is used. However, the replica that can be applied to the machined surface evaluation apparatus of the first embodiment is not limited to such a replica. For example, it is possible to measure a replica that is plate-shaped and both the reflecting surface 104a and the back surface 104b have irregularities on the surface. In such a case, as shown in FIG. 3C, it is possible to obtain an analysis image reflecting the unevenness of both the reflection surface 104a and the back surface 104b.

In the first embodiment, the shape of the replica is not limited to a plate shape, and any shape may be used as long as scattering at a portion other than the reflecting surface does not affect the transmitted light that passes through the reflecting surface. Also good.
Furthermore, in the first embodiment, a replica is used in which a surface obtained by transferring the processed surface is a reflecting surface. However, the first embodiment is not limited to such a configuration, and a replica may be used in which a surface obtained by transferring the surface is further transferred. When such a replica is employed, the processed surface can be evaluated using a reflecting surface that accurately reproduces the left / right / up / down relationship of the unevenness of the processed surface.

(Embodiment 2)
Next, Embodiment 2 of the present invention will be described. The machined surface evaluation apparatus of the present invention determines the shape and roughness of the machined surface directly without specifying the machining method from the machined surface shape. Such a machined surface evaluation apparatus according to Embodiment 2 is suitable for use in, for example, evaluating the state of a machined surface in a metal surface machining process or inspection process.

FIG. 22 is a diagram for explaining a machining surface evaluation apparatus that determines the shape and roughness of a machining surface from an analysis image.
The machined surface evaluation apparatus shown in FIG. 22 has analysis image data 2203 obtained using a replica of the machined surface machined in the process to be evaluated. In this embodiment, it is assumed that a plurality of replicas having different reflection surface roughness are created using processed surfaces having different roughnesses, and analysis image data is stored for each replica. For this reason, the analysis image data 2203 includes, for example, seven analysis image data 2203a to 2203g having different replica roughnesses. Note that, as illustrated in FIG. 6 and the like, the analysis image data 2203a to 2203g includes the analysis image and the roughness of the replica reflecting surface corresponding to the analysis image.

  Further, the processing surface evaluation apparatus shown in FIG. 22 is based on the surface shape determination unit 2201 that determines the shape of the unevenness of the processing surface based on the shape of the range in which the transmitted light indicated by the analysis image data 2203 spread, A roughness determination unit 2202 for determining the roughness of the processed surface is provided. In FIG. 22, the same components as those shown in FIG. 5 are denoted by the same reference numerals, and the description thereof is partially omitted.

  The range / shape determining unit 501 identifies a light receiving range from the image data dp, and determines the size and shape of the range. The shape of the light receiving range is sent to the surface shape determination unit 2201, and the size of the range is sent to the roughness determination unit 2201. The surface shape determination unit 2201 compares the shape determined by the range / shape determination unit 501 with the shape of the light receiving range indicated by the analysis image data 2203a to 2203g, and specifies a matching one.

  In the present embodiment, the range / shape determining unit 501 can also have information such as the generation of grooves corresponding to the shape of the light receiving range and the smoothness. As such information, for example, when the specified shape can be regarded as a substantially circle, it is smooth, or when the ratio of the major axis to the minor axis when the shape is regarded as an ellipse is equal to or greater than a threshold value. The generation of vertical grooves can be considered. In such a configuration, the range / shape determining unit 501 may display information such as the occurrence of a vertical groove on the display 109a via the display control unit 504.

The roughness determination unit 2202 compares the light reception range determined by the range / shape determination unit 501 with the light reception ranges indicated by the analysis image data 2203a to 2203g, and specifies a matching one. Then, the roughness corresponding to the specified analysis image data is displayed on the display 109 a via the display control unit 504.
Furthermore, in this embodiment, the range / shape determination unit 501 extracts a plurality of analysis image data candidates that match the shape of the light receiving range, and notifies the roughness determination unit 2202 of the extracted analysis image data. Then, the roughness determination unit 2202 may identify the received analysis image data that matches the light receiving range. When configured in this manner, it is possible to determine the coincidence between the image data dp obtained by measurement and the analysis image data more accurately.

According to the second embodiment described above, it is possible to evaluate the generation of grooves on the processed surface, the direction of the generated grooves, the degree of generation of the grooves, and the like. Such a machined surface evaluation apparatus according to Embodiment 2 is suitable for determining machining conditions and adjusting jigs in a machining process with a known machining method.
Moreover, the processing surface evaluation apparatus of Embodiment 2 is not limited to such a configuration. That is, the processing surface evaluation apparatus of the second embodiment determines that the analysis image data 2203 is acceptable in the inspection process, for example, when determining only whether the processing surface has smoothness that can be regarded as acceptable in the inspection process or the like. Save only the surface data (best data).

At this time, the surface shape determination unit 2201 and the roughness determination unit 2202 match the range and the shape of the range determined by the range / shape determination unit 501 with the best data by a method such as pattern matching. A message indicating that the inspection standard is passed can be displayed on the display 109a only when it can be considered that the size and the shape of the light receiving range coincide with each other as a result of the object.
According to such a machined surface evaluation apparatus, it can be determined in a shorter time whether or not the machined surface satisfies a predetermined machining quality. For this reason, the processing surface evaluation apparatus which can obtain high working efficiency in an inspection process can be constituted.

It is a figure for demonstrating the fundamental structure of the processing surface evaluation apparatus of Embodiment 1 of this invention. It is the figure which showed the phenomenon which occurs in the structure shown in FIG. The image formed by the transmitted light on the screen shown in FIG. 1 is taken by a digital camera. It is a figure for demonstrating the structure of the processing surface evaluation apparatus of one Embodiment of this invention. It is a functional block diagram of the structure of PC required for Embodiment 1 of this invention. It is an analysis image used as the processing method data of the lapping process of the processing surface evaluation apparatus of this embodiment. It is roughness determination data based on the processing method data shown in FIG. It is the figure which showed the evaluation result by the processing surface evaluation apparatus of this embodiment of the processing surface of maximum height Ry0.2micrometer, and the replica produced based on this processing surface. It is the figure which showed the evaluation result by the processing surface evaluation apparatus of this embodiment of the processing surface of maximum height Ry0.8micrometer, and the replica produced based on this processing surface. It is an analysis image used as the processing method data of hand-finished paper in the processing surface evaluation apparatus of one embodiment of the present invention. It is roughness determination data based on the processing method data shown in FIG. It is an analysis image used as processing method data of electric discharge machining with the processing surface evaluation device of one embodiment of the present invention. It is roughness determination data based on the processing method data shown in FIG. It is an analysis image used as the processing method data of precision casting with the processing surface evaluation apparatus of one Embodiment of this invention. It is roughness determination data based on the processing method data shown in FIG. It is an analysis image used as the processing method data of grinding with the processing surface evaluation apparatus of one embodiment of the present invention. It is roughness determination data based on the processing method data shown in FIG. It is an analysis image used as the processing method data of the hand-finishing file with the processing surface evaluation apparatus of one Embodiment of this invention. It is roughness determination data based on the processing method data shown in FIG. It is the analysis image used as the processing method data of shaping with the processing surface evaluation apparatus of one Embodiment of this invention. It is roughness determination data based on the processing method data shown in FIG. It is a functional block diagram of the structure of PC required for Embodiment 2 of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 101 Digital camera, 103 Laser, 104 Replica, 104a Reflecting surface 104b Back surface, 105 Screen, 108 Microscope, 108a Light-receiving surface 109 PC, 109a Display, 403 Light source 501 Range / shape determination unit, 502 Processing method determination unit, 503 Roughness Determination unit 504 Display control unit, 505 Processing method data, 506, 2202 Roughness determination data 2201 Surface shape determination unit, 2203 Analysis image data

Claims (8)

Using a substantially transparent sample member having a reflecting surface that reflects the state of the processing surface of the object to be evaluated, a processing surface evaluation device for evaluating the state of the processing surface,
A light irradiating means for irradiating light substantially perpendicularly from the back surface corresponding to the surface opposite to the reflecting surface to the reflecting surface;
A light receiving means for receiving the transmitted light irradiated by the light irradiating means and transmitted through the sample member at a light receiving surface;
Roughness determining means for determining the roughness of the processed surface based on a range of transmitted light having a strength equal to or higher than a predetermined intensity in a range where transmitted light spreads on the light receiving surface of the light receiving means;
A machined surface evaluation apparatus comprising: Using a substantially transparent sample member having a reflecting surface that reflects the state of the processing surface of the object to be evaluated, a processing surface evaluation device for evaluating the state of the processing surface,
A light irradiating means for irradiating light substantially perpendicularly from the back surface corresponding to the surface opposite to the reflecting surface to the reflecting surface;
A light receiving means for receiving the transmitted light irradiated by the light irradiating means and transmitted through the sample member at a light receiving surface;
Surface shape determination means for determining the shape of the irregularities on the processing surface based on the shape of the range in which transmitted light spreads on the light receiving surface of the light receiving means;
A machined surface evaluation apparatus comprising:   Preliminarily having processing method information indicating the shape of the range in which the transmitted light spreads on the light receiving surface of the light receiving means and the processing method, the surface shape determining means has the transmitted light spread on the light receiving surface of the light receiving means. The processing surface evaluation apparatus according to claim 2, further comprising processing method determination means for determining a processing method for processing the processing surface by comparing a shape of a range with the processing method information.   Roughness information that correlates the range in which the transmitted light spreads on the light receiving surface of the light receiving unit with roughness is previously stored, and the range in which the transmitted light spreads on the light receiving surface of the light receiving unit is compared with the roughness information. The processing surface evaluation apparatus according to claim 2, further comprising a roughness determination unit that determines the roughness of the machining surface.   The roughness information is information for associating the range in which transmitted light spreads on the light receiving surface of the light receiving unit with the roughness for each processing method, and the roughness determining unit is the processing determined by the processing method determining unit The machined surface evaluation apparatus according to claim 4, wherein the roughness of the machined surface is determined by comparing the roughness information corresponding to the method with a range in which transmitted light spreads on the light receiving surface of the light receiving unit.   The roughness information indicates a range in which transmitted light having an intensity equal to or greater than a predetermined value in a range in which transmitted light spreads on a light receiving surface of the light receiving unit and a roughness of a processing surface in association with each other. The determination means determines the roughness of the processed surface against the roughness information in a range in which transmitted light having an intensity of the predetermined value or more spreads on the light receiving surface of the light receiving means. Or the processing surface evaluation apparatus according to 5;   7. The machined surface evaluation apparatus according to claim 1, wherein the light irradiation unit irradiates a spot light having a substantially uniform intensity distribution on the reflection surface of the irradiation light.   The sample member is a replica reflecting a surface obtained by transferring a processed surface or a surface obtained by further transferring a surface obtained by transferring a processed surface. The machined surface evaluation apparatus according to claim 1.