JP2001116693A - Surface glossiness inspection method and device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To accurately inspect surface glossiness of an inspection object without being influenced by a surface flaw. SOLUTION: Plural glossiness sensors 13 are arranged along a surface of a stainless steel strip 11 being an inspection object. When signal values corresponding to glossiness from the respective glossiness sensors 13 are less than a preset reference value, judging logic of a PC 15 excludes the values as corresponding to a no-plate part nonexistent in the stainless steel strip 11. When a difference between the signal values from the adjacent glossiness sensors 13 exceeds the preset reference value, at least one glossiness sensor 13 excludes the difference from data for calculating glossiness as corresponding to a flaw existing part. Since the glossiness is calculated as an additive average of the signal values from the residual glossiness sensors 13, the proper glossiness can be calculated without being influenced by a flaw. The glossiness uninfluenced by such a flaw can be used when judging the flaw by a surface inspection machine system 12.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and apparatus for inspecting the surface gloss of a metal band or the like.

[0002]

2. Description of the Related Art Conventionally, in the manufacturing process of, for example, stainless steel, it is important to control the quality of the surface, and it is necessary to inspect the glossiness and the presence or absence of flaws so as to obtain a certain surface property. The present applicant discloses prior art relating to automatic surface inspection of a metal strip, for example, as disclosed in Japanese Patent Application Laid-Open No. 9-89801.
It is disclosed in JP-A-9-89802 and JP-A-9-89803.

FIG. 6 shows the principle of detecting flaws on the surface of a metal strip such as stainless steel in each of the aforementioned prior arts. When the surface of the metal strip 1 is irradiated with the laser light 3 from the laser light source 2, the reflected light 4 generates a diffraction pattern 5 on a screen sufficiently separated. If the surface of the metal band 1 irradiated with the laser beam 3 has a flaw, the diffraction pattern 5 has a characteristic shape corresponding to the surface flaw.

FIG. 7 shows a cross section of a portion where the laser beam 3 shown in FIG. The laser light 3 is
A plurality of light beams are irradiated as parallel and coherent light,
The light is reflected by the surface irregularities 6. The surface irregularities 6 can be considered as a set of fine plane mirrors 6a.
, Irregularly reflected light 8 as well as specularly reflected light 7 can be obtained. Since the laser light 3 is coherent light, the diffraction pattern 5 in FIG. 6 is obtained by being enhanced or canceled out according to the correspondence between the optical path difference and the wavelength in the regular reflection light 7 and the irregular reflection light 8.

In the process of manufacturing stainless steel, the type and form of a flaw are determined based on a diffraction pattern 5 obtained by a method as shown in FIGS. 6 and 7, and grades are performed according to a predetermined standard. I have. However, the determination of the surface as a product is ultimately made by human vision. In human vision, flaws that are not so noticeable when the surface gloss is low become more noticeable when the surface gloss increases. JP-A-9-8980
In No. 2, when the detection output of the reflected light 4 obtained by the method as shown in FIGS. 6 and 7 is subjected to data processing, it is normalized by the noise level, and even if it has a high surface gloss, a slight flaw is reliably detected. Making it possible.

In the case of a material such as stainless steel, which has an important surface gloss, and a material which has been subjected to a surface treatment such as plating or painting, the gloss itself is also an important object of quality control. Conventionally, the glossiness of the surface is measured using a glossmeter as necessary.

[0007]

Problems to be Solved by the Invention Japanese Patent Application Laid-Open No. 9-89802
In such prior art, glossiness is also taken into account when determining surface flaws. However, the gloss level to be considered is calculated based on the intensity of the light reflected from the surface of the target object including the flawed portion. In the part with a flaw,
An error also increases in the required gloss value. Since the determination of the flaw is performed using the gloss data having a large error, the error also becomes large in the result of the flaw determination.

In the conventional method for measuring the glossiness of the surface of an object using a photometer, when measuring manually, the glossiness can be measured while avoiding flaws or the like. In the case of the measurement, it is not possible to judge whether the glossiness is actually fluctuating or fluctuating due to the influence of flaws, based only on the glossiness data.

An object of the present invention is to provide a surface gloss inspection method capable of accurately measuring the glossiness of an object even if the surface has a flaw or the like and using the data as glossiness data for surface flaw inspection. And equipment.

[0010]

SUMMARY OF THE INVENTION According to the present invention, a plurality of gloss sensors are arranged at intervals along the surface of an object to be inspected, and the surface of the object is inspected from each of the gloss sensors. Irradiate light to derive a signal corresponding to the gloss level from the reflection intensity, and among the signals from all of the plurality of gloss sensors, exclude a signal value whose corresponding gloss level is less than a predetermined lower limit, A gloss sensor whose difference in signal value from an adjacent gloss sensor is equal to or less than a predetermined reference value is selected, and an average value of gloss corresponding to the signal value from the selected gloss sensor is determined by the inspection object. This is a method for inspecting the surface gloss, which is calculated as the glossiness of the surface.

According to the present invention, a plurality of glossiness sensors are arranged at intervals from each other along the surface of the inspection object.
Each of the gloss sensors irradiates the surface of the inspection object with light, and a signal corresponding to the gloss is derived from the reflection intensity.
Since a signal value whose corresponding glossiness is less than a predetermined lower limit value is excluded, for example, a glossiness corresponding to a case where the inspection object does not exist or a glossiness corresponding to an area not to be subjected to the glossiness inspection, etc. The signal value is determined so as to be equal to or less than the lower limit value, and the influence of glossiness which is not an inspection target is removed. After removing the signal value equal to or less than the lower limit value, a signal value in which the difference between the signal values from the adjacent glossiness sensors does not fall below a predetermined reference value is excluded. When the difference between the signal values is large, it is determined that at least one of the adjacent gloss sensors is detecting the gloss for the flaw area, and the difference between the signal values from the gloss sensor is the reference value. Since the following glossiness not affected by the flaw is selected and the average value is calculated, the glossiness of the surface of the inspection object can be obtained without being affected by the flaw.

In the present invention, the inspection object moves in a predetermined direction, and the plurality of gloss sensors are arranged in a matrix in a direction perpendicular to the one direction and in a direction intersecting the vertical direction. It is characterized by being arranged in a shape.

According to the present invention, it is possible to determine the glossiness of a wide portion by using a plurality of glossiness sensors arranged in a matrix and to determine the glossiness of many inspection objects while moving the inspection object. it can.

Further, the object to be inspected according to the present invention is a long object, moves in the longitudinal direction thereof, and moves in the longitudinal direction of the inspected object based on signal values from the plurality of glossiness sensors.
It is characterized in that glossiness is calculated in a plurality of areas.

According to the present invention, the glossiness of the surface of a long object can be determined at a plurality of locations while moving in the longitudinal direction, and the glossiness as a whole can be determined.

In the present invention, the object to be inspected is a stainless steel material after bright annealing, and when the value calculated as the gloss exceeds a predetermined upper limit, it is determined that the material is a high gloss material. Features.

According to the present invention, the glossiness of the surface of the stainless steel material after the bright annealing treatment is obtained, and when the glossiness exceeds a predetermined upper limit, it is determined that the material is a high glossy material. For example, it is possible to change the criterion for determining the surface flaw and perform appropriate flaw determination in accordance with the glossiness.

Further, the present invention provides a plurality of gloss sensors arranged along the surface of the inspection object, wherein a gap is provided between the gloss sensors, and each gloss sensor is located on the surface of the inspection object. Irradiate light, receive reflected light from the surface of the inspection object, and derive a signal corresponding to the gloss, such a plurality of gloss sensors, and signals from the plurality of gloss sensors are input, A signal value whose corresponding glossiness is less than a predetermined lower limit value is excluded, and a signal value difference from an adjacent glossiness sensor corresponds to a signal value from the glossiness sensor whose value is equal to or less than a predetermined reference value. A processing device for calculating an average value of glossiness.

According to the present invention, a plurality of gloss sensors are arranged along the surface of the inspection object, and light is emitted from each gloss sensor to the surface of the inspection object at intervals between the gloss sensors. And receives a light reflected from the surface of the inspection object to derive a signal corresponding to the glossiness. Since there is an interval between the gloss sensors, it is less affected by the light emitted from the adjacent gloss sensors to the surface of the inspection object. Can be requested.
The processing means excludes, from the signals from the plurality of glossiness sensors, signal values for which the corresponding glossiness is less than a predetermined lower limit value, and sets a difference between signal values between adjacent glossiness sensors as a predetermined reference value. The average value of the glossiness corresponding to the signal value from the glossiness sensor that is equal to or less than the value is calculated. The reason why the glossiness is less than the predetermined lower limit value is that, for example, a portion deviating from the surface of the inspection object, or a portion where a flaw or dirt is large and sufficient reflected light cannot be obtained is a signal value corresponding to the glossiness. Is less than the lower limit and is excluded. The difference in signal value between adjacent gloss sensors is equal to or less than a predetermined reference value when the gloss calculated by the gloss sensor is not affected by flaws or the like. Since the gloss value of the surface of the inspection object is calculated by averaging the signal values from the gloss sensor which is not affected, it is possible to reliably calculate the gloss value which is not affected by a partial flaw or the like.

[0020]

FIG. 1 shows a schematic configuration of a surface gloss inspection apparatus 10 as an embodiment of the present invention. The surface gloss inspection device 10 obtains the gloss of the surface of the stainless steel strip 11 after the bright annealing (BA) treatment. The surface glossiness of the stainless steel strip 11 determined by the surface gloss inspection device 10 is used as a value of the glossiness when the surface inspection device system 12 inspects the surface of the stainless steel strip 11 for flaws. Can be changed according to the glossiness.
Rather than considering the effect of glossiness in the data used by the surface inspection machine system 12 for flaw detection, the glossiness is determined in advance so as not to be affected by flaws and the like. Is used, it is possible to appropriately determine the flaw according to the glossiness.

The glossiness of the surface of the stainless steel strip 11 is detected by a plurality of glossiness sensors 13. Each gloss sensor 13 detects a laser light source that irradiates the surface of the stainless steel strip 11 with a constant illuminance, and detects the amount of reflected light reflected on the surface of the stainless steel strip 11 and outputs a detected reflected light amount of 4 to 20.
It is derived as a signal represented by a current value of mA. For example, at 100% where the amount of reflected light is equal to the amount of incident light, it is 20 mA,
At 0% at which no reflected light is received, the output is taken as 4 mA from the gloss sensor 13 as a current signal. The reflected light amount signal represented by the current value is converted into a digital value corresponding to the reflected light amount by an analog / digital (hereinafter, abbreviated as “A / D”) conversion circuit 14. A / D conversion circuit 1
The digital value converted in 4 is used to determine the glossiness according to a judgment logic represented by a program such as a personal computer (hereinafter abbreviated as “PC”) 15,
It is determined whether or not the glossiness is high.

The gloss sensor 13 is a stainless steel strip 11
In order to detect a change in the reflectance when the sheets are passed through, a plurality of the sheets are arranged at intervals. For example, rows A, B, C and D perpendicular to the passing direction are arranged at regular intervals from the upstream side to the downstream side in the passing direction. Further, since each row is in the width direction of the stainless steel strip 11, individual glossiness sensors 13 are arranged at regular intervals in each row. The positions of the glossiness sensors 13 are shifted between rows adjacent to each other in the sheet passing direction to form a staggered arrangement as a whole. Glossiness sensor 13
By arranging a plurality of, it is possible to detect a change in the glossiness of the surface of the stainless steel strip 11 to be passed. Further, since a plurality of pieces are arranged in the direction of the sheet width along each row of A, B, C, and D, it is possible to cope with a change in the sheet width of the stainless steel strip 11. Since a plurality of rows of A, B, C, and D are arranged along the passing direction of the stainless steel strip 11, it is possible to discriminate whether or not the influence is due to a flaw.

FIG. 2 shows the overall configuration of the processing equipment for the stainless steel strip 11 including the surface gloss inspection device 10 of FIG. The stainless steel strip 11 is supplied from a payoff reel 20 in a coiled state. The stainless steel strip 11 supplied from the pay-off reel 20 is welded by a welder 21 so that the final end of the preceding stainless steel strip 11 and the leading end of the succeeding stainless steel strip 11 are welded and continuously threaded. Is done. Stainless steel strip 11 passed continuously
Receives the target processing in the processing device 22, and performs the surface gloss inspection device 10, the surface inspection device system 12, and the visual inspection position 2
3 and is cut by a shear 24 and wound on a tension reel 25 for each original coil.

When the surface gloss inspection apparatus 10 of the present embodiment is used, the surface inspection system 1 can be applied to a stainless steel strip 11 having a high glossiness in which the processing apparatus 22 performs BA processing.
In step 2, an appropriate surface flaw can be inspected according to the glossiness.

FIG. 3 shows a cross-sectional configuration of a portion for measuring the gloss of the surface of the stainless steel strip 11 using the gloss sensor 13 in the surface gloss inspection apparatus 10 of FIG. The stainless steel strip 11 is wound around a large-diameter guide roll 30. By winding the stainless steel strip 11 around the guide roll 30, the influence of wrinkles, ears, and the like, which are likely to occur at both ends of the stainless steel strip 11, can be eliminated. The gloss sensors 13 in each row are spaced apart from each other along the surface of the stainless steel strip 11 bent by the guide roll 30. This interval is maintained at, for example, about 20 to 30 mm.
Each gloss sensor 13 irradiates the surface of the stainless steel strip 11 with laser light 31. The spread of the laser beam 31 is set to several mm as the diameter of a spot formed on the surface of the stainless steel strip 11. The irradiation distance of the laser beam 31 is about 30 mm.

FIG. 4 shows the names given to the individual gloss sensors 13 when the outputs from the plurality of gloss sensors 13 are processed. The gloss sensor 13 is, for example, 16
In the case where n columns are used in each of the four rows A, B, C, and D, the individual names of the sensors are Ai, Bi, Ci, Di (i = 1 to 1, respectively). n). In the present embodiment, n = 4. In FIG. 1, reflected light quantity signals from a plurality of gloss sensors 13 are multiplexed on the gloss sensor 13 side and sent to an A / D conversion circuit 14 or A / D converters in parallel.
It can be sent to the conversion circuit 14. When sent in parallel, an A / D conversion circuit 14 is provided for each reflected light amount signal to convert the reflected light amount signal into a digital value, or one A / D conversion circuit 14 is used to switch 16 reflected light amount signals and perform A / D conversion. / D conversion.

In the PC 15 of FIG. 1, the A / D conversion circuit 14
First, pre-processing is performed on the data output from. A /
With the signal value from the D conversion circuit 14 as the reflectance, the lower limit of the reflectance is LL, and the upper limit is HL, the following processes are performed. Signal values less than the lower limit value LL are ignored because they are detected values from a portion where the stainless steel strip 11 does not exist. If the difference between the signal values from adjacent gloss sensors 13 in the same row exceeds a certain value, it is regarded as a flaw and is not considered in the gloss.

The signal values from all the gloss sensors 13 are added, and the sum of the signal values satisfying the condition and the signal value satisfying the condition are subtracted. The result obtained by dividing the number of valid sensors, that is, the value obtained by subtracting the number of sensors satisfying the conditions (1) and (2) from the total number is calculated as an average value of glossiness. If the average value is equal to or greater than the upper limit value HL, the stainless steel strip 11 which has been inspected for glossiness is determined as a high gloss material. In the stainless steel strip 11 determined as a high gloss material, the criterion for determining the surface flaw becomes strict. The above condition can be expressed by the following first equation.

[0029]

(Equation 1)

FIG. 5 shows the basic concept of calculating the gloss in this embodiment. The procedure starts from step s1, and in step s2, the amount of reflected light detected by each gloss sensor 13 is measured in a matrix as shown in FIG. In step s3, a plateless portion corresponding to a portion where the stainless steel strip 11 does not exist is excluded according to the above-described conditions. In step s4, flaws are excluded according to the above-described conditions. In step s5, an average value is calculated according to the above-described first equation, and
The procedure ends in step 6.

For the stainless steel strip 11 to be treated as shown in FIG. 2, for example, at a position several tens of meters from the welded portion of the stainless steel strip 11 by the welder 21, within a range that can be regarded as the leading part for each coil. If the glossiness of the surface is measured, it can be regarded as a typical glossiness of the entire coil thereafter, and the surface inspection system 12 can be operated based on the glossiness. In addition, if the tracking processing accompanying the passing of the stainless steel strip 11 is performed between the surface gloss inspection device 10 and the surface inspection machine system 12,
The glossiness measured by the surface gloss inspection device 10 in real time can make the determination standard of the surface inspection system 12 follow.

In the present embodiment, the gloss sensor 13 is
Although a total of 16 rows are arranged in 4 rows, the number of glossiness sensors 13 can be changed according to required accuracy or the like. In addition, when the passing speed of the inspection object becomes relatively slow, measurement is performed while performing scanning for changing the position of the gloss sensor 13, and a wide range of gloss can be obtained with a small number of gloss sensors. It can also be detected. In addition, although the stainless steel strip 11 to be inspected is continuously passed in the longitudinal direction, the same applies to a stainless steel plate or another metal plate that is transported in a state of a cut plate or the like that has been individually cut. Inspection of glossiness can be carried out. In addition, although the processing device 22 of FIG. 2 performs a BA process and the like, even when performing a pickling process, a plating process, or a coating process, the glossiness of the surface is similarly reduced. Can be inspected.

[0033]

As described above, according to the present invention, a plurality of glossiness sensors are used to avoid the influence of a part where the object does not exist or a part where the surface has a flaw. Can be accurately determined.

According to the invention, the gloss of the surface of the inspection object moving in one direction is determined by using a plurality of gloss sensors.
The gloss can be obtained from a wide range of the surface of the inspection object.

Further, according to the present invention, the glossiness can be obtained over a wide range of the surface of the inspection object while moving the inspection object in the longitudinal direction with respect to the long inspection object.

Further, according to the present invention, the glossiness of the surface of a stainless steel material having a high glossiness after the bright annealing treatment can be obtained without being affected by surface flaws, and the predetermined upper limit value can be determined. It can be determined whether or not the high gloss material exceeds.

Further, according to the present invention, the surface of the inspection object is irradiated with light from a plurality of gloss sensors, respectively.
The reflected light from the surface of the inspection object is received, a signal corresponding to the glossiness is derived, and the overall glossiness can be obtained as an average value of the glossiness in the processing device. Since there is an interval between the glossiness sensors, it is possible to reduce the influence of light applied to the surface of the inspection object from an adjacent glossiness sensor.

[Brief description of the drawings]

FIG. 1 is a surface gloss inspection apparatus 10 according to an embodiment of the present invention.
3 is a block diagram showing a schematic electric configuration of FIG.

FIG. 2 is a simplified side view showing a schematic configuration of a continuous processing device for a stainless steel strip 11 including the surface gloss inspection device 10 of FIG.

FIG. 3 is a simplified side view showing an arrangement state of a gloss sensor 13 with respect to a stainless steel strip 11 in the surface gloss inspection device 10 of FIG.

FIG. 4 is a diagram showing an arrangement state of a plurality of glossiness sensors 13 and an individual name when the arrangement is performed in the surface gloss inspection device 10 of FIG. 1;

FIG. 5 is a flowchart showing a basic procedure for calculating the glossiness of the surface of the inspection object by the surface gloss inspection device 10 of FIG.

FIG. 6 is a diagram showing the principle of irradiating a laser beam onto the surface of a metal band and detecting flaws on the surface of the metal band based on a diffraction pattern of reflected light.

FIG. 7 shows a laser beam 3 applied to the surface irregularities 6 of the metal band in FIG.
FIG. 4 is a partial cross-sectional view showing specularly reflected light and irregularly reflected light generated when the light is irradiated.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Surface gloss inspection apparatus 11 Stainless steel strip 12 Surface inspection machine system 13 Glossiness sensor 15 PC 20 Payoff reel 21 Welder 22 Processing unit 24 Shear 25 Tension reel 30 Guide roll 31 Laser beam

Claims (5)

[Claims] A plurality of gloss sensors are arranged at intervals along the surface of the inspection object, and each of the gloss sensors irradiates light to the surface of the inspection object to reflect intensity. A signal corresponding to the glossiness is derived from among the signals from all of the plurality of glossiness sensors, and a signal value whose corresponding glossiness is less than a predetermined lower limit value is excluded.
A gloss sensor whose difference in signal value from an adjacent gloss sensor is equal to or less than a predetermined reference value is selected, and an average value of gloss corresponding to the signal value from the selected gloss sensor is determined by the inspection object. A surface gloss inspection method characterized in that the surface gloss is calculated as the glossiness of the surface. 2. The method according to claim 1, wherein the inspection object moves in a predetermined direction, the plurality of glossiness sensors include a direction perpendicular to the one direction,
The surface gloss inspection method according to claim 1, wherein the surface gloss is arranged in a matrix in a direction intersecting with the vertical direction. 3. The object to be inspected is a long object, moves in the longitudinal direction, and, based on signal values from the plurality of gloss sensors, a plurality of areas in the longitudinal direction of the object to be inspected. The surface gloss inspection method according to claim 1, wherein the glossiness is calculated by: 4. The inspection object is a stainless steel material after a bright annealing treatment, and a value calculated as the glossiness is:
The glossiness inspection method according to any one of claims 1 to 3, wherein when the value exceeds a predetermined upper limit value, the material is determined to be a high gloss material. 5. A plurality of gloss sensors arranged along a surface of an inspection object, wherein a distance is provided between the gloss sensors, and each of the gloss sensors irradiates light to the inspection object surface. A plurality of such gloss sensors, which receive reflected light from the surface of the inspection object and derive a signal corresponding to the gloss, are input with signals from the plurality of gloss sensors, and the corresponding gloss is input. A signal value whose degree is less than a predetermined lower limit value is excluded, and a difference in signal value between adjacent gloss sensors is equal to or less than a predetermined reference value. A surface gloss inspection device, comprising: a processing device for calculating an average value.